,,darwin ,,and ,,modern ,,science       
,,essays ,,in ,,commemoration ,,of ,,the
 ,,centenary ,,of ,,the ,,birth ,,of    
,,charles ,,darwin ,,and ,,of ,,the     
,,fiftieth ,,anniversary ,,of ,,the     
,,publication ,,of ,,the ,,origin ,,of  
,,species   ,by ,a4,c4 ,seward    ,my   
success as a man of science1 whatever   
this may have amounted to1 has been     
determined1 as far as ,i can judge1 by  
complex and diversified mental qualities
 and conditions4 ,of these1 the most    
important have been--the love of        
science--unbounded patience in long     
reflecting over any subject--industry in
 observing and collecting facts--and a  
fair share of invention as well as of   
common sense4 ,with such moderate       
abilities as ,i possess1 it is truly    
surprising that ,i should have          
influenced to a considerable extent the 
belief of scientific men on some        
important points4  ,autobiography       
7#ahha72 ,the ,life and ,letters of     
,charles ,darwin1 ,vol4 #a4 page #ajg4  

,,preface  ,at the suggestion of the    
,cambridge ,philosophical ,society1 the 
,syndics of the ,university ,press      
decided in ,march1 #aijh1 to arrange for
 the publication of a series of ,essays 
in commemoration of the ,centenary of   
the birth of ,charles ,darwin and of the
 ,fiftieth anniversary of the           
publication of ,the ,origin of ,species4
 ,the preliminary arrangements were made
 by a committee consisting of the       
following representatives of the        
,council of the ,philosophical ,society 
and of the ,press ,syndicate3 ,dr ,h4,k4
 ,anderson1 ,prof4 ,bateson1 ,mr        
,francis ,darwin1 ,dr ,hobson1 ,dr      
,marr1 ,prof4 ,sedgwick1 ,mr ,david     
,sharp1 ,mr ,shipley1 ,prof4 ,sorley1   
,prof4 ,seward4 ,in the course of the   
preparation of the volume1 the original 
scheme and list of authors have been    
modified3 a few of those invited to     
contribute essays were1 for various     
reasons1 unable to do so1 and some      
alterations have been made in the titles

 of articles4 ,for the selection of     
authors and for the choice of subjects1 
the committee are mainly responsible1   
but for such share of the work in the   
preparation of the volume as usually    
falls to the lot of an editor ,i accept 
full responsibility4  ,authors were     
asked to address themselves primarily to
 the educated layman rather than to the 
expert4 ,it was hoped that the          
publication of the essays would serve   
the double purpose of illustrating the  
far-reaching influence of ,darwin's work
 on the progress of knowledge and the   
present attitude of original            
investigators and thinkers towards the  
views embodied in ,darwin's works4  ,in 
regard to the interpretation of a       
passage in ,the ,origin of ,species     
quoted by ,hugo de ,vries1 it seemed    
advisable to add an editorial footnote2 
but1 with this exception1 ,i have not   
felt it necessary to record any opinion 
on views stated in the essays4  ,in     
reading the essays in proof ,i have     

availed myself freely of the willing    
assistance of several ,cambridge        
friends1 among whom ,i wish more        
especially to thank ,mr ,francis ,darwin
 for the active interest he has taken in
 the preparation of the volume4 ,mrs    
,j4,a4 ,thomson kindly undertook the    
translation of the essays by ,prof4     
,weismann and ,prof4 ,schwalbe2 ,mrs    
,james ,ward was good enough to assist  
me by translating ,prof4 ,bougle's      
article on ,sociology1 and to ,mr       
,mc,cabe ,i am indebted for the         
translation of the essay by ,prof4      
,haeckel4 ,for the translation of the   
botanical articles by ,prof4 ,goebel1   
,prof4 ,klebs and ,prof4 ,strasburger1  
,i am responsible2 in the revision of   
the translation of ,prof4 ,strasburger's
 essay ,madame ,errera of ,brussels     
rendered valuable help4 ,mr ,wright1 the
 ,secretary of the ,press ,syndicate1   
and ,mr ,waller1 the ,assistant         
,secretary1 have cordially cooperated   
with me in my editorial work2 nor can ,i

 omit to thank the readers of the       
,university ,press for keeping watchful 
eyes on my shortcomings in the          
correction of proofs4  ,the two         
portraits of ,darwin are reproduced by  
permission of ,messrs ,maull and ,fox   
and ,messrs ,elliott and ,fry4 ,the     
photogravure of the study at ,down is   
reproduced from an etching by ,mr ,axel 
,haig1 lent by ,mr ,francis ,darwin2 the
 coloured plate illustrating ,prof4     
,weismann's essay was originally        
published by him in his ,vortrage uber  
,descendenztheorie which afterwards     
appeared 7#aijd7 in ,english under the  
title ,the ,evolution ,theory4 ,copies  
of this plate were supplied by ,messrs  
,fischer of ,jena4  ,the ,syndics of the
 ,university ,press have agreed1 in the 
event of this volume being a financial  
success1 to hand over the profits to a  
,university fund for the endowment of   
biological research4  ,it is clearly    
impossible to express adequately in a   
single volume of ,essays the influence  

of ,darwin's contributions to knowledge 
on the subsequent progress of scientific
 inquiry4 ,as ,huxley said in #ahhe3    
,whatever be the ultimate verdict of    
posterity upon this or that opinion     
which ,mr ,darwin has propounded2       
whatever adumbrations or anticipations  
of his doctrines may be found in the    
writings of his predecessors2 the broad 
fact remains that1 since the publication
 and by reason of the publication of    
,the ,origin of ,species the fundamental
 conceptions and the aims of the        
students of living ,nature have been    
completely changed444 ,but the impulse  
thus given to scientific thought rapidly
 spread beyond the ordinarily recognised
 limits of ,biology4 ,psychology1       
,ethics1 ,cosmology were stirred to     
their foundations1 and ',the ,origin of 
,species' proved itself to be the fixed 
point which the general doctrine needed 
in order to move the world4  ,in the    
contributions to this ,memorial ,volume1
 some of the authors have more          

especially concerned themselves with the
 results achieved by ,darwin's own work1
 while others pass in review the        
progress of research on lines which1    
though unknown or but little followed in
 his day1 are the direct outcome of his 
work4  ,the divergence of views among   
biologists in regard to the origin of   
species and as to the most promising    
directions in which to seek for truth is
 illustrated by the different opinions  
of contributors4 ,whether ,darwin's     
views on the modus operandi of          
evolutionary forces receive further     
confirmation in the future1 or whether  
they are materially modified1 in no way 
affects the truth of the statement that1
 by employing his life in adding a      
little to ,natural ,science1 he         
revolutionised the world of thought4    
,darwin wrote in #ahgb to ,alfred       
,russel ,wallace3 ,how grand is the     
onward rush of science3 it is enough to 
console us for the many errors which we 
have committed1 and for our efforts     

being overlaid and forgotten in the mass
 of new facts and new views which are   
daily turning up4 ,in the onward rush1  
it is easy for students convinced of the
 correctness of their own views and     
equally convinced of the falsity of     
those of their fellow-workers to forget 
the lessons of ,darwin's life4 ,in his  
autobiographical sketch1 he tells us1 ,i
 have steadily endeavoured to keep my   
mind free so as to give up any          
hypothesis1 however much beloved444as   
soon as facts are shown to be opposed to
 it4 ,writing to ,mr ,j4 ,scott1 he     
says1 ,it is a golden rule1 which ,i try
 to follow1 to put every fact which is  
opposed to one's preconceived opinion in
 the strongest light4 ,absolute accuracy
 is the hardest merit to attain1 and the
 highest merit4 ,any deviation is ruin4 
,he acted strictly in accordance with   
his determination expressed in a letter 
to ,lyell in #ahdd1 ,i shall keep out of
 controversy1 and just give my own      
facts4 ,as was said of another son of   

,cambridge1 ,sir ,george ,stokes1 ,he   
would no more have thought of disputing 
about priority1 or the authorship of an 
idea1 than of writing a report for a    
company promoter4 ,darwin's life affords
 a striking confirmation of the truth of
 ,hazlitt's aphorism1 ,where the pursuit
 of truth has been the habitual study of
 any man's life1 the love of truth will 
be his ruling passion4 ,great as was the
 intellect of ,darwin1 his character1 as
 ,huxley wrote1 was even nobler than his
 intellect4  ,a4,c4 ,,seward4  ,botany  
,school1 ,cambridge1 ,march #bj1 #aiji4 
,,contents ,i4 ,,introductory ,,letter  
,,to ,,the ,,editor from ,,sir ,,joseph 
,,dalton ,,hooker1 ,o4,m4  ,,ii4        
,,darwin',s ,,predecessors3  ,j4        
,,arthur ,,thomson1 ,professor of       
,natural ,history in the ,university of 
,aberdeen4  ,,iii4 ,,the ,,selection    
,,theory3  ,,august ,,weismann1         
,professor of ,zoology in the           
,university of ,freiburg 7,baden74      
,,iv4 ,,variation3  ,,hugo ,,de ,,vries1

 ,professor of ,botany in the           
,university of ,amsterdam4  ,v4         
,,heredity ,,and ,,variation ,,in       
,,modern ,,lights3  ,w4 ,,bateson1      
,professor of ,biology in the           
,university of ,cambridge4  ,,vi4 ,,the 
,,minute ,,structure ,,of ,,cells ,,in  
,,relation ,,to ,,heredity3  ,,eduard   
,,strasburger1 ,professor of ,botany in 
the ,university of ,bonn4  ,,vii4 ,,the 
,,descent ,,of ,,man3  ,g4 ,,schwalbe1  
,professor of ,anatomy in the           
,university of ,strassburg4  ,,viii4    
,,charles ,,darwin ,,as ,,an            
,,anthropologist3  ,,ernst ,,haeckel1   
,professor of ,zoology in the           
,university of ,jena4  ,,ix4 ,,some     
,,primitive ,,theories ,,of ,,the       
,,origin ,,of ,,man3  ,j4,g4 ,,frazer1  
,fellow of ,trinity ,college1           
,cambridge4  ,x4 ,,the ,,influence ,,of 
,,darwin ,,on ,,the ,,study ,,of        
,,animal ,,embryology3  ,a4 ,,sedgwick1 
,professor of ,zoology and ,comparative 
,anatomy in the ,university of          

,cambridge4  ,,xi4 ,,the                
,,palaeontological ,,record4 ,i4        
,,animals3  ,w4,b4 ,,scott1 ,professor  
of ,geology in the ,university of       
,princeton4  ,,xii4 ,,the               
,,palaeontological ,,record4 ,,ii4      
,,plants3  ,d4,h4 ,,scott1 ,president of
 the ,linnean ,society of ,london4      
,,xiii4 ,,the ,,influence ,,of          
,,environment ,,on ,,the ,,forms ,,of   
,,plants3  ,,georg ,,klebs1 ,professor  
of ,botany in the ,university of        
,heidelberg4  ,,xiv4 ,,experimental     
,,study ,,of ,,the ,,influence ,,of     
,,environment ,,on ,,animals3 ,,jacques 
,,loeb1 ,professor of ,physiology in the
 ,university of ,california4  ,,xv4     
,,the ,,value ,,of ,,colour ,,in ,,the  
,,struggle ,,for ,,life3  ,e4,b4        
,,poulton1 ,hope ,professor of ,zoology 
in the ,university of ,oxford4  ,,xvi4  
,,geographical ,,distribution ,,of      
,,plants3  ,,sir ,,william              
,,thiselton-,,dyer4  ,,xvii4            
,,geographical ,,distribution ,,of      

,,animals3  ,,hans ,,gadow1 ,strickland 
,curator and ,lecturer on ,zoology in   
the ,university of ,cambridge4  ,,xviii4
 ,,darwin ,,and ,,geology3  ,j4,w4      
,,judd4  ,,xix4 ,,darwin',s ,,work ,,on 
,,the ,,movements ,,of ,,plants3        
,,francis ,,darwin4  ,,xx4 ,,the        
,,biology ,,of ,,flowers3  ,k4 ,,goebel1
 ,professor of ,botany in the           
,university of ,munich4  ,,xxi4 ,,mental
 ,,factors ,,in ,,evolution3  ,c4       
,,lloyd ,,morgan1 ,professor of         
,psychology at ,university ,college1    
,bristol4  ,,xxii4 ,,the ,,influence    
,,of ,,the ,,conception ,,of ,,evolution
 ,,on ,,modern ,,philosophy3 ,h4        
,,hoffding1 ,professor of ,philosophy in
 the ,university of ,copenhagen4        
,,xxiii4 ,,darwinism ,,and ,,sociology3 
,c4 ,,bougle1 ,professor of ,social     
,philosophy in the ,university of       
,toulouse1 and ,deputy-,professor at the
 ,sorbonne1 ,paris4  ,,xxiv4 ,,the      
,,influence ,,of ,,darwin ,,upon        
,,religious ,,thought3  ,,rev4 ,p4,n4   

,,waggett4  ,,xxv4 ,,the ,,influence    
,,of ,,darwinism ,,on ,,the ,,study ,,of
 ,,religions3  ,,jane ,,ellen           
,,harrison1 ,staff-,lecturer and        
sometime ,fellow of ,newnham ,college1  
,cambridge4  ,,xxvi4 ,,evolution ,,and  
,,the ,,science ,,of ,,language3  ,p4   
,,giles1 ,reader in ,comparative        
,philology in the ,university of        
,cambridge4  ,,xxvii4 ,,darwinism ,,and 
,,history3  ,j4,b4 ,,bury1 ,regius      
,professor of ,modern ,history in the   
,university of ,cambridge4  ,,xxviii4   
,,the ,,genesis ,,of ,,double ,,stars3  
,,sir ,,george ,,darwin1 ,plumian       
,professor of ,astronomy and            
,experimental ,philosophy in the        
,university of ,cambridge4  ,,xxix4     
,,the ,,evolution ,,of ,,matter3        
,w4,c4,d4 ,,whetham1 ,fellow of ,trinity
 ,college1 ,cambridge4  ,,index4        
,,dates ,,of ,,the ,,publication ,of    
,,charles ,,darwin',s ,,books ,,and ,,of
 ,,the ,,principal ,,events ,,in ,,his  
,,life  #ahji3  ,charles ,darwin born at

 ,shrewsbury1 ,february #ab4  #ahag3    
,at #h #a_/b years old ,i went to ,mr   
,case's school4 7,a day-school at       
,shrewsbury kept by the ,rev ,g4 ,case1 
,minister of the ,unitarian ,chapel47   
#ahah3  ,i was at school at ,shrewsbury 
under a great scholar1 ,dr ,butler2 ,i  
learnt absolutely nothing1 except by    
amusing myself by reading and           
experimenting in ,chemistry4  #ahbe3    
,as ,i was doing no good at school1 my  
father wisely took me away at a rather  
earlier age than usual1 and sent me     
7,oct4 #ahbe7 to ,edinburgh ,university 
with my brother1 where ,i stayed for two
 years4  #ahbh3  ,began residence at    
,christ's ,college1 ,cambridge4  ,i went
 to ,cambridge early in the year #ahbh1 
and soon became acquainted with         
,professor ,henslow444,nothing could be 
more simple1 cordial and unpretending   
than the encouragement which he afforded
 to all young naturalists4  ,during the 
three years which ,i spent at ,cambridge
 my time was wasted1 as far as the      

academical studies were concerned1 as   
completely as at ,edinburgh and at      
school4  ,in order to pass the ,b4,a4   
,examination1 it was444necessary to get 
up ,paley's ',evidences of              
,christianity1' and his ',moral         
,philosophy'444 ,the careful study of   
these works1 without attempting to learn
 any part by rote1 was the only part of 
the academical course which444was of the
 least use to me in the education of my 
mind4  #ahca3  ,passed the examination  
for the ,b4,a4 degree in ,january and   
kept the following terms4  ,i gained a  
good place among the oi polloi or crowd 
of men who do not go in for honours4  ,i
 am very busy1444and see a great deal of
 ,henslow1 whom ,i do not know whether  
,i love or respect most4  ,dec4 #bg4    
,sailed from ,england on our            
circumnavigation1 in ,h4,m4,s4 ,beagle1 
a barque of #bce tons carrying #f guns1 
under ,capt4 ,fitz,roy4  ,there is      
indeed a tide in the affairs of men4    
#ahcf3  ,oct4 #d4 ,reached ,shrewsbury  

after absence of #e years and #b days4  
,you cannot imagine how gloriously      
delightful my first visit was at home2  
it was worth the banishment4  ,dec4 #ac4
 ,went to live at ,cambridge            
7,fitzwilliam ,street74  ,the only evil 
,i found in ,cambridge was its being too
 pleasant4  #ahcg3  ,on my return home  
7in the ',beagle'7 in the autumn of     
#ahcf ,i immediately began to prepare my
 journal for publication1 and then saw  
how many facts indicated the common     
descent of species444 ,in ,july 7#ahcg7 
,i opened my first note-book for facts  
in relation to the ,origin of ,species1 
about which ,i had long reflected1 and  
never ceased working for the next twenty
 years444 ,had been greatly struck from 
about the month of previous ,march on   
character of ,south ,american fossils1  
and species on ,galapagos ,archipelago4 
,these facts 7especially latter71 origin
 of all my views4  ,on ,march #g1 #ahcg 
,i took lodgings in 7#cf7 ,great        
,marlborough ,street in ,london1 and    

remained there for nearly two years1    
until ,i was married4  #ahch3  ,in      
,october1 that is fifteen months after  
,i had begun my systematic enquiry1 ,i  
happened to read for amusement ',malthus
 on ,population1' and being well        
prepared to appreciate the struggle for 
existence which everywhere goes on from 
long-continued observation of the habits
 of animals and plants1 it at once      
struck me that under these circumstances
 favourable variations would tend to be 
preserved1 and unfavourable ones to be  
destroyed4 ,the result of this would be 
the formation of new species4 ,here then
 ,i had at last got a theory by which to
 work2 but ,i was so anxious to avoid   
prejudice1 that ,i determined not for   
some time to write even the briefest    
sketch of it4  #ahci3  ,married at ,maer
 7,staffordshire7 to his first cousin   
,emma ,wedgwood1 daughter of ,josiah    
,wedgwood4  ,i marvel at my good fortune
 that she1 so infinitely my superior in 
every single moral quality1 consented to

 be my wife4 ,she has been my wise      
adviser and cheerful comforter          
throughout life1 which without her would
 have been during a very long period a  
miserable one from ill-health4 ,she has 
earned the love of every soul near her  
7,autobiography74  ,dec4 #ca4 ,entered  
#ab ,upper ,gower street 7now #aaj      
,gower street1 ,london74 ,there never   
was so good a house for me1 and ,i      
devoutly trust you 7his future wife7    
will approve of it equally4 ,the little 
garden is worth its weight in gold4     
,published ,journal and ,researches1    
being ,vol4 ,,iii4 of the ,narrative of 
the ,surveying ,voyage of ,h4,m4,s4     
',adventure' and ',beagle'444           
,publication of the ,zoology of the     
,voyage of ,h4,m4,s4 ',beagle'1 ,part   
,,ii41 ,mammalia1 by ,g4,r4 ,waterhouse1
 with a ,notice of their habits and     
ranges1 by ,charles ,darwin4  #ahdj3    
,contributed ,geological ,introduction  
to ,part ,i4 7,fossil ,mammalia7 of the 
,zoology of the ,voyage of ,h4,m4,s4    

',beagle' by ,richard ,owen4  #ahdb3    
,in ,june #ahdb ,i first allowed myself 
the satisfaction of writing a very brief
 abstract of my 7species7 theory in     
pencil in #ce pages2 and this was       
enlarged during the summer of #ahdd into
 one of #bcj pages1 which ,i had fairly 
copied out and still 7#ahgf7 possess4   
7,the first draft of ,the ,origin of    
,species1 edited by ,mr ,francis        
,darwin1 will be published this year    
7#aiji7 by the ,syndics of the          
,cambridge ,university ,press47  ,sept4 
#ad4 ,settled at the village of ,down in
 ,kent4  ,i think ,i was never in a more
 perfectly quiet country4  ,publication 
of ,the ,structure and ,distribution of 
,coral ,reefs2 being ,part ,i4 of the   
,geology of the ,voyage of the ,beagle4 
#ahdd3  ,publication of ,geological     
,observations on the ,volcanic ,islands 
visited during the ,voyage of ,h4,m4,s4 
',beagle'2 being ,part ,,ii4 of the     
,geology of the ,voyage of the          
',beagle'4  ,i think much more highly of

 my book on ,volcanic ,islands since ,mr
 ,judd1 by far the best judge on the    
subject in ,england1 has1 as ,i hear1   
learnt much from it4 7,autobiography1   
#ahgf47  #ahde3  ,publication of the    
,journal of ,researches as a separate   
book4  #ahdf3  ,publication of          
,geological ,observations on ,south     
,america2 being ,part ,,iii4 of the     
,geology of the ,voyage of the          
',beagle'4  #ahea3  ,publication of a   
,monograph of the ,fossil ,lepadidae and
 of a ,monograph of the sub-class       
,cirripedia4  ,i fear the study of the  
,cirripedia will ever remain 'wholly    
unapplied1' and yet ,i feel that such   
study is better than castle-building4   
#ahed3  ,publication of ,monographs of  
the ,balanidae and ,verrucidae4  ,i     
worked steadily on this subject         
for444eight years1 and ultimately       
published two thick volumes1 describing 
all the known living species1 and two   
thin quartos on the extinct species444  
,my work was of considerable use to me1 

when ,i had to discuss in the ,origin of
 ,species the principles of a natural   
classification4 ,nevertheless1 ,i doubt 
whether the work was worth the          
consumption of so much time4  ,from     
,september #ahed ,i devoted my whole    
time to arranging my huge pile of notes1
 to observing1 and to experimenting in  
relation to the transmutation of        
species4  #ahef3  ,early in #ahef ,lyell
 advised me to write out my views pretty
 fully1 and ,i began at once to do so on
 a scale three or four times as         
extensive as that which was afterwards  
followed in my ',origin of ,species'4   
#aheh3  ,joint paper by ,charles ,darwin
 and ,alfred ,russel ,wallace ,on the   
,tendency of ,species to form           
,varieties2 and on the perpetuation of  
,varieties and ,species by ,natural     
,means of ,selection1 communicated to   
the ,linnean ,society by ,sir ,charles  
,lyell and ,sir ,joseph ,hooker4  ,i was
 at first very unwilling to consent 7to 
the communication of his ,,ms4 to the   

,society7 as ,i thought ,mr ,wallace    
might consider my doing so              
unjustifiable1 for ,i did not then know 
how generous and noble was his          
disposition4  ,july #bj to ,aug4 #ab at 
,sandown 7,isle of ,wight7 began        
abstract of ,species book4  #ahei3      
,nov4 #bd4 ,publication of ,the ,origin 
of ,species 7#abej copies74  ,oh1 good  
heavens1 the relief to my head and body 
to banish the whole subject from my     
mind6444 ,but1 alas1 how frequent1 how  
almost universal it is in an author to  
persuade himself of the truth of his own
 dogmas4 ,my only hope is that ,i       
certainly see many difficulties of      
gigantic stature4  #ahfj3  ,publication 
of the second edition of the ,origin    
7#cjjj copies74  ,publication of a      
,naturalist's ,voyage4  #ahfa3          
,publication of the third edition of the
 ,origin 7#bjjj copies74  ,i am going to
 write a little book444 on ,orchids1 and
 to-day ,i hate them worse than         
everything4  #ahfb3  ,publication of the

 book ,on the various contrivances by   
which ,orchids are fertilised by        
,insects4  #ahfe3  ,read paper before   
the ,linnean ,society ,on the ,movements
 and ,habits of ,climbing plants4       
7,published as a book in #ahge47  #ahff3
  ,publication of the fourth edition of 
the ,origin 7#abej copies74  #ahfh3  ,i 
have sent the ,,ms4 of my big book1 and 
horridly1 disgustingly big it will be1  
to the printers4  ,publication of the   
,variation of ,animals and ,plants under
 ,domestication4  ,about my book1 ,i    
will give you 7,sir ,joseph ,hooker7 a  
bit of advice4 ,skip the whole of ,vol4 
,i1 except the last chapter1 7and that  
need only be skimmed71 and skip largely 
in the #bnd volume2 and then you will   
say it is a very good book4  ,towards   
the end of the work ,i give my          
well-abused hypothesis of ,pangenesis4  
,an unverified hypothesis is of little  
or no value2 but if anyone should       
hereafter be led to make observations by
 which some such hypothesis could be    

established1 ,i shall have done good    
service1 as an astonishing number of    
isolated facts can be thus connected    
together and rendered intelligible4     
#ahfi3  ,publication of the fifth       
edition of the ,origin4  #ahga3         
,publication of ,the ,descent of ,man4  
,although in the ',origin of ,species'  
the derivation of any particular species
 is never discussed1 yet ,i thought it  
best1 in order that no honourable man   
should accuse me of concealing my views1
 to add that by the work 'light would be
 thrown on the origin of man and his    
history'4  #ahgb3  ,publication of the  
sixth edition of the ,origin4           
,publication of ,the ,expression of the 
,emotions in ,man and ,animals4  #ahgd3 
,publication of the second edition of   
,the ,descent of ,man4  ,the new edition
 of the ,descent has turned out an awful
 job4 ,it took me ten days merely to    
glance over letters and reviews with    
criticisms and new facts4 ,it is a devil
 of a job4  ,publication of the second  

edition of ,the ,structure and          
,distribution of ,coral ,reefs4  #ahge3 
,publication of ,insectivorous ,plants4 
,i begin to think that every one who    
publishes a book is a fool4             
,publication of the second edition of   
,variation in ,animals and ,plants4     
,publication of ,the ,movements and     
,habits of ,climbing ,plants as a       
separate book4  #ahgf3  ,wrote          
,autobiographical ,sketch 7,life and    
,letters1 ,vol4 ,i41 ,chap ,,ii474      
,publication of ,the ,effects of ,cross 
and ,self fertilisation4  ,i now 7#ahha7
 believe1 however1444that ,i ought to   
have insisted more strongly than ,i did 
on the many adaptations for             
self-fertilisation4  ,publication of the
 second edition of ,observations on     
,volcanic ,islands4  #ahgg3             
,publication of ,the ,different ,forms  
of ,flowers on ,plants of the same      
species4  ,i do not suppose that ,i     
shall publish any more books444 ,i      
cannot endure being idle1 but heaven    

knows whether ,i am capable of any more 
good work4  ,publication of the second  
edition of the ,orchid book4  #ahgh3    
,publication of the second edition of   
,the ,effects of ,cross and ,self       
fertilisation4  #ahgi3  ,publication of 
an ,english translation of ,ernst       
,krause's ,erasmus ,darwin1 with a      
notice by ,charles ,darwin4 ,i am       
,,extremely glad that you approve of the
 little ',life' of our ,grandfather1 for
 ,i have been repenting that ,i ever    
undertook it1 as the work was quite     
beyond my tether4 7,to ,mr ,francis     
,galton1 ,nov4 #ad1 #ahgi47  #ahhj3     
,publication of ,the ,power of ,movement
 in ,plants4  ,it has always pleased me 
to exalt plants in the scale of         
organised beings4  ,publication of the  
second edition of ,the ,different ,forms
 of ,flowers4  #ahha3  ,wrote a         
continuation of the ,autobiography4     
,publication of ,the ,formation of      
,vegetable ,mould1 through the ,action  
of ,worms4  ,it is the completion of a  

short paper read before the ,geological 
,society more than forty years ago1 and 
has revived old geological thoughts444  
,as far as ,i can judge it will be a    
curious little book4  #ahhb3  ,charles  
,darwin died at ,down1 ,april #ai1 and  
was buried in ,westminster ,abbey1      
,april #bf1 in the north aisle of the   
,nave a few feet from the grave of ,sir 
,isaac ,newton4  ,as for myself1 ,i     
believe that ,i have acted rightly in   
steadily following and devoting my life 
to ,science4 ,i feel no remorse from    
having committed any great sin1 but have
 often and often regretted that ,i have 
not done more direct good to my fellow  
creatures4  ,the quotations in the above
 ,epitome are taken from the            
,autobiography and published ,letters3--
  ,the ,life and ,letters of ,charles   
,darwin1 including an ,autobiographical 
,chapter4 ,edited by his son1 ,francis  
,darwin1 #c ,vols41 ,london1 #ahhg4     
,charles ,darwin3 ,his life told in an  
,autobiographical ,chapter1 and in a    

selected series of his published        
,letters4 ,edited by his son1 ,francis  
,darwin1 ,london1 #aijb4  ,more ,letters
 of ,charles ,darwin4 ,a record of his  
work in a series of hitherto unpublished
 ,letters4 ,edited by ,francis ,darwin  
and ,a4,c4 ,seward1 #b ,vols41 ,london1 
#aijc4     ,i4 ,,introductory ,,letter  
,from ,sir ,joseph ,dalton ,hooker1     
,o4,m41 ,g4,c4,s4,i41 ,c4,b41 ,m4,d41   
,d4,c4,l41 ,,ll4,d41 ,f4,r4,s41 ,,etc4  
,the ,camp1  near ,sunningdale1         
,january #ae1 #aiji4  ,dear ,professor  
,seward1  ,the publication of a ,series 
of ,essays in ,commemoration of the     
century of the birth of ,charles ,darwin
 and of the fiftieth anniversary of the 
publication of ,the ,origin of ,species 
is assuredly welcome and is a subject of
 congratulation to all students of      
,science4  ,these ,essays on the        
progress of ,science and ,philosophy as 
affected by ,darwin's labours have been 
written by men known for their ability  
to discuss the problems which he so     

successfully worked to solve4 ,they     
cannot but prove to be of enduring      
value1 whether for the information of   
the general reader or as guides to      
investigators occupied with problems    
similar to those which engaged the      
attention of ,darwin4  ,the essayists   
have been fortunate in having for       
reference the five published volumes of 
,charles ,darwin's ,life and            
,correspondence4 ,for there is set forth
 in his own words the inception in his  
mind of the problems1 geological1       
zoological and botanical1 hypothetical  
and theoretical1 which he set himself to
 solve and the steps by which he        
proceeded to investigate them with the  
view of correlating the phenomena of    
life with the evolution of living       
things4 ,in his letters he expressed    
himself in language so lucid and so     
little burthened with technical terms   
that they may be regarded as models for 
those who were asked to address         
themselves primarily to the educated    

reader rather than to the expert4  ,i   
may add that by no one can the perusal  
of the ,essays be more vividly          
appreciated than by the writer of these 
lines4 ,it was my privilege for forty   
years to possess the intimate friendship
 of ,charles ,darwin and to be his      
companion during many of his working    
hours in ,study1 ,laboratory1 and       
,garden4 ,i was the recipient of letters
 from him1 relating mainly to the       
progress of his researches1 the copies  
of which 7the originals are now in the  
possession of his family7 cover upwards 
of a thousand pages of foolscap1 each   
page containing1 on an average1 three   
hundred words4  ,that the editorship of 
these ,essays has been entrusted to a   
,cambridge ,professor of ,botany must be
 gratifying to all concerned in their   
production and in their perusal1        
recalling as it does the fact that      
,charles ,darwin's instructor in        
scientific methods was his lifelong     
friend the late ,rev4 ,j4,s4 ,henslow at

 that time ,professor of ,botany in the 
,university4 ,it was owing to his       
recommendation that his pupil was       
appointed ,naturalist to ,h4,m4,s4      
,beagle1 a service which ,darwin himself
 regarded as marking the dawn of his    
scientific career4  ,very sincerely     
yours1  ,j4,d4 ,,hooker4     ,,ii4      
,,darwin',s ,,predecessors4 ,by ,j4     
,arthur ,thomson4  ,professor of        
,natural ,history in the ,university of 
,aberdeen4   ,in seeking to discover    
,darwin's relation to his predecessors  
it is useful to distinguish the various 
services which he rendered to the theory
 of organic evolution4  7,i7 ,as        
everyone knows1 the general idea of the 
,doctrine of ,descent is that the plants
 and animals of the present-day are the 
lineal descendants of ancestors on the  
whole somewhat simpler1 that these again
 are descended from yet simpler forms1  
and so on backwards towards the literal 
,protozoa and ,protophyta about which we
 unfortunately know nothing4 ,now no one

 supposes that ,darwin originated this  
idea1 which in rudiment at least is as  
old as ,aristotle4 ,what ,darwin did was
 to make it current intellectual coin4  
,he gave it a form that commended itself
 to the scientific and public           
intelligence of the day1 and he won     
wide-spread conviction by showing with  
consummate skill that it was an         
effective formula to work with1 a key   
which no lock refused4 ,in a scholarly1 
critical1 and pre-eminently fair-minded 
way1 admitting difficulties and removing
 them1 foreseeing objections and        
forestalling them1 he showed that the   
doctrine of descent supplied a modal    
interpretation of how our present-day   
fauna and flora have come to be4  7,,ii7
 ,in the second place1 ,darwin applied  
the evolution-idea to particular        
problems1 such as the descent of man1   
and showed what a powerful organon it   
is1 introducing order into masses of    
uncorrelated facts1 interpreting enigmas
 both of structure and function1 both   

bodily and mental1 and1 best of all1    
stimulating and guiding further         
investigation4 ,but here again it cannot
 be claimed that ,darwin was original4  
,the problem of the descent or ascent of
 man1 and other particular cases of     
evolution1 had attracted not a few      
naturalists before ,darwin's day1 though
 no one 7except ,herbert ,spencer in the
 psychological domain 7#ahee77 had come 
near him in precision and thoroughness  
of inquiry4  7,,iii7 ,in the third      
place1 ,darwin contributed largely to a 
knowledge of the factors in the         
evolution-process1 especially by his    
analysis of what occurs in the case of  
domestic animals and cultivated plants1 
and by his elaboration of the theory of 
,natural ,selection1 which ,alfred      
,russel ,wallace independently stated at
 the same time1 and of which there had  
been a few previous suggestions of a    
more or less vague description4 ,it was 
here that ,darwin's originality was     
greatest1 for he revealed to naturalists

 the many different forms--often very   
subtle--which natural selection takes1  
and with the insight of a disciplined   
scientific imagination he realised what 
a mighty engine of progress it has been 
and is4  7,,iv7 ,as an epoch-marking    
contribution1 not only to ,aetiology but
 to ,natural ,history in the widest     
sense1 we rank the picture which ,darwin
 gave to the world of the web of life1  
that is to say1 of the inter-relations  
and linkages in ,nature4 ,for the       
,biology of the individual--if that be  
not a contradiction in terms--no idea is
 more fundamental than that of the      
correlation of organs1 but ,darwin's    
most characteristic contribution was not
 less fundamental1--it was the idea of  
the correlation of organisms4 ,this1    
again1 was not novel2 we find it in the 
works of naturalist like ,christian     
,conrad ,sprengel1 ,gilbert ,white1 and 
,alexander von ,humboldt1 but the       
realisation of its full import was      
distinctively ,darwinian4  ,,as         

,,regards ,,the ,,general ,,idea ,,of   
,,organic ,,evolution4  ,while it is    
true1 as ,prof4 ,h4,f4 ,osborn puts it1 
that ',before and after ,darwin' will   
always be the ante et post urbem        
conditam of biological history1 it is   
also true that the general idea of      
organic evolution is very ancient4 ,in  
his admirable sketch ,from the ,greeks  
to ,darwin 7,columbia ,university       
,biological ,series1 ,vol4 ,i4 ,new     
,york and ,london1 #ahid4 ,we must      
acknowledge our great indebtness to this
 fine piece of work471 ,prof4 ,osborn   
has shown that several of the ancient   
philosophers looked upon ,nature as a   
gradual development and as still in     
process of change4 ,in the suggestions  
of ,empedocles1 to take the best        
instance1 there were four sparks of     
truth1--first1 that the development of  
life was a gradual process2 second1 that
 plants were evolved before animals2    
third1 that imperfect forms were        
gradually replaced 7not succeeded7 by   

perfect forms2 fourth1 that the natural 
cause of the production of perfect forms
 was the extinction of the imperfect4   
7,op4 cit4 page #da47 ,but the          
fundamental idea of one stage giving    
origin to another was absent4 ,as the   
blue ,aegean teemed with treasures of   
beauty and threw many upon its shores1  
so did ,nature produce like a fertile   
artist what had to be rejected as well  
as what was able to survive1 but the    
idea of one species emerging out of     
another was not yet conceived4          
,aristotle's views of ,nature 7,see     
,g4,j4 ,romanes1 ,aristotle as a        
,naturalist1 ,contemporary ,review1     
,vol4 ,,lix4 page #bge1 #ahia2 ,g4      
,pouchet ,la ,biologie ,aristotelique1  
,paris1 #ahhe2 ,e4 ,zeller1 ,a ,history 
of ,greek ,philosophy1 ,london1 #ahha1  
and ,ueber die griechischen ,vorganger  
,darwin's1 ,abhandl4 ,berlin ,akad4     
#ahgh1 pages #aaa-abd47 seem to have    
been more definitely evolutionist than  
those of his predecessors1 in this      

sense1 at least1 that he recognised not 
only an ascending scale1 but a genetic  
series from polyp to man and an age-long
 movement towards perfection4 ,it is due
 to the resistance of matter to form    
that ,nature can only rise by degrees   
from lower to higher types4 ,nature     
produces those things which1 being      
continually moved by a certain principle
 contained in themselves1 arrive at a   
certain end4  ,to discern the outcrop of
 evolution-doctrine in the long interval
 between ,aristotle and ,bacon seems to 
be very difficult1 and some of the      
instances that have been cited strike   
one as forced4 ,epicurus and ,lucretius1
 often called poets of evolution1 both  
pictured animals as arising directly out
 of the earth1 very much as ,milton's   
lion long afterwards pawed its way out4 
,even when we come to ,bruno who wrote  
that to the sound of the harp of the    
,universal ,apollo 7the ,world ,spirit71
 the lower organisms are called by      
stages to higher1 and the lower stages  

are connected by intermediate forms with
 the higher1 there is great room1 as    
,prof4 ,osborn points out 7op4 cit4 page
 #ha471 for difference of opinion as to 
how far he was an evolutionist in our   
sense of the term4  ,the awakening of   
natural science in the sixteenth century
 brought the possibility of a concrete  
evolution theory nearer1 and in the     
early seventeenth century we find       
evidences of a new spirit--in the       
embryology of ,harvey and the           
classifications of ,ray4 ,besides sober 
naturalists there were speculative      
dreamers in the sixteenth and           
seventeenth centuries who had at least  
got beyond static formulae1 but1 as     
,professor ,osborn points out 7op4 cit4 
page #hg471 it is a very striking fact1 
that the basis of our modern methods of 
studying the ,evolution problem was     
established not by the early naturalists
 nor by the speculative writers1 but by 
the ,philosophers4 ,he refers to ,bacon1
 ,descartes1 ,leibnitz1 ,hume1 ,kant1   

,lessing1 ,herder1 and ,schelling4 ,they
 alone were upon the main track of      
modern thought4 ,it is evident that they
 were groping in the dark for a working 
theory of the ,evolution of life1 and it
 is remarkable that they clearly        
perceived from the outset that the point
 to which observation should be directed
 was not the past but the present       
mutability of species1 and further1 that
 this mutability was simply the         
variation of individuals on an extended 
scale4  ,bacon seems to have been one of
 the first to think definitely about the
 mutability of species1 and he was far  
ahead of his age in his suggestion of   
what we now call a ,station of          
,experimental ,evolution4 ,leibnitz     
discusses in so many words how the      
species of animals may be changed and   
how intermediate species may once have  
linked those that now seem              
discontinuous4 ,all natural orders of   
beings present but a single chain444    
,all advances by degrees in ,nature1 and

 nothing by leaps4 ,similar evolutionist
 statements are to be found in the works
 of the other philosophers1 to whom     
,prof4 ,osborn refers1 who were1 indeed1
 more scientific than the naturalists of
 their day4 ,it must be borne in mind   
that the general idea of organic        
evolution--that the present is the child
 of the past--is in great part just the 
idea of human history projected upon the
 natural world1 differentiated by the   
qualification that the continuous       
,becoming has been wrought out by forces
 inherent in the organisms themselves   
and in their environment4  ,a reference 
to ,kant 7,see ,brock1 ,die ,stellung   
,kant's zur ,deszendenztheorie1 ,biol4  
,centralbl4 ,,viii4 #ahhi1 pages        
#fda-fdh4 ,fritz ,schultze1 ,kant und   
,darwin1 ,jena1 #ahge47 should come in  
historical order after ,buffon1 with    
whose writings he was acquainted1 but he
 seems1 along with ,herder and          
,schelling1 to be best regarded as the  
culmination of the evolutionist         

philosophers--of those at least who     
interested themselves in scientific     
problems4 ,in a famous passage he speaks
 of the agreement of so many kinds of   
animals in a certain common plan of     
structure444 an analogy of forms which  
strengthens the supposition that they   
have an actual blood-relationship1 due  
to derivation from a common parent4 ,he 
speaks of the great ,family of          
creatures1 for as a ,family we must     
conceive it1 if the above-mentioned     
continuous and connected relationship   
has a real foundation4 ,prof4 ,osborn   
alludes to the scientific caution which 
led ,kant1 biology being what it was1 to
 refuse to entertain the hope that a    
,newton may one day arise even to make  
the production of a blade of grass      
comprehensible1 according to natural    
laws ordained by no intention4 ,as      
,prof4 ,haeckel finely observes1 ,darwin
 rose up as ,kant's ,newton4 7,mr       
,alfred ,russel ,wallace writes3 ,we    
claim for ,darwin that he is the ,newton

 of natural history1 and that1 just so  
surely as that the discovery and        
demonstration by ,newton of the law of  
gravitation established order in place  
of chaos and laid a sure foundation for 
all future study of the starry heavens1 
so surely has ,darwin1 by his discovery 
of the law of natural selection and his 
demonstration of the great principle of 
the preservation of useful variations in
 the struggle for life1 not only thrown 
a flood of light on the process of      
development of the whole organic world1 
but also established a firm foundation  
for all future study of nature4         
7,darwinism1 ,london1 #ahhi1 page #i74  
,see also ,prof4 ,karl ,pearson's       
,grammar of ,science 7#bnd edition71    
,london1 #aijj1 page #cb4 ,see ,osborn1 
op4 cit4 ,page #ajj477  ,the scientific 
renaissance brought a wealth of fresh   
impressions and some freedom from the   
tyranny of tradition1 and the twofold   
stimulus stirred the speculative        
activity of a great variety of men from 

old ,claude ,duret of ,moulins1 of whose
 weird transformism 7#afji7 ,dr ,henry  
de ,varigny 7,experimental ,evolution4  
,london1 #ahib4 ,chap4 #a4 page #ad47   
gives us a glimpse1 to ,lorenz ,oken    
7#agii-ahea7 whose writings are such    
mixtures of sense and nonsense that some
 regard him as a far-seeing prophet and 
others as a fatuous follower of         
intellectual will-o'-the-wisps4         
,similarly1 for ,de ,maillet1           
,maupertuis1 ,diderot1 ,bonnet1 and     
others1 we must agree with ,professor   
,osborn that they were not actually in  
the main ,evolution movement4 ,some have
 been included in the roll of honour on 
very slender evidence1 ,robinet for     
instance1 whose evolutionism seems to us
 extremely dubious4 7,see ,j4 ,arthur   
,thomson1 ,the ,science of ,life4       
,london1 #ahii4 ,chap4 ,,xvi4 ,evolution
 of ,evolution ,theory47  ,the first    
naturalist to give a broad and concrete 
expression to the evolutionist doctrine 
of descent was ,buffon 7#agjg-aghh71 but

 it is interesting to recall the fact   
that his contemporary ,linnaeus         
7#agjg-aggh71 protagonist of the        
counter-doctrine of the fixity of       
species 7,see ,carus ,sterne 7,ernest   
,krause71 ,die allgemeine               
,weltanschauung in ihrer historischen   
,entwickelung4 ,stuttgart1 #ahhi4       
,chapter entitled ,bestandigkeit oder   
,veranderlichkeit der ,naturwesen471    
went the length of admitting 7in #agfb7 
that new species might arise by         
intercrossing4 ,buffon's position among 
the pioneers of the evolution-doctrine  
is weakened by his habit of vacillating 
between his own conclusions and the     
orthodoxy of the ,sorbonne1 but there is
 no doubt that he had a firm grasp of   
the general idea of l'enchainement des  
etres4  ,erasmus ,darwin 7#agca-ahjb71  
probably influenced by ,buffon1 was     
another firm evolutionist1 and the      
outline of his argument in the ,zoonomia
 7,zoonomia1 or the ,laws of ,organic   
,life1 #b vols4 ,london1 #agid2 ,osborn 

op4 cit4 page #ade47 might serve in part
 at least to-day4 ,when we revolve in   
our minds the metamorphoses of animals1 
as from the tadpole to the frog2        
secondly1 the changes produced by       
artificial cultivation1 as in the breeds
 of horses1 dogs1 and sheep2 thirdly1   
the changes produced by conditions of   
climate and of season1 as in the sheep  
of warm climates being covered with hair
 instead of wool1 and the hares and     
partridges of northern climates becoming
 white in winter3 when1 further1 we     
observe the changes of structure        
produced by habit1 as seen especially in
 men of different occupations2 or the   
changes produced by artificial          
mutilation and prenatal influences1 as  
in the crossing of species and          
production of monsters2 fourth1 when we 
observe the essential unity of plan in  
all warm-blooded animals1--we are led to
 conclude that they have been alike     
produced from a similar living          
filament444 ,from thus meditating upon  

the minute portion of time in which many
 of the above changes have been         
produced1 would it be too bold to       
imagine1 in the great length of time    
since the earth began to exist1 perhaps 
millions of years before the            
commencement of the history of mankind1 
that all warm-blooded animals have      
arisen from one living filament8444     
,this idea of the gradual generation of 
all things seems to have been as        
familiar to the ancient philosophers as 
to the modern ones1 and to have given   
rise to the beautiful hieroglyphic      
figure of the proton oon1 or first great
 egg1 produced by night1 that is1 whose 
origin is involved in obscurity1 and    
animated by ,eros1 that is1 by ,divine  
,love2 from whence proceeded all things 
which exist4  ,lamarck 7#agdd-ahbi7     
seems to have become an evolutionist    
independently of ,erasmus ,darwin's     
influence1 though the parallelism       
between them is striking4 ,he probably  
owed something to ,buffon1 but he       

developed his theory along a different  
line4 ,whatever view be held in regard  
to that theory there is no doubt that   
,lamarck was a thorough-going           
evolutionist4 ,professor ,haeckel speaks
 of the ,philosophie ,zoologique as the 
first connected and thoroughly logical  
exposition of the theory of descent4    
7,see ,alpheus ,s4 ,packard1 ,lamarck1  
the ,founder of ,evolution1 ,his ,life  
and ,work1 with ,translations of his    
writings on ,organic ,evolution4        
,london1 #aija47  ,besides the three old
 masters1 as we may call them1 ,buffon1 
,erasmus ,darwin1 and ,lamarck1 there   
were other quite convinced              
pre-,darwinian evolutionists4 ,the      
historian of the theory of descent must 
take account of ,treviranus whose       
,biology or ,philosophy of ,animate     
,nature is full of evolutionary         
suggestions2 of ,etienne ,geoffroy ,st  
,hilaire1 who in #ahcj1 before the      
,french ,academy of ,sciences1 fought   
with ,cuvier1 the fellow-worker of his  

youth1 an intellectual duel on the      
question of descent2 of ,goethe1 one of 
the founders of morphology and the      
greatest poet of ,evolution--who1 in his
 eighty-first year1 heard the tidings of
 ,geoffroy ,st ,hilaire's defeat with an
 interest which transcended the         
political anxieties of the time2 and of 
many others who had gained with more or 
less confidence and clearness a new     
outlook on ,nature4 ,it will be         
remembered that ,darwin refers to       
thirty-four more or less evolutionist   
authors in his ,historical ,sketch1 and 
the list might be added to4 ,especially 
when we come near to #aheh do the       
numbers increase1 and one of the most   
remarkable1 as also most independent    
champions of the evolution-idea before  
that date was ,herbert ,spencer1 who not
 only marshalled the arguments in a very
 forcible way in #aheb1 but applied the 
formula in detail in his ,principles of 
,psychology in #ahee4 7,see ,edward     
,clodd1 ,pioneers of ,evolution1        

,london1 page #afa1 #ahig47  ,it is     
right and proper that we should shake   
ourselves free from all creationist     
appreciations of ,darwin1 and that we   
should recognise the services of        
pre-,darwinian evolutionists who helped 
to make the time ripe1 yet one cannot   
help feeling that the citation of them  
is apt to suggest two fallacies4 ,it may
 suggest that ,darwin simply entered    
into the labours of his predecessors1   
whereas1 as a matter of fact1 he knew   
very little about them till after he had
 been for years at work4 ,to write1 as  
,samuel ,butler did1 ,buffon planted1   
,erasmus ,darwin and ,lamarck watered1  
but it was ,mr ,darwin who said ',that  
fruit is ripe1' and shook it into his   
lap444 seems to us a quite misleading   
version of the facts of the case4 ,the  
second fallacy which the historical     
citation is a little apt to suggest is  
that the filiation of ideas is a simple 
problem4 ,on the contrary1 the history  
of an idea1 like the pedigree of an     

organism1 is often very intricate1 and  
the evolution of the evolution-idea is  
bound up with the whole progress of the 
world4 ,thus in order to interpret      
,darwin's clear formulation of the idea 
of organic evolution and his convincing 
presentation of it1 we have to do more  
than go back to his immediate           
predecessors1 such as ,buffon1 ,erasmus 
,darwin1 and ,lamarck2 we have to       
inquire into the acceptance of          
evolutionary conceptions in regard to   
other orders of facts1 such as the earth
 and the solar system 7,see ,chapter    
,,ix4 ,the ,genetic ,view of ,nature in 
,j4,t4 ,merz's ,history of ,european    
,thought in the ,nineteenth ,century1   
,vol4 #b1 ,edinburgh and ,london1       
#aijc472 we have to realise how the     
growing success of scientific           
interpretation along other lines gave   
confidence to those who refused to admit
 that there was any domain from which   
science could be excluded as a          
trespasser2 we have to take account of  

the development of philosophical        
thought1 and even of theological and    
religious movements2 we should also1 if 
we are wise enough1 consider social     
changes4 ,in short1 we must abandon the 
idea that we can understand the history 
of any science as such1 without         
reference to contemporary evolution in  
other departments of activity4  ,while  
there were many evolutionists before    
,darwin1 few of them were expert        
naturalists and few were known outside a
 small circle2 what was of much more    
importance was that the genetic view of 
nature was insinuating itself in regard 
to other than biological orders of      
facts1 here a little and there a little1
 and that the scientific spirit had     
ripened since the days when ,cuvier     
laughed ,lamarck out of court4 ,how was 
it that ,darwin succeeded where others  
had failed8 ,because1 in the first      
place1 he had clear visions--pensees de 
la jeunesse1 executees par l'age        
mur--which a ,university curriculum had 

not made impossible1 which the ,beagle  
voyage made vivid1 which an unrivalled  
,british doggedness made real--visions  
of the web of life1 of the fountain of  
change within the organism1 of the      
struggle for existence and its          
winnowing1 and of the spreading         
genealogical tree4 ,because1 in the     
second place1 he put so much grit into  
the verification of his visions1 putting
 them to the proof in an argument which 
is of its kind--direct demonstration    
being out of the question--quite        
unequalled4 ,because1 in the third      
place1 he broke down the opposition     
which the most scientific had felt to   
the seductive modal formula of evolution
 by bringing forward a more plausible   
theory of the process than had been     
previously suggested4 ,nor can one      
forget1 since questions of this         
magnitude are human and not merely      
academic1 that he wrote so that all men 
could understand4  ,,as ,,regards ,,the 
,,factors ,,of ,,evolution4  ,it is     

admitted by all who are acquainted with 
the history of biology that the general 
idea of organic evolution as expressed  
in the ,doctrine of ,descent was quite  
familiar to ,darwin's grandfather1 and  
to others before and after him1 as we   
have briefly indicated4 ,it must also be
 admitted that some of these pioneers of
 evolutionism did more than apply the   
evolution-idea as a modal formula of    
becoming1 they began to inquire into the
 factors in the process4 ,thus there    
were pre-,darwinian theories of         
evolution1 and to these we must now     
briefly refer4 7,see ,prof4 ,w4,a4      
,locy's ,biology and its ,makers4 ,new  
,york1 #aijh4 ,part ,,ii4 ,the ,doctrine
 of ,organic ,evolution47  ,in all      
biological thinking we have to work with
 the categories                         
,organism--,function--,environment1 and 
theories of evolution may be classified 
in relation to these4 ,to some it has   
always seemed that the fundamental fact 
is the living organism1--a creative     

agent1 a striving will1 a changeful     
,proteus1 selecting its environment1    
adjusting itself to it1                 
self-differentiating and self-adaptive4 
,the necessity of recognising the       
importance of the organism is admitted  
by all ,darwinians who start with inborn
 variations1 but it is open to question 
whether the whole truth of what we might
 call the ,goethian position is         
exhausted in the postulate of inherent  
variability4  ,to others it has always  
seemed that the emphasis should be laid 
on ,function1--on use and disuse1 on    
doing and not doing4 ,practice makes    
perfect2 c'est a force de forger qu'on  
devient forgeron4 ,this is one of the   
fundamental ideas of ,lamarckism2 to    
some extent it met with ,darwin's       
approval2 and it finds many supporters  
to-day4 ,one of the ablest of these--,mr
 ,francis ,darwin--has recently given   
strong reasons for combining a          
modernised ,lamarckism with what we     
usually regard as sound ,darwinism4     

7,presidential ,address to the ,british 
,association meeting at ,dublin in      
#aijh47  ,to others it has always seemed
 that the emphasis should be laid on the
 ,environment1 which wakes the organism 
to action1 prompts it to change1 makes  
dints upon it1 moulds it1 prunes it1 and
 finally1 perhaps1 kills it4 ,it is     
again impossible to doubt that there is 
truth in this view1 for even if         
environmentally induced modifications be
 not transmissible1 environmentally     
induced variations are2 and even if the 
direct influence of the environment be  
less important than many enthusiastic   
supporters of this view--may we call    
them ,buffonians--think1 there remains  
the indirect influence which ,darwinians
 in part rely on1--the eliminative      
process4 ,even if the extreme view be   
held that the only form of discriminate 
elimination that counts is              
inter-organismal competition1 this might
 be included under the rubric of the    
animate environment4  ,in many passages 

,buffon 7,see in particular ,samuel     
,butler1 ,evolution ,old and ,new1      
,london1 #ahgi2 ,j4,l4 de ,lanessan1    
,buffon et ,darwin1 ,revue              
,scientifique1 ,,xliii4 pages #che-cia1 
#dbe-dcb1 #ahhi47 definitely suggested  
that environmental                      
influences--especially of climate and   
food--were directly productive of       
changes in organisms1 but he did not    
discuss the question of the             
transmissibility of the modifications so
 induced1 and it is difficult to gather 
from his inconsistent writings what     
extent of transformation he really      
believed in4 ,prof4 ,osborn says of     
,buffon3 ,the struggle for existence1   
the elimination of the least-perfected  
species1 the contest between the        
fecundity of certain species and their  
constant destruction1 are all clearly   
expressed in various passages4 ,he      
quotes two of these 7op4 cit4 page      
#acf473  ,le cours ordinaire de la      
nature vivante1 est en general toujours 

constant1 toujours le meme2 son         
mouvement1 toujours regulier1 roule sur 
deux points inebranlables3 l'un1 la     
fecondite sans bornes donnee a toutes   
les especes2 l'autre1 les obstacles sans
 nombre qui reduisent cette fecondite a 
une mesure determinee et ne laissent en 
tout temps qu'a peu pres la meme        
quantite d'individus de chaque espece444
 ,les especes les moins parfaites1 les  
plus delicates1 les plus pesantes1 les  
moins agissantes1 les moins armees1     
etc41 ont deja disparu ou disparaitront4
  ,erasmus ,darwin 7,see ,ernst ,krause 
and ,charles ,darwin1 ,erasmus ,darwin1 
,london1 #ahgi47 had a firm grip of the 
idea of the gradual formation and       
improvement of the ,animal world1 and he
 had his theory of the process4 ,no     
sentence is more characteristic than    
this3 ,all animals undergo              
transformations which are in part       
produced by their own exertions1 in     
response to pleasures and pains1 and    
many of these acquired forms or         

propensities are transmitted to their   
posterity4 ,this is ,lamarckism before  
,lamarck1 as his grandson pointed out4  
,his central idea is that wants         
stimulate efforts and that these result 
in improvements1 which subsequent       
generations make better still4 ,he      
realised something of the struggle for  
existence and even pointed out that this
 advantageously checks the rapid        
multiplication4 ,as ,dr ,krause points  
out1 ,darwin just misses the connection 
between this struggle and the ,survival 
of the ,fittest4 7,osborn op4 cit4 page 
#adb47  ,lamarck 7#agdd-ahbi7 7,see ,e4 
,perrier ,la ,philosophie ,zoologique   
avant ,darwin1 ,paris1 #ahhd2 ,a4 de    
,quatrefages1 ,darwin et ses            
,precurseurs ,francais1 ,paris1 #ahgj2  
,packard op4 cit42 also ,claus1 ,lamarck
 als ,begrunder der ,descendenzlehre1   
,wien1 #ahhh2 ,haeckel1 ,natural        
,history of ,creation1 ,english         
translation ,london1 #ahgi2 ,lang ,zur  
,charakteristik der ,forschungswege von 

,lamarck und ,darwin1 ,jena1 #ahhi47    
seems to have thought out his theory of 
evolution without any knowledge of      
,erasmus ,darwin's which it closely     
resembled4 ,the central idea of his     
theory was the cumulative inheritance of
 functional modifications4 ,changes in  
environment bring about changes in the  
habits of animals4 ,changes in their    
wants necessarily bring about parallel  
changes in their habits4 ,if new wants  
become constant or very lasting1 they   
form new habits1 the new habits involve 
the use of new parts1 or a different use
 of old parts1 which results finally in 
the production of new organs and the    
modification of old ones4 ,he differed  
from ,buffon in not attaching           
importance1 as far as animals are       
concerned1 to the direct influence of   
the environment1 for environment can    
effect no direct change whatever upon   
the organisation of animals1 but in     
regard to plants he agreed with ,buffon 
that external conditions directly       

moulded them4  ,treviranus 7#aggf-ahcg7 
7,see ,huxley's article ,evolution in   
,biology1 ,encyclopaedia ,britannica    
7#ith edit471 #ahgh1 pages #gdd-gea1 and
 ,sully's article1 ,evolution in        
,philosophy1 ibid4 pages #gea-ggb471    
whom ,huxley ranked beside ,lamarck1 was
 on the whole ,buffonian1 attaching     
chief importance to the influence of a  
changeful environment both in modifying 
and in eliminating1 but he was also     
,goethian1 for instance in his idea that
 species like individuals pass through  
periods of growth1 full bloom1 and      
decline4 ,thus1 it is not only the great
 catastrophes of ,nature which have     
caused extinction1 but the completion of
 cycles of existence1 out of which new  
cycles have begun4 ,a characteristic    
sentence is quoted by ,prof4 ,osborn3   
,in every living being there exists a   
capability of an endless variety of     
form-assumption2 each possesses the     
power to adapt its organisation to the  
changes of the outer world1 and it is   

this power1 put into action by the      
change of the universe1 that has raised 
the simple zoophytes of the primitive   
world to continually higher stages of   
organisation1 and has introduced a      
countless variety of species into       
animate ,nature4  ,goethe 7#agdi-ahcb7  
7,see ,haeckel1 ,die ,naturanschauung   
von ,darwin1 ,goethe und ,lamarck1      
,jena1 #ahhb471 who knew ,buffon's work 
but not ,lamarck's1 is peculiarly       
interesting as one of the first to use  
the evolution-idea as a guiding         
hypothesis1 e4g4 in the interpretation  
of vestigial structures in man1 and to  
realise that organisms express an       
attempt to make a compromise between    
specific inertia and individual change4 
,he gave the finest expression that     
science has yet known--if it has known  
it--of the kernel-idea of what is called
 bathmism1 the idea of an inherent      
growth-force--and at the same time he   
held that the way of life powerfully    
reacts upon all form and that the       

orderly growth of form yields to change 
from externally acting causes4  ,besides
 ,buffon1 ,erasmus ,darwin1 ,lamarck1   
,treviranus1 and ,goethe1 there were    
other pioneers of evolution1 whose views
 have been often discussed and          
appraised4 ,etienne ,geoffroy           
,saint-,hilaire 7#aggb-ahdd71 whose work
 ,goethe so much admired1 was on the    
whole ,buffonian1 emphasising the direct
 action of the changeful milieu4        
,species vary with their environment1   
and existing species have descended by  
modification from earlier and somewhat  
simpler species4 ,he had a glimpse of   
the selection idea1 and believed in     
mutations or sudden leaps--induced in   
the embryonic condition by external     
influences4 ,the complete history of    
evolution-theories will include many    
instances of guesses at truth which were
 afterwards substantiated1 thus the     
geographer von ,buch 7#aggc-ahec7       
detected the importance of the          
,isolation factor on which ,wagner1     

,romanes1 ,gulick and others have laid  
great stress1 but we must content       
ourselves with recalling one other      
pioneer1 the author of the ,vestiges of 
,creation 7#ahdd71 a work which passed  
through ten editions in nine years and  
certainly helped to harrow the soil for 
,darwin's sowing4 ,as ,darwin said1 it  
did excellent service in this country in
 calling attention to the subject1 in   
removing prejudice1 and in thus         
preparing the ground for the reception  
of analogous views4 7,origin of ,species
 7#fth edition71 page xvii47 ,its       
author1 ,robert ,chambers 7#ahjb-ahga7  
was in part a ,buffonian--maintaining   
that environment moulded organisms      
adaptively1 and in part a               
,goethian--believing in an inherent     
progressive impulse which lifted        
organisms from one grade of organisation
 to another4  ,,as ,,regards ,,natural  
,,selection4  ,the only thinker to whom 
,darwin was directly indebted1 so far as
 the theory of ,natural ,selection is   

concerned1 was ,malthus1 and we may once
 more quote the well-known passage in   
the ,autobiography3 ,in ,october1 #ahch1
 that is1 fifteen months after ,i had   
begun my systematic enquiry1 ,i happened
 to read for amusement ',malthus on     
,population'1 and being well prepared to
 appreciate the struggle for existence  
which everywhere goes on from           
long-continued observation of the habits
 of animals and plants1 it at once      
struck me that under these circumstances
 favourable variations would tend to be 
preserved1 and unfavourable ones to be  
destroyed4 ,the result of this would be 
the formation of new species4 7,the     
,life and ,letters of ,charles ,darwin1 
,vol4 #a4 page #hc4 ,london1 #ahhg47    
,although ,malthus gives no adumbration 
of the idea of ,natural ,selection in   
his exposition of the eliminative       
processes which go on in mankind1 the   
suggestive value of his essay is        
undeniable1 as is strikingly borne out  
by the fact that it gave to ,alfred     

,russel ,wallace also the long-sought   
clue to the effective agent in the      
evolution of organic species4 7,a4,r4   
,wallace1 ,my ,life1 ,a ,record of      
,events and ,opinions1 ,london1 #aije1  
,vol4 #a4 page #bcb47 ,one day in       
,ternate when he was resting between    
fits of fever1 something brought to his 
recollection the work of ,malthus which 
he had read twelve years before4 ,i     
thought of his clear exposition of 'the 
positive checks to increase'--disease1  
accidents1 war1 and famine--which keep  
down the population of savage races to  
so much lower an average than that of   
more civilized peoples4 ,it then        
occurred to me that these causes or     
their equivalents are continually acting
 in the case of animals also2 and as    
animals usually breed much more rapidly 
than does mankind1 the destruction every
 year from these causes must be enormous
 in order to keep down the numbers of   
each species1 since they evidently do   
not increase regularly from year to     

year1 as otherwise the world would long 
ago have been densely crowded with those
 that breed most quickly4 ,vaguely      
thinking over the enormous and constant 
destruction which this implied1 it      
occurred to me to ask the question1 ,why
 do some die and some live8 ,and the    
answer was clearly1 that on the whole   
the best fitted live4 ,from the effects 
of disease the most healthy escaped2    
from enemies the strongest1 the         
swiftest1 or the most cunning2 from     
famine the best hunters or those with   
the best digestion2 and so on4 ,then it 
suddenly flashed upon me that this      
self-acting process would necessarily   
,,improve ,,the ,,race1 because in every
 generation the inferior would          
inevitably be killed off and the        
superior would remain--that is1 ,,the   
,,fittest ,,would ,,survive4 7,ibid4    
,vol4 #a4 page #cfa47 ,we need not      
apologise for this long quotation1 it is
 a tribute to ,darwin's magnanimous     
colleague1 the ,nestor of the           

evolutionist camp1--and it probably     
indicates the line of thought which     
,darwin himself followed4 ,it is        
interesting also to recall the fact that
 in #aheb1 when ,herbert ,spencer wrote 
his famous ,leader article on ,the      
,development ,hypothesis in which he    
argued powerfully for the thesis that   
the whole animate world is the result of
 an age-long process of natural         
transformation1 he wrote for ,the       
,westminster ,review another important  
essay1 ,a ,theory of ,population deduced
 from the ,general ,law of ,animal      
,fertility1 towards the close of which  
he came within an ace of recognising    
that the struggle for existence was a   
factor in organic evolution4 ,at a time 
when pressure of population was         
practically interesting men's minds1    
,darwin1 ,wallace1 and ,spencer were    
being independently led from a social   
problem to a biological theory4 ,there  
could be no better illustration1 as     
,prof4 ,patrick ,geddes has pointed out1

 of the ,comtian thesis that science is 
a social phenomenon4  ,therefore1 as far
 more important than any further        
ferreting out of vague hints of ,natural
 ,selection in books which ,darwin never
 read1 we would indicate by a quotation 
the view that the central idea in       
,darwinism is correlated with           
contemporary social evolution4 ,the     
substitution of ,darwin for ,paley as   
the chief interpreter of the order of   
nature is currently regarded as the     
displacement of an anthropomorphic view 
by a purely scientific one3 a little    
reflection1 however1 will show that what
 has actually happened has been merely  
the replacement of the anthropomorphism 
of the eighteenth century by that of the
 nineteenth4 ,for the place vacated by  
,paley's theological and metaphysical   
explanation has simply been occupied by 
that suggested to ,darwin and ,wallace  
by ,malthus in terms of the prevalent   
severity of industrial competition1 and 
those phenomena of the struggle for     

existence which the light of            
contemporary economic theory has enabled
 us to discern1 have thus come to be    
temporarily exalted into a complete     
explanation of organic progress4 7,p4   
,geddes1 article ,biology1 ,chambers's  
,encyclopaedia47 ,it goes without saying
 that the idea suggested by ,malthus was
 developed by ,darwin into a biological 
theory which was then painstakingly     
verified by being used as an            
interpretative formula1 and that the    
validity of a theory so established is  
not affected by what suggested it1 but  
the practical question which this line  
of thought raises in the mind is this3  
if ,biology did thus borrow with such   
splendid results from social theory1 why
 should we not more deliberately repeat 
the experiment8  ,darwin was            
characteristically frank and generous in
 admitting that the principle of        
,natural ,selection had been            
independently recognised by ,dr ,w4,c4  
,wells in #ahac and by ,mr ,patrick     

,matthew in #ahca1 but he had no        
knowledge of these anticipations when he
 published the first edition of ,the    
,origin of ,species4 ,wells1 whose      
,essay on ,dew is still remembered1 read
 in #ahac before the ,royal ,society a  
short paper entitled ,an account of a   
,white ,female1 part of whose skin      
resembles that of a ,negro 7published in
 #ahah74 ,in this communication1 as     
,darwin said1 he observes1 firstly1 that
 all animals tend to vary in some       
degree1 and1 secondly1 that             
agriculturists improve their            
domesticated animals by selection2 and  
then1 he adds1 but what is done in this 
latter case 'by art1 seems to be done   
with equal efficacy1 though more slowly1
 by nature1 in the formation of         
varieties of mankind1 fitted for the    
country which they inhabit4' 7,origin of
 ,species 7#fth edition7 page xv47 ,thus
 ,wells had the clear idea of survival  
dependent upon a favourable variation1  
but he makes no more use of the idea and

 applies it only to man4 ,there is not  
in the paper the least hint that the    
author ever thought of generalising the 
remarkable sentence quoted above4  ,of  
,mr ,patrick ,matthew1 who buried his   
treasure in an appendix to a work on    
,naval ,timber and ,arboriculture1      
,darwin said that he clearly saw the    
full force of the principle of natural  
selection4 ,in #ahfj ,darwin wrote--very
 characteristically--about this to      
,lyell3 ,mr ,patrick ,matthew publishes 
a long extract from his work on ,naval  
,timber and ,arboriculture1 published in
 #ahca1 in which he briefly but         
completely anticipates the theory of    
,natural ,selection4 ,i have ordered the
 book1 as some passages are rather      
obscure1 but it is certainly1 ,i think1 
a complete but not developed            
anticipation4 ,erasmus always said that 
surely this would be shown to be the    
case some day4 ,anyhow1 one may be      
excused in not having discovered the    
fact in a work on ,naval ,timber4 7,life

 and ,letters ,,ii4 page #cja47  ,de    
,quatrefages and ,de ,varigny have      
maintained that the botanist ,naudin    
stated the theory of evolution by       
natural selection in #aheb4 ,he explains
 very clearly the process of artificial 
selection1 and says that in the garden  
we are following ,nature's method4 ,we  
do not think that ,nature has made her  
species in a different fashion from that
 in which we proceed ourselves in order 
to make our variations4 ,but1 as ,darwin
 said1 he does not show how selection   
acts under nature4 ,similarly it must be
 noted in regard to several             
pre-,darwinian pictures of the struggle 
for existence 7such as ,herder's1 who   
wrote in #agij ,all is in struggle444   
each one for himself and so on71 that a 
recognition of this is only the first   
step in ,darwinism4  ,profs4 ,e4        
,perrier and ,h4,f4 ,osborn have called 
attention to a remarkable anticipation  
of the selection-idea which is to be    
found in the speculations of ,etienne   

,geoffroy ,st ,hilaire 7#ahbe-ahbh7 on  
the evolution of modern ,crocodilians   
from the ancient ,teleosaurs4 ,changing 
environment induced changes in the      
respiratory system and far-reaching     
consequences followed4 ,the atmosphere1 
acting upon the pulmonary cells1 brings 
about modifications which are favourable
 or destructive 7'funestes'72 these are 
inherited1 and they influence all the   
rest of the organisation of the animal  
because if these modifications lead to  
injurious effects1 the animals which    
exhibit them perish and are replaced by 
others of a somewhat different form1 a  
form changed so as to be adapted to 7a  
la convenance7 the new environment4     
,prof4 ,e4,b4 ,poulton 7,science        
,progress1 ,new ,series1 ,vol4 ,i4      
#ahig4 ,a ,remarkable ,anticipation of  
,modern ,views on ,evolution4 ,see also 
,chap4 ,,vi4 in ,essays on ,evolution1  
,oxford1 #aijh47 has shown that the     
anthropologist ,james ,cowles ,prichard 
7#aghf-ahdh7 must be included1 even in  

spite of himself1 among the precursors  
of ,darwin4 ,in some passages of the    
second edition of his ,researches into  
the ,physical ,history of ,mankind      
7#ahbf71 he certainly talks evolution   
and anticipates ,prof4 ,weismann in     
denying the transmission of acquired    
characters4 ,he is1 however1 sadly      
self-contradictory and his evolutionism 
weakens in subsequent editions--the only
 ones that ,darwin saw4 ,prof4 ,poulton 
finds in ,prichard's work a recognition 
of the operation of ,natural ,selection4
 ,after enquiring how it is that 'these 
varieties are developed and preserved in
 connection with particular climates and
 differences of local situation1' he    
gives the following very significant    
answer3 ',one cause which tends to      
maintain this relation is obvious4      
,individuals and families1 and even     
whole colonies1 perish and disappear in 
climates for which they are1 by         
peculiarity of constitution1 not        
adapted4 ,of this fact proofs have been 

already mentioned4' ,mr ,francis ,darwin
 and ,prof4 ,a4,c4 ,seward discuss      
,prichard's anticipations in ,more      
,letters of ,charles ,darwin1 ,vol4 ,i4 
page #dc1 and come to the conclusion    
that the evolutionary passages are      
entirely neutralised by others of an    
opposite trend4 ,there is the same      
difficulty with ,buffon4  ,hints of the 
idea of ,natural ,selection have been   
detected elsewhere4 ,james ,watt 7,see  
,prof4 ,patrick ,geddes's article       
,variation and ,selection1              
,encyclopaedia ,britannica 7#ith        
edition7 #ahhh471 for instance1 has been
 reported as one of the anticipators    
7#ahea74 ,but we need not prolong the   
inquiry further1 since ,darwin did not  
know of any anticipations until after he
 had published the immortal work of     
#ahei1 and since none of those who got  
hold of the idea made any use of it4    
,what ,darwin did was to follow the clue
 which ,malthus gave him1 to realise1   
first by genius and afterwards by       

patience1 how the complex and subtle    
struggle for existence works out a      
natural selection of those organisms    
which vary in the direction of fitter   
adaptation to the conditions of their   
life4 ,so much success attended his     
application of the ,selection-formula   
that for a time he regarded ,natural    
,selection as almost the sole factor in 
evolution1 variations being             
pre-supposed2 gradually1 however1 he    
came to recognise that there was some   
validity in the factors which had been  
emphasized by ,lamarck and by ,buffon1  
and in his well-known summing up in the 
sixth edition of the ,origin he says of 
the transformation of species3 ,this has
 been effected chiefly through the      
natural selection of numerous           
successive1 slight1 favourable          
variations2 aided in an important manner
 by the inherited effects of the use and
 disuse of parts2 and in an unimportant 
manner1 that is1 in relation to adaptive
 structures1 whether past or present1 by

 the direct action of external          
conditions1 and by variations which seem
 to us in our ignorance to arise        
spontaneously4  ,to sum up3 the idea of 
organic evolution1 older than           
,aristotle1 slowly developed from the   
stage of suggestion to the stage of     
verification1 and the first convincing  
verification was ,darwin's2 from being  
an a priori anticipation it has become  
an interpretation of nature1 and ,darwin
 is still the chief interpreter2 from   
being a modal interpretation it has     
advanced to the rank of a causal theory1
 the most convincing part of which men  
will never cease to call ,darwinism4    
,,iii4 ,,the ,,selection ,,theory1 ,by  
,august ,weismann4  ,professor of       
,zoology in the ,university of ,freiburg
 7,baden74   ,i4 ,,the ,,idea ,,of      
,,selection4  ,many and diverse were the
 discoveries made by ,charles ,darwin in
 the course of a long and strenuous     
life1 but none of them has had so       
far-reaching an influence on the science

 and thought of his time as the theory  
of selection4 ,i do not believe that the
 theory of evolution would have made its
 way so easily and so quickly after     
,darwin took up the cudgels in favour of
 it1 if he had not been able to support 
it by a principle which was capable of  
solving1 in a simple manner1 the        
greatest riddle that living nature      
presents to us1--,i mean the            
purposiveness of every living form      
relative to the conditions of its life  
and its marvellously exact adaptation to
 these4  ,everyone knows that ,darwin   
was not alone in discovering the        
principle of selection1 and that the    
same idea occurred simultaneously and   
independently to ,alfred ,russel        
,wallace4 ,at the memorable meeting of  
the ,linnean ,society on #ast ,july1    
#aheh1 two papers were read             
7communicated by ,lyell and ,hooker7    
both setting forth the same idea of     
selection4 ,one was written by ,charles 
,darwin in ,kent1 the other by ,alfred  

,wallace in ,ternate1 in the ,malay     
,archipelago4 ,it was a splendid proof  
of the magnanimity of these two         
investigators1 that they thus1 in all   
friendliness and without envy1 united in
 laying their ideas before a scientific 
tribunal3 their names will always shine 
side by side as two of the brightest    
stars in the scientific sky4  ,but it is
 with ,charles ,darwin that ,i am here  
chiefly concerned1 since this paper is  
intended to aid in the commemoration of 
the hundredth anniversary of his birth4 
,the idea of selection set forth by the 
two naturalists was at the time         
absolutely new1 but it was also so      
simple that ,huxley could say of it     
later1 ,how extremely stupid not to have
 thought of that4 ,as ,darwin was led to
 the general doctrine of descent1 not   
through the labours of his predecessors 
in the early years of the century1 but  
by his own observations1 so it was in   
regard to the principle of selection4   
,he was struck by the innumerable cases 

of adaptation1 as1 for instance1 that of
 the woodpeckers and tree-frogs to      
climbing1 or the hooks and feather-like 
appendages of seeds1 which aid in the   
distribution of plants1 and he said to  
himself that an explanation of          
adaptations was the first thing to be   
sought for in attempting to formulate a 
theory of evolution4  ,but since        
adaptations point to ,,changes which    
have been undergone by the ancestral    
forms of existing species1 it is        
necessary1 first of all1 to inquire how 
far species in general are ,,variable4  
,thus ,darwin's attention was directed  
in the first place to the phenomenon of 
variability1 and the use man has made of
 this1 from very early times1 in the    
breeding of his domesticated animals and
 cultivated plants4 ,he inquired        
carefully how breeders set to work1 when
 they wished to modify the structure and
 appearance of a species to their own   
ends1 and it was soon clear to him that 
,,selection ,,for ,,breeding ,,purposes 

played the chief part4  ,but how was it 
possible that such processes should     
occur in free nature8 ,who is here the  
breeder1 making the selection1 choosing 
out one individual to bring forth       
offspring and rejecting others8 ,that   
was the problem that for a long time    
remained a riddle to him4  ,darwin      
himself relates how illumination        
suddenly came to him4 ,he had been      
reading1 for his own pleasure1 ,malthus'
 book on ,population1 and1 as he had    
long known from numerous observations1  
that every species gives rise to many   
more descendants than ever attain to    
maturity1 and that1 therefore1 the      
greater number of the descendants of a  
species perish without reproducing1 the 
idea came to him that the decision as to
 which member of a species was to       
perish1 and which was to attain to      
maturity and reproduction might not be a
 matter of chance1 but might be         
determined by the constitution of the   
individuals themselves1 according as    

they were more or less fitted for       
survival4 ,with this idea the foundation
 of the theory of selection was laid4   
,in ,,artificial ,,selection the breeder
 chooses out for pairing only such      
individuals as possess the character    
desired by him in a somewhat higher     
degree than the rest of the race4 ,some 
of the descendants inherit this         
character1 often in a still higher      
degree1 and if this method be pursued   
throughout several generations1 the race
 is transformed in respect of that      
particular character4  ,,natural        
,,selection depends on the same three   
factors as ,,artificial ,,selection3 on 
,,variability1 ,,inheritance1 and       
,,selection ,,for ,,breeding1 but this  
last is here carried out not by a       
breeder but by what ,darwin called the  
struggle for existence4 ,this last      
factor is one of the special features of
 the ,darwinian conception of nature4   
,that there are carnivorous animals     
which take heavy toll in every          

generation of the progeny of the animals
 on which they prey1 and that there are 
herbivores which decimate the plants in 
every generation had long been known1   
but it is only since ,darwin's time that
 sufficient attention has been paid to  
the facts that1 in addition to this     
regular destruction1 there exists       
between the members of a species a keen 
competition for space and food1 which   
limits multiplication1 and that numerous
 individuals of each species perish     
because of unfavourable climatic        
conditions4 ,the struggle for existence1
 which ,darwin regarded as taking the   
place of the human breeder in free      
nature1 is not a direct struggle between
 carnivores and their prey1 but is the  
assumed competition for survival between
 individuals ,,of ,,the ,,same species1 
of which1 on an average1 only those     
survive to reproduce which have the     
greatest power of resistance1 while the 
others1 less favourably constituted1    
perish early4 ,this struggle is so keen1

 that1 within a limited area1 where the 
conditions of life have long remained   
unchanged1 of every species1 whatever be
 the degree of fertility1 only two1 ,,on
 ,,an ,,average1 of the descendants of  
each pair survive2 the others succumb   
either to enemies1 or to disadvantages  
of climate1 or to accident4 ,a high     
degree of fertility is thus not an      
indication of the special success of a  
species1 but of the numerous dangers    
that have attended its evolution4 ,of   
the six young brought forth by a pair of
 elephants in the course of their lives 
only two survive in a given area2       
similarly1 of the millions of eggs which
 two thread-worms leave behind them only
 two survive4 ,it is thus possible to   
estimate the dangers which threaten a   
species by its ratio of elimination1 or1
 since this cannot be done directly1 by 
its fertility4  ,although a great number
 of the descendants of each generation  
fall victims to accident1 among those   
that remain it is still the greater or  

lesser fitness of the organism that     
determines the selection for breeding   
purposes1 and it would be               
incomprehensible if1 in this            
competition1 it were not ultimately1    
that is1 on an average1 the best        
equipped which survive1 in the sense of 
living long enough to reproduce4  ,thus 
the principle of natural selection is   
,,the ,,selection ,,of ,,the ,,best     
,,for ,,reproduction1 whether the best  
refers to the whole constitution1 to one
 or more parts of the organism1 or to   
one or more stages of development4      
,every organ1 every part1 every         
character of an animal1 fertility and   
intelligence included1 must be improved 
in this manner1 and be gradually brought
 up in the course of generations to its 
highest attainable state of perfection4 
,and not only may improvement of parts  
be brought about in this way1 but new   
parts and organs may arise1 since1      
through the slow and minute steps of    
individual or fluctuating variations1 a 

part may be added here or dropped out   
there1 and thus something new is        
produced4  ,the principle of selection  
solved the riddle as to how what was    
purposive could conceivably be brought  
about without the intervention of a     
directing power1 the riddle which       
animate nature presents to our          
intelligence at every turn1 and in face 
of which the mind of a ,kant could find 
no way out1 for he regarded a solution  
of it as not to be hoped for4 ,for1 even
 if we were to assume an evolutionary   
force that is continually transforming  
the most primitive and the simplest     
forms of life into ever higher forms1   
and the homogeneity of primitive times  
into the infinite variety of the        
present1 we should still be unable to   
infer from this alone how each of the   
numberless forms adapted to particular  
conditions of life should have appeared 
,,precisely ,,at ,,the ,,right ,,moment 
,,in ,,the ,,history ,,of ,,the ,,earth 
to which their adaptations were         

appropriate1 and precisely at the proper
 place in which all the conditions of   
life to which they were adapted         
occurred3 the humming-birds at the same 
time as the flowers2 the trichina at the
 same time as the pig2 the bark-coloured
 moth at the same time as the oak1 and  
the wasp-like moth at the same time as  
the wasp which protects it4 ,without    
processes of selection we should be     
obliged to assume a pre-established     
harmony after the famous ,leibnitzian   
model1 by means of which the clock of   
the evolution of organisms is so        
regulated as to strike in exact         
synchronism with that of the history of 
the earth6 ,all forms of life are       
strictly adapted to the conditions of   
their life1 and can persist under these 
conditions alone4  ,there must therefore
 be an intrinsic connection between the 
conditions and the structural           
adaptations of the organism1 and1       
,,since ,,the ,,conditions ,,of ,,life  
,,cannot ,,be ,,determined ,,by ,,the   

,,animal ,,itself1 ,,the ,,adaptations  
,,must ,,be ,,called ,,forth ,,by ,,the 
,,conditions4  ,the selection theory    
teaches us how this is conceivable1     
since it enables us to understand that  
there is a continual production of what 
is non-purposive as well as of what is  
purposive1 but the purposive alone      
survives1 while the non-purposive       
perishes in the very act of arising4    
,this is the old wisdom taught long ago 
by ,empedocles4  ,,ii4 ,,the            
,,lamarckian ,,principle4  ,lamarck1 as 
is well known1 formulated a definite    
theory of evolution at the beginning of 
the nineteenth century1 exactly fifty   
years before the ,darwin-,wallace       
principle of selection was given to the 
world4 ,this brilliant investigator also
 endeavoured to support his theory by   
demonstrating forces which might have   
brought about the transformations of the
 organic world in the course of the     
ages4 ,in addition to other factors1 he 
laid special emphasis on the increased  

or diminished use of the parts of the   
body1 assuming that the strengthening or
 weakening which takes place from this  
cause during the individual life1 could 
be handed on to the offspring1 and thus 
intensified and raised to the rank of a 
specific character4 ,darwin also        
regarded this ,,lamarckian ,,principle1 
as it is now generally called1 as a     
factor in evolution1 but he was not     
fully convinced of the transmissibility 
of acquired characters4  ,as ,i have    
here to deal only with the theory of    
selection1 ,i need not discuss the      
,lamarckian hypothesis1 but ,i must     
express my opinion that there is room   
for much doubt as to the cooperation of 
this principle in evolution4 ,not only  
is it difficult to imagine how the      
transmission of functional modifications
 could take place1 but1 up to the       
present time1 notwithstanding the       
endeavours of many excellent            
investigators1 not a single actual proof
 of such inheritance has been brought   

forward4 ,semon's experiments on plants 
are1 according to the botanist ,pfeffer1
 not to be relied on1 and even the      
recent1 beautiful experiments made by   
,dr ,kammerer on salamanders1 cannot1 as
 ,i hope to show elsewhere1 be regarded 
as proof1 if only because they do not   
deal at all with functional             
modifications1 that is1 with            
modifications brought about by use1 and 
it is to these ,,alone that the         
,lamarckian principle refers4  ,,iii4   
,,objections ,,to ,,the ,,theory ,,of   
,,selection4  7a7 ,saltatory evolution4 
,the ,darwinian doctrine of evolution   
depends essentially on ,,the            
,,cumulative ,,augmentation of minute   
variations in the direction of utility4 
,but can such minute variations1 which  
are undoubtedly continually appearing   
among the individuals of the same       
species1 possess any selection-value2   
can they determine which individuals are
 to survive1 and which are to succumb2  
can they be increased by natural        

selection till they attain to the       
highest development of a purposive      
variation8  ,to many this seems so      
improbable that they have urged a theory
 of evolution by leaps from species to  
species4 ,kolliker1 in #ahgb1 compared  
the evolution of species with the       
processes which we can observe in the   
individual life in cases of alternation 
of generations4 ,but a polyp only gives 
rise to a medusa because it has itself  
arisen from one1 and there can be no    
question of a medusa ever having arisen 
suddenly and de novo from a polyp-bud1  
if only because both forms are adapted  
in their structure as a whole1 and in   
every detail to the conditions of their 
life4 ,a sudden origin1 in a natural    
way1 of numerous adaptations is         
inconceivable4 ,even the degeneration of
 a medusoid from a free-swimming animal 
to a mere brood-sac 7gonophore7 is not  
sudden and saltatory1 but occurs by     
imperceptible modifications throughout  
hundreds of years1 as we can learn from 

the numerous stages of the process of   
degeneration persisting at the same time
 in different species4  ,if1 then1 the  
degeneration to a simple brood-sac takes
 place only by very slow transitions1   
each stage of which may last for        
centuries1 how could the much more      
complex ,,ascending evolution possibly  
have taken place by sudden leaps8 ,i    
regard this argument as capable of      
further extension1 for wherever in      
nature we come upon degeneration1 it is 
taking place by minute steps and with a 
slowness that makes it not directly     
perceptible1 and ,i believe that this in
 itself justifies us in concluding that 
,,the ,,same ,,must ,,be ,,true ,,of    
,,ascending evolution4 ,but in the      
latter case the goal can seldom be      
distinctly recognised while in cases of 
degeneration the starting-point of the  
process can often be inferred1 because  
several nearly related species may      
represent different stages4  ,in recent 
years ,bateson in particular has        

championed the idea of saltatory1 or    
so-called discontinuous evolution1 and  
has collected a number of cases in which
 more or less marked variations have    
suddenly appeared4 ,these are taken for 
the most part from among domesticated   
animals which have been bred and crossed
 for a long time1 and it is hardly to be
 wondered at that their much mixed and  
much influenced germ-plasm should1 under
 certain conditions1 give rise to       
remarkable phenomena1 often indeed      
producing forms which are strongly      
suggestive of monstrosities1 and which  
would undoubtedly not survive in free   
nature1 unprotected by man4 ,i should   
regard such cases as due to an          
intensified germinal selection--though  
this is to anticipate a little--and from
 this point of view it cannot be denied 
that they have a special interest4 ,but 
they seem to me to have no significance 
as far as the transformation of species 
is concerned1 if only because of the    
extreme rarity of their occurrence4     

,there are1 however1 many variations    
which have appeared in a sudden and     
saltatory manner1 and some of these     
,darwin pointed out and discussed in    
detail3 the copper beech1 the weeping   
trees1 the oak with fern-like leaves1   
certain garden-flowers1 etc4 ,but none  
of them have persisted in free nature1  
or evolved into permanent types4  ,on   
the other hand1 wherever enduring types 
have arisen1 we find traces of a gradual
 origin by successive stages1 even if1  
at first sight1 their origin may appear 
to have been sudden4 ,this is the case  
with ,,seasonal ,,dimorphism1 the first 
known cases of which exhibited marked   
differences between the two generations1
 the winter and the summer brood4 ,take 
for instance the much discussed and     
studied form ,vanessa 7,araschnia7      
levana-prorsa4 ,here the differences    
between the two forms are so great and  
so apparently disconnected1 that one    
might almost believe it to be a sudden  
mutation1 were it not that old          

transition-stages can be called forth by
 particular temperatures1 and we know   
other butterflies1 as for instance our  
,garden ,whites1 in which the           
differences between the two generations 
are not nearly so marked2 indeed1 they  
are so little apparent that they are    
scarcely likely to be noticed except by 
experts4 ,thus here again there are     
small initial steps1 some of which1     
indeed1 must be regarded as adaptations1
 such as the green-sprinkled or lightly 
tinted under-surface which gives them a 
deceptive resemblance to parsley or to  
,cardamine leaves4  ,even if saltatory  
variations do occur1 we cannot assume   
that these ,,have ,,ever ,,led ,,to     
,,forms ,,which ,,are ,,capable ,,of    
,,survival ,,under ,,the ,,conditions   
,,of ,,wild ,,life4 ,experience has     
shown that in plants which have suddenly
 varied the power of persistence is     
diminished4 ,korschinksky attributes to 
them weaknesses of organisation in      
general2 they bloom late1 ripen few of  

their seeds1 and show great             
sensitiveness to cold4 ,these are not   
the characters which make for success in
 the struggle for existence4  ,we must  
briefly refer here to the views--much   
discussed in the last decade--of ,h4 de 
,vries1 who believes that the roots of  
transformation must be sought for in    
,,saltatory ,,variations ,,arising      
,,from ,,internal ,,causes1 and         
distinguishes such ,,mutations1 as he   
has called them1 from ordinary          
individual variations1 in that they     
breed true1 that is1 with strict        
inbreeding they are handed on pure to   
the next generation4 ,i have elsewhere  
endeavoured to point out the weaknesses 
of this theory 7,vortrage uber          
,descendenztheorie1 ,jena1 #aijd1 ,,ii4 
#bfi4 ,english ,translation ,london1    
#aijd1 ,,ii4 page #cag471 and ,i am the 
less inclined to return to it here that 
it now appears 7,see ,poulton1 ,essays  
on ,evolution1 ,oxford1 #aijh1 pages    
xix-xxii47 that the far-reaching        

conclusions drawn by de ,vries from his 
observations on the ,evening ,primrose1 
,oenothera lamarckiana1 rest upon a very
 insecure foundation4 ,the plant from   
which de ,vries saw numerous            
species--his mutations--arise was not1  
as he assumed1 a ,,wild ,,species that  
had been introduced to ,europe from     
,america1 but was probably a hybrid form
 which was first discovered in the      
,jardin des ,plantes in ,paris1 and     
which does not appear to exist anywhere 
in ,america as a wild species4  ,this   
gives a severe shock to the ,mutation   
theory1 for the other ,,actually ,,wild 
species with which de ,vries            
experimented showed no mutations but    
yielded only negative results4  ,thus we
 come to the conclusion that ,darwin    
7,origin of ,species 7#fth edition71    
pages #agf et seq47 was right in        
regarding transformations as taking     
place by minute steps1 which1 if useful1
 are augmented in the course of         
innumerable generations1 because their  

possessors more frequently survive in   
the struggle for existence4  7b7        
,,selection-,,value ,,of ,,the ,,initial
 ,,steps4  ,is it possible that the     
significant deviations which we know as 
individual variations can form the      
beginning of a process of selection8    
,can they decide which is to perish and 
which to survive8 ,to use a phrase of   
,romanes1 can they have                 
,,selection-,,value8  ,darwin himself   
answered this question1 and brought     
together many excellent examples to show
 that differences1 apparently           
insignificant because very small1 might 
be of decisive importance for the life  
of the possessor4 ,but it is by no means
 enough to bring forward cases of this  
kind1 for the question is not merely    
whether finished adaptations have       
selection-value1 but whether the first  
beginnings of these1 and whether the    
small1 ,i might almost say minimal      
increments1 which have led up from these
 beginnings to the perfect adaptation1  

have also had selection-value4 ,to this 
question even one who1 like myself1 has 
been for many years a convinced adherent
 of the theory of selection1 can only   
reply3 ,,we ,,must ,,assume ,,so1 ,,but 
,,we ,,cannot ,,prove ,,it ,,in ,,any   
,,case4 ,it is not upon demonstrative   
evidence that we rely when we champion  
the doctrine of selection as a          
scientific truth2 we base our argument  
on quite other grounds4 ,undoubtedly    
there are many apparently insignificant 
features1 which can nevertheless be     
shown to be adaptations--for instance1  
the thickness of the basin-shaped shell 
of the limpets that live among the      
breakers on the shore4 ,there can be no 
doubt that the thickness of these       
shells1 combined with their flat form1  
protects the animals from the force of  
the waves breaking upon them1--but how  
have they become so thick8 ,what        
proportion of thickness was sufficient  
to decide that of two variants of a     
limpet one should survive1 the other be 

eliminated8 ,we can say nothing more    
than that we infer from the present     
state of the shell1 that it must have   
varied in regard to differences in      
shell-thickness1 and that these         
differences must have had               
selection-value1--no proof therefore1   
but an assumption which we must show to 
be convincing4  ,for a long time the    
marvellously complex ,,radiate and      
,,lattice-,,work skeletons of           
,radiolarians were regarded as a mere   
outflow of ,nature's infinite wealth of 
form1 as an instance of a purely        
morphological character with no         
biological significance4 ,but recent    
investigations have shown that these1   
too1 have an adaptive significance      
7,hacker74 ,the same thing has been     
shown by ,schutt in regard to the lowly 
unicellular plants1 the ,peridineae1    
which abound alike on the surface of the
 ocean and in its depths4 ,it has been  
shown that the long skeletal processes  
which grow out from these organisms have

 significance not merely as a supporting
 skeleton1 but also as an extension of  
the superficial area1 which increases   
the contact with the water-particles1   
and prevents the floating organisms from
 sinking4 ,it has been established that 
the processes are considerably shorter  
in the colder layers of the ocean1 and  
that they may be twelve times as long   
7,chun1 ,reise der ,valdivia1 ,leipzig1 
#aijd47 in the warmer layers1 thus      
corresponding to the greater or smaller 
amount of friction which takes place in 
the denser and less dense layers of the 
water4  ,the ,peridineae of the warmer  
ocean layers have thus become           
long-rayed1 those of the colder layers  
short-rayed1 not through the direct     
effect of friction on the protoplasm1   
but through processes of selection1     
which favoured the longer rays in warm  
water1 since they kept the organism     
afloat1 while those with short rays sank
 and were eliminated4 ,if we put the    
question as to selection-value in this  

case1 and ask how great the variations  
in the length of processes must be in   
order to possess selection-value2 what  
can we answer except that these         
variations must have been minimal1 and  
yet sufficient to prevent too rapid     
sinking and consequent elimination8 ,yet
 this very case would give the ideal    
opportunity for a mathematical          
calculation of the minimal              
selection-value1 although of course it  
is not feasible from lack of data to    
carry out the actual calculation4  ,but 
even in organisms of more than          
microscopic size there must frequently  
be minute1 even microscopic differences 
which set going the process of          
selection1 and regulate its progress to 
the highest possible perfection4  ,many 
tropical trees possess thick1 leathery  
leaves1 as a protection against the     
force of the tropical rain drops4 ,the  
,,direct influence of the rain cannot be
 the cause of this power of resistance1 
for the leaves1 while they were still   

thin1 would simply have been torn to    
pieces4 ,their toughness must therefore 
be referred to selection1 which would   
favour the trees with slightly thicker  
leaves1 though we cannot calculate with 
any exactness how great the first stages
 of increase in thickness must have     
been4 ,our hypothesis receives further  
support from the fact that1 in many such
 trees1 the leaves are drawn out into a 
beak-like prolongation 7,stahl and      
,haberlandt7 which facilitates the rapid
 falling off of the rain water1 and also
 from the fact that the leaves1 while   
they are still young1 hang limply down  
in bunches which offer the least        
possible resistance to the rain4 ,thus  
there are here three adaptations which  
can only be interpreted as due to       
selection4 ,the initial stages of these 
adaptations must undoubtedly have had   
selection-value4  ,but even in regard to
 this case we are reasoning in a circle1
 not giving proofs1 and no one who does 
not wish to believe in the              

selection-value of the initial stages   
can be forced to do so4 ,among the many 
pieces of presumptive evidence a        
particularly weighty one seems to me to 
be ,,the ,,smallness ,,of ,,the ,,steps 
,,of ,,progress which we can observe in 
certain cases1 as for instance in       
leaf-imitation among butterflies1 and in
 mimicry generally4 ,the resemblance to 
a leaf1 for instance of a particular    
,kallima1 seems to us so close as to be 
deceptive1 and yet we find in another   
individual1 or it may be in many others1
 a spot added which increases the       
resemblance1 and which could not have   
become fixed unless the increased       
deceptiveness so produced had frequently
 led to the overlooking of its much     
persecuted possessor4 ,but if we take   
the selection-value of the initial      
stages for granted1 we are confronted   
with the further question which ,i      
myself formulated many years ago3 ,how  
does it happen ,,that ,,the ,,necessary 
,,beginnings ,,of ,a ,,useful           

,,variation ,,are ,,always ,,present8   
,how could insects which live upon or   
among green leaves become all green1    
while those that live on bark become    
brown8 ,how have the desert animals     
become yellow and the ,arctic animals   
white8 ,why were the necessary          
variations always present8 ,how could   
the green locust lay brown eggs1 or the 
privet caterpillar develop white and    
lilac-coloured lines on its green skin8 
,it is of no use answering to this that 
the question is wrongly formulated      
7,plate1 ,selektionsprinzip u4 ,probleme
 der ,artbildung 7#crd edition71        
,leipzig1 #aijh47 and that it is the    
converse that is true2 that the process 
of selection takes place in accordance  
with the variations that present        
themselves4 ,this proposition is        
undeniably true1 but so also is another1
 which apparently negatives it3 the     
variation required has in the majority  
of cases actually presented itself4     
,selection cannot solve this            

contradiction2 it does not call forth   
the useful variation1 but simply works  
upon it4 ,the ultimate reason why one   
and the same insect should occur in     
green and in brown1 as often happens in 
caterpillars and locusts1 lies in the   
fact that variations towards brown      
presented themselves1 and so also did   
variations towards green3 ,,the ,,kernel
 ,,of ,,the ,,riddle ,,lies ,,in ,,the  
,,varying1 and for the present we can   
only say1 that small variations in      
different directions present themselves 
in every species4 ,otherwise so many    
different kinds of variations could not 
have arisen4 ,i have endeavoured to     
explain this remarkable fact by means of
 the intimate processes that must take  
place within the germ-plasm1 and ,i     
shall return to the problem when dealing
 with germinal selection4  ,we have1    
however1 to make still greater demands  
on variation1 for it is not enough that 
the necessary variation should occur in 
isolated individuals1 because in that   

case there would be small prospect of   
its being preserved1 notwithstanding its
 utility4 ,darwin at first believed1    
that even single variations might lead  
to transformation of the species1 but   
later he became convinced that this was 
impossible1 at least without the        
cooperation of other factors1 such as   
isolation and sexual selection4  ,in the
 case of the ,,green ,,caterpillars     
,,with ,,bright ,,longitudinal          
,,stripes1 numerous individuals         
exhibiting this useful variation must   
have been produced to start with4 ,in   
all higher1 that is1 multicellular      
organisms1 the germ-substance is the    
source of all transmissible variations1 
and this germ-plasm is not a simple     
substance but is made up of many primary
 constituents4 ,the question can        
therefore be more precisely stated thus3
 ,how does it come about that in so many
 cases the useful variations present    
themselves in numbers just where they   
are required1 the white oblique lines in

 the leaf-caterpillar on the under      
surface of the body1 the accompanying   
coloured stripes just above them8 ,and1 
further1 how has it come about that in  
grass caterpillars1 not oblique but     
longitudinal stripes1 which are more    
effective for concealment among grass   
and plants1 have been evolved8 ,and     
finally1 how is it that the same        
,hawk-moth caterpillars1 which to-day   
show oblique stripes1 possessed         
longitudinal stripes in ,tertiary times8
 ,we can read this fact from the history
 of their development1 and ,i have      
before attempted to show the biological 
significance of this change of colour4  
7,studien zur ,descendenz-,theorie      
,,ii41 ,die ,enstehung der ,zeichnung   
bei den ,schmetterlings-raupen1         
,leipzig1 #ahgf47  ,for the present ,i  
need only draw the conclusion that one  
and the same caterpillar may exhibit the
 initial stages of both1 and that it    
depends on the manner in which these    
marking elements are ,,intensified and  

,,combined by natural selection whether 
whitish longitudinal or oblique stripes 
should result4 ,in this case then the   
useful variations were actually always  
there1 and we see that in the same group
 of ,lepidoptera1 e4g4 species of       
,sphingidae1 evolution has occurred in  
both directions according to whether the
 form lived among grass or on broad     
leaves with oblique lateral veins1 and  
we can observe even now that the species
 with oblique stripes have longitudinal 
stripes when young1 that is to say1     
while the stripes have no biological    
significance4 ,the white places in the  
skin which gave rise1 probably first as 
small spots1 to this protective marking 
could be combined in one way or another 
according to the requirements of the    
species4 ,they must therefore either    
have possessed selection-value from the 
first1 or1 if this was not the case at  
their earliest occurrence1 there must   
have been ,,some ,,other ,,factors which
 raised them to the point of            

selection-value4 ,i shall return to this
 in discussing germinal selection4 ,but 
the case may be followed still farther1 
and leads us to the same alternative on 
a still more secure basis4  ,many years 
ago ,i observed in caterpillars of      
,smerinthus populi 7the poplar          
hawk-moth71 which also possess white    
oblique stripes1 that certain           
individuals showed ,,red ,,spots above  
these stripes2 these spots occurred only
 on certain segments1 and never flowed  
together to form continuous stripes4 ,in
 another species 7,smerinthus tiliae7   
similar blood-red spots unite to form a 
line-like coloured seam in the last     
stage of larval life1 while in ,s4      
ocellata rust-red spots appear in       
individual caterpillars1 but more rarely
 than in ,s4 ,populi1 and they show no  
tendency to flow together4  ,thus we    
have here the origin of a new character1
 arising from small beginnings1 at least
 in ,s4 tiliae1 in which species the    
coloured stripes are a normal specific  

character4 ,in the other species1 ,s4   
populi and ,s4 ocellata1 we find the    
beginnings of the same variation1 in one
 more rarely than in the other1 and we  
can imagine that1 in the course of time1
 in these two species1 coloured lines   
over the oblique stripes will arise4 ,in
 any case these spots are the elements  
of variation1 out of which coloured     
lines ,,may be evolved1 if they are     
combined in this direction through the  
agency of natural selection4 ,in ,s4    
populi the spots are often small1 but   
sometimes it seems as though several had
 united to form large spots4 ,whether a 
process of selection in this direction  
will arise in ,s4 populi and ,s4        
ocellata1 or whether it is now going on 
cannot be determined1 since we cannot   
tell in advance what biological value   
the marking might have for these two    
species4 ,it is conceivable that the    
spots may have no selection-value as far
 as these species are concerned1 and may
 therefore disappear again in the course

 of phylogeny1 or1 on the other hand1   
that they may be changed in another     
direction1 for instance towards         
imitation of the rust-red fungoid       
patches on poplar and willow leaves4 ,in
 any case we may regard the smallest    
spots as the initial stages of          
variation1 the larger as a cumulative   
summation of these4 ,therefore either   
these initial stages must already       
possess selection-value1 or1 as ,i said 
before3 ,,there ,,must ,,be ,,some      
,,other ,,reason ,,for ,,their          
,,cumulative ,,summation4 ,i should like
 to give one more example1 in which we  
can infer1 though we cannot directly    
observe1 the initial stages4  ,all the  
,holothurians or sea-cucumbers have in  
the skin calcareous bodies of different 
forms1 usually thick and irregular1     
which make the skin tough and resistant4
 ,in a small group of them--the species 
of ,synapta--the calcareous bodies occur
 in the form of delicate anchors of     
microscopic size4 ,up till #ahig these  

anchors1 like many other delicate       
microscopic structures1 were regarded as
 curiosities1 as natural marvels4 ,but a
 ,swedish observer1 ,oestergren1 has    
recently shown that they have a         
biological significance3 they serve the 
footless ,synapta as auxiliary organs of
 locomotion1 since1 when the body swells
 up in the act of creeping1 they press  
firmly with their tips1 which are       
embedded in the skin1 against the       
substratum on which the animal creeps1  
and thus prevent slipping backwards4 ,in
 other ,holothurians this slipping is   
made impossible by the fixing of the    
tube-feet4 ,the anchors act             
automatically1 sinking their tips       
towards the ground when the             
corresponding part of the body thickens1
 and returning to the original position 
at an angle of #de degrees to the upper 
surface when the part becomes thin      
again4 ,the arms of the anchor do not   
lie in the same plane as the shaft1 and 
thus the curve of the arms forms the    

outermost part of the anchor1 and offers
 no further resistance to the gliding of
 the animal4 ,every detail of the       
anchor1 the curved portion1 the little  
teeth at the head1 the arms1 etc41 can  
be interpreted in the most beautiful    
way1 above all the form of the anchor   
itself1 for the two arms prevent it from
 swaying round to the side4 ,the        
position of the anchors1 too1 is        
definite and significant2 they lie      
obliquely to the longitudinal axis of   
the animal1 and therefore they act alike
 whether the animal is creeping         
backwards or forwards4 ,moreover1 the   
tips would pierce through the skin if   
the anchors lay in the longitudinal     
direction4 ,synapta burrows in the sand2
 it first pushes in the thin anterior   
end1 and thickens this again1 thus      
enlarging the hole1 then the anterior   
tentacles displace more sand1 the body  
is worked in a little farther1 and the  
process begins anew4 ,in the first act  
the anchors are passive1 but they begin 

to take an active share in the forward  
movement when the body is contracted    
again4 ,frequently the animal retains   
only the posterior end buried in the    
sand1 and then the anchors keep it in   
position1 and make rapid withdrawal     
possible4  ,thus we have in these       
apparently random forms of the          
calcareous bodies1 complex adaptations  
in which every little detail as to      
direction1 curve1 and pointing is       
exactly determined4 ,that they have     
selection-value in their present        
perfected form is beyond all doubt1     
since the animals are enabled by means  
of them to bore rapidly into the ground 
and so to escape from enemies4 ,we do   
not know what the initial stages were1  
but we cannot doubt that the little     
improvements1 which occurred as         
variations of the originally simple     
slimy bodies of the ,holothurians1 were 
preserved because they already possessed
 selection-value for the ,synaptidae4   
,for such minute microscopic structures 

whose form is so delicately adapted to  
the role they have to play in the life  
of the animal1 cannot have arisen       
suddenly and as a whole1 and every new  
variation of the anchor1 that is1 in the
 direction of the development of the two
 arms1 and every curving of the shaft   
which prevented the tips from projecting
 at the wrong time1 in short1 every     
little adaptation in the modelling of   
the anchor must have possessed          
selection-value4 ,and that such minute  
changes of form fall within the sphere  
of fluctuating variations1 that is to   
say1 ,,that ,,they ,,occur is beyond all
 doubt4  ,in many of the ,synaptidae the
 anchors are replaced by calcareous rods
 bent in the form of an ,s1 which are   
said to act in the same way4 ,others1   
such as those of the genus ,ankyroderma1
 have anchors which project considerably
 beyond the skin1 and1 according to     
,oestergren1 serve to catch             
plant-particles and other substances and
 so mask the animal4 ,thus we see that  

in the ,synaptidae the thick and        
irregular calcareous bodies of the      
,holothurians have been modified and    
transformed in various ways in          
adaptation to the footlessness of these 
animals1 and to the peculiar conditions 
of their life1 and we must conclude that
 the earlier stages of these changes    
presented themselves to the processes of
 selection in the form of microscopic   
variations4 ,for it is as impossible to 
think of any origin other than through  
selection in this case as in the case of
 the toughness1 and the drip-tips of    
tropical leaves4 ,and as these last     
could not have been produced directly by
 the beating of the heavy rain-drops    
upon them1 so the calcareous anchors of 
,synapta cannot have been produced      
directly by the friction of the sand and
 mud at the bottom of the sea1 and1     
since they are parts whose function is  
,,passive the ,lamarckian factor of use 
and disuse does not come into question4 
,the conclusion is unavoidable1 that the

 microscopically small variations of the
 calcareous bodies in the ancestral     
forms have been intensified and         
accumulated in a particular direction1  
till they have led to the formation of  
the anchor4 ,whether this has taken     
place by the action of natural selection
 alone1 or whether the laws of variation
 and the intimate processes within the  
germ-plasm have cooperated will become  
clear in the discussion of germinal     
selection4 ,this whole process of       
adaptation has obviously taken place    
within the time that has elapsed since  
this group of sea-cucumbers lost their  
tube-feet1 those characteristic organs  
of locomotion which occur in no group   
except the ,echinoderms1 and yet have   
totally disappeared in the ,synaptidae4 
,and after all what would animals that  
live in sand and mud do with tube-feet8 
7c7 ,,coadaptation4  ,darwin pointed out
 that one of the essential differences  
between artificial and natural selection
 lies in the fact that the former can   

modify only a few characters1 usually   
only one at a time1 while ,nature       
preserves in the struggle for existence 
all the variations of a species1 at the 
same time and in a purely mechanical    
way1 if they possess selection-value4   
,herbert ,spencer1 though himself an    
adherent of the theory of selection1    
declared in the beginning of the        
nineties that in his opinion the range  
of this principle was greatly           
over-estimated1 if the great changes    
which have taken place in so many       
organisms in the course of ages are to  
be interpreted as due to this process of
 selection alone1 since no              
transformation of any importance can be 
evolved by itself2 it is always         
accompanied by a host of secondary      
changes4 ,he gives the familiar example 
of the ,giant ,stag of the ,irish peat1 
the enormous antlers of which required  
not only a much stronger skull cap1 but 
also greater strength of the sinews1    
muscles1 nerves and bones of the whole  

anterior half of the animal1 if their   
mass was not to weigh down the animal   
altogether4 ,it is inconceivable1 he    
says1 that so many processes of         
selection should take place             
,,simultaneously1 and we are therefore  
forced to fall back on the ,lamarckian  
factor of the use and disuse of         
functional parts4 ,and how1 he asks1    
could natural selection follow two      
opposite directions of evolution in     
different parts of the body at the same 
time1 as for instance in the case of the
 kangaroo1 in which the forelegs must   
have become shorter1 while the hind legs
 and the tail were becoming longer and  
stronger8  ,spencer's main object was to
 substantiate the validity of the       
,lamarckian principle1 the cooperation  
of which with selection had been doubted
 by many4 ,and it does seem as though   
this principle1 if it operates in nature
 at all1 offers a ready and simple      
explanation of all such secondary       
variations4 ,not only muscles1 but      

nerves1 bones1 sinews1 in short all     
tissues which function actively1        
increase in strength in proportion as   
they are used1 and conversely they      
decrease when the claims on them        
diminish4 ,all the parts1 therefore1    
which depend on the part that varied    
first1 as for instance the enlarged     
antlers of the ,irish ,elk1 must have   
been increased or decreased in strength1
 in exact proportion to the claims made 
upon them1--just as is actually the     
case4  ,but beautiful as this           
explanation would be1 ,i regard it as   
untenable1 because it assumes the       
,,transmissibility ,,of ,,functional    
,,modifications 7so-called acquired     
characters71 and this is not only       
undemonstrable1 but is scarcely         
theoretically conceivable1 for the      
secondary variations which accompany or 
follow the first as correlative         
variations1 occur also in cases in which
 the animals concerned are sterile and  
,,therefore ,,cannot ,,transmit         

,,anything ,,to ,,their ,,descendants4  
,this is true of ,,worker ,,bees1 and   
particularly of ,,ants1 and ,i shall    
here give a brief survey of the present 
state of the problem as it appears to   
me4  ,much has been written on both     
sides of this question since the        
published controversy on the subject in 
the nineties between ,herbert ,spencer  
and myself4 ,i should like to return to 
the matter in detail1 if the space at my
 disposal permitted1 because it seems to
 me that the arguments ,i advanced at   
that time are equally cogent to-day1    
notwithstanding all the objections that 
have since been urged against them4     
,moreover1 the matter is by no means one
 of subordinate interest2 it is the very
 kernel of the whole question of the    
reality and value of the principle of   
selection4 ,for if selection alone does 
not suffice to explain ,,harmonious     
,,adaptation as ,i have called          
,spencer's ,,coadaptation1 and if we    
require to call in the aid of the       

,lamarckian factor it would be          
questionable whether selection could    
explain any adaptations whatever4 ,in   
this particular case--of worker         
bees--the ,lamarckian factor may be     
excluded altogether1 for it can be      
demonstrated that here at any rate the  
effects of use and disuse cannot be     
transmitted4  ,but if it be asked why we
 are unwilling to admit the cooperation 
of the ,darwinian factor of selection   
and the ,lamarckian factor1 since this  
would afford us an easy and satisfactory
 explanation of the phenomena1 ,i       
answer3 ,,because ,,the ,,lamarckian    
,,principle ,,is ,,fallacious1 ,,and    
,,because ,,by ,,accepting ,,it ,,we    
,,close ,,the ,,way ,,towards ,,deeper  
,,insight4 ,it is not a spirit of       
combativeness or a desire for           
self-vindication that induces me to take
 the field once more against the        
,lamarckian principle1 it is the        
conviction that the progress of our     
knowledge is being obstructed by the    

acceptance of this fallacious principle1
 since the facile explanation it        
apparently affords prevents our seeking 
after a truer explanation and a deeper  
analysis4  ,the workers in the various  
species of ants are sterile1 that is to 
say1 they take no regular part in the   
reproduction of the species1 although   
individuals among them may occasionally 
lay eggs4 ,in addition to this they have
 lost the wings1 and the receptaculum   
seminis1 and their compound eyes have   
degenerated to a few facets4 ,how could 
this last change have come about through
 disuse1 since the eyes of workers are  
exposed to light in the same way as are 
those of the sexual insects and thus in 
this particular case are not liable to  
disuse at all8 ,the same is true of the 
receptaculum seminis1 which can only    
have been disused as far as its         
glandular portion and its stalk are     
concerned1 and also of the wings1 the   
nerves tracheae and epidermal cells of  
which could not cease to function until 

the whole wing had degenerated1 for the 
chitinous skeleton of the wing does not 
function at all in the active sense4    
,but1 on the other hand1 the workers in 
all species have undergone modifications
 in a positive direction1 as1 for       
instance1 the greater development of    
brain4 ,in many species large workers   
have evolved1--the so-called ,,soldiers1
 with enormous jaws and teeth1 which    
defend the colony1--and in others there 
are ,,small workers which have taken    
over other special functions1 such as   
the rearing of the young ,aphides4 ,this
 kind of division of the workers into   
two castes occurs among several tropical
 species of ants1 but it is also present
 in the ,italian species1 ,colobopsis   
truncata4 ,beautifully as the size of   
the jaws could be explained as due to   
the increased use made of them by the   
soldiers1 or the enlarged brain as due  
to the mental activities of the workers1
 the fact of the infertility of these   
forms is an insurmountable obstacle to  

accepting such an explanation4 ,neither 
jaws nor brain can have been evolved on 
the ,lamarckian principle4  ,the problem
 of coadaptation is no easier in the    
case of the ant than in the case of the 
,giant ,stag4 ,darwin himself gave a    
pretty illustration to show how imposing
 the difference between the two kinds of
 workers in one species would seem if we
 translated it into human terms4 ,in    
regard to the ,driver ants 7,anomma7 we 
must picture to ourselves a piece of    
work1 for instance the building of a    
house1 being carried on by two kinds of 
workers1 of which one group was five    
feet four inches high1 the other sixteen
 feet high4 7,origin of ,species 7#fth  
edition71 page #bcb47  ,although the ant
 is a small animal as compared with man 
or with the ,irish ,elk1 the soldier    
with its relatively enormous jaws is    
hardly less heavily burdened than the   
,elk with its antlers1 and in the ant's 
case1 too1 a strengthening of the       
skeleton1 of the muscles1 the nerves of 

the head1 and of the legs must have     
taken place parallel with the           
enlargement of the jaws4 ,,harmonious   
,,adaptation 7coadaptation7 has here    
been active in a high degree1 and yet   
these soldiers are sterile6 ,there thus 
remains nothing for it but to refer all 
their adaptations1 positive and negative
 alike1 to processes of selection which 
have taken place in the rudiments of the
 workers within the egg and sperm-cells 
of their parents4 ,there is no way out  
of the difficulty except the one ,darwin
 pointed out4 ,he himself did not find  
the solution of the riddle at once4 ,at 
first he believed that the case of the  
workers among social insects presented  
the most serious special difficulty in  
the way of his theory of natural        
selection2 and it was only after it had 
become clear to him1 that it was not the
 sterile insects themselves but their   
parents that were selected1 according as
 they produced more or less well adapted
 workers1 that he was able to refer to  

this very case of the conditions among  
ants ,,in ,,order ,,to ,,show ,,the     
,,power ,,of ,,natural ,,selection      
7,origin of ,species1 page #bcc2 see    
also edition #a1 page #bdb474 ,he       
explains his view by a simple but       
interesting illustration4 ,gardeners    
have produced1 by means of long         
continued artificial selection1 a       
variety of ,stock1 which bears entirely 
double1 and therefore infertile flowers 
7,ibid4 page #bcj474 ,nevertheless the  
variety continues to be reproduced from 
seed1 because in addition to the double 
and infertile flowers1 the seeds always 
produce a certain number of single1     
fertile blossoms1 and these are used to 
reproduce the double variety4 ,these    
single and fertile plants correspond to 
the males and females of an ant-colony1 
the infertile plants1 which are         
regularly produced in large numbers1 to 
the neuter workers of the colony4  ,this
 illustration is entirely apt1 the only 
difference between the two cases        

consisting in the fact that the         
variation in the flower is not a useful1
 but a disadvantageous one1 which can   
only be preserved by artificial         
selection on the part of the gardener1  
while the transformations that have     
taken place parallel with the sterility 
of the ants are useful1 since they      
procure for the colony an advantage in  
the struggle for existence1 and they are
 therefore preserved by natural         
selection4 ,even the sterility itself in
 this case is not disadvantageous1 since
 the fertility of the true females has  
at the same time considerably increased4
 ,we may therefore regard the sterile   
forms of ants1 which have gradually been
 adapted in several directions to       
varying functions1 ,,as ,a ,,certain    
,,proof that selection really takes     
place in the germ-cells of the fathers  
and mothers of the workers1 and that    
,,special ,,complexes ,,of ,,primordia  
7,,ids7 are present in the workers and  
in the males and females1 and these     

complexes contain the primordia of the  
individual parts 7,,determinants74 ,but 
since all living entities vary1 the     
determinants must also vary1 now in a   
favourable1 now in an unfavourable      
direction4 ,if a female produces eggs1  
which contain favourably varying        
determinants in the worker-ids1 then    
these eggs will give rise to workers    
modified in the favourable direction1   
and if this happens with many females1  
the colony concerned will contain a     
better kind of worker than other        
colonies4  ,i digress here in order to  
give an account of the intimate         
processes1 which1 according to my view1 
take place within the germ-plasm1 and   
which ,i have called ,,germinal         
,,selection4 ,these processes are of    
importance since they form the roots of 
variation1 which in its turn is the root
 of natural selection4 ,i cannot here do
 more than give a brief outline of the  
theory in order to show how the         
,darwin-,wallace theory of selection has

 gained support from it4  ,with others1 
,i regard the minimal amount of         
substance which is contained within the 
nucleus of the germ-cells1 in the form  
of rods1 bands1 or granules1 as the     
,,germ-,,substance or ,,germ-,,plasm1   
and ,i call the individual granules     
,,ids4 ,there is always a multiplicity  
of such ids present in the nucleus1     
either occurring individually1 or united
 in the form of rods or bands           
7chromosomes74 ,each id contains the    
primary constituents of a ,,whole       
individual1 so that several ids are     
concerned in the development of a new   
individual4  ,in every being of complex 
structure thousands of primary          
constituents must go to make up a single
 id2 these ,i call ,,determinants1 and  
,i mean by this name very small         
individual particles1 far below the     
limits of microscopic visibility1 vital 
units which feed1 grow1 and multiply by 
division4 ,these determinants control   
the parts of the developing embryo1--in 

what manner need not here concern us4   
,the determinants differ among          
themselves1 those of a muscle are       
differently constituted from those of a 
nerve-cell or a glandular cell1 etc41   
and every determinant is in its turn    
made up of minute vital units1 which ,i 
call ,,biophors1 or the bearers of life4
 ,according to my view1 these           
determinants not only assimilate1 like  
every other living unit1 but they ,,vary
 in the course of their growth1 as every
 living unit does2 they may vary        
qualitatively if the elements of which  
they are composed vary1 they may grow   
and divide more or less rapidly1 and    
their variations give rise to           
,,corresponding variations of the organ1
 cell1 or cell-group which they         
determine4 ,that they are undergoing    
ceaseless fluctuations in regard to size
 and quality seems to me the inevitable 
consequence of their unequal nutrition2 
for although the germ-cell as a whole   
usually receives sufficient nutriment1  

minute fluctuations in the amount       
carried to different parts within the   
germ-plasm cannot fail to occur4  ,now1 
if a determinant1 for instance of a     
sensory cell1 receives for a            
considerable time more abundant         
nutriment than before1 it will grow more
 rapidly--become bigger1 and divide more
 quickly1 and1 later1 when the id       
concerned develops into an embryo1 this 
sensory cell will become stronger than  
in the parents1 possibly even twice as  
strong4 ,this is an instance of a       
,,hereditary ,,individual ,,variation1  
arising from the germ4  ,the nutritive  
stream which1 according to our          
hypothesis1 favours the determinant ,n  
by chance1 that is1 for reasons unknown 
to us1 may remain strong for a          
considerable time1 or may decrease      
again2 but even in the latter case it is
 conceivable that the ascending movement
 of the determinant may continue1       
because the strengthened determinant now
 ,,actively nourishes itself more       

abundantly1--that is to say1 it attracts
 the nutriment to itself1 and to a      
certain extent withdraws it from its    
fellow-determinants4 ,in this way1 it   
may--as it seems to me--get into        
,,permanent ,,upward ,,movement1 ,,and  
,,attain ,a ,,degree ,,of ,,strength    
,,from ,,which ,,there ,,is ,,no        
,,falling ,,back4 ,then positive or     
negative selection sets in1 favouring   
the variations which are advantageous1  
setting aside those which are           
disadvantageous4  ,in a similar manner a
 ,,downward variation of the            
determinants may take place1 if its     
progress be started by a diminished flow
 of nutriment4 ,the determinants which  
are weakened by this diminished flow    
will have less affinity for attracting  
nutriment because of their diminished   
strength1 and they will assimilate more 
feebly and grow more slowly1 unless     
chance streams of nutriment help them to
 recover themselves4 ,but1 as will      
presently be shown1 a change of         

direction cannot take place at ,,every  
stage of the degenerative process4 ,if a
 certain critical stage of downward     
progress be passed1 even favourable     
conditions of food-supply will no longer
 suffice permanently to change the      
direction of the variation4 ,only two   
cases are conceivable2 if the           
determinant corresponds to a ,,useful   
organ1 only its removal can bring back  
the germ-plasm to its former level2     
therefore personal selection removes the
 id in question1 with its determinants1 
from the germ-plasm1 by causing the     
elimination of the individual in the    
struggle for existence4 ,but there is   
another conceivable case2 the           
determinants concerned may be those of  
an organ which has become ,,useless1 and
 they will then continue unobstructed1  
but with exceeding slowness1 along the  
downward path1 until the organ becomes  
vestigial1 and finally disappears       
altogether4  ,the fluctuations of the   
determinants hither and thither may thus

 be transformed into a lasting ascending
 or descending movement2 and ,,this ,,is
 ,,the ,,crucial ,,point ,,of ,,these   
,,germinal ,,processes4  ,this is not a 
fantastic assumption2 we can read it in 
the fact of the degeneration of disused 
parts4 ,,useless ,,organs ,,are ,,the   
,,only ,,ones ,,which ,,are ,,not       
,,helped ,,to ,,ascend ,,again ,,by     
,,personal ,,selection1 ,,and           
,,therefore ,,in ,,their ,,case ,,alone 
,,can ,,we ,,form ,,any ,,idea ,,of     
,,how ,,the ,,primary ,,constituents    
,,behave1 ,,when ,,they ,,are ,,subject 
,,solely ,,to ,,intra-,,germinal        
,,forces4  ,the whole determinant system
 of an id1 as ,i conceive it1 is in a   
state of continual fluctuation upwards  
and downwards4 ,in most cases the       
fluctuations will counteract one        
another1 because the passive streams of 
nutriment soon change1 but in many cases
 the limit from which a return is       
possible will be passed1 and then the   
determinants concerned will continue to 

vary in the same direction1 till they   
attain positive or negative             
selection-value4 ,at this stage personal
 selection intervenes and sets aside the
 variation if it is disadvantageous1 or 
favours--that is to say1 preserves--it  
if it is advantageous4 ,only ,,the      
,,determinant ,,of ,a ,,useless ,,organ 
,,is ,,uninfluenced ,,by ,,personal     
,,selection1 and1 as experience shows1  
it sinks downwards2 that is1 the organ  
that corresponds to it degenerates very 
slowly but uninterruptedly till1 after  
what must obviously be an immense       
stretch of time1 it disappears from the 
germ-plasm altogether4  ,thus we find in
 the fact of the degeneration of disused
 parts the proof that not all the       
fluctuations of a determinant return to 
equilibrium again1 but that1 when the   
movement has attained to a certain      
strength1 it continues ,,in ,,the ,,same
 ,,direction4 ,we have entire certainty 
in regard to this as far as the downward
 progress is concerned1 and we must     

assume it also in regard to ascending   
variations1 as the phenomena of         
artificial selection certainly justify  
us in doing4 ,if the ,japanese breeders 
were able to lengthen the tail feathers 
of the cock to six feet1 it can only    
have been because the determinants of   
the tail-feathers in the germ-plasm had 
already struck out a path of ascending  
variation1 and this movement was taken  
advantage of by the breeder1 who        
continually selected for reproduction   
the individuals in which the ascending  
variation was most marked4 ,for all     
breeding depends upon the unconscious   
selection of germinal variations4  ,of  
course these germinal processes cannot  
be proved mathematically1 since we      
cannot actually see the play of forces  
of the passive fluctuations and their   
causes4 ,we cannot say how great these  
fluctuations are1 and how quickly or    
slowly1 how regularly or irregularly    
they change4 ,nor do we know how far a  
determinant must be strengthened by the 

passive flow of the nutritive stream if 
it is to be beyond the danger of        
unfavourable variations1 or how far it  
must be weakened passively before it    
loses the power of recovering itself by 
its own strength4 ,it is no more        
possible to bring forward actual proofs 
in this case than it was in regard to   
the selection-value of the initial      
stages of an adaptation4 ,but if we     
consider that all heritable variations  
must have their roots in the germ-plasm1
 and further1 that when personal        
selection does not intervene1 that is to
 say1 in the case of parts which have   
become useless1 a degeneration of the   
part1 and therefore also of its         
determinant must inevitably take place2 
then we must conclude that processes    
such as ,i have assumed are running     
their course within the germ-plasm1 and 
we can do this with as much certainty as
 we were able to infer1 from the        
phenomena of adaptation1 the            
selection-value of their initial stages4

 ,the fact of the degeneration of       
disused parts seems to me to afford     
irrefutable proof that the fluctuations 
within the germ-plasm ,,are ,,the ,,real
 ,,root ,,of ,,all ,,hereditary         
,,variation1 and the preliminary        
condition for the occurrence of the     
,darwin-,wallace factor of selection4   
,germinal selection supplies the stones 
out of which personal selection builds  
her temples and palaces3 ,,adaptations4 
,the importance for the theory of the   
process of degeneration of disused parts
 cannot be over-estimated1 especially   
when it occurs in sterile animal forms1 
where we are free from the doubt as to  
the alleged ,,lamarckian ,,factor which 
is apt to confuse our ideas in regard to
 other cases4  ,if we regard the        
variation of the many determinants      
concerned in the transformation of the  
female into the sterile worker as having
 come about through the gradual         
transformation of the ids into          
worker-ids1 we shall see that the       

germ-plasm of the sexual ants must      
contain three kinds of ids1 male1       
female1 and worker ids1 or if the       
workers have diverged into soldiers and 
nest-builders1 then four kinds4 ,we     
understand that the worker-ids arose    
because their determinants struck out a 
useful path of variation1 whether upward
 or downward1 and that they continued in
 this path until the highest attainable 
degree of utility of the parts          
determined was reached4 ,but in addition
 to the organs of positive or negative  
selection-value1 there were some which  
were indifferent as far as the success  
and especially the functional capacity  
of the workers was concerned3 wings1    
ovarian tubes1 receptaculum seminis1 a  
number of the facets of the eye1 perhaps
 even the whole eye4 ,as to the ovarian 
tubes it is possible that their         
degeneration was an advantage for the   
workers1 in saving energy1 and if so    
selection would favour the degeneration2
 but how could the presence of eyes     

diminish the usefulness of the workers  
to the colony8 or the minute            
receptaculum seminis1 or even the wings8
 ,these parts have therefore degenerated
 ,,because ,,they ,,were ,,of ,,no      
,,further ,,value ,,to ,,the ,,insect4  
,but if selection did not influence the 
setting aside of these parts because    
they were neither of advantage nor of   
disadvantage to the species1 then the   
,darwinian factor of selection is here  
confronted with a puzzle which it cannot
 solve alone1 but which at once becomes 
clear when germinal selection is added4 
,for the determinants of organs that    
have no further value for the organism1 
must1 as we have already explained1     
embark on a gradual course of retrograde
 development4  ,in ants the degeneration
 has gone so far that there are no      
wing-rudiments present in ,,any species1
 as is the case with so many            
butterflies1 flies1 and locusts1 but in 
the larvae the imaginal discs of the    
wings are still laid down4 ,with regard 

to the ovaries1 degeneration has reached
 different levels in different species  
of ants1 as has been shown by the       
researches of my former pupil1          
,elizabeth ,bickford4 ,in many species  
there are twelve ovarian tubes1 and they
 decrease from that number to one2      
indeed1 in one species no ovarian tube  
at all is present4 ,so much at least is 
certain from what has been said1 that in
 this case ,,everything depends on the  
fluctuations of the elements of the     
germ-plasm4 ,germinal selection1 here as
 elsewhere1 presents the variations of  
the determinants1 and personal selection
 favours or rejects these1 or1--if it be
 a question of organs which have become 
useless1--it does not come into play at 
all1 and allows the descending variation
 free course4  ,it is obvious that even 
the problem of ,,coadaptation ,,in      
,,sterile ,,animals can thus be         
satisfactorily explained4 ,if the       
determinants are oscillating upwards and
 downwards in continual fluctuation1 and

 varying more pronouncedly now in one   
direction now in the other1 useful      
variations of every determinant will    
continually present themselves anew1 and
 may1 in the course of generations1 be  
combined with one another in various    
ways4 ,but there is one character of the
 determinants that greatly facilitates  
this complex process of selection1 that1
 after a certain limit has been reached1
 they go on varying in the same         
direction4 ,from this it follows that   
development along a path once struck out
 may proceed without the continual      
intervention of personal selection4     
,this factor only operates1 so to speak1
 at the beginning1 when it selects the  
determinants which are varying in the   
right direction1 and again at the end1  
when it is necessary to put a check upon
 further variation4 ,in addition to     
this1 enormously long periods have been 
available for all these adaptations1 as 
the very gradual transition stages      
between females and workers in many     

species plainly show1 and thus this     
process of transformation loses the     
marvellous and mysterious character that
 seemed at the first glance to invest   
it1 and takes rank1 without any         
straining1 among the other processes of 
selection4 ,it seems to me that1 from   
the facts that sterile animal forms can 
adapt themselves to new vital functions1
 their superfluous parts degenerate1 and
 the parts more used adapt themselves in
 an ascending direction1 those less used
 in a descending direction1 we must draw
 the conclusion that harmonious         
adaptation here comes about ,,without   
,,the ,,cooperation ,,of ,,the          
,,lamarckian ,,principle4 ,this         
conclusion once established1 however1 we
 have no reason to refer the thousands  
of cases of harmonious adaptation1 which
 occur in exactly the same way among    
other animals or plants1 to a principle1
 the ,,active ,,intervention ,,of       
,,which ,,in ,,the ,,transformation ,,of
 ,,species ,,is ,,nowhere ,,proved4 ,,we

 ,,do ,,not ,,require ,,it ,,to         
,,explain ,,the ,,facts1 ,,and          
,,therefore ,,we ,,must ,,not ,,assume  
,,it4  ,the fact of coadaptation1 which 
was supposed to furnish the strongest   
argument against the principle of       
selection1 in reality yields the        
clearest evidence in favour of it4 ,we  
,,must assume it1 ,,because ,,no ,,other
 ,,possibility ,,of ,,explanation ,,is  
,,open ,,to ,,us1 ,,and ,,because       
,,these ,,adaptations ,,actually        
,,exist1 ,,that ,,is ,,to ,,say1 ,,have 
,,really ,,taken ,,place4 ,with this    
conviction ,i attempted1 as far back as 
#ahid1 when the idea of germinal        
selection had not yet occurred to me1 to
 make harmonious adaptation             
7coadaptation7 more easily intelligible 
in some way or other1 and so ,i was led 
to the idea1 which was subsequently     
expounded in detail by ,baldwin1 and    
,lloyd ,morgan1 and also by ,osborn1 and
 ,gulick as ,,organic ,,selection4 ,it  
seemed to me that it was not necessary  

that all the germinal variations        
required for secondary variations should
 have occurred ,,simultaneously1 since1 
for instance1 in the case of the stag1  
the bones1 muscles1 sinews1 and nerves  
would be incited by the increasing      
heaviness of the antlers to greater     
activity in ,,the ,,individual ,,life1  
and so would be strengthened4 ,the      
antlers can only have increased in size 
by very slow degrees1 so that the       
muscles and bones may have been able to 
keep pace with their growth in the      
individual life1 until the requisite    
germinal variations presented           
themselves4 ,in this way a disharmony   
between the increasing weight of the    
antlers and the parts which support and 
move them would be avoided1 since time  
would be given for the appropriate      
germinal variations to occur1 and so to 
set agoing the ,,hereditary variation of
 the muscles1 sinews1 and bones4 7,the  
,effect of ,external ,influences upon   
,development1 ,romanes ,lecture1        

,oxford1 #ahid47  ,i still regard this  
idea as correct1 but ,i attribute less  
importance to organic selection than ,i 
did at that time1 in so far that ,i do  
not believe that it ,,alone could effect
 complex harmonious adaptations4        
,germinal selection now seems to me to  
play the chief part in bringing about   
such adaptations4 ,something the same is
 true of the principle ,i have called   
,panmixia4 ,as ,i became more and more  
convinced1 in the course of years1 that 
the ,,lamarckian ,,principle ought not  
to be called in to explain the dwindling
 of disused parts1 ,i believed that this
 process might be simply explained as   
due to the cessation of the conservative
 effect of natural selection4 ,i said to
 myself that1 from the moment in which a
 part ceases to be of use1 natural      
selection withdraws its hand from it1   
and then it must inevitably fall from   
the height of its adaptiveness1 because 
inferior variants would have as good a  
chance of persisting as better ones1    

since all grades of fitness of the part 
in question would be mingled with one   
another indiscriminately4 ,this is      
undoubtedly true1 as ,romanes pointed   
out ten years before ,i did1 and this   
mingling of the bad with the good       
probably does bring about a             
deterioration of the part concerned4    
,but it cannot account for the steady   
diminution1 which always occurs when a  
part is in process of becoming          
rudimentary1 and which goes on until it 
ultimately disappears altogether4 ,the  
process of dwindling cannot therefore be
 explained as due to panmixia alone2 we 
can only find a sufficient explanation  
in germinal selection4  ,,iv4           
,,derivatives ,,of ,,the ,,theory ,,of  
,,selection4  ,the impetus in all       
directions given by ,darwin through his 
theory of selection has been an         
immeasurable one1 and its influence is  
still felt4 ,it falls within the        
province of the historian of science to 
enumerate all the ideas which1 in the   

last quarter of the nineteenth century1 
grew out of ,darwin's theories1 in the  
endeavour to penetrate more deeply into 
the problem of the evolution of the     
organic world4 ,within the narrow limits
 to which this paper is restricted1 ,i  
cannot attempt to discuss any of these4 
,v4 ,,arguments ,,for ,,the ,,reality   
,,of ,,the ,,processes ,,of ,,selection4
  7a7 ,,sexual ,,selection4  ,sexual    
selection goes hand in hand with natural
 selection4 ,from the very first ,i have
 regarded sexual selection as affording 
an extremely important and interesting  
corroboration of natural selection1 but1
 singularly enough1 it is precisely     
against this theory that an adverse     
judgment has been pronounced in so many 
quarters1 and it is only quite recently1
 and probably in proportion as the      
wealth of facts in proof of it          
penetrates into a wider circle1 that we 
seem to be approaching a more general   
recognition of this side of the problem 
of adaptation4 ,thus ,darwin's words in 

his preface to the second edition       
7#ahgd7 of his book1 ,the ,descent of   
,man and ,sexual ,selection1 are being  
justified3 ,my conviction as to the     
operation of natural selection remains  
unshaken1 and further1 ,if naturalists  
were to become more familiar with the   
idea of sexual selection1 it would1 ,i  
think1 be accepted to a much greater    
extent1 and already it is fully and     
favourably accepted by many competent   
judges4 ,darwin was able to speak thus  
because he was already acquainted with  
an immense mass of facts1 which1 taken  
together1 yield overwhelming evidence of
 the validity of the principle of sexual
 selection4  ,,natural ,,selection      
chooses out for reproduction the        
individuals that are best equipped for  
the struggle for existence1 and it does 
so at every stage of development2 it    
thus improves the species in all its    
stages and forms4 ,,sexual ,,selection  
operates only on individuals that are   
already capable of reproduction1 and    

does so only in relation to the         
attainment of reproduction4 ,it arises  
from the rivalry of one sex1 usually the
 male1 for the possession of the other1 
usually the female4 ,its influence can  
therefore only ,,directly affect one    
sex1 in that it equips it better for    
attaining possession of the other4 ,but 
the effect may extend indirectly to the 
female sex1 and thus the whole species  
may be modified1 without1 however1      
becoming any more capable of resistance 
in the struggle for existence1 for      
sexual selection only gives rise to     
adaptations which are likely to give    
their possessor the victory over rivals 
in the struggle for possession of the   
female1 and which are therefore peculiar
 to the wooing sex3 the manifold        
secondary sexual characters4 ,the       
diversity of these characters is so     
great that ,i cannot here attempt to    
give anything approaching a complete    
treatment of them1 but ,i should like to
 give a sufficient number of examples to

 make the principle itself1 in its      
various modes of expression1 quite      
clear4  ,one of the chief preliminary   
postulates of sexual selection is the   
unequal number of individuals in the two
 sexes1 for if every male immediately   
finds his mate there can be no          
competition for the possession of the   
female4 ,darwin has shown that1 for the 
most part1 the inequality between the   
sexes is due simply to the fact that    
there are more males than females1 and  
therefore the males must take some pains
 to secure a mate4 ,but the inequality  
does not always depend on the numerical 
preponderance of the males1 it is often 
due to polygamy2 for1 if one male claims
 several females1 the number of females 
in proportion to the rest of the males  
will be reduced4 ,since it is almost    
always the males that are the wooers1 we
 must expect to find the occurrence of  
secondary sexual characters chiefly     
among them1 and to find it especially   
frequent in polygamous species4 ,and    

this is actually the case4  ,if we were 
to try to guess--without knowing the    
facts--what means the male animals make 
use of to overcome their rivals in the  
struggle for the possession of the      
female1 we might name many kinds of     
means1 but it would be difficult to     
suggest any which is not actually       
employed in some animal group or other4 
,i begin with the mere difference in    
strength1 through which the male of many
 animals is so sharply distinguished    
from the female1 as1 for instance1 the  
lion1 walrus1 sea-elephant1 and others4 
,among these the males fight violently  
for the possession of the female1 who   
falls to the victor in the combat4 ,in  
this simple case no one can doubt the   
operation of selection1 and there is    
just as little room for doubt as to the 
selection-value of the initial stages of
 the variation4 ,differences in bodily  
strength are apparent even among human  
beings1 although in their case the      
struggle for the possession of the      

female is no longer decided by bodily   
strength alone4  ,combats between male  
animals are often violent and obstinate1
 and the employment of the natural      
weapons of the species in this way has  
led to perfecting of these1 e4g4 the    
tusks of the boar1 the antlers of the   
stag1 and the enormous1 antler-like jaws
 of the stag-beetle4 ,here again it is  
impossible to doubt that variations in  
these organs presented themselves1 and  
that these were considerable enough to  
be decisive in combat1 and so to lead to
 the improvement of the weapon4  ,among 
many animals1 however1 the females at   
first withdraw from the males2 they are 
coy1 and have to be sought out1 and     
sometimes held by force4 ,this tracking 
and grasping of the females by the males
 has given rise to many different       
characters in the latter1 as1 for       
instance1 the larger eyes of the male   
bee1 and especially of the males of the 
,ephemerids 7,may-flies71 some species  
of which show1 in addition to the usual 

compound eyes1 large1 so-called         
turban-eyes1 so that the whole head is  
covered with seeing surfaces4 ,in these 
species the females are very greatly in 
the minority 7#a-ajj71 and it is easy to
 understand that a keen competition for 
them must take place1 and that1 when the
 insects of both sexes are floating     
freely in the air1 an unusually wide    
range of vision will carry with it a    
decided advantage4 ,here again the      
actual adaptations are in accordance    
with the preliminary postulates of the  
theory4 ,we do not know the stages      
through which the eye has passed to its 
present perfected state1 but1 since the 
number of simple eyes 7facets7 has      
become very much greater in the male    
than in the female1 we may assume that  
their increase is due to a gradual      
duplication of the determinants of the  
ommatidium in the germ-plasm1 as ,i have
 already indicated in regard to         
sense-organs in general4 ,in this case1 
again1 the selection-value of the       

initial stages hardly admits of doubt2  
better vision ,,directly secures        
reproduction4  ,in many cases ,,the     
,,organ ,,of ,,smell shows a similar    
improvement4 ,many lower ,crustaceans   
7,daphnidae7 have better developed      
organs of smell in the male sex4 ,the   
difference is often slight and amounts  
only to one or two olfactory filaments1 
but certain species show a difference of
 nearly a hundred of these filaments    
7,leptodora74 ,the same thing occurs    
among insects4  ,we must briefly        
consider the clasping or grasping organs
 which have developed in the males among
 many lower ,crustaceans1 but here      
natural selection plays its part along  
with sexual selection1 for the union of 
the sexes is an indispensable condition 
for the maintenance of the species1 and 
as ,darwin himself pointed out1 in many 
cases the two forms of selection merge  
into each other4 ,this fact has always  
seemed to me to be a proof of natural   
selection1 for1 in regard to sexual     

selection1 it is quite obvious that the 
victory of the best-equipped could have 
brought about the improvement only of   
the organs concerned1 the factors in the
 struggle1 such as the eye and the      
olfactory organ4  ,we come now to the   
,,excitants2 that is1 to the group of   
sexual characters whose origin through  
processes of selection has been most    
frequently called in question4 ,we may  
cite the ,,love-,,calls produced by many
 male insects1 such as crickets and     
cicadas4 ,these could only have arisen  
in animal groups in which the female did
 not rapidly flee from the male1 but was
 inclined to accept his wooing from the 
first4 ,thus1 notes like the chirping of
 the male cricket serve to entice the   
females4 ,at first they were merely the 
signal which showed the presence of a   
male in the neighbourhood1 and the      
female was gradually enticed nearer and 
nearer by the continued chirping4 ,the  
male that could make himself heard to   
the greatest distance would obtain the  

largest following1 and would transmit   
the beginnings1 and1 later1 the         
improvement of his voice to the greatest
 number of descendants4 ,but sexual     
excitement in the female became         
associated with the hearing of the      
love-call1 and then the sound-producing 
organ of the male began to improve1     
until it attained to the emission of the
 long-drawn-out soft notes of the       
mole-cricket or the maenad-like cry of  
the cicadas4 ,i cannot here follow the  
process of development in detail1 but   
will call attention to the fact that the
 original purpose of the voice1 the     
announcing of the male's presence1      
became subsidiary1 and the exciting of  
the female became the chief goal to be  
aimed at4 ,the loudest singers awakened 
the strongest excitement1 and the       
improvement resulted as a matter of     
course4 ,i conceive of the origin of    
bird-song in a somewhat similar manner1 
first as a means of enticing1 then of   
exciting the female4  ,one more kind of 

secondary sexual character must here be 
mentioned3 the odour which emanates from
 so many animals at the breeding season4
 ,it is possible that this odour also   
served at first merely to give notice of
 the presence of individuals of the     
other sex1 but it soon became an        
excitant1 and as the individuals which  
caused the greatest degree of excitement
 were preferred1 it reached as high a   
pitch of perfection as was possible to  
it4 ,i shall confine myself here to the 
comparatively recently discovered       
fragrance of butterflies4 ,since ,fritz 
,muller found out that certain          
,brazilian butterflies gave off         
fragrance like a flower1 we have become 
acquainted with many such cases1 and we 
now know that in all lands1 not only    
many diurnal ,lepidoptera but nocturnal 
ones also give off a delicate odour1    
which is agreeable even to man4 ,the    
ethereal oil to which this fragrance is 
due is secreted by the skin-cells1      
usually of the wing1 as ,i showed soon  

after the discovery of the              
,,scent-,,scales4 ,this is the case in  
the males2 the females have no ,,special
 scent-scales recognisable as such by   
their form1 but they must1 nevertheless1
 give off an extremely delicate         
fragrance1 although our imperfect organ 
of smell cannot perceive it1 for the    
males become aware of the presence of a 
female1 even at night1 from a long      
distance off1 and gather round her4 ,we 
may therefore conclude1 that both sexes 
have long given forth a very delicate   
perfume1 which announced their presence 
to others of the same species1 and that 
in many species 7,,not ,,in ,,all7 these
 small beginnings became1 in the males1 
particularly strong scent-scales of     
characteristic form 7lute1 brush1 or    
lyre-shaped74 ,at first these scales    
were scattered over the surface of the  
wing1 but gradually they concentrated   
themselves1 and formed broad1 velvety   
bands1 or strong1 prominent brushes1 and
 they attained their highest pitch of   

evolution when they became enclosed     
within pits or folds of the skin1 which 
could be opened to let the delicious    
fragrance stream forth suddenly towards 
the female4 ,thus in this case also we  
see that characters1 the original use of
 which was to bring the sexes together1 
and so to maintain the species1 have    
been evolved in the males into means for
 exciting the female4 ,and we can hardly
 doubt1 that the females are most       
readily enticed to yield to the         
butterfly that sends out the strongest  
fragrance1--that is to say1 that excites
 them to the highest degree4 ,it is a   
pity that our organs of smell are not   
fine enough to examine the fragrance of 
male ,lepidoptera in general1 and to    
compare it with other perfumes which    
attract these insects4 7,see ,poulton1  
,essays on ,evolution1 #aijh1 pages     
#caf1 #cag47 ,as far as we can perceive 
them they resemble the fragrance of     
flowers1 but there are ,lepidoptera     
whose scent suggests musk4 ,a smell of  

musk is also given off by several       
plants3 it is a sexual excitant in the  
musk-deer1 the musk-sheep1 and the      
crocodile4  ,as far as we know1 then1 it
 is perfumes similar to those of flowers
 that the male ,lepidoptera give off in 
order to entice their mates1 and this is
 a further indication that animals1 like
 plants1 can to a large extent meet the 
claims made upon them by life1 and      
produce the adaptations which are most  
purposive1--a further proof1 too1 of my 
proposition that the useful variations1 
so to speak1 are ,,always ,,there4 ,the 
flowers developed the perfumes which    
entice their visitors1 and the male     
,lepidoptera developed the perfumes     
which entice and excite their mates4    
,there are many pretty little problems  
to be solved in this connection1 for    
there are insects1 such as some flies1  
that are attracted by smells which are  
unpleasant to us1 like those from       
decaying flesh and carrion4 ,but there  
are also certain flowers1 some orchids  

for instance1 which give forth no very  
agreeable odour1 but one which is to us 
repulsive and disgusting2 and we should 
therefore expect that the males of such 
insects would give off a smell          
unpleasant to us1 but there is no case  
known to me in which this has been      
demonstrated4  ,in cases such as we have
 discussed1 it is obvious that there is 
no possible explanation except through  
selection4 ,this brings us to the last  
kind of secondary sexual characters1 and
 the one in regard to which doubt has   
been most frequently                    
expressed1--decorative colours and      
decorative forms1 the brilliant plumage 
of the male pheasant1 the humming-birds1
 and the bird of ,paradise1 as well as  
the bright colours of many species of   
butterfly1 from the beautiful blue of   
our little ,lycaenidae to the           
magnificent azure of the large          
,morphinae of ,brazil4 ,in a great many 
cases1 though not by any means in all1  
the male butterflies are more beautiful 

than the females1 and in the ,tropics in
 particular they shine and glow in the  
most superb colours4 ,i really see no   
reason why we should doubt the power of 
sexual selection1 and ,i myself stand   
wholly on ,darwin's side4 ,even though  
we certainly cannot assume that the     
females exercise a conscious choice of  
the handsomest mate1 and deliberate like
 the judges in a court of justice over  
the perfections of their wooers1 we have
 no reason to doubt that distinctive    
forms 7decorative feathers7 and colours 
have a particularly exciting effect upon
 the female1 just as certain odours have
 among animals of so many different     
groups1 including the butterflies4 ,the 
doubts which existed for a considerable 
time1 as a result of fallacious         
experiments1 as to whether the colours  
of flowers really had any influence in  
attracting butterflies have now been set
 at rest through a series of more       
careful investigations2 we now know that
 the colours of flowers are there on    

account of the butterflies1 as ,sprengel
 first showed1 and that the blossoms of 
,phanerogams are selected in relation to
 them1 as ,darwin pointed out4          
,certainly it is not possible to bring  
forward any convincing proof of the     
origin of decorative colours through    
sexual selection1 but there are many    
weighty arguments in favour of it1 and  
these form a body of presumptive        
evidence so strong that it almost       
amounts to certainty4  ,in the first    
place1 there is the analogy with other  
secondary sexual characters4 ,if the    
song of birds and the chirping of the   
cricket have been evolved through sexual
 selection1 if the penetrating odours of
 male animals1--the crocodile1 the      
musk-deer1 the beaver1 the carnivores1  
and1 finally1 the flower-like fragrances
 of the butterflies have been evolved to
 their present pitch in this way1 why   
should decorative colours have arisen in
 some other way8 ,why should the eye be 
less sensitive to ,,specifically ,,male 

colours and other ,,visible signs       
,,enticing ,,to ,,the ,,female1 than the
 olfactory sense to specifically male   
odours1 or the sense of hearing to      
specifically male sounds8 ,moreover1 the
 decorative feathers of birds are almost
 always spread out and displayed before 
the female during courtship4 ,i have    
elsewhere 7,the ,evolution ,theory1     
,london1 #aijd1 ,i4 page #bai47 pointed 
out that decorative colouring and       
sweet-scentedness may replace one       
another in ,lepidoptera as well as in   
flowers1 for just as some modestly      
coloured flowers 7mignonette and violet7
 have often a strong perfume1 while     
strikingly coloured ones are sometimes  
quite devoid of fragrance1 so we find   
that the most beautiful and             
gaily-coloured of our native            
,lepidoptera1 the species of ,vanessa1  
have no scent-scales1 while these are   
often markedly developed in grey        
nocturnal ,lepidoptera4 ,both           
attractions may1 however1 be combined in

 butterflies1 just as in flowers4 ,of   
course1 we cannot explain why both means
 of attraction should exist in one      
genus1 and only one of them in another1 
since we do not know the minutest       
details of the conditions of life of the
 genera concerned4 ,but from the        
sporadic distribution of scent-scales in
 ,lepidoptera1 and from their occurrence
 or absence in nearly related species1  
we may conclude that fragrance is a     
relatively ,,modern acquirement1 more   
recent than brilliant colouring4  ,one  
thing in particular that stamps         
decorative colouring as a product of    
selection is ,,its ,,gradual            
,,intensification by the addition of new
 spots1 which we can quite well observe1
 because in many cases the colours have 
been first acquired by the males1 and   
later transmitted to the females by     
inheritance4 ,the scent-scales are never
 thus transmitted1 probably for the same
 reason that the decorative colours of  
many birds are often not transmitted to 

the females3 because with these they    
would be exposed to too great           
elimination by enemies4 ,wallace was the
 first to point out that in species with
 concealed nests the beautiful feathers 
of the male occurred in the female also1
 as in the parrots1 for instance1 but   
this is not the case in species which   
brood on an exposed nest4 ,in the       
parrots one can often observe that the  
general brilliant colouring of the male 
is found in the female1 but that certain
 spots of colour are absent1 and these  
have probably been acquired             
comparatively recently by the male and  
have not yet been transmitted to the    
female4  ,isolation of the group of     
individuals which is in process of      
varying is undoubtedly of great value in
 sexual selection1 for even a solitary  
conspicuous variation will become       
dominant much sooner in a small isolated
 colony1 than among a large number of   
members of a species4  ,anyone who      
agrees with me in deriving variations   

from germinal selection will regard that
 process as an essential aid towards    
explaining the selection of distinctive 
courtship-characters1 such as coloured  
spots1 decorative feathers1 horny       
outgrowths in birds and reptiles1 combs1
 feather-tufts1 and the like1 since the 
beginnings of these would be presented  
with relative frequency in the struggle 
between the determinants within the     
germ-plasm4 ,the process of transmission
 of decorative feathers to the female   
results1 as ,darwin pointed out and     
illustrated by interesting examples1 in 
the ,,colour-,,transformation ,,of ,a   
,,whole ,,species1 and this process1 as 
the phyletically older colouring of     
young birds shows1 must1 in the course  
of thousands of years1 have repeated    
itself several times in a line of       
descent4  ,if we survey the wealth of   
phenomena presented to us by secondary  
sexual characters1 we can hardly fail to
 be convinced of the truth of the       
principle of sexual selection4 ,and     

certainly no one who has accepted       
natural selection should reject sexual  
selection1 for1 not only do the two     
processes rest upon the same basis1 but 
they merge into one another1 so that it 
is often impossible to say how much of a
 particular character depends on one and
 how much on the other form of          
selection4  7b7 ,,natural ,,selection4  
,an actual proof of the theory of sexual
 selection is out of the question1 if   
only because we cannot tell when a      
variation attains to selection-value4   
,it is certain that a delicate sense of 
smell is of value to the male moth in   
his search for the female1 but whether  
the possession of one additional        
olfactory hair1 or of ten1 or of twenty 
additional hairs leads to the success of
 its possessor we are unable to tell4   
,and we are groping even more in the    
dark when we discuss the excitement     
caused in the female by agreeable       
perfumes1 or by striking and beautiful  
colours4 ,that these do make an         

impression is beyond doubt2 but we can  
only assume that slight intensifications
 of them give any advantage1 and we     
,,must assume this ,,since ,,otherwise  
,,secondary ,,sexual ,,characters       
,,remain ,,inexplicable4  ,the same     
thing is true in regard to natural      
selection4 ,it is not possible to bring 
forward any actual proof of the         
selection-value of the initial stages1  
and the stages in the increase of       
variations1 as has been already shown4  
,but the selection-value of a finished  
adaptation can in many cases be         
statistically determined4 ,cesnola and  
,poulton have made valuable experiments 
in this direction4 ,the former attached 
forty-five individuals of the green1 and
 sixty-five of the brown variety of the 
praying mantis 7,mantis religiosa71 by a
 silk thread to plants1 and watched them
 for seventeen days4 ,the insects which 
were on a surface of a colour similar to
 their own remained uneaten1 while      
twenty-five green insects on brown parts

 of plants had all disappeared in eleven
 days4  ,the experiments of ,poulton and
 ,sanders 7,report of the ,british      
,association 7,bristol1 #ahih71 ,london1
 #ahii1 pages #ijf-iji47 were made with 
#fjj pupae of ,vanessa urticae1 the     
tortoise-shell butterfly4 ,the pupae    
were artificially attached to nettles1  
tree-trunks1 fences1 walls1 and to the  
ground1 some at ,oxford1 some at ,st    
,helens in the ,isle of ,wight4 ,in the 
course of a month #ic per cent of the   
pupae at ,oxford were killed1 chiefly by
 small birds1 while at ,st ,helens #fh  
per cent perished4 ,the experiments     
showed very clearly that the colour and 
character of the surface on which the   
pupa rests--and thus its own            
conspicuousness--are of the greatest    
importance4 ,at ,oxford only the four   
pupae which were fastened to nettles    
emerged2 all the rest--on bark1 stones  
and the like--perished4 ,at ,st ,helens 
the elimination was as follows3 on      
fences where the pupae were conspicuous1

 #ib per cent2 on bark1 #ff per cent2 on
 walls1 #ed per cent2 and among nettles1
 #eg per cent4 ,these interesting       
experiments confirm our views as to     
protective coloration1 and show further1
 ,,that ,,the ,,ratio ,,of ,,elimination
 ,,in ,,the ,,species ,,is ,a ,,very    
,,high ,,one1 ,,and ,,that ,,therefore  
,,selection ,,must ,,be ,,very ,,keen4  
,we may say that the process of         
selection follows as a logical necessity
 from the fulfilment of the three       
preliminary postulates of the theory3   
variability1 heredity1 and the struggle 
for existence1 with its enormous ratio  
of elimination in all species4 ,to this 
we must add a fourth factor1 the        
,,intensification of variations which   
,darwin established as a fact1 and which
 we are now able to account for         
theoretically on the basis of germinal  
selection4 ,it may be objected that     
there is considerable uncertainty about 
this ,,logical proof1 because of our    
inability to demonstrate the            

selection-value of the initial stages   
and the individual stages of increase4  
,we have therefore to fall back on      
,,presumptive ,,evidence4 ,this is to be
 found in ,,the ,,interpretative ,,value
 ,,of ,,the ,,theory4 ,let us consider  
this point in greater detail4  ,in the  
first place1 it is necessary to         
emphasise what is often overlooked1     
namely1 that the theory not only        
explains the ,,transformations of       
species1 it also explains ,,their       
,,remaining ,,the ,,same2 in addition to
 the principle of varying1 it contains  
within itself that of ,,persisting4 ,it 
is part of the essence of selection1    
that it not only causes a part to ,,vary
 till it has reached its highest pitch  
of adaptation1 but that it ,,maintains  
,,it ,,at ,,this ,,pitch4 ,,this        
,,conserving ,,influence ,,of ,,natural 
,,selection is of great importance1 and 
was early recognised by ,darwin2 it     
follows naturally from the principle of 
the survival of the fittest4  ,we       

understand from this how it is that a   
species which has become fully adapted  
to certain conditions of life ceases to 
vary1 but remains constant1 as long as  
the conditions of life ,,for ,,it remain
 unchanged1 whether this be for         
thousands of years1 or for whole        
geological epochs4 ,but the most        
convincing proof of the power of the    
principle of selection lies in the      
innumerable multitude of phenomena which
 cannot be explained in any other way4  
,to this category belong all structures 
which are only ,,passively of advantage 
to the organism1 because none of these  
can have arisen by the alleged          
,,lamarckian ,,principle4 ,these have   
been so often discussed that we need do 
no more than indicate them here4 ,until 
quite recently the sympathetic          
coloration of animals--for instance1 the
 whiteness of ,arctic animals--was      
referred1 at least in part1 to the      
,,direct influence of external factors1 
but the facts can best be explained by  

referring them to the processes of      
selection1 for then it is unnecessary to
 make the gratuitous assumption that    
many species are sensitive to the       
stimulus of cold and that others are    
not4 ,the great majority of ,arctic     
land-animals1 mammals and birds1 are    
white1 and this proves that they were   
all able to present the variation which 
was most useful for them4 ,the sable is 
brown1 but it lives in trees1 where the 
brown colouring protects and conceals it
 more effectively4 ,the musk-sheep      
7,ovibos moschatus7 is also brown1 and  
contrasts sharply with the ice and snow1
 but it is protected from beasts of prey
 by its gregarious habit1 and therefore 
it is of advantage to be visible from as
 great a distance as possible4 ,that so 
many species have been able to give rise
 to white varieties does not depend on a
 special sensitiveness of the skin to   
the influence of cold1 but to the fact  
that ,mammals and ,birds have a general 
tendency to vary towards white4 ,even   

with us1 many birds--starlings1         
blackbirds1 swallows1 etc4--occasionally
 produce white individuals1 but the     
white variety does not persist1 because 
it readily falls a victim to the        
carnivores4 ,this is true of white      
fawns1 foxes1 deer1 etc4 ,the whiteness1
 therefore1 arises from internal causes1
 and only persists when it is useful4 ,a
 great many animals living in a ,,green 
,,environment have become clothed in    
green1 especially insects1 caterpillars1
 and ,mantidae1 both persecuted and     
persecutors4  ,that it is not the direct
 effect of the environment which calls  
forth the green colour is shown by the  
many kinds of caterpillar which rest on 
leaves and feed on them1 but are        
nevertheless brown4 ,these feed by night
 and betake themselves through the day  
to the trunk of the tree1 and hide in   
the furrows of the bark4 ,we cannot1    
however1 conclude from this that they   
were ,,unable to vary towards green1 for
 there are ,arctic animals which are    

white only in winter and brown in summer
 7,alpine hare1 and the ptarmigan of the
 ,alps71 and there are also green       
leaf-insects which remain green only    
while they are young and difficult to   
see on the leaf1 but which become brown 
again in the last stage of larval life1 
when they have outgrown the leaf4 ,they 
then conceal themselves by day1         
sometimes only among withered leaves on 
the ground1 sometimes in the earth      
itself4 ,it is interesting that in one  
genus1 ,chaerocampa1 one species is     
brown in the last stage of larval life1 
another becomes brown earlier1 and in   
many species the last stage is not      
wholly brown1 a part remaining green4   
,whether this is a case of a double     
adaptation1 or whether the green is     
being gradually crowded out by the      
brown1 the fact remains that the same   
species1 even the same individual1 can  
exhibit both variations4 ,the case is   
the same with many of the leaf-like     
,orthoptera1 as1 for instance1 the      

praying mantis 7,mantis religiosa7 which
 we have already mentioned4  ,but the   
best proofs are furnished by those      
often-cited cases in which the insect   
bears a deceptive resemblance to another
 object4 ,we now know many such cases1  
such as the numerous imitations of green
 or withered leaves1 which are brought  
about in the most diverse ways1         
sometimes by mere variations in the form
 of the insect and in its colour1       
sometimes by an elaborate marking1 like 
that which occurs in the ,indian        
leaf-butterflies1 ,kallima inachis4 ,in 
the single butterfly-genus ,anaea1 in   
the woods of ,south ,america1 there are 
about a hundred species which are all   
gaily coloured on the upper surface1 and
 on the reverse side exhibit the most   
delicate imitation of the colouring and 
pattern of a leaf1 generally without any
 indication of the leaf-ribs1 but       
extremely deceptive nevertheless4       
,anyone who has seen only one such      
butterfly may doubt whether many of the 

insignificant details of the marking can
 really be of advantage to the insect4  
,such details are for instance the      
apparent holes and splits in the        
apparently dry or half-rotten leaf1     
which are usually due to the fact that  
the scales are absent on a circular or  
oval patch so that the colourless       
wing-membrane lies bare1 and one can    
look through the spot as through a      
window4 ,whether the bird which is      
seeking or pursuing the butterflies     
takes these holes for dewdrops1 or for  
the work of a devouring insect1 does not
 affect the question2 the mirror-like   
spot undoubtedly increases the general  
deceptiveness1 for the same thing occurs
 in many leaf-butterflies1 though not in
 all1 and in some cases it is replaced  
in quite a peculiar manner4 ,in one     
species of ,anaea 7,a4 divina71 the     
resting butterfly looks exactly like a  
leaf out of the outer edge of which a   
large semicircular piece has been eaten1
 possibly by a caterpillar2 but if we   

look more closely it is obvious that    
there is no part of the wing absent1 and
 that the semicircular piece is of a    
clear1 pale yellow colour1 while the    
rest of the wing is of a strongly       
contrasted dark brown4  ,but the        
deceptive resemblance may be caused in  
quite a different manner4 ,i have often 
speculated as to what advantage the     
brilliant white ,c could give to the    
otherwise dusky-coloured ,comma         
butterfly 7,grapta ,c4 album74          
,poulton's recent observations 7,proc4  
,ent4 ,soc41 ,london1 ,may #f1 #aijc47  
have shown that this represents the     
imitation of a crack such as is often   
seen in dry leaves1 and is very         
conspicuous because the light shines    
through it4  ,the utility obviously lies
 in presenting to the bird the very     
familiar picture of a broken leaf with a
 clear shining slit1 and we may         
conclude1 from the imitation of such    
small details1 that the birds are very  
sharp observers and that the smallest   

deviation from the usual arrests their  
attention and incites them to closer    
investigation4 ,it is obvious that such 
detailed--we might almost say such      
subtle--deceptive resemblances could    
only have come about in the course of   
long ages through the acquirement from  
time to time of something new which     
heightened the already existing         
resemblance4  ,in face of facts like    
these there can be no question of       
chance1 and no one has succeeded so far 
in finding any other explanation to     
replace that by selection4 ,for the     
rest1 the apparent leaves are by no     
means perfect copies of a leaf2 many of 
them only represent the torn or broken  
piece1 or the half or two-thirds of a   
leaf1 but then the leaves themselves    
frequently do not present themselves to 
the eye as a whole1 but partially       
concealed among other leaves4 ,even     
those butterflies which1 like the       
species of ,kallima and ,anaea1         
represent the whole of a leaf with      

stalk1 ribs1 apex1 and the whole        
breadth1 are not actual copies which    
would satisfy a botanist2 there is often
 much wanting4 ,in ,kallima the lateral 
ribs of the leaf are never all included 
in the markings2 there are only two or  
three on the left side and at most four 
or five on the right1 and in many       
individuals these are rather obscure1   
while in others they are comparatively  
distinct4 ,this furnishes us with fresh 
evidence in favour of their origin      
through processes of selection1 for a   
botanically perfect picture could not   
arise in this way2 there could only be a
 fixing of such details as heightened   
the deceptive resemblance4  ,our        
postulate of origin through selection   
also enables us to understand why the   
leaf-imitation is on the lower surface  
of the wing in the diurnal ,lepidoptera1
 and on the upper surface in the        
nocturnal forms1 corresponding to the   
attitude of the wings in the resting    
position of the two groups4  ,the       

strongest of all proofs of the theory1  
however1 is afforded by cases of true   
mimicry1 those adaptations discovered by
 ,bates in #ahfa1 consisting in the     
imitation of one species by another1    
which becomes more and more like its    
model4 ,the model is always a species   
that enjoys some special protection from
 enemies1 whether because it is         
unpleasant to taste1 or because it is in
 some way dangerous4  ,it is chiefly    
among insects and especially among      
butterflies that we find the greatest   
number of such cases4 ,several of these 
have been minutely studied1 and every   
detail has been investigated1 so that it
 is difficult to understand how there   
can still be disbelief in regard to     
them4 ,if the many and exact            
observations which have been carefully  
collected and critically discussed1 for 
instance by ,poulton 7,essays on        
,evolution1 #ahhi-aijg1 ,oxford1 #aijh1 
passim1 e4g4 page #bfi47 were thoroughly
 studied1 the arguments which are still 

frequently urged against mimicry would  
be found untenable2 we can hardly hope  
to find more convincing proof of the    
actuality of the processes of selection 
than these cases put into our hands4    
,the preliminary postulates of the      
theory of mimicry have been disputed1   
for instance1 that diurnal butterflies  
are persecuted and eaten by birds1 but  
observations specially directed towards 
this point in ,india1 ,africa1 ,america 
and ,europe have placed it beyond all   
doubt4 ,if it were necessary ,i could   
myself furnish an account of my own     
observations on this point4  ,in the    
same way it has been established by     
experiment and observation in the field 
that in all the great regions of        
distribution there are butterflies which
 are rejected by birds and lizards1     
their chief enemies1 on account of their
 unpleasant smell or taste4 ,these      
butterflies are usually gaily and       
conspicuously coloured and thus--as     
,wallace first interpreted it--are      

furnished with an easily recognisable   
sign3 a sign of unpalatableness or      
,,warning ,,colours4 ,if they were not  
thus recognisable easily and from a     
distance1 they would frequently be      
pecked at by birds1 and then rejected   
because of their unpleasant taste2 but  
as it is1 the insect-eaters recognise   
them at once as unpalatable booty and   
ignore them4 ,such ,,immune 7,the       
expression does not refer to all the    
enemies of this butterfly2 against      
ichneumon-flies1 for instance1 their    
unpleasant smell usually gives no       
protection47 species1 wherever they     
occur1 are imitated by other palatable  
species1 which thus acquire a certain   
degree of protection4  ,it is true that 
this explanation of the bright1         
conspicuous colours is only a           
hypothesis1 but its                     
foundations1--unpalatableness1 and the  
liability of other butterflies to be    
eaten1--are certain1 and its            
consequences--the existence of mimetic  

palatable forms--confirm it in the most 
convincing manner4 ,of the many cases   
now known ,i select one1 which is       
especially remarkable1 and which has    
been thoroughly investigated1 ,papilio  
dardanus 7merope71 a large1 beautiful1  
diurnal butterfly which ranges from     
,abyssinia throughout the whole of      
,africa to the south coast of ,cape     
,colony4  ,the males of this form are   
everywhere ,,almost the same in colour  
and in form of wings1 save for a few    
variations in the sparse black markings 
on the pale yellow ground4 ,but the     
females occur in several quite different
 forms and colourings1 and one of these 
only1 the ,abyssinian form1 is like the 
male1 while the other three or four are 
,,mimetic1 that is to say1 they copy a  
butterfly of quite a different family   
the ,danaids1 which are among the       
,,immune forms4 ,in each region the     
females have thus copied two or three   
different immune species4 ,there is much
 that is interesting to be said in      

regard to these species1 but it would be
 out of keeping with the general tenor  
of this paper to give details of this   
very complicated case of polymorphism in
 ,p4 dardanus4 ,anyone who is interested
 in the matter will find a full and     
exact statement of the case in as far as
 we know it1 in ,poulton's ,essays on   
,evolution 7pages #cgc-cge74 7,professor
 ,poulton has corrected some wrong      
descriptions which ,i had unfortunately 
overlooked in the ,plates of my book    
,vortrage uber ,descendenztheorie1 and  
which refer to ,papilio dardanus        
7merope74 ,these mistakes are of no     
importance as far as and understanding  
of the mimicry-theory is concerned1 but 
,i hope shortly to be able to correct   
them in a later edition47 ,i need only  
add that three different mimetic female 
forms have been reared from the eggs of 
a single female in ,south ,africa4 ,the 
resemblance of these forms to their     
immune models goes so far that even the 
details of the ,,local forms of the     

models are copied by the mimetic        
species4  ,it remains to be said that in
 ,madagascar a butterfly1 ,papilio      
meriones1 occurs1 of which both sexes   
are very similar in form and markings to
 the non-mimetic male of ,p4 dardanus1  
so that it probably represents the      
ancestor of this latter species4  ,in   
face of such facts as these every       
attempt at another explanation must     
fail4 ,similarly all the other details  
of the case fulfil the preliminary      
postulates of selection1 and leave no   
room for any other interpretation4 ,that
 the males do not take on the protective
 colouring is easily explained1 because 
they are in general more numerous1 and  
the females are more important for the  
preservation of the species1 and must   
also live longer in order to deposit    
their eggs4 ,we find the same state of  
things in many other species1 and in one
 case 7,elymnias undularis7 in which the
 male is also mimetically coloured1 it  
copies quite a differently coloured     

immune species from the model followed  
by the female4 ,this is quite           
intelligible when we consider that if   
there were ,,too ,,many false immune    
types1 the birds would soon discover    
that there were palatable individuals   
among those with unpalatable warning    
colours4 ,hence the imitation of        
different immune species by ,papilio    
dardanus6  ,i regret that lack of space 
prevents my bringing forward more       
examples of mimicry and discussing them 
fully4 ,but from the case of ,papilio   
dardanus alone there is much to be      
learnt which is of the highest          
importance for our understanding of     
transformations4 ,it shows us chiefly   
what ,i once called1 somewhat strongly  
perhaps1 ,,the ,,omnipotence ,,of       
,,natural ,,selection in answer to an   
opponent who had spoken of its          
inadequacy4 ,we here see that one and   
the same species is capable of producing
 four or five different patterns of     
colouring and marking2 thus the         

colouring and marking are not1 as has   
often been supposed1 a necessary outcome
 of the specific nature of the species1 
but a true adaptation1 which cannot     
arise as a direct effect of climatic    
conditions1 but solely through what ,i  
may call the sorting out of the         
variations produced by the species1     
according to their utility4 ,that       
caterpillars may be either green or     
brown is already something more than    
could have been expected according to   
the old conception of species1 but that 
one and the same butterfly should be now
 pale yellow1 with black2 now red with  
black and pure white2 now deep black    
with large1 pure white spots2 and again 
black with a large ochreous-yellow spot1
 and many small white and yellow spots2 
that in one sub-species it may be tailed
 like the ancestral form1 and in another
 tailless like its ,danaid model1--all  
this shows a far-reaching capacity for  
variation and adaptation that wide never
 have expected if we did not see the    

facts before us4 ,how it is possible    
that the primary colour-variations      
should thus be intensified and combined 
remains a puzzle even now2 we are       
reminded of the modern three-colour     
printing1--perhaps similar combinations 
of the primary colours take place in    
this case2 in any case the direction of 
these primary variations is determined  
by the artist whom we know as natural   
selection1 for there is no other        
conceivable way in which the model could
 affect the butterfly that is becoming  
more and more like it4 ,the same climate
 surrounds all four forms of female2    
they are subject to the same conditions 
of nutrition4 ,moreover1 ,papilio       
dardanus is by no means the only species
 of butterfly which exhibits different  
kinds of colour-pattern on its wings4   
,many species of the ,asiatic genus     
,elymnias have on the upper surface a   
very good imitation of an immune        
,euploeine 7,danainae71 often with a    
steel-blue ground-colour1 while the     

under surface is well concealed when the
 butterfly is at rest1--thus there are  
two kinds of protective coloration each 
with a different meaning6 ,the same     
thing may be observed in many           
non-mimetic butterflies1 for instance in
 all our species of ,vanessa1 in which  
the under side shows a grey-brown or    
brownish-black protective coloration1   
but we do not yet know with certainty   
what may be the biological significance 
of the gaily coloured upper surface4    
,in general it may be said that mimetic 
butterflies are comparatively rare      
species1 but there are exceptions1 for  
instance ,limenitis archippus in ,north 
,america1 of which the immune model     
7,danaida plexippus7 also occurs in     
enormous numbers4  ,in another          
mimicry-category the imitators are often
 more numerous than the models1 namely  
in the case of the imitation of         
,,dangerous ,,insects by harmless       
species4 ,bees and wasps are dreaded for
 their sting1 and they are copied by    

harmless flies of the genera ,eristalis 
and ,syrphus1 and these mimics often    
occur in swarms about flowering plants  
without damage to themselves or to their
 models2 they are feared and are        
therefore left unmolested4  ,in regard  
also to the ,,faithfulness ,,of ,,the   
,,copy the facts are quite in harmony   
with the theory1 according to which the 
resemblance must have arisen and        
increased ,,by ,,degrees4 ,we can       
recognise this in many cases1 for even  
now the mimetic species show very       
,,varying ,,degrees ,,of ,,resemblance  
to their immune model4 ,if we compare1  
for instance1 the many different        
imitators of ,danaida chrysippus we find
 that1 with their brownish-yellow       
ground-colour1 and the position and     
size1 and more or less sharp limitation 
of their clear marginal spots1 they have
 reached very different degrees of      
nearness to their model4 ,or compare the
 female of ,elymnias undularis with its 
model ,danaida genutia2 there is a      

general resemblance1 but the marking of 
the ,danaida is very roughly imitated in
 ,elymnias4  ,another fact that bears   
out the theory of mimicry is1 that even 
when the resemblance in colour-pattern  
is very great1 the ,,wing-,,venation1   
which is so constant1 and so important  
in determining the systematic position  
of butterflies1 is never affected by the
 variation4 ,the pursuers of the        
butterfly have no time to trouble about 
entomological intricacies4  ,i must not 
pass over a discovery of ,poulton's     
which is of great theoretical           
importance--that mimetic butterflies may
 reach the same effect by very different
 means4 7,journ4 ,linn4 ,soc4 ,london   
7,zool471 ,vol4 ,,xxvi4 #ahih1 pages    
#eih-fjb47 ,thus the glass-like         
transparency of the wing of a certain   
,ithomiine 7,methona7 and its ,pierine  
mimic 7,dismorphia orise7 depends on a  
diminution in the size of the scales2 in
 the ,danaine genus ,ituna it is due to 
the fewness of the scales1 and in a     

third imitator1 a moth 7,castnia linus  
var4 heliconoides7 the glass-like       
appearance of the wing is due neither to
 diminution nor to absence of scales1   
but to their absolute colourlessness and
 transparency1 and to the fact that they
 stand upright4 ,in another moth mimic  
7,anthomyza7 the arrangement of the     
transparent scales is normal4 ,thus it  
is not some unknown external influence  
that has brought about the transparency 
of the wing in these five forms1 as has 
sometimes been supposed4 ,nor is it a   
hypothetical ,,internal evolutionary    
tendency1 for all three vary in a       
different manner4 ,the cause of this    
agreement can only lie in selection1    
which preserves and intensifies in each 
species the favourable variations that  
present themselves4 ,the great          
faithfulness of the copy is astonishing 
in these cases1 for it is not ,,the     
,,whole wing which is transparent2      
certain markings are black in colour1   
and these contrast sharply with the     

glass-like ground4 ,it is obvious that  
the pursuers of these butterflies must  
be very sharp-sighted1 for otherwise the
 agreement between the species could    
never have been pushed so far4 ,the less
 the enemies see and observe1 the more  
defective must the imitation be1 and if 
they had been blind1 no visible         
resemblance between the species which   
required protection could ever have     
arisen4  ,a seemingly irreconcilable    
contradiction to the mimicry theory is  
presented in the following cases1 which 
were known to ,bates1 who1 however1     
never succeeded in bringing them into   
line with the principle of mimicry4  ,in
 ,south ,america there are1 as we have  
already said1 many mimics of the immune 
,ithomiinae 7or as ,bates called them   
,heliconidae74 ,among these there occur 
not merely species which are edible1 and
 thus require the protection of a       
disguise1 but others which are rejected 
on account of their unpalatableness4    
,how could the ,ithomiine dress have    

developed in their case1 and of what use
 is it1 since the species would in any  
case be immune8 ,in ,eastern ,brazil1   
for instance1 there are four            
butterflies1 which bear a most confusing
 resemblance to one another in colour1  
marking1 and form of wing1 and all four 
are unpalatable to birds4 ,they belong  
to four different genera and three      
sub-families1 and we have to inquire3   
,whence came this resemblance and what  
end does it serve8 ,for a long time no  
satisfactory answer could be found1 but 
,fritz ,muller 7,in ,kosmos1 #ahgi1 page
 #ajj471 seventeen years after ,bates1  
offered a solution to the riddle1 when  
he pointed out that young birds could   
not have an instinctive knowledge of the
 unpalatableness of the ,ithomiines1 but
 must learn by experience which species 
were edible and which inedible4 ,thus   
each young bird must have tasted at     
least one individual of each inedible   
species and discovered its              
unpalatability1 before it learnt to     

avoid1 and thus to spare the species4   
,but if the four species resemble each  
other very closely the bird will regard 
them all as of the same kind1 and avoid 
them all4 ,thus there developed a       
process of selection which resulted in  
the survival of the ,ithomiine-like     
individuals1 and in so great an increase
 of resemblance between the four        
species1 that they are difficult to     
distinguish one from another even in a  
collection4 ,the advantage for the four 
species1 living side by side as they do 
e4g4 in ,bahia1 lies in the fact that   
only one individual from the            
,,mimicry-,,ring 7inedible association7 
need be tasted by a young bird1 instead 
of at least four individuals1 as would  
otherwise be the case4 ,as the number of
 young birds is great1 this makes a     
considerable difference in the ratio of 
elimination4  ,these interesting        
mimicry-rings 7trusts71 which have much 
significance for the theory1 have been  
the subject of numerous and careful     

investigations1 and at least their      
essential features are now fully        
established4 ,muller took for granted1  
without making any investigations1 that 
young birds only learn by experience to 
distinguish between different kinds of  
victims4 ,but ,lloyd ,morgan's 7,habit  
and ,instinct1 ,london1 #ahif47         
experiments with young birds proved that
 this is really the case1 and at the    
same time furnished an additional       
argument against the ,,lamarckian       
,,principle4  ,in addition to the       
mimicry-rings first observed in ,south  
,america1 others have been described    
from ,tropical ,india by ,moore1 and by 
,poulton and ,dixey from ,africa1 and we
 may expect to learn many more          
interesting facts in this connection4   
,here again the preliminary postulates  
of the theory are satisfied4 ,and how   
much more that would lead to the same   
conclusion might be added6  ,as in the  
case of mimicry many species have come  
to resemble one another through         

processes of selection1 so we know whole
 classes of phenomena in which plants   
and animals have become adapted to one  
another1 and have thus been modified to 
a considerable degree4 ,i refer         
particularly to the relation between    
flowers and insects2 but as there is an 
article on ,the ,biology of ,flowers in 
this volume1 ,i need not discuss the    
subject1 but will confine myself to     
pointing out the significance of these  
remarkable cases for the theory of      
selection4 ,darwin has shown that the   
originally inconspicuous blossoms of the
 phanerogams were transformed into      
flowers through the visits of insects1  
and that1 conversely1 several large     
orders of insects have been gradually   
modified by their association with      
flowers1 especially as regards the parts
 of their body actively concerned4 ,bees
 and butterflies in particular have     
become what they are through their      
relation to flowers4 ,in this case again
 all that is apparently contradictory to

 the theory can1 on closer              
investigation1 be beautifully           
interpreted in corroboration of it4     
,selection can give rise only to what is
 of use to the organism actually        
concerned1 never to what is of use to   
some other organism1 and we must        
therefore expect to find that in flowers
 only characters of use to ,,themselves 
have arisen1 never characters which are 
of use to insects only1 and conversely  
that in the insects characters useful to
 them and not merely to the plants would
 have originated4 ,for a long time it   
seemed as if an exception to this rule  
existed in the case of the fertilisation
 of the yucca blossoms by a little moth1
 ,pronuba yuccasella4 ,this little moth 
has a sickle-shaped appendage to its    
mouth-parts which occurs in no other    
,lepidopteron1 and which is used for    
pushing the yellow pollen into the      
opening of the pistil1 thus fertilising 
the flower4 ,thus it appears as if a new
 structure1 which is useful only to the 

plant1 has arisen in the insect4 ,but   
the difficulty is solved as soon as we  
learn that the moth lays its eggs in the
 fruit-buds of the ,yucca1 and that the 
larvae1 when they emerge1 feed on the   
developing seeds4 ,in effecting the     
fertilisation of the flower the moth is 
at the same time making provision for   
its own offspring1 since it is only     
after fertilisation that the seeds begin
 to develop4 ,there is thus nothing to  
prevent our referring this structural   
adaptation in ,pronuba yuccasella to    
processes of selection1 which have      
gradually transformed the maxillary     
palps of the female into the            
sickle-shaped instrument for collecting 
the pollen1 and which have at the same  
time developed in the insect the        
instinct to press the pollen into the   
pistil4  ,in this domain1 then1 the     
theory of selection finds nothing but   
corroboration1 and it would be          
impossible to substitute for it any     
other explanation1 which1 now that the  

facts are so well known1 could be       
regarded as a serious rival to it4 ,that
 selection is a factor1 and a very      
powerful factor in the evolution of     
organisms1 can no longer be doubted4    
,even although we cannot bring forward  
formal proofs of it ,,in ,,detail1      
cannot calculate definitely the size of 
the variations which present themselves1
 and their selection-value1 cannot1 in  
short1 reduce the whole process to a    
mathematical formula1 yet we must assume
 selection1 because it is the only      
possible explanation applicable to whole
 classes of phenomena1 and because1 on  
the other hand1 it is made up of factors
 which we know can be proved actually to
 exist1 and which1 ,,if they exist1 must
 of logical necessity cooperate in the  
manner required by the theory4 ,,we     
,,must ,,accept ,,it ,,because ,,the    
,,phenomena ,,of ,,evolution ,,and      
,,adaptation ,,must ,,have ,a ,,natural 
,,basis1 ,,and ,,because ,,it ,,is ,,the
 ,,only ,,possible ,,explanation ,,of   

,,them4 7,this has been discussed in    
many of my earlier works4 ,see for      
instance ,the ,all-,sufficiency of      
,natural ,selection1 a reply to ,herbert
 ,spencer1 ,london1 #ahic47  ,many      
people are willing to admit that        
selection explains adaptations1 but they
 maintain that only a part of the       
phenomena are thus explained1 because   
everything does not depend upon         
adaptation4 ,they regard adaptation as1 
so to speak1 a special effort on the    
part of ,nature1 which she keeps in     
readiness to meet particularly difficult
 claims of the external world on        
organisms4 ,but if we look at the matter
 more carefully we shall find that      
adaptations are by no means exceptional1
 but that they are present everywhere in
 such enormous numbers1 that it would be
 difficult in regard to any structure   
whatever1 to prove that adaptation had  
,,not played a part in its evolution4   
,how often has the senseless objection  
been urged against selection that it can

 create nothing1 it can only reject4 ,it
 is true that it cannot create either   
the living substance or the variations  
of it2 both must be given4 ,but in      
rejecting one thing it preserves        
another1 intensifies it1 combines it1   
and in this way ,,creates what is new4  
,,everything in organisms depends on    
adaptation2 that is to say1 everything  
must be admitted through the narrow door
 of selection1 otherwise it can take no 
part in the building up of the whole4   
,but1 it is asked1 what of the direct   
effect of external conditions1          
temperature1 nutrition1 climate and the 
like8 ,undoubtedly these can give rise  
to variations1 but they too must pass   
through the door of selection1 and if   
they cannot do this they are rejected1  
eliminated from the constitution of the 
species4  ,it may1 perhaps1 be objected 
that such external influences are often 
of a compelling power1 and that every   
animal ,,must submit to them1 and that  
thus selection has no choice and can    

neither select nor reject4 ,there may be
 such cases2 let us assume for instance 
that the effect of the cold of the      
,arctic regions was to make all the     
mammals become black2 the result would  
be that they would all be eliminated by 
selection1 and that no mammals would be 
able to live there at all4 ,but in most 
cases a certain percentage of animals   
resists these strong influences1 and    
thus selection secures a foothold on    
which to work1 eliminating the          
unfavourable variation1 and establishing
 a useful colouring1 consistent with    
what is required for the maintenance of 
the species4  ,everything depends upon  
adaptation6 ,we have spoken much of     
adaptation in colouring1 in connection  
with the examples brought into          
prominence by ,darwin1 because these are
 conspicuous1 easily verified1 and at   
the same time convincing for the theory 
of selection4 ,but is it only desert and
 polar animals whose colouring is       
determined through adaptation8 ,or the  

leaf-butterflies1 and the mimetic       
species1 or the terrifying markings1 and
 warning-colours and a thousand other   
kinds of sympathetic colouring8 ,it is1 
indeed1 never the colouring alone which 
makes up the adaptation2 the structure  
of the animal plays a part1 often a very
 essential part1 in the protective      
disguise1 and thus ,,many variations may
 cooperate towards ,,one common end4    
,and it is to be noted that it is by no 
means only external parts that are      
changed2 internal parts are ,,always    
modified at the same time--for instance1
 the delicate elements of the nervous   
system on which depend the ,,instinct of
 the insect to hold its wings1 when at  
rest1 in a perfectly definite position1 
which1 in the leaf-butterfly1 has the   
effect of bringing the two pieces on    
which the marking occurs on the anterior
 and posterior wing into the same       
direction1 and thus displaying as a     
whole the fine curve of the midrib on   
the seeming leaf4 ,but the wing-holding 

instinct is not regulated in the same   
way in all leaf-butterflies2 even our   
indigenous species of ,vanessa1 with    
their protective ground-colouring1 have 
quite a distinctive way of holding their
 wings so that the greater part of the  
anterior wing is covered by the         
posterior when the butterfly is at rest4
 ,but the protective colouring appears  
on the posterior wing and on the tip of 
the anterior1 ,,to ,,precisely ,,the    
,,distance ,,to ,,which ,,it ,,is ,,left
 ,,uncovered4 ,this occurs1 as          
,standfuss has shown1 in different      
degree in our two most nearly allied    
species1 the uncovered portion being    
smaller in ,v4 urticae than in ,v4      
polychloros4 ,in this case1 as in most  
leaf-butterflies1 the holding of the    
wing was probably the primary character2
 only after that was thoroughly         
established did the protective marking  
develop4 ,in any case1 the instinctive  
manner of holding the wings is          
associated with the protective          

colouring1 and must remain as it is if  
the latter is to be effective4 ,how     
greatly instincts may change1 that is to
 say1 may be adapted1 is shown by the   
case of the ,noctuid shark moth1 ,xylina
 vetusta4 ,this form bears a most       
deceptive resemblance to a piece of     
rotten wood1 and the appearance is      
greatly increased by the modification of
 the innate impulse to flight common to 
so many animals1 which has here been    
transformed into an almost contrary     
instinct4 ,this moth does not fly away  
from danger1 but feigns death1 that is1 
it draws antennae1 legs and wings close 
to the body1 and remains perfectly      
motionless4 ,it may be touched1 picked  
up1 and thrown down again1 and still it 
does not move4 ,this remarkable instinct
 must surely have developed             
simultaneously with the wood-colouring2 
at all events1 both cooperating         
variations are now present1 and prove   
that both the external and the most     
minute internal structure have undergone

 a process of adaptation4  ,the case is 
the same with all structural variations 
of animal parts1 which are not          
absolutely insignificant4 ,when the     
insects acquired wings they must also   
have acquired the mechanism with which  
to move them--the musculature1 and the  
nervous apparatus necessary for its     
automatic regulation4 ,all instincts    
depend upon compound reflex mechanisms  
and are just as indispensable as the    
parts they have to set in motion1 and   
all may have arisen through processes of
 selection if the reasons which ,i have 
elsewhere given for this view are       
correct4 7,the ,evolution ,theory1      
,london1 #aijd1 page #add47  ,thus there
 is no lack of adaptations within the   
organism1 and particularly in its most  
important and complicated parts1 so that
 we may say that there is no actively   
functional organ that has not undergone 
a process of adaptation relative to its 
function and the requirements of the    
organism4 ,not only is every gland      

structurally adapted1 down to the very  
minutest histological details1 to its   
function1 but the function is equally   
minutely adapted to the needs of the    
body4 ,every cell in the mucous lining  
of the intestine is exactly regulated in
 its relation to the different nutritive
 substances1 and behaves in quite a     
different way towards the fats1 and     
towards nitrogenous substances1 or      
peptones4  ,i have elsewhere called     
attention to the many adaptations of the
 whale to the surrounding medium1 and   
have pointed out--what has long been    
known1 but is not universally admitted1 
even now--that in it a great number of  
important organs have been transformed  
in adaptation to the peculiar conditions
 of aquatic life1 although the ancestors
 of the whale must have lived1 like     
other hair-covered mammals1 on land4 ,i 
cited a number of these                 
transformations--the fish-like form of  
the body1 the hairlessness of the skin1 
the transformation of the fore-limbs to 

fins1 the disappearance of the          
hind-limbs and the development of a tail
 fin1 the layer of blubber under the    
skin1 which affords the protection from 
cold necessary to a warm-blooded animal1
 the disappearance of the ear-muscles   
and the auditory passages1 the          
displacement of the external nares to   
the forehead for the greater security of
 the breathing-hole during the brief    
appearance at the surface1 and certain  
remarkable changes in the respiratory   
and circulatory organs which enable the 
animal to remain for a long time under  
water4 ,i might have added many more1   
for the list of adaptations in the whale
 to aquatic life is by no means         
exhausted2 they are found in the        
histological structure and in the       
minutest combinations in the nervous    
system4 ,for it is obvious that a       
tail-fin must be used in quite a        
different way from a tail1 which serves 
as a fly-brush in hoofed animals1 or as 
an aid to springing in the kangaroo or  

as a climbing organ2 it will require    
quite different reflex-mechanisms and   
nerve-combinations in the motor centres4
  ,i used this example in order to show 
how unnecessary it is to assume a       
special internal evolutionary power for 
the phylogenesis of species1 for this   
whole order of whales is1 so to speak1  
,,made ,,up ,,of ,,adaptations2 it      
deviates in many essential respects from
 the usual mammalian type1 and all the  
deviations are adaptations to aquatic   
life4 ,but if precisely the most        
essential features of the organisation  
thus depend upon adaptation1 what is    
left for a phyletic force to do1 since  
it is these essential features of the   
structure it would have to determine8   
,there are few people now who believe in
 a phyletic evolutionary power1 which is
 not made up of the forces known to     
us--adaptation and heredity--but the    
conviction that ,,every part of an      
organism depends upon adaptation has not
 yet gained a firm footing4             

,nevertheless1 ,i must continue to      
regard this conception as the correct   
one1 as ,i have long done4  ,i may be   
permitted one more example4 ,the feather
 of a bird is a marvellous structure1   
and no one will deny that as a whole it 
depends upon adaptation4 ,but what part 
of it ,,does ,,not depend upon          
adaptation8 ,the hollow quill1 the shaft
 with its hard1 thin1 light cortex1 and 
the spongy substance within it1 its     
square section compared with the round  
section of the quill1 the flat barbs1   
their short1 hooked barbules which1 in  
the flight-feathers1 hook into one      
another with just sufficient firmness to
 resist the pressure of the air at each 
wing-beat1 the lightness and firmness of
 the whole apparatus1 the elasticity of 
the vane1 and so on4 ,and yet all this  
belongs to an organ which is only       
passively functional1 and therefore can 
have nothing to do with the ,,lamarckian
 ,,principle4 ,nor can the feather have 
arisen through some magical effect of   

temperature1 moisture1 electricity1 or  
specific nutrition1 and thus selection  
is again our only anchor of safety4     
,but--it will be objected--the substance
 of which the feather consists1 this    
peculiar kind of horny substance1 did   
not first arise through selection in the
 course of the evolution of the birds1  
for it formed the covering of the scales
 of their reptilian ancestors4 ,it is   
quite true that a similar substance     
covered the scales of the ,reptiles1 but
 why should it not have arisen among    
them through selection8 ,or in what     
other way could it have arisen1 since   
scales are also passively useful parts8 
,it is true that if we are only to call 
adaptation what has been acquired by the
 species we happen to be considering1   
there would remain a great deal that    
could not be referred to selection2 but 
we are postulating an evolution which   
has stretched back through aeons1 and in
 the course of which innumerable        
adaptations took place1 which had not   

merely ephemeral persistence in a genus1
 a family or a class1 but which was     
continued into whole ,phyla of animals1 
with continual fresh adaptations to the 
special conditions of each species1     
family1 or class1 yet with persistence  
of the fundamental elements4 ,thus the  
feather1 once acquired1 persisted in all
 birds1 and the vertebral column1 once  
gained by adaptation in the lowest      
forms1 has persisted in all the         
,vertebrates1 from ,amphioxus upwards1  
although with constant readaptation to  
the conditions of each particular group4
 ,thus everything we can see in animals 
is adaptation1 whether of to-day1 or of 
yesterday1 or of ages long gone by2     
every kind of cell1 whether glandular1  
muscular1 nervous1 epidermic1 or        
skeletal1 is adapted to absolutely      
definite and specific functions1 and    
every organ which is composed of these  
different kinds of cells contains them  
in the proper proportions1 and in the   
particular arrangement which best serves

 the function of the organ2 it is thus  
adapted to its function4  ,all parts of 
the organism are tuned to one another1  
that is1 ,,they ,,are ,,adapted ,,to    
,,one ,,another1 and in the same way    
,,the ,,organism ,,as ,a ,,whole ,,is   
,,adapted ,,to ,,the ,,conditions ,,of  
,,its ,,life1 ,,and ,,it ,,is ,,so ,,at 
,,every ,,stage ,,of ,,its ,,evolution4 
,but all adaptations ,,can be referred  
to selection2 the only point that       
remains doubtful is whether they all    
,,must be referred to it4  ,however that
 may be1 whether the ,,lamarckian       
,,principle is a factor that has        
cooperated with selection in evolution1 
or whether it is altogether fallacious1 
the fact remains1 that selection is the 
cause of a great part of the phyletic   
evolution of organisms on our earth4    
,those who agree with me in rejecting   
the ,,lamarckian ,,principle will regard
 selection as the only ,,guiding factor 
in evolution1 which creates what is new 
out of the transmissible variations1 by 

ordering and arranging these1 selecting 
them in relation to their number and    
size1 as the architect does his         
building-stones so that a particular    
style must result4 7,variation under    
,domestication1 #ahge ,,ii4 pages #dbf1 
#dbg47 ,but the building-stones         
themselves1 the variations1 have their  
basis in the influences which cause     
variation in those vital units which are
 handed on from one generation to       
another1 whether1 taken together they   
form the ,,whole organism1 as in        
,bacteria and other low forms of life1  
or only a germ-substance1 as in         
unicellular and multicellular organisms4
 7,the ,author and ,editor are indebted 
to ,professor ,poulton for kindly       
assisting in the revision of the proof  
of this ,essay47     ,,iv4 ,,variation4 
,by ,,hugo ,,de ,,vries4  ,professor of 
,botany in the ,university of           
,amsterdam4   ,i4 ,,different ,,kinds   
,,of ,,variability4  ,before ,darwin1   
little was known concerning the         

phenomena of variability4 ,the fact1    
that hardly two leaves on a tree were   
exactly the same1 could not escape      
observation3 small deviations of the    
same kind were met with everywhere1     
among individuals as well as among the  
organs of the same plant4 ,larger       
aberrations1 spoken of as monstrosities1
 were for a long time regarded as lying 
outside the range of ordinary phenomena4
 ,a special branch of inquiry1 that of  
,teratology1 was devoted to them1 but it
 constituted a science by itself1       
sometimes connected with morphology1 but
 having scarcely any bearing on the     
processes of evolution and heredity4    
,darwin was the first to take a broad   
survey of the whole range of variations 
in the animal and vegetable kingdoms4   
,his theory of ,natural ,selection is   
based on the fact of variability4 ,in   
order that this foundation should be as 
strong as possible he collected all the 
facts1 scattered in the literature of   
his time1 and tried to arrange them in a

 scientific way4 ,he succeeded in       
showing that variations may be grouped  
along a line of almost continuous       
gradations1 beginning with simple       
differences in size and ending with     
monstrosities4 ,he was struck by the    
fact that1 as a rule1 the smaller the   
deviations1 the more frequently they    
appear1 very abrupt breaks in characters
 being of rare occurrence4  ,among these
 numerous degrees of variability ,darwin
 was always on the look out for those   
which might1 with the greatest          
probability1 be considered as affording 
material for natural selection to act   
upon in the development of new species4 
,neither of the extremes complied with  
his conceptions4 ,he often pointed out1 
that there are a good many small        
fluctuations1 which in this respect must
 be absolutely useless4 ,on the other   
hand1 he strongly combated the belief1  
that great changes would be necessary to
 explain the origin of species4 ,some   
authors had propounded the idea that    

highly adapted organs1 e4g4 the wings of
 a bird1 could not have been developed  
in any other way than by a comparatively
 sudden modification of a well defined  
and important kind4 ,such a conception  
would allow of great breaks or          
discontinuity in the evolution of highly
 differentiated animals and plants1     
shortening the time for the evolution of
 the whole organic kingdom and getting  
over numerous difficulties inherent in  
the theory of slow and gradual progress4
 ,it would1 moreover1 account for the   
genetic relation of the larger groups of
 both animals and plants4 ,it would1 in 
a word1 undoubtedly afford an easy means
 of simplifying the problem of descent  
with modification4  ,darwin1 however1   
considered such hypotheses as hardly    
belonging to the domain of science2 they
 belong1 he said1 to the realm of       
miracles4 ,that species have a capacity 
for change is admitted by all           
evolutionists2 but there is no need to  
invoke modifications other than those   

represented by ordinary variability4 ,it
 is well known that in artificial       
selection this tendency to vary has     
given rise to numerous distinct races1  
and there is no reason for denying that 
it can do the same in nature1 by the aid
 of natural selection4 ,on both lines an
 advance may be expected with equal     
probability4  ,his main argument1       
however1 is that the most striking and  
most highly adapted modifications may be
 acquired by successive variations4     
,each of these may be slight1 and they  
may affect different organs1 gradually  
adapting them to the same purpose4 ,the 
direction of the adaptations will be    
determined by the needs in the struggle 
for life1 and natural selection will    
simply exclude all such changes as occur
 on opposite or deviating lines4 ,in    
this way1 it is not variability itself  
which is called upon to explain         
beautiful adaptations1 but it is quite  
sufficient to suppose that natural      
selection has operated during long      

periods in the same way4 ,eventually1   
all the acquired characters1 being      
transmitted together1 would appear to   
us1 as if they had all been             
simultaneously developed4  ,correlations
 must play a large part in such special 
evolutions3 when one part is modified1  
so will be other parts4 ,the            
distribution of nourishment will come in
 as one of the causes1 the reactions of 
different organs to the same external   
influences as another4 ,but no doubt the
 more effective cause is that of the    
internal correlations1 which1 however1  
are still but dimly understood4 ,darwin 
repeatedly laid great stress on this    
view1 although a definite proof of its  
correctness could not be given in his   
time4 ,such proof requires the direct   
observation of a mutation1 and it should
 be stated here that even the first     
observations made in this direction have
 clearly confirmed ,darwin's ideas4 ,the
 new evening primroses which have sprung
 in my garden from the old form of      

,oenothera ,lamarckiana1 and which have 
evidently been derived from it1 in each 
case1 by a single mutation1 do not      
differ from their parent species in one 
character only1 but in almost all their 
organs and qualities4 ,oenothera gigas1 
for example1 has stouter stems and      
denser foliage2 the leaves are larger   
and broader2 its thick flower-buds      
produce gigantic flowers1 but only small
 fruits with large seeds4 ,correlative  
changes of this kind are seen in all my 
new forms1 and they lend support to the 
view that in the gradual development of 
highly adapted structures1 analogous    
correlations may have played a large    
part4 ,they easily explain large        
deviations from an original type1       
without requiring the assumption of too 
many steps4  ,monstrosities1 as their   
name implies1 are widely different in   
character from natural species2 they    
cannot1 therefore1 be adduced as        
evidence in the investigation of the    
origin of species4 ,there is no doubt   

that they may have much in common as    
regards their manner of origin1 and that
 the origin of species1 once understood1
 may lead to a better understanding of  
the monstrosities4 ,but the reverse is  
not true1 at least not as regards the   
main lines of development4 ,here1 it is 
clear1 monstrosities cannot have played 
a part of any significance4             
,reversions1 or atavistic changes1 would
 seem to give a better support to the   
theory of descent through modifications4
 ,these have been of paramount          
importance on many lines of evolution of
 the animal as well as of the vegetable 
kingdom4 ,it is often assumed that      
monocotyledons are descended from some  
lower group of dicotyledons1 probably   
allied to that which includes the       
buttercup family4 ,on this view the     
monocotyledons must be assumed to have  
lost the cambium and all its influence  
on secondary growth1 the differentiation
 of the flower into calyx and corolla1  
the second cotyledon or seed-leaf and   

several other characters4 ,losses of    
characters such as these may have been  
the result of abrupt changes1 but this  
does not prove that the characters      
themselves have been produced with equal
 suddenness4 ,on the contrary1 ,darwin  
shows very convincingly that a          
modification may well be developed by a 
series of steps1 and afterwards suddenly
 disappear4 ,many monstrosities1 such as
 those represented by twisted stems1    
furnish direct proofs in support of this
 view1 since they are produced by the   
loss of one character and this loss     
implies secondary changes in a large    
number of other organs and qualities4   
,darwin criticises in detail the        
hypothesis of great and abrupt changes  
and comes to the conclusion that it does
 not give even a shadow of an           
explanation of the origin of species4   
,it is as improbable as it is           
unnecessary4  ,sports and spontaneous   
variations must now be considered4 ,it  
is well known that they have produced a 

large number of fine horticultural      
varieties4 ,the cut-leaved maple and    
many other trees and shrubs with split  
leaves are known to have been produced  
at a single step2 this is true in the   
case of the single-leaf strawberry plant
 and of the laciniate variety of the    
greater celandine3 many white flowers1  
white or yellow berries and numerous    
other forms had a similar origin4 ,but  
changes such as these do not come under 
the head of adaptations1 as they consist
 for the most part in the loss of some  
quality or organ belonging to the       
species from which they were derived4   
,darwin thinks it impossible to         
attribute to this cause the innumerable 
structures1 which are so well adapted to
 the habits of life of each species4 ,at
 the present time we should say that    
such adaptations require progressive    
modifications1 which are additions to   
the stock of qualities already possessed
 by the ancestors1 and cannot1          
therefore1 be explained on the ground of

 a supposed analogy with sports1 which  
are for the most part of a retrogressive
 nature4  ,excluding all these more or  
less sudden changes1 there remains a    
long series of gradations of            
variability1 but all of these are not   
assumed by ,darwin to be equally fit for
 the production of new species4 ,in the 
first place1 he disregards all mere     
temporary variations1 such as size1     
albinism1 etc42 further1 he points out  
that very many species have almost      
certainly been produced by steps1 not   
greater1 and probably not very much     
smaller1 than those separating closely  
related varieties4 ,for varieties are   
only small species4 ,next comes the     
question of polymorphic species3 their  
occurrence seems to have been a source  
of much doubt and difficulty in         
,darwin's mind1 although at present it  
forms one of the main supports of the   
prevailing explanation of the origin of 
new species4 ,darwin simply states that 
this kind of variability seems to be of 

a peculiar nature2 since polymorphic    
species are now in a stable condition   
their occurrence gives no clue as to the
 mode of origin of new species4         
,polymorphic species are the expression 
of the result of previous variability   
acting on a large scale2 but they now   
simply consist of more or less numerous 
elementary species1 which1 as far as we 
know1 do not at present exhibit a larger
 degree of variability than any other   
more uniform species4 ,the vernal       
whitlow-grass 7,draba verna7 and the    
wild pansy are the best known examples2 
both have spread over almost the whole  
of ,europe and are split up into        
hundreds of elementary forms4 ,these    
sub-species show no signs of any        
extraordinary degree of variability1    
when cultivated under conditions        
necessary for the exclusion of          
inter-crossing4 ,hooker has shown1 in   
the case of some ferns distributed over 
still wider areas1 that the extinction  
of some of the intermediate forms in    

such groups would suffice to justify the
 elevation of the remaining types to the
 rank of distinct species4 ,polymorphic 
species may now be regarded as the link 
which unites ordinary variability with  
the historical production of species4   
,but it does not appear that they had   
this significance for ,darwin2 and1 in  
fact1 they exhibit no phenomena which   
could explain the processes by which one
 species has been derived from another4 
,by thus narrowing the limits of the    
species-producing variability ,darwin   
was led to regard small deviations as   
the source from which natural selection 
derives material upon which to act4 ,but
 even these are not all of the same     
type1 and ,darwin was well aware of the 
fact4  ,it should here be pointed out   
that in order to be selected1 a change  
must first have been produced4 ,this    
proposition1 which now seems            
self-evident1 has1 however1 been a      
source of much difference of opinion    
among ,darwin's followers4 ,the opinion 

that natural selection produces changes 
in useful directions has prevailed for a
 long time4 ,in other words1 it was     
assumed that natural selection1 by the  
simple means of singling out1 could     
induce small and useful changes to      
increase and to reach any desired degree
 of deviation from the original type4   
,in my opinion this view was never      
actually held by ,darwin4 ,it is in     
contradiction with the acknowledged aim 
of all his work1--the explanation of the
 origin of species by means of natural  
forces and phenomena only4 ,natural     
selection acts as a sieve2 it does not  
single out the best variations1 but it  
simply destroys the larger number of    
those which are1 from some cause or     
another1 unfit for their present        
environment4 ,in this way it keeps the  
strains up to the required standard1    
and1 in special circumstances1 may even 
improve them4  ,returning to the        
variations which afford the material for
 the sieving-action of natural          

selection1 we may distinguish two main  
kinds4 ,it is true that the distinction 
between these was not clear at the time 
of ,darwin1 and that he was unable to   
draw a sharp line between them4         
,nevertheless1 in many cases1 he was    
able to separate them1 and he often     
discussed the question which of the two 
would be the real source of the         
differentiation of species4 ,certain    
variations constantly occur1 especially 
such as are connected with size1 weight1
 colour1 etc4 ,they are usually too     
small for natural selection to act upon1
 having hardly any influence in the     
struggle for life3 others are more rare1
 occurring only from time to time1      
perhaps once or twice in a century1     
perhaps even only once in a thousand    
years4 ,moreover1 these are of another  
type1 not simply affecting size1 number 
or weight1 but bringing about something 
new1 which may be useful or not4        
,whenever the variation is useful       
natural selection will take hold of it  

and preserve it2 in other cases the     
variation may either persist or         
disappear4  ,in his criticism of        
miscellaneous objections brought forward
 against the theory of natural selection
 after the publication of the first     
edition of ,the ,origin of ,species1    
,darwin stated his view on this point   
very clearly3--,the doctrine of natural 
selection or the survival of the        
fittest1 which implies that when        
variations or individual differences of 
a beneficial nature happen to arise1    
these will be preserved4 7,origin of    
,species 7#fth edition71 page #afi1     
#ahhb47 ,in this sentence the words     
,,happen ,,to ,,arise appear to me of   
prominent significance4 ,they are       
evidently due to the same general       
conception which prevailed in ,darwin's 
,pangenesis hypothesis4 7,cf4 de ,vries1
 ,intracellulare ,pangenesis1 page #gc1 
,jena1 #ahhi1 and ,die                  
,mutationstheorie1 ,i4 page #fc4        
,leipzig1 #aija47  ,a distinction is    

indicated between ordinary fluctuations 
which are always present1 and such      
variations as happen to arise from time 
to time4 77,i think it right to point   
out that the interpretation of this     
passage from the ,origin by ,professor  
de ,vries is not accepted as correct    
either by ,mr ,francis ,darwin or by    
myself4 ,we do not believe that ,darwin 
intended to draw any distinction between
 ,,two ,,types of variation2 the words  
when variations or individual           
differences of a beneficial nature      
happen to arise are not in our opinion  
meant to imply a distinction between    
ordinary fluctuations and variations    
which happen to arise1 but we believe   
that or is here used in the sense of    
,,alias4 ,with the permission of        
,professor de ,vries1 the following     
extract is quoted from a letter in which
 he replied to the objection raised to  
his reading of the passage in question3 
,as to your remarks on the passage on   
page #f1 ,i agree that it is now        

impossible to see clearly how far       
,darwin went in his distinction of the  
different kinds of variability4         
,distinctions were only dimly guessed at
 by him4 ,but in our endeavour to arrive
 at a true conception of his view ,i    
think that the chapter on ,pangenesis   
should be our leading guide1 and that we
 should try to interpret the more       
difficult passages by that chapter4 ,a  
careful and often repeated study of the 
,pangenesis hypothesis has convinced me 
that ,darwin1 when he wrote that        
chapter1 was well aware that ordinary   
variability has nothing to do with      
evolution1 but that other kinds of      
variation were necessary4 ,in some      
chapters he comes nearer to a clear     
distinction than in others4 ,to my mind 
the expression 'happen to arise' is the 
sharpest indication of his inclining in 
this direction4 ,i am quite convinced   
that numerous expressions in his book   
become much clearer when looked at in   
this way4  ,the statement in this       

passage that ,darwin was well aware that
 ordinary variability has nothing to do 
with evolution1 but that other kinds of 
variation were necessary is contradicted
 by many passages in the ,origin4       
,a4,c4,s477 ,the latter afford the      
material for natural selection to act   
upon on the broad lines of organic      
development1 but the first do not4      
,fortuitous variations are the          
species-producing kind1 which the theory
 requires2 continuous fluctuations      
constitute1 in this respect1 a useless  
type4  ,of late1 the study of           
variability has returned to the         
recognition of this distinction4        
,darwin's variations1 which from time to
 time happen to arise1 are ,,mutations1 
the opposite type being commonly        
designed fluctuations4 ,a large mass of 
facts1 collected during the last few    
decades1 has confirmed this view1 which 
in ,darwin's time could only be         
expressed with much reserve1 and        
everyone knows that ,darwin was always  

very careful in statements of this kind4
  ,from the same chapter ,i may here    
cite the following paragraph3 ,thus as  
,i am inclined to believe1 morphological
 differences1444 such as the arrangement
 of the leaves1 the divisions of the    
flower or of the ovarium1 the position  
of the ovules1 etc4--first appeared in  
many cases as fluctuating variations1   
which sooner or later became constant   
through the nature of the organism and  
of the surrounding conditions444 but    
,,not ,,through ,,natural ,,selection   
7,the italics are mine 7,h4 de ,v47472  
for as these morphological characters do
 not affect the welfare of the species1 
any slight deviation in them could not  
have been governed or accumulated       
through this latter agency4 7,origin of 
,species 7#fth edition71 page #agf47 ,we
 thus see that in ,darwin's opinion1 all
 small variations had not the same      
importance4 ,in favourable circumstances
 some could become constant1 but others 
could not4  ,since the appearance of the

 first edition of ,the ,origin of       
,species fluctuating variability has    
been thoroughly studied by ,quetelet4   
,he discovered the law1 which governs   
all phenomena of organic life falling   
under this head4 ,it is a very simple   
law1 and states that individual         
variations follow the laws of           
probability4 ,he proved it1 in the first
 place1 for the size of the human body1 
using the measurements published for    
,belgian recruits2 he then extended it  
to various other measurements of parts  
of the body1 and finally concluded that 
it must be of universal validity for all
 organic beings4 ,it must hold true for 
all characters in man1 physical as well 
as intellectual and moral qualities2 it 
must hold true for the plant kingdom as 
well as for the animal kingdom2 in      
short1 it must include the whole living 
world4  ,quetelet's law may be most     
easily studied in those cases where the 
variability relates to measure1 number  
and weight1 and a vast number of facts  

have since confirmed its exactness and  
its validity for all kinds of organisms1
 organs and qualities4 ,but if we       
examine it more closely1 we find that it
 includes just those minute variations1 
which1 as ,darwin repeatedly pointed    
out1 have often no significance for the 
origin of species4 ,in the phenomena1   
described by ,quetelet's law nothing    
happens to arise2 all is governed by the
 common law1 which states that small    
deviations from the mean type are       
frequent1 but that larger aberrations   
are rare1 the rarer as they are larger4 
,any degree of variation will be found  
to occur1 if only the number of         
individuals studied is large enough3 it 
is even possible to calculate before    
hand1 how many specimens must be        
compared in order to find a previously  
fixed degree of deviation4  ,the        
variations1 which from time to time     
happen to appear1 are evidently not     
governed by this law4 ,they cannot1 as  
yet1 be produced at will3 no sowings of 

thousands or even of millions of plants 
will induce them1 although by such means
 the chance of their occurring will     
obviously be increased4 ,but they are   
known to occur1 and to occur suddenly   
and abruptly4 ,they have been observed  
especially in horticulture1 where they  
are ranged in the large and ill-defined 
group called sports4 ,korschinsky has   
collected all the evidence which        
horticultural literature affords on this
 point4 7,s4 ,korschinsky1              
,heterogenesis und ,evolution1 ,flora1  
,vol4 ,,lxxxix4 pages #bdj-cfc1 #aija47 
,several cases of the first appearance  
of a horticultural novelty have been    
recorded3 this has always happened in   
the same way2 it appeared suddenly and  
unexpectedly without any definite       
relation to previously existing         
variability4 ,dwarf types are one of the
 commonest and most favourite varieties 
of flowering plants2 they are not       
originated by a repeated selection of   
the smallest specimens1 but appear at   

once1 without intermediates and without 
any previous indication4 ,in many       
instances they are only about half the  
height of the original type1 thus       
constituting obvious novelties4 ,so it  
is in other cases described by          
,korschinsky3 these sports or mutations 
are now recognised to be the main source
 of varieties of horticultural plants4  
,as already stated1 ,i do not pretend   
that the production of horticultural    
novelties is the prototype of the origin
 of new species in nature4 ,i assume    
that they are1 as a rule1 derived from  
the parent species by the loss of some  
organ or quality1 whereas the main lines
 of the evolution of the animal and     
vegetable kingdom are of course         
determined by progressive changes4      
,darwin himself has often pointed out   
this difference4 ,but the saltatory     
origin of horticultural novelties is as 
yet the simplest parallel for natural   
mutations1 since it relates to forms and
 phenomena1 best known to the general   

student of evolution4  ,the point which 
,i wish to insist upon is this4 ,the    
difference between small and ever       
present fluctuations and rare and more  
sudden variations was clear to ,darwin1 
although the facts known at his time    
were too meagre to enable a sharp line  
to be drawn between these two great     
classes of variability4 ,since ,darwin's
 time evidence1 which proves the        
correctness of his view1 has accumulated
 with increasing rapidity4 ,fluctuations
 constitute one type2 they are never    
absent and follow the law of chance1 but
 they do not afford the material from   
which to build new species4 ,mutations1 
on the other hand1 only happen to occur 
from time to time4 ,they do not         
necessarily produce greater changes than
 fluctuations1 but such as may become1  
or rather are from their very nature1   
constant4 ,it is this constancy which is
 the mark of specific characters1 and on
 this basis every new specific character
 may be assumed to have arisen by       

mutation4  ,some authors have tried to  
show that the theory of mutation is     
opposed to ,darwin's views4 ,but this is
 erroneous4 ,on the contrary1 it is in  
fullest harmony with the great principle
 laid down by ,darwin4 ,in order to be  
acted upon by that complex of           
environmental forces1 which ,darwin has 
called natural selection1 the changes   
must obviously first be there4 ,the     
manner in which they are produced is of 
secondary importance and has hardly any 
bearing on the theory of descent with   
modification4 7,life and ,letters ,,ii4 
#abe47  ,a critical survey of all the   
facts of variability of plants in nature
 as well as under cultivation has led me
 to the conviction1 that ,darwin was    
right in stating that those rare        
beneficial variations1 which from time  
to time happen to arise1--the now       
so-called mutations--are the real source
 of progress in the whole realm of the  
organic world4  ,,ii4 ,,external ,,and  
,,internal ,,causes ,,of ,,variability4 

,all phenomena of animal and plant life 
are governed by two sets of causes2 one 
of these is external1 the other         
internal4 ,as a rule the internal causes
 determine the nature of a              
phenomenon--what an organism can do and 
what it cannot do4 ,the external causes1
 on the other hand1 decide when a       
certain variation will occur1 and to    
what extent its features may be         
developed4  ,as a very clear and wholly 
typical instance ,i cite the cocks-combs
 7,celosia74 ,this race is distinguished
 from allied forms by its faculty of    
producing the well-known broad and much 
twisted combs4 ,every single individual 
possesses this power1 but all           
individuals do not exhibit it in its    
most complete form4 ,in some cases this 
faculty may not be exhibited at the top 
of the main stem1 although developed in 
lateral branches3 in others it begins   
too late for full development4 ,much    
depends upon nourishment and            
cultivation1 but almost always the      

horticulturist has to single out the    
best individuals and to reject those    
which do not come up to the standard4   
,the internal causes are of a historical
 nature4 ,the external ones may be      
defined as nourishment and environment4 
,in some cases nutrition is the main    
factor1 as1 for instance1 in fluctuating
 variability1 but in natural selection  
environment usually plays the larger    
part4  ,the internal or historical      
causes are constant during the life-time
 of a species1 using the term species in
 its most limited sense1 as designating 
the so-called elementary species or the 
units out of which the ordinary species 
are built up4 ,these historical causes  
are simply the specific characters1     
since in the origin of a species one or 
more of these must have been changed1   
thus producing the characters of the new
 type4 ,these changes must1 of course1  
also be due partly to internal and      
partly to external causes4  ,in contrast
 to these changes of the internal       

causes1 the ordinary variability which  
is exhibited during the life-time of a  
species is called fluctuating           
variability4 ,the name mutations or     
mutating variability is then given to   
the changes in the specific characters4 
,it is desirable to consider these two  
main divisions of variability           
separately4  ,in the case of            
fluctuations the internal causes1 as    
well as the external ones1 are often    
apparent4 ,the specific characters may  
be designated as the mean about which   
the observed forms vary4 ,almost every  
character may be developed to a greater 
or a less degree1 but the variations of 
the single characters producing a small 
deviation from the mean are usually the 
commonest4 ,the limits of these         
fluctuations may be called wide or      
narrow1 according to the way we look at 
them1 but in numerous cases the extreme 
on the favoured side hardly surpasses   
double the value of that on the other   
side4 ,the degree of this development1  

for every individual and for every      
organ1 is dependent mainly on nutrition4
 ,better nourishment or an increased    
supply of food produces a higher        
development2 only it is not always easy 
to determine which direction is the     
fuller and which is the poorer one4 ,the
 differences among individuals grown    
from different seeds are described as   
examples of individual variability1 but 
those which may be observed on the same 
plant1 or on cuttings1 bulbs or roots   
derived from one individual are referred
 to as cases of partial variability4    
,partial variability1 therefore1        
determines the differences among the    
flowers1 fruits1 leaves or branches of  
one individual3 in the main1 it follows 
the same laws as individual variability1
 but the position of a branch on a plant
 also determines its strength1 and the  
part it may take in the nourishment of  
the whole4 ,composite flowers and umbels
 therefore have1 as a rule1 fewer rays  
on weak branches than on the strong main

 ones4 ,the number of carpels in the    
fruits of poppies becomes very small on 
the weak lateral branches1 which are    
produced towards the autumn1 as well as 
on crowded1 and therefore on weakened   
individuals4 ,double flowers follow the 
same rule1 and numerous other instances 
could easily be adduced4  ,mutating     
variability occurs along three main     
lines4 ,either a character may          
disappear1 or1 as we now say1 become    
latent2 or a latent character may       
reappear1 reproducing thereby a         
character which was once prominent in   
more or less remote ancestors4 ,the     
third and most interesting case is that 
of the production of quite new          
characters which never existed in the   
ancestors4 ,upon this progressive       
mutability the main development of the  
animal and vegetable kingdom evidently  
depends4 ,in contrast to this1 the two  
other cases are called retrogressive and
 degressive mutability4 ,in nature      
retrogressive mutability plays a large  

part2 in agriculture and in horticulture
 it gives rise to numerous varieties1   
which have in the past been preserved1  
either on account of their usefulness or
 beauty1 or simply as fancy-types4 ,in  
fact the possession of numbers of       
varieties may be considered as the main 
character of domesticated animals and   
cultivated plants4  ,in the case of     
retrogressive and degressive mutability 
the internal cause is at once apparent1 
for it is this which causes the         
disappearance or reappearance of some   
character4 ,with progressive mutations  
the case is not so simple1 since the new
 character must first be produced and   
then displayed4 ,these two processes are
 theoretically different1 but they may  
occur together or after long intervals4 
,the production of the new character ,i 
call premutation1 and the displaying    
mutation4 ,both of course must have     
their external as well as their internal
 causes1 as ,i have repeatedly pointed  
out in my work on the ,mutation ,theory4

 7,die ,mutationstheorie1 #b vols41     
,leipzig1 #aija47  ,it is probable that 
nutrition plays as important a part     
among the external causes of mutability 
as it does among those of fluctuating   
variability4 ,observations in support of
 this view1 however1 are too scanty to  
allow of a definite judgment4 ,darwin   
assumed an accumulative influence of    
external causes in the case of the      
production of new varieties or species4 
,the accumulation might be limited to   
the life-time of a single individual1 or
 embrace that of two or more            
generations4 ,in the end a degree of    
instability in the equilibrium of one or
 more characters might be attained1     
great enough for a character to give way
 under a small shock produced by changed
 conditions of life4 ,the character     
would then be thrown over from the old  
state of equilibrium into a new one4    
,characters which happen to be in this  
state of unstable equilibrium are called
 mutable4 ,they may be either latent or 

active1 being in the former case derived
 from old active ones or produced as new
 ones 7by the process1 designated       
premutation74 ,they may be inherited in 
this mutable condition during a long    
series of generations4 ,i have shown    
that in the case of the evening primrose
 of ,lamarck this state of mutability   
must have existed for at least half a   
century1 for this species was introduced
 from ,texas into ,england about the    
year #ahfj1 and since then all the      
strains derived from its first          
distribution over the several countries 
of ,europe show the same phenomena in   
producing new forms4 ,the production of 
the dwarf evening primrose1 or          
,oenothera nanella1 is assumed to be due
 to one of the factors1 which determines
 the tall stature of the parent form1   
becoming latent2 this would1 therefore1 
afford an example of retrogressive      
mutation4 ,most of the other types of my
 new mutants1 on the other hand1 seem to
 be due to progressive mutability4  ,the

 external causes of this curious period 
of mutability are as yet wholly unknown 
and can hardly be guessed at1 since the 
origin of the ,oenothera ,lamarckiana is
 veiled in mystery4 ,the seeds1         
introduced into ,england about #ahfj1   
were said to have come from ,texas1 but 
whether from wild or from cultivated    
plants we do not know4 ,nor has the     
species been recorded as having been    
observed in the wild condition4 ,this1  
however1 is nothing peculiar4 ,the      
,european types of ,oenothera biennis   
and ,o4 muricata are in the same        
condition4 ,the first is said to have   
been introduced from ,virginia1 and the 
second from ,canada1 but both probably  
from plants cultivated in the gardens of
 these countries4 ,whether the same     
elementary species are still growing on 
those spots is unknown1 mainly because  
the different sub-species of the species
 mentioned have not been systematically 
studied and distinguished4  ,the origin 
of new species1 which is in part the    

effect of mutability1 is1 however1 due  
mainly to natural selection4 ,mutability
 provides the new characters and new    
elementary species4 ,natural selection1 
on the other hand1 decides what is to   
live and what to die4 ,mutability seems 
to be free1 and not restricted to       
previously determined lines4 ,selection1
 however1 may take place along the same 
main lines in the course of long        
geological epochs1 thus directing the   
development of large branches of the    
animal and vegetable kingdom4 ,in       
natural selection it is evident that    
nutrition and environment are the main  
factors4 ,but it is probable that1 while
 nutrition may be one of the main causes
 of mutability1 environment may play the
 chief part in the decisions ascribed to
 natural selection4 ,relations to       
neighbouring plants and to injurious or 
useful animals1 have been considered the
 most important determining factors ever
 since the time when ,darwin pointed out
 their prevailing influence4  ,from this

 discussion of the main causes of       
variability we may derive the           
proposition that the study of every     
phenomenon in the field of heredity1 of 
variability1 and of the origin of new   
species will have to be considered from 
two standpoints2 on one hand we have the
 internal causes1 on the other the      
external ones4 ,sometimes the first are 
more easily detected1 in other cases the
 latter are more accessible to          
investigation4 ,but the complete        
elucidation of any phenomenon of life   
must always combine the study of the    
influence of internal with that of      
external causes4  ,,iii4 ,,polymorphic  
,,variability ,,in ,,cereals4  ,one of  
the propositions of ,darwin's theory of 
the struggle for life maintains that the
 largest amount of life can be supported
 on any area1 by great diversification  
or divergence in the structure and      
constitution of its inhabitants4 ,every 
meadow and every forest affords a proof 
of this thesis4 ,the numerical          

proportion of the different species of  
the flora is always changing according  
to external influences4 ,thus1 in a     
given meadow1 some species will flower  
abundantly in one year and then almost  
disappear1 until1 after a series of     
years1 circumstances allow them again to
 multiply rapidly4 ,other species1 which
 have taken their places1 will then     
become rare4 ,it follows from this      
principle1 that notwithstanding the     
constantly changing conditions1 a       
suitable selection from the constituents
 of a meadow will ensure a continued    
high production4 ,but1 although the     
principle is quite clear1 artificial    
selection has1 as yet1 done very little 
towards reaching a really high standard4
  ,the same holds good for cereals4 ,in 
ordinary circumstances a field will give
 a greater yield1 if the crop grown     
consists of a number of sufficiently    
differing types4 ,hence it happens that 
almost all older varieties of wheat are 
mixtures of more or less diverging      

forms4 ,in the same variety the         
numerical composition will vary from    
year to year1 and in oats this may1 in  
bad years1 go so far as to destroy more 
than half of the harvest1 the wind-oats 
7,avena fatua71 which scatter their     
grain to the winds as soon as it ripens1
 increasing so rapidly that they assume 
the dominant place4 ,a severe winter1 a 
cold spring and other extreme conditions
 of life will destroy one form more     
completely than another1 and it is      
evident that great changes in the       
numerical composition of the mixture may
 thus be brought about4  ,this mixed    
condition of the common varieties of    
cereals was well known to ,darwin4 ,for 
him it constituted one of the many types
 of variability4 ,it is of that peculiar
 nature to which1 in describing other   
groups1 he applies the term polymorphy4 
,it does not imply that the single      
constituents of the varieties are at    
present really changing their           
characters4 ,on the other hand1 it does 

not exclude the possibility of such     
changes4 ,it simply states that         
observation shows the existence of      
different forms2 how these have         
originated is a question which it does  
not deal with4 ,in his well-known       
discussion of the variability of        
cereals1 ,darwin is mainly concerned    
with the question1 whether under        
cultivation they have undergone great   
changes or only small ones4 ,the        
decision ultimately depends on the      
question1 how many forms have originally
 been taken into cultivation4 ,assuming 
five or six initial species1 the        
variability must be assumed to have been
 very large1 but on the assumption that 
there were between ten and fifteen      
types1 the necessary range of           
variability is obviously much smaller4  
,but in regard to this point1 we are of 
course entirely without historical data4
  ,few of the varieties of wheat show   
conspicuous differences1 although their 
number is great4 ,if we compare the     

differentiating characters of the       
smaller types of cereals with those of  
ordinary wild species1 even within the  
same genus or family1 they are obviously
 much less marked4 ,all these small     
characters1 however1 are strictly       
inherited1 and this fact makes it very  
probable that the less obvious          
constituents of the mixtures in ordinary
 fields must be constant and pure as    
long as they do not intercross4 ,natural
 crossing is in most cereals a          
phenomenon of rare occurrence1 common   
enough to admit of the production of all
 possible hybrid combinations1 but      
requiring the lapse of a long series of 
years to reach its full effect4  ,darwin
 laid great stress on this high amount  
of variability in the plants of the same
 variety1 and illustrated it by the     
experience of ,colonel ,le ,couteur 7,on
 the ,varieties1 ,properties1 and       
,classification of ,wheat1 ,jersey1     
#ahcg47 on his farm on the isle of      
,jersey1 who cultivated upwards of #aej 

varieties of wheat1 which he claimed    
were as pure as those of any other      
agriculturalist4 ,but ,professor ,la    
,gasca of ,madrid1 who visited him1 drew
 attention to aberrant ears1 and pointed
 out1 that some of them might be better 
yielders than the majority of plants in 
the crop1 whilst others might be poor   
types4 ,thence he concluded that the    
isolation of the better ones might be a 
means of increasing his crops4 ,le      
,couteur seems to have considered the   
constancy of such smaller types after   
isolation as absolutely probable1 since 
he did not even discuss the possibility 
of their being variable or of their     
yielding a changeable or mixed progeny4 
,this curious fact proves that he       
considered the types1 discovered in his 
fields by ,la ,gasca to be of the same  
kind as his other varieties1 which until
 that time he had relied upon as being  
pure and uniform4 ,thus we see1 that for
 him1 the variability of cereals was    
what we now call polymorphy4 ,he looked 

through his fields for useful           
aberrations1 and collected twenty-three 
new types of wheat4 ,he was1 moreover1  
clear about one point1 which1 on being  
rediscovered after half a century1 has  
become the starting-point for the new   
,swedish principle of selecting         
agricultural plants4 ,it was the        
principle of single-ear sowing1 instead 
of mixing the grains of all the selected
 ears together4 ,by sowing each ear on a
 separate plot he intended not only to  
multiply them1 but also to compare their
 value4 ,this comparison ultimately led 
him to the choice of some few valuable  
sorts1 one of which1 the ,bellevue de   
,talavera1 still holds its place among  
the prominent sorts of wheat cultivated 
in ,france4 ,this variety seems to be   
really a uniform type1 a quality very   
useful under favourable conditions of   
cultivation1 but which seems to have    
destroyed its capacity for further      
improvement by selection4  ,the         
principle of single-ear sowing1 with a  

view to obtain pure and uniform strains 
without further selection1 has1 until a 
few years ago1 been almost entirely lost
 sight of4 ,only a very few             
agriculturists have applied it3 among   
these are ,patrick ,shirreff 7,die      
,verbesserung der ,getreide-,arten1     
translated by ,r4 ,hesse1 ,halle1       
#ahhj47 in ,scotland and ,willet ,m4    
,hays 7,wheat1 varieties1 breeding1     
cultivation1 ,univ4 ,minnesota1         
,agricultural ,experimental ,station1   
,bull4 no4 #fb1 #ahii47 in ,minnesota4  
,patrick ,shirreff observed the fact1   
that in large fields of cereals1 single 
plants may from time to time be found   
with larger ears1 which justify the     
expectation of a far greater yield4 ,in 
the course of about twenty-five years he
 isolated in this way two varieties of  
wheat and two of oats4 ,he simply       
multiplied them as fast as possible1    
without any selection1 and put them on  
the market4  ,hays was struck by the    
fact that the yield of wheat in         

,minnesota was far beneath that in the  
neighbouring ,states4 ,the local        
varieties were ,fife and ,blue ,stem4   
,they gave him1 on inspection1 some     
better specimens1 phenomenal yielders as
 he called them4 ,these were simply     
isolated and propagated1 and1 after     
comparison with the parent-variety and  
with some other selected strains of less
 value1 were judged to be of sufficient 
importance to be tested by cultivation  
all over the ,state of ,minnesota4 ,they
 have since almost supplanted the       
original types1 at least in most parts  
of the ,state1 with the result that the 
total yield of wheat in ,minnesota is   
said to have been increased by about a  
million dollars yearly4  ,definite      
progress in the method of single-ear    
sowing has1 however1 been made only     
recently4 ,it had been foreshadowed by  
,patrick ,shirreff1 who after the       
production of the four varieties already
 mentioned1 tried to carry out his work 
on a larger scale1 by including numerous

 minor deviations from the main type4   
,he found by doing so that the chances  
of obtaining a better form were         
sufficiently increased to justify the   
trial4 ,but it was ,nilsson who         
discovered the almost inexhaustible     
polymorphy of cereals and other         
agricultural crops and made it the      
starting-point for a new and entirely   
trustworthy method of the highest       
utility4 ,by this means he has produced 
during the last fifteen years a number  
of new and valuable races1 which have   
already supplanted the old types on     
numerous farms in ,sweden and which are 
now being introduced on a large scale   
into ,germany and other ,european       
countries4  ,it is now twenty years     
since the station at ,svalof was        
founded4 ,during the first period of its
 work1 embracing about five years1      
selection was practised on the principle
 which was then generally used in       
,germany4 ,in order to improve a race a 
sample of the best ears was carefully   

selected from the best fields of the    
variety4 ,these ears were considered as 
representatives of the type under       
cultivation1 and it was assumed that by 
sowing their grains on a small plot a   
family could be obtained1 which could   
afterwards be improved by a continuous  
selection4 ,differences between the     
collected ears were either not observed 
or disregarded4 ,at ,svalof this method 
of selection was practised on a far     
larger scale than on any ,german farm1  
and the result was1 broadly speaking1   
the same4 ,this may be stated in the    
following words3 improvement in a few   
cases1 failure in all the others4 ,some 
few varieties could be improved and     
yielded excellent new types1 some of    
which have since been introduced into   
,swedish agriculture and are now        
prominent races in the southern and     
middle parts of the country4 ,but the   
station had definite aims1 and among    
them was the improvement of the         
,chevalier barley4 ,this1 in ,middle    

,sweden1 is a fine brewer's barley1 but 
liable to failure during unfavourable   
summers on account of its slender stems4
 ,it was selected with a view of giving 
it stiffer stems1 but in spite of all   
the care and work bestowed upon it no   
satisfactory result was obtained4  ,this
 experience1 combined with a number of  
analogous failures1 could not fail to   
throw doubt upon the whole method4 ,it  
was evident that good results were only 
exceptions1 and that in most cases the  
principle was not one that could be     
relied upon4 ,the exceptions might be   
due to unknown causes1 and not to the   
validity of the method2 it became       
therefore of much more interest to      
search for the causes than to continue  
the work along these lines4  ,in the    
year #ahib a number of different        
varieties of cereals were cultivated on 
a large scale and a selection was again 
made from them4 ,about two hundred      
samples of ears were chosen1 each       
apparently constituting a different     

type4 ,their seeds were sown on separate
 plots and manured and treated as much  
as possible in the same manner4 ,the    
plots were small and arranged in rows so
 as to facilitate the comparison of     
allied types4 ,during the whole period  
of growth and during the ripening of the
 ears the plots were carefully studied  
and compared3 they were harvested       
separately2 ears and kernels were       
counted and weighed1 and notes were made
 concerning layering1 rust and other    
cereal pests4  ,the result of this      
experiment was1 in the main1 no distinct
 improvement4 ,nilsson was especially   
struck by the fact that the plots1 which
 should represent distinct types1 were  
far from uniform4 ,many of them were as 
multiform as the fields from which the  
parent-ears were taken4 ,others showed  
variability in a less degree1 but in    
almost all of them it was clear that a  
pure race had not been obtained4 ,the   
experiment was a fair one1 inasmuch as  
it demonstrated the polymorphic         

variability of cereals beyond all doubt 
and in a degree hitherto unsuspected2   
but from the standpoint of the          
selectionist it was a failure4          
,fortunately there were1 however1 one or
 two exceptions4 ,a few lots showed a   
perfect uniformity in regard to all the 
stalks and ears3 these were small       
families4 ,this fact suggested the idea 
that each might have been derived from a
 single ear4 ,during the selection in   
the previous summer1 ,nilsson had tried 
to find as many ears as possible of each
 new type which he recognised in his    
fields4 ,but the variability of his     
crops was so great1 that he was rarely  
able to include more than two or three  
ears in the same group1 and1 in a few   
cases1 he found only one representative 
of the supposed type4 ,it might1        
therefore1 be possible that those small 
uniform plots were the direct progeny of
 ears1 the grains of which had not been 
mixed with those from other ears before 
sowing4 ,exact records had1 of course1  

been kept of the chosen samples1 and the
 number of ears had been noted in each  
case4 ,it was1 therefore1 possible to   
answer the question and it was found    
that those plots alone were uniform on  
which the kernels of one single ear only
 had been sown4 ,nilsson concluded that 
the mixture of two or more ears in a    
single sowing might be the cause of the 
lack of uniformity in the progeny4      
,apparently similar ears might be       
different in their progeny4  ,once      
discovered1 this fact was elevated to   
the rank of a leading principle and     
tested on as large a scale as possible4 
,the fields were again carefully        
investigated and every single ear1 which
 showed a distinct divergence from the  
main type in one character or another1  
was selected4 ,a thousand samples were  
chosen1 but this time each sample       
consisted of one ear only4 ,next year1  
the result corresponded to the          
expectation4 ,uniformity prevailed      
almost everywhere2 only a few lots      

showed a discrepancy1 which might be    
ascribed to the accidental selection of 
hybrid ears4 ,it was now clear that the 
progeny of single ears was1 as a rule1  
pure1 whereas that of mixed ears was    
impure4 ,the single-ear selection or    
single-ear sowing1 which had fallen into
 discredit in ,germany and elsewhere in 
,europe1 was rediscovered4 ,it proved to
 be the only trustworthy principle of   
selection4 ,once isolated1 such         
single-parent races are constant from   
seed and remain true to their type4 ,no 
further selection is needed2 they have  
simply to be multiplied and their real  
value tested4  ,patrick ,shirreff1 in   
his early experiments1 ,le ,couteur1    
,hays and others had observed the rare  
occurrence of exceptionally good        
yielders and the value of their         
isolation to the agriculturist4 ,the    
possibility of error in the choice of   
such striking specimens and the         
necessity of judging their value by     
their progeny were also known to these  

investigators1 but they had not the     
slightest idea of all the possibilities 
suggested by their principle4 ,nilsson1 
who is a botanist as well as an         
agriculturist1 discovered that1 besides 
these exceptionably good yielders1 every
 variety of a cereal consists of        
hundreds of different types1 which find 
the best conditions for success when    
grown together1 but which1 after        
isolation1 prove to be constant4 ,their 
preference for mixed growth is so       
definite1 that once isolated1 their     
claims on manure and treatment are found
 to be much higher than those of the    
original mixed variety4 ,moreover1 the  
greatest care is necessary to enable    
them to retain their purity1 and as soon
 as they are left to themselves they    
begin to deteriorate through accidental 
crosses and admixtures and rapidly      
return to the mixed condition4          
,reverting now to ,darwin's discussion  
of the variability of cereals1 we may   
conclude that subsequent investigation  

has proved it to be exactly of the kind 
which he describes4 ,the only difference
 is that in reality it reaches a degree1
 quite unexpected by ,darwin and his    
contemporaries4 ,but it is polymorphic  
variability in the strictest sense of   
the word4 ,how the single constituents  
of a variety originate we do not see4   
,we may assume1 and there can hardly be 
a doubt about the truth of the          
assumption1 that a new character1 once  
produced1 will slowly but surely be     
combined through accidental crosses with
 a large number of previously existing  
types1 and so will tend to double the   
number of the constituents of the       
variety4 ,but whether it first appears  
suddenly or whether it is only slowly   
evolved we cannot determine4 ,it would1 
of course1 be impossible to observe     
either process in such a mixture4 ,only 
cultures of pure races1 of single-parent
 races as we have called them1 can      
afford an opportunity for this kind of  
observation4 ,in the fields of ,svalof  

new and unexpected qualities have       
recently been seen1 from time to time1  
to appear suddenly4 ,these characters   
are as distinct as the older ones and   
appear to be constant from the moment of
 their origin4  ,darwin has repeatedly  
insisted that man does not cause        
variability4 ,he simply selects the     
variations given to him by the hand of  
nature4 ,he may repeat this process in  
order to accumulate different new       
characters in the same family1 thus     
producing varieties of a higher order4  
,this process of accumulation would1 if 
continued for a longer time1 lead to the
 augmentation of the slight differences 
characteristic of varieties into the    
greater differences characteristic of   
species and genera4 ,it is in this way  
that horticultural and agricultural     
experience contribute to the problem of 
the conversion of varieties into        
species1 and to the explanation of the  
admirable adaptations of each organism  
to its complex conditions of life4 ,in  

the long run new forms1 distinguished   
from their allies by quite a number of  
new characters1 would1 by the           
extermination of the older              
intermediates1 become distinct species4 
,thus we see that the theory of the     
origin of species by means of natural   
selection is quite independent of the   
question1 how the variations to be      
selected arise4 ,they may arise slowly1 
from simple fluctuations1 or suddenly1  
by mutations2 in both cases natural     
selection will take hold of them1 will  
multiply them if they are beneficial1   
and in the course of time accumulate    
them1 so as to produce that great       
diversity of organic life1 which we so  
highly admire4  ,darwin has left the    
decision of this difficult and obviously
 subordinate point to his followers4    
,but in his ,pangenesis hypothesis he   
has given us the clue for a close study 
and ultimate elucidation of the subject 
under discussion4     ,v4 ,,heredity    
,,and ,,variation ,,in ,,modern         

,,lights4 ,by ,w4 ,bateson1 ,m4,a41     
,f4,r4,s4  ,professor of ,biology in the
 ,university of ,cambridge4   ,darwin's 
work has the property of greatness in   
that it may be admired from more aspects
 than one4 ,for some the perception of  
the principle of ,natural ,selection    
stands out as his most wonderful        
achievement to which all the rest is    
subordinate4 ,others1 among whom ,i     
would range myself1 look up to him      
rather as the first who plainly         
distinguished1 collected1 and           
comprehensively studied that new class  
of evidence from which hereafter a true 
understanding of the process of         
,evolution may be developed4 ,we each   
prefer our own standpoint of admiration2
 but ,i think that it will be in their  
wider aspect that his labours will most 
command the veneration of posterity4  ,a
 treatise written to advance knowledge  
may be read in two moods4 ,the reader   
may keep his mind passive1 willing      
merely to receive the impress of the    

writer's thought2 or he may read with   
his attention strained and alert1 asking
 at every instant how the new knowledge 
can be used in a further advance1       
watching continually for fresh footholds
 by which to climb higher still4 ,of    
,shelley it has been said that he was a 
poet for poets3 so ,darwin was a        
naturalist for naturalists4 ,it is when 
his writings are used in the critical   
and more exacting spirit with which we  
test the outfit for our own enterprise  
that we learn their full value and      
strength4 ,whether we glance back and   
compare his performance with the efforts
 of his predecessors1 or look forward   
along the course which modern research  
is disclosing1 we shall honour most in  
him not the rounded merit of finite     
accomplishment1 but the creative power  
by which he inaugurated a line of       
discovery endless in variety and        
extension4 ,let us attempt thus to see  
his work in true perspective between the
 past from which it grew1 and the       

present which is its consequence4       
,darwin attacked the problem of         
,evolution by reference to facts of     
three classes3 ,variation2 ,heredity2   
,natural ,selection4 ,his work was not  
as the laity suppose1 a sudden and      
unheralded revelation1 but the first    
fruit of a long and hitherto barren     
controversy4 ,the occurrence of         
variation from type1 and the hereditary 
transmission of such variation had of   
course been long familiar to practical  
men1 and inferences as to the possible  
bearing of those phenomena on the nature
 of specific difference had been from   
time to time drawn by naturalists4      
,maupertuis1 for example1 wrote ,ce qui 
nous reste a examiner1 c'est comment    
d'un seul individu1 il a pu naitre tant 
d'especes si differentes4 ,and again ,la
 ,nature contient le fonds de toutes ces
 varietes3 mais le hasard ou l'art les  
mettent en oeuvre4 ,c'est ainsi que ceux
 dont l'industrie s'applique a          
satisfaire le gout des curieux1 sont1   

pour ainsi dire1 creatures d'especes    
nouvelles4 7,venus ,physique1 contenant 
deux ,dissertations1 l'une sur l'origine
 des ,hommes et des ,animaux3 ,et       
l'autre sur l'origine des ,noirs ,la    
,haye1 #agdf1 pages #abd and #abi4 ,for 
an introduction to the writings of      
,maupertuis ,i am indebted to an article
 by ,professor ,lovejoy in ,popular     
,sci4 ,monthly1 #aijb47  ,such passages1
 of which many 7though few so emphatic7 
can be found in eighteenth century      
writers1 indicate a true perception of  
the mode of ,evolution4 ,the            
speculations hinted at by ,buffon 7,for 
the fullest account of the views of     
these pioneers of ,evolution1 see the   
works of ,samuel ,butler1 especially    
,evolution1 ,old and ,new 7#bnd edition7
 #ahhb4 ,butler's claims on behalf of   
,buffon have met with some acceptance2  
but after reading what ,butler has said1
 and a considerable part of ,buffon's   
own works1 the word hinted seems to me a
 sufficiently correct description of the

 part he played4 ,it is interesting to  
note that in the chapter on the ,ass1   
which contains some of his evolutionary 
passages1 there is a reference to       
plusieurs idees tres-elevees sur la     
generation contained in the ,letters of 
,maupertuis471 developed by ,erasmus    
,darwin1 and independently proclaimed   
above all by ,lamarck1 gave to the      
doctrine of descent a wide renown4 ,the 
uniformitarian teaching which ,lyell    
deduced from geological observation had 
gained acceptance4 ,the facts of        
geographical distribution 7,see         
especially ,w4 ,lawrence1 ,lectures on  
,physiology1 ,london1 #ahbc1 pages #bac 
f47 had been shown to be obviously      
inconsistent with the ,mosaic legend4   
,prichard1 and ,lawrence1 following the 
example of ,blumenbach1 had successfully
 demonstrated that the races of ,man    
could be regarded as different forms of 
one species1 contrary to the opinion up 
till then received4 ,these treatises all
 begin1 it is true1 with a profound     

obeisance to the sons of ,noah1 but that
 performed1 they continue on strictly   
modern lines4 ,the question of the      
mutability of species was thus          
prominently raised4  ,those who rate    
,lamarck no higher than did ,huxley in  
his contemptuous phrase buccinator      
tantum1 will scarcely deny that the     
sound of the trumpet had carried far1 or
 that its note was clear4 ,if then there
 were few who had already turned to     
evolution with positive conviction1 all 
scientific men must at least have known 
that such views had been promulgated2   
and many must1 as ,huxley says1 have    
taken up his own position of critical   
expectancy4 7,see the chapter           
contributed to the ,life and ,letters of
 ,charles ,darwin ,,ii4 page #aie4 ,i do
 not clearly understand the sense in    
which ,darwin wrote 7,autobiography1    
ibid4 ,i4 page #hg73 ,it has sometimes  
been said that the success of the       
,origin proved 'that the subject was in 
the air1' or 'that men's minds were     

prepared for it4' ,i do not think that  
this is strictly true1 for ,i           
occasionally sounded not a few          
naturalists1 and never happened to come 
across a single one who seemed to doubt 
about the permanence of species4 ,this  
experience may perhaps have been an     
accident due to ,darwin's isolation4    
,the literature of the period abounds   
with indications of critical expectancy4
 ,a most interesting expression of that 
feeling is given in the charming account
 of the ,early ,days of ,darwinism by   
,alfred ,newton1 ,macmillan's ,magazine1
 ,,lvii4 #ahhh1 page #bda4 ,he tells how
 in #aheh when spending a dreary summer 
in ,iceland1 he and his friend1 the     
ornithologist ,john ,wolley1 in default 
of active occupation1 spent their days  
in discussion4 ,both of us taking a keen
 interest in ,natural ,history1 it was  
but reasonable that a question1 which in
 those days was always coming up        
wherever two or more naturalists were   
gathered together1 should be continually

 recurring4 ,that question was1 ',what  
is a species8' and connected therewith  
was the other question1 ',how did a     
species begin8'444 ,now we were of      
course fairly well acquainted with what 
had been published on these subjects4   
,he then enumerates some of these       
publications1 mentioning among others   
,t4 ,vernon ,wollaston's ,variation of  
,species--a work which has in my opinion
 never been adequately appreciated4 ,he 
proceeds3 ,of course we never arrived at
 anything like a solution of these      
problems1 general or special1 but we    
felt very strongly that a solution ought
 to be found1 and that quickly1 if the  
study of ,botany and ,zoology was to    
make any great advance4 ,he then        
describes how on his return home he     
received the famous number of the       
,linnean ,journal on a certain evening4 
,i sat up late that night to read it2   
and never shall ,i forget the impression
 it made upon me4 ,herein was contained 
a perfectly simple solution of all the  

difficulties which had been troubling me
 for months past444 ,i went to bed      
satisfied that a solution had been      
found47  ,why1 then1 was it1 that       
,darwin succeeded where the rest had    
failed8 ,the cause of that success was  
two-fold4 ,first1 and obviously1 in the 
principle of ,natural ,selection he had 
a suggestion which would work4 ,it might
 not go the whole way1 but it was true  
as far as it went4 ,evolution could thus
 in great measure be fairly represented 
as a consequence of demonstrable        
processes4 ,darwin seldom endangers the 
mechanism he devised by putting on it   
strains much greater than it can bear4  
,he at least was under no illusion as to
 the omnipotence of ,selection2 and he  
introduces none of the forced pleading  
which in recent years has threatened to 
discredit that principle4  ,for example1
 in the latest text of the ,origin      
7,origin1 7#fth edition 7#ahhb71 page   
#dba477 we find him saying3  ,but as my 
conclusions have lately been much       

misrepresented1 and it has been stated  
that ,i attribute the modification of   
species exclusively to natural          
selection1 ,i may be permitted to remark
 that in the first edition of this work1
 and subsequently1 ,i placed in a most  
conspicuous position--namely1 at the    
close of the ,introduction--the         
following words3 ',i am convinced that  
natural selection has been the main but 
not the exclusive means of              
modification4'  ,but apart from the     
invention of this reasonable hypothesis1
 which may well1 as ,huxley estimated1  
be the guide of biological and          
psychological speculation for the next  
three or four generations1 ,darwin made 
a more significant and imperishable     
contribution4 ,not for a few            
generations1 but through all ages he    
should be remembered as the first who   
showed clearly that the problems of     
,heredity and ,variation are soluble by 
observation1 and laid down the course by
 which we must proceed to their         

solution4 7,whatever be our estimate of 
the importance of ,natural ,selection1  
in this we all agree4 ,samuel ,butler1  
the most brilliant1 and by far the most 
interesting of ,darwin's                
opponents--whose works are at length    
emerging from oblivion--in his ,preface 
7#ahhb7 to the #bnd edition of          
,evolution1 ,old and ,new1 repeats his  
earlier expression of homage to one whom
 he had come to regard as an enemy3 ,to 
the end of time1 if the question be     
asked1 ',who taught people to believe in
 ,evolution8' the answer must be that it
 was ,mr4 ,darwin4 ,this is true1 and it
 is hard to see what palm of higher     
praise can be awarded to any            
philosopher47 ,the moment of inspiration
 did not come with the reading of       
,malthus1 but with the opening of the   
first note-book on ,transmutation of    
,species4 7,life and ,letters1 ,i4 pages
 #bgf and #hc47 ,evolution is a process 
of ,variation and ,heredity4 ,the older 
writers1 though they had some vague idea

 that it must be so1 did not study      
,variation and ,heredity4 ,darwin did1  
and so begat not a theory1 but a        
science4  ,the extent to which this is  
true1 the scientific world is only      
beginning to realise4 ,so little was the
 fact appreciated in ,darwin's own time 
that the success of his writings was    
followed by an almost total cessation of
 work in that special field4 ,of the    
causes which led to this remarkable     
consequence ,i have spoken elsewhere4   
,they proceeded from circumstances      
peculiar to the time2 but whatever the  
causes there is no doubt that this      
statement of the result is historically 
exact1 and those who make it their      
business to collect facts elucidating   
the physiology of ,heredity and         
,variation are well aware that they will
 find little to reward their quest in   
the leading scientific ,journals of the 
,darwinian epoch4  ,in those thirty     
years the original stock of evidence    
current and in circulation even         

underwent a process of attrition4 ,as in
 the story of the ,eastern sage who     
first wrote the collected learning of   
the universe for his sons in a thousand 
volumes1 and by successive compression  
and burning reduced them to one1 and    
from this by further burning distilled  
the single ejaculation of the ,faith1   
,there is no god but ,god and ,mohamed  
is the ,prophet of ,god1 which was all  
his maturer wisdom deemed essential3--so
 in the books of that period do we find 
the corpus of genetic knowledge dwindle 
to a few prerogative instances1 and     
these at last to the brief formula of an
 unquestioned creed4  ,and yet in all   
else that concerns biological science   
this period was1 in very truth1 our     
,golden ,age1 when the natural history  
of the earth was explored as never      
before2 morphology and embryology were  
exhaustively ransacked2 the physiology  
of plants and animals began to rival    
chemistry and physics in precision of   
method and in the rapidity of its       

advances2 and the foundations of        
pathology were laid4  ,in contrast with 
this immense activity elsewhere the     
neglect which befel the special         
physiology of ,descent1 or ,genetics as 
we now call it1 is astonishing4 ,this   
may of course be interpreted as meaning 
that the favoured studies seemed to     
promise a quicker return for effort1 but
 it would be more true to say that those
 who chose these other pursuits did so  
without making any such comparison2 for 
the idea that the physiology of         
,heredity and ,variation was a coherent 
science1 offering possibilities of      
extraordinary discovery1 was not present
 to their minds at all4 ,in a word1 the 
existence of such a science was well    
nigh forgotten4 ,it is true that in     
ancillary periodicals1 as for example   
those that treat of entomology or       
horticulture1 or in the writings of the 
already isolated systematists 7,this    
isolation of the systematists is the one
 most melancholy sequela of ,darwinism4 

,it seems an irony that we should read  
in the peroration to the ,origin that   
when the ,darwinian view is accepted    
,systematists will be able to pursue    
their labours as at present2 but they   
will not be incessantly haunted by the  
shadowy doubt whether this or that form 
be a true species4 ,this1 ,i feel sure1 
and ,i speak after experience1 will be  
no slight relief4 ,the endless disputes 
whether or not some fifty species of    
,british brambles are good species will 
cease4 ,origin1 #fth edition 7#ahhb71   
page #dbe4 ,true they have ceased to    
attract the attention of those who lead 
opinion1 but anyone who will turn to the
 literature of systematics will find    
that they have not ceased in any other  
sense4 ,should there not be something   
disquieting in the fact that among the  
workers who come most into contact with 
specific differences1 are to be found   
the only men who have failed to be      
persuaded of the unreality of those     
differences871 observations with this   

special bearing were from time to time  
related1 but the class of fact on which 
,darwin built his conceptions of        
,heredity and ,variation was not seen in
 the highways of biology4 ,it formed no 
part of the official curriculum of      
biological students1 and found no place 
among the subjects which their teachers 
were investigating4  ,during this period
 nevertheless one distinct advance was  
made1 that with which ,weismann's name  
is prominently connected4 ,in ,darwin's 
genetic scheme the hereditary           
transmission of parental experience and 
its consequences played a considerable  
role4 ,exactly how great that role was  
supposed to be1 he with his habitual    
caution refrained from specifying1 for  
the sufficient reason that he did not   
know4 ,nevertheless much of the process 
of ,evolution1 especially that by which 
organs have become degenerate and       
rudimentary1 was certainly attributed by
 ,darwin to such inheritance1 though    
since belief in the inheritance of      

acquired characters fell into disrepute1
 the fact has been a good deal          
overlooked4 ,the ,origin without use and
 disuse would be a materially different 
book4 ,a certain vacillation is         
discernible in ,darwin's utterances on  
this question1 and the fact gave to the 
astute ,butler an opportunity for his   
most telling attack4 ,the discussion    
which best illustrates the genetic views
 of the period arose in regard to the   
production of the rudimentary condition 
of the wings of many beetles in the     
,madeira group of islands1 and by       
comparing passages from the ,origin     
7#fth edition pages #aji and #dja4 ,see 
,butler1 ,essays on ,life1 ,art1 and    
,science1 page #bfe1 reprinted #aijh1   
and ,evolution1 ,old and ,new1 chapter  
,,xxii4 7#bnd edition71 #ahhb47 ,butler 
convicts ,darwin of saying first that   
this condition was in the main the      
result of ,selection1 with disuse       
aiding1 and in another place that the   
main cause of degeneration was disuse1  

but that ,selection had aided4 ,to      
,darwin however ,i think the point would
 have seemed one of dialectics merely4  
,to him the one paramount purpose was to
 show that somehow an ,evolution by     
means of ,variation and ,heredity might 
have brought about the facts observed1  
and whether they had come to pass in the
 one way or the other was a matter of   
subordinate concern4   ,to us moderns   
the question at issue has a diminished  
significance4 ,for over all such debates
 a change has been brought by           
,weismann's challenge for evidence that 
use and disuse have any transmitted     
effects at all4 ,hitherto the           
transmission of many acquired           
characteristics had seemed to most      
naturalists so obvious as not to call   
for demonstration4 7,w4 ,lawrence was   
one of the few who consistently         
maintained the contrary opinion4        
,prichard1 who previously had expressed 
himself in the same sense1 does not1 ,i 
believe repeat these views in his later 

writings1 and there are signs that he   
came to believe in the transmission of  
acquired habits4 ,see ,lawrence1 ,lect4 
,physiol4 #ahbc1 pages #dcf-dcg1 #ddg   
,prichard1 ,edin4 ,inaug4 ,disp4 #ahjh  
7not seen by me71 quoted ibid4 and ,nat4
 ,hist4 ,man1 #ahdc1 pages #cd f47      
,weismann's demand for facts in support 
of the main proposition revealed at once
 that none having real cogency could be 
produced4 ,the time-honoured examples   
were easily shown to be capable of      
different explanations4 ,a few certainly
 remain which cannot be so summarily    
dismissed1 but--though it is manifestly 
impossible here to do justice to such a 
subject--,i think no one will dispute   
that these residual and doubtful        
phenomena1 whatever be their true       
nature1 are not of a kind to help us    
much in the interpretation of any of    
those complex cases of adaptation which 
on the hypothesis of unguided ,natural  
,selection are especially difficult to  
understand4 ,use and disuse were invoked

 expressly to help us over these hard   
places2 but whatever changes can be     
induced in offspring by direct treatment
 of the parents1 they are not of a kind 
to encourage hope of real assistance    
from that quarter4 ,it is not to be     
denied that through the collapse of this
 second line of argument the ,selection 
hypothesis has had to take an increased 
and perilous burden4 ,various ways of   
meeting the difficulty have been        
proposed1 but these mostly resolve      
themselves into improbable attempts to  
expand or magnify the powers of ,natural
 ,selection4  ,weismann's               
interpellation1 though negative in      
purpose1 has had a lasting and          
beneficial effect1 for through his      
thorough demolition of the old loose and
 distracting notions of inherited       
experience1 the ground has been cleared 
for the construction of a true knowledge
 of heredity based on experimental fact4
  ,in another way he made a contribution
 of a more positive character1 for his  

elaborate speculations as to the genetic
 meaning of cytological appearances have
 led to a minute investigation of the   
visible phenomena occurring in those    
divisions by which germ-cells arise4    
,though the particular views he         
advocated have very largely proved      
incompatible with the observed facts of 
heredity1 yet we must acknowledge that  
it was chiefly through the stimulus of  
,weismann's ideas that those advances in
 cytology were made2 and though the     
doctrine of the continuity of germ-plasm
 cannot be maintained in the form       
originally propounded1 it is in the main
 true and illuminating4 7,it is         
interesting to see how nearly ,butler   
was led by natural penetration1 and from
 absolutely opposite conclusions1 back  
to this underlying truth3 ,so that each 
ovum when impregnate should be          
considered not as descended from its    
ancestors1 but as being a continuation  
of the personality of every ovum in the 
chain of its ancestry1 which every ovum 

,,it ,,actually ,,is quite as truly as  
the octogenarian ,,is the same identity 
with the ovum from which he has been    
developed4 ,this process cannot stop    
short of the primordial cell1 which     
again will probably turn out to be but a
 brief resting-place4 ,we therefore     
prove each one of us to ,,be ,,actually 
the primordial cell which never died nor
 dies1 but has differentiated itself    
into the life of the world1 all living  
beings whatever1 being one with it and  
members one of another1 ,life and       
,habit1 #ahgh1 page #hf47 ,nevertheless 
in the present state of knowledge we are
 still as a rule quite unable to connect
 cytological appearances with any       
genetic consequence and save in one     
respect 7obviously of extreme           
importance--to be spoken of later7 the  
two sets of phenomena might1 for all we 
can see1 be entirely distinct4  ,i      
cannot avoid attaching importance to    
this want of connection between the     
nuclear phenomena and the features of   

bodily organisation4 ,all attempts to   
investigate ,heredity by cytological    
means lie under the disadvantage that it
 is the nuclear changes which can alone 
be effectively observed4 ,important as  
they must surely be1 ,i have never been 
persuaded that the rest of the cell     
counts for nothing4 ,what we know of the
 behaviour and variability of           
chromosomes seems in my opinion quite   
incompatible with the belief that they  
alone govern form1 and are the sole     
agents responsible in heredity4 7,this  
view is no doubt contrary to the        
received opinion4 ,i am however         
interested to see it lately maintained  
by ,driesch 7,science and ,philosophy of
 the ,organism1 ,london1 #aijg1 page    
#bcc71 and from the recent observations 
of ,godlewski it has received distinct  
experimental support47  ,if1 then1      
progress was to be made in ,genetics1   
work of a different kind was required4  
,to learn the laws of ,heredity and     
,variation there is no other way than   

that which ,darwin himself followed1 the
 direct examination of the phenomena4 ,a
 beginning could be made by collecting  
fortuitous observations of this class1  
which have often thrown a suggestive    
light1 but such evidence can be at best 
but superficial and some more           
penetrating instrument of research is   
required4 ,this can only be provided by 
actual experiments in breeding4  ,the   
truth of these general considerations   
was becoming gradually clear to many of 
us when in #aijj ,mendel's work was     
rediscovered4 ,segregation1 a phenomenon
 of the utmost novelty1 was thus        
revealed4 ,from that moment not only in 
the problem of the origin of species1   
but in all the great problems of biology
 a new era began4 ,so unexpected was the
 discovery that many naturalists were   
convinced it was untrue1 and at once    
proclaimed ,mendel's conclusions as     
either altogether mistaken1 or if true1 
of very limited application4 ,many      
fantastic notions about the workings of 

,heredity had been asserted as general  
principles before3 this was probably    
only another fancy of the same class4   
,nevertheless those who had a           
preliminary acquaintance with the facts 
of ,variation were not wholly unprepared
 for some such revelation4 ,the         
essential deduction from the discovery  
of segregation was that the characters  
of living things are dependent on the   
presence of definite elements or        
factors1 which are treated as units in  
the processes of ,heredity4 ,these      
factors can thus be recombined in       
various ways4 ,they act sometimes       
separately1 and sometimes they interact 
in conjunction with each other1         
producing their various effects4 ,all   
this indicates a definiteness and       
specific order in heredity1 and         
therefore in variation4 ,this order     
cannot by the nature of the case be     
dependent on ,natural ,selection for its
 existence1 but must be a consequence of
 the fundamental chemical and physical  

nature of living things4 ,the study of  
,variation had from the first shown that
 an orderliness of this kind was        
present4 ,the bodies and the properties 
of living things are cosmic1 not        
chaotic4 ,no matter how low in the scale
 we go1 never do we find the slightest  
hint of a diminution in that            
all-pervading orderliness1 nor can we   
conceive an organism existing for a     
moment in any other state4 ,moreover not
 only does this order prevail in normal 
forms1 but again and again it is to be  
seen in newly-sprung varieties1 which by
 general consent cannot have been       
subjected to a prolonged ,selection4    
,the discovery of ,mendelian elements   
admirably coincided with and at once    
gave a rationale of these facts4        
,genetic ,variation is then primarily   
the consequence of additions to1 or     
omissions from1 the stock of elements   
which the species contains4 ,the further
 investigation of the species-problem   
must thus proceed by the analytical     

method which breeding experiments       
provide4  ,in the nine years which have 
elapsed since ,mendel's clue became     
generally known1 progress has been      
rapid4 ,we now understand the process by
 which a polymorphic race maintains its 
polymorphism4 ,when a family consists of
 dissimilar members1 given the numerical
 proportions in which these members are 
occurring1 we can represent their       
composition symbolically and state what 
types can be transmitted by the various 
members4 ,the difficulty of the swamping
 effects of intercrossing is practically
 at an end4 ,even the famous puzzle of  
sex-limited inheritance is solved1 at   
all events in its more regular          
manifestations1 and we know now how it  
is brought about that the normal sisters
 of a colour-blind man can transmit the 
colour-blindness while his normal       
brothers cannot transmit it4  ,we are   
still only on the fringe of the inquiry4
 ,it can be seen extending and ramifying
 in many directions4 ,to enumerate these

 here would be impossible4 ,a whole new 
range of possibilities is being brought 
into view by study of the interrelations
 between the simple factors4 ,by        
following up the evidence as to         
segregation1 indications have been      
obtained which can only be interpreted  
as meaning that when many factors are   
being simultaneously redistributed among
 the germ-cells1 certain of them exert  
what must be described as a repulsion   
upon other factors4 ,we cannot surmise  
whither this discovery may lead4  ,in   
the new light all the old problems wear 
a fresh aspect4 ,upon the question of   
the nature of ,sex1 for example1 the    
bearing of ,mendelian evidence is close4
 ,elsewhere ,i have shown that from     
several sets of parallel experiments the
 conclusion is almost forced upon us    
that1 in the types investigated1 of the 
two sexes the female is to be regarded  
as heterozygous in sex1 containing one  
unpaired dominant element1 while the    
male is similarly homozygous in the     

absence of that element4 7,in other     
words1 the ova are each ,,either female1
 ,,or male 7i4e4 non-female71 but the   
sperms are all non-female47 ,it is not a
 little remarkable that on this         
point--which is the only one where      
observations of the nuclear processes of
 gameto-genesis have yet been brought   
into relation with the visible          
characteristics of the organisms        
themselves--there should be diametrical 
opposition between the results of       
breeding experiments and those derived  
from cytology4  ,those who have followed
 the researches of the ,american school 
will be aware that1 after it had been   
found in certain insects that the       
spermatozoa were of two kinds according 
as they contained or did not contain the
 accessory chromosome1 ,e4,b4 ,wilson   
succeeded in proving that the sperms    
possessing this accessory body were     
destined to form ,,females on           
fertilisation1 while sperms without it  
form males1 the eggs being apparently   

indifferent4 ,perhaps the most striking 
of all this series of observations is   
that lately made by ,t4,h4 ,morgan      
7,morgan1 ,proc4 ,soc4 ,exp4 ,biol4     
,med4 ,v4 #aijh1 and von ,baehr1 ,zool4 
,anz4 ,,xxxii4 page #ejg1 #aijh471 since
 confirmed by von ,baehr1 that in a     
,phylloxeran two kinds of spermatids are
 formed1 respectively with and without  
an accessory 7in this case1 ,,double7   
chromosome4 ,of these1 only those       
possessing the accessory body become    
functional spermatozoa1 the others      
degenerating4 ,we have thus an          
elucidation of the puzzling fact that in
 these forms fertilisation results in   
the formation of ,,females only4 ,how   
the males are formed--for of course     
males are eventually produced by the    
parthenogenetic females--we do not know4
  ,if the accessory body is really to be
 regarded as bearing the factor for     
femaleness1 then in ,mendelian terms    
female is ,,dd and male is ,,dr4 ,the   
eggs are indifferent and the spermatozoa

 are each male1 ,,or female4 ,but       
according to the evidence derived from a
 study of the sex-limited descent of    
certain features in other animals the   
conclusion seems equally clear that in  
them female must be regarded as ,,dr and
 male as ,,rr4 ,the eggs are thus each  
either male or female and the           
spermatozoa are indifferent4 ,how this  
contradictory evidence is to be         
reconciled we do not yet know4 ,the     
breeding work concerns fowls1 canaries1 
and the ,currant moth 7,abraxas         
grossulariata74 ,the accessory          
chromosome has been now observed in most
 of the great divisions of insects 7,as 
,wilson has proved1 the unpaired body is
 not a universal feature even in those  
orders in which it has been observed4   
,nearly allied types may differ4 ,in    
some it is altogether unpaired4 ,in     
others it is paired with a body of much 
smaller size1 and by selection of       
various types all gradations can be     
demonstrated ranging to the condition in

 which the members of the pair are      
indistinguishable from each other471    
except1 as it happens1 ,lepidoptera4 ,at
 first sight it seems difficult to      
suppose that a feature apparently so    
fundamental as sex should be differently
 constituted in different animals1 but  
that seems at present the least         
improbable inference4 ,i mention these  
two groups of facts as illustrating the 
nature and methods of modern genetic    
work4 ,we must proceed by minute and    
specific analytical investigation4      
,wherever we look we find traces of the 
operation of precise and specific rules4
  ,in the light of present knowledge it 
is evident that before we can attack the
 ,species-problem with any hope of      
success there are vast arrears to be    
made up4 ,he would be a bold man who    
would now assert that there was no sense
 in which the term ,species might not   
have a strict and concrete meaning in   
contradistinction to the term ,variety4 
,we have been taught to regard the      

difference between species and variety  
as one of degree4 ,i think it unlikely  
that this conclusion will bear the test 
of further research4 ,to ,darwin the    
question1 ,what is a variation8         
presented no difficulties4 ,any         
difference between parent and offspring 
was a variation4 ,now we have to be more
 precise4 ,first we must1 as de ,vries  
has shown1 distinguish real1 genetic1   
variation from ,,fluctuational          
variations1 due to environmental and    
other accidents1 which cannot be        
transmitted4 ,having excluded these     
sources of error the variations observed
 must be expressed in terms of the      
factors to which they are due before    
their significance can be understood4   
,for example1 numbers of the variations 
seen under domestication1 and not a few 
witnessed in nature1 are simply the     
consequence of some ingredient being in 
an unknown way omitted from the         
composition of the varying individual4  
,the variation may on the contrary be   

due to the addition of some new element1
 but to prove that it is so is by no    
means an easy matter4 ,casual           
observation is useless1 for though these
 latter variations will always be       
dominants1 yet many dominant            
characteristics may arise from another  
cause1 namely the meeting of            
complementary factors1 and special study
 of each case in two generations at     
least is needed before these two        
phenomena can be distinguished4  ,when  
such considerations are fully           
appreciated it will be realised that    
medleys of most dissimilar occurrences  
are all confused together under the term
 ,variation4 ,one of the first objects  
of genetic analysis is to disentangle   
this mass of confusion4  ,to those who  
have made no study of heredity it       
sometimes appears that the question of  
the effect of conditions in causing     
variation is one which we should        
immediately investigate1 but a little   
thought will show that before any       

critical inquiry into such possibilities
 can be attempted1 a knowledge of the   
working of heredity under conditions as 
far as possible uniform must be         
obtained4 ,at the time when ,darwin was 
writing1 if a plant brought into        
cultivation gave off an albino variety1 
such an event was without hesitation    
ascribed to the change of life4 ,now we 
see that albino ,,gametes1 germs1 that  
is to say1 which are destitute of the   
pigment-forming factor1 may have been   
originally produced by individuals      
standing an indefinite number of        
generations back in the ancestry of the 
actual albino1 and it is indeed almost  
certain that the variation to which the 
appearance of the albino is due cannot  
have taken place in a generation later  
than that of the grandparents4 ,it is   
true that when a new ,,dominant appears 
we should feel greater confidence that  
we were witnessing the original         
variation1 but such events are of       
extreme rarity1 and no such case has    

come under the notice of an experimenter
 in modern times1 as far as ,i am aware4
 ,that they must have appeared is clear 
enough4 ,nothing corresponding to the   
,brown-breasted ,game fowl is known     
wild1 yet that colour is a most definite
 dominant1 and at some moment since     
,gallus bankiva was domesticated1 the   
element on which that special colour    
depends must have at least once been    
formed in the germ-cell of a fowl2 but  
we need harder evidence than any which  
has yet been produced before we can     
declare that this novelty came through  
over-feeding1 or change of climate1 or  
any other disturbance consequent on     
domestication4 ,when we reflect on the  
intricacies of genetic problems as we   
must now conceive them there come       
moments when we feel almost thankful    
that the ,mendelian principles were     
unknown to ,darwin4 ,the time called for
 a bold pronouncement1 and he made it1  
to our lasting profit and delight4 ,with
 fuller knowledge we pass once more into

 a period of cautious expectation and   
reserve4  ,in every arduous enterprise  
it is pleasanter to look back at        
difficulties overcome than forward to   
those which still seem insurmountable1  
but in the next stage there is nothing  
to be gained by disguising the fact that
 the attributes of living things are not
 what we used to suppose4 ,if they are  
more complex in the sense that the      
properties they display are throughout  
so regular 7,i have in view1 for        
example1 the marvellous and specific    
phenomena of regeneration1 and those    
discovered by the students of           
,entwicklungsmechanik4 ,the             
circumstances of its occurrence here    
preclude any suggestion that this       
regularity has been brought about by the
 workings of ,selection4 ,the attempts  
thus to represent the phenomena have    
resulted in mere parodies of scientific 
reasoning47 that the ,selection of      
minute random variations is an          
unacceptable account of the origin of   

their diversity1 yet by virtue of that  
very regularity the problem is limited  
in scope and thus simplified4  ,to begin
 with1 we must relegate ,selection to   
its proper place4 ,selection permits the
 viable to continue and decides that the
 non-viable shall perish2 just as the   
temperature of our atmosphere decides   
that no liquid carbon shall be found on 
the face of the earth3 but we do not    
suppose that the form of the diamond has
 been gradually achieved by a process of
 ,selection4 ,so again1 as the course of
 descent branches in the successive     
generations1 ,selection determines along
 which branch ,evolution shall proceed1 
but it does not decide what novelties   
that branch shall bring forth4 ,la      
,nature contient le fonds de toutes ces 
varietes1 mais le hazard ou l'art les   
mettent en oeuvre1 as ,maupertuis most  
truly said4  ,not till knowledge of the 
genetic properties of organisms has     
attained to far greater completeness can
 evolutionary speculations have more    

than a suggestive value4 ,by genetic    
experiment1 cytology and physiological  
chemistry aiding1 we may hope to acquire
 such knowledge4 ,in #ahgb ,nathusius   
wrote 7,vortrage uber ,viehzucht und    
,rassenerkenntniss1 page #abj1 ,berlin1 
#ahgb473 ,das ,gesetz der ,vererbung ist
 noch nicht erkannt2 der ,apfel ist noch
 nicht vom ,baum der ,erkenntniss       
gefallen1 welcher1 der ,sage nach1      
,newton auf den rechten ,weg zur        
,ergrundung der ,gravitationsgesetze    
fuhrte4 ,we cannot pretend that the     
words are not still true1 but in        
,mendelian analysis the seeds of that   
apple-tree at last are sown4  ,if we    
were asked what discovery would do most 
to forward our inquiry1 what one bit of 
knowledge would more than any other     
illuminate the problem1 ,i think we may 
give the answer without hesitation4 ,the
 greatest advance that we can foresee   
will be made when it is found possible  
to connect the geometrical phenomena of 
development with the chemical4 ,the     

geometrical symmetry of living things is
 the key to a knowledge of their        
regularity1 and the forces which cause  
it4 ,in the symmetry of the dividing    
cell the basis of that resemblance we   
call ,heredity is contained4 ,to imitate
 the morphological phenomena of life we 
have to devise a system which can       
divide4 ,it must be able to divide1 and 
to segment as--grossly--a vibrating     
plate or rod does1 or as an icicle can  
do as it becomes ribbed in a continuous 
stream of water2 but with this          
distinction1 that the distribution of   
chemical differences and properties must
 simultaneously be decided and disposed 
in orderly relation to the pattern of   
the segmentation4 ,even if a model which
 would do this could be constructed it  
might prove to be a useful beginning4   
,this may be looking too far ahead4 ,if 
we had to choose some one piece of more 
proximate knowledge which we would more 
especially like to acquire1 ,i suppose  
we should ask for the secret of         

interracial sterility4 ,nothing has yet 
been discovered to remove the grave     
difficulty1 by which ,huxley in         
particular was so much oppressed1 that  
among the many varieties produced under 
domestication--which we all regard as   
analogous to the species seen in        
nature--no clear case of interracial    
sterility has been demonstrated4 ,the   
phenomenon is probably the only one to  
which the domesticated products seem to 
afford no parallel4 ,no solution of the 
difficulty can be offered which has     
positive value1 but it is perhaps worth 
considering the facts in the light of   
modern ideas4 ,it should be observed    
that we are not discussing              
incompatibility of two species to       
produce offspring 7a totally distinct   
phenomenon71 but the sterility of the   
offspring which many of them do produce4
  ,when two species1 both perfectly     
fertile severally1 produce on crossing a
 sterile progeny1 there is a presumption
 that the sterility is due to the       

development in the hybrid of some       
substance which can only be formed by   
the meeting of two complementary        
factors4 ,that some such account is     
correct in essence may be inferred from 
the well-known observation that if the  
hybrid is not totally sterile but only  
partially so1 and thus is able to form  
some good germ-cells which develop into 
new individuals1 the sterility of these 
daughter-individuals is sensibly reduced
 or may be entirely absent4 ,the        
fertility once re-established1 the      
sterility does not return in the later  
progeny1 a fact strongly suggestive of  
segregation4 ,now if the sterility of   
the cross-bred be really the consequence
 of the meeting of two complementary    
factors1 we see that the phenomenon     
could only be produced among the        
divergent offspring of one species by   
the acquisition of at least ,,two new   
factors2 for if the acquisition of a    
single factor caused sterility the line 
would then end4 ,moreover each factor   

must be separately acquired by distinct 
individuals1 for if both were present   
together1 the possessors would by       
hypothesis be sterile4 ,and in order to 
imitate the case of species each of     
these factors must be acquired by       
distinct breeds4 ,the factors need not1 
and probably would not1 produce any     
other perceptible effects2 they might1  
like the colour-factors present in white
 flowers1 make no difference in the form
 or other characters4 ,not till the     
cross was actually made between the two 
complementary individuals would either  
factor come into play1 and the effects  
even then might be unobserved until an  
attempt was made to breed from the      
cross-bred4  ,next1 if the factors      
responsible for sterility were acquired1
 they would in all probability be       
peculiar to certain individuals and     
would not readily be distributed to the 
whole breed4 ,any member of the breed   
also into which ,,both the factors were 
introduced would drop out of the        

pedigree by virtue of its sterility4    
,hence the evidence that the various    
domesticated breeds say of dogs or fowls
 can when mated together produce fertile
 offspring1 is beside the mark4 ,the    
real question is1 ,do they ever produce 
sterile offspring8 ,i think the evidence
 is clearly that sometimes they do1     
oftener perhaps than is commonly        
supposed4 ,these suggestions are quite  
amenable to experimental tests4 ,the    
most obvious way to begin is to get a   
pair of parents which are known to have 
had any sterile offspring1 and to find  
the proportions in which these steriles 
were produced4 ,if1 as ,i anticipate1   
these proportions are found to be       
definite1 the rest is simple4  ,in      
passing1 certain other considerations   
may be referred to4 ,first1 that there  
are observations favouring the view that
 the production of totally sterile      
cross-breds is seldom a universal       
property of two species1 and that it may
 be a matter of individuals1 which is   

just what on the view here proposed     
would be expected4 ,moreover1 as we all 
know now1 though incompatibility may be 
dependent to some extent on the degree  
to which the species are dissimilar1 no 
such principle can be demonstrated to   
determine sterility or fertility in     
general4 ,for example1 though all our   
,finches can breed together1 the hybrids
 are all sterile4 ,of ,ducks some       
species can breed together without      
producing the slightest sterility2      
others have totally sterile offspring1  
and so on4 ,the hybrids between several 
genera of ,orchids are perfectly fertile
 on the female side1 and some on the    
male side also1 but the hybrids produced
 between the ,turnip 7,brassica napus7  
and the ,swede 7,brassica campestris71  
which1 according to our estimates of    
affinity should be nearly allied forms1 
are totally sterile4 7,see ,sutton1     
,a4,w41 ,journ4 ,linn4 ,soc4 ,,xxxviii4 
page #cda1 #aijh47 ,lastly1 it may be   
recalled that in sterility we are almost

 certainly considering a meristic       
phenomenon4 ,,failure ,,to ,,divide is1 
we may feel fairly sure1 the immediate  
cause of the sterility4 ,now1 though we 
know very little about the heredity of  
meristic differences1 all that we do    
know points to the conclusion that the  
less-divided is dominant to the         
more-divided1 and we are thus justified 
in supposing that there are factors     
which can arrest or prevent             
cell-division4 ,my conjecture therefore 
is that in the case of sterility of     
cross-breds we see the effect produced  
by a complementary pair of such factors4
 ,this and many similar problems are now
 open to our analysis4  ,the question is
 sometimes asked1 ,do the new lights on 
,variation and ,heredity make the       
process of ,evolution easier to         
understand8 ,on the whole the answer may
 be given that they do4 ,there is some  
appearance of loss of simplicity1 but   
the gain is real4 ,as was said above1   
the time is not ripe for the discussion 

of the origin of species4 ,with faith in
 ,evolution unshaken--if indeed the word
 faith can be used in application to    
that which is certain--we look on the   
manner and causation of adapted         
differentiation as still wholly         
mysterious4 ,as ,samuel ,butler so truly
 said3 ,to me it seems that the ',origin
 of ,variation1' whatever it is1 is the 
only true ',origin of ,species' 7,life  
and ,habit1 ,london1 page #bfc1 #ahgh471
 and of that ,origin not one of us knows
 anything4 ,but given ,variation--and it
 is given3 assuming further that the    
variations are not guided into paths of 
adaptation--and both to the ,darwinian  
and to the modern school this hypothesis
 appears to be sound if unproven--an    
evolution of species proceeding by      
definite steps is more1 rather than     
less1 easy to imagine than an evolution 
proceeding by the accumulation of       
indefinite and insensible steps4 ,those 
who have lost themselves in             
contemplating the miracles of           

,adaptation 7whether real or spurious7  
have not unnaturally fixed their hopes  
rather on the indefinite than on the    
definite changes4 ,the reasons are      
obvious4 ,by suggesting that the steps  
through which an adaptative mechanism   
arose were indefinite and insensible1   
all further trouble is spared4 ,while it
 could be said that species arise by an 
insensible and imperceptible process of 
variation1 there was clearly no use in  
tiring ourselves by trying to perceive  
that process4 ,this labour-saving       
counsel found great favour4 ,all that   
had to be done to develop               
evolution-theory was to discover the    
good in everything1 a task which1 in the
 complete absence of any control or test
 whereby to check the truth of the      
discovery1 is not very onerous4 ,the    
doctrine que tout est au mieux was      
therefore preached with fresh vigour1   
and examples of that illuminating       
principle were discovered with a        
facility that ,pangloss himself might   

have envied1 till at last even the      
spectators wearied of such dazzling     
performances4  ,but in all seriousness1 
why should indefinite and unlimited     
variation have been regarded as a more  
probable account of the origin of       
,adaptation8 ,only1 ,i think1 because   
the obstacle was shifted one plane back1
 and so looked rather less prominent4   
,the abundance of ,adaptation1 we all   
grant1 is an immense1 almost an         
unsurpassable difficulty in all         
non-,lamarckian views of ,evolution2 but
 if the steps by which that adaptation  
arose were fortuitous1 to imagine them  
insensible is assuredly no help4 ,in one
 most important respect indeed1 as has  
often been observed1 it is a            
multiplication of troubles4 ,for the    
smaller the steps1 the less could       
,natural ,selection act upon them4      
,definite variations--and of the        
occurrence of definite variations in    
abundance we have now the most          
convincing proof--have at least the     

obvious merit that they can make and    
often do make a real difference in the  
chances of life4  ,there is another     
aspect of the ,adaptation problem to    
which ,i can only allude very briefly4  
,may not our present ideas of the       
universality and precision of           
,adaptation be greatly exaggerated8 ,the
 fit of organism to its environment is  
not after all so very close--a          
proposition unwelcome perhaps1 but one  
which could be illustrated by very      
copious evidence4 ,natural ,selection is
 stern1 but she has her tolerant moods4 
,we have now most certain and           
irrefragable proof that much            
definiteness exists in living things    
apart from ,selection1 and also much    
that may very well have been preserved  
and so in a sense constituted by        
,selection4 ,here the matter is likely  
to rest4 ,there is a passage in the     
sixth edition of the ,origin which has  
,i think been overlooked4 ,on page #gj  
,darwin says ,the tuft of hair on the   

breast of the wild turkey-cock cannot be
 of any use1 and it is doubtful whether 
it can be ornamental in the eyes of the 
female bird4 ,this tuft of hair is a    
most definite and unusual structure1 and
 ,i am afraid that the remark that it   
cannot be of any use may have been made 
inadvertently2 but it may have been     
intended1 for in the first edition the  
usual qualification was given and must  
therefore have been deliberately        
excised4 ,anyhow ,i should like to think
 that ,darwin did throw over that tuft  
of hair1 and that he felt relief when he
 had done so4 ,whether however we have  
his great authority for such a course or
 not1 ,i feel quite sure that we shall  
be rightly interpreting the facts of    
nature if we cease to expect to find    
purposefulness wherever we meet with    
definite structures or patterns4 ,such  
things are1 as often as not1 ,i suspect 
rather of the nature of tool-marks1 mere
 incidents of manufacture1 benefiting   
their possessor not more than the       

wire-marks in a sheet of paper1 or the  
ribbing on the bottom of an oriental    
plate renders those objects more        
attractive in our eyes4  ,if ,variation 
may be in any way definite1 the question
 once more arises1 may it not be        
definite in direction8 ,the belief that 
it is has had many supporters1 from     
,lamarck onwards1 who held that it was  
guided by need1 and others who1 like    
,nageli1 while laying no emphasis on    
need1 yet were convinced that there was 
guidance of some kind4 ,the latter view 
under the name of ,orthogenesis1 devised
 ,i believe by ,eimer1 at the present   
day commends itself to some naturalists4
 ,the objection to such a suggestion is 
of course that no fragment of real      
evidence can be produced in its support4
 ,on the other hand1 with the           
experimental proof that variation       
consists largely in the unpacking and   
repacking of an original complexity1 it 
is not so certain as we might like to   
think that the order of these events is 

not pre-determined4 ,for instance the   
original pack may have been made in such
 a way that at the nth division of the  
germ-cells of a ,sweet ,pea a           
colour-factor might be dropped1 and that
 at the n plus n prime division the     
hooded variety be given off1 and so on4 
,i see no ground whatever for holding   
such a view1 but in fairness the        
possibility should not be forgotten1 and
 in the light of modern research it     
scarcely looks so absurdly improbable as
 before4  ,no one can survey the work of
 recent years without perceiving that   
evolutionary orthodoxy developed too    
fast1 and that a great deal has got to  
come down2 but this satisfaction at     
least remains1 that in the experimental 
methods which ,mendel inaugurated1 we   
have means of reaching certainty in     
regard to the physiology of ,heredity   
and ,variation upon which a more lasting
 structure may be built4     ,,vi4 ,,the
 ,,minute ,,structure ,,of ,,cells ,,in 
,,relation ,,to ,,heredity4 ,by ,eduard 

,strasburger4  ,professor of ,botany in 
the ,university of ,bonn4  ,since #ahge 
an unexpected insight has been gained   
into the internal structure of cells4   
,those who are familiar with the results
 of investigations in this branch of    
,science are convinced that any modern  
theory of heredity must rest on a basis 
of cytology and cannot be at variance   
with cytological facts4 ,many           
histological discoveries1 both such as  
have been proved correct and others     
which may be accepted as probably well  
founded1 have acquired a fundamental    
importance from the point of view of the
 problems of heredity4  ,my aim is to   
describe the present position of our    
knowledge of ,cytology4 ,the account    
must be confined to essentials and      
cannot deal with far-reaching and       
controversial questions4 ,in cases where
 difference of opinion exists1 ,i adopt 
my own view for which ,i hold myself    
responsible4 ,i hope to succeed in      
making myself intelligible even without 

the aid of illustrations3 in order to   
convey to the uninitiated an adequate   
idea of the phenomena connected with the
 life of a cell1 a greater number of    
figures would be required than could be 
included within the scope of this       
article4  ,so long as the most eminent  
investigators 7,as for example the      
illustrious ,wilhelm ,hofmeister in his 
,lehre von der ,pflanzenzelle 7#ahfg747 
believed that the nucleus of a cell was 
destroyed in the course of each division
 and that the nuclei of the             
daughter-cells were produced de novo1   
theories of heredity were able to       
dispense with the nucleus4 ,if they     
sought1 as did ,charles ,darwin1 who    
showed a correct grasp of the problem in
 the enunciation of his ,pangenesis     
hypothesis1 for histological connecting 
links1 their hypotheses1 or at least the
 best of them1 had reference to the cell
 as a whole4 ,it was known to ,darwin   
that the cell multiplied by division and
 was derived from a similar pre-existing

 cell4 ,towards #ahgj it was first      
demonstrated that cell-nuclei do not    
arise de novo1 but are invariably the   
result of division of pre-existing      
nuclei4 ,better methods of investigation
 rendered possible a deeper insight into
 the phenomena accompanying cell and    
nuclear divisions and at the same time  
disclosed the existence of remarkable   
structures4 ,the work of ,o4 ,butschli1 
,o4 ,hertwig1 ,w4 ,flemming ,h4 ,fol and
 of the author of this article 7,for    
further reference to literature1 see my 
article on ,die ,ontogenie der ,zelle   
seit #ahge1 in the ,progressus ,rei     
,botanicae1 ,vol4 ,i4 page #a1 ,jena1   
#aijg471 have furnished conclusive      
evidence in favour of these facts4 ,it  
was found that when the reticular       
framework of a nucleus prepares to      
divide1 it separates into single        
segments4 ,these then become thicker and
 denser1 taking up with avidity certain 
stains1 which are used as aids to       
investigation1 and finally form longer  

or shorter1 variously bent1 rodlets of  
uniform thickness4 ,in these organs     
which1 on account of their special      
property of absorbing certain stains1   
were styled ,chromosomes 7,by ,w4       
,waldeyer in #ahhh471 there may usually 
be recognised a separation into thicker 
and thinner discs2 the former are often 
termed ,chromomeres4 7,discovered by ,w4
 ,pfitzner in #ahhj47 ,in the course of 
division of the nucleus1 the single rows
 of chromomeres in the chromosomes are  
doubled and this produces a band-like   
flattening and leads to the longitudinal
 splitting by which each chromosome is  
divided into two exactly equal halves4  
,the nuclear membrane then disappears   
and fibrillar cell-plasma or cytoplasm  
invades the nuclear area4 ,in animal    
cells these fibrillae in the cytoplasm  
centre on definite bodies 7,their       
existence and their multiplication by   
fission were demonstrated by ,e4 van    
,beneden and ,th4 ,boveri in #ahhg471   
which it is customary to speak of as    

,centrosomes4 ,radiating lines in the   
adjacent cell-plasma suggest that these 
bodies constitute centres of force4 ,the
 cells of the higher plants do not      
possess such individualised centres2    
they have probably disappeared in the   
course of phylogenetic development3 in  
spite of this1 however1 in the nuclear  
division-figures the fibrillae of the   
cell-plasma are seen to radiate from two
 opposite poles4 ,in both animal and    
plant cells a fibrillar bipolar spindle 
is formed1 the fibrillae of which grasp 
the longitudinally divided chromosomes  
from two opposite sides and arrange them
 on the equatorial plane of the spindle 
as the so-called nuclear or equatorial  
plate4 ,each half-chromosome is         
connected with one of the spindle poles 
only and is then drawn towards that     
pole4 7,these important facts1 suspected
 by ,w4 ,flemming in #ahhb1 were        
demonstrated by ,e4 ,heuser1 ,l4        
,guignard1 ,e4 van ,beneden1 ,m4        
,nussbaum1 and ,c4 ,rabl47  ,the        

formation of the daughter-nuclei is then
 effected4 ,the changes which the       
daughter-chromosomes undergo in the     
process of producing the daughter-nuclei
 repeat in the reverse order the changes
 which they went through in the course  
of their progressive differentiation    
from the mother-nucleus4 ,the division  
of the cell-body is completed midway    
between the two daughter-nuclei4 ,in    
animal cells1 which possess no          
chemically differentiated membrane1     
separation is effected by simple        
constriction1 while in the case of plant
 cells provided with a definite wall1   
the process begins with the formation of
 a cytoplasmic separating layer4  ,the  
phenomena observed in the course of the 
division of the nucleus show beyond     
doubt that an exact halving of its      
substance is of the greatest importance4
 7,first shown by ,w4 ,roux in #ahhc47  
,compared with the method of division of
 the nucleus1 that of the cytoplasm     
appears to be very simple4 ,this led to 

the conception that the cell-nucleus    
must be the chief if not the sole       
carrier of hereditary characters in the 
organism4 ,it is for this reason that   
the detailed investigation of           
fertilisation phenomena immediately     
followed researches into the nucleus4   
,the fundamental discovery of the union 
of two nuclei in the sexual act was then
 made 7,by ,o4 ,hertwig in #ahge47 and  
this afforded a new support for the     
correct conception of the nuclear       
functions4 ,the minute study of the     
behaviour of the other constituents of  
sexual cells during fertilisation led to
 the result1 that the nucleus alone is  
concerned with handing on hereditary    
characters 7,this was done by ,o4       
,hertwig and the author of this essay   
simultaneously in #ahhd47 from one      
generation to another4 ,especially      
important1 from the point of view of    
this conclusion1 is the study of        
fertilisation in ,angiosperms           
7,flowering plants72 in these plants the

 male sexual cells lose their cell-body 
in the pollen-tube and the nucleus      
only--the sperm-nucleus--reaches the    
egg4 ,the cytoplasm of the male sexual  
cell is therefore not necessary to      
ensure a transference of hereditary     
characters from parents to offspring4 ,i
 lay stress on the case of the          
,angiosperms because researches recently
 repeated with the help of the latest   
methods failed to obtain different      
results4 ,as regards the descendants of 
angiospermous plants1 the same laws of  
heredity hold good as for other sexually
 differentiated organisms2 we may1      
therefore1 extend to the latter what the
 ,angiosperms so clearly teach us4  ,the
 next advance in the hitherto rapid     
progress in our knowledge of nuclear    
division was delayed1 because it was not
 at once recognised that there are two  
absolutely different methods of nuclear 
division4 ,all such nuclear divisions   
were united under the head of indirect  
or mitotic divisions2 these were also   

spoken of as karyo-kineses1 and were    
distinguished from the direct or        
amitotic divisions which are            
characterised by a simple constriction  
of the nuclear body4 ,so long as the two
 kinds of indirect nuclear division were
 not clearly distinguished1 their       
correct interpretation was impossible4  
,this was accomplished after long and   
laborious research1 which has recently  
been carried out and with results which 
should1 perhaps1 be regarded as         
provisional4  ,soon after the new study 
of the nucleus began1 investigators were
 struck by the fact that the course of  
nuclear division in the mother-cells1 or
 more correctly in the                  
grandmother-cells1 of spores1           
pollen-grains1 and embryo-sacs of the   
more highly organised plants and in the 
spermatozoids and eggs of the higher    
animals1 exhibits similar phenomena1    
distinct from those which occur in the  
somatic cells4  ,in the nuclei of all   
those cells which we may group together 

as gonotokonts 7,at the suggestion of   
,j4,p4 ,lotsy in #aijd47 7i4e4 cells    
concerned in reproduction7 there are    
fewer chromosomes than in the adjacent  
body-cells 7somatic cells74 ,it was     
noticed also that there is a peculiarity
 characteristic of the gonotokonts1     
namely the occurrence of two nuclear    
divisions rapidly succeeding one        
another4 ,it was afterwards recognised  
that in the first stage of nuclear      
division in the gonotokonts the         
chromosomes unite in pairs3 it is these 
chromosome-pairs1 and not the two       
longitudinal halves of single           
chromosomes1 which form the nuclear     
plate in the equatorial plane of the    
nuclear spindle4 ,it has been proposed  
to call these pairs gemini4 7,j4,e4,s4  
,moore and ,a4,l4 ,embleton1 ,proc4     
,roy4 ,soc4 ,london1 ,vol4 ,,lxxvii4    
page #eee1 #aijf2 ,v4 ,gregoire1 #aijg47
 ,in the course of this division the    
spindle-fibrillae attach themselves to  
the gemini1 i4e4 to entire chromosomes  

and direct them to the points where the 
new daughter-nuclei are formed1 that is 
to those positions towards which the    
longitudinal halves of the chromosomes  
travel in ordinary nuclear divisions4   
,it is clear that in this way the number
 of chromosomes which the               
daughter-nuclei contain1 as the result  
of the first stage in division in the   
gonotokonts1 will be reduced by one     
half1 while in ordinary divisions the   
number of chromosomes always remains the
 same4 ,the first stage in the division 
of the nucleus in the gonotokonts has   
therefore been termed the reduction     
division4 7,in #ahhg ,w4 ,flemming      
termed this the heterotypic form of     
nuclear division47 ,this stage in       
division determines the conditions for  
the second division which rapidly       
ensues4 ,each of the paired chromosomes 
of the mother-nucleus has already1 as in
 an ordinary nuclear division1 completed
 the longitudinal fission1 but in this  
case it is not succeeded by the         

immediate separation of the longitudinal
 halves and their allotment to different
 nuclei4 ,each chromosome1 therefore1   
takes its two longitudinal halves into  
the same daughter-nucleus4 ,thus1 in    
each daughter-nucleus the longitudinal  
halves of the chromosomes are present   
ready for the next stage in the         
division2 they only require to be       
arranged in the nuclear plate and then  
distributed among the                   
granddaughter-nuclei4 ,this method of   
division1 which takes place with        
chromosomes already split1 and which    
have only to provide for the            
distribution of their longitudinal      
halves to the next nuclear generation1  
has been called homotypic nuclear       
division4 7,the name was proposed by ,w4
 ,flemming in #ahhg2 the nature of this 
type of division was1 however1 not      
explained until later47  ,reduction     
division and homotypic nuclear division 
are included together under the term    
allotypic nuclear division and are      

distinguished from the ordinary or      
typical nuclear division4 ,the name     
,meiosis 7,by ,j4 ,bretland ,farmer and 
,j4,e4,s4 ,moore in #aije47 has also    
been proposed for these two allotypic   
nuclear divisions4 ,the typical         
divisions are often spoken of as        
somatic4  ,observers who were actively  
engaged in this branch of recent        
histological research soon noticed that 
the chromosomes of a given organism are 
differentiated in definite numbers from 
the nuclear network in the course of    
division4 ,this is especially striking  
in the gonotokonts1 but it applies also 
to the somatic tissues4 ,in the latter1 
one usually finds twice as many         
chromosomes as in the gonotokonts4 ,thus
 the conclusion was gradually reached   
that the doubling of chromosomes1 which 
necessarily accompanies fertilisation1  
is maintained in the product of         
fertilisation1 to be again reduced to   
one half in the gonotokonts at the stage
 of reduction-division4 ,this enabled us

 to form a conception as to the essence 
of true alternation of generations1 in  
which generations containing single and 
double chromosomes alternate with one   
another4  ,the single-chromosome        
generation1 which ,i will call the      
,,haploid1 must have been the primitive 
generation in all organisms2 it might   
also persist as the only generation4    
,every sexual differentiation in        
organisms1 which occurred in the course 
of phylogenetic development1 was        
followed by fertilisation and therefore 
by the creation of a diploid or         
double-chromosome product4 ,so long as  
the germination of the product of       
fertilisation1 the zygote1 began with a 
reducing process1 a special ,,diploid   
generation was not represented4 ,this1  
however1 appeared later as a product of 
the further evolution of the zygote1 and
 the reduction division was             
correspondingly postponed4 ,in animals1 
as in plants1 the diploid generation    
attained the higher development and     

gradually assumed the dominant position4
 ,the haploid generation suffered a     
proportional reduction1 until it finally
 ceased to have an independent existence
 and became restricted to the role of   
producing the sexual products within the
 body of the diploid generation4 ,those 
who do not possess the necessary special
 knowledge are unable to realise what   
remains of the first haploid generation 
in a phanerogamic plant or in a         
vertebrate animal4 ,in ,angiosperms this
 is actually represented only by the    
short developmental stages which extend 
from the pollen mother-cells to the     
sperm-nucleus of the pollen-tube1 and   
from the embryo-sac mother-cell to the  
egg and the endosperm tissue4 ,the      
embryo-sac remains enclosed in the      
diploid ovule1 and within this from the 
fertilised egg is formed the embryo     
which introduces the new diploid        
generation4 ,on the full development of 
the diploid embryo of the next          
generation1 the diploid ovule of the    

preceding diploid generation is         
separated from the latter as a ripe     
seed4 ,the uninitiated sees in the more 
highly organised plants only a          
succession of diploid generations4      
,similarly all the higher animals appear
 to us as independent organisms with    
diploid nuclei only4 ,the haploid       
generation is confined in them to the   
cells produced as the result of the     
reduction division of the gonotokonts2  
the development of these is completed   
with the homotypic stage of division    
which succeeds the reduction division   
and produces the sexual products4  ,the 
constancy of the numbers in which the   
chromosomes separate themselves from the
 nuclear network during division gave   
rise to the conception that1 in a       
certain degree1 chromosomes possess     
individuality4 ,indeed the most careful 
investigations 7,particularly those of  
,v4 ,gregoire and his pupils47 have     
shown that the segments of the nuclear  
network1 which separate from one another

 and condense so as to produce          
chromosomes for a new division1         
correspond to the segments produced from
 the chromosomes of the preceding       
division4 ,the behaviour of such nuclei 
as possess chromosomes of unequal size  
affords confirmatory evidence of the    
permanence of individual chromosomes in 
corresponding sections of an apparently 
uniform nuclear network4 ,moreover at   
each stage in division chromosomes with 
the same differences in size reappear4  
,other cases are known in which thicker 
portions occur in the substance of the  
resting nucleus1 and these agree in     
number with the chromosomes4 ,in this   
network1 therefore1 the individual      
chromosomes must have retained their    
original position4 ,but the chromosomes 
cannot be regarded as the ultimate      
hereditary units in the nuclei1 as their
 number is too small4 ,moreover1 related
 species not infrequently show a        
difference in the number of their       
chromosomes1 whereas the number of      

hereditary units must approximately     
agree4 ,we thus picture to ourselves the
 carriers of hereditary characters as   
enclosed in the chromosomes2 the        
transmitted fixed number of chromosomes 
is for us only the visible expression of
 the conception that the number of      
hereditary units which the chromosomes  
carry must be also constant4 ,the       
ultimate hereditary units may1 like the 
chromosomes themselves1 retain a        
definite position in the resting        
nucleus4 ,further1 it may be assumed    
that during the separation of the       
chromosomes from one another and during 
their assumption of the rod-like form1  
the hereditary units become aggregated  
in the chromomeres and that these are   
characterised by a constant order of    
succession4 ,the hereditary units then  
grow1 divide into two and are uniformly 
distributed by the fission of the       
chromosomes between their longitudinal  
halves4  ,as the contraction and        
rod-like separation of the chromosomes  

serve to isnure the transmission of all 
hereditary units in the products of     
division of a nucleus1 so1 on the other 
hand1 the reticular distension of each  
chromosome in the so-called resting     
nucleus may effect a separation of the  
carriers of hereditary units from each  
other and facilitate the specific       
activity of each of them4  ,in the      
stages preliminary to their division1   
the chromosomes become denser and take  
up a substance which increases their    
staining capacity2 this is called       
chromatin4 ,this substance collects in  
the chromomeres and may form the        
nutritive material for the carriers of  
hereditary units which we now believe to
 be enclosed in them4 ,the chromatin    
cannot itself be the hereditary         
substance1 as it afterwards leaves the  
chromosomes1 and the amount of it is    
subject to considerable variation in the
 nucleus1 according to its stage of     
development4 ,conjointly with the       
materials which take part in the        

formation of the nuclear spindle and    
other processes in the cell1 the        
chromatin accumulates in the resting    
nucleus to form the nucleoli4           
,naturally connected with the conclusion
 that the nuclei are the carriers of    
hereditary characters in the organism1  
is the question whether enucleate       
organisms can also exist4 ,phylogenetic 
considerations give an affirmative      
answer to this question4 ,the           
differentiation into nucleus and        
cytoplasm represents a division of      
labour in the protoplast4 ,a study of   
organisms which belong to the lowest    
class of the organic world teaches us   
how this was accomplished4 ,instead of  
well-defined nuclei1 scattered granules 
have been described in the protoplasm of
 several of these organisms 7,bacteria1 
,cyanophyceae1 ,protozoa471             
characterised by the same reactions as  
nuclear material1 provided also with a  
nuclear network1 but without a limiting 
membrane4 7,this is the result of the   

work of ,r4 ,hertwig and of the most    
recently published investigations47     
,thus the carriers of hereditary        
characters may originally have been     
distributed in the common protoplasm1   
afterwards coming together and          
eventually assuming a definite form as  
special organs of the cell4 ,it may be  
also assumed that in the protoplasm and 
in the primitive types of nucleus1 the  
carriers of the same hereditary unit    
were represented in considerable        
quantity2 they became gradually         
differentiated to an extent commensurate
 with newly acquired characters4 ,it was
 also necessary that1 in proportion as  
this happened1 the mechanism of nuclear 
division must be refined4 ,at first     
processes resembling a simple           
constriction would suffice to provide   
for the distribution of all hereditary  
units to each of the products of        
division1 but eventually in both organic
 kingdoms nuclear division1 which alone 
insured the qualitative identity of the 

products of division1 became a more     
marked feature in the course of         
cell-multiplication4  ,where direct     
nuclear division occurs by constriction 
in the higher organisms1 it does not    
result in the halving of hereditary     
units4 ,so far as my observations go1   
direct nuclear division occurs in the   
more highly organised plants only in    
cells which have lost their specific    
functions4 ,such cells are no longer    
capable of specific reproduction4 ,an   
interesting case in this connection is  
afforded by the internodal cells of the 
,characeae1 which possess only          
vegetative functions4 ,these cells grow 
vigorously and their cytoplasm          
increases1 their growth being           
accompanied by a correspondingly direct 
multiplication of the nuclei4 ,they     
serve chiefly to nourish the plant1 but1
 unlike the other cells1 they are       
incapable of producing any offspring4   
,this is a very instructive case1       
because it clearly shows that the nuclei

 are not only carriers of hereditary    
characters1 but that they also play a   
definite part in the metabolism of the  
protoplasts4  ,attention was drawn to   
the fact that during the reducing       
division of nuclei which contain        
chromosomes of unequal size1 gemini are 
constantly produced by the pairing of   
chromosomes of the same size4 ,this led 
to the conclusion that the pairing      
chromosomes are homologous1 and that one
 comes from the father1 the other from  
the mother4 7,first stated by ,t4,h4    
,montgomery in #aija and by ,w4,s4      
,sutton in #aijb47 ,this evidently      
applies also to the pairing of          
chromosomes in those reduction-divisions
 in which differences in size do not    
enable us to distinguish the individual 
chromosomes4 ,in this case also each    
pair would be formed by two homologous  
chromosomes1 the one of paternal1 the   
other of maternal origin4 ,when the     
separation of these chromosomes and     
their distribution to both              

daughter-nuclei occur a chromosome of   
each kind is provided for each of these 
nuclei4 ,it would seem that the         
components of each pair might pass to   
either pole of the nuclear spindle1 so  
that the paternal and maternal          
chromosomes would be distributed in     
varying proportion between the          
daughter-nuclei2 and it is not          
impossible that one daughter-nucleus    
might occasionally contain paternal     
chromosomes only and its sister-nucleus 
exclusively maternal chromosomes4  ,the 
fact that in nuclei containing          
chromosomes of various sizes1 the       
chromosomes which pair together in      
reduction-division are always of equal  
size1 constitutes a further and more    
important proof of their qualitative    
difference4 ,this is supported also by  
ingenious experiments which led to an   
unequal distribution of chromosomes in  
the products of division of a           
sea-urchin's egg1 with the result that a
 difference was induced in their further

 development4 7,demonstrated by ,th4    
,boveri in #aijb47  ,the recently       
discovered fact that in diploid nuclei  
the chromosomes are arranged in pairs   
affords additional evidence in favour of
 the unequal value of the chromosomes4  
,this is still more striking in the case
 of chromosomes of different sizes4 ,it 
has been shown that in the first        
division-figure in the nucleus of the   
fertilised egg the chromosomes of       
corresponding size form pairs4 ,they    
appear with this arrangement in all     
subsequent nuclear divisions in the     
diploid generation4 ,the longitudinal   
fissions of the chromosomes provide for 
the unaltered preservation of this      
condition4 ,in the reduction nucleus of 
the gonotokonts the homologous          
chromosomes being near together need not
 seek out one another2 they are ready to
 form gemini4 ,the next stage is their  
separation to the haploid               
daughter-nuclei1 which have resulted    
from the reduction process4  ,peculiar  

phenomena in the reduction nucleus      
accompany the formation of gemini in    
both organic kingdoms4 7,this has been  
shown more particularly by the work of  
,l4 ,guignard1 ,m4 ,mottier1 ,j4,b4     
,farmer1 ,c4,b4 ,wilson1 ,v4 ,hacker and
 more recently by ,v4 ,gregoire and his 
pupil ,c4,a4 ,allen1 by the researches  
conducted in the ,bonn ,botanical       
,institute1 and by ,a4 and ,k4,e4       
,schreiner47 ,probably for the purpose  
of entering into most intimate relation1
 the pairs are stretched to long threads
 in which the chromomeres come to lie   
opposite one another4 7,c4,a4 ,allen1   
,a4 and ,k4,e4 ,schreiner1 and          
,strasburger47 ,it seems probable that  
these are homologous chromomeres1 and   
that the pairs afterwards unite for a   
short time1 so that an exchange of      
hereditary units is rendered possible4  
7,h4 de ,vries and ,strasburger47 ,this 
cannot be actually seen1 but certain    
facts of heredity point to the          
conclusion that this occurs4 ,it follows

 from these phenomena that any exchange 
which may be effected must be one of    
homologous carriers of hereditary units 
only4 ,these units continue to form     
exchangeable segments after they have   
undergone unequal changes2 they then    
constitute allelotropic pairs4 ,we may  
thus calculate what sum of possible     
combinations the exchange of homologous 
hereditary units between the pairing    
chromosomes provides for before the     
reduction division and the subsequent   
distribution of paternal and maternal   
chromosomes in the haploid              
daughter-nuclei4 ,these nuclei then     
transmit their characters to the sexual 
cells1 the conjugation of which in      
fertilization again produces the most   
varied combinations4 7,a4 ,weismann gave
 the impulse to these ideas in his      
theory on ,amphimixis47 ,in this way all
 the cooperations which the carriers of 
hereditary characters are capable of in 
a species are produced2 this must give  
it an appreciable advantage in the      

struggle for life4  ,the admirers of    
,charles ,darwin must deeply regret that
 he did not live to see the results     
achieved by the new ,cytology4 ,what    
service would they have been to him in  
the presentation of his hypothesis of   
,pangenesis2 what an outlook into the   
future would they have given to his     
active mind6  ,the ,darwinian hypothesis
 of ,pangenesis rests on the conception 
that all inheritable properties are     
represented in the cells by small       
invisible particles or gemmules and that
 these gemmules increase by division4   
,cytology began to develop on new lines 
some years after the publication in     
#ahfh of ,charles ,darwin's ,provisional
 hypothesis of ,pangenesis 7,animals and
 ,plants under ,domestication1 ,london1 
#ahfh1 ,chapter ,,xxvii471 and when he  
died in #ahhb it was still in its       
infancy4 ,darwin would have soon        
suggested the substitution of the nuclei
 for his gemmules4 ,at least the great  
majority of present-day investigators in

 the domain of cytology have been led to
 the conclusion that the nucleus is the 
carrier of hereditary characters1 and   
they also believe that hereditary       
characters are represented in the       
nucleus as distinct units4 ,such would  
be ,darwin's gemmules1 which in         
conformity with the name of his         
hypothesis may be called pangens 7,so   
called by ,h4 de ,vries in #ahhi473     
these pangens multiply by division4 ,all
 recently adopted views may be thus     
linked on to this part of ,darwin's     
hypothesis4 ,it is otherwise with       
,darwin's conception to which           
,pangenesis owes its name1 namely the   
view that all cells continually give off
 gemmules1 which migrate to other places
 in the organism1 where they unite to   
form reproductive cells4 ,when ,darwin  
foresaw this possibility1 the continuity
 of the germinal substance was still    
unknown 7,demonstrated by ,nussbaum in  
#ahhj1 by ,sachs in #ahhb1 and by       
,weismann in #ahhe471 a fact which      

excludes a transference of gemmules4    
,but even ,charles ,darwin's genius was 
confined within finite boundaries by the
 state of science in his day4  ,it is   
not my province to deal with other      
theories of development which followed  
from ,darwin's ,pangenesis1 or to       
discuss their histological              
probabilities4 ,we can1 however1 affirm 
that ,charles ,darwin's idea that       
invisible gemmules are the carriers of  
hereditary characters and that they     
multiply by division has been removed   
from the position of a provisional      
hypothesis to that of a well-founded    
theory4 ,it is supported by histology1  
and the results of experimental work in 
heredity1 which are now assuming        
extraordinary prominence1 are in close  
agreement with it4     ,,vii4 ,,the     
,,descent ,,of ,,man4 ,by ,g4 ,schwalbe4
  ,professor of ,anatomy in the         
,university of ,strassburg4  ,the       
problem of the origin of the human race1
 of the descent of man1 is ranked by    

,huxley in his epoch-making book ,man's 
,place in ,nature1 as the deepest with  
which biology has to concern itself1 the
 question of questions1--the problem    
which underlies all others4 ,in the same
 brilliant and lucid exposition1 which  
appeared in #ahfc1 soon after the       
publication of ,darwin's ,origin of     
,species1 ,huxley stated his own views  
in regard to this great problem4 ,he    
tells us how the idea of a natural      
descent of man gradually grew up in his 
mind1 it was especially the assertions  
of ,owen in regard to the total         
difference between the human and the    
simian brain that called forth strong   
dissent from the great anatomist        
,huxley1 and he easily succeeded in     
showing that ,owen's supposed           
differences had no real existence2 he   
even established1 on the basis of his   
own anatomical investigations1 the      
proposition that the anatomical         
differences between the ,marmoset and   
the ,chimpanzee are much greater than   

those between the ,chimpanzee and ,man4 
,but why do we thus introduce the study 
of ,darwin's ,descent of ,man1 which is 
to occupy us here1 by insisting on the  
fact that ,huxley had taken the field in
 defence of the descent of man in #ahfc1
 while ,darwin's book on the subject did
 not appear till #ahga8 ,it is in order 
that we may clearly understand how it   
happened that from this time onwards    
,darwin and ,huxley followed the same   
great aim in the most intimate          
association4  ,huxley and ,darwin       
working at the same ,problema maximum6  
,huxley fiery1 impetuous1 eager for     
battle1 contemptuous of the resistance  
of a dull world1 or energetically       
triumphing over it4 ,darwin calm1       
weighing every problem slowly1 letting  
it mature thoroughly1--not a fighter1   
yet having the greater and more lasting 
influence by virtue of his immense mass 
of critically sifted proofs4 ,darwin's  
friend1 ,huxley1 was the first to do him
 justice1 to understand his nature1 and 

to find in it the reason why the        
detailed and carefully considered book  
on the descent of man made its          
appearance so late4 ,huxley1 always     
generous1 never thought of claiming     
priority for himself4 ,in enthusiastic  
language he tells how ,darwin's immortal
 work1 ,the ,origin of ,species1 first  
shed light for him on the problem of the
 descent of man2 the recognition of a   
vera causa in the transformation of     
species illuminated his thoughts as with
 a flash4 ,he was now content to leave  
what perplexed him1 what he could not   
yet solve1 as he says himself1 in the   
mighty hands of ,darwin4 ,happy in the  
bustle of strife against old and        
deep-rooted prejudices1 against         
intolerance and superstition1 he wielded
 his sharp weapons on ,darwin's behalf2 
wearing ,darwin's armour he joyously    
overthrew adversary after adversary4    
,darwin spoke of ,huxley as his general 
agent4 7,life and ,letters of ,thomas   
,henry ,huxley1 ,vol4 ,i4 page #aga1    

,london1 #aijj47 ,huxley says of himself
 ,i am ,darwin's bulldog4 7,ibid4 page  
#cfc47  ,thus ,huxley openly            
acknowledged that it was ,darwin's      
,origin of ,species that first set the  
problem of the descent of man in its    
true light1 that made the question of   
the origin of the human race a pressing 
one4 ,that this was the logical         
consequence of his book ,darwin himself 
had long felt4 ,he had been reproached  
with intentionally shirking the         
application of his theory to ,man4 ,let 
us hear what he says on this point in   
his autobiography3 ,as soon as ,i had   
become1 in the year #ahcg or #ahch1     
convinced that species were mutable     
productions1 ,i could not avoid the     
belief that man must come under the same
 law4 ,accordingly ,i collected notes on
 the subject for my own satisfaction1   
and not for a long time with any        
intention of publishing4 ,although in   
the ',origin of ,species' the derivation
 of any particular species is never     

discussed1 yet ,i thought it best1 in   
order ,,that ,,no ,,honourable ,,man    
,,should ,,accuse ,,me ,,of ,,concealing
 ,,my ,,views 7,no italics in           
original471 to add that by the work     
'light would be thrown on the origin of 
man and his history4' ,it would have    
been useless and injurious to the       
success of the book to have paraded1    
without giving any evidence1 my         
conviction with respect to his origin4  
7,life and ,letters of ,charles ,darwin1
 ,vol4 #a4 page #ic47  ,in a letter     
written in ,january1 #ahfj1 to the ,rev4
 ,l4 ,blomefield1 ,darwin expresses     
himself in similar terms4 ,with respect 
to man1 ,i am very far from wishing to  
obtrude my belief2 but ,i thought it    
dishonest to quite conceal my opinion4  
7,ibid4 ,vol4 ,,ii4 page #bfc47  ,the   
brief allusion in the ,origin of        
,species is so far from prominent and so
 incidental that it was excusable to    
assume that ,darwin had not touched upon
 the descent of man in this work4 ,it   

was solely the desire to have his mass  
of evidence sufficiently complete1      
solely ,darwin's great characteristic of
 never publishing till he had carefully 
weighed all aspects of his subject for  
years1 solely1 in short1 his most       
fastidious scientific conscience that   
restrained him from challenging the     
world in #ahei with a book in which the 
theory of the descent of man was fully  
set forth4 ,three years1 frequently     
interrupted by ill-health1 were needed  
for the actual writing of the book      
7,life and ,letters1 ,vol4 ,i4 page     
#id473 the first edition1 which appeared
 in #ahga1 was followed in #ahgd by a   
much improved second edition1 the       
preparation of which he very reluctantly
 undertook4 7,ibid4 ,vol4 ,,iii4 page   
#age47  ,this1 briefly1 is the history  
of the work1 which1 with the ,origin of 
,species1 marks an epoch in the history 
of biological sciences--the work with   
which the cautious1 peace-loving        
investigator ventured forth from his    

contemplative life into the arena of    
strife and unrest1 and laid himself open
 to all the annoyances that deep-rooted 
belief and prejudice1 and the prevailing
 tendency of scientific thought at the  
time could devise4  ,darwin did not take
 this step lightly4 ,of great interest  
in this connection is a letter written  
to ,wallace on ,dec4 #bb1 #aheg 7,ibid4 
,vol4 ,,ii4 page #aji471 in which he    
says ,you ask whether ,i shall discuss  
'man4' ,i think ,i shall avoid the whole
 subject1 as so surrounded with         
prejudices2 though ,i fully admit that  
it is the highest and most interesting  
problem for the naturalist4 ,but his    
conscientiousness compelled him to state
 briefly his opinion on the subject in  
the ,origin of ,species in #ahei4       
,nevertheless he did not escape         
reproaches for having been so reticent4 
,this is unmistakably apparent from a   
letter to ,fritz ,muller dated ,february
 #bb 7#ahfi871 in which he says3 ,i am  
thinking of writing a little essay on   

the ,origin of ,mankind1 as ,i have been
 taunted with concealing my opinions4   
7,ibid4 ,vol4 ,,iii4 page #aab47  ,it   
might be thought that ,darwin behaved   
thus hesitatingly1 and was so slow in   
deciding on the full publication of his 
collected material in regard to the     
descent of man1 because he had religious
 difficulties to overcome4  ,but this   
was not the case1 as we can see from his
 admirable confession of faith1 the     
publication of which we owe to his son  
,francis4 7,ibid4 ,vol4 ,i4 pages       
#cjd-cag47 ,whoever wishes really to    
understand the lofty character of this  
great man should read these immortal    
lines in which he unfolds to us in      
simple and straightforward words the    
development of his conception of the    
universe4 ,he describes how1 though he  
was still quite orthodox during his     
voyage round the world on board the     
,beagle1 he came gradually to see1      
shortly afterwards 7#ahcf-ahci7 that the
 ,old ,testament was no more to be      

trusted than the ,sacred ,books of the  
,hindoos2 the miracles by which         
,christianity is supported1 the         
discrepancies between the accounts in   
the different ,gospels1 gradually led   
him to disbelieve in ,christianity as a 
divine revelation4 ,thus1 he writes     
7,life and ,letters1 ,vol4 #a4 page     
#cji471 disbelief crept over me at a    
very slow rate1 but was at last         
complete4 ,the rate was so slow that ,i 
felt no distress4 ,but ,darwin was too  
modest to presume to go beyond the      
limits laid down by science4 ,he wanted 
nothing more than to be able to go1     
freely and unhampered by belief in      
authority or in the ,bible1 as far as   
human knowledge could lead him4 ,we     
learn this from the concluding words of 
his chapter on religion3 ,the mystery of
 the beginning of all things is         
insoluble by us2 and ,i for one must be 
content to remain an ,agnostic4 7,loc4  
cit4 page #cac47  ,darwin was always    
very unwilling to give publicity to his 

views in regard to religion4 ,in a      
letter to ,asa ,gray on ,may #bb1 #ahfj 
7,ibid4 ,vol4 ,,ii4 page #caj471 he     
declares that it is always painful to   
him to have to enter into discussion of 
religious problems4 ,he had1 he said1 no
 intention of writing atheistically4    
,finally1 let us cite one characteristic
 sentence from a letter from ,darwin to 
,c4 ,ridley 7,ibid4 ,vol4 ,,iii4 page4  
#bcf4 7,c4 ,ridley1 ,mr ,francis ,darwin
 points out to me1 should be ,h4,n4     
,ridley4 ,a4,c4,s477 7,nov4 #bh1 #ahgh47
 ,a clergyman1 ,dr ,pusey1 had asserted 
that ,darwin had written the ,origin of 
,species with some relation to theology4
 ,darwin writes emphatically1 ,many     
years ago1 when ,i was collecting facts 
for the ',origin'1 my belief in what is 
called a personal ,god was as firm as   
that of ,dr ,pusey himself1 and as to   
the eternity of matter ,i never troubled
 myself about such insoluble questions4 
,the expression many years ago refers to
 the time of his voyage round the world1

 as has already been pointed out4       
,darwin means by this utterance that the
 views which had gradually developed in 
his mind in regard to the origin of     
species were quite compatible with the  
faith of the ,church4  ,if we consider  
all these utterances of ,darwin in      
regard to religion and to his outlook on
 life 7,weltanschauung71 we shall see at
 least so much1 that religious          
reflection could in no way have         
influenced him in regard to the writing 
and publishing of his book on ,the      
,descent of ,man4 ,darwin had early won 
for himself freedom of thought1 and to  
this freedom he remained true to the end
 of his life1 uninfluenced by the       
customs and opinions of the world around
 him4  ,darwin was thus inwardly        
fortified and armed against the host of 
calumnies1 accusations1 and attacks     
called forth by the publication of the  
,origin of ,species1 and to an even     
greater extent by the appearance of the 
,descent of ,man4 ,but in his defence he

 could rely on the aid of a band of     
distinguished auxiliaries of the rarest 
ability4 ,his faithful confederate1     
,huxley1 was joined by the botanist     
,hooker1 and1 after longer resistance1  
by the famous geologist ,lyell1 whose   
conversion afforded ,darwin peculiar    
satisfaction4 ,all three took the field 
with enthusiasm in defence of the       
natural descent of man4 ,from ,wallace1 
on the other hand1 though he shared with
 him the idea of natural selection1     
,darwin got no support in this matter4  
,wallace expressed himself in a strange 
manner4 ,he admitted everything in      
regard to the morphological descent of  
man1 but maintained1 in a mystic way1   
that something else1 something of a     
spiritual nature must have been added to
 what man inherited from his animal     
ancestors4 ,darwin1 whose esteem for    
,wallace was extraordinarily high1 could
 not understand how he could give       
utterance to such a mystical view in    
regard to man2 the idea seemed to him so

 incredibly strange that he thought some
 one else must have added these         
sentences to ,wallace's paper4  ,even   
now there are thinkers who1 like        
,wallace1 shrink from applying to man   
the ultimate consequences of the theory 
of descent4 ,the idea that man is       
derived from ape-like forms is to them  
unpleasant and humiliating4  ,so far ,i 
have been depicting the development of  
,darwin's work on the descent of man4   
,in what follows ,i shall endeavour to  
give a condensed survey of the contents 
of the book4  ,it must at once be said  
that the contents of ,darwin's work fall
 into two parts1 dealing with entirely  
different subjects4 ,the ,descent of    
,man includes a very detailed           
investigation in regard to secondary    
sexual characters in the animal series1 
and on this investigation ,darwin       
founded a new theory1 that of sexual    
selection4 ,with astonishing patience he
 gathered together an immense mass of   
material1 and showed1 in regard to      

,arthropods and ,vertebrates1 the wide  
distribution of secondary characters1   
which develop almost exclusively in the 
male1 and which enable him1 on the one  
hand1 to get the better of his rivals in
 the struggle for the female by the     
greater perfection of his weapons1 and  
on the other hand1 to offer greater     
allurements to the female through the   
higher development of decorative        
characters1 of song1 or of              
scent-producing glands4 ,the best       
equipped males will thus crowd out the  
less well-equipped in the matter of     
reproduction1 and thus the relevant     
characters will be increased and        
perfected through sexual selection4 ,it 
is1 of course1 a necessary assumption   
that these secondary sexual characters  
may be transmitted to the female1       
although perhaps in rudimentary form4   
,as we have said1 this theory of sexual 
selection takes up a great deal of space
 in ,darwin's book1 and it need only be 
considered here in so far as ,darwin    

applied it to the descent of man4 ,to   
this latter problem the whole of ,part  
,i is devoted1 while ,part ,,iii        
contains a discussion of sexual         
selection in relation to man1 and a     
general summary4 ,part ,,ii treats of   
sexual selection in general1 and may be 
disregarded in our present study4       
,moreover1 many interesting details must
 necessarily be passed over in what     
follows1 for want of space4  ,the first 
part of the ,descent of ,man begins with
 an enumeration of the proofs of the    
animal descent of man taken from the    
structure of the human body4 ,darwin    
chiefly emphasises the fact that the    
human body consists of the same organs  
and of the same tissues as those of the 
other mammals2 he shows also that man is
 subject to the same diseases and       
tormented by the same parasites as the  
apes4 ,he further dwells on the general 
agreement exhibited by young1 embryonic 
forms1 and he illustrates this by two   
figures placed one above the other1 one 

representing a human embryo1 after      
,eaker1 the other a dog embryo1 after   
,bischoff4 7,descent of ,man 7,popular  
,edition1 #aija71 fig4 #a1 page #ad47   
,darwin finds further proofs of the     
animal origin of man in the reduced     
structures1 in themselves extremely     
variable1 which are either absolutely   
useless to their possessors1 or of so   
little use that they could never have   
developed under existing conditions4 ,of
 such vestiges he enumerates3 the       
defective development of the panniculus 
carnosus 7muscle of the skin7 so widely 
distributed among mammals1 the          
ear-muscles1 the occasional persistence 
of the animal ear-point in man1 the     
rudimentary nictitating membrane 7plica 
semilunaris7 in the human eye1 the      
slight development of the organ of      
smell1 the general hairiness of the     
human body1 the frequently defective    
development or entire absence of the    
third molar 7the wisdom tooth71 the     
vermiform appendix1 the occasional      

reappearance of a bony canal 7foramen   
supracondyloideum7 at the lower end of  
the humerus1 the rudimentary tail of man
 7the so-called taillessness71 and so   
on4 ,of these rudimentary structures the
 occasional occurrence of the animal    
ear-point in man is most fully          
discussed4 ,darwin's attention was      
called to this interesting structure by 
the sculptor ,woolner4 ,he figures such 
a case observed in man1 and also the    
head of an alleged orang-foetus1 the    
photograph of which he received from    
,nitsche4  ,darwin's interpretation of  
,woolner's case as having arisen through
 a folding over of the free edge of a   
pointed ear has been fully borne out by 
my investigations on the external ear4  
7,g4 ,schwalbe1 ,das ,darwin'sche       
,spitzohr beim menschlichen ,embryo1    
,anatom4 ,anzeiger1 #ahhi1 pages        
#agf-ahi1 and other papers47 ,in        
particular1 it was established by these 
investigations that the human foetus1   
about the middle of its embryonic life1 

possesses a pointed ear somewhat similar
 to that of the monkey genus ,macacus4  
,one of ,darwin's statements in regard  
to the head of the orang-foetus must be 
corrected4 ,a ,,large ear with a point  
is shown in the photograph 7,descent of 
,man1 fig4#c1 page #bd471 but it can    
easily be demonstrated--and ,deniker has
 already pointed this out--that the     
figure is not that of an orang-foetus at
 all1 for that form has much smaller    
ears with no point2 nor can it be a     
gibbon-foetus1 as ,deniker supposes1 for
 the gibbon ear is also without a point4
 ,i myself regard it as that of a       
,macacus-embryo4 ,but this mistake1     
which is due to ,nitsche1 in no way     
affects the fact recognised by ,darwin1 
that ear-forms showing the point        
characteristic of the animal ear occur  
in man with extraordinary frequency4    
,finally1 there is a discussion of those
 rudimentary structures which occur only
 in ,,one sex1 such as the rudimentary  
mammary glands in the male1 the vesicula

 prostatica1 which corresponds to the   
uterus of the female1 and others4 ,all  
these facts tell in favour of the common
 descent of man and all other           
vertebrates4 ,the conclusion of this    
section is characteristic3 ,,it ,,is    
,,only ,,our ,,natural ,,prejudice1     
,,and ,,that ,,arrogance ,,which ,,made 
,,our ,,forefathers ,,declare ,,that    
,,they ,,were ,,descended ,,from        
,,demi-,,gods1 ,,which ,,leads ,,us ,,to
 ,,demur ,,to ,,this ,,conclusion4 ,,but
 ,,the ,,time ,,will ,,before ,,long    
,,come1 ,,when ,,it ,,will ,,be         
,,thought ,,wonderful ,,that            
,,naturalists1 ,,who ,,were ,,well      
,,acquainted ,,with ,,the ,,comparative 
,,structure ,,and ,,development ,,of    
,,man1 ,,and ,,other ,,mammals1 ,,should
 ,,have ,,believed ,,that ,,each ,,was  
,,the ,,work ,,of ,a ,,separate ,,act   
,,of ,,creation4 7,ibid4 page #cf47  ,in
 the second chapter there is a more     
detailed discussion1 again based upon an
 extraordinary wealth of facts1 of the  

problem as to the manner in which1 and  
the causes through which1 man evolved   
from a lower form4 ,precisely the same  
causes are here suggested for the origin
 of man1 as for the origin of species in
 general4 ,variability1 which is a      
necessary assumption in regard to all   
transformations1 occurs in man to a high
 degree4 ,moreover1 the rapid           
multiplication of the human race creates
 conditions which necessitate an        
energetic struggle for existence1 and   
thus afford scope for the intervention  
of natural selection4 ,of the exercise  
of ,,artificial selection in the human  
race1 there is nothing to be said1      
unless we cite such cases as the        
grenadiers of ,frederick ,william ,i1 or
 the population of ancient ,sparta4 ,in 
the passages already referred to and in 
those which follow1 the transmission of 
acquired characters1 upon which ,darwin 
does not dwell1 is taken for granted4   
,in man1 direct effects of changed      
conditions can be demonstrated 7for     

instance in regard to bodily size71 and 
there are also proofs of the influence  
exerted on his physical constitution by 
increased use or disuse4 ,reference is  
here made to the fact1 established by   
,forbes1 that the ,quechua-,indians of  
the high plateaus of ,peru show a       
striking development of lungs and       
thorax1 as a result of living constantly
 at high altitudes4  ,such special forms
 of variation as arrests of development 
7microcephalism7 and reversion to lower 
forms are next discussed4 ,darwin       
himself felt 7,descent of ,man1 page    
#ed47 that these subjects are so nearly 
related to the cases mentioned in the   
first chapter1 that many of them might  
as well have been dealt with there4 ,it 
seems to me that it would have been     
better so1 for the citation of          
additional instances of reversion at    
this place rather disturbs the logical  
sequence of his ideas as to the         
conditions which have brought about the 
evolution of man from lower forms4 ,the 

instances of reversion here discussed   
are microcephalism1 which ,darwin       
wrongly interpreted as atavistic1       
supernumerary mammae1 supernumerary     
digits1 bicornuate uterus1 the          
development of abnormal muscles1 and so 
on4 ,brief mention is also made of      
correlative variations observed in man4 
,darwin next discusses the question as  
to the manner in which man attained to  
the erect position from the state of a  
climbing quadruped4 ,here again he puts 
the influence of ,natural ,selection in 
the first rank4 ,the immediate          
progenitors of man had to maintain a    
struggle for existence in which success 
was to the more intelligent1 and to     
those with social instincts4 ,the hand  
of these climbing ancestors1 which had  
little skill and served mainly for      
locomotion1 could only undergo further  
development when some early member of   
the ,primate series came to live more on
 the ground and less among trees4  ,a   
bipedal existence thus became possible1 

and with it the liberation of the hand  
from locomotion1 and the one-sided      
development of the human foot4 ,the     
upright position brought about          
correlated variations in the bodily     
structure2 with the free use of the hand
 it became possible to manufacture      
weapons and to use them2 and this again 
resulted in a degeneration of the       
powerful canine teeth and the jaws1     
which were then no longer necessary for 
defence4 ,above all1 however1 the       
intelligence immediately increased1 and 
with it skull and brain4 ,the nakedness 
of man1 and the absence of a tail       
7rudimentariness of the tail vertebrae7 
are next discussed4 ,darwin is inclined 
to attribute the nakedness of man1 not  
to the action of natural selection on   
ancestors who originally inhabited a    
tropical land1 but to sexual selection1 
which1 for aesthetic reasons1 brought   
about the loss of the hairy covering in 
man1 or primarily in woman4 ,an         
interesting discussion of the loss of   

the tail1 which1 however1 man shares    
with the anthropoid apes1 some other    
monkeys and lemurs1 forms the conclusion
 of the almost superabundant material   
which ,darwin worked up in the second   
chapter4 ,his object was to show that   
some of the most distinctive human      
characters are in all probability       
directly or indirectly due to natural   
selection4 ,with characteristic modesty 
he adds 7,descent of ,man1 page #ib473  
,hence1 if ,i have erred in giving to   
natural selection great power1 which ,i 
am very far from admitting1 or in having
 exaggerated its power1 which is in     
itself probable1 ,i have at least1 as ,i
 hope1 done good service in aiding to   
overthrow the dogma of separate         
creations4 ,at the end of the chapter he
 touches upon the objection as to man's 
helpless and defenceless condition4     
,against this he urges his intelligence 
and social instincts4  ,the two         
following chapters contain a detailed   
discussion of the objections drawn from 

the supposed great differences between  
the mental powers of men and animals4   
,darwin at once admits that the         
differences are enormous1 but not that  
any fundamental difference between the  
two can be found4 ,very characteristic  
of him is the following passage3 ,in    
what manner the mental powers were first
 developed in the lowest organisms1 is  
as hopeless an enquiry as how life      
itself first originated4 ,these are     
problems for the distant future1 if they
 are ever to be solved by man4 7,ibid4  
page #ajj47  ,after some brief          
observations on instinct and            
intelligence1 ,darwin brings forward    
evidence to show that the greater number
 of the emotional states1 such as       
pleasure and pain1 happiness and misery1
 love and hate are common to man and the
 higher animals4 ,he goes on to give    
various examples showing that wonder and
 curiosity1 imitation1 attention1 memory
 and imagination 7dreams of animals71   
can also be observed in the higher      

mammals1 especially in apes4 ,in regard 
even to reason there are no sharply     
defined limits4 ,a certain faculty of   
deliberation is characteristic of some  
animals1 and the more thoroughly we know
 an animal the more intelligence we are 
inclined to credit it with4 ,examples   
are brought forward of the intelligent  
and deliberate actions of apes1 dogs and
 elephants4 ,but although no sharply    
defined differences exist between man   
and animals1 there is1 nevertheless1 a  
series of other mental powers which are 
characteristics usually regarded as     
absolutely peculiar to man4 ,some of    
these characteristics are examined in   
detail1 and it is shown that the        
arguments drawn from them are not       
conclusive4 ,man alone is said to be    
capable of progressive improvement2 but 
against this must be placed as something
 analogous in animals1 the fact that    
they learn cunning and caution through  
long continued persecution4 ,even the   
use of tools is not in itself peculiar  

to man 7monkeys use sticks1 stones and  
twigs71 but man alone fashions and uses 
implements ,,designed ,,for ,a ,,special
 ,,purpose4 ,in this connection the     
remarks taken from ,lubbock in regard to
 the origin and gradual development of  
the earliest flint implements will be   
read with interest2 these are similar to
 the observations on modern eoliths1 and
 their bearing on the development of the
 stone-industry4 ,it is interesting to  
learn from a letter to ,hooker 7,life   
and ,letters1 ,vol4 ,,ii4 page #afa1    
,june #bb1 #ahei471 that ,darwin himself
 at first doubted whether the stone     
implements discovered by ,boucher de    
,perthes were really of the nature of   
tools4 ,with the relentless candour as  
to himself which characterised him1 he  
writes four years later in a letter to  
,lyell in regard to this view of        
,boucher de ,perthes' discoveries3 ,i   
know something about his errors1 and    
looked at his book many years ago1 and  
am ashamed to think that ,i concluded   

the whole was rubbish6 ,yet he has done 
for man something like what ,agassiz did
 for glaciers4 7,ibid4 ,vol4 ,,iii4 page
 #ae1 ,march #ag1 #ahfc47  ,to return to
 ,darwin's further comparisons between  
the higher mental powers of man and     
animals4 ,he takes much of the force    
from the argument that man alone is     
capable of abstraction and              
self-consciousness by his own           
observations on dogs4 ,one of the main  
differences between man and animals1    
speech1 receives detailed treatment4 ,he
 points out that various animals 7birds1
 monkeys1 dogs7 have a large number of  
different sounds for different emotions1
 that1 further1 man produces in common  
with animals a whole series of          
inarticulate cries combined with        
gestures1 and that dogs learn to        
understand whole sentences of human     
speech4 ,in regard to human language1   
,darwin expresses a view contrary to    
that held by ,max ,muller 7,descent of  
,man1 page #acb473 ,i cannot doubt that 

language owes its origin to the         
imitation and modification of various   
natural sounds1 the voices of other     
animals1 and man's own instinctive      
cries1 aided by signs and gestures4 ,the
 development of actual language         
presupposes a higher degree of          
intelligence than is found in any kind  
of ape4 ,darwin remarks on this point   
7,ibid4 pages #acf1 #acg473 ,the fact of
 the higher apes not using their vocal  
organs for speech no doubt depends on   
their intelligence not having been      
sufficiently advanced4  ,the sense of   
beauty1 too1 has been alleged to be     
peculiar to man4 ,in refutation of this 
assertion ,darwin points to the         
decorative colours of birds1 which are  
used for display4 ,and to the last      
objection1 that man alone has religion1 
that he alone has a belief in ,god1 it  
is answered that numerous races have    
existed1 and still exist1 who have no   
idea of one or more gods1 and who have  
no words in their languages to express  

such an idea4 7,ibid4 page #adc47  ,the 
result of the investigations recorded in
 this chapter is to show that1 great as 
the difference in mental powers between 
man and the higher animals may be1 it is
 undoubtedly only a difference of degree
 and not of kind4 7,descent of ,man1    
page #aic47  ,in the fourth chapter     
,darwin deals with the ,,moral ,,sense  
or ,,conscience1 which is the most      
important of all differences between man
 and animals4 ,it is a result of social 
instincts1 which lead to sympathy for   
other members of the same society1 to   
non-egoistic actions for the good of    
others4 ,darwin shows that social       
tendencies are found among many animals1
 and that among these love and          
kin-sympathy exist1 and he gives        
examples of animals 7especially dogs7   
which may exhibit characters that we    
should call moral in man 7e4g4          
disinterested self-sacrifice for the    
sake of others74 ,the early ape-like    
progenitors of the human race were      

undoubtedly social4 ,with the increase  
of intelligence the moral sense develops
 farther2 with the acquisition of speech
 public opinion arises1 and finally1    
moral sense becomes habit4 ,the rest of 
,darwin's detailed discussions on moral 
philosophy may be passed over4  ,the    
fifth chapter may be very briefly       
summarised4 ,in it ,darwin shows that   
the intellectual and moral faculties are
 perfected through natural selection4   
,he inquires how it can come about that 
a tribe at a low level of evolution     
attains to a higher1 although the best  
and bravest among them often pay for    
their fidelity and courage with their   
lives without leaving any descendants4  
,in this case it is the sentiment of    
glory1 praise and blame1 the admiration 
of others1 which bring about the        
increase of the better members of the   
tribe4 ,property1 fixed dwellings1 and  
the association of families into a      
community are also indispensable        
requirements for civilisation4 ,in the  

longer second section of the fifth      
chapter ,darwin acts mainly as recorder4
 ,on the basis of numerous              
investigations1 especially those of     
,greg1 ,wallace1 and ,galton1 he        
inquires how far the influence of       
natural selection can be demonstrated in
 regard to civilised nations4 ,in the   
final section1 which deals with the     
proofs that all civilised nations were  
once barbarians1 ,darwin again uses the 
results gained by other investigators1  
such as ,lubbock and ,tylor4 ,there are 
two sets of facts which prove the       
proposition in question4 ,in the first  
place1 we find traces of a former lower 
state in the customs and beliefs of all 
civilised nations1 and in the second    
place1 there are proofs to show that    
savage races are independently able to  
raise themselves a few steps in the     
scale of civilisation1 and that they    
have thus raised themselves4  ,in the   
sixth chapter of the work1 ,morphology  
comes into the foreground once more4    

,darwin first goes back1 however1 to the
 argument based on the great difference 
between the mental powers of the highest
 animals and those of man4 ,that this is
 only quantitative1 not qualitative1 he 
has already shown4 ,very instructive in 
this connection is the reference to the 
enormous difference in mental powers in 
another class4 ,no one would draw from  
the fact that the cochineal insect      
7,coccus7 and the ant exhibit enormous  
differences in their mental powers1 the 
conclusion that the ant should therefore
 be regarded as something quite         
distinct1 and withdrawn from the class  
of insects altogether4  ,darwin next    
attempts to establish the ,,specific    
genealogical tree of man1 and carefully 
weighs the differences and resemblances 
between the different families of the   
,primates4 ,the erect position of man is
 an adaptive character1 just as are the 
various characters referable to aquatic 
life in the seals1 which1               
notwithstanding these1 are ranked as a  

mere family of the ,carnivores4 ,the    
following utterance is very             
characteristic of ,darwin 7,descent of  
,man1 page #bca473 ,if man had not been 
his own classifier1 he would never have 
thought of founding a separate order for
 his own reception4 ,in numerous        
characters not mentioned in systematic  
works1 in the features of the face1 in  
the form of the nose1 in the structure  
of the external ear1 man resembles the  
apes4 ,the arrangement of the hair in   
man has also much in common with the    
apes2 as also the occurrence of hair on 
the forehead of the human embryo1 the   
beard1 the convergence of the hair of   
the upper and under arm towards the     
elbow1 which occurs not only in the     
anthropoid apes1 but also in some       
,american monkeys4 ,darwin here adopts  
,wallace's explanation of the origin of 
the ascending direction of the hair in  
the forearm of the orang1--that it has  
arisen through the habit of holding the 
hands over the head in rain4 ,but this  

explanation cannot be maintained when we
 consider that this disposition of the  
hair is widely distributed among the    
most different mammals1 being found in  
the dog1 in the sloth1 and in many of   
the lower monkeys4  ,after further      
careful analysis of the anatomical      
characters ,darwin reaches the          
conclusion that the ,new ,world monkeys 
7,platyrrhine7 may be excluded from the 
genealogical tree altogether1 but that  
man is an offshoot from the ,old ,world 
monkeys 7,catarrhine7 whose progenitors 
existed as far back as the ,miocene     
period4 ,among these ,old ,world monkeys
 the forms to which man shows the       
greatest resemblance are the anthropoid 
apes1 which1 like him1 possess neither  
tail nor ischial callosities4 ,the      
platyrrhine and catarrhine monkeys have 
their primitive ancestor among extinct  
forms of the ,lemuridae4 ,darwin also   
touches on the question of the original 
home of the human race and supposes that
 it may have been in ,africa1 because it

 is there that man's nearest relatives1 
the gorilla and the chimpanzee1 are     
found4 ,but he regards speculation on   
this point as useless4 ,it is remarkable
 that1 in this connection1 ,darwin      
regards the loss of the hair-covering in
 man as having some relation to a warm  
climate1 while elsewhere he is inclined 
to make sexual selection responsible for
 it4 ,darwin recognises the great gap   
between man and his nearest relatives1  
but similar gaps exist at other parts of
 the mammalian genealogical tree3 the   
allied forms have become extinct4 ,after
 the extermination of the lower races of
 mankind1 on the one hand1 and of the   
anthropoid apes on the other1 which will
 undoubtedly take place1 the gulf will  
be greater than ever1 since the baboons 
will then bound it on the one side1 and 
the white races on the other4 ,little   
weight need be attached to the lack of  
fossil remains to fill up this gap1     
since the discovery of these depends    
upon chance4 ,the last part of the      

chapter is devoted to a discussion of   
the earlier stages in the genealogy of  
man4 ,here ,darwin accepts in the main  
the genealogical tree1 which had        
meantime been published by ,haeckel1 who
 traces the pedigree back through       
,monotremes1 ,reptiles1 ,amphibians1 and
 ,fishes1 to ,amphioxus4  ,then follows 
an attempt to reconstruct1 from the     
atavistic characters1 a picture of our  
primitive ancestor who was undoubtedly  
an arboreal animal4 ,the occurrence of  
rudiments of parts in one sex which only
 come to full development in the other  
is next discussed4 ,this state of things
 ,darwin regards as derived from an     
original hermaphroditism4 ,in regard to 
the mammary glands of the male he does  
not accept the theory that they are     
vestigial1 but considers them rather as 
not fully developed4  ,the last chapter 
of ,part ,i deals with the question     
whether the different races of man are  
to be regarded as different species1 or 
as sub-species of a race of monophyletic

 origin4 ,the striking differences      
between the races are first emphasised1 
and the question of the fertility or    
infertility of hybrids is discussed4    
,that fertility is the more usual is    
shown by the excessive fertility of the 
hybrid population of ,brazil4 ,this1 and
 the great variability of the           
distinguishing characters of the        
different races1 as well as the fact    
that all grades of transition stages are
 found between these1 while considerable
 general agreement exists1 tell in      
favour of the unity of the races and    
lead to the conclusion that they all had
 a common primitive ancestor4  ,darwin  
therefore classifies all the different  
races as sub-species of ,,one ,,and     
,,the ,,same ,,species4 ,then follows an
 interesting inquiry into the reasons   
for the extinction of human races4 ,he  
recognises as the ultimate reason the   
injurious effects of a change of the    
conditions of life1 which may bring     
about an increase in infantile          

mortality1 and a diminished fertility4  
,it is precisely the reproductive       
system1 among animals also1 which is    
most susceptible to changes in the      
environment4  ,the final section of this
 chapter deals with the formation of the
 races of mankind4 ,darwin discusses the
 question how far the direct effect of  
different conditions of life1 or the    
inherited effects of increased use or   
disuse may have brought about the       
characteristic differences between the  
different races4 ,even in regard to the 
origin of the colour of the skin he     
rejects the transmitted effects of an   
original difference of climate as an    
explanation4 ,in so doing he is         
following his tendency to exclude       
,lamarckian explanations as far as      
possible4 ,but here he makes gratuitous 
difficulties from which1 since natural  
selection fails1 there is no escape     
except by bringing in the principle of  
sexual selection1 to which1 he regarded 
it as possible1 skin-colouring1         

arrangement of hair1 and form of        
features might be traced4 ,but with his 
characteristic conscientiousness he     
guards himself thus3 ,i do not intend to
 assert that sexual selection will      
account for all the differences between 
the races4 7,descent of ,man1 page      
#cjh47  ,i may be permitted a remark as 
to ,darwin's attitude towards ,lamarck4 
,while1 at an earlier stage1 when he was
 engaged in the preliminary labours for 
his immortal work1 ,the ,origin of      
,species1 ,darwin expresses himself very
 forcibly against the views of ,lamarck1
 speaking of ,lamarckian nonsense1      
7,life and ,letters1 ,vol4 ,,ii4 page   
#bc471 and of ,lamarck's absurd1 though 
clever work 7,loc4 cit4 page #ci47 and  
expressly declaring1 ,i attribute very  
little to the direct action of climate1 
etc4 7,loc4 cit4 7#ahef71 page #hb47 yet
 in later life he became more and more  
convinced of the influence of external  
conditions4 ,in #ahgf1 that is1 two     
years after the appearance of the second

 edition of ,the ,descent of ,man1 he   
writes with his usual candid honesty3   
,in my opinion the greatest error which 
,i have committed1 has been not allowing
 sufficient weight to the direct action 
of the environment1 i4e4 food1 climate1 
etc4 independently of natural selection4
 7,ibid4 ,vol4 ,,iii4 page #aei47 ,it is
 certain from this change of opinion    
that1 if he had been able to make up his
 mind to issue a third edition of ,the  
,descent of ,man1 he would have ascribed
 a much greater influence to the effect 
of external conditions in explaining the
 different characters of the races of   
man than he did in the second edition4  
,he would also undoubtedly have         
attributed less influence to sexual     
selection as a factor in the origin of  
the different bodily characteristics1 if
 indeed he would not have excluded it   
altogether4  ,in ,part ,,iii of the     
,descent two additional chapters are    
devoted to the discussion of sexual     
selection in relation to man4 ,these may

 be very briefly referred to4 ,darwin   
here seeks to show that sexual selection
 has been operative on man and his      
primitive progenitor4 ,space fails me to
 follow out his interesting arguments4  
,i can only mention that he is inclined 
to trace back hairlessness1 the         
development of the beard in man1 and the
 characteristic colour of the different 
human races to sexual selection4 ,since 
bareness of the skin could be no        
advantage1 but rather a disadvantage1   
this character cannot have been brought 
about by natural selection4 ,darwin also
 rejected a direct influence of climate 
as a cause of the origin of the         
skin-colour4 ,i have already expressed  
the opinion1 based on the development of
 his views as shown in his letters1 that
 in a third edition ,darwin would       
probably have laid more stress on the   
influence of external environment4 ,he  
himself feels that there are gaps in his
 proofs here1 and says in               
self-criticism3 ,the views here         

advanced1 on the part which sexual      
selection has played in the history of  
man1 want scientific precision4         
7,descent of ,man1 page #ibd47 ,i need  
here only point out that it is          
impossible to explain the graduated     
stages of skin-colour by sexual         
selection1 since it would have produced 
races sharply defined by their colour   
and not united to other races by        
transition stages1 and this1 it is well 
known1 is not the case4 ,moreover1 the  
fact established by me 7,die ,hautfarbe 
des ,menschen1 ,mitteilungen der        
,anthropologischen ,gesellschaft in     
,wien1 ,vol4 ,,xxxiv4 pages #cca-ceb471 
that in all races the ventral side of   
the trunk is paler than the dorsal side1
 and the inner surface of the           
extremities paler than the outer side1  
cannot be explained by sexual selection 
in the ,darwinian sense4  ,with this ,i 
conclude my brief survey of the rich    
contents of ,darwin's book4 ,i may be   
permitted to conclude by quoting the    

magnificent final words of ,the ,descent
 of ,man3 ,we must1 however1            
acknowledge1 as it seems to me1 that    
man1 with all his noble qualities1 with 
sympathy which feels for the most       
debased1 with benevolence which extends 
not only to other men but to the        
humblest living creature1 with his      
god-like intellect which has penetrated 
into the movements and constitution of  
the solar system--with all these exalted
 powers--,man still bears in his bodily 
frame the indelible stamp of his lowly  
origin4 7,ibid4 page #idg47  ,what has  
been the fate of ,darwin's doctrines    
since his great achievement8 ,how have  
they been received and followed up by   
the scientific and lay world8 ,and what 
do the successors of the mighty hero and
 genius think now in regard to the      
origin of the human race8  ,at the      
present time we are incomparably more   
favourably placed than ,darwin was for  
answering this question of all          
questions4 ,we have at our command an   

incomparably greater wealth of material 
than he had at his disposal4 ,and we are
 more fortunate than he in this respect1
 that we now know transition-forms which
 help to fill up the gap1 still great1  
between the lowest human races and the  
highest apes4 ,let us consider for a    
little the more essential additions to  
our knowledge since the publication of  
,the ,descent of ,man4  ,since that time
 our knowledge of animal embryos has    
increased enormously4 ,while ,darwin was
 obliged to content himself with        
comparing a human embryo with that of a 
dog1 there are now available the        
youngest embryos of monkeys of all      
possible groups 7,orang1 ,gibbon1       
,semnopithecus1 ,macacus71 thanks to    
,selenka's most successful tour in the  
,east ,indies in search of such         
material4 ,we can now compare           
corresponding stages of the lower       
monkeys and of the ,anthropoid apes with
 human embryos1 and convince ourselves  
of their great resemblance to one       

another1 thus strengthening enormously  
the armour prepared by ,darwin in       
defence of his view on man's nearest    
relatives4 ,it may be said that         
,selenka's material fils up the blanks  
in ,darwin's array of proofs in the most
 satisfactory manner4  ,the deepening of
 our knowledge of comparative anatomy   
also gives us much surer foundations    
than those on which ,darwin was obliged 
to build4 ,just of late there have been 
many workers in the domain of the       
anatomy of apes and lemurs1 and their   
investigations extend to the most       
different organs4 ,our knowledge of     
fossil apes and lemurs has also become  
much wider and more exact since         
,darwin's time3 the fossil lemurs have  
been especially worked up by ,cope1     
,forsyth ,major1 ,ameghino1 and others4 
,darwin knew very little about fossil   
monkeys4 ,he mentions two or three      
anthropoid apes as occurring in the     
,miocene of ,europe 7,descent of ,man1  
page #bdj471 but only names             

,dryopithecus1 the largest form from the
 ,miocene of ,france4 ,it was           
erroneously supposed that this form was 
related to ,hylobates4 ,we now know not 
only a form that actually stands near to
 the gibbon 7,pliopithecus71 and remains
 of other anthropoids 7,pliohylobates   
and the fossil chimpanzee1              
,palaeopithecus71 but also several lower
 catarrhine monkeys1 of which           
,mesopithecus1 a form nearly related to 
the modern ,sacred ,monkeys 7a species  
of ,semnopithecus7 and found in strata  
of the ,miocene period in ,greece1 is   
the most important4 ,quite recently1    
too1 ,ameghino's investigations have    
made us acquainted with fossil monkeys  
from ,south ,america 7,anthropops1      
,homunculus71 which1 according to their 
discoverer1 are to be regarded as in the
 line of human descent4  ,what ,darwin  
missed most of all--intermediate forms  
between apes and man--has been recently 
furnished4 7,e4 ,dubois1 as is well     
known1 discovered in #ahic1 near ,trinil

 in ,java1 in the alluvial deposits of  
the river ,bengawan1 an important form  
represented by a skull-cap1 some molars1
 and a femur4 ,his opinion--much        
disputed as it has been--that in this   
form1 which he named ,pithecanthropus1  
he has found a long-desired             
transition-form is shared by the present
 writer4 ,and although the geological   
age of these fossils1 which1 according  
to ,dubois1 belong to the uppermost     
,tertiary series1 the ,pliocene1 has    
recently been fixed at a later date 7the
 older ,diluvium771 the ,,morphological 
,,value of these interesting remains1   
that is1 the intermediate position of   
,pithecanthropus1 still holds good4     
,volz says with justice 7,das           
geologische ,alter der                  
,pithecanthropus-,schichten bei ,trinil1
 ,ost-,java4 ,neues ,jahrb4             
f4,mineralogie4 ,festband1 #aijg471 that
 even if ,pithecanthropus is not ,,the  
missing link1 it is undoubtedly ,a      
missing link4  ,as on the one hand there

 has been found in ,pithecanthropus a   
form which1 though intermediate between 
apes and man1 is nevertheless more      
closely allied to the apes1 so on the   
other hand1 much progress has been made 
since ,darwin's day in the discovery and
 description of the older human remains4
 ,since the famous roof of a skull and  
the bones of the extremities belonging  
to it were found in #ahef in the        
,neandertal near ,dusseldorf1 the most  
varied judgments have been expressed in 
regard to the significance of the       
remains and of the skull in particular4 
,in ,darwin's ,descent of ,man there is 
only a passing allusion to them         
7,descent of ,man1 page #hb47 in        
connection with the discussion of the   
skull-capacity1 although the            
investigations of ,schaaffhausen1 ,king1
 and ,huxley were then known4 ,i believe
 ,i have shown1 in a series of papers1  
that the skull in question belongs to a 
form different from any of the races of 
man now living1 and1 with ,king and     

,cope1 ,i regard it as at least a       
different species from living man1 and  
have therefore designated it ,homo      
primigenius4 ,the form unquestionably   
belongs to the older ,diluvium1 and in  
the later ,diluvium human forms already 
appear1 which agree in all essential    
points with existing human races4  ,as  
far back as #ahhf the value of the      
,neandertal skull was greatly enhanced  
by ,fraipont's discovery of two skulls  
and skeletons from ,spy in ,belgium4    
,these are excellently described by     
their discoverer 7,la race humaine de   
,neanderthal ou de ,canstatt en         
,belgique4 ,arch4 de ,biologie1 ,,vii4  
#ahhg471 and are regarded as belonging  
to the same group of forms as the       
,neandertal remains4 ,in #ahii and the  
following years came the discovery by   
,gorjanovic-,kramberger of different    
skeletal parts of at least ten          
individuals in a cave near ,krapina in  
,croatia4 7,gorjanovic-,kramberger ,der 
diluviale ,mensch von ,krapina in       

,kroatien1 #aijf47 ,it is in particular 
the form of the lower jaw which is      
different from that of all recent races 
of man1 and which clearly indicates the 
lowly position of ,homo primigenius1    
while1 on the other hand1 the long-known
 skull from ,gibraltar1 which ,i        
7,studien zur ,vorgeschichte des        
,menschen1 #aijf1 pages #aed ff47 have  
referred to ,homo primigenius1 and which
 has lately been examined in detail by  
,sollas 7,on the cranial and facial     
characters of the ,neandertal ,race4    
,trans4 ,r4 ,soc4 ,london1 vol4 #aii1   
#aijh1 page #bha471 has made us         
acquainted with the surprising shape of 
the eye-orbit1 of the nose1 and of the  
whole upper part of the face4 ,isolated 
lower jaws found at ,la ,naulette in    
,belgium1 and at ,malarnaud in ,france1 
increase our material which is now as   
abundant as could be desired4 ,the most 
recent discovery of all is that of a    
skull dug up in ,august of this year    
7#aijh7 by ,klaatsch and ,hauser in the 

lower grotto of the ,le ,moustier in    
,southern ,france1 but this skull has   
not yet been fully described4 ,thus     
,homo primigenius must also be regarded 
as occupying a position in the gap      
existing between the highest apes and   
the lowest human races1                 
,pithecanthropus1 standing in the lower 
part of it1 and ,homo primigenius in the
 higher1 near man4 ,in order to prevent 
misunderstanding1 ,i should like here to
 emphasise that in arranging this       
structural series--anthropoid apes1     
,pithecanthropus1 ,homo primigenius1    
,homo sapiens--,i have no intention of  
establishing it as a direct genealogical
 series4 ,i shall have something to say 
in regard to the genetic relations of   
these forms1 one to another1 when       
discussing the different theories of    
descent current at the present day4     
77,since this essay was written         
,schoetensack has discovered near       
,heidelberg and briefly described an    
exceedingly interesting lower jaw from  

rocks between the ,pliocene and         
,diluvial beds4 ,this exhibits          
interesting differences from the forms  
of lower jaw of ,homo primigenius4      
7,schoetensack ,der ,unterkiefer des    
,homo heidelbergensis4 ,leipzig1 #aijh47
 ,g4,s477  ,in quite a different domain 
from that of morphological relationship1
 namely in the physiological study of   
the blood1 results have recently been   
gained which are of the highest         
importance to the doctrine of descent4  
,uhlenhuth1 ,nuttall1 and others have   
established the fact that the           
blood-serum of a rabbit which has       
previously had human blood injected into
 it1 forms a precipitate with human     
blood4 ,this biological reaction was    
tried with a great variety of mammalian 
species1 and it was found that those far
 removed from man gave no precipitate   
under these conditions4 ,but as in other
 cases among mammals all nearly related 
forms yield an almost equally marked    
precipitate1 so the serum of a rabbit   

treated with human blood and then added 
to the blood of an anthropoid ape gives 
,,almost as marked a precipitate as in  
human blood2 the reaction to the blood  
of the lower ,eastern monkeys is weaker1
 that to the ,western monkeys weaker    
still2 indeed in this last case there is
 only a slight clouding after a         
considerable time and no actual         
precipitate4 ,the blood of the          
,lemuridae 7,nuttall7 gives no reaction 
or an extremely weak one1 that of the   
other mammals none whatever4 ,we have in
 this not only a proof of the literal   
blood-relationship between man and apes1
 but the degree of relationship with the
 different main groups of apes can be   
determined beyond possibility of        
mistake4  ,finally1 it must be briefly  
mentioned that in regard to remains of  
human handicraft also1 the material at  
our disposal has greatly increased of   
late years1 that1 as a result of this1  
the opinions of archaeologists have     
undergone many changes1 and that1 in    

particular1 their views in regard to the
 age of the human race have been greatly
 influenced4 ,there is a tendency at the
 present time to refer the origin of man
 back to ,tertiary times4 ,it is true   
that no remains of ,tertiary man have   
been found1 but flints have been        
discovered which1 according to the      
opinion of most investigators1 bear     
traces either of use1 or of very        
primitive workmanship4 ,since ,rutot's  
time1 following ,mortillet's example1   
investigators have called these eoliths1
 and they have been traced back by      
,verworn to the ,miocene of the         
,auvergne1 and by ,rutot even to the    
upper ,oligocene4 ,although these       
eoliths are even nowadays the subject of
 many different views1 the preoccupation
 with them has kept the problem of the  
age of the human race continually before
 us4  ,geology1 too1 has made great     
progress since the days of ,darwin and  
,lyell1 and has endeavoured with        
satisfactory results to arrange the     

human remains of the ,diluvial period in
 chronological order 7,penck74 ,i do not
 intend to enter upon the question of   
the primitive home of the human race2   
since the space at my disposal will not 
allow of my touching even very briefly  
upon all the departments of science     
which are concerned in the problem of   
the descent of man4 ,how ,darwin would  
have rejoiced over each of the          
discoveries here briefly outlined6 ,what
 use he would have made of the new and  
precious material1 which would have     
prevented the discouragement from which 
he suffered when preparing the second   
edition of ,the ,descent of ,man6 ,but  
it was not granted to him to see this   
progress towards filling up the gaps in 
his edifice of which he was so painfully
 conscious4  ,he did1 however1 have the 
satisfaction of seeing his ideas        
steadily gaining ground1 notwithstanding
 much hostility and deep-rooted         
prejudice4 ,even in the years between   
the appearance of ,the ,origin of       

,species and of the first edition of the
 ,descent1 the idea of a natural descent
 of man1 which was only briefly         
indicated in the work of #ahei1 had been
 eagerly welcomed in some quarters4 ,it 
has been already pointed out how        
brilliantly ,huxley contributed to the  
defence and diffusion of ,darwin's      
doctrines1 and how in ,man's ,place in  
,nature he has given us a classic work  
as a foundation for the doctrine of the 
descent of man4 ,as ,huxley was         
,darwin's champion in ,england1 so in   
,germany ,carl ,vogt1 in particular1    
made himself master of the ,darwinian   
ideas4 ,but above all it was ,haeckel   
who1 in energy1 eagerness for battle1   
and knowledge may be placed side by side
 with ,huxley1 who took over the        
leadership in the controversy over the  
new conception of the universe4 ,as far 
back as #ahff1 in his ,generelle        
,morphologie1 he had inquired minutely  
into the question of the descent of man1
 and not content with urging merely the 

general theory of descent from lower    
animal forms1 he drew up for the first  
time genealogical trees showing the     
close relationships of the different    
animal groups2 the last of these        
illustrated the relationships of        
,mammals1 and among them of all groups  
of the ,primates1 including man4 ,it was
 ,haeckel's genealogical trees that     
formed the basis of the special         
discussion of the relationships of man1 
in the sixth chapter of ,darwin's       
,descent of ,man4  ,in the last section 
of this essay ,i shall return to        
,haeckel's conception of the special    
descent of man1 the main features of    
which he still upholds1 and rightly so4 
,haeckel has contributed more than any  
one else to the spread of the ,darwinian
 doctrine4  ,i can only allow myself a  
few words as to the spread of the theory
 of the natural descent of man in other 
countries4 ,the ,parisian               
anthropological school1 founded and     
guided by the genius of ,broca1 took up 

the idea of the descent of man1 and made
 many notable contributions to it       
7,broca1 ,manouvrier1 ,mahoudeau1       
,deniker and others74 ,in ,england      
itself ,darwin's work did not die4      
,huxley took care of that1 for he1 with 
his lofty and unprejudiced mind1        
dominated and inspired ,english biology 
until his death on ,june #bi1 #ahie4 ,he
 had the satisfaction shortly before his
 death of learning of ,dubois'          
discovery1 which he illustrated by a    
humorous sketch4 7,life and ,letters of 
,thomas ,henry ,huxley1 ,vol4 ,,ii4 page
 #cid47 ,but there are still many       
followers in ,darwin's footsteps in     
,england4 ,keane has worked at the      
special genealogical tree of the        
,primates2 ,keith has inquired which of 
the anthropoid apes has the greatest    
number of characters in common with man2
 ,morris concerns himself with the      
evolution of man in general1 especially 
with his acquisition of the erect       
position4 ,the recent discoveries of    

,pithecanthropus and ,homo primigenius  
are being vigorously discussed2 but the 
present writer is not in a position to  
form an opinion of the extent to which  
the idea of descent has penetrated      
throughout ,england generally4  ,in     
,italy independent work in the domain of
 the descent of man is being produced1  
especially by ,morselli2 with him are   
associated1 in the investigation of     
related problems1 ,sergi and            
,giuffrida-,ruggeri4 ,from the ranks of 
,american investigators we may single   
out in particular the eminent geologist 
,cope1 who championed with much decision
 the idea of the specific difference of 
,homo neandertalensis 7primigenius7 and 
maintained a more direct descent of man 
from the fossil ,lemuridae4 ,in ,south  
,america too1 in ,argentina1 new life is
 stirring in this department of science4
 ,ameghino in ,buenos ,ayres has        
awakened the fossil primates of the     
,pampas formation to new life2 he even  
believes that in ,tetraprothomo1        

represented by a femur1 he has          
discovered a direct ancestor of man4    
,lehmann-,nitsche is working at the     
other side of the gulf between apes and 
men1 and he describes a remarkable first
 cervical vertebra 7atlas7 from ,monte  
,hermoso as belonging to a form which   
may bear the same relation to ,homo     
sapiens in ,south ,america as ,homo     
primigenius does in the ,old ,world4    
,after a minute investigation he        
establishes a human species ,homo       
neogaeus1 while ,ameghino ascribes this 
atlas vertebra to his ,tetraprothomo4   
,thus throughout the whole scientific   
world there is arising a new life1 an   
eager endeavour to get nearer to        
,huxley's problema maximum1 to penetrate
 more deeply into the origin of the     
human race4 ,there are to-day very few  
experts in anatomy and zoology who deny 
the animal descent of man in general4   
,religious considerations1 old          
prejudices1 the reluctance to accept    
man1 who so far surpasses mentally all  

other creatures1 as descended from      
soulless animals1 prevent a few         
investigators from giving full adherence
 to the doctrine4 ,but there are very   
few of these who still postulate a      
special act of creation for man4        
,although the majority of experts in    
anatomy and zoology accept              
unconditionally the descent of man from 
lower forms1 there is much diversity of 
opinion among them in regard to the     
special line of descent4  ,in trying to 
establish any special hypothesis of     
descent1 whether by the graphic method  
of drawing up genealogical trees or     
otherwise1 let us always bear in mind   
,darwin's words 7,descent of ,man1 page 
#bbi47 and use them as a critical       
guiding line3 ,as we have no record of  
the lines of descent1 the pedigree can  
be discovered only by observing the     
degrees of resemblance between the      
beings which are to be classed4 ,darwin 
carries this further by stating that    
resemblances in several unimportant     

structures1 in useless and rudimentary  
organs1 or not now functionally active1 
or in an embryological condition1 are by
 far the most serviceable for           
classification4 7,loc4 cit47 ,it has    
also to be remembered that ,,numerous   
separate points of agreement are of much
 greater importance than the amount of  
similarity or dissimilarity in a few    
points4  ,the hypotheses as to descent  
current at the present day may be       
divided into two main groups4 ,the first
 group seeks for the roots of the human 
race not among any of the families of   
the apes--the anatomically nearest      
forms--nor among their very similar but 
less specialised ancestral forms1 the   
fossil representatives of which we can  
know only in part1 but1 setting the     
monkeys on one side1 it seeks for them  
lower down among the fossil ,eocene     
,pseudo-lemuridae or ,lemuridae 7,cope71
 or even among the primitive            
pentadactylous ,eocene forms1 which may 
either have led directly to the         

evolution of man 7,adloff71 or have     
given rise to an ancestral form common  
to apes and men 7,klaatsch 7,klaatsch in
 his last publications speaks in the    
main only of an ancestral form common to
 men and anthropoid apes471             
,giuffrida-,ruggeri74 ,the common       
ancestral form1 from which man and apes 
are thus supposed to have arisen        
independently1 may explain the numerous 
resemblances which actually exist       
between them4 ,that is to say1 all the  
characters upon which the great         
structural resemblance between apes and 
man depends must have been present in   
their common ancestor4 ,let us take an  
example of such a common character4 ,the
 bony external ear-passage is in general
 as highly developed in the lower       
,eastern monkeys and the anthropoid apes
 as in man4 ,this character must1       
therefore1 have already been present in 
the common primitive form4 ,in that case
 it is not easy to understand why the   
,western monkeys have not also inherited

 the character1 instead of possessing   
only a tympanic ring4 ,but it becomes   
more intelligible if we assume that     
forms with a primitive tympanic ring    
were the original type1 and that from   
these were evolved1 on the one hand1 the
 existing ,new ,world monkeys with      
persistent tympanic ring1 and on the    
other an ancestral form common to the   
lower ,old ,world monkeys1 the          
anthropoid apes and man4 ,for man shares
 with these the character in question1  
and it is also one of the unimportant   
characters required by ,darwin4 ,thus we
 have two divergent lines arising from  
the ancestral form1 the ,western monkeys
 7,platyrrhine7 on the one hand1 and an 
ancestral form common to the lower      
,eastern monkeys1 the anthropoid apes1  
and man1 on the other4 ,but             
considerations similar to those which   
showed it to be impossible that man     
should have developed from an ancestor  
common to him and the monkeys1 yet      
outside of and parallel with these1 may 

be urged also against the likelihood of 
a parallel evolution of the lower       
,eastern monkeys1 the anthropoid apes1  
and man4 ,the anthropoid apes have in   
common with man many characters which   
are not present in the lower ,old ,world
 monkeys4 ,these characters must        
therefore have been present in the      
ancestral form common to the three      
groups4 ,but here1 again1 it is         
difficult to understand why the lower   
,eastern monkeys should not also have   
inherited these characters4 ,as this is 
not the case1 there remains no          
alternative but to assume divergent     
evolution from an indifferent form4 ,the
 lower ,eastern monkeys are carrying on 
the evolution in one direction--,i might
 almost say towards a blind alley--while
 anthropoids and men have struck out a  
progressive path1 at first in common1   
which explains the many points of       
resemblance between them1 without       
regarding man as derived directly from  
the anthropoids4 ,their many striking   

points of agreement indicate a common   
descent1 and cannot be explained as     
phenomena of convergence4  ,i believe ,i
 have shown in the above sketch that a  
theory which derives man directly from  
lower forms without regarding apes as   
transition-types leads ad absurdum4 ,the
 close structural relationship between  
man and monkeys can only be understood  
if both are brought into the same line  
of evolution4 ,to trace man's line of   
descent directly back to the old ,eocene
 mammals1 alongside of1 but with no     
relation to these very similar forms1 is
 to abandon the method of exact         
comparison1 which1 as ,darwin rightly   
recognised1 alone justifies us in       
drawing up genealogical trees on the    
basis of resemblances and differences4  
,the farther down we go the more does   
the ground slip from beneath our feet4  
,even the ,lemuridae show very numerous 
divergent conditions1 much more so the  
,eocene mammals 7,creodonta1            
,condylarthra71 the chief resemblance of

 which to man consists in the possession
 of pentadactylous hands and feet6 ,thus
 the farther course of the line of      
descent disappears in the darkness of   
the ancestry of the mammals4 ,with just 
as much reason we might pass by the     
,vertebrates altogether1 and go back to 
the lower ,invertebrates1 but in that   
case it would be much easier to say that
 man has arisen independently1 and has  
evolved1 without relation to any        
animals1 from the lowest primitive form 
to his present isolated and dominant    
position4 ,but this would be to deny all
 value to classification1 which must    
after all be the ultimate basis of a    
genealogical tree4 ,we can1 as ,darwin  
rightly observed1 only infer the line of
 descent from the degree of resemblance 
between single forms4 ,if we regard man 
as directly derived from primitive forms
 very far back1 we have no way of       
explaining the many points of agreement 
between him and the monkeys in general1 
and the anthropoid apes in particular4  

,these must remain an inexplicable      
marvel4  ,i have thus1 ,i trust1 shown  
that the first class of special theories
 of descent1 which assumes that man has 
developed1 parallel with the monkeys1   
but without relation to them1 from very 
low primitive forms cannot be upheld1   
because it fails to take into account   
the close structural affinity of man and
 monkeys4 ,i cannot but regard this     
hypothesis as lamentably retrograde1 for
 it makes impossible any application of 
the facts that have been discovered in  
the course of the anatomical and        
embryological study of man and monkeys1 
and indeed prejudges investigations of  
that class as pointless4 ,the whole     
method is perverted2 an unjustifiable   
theory of descent is first formulated   
with the aid of the imagination1 and    
then we are asked to declare that all   
structural relations between man and    
monkeys1 and between the different      
groups of the latter1 are               
valueless1--the fact being that they are

 the only true basis on which a         
genealogical tree can be constructed4   
,so much for this most modern method of 
classification1 which has probably found
 adherents because it would deliver us  
from the relationship to apes which many
 people so much dislike4 ,in contrast to
 it we have the second class of special 
hypotheses of descent1 which keeps      
strictly to the nearest structural      
relationships4 ,this is the only basis  
that justifies the drawing up of a      
special hypothesis of descent4 ,if this 
fundamental proposition be recognised1  
it will be admitted that the doctrine of
 special descent upheld by ,haeckel1 and
 set forth in ,darwin's ,descent of     
,man1 is still valid to-day4 ,in the    
genealogical tree1 man's place is quite 
close to the anthropoid apes2 these     
again have as their nearest relatives   
the lower ,old ,world monkeys1 and their
 progenitors must be sought among the   
less differentiated ,platyrrhine        
monkeys1 whose most important characters

 have been handed on to the present day 
,new ,world monkeys4 ,how the different 
genera are to be arranged within the    
general scheme indicated depends in the 
main on the classificatory value        
attributed to individual characters4    
,this is particularly true in regard to 
,pithecanthropus1 which ,i consider as  
the root of a branch which has sprung   
from the anthropoid ape root and has led
 up to man2 the latter ,i have          
designated the family of the ,hominidae4
  ,for the rest1 there are1 as we have  
said1 various possible ways of          
constructing the narrower genealogy     
within the limits of this branch        
including men and apes1 and these       
methods will probably continue to change
 with the accumulation of new facts4    
,haeckel himself has modified his       
genealogical tree of the ,primates in   
certain details since the publication of
 his ,generelle ,morphologie in #ahff1  
but its general basis remains the same4 
7,haeckel's latest genealogical tree is 

to be found in his most recent work1    
,unsere ,ahnenreihe4 ,jena1 #aijh47 ,all
 the special genealogical trees drawn up
 on the lines laid down by ,haeckel and 
,darwin--and that of ,dubois may be     
specially mentioned--are based1 in      
general1 on the close relationship of   
monkeys and men1 although they may vary 
in detail4 ,various hypotheses have been
 formulated on these lines1 with special
 reference to the evolution of man4     
,pithecanthropus is regarded by some    
authorities as the direct ancestor of   
man1 by others as a side-track failure  
in the attempt at the evolution of man4 
,the problem of the monophyletic or     
polyphyletic origin of the human race   
has also been much discussed4 ,sergi    
7,sergi ,g4 ,europa1 #aijh47 inclines   
towards the assumption of a polyphyletic
 origin of the three main races of man1 
the ,african primitive form of which has
 given rise also to the gorilla and     
chimpanzee1 the ,asiatic to the ,orang1 
the ,gibbon1 and ,pithecanthropus4      

,kollmann regards existing human races  
as derived from small primitive races   
7pigmies71 and considers that ,homo     
primigenius must have arisen in a       
secondary and degenerative manner4  ,but
 this is not the place1 nor have ,i the 
space to criticise the various special  
theories of descent4 ,one1 however1 must
 receive particular notice4 ,according  
to ,ameghino1 the ,south ,american      
monkeys 7,pitheculites7 from the oldest 
,tertiary of the ,pampas are the forms  
from which have arisen the existing     
,american monkeys on the one hand1 and  
on the other1 the extinct ,south        
,american ,homunculidae1 which are also 
small forms4 ,from these last1          
anthropoid apes and man have1 he        
believes1 been evolved4 ,among the      
progenitors of man1 ,ameghino reckons   
the form discovered by him              
7,tetraprothomo71 from which a ,south   
,american primitive man1 ,homo pampaeus1
 might be directly evolved1 while on the
 other hand all the lower ,old ,world   

monkeys may have arisen from older      
fossil ,south ,american forms           
7,clenialitidae71 the distribution of   
which may be explained by the bridge    
formerly existing between ,south        
,america and ,africa1 as may be the     
derivation of all existing human races  
from ,homo pampaeus4 7,see ,ameghino's  
latest paper1 ,notas preliminares sobre 
el ,tetraprothomo argentinus1 etc4      
,anales del ,museo nacional de ,buenos  
,aires1 ,,xvi4 pages #ajg-bdb1 #aijg47  
,the fossil forms discovered by         
,ameghino deserve the most minute       
investigation1 as does also the fossil  
man from ,south ,america of which       
,lehmann-,nitsche 7,nouvelles recherches
 sur la formation pampeenne et l'homme  
fossile de la ,republique ,argentine4   
,rivista del ,museo de la ,plata1 ,t4   
,,xiv4 pages #aic-dhh47 has made a      
thorough study4  ,it is obvious that1   
notwithstanding the necessity for       
fitting man's line of descent into the  
genealogical tree of the ,primates1     

especially the apes1 opinions in regard 
to it differ greatly in detail4 ,this   
could not be otherwise1 since the       
different ,primate forms1 especially the
 fossil forms1 are still far from being 
exhaustively known4 ,but one thing      
remains certain1--the idea of the close 
relationship between man and monkeys set
 forth in ,darwin's ,descent of ,man4   
,only those who deny the many points of 
agreement1 the sole basis of            
classification1 and thus of a natural   
genealogical tree1 can look upon the    
position of ,darwin and ,haeckel as     
antiquated1 or as standing on an        
insufficient foundation4 ,for such a    
genealogical tree is nothing more than a
 summarised representation of what is   
known in regard to the degree of        
resemblance between the different forms4
  ,darwin's work in regard to the       
descent of man has not been surpassed2  
the more we immerse ourselves in the    
study of the structural relationships   
between apes and man1 the more is our   

path illumined by the clear light       
radiating from him1 and through his calm
 and deliberate investigation1 based on 
a mass of material in the accumulation  
of which he has never had an equal4     
,darwin's fame will be bound up for all 
time with the unprejudiced investigation
 of the question of all questions1 the  
descent of the human race4     ,,viii4  
,,charles ,,darwin ,,as ,,an            
,,anthropologist4 ,by ,ernst ,haeckel4  
,professor of ,zoology in the           
,university of ,jena4  ,the great       
advance that anthropology has made in   
the second half of the nineteenth       
century is due in the first place1 to   
,darwin's discovery of the origin of    
man4 ,no other problem in the whole     
field of research is so momentous as    
that of ,man's place in nature1 which   
was justly described by ,huxley 7#ahfc7 
as the most fundamental of all          
questions4 ,yet the scientific solution 
of this problem was impossible until the
 theory of descent had been established4

  ,it is now a hundred years since the  
great ,french biologist ,jean ,lamarck  
published his ,philosophie ,zoologique4 
,by a remarkable coincidence the year in
 which that work was issued1 #ahji1 was 
the year of the birth of his most       
distinguished successor1 ,charles       
,darwin4 ,lamarck had already recognised
 that the descent of man from a series  
of other ,vertebrates--that is1 from a  
series of ,ape-like ,primates--was      
essentially involved in the general     
theory of transformation which he had   
erected on a broad inductive basis2 and 
he had sufficient penetration to detect 
the agencies that had been at work in   
the evolution of the erect bimanous man 
from the arboreal and quadrumanous ape4 
,he had1 however1 few empirical         
arguments to advance in support of his  
hypothesis1 and it could not be         
established until the further           
development of the biological           
sciences--the founding of comparative   
embryology by ,baer 7#ahbh7 and of the  

cell-theory by ,schleiden and ,schwann  
7#ahch71 the advance of physiology under
 ,johannes ,muller 7#ahcc71 and the     
enormous progress of palaeontology and  
comparative anatomy between #ahbj and   
#ahfj--provided this necessary          
foundation4 ,darwin was the first to    
coordinate the ample results of these   
lines of research4 ,with no less        
comprehensiveness than discrimination he
 consolidated them as a basis of a      
modified theory of descent1 and         
associated with them his own theory of  
natural selection1 which we take to be  
distinctive of ,darwinism in the        
stricter sense4 ,the illuminating truth 
of these cumulative arguments was so    
great in every branch of biology that1  
in spite of the most vehement           
opposition1 the battle was won within a 
single decade1 and ,darwin secured the  
general admiration and recognition that 
had been denied to his forerunner1      
,lamarck1 up to the hour of his death   
7#ahbi74  ,before1 however1 we consider 

the momentous influence that ,darwinism 
has had in anthropology1 we shall find  
it useful to glance at its history in   
the course of the last half century1 and
 notice the various theories that have  
contributed to its advance4 ,the first  
attempt to give extensive expression to 
the reform of biology by ,darwin's work 
will be found in my ,generelle          
,morphologie 7#ahff7 7,generelle        
,morphologie der ,organismen1 #b vols41 
,berlin1 #ahff47 which was followed by a
 more popular treatment of the subject  
in my ,naturliche ,schopfungsgeschichte 
7#ahfh7 7,english translation2 ,the     
,history of ,creation1 ,london1 #ahgf471
 a compilation from the earlier work4   
,in the first volume of the ,generelle  
,morphologie ,i endeavoured to show the 
great importance of evolution in        
settling the fundamental questions of   
biological philosophy1 especially in    
regard to comparative anatomy4 ,in the  
second volume ,i dealt broadly with the 
principle of evolution1 distinguishing  

ontogeny and phylogeny as its two       
coordinate main branches1 and           
associating the two in the ,biogenetic  
,law4 ,the ,law may be formulated thus3 
,ontogeny 7embryology or the development
 of the individual7 is a concise and    
compressed recapitulation of phylogeny  
7the palaeontological or genealogical   
series7 conditioned by laws of heredity 
and adaptation4 ,the ,systematic        
introduction to general evolution1 with 
which the second volume of the          
,generelle ,morphologie opens1 was the  
first attempt to draw up a natural      
system of organisms 7in harmony with the
 principles of ,lamarck and ,darwin7 in 
the form of a hypothetical pedigree1 and
 was provisionally set forth in eight   
genealogical tables4  ,in the nineteenth
 chapter of the ,generelle              
,morphologie--a part of which has been  
republished1 without any alteration1    
after a lapse of forty years--,i made a 
critical study of ,lamarck's theory of  
descent and of ,darwin's theory of      

selection1 and endeavoured to bring the 
complex phenomena of heredity and       
adaptation under definite laws for the  
first time4 ,heredity ,i divided into   
conservative and progressive3 adaptation
 into indirect 7or potential7 and direct
 7or actual74 ,i then found it possible 
to give some explanation of the         
correlation of the two physiological    
functions in the struggle for life      
7selection71 and to indicate the        
important laws of divergence 7or        
differentiation7 and complexity 7or     
division of labour71 which are the      
direct and inevitable outcome of        
selection4 ,finally1 ,i marked off      
dysteleology as the science of the      
aimless 7vestigial1 abortive1 atrophied1
 and useless7 organs and parts of the   
body4 ,in all this ,i worked from a     
strictly monistic standpoint1 and sought
 to explain all biological phenomena on 
the mechanical and naturalistic lines   
that had long been recognised in the    
study of inorganic nature4 ,then        

7#ahff71 as now1 being convinced of the 
unity of nature1 the fundamental        
identity of the agencies at work in the 
inorganic and the organic worlds1 ,i    
discarded vitalism1 teleology1 and all  
hypotheses of a mystic character4  ,it  
was clear from the first that it was    
essential1 in the monistic conception of
 evolution1 to distinguish between the  
laws of conservative and progressive    
heredity4 ,conservative heredity        
maintains from generation to generation 
the enduring characters of the species4 
,each organism transmits to its         
descendants a part of the morphological 
and physiological qualities that it has 
received from its parents and ancestors4
 ,on the other hand1 progressive        
heredity brings new characters to the   
species--characters that were not found 
in preceding generations4 ,each organism
 may transmit to its offspring a part of
 the morphological and physiological    
features that it has itself acquired1 by
 adaptation1 in the course of its       

individual career1 through the use or   
disuse of particular organs1 the        
influence of environment1 climate1      
nutrition1 etc4 ,at that time ,i gave   
the name of progressive heredity to this
 inheritance of acquired characters1 as 
a short and convenient expression1 but  
have since changed the term to          
transformative heredity 7as             
distinguished from conservative74 ,this 
term is preferable1 as inherited        
regressive modifications 7degeneration1 
retrograde metamorphisis1 etc47 come    
under the same head4  ,transformative   
heredity--or the transmission of        
acquired characters--is one of the most 
important principles in evolutionary    
science4 ,unless we admit it most of the
 facts of comparative anatomy and       
physiology are inexplicable4 ,that was  
the conviction of ,darwin no less than  
of ,lamarck1 of ,spencer as well as     
,virchow1 of ,huxley as well as         
,gegenbaur1 indeed of the great majority
 of speculative biologists4 ,this       

fundamental principle was for the first 
time called in question and assailed in 
#ahhe by ,august ,weismann of ,freiburg1
 the eminent zoologist to whom the      
theory of evolution owes a great deal of
 valuable support1 and who has attained 
distinction by his extension of the     
theory of selection4 ,in explanation of 
the phenomena of heredity he introduced 
a new theory1 the theory of the         
continuity of the germ-plasm4 ,according
 to him the living substance in all     
organisms consists of two quite distinct
 kinds of plasm1 somatic and germinal4  
,the permanent germ-plasm1 or the active
 substance of the two germ-cells        
7egg-cell and sperm-cell71 passes       
unchanged through a series of           
generations1 and is not affected by     
environmental influences4 ,the          
environment modifies only the           
soma-plasm1 the organs and tissues of   
the body4 ,the modifications that these 
parts undergo through the influence of  
the environment or their own activity   

7use and habit71 do not affect the      
germ-plasm1 and cannot therefore be     
transmitted4  ,this theory of the       
continuity of the germ-plasm has been   
expounded by ,weismann during the last  
twenty-four years in a number of able   
volumes1 and is regarded by many        
biologists1 such as ,mr ,francis        
,galton1 ,sir ,e4 ,ray ,lankester1 and  
,professor ,j4 ,arthur ,thomson 7who has
 recently made a thoroughgoing defence  
of it in his important work ,heredity   
7,london1 #aijh4771 as the most striking
 advance in evolutionary science4 ,on   
the other hand1 the theory has been     
rejected by ,herbert ,spencer1 ,sir ,w4 
,turner1 ,gegenbaur1 ,kolliker1         
,hertwig1 and many others4 ,for my part 
,i have1 with all respect for the       
distinguished ,darwinian1 contested the 
theory from the first1 because its whole
 foundation seems to me erroneous1 and  
its deductions do not seem to be in     
accord with the main facts of           
comparative morphology and physiology4  

,weismann's theory in its entirety is a 
finely conceived molecular hypothesis1  
but it is devoid of empirical basis4    
,the notion of the absolute and         
permanent independence of the           
germ-plasm1 as distinguished from the   
soma-plasm1 is purely speculative2 as is
 also the theory of germinal selection4 
,the determinants1 ids1 and idants1 are 
purely hypothetical elements4 ,the      
experiments that have been devised to   
demonstrate their existence really prove
 nothing4  ,it seems to me quite        
improper to describe this hypothetical  
structure as ,neodarwinism4 ,darwin was 
just as convinced as ,lamarck of the    
transmission of acquired characters and 
its great importance in the scheme of   
evolution4 ,i had the good fortune to   
visit ,darwin at ,down three times and  
discuss with him the main principles of 
his system1 and on each occasion we were
 fully agreed as to the incalculable    
importance of what ,i call              
transformative inheritance4 ,it is only 

proper to point out that ,weismann's    
theory of the germ-plasm is in express  
contradiction to the fundamental        
principles of ,darwin and ,lamarck4 ,nor
 is it more acceptable in what one may  
call its ultradarwinism--the idea that  
the theory of selection explains        
everything in the evolution of the      
organic world4 ,this belief in the      
omnipotence of natural selection was not
 shared by ,darwin himself4 ,assuredly1 
,i regard it as of the utmost value1 as 
the process of natural selection through
 the struggle for life affords an       
explanation of the mechanical origin of 
the adapted organisation4 ,it solves the
 great problem3 how could the finely    
adapted structure of the animal or plant
 body be formed unless it was built on a
 preconceived plan8 ,it thus enables us 
to dispense with the teleology of the   
metaphysician and the dualist1 and to   
set aside the old mythological and      
poetic legends of creation4 ,the idea   
had occurred in vague form to the great 

,empedocles #bjjj years before the time 
of ,darwin1 but it was reserved for     
modern research to give it ample        
expression4 ,nevertheless1 natural      
selection does not of itself give the   
solution of all our evolutionary        
problems4 ,it has to be taken in        
conjunction with the transformism of    
,lamarck1 with which it is in complete  
harmony4  ,the monumental greatness of  
,charles ,darwin1 who surpasses every   
other student of science in the         
nineteenth century by the loftiness of  
his monistic conception of nature and   
the progressive influence of his ideas1 
is perhaps best seen in the fact that   
not one of his many successors has      
succeeded in modifying his theory of    
descent in any essential point or in    
discovering an entirely new standpoint  
in the interpretation of the organic    
world4 ,neither ,nageli nor ,weismann1  
neither ,de ,vries nor ,roux1 has done  
this4 ,nageli1 in his                   
,mechanisch-,physiologische ,theorie der

 ,abstammungslehre 7,munich1 #ahhd471   
which is to a great extent in agreement 
with ,weismann1 constructed a theory of 
the idioplasm1 that represents it 7like 
the germ-plasm7 as developing           
continuously in a definite direction    
from internal causes4 ,but his internal 
principle of progress is at the bottom  
just as teleological as the vital force 
of the ,vitalists1 and the micellar     
structure of the idioplasm is just as   
hypothetical as the dominant structure  
of the germ-plasm4 ,in #ahhi ,moritz    
,wagner sought to explain the origin of 
species by migration and isolation1 and 
on that basis constructed a special     
migration-theory4 ,this1 however1 is not
 out of harmony with the theory of      
selection4 ,it merely elevates one      
single factor in the theory to a        
predominant position4 ,isolation is only
 a special case of selection1 as ,i had 
pointed out in the fifteenth chapter of 
my ,natural history of creation4 ,the   
mutation-theory of ,de ,vries 7,die     

,mutationstheorie1 ,leipzig1 #aijc471   
that would explain the origin of species
 by sudden and saltatory variations     
rather than by gradual modification1 is 
regarded by many botanists as a great   
step in advance1 but it is generally    
rejected by zoologists4 ,it affords no  
explanation of the facts of adaptation1 
and has no causal value4  ,much more    
important than these theories is that of
 ,wilhelm ,roux 7,der ,kampf der ,theile
 im ,organismus1 ,leipzig1 #ahha47 of   
the struggle of parts within the        
organism1 a supplementation of the      
theory of mechanical adaptation4 ,he    
explains the functional autoformation of
 the purposive structure by a           
combination of ,darwin's principle of   
selection with ,lamarck's idea of       
transformative heredity1 and applies the
 two in conjunction to the facts of     
histology4 ,he lays stress on the       
significance of functional adaptation1  
which ,i had described in #ahff1 under  
the head of cumulative adaptation1 as   

the most important factor in evolution4 
,pointing out its influence in the      
cell-life of the tissues1 he puts       
cellular selection above personal       
selection1 and shows how the finest     
conceivable adaptations in the structure
 of the tissue may be brought about     
quite mechanically1 without preconceived
 plan4 ,this mechanical teleology is a  
valuable extension of ,darwin's monistic
 principle of selection to the whole    
field of cellular physiology and        
histology1 and is wholly destructive of 
dualistic vitalism4  ,the most important
 advance that evolution has made since  
,darwin and the most valuable           
amplification of his theory of selection
 is1 in my opinion1 the work of ,richard
 ,semon3 ,die ,mneme als erhaltendes    
,prinzip im ,wechsel des organischen    
,geschehens 7,leipzig1 #aijd474 ,he     
offers a psychological explanation of   
the facts of heredity by reducing them  
to a process of 7unconscious7 memory4   
,the physiologist ,ewald ,hering had    

shown in #ahgj that memory must be      
regarded as a general function of       
organic matter1 and that we are quite   
unable to explain the chief vital       
phenomena1 especially those of          
reproduction and inheritance1 unless we 
admit this unconscious memory4 ,in my   
essay ,die ,perigenesis der ,plastidule 
7,berlin1 #ahgf47 ,i elaborated this    
far-reaching idea1 and applied the      
physical principle of transmitted motion
 to the plastidules1 or active molecules
 of plasm4 ,i concluded that heredity is
 the memory of the plastidules1 and     
variability their power of              
comprehension4 ,this provisional attempt
 to give a mechanical explanation of the
 elementary processes of evolution ,i   
afterwards extended by showing that     
sensitiveness is 7as ,carl ,nageli1     
,ernst ,mach1 and ,albrecht ,rau express
 it7 a general quality of matter4 ,this 
form of panpsychism finds its simplest  
expression in the trinity of substance4 
,to the two fundamental attributes that 

,spinoza ascribed to                    
substance--,extension 7matter as        
occupying space7 and ,cogitation        
7energy1 force7--we now add the third   
fundamental quality of ,psychoma        
7sensitiveness1 soul74 ,i further       
elaborated this trinitarian conception  
of substance in the nineteenth chapter  
of my ,die ,lebenswunder 7#aijd7        
7,wonders of ,life1 ,london1 #aijd471   
and it seems to me well calculated to   
afford a monistic solution of many of   
the antitheses of philosophy4  ,this    
important ,mneme-theory of ,semon and   
the luminous physiological experiments  
and observations associated with it not 
only throw considerable light on        
transformative inheritance1 but provide 
a sound physiological foundation for the
 biogenetic law4 ,i had endeavoured to  
show in #ahgd1 in the first chapter of  
my ,anthropogenie 7,english translation2
 ,the ,evolution of ,man1 #b volumes1   
,london1 #ahgi and #aije471 that this   
fundamental law of organic evolution    

holds good generally1 and that there is 
everywhere a direct causal connection   
between ontogeny and phylogeny4         
,phylogenesis is the mechanical cause of
 ontogenesis2 in other words1 ,the      
evolution of the stem or race is--in    
accordance with the laws of heredity and
 adaptation--the real cause of all the  
changes that appear1 in a condensed     
form1 in the development of the         
individual organism from the ovum1 in   
either the embryo or the larva4  ,it is 
now fifty years since ,charles ,darwin  
pointed out1 in the thirteenth chapter  
of his epoch-making ,origin of ,species1
 the fundamental importance of          
embryology in connection with his theory
 of descent3  ,the leading facts in     
embryology1 which are second to none in 
importance1 are explained on the        
principle of variations in the many     
descendants from some one ancient       
progenitor1 having appeared at a not    
very early period of life1 and having   
been inherited at a corresponding       

period4 7,origin of ,species 7#fth      
edition71 page #cif47  ,he then shows   
that the striking resemblance of the    
embryos and larvae of closely related   
animals1 which in the mature stage      
belong to widely different species and  
genera1 can only be explained by their  
descent from a common progenitor4 ,fritz
 ,muller made a closer study of these   
important phenomena in the instructive  
instance of the ,crustacean larva1 as   
given in his able work ,fur ,darwin     
7#ahfd74 7,english translation2 ,facts  
and ,arguments for ,darwin1 ,london1    
#ahfi47 ,i then1 in #ahgb1 extended the 
range so as to include all animals 7with
 the exception of the unicellular       
,protozoa7 and showed1 by means of the  
theory of the ,gastraea1 that all       
multicellular1 tissue-forming           
animals--all the ,metazoa--develop in   
essentially the same way from the       
primary germ-layers4 ,i conceived the   
embryonic form1 in which the whole      
structure consists of only two layers of

 cells1 and is known as the gastrula1 to
 be the ontogenetic recapitulation1     
maintained by tenacious heredity1 of a  
primitive common progenitor of all the  
,metazoa1 the ,gastraea4 ,at a later    
date 7#ahie7 ,monticelli discovered that
 this conjectural ancestral form is     
still preserved in certain primitive    
,coelenterata--,pemmatodiscus1          
,kunstleria1 and the nearly-related     
,orthonectida4  ,the general application
 of the biogenetic law to all classes of
 animals and plants has been proved in  
my ,systematische ,phylogenie4 7#c      
volumes1 ,berlin1 #ahid-if47 ,it has1   
however1 been frequently challenged1    
both by botanists and zoologists1       
chiefly owing to the fact that many have
 failed to distinguish its two essential
 elements1 palingenesis and cenogenesis4
 ,as early as #ahgd ,i had emphasised1  
in the first chapter of my ,evolution of
 ,man1 the importance of discriminating 
carefully between these two sets of     
phenomena3  ,in the evolutionary        

appreciation of the facts of embryology 
we must take particular care to         
distinguish sharply and clearly between 
the primary1 palingenetic evolutionary  
processes and the secondary1 cenogenetic
 processes4 ,the palingenetic phenomena1
 or embryonic ,,recapitulations1 are due
 to heredity1 to the transmission of    
characters from one generation to       
another4 ,they enable us to draw direct 
inferences in regard to corresponding   
structures in the development of the    
species 7e4g4 the chorda or the         
branchial arches in all vertebrate      
embryos74 ,the cenogenetic phenomena1 on
 the other hand1 or the embryonic       
,,variations1 cannot be traced to       
inheritance from a mature ancestor1 but 
are due to the adaptation of the embryo 
or the larva to certain conditions of   
its individual development 7e4g4 the    
amnion1 the allantois1 and the vitelline
 arteries in the embryos of the higher  
vertebrates74 ,these cenogenetic        
phenomena are later additions2 we must  

not infer from them that there were     
corresponding processes in the ancestral
 history1 and hence they are apt to     
mislead4  ,the fundamental importance of
 these facts of comparative anatomy1    
atavism1 and the rudimentary organs1 was
 pointed out by ,darwin in the first    
part of his classic work1 ,the ,descent 
of ,man and ,selection in ,relation to  
,sex 7#ahga74 7,descent of ,man         
7,popular ,edition71 page #ibg47 ,in the
 ,general summary and conclusion        
7chapter ,,xxi47 he was able to say1    
with perfect justice3 ,he who is not    
content to look1 like a savage1 at the  
phenomena of nature as disconnected1    
cannot any longer believe that man is   
the work of a separate act of creation4 
,he will be forced to admit that the    
close resemblance of the embryo of man  
to that1 for instance1 of a dog--the    
construction of his skull1 limbs1 and   
whole frame on the same plan with that  
of other mammals1 independently of the  
uses to which the parts may be put--the 

occasional reappearance of various      
structures1 for instance of several     
muscles1 which man does not normally    
possess1 but which are common to the    
,quadrumana--and a crowd of analogous   
facts--all point in the plainest manner 
to the conclusion that man is the       
co-descendant with other mammals of a   
common progenitor4  ,these few lines of 
,darwin's have a greater scientific     
value than hundreds of those so-called  
anthropological treatises1 which give   
detailed descriptions of single organs1 
or mathematical tables with series of   
numbers and what are claimed to be exact
 analyses1 but are devoid of synoptic   
conclusions and a philosophical spirit4 
,charles ,darwin is not generally       
recognised as a great anthropologist1   
nor does the school of modern           
anthropologists regard him as a leading 
authority4 ,in ,germany1 especially1 the
 great majority of the members of the   
anthropological societies took up an    
attitude of hostility to him from the   

very beginning of the controversy in    
#ahfj4 ,the ,descent of ,man was not    
merely rejected1 but even the discussion
 of it was forbidden on the ground that 
it was unscientific4  ,the centre of    
this inveterate hostility for thirty    
years--especially after #ahgg--was      
,rudolph ,virchow of ,berlin1 the       
leading investigator in pathological    
anatomy1 who did so much for the reform 
of medicine by his establishment of     
cellular pathology in #aheh4 ,as a      
prominent representative of exact or    
descriptive anthropology1 and lacking a 
broad equipment in comparative anatomy  
and ontogeny1 he was unable to accept   
the theory of descent4 ,in earlier      
years1 and especially during his        
splendid period of activity at ,wurzburg
 7#ahdh-ahef71 he had been a consistent 
free-thinker1 and had in a number of    
able articles 7collected in his         
,gesammelte ,abhandlungen7 7,gesammelte 
,abhandlungen zur wissenschaftlichen    
,medizin1 ,berlin1 #ahef47 upheld the   

unity of human nature1 the              
inseparability of body and spirit4 ,in  
later years at ,berlin1 where he was    
more occupied with political work and   
sociology 7especially after #ahff71 he  
abandoned the positive monistic position
 for one of agnosticism and scepticism1 
and made concessions to the dualistic   
dogma of a spiritual world apart from   
the material frame4  ,in the course of a
 ,scientific ,congress at ,munich in    
#ahgg the conflict of these antithetic  
views of nature came into sharp relief4 
,at this memorable ,congress ,i had     
undertaken to deliver the first address 
7,september #ahth7 on the subject of    
,modern evolution in relation to the    
whole of science4 ,i maintained that    
,darwin's theory not only solved the    
great problem of the origin of species1 
but that its implications1 especially in
 regard to the nature of man1 threw     
considerable light on the whole of      
science1 and on anthropology in         
particular4 ,the discovery of the real  

origin of man by evolution from a long  
series of mammal ancestors threw light  
on his place in nature in every aspect1 
as ,huxley had already shown in his     
excellent lectures of #ahfc4 ,just as   
all the organs and tissues of the human 
body had originated from those of the   
nearest related mammals1 certain        
ape-like forms1 so we were bound to     
conclude that his mental qualities also 
had been derived from those of his      
extinct primate ancestor4  ,this        
monistic view of the origin and nature  
of man1 which is now admitted by nearly 
all who have the requisite acquaintance 
with biology1 and approach the subject  
without prejudice1 encountered a sharp  
opposition at that time4 ,the opposition
 found its strongest expression in an   
address that ,virchow delivered at      
,munich four days afterwards 7,september
 #bbnd71 on ,the freedom of science in  
the modern ,state4 ,he spoke of the     
theory of evolution as an unproved      
hypothesis1 and declared that it ought  

not to be taught in the schools1 because
 it was dangerous to the ,state4 ,we    
must not1 he said1 teach that man has   
descended from the ape or any other     
animal4 ,when ,darwin1 usually so       
lenient in his judgment1 read the       
,english translation of ,virchow's      
speech1 he expressed his disapproval in 
strong terms4 ,but the great authority  
that ,virchow had--an authority well    
founded in pathology and sociology--and 
his prestige as ,president of the       
,german ,anthropological ,society1 had  
the effect of preventing any member of  
the ,society from raising serious       
opposition to him for thirty years4     
,numbers of journals and treatises      
repeated his dogmatic statement3 ,it is 
quite certain that man has descended    
neither from the ape nor from any other 
animal4 ,in this he persisted till his  
death in #aijb4 ,since that time the    
whole position of ,german anthropology  
has changed4 ,the question is no longer 
whether man was created by a distinct   

supernatural act or evolved from other  
mammals1 but to which line of the animal
 hierarchy we must look for the actual  
series of ancestors4 ,the interested    
reader will find an account of this     
battle of ,munich 7#ahgg7 in my three   
,berlin lectures 7,april1 #aije7 7,der  
,kampf um die ,entwickelungs-,gedanken4 
7,english translation2 ,last ,words on  
,evolution1 ,london1 #aijf477  ,the main
 points in our genealogical tree were   
clearly recognised by ,darwin in the    
sixth chapter of the ,descent of ,man4  
,lowly organised fishes1 like the       
lancelet 7,amphioxus71 are descended    
from lower invertebrates resembling the 
larvae of an existing ,tunicate         
7,appendicularia74 ,from these primitive
 fishes were evolved higher fishes of   
the ganoid type and others of the type  
of ,lepidosiren 7,dipneusta74 ,it is a  
very small step from these to the       
,amphibia3  ,in the class of mammals the
 steps are not difficult to conceive    
which led from the ancient ,monotremata 

to the ancient ,marsupials2 and from    
these to the early progenitors of the   
placental mammals4 ,we may thus ascend  
to the ,lemuridae2 and the interval is  
not very wide from these to the         
,simiadae4 ,the ,simiadae then branched 
off into two great stems1 the ,new      
,world and ,old ,world monkeys2 and from
 the latter1 at a remote period1 ,man1  
the wonder and glory of the ,universe1  
proceeded4 7,descent of ,man 7,popular  
,edition71 page #bee47  ,in these few   
lines ,darwin clearly indicated the way 
in which we were to conceive our        
ancestral series within the vertebrates4
 ,it is fully confirmed by all the      
arguments of comparative anatomy and    
embryology1 of palaeontology and        
physiology2 and all the research of the 
subsequent forty years has gone to      
establish it4 ,the deep interest in     
geology which ,darwin maintained        
throughout his life and his complete    
knowledge of palaeontology enabled him  
to grasp the fundamental importance of  

the palaeontological record more clearly
 than anthropologists and zoologists    
usually do4  ,there has been much debate
 in subsequent decades whether ,darwin  
himself maintained that man was         
descended from the ape1 and many writers
 have sought to deny it4 ,but the lines 
,i have quoted verbatim from the        
conclusion of the sixth chapter of the  
,descent of ,man 7#ahga7 leave no doubt 
that he was as firmly convinced of it as
 was his great precursor ,jean ,lamarck 
in #ahji4 ,moreover1 ,darwin adds1 with 
particular explicitness1 in the general 
summary and conclusion 7chapter ,,xxi47 
of that standard work 7,descent of ,man1
 page #icj473  ,by considering the      
embryological structure of man--the     
homologies which he presents with the   
lower animals1--the rudiments which he  
retains1--and the reversions to which he
 is liable1 we can partly recall in     
imagination the former condition of our 
early progenitors2 and can approximately
 place them in their proper place in the

 zoological series4 ,we thus learn that 
man is descended from a hairy1 tailed   
quadruped1 probably arboreal in its     
habits1 and an inhabitant of the ,old   
,world4 ,this creature1 if its whole    
structure had been examined by a        
naturalist1 would have been classed     
amongst the ,quadrumana1 as surely as   
the still more ancient progenitor of the
 ,old and ,new ,world monkeys4  ,these  
clear and definite lines leave no doubt 
that ,darwin--so critical and cautious  
in regard to important conclusions--was 
quite as firmly convinced of the descent
 of man from the apes 7the ,catarrhinae1
 in particular7 as ,lamarck was in #ahji
 and ,huxley in #ahfc4  ,it is to be    
noted particularly that1 in these and   
other observations on the subject1      
,darwin decidedly assumes the           
monophyletic origin of the mammals1     
including man4 ,it is my own conviction 
that this is of the greatest importance4
 ,a number of difficult questions in    
regard to the development of man1 in    

respect of anatomy1 physiology1         
psychology1 and embryology1 are easily  
settled if we do not merely extend our  
progonotaxis to our nearest relatives1  
the anthropoid apes and the tailed      
monkeys from which these have descended1
 but go further back and find an        
ancestor in the group of the ,lemuridae1
 and still further back to the          
,marsupials and ,monotremata4 ,the      
essential identity of all the ,mammals  
in point of anatomical structure and    
embryonic development--in spite of their
 astonishing differences in external    
appearance and habits of life--is so    
palpably significant that modern        
zoologists are agreed in the hypothesis 
that they have all sprung from a common 
root1 and that this root may be sought  
in the earlier ,palaeozoic ,amphibia4   
,the fundamental importance of this     
comparative morphology of the ,mammals1 
as a sound basis of scientific          
anthropology1 was recognised just before
 the beginning of the nineteenth        

century1 when ,lamarck first emphasised 
7#agid7 the division of the animal      
kingdom into ,vertebrates and           
,invertebrates4 ,even thirteen years    
earlier 7#agha71 when ,goethe made a    
close study of the mammal skeleton in   
the ,anatomical ,institute at ,jena1 he 
was intensely interested to find that   
the composition of the skull was the    
same in man as in the other mammals4    
,his discovery of the os intermaxillare 
in man 7#aghd71 which was contradicted  
by most of the anatomists of the time1  
and his ingenious vertebral theory of   
the skull1 were the splendid fruit of   
his morphological studies4 ,they remind 
us how ,germany's greatest philosopher  
and poet was for many years ardently    
absorbed in the comparative anatomy of  
man and the mammals1 and how he divined 
that their wonderful identity in        
structure was no mere superficial       
resemblance1 but pointed to a deep      
internal connection4 ,in my ,generelle  
,morphologie 7#ahff71 in which ,i       

published the first attempts to         
construct phylogenetic trees1 ,i have   
given a number of remarkable theses of  
,goethe1 which may be called phyletic   
prophecies4 ,they justify us in         
regarding him as a precursor of ,darwin4
  ,in the ensuing forty years ,i have   
made many conscientious efforts to      
penetrate further along that line of    
anthropological research that was opened
 up by ,goethe1 ,lamarck1 and ,darwin4  
,i have brought together the many       
valuable results that have constantly   
been reached in comparative anatomy1    
physiology1 ontogeny1 and palaeontology1
 and maintained the effort to reform the
 classification of animals and plants in
 an evolutionary sense4 ,the first rough
 drafts of pedigrees that were published
 in the ,generelle ,morphologie have    
been improved time after time in the ten
 editions of my ,naturaliche            
,schopfungsgeschichte 7#ahfh-aijb74     
7,english translation2 ,the ,history of 
,creation1 ,london1 #ahgf47 ,a sounder  

basis for my phyletic hypotheses1       
derived from a discriminating           
combination of the three great          
records--morphology1 ontogeny1 and      
palaeontology--was provided in the three
 volumes of my ,systematische           
,phylogenie 7,berlin1 #ahid-if47 7#ahid 
,protists and ,plants1 #ahie            
,vertebrates1 #ahif ,invertebrates74 ,in
 my ,anthropogenie 7,leipzig1 #ahgd1    
#eth edition #aije4 ,english            
translation2 ,the ,evolution of ,man1   
,london1 #aije47 ,i endeavoured to      
employ all the known facts of           
comparative ontogeny 7embryology7 for   
the purpose of completing my scheme of  
human phylogeny 7evolution74 ,i         
attempted to sketch the historical      
development of each organ of the body1  
beginning with the most elementary      
structures in the germ-layers of the    
,gastraea4 ,at the same time ,i drew up 
a corrected statement of the most       
important steps in the line of our      
ancestral series4  ,at the fourth       

,international ,congress of ,zoology at 
,cambridge 7,august #bfth1 #ahih7 ,i    
delivered an address on ,our present    
knowledge of the ,descent of ,man4 ,it  
was translated into ,english1 enriched  
with many valuable notes and additions1 
by my friend and pupil in earlier days  
,dr ,hans ,gadow 7,cambridge71 and      
published under the title3 ,the ,last   
,link2 our present knowledge of the     
,descent of ,man4 7,london1 #ahih47 ,the
 determination of the chief animal forms
 that occur in the line of our ancestry 
is there restricted to thirty types1 and
 these are distributed in six main      
groups4  ,the first half of this        
,progonotaxis hominis1 which has no     
support from fossil evidence1 comprises 
three groups3 7i7 ,protista 7unicellular
 organisms1 #a-e3 7ii7 ,invertebrate    
,metazoa 7,coelenteria #f-h1 ,vermalia  
#i-aa73 7iii7 ,monorrhine ,vertebrates  
7,acrania #ab-ac1 ,cyclostoma #ad-ae74  
,the second half1 which is based on     
fossil records1 also comprises three    

groups3 7iv7 ,palaeozoic cold-blooded   
,craniota 7,fishes #af-ah1 ,amphibia    
#ai1 ,reptiles #bj3 7v7 ,mesozoic       
,mammals 7,monotrema #ba1 ,marsupialia  
#bb1 ,mallotheria #bc73 7vi7 ,cenozoic  
,primates 7,lemuridae #bd-be1 ,tailed   
,apes #bf-bg1 ,anthropomorpha #bh-cj74  
,an improved and enlarged edition of    
this hypothetic ,progonotaxis hominis   
was published in #aijh1 in my essay     
,unsere ,ahnenreihe4 7,festschrift zur  
#cej-;jahrigen ,jubelfeier der          
,thuringer ,universitat ,jena4 ,jena1   
#aijh47  ,if ,i have succeeded in       
furthering1 in some degree1 by these    
anthropological works1 the solution of  
the great problem of ,man's place in    
nature1 and particularly in helping to  
trace the definite stages in our        
ancestral series1 ,i owe the success1   
not merely to the vast progress that    
biology has made in the last half       
century1 but largely to the luminous    
example of the great investigators who  
have applied themselves to the problem1 

with so much assiduity and genius1 for a
 century and a quarter--,i mean ,goethe 
and ,lamarck1 ,gegenbaur and ,huxley1   
but1 above all1 ,charles ,darwin4 ,it   
was the great genius of ,darwin that    
first brought together the scattered    
material of biology and shaped it into  
that symmetrical temple of scientific   
knowledge1 the theory of descent4 ,it   
was ,darwin who put the crown on the    
edifice by his theory of natural        
selection4 ,not until this broad        
inductive law was firmly established was
 it possible to vindicate the special   
conclusion1 the descent of man from a   
series of other ,vertebrates4 ,by his   
illuminating discovery ,darwin did more 
for anthropology than thousands of those
 writers1 who are more specifically     
titled anthropologists1 have done by    
their technical treatises4 ,we may1     
indeed1 say that it is not merely as an 
exact observer and ingenious            
experimenter1 but as a distinguished    
anthropologist and far-seeing thinker1  

that ,darwin takes his place among the  
greatest men of science of the          
nineteenth century4  ,to appreciate     
fully the immortal merit of ,darwin in  
connection with anthropology1 we must   
remember that not only did his chief    
work1 ,the ,origin of ,species1 which   
opened up a new era in natural history  
in #ahei1 sustain the most virulent and 
widespread opposition for a lengthy     
period1 but even thirty years later1    
when its principles were generally      
recognised and adopted1 the application 
of them to man was energetically        
contested by many high scientific       
authorities4 ,even ,alfred ,russel      
,wallace1 who discovered the principle  
of natural selection independently in   
#aheh1 did not concede that it was      
applicable to the higher mental and     
moral qualities of man4 ,dr ,wallace    
still holds a spiritualist and dualist  
view of the nature of man1 contending   
that he is composed of a material frame 
7descended from the apes7 and an        

immortal immaterial soul 7infused by a  
higher power74 ,this dual conception1   
moreover1 is still predominant in the   
wide circles of modern theology and     
metaphysics1 and has the general and    
influential adherence of the more       
conservative classes of society4  ,in   
strict contradiction to this mystical   
dualism1 which is generally connected   
with teleology and vitalism1 ,darwin    
always maintained the complete unity of 
human nature1 and showed convincingly   
that the psychological side of man was  
developed1 in the same way as the body1 
from the less advanced soul of the      
anthropoid ape1 and1 at a still more    
remote period1 from the cerebral        
functions of the older vertebrates4 ,the
 eighth chapter of the ,origin of       
,species1 which is devoted to instinct1 
contains weighty evidence that the      
instincts of animals are subject1 like  
all other vital processes1 to the       
general laws of historic development4   
,the special instincts of particular    

species were formed by adaptation1 and  
the modifications thus acquired were    
handed on to posterity by heredity2 in  
their formation and preservation natural
 selection plays the same part as in the
 transformation of every other          
physiological function4 ,the higher     
moral qualities of civilised man have   
been derived from the lower mental      
functions of the uncultivated barbarians
 and savages1 and these in turn from the
 social instincts of the mammals4 ,this 
natural and monistic psychology of      
,darwin's was afterwards more fully     
developed by his friend ,george ,romanes
 in his excellent works ,mental         
,evolution in ,animals and ,mental      
,evolution in ,man4 7,london1 #ahhe2    
#ahhh47  ,many valuable and most        
interesting contributions to this       
monistic psychology of man were made by 
,darwin in his fine work on ,the        
,descent of ,man and ,selection in      
,relation to ,sex1 and again in his     
supplementary work1 ,the ,expression of 

the ,emotions in ,man and ,animals4 ,to 
understand the historical development of
 ,darwin's anthropology one must read   
his life and the introduction to ,the   
,descent of ,man4 ,from the moment that 
he was convinced of the truth of the    
principle of descent--that is to say1   
from his thirtieth year1 in #ahch--;he  
recognised clearly that man could not be
 excluded from its range4 ,he recognised
 as a logical necessity the important   
conclusion that man is the co-descendant
 with other species of some ancient1    
lower1 and extinct form4 ,for many years
 he gathered notes and arguments in     
support of this thesis1 and for the     
purpose of showing the probable line of 
man's ancestry4 ,but in the first       
edition of ,the ,origin of ,species     
7#ahei7 he restricted himself to the    
single line1 that by this work light    
would be thrown on the origin of man and
 his history4 ,in the fifty years that  
have elapsed since that time the science
 of the origin and nature of man has    

made astonishing progress1 and we are   
now fairly agreed in a monistic         
conception of nature that regards the   
whole universe1 including man1 as a     
wonderful unity1 governed by unalterable
 and eternal laws4 ,in my philosophical 
book ,die ,weltratsel 7#ahii7 7,the     
,riddle of the ,universe1 ,london1      
#aijj47 and in the supplementary volume 
,die ,lebenswunder 7#aijd7 ,the ,wonders
 of ,life1 ,london1 7#aijd471 ,i have   
endeavoured to show that this pure      
monism is securely established1 and that
 the admission of the all-powerful rule 
of the same principle of evolution      
throughout the universe compels us to   
formulate a single supreme law--the     
all-embracing ,law of ,substance1 or the
 united laws of the constancy of matter 
and the conservation of energy4 ,we     
should never have reached this supreme  
general conception if ,charles          
,darwin--a monistic philosopher in the  
true sense of the word--had not prepared
 the way by his theory of descent by    

natural selection1 and crowned the great
 work of his life by the association of 
this theory with a naturalistic         
anthropology4   ,,ix4 ,,some ,,primitive
 ,,theories ,,of ,,the ,,origin ,,of    
,,man4  ,by ,j4,g4 ,,frazer4 ,fellow of 
,trinity ,college1 ,cambridge4  ,on a   
bright day in late autumn a good many   
years ago ,i had ascended the hill of   
,panopeus in ,phocis to examine the     
ancient ,greek fortifications which     
crest its brow4 ,it was the first of    
,november1 but the weather was very hot2
 and when my work among the ruins was   
done1 ,i was glad to rest under the     
shade of a clump of fine holly-oaks1 to 
inhale the sweet refreshing perfume of  
the wild thyme which scented all the    
air1 and to enjoy the distant prospects1
 rich in natural beauty1 rich too in    
memories of the legendary and historic  
past4 ,to the south the finely-cut peak 
of ,helicon peered over the low         
intervening hills4 ,in the west loomed  
the mighty mass of ,parnassus1 its      

middle slopes darkened by pine-woods    
like shadows of clouds brooding on the  
mountain-side2 while at its skirts      
nestled the ivy-mantled walls of ,daulis
 overhanging the deep glen1 whose       
romantic beauty accords so well with the
 loves and sorrows of ,procne and       
,philomela1 which ,greek tradition      
associated with the spot4 ,northwards1  
across the broad plain to which the hill
 of ,panopeus descends1 steep and bare1 
the eye rested on the gap in the hills  
through which the ,cephissus winds his  
tortuous way to flow under grey willows1
 at the foot of barren stony hills1 till
 his turbid waters lose themselves1 no  
longer in the vast reedy swamps of the  
now vanished ,copaic ,lake1 but in the  
darkness of a cavern in the limestone   
rock4 ,eastward1 clinging to the slopes 
of the bleak range of which the hill of 
,panopeus forms part1 were the ruins of 
,chaeronea1 the birthplace of ,plutarch2
 and out there in the plain was fought  
the disastrous battle which laid ,greece

 at the feet of ,macedonia4 ,there1 too1
 in a later age ,east and ,west met in  
deadly conflict1 when the ,roman armies 
under ,sulla defeated the ,asiatic hosts
 of ,mithridates4 ,such was the         
landscape spread out before me on one of
 those farewell autumn days of almost   
pathetic splendour1 when the departing  
summer seems to linger fondly1 as if    
loth to resign to winter the enchanted  
mountains of ,greece4 ,next day the     
scene had changed3 summer was gone4 ,a  
grey ,november mist hung low on the     
hills which only yesterday had shone    
resplendent in the sun1 and under its   
melancholy curtain the dead flat of the 
,chaeronean plain1 a wide treeless      
expanse shut in by desolate slopes1 wore
 an aspect of chilly sadness befitting  
the battlefield where a nation's freedom
 was lost4  ,but crowded as the prospect
 from ,panopeus is with memories of the 
past1 the place itself1 now so still and
 deserted1 was once the scene of an     
event even more ancient and memorable1  

if ,greek story-tellers can be trusted4 
,for here1 they say1 the sage           
,prometheus created our first parents by
 fashioning them1 like a potter1 out of 
clay4 7,pausanias ,x4 #d4d4 ,compare    
,apollodorus1 ,bibliotheca1 ,i4 #g4 #a2 
,ovid1 ,metamorph4 ,i4 #hb sq42         
,juvenal1 ,sat4 ,,xiv4 #ce4 ,according  
to another version of the tale1 this    
creation of mankind took place not at   
,panopeus1 but at ,iconium in ,lycaonia4
 ,after the original race of mankind had
 been destroyed in the great flood of   
,deucalion1 the ,greek ,noah1 ,zeus     
commanded ,prometheus and ,athena to    
create men afresh by moulding images out
 of clay1 breathing the winds into them1
 and making them live4 ,see             
,etymologicum ,magnum1 s4v4 ',ikonion1  
pages #dgj sq4 ,it is said that         
,prometheus fashioned the animals as    
well as men1 giving to each kind of     
beast its proper nature4 ,see ,philemon1
 quoted by ,stobaeus1 ,florilegium ,,ii4
 #bg4 ,the creation of man by           

,prometheus is figured on ancient works 
of art4 ,see ,j4 ,toutain1 ,etudes de   
,mythologie et d',histoire des          
,religions ,antiques 7,paris1 #aiji71   
page #aij4 ,according to ,hesiod 7,works
 and ,days1 #fj sqq47 it was ,hephaestus
 who at the bidding of ,zeus moulded the
 first woman out of moist earth47 ,the  
very spot where he did so can still be  
seen4 ,it is a forlorn little glen or   
rather hollow behind the hill of        
,panopeus1 below the ruined but still   
stately walls and towers which crown the
 grey rocks of the summit4 ,the glen1   
when ,i visited it that hot day after   
the long drought of summer1 was quite   
dry2 no water trickled down its bushy   
sides1 but in the bottom ,i found a     
reddish crumbling earth1 a relic perhaps
 of the clay out of which the potter    
,prometheus moulded the ,greek ,adam and
 ,eve4 ,in a volume dedicated to the    
honour of one who has done more than any
 other in modern times to shape the     
ideas of mankind as to their origin it  

may not be out of place to recall this  
crude ,greek notion of the creation of  
the human race1 and to compare or       
contrast it with other rudimentary      
speculations of primitive peoples on the
 same subject1 if only for the sake of  
marking the interval which divides the  
childhood from the maturity of science4 
,the simple notion that the first man   
and woman were modelled out of clay by a
 god or other superhuman being is found 
in the traditions of many peoples4 ,this
 is the ,hebrew belief recorded in      
,genesis3 ,the ,lord ,god formed man of 
the dust of the ground1 and breathed    
into his nostrils the breath of life2   
and man became a living soul4 7,genesis 
ii4#g47 ,to the ,hebrews this derivation
 of our species suggested itself all the
 more naturally because in their        
language the word for ground 7adamah7 is
 in form the feminine of the word for   
man 7adam74 7,s4,r4 ,driver and         
,w4,h4,bennett1 in their commentaries on
 ,genesis ii4 #g47 ,from various        

allusions in ,babylonian literature it  
would seem that the ,babylonians also   
conceived man to have been moulded out  
of clay4 7,h4 ,zimmern1 in ,e4          
,schrader's ,die ,keilinschriften und   
das ,alte ,testament #c 7,berlin1       
#aijb71 page #ejf47 ,according to       
,berosus1 the ,babylonian priest whose  
account of creation has been preserved  
in a ,greek version1 the god ,bel cut   
off his own head1 and the other gods    
caught the flowing blood1 mixed it with 
earth1 and fashioned men out of the     
bloody paste2 and that1 they said1 is   
why men are so wise1 because their      
mortal clay is tempered with divine     
blood4 7,eusebius1 ,chronicon1 ed4 ,a4  
,schoene1 ,vol4 ,i4 7,berlin1 #ahge71   
col4 #af47 ,in ,egyptian mythology      
,khnoumou1 the ,father of the gods1 is  
said to have moulded men out of clay4   
7,g4 ,maspero1 ,histoire ,ancienne des  
,peuples de l',orient ,classique1 ,i4   
7,paris1 #ahie71 page #abh47 ,we cannot 
doubt that such crude conceptions of the

 origin of our race were handed down to 
the civilised peoples of antiquity by   
their savage or barbarous forefathers4  
,certainly stories of the same sort are 
known to be current among savages and   
barbarians4  ,thus the ,australian      
blacks in the neighbourhood of          
,melbourne said that ,pund-jel1 the     
creator1 cut three large sheets of bark 
with his big knife4 ,on one of these he 
placed some clay and worked it up with  
his knife into a proper consistence4 ,he
 then laid a portion of the clay on one 
of the other pieces of bark and shaped  
it into a human form2 first he made the 
feet1 then the legs1 then the trunk1 the
 arms1 and the head4 ,thus he made a    
clay man on each of the two pieces of   
bark2 and being well pleased with them  
he danced round them for joy4 ,next he  
took stringy bark from the ,eucalyptus  
tree1 made hair of it1 and stuck it on  
the heads of his clay men4 ,then he     
looked at them again1 was pleased with  
his work1 and again danced round them   

for joy4 ,he then lay down on them1 blew
 his breath hard into their mouths1     
their noses1 and their navels2 and      
presently they stirred1 spoke1 and rose 
up as full-grown men4 7,r4 ,brough      
,smyth1 ,the ,aborigines of ,victoria   
7,melbourne1 #ahgh71 ,i4 #dbd4 ,this and
 many of the following legends of       
creation have been already cited by me  
in a note on ,pausanias ,x4 #d4 #d      
7,pausanias's ,description of ,greece1  
translated with a ,commentary 7,london1 
#ahih71 ,vol ,v4 pages #bbj sq4747 ,the 
,maoris of ,new ,zealand say that ,tiki 
made man after his own image4 ,he took  
red clay1 kneaded it1 like the          
,babylonian ,bel1 with his own blood1   
fashioned it in human form1 and gave the
 image breath4 ,as he had made man in   
his own likeness he called him          
,tiki-ahua or ,tiki's likeness4 7,r4    
,taylor ,te ,ika ,a ,maui1 or ,new      
,zealand and its ,inhabitants1 ,second  
,edition 7,london1 #ahgj71 page #aag4   
,compare ,e4 ,shortland1 ,maori         

,religion and ,mythology 7,london1      
#ahhb71 pages #ba sq47 ,a very generally
 received tradition in ,tahiti was that 
the first human pair was made by        
,taaroa1 the chief god4 ,they say that  
after he had formed the world he created
 man out of red earth1 which was also   
the food of mankind until bread-fruit   
was produced4 ,further1 some say that   
one day ,taaroa called for the man by   
name1 and when he came he made him fall 
asleep4 ,as he slept1 the creator took  
out one of his bones 7ivi7 and made a   
woman of it1 whom he gave to the man to 
be his wife1 and the pair became the    
progenitors of mankind4 ,this narrative 
was taken down from the lips of the     
natives in the early years of the       
mission to ,tahiti4 ,the missionary who 
records it observes3 ,this always       
appeared to me a mere recital of the    
,mosaic account of creation1 which they 
had heard from some ,european1 and ,i   
never placed any reliance on it1        
although they have repeatedly told me it

 was a tradition among them before any  
foreigner arrived4 ,some have also      
stated that the woman's name was ,ivi1  
which would be by them pronounced as if 
written ,eve4 ,ivi is an aboriginal     
word1 and not only signifies a bone1 but
 also a widow1 and a victim slain in    
war4 ,notwithstanding the assertion of  
the natives1 ,i am disposed to think    
that ,ivi1 or ,eve1 is the only         
aboriginal part of the story1 as far as 
it respects the mother of the human     
race4 7,w4 ,ellis1 ,polynesian          
,researches1 ,second ,edition 7,london1 
#ahcb71 ,i4 #aaj sq4 ,ivi or iwi is the 
regular word for bone in the various    
,polynesian languages4 ,see ,e4         
,tregear1 ,the ,maori-,polynesian       
,comparative ,dictionary 7,wellington1  
,new ,zealand1 #ahia71 page #aji47      
,however1 the same tradition has been   
recorded in other parts of ,polynesia   
besides ,tahiti4 ,thus the natives of   
,fakaofo or ,bowditch ,island say that  
the first man was produced out of a     

stone4 ,after a time he bethought him of
 making a woman4 ,so he gathered earth  
and moulded the figure of a woman out of
 it1 and having done so he took a rib   
out of his left side and thrust it into 
the earthen figure1 which thereupon     
started up a live woman4 ,he called her 
,ivi 7,eevee7 or rib and took her to    
wife1 and the whole human race sprang   
from this pair4 7,g4 ,turner1 ,samoa    
7,london1 #ahhd71 pages #bfg sq47 ,the  
,maoris also are reported to believe    
that the first woman was made out of the
 first man's ribs4 7,j4,l4 ,nicholas1   
,narrative of a ,voyage to ,new ,zealand
 7,london1 #ahag71 ,i4 #ei1 who writes  
and to add still more to this strange   
coincidence1 the general term for bone  
is ',hevee'47 ,this wide diffusion of   
the story in ,polynesia raises a doubt  
whether it is merely1 as ,ellis thought1
 a repetition of the ,biblical narrative
 learned from ,europeans4 ,in ,nui1 or  
,netherland ,island1 it was the god     
,aulialia who made earthen models of a  

man and woman1 raised them up1 and made 
them live4 ,he called the man ,tepapa   
and the woman ,tetata4 7,g4 ,turner1    
,samoa1 pages #cjj sq47  ,in the ,pelew 
,islands they say that a brother and    
sister made men out of clay kneaded with
 the blood of various animals1 and that 
the characters of these first men and of
 their descendants were determined by   
the characters of the animals whose     
blood had been kneaded with the         
primordial clay2 for instance1 men who  
have rat's blood in them are thieves1   
men who have serpent's blood in them are
 sneaks1 and men who have cock's blood  
in them are brave4 7,j4 ,kubary1 ,die   
,religion der ,pelauer1 in ,a4          
,bastian's ,allerlei aus ,volks- und    
,menschenkunde 7,berlin1 #ahhh71 ,i4 #c1
 #ef47 ,according to a ,melanesian      
legend1 told in ,mota1 one of the ,banks
 ,islands1 the hero ,qat moulded men of 
clay1 the red clay from the marshy      
river-side at ,vanua ,lava4 ,at first he
 made men and pigs just alike1 but his  

brothers remonstrated with him1 so he   
beat down the pigs to go on all fours   
and made men walk upright4 ,qat         
fashioned the first woman out of supple 
twigs1 and when she smiled he knew she  
was a living woman4 7,r4,h4 ,codrington1
 ,the ,melanesians 7,oxford1 #ahia71    
page #aeh47 ,a somewhat different       
version of the ,melanesian story is told
 at ,lakona1 in ,santa ,maria4 ,there   
they say that ,qat and another spirit   
7vui7 called ,marawa both made men4 ,qat
 made them out of the wood of           
dracaena-trees4 ,six days he worked at  
them1 carving their limbs and fitting   
them together4 ,then he allowed them six
 days to come to life4 ,three days he   
hid them away1 and three days more he   
worked to make them live4 ,he set them  
up and danced to them and beat his drum1
 and little by little they stirred1 till
 at last they could stand all by        
themselves4 ,then ,qat divided them into
 pairs and called each pair husband and 
wife4 ,marawa also made men out of a    

tree1 but it was a different tree1 the  
tavisoviso4 ,he likewise worked at them 
six days1 beat his drum1 and made them  
live1 just as ,qat did4 ,but when he saw
 them move1 he dug a pit and buried them
 in it for six days1 and then1 when he  
scraped away the earth to see what they 
were doing1 he found them all rotten and
 stinking4 ,that was the origin of      
death4 7,r4,h4 ,codrington op4 cit41    
pages #aeg sq47  ,the inhabitants of    
,noo-,hoo-roa1 in the ,kei ,islands say 
that their ancestors were fashioned out 
of clay by the supreme god1 ,dooadlera1 
who breathed life into the clay figures4
 7,c4,m4 ,pleyte1 ,ethnographische      
,beschrijving der ,kei-,eilanden1       
,tijdschrift van het ,nederlandsch      
,aardrijkskundig ,genootschap1 ,tweede  
,serie ,x4 7#ahic71 page #efd47 ,the    
aborigines of ,minahassa1 in the north  
of ,celebes1 say that two beings called 
,wailan ,wangko and ,wangi were alone on
 an island1 on which grew a cocoa-nut   
tree4 ,said ,wailan ,wangko to ,wangi1  

,remain on earth while ,i climb up the  
tree4 ,said ,wangi to ,wailan ,wangko1  
,good4 ,but then a thought occurred to  
,wangi and he climbed up the tree to ask
 ,wailan ,wangko why he1 ,wangi1 should 
remain down there all alone4 ,said      
,wailan ,wangko to ,wangi1 ,return and  
take earth and make two images1 a man   
and a woman4 ,wangi did so1 and both    
images were men who could move but could
 not speak4 ,so ,wangi climbed up the   
tree to ask ,wailan ,wangko1 ,how now8  
,the two images are made1 but they      
cannot speak4 ,said ,wailan ,wangko to  
,wangi1 ,take this ginger and go and    
blow it on the skulls and the ears of   
these two images1 that they may be able 
to speak2 call the man ,adam and the    
woman ,ewa4 7,n4 ,graafland ,de         
,minahassa 7,rotterdam1 #ahfi71 ,i4     
pages #if sq47 ,in this narrative the   
names of the man and woman betray       
,european influence1 but the rest of the
 story may be aboriginal4 ,the ,dyaks of
 ,sakarran in ,british ,borneo say that 

the first man was made by two large     
birds4 ,at first they tried to make men 
out of trees1 but in vain4 ,then they   
hewed them out of rocks1 but the figures
 could not speak4 ,then they moulded a  
man out of damp earth and infused into  
his veins the red gum of the            
kumpang-tree4 ,after that they called to
 him and he answered2 they cut him and  
blood flowed from his wounds4           
7,horsburgh1 quoted by ,h4 ,ling ,roth1 
,the ,natives of ,sarawak and of        
,british ,north ,borneo 7,london1       
#ahif71 ,i4 pages #bii sq4 ,compare ,the
 ,lord ,bishop of ,labuan1 ,on the ,wild
 ,tribes of the ,north-,west ,coast of  
,borneo1 ,transactions of the           
,ethnological ,society of ,london1 ,new 
,series1 ,,ii4 7#ahfc71 page #bg47  ,the
 ,kumis of ,south-,eastern ,india       
related to ,captain ,lewin1 the ,deputy 
,commissioner of ,hill ,tracts1 the     
following tradition of the creation of  
man4 ,god made the world and the trees  
and the creeping things first1 and after

 that he set to work to make one man and
 one woman1 forming their bodies of     
clay2 but each night1 on the completion 
of his work1 there came a great snake1  
which1 while ,god was sleeping1 devoured
 the two images4 ,this happened twice or
 thrice1 and ,god was at his wit's end1 
for he had to work all day1 and could   
not finish the pair in less than twelve 
hours2 besides1 if he did not sleep1 he 
would be no good1 said ,captain ,lewin's
 informant4 ,if he were not obliged to  
sleep1 there would be no death1 nor     
would mankind be afflicted with illness4
 ,it is when he rests that the snake    
carries us off to this day4 ,well1 he   
was at his wit's end1 so at last he got 
up early one morning and first made a   
dog and put life into it1 and that      
night1 when he had finished the images1 
he set the dog to watch them1 and when  
the snake came1 the dog barked and      
frightened it away4 ,this is the reason 
at this day that when a man is dying the
 dogs begin to howl2 but ,i suppose ,god

 sleeps heavily now-a-days1 or the snake
 is bolder1 for men die all the same4   
7,capt4 ,t4,h4 ,lewin1 ,wild ,races of  
,south-,eastern ,india 7,london1 #ahgj71
 pages #bbd-bf47 ,the ,khasis of ,assam 
tell a similar tale4 7,a4 ,bastian1     
,volkerstamme am ,brahmaputra und       
verwandtschaftliche ,nachbarn 7,berlin1 
#ahhc71 page #h2 ,major ,p4,r4,t4       
,gurdon1 ,the ,khasis 7,london1 #aijg71 
page #ajf47  ,the ,ewe-speaking tribes  
of ,togo-land1 in ,west ,africa1 think  
that ,god still makes men out of clay4  
,when a little of the water with which  
he moistens the clay remains over1 he   
pours it on the ground and out of that  
he makes the bad and disobedient people4
 ,when he wishes to make a good man he  
makes him out of good clay2 but when he 
wishes to make a bad man1 he employs    
only bad clay for the purpose4 ,in the  
beginning ,god fashioned a man and set  
him on the earth2 after that he         
fashioned a woman4 ,the two looked at   
each other and began to laugh1 whereupon

 ,god sent them into the world4 7,j4    
,spieth1 ,die ,ewe-,stamme1 ,material   
zur ,kunde des ,ewe-,volkes in          
,deutsch-,togo 7,berlin1 #aijf71 pages  
#hbh1 #hdj47 ,the ,innuit or ,esquimaux 
of ,point ,barrow1 in ,alaska1 tell of a
 time when there was no man in the land1
 till a spirit named a se lu1 who       
resided at ,point ,barrow1 made a clay  
man1 set him up on the shore to dry1    
breathed into him and gave him life4    
7,report of the ,international          
,expedition to ,point ,barrow           
7,washington1 #ahhe71 page #dg47 ,other 
,esquimaux of ,alaska relate how the    
,raven made the first woman out of clay 
to be a companion to the first man2 he  
fastened water-grass to the back of the 
head to be hair1 flapped his wings over 
the clay figure1 and it arose1 a        
beautiful young woman4 7,e4,w4 ,nelson1 
,the ,eskimo about ,bering ,strait1     
,eighteenth ,annual ,report of the      
,bureau of ,american ,ethnology1 ,part  
,i4 7,washington1 #ahii71 page #ded47   

,the ,acagchemem ,indians of ,california
 said that a powerful being called      
,chinigchinich created man out of clay  
which he found on the banks of a lake2  
male and female created he them1 and the
 ,indians of the present day are their  
descendants4 7,friar ,geronimo ,boscana1
 ,chinigchinich1 appended to 7,a4       
,robinson's7 ,life in ,california 7,new 
,york1 #ahdf71 page #bdg47 ,a priest of 
the ,natchez ,indians in ,louisiana told
 ,du ,pratz that ,god had kneaded some  
clay1 such as that which potters use and
 had made it into a little man2 and that
 after examining it1 and finding it well
 formed1 he blew up his work1 and       
forthwith that little man had life1     
grew1 acted1 walked1 and found himself a
 man perfectly well shaped4 ,as to the  
mode in which the first woman was       
created1 the priest had no information1 
but thought she was probably made in the
 same way as the first man2 so ,du      
,pratz corrected his imperfect notions  
by reference to ,scripture4 7,m4 ,le    

,page ,du ,pratz1 ,the ,history of      
,louisiana 7,london1 #aggd71 page #ccj47
 ,the ,michoacans of ,mexico said that  
the great god ,tucapacha first made man 
and woman out of clay1 but that when the
 couple went to bathe in a river they   
absorbed so much water that the clay of 
which they were composed all fell to    
pieces4 ,then the creator went to work  
again and moulded them afresh out of    
ashes1 and after that he essayed a third
 time and made them of metal4 ,this last
 attempt succeeded4 ,the metal man and  
woman bathed in the river without       
falling to pieces1 and by their union   
they became the progenitors of mankind4 
7,a4 de ,herrera1 ,general ,history of  
the vast ,continent and ,islands of     
,america1 translated into ,english by   
,capt4 ,j4 ,stevens 7,london1 #agbe1    
#agbf71 ,,iii4 #bed2 ,brasseur de       
,bourbourg1 ,histoire des ,nations      
,civilisees du ,mexique et de           
l',amerique-,centrale 7,paris1          
#aheg--ahei71 ,,iii4 #hj sq2 compare id4

 ,i4 #ed sq47  ,according to a legend of
 the ,peruvian ,indians1 which was told 
to a ,spanish priest in ,cuzco about    
half a century after the conquest1 it   
was in ,tiahuanaco that man was first   
created1 or at least was created afresh 
after the deluge4 ,there 7in            
,tiahuanaco71 so runs the legend1 the   
,creator began to raise up the people   
and nations that are in that region1    
making one of each nation of clay1 and  
painting the dresses that each one was  
to wear2 those that were to wear their  
hair1 with hair1 and those that were to 
be shorn1 with hair cut4 ,and to each   
nation was given the language1 that was 
to be spoken1 and the songs to be sung1 
and the seeds and food that they were to
 sow4 ,when the ,creator had finished   
painting and making the said nations and
 figures of clay1 he gave life and soul 
to each one1 as well men as women1 and  
ordered that they should pass under the 
earth4 ,thence each nation came up in   
the places to which he ordered them to  

go4 7,e4,j4 ,payne1 ,history of the ,new
 ,world called ,america1 ,i4 7,oxford1  
#ahib71 page #dfb47  ,these examples    
suffice to prove that the theory of the 
creation of man out of dust or clay has 
been current among savages in many parts
 of the world4 ,but it is by no means   
the only explanation which the savage   
philosopher has given of the beginnings 
of human life on earth4 ,struck by the  
resemblances which may be traced between
 himself and the beasts1 he has often   
supposed1 like ,darwin himself1 that    
mankind has been developed out of lower 
forms of animal life4 ,for the simple   
savage has none of that high notion of  
the transcendant dignity of man which   
makes so many superior persons shrink   
with horror from the suggestion that    
they are distant cousins of the brutes4 
,he on the contrary is not too proud to 
own his humble relations2 indeed his    
difficulty often is to perceive the     
distinction between him and them4       
,questioned by a missionary1 a ,bushman 

of more than average intelligence could 
not state any difference between a man  
and a brute--he did not know but a      
buffalo might shoot with bows and arrows
 as well as man1 if it had them4        
7,reverend ,john ,campbell1 ,travels in 
,south ,africa 7,london1 #ahbb1 ,,ii4   
page #cd47 ,when the ,russians first    
landed on one of the ,alaskan islands1  
the natives took them for cuttle-fish on
 account of the buttons on their        
clothes4 7,i4 ,petroff1 ,report on the  
,population1 ,industries1 and ,resources
 of ,alaska1 page #ade47 ,the ,giliaks  
of the ,amoor think that the outward    
form and size of an animal are only     
apparent2 in substance every beast is a 
real man1 just like a ,giliak himself1  
only endowed with an intelligence and   
strength1 which often surpass those of  
mere ordinary human beings4 7,l4        
,sternberg1 ,die ,religion der          
,giljaken1 ,archiv fur                  
,religionswissenschaft1 ,,viii4 7#aije71
 page #bdh47 ,the ,borororos1 an ,indian

 tribe of ,brazil1 will have it that    
they are parrots of a gorgeous red      
plumage which live in their native      
forests4 ,accordingly they treat the    
birds as their fellow-tribesmen1 keeping
 them in captivity1 refusing to eat     
their flesh1 and mourning for them when 
they die4 7,k4 von den ,steinen1 ,unter 
den ,naturvolkern ,zentral-,brasiliens  
7,berlin1 #ahid71 pages #ceb sq41       
#eab477  ,this sense of the close       
relationship of man to the lower        
creation is the essence of totemism1    
that curious system of superstition     
which unites by a mystic bond a group of
 human kinsfolk to a species of animals 
or plants4 ,where that system exists in 
full force1 the members of a totem clan 
identify themselves with their totem    
animals in a way and to an extent which 
we find it hard even to imagine4 ,for   
example1 men of the ,cassowary clan in  
,mabuiag think that cassowaries are men 
or nearly so4 ,cassowary1 he all same as
 relation1 he belong same family1 is the

 account they give of their relationship
 with the long-legged bird4 ,conversely 
they hold that they themselves are      
cassowaries for all practical purposes4 
,they pride themselves on having long   
thin legs like a cassowary4 ,this       
reflection affords them peculiar        
satisfaction when they go out to fight1 
or to run away1 as the case may be2 for 
at such times a ,cassowary man will say 
to himself1 ,my leg is long and thin1 ,i
 can run and not feel tired2 my legs    
will go quickly and the grass will not  
entangle them4 ,members of the          
,cassowary clan are reputed to be       
pugnacious1 because the cassowary is a  
bird of very uncertain temper and can   
kick with extreme violence4 7,a4,c4     
,haddon1 ,the ,ethnography of the       
,western ,tribe of ,torres ,straits1    
,journal of the ,anthropological        
,institute1 ,,xix4 7#ahij71 page #cic2  
,reports of the ,cambridge              
,anthropological ,expedition to ,torres 
,straits1 ,v4 7,cambridge1 #aijd71 pages

 #aff1 #ahd47 ,so among the ,ojibways   
men of the ,bear clan are reputed to be 
surly and pugnacious like bears1 and men
 of the ,crane clan to have clear       
ringing voices like cranes4 7,w4,w4     
,warren1 ,history of the ,ojibways1     
,collections of the ,minnesota          
,historical ,society1 ,v4 7,saint ,paul1
 ,minn4 #ahhe71 pages #dg1 #di47 ,hence 
the savage will often speak of his totem
 animal as his father or his brother1   
and will neither kill it himself nor    
allow others to do so1 if he can help   
it4 ,for example1 if somebody were to   
kill a bird in the presence of a native 
,australian who had the bird for his    
totem1 the black might say1 ,what for   
you kill that fellow8 that my father6 or
 ,that brother belonging to me you have 
killed2 why did you do it8 7,e4 ,palmer1
 ,notes on some ,australian ,tribes1    
,journal of the ,anthropological        
,institute1 ,,xiii4 7#ahhd71 page #cjj47
 ,bechuanas of the ,porcupine clan are  
greatly afflicted if anybody hurts or   

kills a porcupine in their presence4    
,they say1 ,they have killed our        
brother1 our master1 one of ourselves1  
him whom we sing of2 and so saying they 
piously gather the quills of their      
murdered brother1 spit on them1 and rub 
their eyebrows with them4 ,they think   
they would die if they touched its      
flesh4 ,in like manner ,bechuanas of the
 ,crocodile clan call the crocodile one 
of themselves1 their master1 their      
brother2 and they mark the ears of their
 cattle with a long slit like a         
crocodile's mouth by way of a family    
crest4 ,similarly ,bechuanas of the     
,lion clan would not1 like the members  
of other clans1 partake of lion's flesh2
 for how1 say they1 could they eat their
 grandfather8 ,if they are forced in    
self-defence to kill a lion1 they do so 
with great regret and rub their eyes    
carefully with its skin1 fearing to lose
 their sight if they neglected this     
precaution4 7,t4 ,arbousset et ,f4      
,daumas1 ,relation d'un ,voyage         

d',exploration au ,nord-,est de la      
,colonie du ,cap de ,bonne-,esperance   
7,paris1 #ahdb71 pages #cdi sq41        
#dbb-bd47 ,a ,mandingo porter has been  
known to offer the whole of his month's 
pay to save the life of a python1       
because the python was his totem and he 
therefore regarded the reptile as his   
relation2 he thought that if he allowed 
the creature to be killed1 the whole of 
his own family would perish1 probably   
through the vengeance to be taken by the
 reptile kinsfolk of the murdered       
serpent4 7,m4 le ,docteur ,tautain1     
,notes sur les ,croyances et ,pratiques 
,religieuses des ,banmanas1 ,revue      
d',ethnographie1 ,,iii4 7#ahhe71 pages  
#cif sq42 ,a4 ,rancon1 ,dans la         
,haute-,gambie1 ,voyage d',exploration  
,scientifique 7,paris1 #ahid71 page     
#dde47  ,sometimes1 indeed1 the savage  
goes further and identifies the revered 
animal not merely with a kinsman but    
with himself2 he imagines that one of   
his own more or less numerous souls1 or 

at all events that a vital part of      
himself1 is in the beast1 so that if it 
is killed he must die4 ,thus1 the       
,balong tribe of the ,cameroons1 in     
,west ,africa1 think that every man has 
several souls1 of which one is lodged in
 an elephant1 a wild boar1 a leopard1 or
 what not4 ,when any one comes home1    
feels ill1 and says1 ,i shall soon die1 
and is as good as his word1 his friends 
are of opinion that one of his souls has
 been shot by a hunter in a wild boar or
 a leopard1 for example1 and that that  
is the real cause of his death4 7,j4    
,keller1 ,ueber das ,land und ,volk der 
,balong1 ,deutsches ,kolonialblatt1 #a  
,october1 #ahie1 page #dhd47 ,a         
,catholic missionary1 sleeping in the   
hut of a chief of the ,fan negroes1     
awoke in the middle of the night to see 
a huge black serpent of the most        
dangerous sort in the act of darting at 
him4 ,he was about to shoot it when the 
chief stopped him1 saying1 ,in killing  
that serpent1 it is me that you would   

have killed4 ,fear nothing1 the serpent 
is my elangela4 7,father ,trilles1 ,chez
 les ,fang1 leurs ,moeurs1 leur ,langue1
 leur ,religion1 ,les ,missions         
,catholiques1 ,,xxx4 7#ahih71 page      
#cbb47 ,at ,calabar there used to be    
some years ago a huge old crocodile     
which was well known to contain the     
spirit of a chief who resided in the    
flesh at ,duke ,town4 ,sporting         
,vice-,consuls1 with a reckless         
disregard of human life1 from time to   
time made determined attempts to injure 
the animal1 and once a peculiarly active
 officer succeeded in hitting it4 ,the  
chief was immediately laid up with a    
wound in his leg4 ,he ,,said that a dog 
had bitten him1 but few people perhaps  
were deceived by so flimsy a pretext4   
7,miss ,mary ,h4 ,kingsley1 ,travels in 
,west ,africa 7,london1 #ahig71 pages   
#ech sq4 ,as to the external or bush    
souls of human beings1 which in this    
part of ,africa are supposed to be      
lodged in the bodies of animals1 see    

,miss ,mary ,h4 ,kingsley op4 cit4 pages
 #dei-dfa2 ,r4 ,henshaw1 ,notes on the  
,efik belief in 'bush soul'1 ,man1      
,,vi47#aijf71 pages #aba sq42 ,j4       
,parkinson1 ,notes on the ,asaba people 
7,ibos7 of the ,niger1 ,journal of the  
,anthropological ,institute1 ,,xxxvi4   
7#aijf71 pages #cad sq47 ,once when ,mr 
,partridge's canoe-men were about to    
catch fish near an ,assiga town in      
,southern ,nigeria1 the natives of the  
town objected1 saying1 ,our souls live  
in those fish1 and if you kill them we  
shall die4 7,charles ,partridge1 ,cross 
,river ,natives 7,london1 #aije71 pages 
#bbe sq47 ,on another occasion1 in the  
same region1 an ,englishman shot a      
hippopotamus near a native village4 ,the
 same night a woman died in the village1
 and her friends demanded and obtained  
from the marksman five pounds as        
compensation for the murder of the      
woman1 whose soul or second self had    
been in that hippopotamus4 7,c4,h4      
,robinson1 ,hausaland 7,london1 #ahif71 

pages #cf sq47 ,similarly at ,ndolo1 in 
the ,congo region1 we hear of a chief   
whose life was bound up with a          
hippopotamus1 but he prudently suffered 
no one to fire at the animal4 7,notes   
,analytiques sur les ,collections       
,ethnographiques du ,musee du ,congo1   
,i4 7,brussels1 #aijb-jf71 page #aej47  
,amongst people who thus fail to        
perceive any sharp line of distinction  
between beasts and men it is not        
surprising to meet with the belief that 
human beings are directly descended from
 animals4 ,such a belief is often found 
among totemic tribes who imagine that   
their ancestors sprang from their       
totemic animals or plants2 but it is by 
no means confined to them4 ,thus1 to    
take instances1 some of the ,californian
 ,indians1 in whose mythology the coyote
 or prairie-wolf is a leading personage1
 think that they are descended from     
coyotes4 ,at first they walked on all   
fours2 then they began to have some     
members of the human body1 one finger1  

one toe1 one eye1 one ear1 and so on2   
then they got two fingers1 two toes1 two
 eyes1 two ears1 and so forth2 till at  
last1 progressing from period to period1
 they became perfect human beings4 ,the 
loss of their tails1 which they still   
deplore1 was produced by the habit of   
sitting upright4 7,h4,r4 ,schoolcraft1  
,indian ,tribes of the ,united ,states1 
,,iv4 7,philadelphia1 #ahef71 pages #bbd
 sq42 compare id4 ,v4 page #bag4 ,the   
descent of some1 not all1 ,indians from 
coyotes is mentioned also by ,friar     
,boscana1 in 7,a4 ,robinson's7 ,life in 
,california 7,new ,york1 #ahdf71 page   
#bii47 ,similarly ,darwin thought that  
the tail has disappeared in man and the 
anthropomorphous apes1 owing to the     
terminal portion having been injured by 
friction during a long lapse of time2   
the basal and embedded portion having   
been reduced and modified1 so as to     
become suitable to the erect or         
semi-erect position4 7,charles ,darwin1 
,the ,descent of ,man1 ,second ,edition 

7,london1 #ahgi71 page #fj47 ,the       
,turtle clam of the ,iroquois think that
 they are descended from real mud       
turtles which used to live in a pool4   
,one hot summer the pool dried up1 and  
the mud turtles set out to find another4
 ,a very fat turtle1 waddling after the 
rest in the heat1 was much incommoded by
 the weight of his shell1 till by a     
great effort he heaved it off           
altogether4 ,after that he gradually    
developed into a man and became the     
progenitor of the ,turtle clan4 7,e4,a4 
,smith1 ,myths of the ,iroquois1 ,second
 ,annual ,report of the ,bureau of      
,ethnology 7,washington1 #ahhc71 page   
#gg47 ,the ,crawfish band of the        
,choctaws are in like manner descended  
from real crawfish1 which used to live  
under ground1 only coming up            
occasionally through the mud to the     
surface4 ,once a party of ,choctaws     
smoked them out1 taught them the        
,choctaw language1 taught them to walk  
on two legs1 made them cut off their toe

 nails and pluck the hair from their    
bodies1 after which they adopted them   
into the tribe4 ,but the rest of their  
kindred1 the crawfish1 are crawfish     
under ground to this day4 7,geo4        
,catlin1 ,north ,american ,indians #d   
7,london1 #ahdd71 ,,ii4 page #abh47 ,the
 ,osage ,indians universally believed   
that they were descended from a male    
snail and a female beaver4 ,a flood     
swept the snail down to the ,missouri   
and left him high and dry on the bank1  
where the sun ripened him into a man4   
,he met and married a beaver maid1 and  
from the pair the tribe of the ,osages  
is descended4 ,for a long time these    
,indians retained a pious reverence for 
their animal ancestors and refrained    
from hunting beavers1 because in killing
 a beaver they killed a brother of the  
,osages4 ,but when white men came among 
them and offered high prices for beaver 
skins1 the ,osages yielded to the       
temptation and took the lives of their  
furry brethren4 7,lewis and ,clarke1    

,travels to the ,source of the ,missouri
 ,river 7,london1 #ahae71 ,i4 #ab 7,vol4
 ,i4 pages #dd sq4 of the ,london       
reprint1 #aije747 ,the ,carp clan of the
 ,ootawak ,indians are descended from   
the eggs of a carp which had been       
deposited by the fish on the banks of a 
stream and warmed by the sun4 7,lettres 
,edifiantes et ,curieuses1 ,nouvelle    
,edition1 ,,vi4 7,paris1 #agha71 page   
#aga47 ,the ,crane clan of the ,ojibways
 are sprung originally from a pair of   
cranes1 which after long wanderings     
settled on the rapids at the outlet of  
,lake ,superior1 where they were changed
 by the ,great ,spirit into a man and   
woman4 7,l4,h4 ,morgan1 ,ancient        
,society 7,london1 #ahgg71 page #ahj47  
,the members of two ,omaha clans were   
originally buffaloes and lived1 oddly   
enough1 under water1 which they splashed
 about1 making it muddy4 ,and at death  
all the members of these clans went back
 to their ancestors the buffaloes4 ,so  
when one of them lay adying1 his friends

 used to wrap him up in a buffalo skin  
with the hair outside and say to him1   
,you came hither from the animals and   
you are going back thither4 ,do not face
 this way again4 ,when you go1 continue 
walking4 7,j4 ,owen ,dorsey1 ,omaha     
,sociology1 ,third ,annual ,report of   
the ,bureau of ,ethnology 7,washington1 
#ahhd71 pages #bbi1 #bcc47 ,the ,haida  
,indians of ,queen ,charlotte ,islands  
believe that long ago the raven1 who is 
the chief figure in the mythology of    
,north-,west ,america1 took a cockle    
from the beach and married it2 the      
cockle gave birth to a female child1    
whom the raven took to wife1 and from   
their union the ,indians were produced4 
7,g4,m4 ,dawson1 ,report on the ,queen  
,charlotte ,islands 7,montreal1 #ahhj71 
pages #adi;,b sq4 7,geological ,survey  
of ,canada72 ,f4 ,poole1 ,queen         
,charlotte ,islands1 page #acf47 ,the   
,delaware ,indians called the           
rattle-snake their grandfather and would
 on no account destroy one of these     

reptiles1 believing that were they to do
 so the whole race of rattle-snakes     
would rise up and bite them4 ,under the 
influence of the white man1 however1    
their respect for their grandfather the 
rattle-snake gradually died away1 till  
at last they killed him without         
compunction or ceremony whenever they   
met him4 ,the writer who records the old
 custom observes that he had often      
reflected on the curious connection     
which appears to subsist in the mind of 
an ,indian between man and the brute    
creation2 all animated nature1 says he1 
in whatever degree1 is in their eyes a  
great whole1 from which they have not   
yet ventured to separate themselves4    
7,rev4 ,john ,heckewelder1 ,an ,account 
of the ,history1 ,manners1 and ,customs1
 of the ,indian ,nations1 who once      
inhabited ,pennsylvania and the         
,neighbouring ,states1 ,transactions of 
the ,historical and ,literary ,committee
 of the ,american ,philosophical        
,society1 ,i4 7,philadelphia1 #ahai71   

pages #bde1 #bdg1 #bdh47  ,some of the  
,indians of ,peru boasted of being      
descended from the puma or ,american    
lion2 hence they adored the lion as a   
god and appeared at festivals like      
,hercules dressed in the skins of lions 
with the heads of the beasts fixed over 
their own4 ,others claimed to be sprung 
from condors and attired themselves in  
great black and white wings1 like that  
enormous bird4 7,garcilasso de la ,vega1
 ,first ,part of the ,royal             
,commentaries of the ,yncas1 ,vol4 ,i4  
page #cbc1 ,vol4 ,,ii4 page #aef        
7,markham's translation747 ,the ,wanika 
of ,east ,africa look upon the hyaena as
 one of their ancestors or as associated
 in some way with their origin and      
destiny4 ,the death of a hyaena is      
mourned by the whole people1 and the    
greatest funeral ceremonies which they  
perform are performed for this brute4   
,the wake held over a chief is as       
nothing compared to the wake held over a
 hyaena2 one tribe only mourns the death

 of its chief1 but all the tribes unite 
to celebrate the obsequies of a hyaena4 
7,charles ,new1 ,life1 ,wanderings1 and 
,labours in ,eastern ,africa 7,london1  
#ahgc7 page #abb47 ,some ,malagasy      
families claim to be descended from the 
babacoote 7,lichanotus brevicaudatus71 a
 large lemur of grave appearance and    
staid demeanour1 which lives in the     
depth of the forest4 ,when they find one
 of these creatures dead1 his human     
descendants bury it solemnly1 digging a 
grave for it1 wrapping it in a shroud1  
and weeping and lamenting over its      
carcase4 ,a doctor who had shot a       
babacoote was accused by the inhabitants
 of a ,betsimisaraka village of having  
killed one of their grandfathers in the 
forest1 and to appease their indignation
 he had to promise not to skin the      
animal in the village but in a solitary 
place where nobody could see him4       
7,father ,abinal1 ,croyances fabuleuses 
des ,malgaches1 ,les ,missions          
,catholiques1 ,,xii4 7#ahhj71 page #ebf2

 ,g4,h4 ,smith1 ,some ,betsimisaraka    
superstitions1 ,the ,antananarivo       
,annual and ,madagascar ,magazine1 ,no4 
#aj 7,antananarivo1 #ahhf71 page #bci2  
,h4,w4 ,little1 ,madagascar1 its        
,history and ,people 7,london1 #ahhd71  
pages #cba sq2 ,a4 van ,gennep1 ,tabou  
et ,totemisme a ,madagascar 7,paris1    
#aijd71 pages #bad sqq47 ,many of the   
,betsimisaraka believe that the curious 
nocturnal animal called the aye-aye     
7,cheiromys madagascariensis7 is the    
embodiment of their forefathers1 and    
hence will not touch it1 much less do it
 an injury4 ,it is said that when one is
 discovered dead in the forest1 these   
people make a tomb for it and bury it   
with all the forms of a funeral4 ,they  
think that if they attempt to entrap it1
 they will surely die in consequence4   
7,g4,a4 ,shaw1 ,the ,aye-aye1           
,antananarivo ,annual and ,madagascar   
,magazine1 ,vol4 ,,ii4 7,antananarivo1  
#ahif71 pages #bja1 #bjc 7,reprint of   
the ,second four ,numbers74 ,compare ,a4

 van ,gennep1 ,tabou et ,totemisme a    
,madagascar1 pages #bbc sq47 ,some      
,malagasy tribes believe themselves     
descended from crocodiles and           
accordingly they deem the formidable    
reptiles their brothers4 ,if one of     
these scaly brothers so far forgets the 
ties of kinship as to devour a man1 the 
chief of the tribe1 or in his absence an
 old man familiar with the tribal       
customs1 repairs at the head of the     
people to the edge of the water1 and    
summons the family of the culprit to    
deliver him up to the arm of justice4 ,a
 hook is then baited and cast into the  
river or lake4 ,next day the guilty     
brother or one of his family is dragged 
ashore1 formally tried1 sentenced to    
death1 and executed4 ,the claims of     
justice being thus satisfied1 the dead  
animal is lamented and buried like a    
kinsman2 a mound is raised over his     
grave and a stone marks the place of his
 head4 7,father ,abinal1 ,croyances     
fabuleuses des ,malgaches1 ,les         

,missions ,catholiques1 ,,xii4 7#ahhj71 
page #ebg2 ,a4 van ,gennep1 ,tabou et   
,totemisme a ,madagascar1 pages #bha    
sq47  ,amongst the ,tshi-speaking tribes
 of the ,gold ,coast in ,west ,africa   
the ,horse-mackerel family traces its   
descent from a real horse-mackerel whom 
an ancestor of theirs once took to wife4
 ,she lived with him happily in human   
shape on shore till one day a second    
wife1 whom the man had married1 cruelly 
taunted her with being nothing but a    
fish4 ,that hurt her so much that       
bidding her husband farewell she        
returned to her old home in the sea1    
with her youngest child in her arms1 and
 never came back again4 ,but ever since 
the ,horse-mackerel people have         
refrained from eating horse-mackerels1  
because the lost wife and mother was a  
fish of that sort4 7,a4,b4 ,ellis1 ,the 
,tshi-speaking ,peoples of the ,gold    
,coast of ,west ,africa 7,london1       
#ahhg71 pages #bjh-aa4 ,a similar tale  
is told by another fish family who      

abstain from eating the fish 7appei7    
from which they take their name 7,a4,b4 
,ellis op4 cit4 pages #baa sq4747 ,some 
of the ,land ,dyaks of ,borneo tell a   
similar tale to explain a similar       
custom4 ,there is a fish which is taken 
in their rivers called a puttin1 which  
they would on no account touch1 under   
the idea that if they did they would be 
eating their relations4 ,the tradition  
respecting it is1 that a solitary old   
man went out fishing and caught a       
puttin1 which he dragged out of the     
water and laid down in his boat4 ,on    
turning round1 he found it had changed  
into a very pretty little girl4         
,conceiving the idea she would make1    
what he had long wished for1 a charming 
wife for his son1 he took her home and  
educated her until she was fit to be    
married4 ,she consented to be the son's 
wife cautioning her husband to use her  
well4 ,some time after their marriage1  
however1 being out of temper1 he struck 
her1 when she screamed1 and rushed away 

into the water2 but not without leaving 
behind her a beautiful daughter1 who    
became afterwards the mother of the     
race4 7,the ,lord ,bishop of ,labuan1   
,on the ,wild ,tribes of the            
,north-,west ,coast of ,borneo1         
,transactions of the ,ethnological      
,society of ,london1 ,new ,series ,,ii4 
7,london1 #ahfc71 pages #bf sq4 ,such   
stories conform to a well-known type    
which may be called the ,swan-,maiden   
type of story1 or ,beauty and the       
,beast1 or ,cupid and ,psyche4 ,the     
occurrence of stories of this type among
 totemic peoples1 such as the           
,tshi-speaking negroes of the ,gold     
,coast1 who tell them to explain their  
totemic taboos1 suggests that all such  
tales may have originated in totemism4  
,i shall deal with this question        
elsewhere47  ,members of a clan in      
,mandailing1 on the west coast of       
,sumatra1 assert that they are descended
 from a tiger1 and at the present day1  
when a tiger is shot1 the women of the  

clan are bound to offer betel to the    
dead beast4 ,when members of this clan  
come upon the tracks of a tiger1 they   
must1 as a mark of homage1 enclose them 
with three little sticks4 ,further1 it  
is believed that the tiger will not     
attack or lacerate his kinsmen1 the     
members of the clan4 7,h4 ,ris1 ,de     
,onderafdeeling ,klein ,mandailing      
,oeloe en ,pahantan en hare ,bevolking  
met uitzondering van de ,oeloes1        
,bijdragen tot de ,tall- ,land- en      
,volkenkunde van ,nederlansch-,indie1   
,,xlvi4 7#ahif71 page #dgc47 ,the       
,battas of ,central ,sumatra are divided
 into a number of clans which have for  
their totems white buffaloes1 goats1    
wild turtle-doves1 dogs1 cats1 apes1    
tigers1 and so forth2 and one of the    
explanations which they give of their   
totems is that these creatures were     
their ancestors1 and that their own     
souls after death can transmigrate into 
the animals4 7,j4,b4 ,neumann1 ,het     
,pane en ,bila-stroomgebied op het      

eiland ,sumatra1 ,tijdschrift van het   
,nederlandsch ,aardrijkskundig          
,genootschap1 ,tweede ,serie1 ,,iii4    
,afdeeling1 ,meer uitgebreide           
,artikelen1 ,no4 #b 7,amsterdam1 #ahhf71
 pages #caa sq42 id4 ib4 ,tweede ,serie1
 ,,iv4 ,afdeeling1 ,meer uitgebreide    
,artikelen1 ,no4 #a 7,amsterdam1 #ahhg71
 pages #h sq47 ,in ,amboyna and the     
neighbouring islands the inhabitants of 
some villages aver that they are        
descended from trees1 such as the       
,capellenia moluccana1 which had been   
fertilised by the ,pandion ,haliaetus4  
,others claim to be sprung from pigs1   
octopuses1 crocodiles1 sharks1 and eels4
 ,people will not burn the wood of the  
trees from which they trace their       
descent1 nor eat the flesh of the       
animals which they regard as their      
ancestors4 ,sicknesses of all sorts are 
believed to result from disregarding    
these taboos4 7,j4,g4,f4 ,riedel1 ,de   
sluik- en kroesharige rassen tusschen   
,selebes en ,papua 7,the ,hague1 #ahhf71

 pages #cb1 #fa2 ,g4,w4,w4,c4 ,baron van
 ,hoevell1 ,ambon en meer bepaaldelijk  
de ,oeliasers 7,dordrecht1 #ahge71 page 
#aeb47 ,similarly in ,ceram persons who 
think they are descended from           
crocodiles1 serpents1 iguanas1 and      
sharks will not eat the flesh of these  
animals4 7,j4,g4,f4 ,riedel op4 cit4    
page #abb47 ,many other peoples of the  
,molucca ,islands entertain similar     
beliefs and observe similar taboos4     
7,j4,g4,f4 ,riedel ,de sluik- en        
kroesharige rassen tusschen ,selebes en 
,papua 7,the ,hague1 #ahhf71 pages #bec1
 #ccd1 #cda1 #cdh1 #dab1 #dad1 #dcb47   
,again1 in ,ponape1 one of the ,caroline
 ,islands1 ,the different families      
suppose themselves to stand in a certain
 relation to animals1 and especially to 
fishes1 and believe in their descent    
from them4 ,they actually name these    
animals 'mothers'2 the creatures are    
sacred to the family and may not be     
injured4 ,great dances1 accompanied with
 the offering of prayers1 are performed 

in their honour4 ,any person who killed 
such an animal would expose himself to  
contempt and punishment1 certainly also 
to the vengeance of the insulted deity4 
,blindness is commonly supposed to be   
the consequence of such a sacrilege4    
7,dr ,hahl1 ,mittheilungen uber ,sitten 
und rechtliche ,verhaltnisse auf        
,ponape1 ,ethnologisches ,notizblatt1   
,vol4 ,,ii4 ,heft #b 7,berlin1 #aija71  
page #aj47  ,some of the aborigines of  
,western ,australia believe that their  
ancestors were swans1 ducks1 or various 
other species of water-fowl before they 
were transformed into men4 7,captain ,g4
 ,grey1 ,a ,vocabulary of the ,dialects 
of ,south ,western ,australia1 ,second  
,edition 7,london1 #ahdj71 pages #bi1   
#cg1 #fa1 #fc1 #ff1 #ga47 ,the ,dieri   
tribe of ,central ,australia1 who are   
divided into totemic clans1 explain     
their origin by the following legend4   
,they say that in the beginning the     
earth opened in the midst of ,perigundi 
,lake1 and the totems 7murdus or madas7 

came trooping out one after the other4  
,out came the crow1 and the shell       
parakeet1 and the emu1 and all the rest4
 ,being as yet imperfectly formed and   
without members or organs of sense1 they
 laid themselves down on the sandhills  
which surrounded the lake then just as  
they do now4 ,it was a bright day and   
the totems lay basking in the sunshine1 
till at last1 refreshed and invigorated 
by it1 they stood up as human beings and
 dispersed in all directions4 ,that is  
why people of the same totem are now    
scattered all over the country4 ,you may
 still see the island in the lake out of
 which the totems came trooping long    
ago4 7,a4,w4 ,howitt1 ,native ,tribes of
 ,south-,east ,australia 7,london1      
#aijd71 pages #dgf1 #ggi sq47 ,another  
,dieri legend relates how ,paralina1 one
 of the ,mura-,muras or mythical        
predecessors of the ,dieri1 perfected   
mankind4 ,he was out hunting kangaroos1 
when he saw four incomplete beings      
cowering together4 ,so he went up to    

them1 smoothed their bodies1 stretched  
out their limbs1 slit up their fingers  
and toes1 formed their mouths1 noses1   
and eyes1 stuck ears on them1 and blew  
into their ears in order that they might
 hear4 ,having perfected their organs   
and so produced mankind out of these    
rudimentary beings1 he went about making
 men everywhere4 7,a4,w4 ,howitt op4    
cit41 pages #dgf1 #ghj sq47 ,yet another
 ,dieri tradition sets forth how the    
,mura-,mura produced the race of man out
 of a species of small black lizards1   
which may still be met with under dry   
bark4 ,to do this he divided the feet of
 the lizards into fingers and toes1 and1
 applying his forefinger to the middle  
of their faces1 created a nose2 likewise
 he gave them human eyes1 mouths and    
ears4 ,he next set one of them upright1 
but it fell down again because of its   
tail2 so he cut off its tail and the    
lizard then walked on its hind legs4    
,that is the origin of mankind4 7,s4    
,gason1 ,the ,manners and ,customs of   

the ,dieyerie tribe of ,australian      
,aborigines1 ,native ,tribes of ,south  
,australia 7,adelaide1 #ahgi71 page     
#bfj4 ,this writer fell into the mistake
 of regarding the ,mura-,mura           
7,mooramoora7 as a ,good-,spirit instead
 of as one of the mythical but more or  
less human predecessors of the ,dieri in
 the country4 ,see ,a4,w4 ,howitt1      
,native ,tribes of ,south-,east         
,australia1 pages #dge sqq47  ,the      
,arunta tribe of ,central ,australia    
similarly tell how in the beginning     
mankind was developed out of various    
rudimentary forms of animal life4 ,they 
say that in those days two beings called
 ,ungambikula1 that is1 out of nothing1 
or self-existing1 dwelt in the western  
sky4 ,from their lofty abode they could 
see1 far away to the east1 a number of  
inapertwa creatures1 that is1           
rudimentary human beings or incomplete  
men1 whom it was their mission to make  
into real men and women4 ,for at that   
time there were no real men and women2  

the rudimentary creatures 7inapertwa7   
were of various shapes and dwelt in     
groups along the shore of the salt water
 which covered the country4 ,these      
embryos1 as we may call them1 had no    
distinct limbs or organs of sight1      
hearing1 and smell2 they did not eat    
food1 and they presented the appearance 
of human beings all doubled up into a   
rounded mass1 in which only the outline 
of the different parts of the body could
 be vaguely perceived4 ,coming down from
 their home in the western sky1 armed   
with great stone knives1 the            
,ungambikula took hold of the embryos1  
one after the other4 ,first of all they 
released the arms from the bodies1 then 
making four clefts at the end of each   
arm they fashioned hands and fingers2   
afterwards legs1 feet1 and toes were    
added in the same way4 ,the figure could
 now stand2 a nose was then moulded and 
the nostrils bored with the fingers4 ,a 
cut with the knife made the mouth1 which
 was pulled open several times to render

 it flexible4 ,a slit on each side of   
the face separated the upper and lower  
eye-lids1 disclosing the eyes1 which    
already existed behind them2 and a few  
strokes more completed the body4 ,thus  
out of the rudimentary creatures were   
formed men and women4 ,these rudimentary
 creatures or embryos1 we are told1 were
 in reality stages in the transformation
 of various animals and plants into     
human beings1 and thus they were        
naturally1 when made into human beings1 
intimately associated with the          
particular animal or plant1 as the case 
may be1 of which they were the          
transformations--in other words1 each   
individual of necessity belonged to a   
totem1 the name of which was of course  
that of the animal or plant of which he 
or she was a transformation4 ,however1  
it is not said that all the totemic     
clans of the ,arunta were thus          
developed2 no such tradition1 for       
example1 is told to explain the origin  
of the important ,witchetty ,grub clan4 

,the clans which are positively known1  
or at least said1 to have originated out
 of embryos in the way described are the
 ,plum ,tree1 the ,grass ,seed1 the     
,large ,lizard1 the ,small ,lizard1 the 
,alexandra ,parakeet1 and the ,small    
,rat clans4 ,when the ,ungambikula had  
thus fashioned people of these totems1  
they circumcised them all1 except the   
,plum ,tree men1 by means of a          
fire-stick4 ,after that1 having done the
 work of creation or evolution1 the     
,ungambikula turned themselves into     
little lizards which bear a name meaning
 snappers-up of flies4 7,baldwin        
,spencer and ,f4,j4 ,gillen1 ,native    
,tribes of ,central ,australia 7,london1
 #ahii71 pages #chh sq42 compare id41   
,northern ,tribes of ,central ,australia
 7,london1 #aijd71 page #aej47  ,this   
,arunta tradition of the origin of man1 
as ,messrs ,spencer and ,gillen1 who    
have recorded it1 justly observe1 is of 
considerable interest2 it is in the     
first place evidently a crude attempt to

 describe the origin of human beings out
 of non-human creatures who were of     
various forms2 some of them were        
representatives of animals1 others of   
plants1 but in all cases they are to be 
regarded as intermediate stages in the  
transition of an animal or plant        
ancestor into a human individual who    
bore its name as that of his or her     
totem4 7,baldwin ,spencer and ,f4,j4    
,gillen1 ,native ,tribes of ,central    
,australia1 pages #cia sq47 ,in a sense 
these speculations of the ,arunta on    
their own origin may be said to combine 
the theory of creation with the theory  
of evolution2 for while they represent  
men as developed out of much simpler    
forms of life1 they at the same time    
assume that this development was        
effected by the agency of two powerful  
beings1 whom so far we may call         
creators4 ,it is well known that at a   
far higher stage of culture a crude form
 of the evolutionary hypothesis was     
propounded by the ,greek philosopher    

,empedocles4 ,he imagined that shapeless
 lumps of earth and water1 thrown up by 
the subterranean fires1 developed into  
monstrous animals1 bulls with the heads 
of men1 men with the heads of bulls1 and
 so forth2 till at last1 these hybrid   
forms being gradually eliminated1 the   
various existing species of animals and 
men were evolved4 7,e4 ,zeller1 ,die    
,philosophie der ,griechen1 ,i4#d       
7,leipsic1 #ahgf71 pages #gah sq42 ,h4  
,ritter et ,l4 ,preller1 ,historia      
,philosophiae ,graecae et ,romanae ex   
fontium locis contexta #e1 pages #ajb   
sq4 ,h4 ,diels1 ,die ,fragmente der     
,vorsokratiker #b1 ,i4 7,berlin1 #aijf71
 pages #aij sqq4 ,compare ,lucretius ,de
 rerum natura1 ,v4 #hcg sqq47 ,the      
theory of the civilised ,greek of       
,sicily may be set beside the similar   
theory of the savage ,arunta of ,central
 ,australia4 ,both represent gropings of
 the human mind in the dark abyss of the
 past2 both were in a measure grotesque 
anticipations of the modern theory of   

evolution4  ,in this essay ,i have made 
no attempt to illustrate all the many   
various and divergent views which       
primitive man has taken of his own      
origin4 ,i have confined myself to      
collecting examples of two radically    
different views1 which may be           
distinguished as the theory of creation 
and the theory of evolution4 ,according 
to the one1 man was fashioned in his    
existing shape by a god or other        
powerful being2 according to the other  
he was evolved by a natural process out 
of lower forms of animal life4 ,roughly 
speaking1 these two theories still      
divide the civilised world between them4
 ,the partisans of each can appeal in   
support of their view to a large        
consensus of opinion2 and if truth were 
to be decided by weighing the one       
consensus against the other1 with       
,genesis in the one scale and ,the      
,origin of ,species in the other1 it    
might perhaps be found1 when the scales 
were finally trimmed1 that the balance  

hung very even between creation and     
evolution4     ,x4 ,,the ,,influence    
,,of ,,darwin ,,on ,,the ,,study ,,of   
,,animal ,,embryology4 ,by ,a4          
,sedgwick1 ,m4,a41 ,f4,r4,s4  ,professor
 of ,zoology and ,comparative ,anatomy  
in the ,university of ,cambridge4  ,the 
publication of ,the ,origin of ,species 
ushered in a new era in the study of    
,embryology4 ,whereas1 before the year  
#ahei the facts of anatomy and          
development were loosely held together  
by the theory of types1 which owed its  
origin to the great anatomists of the   
preceding generation1 to ,cuvier1 ,l4   
,agassiz1 ,j4 ,muller1 and ,r4 ,owen1   
they were now combined together into one
 organic whole by the theory of descent 
and by the hypothesis of recapitulation 
which was deduced from that theory4 ,the
 view 7,first clearly enunciated by     
,fritz ,muller in his well-known work1  
,fur ,darwin1 ,leipzig1 #ahfd2 7,english
 ,edition1 ,facts for ,darwin1 #ahfi747 
that a knowledge of embryonic and larval

 histories would lay bare the secrets of
 race-history and enable the course of  
evolution to be traced1 and so lead to  
the discovery of the natural system of  
classification1 gave a powerful stimulus
 to morphological study in general and  
to embryological investigation in       
particular4 ,in ,darwin's words3        
,embryology rises greatly in interest1  
when we look at the embryo as a picture1
 more or less obscured1 of the          
progenitor1 either in its adult or      
larval state1 of all the members of the 
same great class4 7,origin 7#fth        
edition71 page #cif47 ,in the period    
under consideration the output of       
embryological work has been enormous4   
,no group of the animal kingdom has     
escaped exhaustive examination and no   
effort has been spared to obtain the    
embryos of isolated and out of the way  
forms1 the development of which might   
have an important bearing upon questions
 of phylogeny and classification4       
,marine zoological stations have been   

established1 expeditions have been sent 
to distant countries1 and the methods of
 investigation have been greatly        
improved4 ,the result of this activity  
has been that the main features of the  
developmental history of all the most   
important animals are now known and the 
curiosity as to developmental processes1
 so greatly excited by the promulgation 
of the ,darwinian theory1 has to a      
considerable extent been satisfied4  ,to
 what extent have the results of this   
vast activity fulfilled the expectations
 of the workers who have achieved them8 
,the ,darwin centenary is a fitting     
moment at which to take stock of our    
position4 ,in this inquiry we shall     
leave out of consideration the immense  
and intensely interesting additions to  
our knowledge of ,natural ,history4     
,these may be said to constitute a      
capital fund upon which philosophers1   
poets and men of science will draw for  
many generations4 ,the interest of      
,natural ,history existed long before   

,darwinian evolution was thought of and 
will endure without any reference to    
philosophic speculations4 ,she is a     
mistress in whose face are beauties and 
in whose arms are delights elsewhere    
unattainable4 ,she is and always has    
been pursued for her own sake without   
any reference to philosophy1 science1 or
 utility4  ,darwin's own views of the   
bearing of the facts of embryology upon 
questions of wide scientific interest   
are perfectly clear4 ,he writes 7,origin
 7#fth edition71 page #cie473  ,on the  
other hand it is highly probable that   
with many animals the embryonic or      
larval stages show us1 more or less     
completely1 the condition of the        
progenitor of the whole group in its    
adult state4 ,in the great class of the 
,crustacea1 forms wonderfully distinct  
from each other1 namely1 suctorial      
parasites1 cirripedes1 entomostraca1 and
 even the malacostraca1 appear at first 
as larvae under the nauplius-form2 and  
as these larvae live and feed in the    

open sea1 and are not adapted for any   
peculiar habits of life1 and from other 
reasons assigned by ,fritz ,muller1 it  
is probable that at some very remote    
period an independent adult animal1     
resembling the ,nauplius1 existed1 and  
subsequently produced1 along several    
divergent lines of descent1 the         
above-named great ,crustacean groups4   
,so again it is probable1 from what we  
know of the embryos of mammals1 birds1  
fishes1 and reptiles1 that these animals
 are the modified descendants of some   
ancient progenitor1 which was furnished 
in its adult state with branchiae1 a    
swim-bladder1 four fin-like limbs1 and a
 long tail1 all fitted for an aquatic   
life4  ,as all the organic beings1      
extinct and recent1 which have ever     
lived1 can be arranged within a few     
great classes2 and as all within each   
class have1 according to our theory1    
been connected together by fine         
gradations1 the best1 and1 if our       
collections were nearly perfect1 the    

only possible arrangement1 would be     
genealogical2 descent being the hidden  
bond of connexion which naturalists have
 been seeking under the term of the     
,natural ,system4 ,on this view we can  
understand how it is that1 in the eyes  
of most naturalists1 the structure of   
the embryo is even more important for   
classification than that of the adult4  
,in two or more groups of animals1      
however much they may differ from each  
other in structure and habits in their  
adult condition1 if they pass through   
closely similar embryonic stages1 we may
 feel assured that they all are         
descended from one parent-form1 and are 
therefore closely related4 ,thus1       
community in embryonic structure reveals
 community of descent2 but dissimilarity
 in embryonic development does not prove
 discommunity of descent1 for in one of 
two groups the developmental stages may 
have been suppressed1 or may have been  
so greatly modified through adaptation  
to new habits of life1 as to be no      

longer recognisable4 ,even in groups1 in
 which the adults have been modified to 
an extreme degree1 community of origin  
is often revealed by the structure of   
the larvae2 we have seen1 for instance1 
that cirripedes1 though externally so   
like shell-fish1 are at once known by   
their larvae to belong to the great     
class of crustaceans4 ,as the embryo    
often shows us more or less plainly the 
structure of the less modified and      
ancient progenitor of the group1 we can 
see why ancient and extinct forms so    
often resemble in their adult state the 
embryos of existing species of the same 
class4 ,agassiz believes this to be a   
universal law of nature2 and we may hope
 hereafter to see the law proved true4  
,it can1 however1 be proved true only in
 those cases in which the ancient state 
of the progenitor of the group has not  
been wholly obliterated1 either by      
successive variations having supervened 
at a very early period of growth1 or by 
such variations having been inherited at

 an earlier stage than that at which    
they first appeared4 ,it should also be 
borne in mind1 that the law may be true1
 but yet1 owing to the geological record
 not extending far enough back in time1 
may remain for a long period1 or for    
ever1 incapable of demonstration4 ,the  
law will not strictly hold good in those
 cases in which an ancient form became  
adapted in its larval state to some     
special line of life1 and transmitted   
the same larval state to a whole group  
of descendants2 for such larvae will not
 resemble any still more ancient form in
 its adult state4  ,as this passage     
shows1 ,darwin held that embryology was 
of interest because of the light it     
seems to throw upon ancestral history   
7phylogeny7 and because of the help it  
would give in enabling us to arrive at a
 natural system of classification4 ,with
 regard to the latter point1 he quotes  
with approval the opinion that the      
structure of the embryo is even more    
important for classification than that  

of the adult4 ,what justification is    
there for this view8 ,the phase of life 
chosen for the ordinary anatomical and  
physiological studies1 namely1 the adult
 phase1 is merely one of the large      
number of stages of structure through   
which the organism passes4 ,by far the  
greater number of these are included in 
what is specially called the            
developmental or 7if we include larvae  
with embryos7 embryonic period1 for the 
developmental changes are more numerous 
and take place with greater rapidity at 
the beginning of life than in its later 
periods4 ,as each of these stages is    
equal in value1 for our present purpose1
 to the adult phase1 it clearly follows 
that if there is anything in the view   
that the anatomical study of organisms  
is of importance in determining their   
mutual relations1 the study of the      
organism in its various embryonic 7and  
larval7 stages must have a greater      
importance than the study of the single 
and arbitrarily selected stage of life  

called the adult4  ,but a deeper reason 
than this has been assigned for the     
importance of embryology in             
classification4 ,it has been asserted1  
and is implied by ,darwin in the passage
 quoted1 that the ancestral history is  
repeated in a condensed form in the     
embryonic1 and that a study of the      
latter enables us to form a picture of  
the stages of structure through which   
the organism has passed in its          
evolution4 ,it enables us on this view  
to reconstruct the pedigrees of animals 
and so to form a genealogical tree which
 shall be the true expression of their  
natural relations4  ,the real question  
which we have to consider is to what    
extent the embryological studies of the 
last #ej years have confirmed or        
rendered probable this theory of        
recapitulation4 ,in the first place it  
must be noted that the recapitulation   
theory is itself a deduction from the   
theory of evolution4 ,the facts of      
embryology1 particularly of vertebrate  

embryology1 and of larval history       
receive1 it is argued1 an explanation on
 the view that the successive stages of 
development are1 on the whole1 records  
of adult stages of structure which the  
species has passed through in its       
evolution4 ,whether this statement will 
bear a critical verbal examination ,i   
will not now pause to inquire1 for it is
 more important to determine whether any
 independent facts can be alleged in    
favour of the theory4 ,if it could be   
shown1 as was stated to be the case by  
,l4 ,agassiz1 that ancient and extinct  
forms of life present features of       
structure now only found in embryos1 we 
should have a body of facts of the      
greatest importance in the present      
discussion4 ,but as ,huxley 7,see       
,huxley's ,scientific ,memoirs1 ,london1
 #ahih1 ,vol4 ,i4 page #cjc3 ,there is  
no real parallel between the successive 
forms assumed in the development of the 
life of the individual at present1 and  
those which have appeared at different  

epochs in the past4 ,see also his       
,address to the ,geological ,society of 
,london 7#ahfb7 ',on the                
,palaeontological ,evidence of          
,evolution'1 ibid4 ,vol4 ,,ii4 page     
#eab47 has shown and as the whole course
 of palaeontological and embryological  
investigation has demonstrated1 no such 
statement can be made4 ,the extinct     
forms of life are very similar to those 
now existing and there is nothing       
specially embryonic about them4 ,so that
 the facts1 as we know them1 lend no    
support to theory4  ,but there is       
another class of facts which have been  
alleged in favour of the theory1 viz4   
the facts which have been included in   
the generalisation known as the ,law of 
v4 ,baer4 ,the law asserts that embryos 
of different species of animals of the  
same group are more alike than the      
adults and that1 the younger the embryo1
 the greater are the resemblances4 ,if  
this law could be established it would  
undoubtedly be a strong argument in     

favour of the recapitulation explanation
 of the facts of embryology4 ,but its   
truth has been seriously disputed4 ,if  
it were true we should expect to find   
that the embryos of closely similar     
species would be indistinguishable from 
one another1 but this is notoriously not
 the case4 ,it is more difficult to meet
 the assertion when it is made in the   
form given above1 for here we are       
dealing with matters of opinion4 ,for   
instance1 no one would deny that the    
embryo of a dogfish is different from   
the embryo of a rabbit1 but there is    
room for difference of opinion when it  
is asserted that the difference is less 
than the difference between an adult    
dogfish and an adult rabbit4 ,it would  
be perfectly true to say that the       
differences between the embryos concern 
other organs more than do the           
differences between the adults1 but who 
is prepared to affirm that the presence 
of a cephalic coelom and of cranial     
segments1 of external gills1 of six gill

 slits1 of the kidney tubes opening into
 the muscle-plate coelom1 of an enormous
 yolk-sac1 of a neurenteric canal1 and  
the absence of any trace of an amnion1  
of an allantois and of a primitive      
streak are not morphological facts of as
 high an import as those implied by the 
differences between the adults8 ,the    
generalisation undoubtedly had its      
origin in the fact that there is what   
may be called a family resemblance      
between embryos and larvae1 but this    
resemblance1 which is by no means exact1
 is largely superficial and does not    
extend to anatomical detail4  ,it is    
useless to say1 as ,weismann has stated 
7,the ,evolution ,theory1 by ,a4        
,weismann1 ,english ,translation1 ,vol4 
,,ii4 page #agf1 ,london1 #aijd471 that 
it cannot be disputed that the rudiments
 vestiges his translator means of       
gill-arches and gill-clefts1 which are  
peculiar to one stage of human ontogeny1
 give us every ground for concluding    
that we possessed fish-like ancestors4  

,the question at issue is3 did the      
pharyngeal arches and clefts of         
mammalian embryos ever discharge a      
branchial function in an adult ancestor 
of the mammalia8 ,we cannot therefore1  
without begging the question at issue in
 the grossest manner1 apply to them the 
terms gill-arches and gill-clefts4 ,that
 they are homologous with the           
gill-arches and gill-clefts of fishes is
 true2 but there is no evidence to show 
that they ever discharged a branchial   
function4 ,until such evidence is       
forthcoming1 it is beside the point to  
say that it cannot be disputed that they
 are evidence of a piscine ancestry4    
,it must1 therefore1 be admitted that   
one outcome of the progress of          
embryological and palaeontological      
research for the last #ej years is      
negative4 ,the recapitulation theory    
originated as a deduction from the      
evolution theory and as a deduction it  
still remains4  ,let us before leaving  
the subject apply another test4 ,if the 

evolution theory and the recapitulation 
theory are both true1 how is it that    
living birds are not only without teeth 
but have no rudiments of teeth at any   
stage of their existence8 ,how is it    
that the missing digits in birds and    
mammals1 the missing or reduced limb of 
snakes and whales1 the reduced          
mandibulo-hyoid cleft of elasmobranch   
fishes are not present or relatively    
more highly developed in the embryo than
 in the adult8 ,how is it that when a   
marked variation1 such as an extra      
digit1 or a reduced limb1 or an extra   
segment1 makes its appearance1 it is not
 confined to the adult but can be seen  
all through the development8 ,all the   
clear evidence we can get tends to show 
that marked variations1 whether of      
reduction or increase1 of organs are    
manifest during the whole of the        
development of the organ and do not     
merely affect the adult4 ,and on        
reflection we see that it could hardly  
be otherwise4 ,all such evidence is     

distinctly at variance with the theory  
of recapitulation1 at least as applied  
to embryos4 ,in the case of larvae of   
course the case will be different1 for  
in them the organs are functional1 and  
reduction in the adult will not be      
accompanied by reduction in the larva   
unless a change in the conditions of    
life of the larva enables it to occur4  
,if after #ej years of research and     
close examination of the facts of       
embryology the recapitulation theory is 
still without satisfactory proof1 it    
seems desirable to take a wider sweep   
and to inquire whether the facts of     
embryology cannot be included in a      
larger category4  ,as has been pointed  
out by ,huxley1 development and life are
 co-extensive1 and it is impossible to  
point to any period in the life of an   
organism when the developmental changes 
cease4 ,it is true that these changes   
take place more rapidly at the          
commencement of life1 but they are never
 wholly absent1 and those which occur in

 the later or so-called adult stages of 
life do not differ in their essence1    
however much they may differ in their   
degree1 from those which occur during   
the embryonic and larval periods4 ,this 
consideration at once brings the changes
 of the embryonic period into the same  
category as those of the adult and      
suggests that an explanation which will 
account for the one will account for the
 other4 ,what then is the problem we are
 dealing with8 ,surely it is this3 ,why 
does an organism as soon as it is       
established at the fertilisation of the 
ovum enter upon a cycle of              
transformations which never cease until 
death puts an end to them8 ,in other    
words what is the meaning of that cycle 
of changes which all organisms present  
in a greater or less degree and which   
constitute the very essence of life8 ,it
 is impossible to give an answer to this
 question so long as we remain within   
the precincts of ,biology--and it is not
 my present purpose to penetrate beyond 

those precincts into the realms of      
philosophy4 ,we have to do with an      
ultimate biological fact1 with a        
fundamental property of living matter1  
which governs and includes all its other
 properties4 ,how may this property be  
stated8 ,thus3 it is a property of      
living matter to react in a remarkable  
way to external forces without          
undergoing destruction4 ,the life-cycle1
 of which the embryonic and larval      
periods are a part1 consists of the     
orderly interaction between the organism
 and its environment4 ,the action of the
 environment produces certain           
morphological changes in the organism4  
,these changes enable the organism to   
come into relation with new external    
forces1 to move into what is practically
 a new environment1 which in its turn   
produces further structural changes in  
the organism4 ,these in their turn      
enable1 indeed necessitate1 the organism
 to move again into a new environment1  
and so the process continues until the  

structural changes are of such a nature 
that the organism is unable to adapt    
itself to the environment in which it   
finds itself4 ,the essential condition  
of success in this process is that the  
organism should always shift into the   
environment to which its new structure  
is suited--any failure in this leading  
to the impairment of the organism4 ,in  
most cases the shifting of the          
environment is a very gradual process   
7whether consisting in the very slight  
and gradual alteration in the relation  
of the embryo as a whole to the         
egg-shell or uterine wall1 or in the    
relations of its parts to each other1 or
 in the successive phases of adult      
life71 and the morphological changes in 
connection with each step of it are but 
slight4 ,but in some cases jumps are    
made such as we find in the phenomena   
known as hatching1 birth1 and           
metamorphosis4  ,this property of       
reacting to the environment without     
undergoing destruction is1 as has been  

stated1 a fundamental property of       
organisms4 ,it is impossible to conceive
 of any matter1 to which the term living
 could be applied1 being without it4    
,and with this property of reacting to  
the environment goes the further        
property of undergoing a change which   
alters the relation of the organism to  
the old environment and places it in a  
new environment4 ,if this reasoning is  
correct1 it necessarily follows that    
this property must have been possessed  
by living matter at its first appearance
 on the earth4 ,in other words living   
matter must always have presented a     
life-cycle1 and the question arises what
 kind of modification has that cycle    
undergone8 ,has it increased or         
diminished in duration and complexity   
since organisms first appeared on the   
earth8 ,the current view is that the    
cycle was at first very short and that  
it has increased in length by the       
evolutionary creation of new adult      
phases1 that these new phases are in    

addition to those already existing and  
that each of them as it appears takes   
over from the preceding adult phase the 
functional condition of the reproductive
 organs4 ,according to the same view the
 old adult phases are not obliterated   
but persist in a more or less modified  
form as larval stages4 ,it is further   
supposed that as the life-history       
lengthens at one end by the addition of 
new adult phases1 it is shortened at the
 other by the abbreviation of embryonic 
development and by the absorption of    
some of the early larval stages into the
 embryonic period2 but on the whole the 
lengthening process has exceeded that of
 shortening1 so that the whole          
life-history has1 with the progress of  
evolution1 become longer and more       
complicated4  ,now there can be no doubt
 that the life-history of organisms has 
been shortened in the way above         
suggested1 for cases are known in which 
this can practically be seen to occur at
 the present day4 ,but the process of   

lengthening by the creation of new      
stages at the other end of the          
life-cycle is more difficult to conceive
 and moreover there is no evidence for  
its having occurred4 ,this1 indeed1 may 
have occurred1 as is suggested below1   
but the evidence we have seems to       
indicate that evolutionary modification 
has proceeded by ,,altering and not by  
,,superseding3 that is to say that each 
stage in the life-history1 as we see it 
to-day1 has proceeded from a            
corresponding stage in a former era by  
the modification of that stage and not  
by the creation of a new one4 ,let me1  
at the risk of repetition1 explain my   
meaning more fully by taking a concrete 
illustration4 ,the mandibulo-hyoid cleft
 7spiracle7 of the elasmobranch fishes1 
the lateral digits of the pig's foot1   
the hind-limbs of whales1 the enlarged  
digit of the ostrich's foot are supposed
 to be organs which have been recently  
modified4 ,this modification is not     
confined to the final adult stage of the

 life-history but characterises them    
throughout the whole of their           
development4 ,a stage with a reduced    
spiracle does not proceed in development
 from a preceding stage in which the    
spiracle shows no reduction3 it is      
reduced at its first appearance4 ,the   
same statement may be made of organs    
which have entirely disappeared in the  
adult1 such as bird's teeth and snake's 
fore-limbs3 the adult stage in which    
they have disappeared is not preceded by
 embryonic stages in which the teeth and
 limbs or rudiments of them are present4
 ,in fact the evidence indicates that   
adult variations of any part are        
accompanied by precedent variations in  
the same direction in the embryo4 ,the  
evidence seems to show1 not that a stage
 is added on at the end of the          
life-history1 but only that some of the 
stages in the life-history are modified4
 ,indeed1 on the wider view of          
development taken in this essay1 a view 
which makes it coincident with life1 one

 would not expect often to find1 even if
 new stages are added in the course of  
evolution1 that they are added at the   
end of the series when the organism has 
passed through its reproductive period4 
,it is possible of course that new      
stages have been intercalated in the    
course of the life-history1 though it is
 difficult to see how this has occurred4
 ,it is much more likely1 if we may     
judge from available evidence1 that     
every stage has had its counterpart in  
the ancestral form from which it has    
been derived by descent with            
modification4 ,just as the adult phase  
of the living form differs1 owing to    
evolutionary modification1 from the     
adult phase of the ancestor from which  
it has proceeded1 so each larval phase  
will differ for the same reason from the
 corresponding larval phase in the      
life-history of the ancestor4 ,inasmuch 
as the organism is variable at every    
stage of its independent existence and  
is exposed to the action of natural     

selection there is no reason why it     
should escape modification at any stage4
  ,if there is any truth in these       
considerations it would seem to follow  
that at the dawn of life the life-cycle 
must have been1 either in posse or in   
esse1 at least as long as it is at the  
present time1 and that the peculiarity  
of passing through a series of stages in
 which new characters are successively  
evolved is a primordial quality of      
living matter4  ,before leaving this    
part of the subject1 it is necessary to 
touch upon another aspect of it4 ,what  
are these variations in structure which 
succeed one another in the life-history 
of an organism8 ,i am conscious that ,i 
am here on the threshold of a chamber   
which contains the clue to some of our  
difficulties1 and that ,i cannot enter  
it4 ,looked at from one point of view   
they belong to the class of genetic     
variations1 which depend upon the       
structure or constitution of the        
protoplasm2 but instead of appearing in 

different zygotes 7,a zygote is a       
fertilised ovum1 i4e4 a new organism    
resulting from the fusion of an ovum and
 a spermatozoon471 they are present in  
the same zygote though at different     
times in its life-history4 ,they are of 
the same order as the mutational        
variations of the modern biologist upon 
which the appearance of a new character 
depends4 ,what is a genetic or          
mutational variation8 ,it is a genetic  
character which was not present in      
either of the parents4 ,but these growth
 variations were present in the parents1
 and in this they differ from mutational
 variations4 ,but what are genetic      
characters8 ,they are characters which  
must appear if any development occurs4  
,they are usually contrasted with       
acquired characters1 using the          
expression acquired character in the    
,lamarckian sense4 ,but strictly        
speaking they ,,are acquired characters1
 for the zygote at first has none of the
 characters which it subsequently       

acquires1 but only the power of         
acquiring them in response to the action
 of the environment4 ,but the characters
 so acquired are not what we technically
 understand and what ,lamarck meant by  
acquired characters4 ,they are genetic  
characters1 as defined above4 ,what then
 are ,lamarck's acquired characters8    
,they are variations in genetic         
characters caused in a particular way4  
,there are1 in fact1 two kinds of       
variation in genetic characters         
depending on the mode of causation4     
,firstly1 there are those variations    
consequent upon a variation in the      
constitution of the protoplasm of a     
particular zygote1 and independent of   
the environment in which the organism   
develops1 save in so far as this simply 
calls them forth3 these are the         
so-called genetic or mutational         
variations4 ,secondly1 there are those  
variations which occur in zygotes of    
similar germinal constitution and which 
are caused solely by differences in the 

environment to which the individuals are
 respectively exposed3 these are the    
acquired characters of ,lamarck and of  
authors generally4 ,in consequence of   
this double sense in which the term     
acquired characters may be used1 great  
confusion may and does occur4 ,if the   
protoplasm be compared to a machine1 and
 the external conditions to the hand    
that works the machine1 then it may be  
said that1 as the machine can only work 
in one way1 it can only produce one kind
 of result 7genetic character71 but the 
particular form or quality 7,lamarckian 
acquired character7 of the result will  
depend upon the hand that works the     
machine 7environment71 just as the      
quality of the sound produced by a      
fiddle depends entirely upon the hand   
which plays upon it4 ,it would be       
improper to apply the term mutation to  
those genetic characters which are not  
new characters or new variants of old   
characters1 but such genetic characters 
are of the same nature as those         

characters to which the term mutation   
has been applied4 ,it may be noticed in 
passing that it is very questionable if 
the modern biologist has acted in the   
real interests of science in applying   
the term mutation in the sense in which 
he has applied it4 ,the genetic         
characters of organisms come from one of
 two sources3 either they are old       
characters and are due to the action of 
what we call inheritance or they are new
 and are due to what we call variation4 
,if the term mutation is applied to the 
actual alteration of the machinery of   
the protoplasm1 no objection can be felt
 to its use2 but if it be applied1 as it
 is1 to the product of the action of the
 altered machine1 viz4 to the new       
genetic character1 it leads to          
confusion4 ,inheritance is the          
persistence of the structure of the     
machine2 characters are the products of 
the working of the machine2 variation in
 genetic characters is due to the       
alteration 7mutation7 in the arrangement

 of the machinery1 while variation in   
acquired characters 7,lamarckian7 is due
 to differences in the mode of working  
the machinery4 ,the machinery when it   
starts 7in the new zygote7 has the power
 of grinding out certain results1 which 
we call the characters of the organism4 
,these appear at successive intervals of
 time1 and the orderly manifestation of 
them is what we call the life-history of
 the organism4 ,this brings us back to  
the question with which we started this 
discussion1 viz4 what is the relation of
 these variations in structure1 which   
successively appear in an organism and  
constitute its life-history1 to the     
mutational variations which appear in   
different organisms of the same brood or
 species4 ,the question is brought home 
to us when we ask what is a bud-sport1  
such as a nectarine appearing on a      
peach-tree8 ,from one point of view1 it 
is simply a mutation appearing in       
asexual reproduction2 from another it is
 one of these successional characters   

7growth variations7 which constitute the
 life-history of the zygote1 for it     
appears in the same zygote which first  
produces a peach4 ,here our analogy of a
 machine which only works in one way    
seems to fail us1 for these bud-sports  
do not appear in all parts of the       
organism1 only in certain buds or parts 
of it1 so that one part of the zygotic  
machine would appear to work differently
 to another4 ,to discuss this question  
further would take us too far from our  
subject4 ,suffice it to say that we     
cannot answer it1 any more than we can  
this further question of burning        
interest at the present day1 viz4 to    
what extent and in what manner is the   
machine itself altered by the particular
 way in which it is worked4 ,in         
connection with this question we can    
only submit one consideration3 the      
zygotic machine can1 by its nature1 only
 work once1 so that any alteration in it
 can only be ascertained by studying the
 replicas of it which are produced in   

the reproductive organs4  ,it is a      
peculiarity that the result which we    
call the ripening of the generative     
organs nearly always appears among the  
final products of the action of the     
zygotic machine4 ,it is remarkable that 
this should be the case4 ,what is the   
reason of it8 ,the late appearance of   
functional reproductive organs is almost
 a universal law1 and the explanation of
 it is suggested by expressing the law  
in another way1 viz4 that the machine is
 almost always so constituted that it   
ceases to work efficiently soon after   
the reproductive organs have            
sufficiently discharged their function4 
,why this should occur we cannot        
explain3 it is an ultimate fact of      
nature1 and cannot be included in any   
wider category4 ,the period during which
 the reproductive organs can act may be 
short as in ephemerids or long as in man
 and trees1 and there is no reason to   
suppose that their action damages the   
vital machinery1 though sometimes1 as in

 the case of annual plants              
7,metschnikoff71 it may incidentally do 
so2 but1 long or short1 the cessation of
 their actions is always a prelude to   
the end4 ,when they and their action are
 impaired1 the organism ceases to react 
with precision to the environment1 and  
the organism as a whole undergoes       
retrogressive changes4  ,it has been    
pointed out above that there is reason  
to believe that at the dawn of life the 
life-cycle was1 ,,either ,,in ,,esse    
,,or ,,in ,,posse1 at least as long as  
it is at the present time4 ,the         
qualification implied by the words in   
italics is necessary1 for it is clearly 
possible that the external conditions   
then existing were not suitable for the 
production of all the stages of the     
potential life-history1 and that what we
 call organic evolution has consisted in
 a gradual evolution of new environments
 to which the organism's innate capacity
 of change has enabled it to adapt      
itself4 ,we have warrant for this       

possibility in the case of the ,axolotl 
and in other similar cases of neoteny4  
,and these cases further bring home to  
us the fact1 to which ,i have already   
referred1 that the full development of  
the functional reproductive organs is   
nearly always associated with the final 
stages of the life-history4  ,on this   
view of the succession of characters in 
the life-history of organisms1 how shall
 we explain the undoubted fact that the 
development of buds hardly ever presents
 any phenomena corresponding to the     
embryonic and larval changes8 ,the      
reason is clearly this1 that budding    
usually occurs after the embryonic stage
 is past2 when the characters of        
embryonic life have been worked out by  
the machine4 ,when it takes place at an 
early stage in embryonic life1 as it    
does in cases of so-called embryonic    
fission1 the product shows1 either      
partly or entirely1 phenomena similar to
 those of embryonic development4 ,the   
only case known to me in which budding  

by the adult is accompanied by          
morphological features similar to those 
displayed by embryos is furnished by the
 budding of the medusiform spore-sacs of
 hydrozoon polyps4 ,but this case is    
exceptional1 for here we have to do with
 an attempt1 which fails1 to form a     
free-swimming organism1 the medusa2 and 
the vestiges which appear in the buds   
are the umbrella-cavity1 marginal       
tentacles1 circular canal1 etc41 of the 
medusa arrested in development4  ,but   
the question still remains1 are there no
 cases in which1 as implied by the      
recapitulation theory1 variations in any
 organ are confined to the period in    
which the organ is functional and do not
 affect it in the embryonic stages8 ,the
 teeth of the whalebone whales may be   
cited as a case in which this is said to
 occur2 but here the teeth are only     
imperfectly developed in the embryo and 
are soon absorbed4 ,they have been      
affected by the change which has        
produced their disappearance in the     

adult1 but not to complete extinction4  
,nor are they now likely to be          
extinguished1 for having become         
exclusively embryonic they are largely  
protected from the action of natural    
selection4 ,this consideration brings up
 a most important aspect of the         
question1 so far as disappearing organs 
are concerned4 ,every organ is laid down
 at a certain period in the embryo and  
undergoes a certain course of growth    
until it obtains full functional        
development4 ,when for any cause        
reduction begins1 it is affected at all 
stages of its growth1 unless it has     
functional importance in the larva1 and 
in some cases its life is shortened at  
one or both ends4 ,in cases1 as in that 
of the whale's teeth1 in which it       
entirely disappears in the adult1 the   
latter part of its life is cut off2 in  
others1 the beginning of its life may be
 deferred4 ,this happens1 for instance1 
with the spiracle of many               
,elasmobranchs1 which makes its         

appearance after the hyobranchial cleft1
 not before it as it should do1 being   
anterior to it in position1 and as it   
does in the ,amniota in which it shows  
no reduction in size as compared with   
the other pharyngeal clefts4 ,in those  
,elasmobranchs in which it is absent in 
the adult but present in the embryo     
7e4g4 ,carcharias7 its life is shortened
 at both ends4 ,many more instances of  
organs1 of which the beginning and end  
have been cut off1 might be mentioned2  
e4g4 the muscle-plate coelom of ,aves1  
the primitive streak and the neurenteric
 canal of amniote blastoderms4 ,in yet  
other cases in which the reduced organ  
is almost on the verge of disappearance1
 it may appear for a moment and         
disappear more than once in the course  
of development4 ,as an instance of this 
striking phenomenon ,i may mention the  
neurenteric canal of avine embryos1 and 
the anterior neuropore of ,ascidians4   
,lastly the reduced organ may disappear 
in the developing stages before it does 

so in the adult4 ,as an instance of this
 may be mentioned the mandibular palp of
 those ,crustacea with zoaea larvae4    
,this structure disappears in the larva 
only to reappear in a reduced form in   
later stages4 ,in all these cases we are
 dealing with an organ which1 we        
imagine1 attained a fuller functional   
development at some previous stage in   
race-history1 but in most of them we    
have no proof that it did so4 ,it may   
be1 and the possibility must not be lost
 sight of1 that these organs never were 
anything else than functionless and that
 though they have been got rid of in the
 adult by elimination in the course of  
time1 they have been able to persist in 
embryonic stages which are protected    
from the full action of natural         
selection4 ,there is no reason to       
suppose that living matter at its first 
appearance differed from non-living     
matter in possessing only properties    
conducive to its well-being and         
prolonged existence4 ,no one thinks that

 the properties of the various forms of 
inorganic matter are all strictly       
related to external conditions4 ,of what
 use to the diamond is its high specific
 gravity and high refrangibility1 and to
 gold of its yellow colour and great    
weight8 ,these substances continue to   
exist in virtue of other properties than
 these4 ,it is impossible to suppose    
that the properties of living matter at 
its first appearance were all useful to 
it1 for even now after aeons of         
elimination we find that it possesses   
many useless organs and that many of its
 relations to the external world are    
capable of considerable improvement4    
,in writing this essay ,i have purposely
 refrained from taking a definite       
position with regard to the problems    
touched4 ,my desire has been to write a 
chapter showing the influence of        
,darwin's work so far as ,embryology is 
concerned1 and the various points which 
come up for consideration in discussing 
his views4 ,darwin was the last man who 

would have claimed finality for any of  
his doctrines1 but he might fairly have 
claimed to have set going a process of  
intellectual fermentation which is still
 very far from completion4     ,,xi4    
,,the ,,palaeontological ,,record4 ,by  
,w4,b4 ,scott4  ,professor of ,geology  
in the ,university of ,princeton1       
,u4,s4,a4   ,i4 ,,animals4  ,to no      
branch of science did the publication of
 ,the ,origin of ,species prove to be a 
more vivifying and transforming         
influence than to ,palaeontology4 ,this 
science had suffered1 and to some       
extent1 still suffers from its rather   
anomalous position between geology and  
biology1 each of which makes claim to   
its territory1 and it was held in strict
 bondage to the ,linnean and ,cuvierian 
dogma that species were immutable       
entities4 ,there is1 however1 reason to 
maintain that this strict bondage to a  
dogma now abandoned1 was not without its
 good side1 and served the purpose of   
keeping the infant science in           

leading-strings until it was able to    
walk alone1 and preventing a flood of   
premature generalisations and           
speculations4  ,as ,zittel has said3    
,two directions were from the first     
apparent in palaeontological research--a
 stratigraphical and a biological4      
,stratigraphers wished from             
palaeontology mainly confirmation       
regarding the true order or relative age
 of zones of rock-deposits in the field4
 ,biologists had1 theoretically at      
least1 the more genuine interest in     
fossil organisms as individual forms of 
life4 7,zittel1 ,history of ,geology and
 ,palaeontology1 page #cfc1 ,london1    
#aija47 ,the geological or              
stratigraphical direction of the science
 was given by the work of ,william      
,smith1 the father of historical        
geology1 in the closing decade of the   
eighteenth century4 ,smith was the first
 to make a systematic use of fossils in 
determining the order of succession of  
the rocks which make up the accessible  

crust of the earth1 and this use has    
continued1 without essential change1 to 
the present day4 ,it is true that the   
theory of evolution has greatly modified
 our conceptions concerning the         
introduction of new species and the     
manner in which palaeontological data   
are to be interpreted in terms of       
stratigraphy1 but1 broadly speaking1 the
 method remains fundamentally the same  
as that introduced by ,smith4  ,the     
biological direction of palaeontology   
was due to ,cuvier and his associates1  
who first showed that fossils were not  
merely varieties of existing organisms1 
but belonged to extinct species and     
genera1 an altogether revolutionary     
conception1 which startled the          
scientific world4 ,cuvier made careful  
studies1 especially of fossil           
vertebrates1 from the standpoint of     
zoology and was thus the founder of     
palaeontology as a biological science4  
,his great work on ,ossements ,fossiles 
7,paris1 #ahba7 has never been surpassed

 as a masterpiece of the comparative    
method of anatomical investigation1 and 
has furnished to the palaeontologist the
 indispensable implements of research4  
,on the other hand1 ,cuvier's           
theoretical views regarding the history 
of the earth and its successive faunas  
and floras are such as no one believes  
to-day4 ,he held that the earth had been
 repeatedly devastated by great         
cataclysms1 which destroyed every living
 thing1 necessitating an entirely new   
creation1 thus regarding the geological 
periods as sharply demarcated and       
strictly contemporaneous for the whole  
earth1 and each species of animal and   
plant as confined to a single period4   
,cuvier's immense authority and his     
commanding personality dominated        
scientific thought for more than a      
generation and marked out the line which
 the development of palaeontology was to
 follow4 ,the work was enthusiastically 
taken up by many very able men in the   
various ,european countries and in the  

,united ,states1 but1 controlled as it  
was by the belief in the fixity of      
species1 it remained almost entirely    
descriptive and consisted in the        
description and classification of the   
different groups of fossil organisms4   
,as already intimated1 this narrowness  
of view had its compensations1 for it   
deferred generalisations until some     
adequate foundations for these had been 
laid4  ,dominant as it was1 ,cuvier's   
authority was slowly undermined by the  
progress of knowledge and the way was   
prepared for the introduction of more   
rational conceptions4 ,the theory of    
,catastrophism was attacked by several  
geologists1 most effectively by ,sir    
,charles ,lyell1 who greatly amplified  
the principles enunciated by ,hutton and
 ,playfair in the preceding century1 and
 inaugurated a new era in geology4      
,lyell's uniformitarian views of the    
earth's history and of the agencies     
which had wrought its changes1 had      
undoubted effect in educating men's     

minds for the acceptance of essentially 
similar views regarding the organic     
world4 ,in palaeontology too the        
doctrine of the immutability of species1
 though vehemently maintained and       
reasserted1 was gradually weakening4 ,in
 reviewing long series of fossils1      
relations were observed which pointed to
 genetic connections and yet were       
interpreted as purely ideal4 ,agassiz1  
for example1 who never accepted the     
evolutionary theory1 drew attention to  
facts which could be satisfactorily     
interpreted only in terms of that       
theory4 ,among the fossils he indicated 
progressive1 synthetic1 prophetic1 and  
embryonic types1 and pointed out the    
parallelism which obtains between the   
geological succession of ancient animals
 and the ontogenetic development of     
recent forms4 ,in ,darwin's words3 ,this
 view accords admirably well with our   
theory4 7,origin of ,species 7#fth      
edition71 page #caj47 ,of similar import
 were ,owen's views on generalised types

 and archetypes4  ,the appearance of    
,the ,origin of ,species in #ahei       
revolutionised all the biological       
sciences4 ,from the very nature of the  
case1 ,darwin was compelled to give     
careful consideration to the            
palaeontological evidence2 indeed1 it   
was the palaeontology and modern        
distribution of animals in ,south       
,america which first led him to reflect 
upon the great problem4 ,in his own     
words3 ,i had been deeply impressed by  
discovering in the ,pampean formation   
great fossil animals covered with armour
 like that on the existing armadillos2  
secondly1 by the manner in which closely
 allied animals replace one another in  
proceeding southward over the           
,continent2 and thirdly1 by the ,south  
,american character of most of the      
productions of the ,galapagos           
archipelago1 and more especially by the 
manner in which they differ slightly on 
each island of the group4 7,life and    
,letters of ,charles ,darwin1 ,i4 page  

#hb47 ,in the famous tenth and eleventh 
chapters of the ,origin1 the            
palaeontological evidence is examined at
 length and the imperfection of the     
geological record is strongly           
emphasised4 ,the conclusion is reached1 
that1 in view of this extreme           
imperfection1 palaeontology could not   
reasonably be expected to yield complete
 and convincing proof of the            
evolutionary theory4 ,i look at the     
geological record as a history of the   
world imperfectly kept1 and written in a
 changing dialect2 of this history we   
possess the last volume alone1 relating 
only to two or three countries4 ,of this
 volume1 only here and there a short    
chapter has been preserved2 and of each 
page1 only here and there a few lines4  
7,origin of ,species1 page #bhi47 ,yet1 
aside from these inevitable             
difficulties1 he concludes1 that the    
other great leading facts in            
palaeontology agree admirably with the  
theory of descent with modification     

through variation and natural selection4
 7,ibid4 page #cac47  ,darwin's theory  
gave an entirely new significance and   
importance to palaeontology4 ,cuvier's  
conception of the science had been a    
limited1 though a lofty one4 ,how       
glorious it would be if we could arrange
 the organised products of the universe 
in their chronological order6444 ,the   
chronological succession of organised   
forms1 the exact determination of those 
types which appeared first1 the         
simultaneous origin of certain species  
and their gradual decay1 would perhaps  
teach us as much about the mysteries of 
organisation as we can possibly learn   
through experiments with living         
organisms4 7,zittel op4 cit4 page #adj47
 ,this1 however1 was rather the         
expression of a hope for the distant    
future than an account of what was      
attainable1 and in practice the science 
remained almost purely descriptive1     
until ,darwin gave it a new standpoint1 
new problems and an altogether fresh    

interest and charm4 ,the revolution thus
 accomplished is comparable only to that
 produced by the ,copernican astronomy4 
,from the first it was obvious that one 
of the most searching tests of the      
evolutionary theory would be given by   
the advance of palaeontological         
discovery4 ,however imperfect the       
geological record might be1 its         
ascertained facts would necessarily be  
consistent1 under any reasonable        
interpretation1 with the demands of a   
true theory2 otherwise the theory would 
eventually be overwhelmed by the mass of
 irreconcilable data4 ,a very great     
stimulus was thus given to geological   
investigation and to the exploration of 
new lands4 ,in the last forty years1 the
 examination of ,north and ,south       
,america1 of ,africa and ,asia has      
brought to light many chapters in the   
history of life1 which are astonishingly
 full and complete4 ,the flood of new   
material continues to accumulate at such
 a rate that it is impossible to keep   

abreast of it1 and the very wealth of   
the collections is a source of          
difficulty and embarrassment4 ,in modern
 palaeontology phylogenetic questions   
and problems occupy a foremost place    
and1 as a result of the labours of many 
eminent investigators in many lands1 it 
may be said that this science has proved
 to be one of the most solid supports of
 ,darwin's theory4 ,true1 there are very
 many unsolved problems1 and the        
discouraged worker is often tempted to  
believe that the fossils raise more     
questions than they answer4 ,yet1 on the
 other hand1 the whole trend of the     
evidence is so strongly in favour of the
 evolutionary doctrine1 that no other   
interpretation seems at all rational4   
,to present any adequate account of the 
palaeontological record from the        
evolutionary standpoint1 would require a
 large volume and a singularly unequal1 
broken and disjointed history it would  
be4 ,here the record is scanty1         
interrupted1 even unintelligible1 while 

there it is crowded with embarrassing   
wealth of material1 but too often these 
full chapters are separated by such     
stretches of unrecorded time1 that it is
 difficult to connect them4 ,it will be 
more profitable to present a few        
illustrative examples than to attempt an
 outline of the whole history4  ,at the 
outset1 the reader should be cautioned  
not to expect too much1 for the task of 
determining phylogenies fairly bristles 
with difficulties and encounters many   
unanswered questions4 ,even when the    
evidence seems to be as copious and as  
complete as could be wished1 different  
observers will put different            
interpretations upon it1 as in the      
notorious case of the ,steinheim shells4
 7,in the ,miocene beds of ,steinheim1  
,wurtemberg1 occur countless fresh-water
 shells1 which show numerous lines of   
modification1 but these have been very  
differently interpreted by different    
writers47 ,the ludicrous discrepances   
which often appear between the          

phylogenetic trees of various writers   
have cast an undue discredit upon the   
science and have led many zoologists to 
ignore palaeontology altogether as      
unworthy of serious attention4 ,one     
principal cause of these discrepant and 
often contradictory results is our      
ignorance concerning the exact modes of 
developmental change4 ,what one writer  
postulates as almost axiomatic1 another 
will reject as impossible and absurd4   
,few will be found to agree as to how   
far a given resemblance is offset by a  
given unlikeness1 and so long as the    
question is one of weighing evidence and
 balancing probabilities1 complete      
harmony is not to be looked for4 ,these 
formidable difficulties confront us even
 in attempting to work out from abundant
 material a brief chapter in the        
phylogenetic history of some small and  
clearly limited group1 and they become  
disproportionately greater1 when we     
extend our view over vast periods of    
time and undertake to determine the     

mutual relationships of classes and     
types4 ,if the evidence were complete   
and available1 we should hardly be able 
to unravel its infinite complexity1 or  
to find a clue through the mazes of the 
labyrinth4 ,our ideas of the course of  
descent must of necessity be            
diagrammatic4 7,d4,h4 ,scott1 ,studies  
in ,fossil ,botany1 page #ebd4 ,london1 
#aijj47  ,some of the most complete and 
convincing examples of descent with     
modification are to be found among the  
mammals1 and nowhere more abundantly    
than in ,north ,america1 where the      
series of continental formations1       
running through the whole ,tertiary     
period1 is remarkably full4 ,most of    
these formations contain a marvellous   
wealth of mammalian remains and in an   
unusual state of preservation4 ,the     
oldest ,eocene 7,paleocene7 has yielded 
a mammalian fauna which is still of     
prevailingly ,mesozoic character1 and   
contains but few forms which can be     
regarded as ancestral to those of later 

times4 ,the succeeding fauna of the     
lower ,eocene proper 7,wasatch stage7 is
 radically different and1 while a few   
forms continue over from the ,paleocene1
 the majority are evidently recent      
immigrants from some region not yet     
identified4 ,from the ,wasatch onward1  
the development of many phyla may be    
traced in almost unbroken continuity1   
though from time to time the record is  
somewhat obscured by migrations from the
 ,old ,world and ,south ,america4 ,as a 
rule1 however1 it is easy to distinguish
 between the immigrant and the          
indigenous elements of the fauna4  ,from
 their gregarious habits and individual 
abundance1 the history of many hoofed   
animals is preserved with especial      
clearness4 ,so well known as to have    
become a commonplace1 is the phylogeny  
of the horses1 which1 contrary to all   
that would have been expected1 ran the  
greater part of its course in ,north    
,america4 ,so far as it has yet been    
traced1 the line begins in the lower    

,eocene with the genus ,eohippus1 a     
little creature not much larger than a  
cat1 which has a short neck1 relatively 
short limbs1 and in particular1 short   
feet1 with four functional digits and a 
splint-like rudiment in the fore-foot1  
three functional digits and a rudiment  
in the hind-foot4 ,the forearm bones    
7ulna and radius7 are complete and      
separate1 as are also the bones of the  
lower leg 7fibula and tibia74 ,the skull
 has a short face1 with the orbit1 or   
eye-socket1 incompletely enclosed with  
bone1 and the brain-case is slender and 
of small capacity4 ,the teeth are       
short-crowned1 the incisors without     
mark1 or enamel pit1 on the cutting     
edge2 the premolars are all smaller and 
simpler than the molars4 ,the pattern of
 the upper molars is so entirely        
different from that seen in the modern  
horses that1 without the intermediate   
connecting steps1 no one would have     
ventured to derive the later from the   
earlier plan4 ,this pattern is          

quadritubercular1 with four principal1  
conical cusps arranged in two transverse
 pairs1 forming a square1 and two minute
 cuspules between each transverse pair1 
a tooth which is much more pig-like than
 horse-like4 ,in the lower molars the   
cusps have already united to form two   
crescents1 one behind the other1 forming
 a pattern which is extremely common in 
the early representatives of many       
different families1 both of the         
,perissodactyla and the ,artiodactyla4  
,in spite of the manifold differences in
 all parts of the skeleton between      
,eohippus and the recent horses1 the    
former has stamped upon it an equine    
character which is unmistakable1 though 
it can hardly be expressed in words4    
,each one of the different ,eocene and  
,oligocene horizons has its             
characteristic genus of horses1 showing 
a slow1 steady progress in a definite   
direction1 all parts of the structure   
participating in the advance4 ,it is not
 necessary to follow each of these      

successive steps of change1 but it      
should be emphasised that the changes   
are gradual and uninterrupted4 ,the     
genus ,mesohippus1 of the middle        
,oligocene1 may be selected as a kind of
 half-way stage in the long progression4
 ,comparing ,mesohippus with ,eohippus1 
we observe that the former is much      
larger1 some species attaining the size 
of a sheep1 and has a relatively longer 
neck1 longer limbs and much more        
elongate feet1 which are tridactyl1 and 
the middle toe is so enlarged that it   
bears most of the weight1 while the     
lateral digits are very much more       
slender4 ,the fore-arm bones have begun 
to co-ossify and the ulna is greatly    
reduced1 while the fibula1 though still 
complete1 is hardly more than a thread  
of bone4 ,the skull has a longer face   
and a nearly enclosed orbit1 and the    
brain-case is fuller and more capacious1
 the internal cast of which shows that  
the brain was richly convoluted4 ,the   
teeth are still very short-crowned1 but 

the upper incisors plainly show the     
beginning of the mark2 the premolars    
have assumed the molar form1 and the    
upper molars1 though plainly derived    
from those of ,eohippus1 have made a    
long stride toward the horse pattern1 in
 that the separate cusps have united to 
form a continuous outer wall and two    
transverse crests4  ,in the lower       
,miocene the interesting genus          
,desmatippus shows a further advance in 
the development of the teeth1 which are 
beginning to assume the long-crowned    
shape1 delaying the formation of roots2 
a thin layer of cement covers the       
crowns1 and the transverse crests of the
 upper grinding teeth display an        
incipient degree of their modern        
complexity4 ,this tooth-pattern is      
strictly intermediate between the recent
 type and the ancient type seen in      
,mesohippus and its predecessors4 ,the  
upper ,miocene genera1 ,protohippus and 
,hipparion are1 to all intents and      
purposes1 modern in character1 but their

 smaller size1 tridactyl feet and       
somewhat shorter-crowned teeth are      
reminiscences of their ancestry4  ,from 
time to time1 when a land-connection    
between ,north ,america and ,eurasia was
 established1 some of the successive    
equine genera migrated to the ,old      
,world1 but they do not seem to have    
gained a permanent footing there until  
the end of the ,miocene or beginning of 
the ,pliocene1 eventually diversifying  
into the horses1 asses1 and zebras of   
,africa1 ,asia and ,europe4 ,at about   
the same period1 the family extended its
 range to ,south ,america and there gave
 rise to a number of species and genera1
 some of them extremely peculiar4 ,for  
some unknown reason1 all the horse tribe
 had become extinct in the western      
hemisphere before the ,european         
discovery1 but not until after the      
native race of man had peopled the      
continents4  ,in addition to the main   
stem of equine descent1 briefly         
considered in the foregoing paragraphs1 

several side-branches were given off at 
successive levels of the stem4 ,most of 
these branches were short-lived1 but    
some of them flourished for a           
considerable period and ramified into   
many species4  ,apparently related to   
the horses and derived from the same    
root-stock is the family of the         
,palaeotheres1 confined to the ,eocene  
and ,oligocene of ,europe1 dying out    
without descendants4 ,in the earlier    
attempts to work out the history of the 
horses1 as in the famous essay of       
,kowalevsky 7,sur l',anchitherium       
aurelianense ,cuv4 et sur l'histoire    
paleontologique des ,chevaux1 ,mem4 de  
l',acad4 ,imp4 des ,sc4 de ,st          
,petersbourg1 ,,xx4 no4 #e1 #ahgc471 the
 ,palaeotheres were placed in the direct
 line1 because the number of adequately 
known ,eocene mammals was then so small1
 that ,cuvier's types were forced into  
various incongruous positions1 to serve 
as ancestors for unrelated series4  ,the
 ,american family of the ,titanotheres  

may also be distantly related to the    
horses1 but passed through an entirely  
different course of development4 ,from  
the lower ,eocene to the lower sub-stage
 of the middle ,oligocene the series is 
complete1 beginning with small and      
rather lightly built animals4 ,gradually
 the stature and massiveness increase1 a
 transverse pair of nasal horns make    
their appearance and1 as these increase 
in size1 the canine tusks and incisors  
diminish correspondingly4 ,already in   
the oldest known genus the number of    
digits had been reduced to four in the  
fore-foot and three in the hind1 but    
there the reduction stops1 for the      
increasing body-weight made necessary   
the development of broad and heavy feet4
 ,the final members of the series       
comprise only large1 almost elephantine 
animals1 with immensely developed and   
very various nasal horns1 huge and      
massive heads1 and altogether a         
grotesque appearance4 ,the growth of the
 brain did not at all keep pace with the

 increase of the head and body1 and the 
ludicrously small brain may will have   
been one of the factors which determined
 the startlingly sudden disappearance   
and extinction of the group4  ,less     
completely known1 but of unusual        
interest1 is the genealogy of the       
rhinoceros family1 which probably1      
though not certainly1 was likewise of   
,american origin4 ,the group in ,north  
,america at least1 comprised three      
divisions1 or sub-families1 of very     
different proportions1 appearance and   
habits1 representing three divergent    
lines from the same stem4 ,though the   
relationship between the three lines    
seems hardly open to question1 yet the  
form ancestral to all of them has not   
yet been identified4 ,this is because of
 our still very incomplete knowledge of 
several perissodactyl genera of the     
,eocene1 any one of which may eventually
 prove to be the ancestor sought for4   
,the first sub-family is the entirely   
extinct group of ,hyracodonts1 which may

 be traced in successive modifications  
through the upper ,eocene1 lower and    
middle ,oligocene1 then disappearing    
altogether4 ,as yet1 the hyracodonts    
have been found only in ,north ,america1
 and the last genus of the series1      
,hyracodon1 was a cursorial animal4     
,very briefly stated1 the modifications 
consist in a gradual increase in size1  
with greater slenderness of proportions1
 accompanied by elongation of the neck1 
limbs1 and feet1 which become tridactyl 
and very narrow4 ,the grinding teeth    
have assumed the rhinoceros-like pattern
 and the premolars resemble the molars  
in form2 on the other hand1 the front   
teeth1 incisors and canines1 have become
 very small and are useless as weapons4 
,as the animal had no horns1 it was     
quite defenceless and must have found   
its safety in its swift running1 for    
,hyracodon displays many superficial    
resemblances to the contemporary        
,oligocene horses1 and was evidently    
adapted for speed4 ,it may well have    

been the competition of the horses which
 led to the extinction of these         
cursorial rhinoceroses4  ,the second    
sub-family1 that of the ,amynodonts1    
followed a totally different course of  
development1 becoming short-legged and  
short-footed1 massive animals1 the      
proportions of which suggest aquatic    
habits2 they retained four digits in the
 front foot4 ,the animal was well       
provided with weapons in the large      
canine tusks1 but was without horns4    
,some members of this group extended    
their range to the ,old ,world1 but they
 all died out in the middle ,oligocene1 
leaving no successors4  ,the sub-family 
of the true rhinoceroses cannot yet be  
certainly traced farther back than to   
the base of the middle ,oligocene1      
though some fragmentary remains found in
 the lower ,oligocene are probably also 
referable to it4 ,the most ancient and  
most primitive member of this series yet
 discovered1 the genus ,trigonias1 is   
unmistakably a rhinoceros1 yet much less

 massive1 having more the proportions of
 a tapir2 it had four toes in the front 
foot1 three in the hind1 and had a full 
complement of teeth1 except for the     
lower canines1 though the upper canines 
are about to disappear1 and the peculiar
 modification of the incisors1          
characteristic of the true rhinoceroses1
 is already apparent2 the skull is      
hornless4 ,representatives of this      
sub-family continue through the         
,oligocene and ,miocene of ,north       
,america1 becoming rare and localised in
 the ,pliocene and then disappearing    
altogether4 ,in the ,old ,world1 on the 
other hand1 where the line appeared     
almost as early as it did in ,america1  
this group underwent a great expansion  
and ramification1 giving rise not only  
to the ,asiatic and ,african forms1 but 
also to several extinct series4         
,turning now to the ,artiodactyla1 we   
find still another group of mammals1    
that of the camels and llamas1 which has
 long vanished from ,north ,america1 yet

 took its rise and ran the greater part 
of its course in that continent4 ,from  
the lower ,eocene onward the history of 
this series is substantially complete1  
though much remains to be learned       
concerning the earlier members of the   
family4 ,the story is very like that of 
the horses1 to which in many respects it
 runs curiously parallel4 ,beginning    
with very small1 five-toed animals1 we  
observe in the successive genera a      
gradual transformation in all parts of  
the skeleton1 an elongation of the neck1
 limbs and feet1 a reduction of the     
digits from five to two1 and eventually 
the coalescence of the remaining two    
digits into a cannon-bone4 ,the grinding
 teeth1 by equally gradual steps1 take  
on the ruminant pattern4 ,in the upper  
,miocene the line divides into the two  
branches of the camels and llamas1 the  
former migrating to ,eurasia and the    
latter to ,south ,america1 though       
representatives of both lines persisted 
in ,north ,america until a very late    

period4 ,interesting side-branches of   
this line have also been found1 one of  
which ended in the upper ,miocene in    
animals which had almost the proportions
 of the giraffes and must have resembled
 them in appearance4  ,the ,american    
,tertiary has yielded several other     
groups of ruminant-like animals1 some of
 which form beautifully complete        
evolutionary series1 but space forbids  
more than this passing mention of them4 
,it was in ,europe that the             
,artiodactyla had their principal       
development1 and the upper ,eocene1     
,oligocene and ,miocene are crowded with
 such an overwhelming number and variety
 of forms that it is hardly possible to 
marshal them in orderly array and       
determine their mutual relationships4   
,yet in this chaotic exuberance of life1
 certain important facts stand out      
clearly1 among these none is of greater 
interest and importance than the        
genealogy of the true ,ruminants1 or    
,pecora1 which may be traced from the   

upper ,eocene onward4 ,the steps of     
modification and change are very similar
 to those through which the camel phylum
 passed in ,north ,america1 but it is   
instructive to note that1 despite their 
many resemblances1 the two series can be
 connected only in their far distant    
beginnings4 ,the pecoran stock became   
vastly more expanded and diversified    
than did the camel line and was         
evidently more plastic and adaptable1   
spreading eventually over all the       
continents except ,australia1 and       
forming to-day one of the dominant types
 of mammals1 while the camels are on the
 decline and not far from extinction4   
,the ,pecora successively ramified into 
the deer1 antelopes1 sheep1 goats and   
oxen1 and did not reach ,north ,america 
till the ,miocene1 when they were       
already far advanced in specialisation4 
,to this invasion of the ,pecora1 or    
true ruminants1 it seems probable that  
the decline and eventual disappearance  
of the camels is to be ascribed4        

,recent discoveries in ,egypt have      
thrown much light upon a problem which  
long baffled the palaeontologist1       
namely1 the origin of the elephants4    
7,c4,w4 ,andrews1 ,on the ,evolution of 
the ,proboscidea1 ,phil4 ,trans4 ,roy4  
,soc4 ,london1 ,vol4 #aif1 #aijd1 page  
#ii47 ,early representatives of this    
order1 ,mastodons1 had appeared almost  
simultaneously 7in the geological sense 
of that word7 in the upper ,miocene of  
,europe and ,north ,america1 but in     
neither continent was any more ancient  
type known which could plausibly be     
regarded as ancestral to them4          
,evidently1 these problematical animals 
had reached the northern continents by  
migrating from some other region1 but no
 one could say where that region lay4   
,the ,eocene and ,oligocene beds of the 
,fayoum show us that the region sought  
for is ,africa1 and that the elephants  
form just such a series of gradual      
modifications as we have found among    
other hoofed animals4 ,the later steps  

of the transformation1 by which the     
mastodons lost their lower tusks1 and   
their relatively small and simple       
grinding teeth acquired the great size  
and highly complex structure of the true
 elephants1 may be followed in the      
uppermost ,miocene and ,pliocene fossils
 of ,india and southern ,europe4  ,egypt
 has also of late furnished some very   
welcome material which contributes to   
the solution of another unsolved problem
 which had quite eluded research1 the   
origin of the whales4 ,the              
toothed-whales may be traced back in    
several more or less parallel lines as  
far as the lower ,miocene1 but their    
predecessors in the ,oligocene are still
 so incompletely known that safe        
conclusions can hardly be drawn from    
them4 ,in the middle ,eocene of ,egypt1 
however1 has been found a small1        
whale-like animal 7,protocetus71 which  
shows what the ancestral toothed-whale  
was like1 and at the same time seems to 
connect these thoroughly marine mammals 

with land-animals4 ,though already      
entirely adapted to an aquatic mode of  
life1 the teeth1 skull and backbone of  
,protocetus display so many differences 
from those of the later whales and so   
many approximations to those of         
primitive1 carnivorous land-mammals1 as1
 in a large degree1 to bridge over the  
gap between the two groups4 ,thus one of
 the most puzzling of palaeontological  
questions is in a fair way to receive a 
satisfactory answer4 ,the origin of the 
whalebone-whales and their relations to 
the toothed-whales cannot yet be        
determined1 since the necessary fossils 
have not been discovered4  ,among the   
carnivorous mammals1 phylogenetic series
 are not so clear and distinct as among 
the hoofed animals1 chiefly because the 
carnivores are individually much less   
abundant1 and well-preserved skeletons  
are among the prizes of the collector4  
,nevertheless1 much has already been    
learned concerning the mutual relations 
of the carnivorous families1 and several

 phylogenetic series1 notably that of   
the dogs1 are quite complete4 ,it has   
been made extremely probable that the   
primitive dogs of the ,eocene represent 
the central stock1 from which nearly or 
quite all the other families branched   
off1 though the origin and descent of   
the cats have not yet been determined4  
,it should be clearly understood that   
the foregoing account of mammalian      
descent is merely a selection of a few  
representative cases and might be almost
 indefinitely extended4 ,nothing has    
been said1 for example1 of the wonderful
 museum of ancient mammalian life which 
is entombed in the rocks of ,south      
,america1 especially of ,patagonia1 and 
which opens a world so entirely         
different from that of the northern     
continents1 yet exemplifying the same   
laws of descent with modification4 ,very
 beautiful phylogenetic series have     
already been established among these    
most interesting and marvellously       
preserved fossils1 but lack of space    

forbids a consideration of them4  ,the  
origin of the mammalia1 as a class1     
offers a problem of which palaeontology 
can as yet present no definitive        
solution4 ,many morphologists regard the
 early amphibia as the ancestral group  
from which the mammals were derived1    
while most palaeontologists believe that
 the mammals are descended from the     
reptiles4 ,the most ancient known       
mammals1 those from the upper ,triassic 
of ,europe and ,north ,america1 are so  
extremely rare and so very imperfectly  
known1 that they give little help in    
determining the descent of the class1   
but1 on the other hand1 certain         
reptilian orders of the ,permian period1
 especially well represented in ,south  
,africa1 display so many and such close 
approximations to mammalian structure1  
as strongly to suggest a genetic        
relationship4 ,it is difficult to       
believe that all those likenesses should
 have been independently acquired and   
are without phylogenetic significance4  

,birds are comparatively rare as fossils
 and we should therefore look in vain   
among them for any such long and closely
 knit series as the mammals display in  
abundance4 ,nevertheless1 a few         
extremely fortunate discoveries have    
made it practically certain that birds  
are descended from reptiles1 of which   
they represent a highly specialised     
branch4 ,the most ancient representative
 of this class is the extraordinary     
genus ,archaeopteryx from the upper     
,jurassic of ,bavaria1 which1 though an 
unmistakable bird1 retains so many      
reptilian structures and characteristics
 as to make its derivation plain4 ,not  
to linger over anatomical minutiae1 it  
may suffice to mention the absence of a 
horny beak1 which is replaced by        
numerous true teeth1 and the long       
lizard-like tail1 which is made up of   
numerous distinct vertebrae1 each with a
 pair of quill-like feathers attached to
 it4 ,birds with teeth are also found in
 the ,cretaceous1 though in most other  

respects the birds of that period had   
attained a substantially modern         
structure4 ,concerning the              
interrelations of the various orders and
 families of birds1 palaeontology has as
 yet little to tell us4  ,the life of   
the ,mesozoic era was characterised by  
an astonishing number and variety of    
reptiles1 which were adapted to every   
mode of life1 and dominated the air1 the
 sea and the land1 and many of which    
were of colossal proportions4 ,owing to 
the conditions of preservation which    
obtained during the ,mesozoic period1   
the history of the reptiles is a broken 
and interrupted one1 so that we can make
 out many short series1 rather than any 
one of considerable length4 ,while the  
relations of several reptilian orders   
can be satisfactorily determined1 others
 still baffle us entirely1 making their 
first known appearance in a fully       
differentiated state4 ,we can trace the 
descent of the sea-dragons1 the         
,ichthyosaurs and ,plesiosaurs1 from    

terrestrial ancestors1 but the most     
ancient turtles yet discovered show us  
no closer approximation to any other    
order than do the recent turtles2 and   
the oldest known ,pterosaurs1 the flying
 dragons of the ,jurassic1 are already  
fully differentiated4 ,there is1        
however1 no ground for discouragement in
 this1 for the progress of discovery has
 been so rapid of late years1 and our   
knowledge of ,mesozoic life has         
increased with such leaps and bounds1   
that there is every reason to expect a  
solution of many of the outstanding     
problems in the near future4  ,passing  
over the lower vertebrates1 for lack of 
space to give them any adequate         
consideration1 we may briefly take up   
the record of invertebrate life4 ,from  
the overwhelming mass of material it is 
difficult to make a representative      
selection and even more difficult to    
state the facts intelligibly without the
 use of unduly technical language and   
without the aid of illustrations4       

,several groups of the ,mollusca1 or    
shell-fish1 yield very full and         
convincing evidence of their descent    
from earlier and simpler forms1 and of  
these none is of greater interest than  
the ,ammonites1 an extinct order of the 
cephalopoda4 ,the nearest living ally of
 the ammonites is the pearly nautilus1  
the other existing cephalopods1 such as 
the squids1 cuttle-fish1 octopus1 etc41 
are much more distantly related4 ,like  
the nautilus1 the ammonites all possess 
a coiled and chambered shell1 but their 
especial characteristic is the          
complexity of the sutures4 ,by sutures  
is meant the edges of the transverse    
partitions1 or septa1 where these join  
the shell-wall1 and their complexity in 
the fully developed genera is           
extraordinary1 forming patterns like the
 most elaborate oak-leaf embroidery1    
while in the nautiloids the sutures form
 simple curves4 ,in the rocks of the    
,mesozoic era1 wherever conditions of   
preservation are favourable1 these      

beautiful shells are stored in countless
 multitudes1 of an incredible variety of
 form1 size and ornamentation1 as is    
shown by the fact that nearly #ejjj     
species have already been described4    
,the ammonites are particularly well    
adapted for phylogenetic studies1       
because1 by removing the successive     
whorls of the coiled shell1 the         
individual development may be followed  
back in inverse order1 to the           
microscopic protoconch1 or embryonic    
shell1 which lies concealed in the      
middle of the coil4 ,thus the valuable  
aid of embryology is obtained in        
determining relationships4  ,the descent
 of the ammonites1 taken as a group1 is 
simple and clear2 they arose as a branch
 of the nautiloids in the lower         
,devonian1 the shells known as          
goniatites having zigzag1 angulated     
sutures4 ,late in the succeeding        
,carboniferous period appear shells with
 a truly ammonoid complexity of sutures1
 and in the ,permian their number and   

variety cause them to form a striking   
element of the marine faunas4 ,it is in 
the ,mesozoic era1 however1 that these  
shells attain their full development2   
increasing enormously in the ,triassic1 
they culminate in the ,jurassic in the  
number of families1 genera and species1 
in the complexity of the sutures1 and in
 the variety of shell-ornamentation4 ,a 
slow decline begins in the ,cretaceous1 
ending in the complete extinction of the
 whole group at the end of that period4 
,as a final phase in the history of the 
ammonites1 there appear many so-called  
abnormal genera1 in which the shell is  
irregularly coiled1 or more or less     
uncoiled1 in some forms becoming        
actually straight4 ,it is interesting to
 observe that some of these genera are  
not natural groups1 but are             
polyphyletic1 i4e4 are each derived from
 several distinct ancestral genera1     
which have undergone a similar kind of  
degeneration4  ,in the huge assembly of 
ammonites it is not yet possible to     

arrange all the forms in a truly natural
 classification1 which shall express the
 various interrelations of the genera1  
yet several beautiful series have       
already been determined4 ,in these      
series the individual development of the
 later general shows transitory stages  
which are permanent in antecedent       
genera4 ,to give a mere catalogue of    
names without figures would not make    
these series more intelligible4  ,the   
,brachiopoda1 or lamp-shells1 are a     
phylum of which comparatively few       
survive to the present day2 their shells
 have a superficial likeness to those of
 the bivalved ,mollusca1 but are not    
homologous with the latter1 and the     
phylum is really very distinct from the 
molluscs4 ,while greatly reduced now1   
these animals were incredibly abundant  
throughout the ,palaeozoic era1 great   
masses of limestone being often composed
 almost exclusively of their shells1 and
 their variety is in keeping with their 
individual abundance4 ,as in the case of

 the ammonites1 the problem is to       
arrange this great multitude of forms in
 an orderly array that shall express the
 ramifications of the group according to
 a genetic system4 ,for many            
brachiopods1 both recent and fossil1 the
 individual development1 or ontogeny1   
has been worked out and has proved to be
 of great assistance in the problems of 
classification and phylogeny4 ,already  
very encouraging progress has been made 
in the solution of these problems4 ,all 
brachiopods form first a tiny1 embryonic
 shell1 called the protegulum1 which is 
believed to represent the ancestral form
 of the whole group1 and in the more    
advanced genera the developmental stages
 clearly indicate the ancestral genera  
of the series1 the succession of adult  
forms in time corresponding to the order
 of the ontogenetic stages4 ,the        
transformation of the delicate          
calcareous supports of the arms1 often  
exquisitely preserved1 are extremely    
interesting4 ,many of the ,palaeozoic   

genera had these supports coiled like a 
pair of spiral springs1 and it has been 
shown that these genera were derived    
from types in which the supports were   
simply shelly loops4  ,the long extinct 
class of crustacea known as the         
,trilobites are likewise very favourable
 subjects for phylogenetic studies4 ,so 
far as the known record can inform us1  
the trilobites are exclusively          
,palaeozoic in distribution1 but their  
course must have begun long before that 
era1 as is shown by the number of       
distinct types among the genera of the  
lower ,cambrian4 ,the group reached the 
acme of abundance and relative          
importance in the ,cambrian and         
,ordovician2 then followed a long1 slow 
decline1 ending in complete and final   
disappearance before the end of the     
,permian4 ,the newly-hatched and tiny   
trilobite larva1 known as the protaspis1
 is very near to the primitive larval   
form of all the crustacea4 ,by the aid  
of the correlated ontogenetic stages and

 the succession of the adult forms in   
the rocks1 many phylogenetic series have
 been established and a basis for the   
natural arrangement of the whole class  
has been laid4  ,very instructive series
 may also be observed among the         
,echinoderms and1 what is very rare1 we 
are able in this sub-kingdom to         
demonstrate the derivation of one class 
from another4 ,indeed1 there is much    
reason to believe that the extinct class
 ,cystidea of the ,cambrian is the      
ancestral group1 from which all the     
other ,echinoderms1 star-fishes1        
brittle-stars1 sea-urchins1             
feather-stars1 etc41 are descended4     
,the foregoing sketch of the            
palaeontological record is1 of          
necessity1 extremely meagre1 and does   
not represent even an outline of the    
evidence1 but merely a few illustrative 
examples1 selected almost at random from
 an immense body of material4 ,however1 
it will perhaps suffice to show that the
 geological record is not so hopelessly 

incomplete as ,darwin believed it to be4
 ,since ,the ,origin of ,species was    
written1 our knowledge of that record   
has been enormously extended and we now 
possess1 no complete volumes1 it is     
true1 but some remarkably full and      
illuminating chapters4 ,the main        
significance of the whole lies in the   
fact1 that ,,just ,,in ,,proportion ,,to
 ,,the ,,completeness ,,of ,,the        
,,record ,,is ,,the ,,unequivocal       
,,character ,,of ,,its ,,testimony ,,to 
,,the ,,truth ,,of ,,the ,,evolutionary 
,,theory4  ,the test of a true1 as      
distinguished from a false1 theory is   
the manner in which newly discovered and
 unanticipated facts arrange themselves 
under it4 ,no more striking illustration
 of this can be found than in the       
contrasted fates of ,cuvier's theory and
 of that of ,darwin4 ,even before       
,cuvier's death his views had been      
undermined and the progress of discovery
 soon laid them in irreparable ruin1    
while the activity of half-a-century in 

many different lines of inquiry has     
established the theory of evolution upon
 a foundation of ever growing solidity4 
,it is ,darwin's imperishable glory that
 he prescribed the lines along which all
 the biological sciences were to advance
 to conquests not dreamed of when he    
wrote4     ,,xii4 ,,the                 
,,palaeontological ,,record4 ,by ,d4,h4 
,scott1 ,f4,r4,s4  ,president of the    
,linnean ,society4   ,,ii4 ,,plants4    
,there are several points of view from  
which the subject of the present essay  
may be regarded4 ,we may consider the   
fossil record of plants in its bearing3 
,i4 on the truth of the doctrine of     
,evolution2 ,,ii4 on ,phylogeny1 or the 
course of ,evolution2 ,,iii4 on the     
theory of ,natural ,selection4 ,the     
remarks which follow1 illustrating      
certain aspects only of an extensive    
subject1 may conveniently be grouped    
under these three headings4  ,i4 ,,the  
,,truth ,,of ,,evolution4  ,when ,the   
,origin of ,species was written1 it was 

necessary to show that the ,geological  
,record was favourable to1 or at least  
consistent with1 the ,theory of         
,descent4 ,the point is argued1 closely 
and fully1 in ,chapter ,x4 ,on the      
,imperfection of the ,geological        
,record1 and ,chapter ,,xi4 ,on the     
,geological ,succession of ,organic     
,beings2 there is1 however1 little about
 plants in these chapters4 ,at the      
present time the truth of ,evolution is 
no longer seriously disputed1 though    
there are writers1 like ,reinke1 who    
insist1 and rightly so1 that the        
doctrine is still only a belief1 rather 
than an established fact of science4    
7,j4 ,reinke1 ,kritische                
,abstammungslehre1                      
,wiesner-,festschrift1 page #aa1        
,vienna1 #aijh47 ,evidently1 then1      
however little the ,theory of ,descent  
may be questioned in our own day1 it is 
desirable to assure ourselves how the   
case stands1 and in particular how far  
the evidence from fossil plants has     

grown stronger with time4  ,as regards  
direct evidence for the derivation of   
one species from another1 there has     
probably been little advance since      
,darwin wrote1 at least so we must infer
 from the emphasis laid on the          
discontinuity of successive fossil      
species by great systematic authorities 
like ,grand',eury and ,zeiller in their 
most recent writings4 ,we must either   
adopt the mutationist views of those    
authors 7referred to in the last section
 of this essay7 or must still rely on   
,darwin's explanation of the absence of 
numerous intermediate varieties4 ,the   
attempts which have been made to trace1 
in the ,tertiary rocks1 the evolution of
 recent species1 cannot1 owing to the   
imperfect character of the evidence1 be 
regarded as wholly satisfactory4  ,when 
we come to groups of a somewhat higher  
order we have an interesting history of 
the evolution of a recent family in the 
work1 not yet completed1 of ,kidston and
 ,gwynne-,vaughan on the fossil         

,osmundaceae4 7,trans4 ,royal ,soc4     
,edinburgh1 ,vol4 #de1 ,part ,,iii4     
#aijg1 ,vol4 #df1 ,part ,,ii4 #aijh1    
,vol4 #df1 ,part ,,iii4 #aiji47 ,the    
authors are able1 mainly on anatomical  
evidence1 to trace back this now limited
 group of ,ferns1 through the ,tertiary 
and ,mesozoic to the ,permian1 and to   
show1 with great probability1 how their 
structure has been derived from that of 
early ,palaeozoic types4  ,the history  
of the ,ginkgoaceae1 now represented    
only by the isolated maidenhair tree1   
scarcely known in a wild state1 offers  
another striking example of a family    
which can be traced with certainty to   
the older ,mesozoic and perhaps further 
back still4 7,see ,seward and ,gowan1   
,the ,maidenhair ,tree 7,gingko biloba71
 ,annals of ,botany1 ,vol4 ,,xiv4 #aijj1
 page #aji2 also ,a4 ,sprecher ,le      
,ginkgo biloba1 ,l41 ,geneva1 #aijg47   
,on the wider question of the derivation
 of the great groups of plants1 a very  
considerable advance has been made1 and1

 so far as the higher plants are        
concerned1 we are now able to form a far
 better conception than before of the   
probable course of evolution4 ,this is a
 matter of phylogeny1 and the facts will
 be considered under that head2 our     
immediate point is that the new         
knowledge of the relations between the  
classes of plants in question materially
 strengthens the case for the theory of 
descent4 ,the discoveries of the last   
few years throw light especially on the 
relation of the ,angiosperms to the     
,gymnosperms1 on that of the            
,seed-plants generally to the ,ferns1   
and on the interrelations between the   
various classes of the higher           
,cryptogams4  ,that the fossil record   
has not done still more for ,evolution  
is due to the fact that it begins too   
late--a point on which ,darwin laid     
stress 7,origin of ,species 7#fth       
edition71 page #bhf47 and which has more
 recently been elaborated by ,poulton4  
7,essays on ,evolution1 pages #df et    

seq41 ,oxford1 #aijh47 ,an immense      
proportion of the whole evolutionary    
history lies behind the lowest          
fossiliferous rocks1 and the case is    
worse for plants than for animals1 as   
the record for the former begins1 for   
all practical purposes1 much higher up  
in the rocks4  ,it may be well here to  
call attention to a question1 often     
overlooked1 which has lately been       
revived by ,reinke4 7,reinke1 loc4 cit4 
page #ac47 ,as all admit1 we know       
nothing of the origin of life2          
consequently1 for all we can tell1 it is
 as probable that life began1 on this   
planet1 with many living things1 as with
 one4 ,if the first organic beings were 
many1 they may have been heterogeneous1 
or at least exposed to different        
conditions1 from their origin2 in either
 case there would have been a number of 
distinct series from the beginning1 and 
if so we should not be justified in     
assuming that all organisms are related 
to one another4 ,there may conceivably  

be several of the original lines of     
descent still surviving1 or represented 
among extinct forms--to reverse the     
remark of a distinguished botanist1     
there may be several ,vegetable         
,kingdoms6 ,however improbable this may 
sound1 the possibility is one to be     
borne in mind4  ,that all ,,vascular    
plants really belong to one stock seems 
certain1 and here the palaeontological  
record has materially strengthened the  
case for a monophyletic history4 ,the   
,bryophyta are not likely to be         
absolutely distinct1 for their sexual   
organs1 and the stomata of the ,mosses  
strongly suggest community of descent   
with the higher plants2 if this be so it
 no doubt establishes a certain         
presumption in favour of a common origin
 for plants generally1 for the gap      
between ,mosses and ,ferns has been     
regarded as the widest in the ,vegetable
 ,kingdom4 ,the direct evidence of      
consanguinity is however much weaker    
when we come to the ,algae1 and it is   

conceivable 7even if improbable7 that   
the higher plants may have had a        
distinct ancestry 7now wholly lost7 from
 the beginning4 ,the question had been  
raised in ,darwin's time1 and he        
referred to it in these words3 ,no doubt
 it is possible1 as ,mr ,g4,h4 ,lewes   
has urged1 that at the first            
commencement of life many different     
forms were evolved2 but if so1 we may   
conclude that only a very few have left 
modified descendants4 7,origin of       
,species1 page #dbe47 ,this question1   
though it deserves attention1 does not  
immediately affect the subject of the   
palaeontological record of plants1 for  
there can be no reasonable doubt as to  
the interrelationship of those groups on
 which the record at present throws     
light4  ,the past history of plants by  
no means shows a regular progression    
from the simple to the complex1 but     
often the contrary4 ,this apparent      
anomaly is due to two causes4  #a4 ,the 
palaeobotanical record is essentially   

the story of the successive ascendancy  
of a series of dominant families1 each  
of which attained its maximum1 in       
organisation as well as in extent1 and  
then sank into comparative obscurity1   
giving place to other families1 which   
under new conditions were better able to
 take a leading place4 ,as each family  
ran its downward course1 either its     
members underwent an actual reduction in
 structure as they became relegated to  
herbaceous or perhaps aquatic life 7this
 may have happened with the ,horsetails 
and with ,isoetes if derived from       
,lepidodendreae71 or the higher branches
 of the family were crowded out         
altogether and only the poor relations  
were able to maintain their position by 
evading the competition of the ascendant
 races2 this is also illustrated by the 
history of the ,lycopod phylum4 ,in     
either case there would result a        
lowering of the type of organisation    
within the group4  #b4 ,the course of   
real progress is often from the complex 

to the simple4 ,if1 as we shall find    
some grounds for believing1 the         
,angiosperms came from a type with a    
flower resembling in its complexity that
 of ,mesozoic ,cycads1 almost the whole 
evolution of the flower in the highest  
plants has been a process of reduction4 
,the stamen1 in particular1 has         
undoubtedly become extremely simplified 
during evolution2 in the most primitive 
known seed-plants it was a highly       
compound leaf or pinna2 its reduction   
has gone on in the ,conifers and modern 
,cycads1 as well as in the ,angiosperms1
 though in different ways and to a      
varying extent4  ,the seed offers       
another striking example2 the           
,palaeozoic seeds 7if we leave the      
seed-like organs of certain ,lycopods   
out of consideration7 were always1 so   
far as we know1 highly complex          
structures1 with an elaborate vascular  
system1 a pollen-chamber1 and often a   
much-differentiated testa4 ,in the      
present day such seeds exist only in a  

few ,gymnosperms which retain their     
ancient characters--in all the higher   
,spermophytes the structure is very much
 simplified1 and this holds good even in
 the ,coniferae1 where there is no      
countervailing complication of ovary and
 stigma4  ,reduction1 in fact1 is not   
always1 or even generally1 the same     
thing as degeneration4 ,simplification  
of parts is one of the most usual means 
of advance for the organism as a whole4 
,a large proportion of the higher plants
 are microphyllous in comparison with   
the highly megaphyllous fern-like forms 
from which they appear to have been     
derived4  ,darwin treated the general   
question of advance in organisation with
 much caution1 saying3 ,the geological  
record444 does not extend far enough    
back1 to show with unmistakeable        
clearness that within the known history 
of the world organisation has largely   
advanced4 7,origin of ,species1 page    
#cjh47 ,further on 7,ibid4 page #cji47  
he gives two standards by which advance 

may be measured3 ,we ought not solely to
 compare the highest members of a class 
at any two periods444 but we ought to   
compare all the members1 high and low1  
at the two periods4 ,judged by either   
standard the ,horsetails and ,club      
,mosses of the ,carboniferous were      
higher than those of our own day1 and   
the same is true of the ,mesozoic       
,cycads4 ,there is a general advance in 
the succession of classes1 but not      
within each class4  ,darwin's argument  
that the inhabitants of the world at    
each successive period in its history   
have beaten their predecessors in the   
race for life1 and are1 in so far1      
higher in the scale 7,origin of         
,species1 page #cae47 is unanswerable1  
but we must remember that higher in the 
scale only means better adapted to the  
existing conditions4 ,darwin points out 
7,ibid4 page #bgi47 that species have   
remained unchanged for long periods1    
probably longer than the periods of     
modification1 and only underwent change 

when the conditions of their life were  
altered4 ,higher organisation1 judged by
 the test of success1 is thus purely    
relative to the changing conditions1 a  
fact of which we have a striking        
illustration in the sudden incoming of  
the ,angiosperms with all their         
wonderful floral adaptations to         
fertilisation by the higher families of 
,insects4  ,,ii4 ,,phylogeny4  ,the     
question of phylogeny is really         
inseparable from that of the truth of   
the doctrine of evolution1 for we cannot
 have historical evidence that evolution
 has actually taken place without at the
 same time having evidence of the course
 it has followed4  ,as already pointed  
out1 the progress hitherto made has been
 rather in the way of joining up the    
great classes of plants than in tracing 
the descent of particular species or    
genera of the recent flora4 ,there      
appears to be a difference in this      
respect from the ,animal record1 which  
tells us so much about the descent of   

living species1 such as the elephant or 
the horse4 ,the reason for this         
difference is no doubt to be found in   
the fact that the later part of the     
palaeontological record is the most     
satisfactory in the case of animals and 
the least so in the case of plants4 ,the
 ,tertiary plant-remains1 in the great  
majority of instances1 are impressions  
of leaves1 the conclusions to be drawn  
from which are highly precarious2 until 
the whole subject of ,angiospermous     
palaeobotany has been reinvestigated1 it
 would be rash to venture on any        
statements as to the descent of the     
families of ,dicotyledons or            
,monocotyledons4  ,our attention will be
 concentrated on the following          
questions1 all relating to the phylogeny
 of main groups of plants3 i4 ,the      
,origin of the ,angiosperms4 ii4 ,the   
,origin of the ,seed-plants4 iii4 ,the  
,origin of the different classes of the 
,higher ,cryptogamia4  i4 ,,the ,,origin
 ,,of ,,the ,,angiosperms4  ,the first  

of these questions has long been the    
great crux of botanical phylogeny1 and  
until quite recently no light had been  
thrown upon the difficulty4 ,the        
,angiosperms are the ,flowering ,plants1
 par excellence1 and form1 beyond       
comparison1 the dominant sub-kingdom in 
the flora of our own age1 including1    
apart from a few ,conifers and ,ferns1  
all the most familiar plants of our     
fields and gardens1 and practically all 
plants of service to man4 ,all recent   
work has tended to separate the         
,angiosperms more widely from the other 
seed-plants now living1 the             
,gymnosperms4 ,vast as is the range of  
organisation presented by the great     
modern sub-kingdom1 embracing forms     
adapted to every environment1 there is  
yet a marked uniformity in certain      
points of structure1 as in the          
development of the embryo-sac and its   
contents1 the pollination through the   
intervention of a stigma1 the strange   
phenomenon of double fertilisation 7,one

 sperm fertilising the egg1 while the   
other unites with the embryo-sac        
nucleus1 itself the product of a nuclear
 fusion1 to give rise to a nutritive    
tissue1 the endosperm471 the structure  
of the stamens1 and the arrangement of  
the parts of the flower4 ,all these     
points are common to ,monocotyledons and
 ,dicotyledons1 and separate the        
,angiosperms collectively from all other
 plants4  ,in geological history the    
,angiosperms first appear in the ,lower 
,cretaceous1 and by ,upper ,cretaceous  
times had already swamped all other     
vegetation and seized the dominant      
position which they still hold4 ,thus   
they are isolated structurally from the 
rest of the ,vegetable ,kingdom1 while  
historically they suddenly appear1      
almost in full force1 and apparently    
without intermediaries with other       
groups4 ,to quote ,darwin's vigorous    
words3 ,the rapid development1 as far as
 we can judge1 of all the higher plants 
within recent geological times is an    

abominable mystery4 7,more ,letters of  
,charles ,darwin1 ,vol4 ,,ii4 page #bj1 
letter to ,j4,d4 ,hooker1 #ahgi47 ,a    
couple of years later he made a bold    
suggestion 7which he only called an idle
 thought7 to meet this difficulty4 ,he  
says3 ,i have been so astonished at the 
apparently sudden coming in of the      
higher phanerogams1 that ,i have        
sometimes fancied that development might
 have slowly gone on for an immense     
period in some isolated continent or    
large island1 perhaps near the ,south   
,pole4 7,ibid1 page #bf1 letter to      
,hooker1 #ahha47 ,this idea of an       
,angiospermous invasion from some lost  
southern land has sometimes been revived
 since1 but has not1 so far as the      
writer is aware1 been supported by      
evidence4 ,light on the problem has come
 from a different direction4  ,the      
immense development of plants with the  
habit of ,cycads1 during the ,mesozoic  
,period up to the ,lower ,cretaceous1   
has long been known4 ,the existing      

,order ,cycadaceae is a small family1   
with #i genera and perhaps #ajj species1
 occurring in the tropical and          
sub-tropical zones of both the ,old and 
,new ,world1 but nowhere forming a      
dominant feature in the vegetation4     
,some few attain the stature of small   
trees1 while in the majority the stem is
 short1 though often living to a great  
age4 ,the large pinnate or rarely       
bipinnate leaves give the ,cycads a     
superficial resemblance in habit to     
,palms4 ,recent ,cycads are dioecious2  
throughout the family the male          
fructification is in the form of a cone1
 each scale of the cone representing a  
stamen1 and bearing on its lower surface
 numerous pollen-sacs1 grouped in sori  
like the sporangia of ,ferns4 ,in all   
the genera1 except ,cycas itself1 the   
female fructifications are likewise     
cones1 each carpel bearing two ovules on
 its margin4 ,in ,cycas1 however1 no    
female cone is produced1 but the        
leaf-like carpels1 bearing from two to  

six ovules each1 are borne directly on  
the main stem of the plant in rosettes  
alternating with those of the ordinary  
leaves--the most primitive arrangement  
known in any living seed-plant4 ,the    
whole ,order is relatively primitive1 as
 shown most strikingly in its           
cryptogamic mode of fertilisation1 by   
means of spermatozoids1 which it shares 
with the maidenhair tree alone1 among   
recent seed-plants4  ,in all the older  
,mesozoic rocks1 from the ,trias to the 
,lower ,cretaceous1 plants of the ,cycad
 class 7,cycadophyta1 to use ,nathorst's
 comprehensive name7 are extraordinarily
 abundant in all parts of the world2 in 
fact they were almost as prominent in   
the flora of those ages as the          
,dicotyledons are in that of our own    
day4 ,in habit and to a great extent in 
anatomy1 the ,mesozoic ,cycadophyta for 
the most part much resemble the recent  
,cycadaceae4 ,but1 strange to say1 it is
 only in the rarest cases that the      
fructification has proved to be of the  

simple type characteristic of the recent
 family2 the vast majority of the       
abundant fertile specimens yielded by   
the ,mesozoic rocks possess a type of   
reproductive apparatus far more         
elaborate than anything known in        
,cycadaceae or other ,gymnosperms4 ,the 
predominant ,mesozoic family1           
characterised by this advanced          
reproductive organisation1 is known as  
the ,bennettiteae2 in habit these plants
 resembled the more stunted ,cycads of  
the recent flora1 but differed from them
 in the presence of numerous lateral    
fructifications1 like large buds1 borne 
on the stem among the crowded bases of  
the leaves4 ,the organisation of these  
fructifications was first worked out on 
,european specimens by ,carruthers1     
,solms-,laubach1 ,lignier and others1   
but these observers had only more or    
less ripe fruits to deal with2 the      
complete structure of the flower has    
only been elucidated within the last few
 years by the researches of ,wieland on 

the magnificent ,american material1     
derived from the ,upper ,jurassic and   
,lower ,cretaceous beds of ,maryland1   
,dakota and ,wyoming4 7,g4,r4 ,wieland1 
,american ,fossil ,cycads1 ,carnegie    
,institution1 ,washington1 #aijf47 ,the 
word flower is used deliberately1 for   
reasons which will be apparent from the 
following brief description1 based on   
,wieland's observations4  ,the          
fructification is attached to the stem  
by a thick stalk1 which1 in its upper   
part1 bears a large number of spirally  
arranged bracts1 forming collectively a 
kind of perianth and completely         
enclosing the essential organs of       
reproduction4 ,the latter consist of a  
whorl of stamens1 of extremely elaborate
 structure1 surrounding a central cone  
or receptacle bearing numerous ovules4  
,the stamens resemble the fertile fronds
 of a fern2 they are of a compound1     
pinnate form1 and bear very large       
numbers of pollen-sacs1 each of which is
 itself a compound structure consisting 

of a number of compartments in which the
 pollen was formed4 ,in their lower part
 the stamens are fused together by their
 stalks1 like the monadelphous stamens  
of a mallow4 ,the numerous ovules borne 
on the central receptacle are stalked1  
and are intermixed with sterile scales2 
the latter are expanded at their outer  
ends1 which are united to form a kind of
 pericarp or ovary-wall1 only           
interrupted by the protruding micropyles
 of the ovules4 ,there is thus an       
approach to the closed pistil of an     
,angiosperm1 but it is evident that the 
ovules received the pollen directly4    
,the whole fructification is of large   
size2 in the case of ,cycadeoidea       
dacotensis1 one of the species          
investigated by ,wieland1 the total     
length1 in the bud condition1 is about  
#ab cm41 half of which belongs to the   
peduncle4  ,the general arrangement of  
the organs is manifestly the same as in 
a typical ,angiospermous flower1 with a 
central pistil1 a surrounding whorl of  

stamens and an enveloping perianth2     
there is1 as we have seen1 some approach
 to the closed ovary of an ,angiosperm2 
another point1 first discovered nearly  
#bj years ago by ,solms-,laubach in his 
investigation of a ,british species1 is 
that the seed was practically           
exalbuminous1 its cavity being filled by
 the large1 dicotyledonous embryo1      
whereas in all known ,gymnosperms a     
large part of the sac is occupied by a  
nutritive tissue1 the prothallus or     
endosperm2 here also we have a condition
 only met with elsewhere among the      
higher ,flowering ,plants4  ,taking all 
the characters into account1 the        
indications of affinity between the     
,mesozoic ,cycadophyta and the          
,angiosperms appear extremely           
significant1 as was recognised by       
,wieland when he first discovered the   
hermaphrodite nature of the             
,bennettitean flower4 ,the ,angiosperm  
with which he specially compared the    
fossil type was the ,tulip tree         

7,liriodendron7 and certainly there is a
 remarkable analogy with the            
,magnoliaceous flowers1 and with those  
of related orders such as ,ranunculaceae
 and the ,water-lilies4 ,it cannot1 of  
course1 be maintained that the          
,bennettiteae1 or any other ,mesozoic   
,cycadophyta at present known1 were on  
the direct line of descent of the       
,angiosperms1 for there are some        
important points of difference1 as1 for 
example1 in the great complexity of the 
stamens1 and in the fact that the       
ovary-wall or pericarp was not formed by
 the carpels themselves1 but by the     
accompanying sterile scale-leaves4      
,botanists1 since the discovery of the  
bisexual flowers of the ,bennettiteae1  
have expressed different views as to the
 nearness of their relation to the      
higher ,flowering ,plants1 but the      
points of agreement are so many that it 
is difficult to resist the conviction   
that a real relation exists1 and that   
the ancestry of the ,angiosperms1 so    

long shrouded in complete obscurity1 is 
to be sought among the great plexus of  
,cycad-like plants which dominated the  
flora of the world in ,mesozoic times4  
7,on this subject see1 in addition to   
,wieland's great work above cited1      
,f4,w4 ,oliver1 ,pteridosperms and      
,angiosperms1 ,new ,phytologist1 ,vol4  
,v4 #aijf2 ,d4,h4 ,scott1 ,the          
,flowering ,plants of the ,mesozoic ,age
 in the ,light of ,recent ,discoveries1 
,journal ,r4 ,microscop4 ,soc4 #aijg1   
and especially ,e4,a4,n4 ,arber and ,j4 
,parkin1 ,on the ,origin of             
,angiosperms1 ,journal ,linn4 ,soc4     
7,bot47 ,vol4 ,,xxxviii4 page #bi1      
#aijg47  ,the great complexity of the   
,bennettitean flower1 the earliest known
 fructification to which the word flower
 can be applied without forcing the     
sense1 renders it probable1 as ,wieland 
and others have pointed out1 that the   
evolution of the flower in ,angiosperms 
has consisted essentially in a process  
of reduction1 and that the simplest     

forms of flower are not to be regarded  
as the most primitive4 ,the older       
morphologists generally took the view   
that such simple flowers were to be     
explained as reductions from a more     
perfect type1 and this opinion1 though  
abandoned by many later writers1 appears
 likely to be true when we consider the 
elaboration of floral structure attained
 among the ,mesozoic ,cycadophyta1 which
 preceded the ,angiosperms in evolution4
  ,if1 as now seems probable1 the       
,angiosperms were derived from ancestors
 allied to the ,cycads1 it would        
naturally follow that the ,dicotyledons 
were first evolved1 for their structure 
has most in common with that of the     
,cycadophyta4 ,we should then have to   
regard the ,monocotyledons as a         
side-line1 diverging probably at a very 
early stage from the main dicotyledonous
 stock1 a view which many botanists have
 maintained1 of late1 on other grounds4 
7,see especially ,ethel ,sargant1 ,the  
,reconstruction of a ,race of ,primitive

 ,angiosperms1 ,annals of ,botany1 ,vol4
 ,,xxii4 page #aba1 #aijh47 ,so far1    
however1 as the palaeontological record 
shows1 the ,monocotyledons were little  
if at all later in their appearance than
 the ,dicotyledons1 though always       
subordinate in numbers4 ,the typical and
 beautifully preserved ,palm-wood from  
,cretaceous rocks is striking evidence  
of the early evolution of a             
characteristic monocotyledonous family4 
,it must be admitted that the whole     
question of the evolution of            
,monocotyledons remains to be solved4   
,accepting1 provisionally1 the theory of
 the cycadophytic origin of             
,angiosperms1 it is interesting to see  
to what further conclusions we are led4 
,the ,bennettiteae1 at any rate1 were   
still at the gymnospermous level as     
regards their pollination1 for the      
exposed micropyles of the ovules were in
 a position to receive the pollen       
directly1 without the intervention of a 
stigma4 ,it is thus indicated that the  

,angiosperms sprang from a gymnospermous
 source1 and that the two great phyla of
 ,seed-plants have not been distinct    
from the first1 though no doubt the     
great majority of known ,gymnosperms1   
especially the ,coniferae1 represent    
branch-lines of their own4  ,the stamens
 of the ,bennettiteae are arranged      
precisely as in an angiospermous flower1
 but in form and structure they are like
 the fertile fronds of a ,fern1 in fact 
the compound pollen-sacs1 or synangia as
 they are technically called1 almost    
exactly agree with the spore-sacs of a  
particular family of ,ferns--the        
,marattiaceae1 a limited group1 now     
mainly tropical1 which was probably more
 prominent in the later ,palaeozoic     
times than at present4 ,the scaly hairs1
 or ramenta1 which clothe every part of 
the plant1 are also like those of       
,ferns4  ,it is not likely that the     
characters in which the ,bennettiteae   
resemble the ,ferns came to them        
directly from ancestors belonging to    

that class2 an extensive group of       
,seed-plants1 the ,pteridospermeae1     
existed in ,palaeozoic times and bear   
evident marks of affinity with the ,fern
 phylum4 ,the fern-like characters so   
remarkably persistent in the highly     
organised ,cycadophyta of the ,mesozoic 
were in all likelihood derived through  
the ,pteridosperms1 plants which show an
 unmistakable approach to the           
cycadophytic type4  ,the family         
,bennettiteae thus presents an          
extraordinary association of characters1
 exhibiting1 side by side1 features     
which belong to the ,angiosperms1 the   
,gymnosperms and the ,ferns4  ii4       
,,origin ,,of ,,seed-,,plants4  ,the    
general relation of the gymnospermous   
,seed-plants to the ,higher ,cryptogamia
 was cleared up1 independently of fossil
 evidence1 by the brilliant researches  
of ,hofmeister1 dating from the middle  
of the past century4 7,w4 ,hofmeister1  
,on the ,germination1 ,development and  
,fructification of the ,higher          

,cryptogamia1 ,ray ,society1 ,london1   
#ahfb4 ,the original ,german treatise   
appeared in #ahea47 ,he showed that the 
embryo-sac of the ,coniferae may be     
looked upon as a spore remaining        
enclosed in its sporangium2 the         
prothallium which it forms does not come
 to the light4 7,ibid4 page #dch47 ,he  
thus determined the homologies on the   
female side4 ,recognising1 as some      
previous observers had already done1    
that the microspores of those           
,cryptogams in which two kinds of spore 
are developed1 are equivalent to the    
pollen-grains of the higher plants1 he  
further pointed out that fertilisation  
in the ,rhizocarpeae and ,selaginellae  
takes place by free spermatozoa1 and in 
the ,coniferae by a pollen-tube1 in the 
interior of which spermatozoa are       
probably formed--a remarkable instance  
of prescience1 for though spermatozoids 
have not been found in the ,conifers    
proper1 they were demonstrated in the   
allied groups ,cycadaceae and ,ginkgo1  

in #ahif1 by the ,japanese botanists    
,ikeno and ,hirase4 ,a new link was thus
 established between the ,gymnosperms   
and the ,cryptogams4  ,it remained      
uncertain1 however1 from which line of  
,cryptogams the gymnospermous           
,seed-plants had sprung4 ,the great     
point of morphological comparison was   
the presence of two kinds of spore1 and 
this was known to occur in the recent   
,lycopods and ,water-ferns              
7,rhizocarpeae7 and was also found in   
fossil representatives of the third     
phylum1 that of the ,horsetails4 ,as a  
matter of fact all the three great      
,cryptogamic classes have found         
champions to maintain their claim to the
 ancestry of the ,seed-plants1 and in   
every case fossil evidence was called   
in4 ,for a long time the ,lycopods were 
the favourites1 while the ,ferns found  
the least support4 ,the writer          
remembers1 however1 in the year #ahha1  
hearing the late ,prof4 ,sachs maintain1
 in a lecture to his class1 that the    

descent of the ,cycads could be traced1 
not merely from ,ferns1 but from a      
definite family of ,ferns1 the          
,marattiaceae1 a view which1 though in a
 somewhat crude form1 anticipated more  
modern ideas4  ,williamson appears to   
have been the first to recognise the    
presence1 in the ,carboniferous flora1  
of plants combining the characters of   
,ferns and ,cycads4 7,see especially his
 ,organisation of the ,fossil ,plants of
 the ,coal-,measures1 ,part ,,xiii4     
,phil4 ,trans4 ,royal ,soc4 #ahhg ,b4   
page #bii47 ,this conclusion was first  
reached in the case of the genera       
,heterangium and ,lyginodendron1 plants1
 which with a wholly fern-like habit1   
were found to unite an anatomical       
structure holding the balance between   
that of ,ferns and ,cycads1 ,heterangium
 inclining more to the former and       
,lyginodendron to the latter4 ,later    
researches placed ,williamson's original
 suggestion on a firmer basis1 and      
clearly proved the intermediate nature  

of these genera1 and of a number of     
others1 so far as their vegetative      
organs were concerned4 ,this stage in   
our knowledge was marked by the         
institution of the class ,cycadofilices 
by ,potonie in #ahig4  ,nothing1        
however1 was known of the organs of     
reproduction of the ,cycadofilices1     
until ,f4,w4 ,oliver1 in #aijc1         
identified a fossil seed1 ,lagenostoma  
,lomaxi1 as belonging to ,lyginodendron1
 the identification depending1 in the   
first instance1 on the recognition of an
 identical form of gland1 of very       
characteristic structure1 on the        
vegetative organs of ,lyginodendron and 
on the cupule enveloping the seed4 ,this
 evidence was supported by the discovery
 of a close anatomical agreement in     
other respects1 as well as by constant  
association between the seed and the    
plant4 7,f4,w4 ,oliver and ,d4,h4       
,scott1 ,on the ,structure of the       
,palaeozoic ,seed1 ,lagenostoma ,lomaxi1
 etc4 ,phil4 ,trans4 ,royal ,soc4 ,vol4 

#aig ,b4 #aijd47 ,the structure of the  
seed of ,lyginodendron1 proved to be of 
the same general type as that of the    
,cycads1 as shown especially by the     
presence of a pollen-chamber or special 
cavity for the reception of the         
pollen-grains1 an organ only known in   
the ,cycads and ,ginkgo among recent    
plants4  ,within a few months after the 
discovery of the seed of ,lyginodendron1
 ,kidston found the large1 nut-like seed
 of a ,neuropteris1 another fern-like   
,carboniferous plant1 in actual         
connection with the pinnules of the     
frond1 and since then seeds have been   
observed on the frond in species of     
,aneimites and ,pecopteris1 and a vast  
body of evidence1 direct or indirect1   
has accumulated1 showing that a large   
proportion of the ,palaeozoic plants    
formerly classed as ,ferns were in      
reality reproduced by seeds of the same 
type as those of recent ,cycadaceae4 7,a
 summary of the evidence will be found  
in the writer's article ,on the present 

position of ,palaeozoic ,botany1        
,progressus ,rei ,botanicae1 #aijg1 page
 #aci1 and ,studies in ,fossil ,botany1 
,vol4 ,,ii4 7#bnd edition7 ,london1     
#aiji47 ,at the same time1 the          
anatomical structure1 where it is open  
to investigation1 confirms the          
suggestion given by the habit1 and shows
 that these early seed-bearing plants   
had a real affinity with ,ferns4 ,this  
conclusion received strong corroboration
 when ,kidston1 in #aije1 discovered the
 male organs of ,lyginodendron1 and     
showed that they were identical with a  
fructification of the genus             
,crossotheca1 hitherto regarded as      
belonging to ,marattiaceous ,ferns4     
7,kidston1 ,on the ,microsporangia of   
the ,pteridospermeae1 etc4 ,phil4       
,trans4 ,royal ,soc4 ,vol4 #aih1 ,b4    
#aijf47  ,the general conclusion which  
follows from the various observations   
alluded to1 is that in ,palaeozoic times
 there was a great body of plants       
7including1 as it appears1 a large      

majority of the fossils previously      
regarded as ,ferns7 which had attained  
the rank of ,spermophyta1 bearing seeds 
of a ,cycadean type on fronds scarcely  
differing from the vegetative foliage1  
and in other respects1 namely anatomy1  
habit and the structure of the          
pollen-bearing organs1 retaining many of
 the characters of ,ferns4 ,from this   
extensive class of plants1 to which the 
name ,pteridospermeae has been given1 it
 can scarcely be doubted that the       
abundant ,cycadophyta1 of the succeeding
 ,mesozoic period1 were derived4 ,this  
conclusion is of far-reaching           
significance1 for we have already found 
reason to think that the ,angiosperms   
themselves sprang1 in later times1 from 
the ,cycadophytic stock2 it thus appears
 that the ,fern-phylum1 taken in a broad
 sense1 ultimately represents the source
 from which the main line of descent of 
the ,phanerogams took its rise4  ,it    
must further be borne in mind that in   
the ,palaeozoic period there existed    

another group of seed-bearing plants1   
the ,cordaiteae1 far more advanced than 
the ,pteridospermeae1 and in many       
respects approaching the ,coniferae1    
which themselves begin to appear in the 
latest ,palaeozoic rocks4 ,the          
,cordaiteae1 while wholly different in  
habit from the contemporary fern-like   
,seed-plants1 show unmistakable signs of
 a common origin with them4 ,not only is
 there a whole series of forms          
connecting the anatomical structure of  
the ,cordaiteae with that of the        
,lyginodendreae among ,pteridosperms1   
but a still more important point is that
 the seeds of the ,cordaiteae1 which    
have long been known1 are of the same   
,cycadean type as those of the          
,pteridosperms1 so that it is not always
 possible1 as yet1 to discriminate      
between the seeds of the two groups4    
,these facts indicate that the same     
fern-like stock which gave rise to the  
,cycadophyta and through them1 as       
appears probable1 to the ,angiosperms1  

was also the source of the ,cordaiteae1 
which in their turn show manifest       
affinity with some at least of the      
,coniferae4 ,unless the latter are an   
artificial group1 a view which does not 
commend itself to the writer1 it would  
appear probable that the ,gymnosperms   
generally1 as well as the ,angiosperms1 
were derived from an ancient race of    
,cryptogams1 most nearly related to the 
,ferns4 7,some botanists1 however1      
believe that the ,coniferae1 or some of 
them1 are probably more nearly related  
to the ,lycopods4 ,see ,seward and      
,ford1 ,the ,araucarieae1 ,recent and   
,extinct1 ,phil4 ,trans4 ,royal ,soc4   
,vol4 #aih ,b4 #aijf47  ,it may be      
mentioned here that the small           
gymnospermous group ,gnetales 7including
 the extraordinary ,west ,african plant 
,welwitschia7 which were formerly       
regarded by some authorities as akin to 
the ,equisetales1 have recently been    
referred1 on better grounds1 to a common
 origin with the ,angiosperms1 from the 

,mesozoic ,cycadophyta4  ,the tendency1 
therefore1 of modern work on the        
palaeontological record of the          
,seed-plants has been to exalt the      
importance of the ,fern-phylum1 which1  
on present evidence1 appears to be that 
from which the great majority1 possibly 
the whole1 of the ,spermophyta have been
 derived4  ,one word of caution1        
however1 is necessary4 ,the ,seed-plants
 are of enormous antiquity2 both the    
,pteridosperms and the more highly      
organised family ,cordaiteae1 go back as
 far in geological history 7namely to   
the ,devonian7 as the ,ferns themselves 
or any other ,vascular ,cryptogams4 ,it 
must therefore be understood that in    
speaking of the derivation of the       
,spermophyta from the ,fern-phylum1 we  
refer to that phylum at a very early    
stage1 probably earlier than the most   
ancient period to which our record of   
land-plants extends4 ,the affinity      
between the oldest ,seed-plants and the 
,ferns1 in the widest sense1 seems      

established1 but the common stock from  
which they actually arose is still      
unknown2 though no doubt nearer to the  
,ferns than to any other group1 it must 
have differed widely from the ,ferns as 
we now know them1 or perhaps even from  
any which the fossil record has yet     
revealed to us4  iii4 ,,the ,,origin    
,,of ,,the ,,higher ,,cryptogamia4  ,the
 ,sub-kingdom of the higher             
,spore-plants1 the ,cryptogamia         
possessing a vascular system1 was more  
prominent in early geological periods   
than at present4 ,it is true that the   
dominance of the ,pteridophyta in       
,palaeozoic times has been much         
exaggerated owing to the assumption that
 everything which looked like a ,fern   
really was a ,fern4 ,but1 allowing for  
the fact1 now established1 that most of 
the ,palaeozoic fern-like plants were   
already ,spermophyta1 there remains a   
vast mass of ,cryptogamic forms of that 
period1 and the familiar statement that 
they formed the main constituent of the 

,coal-forests still holds good4 ,the    
three classes1 ,ferns 7,filicales71     
,horsetails 7,equisetales7 and          
,club-mosses 7,lycopodiales71 under     
which we now group the ,vascular        
,cryptogams1 all extend back in         
geological history as far as we have any
 record of the flora of the land2 in the
 ,palaeozoic1 however1 a fourth class1  
the ,sphenophyllales1 was present4  ,as 
regards the early history of the ,ferns1
 which are of special interest from     
their relation to the ,seed-plants1 it  
is impossible to speak quite positively1
 owing to the difficulty of             
discriminating between true fossil      
,ferns and the ,pteridosperms which so  
closely simulated them4 ,the difficulty 
especially affects the question of the  
position of ,marattiaceous ,ferns in the
 ,palaeozoic ,floras4 ,this family1 now 
so restricted1 was until recently       
believed to have been one of the most   
important groups of ,palaeozoic plants1 
especially during later ,carboniferous  

and ,permian times4 ,evidence both from 
anatomy and from sporangial characters  
appeared to establish this conclusion4  
,of late1 however1 doubts have arisen1  
owing to the discovery that some        
supposed members of the ,marattiaceae   
bore seeds1 and that a form of          
fructification previously referred to   
that family 7,crossotheca7 was really   
the pollen-bearing apparatus of a       
,pteridosperm 7,lyginodendron74 ,the    
question presents much difficulty2      
though it seems certain that our ideas  
of the extent of the family in          
,palaeozoic times will have to be       
restricted1 there is still a decided    
balance of evidence in favour of the    
view that a considerable body of        
,marattiaceous ,ferns actually existed4 
,the plants in question were of large   
size 7often arborescent7 and highly     
organised--they represent1 in fact1 one 
of the highest developments of the      
,fern-stock1 rather than a primitive    
type of the class4  ,there was1 however1

 in the ,palaeozoic period1 a           
considerable group of comparatively     
simple ,ferns 7for which ,arber has     
proposed the collective name            
,primofilices72 the best known of these 
are referred to the family              
,botryopterideae1 consisting of plants  
of small or moderate dimensions1 with1  
on the whole1 a simple anatomical       
structure1 in certain cases actually    
simpler than that of any recent ,ferns4 
,on the other hand the sporangia of     
these plants were usually borne on      
special fertile fronds1 a mark of rather
 high differentiation4 ,this group goes 
back to the ,devonian and includes some 
of the earliest types of ,fern with     
which we are acquainted4 ,it is probable
 that the ,primofilices 7though not the 
particular family ,botryopterideae7     
represent the stock from which the      
various families of modern ,ferns1      
already developed in the ,mesozoic      
period1 may have sprung4  ,none of the  
early ,ferns show any clear approach to 

other classes of ,vascular ,cryptogams2 
so far as the fossil record affords any 
evidence1 ,ferns have always been plants
 with relatively large and usually      
compound leaves4 ,there is no indication
 of their derivation from a             
microphyllous ancestry1 though1 as we   
shall see1 there is some slight evidence
 for the converse hypothesis4 ,whatever 
the origin of the ,ferns may have been  
it is hidden in the older rocks4  ,it   
has1 however1 been held that certain    
other ,cryptogamic phyla had a common   
origin with the ,ferns4 ,the            
,equisetales are at present a           
well-defined group2 even in the rich    
,palaeozoic floras the habit1 anatomy   
and reproductive characters usually     
render the members of this class        
unmistakable1 in spite of the great     
development and stature which they then 
attained4 ,it is interesting1 however1  
to find that in the oldest known        
representatives of the ,equisetales the 
leaves were highly developed and        

dichotomously divided1 thus differing   
greatly from the mere scale-leaves of   
the recent ,horsetails1 or even from the
 simple linear leaves of the later      
,calamites4 ,the early members of the   
class1 in their forked leaves1 and in   
anatomical characters1 show an          
approximation to the ,sphenophyllales1  
which are chiefly represented by the    
large genus ,sphenophyllum1 ranging     
through the ,palaeozoic from the ,middle
 ,devonian onwards4 ,these were plants  
with rather slender1 ribbed stems1      
bearing whorls of wedge-shaped or deeply
 forked leaves1 six being the typical   
number in each whorl4 ,from their weak  
habit it has been conjectured1 with much
 probability1 that they may have been   
climbing plants1 like the scrambling    
,bedstraws of our hedgerows4 ,the       
anatomy of the stem is simple and       
root-like2 the cones are remarkable for 
the fact that each scale or sporophyll  
is a double structure1 consisting of a  
lower1 usually sterile lobe and one or  

more upper lobes bearing the sporangia2 
in one species both parts of the        
sporophyll were fertile4 ,sphenophyllum 
was evidently much specialised2 the only
 other known genus is based on an       
isolated cone1 ,cheirostrobus1 of ,lower
 ,carboniferous age1 with an            
extraordinarily complex structure4 ,in  
this genus especially1 but also in the  
entire group1 there is an evident       
relation to the ,equisetales2 hence it  
is of great interest that ,nathorst has 
described1 from the ,devonian of ,bear  
,island in the ,arctic regions1 a new   
genus ,pseudobornia1 consisting of large
 plants1 remarkable for their highly    
compound leaves which1 when found       
detached1 were taken for the fronds of a
 ,fern4 ,the whorled arrangement of the 
leaves1 and the habit of the plant1     
suggest affinities either with the      
,equisetales or the ,sphenophyllales2   
,nathorst makes the genus the type of a 
new class1 the ,pseudoborniales4 7,a4,g4
 ,nathorst1 ,zur ,oberdevonischen ,flora

 der ,baren-,insel1 ,kongl4 ,svenska    
,vetenskaps-,akademiens ,handlingar ,bd4
 #cf1 ,no4 #c1 ,stockholm1 #aijb47  ,the
 available data1 though still very      
fragmentary1 certainly suggest that both
 ,equisetales and ,sphenophyllales may  
have sprung from a common stock having  
certain fern-like characters4 ,on the   
other hand the ,sphenophylls1 and       
especially the peculiar genus           
,cheirostrobus1 have in their anatomy a 
good deal in common with the ,lycopods1 
and of late years they have been        
regarded as the derivatives of a stock  
common to that class and the            
,equisetales4 ,at any rate the          
characters of the ,sphenophyllales and  
of the new group ,pseudoborniales       
suggest the existence1 at a very early  
period1 of a synthetic race of plants1  
combining the characters of various     
phyla of the ,vascular ,cryptogams4 ,it 
may further be mentioned that the       
,psilotaceae1 an isolated epiphytic     
family hitherto referred to the         

,lycopods1 have been regarded by several
 recent authors as the last survivors of
 the ,sphenophyllales1 which they       
resemble both in their anatomy and in   
the position of their sporangia4  ,the  
,lycopods1 so far as their early history
 is known1 are remarkable rather for    
their high development in ,palaeozoic   
times than for any indications of a more
 primitive ancestry4 ,in the recent     
,flora1 two of the four living genera   
7,excluding ,psilotaceae47 7,selaginella
 and ,isoetes7 have spores of two kinds1
 while the other two 7,lycopodium and   
,phylloglossum7 are homosporous4        
,curiously enough1 no certain instance  
of a homosporous ,palaeozoic ,lycopod   
has yet been discovered1 though         
well-preserved fructifications are      
numerous4 ,wherever the facts have been 
definitely ascertained1 we find two     
kinds of spore1 differentiated quite as 
sharply as in any living members of the 
group4 ,some of the ,palaeozoic         
,lycopods1 in fact1 went further1 and   

produced bodies of the nature of seeds1 
some of which were actually regarded1   
for many years1 as the seeds of         
,gymnosperms4 ,this specially advanced  
form of fructification goes back at     
least as far as the ,lower              
,carboniferous1 while the oldest known  
genus of ,lycopods1 ,bothrodendron1     
which is found in the ,devonian1 though 
not seed-bearing1 was typically         
heterosporous1 if we may judge from the 
,coal-measure species4 ,no doubt        
homosporous ,lycopods existed1 but the  
great prevalence of the higher mode of  
reproduction in days which to us appear 
ancient1 shows how long a course of     
evolution must have already been passed 
through before the oldest known members 
of the group came into being4 ,the other
 characters of the ,palaeozoic ,lycopods
 tell the same tale2 most of them       
attained the stature of trees1 with a   
corresponding elaboration of anatomical 
structure1 and even the herbaceous forms
 show no special simplicity4 ,it appears

 from recent work that herbaceous       
,lycopods1 indistinguishable from our   
recent ,selaginellas1 already existed in
 the time of the ,coal-measures1 while  
one herbaceous form 7,miadesmia7 is     
known to have borne seeds4  ,the utmost 
that can be said for primitiveness of   
character in ,palaeozoic ,lycopods is   
that the anatomy of the stem1 in its    
primary ground-plan1 as distinguished   
from its secondary growth1 was simpler  
than that of most ,lycopodiums and      
,selaginellas at the present day4 ,there
 are also some peculiarities in the     
underground organs 7,stigmaria7 which   
suggest the possibility of a somewhat   
imperfect differentiation between root  
and stem1 but precisely parallel        
difficulties are met with in the case of
 the living ,selaginellas1 and in some  
degree in species of ,lycopodium4  ,in  
spite of their high development in past 
ages the ,lycopods1 recent and fossil1  
constitute1 on the whole1 a homogeneous 
group1 and there is little at present to

 connect them with other phyla4         
,anatomically some relation to the      
,sphenophylls is indicated1 and perhaps 
the recent ,psilotaceae give some       
support to this connection1 for while   
their nearest alliance appears to be    
with the ,sphenophylls1 they approach   
the ,lycopods in anatomy1 habit1 and    
mode of branching4  ,the typically      
microphyllous character of the          
,lycopods1 and the simple relation      
between sporangium and sporophyll which 
obtains throughout the class1 have led  
various botanists to regard them as the 
most primitive phylum of the ,vascular  
,cryptogams4 ,there is nothing in the   
fossil record to disprove this view1 but
 neither is there anything to support   
it1 for this class so far as we know is 
no more ancient than the megaphyllous   
,cryptogams1 and its earliest           
representatives show no special         
simplicity4 ,if the indications of      
affinity with ,sphenophylls are of any  
value the ,lycopods are open to         

suspicion of reduction from a           
megaphyllous ancestry1 but there is no  
direct palaeontological evidence for    
such a history4  ,the general           
conclusions to which we are led by a    
consideration of the fossil record of   
the ,vascular ,cryptogams are still very
 hypothetical1 but may be provisionally 
stated as follows3  ,the ,ferns go back 
to the earliest known period4 ,in       
,mesozoic times practically all the     
existing families had appeared2 in the  
,palaeozoic the class was less extensive
 than formerly believed1 a majority of  
the supposed ,ferns of that age having  
proved to be seed-bearing plants4 ,the  
oldest authentic representatives of the 
,ferns were megaphyllous plants1 broadly
 speaking1 of the same type as those of 
later epochs1 though differing much in  
detail4 ,as far back as the record      
extends they show no sign of becoming   
merged with other phyla in any synthetic
 group4  ,the ,equisetales likewise have
 a long history1 and manifestly attained

 their greatest development in          
,palaeozoic times4 ,their oldest forms  
show an approach to the extinct class   
,sphenophyllales1 which connects them to
 some extent1 by anatomical characters1 
with the ,lycopods4 ,at the same time   
the oldest ,equisetales show a somewhat 
megaphyllous character1 which was more  
marked in the ,devonian                 
,pseudoborniales4 ,some remote affinity 
with the ,ferns 7which has also been    
upheld on other grounds7 may thus be    
indicated4 ,it is possible that in the  
,sphenophyllales we may have the        
much-modified representatives of a very 
ancient synthetic group4  ,the ,lycopods
 likewise attained their maximum in the 
,palaeozoic1 and show1 on the whole1 a  
greater elaboration of structure in     
their early forms than at any later     
period1 while at the same time          
maintaining a considerable degree of    
uniformity in morphological characters  
throughout their history4 ,the          
,sphenophyllales are the only other     

class with which they show any relation2
 if such a connection existed1 the      
common point of origin must lie         
exceedingly far back4  ,the fossil      
record1 as at present known1 cannot1 in 
the nature of things1 throw any direct  
light on what is perhaps the most       
disputed question in the morphology of  
plants--the origin of the alternating   
generations of the higher ,cryptogams   
and the ,spermophyta4 ,at the earliest  
period to which terrestrial plants have 
been traced back all the groups of      
,vascular ,cryptogams were in a highly  
advanced stage of evolution1 while      
innumerable ,seed-plants--presumably the
 descendants of ,cryptogamic            
ancestors--were already flourishing4 ,on
 the other hand we know practically     
nothing of ,palaeozoic ,bryophyta1 and  
the evidence even for their existence at
 that period cannot be termed           
conclusive4 ,while there are thus no    
palaeontological grounds for the        
hypothesis that the ,vascular plants    

came of a ,bryophytic stock1 the        
question of their actual origin remains 
unsolved4  ,,iii4 ,,natural ,,selection4
  ,hitherto we have considered the      
palaeontological record of plants in    
relation to ,evolution4 ,the question   
remains1 whether the record throws any  
light on the theory of which ,darwin and
 ,wallace were the authors--that of     
,natural ,selection4 ,the subject is    
clearly one which must be investigated  
by other methods than those of the      
palaeontologist2 still there are certain
 important points involved1 on which the
 palaeontological record appears to     
bear4  ,one of these points is the      
supposed distinction between            
morphological and adaptive characters1  
on which ,nageli1 in particular1 laid so
 much stress4 ,the question is a        
difficult one2 it was discussed by      
,darwin 7,origin of ,species 7#fth      
edition71 pages #agj-agf471 who1 while  
showing that the apparent distinction is
 in part to be explained by our         

imperfect knowledge of function1        
recognised the existence of important   
morphological characters which are not  
adaptations4 ,the following passage     
expresses his conclusion4 ,thus1 as ,i  
am inclined to believe1 morphological   
differences1 which we consider as       
important--such as the arrangement of   
the leaves1 the divisions of the flower 
or of the ovarium1 the position of the  
ovules1 etc4--first appeared in many    
cases as fluctuating variations1 which  
sooner or later became constant through 
the nature of the organism and of the   
surrounding conditions1 as well as      
through the inter-crossing of distinct  
individuals1 but not through natural    
selection2 for as these morphological   
characters do not affect the welfare of 
the species1 any slight deviations in   
them could not have been governed or    
accumulated through this latter agency4 
7,ibid4 page #agf47  ,this is a         
sufficiently liberal concession2        
,nageli1 however1 went much further when

 he said3 ,i do not know among plants a 
morphological modification which can be 
explained on utilitarian principles4    
7,see ,more ,letters1 ,vol4 ,,ii4 page  
#cge 7footnote747 ,if this were true the
 field of ,natural ,selection would be  
so seriously restricted1 as to leave the
 theory only a very limited importance4 
,it can be shown1 as the writer         
believes1 that many typical             
morphological characters1 on which the  
distinction between great classes of    
plants is based1 were adaptive in       
origin1 and even that their constancy is
 due to their functional importance4    
,only one or two cases will be          
mentioned1 where the fossil evidence    
affects the question4  ,the pollen-tube 
is one of the most important            
morphological characters of the         
,spermophyta as now existing--in fact   
the name ,siphonogama is used by ,engler
 in his classification1 as expressing a 
peculiarly constant character of the    
,seed-plants4 ,yet the pollen-tube is a 

manifest adaptation1 following on the   
adoption of the seed-habit1 and serving 
first to bring the spermatozoids with   
greater precision to their goal1 and    
ultimately to relieve them of the       
necessity for independent movement4 ,the
 pollen-tube is constant because it has 
proved to be indispensable4  ,in the    
,palaeozoic ,seed-plants there are a    
number of instances in which the        
pollen-grains1 contained in the         
pollen-chamber of a seed1 are so        
beautifully preserved that the presence 
of a group of cells within the grain can
 be demonstrated2 sometimes we can even 
see how the cell-walls broke down to    
emit the sperms1 and quite lately it is 
said that the sperms themselves have    
been recognised4 7,f4,w4 ,oliver1 ,on   
,physostoma elegans1 an archaic type of 
seed from the ,palaeozoic ,rocks1       
,annals of ,botany1 ,january1 #aiji4    
,see also the earlier papers there      
cited47 ,in no case1 however1 is there  
as yet any satisfactory evidence for the

 formation of a pollen-tube2 it is      
probable that in these early            
,seed-plants the pollen-grains remained 
at about the evolutionary level of the  
microspores in ,pilularia or            
,selaginella1 and discharged their      
spermatozoids directly1 leaving them to 
find their own way to the female cells4 
,it thus appears that there were once   
,spermophyta without pollen-tubes4 ,the 
pollen-tube method ultimately prevailed1
 becoming a constant morphological      
character1 for no other reason than     
because1 under the new conditions1 it   
provided a more perfect mechanism for   
the accomplishment of the act of        
fertilisation4 ,we have still1 in the   
,cycads and ,ginkgo1 the transitional   
case1 where the tube remains short1     
serves mainly as an anchor and          
water-reservoir1 but yet is able1 by its
 slight growth1 to give the             
spermatozoids a lift in the right       
direction4 ,in other ,seed-plants the   
sperms are mere passengers1 carried all 

the way by the pollen-tube2 this fact   
has alone rendered the ,angiospermous   
method of fertilisation through a stigma
 possible4  ,we may next take the seed  
itself--the very type of a morphological
 character4 ,our fossil record does not 
go far enough back to tell us the origin
 of the seed in the ,cycadophyta and    
,pteridosperms 7the main line of its    
development7 but some interesting       
sidelights may be obtained from the     
,lycopod phylum4 ,in two ,palaeozoic    
genera1 as we have seen1 seed-like      
organs are known to have been developed1
 resembling true seeds in the presence  
of an integument and of a single        
functional embryo-sac1 as well as in    
some other points4 ,we will call these  
organs seeds for the sake of shortness4 
,in one genus 7,lepidocarpon7 the seeds 
were borne on a cone indistinguishable  
from that of the ordinary cryptogamic   
,lepidodendreae1 the typical ,lycopods  
of the period1 while the seed itself    
retained much of the detailed structure 

of the sporangium of that family4 ,in   
the second genus1 ,miadesmia1 the       
seed-bearing plant was herbaceous1 and  
much like a recent ,selaginella4 7,see  
,margaret ,benson1 ,miadesmia           
membranacea1 a new ,palaeozoic ,lycopod 
with a seed-like structure1 ,phil4      
,trans4 ,royal ,soc4 ,vol4 #aii1 ,b4    
#aijh47 ,the seeds of the two genera are
 differently constructed1 and evidently 
had an independent origin4 ,here1 then1 
we have seeds arising casually1 as it   
were1 at different points among plants  
which otherwise retain all the          
characters of their cryptogamic fellows2
 the seed is not yet a morphological    
character of importance4 ,to suppose    
that in these isolated cases the seed   
sprang into being in obedience to a ,law
 of ,advance 7,vervollkommungsprincip71 
from which other contemporary ,lycopods 
were exempt1 involves us in unnecessary 
mysticism4 ,on the other hand it is not 
difficult to see how these seeds may    
have arisen1 as adaptive structures1    

under the influence of ,natural         
,selection4 ,the seed-like structure    
afforded protection to the prothallus1  
and may have enabled the embryo to be   
launched on the world in greater        
security4 ,there was further1 as we may 
suppose1 a gain in certainty of         
fertilisation4 ,as the writer has       
pointed out elsewhere1 the chances      
against the necessary association of the
 small male with the large female spores
 must have been enormously great when   
the cones were borne high up on tall    
trees4 ,the same difficulty may have    
existed in the case of the herbaceous   
,miadesmia1 if1 as ,miss ,benson        
conjectures1 it was an epiphyte4 ,one   
way of solving the problem was for      
pollination to take place while the     
megaspore was still on the parent plant1
 and this is just what the formation of 
an ovule or seed was likely to secure4  
,the seeds of the ,pteridosperms1 unlike
 those of the ,lycopod stock1 have not  
yet been found in statu nascendi--in all

 known cases they were already highly   
developed organs and far removed from   
the cryptogamic sporangium4 ,but in two 
respects we find that these seeds1 or   
some of them1 had not yet realised their
 possibilities4 ,in the seed of         
,lyginodendron and other cases the      
micropyle1 or orifice of the integument1
 was not the passage through which the  
pollen entered2 the open neck of the    
pollen-chamber protruded through the    
micropyle and itself received the       
pollen4 ,we have met with an analogous  
case1 at a more advanced stage of       
evolution1 in the ,bennettiteae1 where  
the wall of the gynaecium1 though       
otherwise closed1 did not provide a     
stigma to catch the pollen1 but allowed 
the micropyles of the ovules to protrude
 and receive the pollen in the old      
gymnospermous fashion4 ,the integument  
in the one case and the pistil in the   
other had not yet assumed all the       
functions to which the organ ultimately 
became adapted4 ,again1 no ,palaeozoic  

seed has yet been found to contain an   
embryo1 though the preservation is often
 good enough for it to have been        
recognised if present4 ,it is probable  
that the nursing of the embryo had not  
yet come to be one of the functions of  
the seed1 and that the whole embryonic  
development was relegated to the        
germination stage4  ,in these two       
points1 the reception of the pollen by  
the micropyle and the nursing of the    
embryo1 it appears that many ,palaeozoic
 seeds were imperfect1 as compared with 
the typical seeds of later times4 ,as   
evolution went on1 one function was     
superadded on another1 and it appears   
impossible to resist the conclusion that
 the whole differentiation of the seed  
was a process of adaptation1 and        
consequently governed by ,natural       
,selection1 just as much as the         
specialisation of the rostellum in an   
,orchid1 or of the pappus in a          
,composite4  ,did space allow1 other    
examples might be added4 ,we may venture

 to maintain that the glimpses which the
 fossil record allows us into early     
stages in the evolution of organs now of
 high systematic importance1 by no means
 justify the belief in any essential    
distinction between morphological and   
adaptive characters4  ,another point1   
closely connected with ,darwin's theory1
 on which the fossil history of plants  
has been supposed to have some bearing1 
is the question of ,mutation1 as opposed
 to indefinite variation4 ,arber and    
,parkin1 in their interesting memoir on 
the ,origin of ,angiosperms1 have       
suggested calling in ,mutation to       
explain the apparently sudden transition
 from the cycadean to the angiospermous 
type of foliage1 in late ,mesozoic      
times1 though they express themselves   
with much caution1 and point out a      
distinct danger that ,mutation may      
become the last resort of the           
phylogenetically destitute6  ,the       
distinguished ,french palaeobotanists1  
,grand',eury 7,c4 ,grand',eury1 ,sur les

 mutations de quelques ,plantes fossiles
 du ,terrain houiller4 ,comptes ,rendus1
 ,,cxlii4 page #be1 #aijf47 and ,zeiller
 7,r4 ,zeiller ,les ,vegetaux fossiles  
et leurs ,enchainements1 ,revue du      
,mois1 ,,iii4 ,february1 #aijg471 are of
 opinion1 to quote the words of the     
latter writer1 that the facts of fossil 
,botany are in agreement with the sudden
 appearance of new forms1 differing by  
marked characters from those that have  
given them birth2 he adds that these    
results give more amplitude to this idea
 of ,mutation1 extending it to groups of
 a higher order1 and even revealing the 
existence of discontinuous series       
between the successive terms of which we
 yet recognise bonds of filiation4      
7,loc4 cit4 page #bc47  ,if ,zeiller's  
opinion should be confirmed1 it would no
 doubt be a serious blow to the         
,darwinian theory4 ,as ,darwin said3    
,under a scientific point of view1 and  
as leading to further investigation1 but
 little advantage is gained by believing

 that new forms are suddenly developed  
in an inexplicable manner from old and  
widely different forms1 over the old    
belief in the creation of species from  
the dust of the earth4 7,origin of      
,species1 page #dbd47  ,it most however 
be pointed out1 that such mutations as  
,zeiller1 and to some extent ,arber and 
,parkin1 appear to have in view1        
bridging the gulf between different     
,orders and ,classes1 bear no relation  
to any mutations which have been        
actually observed1 such as the          
comparatively small changes1 of         
sub-specific value1 described by ,de    
,vries in the type-case of ,oenothera   
,lamarckiana4 ,the results of           
palaeobotanical research have           
undoubtedly tended to fill up gaps in   
the ,natural ,system of plants--that    
many such gaps still persist is not     
surprising2 their presence may well     
serve as an incentive to further        
research but does not1 as it seems to   
the writer1 justify the assumption of   

changes in the past1 wholly without     
analogy among living organisms4  ,as    
regards the succession of species1 there
 are no greater authorities than        
,grand',eury and ,zeiller1 and great    
weight must be attached to their opinion
 that the evidence from continuous      
deposits favours a somewhat sudden      
change from one specific form to        
another4 ,at the same time it will be   
well to bear in mind that the subject of
 the absence of numerous intermediate   
varieties in any single formation was   
fully discussed by ,darwin4 7,origin of 
,species1 pages #bge-bhb1 and page      
#cab472 the explanation which he gave   
may go a long way to account for the    
facts which recent writers have regarded
 as favouring the theory of saltatory   
mutation4  ,the rapid sketch given in   
the present essay can do no more than   
call attention to a few salient points1 
in which the palaeontological records of
 plants has an evident bearing on the   
,darwinian theory4 ,at the present day  

the whole subject of palaeobotany is a  
study in evolution1 and derives its     
chief inspiration from the ideas of     
,darwin and ,wallace4 ,in return it     
contributes something to the            
verification of their teaching2 the     
recent progress of the subject1 in spite
 of the immense difficulties which still
 remain1 has added fresh force to       
,darwin's statement that the great      
leading facts in palaeontology agree    
admirably with the theory of descent    
with modification through variation and 
natural selection4 7,ibid4 page #cac47  
,,xiii4 ,,the ,,influence ,,of          
,,environment ,,on ,,the ,,forms ,,of   
,,plants4 ,by ,georg ,klebs1 ,,ph4,d4   
,professor of ,botany in the ,university
 of ,heidelberg4   ,the dependence of   
plants on their environment became the  
object of scientific research when the  
phenomena of life were first            
investigated and physiology took its    
place as a special branch of science4   
,this occurred in the course of the     

eighteenth century as the result of the 
pioneer work of ,hales1 ,duhamel1       
,ingenhousz1 ,senebier and others4 ,in  
the nineteenth century1 particularly in 
the second half1 physiology experienced 
an unprecedented development in that it 
began to concern itself with the        
experimental study of nutrition and     
growth1 and with the phenomena          
associated with stimulus and movement2  
on the other hand1 physiology neglected 
phenomena connected with the production 
of form1 a department of knowledge which
 was the province of morphology1 a      
purely descriptive science4 ,it was in  
the middle of the last century that the 
growth of comparative morphology and the
 study of phases of development reached 
their highest point4  ,the forms of     
plants appeared to be the expression of 
their inscrutable inner nature2 the     
stages passed through in the development
 of the individual were regarded as the 
outcome of purely internal and hidden   
laws4 ,the feasibility of experimental  

inquiry seemed therefore remote4        
,meanwhile1 the recognition of the great
 importance of such a causal morphology 
emerged from the researches of the      
physiologists of that time1 more        
especially from those of ,hofmeister    
7,hofmeister1 ,allgemeine ,morphologie1 
,leipzig1 #ahfh1 page #egi471 and       
afterwards from the work of ,sachs4     
7,sachs1 ,stoff und ,form der           
,pflanzenorgane1 ,vol4 ,i4 #ahhj2 ,vol4 
,,ii4 #ahhb4 ,gesammelte ,abhandlungen  
uber ,pflanzen-,physiologie1 ,,ii4      
,leipzig1 #ahic47 ,hofmeister1 in       
speaking of this line of inquiry1       
described it as the most pressing and   
immediate aim of the investigator to    
discover to what extent external forces 
acting on the organism are of importance
 in determining its form4 ,this advance 
was the outcome of the influence of that
 potent force in biology which was      
created by ,darwin's ,origin of ,species
 7#ahei74  ,the significance of the     
splendid conception of the              

transformation of species was first     
recognised and discussed by ,lamarck    
7#ahji72 as an explanation of           
transformation he at once seized upon   
the idea--an intelligible view--that the
 external world is the determining      
factor4 ,lamarck 7,lamarck1 ,philosophie
 zoologique1 pages #bbc-bbg4 ,paris1    
#ahji47 endeavoured1 more especially1 to
 demonstrate from the behaviour of      
plants that changes in environment      
induce change in form which eventually  
leads to the production of new species4 
,in the case of animals1 ,lamarck       
adopted the teleological view that      
alterations in the environment first    
lead to alterations in the needs of the 
organisms1 which1 as the result of a    
kind of conscious effort of will1 induce
 useful modifications and even the      
development of new organs4 ,his work has
 not exercised any influence on the     
progress of science3 ,darwin himself    
confessed in regard to ,lamarck's       
work--,i got not a fact or idea from it4

 7,life and ,letters1 ,vol4 ,,ii4 page  
#bae47  ,on a mass of incomparably      
richer and more essential data ,darwin  
based his view of the descent of        
organisms and gained for it general     
acceptance2 as an explanation of        
modification he elaborated the          
ingeniously conceived selection theory4 
,the question of special interest in    
this connection1 namely what is the     
importance of the influence of the      
environment1 ,darwin always answered    
with some hesitation and caution1 indeed
 with a certain amount of indecision4   
,the fundamental principle underlying   
his theory is that of general           
variability as a whole1 the nature and  
extent of which1 especially in          
cultivated organisms1 are fully dealt   
with in his well-known book4 7,darwin1  
,the variation of ,animals and ,plants  
under domestication1 #b vols41 edition  
#a1 #ahfh2 edition #b1 #ahge2 popular   
edition #aije47 ,in regard to the       
question as to the cause of variability 

,darwin adopts a consistently mechanical
 view4 ,he says3 ,these several         
considerations alone render it probable 
that variability of every kind is       
directly or indirectly caused by changed
 conditions of life4 ,or1 to put the    
case under another point of view1 if it 
were possible to expose all the         
individuals of a species during many    
generations to absolutely uniform       
conditions of life1 there would be no   
variability4 7,the variation of ,animals
 and ,plants 7#bnd edition71 ,vol4 ,,ii4
 page #bdb47 ,darwin did not draw       
further conclusions from this general   
principle4  ,variations produced in     
organisms by the environment are        
distinguished by ,darwin as the definite
 and the indefinite4 7,ibid4 ,,ii4 page 
#bfj4 ,see also ,origin of ,species     
7#fth edition71 page #f47 ,the first    
occur when all or nearly all the        
offspring of an individual exposed to   
certain conditions during several       
generations are modified in the same    

manner4 ,indefinite variation is much   
more general and a more important factor
 in the production of new species2 as a 
result of this1 single individuals are  
distinguished from one another by slight
 differences1 first in one then in      
another character4 ,there may also      
occur1 though this is very rare1 more   
marked modifications1 variations which  
seem to us in our ignorance to arise    
spontaneously4 7,origin of ,species     
7#fth edition71 page #dba47 ,the        
selection theory demands the further    
postulate that such changes1 whether    
extremely slight or strongly marked1 are
 inherited4 ,darwin was no nearer to an 
experimental proof of this assumption   
than to the discovery of the actual     
cause of variability4 ,it was not until 
the later years of his life that ,darwin
 was occupied with the perplexing       
problem444 what causes almost every     
cultivated plant to vary 7,life and     
,letters1 ,vol4 ,,iii4 page #cdb473 he  
began to make experiments on the        

influence of the soil1 but these were   
soon given up4  ,in the course of the   
violent controversy which was the       
outcome of ,darwin's work the           
fundamental principles of his teaching  
were not advanced by any decisive       
observations4 ,among the supporters and 
opponents1 ,nageli 7,nageli1 ,theorie   
der ,abstammungslehre1 ,munich1 #ahhd2  
cf4 ,chapter ,,iii47 was one of the few 
who sought to obtain proofs by          
experimental methods4 ,his extensive    
cultural experiments with alpine        
,hieracia led him to form the opinion   
that the changes which are induced by an
 alteration in the food-supply1 in      
climate or in habitat1 are not inherited
 and are therefore of no importance from
 the point of view of the production of 
species4 ,and yet ,nageli did attribute 
an important influence to the external  
world2 he believed that adaptations of  
plants arise as reactions to continuous 
stimuli1 which supply a need and are    
therefore useful4 ,these opinions1 which

 recall the teleological aspect of      
,lamarckism1 are entirely unsupported by
 proof4 ,while other far-reaching       
attempts at an explanation of the theory
 of descent were formulated both in     
,nageli's time and afterwards1 some in  
support of1 others in opposition to     
,darwin1 the necessity of investigating1
 from different standpoints1 the        
underlying causes1 variability and      
heredity1 was more and more realised4   
,to this category belong the statistical
 investigations undertaken by ,quetelet 
and ,galton1 the researches into        
hybridisation1 to which an impetus was  
given by the re-discovery of the        
,mendelian law of segregation1 as also  
by the culture experiments on mutating  
species following the work of de ,vries1
 and lastly the consideration of the    
question how far variation and heredity 
are governed by external influences4    
,these latter problems1 which are       
concerned in general with the causes of 
form-production and form-modification1  

may be treated in a short summary which 
falls under two heads1 one having       
reference to the conditions of          
form-production in single species1 the  
other being concerned with the          
conditions governing the transformation 
of species4  ,i4 ,,the ,,influence ,,of 
,,external ,,conditions ,,on            
,,form-,,production ,,in ,,single       
,,species4  ,the members of plants1     
which we express by the terms stem1     
leaf1 flower1 etc4 are capable of       
modification within certain limits2     
since ,lamarck's time this power of     
modification has been brought more or   
less into relation with the environment4
 ,we are concerned not only with the    
question of experimental demonstration  
of this relationship1 but1 more         
generally1 with an examination of the   
origin of forms1 the sequences of stages
 in development that are governed by    
recognisable causes4 ,we have to        
consider the general problem2 to study  
the conditions of all typical as well as

 of atypic forms1 in other words1 to    
found a physiology of form4  ,if we     
survey the endless variety of           
plant-forms and consider the highly     
complex and still little known processes
 in the interior of cells1 and if we    
remember that the whole of this branch  
of investigation came into existence    
only a few decades ago1 we are able to  
grasp the fact that a satisfactory      
explanation of the factors determining  
form cannot be discovered all at once4  
,the goal is still far away4 ,we are not
 concerned now with the controversial   
question1 whether1 on the whole1 the    
fundamental processes in the development
 of form can be recognised by           
physiological means4 ,a belief in the   
possibility of this can in any case do  
no harm4 ,what we may and must attempt  
is this--to discover points of attack on
 one side or another1 which may enable  
us by means of experimental methods to  
come into closer touch with these       
elusive and difficult problems4 ,while  

we are forced to admit that there is at 
present much that is insoluble there    
remains an inexhaustible supply of      
problems capable of solution4  ,the     
object of our investigations is the     
species2 but as regards the question1   
what is a species1 science of to-day    
takes up a position different from that 
of ,darwin4 ,for him it was the ,linnean
 species which illustrates variation3 we
 now know1 thanks to the work of        
,jordan1 de ,bary1 and particularly to  
that of de ,vries 7de ,vries1 ,die      
,mutationstheorie1 ,leipzig1 #aija1     
,vol4 ,i4 page #cc471 that the ,linnean 
species consists of a large or small    
number of entities1 elementary species4 
,in experimental investigation it is    
essential that observations be made on a
 pure species1 or1 as ,johannsen        
7,johannsen1 ,ueber ,erblichkeit in     
,populationen und reinen ,linien1 ,jena1
 #aijc47 says1 on a pure line4 ,what has
 long been recognised as necessary in   
the investigation of fungi1 bacteria and

 algae must also be insisted on in the  
case of flowering plants2 we must start 
with a single individual which is       
reproduced vegetatively or by strict    
self-fertilisation4 ,in dioecious plants
 we must aim at the reproduction of     
brothers and sisters4  ,we may at the   
outset take it for granted that a pure  
species remains the same under similar  
external conditions2 it varies as these 
vary4 ,,it ,,is ,,characteristic ,,of ,a
 ,,species ,,that ,,it ,,always         
,,exhibits ,a ,,constant ,,relation ,,to
 ,a ,,particular ,,environment4 ,in the 
case of two different species1 e4g4 the 
hay and anthrax bacilli or two varieties
 of ,campanula with blue and white      
flowers respectively1 a similar         
environment produces a constant         
difference4 ,the cause of this is a     
mystery4  ,according to the modern      
standpoint1 the living cell is a complex
 chemico-physical system which is       
regarded as a dynamical system of       
equilibrium1 a conception suggested by  

,herbert ,spencer and which has acquired
 a constantly increasing importance in  
the light of modern developments in     
physical chemistry4 ,the various        
chemical compounds1 proteids1           
carbohydrates1 fats1 the whole series of
 different ferments1 etc4 occur in the  
cell in a definite physical arrangement4
 ,the two systems of two species must as
 a matter of fact possess a constant    
difference1 which it is necessary to    
define by a special term4 ,we say1      
therefore1 that the ,,specific          
,,structure is different4  ,by way of   
illustrating this provisionally1 we may 
assume that the proteids of the two     
species possess a constant chemical     
difference4 ,this conception of specific
 structure is specially important in its
 bearing on a further treatment of the  
subject4 ,in the original cell1         
eventually also in every cell of a      
plant1 the characters which afterwards  
become apparent must exist somewhere2   
they are integral parts of the          

capabilities or potentialities of       
specific structure4 ,thus not only the  
characters which are exhibited under    
ordinary conditions in nature1 but also 
many others which become apparent only  
under special conditions 7,in this      
connection ,i leave out of account1 as  
before1 the idea of material carriers of
 heredity which since the publication of
 ,darwin's ,pangenesis hypothesis has   
been frequently suggested4 ,see my      
remarks in ,variationen der ,bluten1    
,pringsheim's ,jahrb4 ,wiss4 ,bot4      
#aije1 page #bih2 also ,detto1 ,biol4   
,centralbl4 #aijg1 page #ha1 ,die       
,erklarbarkeit der ,ontogenese durch    
materielle ,anlagen471 are to be        
included as such potentialities in      
cells2 the conception of specific       
structure includes the ,,whole ,,of     
,,the ,,potentialities ,,of ,a          
,,species2 specific structure comprises 
that which we must always assume without
 being able to explain it4  ,a          
relatively simple substance1 such as    

oxalate of lime1 is known under a great 
number of different crystalline forms   
belonging to different systems 7,compare
 ,kohl's work on ,anatomisch-phys4      
,untersuchungen uber ,kalksalze1 etc4   
,marburg1 #ahhi472 these may occur as   
single crystals1 concretions or as      
concentric sphaerites4 ,the power to    
assume this variety of form is in some  
way inherent in the molecular structure1
 though we cannot1 even in this case1   
explain the necessary connection between
 structure and crystalline form4 ,these 
potentialities can only become operative
 under the influence of external        
conditions2 their stimulation into      
activity depends on the degree of       
concentration of the various solutions1 
on the nature of the particular calcium 
salt1 on the acid or alkaline reactions4
 ,broadly speaking1 the plant cell      
behaves in a similar way4 ,the          
manifestation of each form1 which is    
inherent as a potentiality in the       
specific structure1 is ultimately to be 

referred to external conditions4  ,an   
insight into this connection is1        
however1 rendered exceedingly difficult1
 often quite impossible1 because the    
environment never directly calls into   
action the potentialities4 ,its         
influence is exerted on what we may call
 the inner world of the organism1 the   
importance of which increases with the  
degree of differentiation4 ,the         
production of form in every plant       
depends upon processes in the interior  
of the cells1 and the nature of these   
determines which among the possible     
characters is to be brought to light4   
,in no single case are we acquainted    
with the internal process responsible   
for the production of a particular form4
 ,all possible factors may play a part1 
such as osmotic pressure1 permeability  
of the protoplasm1 the degree of        
concentration of the various chemical   
substances1 etc42 all these factors     
should be included in the category of   
,,internal ,,conditions4 ,this inner    

world appears the more hidden from our  
ken because it is always represented by 
a certain definite state1 whether we are
 dealing with a single cell or with a   
small group of cells4 ,these have been  
produced from pre-existing cells and    
they in turn from others2 the problem is
 constantly pushed back through a       
succession of generations until it      
becomes identified with that of the     
origin of species4  ,a way1 however1 is 
opened for investigation2 experience    
teaches us that this inner world is not 
a constant factor3 on the contrary1 it  
appears to be very variable4 ,the       
dependence of ,,variable ,,internal on  
,,variable ,,external conditions gives  
us the key with which research may open 
the door4 ,in the lower plants this     
dependence is at once apparent1 each    
cell is directly subject to external    
influences4 ,in the higher plants with  
their different organs1 these influences
 were transmitted to cells in course of 
development along exceedingly complex   

lines4 ,in the case of the growing-point
 of a bud1 which is capable of producing
 a complete plant1 direct influences    
play a much less important part than    
those exerted through other organs1     
particularly through the roots and      
leaves1 which are essential in          
nutrition4 ,these correlations1 as we   
may call them1 are of the greatest      
importance as aids to an understanding  
of form-production4 ,when a bud is      
produced on a particular part of a      
plant1 it undergoes definite internal   
modifications induced by the influence  
of other organs1 the activity of which  
is governed by the environment1 and as  
the result of this it develops along a  
certain direction2 it may1 for example1 
become a flower4 ,the particular        
direction of development is determined  
before the rudiment is differentiated   
and is exerted so strongly that further 
development ensues without interruption1
 even though the external conditions    
vary considerably and exert a positively

 inimical influence3 this produces the  
impression that development proceeds    
entirely independently of the outer     
world4 ,the widespread belief that such 
independence exists is very premature   
and at all events unproven4  ,the state 
of the young rudiment is the outcome of 
previous influences of the external     
world communicated through other organs4
 ,experiments show that in certain      
cases1 if the efficiency of roots and   
leaves as organs concerned with         
nutrition is interfered with1 the       
production of flowers is affected1 and  
their characters1 which are normally    
very constant1 undergo far-reaching     
modifications4 ,to find the right moment
 at which to make the necessary         
alteration in the environment is indeed 
difficult and in many cases not yet     
possible4 ,this is especially the case  
with fertilised eggs1 which in a higher 
degree than buds have acquired1 through 
parental influences1 an apparently fixed
 internal organisation1 and this seems  

to have pre-determined their            
development4 ,it is1 however1 highly    
probable that it will be possible1 by   
influencing the parents1 to alter the   
internal organisation and to switch off 
development on to other lines4  ,having 
made these general observations ,i will 
now cite a few of the many facts at our 
disposal1 in order to illustrate the    
methods and aim of the experimental     
methods of research4 ,as a matter of    
convenience ,i will deal separately with
 modification of development and with   
modification of single organs4  ,i4     
,,effect ,,of ,,environment ,,upon ,,the
 ,,course ,,of ,,development4  ,every   
plant1 whether an alga or a flowering   
plant passes1 under natural conditions1 
through a series of developmental stages
 characteristic of each species1 and    
these consist in a regular sequence of  
definite forms4 ,it is impossible to    
form an opinion from mere observation   
and description as to what inner changes
 are essential for the production of the

 several forms4 ,we must endeavour to   
influence the inner factors by known    
external conditions in such a way that  
the individual stages in development are
 separately controlled and the order of 
their sequence determined at will by    
experimental treatment4 ,such control   
over the course of development may be   
gained with special certainty in the    
case of the lower organisms4  ,with     
these it is practicable to control the  
principal conditions of cultivation and 
to vary them in various ways4 ,by this  
means it has been demonstrated that each
 developmental stage depends upon       
special external conditions1 and in     
cases where our knowledge is sufficient1
 a particular stage may be obtained at  
will4 ,in the ,green ,algae 7,see       
,klebs1 ,die ,bedingung der             
,fortpflanzung444 1 ,jena1 #ahif2 also  
,jahrb4 fur ,wiss4 ,bot4 #ahih and      
#aijj2 ,probleme der ,entwickelung1     
,,iii4 ,biol4 ,centralbl4 #aijd1 page   
#deb471 as in the case of ,fungi1 we may

 classify the stages of development into
 purely vegetative growth 7growth1      
cell-division1 branching71 asexual      
reproduction 7formation of zoospores1   
conidia7 and sexual processes 7formation
 of male and female sexual organs74 ,by 
modifying the external conditions it is 
possible to induce algae or fungi       
7,vaucheria1 ,saprolegnia7 to grow      
continuously for several years or1 in   
the course of a few days1 to die after  
an enormous production of asexual or    
sexual cells4 ,in some instances even an
 almost complete stoppage of growth may 
be caused1 reproductive cells being     
scarcely formed before the organism is  
again compelled to resort to            
reproduction4 ,thus the sequence of the 
different stages in development can be  
modified as we may desire4  ,the result 
of a more thorough investigation of the 
determining conditions appears to       
produce at first sight a confused       
impression of all sorts of              
possibilities4 ,even closely allied     

species exhibit differences in regard to
 the connection between their           
development and external conditions4 ,it
 is especially noteworthy that the same 
form in development may be produced as  
the result of very different alterations
 in the environment4 ,at the same time  
we can undoubtedly detect a certain     
unity in the multiplicity of the        
individual phenomena4  ,if we compare   
the factors essential for the different 
stages in development1 we see that the  
question always resolves itself into one
 of modification of similar conditions  
common to all life-processes4 ,we should
 rather have inferred that there exist  
specific external stimuli for each      
developmental stage1 for instance1      
certain chemical agencies4 ,experiments 
hitherto made support the conclusion    
that ,,quantitative alterations in the  
general conditions of life produce      
different types of development4 ,an alga
 or a fungus grows so long as all the   
conditions of nutrition remain at a     

certain optimum for growth4 ,in order to
 bring about asexual reproduction1 e4g4 
the formation of zoospores1 it is       
sometimes necessary to increase the     
degree of intensity of external factors2
 sometimes1 on the other hand1 these    
must be reduced in intensity4 ,in the   
case of many algae a decrease in        
light-intensity or in the amount of     
salts in the culture solution1 or in the
 temperature1 induces asexual           
reproduction1 while in others1 on the   
contrary1 an increase in regard to each 
of these factors is required to produce 
the same result4 ,this holds good for   
the quantitative variations which induce
 sexual reproduction in algae4 ,the     
controlling factor is found to be a     
reduction in the supply of nutritive    
salts and the exposure of the plants to 
prolonged illumination or1 better still1
 an increase in the intensity of the    
light1 the efficiency of illumination   
depending on the consequent formation of
 organic substances such as             

carbohydrates4  ,the quantitative       
alterations of external conditions may  
be spoken of as releasing stimuli4 ,they
 produce1 in the complex equilibrium of 
the cell1 quantitative modifications in 
the arrangement and distribution of     
mass1 by means of which other chemical  
processes are at once set in motion1 and
 finally a new condition of equilibrium 
is attained4 ,but the commonly expressed
 view that the environment can as a rule
 act only as a releasing agent is       
incorrect1 because it overlooks an      
essential point4 ,the power of a cell to
 receive stimuli is only acquired as the
 result of previous nutrition1 which has
 produced a definite condition of       
concentration of different substances4  
,quantities are in this case the        
determining factors4 ,the distribution  
of quantities is especially important in
 the sexual reproduction of algae1 for  
which a vigorous production of the      
materials formed during                 
carbon-assimilation appears to be       

essential4  ,in the ,flowering plants1  
on the other hand1 for reasons already  
mentioned1 the whole problem is more    
complicated4 ,investigations on changes 
in the course of development of         
fertilised eggs have hitherto been      
unsuccessful2 the difficulty of         
influencing egg-cells deeply immersed in
 tissue constitutes a serious obstacle4 
,other parts of plants are1 however1    
convenient objects of experiment2 e4g4  
the growing apices of buds which serve  
as cuttings for reproductive purposes1  
or buds on tubers1 runners1 rhizomes1   
etc4 ,a growing apex consists of cells  
capable of division in which1 as in     
egg-cells1 a complete series of latent  
possibilities of development is         
embodied4 ,which of these possibilities 
becomes effective depends upon the      
action of the outer world transmitted by
 organs concerned with nutrition4  ,of  
the different stages which a flowering  
plant passes through in the course of   
its development we will deal only with  

one in order to show that1 in spite of  
its great complexity1 the problem is1 in
 essentials1 equally open to attack in  
the higher plants and in the simplest   
organisms4 ,the most important stage in 
the life of a flowering plant is the    
transition from purely vegetative growth
 to sexual reproduction--that is1 the   
production of flowers4 ,in certain cases
 it can be demonstrated that there is no
 internal cause1 dependent simply on the
 specific structure1 which compels a    
plant to produce its flowers after a    
definite period of vegetative growth4   
7,klebs1 ,willkurliche                  
,entwickelungsanderungen1 ,jena #aijc2  
see also ,probleme der ,entwickelung1   
,i4 ,,ii4 ,centralbl4 #aijd47  ,one     
extreme case1 that of exceptionally     
early flowering1 has been observed in   
nature and more often in cultivation4 ,a
 number of plants under certain         
conditions are able to flower soon after
 germination4 7,cf4 numerous records of 
this kind by ,diels1 ,jugendformen und  

,bluten1 ,berlin1 #aijf47 ,this         
shortening of the period of development 
is exhibited in the most striking form  
in trees1 as in the oak 7,mobius1       
,beitrage zur ,lehre von der            
,fortpflanzung1 ,jena1 #ahig1 page      
#hi471 flowering seedlings of which have
 been observed from one to three years  
old1 whereas normally the tree does not 
flower until it is sixty or eighty years
 old4  ,another extreme case is         
represented by prolonged vegetative     
growth leading to the complete          
suppression of flower-production4 ,this 
result may be obtained with several     
plants1 such as ,glechoma1 the sugar    
beet1 ,digitalis1 and others1 if they   
are kept during the winter in a warm1   
damp atmosphere1 and in rich soil2 in   
the following spring or summer they fail
 to flower4 7,klebs1 ,willkurliche      
,aenderungen1 etc4 ,jena1 #aijc1 page   
#acj47 ,theoretically1 however1         
experiments are of greater importance in
 which the production of flowers is     

inhibited by very favourable conditions 
of nutrition 7,klebs1 ,ueber kunstliche 
,metamorphosen1 ,stuttgart1 #aijf1 page 
#aae7 7,abh4 ,naturf4 ,ges4 ,halle1     
,,xxv47 occurring at the normal         
flowering period4 ,even in the case of  
plants of ,sempervivum several years    
old1 which1 as is shown by control      
experiments on precisely similar plants1
 are on the point of flowering1         
flowering is rendered impossible if they
 are forced to very vigorous growth by  
an abundant supply of water and salts in
 the spring4 ,flowering1 however1       
occurs1 if such plants are cultivated in
 relatively dry sandy soil and in the   
presence of strong light4 ,careful      
researches into the conditions of growth
 have led1 in the cases ,sempervivum1 to
 the following results3 7#a7 ,with a    
strong light and vigorous               
carbon-assimilation a considerably      
increased supply of water and nutritive 
salts produces active vegetative growth4
 7#b7 ,with a vigorous                  

carbon-assimilation in strong light1 and
 a decrease in the supply of water and  
salts active flower-production is       
induced4 7#c7 ,if an average supply of  
water and salts is given both processes 
are possible2 the intensity of          
carbon-assimilation determines which of 
the two is manifested4 ,a diminution in 
the production of organic substances1   
particularly of carbohydrates1 induces  
vegetative growth4 ,this can be effected
 by culture in feeble light or in light 
deprived of the yellow-red rays3 on the 
other hand1 flower-production follows an
 increase in light-intensity4 ,these    
results are essentially in agreement    
with well-known observations on         
cultivated plants1 according to which1  
the application of much moisture1 after 
a plentiful supply of manure composed of
 inorganic salts1 hinders the           
flower-production of many vegetables1   
while a decrease in the supply of water 
and salts favours flowering4  ii4       
,,influence ,,of ,,the ,,environment    

,,on ,,the ,,form ,,of ,,single         
,,organs4 7,a considerable number of    
observations bearing on this question   
are given by ,goebel in his             
,experimentelle ,morphologie der        
,pflanzen1 ,leipzig1 #aijh4 ,it is not  
possible to deal here with the          
alteration in anatomical structure2 cf4 
,kuster1 ,pathologische                 
,pflanzenanatomie1 ,jena1 #aijc47  ,if  
we look closely into the development of 
a flowering plant1 we notice that in a  
given species differently formed organs 
occur in definite positions4 ,in a      
potato plant colourless runners are     
formed from the base of the main stem   
which grow underground and produce      
tubers at their tips3 from a higher     
level foliage shoots arise nearer the   
apex4 ,external appearances suggest that
 both the place of origin and the form  
of these organs were predetermined in   
the egg-cell or in the tuber4 ,but it   
was shown experimentally by the         
well-known investigator ,knight         

7,knight1 ,selection from the           
,physiological and ,horticultural       
,papers1 ,london1 #ahda47 that tubers   
may be developed on the aerial stem in  
place of foliage shoots4 ,these         
observations were considerably extended 
by ,vochting4 7,vochting1 ,ueber die    
,bildung der ,knollen1 ,cassel1 #ahhg2  
see also ,bot4 ,zeit4 #aijb1 #hg47 ,in  
one kind of potato1 germinating tubers  
were induced to form foliage shoots     
under the influence of a higher         
temperature2 at a lower temperature they
 formed tuber-bearing shoots4 ,many     
other examples of the conversion of     
foliage-shoots into runners and         
rhizomes1 or vice versa1 have been      
described by ,goebel and others4 ,as in 
the asexual reproduction of algae       
quantitative alteration in the amount of
 moisture1 light1 temperature1 etc4     
determines whether this or that form of 
shoot is produced4 ,if the primordia of 
these organs are exposed to altered     
conditions of nutrition at a            

sufficiently early stage a complete     
substitution of one organ for another is
 effected4 ,if the rudiment has reached 
a certain stage in development before it
 is exposed to these influences1        
extraordinary intermediate forms are    
obtained1 bearing the characters of both
 organs4  ,the study of regeneration    
following injury is of greater          
importance as regards the problem of the
 development and place of origin of     
organs4 7,reference may be made to the  
full summary of results given by ,goebel
 in his ,experimentelle ,morphologie1   
,leipzig and ,berlin1 #aijh1 ,section   
,,iv47 ,only in relatively very rare    
cases is there a complete re-formation  
of the injured organ itself1 as e4g4 in 
the growing-apex4 ,much more commonly   
injury leads to the development of      
complementary formations1 it may be the 
rejuvenescence of a hitherto dormant    
rudiment1 or it may be the formation of 
such ab initio4 ,in all organs1 stems1  
roots1 leaves1 as well as               

inflorescences1 this kind of            
regeneration1 which occurs in a great   
variety of ways according to the        
species1 may be observed on detached    
pieces of the plant4 ,cases are also    
known1 such1 for example1 as the leaves 
of many plants which readily form roots 
but not shoots1 where a complete        
regeneration does not occur4  ,the      
widely spread power of reacting to      
wounding affords a very valuable means  
of inducing a fresh development of buds 
and roots on places where they do not   
occur in normal circumstances4 ,injury  
creates special conditions1 but little  
is known as yet in regard to alterations
 directly produced in this way4 ,where  
the injury consists in the separation of
 an organ from its normal connections1  
the factors concerned are more          
comprehensible4 ,a detached leaf1 e4g41 
is at once cut off from a supply of     
water and salts1 and is deprived of the 
means of getting rid of organic         
substances which it produces2 the result

 is a considerable alteration in the    
degree of concentration4 ,no            
experimental investigation on these     
lines has yet been made4 ,our ignorance 
has often led to the view that we are   
dealing with a force whose specific     
quality is the restitution of the parts 
lost by operation2 the proof1 therefore1
 that in certain cases a similar        
production of new roots or buds may be  
induced without previous injury and     
simply by a change in external          
conditions assumes an importance4       
7,klebs1 ,willkurliche ,entwickelung1   
page #ajj2 also1 ,probleme der          
,entwickelung1 ,biol4 ,centralbl4 #aijd1
 page #faj47  ,a specially striking     
phenomenon of regeneration1 exhibited   
also by uninjured plants1 is afforded by
 polarity1 which was discovered by      
,vochting4 7,see the classic work of    
,vochting1 ,ueber ,organbildung im      
,pflanzenreich1 ,i4 ,bonn1 #ahhh2 also  
,bot4 ,zeit4 #aijf1 page #aja2 cf4      
,goebel1 ,experimentelle ,morphologie1  

,leipzig and ,berlin1 #aijh1 ,section   
,v1 ,polaritat47 ,it is found1 for      
example1 that roots are formed from the 
base of a detached piece of stem and    
shoots from the apex4 ,within the limits
 of this essay it is impossible to go   
into this difficult question2 it is1    
however1 important from the point of    
view of our general survey to emphasise 
the fact that the physiological         
distinctions between base and apex of   
pieces of stem are only of a            
quantitative kind1 that is1 they consist
 in the inhibition of certain phenomena 
or in favouring them4 ,as a matter of   
fact roots may be produced from the     
apices of willows and cuttings of other 
plants2 the distinction is thus         
obliterated under the influence of      
environment4 ,the fixed polarity of     
cuttings from full grown stems cannot be
 destroyed2 it is the expression of     
previous development4 ,vochting speaks  
of polarity as a fixed inherited        
character4 ,this is an unconvincing     

conclusion1 as nothing can be deduced   
from our present knowledge as to the    
causes which led up to polarity4 ,we    
know that the fertilised egg1 like the  
embryo1 is fixed at one end by which it 
hangs freely in the embryo-sac and      
afterwards in the endosperm4 ,from the  
first1 therefore1 the two ends have     
different natures1 and these are        
revealed in the differentiation into    
root-apex and stem-apex4 ,a definite    
direction in the flow of food-substances
 is correlated with this arrangement1   
and this eventually leads to a polarity 
in the tissues4 ,this view requires     
experimental proof1 which in the case of
 the egg-cells of flowering plants      
hardly appears possible2 but it derives 
considerable support from the fact that 
in herbaceous plants1 e4g4 ,sempervivum 
7,klebs1 ,variationen der ,bluten1      
,jahrb4 ,wiss4 ,bot4 #aije1 page #bfj471
 rosettes or flower-shoots are formed in
 response to external conditions at the 
base1 in the middle1 or at the apex of  

the stem1 so that polarity as it occurs 
under normal conditions cannot be the   
result of unalterable hereditary        
factors4 ,on the other hand1 the lower  
plants should furnish decisive evidence 
on this question1 and the experiments of
 ,stahl1 ,winkler1 ,kniep1 and others   
indicate the right method of attacking  
the problem4  ,the relation of leaf-form
 to environment has often been          
investigated and is well known4 ,the    
leaves of bog and water plants          
7,cf4,goebel1 loc4 cit4 chapter ,,ii42  
also ,gluck1 ,untersuchungen uber       
,wasser- und ,sumpfgewachse1 ,jena1     
,vols4 ,i4-,,ii4 #aije-jf47 afford the  
most striking examples of modifications3
 according as they are grown in water1  
moist or dry air1 the form of the       
species characteristic of the particular
 habitat is produced1 since the stems   
are also modified4 ,to the same group of
 phenomena belongs the modification of  
the forms of leaves and stems in plants 
on transplantation from the plains to   

the mountains 7,bonnier1 ,recherches sur
 l',anatomie experimentale des          
,vegetaux1 ,corbeil1 #ahie47 or vice    
versa4 ,such variations are by no means 
isolated examples4 ,all plants exhibit a
 definite alteration in form as the     
result of prolonged cultivation in moist
 or dry air1 in strong or feeble light1 
or in darkness1 or in salt solutions of 
different composition and strength4     
,every individual which is exposed to   
definite combinations of external       
factors exhibits eventually the same    
type of modification4 ,this is the type 
of variation which ,darwin termed       
definite4 ,it is easy to realise that   
indefinite or fluctuating variations    
belong essentially to the same class of 
phenomena2 both are reactions to changes
 in environment4 ,in the production of  
individual variations two different     
influences undoubtedly cooperate4 ,one  
set of variations is caused by different
 external conditions1 during the        
production1 either of sexual cells or of

 vegetative primordia2 another set is   
the result of varying external          
conditions during the development of the
 embryo into an adult plant4 ,the two   
sets of influences cannot as yet be     
sharply differentiated4 ,if1 for        
purposes of vegetative reproduction1 we 
select pieces of the same parent-plant  
of a pure species1 the second type of   
variation predominates4 ,individual     
fluctuations depend essentially in such 
cases on small variations in environment
 during development4  ,these relations  
must be borne in mind if we wish to     
understand the results of statistical   
methods4 ,since the work of ,quetelet1  
,galton1 and others the statistical     
examination of individual differences in
 animals and plants has become a special
 science1 which is primarily based on   
the consideration that the application  
of the theory of probability renders    
possible mathematical statement and     
control of the results4 ,the facts show 
that any character1 size of leaf1 length

 of stem1 the number of members in a    
flower1 etc4 do not vary haphazard but  
in a very regular manner4 ,in most cases
 it is found that there is a value which
 occurs most commonly1 the average or   
medium value1 from which the larger and 
smaller deviations1 the so-called plus  
and minus variations fall away in a     
continuous series and end in a limiting 
value4 ,in the simpler cases a falling  
off occurs equally on both sides of the 
curve2 the curve constructed from such  
data agrees very closely with the       
,gaussian curve of error4 ,in more      
complicated cases irregular curves of   
different kinds are obtained which may  
be calculated on certain suppositions4  
,the regular fluctuations about a mean  
according to the rule of probability is 
often attributed to some law underlying 
variability4 7de ,vries1                
,mutationstheorie1 ,vol4 ,i4 page #ce1  
,leipzig1 #aija47 ,but there is no such 
law which compels a plant to vary in a  
particular manner4 ,every experimental  

investigation shows1 as we have already 
remarked1 that the fluctuation of       
characters depends on fluctuation in the
 external factors4 ,the applicability of
 the method of probability follows from 
the fact that the numerous individuals  
of a species are influenced by a limited
 number of variable conditions4 7,klebs1
 ,willkurl4 ,ent4 ,jena1 #aijc1 page    
#ada47 ,as each of these conditions     
includes within certain limits all      
possible values and exhibits all        
possible combinations1 it follows that1 
according to the rules of probability1  
there must be a mean value1 about which 
the larger and smaller deviations are   
distributed4 ,any character will be     
found to have the mean value which      
corresponds with that combination of    
determining factors which occurs most   
frequently4 ,deviations towards plus and
 minus values will be correspondingly   
produced by rarer conditions4  ,a       
conclusion of fundamental importance may
 be drawn from this conception1 which   

is1 to a certain extent1 supported by   
experimental investigation4 7,klebs1    
,studien uber ,variation1 ,arch4 fur    
,entw4 #aijg47 ,there is no normal curve
 for a particular ,,character1 there is 
only a curve for the varying            
combinations of conditions occurring in 
nature or under cultivation4 ,under     
other conditions entirely different     
curves may be obtained with other       
variants as a mean value4 ,if1 for      
example1 under ordinary conditions the  
number #aj is the most frequent variant 
for the stamens of ,sedum spectabile1 in
 special circumstances 7red light7 this 
is replaced by the number #e4 ,the more 
accurately we know the conditions for a 
particular form or number1 and are able 
to reproduce it by experiment1 the      
nearer we are to achieving our aim of   
rendering a particular variation        
impossible or of making it dominant4    
,in addition to the individual          
variations of a species1 more pronounced
 fluctuations occur relatively rarely   

and sporadically which are spoken of as 
single variations1 or if specially      
striking as abnormalities or            
monstrosities4 ,these forms have long   
attracted the attention of              
morphologists2 a large number of        
observations of this kind are given in  
the handbooks of ,masters 7,masters1    
,vegetable ,teratology1 ,london1 #ahfi47
 and ,penzig 7,penzig1                  
,pflanzen-,teratologie1 ,vols ,i4 and   
,,ii4 ,genua1 #ahij-id47 ,these         
variations1 which used to be regarded as
 curiosities1 have now assumed          
considerable importance in connection   
with the causes of form-development4    
,they also possess special interest in  
relation to the question of heredity1 a 
subject which does not at present       
concern us1 as such deviations from     
normal development undoubtedly arise as 
individual variations induced by the    
influence of environment4  ,abnormal    
developments of all kinds in stems1     
leaves1 and flowers1 may be produced by 

parasites1 insects1 or fungi4 ,they may 
also be induced by injury1 as           
,blaringhem 7,blaringhem1 ,mutation et  
traumatismes1 ,paris1 #aijg47 has more  
particularly demonstrated1 which1 by    
cutting away the leading shoots of      
branches in an early stage of           
development1 caused fasciation1 torsion1
 anomalous flowers1 etc4 ,the           
experiments of ,blaringhem point to the 
probability that disturbances in the    
conditions of food-supply consequent on 
injury are the cause of the production  
of monstrosities4 ,this is certainly the
 case in my experiments with species of 
,sempervivum 7,klebs1 ,kunstliche       
,metamorphosen1 ,stuttgart1 #aijf472    
individuals1 which at first formed      
normal flowers1 produced a great variety
 of abnormalities as the result of      
changes in nutrition1 we may call to    
mind the fact that the formation of     
inflorescences occurs normally when a   
vigorous production of organic          
compounds1 such as starch1 sugar1 etc4  

follows a diminution in the supply of   
mineral salts4 ,on the other hand1 the  
development of inflorescences is        
entirely suppressed if1 at a suitable   
moment before the actual foundations    
have been laid1 water and mineral salts 
are supplied to the roots4 ,if1 during  
the week when the inflorescence has just
 been laid down and is growing very     
slowly1 the supply of water and salts is
 increased1 the internal conditions of  
the cells are essentially changed4 ,at a
 later stage1 after the elongation of   
the inflorescence1 rosettes of leaves   
are produced instead of flowers1 and    
structures intermediate between the two 
kinds of organs2 a number of peculiar   
plant-forms are thus obtained 7,cf4     
,lotsy1 ,vorlesungen uber               
,deszendenztheorien1 ,vol4 ,,ii4 pl4 #c1
 ,jena1 #aijh47 ,abnormalities in the   
greatest variety are produced in flowers
 by varying the time at which the       
stimulus is applied1 and by the         
cooperation of other factors such as    

temperature1 darkness1 etc4 ,in number  
and arrangement the several floral      
members vary within wide limits2 sepals1
 petals1 stamens1 and carpels are       
altered in form and colour1 a           
transformation of stamens to carpels and
 from carpels to stamens occurs in      
varying degrees4 ,the majority of the   
deviations observed had not previously  
been seen either under natural          
conditions or in cultivation2 they were 
first brought to light through the      
influence of external factors4  ,such   
transformations of flowers become       
apparent at a time1 which is separated  
by about two months from the period at  
which the particular cause began to act4
 ,there is1 therefore1 no close         
connection between the appearance of the
 modifications and the external         
conditions which prevail at the moment4 
,when we are ignorant of the causes     
which are operative so long before the  
results are seen1 we gain the impression
 that such variations as occur are      

spontaneous or autonomous expressions of
 the inner nature of the plant4 ,it is  
much more likely that1 as in            
,sempervivum1 they were originally      
produced by an external stimulus which  
had previously reached the sexual cells 
or the young embryo4 ,in any case       
abnormalities of this kind appear to be 
of a special type as compared with      
ordinary fluctuating variations4 ,darwin
 pointed out this difference2 ,bateson  
7,bateson1 ,materials for the study of  
,variation1 ,london1 #ahid1 page #e47   
has attempted to make the distinction   
sharper1 at the same time emphasising   
its importance in heredity4  ,bateson   
applies the term ,,continuous to small  
variations connected with one another by
 transitional stages1 while those which 
are more striking and characterised from
 the first by a certain completeness1 he
 names ,,discontinuous4 ,he drew        
attention to a great difficulty which   
stands in the way of ,lamarck's         
hypothesis1 as also of ,darwin's view4  

,according to both theories1 specific   
diversity of form is consequent upon    
diversity of environment1 and diversity 
of environment is thus the ultimate     
measure of diversity of specific form4  
,here then we meet the difficulty that  
diverse environments often shade into   
each other insensibly and form a        
continuous series1 whereas the ,specific
 ,forms of life which are subject to    
them on the whole form a ,discontinuous 
,series4 ,this difficulty is1 however1  
not of fundamental importance as well   
authenticated facts have been adduced   
showing that by alteration of the       
environment discontinuous variations1   
such as alterations in the number and   
form of members of a flower1 may be     
produced4 ,we can as yet no more explain
 how this happens than we can explain   
the existence of continuous variations4 
,we can only assert that both kinds of  
variation arise in response to          
quantitative alterations in external    
conditions4 ,the question as to which   

kind of variation is produced depends on
 the greater or less degree of          
alteration2 it is correlated with the   
state of the particular cells at the    
moment4  ,in this short sketch it is    
only possible to deal superficially with
 a small part of the subject4 ,it has   
been clearly shown that in view of the  
general dependence of development on the
 factors of the environment a number of 
problems are ready for experimental     
treatment4 ,one must1 however1 not      
forget that the science of the          
physiology of form has not progressed   
beyond its initial stages4 ,just now our
 first duty is to demonstrate the       
dependence on external factors in as    
many forms of plants as possible1 in    
order to obtain a more thorough control 
of all the different plant-forms4 ,the  
problem is not only to produce at will  
7and independently of their normal mode 
of life7 forms which occur in nature1   
but also to stimulate into operation    
potentialities which necessarily lie    

dormant under the conditions which      
prevail in nature4 ,the constitution of 
a species is much richer in             
possibilities of development than would 
appear to be the case under normal      
conditions4 ,it remains for man to      
stimulate into activity all the         
potentialities4  ,but the control of    
plant-form is only a preliminary        
step--the foundation stones on which to 
erect a coherent scientific structure4  
,we must discover what are the internal 
processes in the cell produced by       
external factors1 which as a necessary  
consequence result in the appearance of 
a definite form4 ,we are here brought   
into contact with the most obscure      
problem of life4 ,progress can only be  
made pari passu with progress in physics
 and chemistry1 and with the growth of  
our knowledge of nutrition1 growth1 etc4
  ,let us take one of the simplest      
cases--an alteration in form4 ,a        
cylindrical cell of the alga            
,stigeoclonium assumes1 as ,livingstone 

7,livingstone1 ,on the nature of the    
stimulus which causes the change of     
form1 etc4 ,botanical ,gazette1 ,,xxx4  
#aijj2 also ,,xxxii4 #aija47 has shown1 
a spherical form when the osmotic       
pressure of the culture fluid is        
increased2 or a spore of ,mucor1 which1 
in a sugar solution grows into a        
branched filament1 in the presence of a 
small quantity of acid 7hydrogen ions7  
becomes a comparatively large sphere4   
7,ritter1 ,ueber ,kugelhefe1 etc4 ,ber4 
bot4 ,gesell4 ,berlin1 ,,xxv4 page #bee1
 #aijg47 ,in both cases there has       
undoubtedly been an alteration in the   
osmotic pressure of the cell-sap1 but   
this does not suffice to explain the    
alteration in form1 since the unknown   
alterations1 which are induced in the   
protoplasm1 must in their turn influence
 the cell-membrane4 ,in the case of the 
very much more complex alterations in   
form1 such as we encounter in the course
 of development of plants1 there do not 
appear to be any clues which lead us to 

a deeper insight into the phenomena4    
,nevertheless we continue the attempt1  
seeking with the help of any available  
hypothesis for points of attack1 which  
may enable us to acquire a more complete
 mastery of physiological methods4 ,to  
quote a single example2 ,i may put the  
question1 what internal changes produce 
a transition from vegetative growth to  
sexual reproduction8  ,the facts1 which 
are as clearly established from the     
lower as for the higher plants1 teach us
 that quantitative alteration in the    
environment produces such a transition4 
,this suggests the conclusion that      
quantitative internal changes in the    
cells1 and with them disturbances in the
 degree of concentration1 are induced1  
through which the chemical reactions are
 led in the direction of sexual         
reproduction4 ,an increase in the       
production of organic substances in the 
presence of light1 chiefly of the       
carbohydrates1 with a simultaneous      
decrease in the amount of inorganic     

salts and water1 are the cause of the   
disturbance and at the same time of the 
alteration in the direction of          
development4 ,possibly indeed mineral   
salts as such are not in question1 but  
only in the form of other organic       
combinations1 particularly proteid      
material1 so that we are concerned with 
an alteration in the relation of the    
carbohydrates and proteids4 ,the        
difficulties of such researches are very
 great because the methods are not yet  
sufficiently exact to demonstrate the   
frequently small quantitative           
differences in chemical composition4    
,questions relating to the enzymes1     
which are of the greatest importance in 
all these life-processes1 are especially
 complicated4 ,in any case it is the    
necessary result of such an hypothesis  
that we must employ chemical methods of 
investigation in dealing with problems  
connected with the physiology of form4  
,,ii4 ,,influence ,,of ,,environment    
,,on ,,the ,,transformation ,,of        

,,species4  ,the study of the physiology
 of form-development in a pure species  
has already yielded results and makes   
slow but sure progress4 ,the physiology 
of the possibility of the transformation
 of one species into another is based1  
as yet1 rather on pious hope than on    
accomplished fact4 ,from the first it   
appeared to be hopeless to investigate  
physiologically the origin of ,linnean  
species and at the same time that of the
 natural system1 an aim which ,darwin   
had before him in his enduring work4    
,the historical sequence of events1 of  
which an organism is the expression1 can
 only be treated hypothetically with the
 help of facts supplied by comparative  
morphology1 the history of development1 
geographical distribution1 and          
palaeontology4 7,see ,lotsy1            
,vorlesungen 7,jena1 ,i4 #aijf1 ,,ii4   
#aijh71 for summary of the facts47 ,a   
glance at the controversy which is going
 on today in regard to different        
hypotheses shows that the same material 

may lead different investigators to form
 entirely different opinions4 ,our      
ultimate aim is to find a solution of   
the problem as to the cause of the      
origin of species4 ,indeed such attempts
 are now being made3 they are justified 
by the fact that under cultivation new  
and permanent strains are produced2 the 
fundamental importance of this was first
 grasped by ,darwin4 ,new points of view
 in regard to these lines of inquiry    
have been adopted by ,h4 de ,vries who  
has succeeded in obtaining from         
,oenothera ,lamarckiana a number of     
constant elementary species4 ,even if it
 is demonstrated that he was simply     
dealing with the complex splitting up of
 a hybrid 7,bateson1 ,reports to the    
,evolution ,committee of the ,royal     
,society1 ,london1 #aijb2 cf4 also      
,lotsy1 ,vorlesungen1 ,vol4 ,i4 page    
#bcd471 the facts adduced in no sense   
lose their very great value4  ,we must  
look at the problem in its simplest     
form2 we find it in every case where a  

new race differs essentially from the   
original type in a single character     
only2 for example1 in the colour of the 
flowers or in the petalody of the       
stamens 7doubling of flowers74 ,in this 
connection we must keep in view the fact
 that every visible character in a plant
 is the resultant of the cooperation of 
specific structure1 with its various    
potentialities1 and the influence of the
 environment4 ,we know1 that in a pure  
species all characters vary1 that a     
blue-flowering ,campanula or a red      
,sempervivum can be converted by        
experiment into white-flowering forms1  
that a transformation of stamens into   
petals may be caused by fungi or by the 
influence of changed conditions of      
nutrition1 or that plants in dry and    
poor soil become dwarfed4 ,but so far as
 the experiments justify a conclusion1  
it would appear that such alterations   
are not inherited by the offspring4     
,like all other variations they appear  
only so long as special conditions      

prevail in the surroundings4  ,it has   
been shown that the case is quite       
different as regards the                
white-flowering1 double or dwarf races1 
because these retain their characters   
when cultivated under practically       
identical conditions1 and side by side  
with the blue1 single-flowering or tall 
races4 ,the problem may therefore be    
stated thus3 how can a character1 which 
appears in the one case only under the  
strictly limited conditions of the      
experiment1 in other cases become       
apparent under the very much wider      
conditions of ordinary cultivation8 ,if 
a character appears1 in these           
circumstances1 in the case of all       
individuals1 we then speak of constant  
races4 ,in such simple cases the        
essential point is not the creation of a
 new character but rather an            
,,alteration ,,of ,,this ,,character    
,,in ,,accordance ,,with ,,the          
,,environment4 ,in the examples         
mentioned the modified character in the 

simple varieties 7or a number of        
characters in elementary species7       
appears more or less suddenly and is    
constant in the above sense4 ,the result
 is what de ,vries has termed a         
,mutation4 ,in this connection we must  
bear in mind the fact that no           
difference1 recognisable externally1    
need exist between individual variation 
and mutation4 ,even the most minute     
quantitative difference between two     
plants may be of specific value if it is
 preserved under similar external       
conditions during many successive       
generations4 ,we do not know how this   
happens4 ,we may state the problem in   
other terms2 by saying that the specific
 structure must be altered4 ,it is      
possible1 to some extent1 to explain    
this sudden alteration1 if we regard it 
as a chemical alteration of structure   
either in the specific qualities of the 
proteids or of the unknown carriers of  
life4 ,in the case of many organic      
compounds their morphological characters

 7the physical condition1 crystalline   
form1 etc47 are at once changed by      
alteration of atomic relations or by    
incorporation of new radicals4 7,for    
instance ethylchloride 7,c#b;,h#e;,cl7  
is a gas at #ba deg ,c41                
ethylenechloride 7,c#b;,h#d;,cl#b7 a    
fluid boiling at #hd deg ,c41 beta      
trichlorethane 7,c#b;,h#c;,cl#c7 a fluid
 boiling at #aac deg ,c41 perchlorethane
 7,c#b;,cl#f7 a crystalline substance4  
,klebs1 7,willkurliche                  
,entwickelungsanderungen page #aeh47    
,much more important1 however1 would be 
an answer to the question1 whether an   
individual variation can be converted   
experimentally into an inherited        
character--a mutation in de ,vries's    
sense4  ,in all circumstances we may    
recognise as a guiding principle the    
assumption adopted by ,lamarck1 ,darwin1
 and many others1 that the inheritance  
of any one character1 or in more general
 terms1 the transformation of one       
species into another1 is1 in the last   

instance1 to be referred to a change in 
the environment4 ,from a                
causal-mechanical point of view it is   
not a priori conceivable that one       
species can ever become changed into    
another so long as external conditions  
remain constant4 ,the inner structure of
 a species must be essentially altered  
by external influences4 ,two methods of 
experimental research may be adopted1   
the effect of crossing distinct species 
and1 secondly1 the effect of definite   
factors of the environment4  ,the       
subject of hybridisation is dealt with  
in another part of this essay4 ,it is   
enough to refer here to the most        
important fact1 that as the result of   
combinations of characters of different 
species new and constant forms are      
produced4 ,further1 ,tschermack1        
,bateson and others have demonstrated   
the possibility that hitherto unknown   
inheritable characters may be produced  
by hybridisation4  ,the other method of 
producing constant races by the         

influence of special external conditions
 has often been employed4 ,the sporeless
 races of ,bacteria and ,yeasts 7,cf4   
,detto1 ,die ,theorie der direkten      
,anpassung444 1 pages #ih et seq41      
,jena1 #aijd2 see also ,lotsy1          
,vorlesungen1 ,,ii4 pages #fcf et seq41 
where other similar cases are           
described47 are well known1 in which an 
internal alteration of the cells is     
induced by the influence of poison or   
higher temperature1 so that the power of
 producing spores even under normal     
conditions appears to be lost4 ,a       
similar state of things is found in some
 races which under certain definite     
conditions lose their colour or their   
virulence4 ,among the phanerogams the   
investigations of ,schubler on cereals  
afford parallel cases1 in which the     
influence of a northern climate produces
 individuals which ripen their seeds    
early2 these seeds produce plants which 
seed early in southern countries4       
,analogous results were obtained by     

,cieslar in his experiments2 seeds of   
conifers from the ,alps when planted in 
the plains produced plants of slow      
growth and small diameter4  ,all these  
observations are of considerable        
interest theoretically2 they show that  
the action of environment certainly     
induces such internal changes1 and that 
these are transmitted to the next       
generation4 ,but as regards the main    
question1 whether constant races may be 
obtained by this means1 the experiments 
cannot as yet supply a definite answer4 
,in phanerogams1 the influence very soon
 dies out in succeeding generations2 in 
the case of bacteria1 in which it is    
only a question of the loss of a        
character it is relatively easy for this
 to reappear4 ,it is not impossible1    
that in all such cases there is a       
material hanging-on of certain internal 
conditions1 in consequence of which the 
modification of the character persists  
for a time in the descendants1 although 
the original external conditions are no 

longer present4  ,thus a slow dying-out 
of the effect of a stimulus was seen in 
my experiments on ,veronica chamaedrys4 
7,klebs1 ,kunstliche ,metamorphosen1    
,stuttgart1 #aijf1 page #acb47 ,during  
the cultivation of an artificially      
modified inflorescence ,i obtained a    
race showing modifications in different 
directions1 among which twisting was    
especially conspicuous4 ,this plant1    
however1 does not behave as the twisted 
race of ,dipsacus isolated by de ,vries 
7de ,vries1 ,mutationstheorie1 ,vol4    
,,ii4 ,leipzig1 #aijc1 page #egc471     
which produced each year a definite     
percentage of twisted individuals4 ,in  
the vegetative reproduction of this     
,veronica the torsion appeared in the   
first1 also in the second and third     
year1 but with diminishing intensity4   
,in spite of good cultivation this      
character has apparently now            
disappeared2 it disappeared still more  
quickly in seedlings4 ,in another       
character of the same ,veronica         

chamaedrys the influence of the         
environment was stronger4 ,the          
transformation of the inflorescences to 
foliage-shoots formed the               
starting-point2 it occurred only under  
narrowly defined conditions1 namely on  
cultivation as a cutting in moist air   
and on removal of all other leaf-buds4  
,in the majority 7#g_/aj7 of the plants 
obtained from the transformed shoots1   
the modification appeared in the        
following year without any interference4
 ,of the three plants which were under  
observation several years the first lost
 the character in a short time1 while   
the two others still retain it1 after   
vegetative propagation1 in varying      
degrees4 ,the same character occurs also
 in some of the seedlings2 but anything 
approaching a constant race has not been
 produced4  ,another means of producing 
new races has been attempted by         
,blaringhem4 7,blaringhem1 ,mutation et 
,traumatisme1 ,paris1 #aijg47 ,on       
removing at an early stage the main     

shoots of different plants he observed  
various abnormalities in the newly      
formed basal shoots4 ,from the seeds of 
such plants he obtained races1 a large  
percentage of which exhibited these     
abnormalities4 ,starting from a male    
,maize plant with a fasciated           
inflorescence1 on which a proportion of 
the flowers had become male1 a new race 
was bred in which hermaphrodite flowers 
were frequently produced4 ,in the same  
way ,blaringhem obtained1 among other   
similar results1 a race of barley with  
branched ears4 ,these races1 however1   
behaved in essentials like those which  
have been demonstrated by de ,vries to  
be inconstant1 e4g4 ,trifolium pratense 
quinquefolium and others4 ,the          
abnormality appears in a proportion of  
the individuals and only under very     
special conditions4 ,it must be         
remembered too that ,blaringhem worked  
with old cultivated plants1 which from  
the first had been disposed to split    
into a great variety of races4 ,it is   

possible1 but difficult to prove1 that  
injury contributed to this result4  ,a  
third method has been adopted by        
,mac,dougal 7,mac,dougal1 ,heredity and 
,origin of species1 ,monist1 #aijf2     
,report of department of botanical      
research1 ,fifth ,year-book of the      
,carnegie ,institution of ,washington1  
page #aai1 #aijg47 who injected strong  
7#aj percent7 sugar solution or weak    
solutions of calcium nitrate and zinc   
sulphate into young carpels of different
 plants4 ,from the seeds of a plant of  
,raimannia odorata the carpels of which 
had been thus treated he obtained       
several plants distinguished from the   
parent-forms by the absence of hairs and
 by distinct forms of leaves4 ,further  
examination showed that he had here to  
do with a new elementary species4       
,mac,dougal also obtained a more or less
 distinct mutant of ,oenothera biennis4 
,we cannot as yet form an opinion as to 
how far the effect is due to the wound  
or to the injection of fluid as such1 or

 to its chemical properties4 ,this1     
however1 is not so essential as to      
decide whether the mutant stands in any 
relation to the influence of external   
factors4 ,it is at any rate very        
important that this kind of             
investigation should be carried further4
  ,if it could be shown that new and    
inherited races were obtained by        
,mac,dougal's method1 it would be safe  
to conclude that the same end might be  
gained by altering the conditions of the
 food-stuff conducted to the sexual     
cells4 ,new races or elementary species1
 however1 arise without wounding or     
injection4 ,this at once raises the much
 discussed question1 how far            
garden-cultivation has led to the       
creation of new races8 ,contrary to the 
opinion expressed by ,darwin and others1
 de ,vries 7,mutationstheorie1 ,vol4 ,i4
 pages #dab et seq47 tried to show that 
garden-races have been produced only    
from spontaneous types which occur in a 
wild state or from sub-races1 which the 

breeder has accidentally discovered but 
not originated4 ,in a small number of   
cases only has de ,vries adduced        
definite proof4 ,on the other side we   
have the work of ,korschinsky           
7,korschinsky1 ,heterogenesis und       
,evolution1 ,flora1 #aija47 which shows 
that whole series of garden-races have  
made their appearance only after years  
of cultivation4 ,in the majority of     
races we are entirely ignorant of their 
origin4  ,it is1 however1 a fact that if
 a plant is removed from natural        
conditions into cultivation1 a          
well-marked variation occurs4 ,the      
well-known plant-breeder ,l4 de         
,vilmorin 7,l4 de ,vilmorin1 ,notices   
sur l'amelioration des plantes1 ,paris1 
#ahhf1 page #cf471 speaking from his own
 experience1 states that a plant is     
induced to affoler1 that is to exhibit  
all possible variations from which the  
breeder may make a further selection    
only after cultivation for several      
generations4 ,the effect of cultivation 

was particularly striking in ,veronica  
chamaedrys 7,klebs1 ,kunstliche         
,metamorphosen1 ,stuttgart1 #aijf1 page 
#aeb47 which1 in spite of its wide      
distribution in nature1 varies very     
little4 ,after a few years of           
cultivation this good and constant      
species becomes highly variable4 ,the   
specimens on which the experiments were 
made were three modified inflorescence  
cuttings1 the parent-plants of which    
certainly exhibited no striking         
abnormalities4 ,in a short time many    
hitherto latent potentialities became   
apparent1 so that characters1 never     
previously observed1 or at least very   
rarely1 were exhibited1 such as         
scattered leaf-arrangement1 torsion1    
terminal or branched inflorescences1 the
 conversion of the inflorescence into   
foliage-shoots1 every conceivable       
alteration in the colour of flowers1 the
 assumption of a green colour by parts  
of the flowers1 the proliferation of    
flowers4  ,all this points to some      

disturbance in the species resulting    
from methods of cultivation4 ,it has1   
however1 not yet been possible to       
produce constant races with any one of  
these modified characters4 ,but         
variations appeared among the seedlings1
 some of which1 e4g4 yellow variegation1
 were not inheritable1 while others have
 proved constant4 ,this holds good1 so  
far as we know at present1 for a small  
rose-coloured form which is to be       
reckoned as a mutation4 ,thus the       
prospect of producing new races by      
cultivation appears to be full of       
promise4  ,so long as the view is held  
that good nourishment1 i4e4 a plentiful 
supply of water and salts1 constitutes  
the essential characteristic of         
garden-cultivation1 we can hardly       
conceive that new mutations can be thus 
produced4 ,but perhaps the view here put
 forward in regard to the production of 
form throws new light on this puzzling  
problem4  ,good manuring is in the      
highest degree favourable to vegetative 

growth1 but is in no way equally        
favourable to the formation of flowers4 
,the constantly repeated expression1    
good or favourable nourishment1 is not  
only vague but misleading1 because      
circumstances favourable to growth      
differ from those which promote         
reproduction2 for the production of     
every form there are certain favourable 
conditions of nourishment1 which may be 
defined for each species4 ,experience   
shows that1 within definite and often   
very wide limits1 it does not depend    
upon the ,,absolute ,,amount of the     
various food substances1 but upon their 
respective degrees of concentration4 ,as
 we have already stated1 the production 
of flowers follows a relative increase  
in the amount of carbohydrates formed in
 the presence of light1 as compared with
 the inorganic salts on which the       
formation of albuminous substances      
depends4 7,klebs1 ,kunstliche           
,metamorphosen1 page #aag47 ,the various
 modifications of flowers are due to the

 fact that a relatively too strong      
solution of salts is supplied to the    
rudiments of these organs4 ,as a general
 rule every plant form depends upon a   
certain relation between the different  
chemical substances in the cells and is 
modified by an alteration of that       
relation4  ,during long cultivation     
under conditions which vary in very     
different degrees1 such as moisture1 the
 amount of salts1 light intensity1      
temperature1 oxygen1 it is possible that
 sudden and special disturbances in the 
relations of the cell substances have a 
directive influence on the inner        
organisation of the sexual cells1 so    
that not only inconstant but also       
constant varieties will be formed4      
,definite proof in support of this view 
has not yet been furnished1 and we must 
admit that the question as to the cause 
of heredity remains1 fundamentally1 as  
far from solution as it was in ,darwin's
 time4 ,as the result of the work of    
many investigators1 particularly de     

,vries1 the problem is constantly       
becoming clearer and more definite4 ,the
 penetration into this most difficult   
and therefore most interesting problem  
of life and the creation by experiment  
of new races or elementary species are  
no longer beyond the region of          
possibility4     ,,xiv4 ,,experimental  
,,study ,,of ,,the ,,influence ,,of     
,,environment ,,on ,,animals4 ,by       
,jacques ,loeb1 ,m4,d4 ,professor of    
,physiology in the ,university of       
,california4   ,i4 ,,introductory       
,,remarks4  ,what the biologist calls   
the natural environment of an animal is 
from a physical point of view a rather  
rigid combination of definite forces4   
,it is obvious that by a purposeful and 
systematic variation of these and by the
 application of other forces in the     
laboratory1 results must be obtainable  
which do not appear in the natural      
environment4 ,this is the reasoning     
underlying the modern development of the
 study of the effects of environment    

upon animal life4 ,it was perhaps not   
the least important of ,darwin's        
services to science that the boldness of
 his conceptions gave to the            
experimental biologist courage to enter 
upon the attempt of controlling at will 
the life-phenomena of animals1 and of   
bringing about effects which cannot be  
expected in ,nature4  ,the systematic   
physico-chemical analysis of the effect 
of outside forces upon the form and     
reactions of animals is also our only   
means of unravelling the mechanism of   
heredity beyond the scope of the        
,mendelian law4 ,the manner in which a  
germ-cell can force upon the adult      
certain characters will not be          
understood until we succeed in varying  
and controlling hereditary              
characteristics2 and this can only be   
accomplished on the basis of a          
systematic study of the effects of      
chemical and physical forces upon living
 matter4  ,owing to limitation of space 
this sketch is necessarily very         

incomplete1 and it must not be inferred 
that studies which are not mentioned    
here were considered to be of minor     
importance4 ,all the writer could hope  
to do was to bring together a few       
instances of the experimental analysis  
of the effect of environment1 which     
indicate the nature and extent of our   
control over life-phenomena and which   
also have some relation to the work of  
,darwin4 ,in the selection of these     
instances preference is given to those  
problems which are not too technical for
 the general reader4  ,the forces1 the  
influence of which we shall discuss1 are
 in succession chemical agencies1       
temperature1 light1 and gravitation4 ,we
 shall also treat separately the effect 
of these forces upon form and           
instinctive reactions4   ,,ii4 ,,the    
,,effects ,,of ,,chemical ,,agencies4   
7a7 ,,heterogeneous ,,hybridisation4    
,it was held until recently that        
hybridisation is not possible except    
between closely related species and that

 even among these a successful          
hybridisation cannot always be counted  
upon4 ,this view was well supported by  
experience4 ,it is1 for instance1 well  
known that the majority of marine       
animals lay their unfertilised eggs in  
the ocean and that the males shed their 
sperm also into the sea-water4 ,the     
numerical excess of the spermatozoa over
 the ova in the sea-water is the only   
guarantee that the eggs are fertilised1 
for the spermatozoa are carried to the  
eggs by chance and are not attracted by 
the latter4 ,this statement is the      
result of numerous experiments by       
various authors1 and is contrary to     
common belief4 ,as a rule all or the    
majority of individuals of a species in 
a given region spawn on the same day1   
and when this occurs the sea-water      
constitutes a veritable suspension of   
sperm4 ,it has been shown by experiment 
that in fresh sea-water the sperm may   
live and retain its fertilising power   
for several days4 ,it is thus           

unavoidable that at certain periods more
 than one kind of spermatozoon is       
suspended in the sea-water and it is a  
matter of surprise that the most        
heterogeneous hybridisations do not     
constantly occur4 ,the reason for this  
becomes obvious if we bring together    
mature eggs and equally mature and      
active sperm of a different family4     
,when this is done no egg is1 as a rule1
 fertilised4 ,the eggs of a sea-urchin  
can be fertilised by sperm of their own 
species1 or1 though in smaller numbers1 
by the sperm of other species of        
sea-urchins1 but not by the sperm of    
other groups of echinoderms1 e4g4       
starfish1 brittle-stars1 holothurians or
 crinoids1 and still less by the sperm  
of more distant groups of animals4 ,the 
consensus of opinion seemed to be that  
the spermatozoon must enter the egg     
through a narrow opening or canal1 the  
so-called micropyle1 and that the       
micropyle allowed only the spermatozoa  
of the same or of a closely related     

species to enter the egg4  ,it seemed to
 the writer that the cause of this      
limitation of hybridisation might be of 
another kind and that by a change in the
 constitution of the sea-water it might 
be possible to bring about heterogenous 
hybridisations1 which in normal         
sea-water are impossible4 ,this         
assumption proved correct4 ,sea-water   
has a faintly alkaline reaction 7in     
terms of the physical chemist its       
concentration of hydroxyl ions is about 
7#aj to the power minus six7,n at       
,pacific ,grove1 ,california1 and about 
7#aj to the power minus #e7,n at ,woods 
,hole1 ,massachusetts74 ,if we slightly 
raise the alkalinity of the sea-water by
 adding to it a small but definite      
quantity of sodium hydroxide or some    
other alkali1 the eggs of the sea-urchin
 can be fertilised with the sperm of    
widely different groups of animals1     
possibly with the sperm of any marine   
animal which sheds it into the ocean4   
,in #aijc it was shown that if we add   

from about #j4e to #j4h cubic centimetre
 ,n_/#aj sodium hydroxide to #ej cubic  
centimetres of sea-water1 the eggs of   
,strongylocentrotus purpuratus 7a       
sea-urchin which is found on the coast  
of ,california7 can be fertilised in    
large quantities by the sperm of various
 kinds of starfish1 brittle-stars and   
holothurians2 while in normal sea-water 
or with less sodium hydroxide not a     
single egg of the same female could be  
fertilised with the starfish sperm which
 proved effective in the hyper-alkaline 
sea-water4 ,the sperm of the various    
forms of starfish was not equally       
effective for these hybridisations2 the 
sperm of ,asterias ochracea and ,a4     
capitata gave the best results1 since it
 was possible to fertilise #ej per cent 
or more of the sea-urchin eggs1 while   
the sperm of ,pycnopodia and ,asterina  
fertilised only #b per cent of the same 
eggs4  ,godlewski used the same method  
for the hybridisation of the sea-urchin 
eggs with the sperm of a crinoid        

7,antedon rosacea74 ,kupelwieser        
afterwards obtained results which seemed
 to indicate the possibility of         
fertilising the eggs of                 
,strongylocentrotus with the sperm of a 
mollusc 7,mytilus47 ,recently1 the      
writer succeeded in fertilising the eggs
 of ,strongylocentrotus franciscanus    
with the sperm of a                     
mollusc--,chlorostoma4 ,this result     
could only be obtained in sea-water the 
alkalinity of which had been increased  
7through the addition of #j4h cubic     
centimetre ,n_/#aj sodium hydroxide to  
#ej cubic centimetres of sea-water74 ,we
 thus see that by increasing the        
alkalinity of the sea-water it is       
possible to effect heterogeneous        
hybridisations which are at present     
impossible in the natural environment of
 these animals4  ,it is1 however1       
conceivable that in former periods of   
the earth's history such heterogeneous  
hybridisations were possible4 ,it is    
known that in solutions like sea-water  

the degree of alkalinity must increase  
when the amount of carbon-dioxide in the
 atmosphere is diminished4 ,if it be    
true1 as ,arrhenius assumes1 that the   
,ice age was caused or preceded by a    
diminution in the amount of             
carbon-dioxide in the air1 such a       
diminution must also have resulted in an
 increase of the alkalinity of the      
sea-water1 and one result of such an    
increase must have been to render       
possible heterogeneous hybridisations in
 the ocean which in the present state of
 alkalinity are practically excluded4   
,but granted that such hybridisations   
were possible1 would they have          
influenced the character of the fauna8  
,in other words1 are the hybrids between
 sea-urchin and starfish1 or better     
still1 between sea-urchin and mollusc1  
capable of development1 and if so1 what 
is their character8 ,the first          
experiment made it appear doubtful      
whether these heterogeneous hybrids     
could live4 ,the sea-urchin eggs which  

were fertilised in the laboratory by the
 spermatozoa of the starfish1 as a rule1
 died earlier than those of the pure    
breeds4 ,but more recent results        
indicate that this was due merely to    
deficiencies in the technique of the    
earlier experiments4 ,the writer has    
recently obtained hybrid larvae between 
the sea-urchin egg and the sperm of a   
mollusc 7,chlorostoma7 which1 in the    
laboratory1 developed as well and lived 
as long as the pure breeds of the       
sea-urchin1 and there was nothing to    
indicate any difference in the vitality 
of the two breeds4  ,so far as the      
question of heredity is concerned1 all  
the experiments on heterogeneous        
hybridisation of the egg of the         
sea-urchin with the sperm of starfish1  
brittle-stars1 crinoids and molluscs1   
have led to the same result1 namely1    
that the larvae have purely maternal    
characteristics and differ in no way    
from the pure breed of the form from    
which the egg is taken4 ,by way of      

illustration it may be said that the    
larvae of the sea-urchin reach on the   
third day or earlier 7according to      
species and temperature7 the so-called  
pluteus stage1 in which they possess a  
typical skeleton2 while neither the     
larvae of the starfish nor those of the 
mollusc form a skeleton at the          
corresponding stage4 ,it was1 therefore1
 a matter of some interest to find out  
whether or not the larvae produced by   
the fertilisation of the sea-urchin egg 
with the sperm of starfish or mollusc   
would form the normal and typical       
pluteus skeleton4 ,this was invariably  
the case in the experiments of          
,godlewski1 ,kupelwieser1 ,hagedoorn1   
and the writer4 ,these hybrid larvae    
were exclusively maternal in character4 
,it might be argued that in the case of 
heterogeneous hybridisation the         
sperm-nucleus does not fuse with the    
egg-nucleus1 and that1 therefore1 the   
spermatozoon cannot transmit its        
hereditary substances to the larvae4    

,but these objections are refuted by    
,godlewski's experiments1 in which he   
showed definitely that if the egg of the
 sea-urchin is fertilised with the sperm
 of a crinoid the fusion of the         
egg-nucleus and sperm-nucleus takes     
place in the normal way4 ,it remains for
 further experiments to decide what the 
character of the adult hybrids would be4
  7b74 ,,artificial ,,parthenogenesis4  
,possibly in no other field of ,biology 
has our ability to control              
life-phenomena by outside conditions    
been proved to such an extent as in the 
domain of fertilisation4 ,the reader    
knows that the eggs of the overwhelming 
majority of animals cannot develop      
unless a spermatozoon enters them4 ,in  
this case a living agency is the cause  
of development and the problem arises   
whether it is possible to accomplish the
 same result through the application of 
well-known physico-chemical agencies4   
,this is1 indeed1 true1 and during the  
last ten years living larvae have been  

produced by chemical agencies from the  
unfertilised eggs of sea-urchins1       
starfish1 holothurians and a number of  
annelids and molluscs2 in fact this     
holds true in regard to the eggs of     
practically all forms of animals with   
which such experiments have been tried  
long enough4 ,in each form the method of
 procedure is somewhat different and a  
long series of experiments is often     
required before the successful method is
 found4  ,the facts of ,artificial      
,parthenogenesis1 as the chemical       
fertilisation of the egg is called1     
have1 perhaps1 some bearing on the      
problem of evolution4 ,if we wish to    
form a mental image of the process of   
evolution we have to reckon with the    
possibility that parthenogenetic        
propagation may have preceded sexual    
reproduction4 ,this suggests also the   
possibility that at that period outside 
forces may have supplied the conditions 
for the development of the egg which at 
present the spermatozoon has to supply4 

,for this1 if for no other reason1 a    
brief consideration of the means of     
artificial parthenogenesis may be of    
interest to the student of evolution4   
,it seemed necessary in these           
experiments to imitate as completely as 
possible by chemical agencies the       
effects of the spermatozoon upon the    
egg4 ,when a spermatozoon enters the egg
 of a sea-urchin or certain starfish or 
annelids1 the immediate effect is a     
characteristic change of the surface of 
the egg1 namely the formation of the    
so-called membrane of fertilisation4    
,the writer found that we can produce   
this membrane in the unfertilised egg by
 certain acids1 especially the monobasic
 acids of the fatty series1 e4g4 formic1
 acetic1 propionic1 butyric1 etc4       
,carbon-dioxide is also very efficient  
in this direction4 ,it was also found   
that the higher acids are more efficient
 than the lower ones1 and it is possible
 that the spermatozoon induces          
membrane-formation by carrying into the 

egg a higher fatty acid1 namely oleic   
acid or one of its salts or esters4     
,the physico-chemical process which     
underlies the formation of the membrane 
seems to be the cause of the development
 of the egg4 ,in all cases in which the 
unfertilised egg has been treated in    
such a way as to cause it to form a     
membrane it begins to develop4 ,for the 
eggs of certain animals                 
membrane-formation is all that is       
required to induce a complete           
development of the unfertilised egg1    
e4g4 in the starfish and certain        
annelids4 ,for the eggs of other animals
 a second treatment is necessary1       
presumably to overcome some of the      
injurious effects of acid treatment4    
,thus the unfertilised eggs of the      
sea-urchin ,strongylocentrotus          
purpuratus of the ,californian coast    
begin to develop when membrane-formation
 has been induced by treatment with a   
fatty acid1 e4g4 butyric acid2 but the  
development soon ceases and the eggs    

perish in the early stages of           
segmentation1 or after the first nuclear
 division4 ,but if we treat the same    
eggs1 after membrane-formation1 for from
 #ce to #ee minutes 7at #ae deg ,c47    
with sea-water the concentration        
7osmotic pressure7 of which has been    
raised through the addition of a        
definite amount of some salt or sugar1  
the eggs will segment and develop       
normally1 when transferred back to      
normal sea-water4 ,if care is taken1    
practically all the eggs can be caused  
to develop into plutei1 the majority of 
which may be perfectly normal and may   
live as long as larvae produced from    
eggs fertilised with sperm4  ,it is     
obvious that the sea-urchin egg is      
injured in the process of               
membrane-formation and that the         
subsequent treatment with a hypertonic  
solution only acts as a remedy4 ,the    
nature of this injury became clear when 
it was discovered that all the agencies 
which cause haemolysis1 i4e4 the        

destruction of the red blood corpuscles1
 also cause membrane-formation in       
unfertilised eggs1 e4g4 fatty acids or  
ether1 alcohols or chloroform1 etc41 or 
saponin1 solanin1 digitalin1 bile salts 
and alkali4 ,it thus happens that the   
phenomena of artificial parthenogenesis 
are linked together with the phenomena  
of haemolysis which at present play so  
important a role in the study of        
immunity4 ,the difference between       
cytolysis 7or haemolysis7 and           
fertilisation seems to be this1 that the
 latter is caused by a superficial or   
slight cytolysis of the egg1 while if   
the cytolytic agencies have time to act 
on the whole egg the latter is          
completely destroyed4 ,if we put        
unfertilised eggs of a sea-urchin into  
sea-water which contains a trace of     
saponin we notice that1 after a few     
minutes1 all the eggs form the typical  
membrane of fertilisation4 ,if the eggs 
are then taken out of the saponin       
solution1 freed from all traces of      

saponin by repeated washing in normal   
sea-water1 and transferred to the       
hypertonic sea-water for from #ce to #ee
 minutes1 they develop into larvae4 ,if1
 however1 they are left in the sea-water
 containing the saponin they undergo1 a 
few minutes after membrane-formation1   
the disintegration known in pathology as
 ,,cytolysis4 ,membrane-formation is1   
therefore1 caused by a superficial or   
incomplete cytolysis4 ,the writer       
believes that the subsequent treatment  
of the egg with hypertonic sea-water is 
needed only to overcome the destructive 
effects of this partial cytolysis4 ,the 
full reasons for this belief cannot be  
given in a short essay4  ,many          
pathologists assume that haemolysis or  
cytolysis is due to a liquefaction of   
certain fatty or fat-like compounds1 the
 so-called lipoids1 in the cell4 ,if    
this view is correct1 it would be       
necessary to ascribe the fertilisation  
of the egg to the same process4  ,the   
analogy between haemolysis and          

fertilisation throws1 possibly1 some    
light on a curious observation4 ,it is  
well known that the blood corpuscles1 as
 a rule1 undergo cytolysis if injected  
into the blood of an animal which       
belongs to a different family4 ,the     
writer found last year that the blood of
 mammals1 e4g4 the rabbit1 pig1 and     
cattle1 causes the egg of               
,strongylocentrotus to form a typical   
fertilisation-membrane4 ,if such eggs   
are afterwards treated for a short      
period with hypertonic sea-water they   
develop into normal larvae 7plutei74    
,some substance contained in the blood  
causes1 presumably1 a superficial       
cytolysis of the egg and thus starts its
 development4  ,we can also cause the   
development of the sea-urchin egg       
without membrane-formation4 ,the early  
experiments of the writer were done in  
this way and many experimenters still   
use such methods4 ,it is probable that  
in this case the mechanism of           
fertilisation is essentially the same as

 in the case where the                  
membrane-formation is brought about1    
with this difference only1 that the     
cytolytic effect is less when no        
fertilisation-membrane is formed4 ,this 
inference is corroborated by            
observations on the fertilisation of the
 sea-urchin egg with ox blood4 ,it very 
frequently happens that not all of the  
eggs form membranes in this process4    
,those eggs which form membranes begin  
to develop1 but perish if they are not  
treated with hypertonic sea-water4 ,some
 of the other eggs1 however1 which do   
not form membranes1 develop directly    
into normal larvae without any treatment
 with hypertonic sea-water1 provided    
they are exposed to the blood for only a
 few minutes4 ,presumably some blood    
enters the eggs and causes the cytolytic
 effects in a less degree than is       
necessary for membrane-formation1 but in
 a sufficient degree to cause their     
development4 ,the slightness of the     
cytolytic effect allows the egg to      

develop without treatment with          
hypertonic sea-water4  ,since the       
entrance of the spermatozoon causes that
 degree of cytolysis which leads to     
membrane-formation1 it is probable that1
 in addition to the cytolytic or        
membrane-forming substance 7presumably a
 higher fatty acid71 it carries another 
substance into the egg which counteracts
 the deleterious cytolytic effects      
underlying membrane-formation4  ,the    
question may be raised whether the      
larvae produced by artificial           
parthenogenesis can reach the mature    
stage4 ,this question may be answered in
 the affirmative1 since ,delage has     
succeeded in raising several            
parthenogenetic sea-urchin larvae beyond
 the metamorphosis into the adult stage 
and since in all the experiments made by
 the writer the parthenogenetic plutei  
lived as long as the plutei produced    
from fertilised eggs4  7c74 ,,on ,,the  
,,production ,,of ,,twins ,,from ,,one  
,,egg ,,through ,a ,,change ,,in ,,the  

,,chemical ,,constitution ,,of ,,the    
,,sea-,,water4  ,the reader is probably 
familiar with the fact that there exist 
two different types of human twins4 ,in 
the one type the twins differ as much as
 two children of the same parents born  
at different periods2 they may or may   
not have the same sex4 ,in the second   
type the twins have invariably the same 
sex and resemble each other most        
closely4 ,twins of the latter type are  
produced from the same egg1 while twins 
of the former type are produced from two
 different eggs4  ,the experiments of   
,driesch and others have taught us that 
twins originate from one egg in this    
manner1 namely1 that the first two cells
 into which the egg divides after       
fertilisation become separated from each
 other4 ,this separation can be brought 
about by a change in the chemical       
constitution of the sea-water4 ,herbst  
observed that if the fertilised eggs of 
the sea-urchin are put into sea-water   
which is freed from calcium1 the cells  

into which the egg divides have a       
tendency to fall apart4 ,driesch        
afterwards noticed that eggs of the     
sea-urchin treated with sea-water which 
is free from lime have a tendency to    
give rise to twins4 ,the writer has     
recently found that twins can be        
produced not only by the absence of     
lime1 but also through the absence of   
sodium or of potassium2 in other words1 
through the absence of one or two of the
 three important metals in the          
sea-water4 ,there is1 however1 a second 
condition1 namely1 that the solution    
used for the production of twins must   
have a neutral or at least not an       
alkaline reaction4  ,the procedure for  
the production of twins in the          
sea-urchin egg consists simply in       
this3--the eggs are fertilised as usual 
in normal sea-water and then1 after     
repeated washing in a neutral solution  
of sodium chloride 7of the concentration
 of the sea-water71 are placed in a     
neutral mixture of potassium chloride   

and calcium chloride1 or of sodium      
chloride and potassium chloride1 or of  
sodium chloride and calcium chloride1 or
 of sodium chloride and magnesium       
chloride4 ,the eggs must remain in this 
solution until half an hour or an hour  
after they have reached the two-cell    
stage4 ,they are then transferred into  
normal sea-water and allowed to develop4
 ,from #ej to #ij per cent of the eggs  
of ,strongylocentrotus purpuratus       
treated in this manner may develop into 
twins4 ,these twins may remain separate 
or grow partially together and form     
double monsters1 or heal together so    
completely that only slight or even no  
imperfections indicate that the         
individual started its career as a pair 
of twins4 ,it is also possible to       
control the tendency of such twins to   
grow together by a change in the        
constitution of the sea-water4 ,if we   
use as a twin-producing solution a      
mixture of sodium1 magnesium and        
potassium chlorides 7in the proportion  

in which these salts exist in the       
sea-water7 the tendency of the twins to 
grow together is much more pronounced   
than if we use simply a mixture of      
sodium chloride and magnesium chloride4 
,the mechanism of the origin of twins1  
as the result of altering the           
composition of the sea-water1 is        
revealed by observation of the first    
segmentation of the egg in these        
solutions4 ,this cell-division is       
modified in a way which leads to a      
separation of the first two cells4 ,if  
the egg is afterwards transferred back  
into normal sea-water1 each of these two
 cells develops into an independent     
embryo4 ,since normal sea-water contains
 all three metals1 sodium1 calcium1 and 
potassium1 and since it has besides an  
alkaline reaction1 we perceive the      
reason why twins are not normally       
produced from one egg4 ,these           
experiments suggest the possibility of a
 chemical cause for the origin of twins 
from one egg or of double monstrosities 

in mammals4 ,if1 for some reason1 the   
liquids which surround the human egg a  
short time before and after the first   
cell-division are slightly acid1 and at 
the same time lacking in one of the     
three important metals1 the conditions  
for the separation of the first two     
cells and the formation of identical    
twins are provided4  ,in conclusion it  
may be pointed out that the reverse     
result1 namely1 the fusion of normally  
double organs1 can also be brought about
 experimentally through a change in the 
chemical constitution of the sea-water4 
,stockard succeeded in causing the eyes 
of fish embryos 7,fundulus heteroclitus7
 to fuse into a single cyclopean eye    
through the addition of magnesium       
chloride to the sea-water4 ,when he     
added about #f grams of magnesium       
chloride to #ajj cubic centimetres of   
sea-water and placed the fertilised eggs
 in the mixture1 about #ej per cent of  
the eggs gave rise to one-eyed embryos4 
,when the embryos were studied the      

one-eyed condition was found to result  
from the union or fusion of the         
'anlagen' of the two eyes4 ,cases were  
observed which showed various degrees in
 this fusion2 it appeared as though the 
optic vessels were formed too far       
forward and ventral1 so that their      
antero-ventro-median surfaces fused4    
,this produces one large optic cup1     
which in all cases gives more or less   
evidence of its double nature4          
7,stockard1 ,archiv f4                  
,entwickelungsmechanik1 ,vol4 #bc1 page 
#bdi1 #aijg47  ,we have confined        
ourselves to a discussion of rather     
simple effects of the change in the     
constitution of the sea-water upon      
development4 ,it is a priori obvious1   
however1 that an unlimited number of    
pathological variations might be        
produced by a variation in the          
concentration and constitution of the   
sea-water1 and experience confirms this 
statement4 ,as an example we may mention
 the abnormalities observed by ,herbst  

in the development of sea-urchins       
through the addition of lithium to      
sea-water4 ,it is1 however1 as yet      
impossible to connect in a rational way 
the effects produced in this and similar
 cases with the cause which produced    
them2 and it is also impossible to      
define in a simple way the character of 
the change produced4  ,,iii4 ,,the      
,,influence ,,of ,,temperature4  7a7    
,,the ,,influence ,,of ,,temperature    
,,upon ,,the ,,density ,,of ,,pelagic   
,,organisms ,,and ,,the ,,duration ,,of 
,,life4  ,it has often been noticed by  
explorers who have had a chance to      
compare the faunas in different climates
 that in polar seas such species as     
thrive at all in those regions occur1 as
 a rule1 in much greater density than   
they do in the moderate or warmer       
regions of the ocean4 ,this refers to   
those members of the fauna which live at
 or near the surface1 since they alone  
lend themselves to a statistical        
comparison4 ,in his account of the      

,valdivia expedition1 ,chun 7,chun1 ,aus
 den ,tiefen des ,weltmeeres1 page #bbe1
 ,jena1 #aijc47 calls especial attention
 to this quantitative difference in the 
surface fauna and flora of different    
regions4 ,in the icy water of the       
,antarctic1 the temperature of which is 
below #j deg ,c41 we find an            
astonishingly rich animal and plant     
life4 ,the same condition with which we 
are familiar in the ,arctic seas is     
repeated here1 namely1 that the quantity
 of plankton material exceeds that of   
the temperate and warm seas4 ,and again1
 in regard to the pelagic fauna in the  
region of the ,kerguelen ,islands1 he   
states3 ,the ocean is alive with        
transparent jelly fish1 ,ctenophores    
7,bolina and ,callianira7 and of        
,siphonophore colonies of the genus     
,agalma4  ,the paradoxical character of 
this general observation lies in the    
fact that a low temperature retards     
development1 and hence should be        
expected to have the opposite effect    

from that mentioned by ,chun4 ,recent   
investigations have led to the result   
that life-phenomena are affected by     
temperature in the same sense as the    
velocity of chemical reactions4 ,in the 
case of the latter van't ,hoff had shown
 that a decrease in temperature by #aj  
degrees reduces their velocity to one   
half or less1 and the same has been     
found for the influence of temperature  
on the velocity of physiological        
processes4 ,thus ,snyder and ,t4,b4     
,robertson found that the rate of       
heartbeat in the tortoise and in        
,daphnia is reduced to about one-half if
 the temperature is lowered #aj deg ,c41
 and ,maxwell1 ,keith ,lucas1 and       
,snyder found the same influence of     
temperature for the rate with which an  
impulse travels in the nerve4 ,peter    
observed that the rate of development in
 a sea-urchin's egg is reduced to less  
than one-half if the temperature 7within
 certain limits7 is reduced by #aj      
degrees4 ,the same effect of temperature

 upon the rate of development holds for 
the egg of the frog1 as ,cohen and      
,peter calculated from the experiments  
of ,o4 ,hertwig4 ,the writer found the  
same temperature-coefficient for the    
rate of maturation of the egg of a      
mollusc 7,lottia74  ,all these facts    
prove that the velocity of development  
of animal life in ,arctic regions1 where
 the temperature is near the freezing   
point of water1 must be from two to     
three times smaller than in regions     
where the temperature of the ocean is   
about #aj deg ,c4 and from four to nine 
times smaller than in seas the          
temperature of which is about #bj deg   
,c4 ,it is1 therefore1 exactly the      
reverse of what we should expect when   
authors state that the density of       
organisms at or near the surface of the 
ocean in polar regions is greater than  
in more temperate regions4  ,the writer 
believes that this paradox finds its    
explanation in experiments which he has 
recently made on the influence of       

temperature on the duration of life of  
cold-blooded marine animals4 ,the       
experiments were made on the fertilised 
and unfertilised eggs of the sea-urchin1
 and yielded the result that for the    
lowering of temperature by #a deg ,c4   
the duration of life was about doubled4 
,lowering the temperature by #aj degrees
 therefore prolongs the life of the     
organism #b to the power #aj1 i4e4 over 
a thousand times1 and a lowering by #bj 
degrees prolongs it about one million   
times4 ,since this prolongation of life 
is far in excess of the retardation of  
development through a lowering of       
temperature1 it is obvious that1 in     
spite of the retardation of development 
in ,arctic seas1 animal life must be    
denser there than in temperate or       
tropical seas4 ,the excessive increase  
of the duration of life at the poles    
will necessitate the simultaneous       
existence of more successive generations
 of the same species in these regions   
than in the temperate or tropical       

regions4  ,the writer is inclined to    
believe that these results have some    
bearing upon a problem which plays an   
important role in theories of evolution1
 namely1 the cause of natural death4 ,it
 has been stated that the processes of  
differentiation and development lead    
also to the natural death of the        
individual4 ,if we express this in      
chemical terms it means that the        
chemical processes which underlie       
development also determine natural      
death4 ,physical chemistry has taught us
 to identify two chemical processes even
 if only certain of their features are  
known4 ,one of these means of           
identification is the temperature       
coefficient4 ,when two chemical         
processes are identical1 their velocity 
must be reduced by the same amount if   
the temperature is lowered to the same  
extent4 ,the temperature coefficient for
 the duration of life of cold-blooded   
organisms seems1 however1 to differ     
enormously from the temperature         

coefficient for their rate of           
development4 ,for a difference in       
temperature of #aj deg ,c4 the duration 
of life is altered five hundred times as
 much as the rate of development2 and1  
for a change of #bj deg ,c41 it is      
altered more than a hundred thousand    
times as much4 ,from this we may        
conclude that1 at least for the         
sea-urchin eggs and embryo1 the chemical
 processes which determine natural death
 are certainly not identical with the   
processes which underlie their          
development4 ,t4,b4 ,robertson has also 
arrived at the conclusion1 for quite    
different reasons1 that the process of  
senile decay is essentially different   
from that of growth and development4    
7b7 ,,changes ,,in ,,the ,,colour ,,of  
,,butterflies ,,produced ,,through ,,the
 ,,influence ,,of ,,temperature4  ,the  
experiments of ,dorfmeister1 ,weismann1 
,merrifield1 ,standfuss1 and ,fischer1  
on seasonal dimorphism and the          
aberration of colour in butterflies have

 so often been discussed in biological  
literature that a short reference to    
them will suffice4 ,by seasonal         
dimorphism is meant the fact that       
species may appear at different seasons 
of the year in a somewhat different form
 or colour4 ,vanessa prorsa is the      
summer form1 ,vanessa levana the winter 
form of the same species4 ,by keeping   
the pupae of ,vanessa prorsa several    
weeks at a temperature of from #j deg to
 #a deg ,weismann succeeded in obtaining
 from the summer chrysalids specimens   
which resembled the winter variety1     
,vanessa levana4  ,if we wish to get a  
clear understanding of the causes of    
variation in the colour and pattern of  
butterflies1 we must direct our         
attention to the experiments of         
,fischer1 who worked with more extreme  
temperatures than his predecessors1 and 
found that almost identical aberrations 
of colour could be produced by both     
extremely high and extremely low        
temperatures4 ,this can be clearly seen 

from the following tabulated results of 
his observations4 ,at the head of each  
column the reader finds the temperature 
to which ,fischer submitted the pupae1  
and in the vertical column below are    
found the varieties that were produced4 
,in the vertical column ,a are given the
 normal forms3  7,temperatures in deg   
,c47    #j to -#bj     #j to #aj    ,a4 
#ce to #cg    #cf to #da  #db to #df    
7,normal forms7    ichnusoides  polaris 
urticae      ichnusa       polaris      
ichnusoides     7nigrita7               
7nigrita7    antigone     fischeri    io
             -           fischeri       
antigone     7iokaste7                  
7iokaste7    testudo      dixeyi        
polychloros  erythromelas  dixeyi       
testudo    hygiaea      artemis         
antiopa      epione        artemis      
hygiaea    elymi        wiskotti        
cardui         -           wiskotti     
elymi    klymene      merrifieldi       
atalanta       -           merrifieldi  
klymene    weismanni    porima          

prorsa         -           porima       
weismanni  ,the reader will notice that 
the aberrations produced at a very low  
temperature 7from #j to -#bj deg ,c47   
are absolutely identical with the       
aberrations produced by exposing the    
pupae to extremely high temperatures    
7#db to #df deg ,c474 ,moreover the     
aberrations produced by a moderately low
 temperature 7from #j to #aj deg ,c47   
are identical with the aberrations      
produced by a moderately high           
temperature 7#cf to #da deg ,c47  ,from 
these observations ,fischer concludes   
that it is erroneous to speak of a      
specific effect of high and of low      
temperatures1 but that there must be a  
common cause for the aberration found at
 the high as well as at the low         
temperature limits4 ,this cause he seems
 to find in the inhibiting effects of   
extreme temperatures upon development4  
,if we try to analyse such results as   
,fischer's from a physico-chemical point
 of view1 we must realise that what we  

call life consists of a series of       
chemical reactions1 which are connected 
in a catenary way2 inasmuch as one      
reaction or group of reactions 7a7 7e4g4
 hydrolyses7 causes or furnishes the    
material for a second reaction or group 
of reactions 7b7 7e4g4 oxydations74 ,we 
know that the temperature coefficient   
for physiological processes varies      
slightly at various parts of the scale2 
as a rule it is higher near #j and lower
 near #cj deg4 ,but we know also that   
the temperature coefficients do not vary
 equally from the various physiological 
processes4 ,it is1 therefore1 to be     
expected that the temperature           
coefficients for the group of reactions 
of the type 7a7 will not be identical   
through the whole scale with the        
temperature coefficients for the        
reactions of the type 7b74 ,if therefore
 a certain substance is formed at the   
normal temperature of the animal in such
 quantities as are needed for the       
catenary reaction 7b71 it is not to be  

expected that this same perfect balance 
will be maintained for extremely high or
 extremely low temperatures2 it is more 
probable that one group of reactions    
will exceed the other and thus produce  
aberrant chemical effects1 which may    
underlie the colour aberrations observed
 by ,fischer and other experimenters4   
,it is important to notice that ,fischer
 was also able to produce aberrations   
through the application of narcotics4   
,wolfgang ,ostwald has produced         
experimentally1 through variation of    
temperature1 dimorphism of form in      
,daphnia4 ,lack of space precludes an   
account of these important experiments1 
as of so many others4  ,,iv4 ,,the      
,,effects ,,of ,,light4  ,at the present
 day nobody seriously questions the     
statement that the action of light upon 
organisms is primarily one of a chemical
 character4 ,while this chemical action 
is of the utmost importance for         
organisms1 the nutrition of which       
depends upon the action of chlorophyll1 

it becomes of less importance for       
organisms devoid of chlorophyll4        
,nevertheless1 we find animals in which 
the formation of organs by regeneration 
is not possible unless they are exposed 
to light4 ,an observation made by the   
writer on the regeneration of polyps in 
a hydroid1 ,eudendrium racemosum1 at    
,woods ,hole1 may be mentioned as an    
instance of this4 ,if the stem of this  
hydroid1 which is usually covered with  
polyps1 is put into an aquarium the     
polyps soon fall off4 ,if the stems are 
kept in an aquarium where light strikes 
them during the day1 a regeneration of  
numerous polyps takes place in a few    
days4 ,if1 however1 the stems of        
,eudendrium are kept permanently in the 
dark1 no polyps are formed even after an
 interval of some weeks2 but they are   
formed in a few days after the same     
stems have been transferred from the    
dark to the light4 ,diffused daylight   
suffices for this effect4 ,goldfarb1 who
 repeated these experiments1 states that

 an exposure of comparatively short     
duration is sufficient for this effect1 
it is possible that the light favours   
the formation of substances which are a 
prerequisite for the origin of polyps   
and their growth4  ,of much greater     
significance than this observation are  
the facts which show that a large number
 of animals assume1 to some extent1 the 
colour of the ground on which they are  
placed4 ,pouchet found through          
experiments upon crustaceans and fish   
that this influence of the ground on the
 colour of animals is produced through  
the medium of the eyes4 ,if the eyes are
 removed or the animals made blind in   
another way these phenomena cease4 ,the 
second general fact found by ,pouchet   
was that the variation in the colour of 
the animal is brought about through an  
action of the nerves on the             
pigment-cells of the skin2 the          
nerve-action being induced through the  
agency of the eye4  ,the mechanism and  
the conditions for the change in        

colouration were made clear through the 
beautiful investigations of ,keeble and 
,gamble1 on the colour-change in        
crustaceans4 ,according to these authors
 the pigment-cells can1 as a rule1 be   
considered as consisting of a central   
body from which a system of more or less
 complicated ramifications or processes 
spreads out in all directions4 ,as a    
rule1 the centre of the cell contains   
one or more different pigments which    
under the influence of nerves can spread
 out separately or together into the    
ramifications4 ,these phenomena of      
spreading and retraction of the pigments
 into or from the ramifications of the  
pigment-cells form on the whole the     
basis for the colour changes under the  
influence of environment4 ,thus ,keeble 
and ,gamble observed that ,macromysis   
flexuosa appears transparent and        
colourless or grey on sandy ground4 ,on 
a dark ground their colour becomes      
darker4 ,these animals have two pigments
 in their chromatophores1 a brown       

pigment and a whitish or yellow pigment2
 the former is much more plentiful than 
the latter4 ,when the animal appears    
transparent all the pigment is contained
 in the centre of the cells1 while the  
ramifications are free from pigment4    
,when the animal appears brown both     
pigments are spread out into the        
ramifications4 ,in the condition of     
maximal spreading the animals appear    
black4  ,this is a comparatively simple 
case4 ,much more complicated conditions 
were found by ,keeble and ,gamble in    
other crustaceans1 e4g4 in ,hippolyte   
cranchii1 but the influence of the      
surroundings upon the colouration of    
this form was also satisfactorily       
analysed by these authors4  ,while many 
animals show transitory changes in      
colour under the influence of their     
surroundings1 in a few cases permanent  
changes can be produced4 ,the best      
examples of this are those which were   
observed by ,poulton in the chrysalids  
of various butterflies1 especially the  

small tortoise-shell4 ,these experiments
 are so well known that a short         
reference to them will suffice4 ,poulton
 7,poulton1 ,e4,b41 ,colours of ,animals
 7,the ,international ,scientific       
,series71 ,london1 #ahij1 page #aba47   
found that in gilt or white surroundings
 the pupae became light coloured and    
there was often an immense development  
of the golden spots1 so that in many    
cases the whole surface of the pupae    
glittered with an apparent metallic     
lustre4 ,so remarkable was the          
appearance that a physicist to whom ,i  
showed the chrysalids1 suggested that ,i
 had played a trick and had covered them
 with goldleaf4 ,when black surroundings
 were used the pupae were as a rule     
extremely dark1 with only the smallest  
trace1 and often no trace at all1 of the
 golden spots which are so conspicuous  
in the lighter form4 ,the susceptibility
 of the animal to this influence of its 
surroundings was found to be greatest   
during a definite period when the       

caterpillar undergoes the metamorphosis 
into the chrysalis stage4 ,as far as the
 writer is aware1 no physico-chemical   
explanation1 except possibly ,wiener's  
suggestion of colour-photography by     
mechanical colour adaptation1 has ever  
been offered for the results of the type
 of those observed by ,poulton4   ,v4   
,,effects ,,of ,,gravitation4  7a7      
,,experiments ,,on ,,the ,,egg ,,of     
,,the ,,frog4  ,gravitation can only    
indirectly affect life-phenomena2       
namely1 when we have in a cell two      
different non-miscible liquids 7or a    
liquid and a solid7 of different        
specific gravity1 so that a change in   
the position of the cell or the organ   
may give results which can be traced to 
a change in the position of the two     
substances4 ,this is very nicely        
illustrated by the frog's egg1 which has
 two layers of very viscous protoplasm  
one of which is black and one white4    
,the dark one occupies normally the     
upper position in the egg and may       

therefore be assumed to possess a       
smaller specific gravity than the white 
substance4 ,when the egg is turned with 
the white pole upwards a tendency of the
 white protoplasm to flow down again    
manifests itself4 ,it is1 however1      
possible to prevent or retard this      
rotation of the highly viscous          
protoplasm1 by compressing the eggs     
between horizontal glass plates4 ,such  
compression experiments may lead to     
rather interesting results1 as ,o4      
,schultze first pointed out4 ,pflueger  
had already shown that the first plane  
of division in a fertilised frog's egg  
is vertical and ,roux established the   
fact that the first plane of division is
 identical with the plane of symmetry of
 the later embryo4 ,schultze found that 
if the frog's egg is turned upside down 
at the time of its first division and   
kept in this abnormal position1 through 
compression between two glass plates for
 about #bj hours1 a small number of eggs
 may give rise to twins4 ,it is         

possible1 in this case1 that the        
tendency of the black part of the egg to
 rotate upwards along the surface of the
 egg leads to a separation of its first 
cells1 such a separation leading to the 
formation of twins4  ,t4,h4 ,morgan made
 an interesting additional observation4 
,he destroyed one half of the egg after 
the first segmentation and found that   
the half which remained alive gave rise 
to only one half of an embryo1 thus     
confirming an older observation of      
,roux4 ,when1 however1 ,morgan put the  
egg upside down after the destruction of
 one of the first two cells1 and        
compressed the eggs between two glass   
plates1 the surviving half of the egg   
gave rise to a perfect embryo of half   
size 7and not to a half embryo of normal
 size as before47 ,obviously in this    
case the tendency of the protoplasm to  
flow back to its normal position was    
partially successful and led to a       
partial or complete separation of the   
living from the dead half2 whereby the  

former was enabled to form a whole      
embryo1 which1 of course1 possessed only
 half the size of an embryo originating 
from a whole egg4  7b7 ,,experiments    
,,on ,,hydroids4  ,a striking influence 
of gravitation can be observed in a     
hydroid1 ,antennularia antennina1 from  
the bay of ,naples4 ,this hydroid       
consists of a long straight main stem   
which grows vertically upwards and which
 has at regular intervals very fine and 
short bristle-like lateral branches1 on 
the upper side of which the polyps grow4
 ,the main stem is negatively geotropic1
 i4e4 its apex continues to grow        
vertically upwards when we put it       
obliquely into the aquarium1 while the  
roots grow vertically downwards4 ,the   
writer observed that when the stem is   
put horizontally into the water the     
short lateral branches on the lower side
 give rise to an altogether different   
kind of organ1 namely1 to roots1 and    
these roots grow indefinitely in length 
and attach themselves to solid bodies2  

while if the stem had remained in its   
normal position no further growth would 
have occurred in the lateral branches4  
,from the upper side of the horizontal  
stem new stems grow out1 mostly directly
 from the original stem1 occasionally   
also from the short lateral branches4   
,it is thus possible to force upon this 
hydroid an arrangement of organs which  
is altogether different from the        
hereditary arrangement4 ,the writer had 
called the change in the hereditary     
arrangement of organs or the            
transformation of organs by external    
forces ,,heteromorphosis4 ,we cannot now
 go any further into this subject1 which
 should1 however1 prove of interest in  
relation to the problem of heredity4    
,if it is correct to apply inferences   
drawn from the observation on the frog's
 egg to the behaviour of ,antennularia1 
one might conclude that the cells of    
,antennularia also contain non-miscible 
substances of different specific        
gravity1 and that wherever the          

specifically lighter substance comes in 
contact with the sea-water 7or gets near
 the surface of the cell7 the growth of 
a stem is favoured2 while contact with  
the sea-water of the specifically       
heavier of the substances1 will favour  
the formation of roots4  ,,vi4 ,,the    
,,experimental ,,control ,,of ,,animal  
,,instincts4  7a7 ,,experiments ,,on    
,,the ,,mechanism ,,of ,,heliotropic    
,,reactions ,,in ,,animals4  ,since the 
instinctive reactions of animals are as 
hereditary as their morphological       
character1 a discussion of experiments  
on the physico-chemical character of the
 instinctive reactions of animals should
 not be entirely omitted from this      
sketch4 ,it is obvious that such        
experiments must begin with the simplest
 type of instincts1 if they are expected
 to lead to any results2 and it is also 
obvious that only such animals must be  
selected for this purpose1 the reactions
 of which are not complicated by        
associative memory1 or1 as it may       

preferably be termed1 associative       
hysteresis4  ,the simplest type of      
instincts is represented by the         
purposeful motions of animals to or from
 a source of energy1 e4g4 light2 and it 
is with some of these that we intend to 
deal here4 ,when we expose winged       
aphides 7after they have flown away from
 the plant71 or young caterpillars of   
,porthesia chrysorrhoea 7when they are  
aroused from their winter sleep7 or     
marine or freshwater copepods and many  
other animals1 to diffused daylight     
falling in from a window1 we notice a   
tendency among these animals to move    
towards the source of light4 ,if the    
animals are naturally sensitive1 or if  
they are rendered sensitive through the 
agencies which we shall mention later1  
and if the light is strong enough1 they 
move towards the source of light in as  
straight a line as the imperfections and
 peculiarities of their locomotor       
apparatus will permit4 ,it is also      
obvious that we are here dealing with a 

forced reaction in which the animals    
have no more choice in the direction of 
their motion than have the iron filings 
in their arrangement in a magnetic      
field4 ,this can be proved very nicely  
in the case of starving caterpillars of 
,porthesia4 ,the writer put such        
caterpillars into a glass tube the axis 
of which was at right angles to the     
plane of the window3 the caterpillars   
went to the window side of the tube and 
remained there1 even if leaves of their 
food-plant were put into the tube       
directly behind them4 ,under such       
conditions the animals actually died    
from starvation1 the light preventing   
them from turning to the food1 which    
they eagerly ate when the light allowed 
them to do so4 ,one cannot say that     
these animals1 which we call positively 
helioptropic1 are attracted by the      
light1 since it can be shown that they  
go towards the source of the light even 
if in so doing they move from places of 
a higher to places of a lower degree of 

illumination4  ,the writer has advanced 
the following theory of these           
instinctive reactions4 ,animals of the  
type of those mentioned are             
automatically orientated by the light in
 such a way that symmetrical elements of
 their retina 7or skin7 are struck by   
the rays of light at the same angle4 ,in
 this case the intensity of light is the
 same for both retinae or symmetrical   
parts of the skin4  ,this automatic     
orientation is determined by two        
factors1 first a peculiar               
photo-sensitiveness of the retina 7or   
skin71 and second a peculiar nervous    
connection between the retina and the   
muscular apparatus4 ,in symmetrically   
built heliotropic animals in which the  
symmetrical muscles participate equally 
in locomotion1 the symmetrical muscles  
work with equal energy as long as the   
photo-chemical processes in both eyes   
are identical4 ,if1 however1 one eye is 
struck by stronger light than the other1
 the symmetrical muscles will work      

unequally and in positively heliotropic 
animals those muscles will work with    
greater energy which bring the plane of 
symmetry back into the direction of the 
rays of light and the head towards the  
source of light4 ,as soon as both eyes  
are struck by the rays of light at the  
same angle1 there is no more reason for 
the animal to deviate from this         
direction and it will move in a straight
 line4 ,all this holds good on the      
supposition that the animals are exposed
 to only one source of light and are    
very sensitive to light4  ,additional   
proof for the correctness of this theory
 was furnished through the experiments  
of ,g4,h4 ,parker and ,s4,j4 ,holmes4   
,the former worked on a butterfly1      
,vanessa antiope1 the latter on other   
arthropods4 ,all the animals were in a  
marked degree positively heliotropic4   
,these authors found that if one cornea 
is blackened in such an animal1 it moves
 continually in a circle when it is     
exposed to a source of light1 and in    

these motions the eye which is not      
covered with paint is directed towards  
the centre of the circle4 ,the animal   
behaves1 therefore1 as if the darkened  
eye were in the shade4  7b7 ,,the       
,,production ,,of ,,positive            
,,heliotropism ,,by ,,acids ,,and       
,,other ,,means ,,and ,,the ,,periodic  
,,depth-,,migrations ,,of ,,pelagic     
,,animals4  ,when we observe a dense    
mass of copepods collected from a       
freshwater pond1 we notice that some    
have a tendency to go to the light while
 others go in the opposite direction and
 many1 if not the majority1 are         
indifferent to light4 ,it is an easy    
matter to make the negatively           
heliotropic or the indifferent copepods 
almost instantly positively heliotropic 
by adding a small but definite amount of
 carbon-dioxide in the form of          
carbonated water to the water in which  
the animals are contained4 ,if the      
animals are contained in #ej cubic      
centimetres of water it suffices to add 

from three to six cubic centimetres of  
carbonated water to make all the        
copepods energetically positively       
heliotropic4 ,this heliotropism lasts   
about half an hour 7probably until all  
the carbon-dioxide has again diffused   
into the air47 ,similar results may be  
obtained with any other acid4  ,the same
 experiments may be made with another   
freshwater crustacean1 namely ,daphnia1 
with this difference1 however1 that it  
is as a rule necessary to lower the     
temperature of the water also4 ,if the  
water containing the ,daphniae is cooled
 and at the same time carbon-dioxide    
added1 the animals which were before    
indifferent to light now become most    
strikingly positively heliotropic4      
,marine copepods can be made positively 
heliotropic by the lowering of the      
temperature alone1 or by a sudden       
increase in the concentration of the    
sea-water4  ,these data have a bearing  
upon the depth-migrations of pelagic    
animals1 as was pointed out years ago by

 ,theo4 ,t4 ,groom and the writer4 ,it  
is well known that many animals living  
near the surface of the ocean or        
freshwater lakes1 have a tendency to    
migrate upwards towards evening and     
downwards in the morning and during the 
day4 ,these periodic motions are        
determined to a large extent1 if not    
exclusively1 by the heliotropism of     
these animals4 ,since the consumption of
 carbon-dioxide by the green plants     
ceases towards evening1 the tension of  
this gas in the water must rise and this
 must have the effect of inducing       
positive heliotropism or increasing its 
intensity4 ,at the same time the        
temperature of the water near the       
surface is lowered and this also        
increases the positive heliotropism in  
the organisms4  ,the faint light from   
the sky is sufficient to cause animals  
which are in a high degree positively   
heliotropic to move vertically upwards  
towards the light1 as experiments with  
such pelagic animals1 e4g4 copepods1    

have shown4 ,when1 in the morning1 the  
absorption of carbon-dioxide by the     
green algae begins again and the        
temperature of the water rises1 the     
animals lose their positive             
heliotropism1 and slowly sink down or   
become negatively heliotropic and       
migrate actively downwards4  ,these     
experiments have also a bearing upon the
 problem of the inheritance of          
instincts4 ,the character which is      
transmitted in this case is not the     
tendency to migrate periodically upwards
 and downwards1 but the positive        
heliotropism4 ,the tendency to migrate  
is the outcome of the fact that         
periodically varying external conditions
 induce a periodic change in the sense  
and intensity of the heliotropism of    
these animals4 ,it is of course         
immaterial for the result1 whether the  
carbon-dioxide or any other acid diffuse
 into the animal from the outside or    
whether they are produced inside in the 
tissue cells of the animals4 ,davenport 

and ,cannon found that ,daphniae1 which 
at the beginning of the experiment1     
react sluggishly to light react much    
more quickly after they have been made  
to go to the light a few times4 ,the    
writer is inclined to attribute this    
result to the effect of acids1 e4g4     
carbon-dioxide1 produced in the animals 
themselves in consequence of their      
motion4 ,a similar effect of the acids  
was shown by ,a4,d4 ,waller in the case 
of the response of nerve to stimuli4    
,the writer observed many years ago that
 winged male and female ants are        
positively helioptropic and that their  
heliotropic sensitiveness increases and 
reaches its maximum towards the period  
of nuptial flight4 ,since the workers   
show no heliotropism it looks as if an  
internal secretion from the sexual      
glands were the cause of their          
heliotropic sensitiveness4 ,v4 ,kellogg 
has observed that bees also become      
intensely positively heliotropic at the 
period of their wedding flight1 in fact 

so much so that by letting light fall   
into the observation hive from above1   
the bees are prevented from leaving the 
hive through the exit at the lower end4 
,we notice also the reverse phenomenon1 
namely1 that chemical changes produced  
in the animal destroy its heliotropism4 
,the caterpillars of ,porthesia         
chrysorrhoea are very strongly          
positively heliotropic when they are    
first aroused from their winter sleep4  
,this heliotropic sensitiveness lasts   
only as long as they are not fed4 ,if   
they are kept permanently without food  
they remain permanently positively      
heliotropic until they die from         
starvation4 ,it is to be inferred that  
as soon as these animals take up food1 a
 substance or substances are formed in  
their bodies which diminish or          
annihilate their heliotropic            
sensitiveness4  ,the heliotropism of    
animals is identical with the           
heliotropism of plants4 ,the writer has 
shown that the experiments on the effect

 of acids on the heliotropism of        
copepods can be repeated with the same  
result in ,volvox4 ,it is therefore     
erroneous to try to explain these       
heliotropic reactions of animals on the 
basis of peculiarities 7e4g4 vision7    
which are not found in plants4  ,we may 
briefly discuss the question of the     
transmission through the sex cells of   
such instincts as are based upon        
heliotropism4 ,this problem reduces     
itself simply to that of the method     
whereby the gametes transmit            
heliotropism to the larvae or to the    
adult4 ,the writer has expressed the    
idea that all that is necessary for this
 transmission is the presence in the    
eyes 7or in the skin7 of the animal of a
 photo-sensitive substance4 ,for the    
transmission of this the gametes need   
not contain anything more than a        
catalyser or ferment for the synthesis  
of the photo-sensitive substance in the 
body of the animal4 ,what has been said 
in regard to animal heliotropism might1 

if space permitted1 be extended1 mutatis
 mutandis1 to geotropism and            
stereotropism4  7c7 ,,the ,,tropic      
,,reactions ,,of ,,certain              
,,tissue-,,cells ,,and ,,the            
,,morphogenetic ,,effects ,,of ,,these  
,,reactions4  ,since plant-cells show   
heliotropic reactions identical with    
those of animals1 it is not surprising  
that certain tissue-cells also show     
reactions which belong to the class of  
tropisms4 ,these reactions of           
tissue-cells are of special interest by 
reason of their bearing upon the        
inheritance of morphological characters4
 ,an example of this is found in the    
tiger-like marking of the yolk-sac of   
the embryo of ,fundulus and in the      
marking of the young fish itself4 ,the  
writer found that the former is         
entirely1 and the latter at least in    
part1 due to the creeping of the        
chromatophores upon the blood-vessels4  
,the chromatophores are at first        
scattered irregularly over the yolk-sac 

and show their characteristic           
ramifications4 ,there is at that time no
 definite relation between blood-vessels
 and chromatophores4 ,as soon as a      
ramification of a chromatophore comes in
 contact with a blood-vessel the whole  
mass of the chromatophore creeps        
gradually on the blood-vessel and forms 
a complete sheath around the vessel1    
until finally all the chromatophores    
form a sheath around the vessels and no 
more pigment cells are found in the     
meshes between the vessels4 ,nobody who 
has not actually watched the process of 
the creeping of the chromatophores upon 
the blood-vessels would anticipate that 
the tiger-like colouration of the       
yolk-sac in the later stages of the     
development was brought about in this   
way4 ,similar facts can be observed in  
regard to the first marking of the      
embryo itself4 ,the writer is inclined  
to believe that we are here dealing with
 a case of chemotropism1 and that the   
oxygen of the blood may be the cause of 

the spreading of the chromatophores     
around the blood-vessels4 ,certain      
observations seem to indicate the       
possibility that in the adult the       
chromatophores have1 in some forms at   
least1 a more rigid structure and are   
prevented from acting in the way        
indicated4 ,it seems to the writer that 
such observations as those made on      
,fundulus might simplify the problem of 
the hereditary transmission of certain  
markings4  ,driesch has found that a    
tropism underlies the arrangement of the
 skeleton in the pluteus larvae of the  
sea-urchin4 ,the position of this       
skeleton is predetermined by the        
arrangement of the mesenchyme cells1 and
 ,driesch has shown that these cells    
migrate actively to the place of their  
destination1 possibly led there under   
the influence of certain chemical       
substances4 ,when ,driesch scattered    
these cells mechanically before their   
migration1 they nevertheless reached    
their destination4  ,in the developing  

eggs of insects the nuclei1 together    
with some cytoplasm1 migrate to the     
periphery of the egg4 ,herbst pointed   
out that this might be a case of        
chemotropism1 caused by the oxygen      
surrounding the egg4 ,the writer has    
expressed the opinion that the formation
 of the blastula may be caused generally
 by a tropic reaction of the            
blastomeres1 the latter being forced by 
an outside influence to creep to the    
surface of the egg4  ,these examples may
 suffice to indicate that the           
arrangement of definite groups of cells 
and the morphological effects resulting 
therefrom may be determined by forces   
lying outside the cells4 ,since these   
forces are ubiquitous and constant it   
appears as if we were dealing           
exclusively with the influence of a     
gamete2 while in reality all that it is 
necessary for the gamete to transmit is 
a certain form of irritability4  7d7    
,,factors ,,which ,,determine ,,place   
,,and ,,time ,,for ,,the ,,deposition   

,,of ,,eggs4  ,for the preservation of  
species the instinct of animals to lay  
their eggs in places in which the young 
larvae find their food and can develop  
is of paramount importance4 ,a simple   
example of this instinct is the fact    
that the common fly lays its eggs on    
putrid material which serves as food for
 the young larvae4 ,when a piece of meat
 and of fat of the same animal are      
placed side by side1 the fly will       
deposit its eggs upon the meat on which 
the larvae can grow1 and not upon the   
fat1 on which they would starve4 ,here  
we are dealing with the effect of a     
volatile nitrogenous substance which    
reflexly causes the peristaltic motions 
for the laying of the egg in the female 
fly4  ,kammerer has investigated the    
conditions for the laying of eggs in two
 forms of salamanders1 e4g4 ,salamandra 
atra and ,s4 maculosa4 ,in both forms   
the eggs are fertilised in the body and 
begin to develop in the uterus4 ,since  
there is room only for a few larvae in  

the uterus1 a large number of eggs      
perish and this number is the greater   
the longer the period of gestation4 ,it 
thus happens that when the animals      
retain their eggs a long time1 very few 
young ones are born2 and these are in a 
rather advanced stage of development1   
owing to the long time which elapsed    
since they were fertilised4 ,when the   
animal lays its eggs comparatively soon 
after copulation1 many eggs 7from #ab to
 #gb7 are produced and the larvae are of
 course in an early stage of            
development4 ,in the early stage the    
larvae possess gills and can therefore  
live in water1 while in later stages    
they have no gills and breathe through  
their lungs4 ,kammerer showed that both 
forms of ,salamandra can be induced to  
lay their eggs early or late1 according 
to the physical conditions surrounding  
them4 ,if they are kept in water or in  
proximity to water and in a moist       
atmosphere they have a tendency to lay  
their eggs earlier and a comparatively  

high temperature enhances the tendency  
to shorten the period of gestation4 ,if 
the salamanders are kept in comparative 
dryness they show a tendency to lay     
their eggs rather late and a low        
temperature enhances this tendency4     
,since ,salamandra atra is found in     
rather dry alpine regions with a        
relatively low temperature and          
,salamandra maculosa in lower regions   
with plenty of water and a higher       
temperature1 the fact that ,s4 atra     
bears young which are already developed 
and beyond the stage of aquatic life1   
while ,s4 maculosa bears young ones in  
an earlier stage1 has been termed       
adaptation4 ,kammerer's experiments1    
however1 show that we are dealing with  
the direct effects of definite outside  
forces4 ,while we may speak of          
adaptation when all or some of the      
variables which determine a reaction are
 unknown1 it is obviously in the        
interest of further scientific progress 
to connect cause and effect directly    

whenever our knowledge allows us to do  
so4  ,,vii4 ,,concluding ,,remarks4     
,the discovery of ,de ,vries1 that new  
species may arise by mutation and the   
wide if not universal applicability of  
,mendel's ,law to phenomena of heredity1
 as shown especially by ,bateson and his
 pupils1 must1 for the time being1 if   
not permanently1 serve as a basis for   
theories of evolution4 ,these           
discoveries place before the            
experimental biologist the definite task
 of producing mutations by              
physico-chemical means4 ,it is true that
 certain authors claim to have succeeded
 in this1 but the writer wishes to      
apologise to these authors for his      
inability to convince himself of the    
validity of their claims at the present 
moment4 ,he thinks that only continued  
breeding of these apparent mutants      
through several generations can afford  
convincing evidence that we are here    
dealing with mutants rather than with   
merely pathological variations4  ,what  

was said in regard to the production of 
new species by physico-chemical means   
may be repeated with still more         
justification in regard to the second   
problem of transformation1 namely the   
making of living from inanimate matter4 
,the purely morphological imitations of 
bacteria or cells which physicists have 
now and then proclaimed as artificially 
produced living beings2 or the plays on 
words by which1 e4g4 the regeneration of
 broken crystals and the regeneration of
 lost limbs by a crustacean were        
declared identical1 will not appeal to  
the biologist4 ,we know that growth and 
development in animals and plants are   
determined by definite although         
complicated series of catenary chemical 
reactions1 which result in the synthesis
 of a ,,definite compound or group of   
compounds1 namely1 ,,nucleins4  ,the    
nucleins have the peculiarity of acting 
as ferments or enzymes for their own    
synthesis4 ,thus a given type of nucleus
 will continue to synthesise other      

nuclein of its own kind4 ,this          
determines the continuity of a species2 
since each species has1 probably1 its   
own specific nuclein or nuclear         
material4 ,but it also shows us that    
whoever claims to have succeeded in     
making living matter from inanimate will
 have to prove that he has succeeded in 
producing nuclein material which acts as
 a ferment for its own synthesis and    
thus reproduces itself4 ,nobody has thus
 far succeeded in this1 although nothing
 warrants us in taking it for granted   
that this task is beyond the power of   
science4     ,,xv4 ,,the ,,value ,,of   
,,colour ,,in ,,the ,,struggle ,,for    
,,life4 ,by ,e4,b4 ,poulton4  ,hope     
,professor of ,zoology in the           
,university of ,oxford4                 
,,introduction4  ,the following pages   
have been written almost entirely from  
the historical stand-point4 ,their      
principal object has been to give some  
account of the impressions produced on  
the mind of ,darwin and his great       

compeer ,wallace by various difficult   
problems suggested by the colours of    
living nature4 ,in order to render the  
brief summary of ,darwin's thoughts and 
opinions on the subject in any way      
complete1 it was found necessary to say 
again much that has often been said     
before4 ,no attempt has been made to    
display as a whole the vast contribution
 of ,wallace2 but certain of its        
features are incidentally revealed in   
passages quoted from ,darwin's letters4 
,it is assumed that the reader is       
familiar with the well-known theories of
 ,protective ,resemblance1 ,warning     
,colours1 and ,mimicry both ,batesian   
and ,mullerian4 ,it would have been     
superfluous to explain these on the     
present occasion2 for a far more        
detailed account than could have been   
attempted in these pages has recently   
appeared4 7,poulton1 ,essays on         
,evolution ,oxford1 #aijh1 pages        
#bic-chb47 ,among the older records ,i  
have made a point of bringing together  

the principal observations scattered    
through the note-books and collections  
of ,w4,j4 ,burchell4 ,these have never  
hitherto found a place in any memoir    
dealing with the significance of the    
colours of animals4  ,,incidental       
,,colours4  ,darwin fully recognised    
that the colours of living beings are   
not necessarily of value as colours1 but
 that they may be an incidental result  
of chemical or physical structure4 ,thus
 he wrote to ,t4 ,meehan1 ,oct4 #i1     
#ahgd3 ,i am glad that you are attending
 to the colours of dioecious flowers2   
but it is well to remember that their   
colours may be as unimportant to them as
 those of a gall1 or1 indeed1 as the    
colour of an amethyst or ruby is to     
these gems4 7,more ,letters of ,charles 
,darwin1 ,vol4 ,i4 pages #ced1 #cee4    
,see also the admirable account of      
incidental colours in ,descent of ,man  
7#bnd edition71 #ahgd1 pages #bfa1      
#bfb47  ,incidental colours remain as   
available assets of the organism ready  

to be turned to account by natural      
selection4 ,it is a probable speculation
 that all pigmentary colours were       
originally incidental2 but now and for  
immense periods of time the visible     
tints of animals have been modified and 
arranged so as to assist in the struggle
 with other organisms or in courtship4  
,the dominant colouring of plants1 on   
the other hand1 is an essential element 
in the paramount physiological activity 
of chlorophyll4 ,in exceptional         
instances1 however1 the shapes and      
visible colours of plants may be        
modified in order to promote            
concealment4  ,,teleology ,,and         
,,adaptation4  ,in the department of    
,biology which forms the subject of this
 essay1 the adaptation of means to an   
end is probably more evident than in any
 other2 and it is therefore of interest 
to compare1 in a brief introductory     
section1 the older with the newer       
teleological views4  ,the distinctive   
feature of ,natural ,selection as       

contrasted with other attempts to       
explain the process of ,evolution is the
 part played by the struggle for        
existence4 ,all naturalists in all ages 
must have known something of the        
operations of ,nature red in tooth and  
claw2 but it was left for this great    
theory to suggest that vast             
extermination is a necessary condition  
of progress1 and even of maintaining the
 ground already gained4  ,realising that
 fitness is the outcome of this fierce  
struggle1 thus turned to account for the
 first time1 we are sometimes led to    
associate the recognition of adaptation 
itself too exclusively with ,natural    
,selection4 ,adaptation had been studied
 with the warmest enthusiasm nearly     
forty years before this great theory was
 given to the scientific world1 and it  
is difficult now to realise the impetus 
which the works of ,paley gave to the   
study of ,natural ,history4 ,that they  
did inspire the naturalists of the early
 part of the last century is clearly    

shown in the following passages4  ,in   
the year #ahbd the ,ashmolean ,museum at
 ,oxford was intrusted to the care of   
,j4,s4 ,duncan of ,new ,college4 ,he was
 succeeded in this office by his        
brother1 ,p4,b4 ,duncan1 of the same    
,college1 author of a ,history of the   
,museum1 which shows very clearly the   
influence of ,paley upon the study of   
nature1 and the dominant position given 
to his teachings3 ,happily at this time 
7#ahbd7 a taste for the study of natural
 history had been excited in the        
,university by ,dr ,paley's very        
interesting work on ,natural ,theology1 
and the very popular lectures of ,dr    
,kidd on ,comparative ,anatomy1 and ,dr 
,buckland on ,geology4 ,in the          
arrangement of the contents of the      
,museum the illustration of ,paley's    
work was given the foremost place by    
,j4,s4 ,duncan3 ,the first division     
proposes to familiarize the eye to those
 relations of all natural objects which 
form the basis of argument in ,dr       

,paley's ,natural ,theology2 to induce a
 mental habit of associating the view of
 natural phenomena with the conviction  
that they are the media of ,divine      
manifestation2 and by such association  
to give proper dignity to every branch  
of natural science4 7,from ,history and 
,arrangement of the ,ashmolean ,museum  
by ,p4,b4 ,duncan3 see pages vi1 vii of 
,a ,catalogue of the ,ashmolean ,museum1
 ,oxford1 #ahcf47  ,the great           
naturalist1 ,w4,j4 ,burchell1 in his    
classical work shows the same           
recognition of adaptation in nature at a
 still earlier date4 ,upon the subject  
of collections he wrote 7,travels in the
 ,interior of ,southern ,africa1        
,london1 ,vol4 ,i4 #ahbb1 page #eje4    
,the references to ,burchell's          
observations in the present essay are   
adapted from the author's article in    
,report of the ,british and ,south      
,african ,associations1 #aije1 ,vol4    
,,iii4 pages #eg-aaj473 ,it must not be 
supposed that these charms 7the         

pleasures of ,nature7 are produced by   
the mere discovery of new objects3 it is
 the harmony with which they have been  
adapted by the ,creator to each other1  
and to the situations in which they are 
found1 which delights the observer in   
countries where ,art has not yet        
introduced her discords4 ,the remainder 
of the passage is so admirable that ,i  
venture to quote it3 ,to him who is     
satisfied with amassing collections of  
curious objects1 simply for the pleasure
 of possessing them1 such objects can   
afford1 at best1 but a childish         
gratification1 faint and fleeting2 while
 he who extends his view beyond the     
narrow field of nomenclature1 beholds a 
boundless expanse1 the exploring of     
which is worthy of the philosopher1 and 
of the best talents of a reasonable     
being4  ,on ,september #ad1 #ahaa1      
,burchell was at ,zand ,valley 7,vlei71 
or ,sand ,pool1 a few miles south-west  
of the site of ,prieska1 on the ,orange 
,river4 ,here he found a                

,mesembryanthemum 7,m4 turbiniforme1 now
 ,m4 truncatum7 and also a ,gryllus     
7,acridian71 closely resembling the     
pebbles with which their locality was   
strewn4 ,he says of both of these1 ,the 
intention of ,nature1 in these          
instances1 seems to have been the same  
as when she gave to the ,chameleon the  
power of accommodating its color1 in a  
certain degree1 to that of the object   
nearest to it1 in order to compensate   
for the deficiency of its locomotive    
powers4 ,by their form and colour1 this 
insect may pass unobserved by those     
birds1 which otherwise would soon       
extirpate a species so little able to   
elude its pursuers1 and this juicy      
little ,mesembryanthemum may generally  
escape the notice of cattle and wild    
animals4 7,loc4 cit4 pages #caj1 #caa4  
,see ,sir ,william ,thiselton-,dyer     
,morphological ,notes1 ,,xi42           
,protective ,adaptations1 ,i42 ,annals  
of ,botany1 ,vol4 ,,xx4 page #abd4 ,in  
plates ,,vii41 ,,viii4 and ,,ix4        

accompanying this article the author    
represents the species observed by      
,burchell1 together with others in which
 analogous adaptations exist4 ,he       
writes3 ,burchell was clearly on the    
track on which ,darwin reached the goal4
 ,but the time had not come for         
emancipation from the old teleology4    
,this1 however1 in no respect detracts  
from the merit or value of his work4    
,for1 as ,huxley has pointed out 7,life 
and ,letters of ,thomas ,henry ,huxley1 
,london1 #aijj1 ,i4 page #deg71 the     
facts of the old teleology are          
immediately transferable to ,darwinism1 
which simply supplies them with a       
natural in place of a supernatural      
explanation47 ,burchell here seems to   
miss1 at least in part1 the meaning of  
the relationship between the quiescence 
of the ,acridian and its cryptic        
colouring4 ,quiescence is an essential  
element in the protective resemblance to
 a stone--probably even more            
indispensable than the details of the   

form and colouring4 ,although ,burchell 
appears to overlook this point he fully 
recognised the community between        
protection by concealment and more      
aggressive modes of defence2 for1 in the
 passage of which a part is quoted      
above1 he specially refers to some      
earlier remarks on page #bbf of his     
,vol4 ,i4 ,we here find that even when  
the oxen were resting by the ,juk rivier
 7,yoke river71 on ,july #ai1 #ahaa1    
,burchell observed ,geranium spinosum1  
with a fleshy stem and large white      
flowers4442 and a succulent species of  
,pelargonium444 so defended by the old  
panicles1 grown to hard woody thorns1   
that no cattle could browze upon it4 ,he
 goes on to say1 ,in this arid country1 
where every juicy vegetable would soon  
be eaten up by the wild animals1 the    
,great ,creating ,power1 with           
all-provident wisdom1 has given to such 
plants either an acrid or poisonous     
juice1 or sharp thorns1 to preserve the 
species from annihilation444  ,all these

 modes of defence1 especially adapted to
 a desert environment1 have since been  
generally recognised1 and it is very    
interesting to place beside ,burchell's 
statement the following passage from a  
letter written by ,darwin1 ,aug4 #g1    
#ahfh1 to ,g4,h4 ,lewes2 ,that ,natural 
,selection would tend to produce the    
most formidable thorns will be admitted 
by every one who has observed the       
distribution in ,south ,america and     
,africa 7vide ,livingstone7 of          
thorn-bearing plants1 for they always   
appear where the bushes grow isolated   
and are exposed to the attacks of       
mammals4 ,even in ,england it has been  
noticed that all spine-bearing and      
sting-bearing plants are palatable to   
quadrupeds1 when the thorns are crushed4
 7,more ,letters1 ,i4 page #cjh47       
,,adaptation ,,and ,,natural            
,,selection4  ,i have preferred to show 
the influence of the older teleology    
upon ,natural ,history by quotations    
from a single great and insufficiently  

appreciated naturalist4 ,it might have  
been seen equally well in the pages of  
,kirby and ,spence and those of many    
other writers4 ,if the older naturalists
 who thought and spoke with ,burchell of
 the intention of ,nature and the       
adaptation of beings to each other1 and 
to the situations in which they are     
found1 could have conceived the         
possibility of evolution1 they must have
 been led1 as ,darwin was1 by the same  
considerations to ,natural ,selection4  
,this was impossible for them1 because  
the philosophy which they followed      
contemplated the phenomena of adaptation
 as part of a static immutable system4  
,darwin1 convinced that the system is   
dynamic and mutable1 was prevented by   
these very phenomena from accepting     
anything short of the crowning          
interpretation offered by ,natural      
,selection4 7,i had always been much    
struck by such adaptations 7e4g4        
woodpecker and tree-frog for climbing1  
seeds for dispersal71 and until these   

could be explained it seemed to me      
almost useless to endeavour to prove by 
indirect evidence that species have been
 modified4 ,autobiography in ,life and  
,letters of ,charles ,darwin1 ,vol4 ,i4 
page #hb4 ,the same thought is repeated 
again and again in ,darwin's letters to 
his friends4 ,it is forcibly urged in   
the ,introduction to the ,origin        
7#ahei71 page #c47 ,and the birth of    
,darwin's unalterable conviction that   
adaptation is of dominant importance in 
the organic world1--a conviction        
confirmed and ever again confirmed by   
his experience as a naturalist--may     
probably be traced to the influence of  
the great theologian4 ,thus ,darwin1    
speaking of his ,undergraduate days1    
tells us in his ,autobiography that the 
logic of ,paley's ,evidences of         
,christianity and ,moral ,philosophy    
gave him as much delight as did ,euclid4
  ,the careful study of these works1    
without attempting to learn any part by 
rote1 was the only part of the          

academical course which1 as ,i then felt
 and as ,i still believe1 was of the    
least use to me in the education of my  
mind4 ,i did not at that time trouble   
myself about ,paley's premises2 and     
taking these on trust1 ,i was charmed   
and convinced by the long line of       
argumentation4 7,life and ,letters1 ,i4 
page #dg47  ,when ,darwin came to write 
the ,origin he quoted in relation to    
,natural ,selection one of ,paley's     
conclusions4 ,no organ will be formed1  
as ,paley has remarked1 for the purpose 
of causing pain or for doing an injury  
to its possessor4 7,origin of ,species  
7#ast edition7 #ahei1 page #bja47  ,the 
study of adaptation always had for      
,darwin1 as it has for many1 a peculiar 
charm4 ,his words1 written ,nov4 #bh1   
#ahhj1 to ,sir ,w4 ,thiselton-,dyer1 are
 by no means inapplicable to-day3 ,many 
of the ,germans are very contemptuous   
about making out use of organs2 but they
 may sneer the souls out of their       
bodies1 and ,i for one shall think it   

the most interesting part of natural    
history4 7,more ,letters ,,ii4 page     
#dbh47  ,,protective ,,and ,,aggressive 
,,resemblance3 ,,procryptic ,,and       
,,anticryptic ,,colouring4  ,colouring  
for the purpose of concealment is       
sometimes included under the head       
,mimicry1 a classification adopted by   
,h4,w4 ,bates in his classical paper4   
,such an arrangement is inconvenient1   
and ,i have followed ,wallace in keeping
 the two categories distinct4  ,the     
visible colours of animals are far more 
commonly adapted for ,protective        
,resemblance than for any other purpose4
 ,the concealment of animals by their   
colours1 shapes and attitudes1 must have
 been well known from the period at     
which human beings first began to take  
an intelligent interest in ,nature4 ,an 
interesting early record is that of     
,samuel ,felton1 who 7,dec4 #b1 #agfc7  
figured and gave some account of an     
,acridian 7,phyllotettix7 from ,jamaica4
 ,of this insect he says ,,the ,,thorax 

is like a leaf that is raised           
perpendicularly from the body4 7,phil4  
,trans4 ,roy4 ,soc4 ,vol4 ,,liv4 ,tab4  
,,vi4 page #ee47  ,both ,protective and 
,aggressive ,resemblances were          
appreciated and clearly explained by    
,erasmus ,darwin in #agid3 ,the colours 
of many animals seem adapted to their   
purposes of concealing themselves either
 to avoid danger1 or to spring upon     
their prey4 7,zoonomia1 ,vol4 ,i4 page  
#eji1 ,london1 #agid47  ,protective     
,resemblance of a very marked and       
beautiful kind is found in certain      
plants1 inhabitants of desert areas4    
,examples observed by ,burchell almost  
exactly a hundred years ago have already
 been mentioned4 ,in addition to the    
resemblance to stones ,burchell         
observed1 although he did not publish   
the fact1 a ,south ,african plant       
concealed by its likeness to the dung of
 birds4 7,sir ,william ,thiselton-,dyer 
has suggested the same method of        
concealment 7,annals of ,botany1 ,vol4  

,,xx4 page #abc74 ,referring to         
,anacampseros papyracea1 figured on     
plate ,,ix41 the author says of its     
adaptive resemblance3 ,at the risk of   
suggesting one perhaps somewhat         
far-fetched1 ,i must confess that the   
aspect of the plant always calls to my  
mind the dejecta of some bird1 and the  
more so owing to the whitening of the   
branches towards the tips 7loc4 cit4    
page #abf74 ,the student of insects1 who
 is so familiar with this very form of  
protective resemblance in larvae1 and   
even perfect insects1 will not be       
inclined to consider the suggestion     
far-fetched47 ,the observation is       
recorded in one of the manuscript       
journals kept by the great explorer     
during his journey4 ,i owe the          
opportunity of studying it to the       
kindness of ,mr ,francis ,a4 ,burchell  
of the ,rhodes ,university ,college1    
,grahamstown4 ,the following account is 
given under the date ,july #e1 #ahab1   
when ,burchell was at the ,makkwarin    

,river1 about half-way between the      
,kuruman ,river and ,litakun the old    
capital of the ,bachapins 7,bechuanas73 
,i found a curious little ,crassula 7not
 in flower7 so snow white1 that ,i      
should never has 7have7 distinguished it
 from the white limestones444 ,it was an
 inch high and a little branchy1444 and 
was at first mistaken for the dung of   
birds of the passerine order4 ,i have   
often had occasion to remark that in    
stony place7s7 there grow many small    
succulent plants and abound insects     
7chiefly ,grylli7 which have exactly the
 same colour as the ground and must for 
ever escape observation unless a person 
sit on the ground and observe very      
attentively4  ,the cryptic resemblances 
of animals impressed ,darwin and        
,wallace in very different degrees1     
probably in part due to the fact that   
,wallace's tropical experiences were so 
largely derived from the insect world1  
in part to the importance assigned by   
,darwin to ,sexual ,selection a subject 

which had always greatly interested me1 
as he says in his ,autobiography1 7,life
 and ,letters1 ,vol4 ,i4 page #id47     
,there is no reference to ,cryptic      
,resemblance in ,darwin's section of the
 ,joint ,essay1 although he gives an    
excellent short account of ,sexual      
,selection 7see page #bie74 ,wallace's  
section on the other hand contains the  
following statement3 ,even the peculiar 
colours of many animals1 especially     
insects1 so closely resembling the soil 
or the leaves or the trunks on which    
they habitually reside1 are explained on
 the same principle2 for though in the  
course of ages varieties of many tints  
may have occurred1 ,,yet ,,those ,,races
 ,,having ,,colours ,,best ,,adapted    
,,to ,,concealment ,,from ,,their       
,,enemies ,,would ,,inevitably ,,survive
 ,,the ,,longest4 7,journ4 ,proc4 ,linn4
 ,soc4 ,vol4 ,,iii4 #ahei1 page #fa4    
,the italics are ,wallace's47  ,it would
 occupy too much space to attempt any   
discussion of the difference between the

 views of these two naturalists1 but it 
is clear that ,darwin1 although fully   
believing in the efficiency of          
protective resemblance and replying to  
,st ,george ,mivart's contention that   
,natural ,selection was incompetent to  
produce it 7,origin 7#fth edition7      
,london1 #ahgb1 pages #aha1 #ahb2 see   
also page #ff471 never entirely agreed  
with ,wallace's estimate of its         
importance4 ,thus the following extract 
from a letter to ,sir ,joseph ,hooker1  
,may #ba1 #ahfh1 refers to ,wallace3 ,i 
find ,i must 7and ,i always distrust    
myself when ,i differ from him7 separate
 rather widely from him all about birds'
 nests and protection2 he is riding that
 hobby to death4 7,more ,letters1 ,i4   
page #cjd47 ,it is clear from the       
account given in ,the ,descent of ,man1 
7,london1 #ahgd1 pages #deb-deh4 ,see   
also ,life and ,letters1 ,,iii4 pages   
#abc-abe1 and ,more ,letters1 ,,ii4     
pages #ei-fc1 #gb-gd1 #gf-gh1 #hd-ij1   
#ib1 #ic471 that the divergence was due 

to the fact that ,darwin ascribed more  
importance to ,sexual ,selection than   
did ,wallace1 and ,wallace more         
importance to ,protective ,resemblance  
than ,darwin4 ,thus ,darwin wrote to    
,wallace1 ,oct4 #ab and #ac1 #ahfg3 ,by 
the way1 ,i cannot but think that you   
push protection too far in some cases1  
as with the stripes on the tiger4 7,more
 ,letters1 ,i4 page #bhc47 ,here too    
,darwin was preferring the explanation  
offered by ,sexual ,selection 7,descent 
of ,man 7#bnd edition7 #ahgd1 pages     
#ede1 #edf471 a preference which1       
considering the relation of the         
colouring of the lion and tiger to their
 respective environments1 few           
naturalists will be found to share4 ,it 
is also shown that ,darwin contemplated 
the possibility of cryptic colours such 
as those of ,patagonian animals being   
due to sexual selection influenced by   
the aspect of surrounding nature4       
,nearly a year later ,darwin in his     
letter of ,may #e1 #ahfh81 expressed his

 agreement with ,wallace's views3       
,expect that ,i should put sexual       
selection as an equal1 or perhaps as    
even a more important agent in giving   
colour than ,natural ,selection for     
protection4 7,more ,letters1 ,,ii4 pages
 #gg1 #gh47 ,the conclusion expressed in
 the above quoted passage is opposed by 
the extraordinary development of        
,protective ,resemblance in the immature
 stages of animals1 especially insects4 
,it must not be supposed1 however1 that 
,darwin ascribed an unimportant role to 
,cryptic ,resemblances1 and as          
observations accumulated he came to     
recognise their efficiency in fresh     
groups of the animal kingdom4 ,thus he  
wrote to ,wallace1 ,may #e1 #ahfg3      
,haeckel has recently well shown that   
the transparency and absence of colour  
in the lower oceanic animals1 belonging 
to the most different classes1 may be   
well accounted for on the principle of  
protection4 7,more ,letters1 ,,ii4 page 
#fb4 ,see also ,descent of ,man1 page   

#bfa47 ,darwin also admitted the justice
 of ,professor ,e4,s4 ,morse's          
contention that the shells of molluscs  
are often adaptively coloured4 7,more   
,letters1 ,,ii4 page #ie47 ,but he      
looked upon cryptic colouring and also  
mimicry as more especially ,wallace's   
departments1 and sent to him and to     
,professor ,meldola observations and    
notes bearing upon these subjects4 ,thus
 the following letter given to me by ,dr
 ,a4,r4 ,wallace and now1 by kind       
permission1 published for the first     
time1 accompanied a photograph of the   
chrysalis of ,papilio sarpedon choredon1
 ,feld41 suspended from a leaf of its   
food-plant3  ,july #ith1 ,down1         
,beckenham1 ,kent4  ,my ,dear ,wallace1 
,dr ,g4 ,krefft has sent me the enclosed
 from ,sydney4 ,a nurseryman saw a      
caterpillar feeding on a plant and      
covered the whole up1 but when he       
searched for the cocoon 7pupa71 was long
 before he could find it1 so good was   
its imitation in colour and form to the 

leaf to which it was attached4 ,i hope  
that the world goes well with you4 ,do  
not trouble yourself by acknowledging   
this4  ,ever yours  ,ch4 ,darwin4       
,another deeply interesting letter of   
,darwin's bearing upon protective       
resemblance1 has only recently been     
shown to me by my friend ,professor     
,e4,b4 ,wilson1 the great ,american     
,cytologist4 ,with his kind consent and 
that of ,mr ,francis ,darwin1 this      
letter1 written four months before      
,darwin's death on ,april #ai1 #ahhb1 is
 reproduced here 7,the letter is        
addressed3 ,edmund ,b4 ,wilson1 ,esq41  
,assistant in ,biology1 ,john ,hopkins  
,university1 ,baltimore ,md1 ,u4        
,states473  ,december #ba1 #ahha4  ,dear
 ,sir1  ,i thank you much for having    
taken so much trouble in describing     
fully your interesting and curious case 
of mimickry4  ,i am in the habit of     
looking through many scientific         
,journals1 and though my memory is now  
not nearly so good as it was1 ,i feel   

pretty sure that no such case as yours  
has been described 7amongst the         
nudibranch7 molluscs4 ,you perhaps know 
the case of a fish allied to            
,hippocampus1 7described some years ago 
by ,dr ,gunther in ,proc4 ,zoolog4      
,socy47 which clings by its tail to     
sea-weeds1 and is covered with waving   
filaments so as itself to look like a   
piece of the same sea-weed4 ,the        
parallelism between your and ,dr        
,gunther's case makes both of them the  
more interesting2 considering how far a 
fish and a mollusc stand apart4 ,it     
would be difficult for anyone to explain
 such cases by the direct action of the 
environment4--,i am glad that you intend
 to make further observations on this   
mollusc1 and ,i hope that you will give 
a figure and if possible a coloured     
figure4  ,with all good wishes from an  
old brother naturalist1  ,i remain1     
,dear ,sir1  ,yours faithfully1         
,charles ,darwin4  ,professor ,e4,b4    
,wilson has kindly given the following  

account of the circumstances under which
 he had written to ,darwin3 ,the case to
 which ,darwin's letter refers is that  
of the nudibranch mollusc ,scyllaea1    
which lives on the floating ,sargassum  
and shows a really astonishing          
resemblance to the plant1 having        
leaf-shaped processes very closely      
similar to the fronds of the sea-weed   
both in shape and in colour4 ,the       
concealment of the animal may be judged 
from the fact that we found the animal  
quite by accident on a piece of         
,sargassum that had been in a glass jar 
in the laboratory for some time and had 
been closely examined in the search for 
hydroids and the like without disclosing
 the presence upon it of two large      
specimens of the ,scyllaea 7the animal1 
as ,i recall it1 is about two inches    
long74 ,it was first detected by its    
movements alone1 by someone 7,i think a 
casual visitor to the laboratory7 who   
was looking closely at the ,sargassum   
and exclaimed ',why1 the sea-weed is    

moving its leaves'6 ,we found the       
example in the summer of #ahhj or #ahha 
at ,beaufort1 ,n4,c41 where the ,johns  
,hopkins laboratory was located for the 
time being4 ,it must have been seen by  
many others1 before or since4  ,i wrote 
and sent to ,darwin a short description 
of the case at the suggestion of        
,brooks1 with whom ,i was at the time a 
student4 ,i was1 of course1 entirely    
unknown to ,darwin 7or to anyone else7  
and to me the principal interest of     
,darwin's letter is the evidence that it
 gives of his extraordinary kindness and
 friendliness towards an obscure        
youngster who had of course absolutely  
no claim upon his time or attention4    
,the little incident made an indelible  
impression upon my memory and taught me 
a lesson that was worth learning4       
,,variable ,,protective ,,resemblance4  
,the wonderful power of rapid colour    
adjustment possessed by the cuttle-fish 
was observed by ,darwin in #ahcb at ,st 
,jago1 ,cape de ,verd ,islands1 the     

first place visited during the voyage of
 the ,beagle4 ,from ,rio he wrote to    
,henslow1 giving the following account  
of his observations1 ,may #ah1 #ahcb3 ,i
 took several specimens of an ,octopus  
which possessed a most marvellous power 
of changing its colours1 equalling any  
chameleon1 and evidently accommodating  
the changes to the colour of the ground 
which it passed over4 ,yellowish green1 
dark brown1 and red1 were the prevailing
 colours2 this fact appears to be new1  
as far as ,i can find out4 7,life and   
,letters1 ,i4 pages #bce1 #bcf4 ,see    
also ,darwin's ,journal of ,researches1 
#ahgf1 pages #f-h1 where a far more     
detailed account is given together with 
a reference to ,encycl4 of ,anat4 and   
,physiol47  ,darwin was well aware of   
the power of individual colour          
adjustment1 now known to be possessed by
 large numbers of lepidopterous pupae   
and larvae4 ,an excellent example was   
brought to his notice by ,c4,v4 ,riley  
7,more ,letters ,,ii1 pages #che1       

#chf471 while the most striking of the  
early results obtained with the pupae of
 butterflies--those of ,mrs ,m4,e4      
,barber upon ,papilio nireus--was       
communicated by him to the              
,entomological ,society of ,london4     
7,trans4 ,ent4 ,soc4 ,lond4 #ahgd1 page 
#eai4 ,see also ,more ,letters1 ,,ii4   
page #djc47  ,it is also necessary to   
direct attention to ,c4,w4 ,beebe's     
7,zoologica3 ,n4,y4 ,zool4 ,soc4 ,vol4  
,i4 ,no4 #a1 ,sept4 #be1 #aijg3         
,geographic variation in birds with     
especial reference to the effects of    
humidity47 recent discovery that the    
pigmentation of the plumage of certain  
birds is increased by confinement in a  
superhumid atmosphere4 ,in ,scardafella 
inca1 on which the most complete series 
of experiments was made1 the changes    
took place only at the moults1 whether  
normal and annual or artificially       
induced at shorter periods4 ,there was a
 corresponding increase in the choroidal
 pigment of the eye4 ,at a certain      

advanced stage of feather pigmentation a
 brilliant iridescent bronze or green   
tint made its appearance on those areas 
where iridescence most often occurs in  
allied genera4 ,thus in birds no less   
than in insects1 characters previously  
regarded as of taxonomic value1 can be  
evoked or withheld by the forces of the 
environment4  ,,warning ,,or            
,,aposematic ,,colours4  ,from ,darwin's
 description of the colours and habits  
it is evident that he observed1 in      
#ahcc1 an excellent example of warning  
colouring in a little ,south ,american  
toad 7,phryniscus nigricans74 ,he       
described it in a letter to ,henslow1   
written from ,monte ,video1 ,nov4 #bd1  
#ahcb3 ,as for one little toad1 ,i hope 
it may be new1 that it may be christened
 'diabolicus4' ,milton must allude to   
this very individual when he talks of   
'squat like a toad'2 its colours are by 
,werner 7,nomenclature of ,colours1     
#ahba7 ink black1 vermilion red and buff
 orange4 7,more ,letters1 ,i4 page #ab47

 ,in the ,journal of ,researches 7#ahgf1
 page #ig47 its colours are described as
 follows3 ,if we imagine1 first1 that it
 had been steeped in the blackest ink1  
and then1 when dry1 allowed to crawl    
over a board1 freshly painted with the  
brightest vermilion1 so as to colour the
 soles of its feet and parts of its     
stomach1 a good idea of its appearance  
will be gained4 ,instead of being       
nocturnal in its habits1 as other toads 
are1 and living in damp obscure         
recesses1 it crawls during the heat of  
the day about the dry sand-hillocks and 
arid plains1444  ,the appearance and    
habits recall ,t4 ,belt's well-known    
description of the conspicuous little   
,nicaraguan frog which he found to be   
distasteful to a duck4 7,the ,naturalist
 in ,nicaragua 7#bnd edition7 ,london1  
#ahhh1 page #cba47  ,the recognition of 
the ,warning ,colours of caterpillars is
 due in the first instance to ,darwin1  
who1 reflecting on ,sexual ,selection1  
was puzzled by the splendid colours of  

sexually immature organisms4 ,he applied
 to ,wallace who has an innate genius   
for solving difficulties4 7,descent of  
,man1 page #cbe4 ,on this and the       
following page an excellent account of  
the discovery will be found1 as well as 
in ,wallace's ,natural ,selection1      
,london1 #ahge1 pages #aag-abb47        
,darwin's original letter exists 7,life 
and ,letters1 ,,iii4 pages #ic1 #id471  
and in it we are told that he had taken 
the advice given by ,bates3 ,you had    
better ask ,wallace4 ,after some        
consideration ,wallace replied that he  
believed the colours of conspicuous     
caterpillars and perfect insects were a 
warning of distastefulness and that such
 forms would be refused by birds4       
,darwin's reply 7,life and ,letters1    
,,iii4 pages #id1 #ie47 is extremely    
interesting both for its enthusiasm at  
the brilliancy of the hypothesis and its
 caution in acceptance without full     
confirmation3  ,bates was quite right2  
you are the man to apply to in a        

difficulty4 ,i never heard anything more
 ingenious than your suggestion1 and ,i 
hope you may be able to prove it true4  
,that is a splendid fact about the white
 moths 7,a single white moth which was  
rejected by young turkeys1 while other  
moths were greedily devoured3 ,natural  
,selection1 #ahge1 page #gh472 it warms 
one's very blood to see a theory thus   
almost proved to be true4  ,two years   
later the hypothesis was proved to hold 
for caterpillars of many kinds by ,j4   
,jenner ,weir and ,a4,g4 ,butler1 whose 
observations have since been abundantly 
confirmed by many naturalists4 ,darwin  
wrote to ,weir1 ,may #ac1 #ahfi3 ,your  
verification of ,wallace's suggestion   
seems to me to amount to quite a        
discovery4 7,more ,letters1 ,,ii4 page  
#ga 7footnote747  ,,recognition ,,or    
,,episematic ,,characters4  ,this       
principle does not appear to have been  
in any way foreseen by ,darwin1 although
 he draws special attention to several  
elements of pattern which would now be  

interpreted by many naturalists as      
epismes4 ,he believed that the markings 
in question interfered with the cryptic 
effect1 and came to the conclusion that1
 even when common to both sexes1 they   
are the result of sexual selection      
primarily applied to the male4 7,descent
 of ,man1 page #edd47 ,the most familiar
 of all recognition characters was      
carefully explained by him1 although    
here too explained as an ornamental     
feature now equally transmitted to both 
sexes3 ,the hare on her form is a       
familiar instance of concealment through
 colour2 yet this principle partly fails
 in a closely-allied species1 the       
rabbit1 for when running to its burrow1 
it is made conspicuous to the sportsman1
 and no doubt to all beasts of prey1 by 
its upturned white tail4 7,descent of   
,man1 page #edb47  ,the analogous       
episematic use of the bright colours of 
flowers to attract insects for effecting
 cross-fertilisation and of fruits to   
attract vertebrates for effecting       

dispersal is very clearly explained in  
the ,origin4 7,edition #ahgb1 page #afa4
 ,for a good example of ,darwin's       
caution in dealing with exceptions see  
the allusion to brightly coloured fruit 
in ,more ,letters1 ,,ii4 page #cdh47    
,it is not1 at this point1 necessary to 
treat sematic characters at any greater 
length4 ,they will form the subject of a
 large part of the following section1   
where the models of ,batesian           
7,pseudaposematic7 mimicry are          
considered as well as the ,mullerian    
7,synaposematic7 combinations of        
,warning ,colours4                      
,,mimicry1--,,batesian ,,or             
,,pseudaposematic1 ,,mullerian ,,or     
,,synaposematic4  ,the existence of     
superficial resemblances between animals
 of various degrees of affinity must    
have been observed for hundreds of      
years4 ,among the early examples1 the   
best known to me have been found in the 
manuscript note-books and collections of
 ,w4,j4 ,burchell1 the great traveller  

in ,africa 7#ahaj-ae7 and ,brazil       
7#ahbe-cj74 ,the most interesting of his
 records on this subject are brought    
together in the following paragraphs4   
,conspicuous among well-defended insects
 are the dark steely or iridescent      
greenish blue fossorial wasps or        
sand-wasps1 ,sphex and the allied       
genera4 ,many ,longicorn beetles mimic  
these in colour1 slender shape of body  
and limbs1 rapid movements1 and the     
readiness with which they take to       
flight4 ,on ,dec4 #ba1 #ahab1 ,burchell 
captured one such beetle 7,promeces     
viridis7 at ,kosi ,fountain on the      
journey from the source of the ,kuruman 
,river to ,klaarwater4 ,it is correctly 
placed among the ,longicorns in his     
catalogue1 but opposite to its number is
 the comment ,sphex6 totus purpureus4   
,in our own country the black-and-yellow
 colouring of many stinging insects1    
especially the ordinary wasps1 affords  
perhaps the commonest model for mimicry4
 ,it is reproduced with more or less    

accuracy on moths1 flies and beetles4   
,among the latter it is again a         
,longicorn which offers one of the      
best-known1 although by no means one of 
the most perfect1 examples4 ,the        
appearance of the well-known wasp-beetle
 7,clytus arietis7 in the living state  
is sufficiently suggestive to prevent   
the great majority of people from       
touching it4 ,in ,burchell's ,brazilian 
collection there is a nearly allied     
species 7,neoclytus curvatus7 which     
appears to be somewhat less wasp-like   
than the ,british beetle4 ,the specimen 
bears the number #aahh1 and the date    
,march #bg1 #ahbg1 when ,burchell was   
collecting in the neighbourhood of ,san 
,paulo4 ,turning to the corresponding   
number in the ,brazilian note-book we   
find this record3 ,it runs rapidly like 
an ichneumon or wasp1 of which it has   
the appearance4  ,the formidable1       
well-defended ants are as freely        
mimicked by other insects as the        
sand-wasps1 ordinary wasps and bees4    

,thus on ,february #ag1 #aija1 ,guy     
,a4,k4 ,marshall captured1 near         
,salisbury1 ,mashonaland1 three similar 
species of ants 7,hymenoptera7 with a   
bug 7,hemiptera7 and a ,locustid        
7,orthoptera71 the two latter mimicking 
the former4 ,all the insects1 seven in  
number1 were caught on a single plant1 a
 small bushy vetch4 7,trans4 ,ent4 ,soc4
 ,lond4 #aijb1 page #ece1 plate ,,xix4  
figs4 #ec-ei47  ,this is an interesting 
recent example from ,south ,africa1 and 
large numbers of others might be        
added--the observations of many         
naturalists in many lands2 but nearly   
all of them known since that general    
awakening of interest in the subject    
which was inspired by the great         
hypotheses of ,h4,w4 ,bates and ,fritz  
,muller4 ,we find1 however1 that        
,burchell had more than once recorded   
the mimetic resemblance to ants4 ,an    
extremely ant-like bug 7the larva of a  
species of ,alydus7 in his ,brazilian   
collection is labelled #aada1 with the  

date ,december #h1 #ahbf1 when ,burchell
 was at the ,rio das ,pedras1 ,cubatao1 
near ,santos4 ,in the note-book the     
record is as follows3 #aada ,cimex4 ,i  
collected this for a ,formica4  ,some of
 the chief mimics of ants are the active
 little hunting spiders belonging to the
 family ,attidae4 ,examples have been   
brought forward during many recent      
years1 especially by my friends ,dr and 
,mrs ,peckham1 of ,milwaukee1 the great 
authorities on this group of ,araneae4  
,here too we find an observation of the 
mimetic resemblance recorded by         
,burchell1 and one which adds in the    
most interesting manner to our knowledge
 of the subject4 ,a fragment1 all that  
is now left1 of an ,attid spider1       
captured on ,june #cj1 #ahbh1 at ,goyaz1
 ,brazil1 bears the following note1 in  
this case on the specimen and not in the
 note-book3 ,black444 runs and seems    
like an ant with large extended jaws4   
,my friend ,mr ,r4,i4 ,pocock1 to whom  
,i have submitted the specimen1 tells me

 that it is not one of the group of     
species hitherto regarded as ant-like1  
and he adds1 ,it is most interesting    
that ,burchell should have noticed the  
resemblance to an ant in its movements4 
,this suggests that the perfect         
imitation in shape1 as well as in       
movement1 seen in many species was      
started in forms of an appropriate size 
and colour by the mimicry of movement   
alone4 ,up to the present time ,burchell
 is the only naturalist who has observed
 an example which still exhibits this   
ancestral stage in the evolution of     
mimetic likeness4  ,following the       
teachings of his day1 ,burchell was     
driven to believe that it was part of   
the fixed and inexorable scheme of      
things that these strange superficial   
resemblances existed4 ,thus1 when he    
found other examples of ,hemipterous    
mimics1 including one 7,luteva          
macrophthalma7 with exactly the manners 
of a ,mantis1 he added the sentence1 ,in
 the genus ,cimex 7,linn47 are to be    

found the outward resemblances of       
insects of many other genera and orders 
7,february #ae1 #ahbi74 ,of another     
,brazilian bug1 which is not to be found
 in his collection1 and cannot therefore
 be precisely identified1 he wrote3     
,cimex444 ,nature seems to have intended
 it to imitate a ,sphex1 both in colour 
and the rapid palpitating and movement  
of the antennae 7,november #ae1 #ahbf74 
,at the same time it is impossible not  
to feel the conviction that ,burchell   
felt the advantage of a likeness to     
stinging insects and to aggressive ants1
 just as he recognised the benefits     
conferred on desert plants by spines and
 by concealment4 ,such an interpretation
 of mimicry was perfectly consistent    
with the theological doctrines of his   
day4 7,see ,kirby and ,spence1 ,an      
,introduction to ,entomology 7#ast      
edition71 ,london1 ,vol4 ,,ii4 #ahag1   
page #bbc47  ,the last note ,i have     
selected from ,burchell's manuscript    
refers to one of the chief mimics of the

 highly protected ,lycid beetles4 ,the  
whole assemblage of ,african insects    
with a ,lycoid colouring forms a most   
important combination and one which has 
an interesting bearing upon the theories
 of ,bates and ,fritz ,muller4 ,this    
most wonderful set of mimetic forms1    
described in #aijb by ,guy ,a4,k4       
,marshall1 is composed of               
flower-haunting beetles belonging to the
 family ,lycidae1 and the heterogeneous 
group of varied insects which mimic     
their conspicuous and simple scheme of  
colouring4 ,the ,lycid beetles1 forming 
the centre or models of the whole       
company1 are orange-brown in front for  
about two-thirds of the exposed surface1
 black behind for the remaining third4  
,they are undoubtedly protected by      
qualities which make them excessively   
unpalatable to the bulk of insect-eating
 animals4 ,some experimental proof of   
this has been obtained by ,mr ,guy      
,marshall4 ,what are the forms which    
surround them8 ,according to the        

hypothesis of ,bates they would be1 at  
any rate mainly1 palatable hard-pressed 
insects which only hold their own in the
 struggle for life by a fraudulent      
imitation of the trade-mark of the      
successful and powerful ,lycidae4       
,according to ,fritz ,muller's          
hypothesis we should expect that the    
mimickers would be highly protected1    
successful and abundant species1 which  
7metaphorically speaking7 have found it 
to their advantage to possess an        
advertisement1 a danger-signal1 in      
common with each other1 and in common   
with the beetles in the centre of the   
group4  ,how far does the constitution  
of this wonderful combination--the      
largest and most complicated as yet     
known in all the world--convey to us the
 idea of mimicry working along the lines
 supposed by ,bates or those suggested  
by ,muller8 ,figures #a to #eb of ,mr   
,marshall's coloured plate 7,trans4     
,ent4 ,soc4 ,lond4 #aijb1 plate ,,xviii4
 ,see also page #eag1 where the group is

 analysed47 represent a set of forty-two
 or forty-three species or forms of     
insects captured in ,mashonaland1 and   
all except two in the neighbourhood of  
,salisbury4 ,the combination includes   
six species of ,lycidae2 nine beetles of
 five groups all specially protected by 
nauseous qualities1 ,telephoridae1      
,melyridae1 ,phytophaga1 ,lagriidae1    
,cantharidae2 six ,longicorn beetles2   
one ,coprid beetle2 eight stinging      
,hymenoptera2 three or four parasitic   
,hymenoptera 7,braconidae1 a group much 
mimicked and shown by some experiments  
to be distasteful72 five bugs           
7,hemiptera1 a largely unpalatable      
group72 three moths 7,arctiidae and     
,zygaenidae1 distasteful families72 one 
fly4 ,in fact the whole combination1    
except perhaps one ,phytophagous1 one   
,coprid and the ,longicorn beetles1 and 
the fly1 fall under the hypothesis of   
,muller and not under that of ,bates4   
,and it is very doubtful whether these  
exceptions will be sustained3 indeed the

 suspicion of unpalatability already    
besets the ,longicorns and is always on 
the heels1--,i should say the hind      
tarsi--of a ,phytophagous beetle4  ,this
 most remarkable group which illustrates
 so well the problem of mimicry and the 
alternative hypotheses proposed for its 
solution1 was1 as ,i have said1 first   
described in #aijb4 ,among the most     
perfect of the mimetic resemblances in  
it is that between the ,longicorn       
beetle1 ,amphidesmus analis1 and the    
,lycidae4 ,it was with the utmost       
astonishment and pleasure that ,i found 
this very resemblance had almost        
certainly been observed by ,burchell4 ,a
 specimen of the ,amphidesmus exists in 
his collection and it bears #fea4       
,turning to the same number in the      
,african ,catalogue we find that the    
beetle is correctly placed among the    
,longicorns1 that it was captured at    
,uitenhage on ,nov4 #ah1 #ahac1 and that
 it was found associated with ,lycid    
beetles in flowers 7consocians cum      

,lycis #gh-hg in floribus74 ,looking up 
,nos4 #gh-hg in the collection and      
catalogue1 three species of ,lycidae are
 found1 all captured on ,nov4 #ah1      
#ahac1 at ,uitenhage4 ,burchell         
recognised the wide difference in       
affinity1 shown by the distance between 
the respective numbers2 for his         
catalogue is arranged to represent      
relationships4 ,he observed1 what       
students of mimicry are only just       
beginning to note and record1 the       
coincidence between model and mimic in  
time and space and in habits4 ,we are   
justified in concluding that he observed
 the close superficial likeness although
 he does not in this case expressly     
allude to it4  ,one of the most         
interesting among the early observations
 of superficial resemblance between     
forms remote in the scale of            
classification was made by ,darwin      
himself1 as described in the following  
passage from his letter to ,henslow1    
written from ,monte ,video1 ,aug4 #ae1  

#ahcb3 ,amongst the lower animals       
nothing has so much interested me as    
finding two species of elegantly        
coloured true ,planaria inhabiting the  
dewy forest6 ,the false relation they   
bear to snails is the most extraordinary
 thing of the kind ,i have ever seen4   
7,more ,letters1 ,i4 page #i47  ,many   
years later1 in #ahfg1 he wrote to      
,fritz ,muller suggesting that the      
resemblance of a soberly coloured       
,british ,planarian to a slug might be  
due to mimicry4 7,life and ,letters1    
,,iii4 page #ga47  ,the most interesting
 copy of ,bates's classical memoir on   
,mimicry 7,contributions to an ,insect  
,fauna of the ,amazon ,valley4 ,trans4  
,linn4 ,soc4 ,vol4 ,,xxiii4 #ahfb1 page 
#die471 read before the ,linnean        
,society in #ahfa1 is that given by him 
to the man who has done most to support 
and extend the theory4 ,my kind friend  
has given that copy to me2 it bears the 
inscription3  ,mr ,a4,r4 ,wallace from  
his old travelling companion the        

,author4  ,only a year and a half after 
the publication of the ,origin1 we find 
that ,darwin wrote to ,bates on the     
subject which was to provide such       
striking evidence of the truth of       
,natural ,selection3 ,i am glad to hear 
that you have specially attended to     
'mimetic' analogies--a most curious     
subject2 ,i hope you publish on it4 ,i  
have for a long time wished to know     
whether what ,dr ,collingwood asserts is
 true--that the most striking cases     
generally occur between insects         
inhabiting the same country4 7,the      
letter is dated ,april #d1 #ahfa4 ,more 
,letters1 ,i4 page #ahc47  ,the next    
letter1 written about six months later1 
reveals the remarkable fact that the    
illustrious naturalist who had          
anticipated ,edward ,forbes in the      
explanation of arctic forms on alpine   
heights 7,i was forestalled in only one 
important point1 which my vanity has    
always made me regret1 namely1 the      
explanation by means of the ,glacial    

period of the presence of the same      
species of plants and of some few       
animals on distant mountain summits and 
in the arctic regions4 ,this view       
pleased me so much that ,i wrote it out 
in extenso1 and ,i believe that it was  
read by ,hooker some years before ,e4   
,forbes published his celebrated memoir 
on the subject4 ,in the very few points 
in which we differed1 ,i still think    
that ,i was in the right4 ,i have never1
 of course1 alluded in print to my      
having independently worked out this    
view4 ,autobiography1 ,life and         
,letters1 ,i4 page #hh471 had also      
anticipated ,h4,w4 ,bates in the theory 
of ,mimicry3 ,what a capital paper yours
 will be on mimetic resemblances6 ,you  
will make quite a new subject of it4 ,i 
had thought of such cases as a          
difficulty2 and once1 when corresponding
 with ,dr ,collingwood1 ,i thought of   
your explanation2 but ,i drove it from  
my mind1 for ,i felt that ,i had not    
knowledge to judge one way or the other4

 7,the letter is dated ,sept4 #be1      
#ahfa3 ,more ,letters1 ,i4 page #aig47  
,bates read his paper before the        
,linnean ,society1 ,nov4 #ba1 #ahfa1 and
 ,darwin's impressions on hearing it    
were conveyed in a letter to the author 
dated ,dec4 #c3 ,under a general point  
of view1 ,i am quite convinced 7,hooker 
and ,huxley took the same view some     
months ago7 that a philosophic view of  
nature can solely be driven into        
naturalists by treating special subjects
 as you have done4 ,under a special     
point of view1 ,i think you have solved 
one of the most perplexing problems     
which could be given to solve4 7,life   
and ,letters1 ,,ii4 page #cgh47 ,the    
memoir appeared in the following year1  
and after reading it ,darwin wrote as   
follows1 ,nov4 #bj1 #ahfb3 444 ,in my   
opinion it is one of the most remarkable
 and admirable papers ,i ever read in my
 life444 ,i am rejoiced that ,i passed  
over the whole subject in the ,origin1  
for ,i should have made a precious mess 

of it4 ,you have most clearly stated and
 solved a wonderful problem444 ,your    
paper is too good to be largely         
appreciated by the mob of naturalists   
without souls2 but1 rely on it1 that it 
will have ,,lasting value1 and ,i       
cordially congratulate you on your first
 great work4 ,you will find1 ,i should  
think1 that ,wallace will fully         
appreciate it4 7,life and ,letters1     
,,ii4 pages #cia-cic47 ,four days later1
 ,nov4 #bd1 ,darwin wrote to ,hooker on 
the same subject3 ,i have now finished  
his paper444' it seems to me admirable4 
,to my mind the act of segregation of   
varieties into species was never so     
plainly brought forward1 and there are  
heaps of capital miscellaneous          
observations4 7,more ,letters1 ,i4 page 
#bad47  ,darwin was here referring to   
the tendency of similar varieties of the
 same species to pair together1 and on  
,nov4 #be he wrote to ,bates asking for 
fuller information on this subject4     
7,more ,letters1 ,i4 page #bae4 ,see    

also parts of ,darwin's letter to ,bates
 in ,life and ,letters1 ,,ii4 page      
#cib47 ,if ,bates's opinion were well   
founded1 sexual selection would bear a  
most important part in the establishment
 of such species4 7,see ,poulton1       
,essays on ,evolution1 #aijh1 pages #fe1
 #he-hh47 ,it must be admitted1 however1
 that the evidence is as yet quite      
insufficient to establish this          
conclusion4 ,it is interesting to       
observe how ,darwin at once fixed on the
 part of ,bates's memoir which seemed to
 bear upon sexual selection4 ,a review  
of ,bates's theory of ,mimicry was      
contributed by ,darwin to the ,natural  
,history ,review 7,new ,ser4 ,vol4      
,,iii4 #ahfc1 page #bai47 and an account
 of it is to be found in the ,origin    
7,edition #ahgb1 pages #cge-cgh47 and in
 ,the ,descent of ,man4 7,edition #ahgd1
 pages #cbc-cbe47  ,darwin continually  
writes of the value of hypothesis as the
 inspiration of inquiry4 ,we find an    
example in his letter to ,bates1 ,nov4  

#bb1 #ahfj3 ,i have an old belief that a
 good observer really means a good      
theorist1 and ,i fully expect to find   
your observations most valuable4 7,more 
,letters1 ,i4 page #agf47 ,darwin's     
letter refers to many problems upon     
which ,bates had theorised and observed1
 but as regards ,mimicry itself the     
hypothesis was thought out after the    
return of the letter from the ,amazons1 
when he no longer had the opportunity of
 testing it by the observation of living
 ,nature4 ,it is by no means improbable 
that1 had he been able to apply this    
test1 ,bates would have recognised that 
his division of butterfly resemblances  
into two classes1--one due to the theory
 of mimicry1 the other to the influence 
of local conditions1--could not be      
sustained4  ,fritz ,muller's            
contributions to the problem of ,mimicry
 were all made in ,s4,e4 ,brazil1 and   
numbers of them were communicated1 with 
other observations on natural history1  
to ,darwin1 and by him sent to          

,professor ,r4 ,meldola who published   
many of the facts4 ,darwin's letters to 
,meldola 7,poulton1 ,charles ,darwin and
 the theory of ,natural ,selection1     
,london1 #ahif1 pages #aii-bah47 contain
 abundant proofs of his interest in     
,muller's work upon ,mimicry4 ,one      
deeply interesting letter 7,loc4 cit4   
pages #bja1 #bjb47 dated ,jan4 #bc1     
#ahgb1 proves that ,fritz ,muller before
 he originated the theory of ,common    
,warning ,colours 7,synaposematic       
,resemblance or ,mullerian ,mimicry71   
which will ever be associated with his  
name1 had conceived the idea of the     
production of mimetic likeness by sexual
 selection4  ,darwin's letter to        
,meldola shows that he was by no means  
inclined to dismiss the suggestion as   
worthless1 although he considered it    
daring4 ,you will also see in this      
letter a strange speculation1 which ,i  
should not dare to publish1 about the   
appreciation of certain colours being   
developed in those species which        

frequently behold other forms similarly 
ornamented4 ,i do not feel at all sure  
that this view is as incredible as it   
may at first appear4 ,similar ideas have
 passed through my mind when considering
 the dull colours of all the organisms  
which inhabit dull-coloured regions1    
such as ,patagonia and the ,galapagos   
,is4 ,a little later1 on ,april #e1 he  
wrote to ,professor ,august ,weismann on
 the same subject3 ,it may be suspected 
that even the habit of viewing          
differently coloured surrounding objects
 would influence their taste1 and ,fritz
 ,muller even goes so far as to believe 
that the sight of gaudy butterflies     
might influence the taste of distinct   
species4 7,life and ,letters1 ,,iii4    
page #aeg47  ,this remarkable suggestion
 affords interesting evidence that ,f4  
,muller was not satisfied with the      
sufficiency of ,bates's theory4 ,nor is 
this surprising when we think of the    
numbers of abundant conspicuous         
butterflies which he saw exhibiting     

mimetic likenesses4 ,the common         
instances in his locality1 and indeed   
everywhere in tropical ,america1 were   
anything but the hard-pressed struggling
 forms assumed by the theory of ,bates4 
,they belonged to the groups which were 
themselves mimicked by other            
butterflies4 ,fritz ,muller's suggestion
 also shows that he did not accept      
,bates's alternative explanation of a   
superficial likeness between models     
themselves1 based on some unknown       
influence of local physico-chemical     
forces4 ,at the same time ,muller's own 
suggestion was subject to this          
apparently fatal objection1 that the    
sexual selection he invoked would tend  
to produce resemblances in the males    
rather than the females1 while it is    
well known that when the sexes differ   
the females are almost invariably more  
perfectly mimetic than the males and in 
a high proportion of cases are mimetic  
while the males are non-mimetic4  ,the  
difficulty was met several years later  

by ,fritz ,muller's well-known theory1  
published in #ahgi 7,kosmos1 ,may #ahgi1
 page #ajj471 and immediately translated
 by ,meldola and brought before the     
,entomological ,society4 7,proc4 ,ent4  
,soc4 ,lond4 #ahgi1 page xx47 ,darwin's 
letter to ,meldola dated ,june #f1      
#ahgi1 shows that the first introduction
 of this new and most suggestive        
hypothesis into this country was due to 
the direct influence of ,darwin himself1
 who brought it before the notice of the
 one man who was likely to appreciate it
 at its true value and to find the means
 for its presentation to ,english       
naturalists4 7,charles ,darwin and the  
,theory of ,natural ,selection1 page    
#bad47 ,of the hypothesis itself ,darwin
 wrote ,f4 ,muller's view of the mutual 
protection was quite new to me4 7,ibid4 
page #bac47 ,the hypothesis of          
,mullerian mimicry was at first strongly
 opposed4 ,bates himself could never    
make up his mind to accept it4 ,as the  
,fellows were walking out of the meeting

 at which ,professor ,meldola explained 
the hypothesis1 an eminent entomologist1
 now deceased1 was heard to say to      
,bates3 ,it's a case of save me from my 
friends6 ,the new ideas encountered and 
still encounter to a great extent the   
difficulty that the theory of ,bates had
 so completely penetrated the literature
 of natural history4 ,the present writer
 has observed that naturalists who have 
not thoroughly absorbed the older       
hypothesis are usually far more         
impressed by the newer one than are     
those whose allegiance has already been 
rendered4 ,the acceptance of ,natural   
,selection itself was at first hindered 
by similar causes1 as ,darwin clearly   
recognised3 ,if you argue about the     
non-acceptance of ,natural ,selection1  
it seems to me a very striking fact that
 the ,newtonian theory of gravitation1  
which seems to every one now so certain 
and plain1 was rejected by a man so     
extraordinarily able as ,leibnitz4 ,the 
truth will not penetrate a preoccupied  

mind4 7,to ,sir ,j4 ,hooker1 ,july #bh1 
#ahfh1 ,more ,letters1 ,i4 page #cje4   
,see also the letter to ,a4,r4 ,wallace1
 ,april #cj1 #ahfh1 in ,more ,letters   
,,ii4 page #gg1 lines #f-h from top47   
,there are many naturalists1 especially 
students of insects1 who appear to      
entertain an inveterate hostility to any
 theory of mimicry4 ,some of them are   
eager investigators in the fascinating  
field of geographical distribution1 so  
essential for the study of ,mimicry     
itself4 ,the changes of pattern         
undergone by a species of ,erebia as we 
follow it over different parts of the   
mountain ranges of ,europe is indeed a  
most interesting inquiry1 but not more  
so than the differences between e4g4 the
 ,acraea johnstoni of ,s4,e4 ,rhodesia  
and of ,kilimanjaro4 ,a naturalist who  
is interested by the ,erebia should be  
equally interested by the ,acraea2 and  
so he would be if the student of mimicry
 did not also record that the           
characteristics which distinguish the   

northern from the southern individuals  
of the ,african species correspond with 
the presence1 in the north but not in   
the south1 of certain entirely different
 butterflies4 ,that this additional     
information should so greatly weaken1 in
 certain minds1 the appeal of a         
favourite study1 is a psychological     
problem of no little interest4 ,this    
curious antagonism is ,i believe        
confined to a few students of insects4  
,those naturalists who1 standing rather 
farther off1 are able to see the        
bearings of the subject more clearly1   
will usually admit the general support  
yielded by an ever-growing mass of      
observations to the theories of ,mimicry
 propounded by ,h4,w4 ,bates and ,fritz 
,muller4 ,in like manner natural        
selection itself was in the early days  
often best understood and most readily  
accepted by those who were not          
naturalists4 ,thus ,darwin wrote to     
,d4,t4 ,ansted1 ,oct4 #bg1 #ahfj3 ,i am 
often in despair in making the          

generality of ,,naturalists even        
comprehend me4 ,intelligent men who are 
not naturalists and have not a bigoted  
idea of the term species1 show more     
clearness of mind4 7,more ,letters1 ,i4 
page #age47  ,even before the ,origin   
appeared ,darwin anticipated the first  
results upon the mind of naturalists4   
,he wrote to ,asa ,gray1 ,dec4 #ba1     
#ahei3 ,i have made up my mind to be    
well abused2 but ,i think it of         
importance that my notions should be    
read by intelligent men1 accustomed to  
scientific argument1 though ,,not       
naturalists4 ,it may seem absurd1 but ,i
 think such men will drag after them    
those naturalists who have too firmly   
fixed in their heads that a species is  
an entity4 7,life and ,letters ,,ii4    
page #bde47  ,mimicry was not only one  
of the first great departments of       
zoological knowledge to be studied under
 the inspiration of natural ,selection1 
it is still and will always remain one  
of the most interesting and important of

 subjects in relation to this theory as 
well as to evolution4 ,in mimicry we    
investigate the effect of environment in
 its simplest form3 we trace the effects
 of the pattern of a single species upon
 that of another far removed from it in 
the scale of classification4 ,when there
 is reason to believe that the model is 
an invader from another region and has  
only recently become an element in the  
environment of the species native to its
 second home1 the problem gains a       
special interest and fascination4       
,although we are chiefly dealing with   
the fleeting and changeable element of  
colour we expect to find and we do find 
evidence of a comparatively rapid       
evolution4 ,the invasion of a fresh     
model is for certain species an         
unusually sudden change in the forces of
 the environment and in some instances  
we have grounds for the belief that the 
mimetic response has not been long      
delayed4  ,,mimicry ,,and ,,sex4  ,ever 
since ,wallace's classical memoir on    

mimicry in the ,malayan ,swallowtail    
butterflies1 those naturalists who have 
written on the subject have followed his
 interpretation of the marked prevalence
 of mimetic resemblance in the female   
sex as compared with the male4 ,they    
have believed with ,wallace that the    
greater dangers of the female1 with     
slower flight and often alighting for   
oviposition1 have been in part met by   
the high development of this special    
mode of protection4 ,the fact cannot be 
doubted4 ,it is extremely common for a  
non-mimetic male to be accompanied by a 
beautifully mimetic female and often by 
two or three different forms of female1 
each mimicking a different model4 ,the  
male of a polymorphic mimetic female is1
 in fact1 usually non-mimetic 7e4g4     
,papilio dardanus  merope71 or if a     
mimic 7e4g4 the ,nymphaline genus       
,euripus71 resembles a very different   
model4 ,on the other hand a non-mimetic 
female accompanied by a mimetic male is 
excessively rare4 ,an example is        

afforded by the ,oriental ,nymphaline1  
,cethosia1 in which the males of some   
species are rough mimics of the brown   
,danaines4 ,in some of the orb-weaving  
spiders the males mimic ants1 while the 
much larger females are non-mimetic4    
,when both sexes mimic1 it is very      
common in butterflies and is also known 
in moths1 for the females to be better  
and often far better mimics than the    
males4  ,although still believing that  
,wallace's hypothesis in large part     
accounts for the facts briefly          
summarised above1 the present writer has
 recently been led to doubt whether it  
offers a complete explanation4 ,mimicry 
in the male1 even though less beneficial
 to the species than mimicry in the     
female1 would still surely be           
advantageous4 ,why then is it so often  
entirely restricted to the female8      
,while the attempt to find an answer to 
this question was haunting me1 ,i       
re-read a letter written by ,darwin to  
,wallace1 ,april #ae1 #ahfh1 containing 

the following sentences3 ,when female   
butterflies are more brilliant than     
their males you believe that they have  
in most cases1 or in all cases1 been    
rendered brilliant so as to mimic some  
other species1 and thus escape danger4  
,but can you account for the males not  
having been rendered equally brilliant  
and equally protected8 ,although it may 
be most for the welfare of the species  
that the female should be protected1 yet
 it would be some advantage1 certainly  
no disadvantage1 for the unfortunate    
male to enjoy an equal immunity from    
danger4 ,for my part1 ,i should say that
 the female alone had happened to vary  
in the right manner1 and that the       
beneficial variations had been          
transmitted to the same sex alone4      
,believing in this1 ,i can see no       
improbability 7but from analogy of      
domestic animals a strong probability7  
that variations leading to beauty must  
often have occurred in the males alone1 
and been transmitted to that sex alone4 

,thus ,i should account in many cases   
for the greater beauty of the male over 
the female1 without the need of the     
protective principle4 7,more ,letters1  
,,ii4 pages #gc1 #gd4 ,on the same      
subject--the gay-coloured females of    
,pieris 7,perrhybris 7,mylothris7 pyrrha
 of ,brazil71 ,darwin wrote to ,wallace1
 ,may #e1 #ahfh1 as follows3 ,i believe 
,i quite follow you in believing that   
the colours are wholly due to mimicry2  
and ,i further believe that the male is 
not brilliant from not having received  
through inheritance colour from the     
female1 and from not himself having     
varied2 in short1 that he has not been  
influenced by selection4 ,it should be  
noted that the male of this species does
 exhibit a mimetic pattern on the under 
surface4 ,more ,letters ,,ii4 page #gh47
  ,the consideration of the facts of    
mimicry thus led ,darwin to the         
conclusion that the female happens to   
vary in the right manner more commonly  
than the male1 while the secondary      

sexual characters of males supported the
 conviction that from some unknown cause
 such characters 7viz4 new characters   
arising in one sex and transmitted to it
 alone7 apparently appear oftener in the
 male than in the female4 7,letter from 
,darwin to ,wallace1 ,may #e1 #ahfg1    
,more ,letters1 ,,ii4 ,page #fa47       
,comparing these conflicting arguments  
we are led to believe that the first is 
the stronger4 ,mimicry in the male would
 be no disadvantage but an advantage1   
and when it appears would be and is     
taken advantage of by selection4 ,the   
secondary sexual characters of males    
would be no advantage but a disadvantage
 to females1 and1 as ,wallace thinks1   
are withheld from this sex by selection4
 ,it is indeed possible that mimicry has
 been hindered and often prevented from 
passing to the males by sexual          
selection4 ,we know that ,darwin was    
much impressed 7,descent of ,man1 page  
#cbe47 by ,thomas ,belt's daring and    
brilliant suggestion that the white     

patches which exist1 although ordinarily
 concealed1 on the wings of mimetic     
males of certain ,pierinae              
7,dismorphia71 have been preserved by   
preferential mating4 ,he supposed this  
result to have been brought about by the
 females exhibiting a deep-seated       
preference for males that displayed the 
chief ancestral colour1 inherited from  
periods before any mimetic pattern had  
been evolved in the species4 ,but it has
 always appeared to me that ,belt's     
deeply interesting suggestion requires  
much solid evidence and repeated        
confirmation before it can be accepted  
as a valid interpretation of the facts4 
,in the present state of our knowledge1 
at any rate of insects and especially of
 ,lepidoptera1 it is probable that the  
female is more apt to vary than the male
 and that an important element in the   
interpretation of prevalent female      
mimicry is provided by this fact4  ,in  
order adequately to discuss the question
 of mimicry and sex it would be         

necessary to analyse the whole of the   
facts1 so far as they are known in      
butterflies4 ,on the present occasion it
 is only possible to state the          
inferences which have been drawn from   
general impressions1--inferences which  
it is believed will be sustained by     
future inquiry4  7#a7 ,mimicry may      
occasionally arise in one sex because   
the differences which distinguish it    
from the other sex happen to be such as 
to afford a starting-point for the      
resemblance4 ,here the male is at no    
disadvantage as compared with the       
female1 and the rarity of mimicry in the
 male alone 7e4g4 ,cethosia7 is evidence
 that the great predominance of female  
mimicry is not to be thus explained4    
7#b7 ,the tendency of the female to     
dimorphism and polymorphism has been of 
great importance in determining this    
predominance4 ,thus if the female appear
 in two different forms and the male in 
only one it will be twice as probable   
that she will happen to possess a       

sufficient foundation for the evolution 
of mimicry4  7#c7 ,the appearance of    
melanic or partially melanic forms in   
the female has been of very great       
service1 providing as it does a change  
of ground-colour4 ,thus the mimicry of  
the black generally red-marked ,american
 ,aristolochia swallowtails             
7,pharmacophagus7 by the females of     
,papilio swallowtails was probably begun
 in this way4  7#d7 ,it is probably     
incorrect to assume with ,haase that    
mimicry always arose in the female and  
was later acquired by the male4 ,both   
sexes of the third section of           
swallowtails 7,cosmodesmus7 mimic       
,pharmacophagus in ,america1 far more   
perfectly than do the females of        
,papilio4 ,but this is not due to       
,cosmodesmus presenting us with a later 
stage of history begun in ,papilio2 for 
in ,africa ,cosmodesmus is still mimetic
 7of ,danainae7 in both sexes although  
the resemblances attained are imperfect1
 while many ,african species of ,papilio

 have non-mimetic males with beautifully
 mimetic females4 ,the explanation is   
probably to be sought in the fact that  
the females of ,papilio are more        
variable and more often tend to become  
dimorphic than those of ,cosmodesmus1   
while the latter group has more often   
happened to possess a sufficient        
foundation for the origin of the        
resemblance in patterns which1 from the 
start1 were common to male and female4  
7#e7 ,in very variable species with     
sexes alike1 mimicry can be rapidly     
evolved in both sexes out of very small 
beginnings4 ,thus the reddish marks     
which are common in many individuals of 
,limenitis arthemis were almost         
certainly the starting-point for the    
evolution of the beautifully mimetic ,l4
 archippus4 ,nevertheless in such cases1
 although there is no reason to suspect 
any greater variability1 the female is  
commonly a somewhat better mimic than   
the male and often a very much better   
mimic4 ,wallace's principle seems here  

to supply the obvious interpretation4   
7#f7 ,when the difference between the   
patterns of the model and presumed      
ancestor of the mimic is very great1 the
 female is often alone mimetic2 when the
 difference is comparatively small1 both
 sexes are commonly mimetic4 ,the       
,nymphaline genus ,hypolimnas is a good 
example4 ,in ,hypolimnas itself the     
females mimic ,danainae with patterns   
very different from those preserved by  
the non-mimetic males3 in the sub-genus 
,euralia1 both sexes resemble the black 
and white ,ethiopian ,danaines with     
patterns not very dissimilar from that  
which we infer to have existed in the   
non-mimetic ancestor4  7#g7 ,although a 
melanic form or other large variation   
may be of the utmost importance in      
facilitating the start of a mimetic     
likeness1 it is impossible to explain   
the evolution of any detailed           
resemblance in this manner4 ,and even   
the large colour variation itself may   
well be the expression of a minute and  

continuous change in the chemical and   
physical constitution of pigments4      
,,sexual ,,selection 7,,epigamic        
,,characters74  ,we do not know the date
 at which the idea of ,sexual ,selection
 arose in ,darwin's mind1 but it was    
probably not many years after the sudden
 flash of insight which1 in ,october    
#ahch1 gave to him the theory of        
,natural ,selection4 ,an excellent      
account of ,sexual ,selection occupies  
the concluding paragraph of ,part ,i4 of
 ,darwin's ,section of the ,joint ,essay
 on ,natural ,selection1 read ,july     
#ast1 #aheh1 before the ,linnean        
,society4 7,journ4 ,proc4 ,linn4 ,soc4  
,vol4 ,,iii4 #ahei1 page #ej47 ,the     
principles are so clearly and           
sufficiently stated in these brief      
sentences that it is appropriate to     
quote the whole3 ,besides this natural  
means of selection1 by which those      
individuals are preserved1 whether in   
their egg1 or larval1 or mature state1  
which are best adapted to the place they

 fill in nature1 there is a second      
agency at work in most unisexual        
animals1 tending to produce the same    
effect1 namely1 the struggle of the     
males for the females4 ,these struggles 
are generally decided by the law of     
battle1 but in the case of birds1       
apparently1 by the charms of their song1
 by their beauty or their power of      
courtship1 as in the dancing rock-thrush
 of ,guiana4 ,the most vigorous and     
healthy males1 implying perfect         
adaptation1 must generally gain the     
victory in their contests4 ,this kind of
 selection1 however1 is less rigorous   
than the other2 it does not require the 
death of the less successful1 but gives 
to them fewer descendants4 ,the struggle
 falls1 moreover1 at a time of year when
 food is generally abundant1 and perhaps
 the effect chiefly produced would be   
the modification of the secondary sexual
 characters1 which are not related to   
the power of obtaining food1 or to      
defence from enemies1 but to fighting   

with or rivalling other males4 ,the     
result of this struggle amongst the     
males may be compared in some respects  
to that produced by those agriculturists
 who pay less attention to the careful  
selection of all their young animals1   
and more to the occasional use of a     
choice mate4  ,a full exposition of     
,sexual ,selection appeared in the ,the 
,descent of ,man in #ahga1 and in the   
greatly augmented second edition1 in    
#ahgd4 ,it has been remarked that the   
two subjects1 ,the ,descent of ,man and 
,selection in ,relation to ,sex1 seem to
 fuse somewhat imperfectly into the     
single work of which they form the      
title4 ,the reason for their association
 is clearly shown in a letter to        
,wallace1 dated ,may #bh1 #ahfd3 444 ,i 
suspect that a sort of sexual selection 
has been the most powerful means of     
changing the races of man4 7,more       
,letters1 ,,ii4 page #cc47  ,darwin1 as 
we know from his ,autobiography 7,life  
and ,letters1 ,i4 page #id471 was always

 greatly interested in this hypothesis1 
and it has been shown in the preceding  
pages that he was inclined to look      
favourably upon it as an interpretation 
of many appearances usually explained by
 ,natural ,selection4 ,hence ,sexual    
,selection1 incidentally discussed in   
other sections of the present essay1    
need not be considered at any length1 in
 the section specially allotted to it4  
,although so interested in the subject  
and notwithstanding his conviction that 
the hypothesis was sound1 ,darwin was   
quite aware that it was probably the    
most vulnerable part of the ,origin4    
,thus he wrote to ,h4,w4 ,bates1 ,april 
#d1 #ahfa3 ,if ,i had to cut up myself  
in a review ,i would have 7worried87 and
 quizzed sexual selection2 therefore1   
though ,i am fully convinced that it is 
largely true1 you may imagine how       
pleased ,i am at what you say on your   
belief4 7,more ,letters1 ,i4 page #ahc47
  ,the existence of sound-producing     
organs in the males of insects was1     

,darwin considered1 the strongest       
evidence in favour of the operation of  
sexual selection in this group4 7,life  
and ,letters1 ,,iii4 pages #id1 #ach47  
,such a conclusion has received strong  
support in recent years by the numerous 
careful observations of ,dr ,f4,a4      
,dixey 7,proc4 ,ent4 ,soc4 ,lond4 #aijd1
 page lvi2 #aije1 pages xxxvii1 liv2    
#aijf1 page ii47 and ,dr ,g4,b4         
,longstaff 7,proc4 ,ent4 ,soc4 ,lond4   
#aije1 page xxxv2 ,trans4 ,ent4 ,soc4   
,lond4 #aije1 page #acf2 #aijh1 page    
#fjg47 on the scents of male            
butterflies4 ,the experience of these   
naturalists abundantly confirms and     
extends the account given by ,fritz     
,muller 7,jen4 ,zeit4 ,vol4 ,,xi4 #ahgg1
 page #ii2 ,trans4 ,ent4 ,soc4 ,lond4   
#ahgh1 page #baa47 of the scents of     
certain ,brazilian butterflies4 ,it is a
 remarkable fact that the apparently    
epigamic scents of male butterflies     
should be pleasing to man while the     
apparently aposematic scents in both    

sexes of species with warning colours   
should be displeasing to him4 ,but the  
former is far more surprising than the  
latter4 ,it is not perhaps astonishing  
that a scent which is ex hypothesi      
unpleasant to an insect-eating          
,vertebrate should be displeasing to the
 human sense2 but it is certainly       
wonderful that an odour which is ex     
hypothesi agreeable to a female         
butterfly should also be agreeable to   
man4  ,entirely new light upon the      
seasonal appearance of epigamic         
characters is shed by the recent        
researches of ,c4,w4 ,beebe 7,the       
,american ,naturalist1 ,vol4 ,,xlii4    
,no4 #dic1 ,jan4 #aijh1 page #cd471 who 
caused the scarlet tanager 7,piranga    
erythromelas7 and the bobolink          
7,dolichonyx oryzivorus7 to retain their
 breeding plumage through the whole year
 by means of fattening food1 dim        
illumination1 and reduced activity4     
,gradual restoration to the light and   
the addition of meal-worms to the diet  

invariably brought back the spring song1
 even in the middle of winter4 ,a sudden
 alteration of temperature1 either      
higher or lower1 caused the birds nearly
 to stop feeding1 and one tanager lost  
weight rapidly and in two weeks moulted 
into the olive-green winter plumage4    
,after a year1 and at the beginning of  
the normal breeding season1 individual  
tanagers and bobolinks were gradually   
brought under normal conditions and     
activities1 and in every case moulted   
from nuptial plumage to nuptial plumage4
 ,the dull colours of the winter season 
had been skipped4 ,the author justly    
claims to have established that the     
sequence of plumage in these birds is   
not in any way predestined through      
inheritance4441 but that it may be      
interrupted by certain factors in the   
environmental complex4     ,,xvi4       
,,geographical ,,distribution ,,of      
,,plants4 ,by ,sir ,william             
,thiselton-,dyer1 ,k4,c4,m4,g41         
,c4,i4,e4 ,sc4,d41 ,f4,r4,s4  ,the      

publication of ,the ,origin of ,species 
placed the study of ,botanical          
,geography on an entirely new basis4 ,it
 is only necessary to study the         
monumental ,geographie ,botanique       
raisonnee of ,alphonse ,de ,candolle1   
published four years earlier 7#ahee71 to
 realise how profound and far-reaching  
was the change4 ,after a masterly and   
exhaustive discussion of all available  
data ,de ,candolle in his final         
conclusions could only arrive at a      
deadlock4 ,it is sufficient to quote a  
few sentences3--  ,l'opinion de ,lamarck
 est aujourd'hui abandonee par tous les 
naturalistes qui ont etudie sagement les
 modifications possibles des etres      
organises444  ,et si l'on s'ecarte des  
exagerations de ,lamarck1 si l'on       
suppose un premier type de chaque genre1
 de chaque famille tout au moins1 on se 
trouve encore a l'egard de l'origine de 
ces types en presence de la grande      
question de la creation4  ,le seul parti
 a prendre est donc d'envisager les     

etres organises comme existant depuis   
certaines epoques1 avec leurs qualites  
particulieres4 7,vol4 ,,ii4 page #aajg47
  ,reviewing the position fourteen years
 afterwards1 ,bentham remarked3--,these 
views1 generally received by the great  
majority of naturalists at the time ,de 
,candolle wrote1 and still maintained by
 a few1 must1 if adhered to1 check all  
further enquiry into any connection of  
facts with causes1 and he added1 there  
is little doubt but that if ,de         
,candolle were to revise his work1 he   
would follow the example of so many     
other eminent naturalists1 and444 insist
 that the present geographical          
distribution of plants was in most      
instances a derivative one1 altered from
 a very different former distribution4  
7,pres4 ,addr4 7#ahfi7 ,proc4 ,linn4    
,soc4 #ahfh-fi1 page lxviii47  ,writing 
to ,asa ,gray in #ahef1 ,darwin gave a  
brief preliminary account of his ideas  
as to the origin of species1 and said   
that geographical distribution must be  

one of the tests of their validity4     
7,life and ,letters1 ,,ii4 page #gh47   
,what is of supreme interest is that it 
was also their starting-point4 ,he tells
 us3--,when ,i visited1 during the      
voyage of ,h4,m4,s4 ,beagle1 the        
,galapagos ,archipelago1444 ,i fancied  
myself brought near to the very act of  
creation4 ,i often asked myself how     
these many peculiar animals and plants  
had been produced3 the simplest answer  
seemed to be that the inhabitants of the
 several islands had descended from each
 other1 undergoing modification in the  
course of their descent4 7,the          
,variation of ,animals and ,plants 7#bnd
 edition71 #ahij1 ,i4 pages #i1 #aj47   
,we need not be surprised then1 that in 
writing in #ahde to ,sir ,joseph        
,hooker1 he speaks of that grand        
subject1 that almost keystone of the    
laws of creation1 ,geographical         
,distribution4 7,life and ,letters1 ,i4 
page #ccf47  ,yet ,de ,candolle was1 as 
,bentham saw1 unconsciously feeling his 

way1 like ,lyell1 towards evolution1    
without being able to grasp it4 ,they   
both strove to explain phenomena by     
means of agencies which they saw        
actually at work4 ,if ,de ,candolle gave
 up the ultimate problem as             
insoluble3--,la creation ou premiere    
formation des etres organises echappe1  
par sa nature et par son anciennete1 a  
nos moyens d'observation 7,loc4 cit4    
page #aajf471 he steadily endeavoured to
 minimise its scope4 ,at least half of  
his great work is devoted to the        
researches by which he extricated       
himself from a belief in species having 
had a multiple origin1 the view which   
had been held by successive naturalists 
from ,gmelin to ,agassiz4 ,to account   
for the obvious fact that species       
constantly occupy dissevered areas1 ,de 
,candolle made a minute study of their  
means of transport4 ,this was found to  
dispose of the vast majority of cases1  
and the remainder he accounted for by   
geographical change4 7,loc4 cit4 page   

#aaaf47  ,but ,darwin strenuously       
objected to invoking geographical change
 as a solution of every difficulty4 ,he 
had apparently long satisfied himself as
 to the permanence of continents and    
great oceans4 ,dana1 he tells us was1 ,i
 believe1 the first man who maintained  
this 7,life and ,letters1 ,,iii4 page   
#bdg4 ,dana says3--,the continents and  
oceans had their general outline or form
 defined in earliest time1 ,manual of   
,geology1 revised edition4              
,philadelphia1 #ahfi1 page #gcb4 ,i have
 no access to an earlier edition471 but 
he had himself probably arrived at it   
independently4 ,modern physical research
 tends to confirm it4 ,the earth's      
centre of gravity1 as pointed out by    
,pratt from the existence of the        
,pacific ,ocean1 does not coincide with 
its centre of figure1 and it has been   
conjectured that the ,pacific ,ocean    
dates its origin from the separation of 
the moon from the earth4  ,the          
conjecture appears to be unnecessary4   

,love shows that the force that keeps   
the ,pacific ,ocean on one side of the  
earth is gravity1 directed more towards 
the centre of gravity than the centre of
 the figure4 7,report of the #ggth      
,meeting of the ,british ,association   
7,leicester1 #aijg71 ,london1 #aijh1    
page #dca47 ,i can only summarise the   
conclusions of a technical but masterly 
discussion4 ,the broad general features 
of the distribution of continent and    
ocean can be regarded as the            
consequences of simple causes of a      
dynamical character1 and finally1 ,as   
regards the contour of the great ocean  
basins1 we seem to be justified in      
saying that the earth is approximately  
an oblate spheroid1 but more nearly an  
ellipsoid with three unequal axes1      
having its surface furrowed according to
 the formula for a certain spherical    
harmonic of the third degree 7,ibid4    
page #dcf471 and he shows that this     
furrowed surface must be produced if the
 density is greater in one hemispheroid 

than in the other1 so that the position 
of the centre of gravity is eccentric4  
7,ibid4 page #dca47 ,such a modelling of
 the earth's surface can only be        
referred to a primitive period of       
plasticity4 ,if the furrows account for 
the great ocean basins1 the disposition 
of the continents seems equally to      
follow4 ,sir ,george ,darwin has pointed
 out that they necessarily arise from a 
supposed primitive viscosity or         
plasticity of the earth's mass4 ,for    
during this course of evolution the     
earth's mass must have suffered a       
screwing motion1 so that the polar      
regions have travelled a little from    
west to east relatively to the equator4 
,this affords a possible explanation of 
the north and south trend of our great  
continents4 7,encycl4 ,brit4 7#ith      
edition71 ,vol4 ,,xxiii4 ,tides1 page   
#cgi47  ,it would be trespassing on the 
province of the geologist to pursue the 
subject at any length4 ,but as ,wallace 
7,island ,life 7#bnd edition71 #ahie1   

page #ajc471 who has admirably          
vindicated ,darwin's position1 points   
out1 the question of the permanence of  
our continents444 lies at the root of   
all our inquiries into the great changes
 of the earth and its inhabitants4 ,but 
he proceeds3 ,the very same evidence    
which has been adduced to prove the     
,,general stability and permanence of   
our continental areas also goes to prove
 that they have been subjected to       
wonderful and repeated changes in       
,,detail4 7,loc4 cit4 page #aja47       
,darwin of course would have admitted   
this1 for with a happy expression he    
insisted to ,lyell 7#ahef7 that the     
skeletons1 at least1 of our continents  
are ancient4 7,more ,letters1 ,,ii4 page
 #ace47 ,it is impossible not to admire 
the courage and tenacity with which he  
carried on the conflict single-handed4  
,but he failed to convince ,lyell4 ,for 
we still find him maintaining in the    
last edition of the ,principles3        
,continents therefore1 although         

permanent for whole geological epochs1  
shift their positions entirely in the   
course of ages4 7,lyell's ,principles of
 ,geology 7#aath edition71 ,london1     
#ahgb1 ,i4 page #beh47  ,evidence1      
however1 steadily accumulates in        
,darwin's support4 ,his position still  
remains inexpugnable that it is not     
permissible to invoke geographical      
change to explain difficulties in       
distribution without valid geological   
and physical support4 ,writing to       
,mellard ,reade1 who in #ahgh had said1 
,while believing that the ocean-depths  
are of enormous age1 it is impossible to
 reject other evidences that they have  
once been land1 he pointed out the      
statement from the ',challenger' that   
all sediment is deposited within one or 
two hundred miles from the shores4      
7,more ,letters1 ,,ii4 page #adf47 ,the 
following year ,sir ,archibald ,geikie  
7,geographical ,evolution1 ,proc4 ,r4   
,geogr4 ,soc4 #ahgi1 page #dbg47        
informed the ,royal ,geographical       

,society that ,no part of the results   
obtained by the ',challenger' expedition
 has a profounder interest for          
geologists and geographers than the     
proof which they furnish that the floor 
of the ocean basins has no real analogy 
among the sedimentary formations which  
form most of the framework of the land4 
,nor has ,darwin's earlier argument ever
 been upset4 ,the fact which ,i pointed 
out many years ago1 that all oceanic    
islands are volcanic 7except ,st        
,paul's1 and now that is viewed by some 
as the nucleus of an ancient volcano71  
seem to me a strong argument that no    
continent ever occupied the great       
oceans4 7,more ,letters1 ,,ii4 page     
#adf47  ,dr ,guppy1 who devoted several 
years to geological and botanical       
investigations in the ,pacific1 found   
himself forced to similar conclusions4  
,it may be at once observed1 he says1   
that my belief in the general principle 
that islands have always been islands   
has not been shaken1 and he entirely    

rejects the hypothesis of a ,pacific    
continent4 ,he comes back1 in full view 
of the problems on the spot1 to the     
position from which1 as has been seen1  
,darwin started3 ,if the distribution of
 a particular group of plants or animals
 does not seem to accord with the       
present arrangement of the land1 it is  
by far the safest plan1 even after      
exhausting all likely modes of          
explanation1 not to invoke the          
intervention of geographical changes2   
and ,i scarcely think that our knowledge
 of any one group of organisms is ever  
sufficiently precise to justify a       
recourse to hypothetical alterations in 
the present relations of land and sea4  
7,observations of a ,naturalist in the  
,pacific between #ahif and #ahii1       
,london1 #aijc1 ,i4 page #chj47 ,wallace
 clinches the matter when he finds      
almost the whole of the vast areas of   
the ,atlantic1 ,pacific1 ,indian1 and   
,southern ,oceans1 without a solitary   
relic of the great islands or continents

 supposed to have sunk beneath their    
waves4 7,island ,life1 page #aje47      
,writing to ,wallace 7#ahgf71 ,darwin   
warmly approves the former's protest    
against sinking imaginary continents in 
a quite reckless manner1 as was stated  
by ,forbes1 followed1 alas1 by ,hooker1 
and caricatured by ,wollaston and       
7,andrew7 ,murray4 7,life and ,letters1 
,,iii4 page #bcj47 ,the transport       
question thus became of enormously      
enhanced importance4 ,we need not be    
surprised then at his writing to ,lyell 
in #ahef3--;,i cannot avoid thinking    
that ,forbes's ',atlantis' was an       
ill-service to science1 as checking a   
close study of means of dissemination   
7,ibid4 ,,ii4 page #gh471 and ,darwin   
spared no pains to extend our knowledge 
of them4 ,he implores ,hooker1 ten years
 later1 to admit how little is known on 
the subject1 and summarises with some   
satisfaction what he had himself        
achieved3--,remember how recently you   
and others thought that salt water would

 soon kill seeds444 ,remember that no   
one knew that seeds would remain for    
many hours in the crops of birds and    
retain their vitality2 that fish eat    
seeds1 and that when the fish are       
devoured by birds the seeds can         
germinate1 etc4 ,remember that every    
year many birds are blown to ,madeira   
and to the ,bermudas4 ,remember that    
dust is blown #ajjj miles across the    
,atlantic4 7,more ,letters1 ,i4 page    
#dhc47  ,it has always been the fashion 
to minimise ,darwin's conclusions1 and  
these have not escaped objection4 ,the  
advocatus diaboli has a useful function 
in science4 ,but in attacking ,darwin   
his brief is generally found to be      
founded on a slender basis of facts4    
,thus ,winge and ,knud ,andersen have   
examined many thousands of migratory    
birds and found that their crops and    
stomachs were always empty4 ,they never 
observed any seeds adhering to the      
feathers1 beaks or feet of the birds4   
7,r4,f4 ,scharff1 ,european ,animals1   

page #fd1 ,london1 #aijg47 ,the most    
considerable investigation of the       
problem of ,plant ,dispersal since      
,darwin is that of ,guppy4 ,he gives a  
striking illustration of how easily an  
observer may be led into error by       
relying on negative evidence4  ,when    
,ekstam published1 in #ahie1 the results
 of his observations on the plants of   
,nova ,zembla1 he observed that he      
possessed no data to show whether       
swimming and wading birds fed on        
berries2 and he attached all importance 
to dispersal by winds4 ,on subsequently 
visiting ,spitzbergen he must have been 
at first inclined1 therefore1 to the    
opinion of ,nathorst1 who1 having found 
only a solitary species of bird 7a      
snow-sparrow7 in that region1 naturally 
concluded that birds had been of no     
importance as agents in the             
plant-stocking4 ,however1 ,ekstam's     
opportunities were greater1 and he tells
 us that in the craws of six specimens  
of ,lagopus hyperboreus shot in         

,spitzbergen in ,august he found        
represented almost #be per cent4 of the 
usual phanerogamic flora of that region 
in the form of fruits1 seeds1 bulbils1  
flower-buds1 leaf-buds1 etc444   ,the   
result of ,ekstam's observations in     
,spitzbergen was to lead him to attach a
 very considerable importance in plant  
dispersal to the agency of birds2 and   
when in explanation of the ,scandinavian
 elements in the ,spitzbergen flora he  
had to choose between a former land     
connection and the agency of birds1 he  
preferred the bird4 7,guppy1 op4 cit4   
,,ii4 pages #eaa1 #eab47  ,darwin       
objected to continental extensions on   
geological grounds1 but he also objected
 to ,lyell that they do not account for 
all the phenomena of distribution on    
islands 7,life and ,letters1 ,,ii4 page 
#gg471 such for example as the absence  
of ,acacias and ,banksias in ,new       
,zealand4 ,he agreed with ,de ,candolle 
that it is poor work putting together   
the merely ,,possible means of          

distribution4 ,but he also agreed with  
him that they were the only practicable 
door of escape from multiple origins4   
,if they would not work then every one  
who believes in single centres will have
 to admit continental extensions 7,ibid4
 ,,ii4 page #hb471 and that he regarded 
as a mere counsel of despair3--to make  
continents1 as easily as a cook does    
pancakes4 7,ibid4 ,,ii4 page #gd47  ,the
 question of multiple origins however   
presented itself in another shape where 
the solution was much more difficult4   
,the problem1 as stated by ,darwin1 is  
this3--,the identity of many plants and 
animals1 on mountain-summits1 separated 
from each other by hundreds of miles of 
lowlands444 without the apparent        
possibility of their having migrated    
from one point to the other4 ,he        
continues1 even as long ago as #agdg1   
such facts led ,gmelin to conclude that 
the same species must have been         
independently created at several        
distinct points2 and we might have      

remained in this same belief1 had not   
,agassiz and others called vivid        
attention to the ,glacial period1 which 
affords444 a simple explanation of the  
facts4 7,origin of ,species 7#fth       
edition7 page #ccj47  ,the simple       
explanation was substantially given by  
,e4 ,forbes in #ahdf4 ,it is scarcely   
too much to say that it belongs to the  
same class of fertile and far-reaching  
ideas as natural selection itself4 ,it  
is an extraordinary instance1 if one    
were wanted at all1 of ,darwin's        
magnanimity and intense modesty that    
though he had arrived at the theory     
himself1 he acquiesced in ,forbes       
receiving the well-merited credit4 ,i   
have never1 he says1 of course alluded  
in print to my having independently     
worked out this view4 ,but he would have
 been more than human if he had not     
added3--,i was forestalled in444 one    
important point1 which my vanity has    
always made me regret4 7,life and       
,letters1 ,i4 page #hh47  ,darwin1      

however1 by applying the theory to      
trans-tropical migration1 went far      
beyond ,forbes4 ,the first enunciation  
to this is apparently contained in a    
letter to ,asa ,gray in #aheh4 ,the     
whole is too long to quote1 but the pith
 is contained in one paragraph4 ,there  
is a considerable body of geological    
evidence that during the ,glacial epoch 
the whole world was colder2 ,i inferred 
that1444 from erratic boulder phenomena 
carefully observed by me on both the    
east and west coast of ,south ,america4 
,now ,i am so bold as to believe that at
 the height of the ,glacial epoch1 ,,and
 ,,when ,,all ,,tropical ,,productions  
,,must ,,have ,,been ,,considerably     
,,distressed1 several temperate forms   
slowly travelled into the heart of the  
,tropics1 and even reached the southern 
hemisphere2 and some few southern forms 
penetrated in a reverse direction       
northward4 7,life and ,letters1 ,,ii4   
page #acf47 ,here again it is clear that
 though he credits ,agassiz with having 

called vivid attention to the ,glacial  
period1 he had himself much earlier     
grasped the idea of periods of          
refrigeration4  ,putting aside the fact1
 which has only been made known to us   
since ,darwin's death1 that he had      
anticipated ,forbes1 it is clear that he
 gave the theory a generality of which  
the latter had no conception4 ,this is  
pointed out by ,hooker in his classical 
paper ,on the ,distribution of ,arctic  
,plants 7#ahfj74 ,the theory of a       
southern migration of northern types    
being due to the cold epochs preceding  
and during the glacial1 originated1 ,i  
believe1 with the late ,edward ,forbes2 
the extended one1 of the trans-tropical 
migration1 is ,mr ,darwin's4 7,linn4    
,trans4 ,,xxiii4 page #bec4 ,the attempt
 appears to have been made to claim for 
,heer priority in what ,i may term for  
short the arctic-alpine theory          
7,scharff1 ,european ,animals1 page     
#abh74 ,i find no suggestion of his     
having hit upon it in his correspondence

 with ,darwin or ,hooker4 ,nor am ,i    
aware of any reference to his having    
done so in his later publications4 ,i am
 indebted to his biographer1 ,professor 
,schroter1 of ,zurich1 for an           
examination of his earlier papers with  
an equally negative result47 ,assuming  
that local races have derived from a    
common ancestor1 ,hooker's great paper  
placed the fact of the migration on an  
impregnable basis4 ,and1 as he pointed  
out1 ,darwin has shown that such an     
explanation meets the difficulty of     
accounting for the restriction of so    
many ,american and ,asiatic arctic types
 to their own peculiar longitudinal     
zones1 and for what is a far greater    
difficulty1 the representation of the   
same arctic genera by most closely      
allied species in different longitudes4 
,the facts of botanical geography were  
vital to ,darwin's argument4 ,he had to 
show that they admitted of explanation  
without assuming multiple origins for   
species1 which would be fatal to the    

theory of ,descent4 ,he had therefore to
 strengthen and extend ,de ,candolle's  
work as to means of transport4 ,he      
refused to supplement them by           
hypothetical geographical changes for   
which there was no independent evidence3
 this was simply to attempt to explain  
ignotum per ignotius4 ,he found a real  
and1 as it has turned out1 a            
far-reaching solution in climatic change
 due to cosmical causes which compelled 
the migration of species as a condition 
of their existence4 ,the logical force  
of the argument consists in dispensing  
with any violent assumption1 and in     
showing that the principle of descent is
 adequate to explain the ascertained    
facts4  ,it does not1 ,i think1 detract 
from the merit of ,darwin's conclusions 
that the tendency of modern research has
 been to show that the effects of the   
,glacial period were less simple1 more  
localised and less general than he      
perhaps supposed4 ,he admitted that     
equatorial refrigeration444 must have   

been small4 7,more ,letters1 ,i4 page   
#agg47 ,it may prove possible to        
dispense with it altogether4 ,one cannot
 but regret that as he wrote to         
,bates3--the sketch in the ',origin'    
gives a very meagre account of my fuller
 ,,ms4 essay on this subject4 7,loc4    
cit47 ,wallace fully accepted the effect
 of the ,glacial epoch in bringing about
 the present distribution of ,alpine and
 ,arctic plants in the ,,northern       
,,hemisphere1 but rejected the lowering 
of the temperature of the tropical      
regions during the ,glacial period in   
order to account for their presence in  
the ,,southern hemisphere4 7,more       
,letters1 ,,ii4 page #be 7footnote #a747
 ,the divergence however does not lie   
very deep4 ,wallace attaches more       
importance to ordinary means of         
transport4 ,if plants can pass in       
considerable numbers and variety over   
wide seas and oceans1 it must be yet    
more easy for them to traverse          
continuous areas of land1 wherever      

mountain-chains offer suitable stations4
 7,island ,life 7#bnd edition71 ,london1
 #ahie1 page #eab47 ,and he argues that 
such periodical changes of climate1 of  
which the ,glacial period may be taken  
as a type1 would facilitate if not      
stimulate the process4 7,loc4 cit4 page 
#eah47  ,it is interesting to remark    
that ,darwin drew from the facts of     
plant distribution one of his most      
ingenious arguments in support of this  
theory4 7,see ,more ,letters1 ,i4 page  
#dbd47 ,he tells us1 ,i was led to      
anticipate that the species of the      
larger genera in each country would     
oftener present varieties1 than the     
species of the smaller genera4 7,origin1
 page #dd47 ,he argues where1 if we may 
use the expression1 the manufactory of  
species has been active1 we ought       
generally to find the manufactory still 
in action4 7,ibid4 page #de47 ,this     
proved to be the case4 ,but the labour  
imposed upon him in the study was       
immense4 ,he tabulated local floras     

belting the whole northern hemisphere   
7,more ,letters1 ,i4 page #ajg471       
besides voluminous works such as ,de    
,candolle's ,prodromus4 ,the results    
scarcely fill a couple of pages4 ,this  
is a good illustration of the enormous  
pains which he took to base any         
statement on a secure foundation of     
evidence1 and for this the world1 till  
the publication of his letters1 could   
not do him justice4 ,he was a great     
admirer of ,herbert ,spencer1 whose     
prodigality of original thought         
astonished him4 ,but1 he says1 the      
reflection constantly recurred to me    
that each suggestion1 to be of real     
value to service1 would require years of
 work4 7,ibid4 ,,ii4 page #bce47  ,at   
last the ground was cleared and we are  
led to the final conclusion4 ,if the    
difficulties be not insuperable in      
admitting that in the long course of    
time all the individuals of the same    
species belonging to the same genus1    
have proceeded from some one source2    

then all the grand leading facts of     
geographical distribution are explicable
 on the theory of migration1 together   
with subsequent modification and the    
multiplication of new forms4 7,origin1  
page #cfj47 ,in this single sentence    
,darwin has stated a theory which1 as   
his son ,f4 ,darwin has said with       
justice1 has revolutionized botanical   
geography4 7,the ,botanical ,work of    
,darwin1 ,ann4 ,bot4 #ahii1 page xi47   
,it explains how physical barriers      
separate and form botanical regions2 how
 allied species become concentrated in  
the same areas2 how1 under similar      
physical conditions1 plants may be      
essentially dissimilar1 showing that    
descent and not the surroundings is the 
controlling factor2 how insular floras  
have acquired their peculiarities2 in   
short how the most various and          
apparently uncorrelated problems fall   
easily and inevitably into line4  ,the  
argument from plant distribution was in 
fact irresistible4 ,a proof1 if one were

 wanted1 was the immediate conversion of
 what ,hooker called the stern keen     
intellect 7,more ,letters1 ,i4 page     
#acd47 of ,bentham1 by general consent  
the leading botanical systematist at the
 time4 ,it is a striking historical fact
 that a paper of his own had been set   
down for reading at the ,linnean        
,society on the same day as ,darwin's1  
but had to give way4 ,in this he        
advocated the fixity of species4 ,he    
withdrew it after hearing ,darwin's4 ,we
 can hardly realise now the momentous   
effect on the scientific thought of the 
day of the announcement of the new      
theory4 ,years afterwards 7#ahhb7       
,bentham1 notwithstanding his habitual  
restraint1 could not write of it without
 emotion4 ,i was forced1 however        
reluctantly1 to give up my              
long-cherished convictions1 the results 
of much labour and study4 ,the          
revelation came without preparation4    
,darwin1 he wrote1 never made any       
communications to me in relation to his 

views and labours4 ,but1 he adds1 ,i444 
fully adopted his theories and          
conclusions1 notwithstanding the severe 
pain and disappointment they at first   
occasioned me4 7,life and ,letters1     
,,ii4 page #bid47 ,scientific history   
can have few incidents more worthy4 ,i  
do not know what is most striking in the
 story1 the pathos or the moral dignity 
of ,bentham's attitude4  ,darwin        
necessarily restricted himself in the   
,origin to establishing the general     
principles which would account for the  
facts of distribution1 as a part of his 
larger argument1 without attempting to  
illustrate them in particular cases4    
,this he appears to have contemplated   
doing in a separate work4 ,but writing  
to ,hooker in #ahfh he said3--,i shall  
to the day of my death keep up my full  
interest in ,geographical ,distribution1
 but ,i doubt whether ,i shall ever have
 strength to come in any fuller detail  
than in the ,origin to this grand       
subject4 7,more ,letters1 ,,ii4 page    

#g47 ,this must be always a matter for  
regret4 ,but we may gather some         
indication of his later speculations    
from the letters1 the careful           
publication of which by ,f4 ,darwin has 
rendered a service to science1 the value
 of which it is difficult to exaggerate4
 ,they admit us to the workshop1 where  
we see a great theory1 as it were1 in   
the making4 ,the later ideas that they  
contain were not it is true public      
property at the time4 ,but they were    
communicated to the leading biologists  
of the day and indirectly have had a    
large influence4  ,if ,darwin laid the  
foundation1 the present fabric of       
,botanical ,geography must be credited  
to ,hooker4 ,it was a happy partnership4
 ,the far-seeing1 generalising power of 
the one was supplied with data and      
checked in conclusions by the vast      
detailed knowledge of the other4 ,it may
 be permitted to quote ,darwin's        
generous acknowledgment when writing the
 ,origin3--,i never did pick any one's  

pocket1 but whilst writing my present   
chapter ,i keep on feeling 7even when   
differing most from you7 just as if ,i  
were stealing from you1 so much do ,i   
owe to your writings and conversation1  
so much more than mere acknowledgements 
show4 7,life and ,letters1 ,,ii4 page   
#adh 7footnote747 ,fourteen years before
 he had written to ,hooker3 ,i know ,i  
shall live to see you the first         
authority in ,europe on444 ,geographical
 ,distribution4 7,ibid4 ,i4 page #ccf47 
,we owe it to ,hooker that no one now   
undertakes the flora of a country       
without indicating the range of the     
species it contains4 ,bentham tells us3 
,after ,de ,candolle1 independently of  
the great works of ,darwin444 the first 
important addition to the science of    
geographical botany was that made by    
,hooker in his ,introductory ,essay to  
the ,flora of ,tasmania1 which1 though  
contemporaneous only with the ,origin of
 ,species1 was drawn up with a general  
knowledge of his friend's observations  

and views4 7,pres4 ,addr4 7#ahfi71      
,proc4 ,linn4 ,soc4 #ahfh-fi1 page      
lxxiv47 ,it cannot be doubted that this 
and the great memoir on the             
,distribution of ,arctic ,plants were   
only less epoch-making than the ,origin 
itself1 and must have supplied a        
powerful support to the general theory  
of organic evolution4  ,darwin always   
asserted his entire ignorance of        
,botany4 7,more ,letters1 ,i4 page      
#djj47 ,but this was only part of his   
constant half-humorous                  
self-depreciation4 ,he had been a pupil 
of ,henslow1 and it is evident that he  
had a good working knowledge of         
systematic botany4 ,he could find his   
way about in the literature and always  
cites the names of plants with          
scrupulous accuracy4 ,it was because he 
felt the want of such a work for his own
 researches that he urged the           
preparation of the ,index ,kewensis1 and
 undertook to defray the expense4 ,it   
has been thought singular that he should

 have been elected a correspondant of   
the ,academie des ,sciences in the      
section of ,botany1 but it is not       
surprising that his work in             
,geographical ,botany made the botanists
 anxious to claim him4 ,his heart went  
with them4 ,it has always pleased me1 he
 tells us1 to exalt plants in the scale 
of organised beings4 7,life and         
,letters1 ,i4 page #ih47 ,and he        
declares that he finds any proposition  
more easily tested in botanical works   
7,ibid4 ,,ii4 page #ii47 than in        
zoological4  ,in the ,introductory      
,essay ,hooker dwelt on the continuous  
current of vegetation from ,scandinavia 
to ,tasmania 7,introductory ,essay to   
the ,flora of ,tasmania1 ,london1 #ahei4
 ,reprinted from the ,botany of the     
,antarctic ,expedition1 ,part ,,iii41   
,flora of ,tasmania1 ,vol ,i4 page      
ciii471 but finds little evidence of one
 in the reverse direction4 ,in the ,new 
,world1 ,arctic1 ,scandinavian1 and     
,north ,american genera and species are 

continuously extended from the north to 
the south temperate and even ,antarctic 
zones2 but scarcely one ,antarctic      
species1 or even genus advances north   
beyond the ,gulf of ,mexico 7page civ474
 ,hooker considered that this negatived 
the idea that the ,southern and         
,northern ,floras have had common origin
 within comparatively modern geological 
epochs4 7,loc4 cit47 ,this is no doubt a
 correct conclusion4 ,but it is         
difficult to explain on ,darwin's view  
alone1 of alternating cold in the two   
hemispheres1 the preponderant migration 
from the north to the south4 ,he        
suggests1 therefore1 that it is due to  
the greater extent of land in the north 
and to the northern forms444 having444  
been advanced through natural selection 
and competition to a higher stage of    
perfection or dominating power4 7,origin
 of ,species 7#fth edition71 page #cdj2 
cf4 also ,life and ,letters1 ,,ii4 page 
#adb47 ,the present state of the ,flora 
of ,new ,zealand affords a striking     

illustration of the correctness of this 
view4 ,it is poor in species1 numbering 
only some #adjj1 of which three-fourths 
are endemic4 ,they seem however quite   
unable to resist the invasion of new    
comers and already #fjj species of      
foreign origin have succeeded in        
establishing themselves4  ,if we accept 
the general configuration of the earth's
 surface as permanent a continuous and  
progressive dispersal of species from   
the centre to the circumference1 i4e4   
southwards1 seems inevitable4 ,if an    
observer were placed above a point in   
,st ,george's ,channel from which one   
half of the globe was visible he would  
see the greatest possible quantity of   
land spread out in a sort of stellate   
figure4 ,the maritime supremacy of the  
,english race has perhaps flowed from   
the central position of its home4 ,that 
such a disposition would facilitate a   
centrifugal migration of land organisms 
is at any rate obvious1 and fluctuating 
conditions of climate operating from the

 pole would supply an effective means of
 propulsion4 ,as these became more      
rigorous animals at any rate would move 
southwards to escape them4 ,it would be 
equally the case with plants if no      
insuperable obstacle interposed4 ,this  
implies a mobility in plants1           
notwithstanding what we know of means of
 transport which is at first sight      
paradoxical4 ,bentham has stated this in
 a striking way3 ,fixed and immovable as
 is the individual plant1 there is no   
class in which the race is endowed with 
greater facilities for the widest       
dispersion444 ,plants cast away their   
offspring in a dormant state1 ready to  
be carried to any distance by those     
external agencies which we may deem     
fortuitous1 but without which many a    
race might perish from the exhaustion of
 the limited spot of soil in which it is
 rooted4 7,pres4 ,addr47#ahfi71 ,proc4  
,linn4 ,soc4 #ahfh-fi1 pages lxvi1      
lxvii47  ,i have quoted this passage    
from ,bentham because it emphasises a   

point which ,darwin for his purpose did 
not find it necessary to dwell upon1    
though he no doubt assumed it4          
,dispersal to a distance is1 so to      
speak1 an accidental incident in the    
life of a species4 ,lepidium ,draba1 a  
native of ,south-eastern ,europe1 owes  
its prevalence in the ,isle of ,thanet  
to the disastrous ,walcheren expedition2
 the straw-stuffing of the mattresses of
 the fever-stricken soldiers who were   
landed there was used by a farmer for   
manure4 ,sir ,joseph ,hooker 7,royal    
,institution ,lecture1 ,april #ab1      
#ahgh47 tells us that landing on ,lord  
,auckland's ,island1 which was          
uninhabited1 the first evidence ,i met  
with of its having been previously      
visited by man was the ,english         
chickweed2 and this ,i traced to a mound
 that marked the grave of a ,british    
sailor1 and that was covered with the   
plant1 doubtless the offspring of seed  
that had adhered to the spade or mattock
 with which the grave had been dug4     

,some migration from the spot where the 
individuals of a species have germinated
 is an essential provision against      
extinction4 ,their descendants otherwise
 would be liable to suppression by more 
vigorous competitors4 ,but they would   
eventually be extinguished inevitably1  
as pointed out by ,bentham1 by the      
exhaustion of at any rate some one      
necessary constituent of the soil4      
,gilbert showed by actual analysis that 
the production of a fairy ring is simply
 due to the using up by the fungi of the
 available nitrogen in the enclosed area
 which continually enlarges as they seek
 a fresh supply on the outside margin4  
,anyone who cultivates a garden can     
easily verify the fact that every plant 
has some adaptation for varying degrees 
of seed-dispersal4 ,it cannot be doubted
 that slow but persistent terrestrial   
migration has played an enormous part in
 bringing about existing                
plant-distribution1 or that climatic    
changes would intensify the effect      

because they would force the abandonment
 of a former area and the occupation of 
a new one4 ,we are compelled to admit   
that as an incident of the ,glacial     
period a whole flora may have moved down
 and up a mountain side1 while only some
 of its constituent species would be    
able to take advantage of means of      
long-distance transport4  ,i have dwelt 
on the importance of what ,i may call   
short-distance dispersal as a necessary 
condition of plant life1 because ,i     
think it suggests the solution of a     
difficulty which leads ,guppy to a      
conclusion with which ,i am unable to   
agree4 ,but the work which he has done  
taken as a whole appears to me so       
admirable that ,i do so with the utmost 
respect4 ,he points out1 as ,bentham had
 already done1 that long-distance       
dispersal is fortuitous4 ,and being so  
it cannot have been provided for by     
previous adaptation4 ,he says 7,guppy1  
op4 cit4 ,,ii4 page #ii473 ,it is not   
conceivable that an organism can be     

adapted to conditions outside its       
environment4 ,to this we must agree2    
but1 it may be asked1 do the general    
means of plant dispersal violate so     
obvious a principle8 ,he proceeds3 ,the 
great variety of the modes of dispersal 
of seeds is in itself an indication that
 the dispersing agencies avail          
themselves in a hap-hazard fashion of   
characters and capacities that have been
 developed in other connections4 7,loc4 
cit4 page #ajb47 ,their utility in these
 respects is an accident in the plant's 
life4 7,loc4 cit4 page #ajj47 ,he       
attributes this utility to a determining
 agency1 an influence which constantly  
reappears in various shapes in the      
literature of ,evolution and is         
ultra-scientific in the sense that it   
bars the way to the search for material 
causes4 ,he goes so far as to doubt     
whether fleshy fruits are an adaptation 
for the dispersal of their contained    
seeds4 7,loc4 cit4 page #ajb47 ,writing 
as ,i am from a hillside which is       

covered by hawthorn bushes sown by      
birds1 ,i confess ,i can feel little    
doubt on the subject myself4 ,the       
essential fact which ,guppy brings out  
is that long-distance unlike            
short-distance dispersal is not         
universal and purposeful1 but selective 
and in that sense accidental4 ,but it is
 not difficult to see how under         
favouring conditions one must merge into
 the other4  ,guppy has raised one novel
 point which can only be briefly        
referred to but which is of extreme     
interest4 ,there are grounds for        
thinking that flowers and insects have  
mutually reacted upon one another in    
their evolution4 ,guppy suggests that   
something of the same kind may be true  
of birds4 ,i must content myself with   
the quotation of a single sentence4     
,with the secular drying of the globe   
and the consequent differentiation of   
climate is to be connected the          
suspension to a great extent of the     
agency of birds as plant dispersers in  

later ages1 not only in the ,pacific    
,islands but all over the tropics4 ,the 
changes of climate1 birds and plants    
have gone on together1 the range of the 
bird being controlled by the climate1   
and the distribution of the plant being 
largely dependent on the bird4          
7,loc4cit4 ,,ii4 page #bba47  ,darwin   
was clearly prepared to go further than 
,hooker in accounting for the southern  
flora by dispersion from the north4     
,thus he says3 ,we must1 ,i suppose1    
admit that every yard of land has been  
successively covered with a beech-forest
 between the ,caucasus and ,japan4      
7,more ,letters1 ,,ii4 page #i47 ,hooker
 accounted for the dissevered condition 
of the southern flora by geographical   
change1 but this ,darwin could not      
admit4 ,he suggested to ,hooker that the
 ,australian and ,cape floras might have
 had a point of connection through      
,abyssinia 7,ibid4 ,i4 page #ddg471 an  
idea which was promptly snuffed out4    
,similarly he remarked to ,bentham      

7#ahfi73 ,i suppose you think that the  
,restiaceae1 ,proteaceae1 etc41 etc4    
once extended over the whole world1     
leaving fragments in the south4 7,ibid4 
,i4 page #chj47 ,eventually he          
conjectured that there must have been a 
,tertiary ,antarctic continent1 from    
which various forms radiated to the     
southern extremities of our present     
continents4 7,life and ,letters1 ,,iii4 
page #bca47 ,but characteristically he  
could not admit any land connections and
 trusted to floating ice for            
transporting seed4 7,more ,letters1 ,i4 
page #aaf47 ,i am far from saying that  
this theory is not deserving of serious 
attention1 though there seems to be no  
positive evidence to support it1 and it 
immediately raises the difficulty how   
did such a continent come to be stocked8
  ,we must1 however1 agree with ,hooker 
that the common origin of the northern  
and southern floras must be referred to 
a remote past4 ,that ,darwin had this in
 his mind at the time of the publication

 of the ,origin is clear from a letter  
to ,hooker4 ,the view which ,i should   
have looked at as perhaps most probable 
7though it hardly differs from yours7 is
 that the whole world during the        
,secondary ages was inhabited by        
marsupials1 araucarias 7,mem4--,fossil  
wood of this nature in ,south ,america71
 ,banksia1 etc42 and that these were    
supplanted and exterminated in the      
greater area of the north1 but were left
 alive in the south4 7,ibid4 ,i4 page   
#dec47 ,remembering that ,araucaria1    
unlike ,banksia1 belongs to the earlier 
,jurassic not to the angiospermous      
flora1 this view is a germinal idea of  
the widest generality4  ,the            
extraordinary congestion in species of  
the peninsulas of the ,old ,world points
 to the long-continued action of a      
migration southwards4 ,each is in fact a
 cul-de-sac into which they have poured 
and from which there is no escape4 ,on  
the other hand the high degree of       
specialisation in the southern floras   

and the little power the species possess
 of holding their own in competition or 
in adaptation to new conditions point to
 long-continued isolation4 ,an island444
 will prevent free immigration and      
competition1 hence a greater number of  
ancient forms will survive4 7,ibid4 ,i4 
page #dha47 ,but variability is itself  
subject to variation4 ,the nemesis of a 
high degree of protected specialisation 
is the loss of adaptability4 7,see      
,lyell1 ,the ,geological ,evidences of  
the ,antiquity of ,man1 ,london1 #ahfc1 
page #ddf47 ,it is probable that many   
elements of the southern flora are      
doomed3 there is1 for example1 reason to
 think that the singular ,stapelieae of 
,s4 ,africa are a disappearing group4   
,the tree ,lobelias which linger in the 
mountains of ,central ,africa1 in       
,tropical ,america and in the ,sandwich 
,islands have the aspect of extreme     
antiquity4 ,i may add a further striking
 illustration from ,professor ,seward3  
,the tall1 graceful fronds of ,matonia  

pectinata1 forming miniature forests on 
the slopes of ,mount ,ophir and other   
districts in the ,malay ,peninsula in   
association with ,dipteris conjugata and
 ,dipteris lobbiana1 represent a phase  
of ,mesozoic life which survives ',like 
a dim picture of the drowned past4'     
7,report of the #gcrd ,meeting of the   
,british ,assoc4 7,southport1 #aijc71   
,london1 #aijd1 page #hdd47  ,the       
,matonineae are ferns with an unusually 
complex vascular system and were        
abundant in the northern hemisphere     
during the earlier part of the ,mesozoic
 era4  ,it was fortunate for science    
that ,wallace took up the task which his
 colleague had abandoned4 ,writing to   
him on the publication of his           
,geographical ,distribution of ,animals 
,darwin said3 ,i feel sure that you have
 laid a broad and safe foundation for   
all future work on ,distribution4 ,how  
interesting it will be to see hereafter 
plants treated in strict relation to    
your views4 7,more ,letters1 ,,ii4 page 

#ab47 ,this hope was fulfilled in       
,island ,life4 ,i may quote a passage   
from it which admirably summarises the  
contrast between the northern and the   
southern floras4  ,instead of the       
enormous northern area1 in which highly 
organised and dominant groups of plants 
have been developed gifted with great   
colonising and aggressive powers1 we    
have in the south three comparatively   
small and detached areas1 in which rich 
floras have been developed with         
,,special adaptations to soil1 climate1 
and organic environment1 but            
comparatively impotent and inferior     
beyond their own domain4 7,wallace1     
,island ,life1 pages #ebg1 #ebh47  ,it  
will be noticed that in the summary ,i  
have attempted to give of the history of
 the subject1 efforts have been         
concentrated on bringing into relation  
the temperate floras of the northern and
 southern hemispheres1 but no account   
has been taken of the rich tropical     
vegetation which belts the world and    

little to account for the original      
starting-point of existing vegetation   
generally4 ,it must be remembered on the
 one hand that our detailed knowledge of
 the floras of the tropics is still very
 incomplete and far inferior to that of 
temperate regions2 on the other hand    
palaeontological discoveries have put   
the problem in an entirely new light4   
,well might ,darwin1 writing to ,heer in
 #ahge1 say3 ,many as have been the     
wonderful discoveries in ,geology during
 the last half-century1 ,i think none   
have exceeded in interest your results  
with respect to the plants which        
formerly existed in the arctic regions4 
7,more ,letters1 ,,ii4 page #bdj47  ,as 
early as #ahdh ,debey had described from
 the ,upper ,cretaceous rocks of        
,aix-la-,chapelle ,flowering plants of  
as high a degree of development as those
 now existing4 ,the fact was commented  
upon by ,hooker 7,introd4 ,essay to the 
,flora of ,tasmania1 page xx471 but its 
full significance seems to have been    

scarcely appreciated4 ,for it implied   
not merely that their evolution must    
have taken place but the foundations of 
existing distribution must have been    
laid in a preceding age4 ,we now know   
from the discoveries of the last fifty  
years that the remains of the ,neocomian
 flora occur over an area extending     
through #cj deg of latitude4 ,the       
conclusion is irresistible that within  
this was its centre of distribution and 
probably of origin4  ,darwin was        
immensely impressed with the outburst on
 the world of a fully fledged           
angiospermous vegetation4 ,he warmly    
approved the brilliant theory of        
,saporta that this happened as soon 7as7
 flower-frequenting insects were        
developed and favoured intercrossing4   
7,more ,letters1 ,,ii4 page #ba47       
,writing to him in #ahgg he says3 ,your 
idea that dicotyledonous plants were not
 developed in force until sucking       
insects had been evolved seems to me a  
splendid one4 ,i am surprised that the  

idea never occurred to me1 but this is  
always the case when one first hears a  
new and simple explanation of some      
mysterious phenomenon4 7,life and       
,letters1 ,,iii4 page #bhe4             
,substantially the same idea had        
occurred earlier to ,f4,w4,a4 ,miquel4  
,remarking that sucking insects         
7,haustellata7444 perform in nature the 
important duty of maintaining the       
existence of the vegetable kingdom1 at  
least as far as the higher orders are   
concerned1 he points our that the       
appearance in great numbers of          
haustellate insects occurs at and after 
the ,cretaceous epoch1 when the plants  
with pollen and closed carpels          
7,angiosperms7 are found1 and acquire   
little by little the preponderance in   
the vegetable kingdom4 ,archives        
,neerlandaises1 ,,iii4 7#ahfh74 ,english
 translation in ,journ4 of ,bot4 #ahfi1 
page #aja47  ,even with this help the   
abruptness still remains an almost      
insoluble problem1 though a forecast of 

floral structure is now recognised in   
some ,jurassic and ,lower ,cretaceous   
plants4 ,but the gap between this and   
the structural complexity and diversity 
of angiosperms is enormous4 ,darwin     
thought that the evolution might have   
been accomplished during a period of    
prolonged isolation4 ,writing to ,hooker
 7#ahha7 he says3 ,nothing is more      
extraordinary in the history of the     
,vegetable ,kingdom1 as it seems to me1 
than the ,,apparently very sudden or    
abrupt development of the higher plants4
 ,i have sometimes speculated whether   
there did not exist somewhere during    
long ages an extremely isolated         
continent1 perhaps near the ,south      
,pole4 7,life and ,letters1 ,,iii4 page 
#bdh47  ,the present trend of evidence  
is1 however1 all in favour of a northern
 origin for flowering plants1 and we can
 only appeal to the imperfection of the 
geological record as a last resource to 
extricate us from the difficulty of     
tracing the process4 ,but ,darwin's     

instinct that at some time or other the 
southern hemisphere had played an       
important part in the evolution of the  
vegetable kingdom did not mislead him4  
,nothing probably would have given him  
greater satisfaction than the masterly  
summary in which ,seward has brought    
together the evidence for the origin of 
the ,glossopteris flora in ,gondwana    
land4  ,a vast continental area1 of     
which remnants are preserved in         
,australia1 ,south ,africa and ,south   
,america444 ,a tract of enormous extent 
occupying an area1 part of which has    
since given place to a southern ocean1  
while detached masses persist as        
portions of more modern continents1     
which have enabled us to read in their  
fossil plants and ice-scratched boulders
 the records of a lost continent1 in    
which the ,mesozoic vegetation of the   
northern continent had its birth4       
7,encycl4 ,brit4 7#ajth edition #aijb71 
,vol4 ,,xxxi4 7,palaeobotany2           
,mesozoic71 page #dbb47 ,darwin would   

probably have demurred on physical      
grounds to the extent of the continent1 
and preferred to account for the        
transoceanic distribution of its flora  
by the same means which must have       
accomplished it on land4  ,it must in   
fairness be added that ,guppy's later   
views give some support to the          
conjectural existence of the lost       
continent4 ,the distribution of the     
genus ,dammara 7,agathis7 led him to    
modify his earlier conclusions4 ,he     
tells us3--,in my volume on the geology 
of ,vanua ,levu it was shown that the   
,tertiary period was an age of          
submergence in the ,western ,pacific1   
and a disbelief in any previous         
continental condition was expressed4 ,my
 later view is more in accordance with  
that of ,wichmann1 who1 on geological   
grounds1 contended that the islands of  
the ,western ,pacific were in a         
continental condition during the        
,palaeozoic and ,mesozoic periods1 and  
that their submergence and subsequent   

emergence took place in ,tertiary times4
 7,guppy1 op4 cit4 ,,ii4 page #cjd47    
,the weight of the geological evidence  
,i am unable to scrutinise4 ,but though 
,i must admit the possibility of some   
unconscious bias in my own mind on the  
subject1 ,i am impressed with the fact  
that the known distribution of the      
,glossopteris flora in the southern     
hemisphere is precisely paralleled by   
that of ,proteaceae and ,restiaceae in  
it at the present time4 ,it is not      
unreasonable to suppose that both       
phenomena1 so similar1 may admit of the 
same explanation4 ,i confess it would   
not surprise me if fresh discoveries in 
the distribution of the ,glossopteris   
flora were to point to the possibility  
of its also having migrated southwards  
from a centre of origin in the northern 
hemisphere4  ,darwin1 however1 remained 
sceptical about the travelling of plants
 from the north ,,except ,,during ,,the 
,,tertiary ,,period4 ,but he added1 such
 speculations seem to me hardly         

scientific1 seeing how little we know of
 the old floras4 7,life and ,letters1   
,,iii4 page #bdg47 ,that in later       
geological times the south has been the 
grave of the weakened offspring of the  
aggressive north can hardly be doubted4 
,but if we look to the ,glossopteris    
flora for the ancestry of ,angiosperms  
during the ,secondary period1 ,darwin's 
prevision might be justified1 though he 
has given us no clue as to how he       
arrived at it4  ,it may be true that    
technically ,darwin was not a botanist4 
,but in two pages of the ,origin he has 
given us a masterly explanation of the  
relationship1 with very little identity1
 between the productions of ,north      
,america and ,europe4 7,pages #ccc1     
#ccd47 ,he showed that this could be    
accounted for by their migration        
southwards from a common area1 and he   
told ,wallace that he doubted much      
whether the now called ,palaearctic and 
,neartic regions ought to be separated4 
7,life and ,letters1 ,,iii4 page #bcj47 

,catkin-bearing deciduous trees had long
 been seen to justify ,darwin's doubt3  
oaks1 chestnuts1 beeches1 hazels1       
hornbeams1 birches1 alders1 willows and 
poplars are common both to the ,old and 
,new ,world4 ,newton found that the     
separate regions could not be sustained 
for birds1 and he is now usually        
followed in uniting them as the         
,holartic4 ,one feels inclined to say in
 reading the two pages1 as ,lord ,kelvin
 did to a correspondent who asked for   
some further development of one of his  
papers1 ,it is all there4 ,we have only 
to apply the principle to previous      
geological ages to understand why the   
flora of the ,southern ,united ,states  
preserves a ,cretaceous facies4         
,applying it still further we can       
understand why1 when the northern       
hemisphere gradually cooled through the 
,tertiary period1 the plants of the     
,eocene suggest a comparison of the     
climate and forests with those of the   
,malay ,archipelago and ,tropical       

,america4 7,clement ,reid1 ,encycl4     
,brit4 7#ajth edition71 ,vol4 ,,xxxi4   
7,palaeobotany2 ,tertiary71 page #dce47 
,writing to ,asa ,gray in #ahef with    
respect to the ,united ,states flora1   
,darwin said that nothing has surprised 
me more than the greater generic and    
specific affinity with ,east ,asia than 
with ,west ,america4 7,more ,letters1   
,i4 page #dcd47 ,the recent discoveries 
of a ,tulip tree and a ,sassafras in    
,china afford fresh illustrations4 ,a   
few years later ,asa ,gray found the    
explanation in both areas being centres 
of preservation of the ,cretaceous flora
 from a common origin4 ,it is           
interesting to note that the paper in   
which this was enunciated at once       
established his reputation4  ,in ,europe
 the latitudinal range of the great     
mountain chains gave the ,miocene flora 
no chance of escape during the ,glacial 
period1 and the ,mediterranean appears  
to have equally intercepted the flow of 
alpine plants to the ,atlas4 7,john     

,ball in ,appendix ,g1 page #dch1 in    
,journal of a ,tour in ,morocco and the 
,great ,atlas1 ,j4,d4 ,hooker and ,j4   
,ball1 ,london1 #ahgh47 ,in ,southern   
,europe the myrtle1 the laurel1 the fig 
and the dwarf-palm are the sole         
representatives of as many great        
tropical families4 ,another great       
tropical family1 the ,gesneraceae has   
left single representatives from the    
,pyrenees to the ,balkans2 and in the   
former a diminutive yam still lingers4  
,these are only illustrations of the    
evidence which constantly accumulates   
and which finds no rational explanation 
except that which ,darwin has given to  
it4  ,the theory of southward migration 
is the key to the interpretation of the 
geographical distribution of plants4 ,it
 derived enormous support from the      
researches of ,heer and has now become  
an accepted commonplace4 ,saporta in    
#ahhh described the vegetable kingdom as
 emigrant pour suivre une direction     
determinee et marcher du nord au sud1 a 

la recherche de regions et de stations  
plus favorables1 mieux appropriees aux  
adaptations acquises1 a meme que la     
temperature terrestre perd ses          
conditions premieres4 7,origine         
,paleontologique des arbres1 ,paris1    
#ahhh1 page #bh47 ,if1 as is so often   
the case1 the theory now seems to be a  
priori inevitable1 the historian of     
science will not omit to record that the
 first germ sprang from the brain of    
,darwin4  ,in attempting this sketch of 
,darwin's influence on ,geographical    
,distribution1 ,i have found it         
impossible to treat it from an external 
point of view4 ,his interest in it was  
unflagging2 all ,i could say became     
necessarily a record of that interest   
and could not be detached from it4 ,he  
was in more or less intimate touch with 
everyone who was working at it4 ,in     
reading the letters we move amongst     
great names4 ,with an extraordinary     
charm of persuasive correspondence he   
was constantly suggesting1 criticising  

and stimulating4 ,it is hardly an       
exaggeration to say that from the quiet 
of his study at ,down he was founding   
and directing a wide-world school4      
,,postscriptum4  ,since this essay was  
put in type ,dr ,ernst's striking       
account of the ,new ,flora of the       
,volcanic ,island of ,krakatau          
7,cambridge1 #aiji47 has reached me4    
,all botanists must feel a debt of      
gratitude to ,prof4 ,seward for his     
admirable translation of a memoir which 
in its original form is practically     
unprocurable and to the liberality of   
the ,cambridge ,university ,press for   
its publication4 ,in the preceding pages
 ,i have traced the laborious research  
by which the methods of ,plant          
,dispersal were established by ,darwin4 
,in the island of ,krakatau nature has  
supplied a crucial experiment which1 if 
it had occurred earlier1 would have at  
once secured conviction of their        
efficiency4 ,a quarter of a century ago 
every trace of organic life in the      

island was destroyed and buried under a 
thick covering of glowing stones4 ,now1 
it is again covered with a mantle of    
green1 the growth being in places so    
luxuriant that it is necessary to cut   
one's way laboriously through the       
vegetation4 7,op4 cit4 page #d47 ,ernst 
traces minutely how this has been       
brought about by the combined action of 
wind1 birds and sea currents1 as means  
of transport4 ,the process will         
continue1 and he concludes3--,at last   
after a long interval the vegetation on 
the desolated island will again acquire 
that wealth of variety and luxuriance   
which we see in the fullest development 
which ,nature has reached in the        
primaeval forest in the tropics4 7,op4  
cit4 page #gb47 ,the possibility of such
 a result revealed itself to the insight
 of ,darwin with little encouragement or
 support from contemporary opinion4     
,one of the most remarkable facts       
established by ,ernst is that this has  
not been accomplished by the transport  

of seeds alone4 ,tree stems and branches
 played an important part in the        
colonisation of ,krakatau by plants and 
animals4 ,large piles of floating trees1
 stems1 branches and bamboos are met    
with everywhere on the beach above      
high-water mark and often carried a     
considerable distance inland4 ,some of  
the animals on the island1 such as the  
fat ,iguana 7,varanus salvator7 which   
suns itself in the beds of streams1 may 
have travelled on floating wood1        
possibly also the ancestors of the      
numerous ants1 but certainly plants4    
7,op4 cit4 page #ef47 ,darwin actually  
had a prevision of this4 ,writing to    
,hooker he says3--,would it not be a    
prodigy if an unstocked island did not  
in the course of ages receive colonists 
from coasts whence the currents flow1   
trees are drifted and birds are driven  
by gales8 7,more ,letters1 ,i4 page     
#dhc47 ,and ten years earlier3--,i must 
believe in the444 whole plant or branch 
being washed into the sea2 with floods  

and slips and earthquakes2 this must    
continually be happening4 7,life and    
,letters1 ,,ii4 pages #ef1 #eg47 ,if we 
give to continually a cosmic measure1   
can the fact be doubted8 ,all this1 in  
the light of our present knowledge1 is  
too obvious to us to admit of           
discussion4 ,but it seems to me nothing 
less than pathetic to see how in the    
teeth of the obsession as to continental
 extension1 ,darwin fought single-handed
 for what we now know to be the truth4  
,guppy's heart failed him when he had to
 deal with the isolated case of ,agathis
 which alone seemed inexplicable by     
known means of transport4 ,but when we  
remember that it is a relic of the      
pre-,angiospermous flora1 and is of     
,araucarian ancestry1 it cannot be said 
that the impossibility1 in so prolonged 
a history1 of the bodily transference of
 cone-bearing branches or even of trees1
 compels us as a last resort to fall    
back on continental extension to account
 for its existing distribution4  ,when  

,darwin was in the ,galapagos           
,archipelago1 he tells us that he       
fancied himself brought near to the very
 act of creation4 ,he saw how new       
species might arise from a common stock4
 ,krakatau shows us an earlier stage and
 how by simple agencies1 continually at 
work1 that stock might be supplied4 ,it 
also shows us how the mixed and casual  
elements of a new colony enter into     
competition for the ground and become   
mutually adjusted4 ,the study of ,plant 
,distribution from a ,darwinian         
standpoint has opened up a new field of 
research in ,ecology4 ,the means of     
transport supply the materials for a    
flora1 but their ultimate fate depends  
on their equipment for the struggle for 
existence4 ,the whole subject can no    
longer be regarded as a mere statistical
 inquiry which has seemed doubtless to  
many of somewhat arid interest4 ,the    
fate of every element of the earth's    
vegetation has sooner or later depended 
on its ability to travel and to hold its

 own under new conditions4 ,and the     
means by which it has secured success is
 an each case a biological problem which
 demands and will reward the most       
attentive study4 ,this is the lesson    
which ,darwin has bequeathed to us4 ,it 
is summed up in the concluding paragraph
 of the ,origin 7,origin of ,species    
7#fth edition71 page #dbi473--;,it is   
interesting to contemplate a tangled    
bank1 clothed with many plants of many  
kinds1 with birds singing on the bushes1
 with various insects flitting about1   
and with worms crawling through the damp
 earth1 and to reflect that these       
elaborately constructed forms1 so       
different from each other1 and dependent
 upon each other in so complex a manner1
 have all been produced by laws acting  
around us4     ,,xvii4 ,,geographical   
,,distribution ,,of ,,animals4 ,by ,hans
 ,gadow1 ,m4,a41 ,ph4,d41 ,f4,r4,s4     
,strickland ,curator and ,lecturer on   
,zoology in the ,university of          
,cambridge4   ,the first general ideas  

about geographical distribution may be  
found in some of the brilliant          
speculations contained in ,buffon's     
,histoire ,naturelle4 ,the first special
 treatise on the subject was however    
written in #aggg by ,e4,a4,w4           
,zimmermann1 ,professor of ,natural     
,science at ,brunswick1 whose large     
volume1 ,specimen ,zoologiae            
,geographicae ,quadrupedum4441 deals in 
a statistical way with the mammals2     
important features of the large         
accompanying map of the world are the   
ranges of mountains and the names of    
hundreds of genera indicating their     
geographical range4 ,in a second work he
 laid special stress on domesticated    
animals with reference to the spreading 
of the various races of ,mankind4  ,in  
the following year appeared the         
,philosophia ,entomologica by ,j4,c4    
,fabricius1 who was the first to divide 
the world into eight regions4 ,in #ahjc 
,g4,r4 ,treviranus 7,biologie oder      
,philosophie der lebenden ,natur1 ,vol4 

,,ii4 ,gottingen1 #ahjc47 devoted a long
 chapter of his great work on ,biologie 
to a philosophical and coherent         
treatment of the distribution of the    
whole animal kingdom4 ,remarkable       
progress was made in #ahaj by ,f4       
,tiedemann 7,anatomie und               
,naturgeschichte der ,vogel4            
,heidelberg1 #ahaj47 of ,heidelberg4    
,few1 if any1 of the many subsequent    
,ornithologists seem to have            
appreciated1 or known of1 the ingenious 
way in which ,tiedemann marshalled his  
statistics in order to arrive at general
 conclusions4 ,there are1 for instance1 
long lists of birds arranged in         
accordance with their occurrence in one 
or more continents3 by correlating the  
distribution of the birds with their    
food he concludes that the countries of 
the ,east ,indian flora have no         
vegetable feeders in common with        
,america1 and that it is probably due to
 the great peculiarity of the ,african  
flora that ,africa has few phytophagous 

kinds in common with other countries1   
whilst zoophagous birds have a far more 
independent1 often cosmopolitan1        
distribution4 ,there are also remarkable
 chapters on the influence of           
environment1 distribution1 and          
migration1 upon the structure of the    
,birds6 ,in short1 this anatomist dealt 
with some of the fundamental causes of  
distribution4  ,whilst ,tiedemann       
restricted himself to ,birds1 ,a4       
,desmoulins in #ahbb wrote a short but  
most suggestive paper on the            
,vertebrata1 omitting the birds2 he     
combated the view recently proposed by  
the entomologist ,latreille that        
temperature was the main factor in      
distribution4 ,some of his ten main     
conclusions show a peculiar mixture of  
evolutionary ideas coupled with the     
conception of the stability of species3 
whilst each species must have started   
from but one creative centre1 there may 
be several analogous centres of creation
 so far as genera and families are      

concerned4 ,countries with different    
faunas1 but lying within the same       
climatic zones1 are proof of the        
effective and permanent existence of    
barriers preventing an exchange between 
the original creative centres4  ,the    
first book dealing with the geography   
and classification of the whole animal  
kingdom was written by ,w4 ,swainson 7,a
 ,treatise on the ,geography and        
,classification of ,animals1 ,lardner's 
,cabinet ,cyclopaedia ,london1 #ahce47  
in #ahce4 ,he saw in the five races of  
,man the clue to the mapping of the     
world into as many true zoological      
divisions1 and he reconciled the five   
continents with his mystical quinary    
circles4  ,lyell's ,principles of       
,geology should have marked a new epoch1
 since in his ,elements he treats of the
 past history of the globe and the      
distribution of animals in time1 and in 
his ,principles of their distribution in
 space in connection with the actual    
changes undergone by the surface of the 

world4 ,but as the sub-title of his     
great work ,modern changes of the ,earth
 and its inhabitants indicates1 he      
restricted himself to comparatively     
minor changes1 and1 emphatically        
believing in the permanency of the great
 oceans1 his numerous and careful       
interpretations of the effect of the    
geological changes upon the dispersal of
 animals did after all advance the      
problem but little4  ,hitherto the      
marine faunas had been neglected4 ,this 
was remedied by ,e4 ,forbes1 who        
established nine homozoic zones1 based  
mainly on the study of the mollusca1 the
 determining factors being to a great   
extent the isotherms of the sea1 whilst 
the #be provinces were given by the     
configuration of the land4 ,he was      
followed by ,j4,d4 ,dana1 who1 taking   
principally the ,crustacea as a basis1  
and as leading factors the mean         
temperatures of the coldest and of the  
warmest months1 established five        
latitudinal zones4 ,by using these as   

divisors into an ,american1             
,afro-,european1 ,oriental1 ,arctic and 
,antarctic realm1 most of which were    
limited by an eastern and western       
land-boundary1 he arrived at about      
threescore provinces4  ,in #ahec        
appeared ,l4,k4 ,schmarda's 7,die       
geographische ,verbreitung der ,thiere1 
,wien1 #ahec47 two volumes1 embracing   
the whole subject4 ,various centres of  
creation being1 according to him1 still 
traceable1 he formed the hypothesis that
 these centres were originally islands1 
which later became enlarged and joined  
together to form the great continents1  
so that the original faunas could       
overlap and mix whilst still remaining  
pure at their respective centres4 ,after
 devoting many chapters to the possible 
physical causes and modes of dispersal1 
he divided the land into #ba realms     
which he shortly characterises1 e4g4    
,australia as the only country inhabited
 by marsupials1 monotremes and          
meliphagous birds4 ,ten main marine     

divisions were diagnosed in a similar   
way4 ,although some of these realms were
 not badly selected from the point of   
view of being applicable to more than   
one class of animals1 they were         
obviously too numerous for general      
purposes1 and this drawback was         
overcome1 in #aheg1 by ,p4,l4 ,sclater4 
7,on the general ,geographical          
,distribution of the members of the     
class ,aves1 ,proc4 ,linn4 ,soc4        
7,zoology ,,ii4 #aheh1 pages #acj-ade477
 ,starting with the idea1 that each     
species must have been created within   
and over the geographical area1 which it
 now occupies1 he concluded that the    
most natural primary ontological        
divisions of the ,earth's surface were  
those six regions1 which since their    
adoption by ,wallace in his epoch-making
 work1 have become classical4 ,broadly  
speaking1 these six regions are         
equivalent to the great masses of land2 
they are convenient terms for           
geographical facts1 especially since the

 ,palaearctic region expresses the unity
 of ,europe with the bulk of ,asia4     
,sclater further brigaded the regions of
 the ,old ,world as ,palaeogaea and the 
two ,americas as ,neogaea1 a fundamental
 mistake1 justifiable to a certain      
extent only since he based his regions  
mainly upon the present distribution of 
the ,passerine birds4  ,unfortunately   
these six regions are not of equal      
value4 ,the ,indian countries and the   
,ethiopian region 7,africa south of the 
,sahara7 are obviously nothing but the  
tropical1 southern continuations or     
appendages of one greater complex4      
,further1 the great eastern mass of land
 is so intimately connected with ,north 
,america that this continent has much   
more in common with ,europe and ,asia   
than with ,south ,america4 ,therefore1  
instead of dividing the world           
longitudinally as ,sclater had done1    
,huxley1 in #ahfh 7,on the              
classification and distribution of the  
,alectoromorphae and ,heteromorphae1    

,proc4 ,zool4 ,soc4 #ahfh1 page #bid471 
gave weighty reasons for dividing it    
transversely4 ,accordingly he           
established two primary divisions1      
,arctogaea or the ,north world in a     
wider sense1 comprising ,sclater's      
,indian1 ,african1 ,palaearctic and     
,neartic regions2 and ,notogaea1 the    
,southern world1 which he divided into  
7#a7 ,austro-,columbia 7an unfortunate  
substitute for the neotropical region71 
7#b7 ,australasia1 and 7#c7 ,new        
,zealand1 the number of big regions thus
 being reduced to three but for the     
separation of ,new ,zealand upon rather 
negative characters4 ,sclater was the   
first to accept these four great regions
 and showed1 in #ahgd 7,the geographical
 distribution of ,mammals1 ,manchester  
,science ,lectures1 #ahgd471 that they  
were well borne out by the present      
distribution of the ,mammals4  ,although
 applicable to various other groups of  
animals1 for instance to the tailless   
,amphibia and to ,birds 7,huxley himself

 had been led to found his two          
fundamental divisions on the            
distribution of the ,gallinaceous       
birds71 the combination of ,south       
,america with ,australia was gradually  
found to be too sweeping a measure4 ,the
 obvious and satisfactory solution was  
provided by ,w4,t4 ,blanford            
7,anniversary address 7,geological      
,society1 #ahhi71 ,proc4 ,geol4 ,soc4   
#ahhi-ij1 page #fg2 ,quart4 ,journ4     
,,xlvi #ahij471 who in #ahij recognised 
three main divisions1 namely            
,australian1 ,south ,american1 and the  
rest1 for which the already existing    
terms 7although used partly in a new    
sense1 as proposed by an anonymous      
writer in ,natural ,science1 ,,iii4 page
 #bhi7 ,notogaea1 ,neogaea and          
,arctogaea have been gladly accepted by 
a number of ,english writers4  ,after   
this historical survey of the search for
 larger and largest or fundamental      
centres of animal creation1 which       
resulted in the mapping of the world    

into zoological regions and realms of   
after all doubtful value1 we have to    
return to the year #aheh4 ,the eleventh 
and twelfth chapters of ,the ,origin of 
,species 7#ahei71 dealing with          
,geographical ,distribution1 are based  
upon a great amount of observation1     
experiment and reading4 ,as ,darwin's   
main problem was the origin of species1 
nature's way of making species by       
gradual changes from others previously  
existing1 he had to dispose of the view1
 held universally1 of the independent   
creation of each species and at the same
 time to insist upon a single centre of 
creation for each species2 and in order 
to emphasise his main point1 the theory 
of descent1 he had to disallow          
convergent1 or as they were then called1
 analogous forms4 ,to appreciate the    
difficulty of his position we have to   
take the standpoint of fifty years ago1 
when the immutability of the species was
 an axiom and each was supposed to have 
been created within or over the         

geographical area which it now occupies4
 ,if he once admitted that a species    
could arise from many individuals       
instead of from one pair1 there was no  
way of shutting the door against the    
possibility that these individuals may  
have been so numerous that they occupied
 a very large district1 even so large   
that it had become as discontinuous as  
the distribution of many a species      
actually is4 ,such a concession would at
 once be taken as an admission of       
multiple1 independent1 origin instead of
 descent in ,darwin's sense4  ,for the  
so-called multiple1 independently       
repeated creation of species as an      
explanation of their very wide and often
 quite discontinuous distribution1 he   
substituted colonisation from the       
nearest and readiest source together    
with subsequent modification and better 
adaptation to their new home4  ,he was  
the first seriously to call attention to
 the many accidental means1 which more  
properly should be called occasional    

means of distribution1 especially to    
oceanic islands4 ,his specific1 even    
individual1 centres of creation made    
migrations all the more necessary1 but  
their extent was sadly baulked by the   
prevailing dogma of the permanency of   
the oceans4 ,any number of small changes
 7many islands having existed as halting
 places1 of which not a wreck now       
remains 7,the ,origin of ,species 7#ast 
edition71 page #cif4747 were conceded   
freely1 but few1 if any1 great enough to
 permit migration of truly terrestrial  
creatures4 ,the only means of getting   
across the gaps was by the principle of 
the flotsam and jetsam1 a theory which  
,darwin took over from ,lyell and       
further elaborated so as to make it     
applicable to many kinds of plants and  
animals1 but sadly deficient1 often     
grotesque1 in the case of most          
terrestrial creatures4  ,another very   
fertile source was ,darwin's strong     
insistence upon the great influence     
which the last glacial epoch must have  

had upon the distribution of animals and
 plants4 ,why was the migration of      
northern creatures southwards of        
far-reaching and most significant       
importance8 ,more northerners have      
established themselves in southern lands
 than vice versa1 because there is such 
a great mass of land in the north and   
greater continents imply greater        
intensity of selection4 ,the productions
 of real islands have everywhere largely
 yielded to continental forms4 7,ibid4  
page #chj47444 ,the ,alpine forms have  
almost everywhere largely yielded to the
 more dominant forms generated in the   
larger areas and more efficient         
workshops of the ,north4  ,let us now   
pass in rapid survey the influence of   
the publication of ,the ,origin of      
,species upon the study of ,geographical
 ,distribution in its wider sense4      
,hitherto the following thought ran     
through the minds of most writers3      
,wherever we examine two or more widely 
separated countries their respective    

faunas are very different1 but where two
 faunas can come into contact with each 
other1 they intermingle4 ,consequently  
these faunas represent centres of       
creation1 whence the component creatures
 have spread peripherally so far as     
existing boundaries allowed them to do  
so4 ,this is of course the fundamental  
idea of regions4 ,there is not one of   
the numerous writers who considered the 
possibility that these intermediate     
belts might represent not a mixture of  
species but transitional forms1 the     
result of changes undergone by the most 
peripheral migrants in adaptation to    
their new surroundings4 ,the usual      
standpoint was also that of ,pucheran   
7,note sur l'equateur zoologique1 ,rev4 
et ,mag4 de ,zoologie1 #ahee2 also      
several other papers1 ibid4 #ahfe1      
#ahff1 and #ahfg47 in #ahee4 ,but what a
 change within the next ten years6      
,pucheran explains the agreement in     
coloration between the desert and its   
fauna as une harmonie post-etablie2 the 

,sahara1 formerly a marine basin1 was   
peopled by immigrants from the          
neighbouring countries1 and these new   
animals adapted themselves to the new   
environment4 ,he also discusses1 among  
other similar questions1 the ,isthmus of
 ,panama with regard to its having once 
been a strait4 ,from the same author may
 be quoted the following passage as a   
strong proof of the new influence3 ,by  
the radiation of the contemporaneous    
faunas1 each from one centre1 whence as 
the various parts of the world          
successively were formed and became     
habitable1 they spread and became       
modified according to the local physical
 conditions4  ,the multiple origin of   
each species as advocated by ,sclater   
and ,murray1 although giving the species
 a broader basis1 suffered from the same
 difficulties4 ,there was only one      
alternative to the old orthodox view of 
independent creation1 namely the bold   
acceptance of land-connections to an    
extent for which geological and         

palaeontological science was not yet    
ripe4 ,those who shrank from either     
view1 gave up the problem as mysterious 
and beyond the human intellect4 ,this   
was the expressed opinion of men like   
,swainson1 ,lyell and ,humboldt4 ,only  
,darwin had the courage to say that the 
problem was not insoluble4 ,if we admit 
that in the long course of time the     
individuals of the same species1 and    
likewise of allied species1 have        
proceeded from some one source2 then ,i 
think all the grand leading facts of    
geographical distribution are explicable
 on the theory of migration444 together 
with subsequent modification and the    
multiplication of new forms4 ,we can    
thus understand how it is that in some  
countries the inhabitants are linked to 
the extinct beings which formerly       
inhabited the same continent4 ,we can   
see why two areas1 having nearly the    
same physical conditions1 should often  
be inhabited by very different forms of 
life1444 and we can see why in two      

areas1 however distant from each other1 
there should be a correlation1 in the   
presence of identical species444 and of 
distinct but representative species4    
7,the ,origin of ,species 7#ast         
edition71 pages #djh1 #dji47  ,darwin's 
reluctance to assume great geological   
changes1 such as a land-connection of   
,europe with ,north ,america1 is easily 
explained by the fact that he restricted
 himself to the distribution of the     
present and comparatively recent        
species4 ,i do not believe that it will 
ever be proved that within the recent   
period continents which are now quite   
separate1 have been continuously1 or    
almost continuously1 united with each   
other1 and with the many existing       
oceanic islands4 7,ibid4 page #ceg47    
,again1 believing444 that our continents
 have long remained in nearly the same  
relative position1 though subjected to  
large1 but partial oscillations of      
level1 that means to say within the     
period of existing species1 or within   

the recent period4 7,ibid4 page4 #cgj47 
,the difficulty was to a great extent   
one of his own making4 ,whilst almost   
everybody else believed in the          
immutability of the species1 which      
implies an enormous age1 logically since
 the dawn of creation1 to him the       
actually existing species as the latest 
results of evolution1 were necessarily  
something very new1 so young that only  
the very latest of the geological epochs
 could have affected them4 ,it has since
 come to our knowledge that a great     
number of terrestrial recent species1   
even those of the higher classes of     
,vertebrates1 date much farther back    
than had been thought possible4 ,many of
 them reach well into the ,miocene1 a   
time since which the world seems to have
 assumed the main outlines of the       
present continents4  ,in the year #ahff 
appeared ,a4 ,murray's work on the      
,geographical ,distribution of ,mammals1
 a book which has perhaps received less 
recognition than it deserves4 ,his      

treatment of the general introductory   
questions marks a considerable advance  
of our problem1 although1 and partly    
because1 he did not entirely agree with 
,darwin's views as laid down in the     
first edition of ,the ,origin of        
,species1 which after all was the great 
impulse given to ,murray's work4 ,like  
,forbes he did not shrink from assuming 
enormous changes in the configuration of
 the continents and oceans because the  
theory of descent1 with its necessary   
postulate of great migrations1 required 
them4 ,he stated1 for instance1 that a  
,miocene ,atlantis sufficiently explains
 the common distribution of animals and 
plants in ,europe and ,america up to the
 glacial epoch4 ,and next he considers  
how1 and by what changes1 the           
rehabilitation and distribution of these
 lands themselves were effected         
subsequent to that period4 ,further1 he 
deserves credit for having cleared up a 
misunderstanding of the idea of specific
 centres of creation4 ,whilst for       

instance ,schmarda assumed without      
hesitation that the same species1 if    
occurring at places separated by great  
distances1 or apparently insurmountable 
barriers1 had been there created        
independently 7multiple centres71 ,lyell
 and ,darwin held that each species had 
only one single centre1 and with this   
view most of us agree1 but their        
starting point was to them represented  
by one individual1 or rather one single 
pair4 ,according to ,murray1 on the     
other hand1 this centre of a species is 
formed by all the individuals of a      
species1 all of which equally undergo   
those changes which new conditions may  
impose upon them4 ,in this respect a new
 species has a multiple origin1 but this
 in a sense very different from that    
which was upheld by ,l4 ,agassiz4 ,as   
,murray himself puts it3 ,to my multiple
 origin1 communication and direct       
derivation is essential4 ,the species is
 compounded of many influences brought  
together through many individuals1 and  

distilled by ,nature into one species2  
and1 being once established it may roam 
and spread wherever it finds the        
conditions of life not materially       
different from those of its original    
centre4 7,murray1 ,the ,geographical    
,distribution of ,mammals1 page #ad4    
,london1 #ahff47 ,this declaration      
fairly agrees with more modern views1   
and it must be borne in mind that the   
application of the single-centre        
principle to the genera1 families and   
larger groups in the search for descent 
inevitably leads to one creative centre 
for the whole animal kingdom1 a         
condition as unwarrantable as the myth  
of ,adam and ,eve being the first       
representatives of ,mankind4  ,it looks 
as if it had required almost ten years  
for ,the ,origin of ,species to show its
 full effect1 since the year #ahfh marks
 the publication of ,haeckel's          
,naturliche ,schoepfungsgeschichte in   
addition to other great works4 ,the     
terms ,oecology 7the relation of        

organisms to their environment7 and     
,chorology 7their distribution in space7
 had been given us in his ,generelle    
,morphologie in #ahff4 ,the fourteenth  
chapter of the ,history of ,creation is 
devoted to the distribution of          
organisms1 their chorology1 with the    
emphatic assertion that not until       
,darwin can chorology be spoken of as a 
separate science1 since he supplied the 
acting causes for the elucidation of the
 hitherto accumulated mass of facts4 ,a 
map 7a hypothetical sketch7 shows the   
monophyletic origin and the routes of   
distribution of ,man4  ,natural         
,selection may be all-mighty1           
all-sufficient1 but it requires time1 so
 much that the countless aeons required 
for the evolution of the present fauna  
were soon felt to be one of the most    
serious drawbacks of the theory4        
,therefore every help to ease and       
shorten this process should have been   
welcomed4 ,in #ahfh ,m4 ,wagner 7,the   
first to formulate clearly the          

fundamental idea of a theory of         
migration and its importance in the     
origin of new species was ,l4 von ,buch1
 who in his ,physikalische ,beschreibung
 der ,canarischen ,inseln1 written in   
#ahbe1 wrote as follows3 ,upon the      
continents the individuals of the genera
 by spreading far1 form1 through        
differences of the locality1 food and   
soil1 varieties which finally become    
constant as new species1 since owing to 
the distances they could never be       
crossed with other varieties and thus be
 brought back to the main type4 ,next   
they may again1 perhaps upon different  
roads1 return to the old home where they
 find the old type likewise changed1    
both having become so different that    
they can interbreed no longer4 ,not so  
upon islands1 where the individuals shut
 up in narrow valleys or within narrow  
districts1 can always meet one another  
and thereby destroy every new attempt   
towards the fixing of a new variety4    
,clearly von ,buch explains here why    

island types remain fixed1 and why these
 types themselves have become so        
different from their continental        
congeners4--,actually von ,buch is aware
 of a most important point1 the         
difference in the process of development
 which exists between a new species b1  
which is the result of an ancestral     
species a having itself changed into b  
and thereby vanished itself1 and a new  
species c which arose through separation
 out of the same ancestral a1 which     
itself persists as such unaltered4 ,von 
,buch's prophetic view seems to have    
escaped ,lyell's and even ,wagner's     
notice47 came to the rescue with his    
,darwin'sche ,theorie und das           
,migrations-,gesetz der ,organismen4    
7,leipzig1 #ahfh47 ,he shows that       
migration1 i4e4 change of locality1     
implies new environmental conditions    
7never mind whether these be new stimuli
 to variation1 or only acting as their  
selectors or censors71 and moreover     
secures separation from the original    

stock and thus eliminates or lessens the
 reactionary dangers of panmixia4       
,darwin accepted ,wagner's theory as    
advantageous4 ,through the heated       
polemics of the more ardent             
selectionists ,wagner's theory came to  
grow into an alternative instead of a   
help to the theory of selectional       
evolution4 ,separation is now rightly   
considered a most important factor by   
modern students of geographical         
distribution4  ,for the same year1      
#ahfh1 we have to mention ,huxley1 whose
 ,arctogaea and ,notogaea are nothing   
less than the reconstructed main masses 
of land of the ,mesozoic period4 ,beyond
 doubt the configuration of land at that
 remote period has left recognisable    
traces in the present continents1 but   
whether they can account for the        
distribution of such a much later group 
as the ,gallinaceous birds is more than 
questionable4 ,in any case he took for  
his text a large natural group of birds1
 cosmopolitan as a whole1 but with a    

striking distribution4 ,the             
,peristeropodes1 or pigeon-footed       
division1 are restricted to the         
,australian and ,neotropical regions1 in
 distinction to the ,alectoropodes 7with
 the hallux inserted at a level above   
the front toes7 which inhabit the whole 
of the ,arctogaea1 only a few members   
having spread into the ,south ,world4   
,further1 as ,asia alone has its        
,pheasants and allies1 so is ,africa    
characterised by its ,guinea-fowls and  
relations1 ,america has the ,turkey as  
an endemic genus1 and the ,grouse tribe 
in a wider sense has its centre in the  
holarctic region3 a splendid object     
lesson of descent1 world-wide spreading 
and subsequent differentiation4 ,huxley1
 by the way1 was the first--at least in 
private talk--to state that it will be  
for the morphologist1 the well-trained  
anatomist1 to give the casting vote in  
questions of geographical distribution1 
since he alone can determine whether we 
have to deal with homologous1 or        

analogous1 convergent1 representative   
forms4  ,it seems late to introduce     
,wallace's name in #ahgf1 the year of   
the publication of his standard work4   
7,the ,geographical ,distribution of    
,animals1 #b vols4 ,london1 #ahgf47 ,we 
cannot do better than quote the author's
 own words1 expressing the hope that his
 book should bear a similar relation to 
the eleventh and twelfth chapters of the
 ,origin of ,species as ,darwin's       
,animals and ,plants under              
,domestication does to the first chapter
 of that work1 and to add that he has   
amply succeeded4 ,pleading for a few    
primary centres he accepts ,sclater's   
six regions and does not follow         
,huxley's courageous changes which      
,sclater himself had accepted in #ahgd4 
,holding the view of the permanence of  
the oceans he accounts for the          
colonisation of outlying islands by     
further elaborating the views of ,lyell 
and ,darwin1 especially in his          
fascinating ,island ,life1 with         

remarkable chapters on the ,ice ,age1   
,climate and ,time and other fundamental
 factors4 ,his method of arriving at the
 degree of relationship of the faunas of
 the various regions is eminently       
statistical4 ,long lists of genera      
determine by their numbers the affinity 
and hence the source of colonisation4   
,in order to make sure of his material  
he performed the laborious task of      
evolving a new classification of the    
host of ,passerine birds4 ,this         
statistical method has been followed by 
many authors1 who1 relying more upon    
quantity than quality1 have obscured the
 fact that the key to the present       
distribution lies in the past changes of
 the earth's surface4 ,however1 with    
,wallace begins the modern study of the 
geographical distribution of animals and
 the sudden interest taken in this      
subject by an ever widening circle of   
enthusiasts far beyond the professional 
brotherhood4  ,a considerable literature
 has since grown up1 almost bewildering 

in its range1 diversity of aims and     
style of procedure4 ,it is a chaos1 with
 many paths leading into the maze1 but  
as yet very few take us to a position   
commanding a view of the whole intricate
 terrain with its impenetrable tangle   
and pitfalls4  ,one line of research1   
not initiated but greatly influenced by 
,wallace's works1 became so prominent as
 to almost constitute a period which may
 be characterised as that of the search 
by specialists for either the           
justification or the amending of his    
regions4 ,as class after class of       
animals was brought up to reveal the    
secret of the true regions1 some authors
 saw in their different results nothing 
but the faultiness of previously        
established regions2 others looked upon 
eventual agreements as their final      
corroboration1 especially when for      
instance such diverse groups as mammals 
and scorpions could1 with some          
ingenuity1 be made to harmonise4 ,but   
the obvious result of all these efforts 

was the growing knowledge that almost   
every class seemed to follow principles 
of its own4 ,the regions tallied neither
 in extent nor in numbers1 although most
 of them gravitated more and more       
towards three centres1 namely           
,australia1 ,south ,america and the rest
 of the world4 ,still zoologists        
persisted in the search1 and the various
 modes and capabilities of dispersal of 
the respective groups were thought      
sufficient explanation of the divergent 
results in trying to bring the mapping  
of the world under one scheme4          
,contemporary literature is full of     
devices for the mechanical dispersal of 
animals4 ,marine currents1 warm and     
cold1 were favoured all the more since  
they showed the probable original homes 
of the creatures in question4 ,if these 
could not stand sea-water1 they floated 
upon logs or icebergs1 or they were     
blown across by storms2 fishes were     
lifted over barriers by waterspouts1 and
 there is on record even an hypothetical

 land tortoise1 full of eggs1 which     
colonised an oceanic island after a     
perilous sea voyage upon a tree trunk4  
,accidents will happen1 and beyond doubt
 many freaks of discontinuous           
distribution have to be accounted for by
 some such means4 ,but whilst sufficient
 for the scanty settlers of true oceanic
 islands1 they cannot be held seriously 
to account for the rich fauna of a large
 continent1 over which palaeontology    
shows us that the immigrants have passed
 like waves4 ,it should also be borne in
 mind that there is a great difference  
between flotsam and jetsam4 ,a current  
is an extension of the same medium and  
the animals in it may suffer no change  
during even a long voyage1 since they   
may be brought from one litoral to      
another where they will still be in the 
same or but slightly altered            
environment4 ,but the jetsam is in the  
position of a passenger who has been    
carried off by the wrong train4 ,almost 
every year some ,american land birds    

arrive at our western coasts and none of
 them have gained a permanent footing   
although such visits must have taken    
place since prehistoric times4 ,it was  
therefore argued that only those groups 
of animals should be used for locating  
and defining regions which were         
absolutely bound to the soil4 ,this     
method likewise gave results not        
reconcilable with each other1 even when 
the distribution of fossils was taken   
into account1 but it pointed to the     
absolute necessity of searching for     
former land-connections regardless of   
their extent and the present depths to  
which they may have sunk4  ,that the key
 to the present distribution lies in the
 past had been felt long ago1 but at    
last it was appreciated that the various
 classes of animals and plants have     
appeared in successive geological epochs
 and also at many places remote from    
each other4 ,the key to the distribution
 of any group lies in the configuration 
of land and water of that epoch in which

 it made its first appearance4 ,although
 this sounds like a platitude1 it has   
frequently been ignored4 ,if1 for       
argument's sake1 ,amphibia were evolved 
somewhere upon the great southern       
land-mass of ,carboniferous times       
7supposed by some to have stretched from
 ,south ,america across ,africa to      
,australia71 the distribution of this   
developing class must have proceeded    
upon lines altogether different from    
that of the mammals which dated perhaps 
from lower ,triassic times1 when the old
 south continental belt was already     
broken up4 ,the broad lines of this     
distribution could never coincide with  
that of the other1 older class1 no      
matter whether the original mammalian   
centre was in the ,afro-,indian1        
,australian1 or ,brazilian portion4 ,if 
all the various groups of animals had   
come into existence at the same time and
 at the same place1 then it would be    
possible1 with sufficient geological    
data1 to construct a map showing the    

generalised results applicable to the   
whole animal kingdom4 ,but the premises 
are wrong4 ,whatever regions we may seek
 to establish applicable to all classes1
 we are necessarily mixing up several   
principles1 namely geological1          
historical1 i4e4 evolutionary1 with     
present day statistical facts4 ,we might
 as well attempt one compound picture   
representing a chick's growth into an   
adult bird and a child's growth into    
manhood4  ,in short there are no general
 regions1 not even for each class       
separately1 unless this class be one    
which is confined to a comparatively    
short geological period4 ,most of the   
great classes have far too long a       
history and have evolved many successive
 main groups4 ,let us take the mammals4 
,marsupials live now in ,australia and  
in both ,americas1 because they already 
existed in ,mesozoic times2 ,ungulata   
existed at one time or other all over   
the world except in ,australia1 because 
they are post-,cretaceous2              

,insectivores1 although as old as any   
,placentalia1 are cosmopolitan excepting
 ,south ,america and ,australia2 ,stags 
and ,bears1 as examples of comparatively
 recent ,arctogaeans1 are found         
everywhere with the exception of        
,ethiopia and ,australia4 ,each of these
 groups teaches a valuable historical   
lesson1 but when these are combined into
 the establishment of a few mammalian   
realms1 they mean nothing but           
statistical majorities4 ,if there is one
 at all1 ,australia is such a realm     
backed against the rest of the world1   
but as certainly it is not a mammalian  
creative centre6  ,well then1 if the    
idea of generally applicable regions is 
a mare's nest1 as was the search for the
 ,holy ,grail1 what is the object of the
 study of geographical distribution8 ,it
 is nothing less than the history of the
 evolution of life in space and time in 
the widest sense4 ,the attempt to       
account for the present distribution of 
any group of organisms involves the aid 

of every branch of science4 ,it bids    
fair to become a history of the world4  
,it started in a mild1 statistical way1 
restricting itself to the present fauna 
and flora and to the present            
configuration of land and water4 ,next  
came ,oceanography concerned with the   
depths of the seas1 their currents and  
temperatures2 then enquiries into       
climatic changes1 culminating in        
irreconcilable astronomical hypotheses  
as to glacial epochs2 theories about    
changes of the level of the seas1 mainly
 from the point of view of the physicist
 and astronomer4 ,then came more and    
more to the front the importance of the 
geological record1 hand in hand with the
 palaeontological data and the search   
for the natural affinities1 the genetic 
system of the organisms4 ,now and then  
it almost seems as if the biologists had
 done their share by supplying the      
problems and that the physicists and    
geologists would settle them1 but in    
reality it is not so4 ,the biologists   

not only set the problems1 they alone   
can check the offered solutions4 ,the   
mere fact of palms having flourished in 
,miocene ,spitzbergen led to an         
hypothetical shifting of the axis of the
 world rather than to the assumption1 by
 way of explanation1 that the palms     
themselves might have changed their     
nature4 ,one of the most valuable aids  
in geological research1 often the only  
means for reconstructing the face of the
 earth in by-gone periods1 is afforded  
by fossils1 but only the morphologist   
can pronounce as to their               
trustworthiness as witnesses1 because of
 the danger of mistaking analogous for  
homologous forms4 ,this difficulty      
applies equally to living groups1 and it
 is so important that a few instances   
may not be amiss4  ,there is undeniable 
similarity between the faunas of        
,madagascar and ,south ,america4 ,this  
was supported by the ,centetidae and    
,dendrobatidae1 two entire families1 as 
also by other facts4 ,the value of the  

,insectivores1 ,solenodon in ,cuba1     
,centetes in ,madagascar1 has been much 
lessened by their recognition as an     
extremely ancient group and as a case of
 convergence1 but if they are no longer 
put into the same family1 this amendment
 is really to a great extent due to     
their widely discontinuous distribution4
 ,the only systematic difference of the 
,dendrobatidae from the ,ranidae is the 
absence of teeth1 morphologically a very
 unimportant character1 and it is now   
agreed1 on the strength of their        
distribution1 that these little         
arboreal1 conspicuously coloured frogs1 
,dendrobates in ,south ,america1        
,mantella in ,madagascar1 do not form a 
natural group1 although a third genus1  
,cardioglossa in ,west ,africa1 seems   
also to belong to them4 ,if these       
creatures lived all on the same         
continent1 we should unhesitatingly look
 upon them as forming a well-defined1   
natural little group4 ,on the other hand
 the ,aglossa1 with their three very    

divergent genera1 namely ,pipa in ,south
 ,america1 ,xenopus and ,hymenochirus in
 ,africa1 are so well characterised as  
one ancient group that we use their     
distribution unhesitatingly as a hint of
 a former connection between the two    
continents4 ,we are indeed arguing in   
vicious circles4 ,the ,ratitae as such  
are absolutely worthless since they are 
a most heterogeneous assembly1 and there
 are untold groups1 of the artificiality
 of which many a zoo-geographer had not 
the slightest suspicion when he took his
 statistical material1 the genera and   
families1 from some systematic          
catalogues or similar lists4 ,a         
lamentable instance is that of certain  
flightless ,rails1 recently extinct or  
sub-fossil1 on the isalnds of           
,mauritius1 ,rodriguez and ,chatham4    
,being flightless they have been used in
 support of a former huge ,antarctic    
continent1 instead of ruling them out of
 court as ,rails which1 each in its     
island1 have lost the power of flight1 a

 process which must have taken place so 
recently that it is difficult1 upon     
morphological grounds1 to justify their 
separation into ,aphanapteryx in        
,mauritius1 ,erythromachus in ,rodriguez
 and ,diaphorapteryx on ,chatham        
,island4 ,morphologically they may well 
form but one genus1 since they have     
sprung from the same stock and have     
developed upon the same lines2 they are 
therefore monogenetic3 but since we know
 that they have become what they are    
independently of each other 7now unlike 
any other ,rails71 they are polygenetic 
and therefore could not form one genus  
in the old ,darwinian sense4 ,further1  
they are not a case of convergence1     
since their ancestry is not divergent   
but leads into the same stratum4  ,,the 
,,reconstruction ,,of ,,the ,,geography 
,,of ,,successive ,,epochs4  ,a         
promising method is the study by the    
specialist of a large1 widely           
distributed group of animals from an    
evolutionary point of view4 ,good       

examples of this method are afforded by 
,a4,e4 ,ortmann's 7,the geographical    
distribution of ,freshwater ,decapods   
and its bearing upon ancient geography1 
,proc4 ,amer4 ,phil4 ,soc4 ,vol4 #da1   
#aijb47 exhaustive paper and by ,a4,w4  
,grabau's ,phylogeny of ,fusus and its  
,allies 7,smithsonian ,misc4 ,coll4 #dd1
 #aijd47 ,after many important groups of
 animals have been treated in this      
way--as yet sparingly attempted--the    
results as to hypothetical              
land-connections etc4 are sure to be    
corrective and supplementary1 and their 
problems will be solved1 since they are 
not imaginary4  ,the same problems are  
attacked1 in the reverse way1 by        
starting with the whole fauna of a      
country and thence1 so to speak1 letting
 the research radiate4 ,some groups will
 be considered as autochthonous1 others 
as immigrants1 and the directions       
followed by them will be inquired into2 
the search may lead far and in various  
directions1 and by comparison of        

results1 by making compound maps1       
certain routes will assume definite     
shape1 and if they lead across straits  
and seas they are warrants to search for
 land-connections in the past4 7,a fair 
sample of this method is ,c4,h4         
,eigenmann's ,the ,freshwater ,fishes of
 ,south and ,middle ,america1 ,popular  
,science ,monthly1 ,vol4 #fh1 #aijf47   
,there are now not a few maps purporting
 to show the outlines of land and water 
at various epochs4 ,many of these       
attempts do not tally with each other1  
owing to the lamentable deficiencies of 
geological and fossil data1 but the     
bolder the hypothetical outlines are    
drawn1 the better1 and this is          
preferable to the insertion of bays and 
similar detail which give such maps a   
fallacious look of certainty where none 
exists4 ,moreover it must be borne in   
mind that1 when we draw a broad         
continental belt across an ocean1 this  
belt need never have existed in its     
entirety at any one time4 ,the features 

of dispersal1 intended to be explained  
by it1 would be accomplished just as    
well by an unknown number of islands    
which have joined into larger complexes 
while elsewhere they subsided again3    
like pontoon-bridges which may be opened
 anywhere1 or like a series of          
superimposed dissolving views of land   
and sea-scapes4 ,hence the reconstructed
 maps of ,europe1 the only continent    
tolerably known1 show a considerable    
number of islands in puzzling changes1  
while elsewhere1 e4g4 in ,asia1 we have 
to be satisfied with sweeping           
generalisations4  ,at present about     
half-a-dozen big connections are        
engaging our attention1 leaving as      
comparatively settled the extent and the
 duration of such minor bridges as that 
between ,africa and ,madagascar1        
,tasmania and ,australia1 the ,antilles 
and ,central ,america1 ,europe and      
,north ,africa4 7,not a few of those who
 are fascinated by1 and satisfied with1 
the statistical aspect of distribution  

still have a strong dislike to the use  
of bridges if these lead over deep seas1
 and they get over present discontinuous
 occurrences by a former universal or   
sub-universal distribution of their     
groups47 ,this is indeed an easy method 
of cutting the knot1 but in reality they
 shunt the question only a stage or two 
back1 never troubling to explain how    
their groups managed to attain to that  
sub-universal range2 or do they still   
suppose that the whole world was        
originally one paradise where everything
 lived side by side1 until sin and      
strife and glacial epochs left nothing  
but scattered survivors8  ,the          
permanence of the great ocean-basins had
 become a dogma since it was found that 
a universal elevation of the land to the
 extent of #ajj fathoms would produce   
but little changes1 and when it was     
shown that even the #ajjj fathom-line   
followed the great masses of land rather
 closely1 and still leaving the great   
basins 7although transgression of the   

sea to the same extent would change the 
map of the world beyond recognition71 by
 general consent one mile was allowed as
 the utmost speculative limit of        
subsidence4 ,naturally two or three     
miles1 the average depth of the oceans1 
seems enormous1 and yet such a          
difference in level is as nothing in    
comparison with the size of the ,earth4 
,on a clay model globe ten feet in      
diameter an ocean bed three miles deep  
would scarcely be detected1 and the     
highest mountains would be smaller than 
the unavoidable grains in the glazed    
surface of our model4 ,there are but few
 countries which have not be submerged  
at some time or other4  ,,connection    
,,of ,,south ,,eastern ,,asia ,,with    
,,australia4 ,neumayr's                 
,sino-,australian continent during      
mid-,mesozoic times was probably a much 
changing ,archipelago1 with final       
separations subsequent to the           
,cretaceous period4 ,henceforth         
,australasia was left to its own fate1  

but for a possible connection with the  
antarctic continent4  ,,africa1         
,,madagascar1 ,,india4 ,the ,lemuria of 
,sclater and ,haeckel cannot have been  
more than a broad bridge in ,jurassic   
times2 whether it was ever available for
 the ,lemurs themselves must depend upon
 the time of its duration1 the more     
recent the better1 but it is difficult  
to show that it lasted into the         
,miocene4  ,,africa ,,and ,,south       
,,america4 ,since the opposite coasts   
show an entire absence of marine fossils
 and deposits during the ,mesozoic      
period1 whilst further north and south  
such are known to exist and are mostly  
identical on either side1 ,neumayr      
suggested the existence of a great      
,afro-,son ,american mass of land during
 the ,jurassic epoch4 ,such land is     
almost a necessity and is supported by  
many facts2 it would easily explain the 
distribution of numerous groups of      
terrestrial creatures4 ,moreover to the 
north of this hypothetical land1        

somewhere across from the ,antilles and 
,guiana to ,north ,africa and ,south    
,western ,europe1 existed an almost     
identical fauna of ,corals and          
,molluscs1 indicating either a          
coast-line or a series of islands       
interrupted by shallow seas1 just as one
 would expect if1 and when1 a           
,brazil-,ethiopian mass of land were    
breaking up4 ,lastly from ,central      
,america to the ,mediterranean stretches
 one of the ,tertiary tectonic lines of 
the geologists4 ,here also the great    
question is how long this continent     
lasted4 ,apparently the ,south ,atlantic
 began to encroach from the south so    
that by the later ,cretaceous epoch the 
land was reduced to a comparatively     
narrow ,brazil-,west ,africa1 remnants  
of which persisted certainly into the   
early ,tertiary1 until the ,south       
,atlantic joined across the equator with
 the ,atlantic portion of the ,thetys1  
leaving what remained of ,south ,america
 isolated from the rest of the world4   

,,antarctic ,,connections4 ,patagonia   
and ,argentina seem to have joined      
,antartica during the ,cretaceous epoch1
 and this ,south ,georgian bridge had   
broken down again by mid-,tertiary times
 when ,south ,america became            
consolidated4 ,the ,antarctic continent1
 presuming that it existed1 seems also  
to have been joined1 by way of          
,tasmania1 with ,australia1 also during 
the ,cretaceous epoch1 and it is assumed
 that the great                         
,australia-,antarctic-,patagonian land  
was severed first to the south of       
,tasmania and then at the ,south        
,georgian bridge4 ,no connection1 and   
this is important1 is indicated between 
,antarctica and either ,africa or       
,madagascar4  ,so far we have followed  
what may be called the vicissitudes of  
the great ,permo-,carboniferous         
,gondwana land in its fullest imaginary 
extent1 an enormous equatorial and south
 temperate belt from ,south ,america to 
,africa1 ,south ,india and ,australia1  

which seems to have provided the        
foundation of the present ,southern     
continents1 two of which temporarily    
joined ,antarctica1 of which however we 
know nothing except that it exists now4 
,let us next consider the ,arctic and   
periarctic lands4 ,unfortunately very   
little is known about the region within 
the arctic circle4 ,if it was all land1 
or more likely great changing           
archipelagoes1 faunistic exchange       
between ,north ,america1 ,europe and    
,siberia would present no difficulties1 
but there is one connection which       
engages much attention1 namely a land   
where now lies the ,north temperate and 
,northern part of the ,atlantic ocean4  
,how far south did it ever extend and   
what is the latest date of a direct     
practicable communication1 say from     
,north ,western ,europe to ,greenland8  
,connections1 perhaps often interrupted1
 e4g4 between ,greenland and ,labrador1 
at another time between ,greenland and  
,scandinavia1 seem to have existed at   

least since the ,permo-,carboniferous   
epoch4 ,if they existed also in late    
,cretaceous and in ,tertiary times1 they
 would of course easily explain         
exchanges which we know to have         
repeatedly taken place between ,america 
and ,europe1 but they are not proved    
thereby1 since most of these exchanges  
can almost as easily have occurred      
across the polar regions1 and others    
still more easily by repeated junction  
of ,siberia with ,alaska4  ,let us now  
describe a hypothetical case based on   
the supposition of connecting bridges4  
,not to work in a circle1 we select an  
important group which has not served as 
a basis for the reconstruction of       
bridges2 and it must be a group which we
 feel justified in assuming to be old   
enough to have availed itself of ancient
 land-connections4  ,the occurrence of  
one species of ,peripatus in the whole  
of ,australia1 ,tasmania and ,new       
,zealand 7the latter being joined to    
,australia by way of ,new ,britain in   

,cretaceous times but not later7 puts   
the genus back into this epoch1 no      
unsatisfactory assumption to the        
morphologist4 ,the apparent absence of  
,peripatus in ,madagascar indicates that
 it did not come from the east into     
,africa1 that it was neither            
,afro-,indian1 nor ,afro-,australian2   
nor can it have started in ,south       
,america4 ,we therefore assume as its   
creative centre ,australia or ,malaya in
 the ,cretaceous epoch1 whence its      
occurrence in ,sumatra1 ,malay          
,peninsula1 ,new ,britain1 ,new ,zealand
 and ,australia is easily explained4    
,then extension across ,antarctica to   
,patagonia and ,chile1 whence it could  
spread into the rest of ,south ,america 
as this became consolidated in early    
,tertiary times4 ,for getting to the    
,antilles and into ,mexico it would have
 to wait until the ,miocene1 but long   
before that time it could arrive in     
,africa1 there surviving as a ,congolese
 and a ,cape species4 ,this story is    

unsupported by a single fossil4         
,peripatus may have been sub-universal  
all over greater ,gondwana land in      
,carboniferous times1 and then its      
absence from ,madagascar would be       
difficult to explain1 but the migrations
 suggested above amount to little       
considering that the distance from      
,tasmania to ,south ,america could be   
covered in far less time than that      
represented by the whole of the ,eocene 
epoch alone4  ,there is yet another     
field1 essentially the domain of        
geographical distribution1 the          
cultivation of which promises fair to   
throw much light upon ,nature's way of  
making species4 ,this is the study of   
the organisms with regard to their      
environment4 ,instead of revealing      
pedigrees or of showing how and when the
 creatures got to a certain locality1 it
 investigates how they behaved to meet  
the ever changing conditions of their   
habitats4 ,there is a facies1           
characteristic of1 and often peculiar   

to1 the fauna of tropical moist forests1
 another of deserts1 of high mountains1 
of underground life and so forth2 these 
same facies are stamped upon whole      
associations of animals and plants1     
although these may be--and in widely    
separated countries generally are--drawn
 from totally different families of     
their respective orders4 ,it does not go
 to the root of the matter to say that  
these facies have been brought about by 
the extermination of all the others     
which did not happen to fit into their  
particular environment4 ,one might      
almost say that tropical moist forests  
must have arboreal frogs and that these 
are made out of whatever suitable       
material happened to be available2 in   
,australia and ,south ,america ,hylidae1
 in ,africa ,ranidae1 since there ,hylas
 are absent4 ,the deserts must have     
lizards capable of standing the glare1  
the great changes of temperature1 of    
running over or burrowing into the loose
 sand4 ,when as in ,america ,iguanids   

are available1 some of these are thus   
modified1 while in ,africa and ,asia the
 ,agamids are drawn upon4 ,both in the  
,damara and in the ,transcaspian        
deserts1 a ,gecko has been turned into a
 runner upon sand6  ,we cannot assume   
that at various epochs deserts1 and at  
others moist forests were continuous all
 over the world4 ,the different facies  
and associations were developed at      
various times and places4 ,are we to    
suppose that1 wherever tropical forests 
came into existence1 amongst the stock  
of humivagous lizards were always some  
which presented those nascent variations
 which made them keep step with the     
similarly nascent forests1 the          
overwhelming rest being eliminated8     
,this principle would imply that the    
same stratum of lizards always had      
variations ready to fit any changed     
environment1 forests and deserts1 rocks 
and swamps4 ,the study of ,ecology      
indicates a different procedure1 a      
great1 almost boundless plasticity of   

the organism1 not in the sense of an    
exuberant moulding force1 but of a      
readiness to be moulded1 and of this the
 variations are the visible outcome4 ,in
 most cases identical facies are        
produced by heterogeneous convergences  
and these may seem to be but            
superficial1 affecting only what some   
authors are pleased to call the         
physiological characters2 but           
environment presumably affects first    
those parts by which the organism comes 
into contact with it most directly1 and 
if the internal structures remain       
unchanged1 it is not because these are  
less easily modified but because they   
are not directly affected4 ,when they   
are affected1 they too change deeply    
enough4  ,that the plasticity should    
react so quickly--indeed this very      
quickness seems to have initiated our   
mistaking the variations called forth   
for something performed--and to the     
point1 is itself the outcome of the long
 training which protoplasm has undergone

 since its creation4  ,in ,nature's     
workshop he does not succeed who has    
ready an arsenal of tools for every     
conceivable emergency1 but he who can   
make a tool at the spur of the moment4  
,the ordeal of the practical test is    
,charles ,darwin's glorious conception  
of ,natural ,selection4     ,,xviii4    
,,darwin ,,and ,,geology4 ,by ,j4,w4    
,judd1 ,c4,b41 ,,ll4,d41 ,f4,r4,s4      
7,mr ,francis ,darwin has related how   
his father occasionally came up from    
,down to spend a few days with his      
brother ,erasmus in ,london1 and1 after 
his brother's death1 with his daughter1 
,mrs ,litchfield4 ,on these occasions1  
it was his habit to arrange meetings    
with ,huxley1 to talk over zoological   
questions1 with ,hooker1 to discuss     
botanical problems1 and with ,lyell to  
hold conversations on geology4 ,after   
the death of ,lyell1 ,darwin1 knowing my
 close intimacy with his friend during  
his later years1 used to ask me to meet 
him when he came to town1 and talk      

geology4 ,the talks took place sometimes
 at ,jermyn ,street ,museum1 at other   
times in the ,royal ,college of         
,science1 ,south ,kensington2 but more  
frequently1 after having lunch with him1
 at his brother's or his daughter's     
house4 ,on several occasions1 however1  
,i had the pleasure of visiting him at  
,down4 ,in the postscript of a letter   
7of ,april #ae1 #ahhj7 arranging one of 
these visits1 he writes3 ,since poor1   
dear ,lyell's death1 ,i rarely have the 
pleasure of geological talk with        
anyone47  ,in one of the very           
interesting conversations which ,i had  
with ,charles ,darwin during the last   
seven years of his life1 he asked me in 
a very pointed manner if ,i were able to
 recall the circumstances1 accidental or
 otherwise1 which had led me to devote  
myself to geological studies4 ,he       
informed me that he was making similar  
inquiries of other friends1 and ,i      
gathered from what he said that he      
contemplated at that time a study of the

 causes producing ,,scientific ,,bias in
 individual minds4 ,i have no means of  
knowing how far this project ever       
assumed anything like concrete form1 but
 certain it is that ,darwin himself     
often indulged in the processes of      
mental introspection and analysis2 and  
he has thus fortunately left us--in his 
fragments of autobiography and in his   
correspondence--the materials from which
 may be reconstructed a fairly complete 
history of his own mental development4  
,there are two perfectly distinct       
inquiries which we have to undertake in 
connection with the development of      
,darwin's ideas on the subject of       
evolution3  ,,first4 ,how1 when1 and    
under what conditions was ,darwin led to
 a conviction that species were not     
immutable1 but were derived from        
pre-existing forms8  ,,secondly4 ,by    
what lines of reasoning and research was
 he brought to regard natural selection 
as a vera causa in the process of       
evolution8  ,it is the first of these   

inquiries which specially interests the 
geologist2 though geology undoubtedly   
played a part--and by no means an       
insignificant part--in respect to the   
second inquiry4  ,when1 indeed1 the     
history comes to be written of that     
great revolution of thought in the      
nineteenth century1 by which the        
doctrine of evolution1 from being the   
dream of poets and visionaries1         
gradually grew to be the accepted creed 
of naturalists1 the paramount influence 
exerted by the infant science of        
geology--and especially that resulting  
from the publication of ,lyell's        
epoch-making work1 the ,principles of   
,geology--cannot fail to be regarded as 
one of the leading factors4 ,herbert    
,spencer in his ,autobiography bears    
testimony to the effect produced on his 
mind by the recently published          
,principles1 when1 at the age of twenty1
 he had already begun to speculate on   
the subject of evolution 7,herbert      
,spencer's ,autobiography1 ,london1     

#aijd1 ,vol4 ,i4 pages #age-agg472 and  
,alfred ,russel ,wallace is scarcely    
less emphatic concerning the part played
 by ,lyell's teaching in his scientific 
education4 7,see ,my ,life2 a record of 
,events and ,opinions1 ,london1 #aije1  
,vol4 ,i4 page #cee1 etc4 ,also his     
review of ,lyell's ,principles in       
,quarterly ,review 7,vol4 #abf71 #ahfi1 
pages #cei-cid4 ,see also ,the          
,darwin-,wallace ,celebration by the    
,linnean ,society 7#aiji71 page #aah47  
,huxley wrote in #ahhg ,i owe more than 
,i can tell to the careful study of the 
,principles of ,geology in my young     
days4 7,science and ,pseudo ,science2   
,collected ,essays1 ,london1 #aijb1     
,vol4 ,v4 page #aja47 ,as for ,charles  
,darwin1 he never tired--either in his  
published writings1 his private         
correspondence or his most intimate     
conversations--of ascribing the         
awakening of his enthusiasm and the     
direction of his energies towards the   
elucidation of the problem of           

development to the ,principles of       
,geology and the personal influence of  
its author4 ,huxley has well expressed  
what the author of the ,origin of       
,species so constantly insisted upon1 in
 the statements ,darwin's greatest work 
is the outcome of the unflinching       
application to ,biology of the leading  
idea and the method applied in the      
,principles to ,geology 7,proc4 ,roy4   
,soc4 ,vol4 ,,xliv4 7#ahhh71 page viii42
 ,collected ,essays ,,ii4 page #bfh1    
#aijb471 and ,lyell1 for others1 as for 
myself1 was the chief agent in smoothing
 the road for ,darwin4 7,life and       
,letters of ,charles ,darwin ,,ii4 page 
#aij47  ,we propose therefore to        
consider1 first1 what ,darwin owed to   
geology and its cultivators1 and in the 
second place how he was able in the end 
so fully to pay a great debt which he   
never failed to acknowledge4 ,thanks to 
the invaluable materials contained in   
the ,life and ,letters of ,charles      
,darwin 7#c vols47 published by ,mr     

,francis ,darwin in #ahhg2 and to ,more 
,letters of ,charles ,darwin 7#b vols47 
issued by the same author1 in           
conjunction with ,professor ,a4,c4      
,seward1 in #aijc1 we are permitted to  
follow the various movements in         
,darwin's mind1 and are able to record  
the story almost entirely in his own    
words4 7,the first of these works is    
indicated in the following pages by the 
letters ,l4,l42 the second by ,m4,l47   
,from the point of view of the          
geologist1 ,darwin's life naturally     
divides itself into four periods4 ,in   
the first1 covering twenty-two years1   
various influences were at work         
militating1 now for and now against1 his
 adoption of a geological career2 in the
 second period--the five memorable years
 of the voyage of the ,beagle--the      
ardent sportsman with some              
natural-history tastes1 gradually became
 the most enthusiastic and enlightened  
of geologists2 in the third period1     
lasting ten years1 the valuable         

geological recruit devoted nearly all   
his energies and time to geological     
study and discussion and to preparing   
for publication the numerous            
observations made by him during the     
voyage2 the fourth period1 which covers 
the latter half of his life1 found      
,darwin gradually drawn more and more   
from geological to biological studies1  
though always retaining the deepest     
interest in the progress and fortunes of
 his old love4 ,but geologists gladly   
recognise the fact that ,darwin         
immeasurably better served their science
 by this biological work1 than he could 
possibly have done by confining himself 
to purely geological questions4  ,from  
his earliest childhood1 ,darwin was a   
collector1 though up to the time when1  
at eight years of age1 he went to a     
preparatory school1 seals1 franks and   
similar trifles appear to have been the 
only objects of his quest4 ,but a stone1
 which one of his schoolfellows at that 
time gave to him1 seems to have         

attracted his attention and set him     
seeking for pebbles and minerals2 as the
 result of this newly acquired taste1 he
 says 7writing in #ahch7 ,i distinctly  
recollect the desire ,i had of being    
able to know something about every      
pebble in front of the hall door--it was
 my earliest and only geological        
aspiration at that time4 7,m4,l4 ,i4    
page #c47 ,he further suspects that     
while at ,mr ,case's school ,i do not   
remember any mental pursuits except     
those of collecting stones1 etc444 ,i   
was born a naturalist4 7,m4,l4 ,i4 page 
#d47  ,the court-yard in front of the   
hall door at the ,mount ,house1         
,darwin's birthplace and the home of his
 childhood1 is surrounded by beds or    
rockeries on which lie a number of      
pebbles4 ,some of these pebbles 7in     
quite recent times as ,i am informed7   
have been collected to form a cobbled   
space in front of the gate in the outer 
wall1 which fronts the hall door2 and a 
similar cobbled area1 there is reason to

 believe1 may have existed in ,darwin's 
childhood before the door itself4 ,the  
pebbles1 which were obtained from a     
neighbouring gravel-pit1 being derived  
from the glacial drift1 exhibit very    
striking differences in colour and form4
 ,it was probably this circumstance     
which awakened in the child his love of 
observation and speculation4 ,it is     
certainly remarkable that aspirations of
 the kind should have arisen in the mind
 of a child of #i or #aj6  ,when he went
 to ,shrewsbury ,school1 he relates ,i  
continued collecting minerals with much 
zeal1 but quite unscientifically1--all  
that ,i cared about was a new-,,named   
mineral1 and ,i hardly attempted to     
classify them4 7,l4,l4 ,i4 page #cd47   
,there has stood from very early times  
in ,darwin's native town of ,shrewsbury1
 a very notable boulder which has       
probably marked a boundary and is known 
as the ,bell-stone--giving its name to a
 house and street4 ,darwin tells us in  
his ,autobiography that while he was at 

,shrewsbury ,school at the age of #ac or
 #ad an old ,mr ,cotton in ,shropshire1 
who knew a good deal about rocks pointed
 out to me 444 the 'bell-stone'2 he told
 me that there was no rock of the same  
kind nearer than ,cumberland or         
,scotland1 and he solemnly assured me   
that the world would come to an end     
before anyone would be able to explain  
how this stone came where it now lay6   
,darwin adds ,this produced a deep      
impression on me1 and ,i meditated over 
this wonderful stone4 7,l4,l4 ,i4 page  
#da47  ,the bell-stone has now1 owing to
 the necessities of building1 been      
removed a short distance from its       
original site1 and is carefully         
preserved within the walls of a bank4   
,it is a block of irregular shape #c    
feet long and #b feet wide1 and about #a
 foot thick1 weighing probably not less 
than one-third of a ton4 ,by the        
courtesy of the directors of the        
,national ,provincial ,bank of ,england1
 ,i have been able to make a minute     

examination of it1 and ,professors      
,bonney and ,watts1 with ,mr ,harker and
 ,mr ,fearnsides have given me their    
valuable assistance4 ,the rock is a much
 altered andesite and was probably      
derived from the ,arenig district in    
,north ,wales1 or possibly from a point 
nearer the ,welsh ,border4 7,i am       
greatly indebted to the ,managers of the
 ,bank at ,shrewsbury for kind          
assistance in the examination of this   
interesting memorial3 and ,mr ,h4,t4    
,beddoes1 the ,curator of the           
,shrewsbury ,museum1 has given me some  
archaeological information concerning   
the stone4 ,mr ,richard ,cotton was a   
good local naturalist1 a ,fellow both of
 the ,geological and ,linnean           
,societies2 and to the officers of these
 societies ,i am indebted for           
information concerning him4 ,he died in 
#ahci1 and although he does not appear  
to have published any scientific papers1
 he did far more for science by         
influencing the career of the school    

boy67 ,it was of course brought to where
 ,shrewsbury now stands by the agency of
 a glacier--as ,darwin afterwards       
learnt4  ,we can well believe from the  
perusal of these reminiscences that1 at 
this time1 ,darwin's mind was1 as he    
himself says1 prepared for a            
philosophical treatment of the subject  
of ,geology4 7,l4,l4 ,i4 page #da47     
,when at the age of #af1 however1 he was
 entered as a medical student at        
,edinburgh ,university1 he not only did 
not get any encouragement of his        
scientific tastes1 but was positively   
repelled by the ordinary instruction    
given there4 ,dr ,hope's lectures on    
,chemistry1 it is true1 interested the  
boy1 who with his brother ,erasmus had  
made a laboratory in the toolhouse1 and 
was nicknamed ,gas by his schoolfellows1
 while undergoing solemn and public     
reprimand from ,dr ,butler at           
,shrewsbury ,school for thus wasting his
 time4 7,l4,l4 ,i4 page #ce47 ,but most 
of the other ,edinburgh lectures were   

intolerably dull1 as dull as the        
professors themselves1 something fearful
 to remember4 ,in after life the memory 
of these lectures was like a nightmare  
to him4 ,he speaks in #ahdj of          
,jameson's lectures as something ,i444  
for my sins experienced6 7,l4,l4 ,i4    
page #cdj47 ,darwin especially          
signalises these lectures on ,geology   
and ,zoology1 which he attended in his  
second year1 as being worst of all      
incredibly dull4 ,the sole effect they  
produced on me was the determination    
never so long as ,i lived to read a book
 on ,geology1 or in any way to study the
 science6 7,l4,l4 ,i4 page #da47  ,the  
misfortune was that ,edinburgh at that  
time had become the cockpit in which the
 barren conflict between ,neptunism and 
,plutonism was being waged with blind   
fury and theological bitterness4        
,jameson and his pupils1 on the one     
hand1 and the friends and disciples of  
,hutton1 on the other1 went to the      
wildest extremes in opposing each       

other's peculiar tenets4 ,darwin tells  
us that he actually heard ,jameson in a 
field lecture at ,salisbury ,craigs1    
discoursing on a trap-dyke1 with        
amygdaloidal margins and the strata     
indurated on each side1 with volcanic   
rocks all around us1 say that it was a  
fissure filled with sediment from above1
 adding with a sneer that there were men
 who maintained that it had been        
injected from beneath in a molten       
condition4 7,l4,l4 ,i4 pages #da-db47   
,when ,i think of this lecture1 added   
,darwin1 ,i do not wonder that ,i       
determined never to attend to ,geology4 
7,this was written in #ahgf and ,darwin 
had in the summer of #ahci revisited and
 carefully studied the locality 7,l4,l4 
,i4 page #bij47 ,it is probable that    
most of ,jameson's teaching was of the  
same controversial and unilluminating   
character as this field-lecture at      
,salisbury ,craigs4  ,there can be no   
doubt that1 while at ,edinburgh1 ,darwin
 must have become acquainted with the   

doctrines of the ,huttonian ,school4    
,though so young1 he mixed freely with  
the scientific society of the city1     
,macgillivray1 ,grant1 ,leonard ,horner1
 ,coldstream1 ,ainsworth and others     
being among his acquaintances1 while he 
attended and even read papers at the    
local scientific societies4 ,it is to be
 feared1 however1 that what ,darwin     
would hear most of1 as characteristic of
 the ,huttonian teaching1 would be      
assertions that chalk-flints were       
intrusions of molten silica1 that fossil
 wood and other petrifactions had been  
impregnated with fused materials1 that  
heat--but never water--was always the   
agent by which the induration and       
crystallisation of rock-materials 7even 
siliceous conglomerate1 limestone and   
rock-salt7 had been effected6 ,these    
extravagant anti-,wernerian views the   
young student might well regard as not  
one whit less absurd and repellant than 
the doctrine of the aqueous             
precipitation of basalt4 ,there is no   

evidence that ,darwin1 even if he ever  
heard of them1 was in any way impressed1
 in his early career1 by the suggestive 
passages in ,hutton and ,playfair1 to   
which ,lyell afterwards called          
attention1 and which foreshadowed the   
main principles of ,uniformitarianism4  
,as a matter of fact1 ,i believe that   
the influence of ,hutton and ,playfair  
in the development of a philosophical   
theory of geology has been very greatly 
exaggerated by later writers on the     
subject4 ,just as ,wells and ,matthew   
anticipated the views of ,darwin on     
,natural ,selection1 but without        
producing any real influence on the     
course of biological thought1 so ,hutton
 and ,playfair adumbrated doctrines     
which only became the basis of vivifying
 theory in the hands of ,lyell4 ,alfred 
,russel ,wallace has very justly        
remarked that when ,lyell wrote the     
,principles of ,geology1 the doctrines  
of ,hutton and ,playfair1 so much in    
advance of their age1 seemed to be      

utterly forgotten4 7,quarterly ,review1 
,vol4 ,,cxxvi4 7#ahfi71 page #cfc47 ,in 
proof of this it is only necessary to   
point to the works of the great masters 
of ,english geology1 who preceded       
,lyell1 in which the works of ,hutton   
and his followers are scarcely ever     
mentioned4 ,this is true even of the    
,researches in ,theoretical ,geology and
 the other works of the sagacious ,de la
 ,beche4 7,of the strength and          
persistence of the prejudice felt       
against ,lyell's views by his           
contemporaries1 ,i had a striking       
illustration some little time after     
,lyell's death4 ,one of the old         
geologists who in the early years of the
 century had done really good work in   
connection with the ,geological ,society
 expressed a hope that ,i was not one of
 those who had been carried away by poor
 ,lyell's fads4 ,my surprise was indeed 
great when further conversation showed  
me that the whole of the ,principles    
were included in the fads67 ,darwin     

himself possessed a copy of ,playfair's 
,illustrations of the ,huttonian        
,theory1 and occasionally quotes it2 but
 ,i have met with only one reference to 
,hutton1 and that a somewhat enigmatical
 one1 in all ,darwin's writings4 ,in a  
letter to ,lyell in #ahda1 when his mind
 was much exercised concerning glacial  
questions1 he says ,what a grand new    
feature all this ice work is in         
,geology6 ,how old ,hutton would have   
stared6 7,m4,l4 ,,ii4 page #adi47  ,as a
 consequence of the influences brought  
to bear on his mind during his two      
years' residence in ,edinburgh1 ,darwin1
 who had entered that ,university with  
strong geological aspirations1 left it  
and proceeded to ,cambridge with a      
pronounced distaste for the whole       
subject4 ,the result of this was that1  
during his career as an under-graduate1 
he neglected all the opportunities for  
geological study4 ,during that important
 period of life1 when he was between    
eighteen and twenty years of age1       

,darwin spent his time in riding1       
shooting and beetle-hunting1 pursuits   
which were undoubtedly an admirable     
preparation for his future work as an   
explorer2 but in none of his letters of 
this period does he even mention        
geology4 ,he says1 however1 ,i was so   
sickened with lectures at ,edinburgh    
that ,i did not even attend ,sedgwick's 
eloquent and interesting lectures4      
7,l4,l4 ,i4 page #dh47  ,it was only    
after passing his examination1 and when 
he went up to spend two extra terms at  
,cambridge1 that geology again began to 
attract his attention4 ,the reading of  
,sir ,john ,herschel's ,introduction to 
the ,study of ,natural ,philosophy1 and 
of ,humboldt's ,personal ,narrative1 a  
copy of which last had been given to him
 by his good friend and mentor ,henslow1
 roused his dormant enthusiasm for      
science1 and awakened in his mind a     
passionate desire for travel4 ,and it   
was from ,henslow1 whom he had          
accompanied in his excursions1 but      

without imbibing any marked taste1 at   
that time1 for botany1 that the advice  
came to think of and to begin the study 
of geology4 7,l4,l4 ,i4 page #ef47 ,this
 was in #ahca1 and in the summer        
vacation of that year we find him back  
again at ,shrewsbury working like a     
tiger at geology and endeavouring to    
make a map and section of               
,shropshire--work which he says was not 
as easy as ,i expected4 7,l4,l4 ,i4 page
 #ahi47 ,no better field for geological 
studies could possibly be found than    
,darwin's native county4  ,writing to   
,henslow at this time1 and referring to 
a form of the instrument devised by his 
friend1 ,darwin says3 ,i am very glad to
 say ,i think the clinometer will answer
 admirably4 ,i put all the tables in my 
bedroom at every conceivable angle and  
direction4 ,i will venture to say that  
,i have measured them as accurately as  
any geologist going could do4 ,but he   
adds3 ,i have been working at so many   
things that ,i have not got on much with

 geology4 ,i suspect the first          
expedition ,i take1 clinometer and      
hammer in hand1 will send me back very  
little wiser and a good deal more       
puzzled than when ,i started4 7,l4,l4   
,i4 page #ahi47 ,valuable aid was1      
however1 at hand1 for at this time      
,sedgwick1 to whom ,darwin had been     
introduced by the ever-helpful ,henslow1
 was making one of his expeditions into 
,wales1 and consented to accept the     
young student as his companion during   
the geological tour4 7,l4,l4 ,i4 page   
#ef47 ,we find ,darwin looking forward  
to this privilege with the keenest      
interest4 7,l4,l4 ,i4 page #ahi47  ,when
 at the beginning of ,august 7#ahca71   
,sedgwick arrived at his father's house 
in ,shrewsbury1 where he spent a night1 
,darwin began to receive his first and  
only instruction as a field-geologist4  
,the journey they took together led them
 through ,llangollen1 ,conway1 ,bangor1 
and ,capel ,curig1 at which latter place
 they parted after spending many hours  

in examining the rocks at ,cwm ,idwal   
with extreme care1 seeking for fossils  
but without success4 ,sedgwick's mode of
 instruction was admirable--he from time
 to time sent the pupil off on a line   
parallel to his own1 telling me to bring
 back specimens of the rocks and to mark
 the stratification on a map4 7,l4,l4   
,i4 page #eg47 ,on his return to        
,shrewsbury1 ,darwin wrote to ,henslow1 
,my trip with ,sedgwick answered most   
perfectly1 7,l4,l4 ,i4 page #aie471 and 
in the following year he wrote again    
from ,south ,america to the same friend1
 ,tell ,professor ,sedgwick he does not 
know how much ,i am indebted to him for 
the ,welsh expedition2 it has given me  
an interest in ,geology which ,i would  
not give up for any consideration4 ,i do
 not think ,i ever spent a more         
delightful three weeks than pounding the
 north-west mountains4 7,l4,l4 ,i4 pages
 #bcg-h47  ,it would be a mistake1      
however1 to suppose that at this time   
,darwin had acquired anything like the  

affection for geological study1 which he
 afterwards developed4 ,after parting   
with ,sedgwick1 he walked in a straight 
line by compass and map across the      
mountains to ,barmouth to visit a       
reading party there1 but taking care to 
return to ,shropshire before ,september 
#ast1 in order to be ready for the      
shooting4 ,for as he candidly tells us1 
,i should have thought myself mad to    
give up the first days of               
partridge-shooting for geology or any   
other science6 7,l4,l4 ,i4 page #eh47   
,any regret we may be disposed to feel  
that ,darwin did not use his            
opportunities at ,edinburgh and         
,cambridge to obtain systematic and     
practical instruction in mineralogy and 
geology1 will be mitigated1 however1    
when we reflect on the danger which he  
would run of being indoctrinated with   
the crude catastrophic views of geology1
 which were at that time prevalent in   
all the centres of learning4  ,writing  
to ,henslow in the summer of #ahca1     

,darwin says ,as yet ,i have only       
indulged in hypotheses1 but they are    
such powerful ones that ,i suppose1 if  
they were put into action but for one   
day1 the world would come to an end4    
7,l4,l4 ,i4 page #ahi47  ,may we not    
read in this passage an indication that 
the self-taught geologist had1 even at  
this early stage1 begun to feel a       
distrust for the prevalent              
catastrophism1 and that his mind was    
becoming a field in which the seeds     
which ,lyell was afterwards to sow would
 fall on good ground8  ,the second      
period of ,darwin's geological          
career--the five years spent by him on  
board the ,beagle--was the one in which 
by far the most important stage in his  
mental development was accomplished4 ,he
 left ,england a healthy1 vigorous and  
enthusiastic collector2 he returned five
 years later with unique experiences1   
the germs of great ideas1 and a         
knowledge which placed him at once in   
the foremost ranks of the geologists of 

that day4 ,huxley has well said that    
,darwin found on board the ,beagle that 
which neither the pedagogues of         
,shrewsbury1 nor the professoriate of   
,edinburgh1 nor the tutors of ,cambridge
 had managed to give him4 7,proc4 ,roy4 
,soc4 ,vol4 ,,xliv4 7#ahhh71 page ,,ix47
 ,darwin himself wrote1 referring to the
 date at which the voyage was expected  
to begin3 ,my second life will then     
commence1 and it shall be as a birthday 
for the rest of my life4 7,l4,l4 ,i4    
page #bad472 and looking back on the    
voyage after forty years1 he wrote2 ,the
 voyage of the ',beagle' has been by far
 the most important event in my life1   
and has determined my whole career2444  
,i have always felt that ,i owe to the  
voyage the first real training or       
education of my mind2 ,i was led to     
attend closely to several branches of   
natural history1 and thus my powers of  
observation were improved1 though they  
were always fairly developed4 7,l4,l4   
,i4 page #fa47  ,referring to these     

general studies in natural history1     
however1 ,darwin adds a very significant
 remark3 ,the investigation of the      
geology of the places visited was far   
more important1 as reasoning here comes 
into play4 ,on first examining a new    
district nothing can appear more        
hopeless than the chaos of rocks2 but by
 recording the stratification and nature
 of the rocks and fossils at many       
points1 always reasoning and predicting 
what will be found elsewhere1 light soon
 begins to dawn on the district1 and the
 structure of the whole becomes more or 
less intelligible4 7,l4,l4 ,i4 page     
#fb47  ,the famous voyage began amid    
doubts1 discouragements and             
disappointments4 ,fearful of            
heart-disease1 sad at parting from home 
and friends1 depressed by sea-sickness1 
the young explorer1 after being twice   
driven back by baffling winds1 reached  
the great object of his ambition1 the   
island of ,teneriffe1 only to find that1
 owing to quarantine regulations1       

landing was out of the question4  ,but  
soon this inauspicious opening of the   
voyage was forgotten4 ,henslow had      
advised his pupil to take with him the  
first volume of ,lyell's ,principles of 
,geology1 then just published--but      
cautioned him 7as nearly all the leaders
 in geological science at that day would
 certainly have done7 on no account to  
accept the views therein advocated4     
7,l4,l4 ,i4 page #gc47 ,it is probable  
that the days of waiting1 discomfort and
 sea-sickness at the beginning of the   
voyage were relieved by the reading of  
this volume4 ,for he says that when he  
landed1 three weeks after setting sail  
from ,plymouth1 in ,st ,jago1 the       
largest of the ,cape de ,verde ,islands1
 the volume had already been studied    
attentively2 and the book was of the    
highest service to me in many ways444   
,his first original geological work1 he 
declares1 showed me clearly the         
wonderful superiority of ,lyell's manner
 of treating geology1 compared with that

 of any other author1 whose works ,i had
 with me or ever afterwards read4       
7,l4,l4 ,i4 page #fb47  ,at ,st ,jago   
,darwin first experienced the joy of    
making new discoveries1 and his delight 
was unbounded4 ,writing to his father he
 says1 ,geologising in a volcanic       
country is most delightful2 besides the 
interest attached to itself1 it leads   
you into most beautiful and retired     
spots4 7,l4,l4 ,i4 page #bbh47 ,to      
,henslow he wrote of ,st ,jago3 ,here we
 spent three most delightful weeks444   
,st ,jago is singularly barren1 and     
produces few plants or insects1 so that 
my hammer was my usual companion1 and in
 its company most delightful hours ,i   
spent4 ,the geology was pre-eminently   
interesting1 and ,i believe quite new2  
there are some facts on a large scale of
 upraised coast 7which is an excellent  
epoch for all the volcanic rocks to date
 from71 that would interest ,mr ,lyell4 
7,l4,l4 ,i4 page #bce47 ,after more than
 forty years the memory of this1 his    

first geological work1 seems as fresh as
 ever1 and he wrote in #ahgf1 ,the      
geology of ,st ,jago is very striking1  
yet simple3 a stream of lava formerly   
flowed over the bed of the sea1 formed  
of triturated recent shells and corals1 
which it has baked into a hard white    
rock4 ,since then the whole island has  
been upheaved4 ,but the line of white   
rock revealed to me a new and important 
fact1 namely1 that there had been       
afterwards subsidence round the craters1
 which had since been in action1 and had
 poured forth lava4 7,l4,l4 ,i4 page    
#fe47  ,it was at this time1 probably1  
that ,darwin made his first attempt at  
drawing a sketch-map and section to     
illustrate the observations he had made 
7see his ,volcanic ,islands1 pages #a   
and #i74 ,his first important geological
 discovery1 that of the subsidence of   
strata around volcanic vents 7which has 
since been confirmed by ,mr ,heaphy in  
,new ,zealand and other authors7        
awakened an intense enthusiasm1 and he  

writes3 ,it then first dawned on me that
 ,i might perhaps write a book on the   
geology of the various countries        
visited1 and this made me thrill with   
delight4 ,that was a memorable hour to  
me1 and how distinctly ,i can call to   
mind the low cliff of lava beneath which
 ,i rested1 with the sun glaring hot1 a 
few strange desert plants growing near1 
and with living corals in the tidal     
pools at my feet4 7,l4,l4 ,i4 page #ff47
  ,but it was when the ,beagle1 after   
touching at ,st ,paul's rock and        
,tristan d',acunha 7for a sufficient    
time only to collect specimens71 reached
 the shores of ,south ,america1 that    
,darwin's real work began2 and he was   
able1 while the marine surveys were in  
progress1 to make many extensive        
journeys on land4 ,his letters at this  
time show that geology had become his   
chief delight1 and such exclamations as 
,geology carries the day1 ,i find in    
,geology a never failing interest1 etc4 
abound in his correspondence4  ,darwin's

 time was divided between the study of  
the great deposits of red mud--the      
,pampean formation--with its interesting
 fossil bones and shells affording      
proofs of slow and constant movements of
 the land1 and the underlying masses of 
metamorphic and plutonic rocks4 ,writing
 to ,henslow in ,march1 #ahcd1 he says3 
,i am quite charmed with ,geology1 but1 
like the wise animal between two bundles
 of hay1 ,i do not know which to like   
best2 the old crystalline groups of     
rocks1 or the softer and fossiliferous  
beds4 ,when puzzling about              
stratification1 etc41 ,i feel inclined  
to cry 'a fig for your big oysters1 and 
your bigger megatheriums4' ,but then    
when digging out some fine bones1 ,i    
wonder how any man can tire his arms    
with hammering granite4 7,l4,l4 ,i4 page
 #bdi47 ,we are told by ,darwin that he 
loved to reason about and attempt to    
predict the nature of the rocks in each 
new district before he arrived at it4   
,this love of guessing as to the geology

 of a district he was about to visit is 
amusingly expressed by him in a letter  
7of ,may1 #ahcb7 to his cousin and old  
college-friend1 ,fox4 ,after alluding to
 the beetles he had been collecting--a  
taste his friend had in common with     
himself--he writes of geology that ,it  
is like the pleasure of gambling4       
,speculating on first arriving1 what the
 rocks may be1 ,i often mentally cry out
 #c to #a tertiary against primitive2   
but the latter have hitherto won all the
 bets4 7,l4,l4 ,i4 page #bcc47  ,not the
 least important of the educational     
results of the voyage to ,darwin was the
 acquirement by him of those habits of  
industry and method which enabled him in
 after life to accomplish so much--in   
spite of constant failures of health4   
,from the outset1 he daily undertook and
 resolutely accomplished1 in spite of   
sea-sickness and other distractions1    
four important tasks4 ,in the first     
place he regularly wrote up the pages of
 his ,journal1 in which1 paying great   

attention to literary style and         
composition1 he recorded only matters   
that would be of general interest1 such 
as remarks on scenery and vegetation1 on
 the peculiarities and habits of        
animals1 and on the characters1         
avocations and political institutions of
 the various races of men with whom he  
was brought in contact4 ,it was the     
freshness of these observations that    
gave his ,narrative so much charm4 ,only
 in those cases in which his ideas had  
become fully crystallised1 did he       
attempt to deal with scientific matters 
in this journal4 ,his second task was to
 write in voluminous note-books facts   
concerning animals and plants1 collected
 on sea or land1 which could not be well
 made out from specimens preserved in   
spirit2 but he tells us that1 owing to  
want of skill in dissecting and drawing1
 much of the time spent in this work was
 entirely thrown away1 a great pile of  
,,ms4 which ,i made during the voyage   
has proved almost useless4 7,l4,l4 ,i4  

page #fb47 ,huxley confirmed this       
judgment on his biological work1        
declaring that all his zeal and industry
 resulted1 for the most part1 in a vast 
accumulation of useless manuscript4     
7,proc4 ,roy4 ,soc4 ,vol4 ,,xliv4       
7#ahhh71 page ,,ix47 ,darwin's third    
task was of a very different character  
and of infinitely greater value4 ,it    
consisted in writing notes of his       
journeys on land--the notes being       
devoted to the geology of the districts 
visited by him4 ,these formed the basis1
 not only of a number of geological     
papers published on his return1 but also
 of the three important volumes forming 
,the ,geology of the voyage of the      
',beagle'4 ,on ,july #bdth1 #ahcd1 when 
little more than half of the voyage had 
been completed1 ,darwin wrote to        
,henslow1 ,my notes are becoming bulky4 
,i have about #fjj small quarto pages   
full2 about half of this is ,geology4   
7,m4,l4 ,i4 page #ad47 ,the last1 and   
certainly not the least important of all

 his duties1 consisted in numbering1    
cataloguing1 and packing his specimens  
for despatch to ,henslow1 who had       
undertaken the care of them4 ,in his    
letters he often expresses the greatest 
solicitude lest the value of these      
specimens should be impaired by the     
removal of the numbers corresponding to 
his manuscript lists4 ,science owes much
 to ,henslow's patient care of the      
collections sent to him by ,darwin4 ,the
 latter wrote in ,henslow's biography1  
,during the five years' voyage1 he      
regularly corresponded with me and      
guided my efforts2 he received1 opened1 
and took care of all the specimens sent 
home in many large boxes4 7,life of     
,henslow1 by ,l4 ,jenyns 7,blomefield71 
,london1 #ahfb1 page #ec47  ,darwin's   
geological specimens are now very       
appropriately lodged for the most part  
in the ,sedgwick ,museum1 ,cambridge1   
his original ,catalogue with subsequent 
annotations being preserved with them4  
,from an examination of these catalogues

 and specimens we are able to form a    
fair notion of the work done by ,darwin 
in his little cabin in the ,beagle1 in  
the intervals between his land journeys4
  ,besides writing up his notes1 it is  
evident that he was able to accomplish a
 considerable amount of study of his    
specimens1 before they were packed up   
for despatch to ,henslow4 ,besides      
hand-magnifiers and a microscope1       
,darwin had an equipment for            
blowpipe-analysis1 a contact-goniometer 
and magnet2 and these were in constant  
use by him4 ,his small library of       
reference 7now included in the          
,collection of books placed by ,mr ,f4  
,darwin in the ,botany ,school at       
,cambridge 7,catalogue of the ,library  
of ,charles ,darwin now in the ,botany  
,school1 ,cambridge4 ,compiled by ,h4,w4
 ,rutherford2 with an introduction by   
,francis ,darwin4 ,cambridge1 #aijh477  
appears to have been admirably selected1
 and in all probability contained 7in   
addition to a good many works relating  

to ,south ,america7 a fair number of    
excellent books of reference4 ,among    
those relating to mineralogy1 he        
possessed the manuals of ,phillips1     
,alexander ,brongniart1 ,beudant1 von   
,kobell and ,jameson3 all the           
,cristallographie of ,brochant de       
,villers and1 for blowpipe work1 ,dr    
,children's translation of the book of  
,berzelius on the subject4 ,in addition 
to these1 he had ,henry's ,experimental 
,chemistry and ,ure's ,dictionary 7of   
,chemistry74 ,a work1 he evidently often
 employed1 was ,p4 ,syme's book on      
,werner's ,nomenclature of ,colours2    
while1 for ,petrology1 he used          
,macculloch's ,geological               
,classification of ,rocks4 ,how         
diligently and well he employed his     
instruments and books is shown by the   
valuable observations recorded in the   
annotated ,catalogues drawn up on board 
ship4  ,these catalogues have on the    
right-hand pages numbers and            
descriptions of the specimens1 and on   

the opposite pages notes on the         
specimens--the result of experiments    
made at the time and written in a very  
small hand4 ,of the subsequently made   
pencil notes1 ,i shall have to speak    
later4 7,i am greatly indebted to my    
friend ,mr ,a4 ,harker1 ,f4,r4,s41 for  
his assistance in examining these       
specimens and catalogues4 ,he has also  
arranged the specimens in the ,sedgwick 
,museum1 so as to make reference to them
 easy4 ,the specimens from ,ascension   
and a few others are however in the     
,museum at ,jermyn ,street47  ,it is a  
question of great interest to determine 
the period and the occasion of ,darwin's
 first awakening to the great problem of
 the transmutation of species4 ,he tells
 us himself that his grandfather's      
,zoonomia had been read by him but      
without producing any effect1 and that  
his friend ,grant's rhapsodies on       
,lamarck and his views on evolution only
 gave rise to astonishment4 7,l4,l4 ,i4 
page #ch47  ,huxley1 who had probably   

never seen the privately printed volume 
of letters to ,henslow1 expressed the   
opinion that ,darwin could not have     
perceived the important bearing of his  
discovery of bones in the ,pampean      
,formation1 until they had been studied 
in ,england1 and their analogies        
pronounced upon by competent comparative
 anatomists4 ,and this seemed to be     
confirmed by ,darwin's own entry in his 
pocket-book for #ahcg1 ,in ,july opened 
first notebook on ,transmutation of     
,species4 ,had been greatly struck from 
about the month of previous ,march on   
character of ,south ,american fossils444
  7,l4,l4 ,i4 page #bgf47  ,the second  
volume of ,lyell's ,principles of       
,geology was published in ,january1     
#ahcb1 and ,darwin's copy 7like that of 
the other two volumes1 in a sadly       
dilapidated condition from constant use7
 has in it the inscription1 ,charles    
,darwin1 ,monte ,video4 ,nov4 #ahcb4 ,as
 everyone knows1 ,darwin in dedicating  
the second edition of his ,journal of   

the ,voyage to ,lyell declared1 the     
chief part of whatever scientific merit 
this journal and the other works of the 
author may possess1 has been derived    
from studying the well-known and        
admirable ',principles of ,geology'4    
,in the first chapter of this second    
volume of the ,principles1 ,lyell       
insists on the importance of the species
 question to the geologist1 but goes on 
to point out the difficulty of accepting
 the only serious attempt at a          
transmutation theory which had up to    
that time appeared--that of ,lamarck4   
,in subsequent chapters he discusses the
 questions of the modification and      
variability of species1 of hybridity1   
and of the geographical distribution of 
plants and animals4 ,he then gives vivid
 pictures of the struggle for existence1
 ever going on between various species1 
and of the causes which lead to their   
extinction--not by overwhelming         
catastrophes1 but by the silent and     
almost unobserved action of natural     

causes4 ,this leads him to consider     
theories with regard to the introduction
 of new species1 and1 rejecting the     
fanciful notions of centres or foci of  
creation1 he argues strongly in favour  
of the view1 as most reconcileable with 
observed facts1 that each species may   
have had its origin in a single pair1 or
 individual1 where an individual was    
sufficient1 and species may have been   
created in succession at such times and 
in such places as to enable them to     
multiply and endure for an appointed    
period1 and occupy an appointed space on
 the globe4 7,principles of ,geology1   
,vol4 ,,ii4 7#ast edition #ahcb71 page  
#abd4 ,we now know1 as has been so well 
pointed out by ,huxley1 that ,lyell1 as 
early as #ahbg1 was prepared to accept  
the doctrine of the transmutation of    
species4 ,in that year he wrote to      
,mantell1 ,what changes species may     
really undergo6 ,how impossible will it 
be to distinguish and lay down a line1  
beyond which some of the so-called      

extinct species may have never passed   
into recent ones 7,lyell's ,life and    
,letters ,vol4 ,i4 page #afh74 ,to ,sir 
,john ,herschel in #ahcf1 he wrote1 ,in 
regard to the origination of new        
species1 ,i am very glad to find that   
you think it probable that it may be    
carried on through the intervention of  
intermediate causes4 ,i left this rather
 to be inferred1 not thinking it worth  
while to offend a certain class of      
persons by embodying in words what would
 only be a speculation 7,ibid4 page     
#dfg74 ,he expressed the same views to  
,whewell in #ahcg 7,ibid4 ,vol4 ,,ii4   
page #e471 and to ,sedgwick 7,ibid4     
,vol4 ,,ii4 page #cf7 to whom he says1  
of the theory1 that the creation of new 
species is going on at the present      
day--,i really entertain it1 but ,i have
 studiously avoided laying the doctrine 
down dogmatically as capable of proof   
7see ,huxley in ,l4,l4 ,,ii4 pages      
#aij-aie477  ,after pointing out how    
impossible it would be for a naturalist 

to prove that a newly ,,discovered      
species was really newly ,,created 7,mr 
,f4 ,darwin has pointed out that his    
father 7like ,lyell7 often used the term
 ,creation in speaking of the origin of 
new species 7,l4,l4 ,,ii4 chapter #a4771
 ,lyell argued that no satisfactory     
evidence ,,of ,,the ,,way in which these
 new forms were created1 had as yet been
 discovered1 but that he entertained the
 hope of a possible solution of the     
problem being found in the study of the 
geological record4  ,it is not          
difficult1 in reading these chapters of 
,lyell's great work1 to realise what an 
effect they would have on the mind of   
,darwin1 as new facts were collected and
 fresh observations concerning extinct  
and recent forms were made in his       
travels4 ,we are not surprised to find  
him writing home1 ,i am become a zealous
 disciple of ,mr ,lyell's views1 as     
known in his admirable book4            
,geologising in ,south ,america1 ,i am  
tempted to carry parts to a greater     

extent even than he does4 7,l4,l4 ,i4   
page #bfc47  ,lyell's anticipation that 
the study of the geological record might
 afford a clue to the discovery of how  
new species originate was remarkably    
fulfilled1 within a few months1 by      
,darwin's discovery of fossil bones in  
the red ,pampean mud4  ,it is very true 
that1 as ,huxley remarked1 ,darwin's    
knowledge of comparative anatomy must   
have been1 at that time1 slight2 but    
that he recognised the remarkable       
resemblances between the extinct and    
existing mammals of ,south ,america is  
proved beyond all question by a passage 
in his letter to ,henslow1 written      
,november #bdth1 #ahcb3 ,i have been    
very lucky with fossil bones2 ,i have   
fragments of at least six distinct      
animals444 ,i found a large surface of  
osseous polygonal plates444 ,immediately
 ,i saw them ,i thought they must belong
 to an enormous armadillo1 living       
species of which genus are so abundant  
here1 and he goes on to say that he has 

the lower jaw of some large animal      
which1 from the molar teeth1 ,i should  
think belonged to the ,edentata4 7,m4,l4
 ,i4 pages #aa1 #ab4 ,see ,extracts of  
,letters addressed to ,prof4 ,henslow by
 ,c4 ,darwin 7#ahce71 page #g47  ,having
 found this important clue1 ,darwin     
followed it up with characteristic      
perseverance4 ,in his quest for more    
fossil bones he was indefatigable4 ,mr  
,francis ,darwin tells us1 ,i have often
 heard him speak of the despair with    
which he had to break off the projecting
 extremity of a huge1 partly excavated  
bone1 when the boat waiting for him     
would wait no longer4 7,l4,l4 ,i4 page  
#bgf 7footnote747 ,writing to ,haeckel  
in #ahfd1 ,darwin says3 ,i shall never  
forget my astonishment when ,i dug out a
 gigantic piece of armour1 like that of 
the living armadillo4 7,haeckel1        
,history of ,creation1 ,vol4 ,i4 page   
#acd1 ,london1 #ahgf47  ,in a letter to 
,henslow in #ahcd ,darwin says3 ,i have 
just got scent of some fossil bones444  

what they may be ,i do not know1 but if 
gold or galloping will get them they    
shall be mine4 7,m4,l4 ,i4 page #ae47   
,darwin also showed his sense of the    
importance of the discovery of these    
bones by his solicitude about their safe
 arrival and custody4 ,from the         
,falkland ,isles 7,march1 #ahcd71 he    
writes to ,henslow3 ,i have been alarmed
 by your expression 'cleaning all the   
bones' as ,i am afraid the printed      
numbers will be lost3 the reason ,i am  
so anxious they should not be1 is1 that 
a part were found in a gravel with      
recent shells1 but others in a very     
different bed4 ,now with these latter   
there were bones of an ,agouti1 a genus 
of animals1 ,i believe1 peculiar to     
,america1 and it would be curious to    
prove that some one of the genus        
co-existed with the ,megatherium3 such  
and many other points depend on the     
numbers being carefully preserved4      
7,extracts from ,letters etc41 pages    
#ac-ad47 ,in the abstract of the notes  

read to the ,geological ,society in     
#ahce1 we read3 ,in the gravel of       
,patagonia he 7,darwin7 also found many 
bones of the ,megatherium and of five or
 six other species of quadrupeds1 among 
which he has detected the bones of a    
species of ,agouti4 ,he also met with   
several examples of the polygonal       
plates1 etc4 7,proc4 ,geol4 ,soc4 ,vol4 
,,ii4 pages #baa-bab47  ,darwin's own   
recollections entirely bear out the     
conclusion that he fully recognised1    
,,while ,,in ,,south ,,america1 the     
wonderful significance of the           
resemblances between the extinct and    
recent mammalian faunas4 ,he wrote in   
his ,autobiography3 ,during the voyage  
of the ',beagle' ,i had been deeply     
impressed by discovering in the ,pampean
 formation great fossil animals covered 
with armour like that on the existing   
armadillos4 7,l4,l4 ,i4 page #hb47  ,the
 impression made on ,darwin's mind by   
the discovery of these fossil bones1 was
 doubtless deepened as1 in his progress 

southward from ,brazil to ,patagonia1 he
 found similar species of ,edentate     
animals everywhere replacing one another
 among the living forms1 while1 whenever
 fossils occurred1 they also were seen  
to belong to the same remarkable group  
of animals4 7,while ,darwin was making  
these observations in ,south ,america1 a
 similar generalisation to that at which
 he arrived was being reached1 quite    
independently and almost simultaneously1
 with respect to the fossil and recent  
mammals of ,australia4 ,in the year     
#ahca1 ,clift gave to ,jameson a list of
 bones occurring in the caves and       
breccias of ,australia1 and in          
publishing this list the latter referred
 to the fact that the forms belonged to 
marsupials1 similar to those of the     
existing ,australian fauna4 ,but he also
 stated that1 as a skull had been       
identified 7doubtless erroneously7 as   
having belonged to a hippopotamus1 other
 mammals than marsupials must have      
spread over the island in late ,tertiary

 times4 ,it is not necessary to point   
out that this paper was quite unknown to
 ,darwin while in ,south ,america4      
,lyell first noticed it in the third    
edition of his ,principles1 which was   
published in ,may1 #ahcd 7see ,edinb4   
,new ,phil4 ,journ4 ,vol4 ,x4 7#ahca71  
pages #cid-f1 and ,lyell's ,principles  
7#crd edition71 ,vol4 ,,iii4 page #dba74
 ,darwin referred to this discovery in  
#ahci 7see his ,journal1 page #baj477   
,that the passage in ,darwin's          
pocket-book for #ahcg can only refer to 
an ,,awakening of ,darwin's interest in 
the subject--probably resulting from a  
sight of the bones when they were being 
unpacked--,i think there cannot be the  
smallest doubt2 ,,and ,,we ,,may        
,,therefore ,,confidently ,,fix ,,upon  
,,november1 #ahcb1 ,,as ,,the ,,date    
,,at ,,which ,,darwin ,,commenced ,,that
 ,,long ,,series ,,of ,,observations    
,,and ,,reasonings ,,which ,,eventually 
,,culminated ,,in ,,the ,,preparation   
,,of ,,the ,,origin ,,of ,,species4     

,equally certain is it1 that it was his 
geological work that led ,darwin into   
those paths of research which in the end
 conducted him to his great discoveries4
 ,i quite agree with the view expressed 
by ,mr ,f4 ,darwin and ,professor       
,seward1 that ,darwin1 like ,lyell1     
thought it 'almost useless' to try to   
prove the truth of evolution until the  
cause of change was discovered 7,m4,l4  
,i4 page #ch471 and that possibly he may
 at times have vacillated in his        
opinions1 but ,i believe there is       
evidence that1 from the date mentioned1 
the species question was always more or 
less present in ,darwin's mind4         
7,although we admit with ,huxley that   
,darwin's training in comparative       
anatomy was very small1 yet it may be   
remembered that he was a medical student
 for two years1 and1 if he hated the    
lectures1 he enjoyed the society of     
naturalists4 ,he had with him in the    
little ,beagle library a fair number of 
zoological books1 including works on    

,osteology by ,cuvier1 ,desmarest and   
,lesson1 as well as two ,french         
,encyclopaedias of ,natural ,history4   
,as a sportsman1 he would obtain        
specimens of recent mammals in ,south   
,america1 and would thus have           
opportunities of studying their teeth   
and general anatomy4 ,keen observer1 as 
he undoubtedly was1 we need not then be 
surprised that he was able to make out  
the resemblances between the recent and 
fossil forms47  ,it is clear that1 as   
time went on1 ,darwin became more and   
more absorbed in his geological work4   
,one very significant fact was that the 
once ardent sportsman1 when he found    
that shooting the necessary game and    
zoological specimens interfered with his
 work with the hammer1 gave up his gun  
to his servant4 7,l4,l4 ,i4 page #fc47  
,there is clear evidence that ,darwin   
gradually became aware how futile were  
his attempts to add to zoological       
knowledge by dissection and drawing1    
while he felt ever increasing           

satisfaction with his geological work4  
,the voyage fortunately extended to a   
much longer period 7five years7 than the
 two originally intended1 but after     
being absent nearly three years1 ,darwin
 wrote to his sister in ,november1      
#ahcd1 ,hurrah6 hurrah6 it is fixed that
 the ',beagle' shall not go one mile    
south of ,cape ,tres ,montes 7about #bjj
 miles south of ,chiloe71 and from that 
point to ,valparaiso will be finished in
 about five months4 ,we shall examine   
the ,chonos ,archipelago1 entirely      
unknown1 and the curious inland sea     
behind ,chiloe4 ,for me it is glorious4 
,cape ,tres ,montes is the most southern
 point where there is much geological   
interest1 as there the modern beds end4 
,the ,captain then talks of crossing the
 ,pacific2 but ,i think we shall        
persuade him to finish the coast of     
,peru1 where the climate is delightful1 
the country hideously sterile1 but      
abounding with the highest interest to  
the geologist444 ,i have long been      

grieved and most sorry at the           
interminable length of the voyage       
7though ,i never would have quitted     
it7444 ,i could not make up my mind to  
return4 ,i could not give up all the    
geological castles in the air ,i had    
been building up for the last two years4
 7,l4,l4 ,i4 pages #beg-eh47  ,in       
,april1 #ahce1 he wrote to another      
sister3 ,i returned a week ago from my  
excursion across the ,andes to ,mendoza4
 ,since leaving ,england ,i have never  
made so successful a journey444 how     
deeply ,i have enjoyed it2 it was       
something more than enjoyment2 ,i cannot
 express the delight which ,i felt at   
such a famous winding-up of all my      
geology in ,south ,america4 ,i literally
 could hardly sleep at nights for       
thinking over my day's work4 ,the       
scenery was so new1 and so majestic2    
everything at an elevation of #ab1jjj   
feet bears so different an aspect from  
that in the lower country444 ,to a      
geologist1 also1 there are such manifest

 proofs of excessive violence2 the      
strata of the highest pinnacles are     
tossed about like the crust of a broken 
pie4 7,l4,l4 ,i4 pages #bei-fj47        
,darwin anticipated with intense        
pleasure his visit to the ,galapagos    
,islands4 ,on ,july #abth1 #ahce1 he    
wrote to ,henslow3 ,in a few days' time 
the ,beagle will sail for the ,galapagos
 ,islands4 ,i look forward with joy and 
interest to this1 both as being somewhat
 nearer to ,england and for the sake of 
having a good look at an active volcano4
 ,although we have seen lava in         
abundance1 ,i have never yet beheld the 
crater4 7,m4,l4 ,i4 page #bf47 ,he could
 little anticipate1 as he wrote these   
lines1 the important aid in the solution
 of the species question that would ever
 after make his visit to the ,galapagos 
,islands so memorable4 ,in #ahcb1 as we 
have seen1 the great discovery of the   
relations of living to extinct mammals  
in the same area had dawned upon his    
mind2 in #ahce he was to find a second  

key for opening up the great mystery1 by
 recognising the variations of similar  
types in adjoining islands among the    
,galapagos4  ,the final chapter in the  
second volume of the ,principles had    
aroused in ,darwin's mind a desire to   
study coral-reefs1 which was gratified  
during his voyage across the ,pacific   
and ,indian ,oceans4 ,his theory on the 
subject was suggested about the end of  
#ahcd or the beginning of #ahce1 as he  
himself tells us1 before he had seen a  
coral-reef1 and resulted from his work  
during two years in which he had been   
incessantly attending to the effects on 
the shores of ,south ,america of the    
intermittent elevation of the land1     
together with denudation and the        
deposition of sediment4 7,l4,l4 ,i4 page
 #gj47  ,on arriving at the ,cape of    
,good ,hope in ,july1 #ahcf1 ,darwin was
 greatly gratified by hearing that      
,sedgwick had spoken to his father in   
high terms of praise concerning the work
 done by him in ,south ,america4        

,referring to the news from home1 when  
he reached ,bahia once more1 on the     
return voyage 7,august1 #ahcf71 he says3
 ,the desert1 volcanic rocks1 and wild  
sea of ,ascension444 suddenly wore a    
pleasing aspect1 and ,i set to work with
 a good-will at my old work of ,geology4
 7,l4,l4 ,i4 page #bfe47 ,writing fifty 
years later1 he says3 ,i clambered over 
the mountains of ,ascension with a      
bounding step and made the volcanic     
rocks resound under my geological       
hammer6 7,l4,l4 ,i4 page #ff47  ,that   
his determination was now fixed to      
devote his own labours to the task of   
working out the geological results of   
the voyage1 and that he was prepared to 
leave to more practised hands the study 
of his biological collections1 is clear 
from the letters he sent home at this   
time4 ,from ,st ,helena he wrote to     
,henslow asking that he would propose   
him as a ,fellow of the ,geological     
,society2 and his ,certificate1 in      
,henslow's handwriting1 is dated        

,september #hth1 #ahcf1 being signed    
from personal knowledge by ,henslow and 
,sedgwick4 ,he was proposed on ,november
 #bnd and elected ,november #cjth1 being
 formally admitted to the ,society by   
,lyell1 who was then ,president1 on     
,january #dth1 #ahcg1 on which date he  
also read his first paper4 ,darwin did  
not become a ,fellow of the ,linnean    
,society till eighteen years later 7in  
#ahed74  ,an estimate of the value and  
importance of ,darwin's geological      
discoveries during the voyage of the    
,beagle can best be made when           
considering the various memoirs and     
books in which the author described     
them4 ,he was too cautious to allow     
himself to write his first impressions  
in his ,journal1 and wisely waited till 
he could study his specimens under      
better conditions and with help from    
others on his return4 ,the extracts     
published from his correspondence with  
,henslow and others1 while he was still 
abroad1 showed1 nevertheless1 how great 

was the mass of observation1 how        
suggestive and pregnant with results    
were the reasonings of the young        
geologist4  ,two sets of these extracts 
from ,darwin's letters to ,henslow were 
printed while he was still abroad4 ,the 
first of these was the series of        
,geological ,notes made during a survey 
of the ,east and ,west ,coasts of ,south
 ,america1 in the years #ahcb1 #ahcc1   
#ahcd and #ahce1 with an account of a   
transverse section of the ,cordilleras  
of the ,andes between ,valparaiso and   
,mendoza4 ,professor ,sedgwick1 who read
 these notes to the ,geological ,society
 on ,november #ahth1 #ahce1 stated that 
they were extracted from a series of    
letters 7addressed to ,professor        
,henslow71 containing a great mass of   
information connected with almost every 
branch of natural history1 and that he  
7,sedgwick7 had made a selection of the 
remarks which he thought would be more  
especially interesting to the           
,geological ,society4 ,an abstract of   

three pages was published in the        
,proceedings of the ,geological ,society
 7,vol4 ,,ii4 pages #baj-ab471 but so   
unknown was the author at this time that
 he was described as ,f4 ,darwin1 ,esq41
 of ,st ,john's ,college1 ,cambridge6   
,almost simultaneously 7on ,november    
#afth1 #ahce7 a second set of extracts  
from these letters--this time of a      
general character--were read to the     
,philosophical ,society at ,cambridge1  
and these excited so much interest that 
they were privately printed in pamphlet 
form for circulation among the members4 
,many expeditions and scientific        
missions have been despatched to various
 parts of the world since the return of 
the ,beagle in #ahcf1 but it is doubtful
 whether any1 even the most richly      
endowed of them1 has brought back such  
stores of new information and fresh     
discoveries as did that little ten-gun  
brig--certainly no cabin or laboratory  
was the birth-place of ideas of such    
fruitful character as was that narrow   

end of a chart-room1 where the solitary 
naturalist could climb into his hammock 
and indulge in meditation4  ,the third  
and most active portion of ,darwin's    
career as a geologist was the period    
which followed his return to ,england at
 the end of #ahcf4 ,his immediate       
admission to the ,geological ,society1  
at the beginning of #ahcg1 coincided    
with an important crisis in the history 
of geological science4  ,the band of    
enthusiasts who nearly thirty years     
before had inaugurated the ,geological  
,society--weary of the fruitless        
conflicts between ,neptunists and       
,plutonists--had determined to eschew   
theory and confine their labours to the 
collection of facts1 their publications 
to the careful record of observations4  
,greenough1 the actual founder of the   
,society1 was an ardent ,wernerian1 and 
nearly all his fellow-workers had come1 
more or less directly1 under the        
,wernerian teaching4 ,macculloch alone  
gave valuable support to the ,huttonian 

doctrines1 so far as they related to the
 influence of igneous activity--but the 
most important portion of the now       
celebrated ,theory of the ,earth--that  
dealing with the competency of existing 
agencies to account for changes in past 
geological times--was ignored by all    
alike4 ,macculloch's influence on the   
development of geology1 which might have
 had far-reaching effects1 was to a     
great extent neutralised by his         
peculiarities of mind and temper2 and1  
after a stormy and troublous career1 he 
retired from the society in #ahcb4 ,in  
all the writings of the great pioneers  
in ,english geology1 ,hutton and his    
splendid generalisation are scarcely    
ever referred to4 ,the great doctrines  
of ,uniformitarianism1 which he had     
foreshadowed1 were completely ignored1  
and only his extravagances of           
anti-,wernerianism seem to have been    
remembered4  ,when between #ahcj and    
#ahcb1 ,lyell1 taking up the almost     
forgotten ideas of ,hutton1 von ,hoff   

and ,prevost1 published that bold       
challenge to the ,catastrophists--the   
,principles of ,geology--he was met with
 the strongest opposition1 not only from
 the outside world1 which was amused by 
his absurdities and shocked by his      
impiety--but not less from his          
fellow-workers and friends in the       
,geological ,society4 ,for ,lyell's     
numerous original observations1 and his 
diligent collection of facts his        
contemporaries had nothing but          
admiration1 and they cheerfully admitted
 him to the highest offices in the      
society1 but they met his reasonings on 
geological theory with vehement         
opposition and his conclusions with     
coldness and contempt4  ,there is1      
indeed1 a very striking parallelism     
between the reception of the ,principles
 of ,geology by ,lyell's contemporaries 
and the manner in which the ,origin of  
,species was met a quarter of a century 
later1 as is so vividly described by    
,huxley4 7,l4,l4 ,,ii4 pages #agi-bjd47 

,among ,lyell's fellow-geologists1 two  
only--,g4 ,poulett ,scrope and ,john    
,herschel 7,both ,lyell and ,darwin     
fully realised the value of the support 
of these two friends4 ,scrope in his    
appreciative reviews of the ,principles 
justly pointed out what was the weakest 
point1 the inadequate recognition of    
sub-aerial as compared with marine      
denudation4 ,darwin also admitted that  
,scrope had to a great extent           
forestalled him in his theory of        
,foliation4 ,herschel from the first    
insisted that the leading idea of the   
,principles must be applied to organic  
as well as to inorganic nature and must 
explain the appearance of new species   
7see ,lyell's ,life and ,letters1 ,vol4 
,i4 page #dfg74 ,darwin tells us that   
,herschel's ,introduction to the ,study 
of ,natural ,philosophy with ,humboldt's
 ,personal ,narrative stirred up in me a
 burning zeal in his undergraduate days4
 ,i once heard ,lyell exclaim with      
fervour ,if ever there was a heaven-born

 genius it was ,john                    
,herschel67--declared themselves from   
the first his strong supporters4 ,scrope
 in two luminous articles in the        
,quarterly ,review did for ,lyell what  
,huxley accomplished for ,darwin in his 
famous review in the ,times2 but ,scrope
 unfortunately was at that time immersed
 in the stormy sea of politics1 and     
devoted his great powers of exposition  
to the preparation of fugitive          
pamphlets4 ,herschel1 like ,scrope1 was 
unable to support ,lyell at the         
,geological ,society1 owing to his      
absence on the important astronomical   
mission to the ,cape4  ,it thus came    
about that1 in the frequent conflicts of
 opinion within the walls of the        
,geological ,society1 ,lyell had to bear
 the brunt of battle for                
,uniformitarianism quite alone1 and it  
is to be feared that he found himself   
sadly overmatched when opposed by the   
eloquence of ,sedgwick1 the sarcasm of  
,buckland1 and the dead weight of       

incredulity on the part of ,greenough1  
,conybeare1 ,murchison and other members
 of the band of pioneer workers4 ,as    
time went on there is evidence that the 
opposition of ,de la ,beche and ,whewell
 somewhat relaxed2 the brilliant ,paddy 
,fitton 7as his friends called him7 was 
sometimes found in alliance with ,lyell1
 but was characteristically apt to turn 
his weapon1 as occasion served1 on      
friend or foe alike2 the amiable ,john  
,phillips sat upon the fence4 ,only when
 a new generation arose--including      
,jukes1 ,ramsay1 ,forbes and            
,hooker--did ,lyell find his teachings  
received with anything like favour4  ,we
 can well understand1 then1 how ,lyell  
would welcome such a recruit as young   
,darwin--a man who had declared himself 
more ,lyellian than ,lyell1 and who     
brought to his support facts and        
observations gleaned from so wide a     
field4  ,the first meeting of ,lyell and
 ,darwin was characteristic of the two  
men4 ,darwin at once explained to ,lyell

 that1 with respect to the origin of    
coral-reefs1 he had arrived at views    
directly opposed to those published by  
his master4 ,to give up his own theory1 
cost ,lyell1 as he told ,herschel1 a    
pang at first1 but he was at once       
convinced of the immeasurable           
superiority of ,darwin's theory4 ,i have
 heard members of ,lyell's family tell  
of the state of wild excitement and     
sustained enthusiasm1 which lasted for  
days with ,lyell after this interview1  
and his letters to ,herschel1 ,whewell  
and others show his pleasure at the new 
light thrown upon the subject and his   
impatience to have the matter laid      
before the ,geological ,society4        
,writing forty years afterwards1        
,darwin1 speaking of the time of the    
return of the ,beagle1 says3 ,i saw a   
great deal of ,lyell4 ,one of his chief 
characteristics was his sympathy with   
the work of others1 and ,i was as much  
astonished as delighted at the interest 
which he showed when1 on my return to   

,england1 ,i explained to him my views  
on coral-reefs4 ,this encouraged me     
greatly1 and his advice and example had 
much influence on me4 7,l4,l4 ,i4 page  
#fh47 ,darwin further states that he saw
 more of ,lyell at this time than of any
 other scientific man1 and at his       
request sent his first communication to 
the ,geological ,society4 7,l4,l4 ,i4   
page #fg47  ,mr ,lonsdale 7the able     
curator of the ,geological ,society71   
,darwin wrote to ,henslow1 with whom ,i 
had much interesting conversation1 gave 
me a most cordial reception1 and he     
adds1 ,if ,i was not much more inclined 
for geology than the other branches of  
,natural ,history1 ,i am sure ,mr       
,lyell's and ,lonsdale's kindness ought 
to fix me4 ,you cannot conceive anything
 more thoroughly good-natured than the  
heart-and-soul manner in which he put   
himself in my place and thought what    
would be best to do4 7,l4,l4 ,i4 page   
#bge47  ,within a few days of ,darwin's 
arrival in ,london we find ,lyell       

writing to ,owen as follows3  ,mrs      
,lyell and ,i expect a few friends here 
on ,saturday next1 #bith 7,october71 to 
an early tea party at eight o'clock1 and
 it will give us great pleasure if you  
can join it4 ,among others you will meet
 ,mr ,charles ,darwin1 whom ,i believe  
you have seen1 just returned from ,south
 ,america1 where he has laboured for    
zoologists as well as for               
hammer-bearers4 ,i have also asked your 
friend ,broderip4 7,the ,life of        
,richard ,owen1 ,london1 #ahid1 ,vol4   
,i4 page #ajb47 ,it would probably be on
 this occasion that the services of     
,owen were secured for the work on the  
fossil bones sent home by ,darwin4  ,on 
,november #bnd1 we find ,lyell          
introducing ,darwin as his guest at the 
,geological ,society ,club2 on ,december
 #adth1 ,lyell and ,stokes proposed     
,darwin as a member of the ,club2       
between that date and ,may #crd of the  
following year1 when his election to the
 ,club took place1 he was several times 

dining as a guest4  ,on ,january #dth1  
#ahcg1 as we have already seen1 ,darwin 
was formally admitted to the ,geological
 ,society1 and on the same evening he   
read his first paper 7,i have already   
pointed out that the notes read at the  
,geological ,society on ,nov4 #ah1 #ahce
 were extracts made by ,sedgwick from   
letters sent to ,henslow1 and not a     
paper sent home for publication by      
,darwin47 before the ,society1          
,observations of proofs of recent       
elevation on the coast of ,chili1 made  
during the ,survey of ,h4,m4,s4 ,beagle1
 commanded by ,captain ,fitz,roy1 ,r4,n4
 ,by ,c4 ,darwin1 ,f4,g4,s4 ,this paper 
was preceded by one on the same subject 
by ,mr ,a4 ,caldcleugh1 and the reading 
of a letter and other communications    
from the ,foreign ,office also relating 
to the earthquakes in ,chili4  ,at the  
meeting of the ,council of the          
,geological ,society on ,february #ast1 
,darwin was nominated as a member of the
 new ,council1 and he was elected on    

,february #agth4  ,the meeting of the   
,geological ,society on ,april #aith was
 devoted to the reading by ,owen of his 
paper on ,toxodon1 perhaps the most     
remarkable of the fossil mammals found  
by ,darwin in ,south ,america2 and at   
the next meeting1 on ,may #crd1 ,darwin 
himself read ,a ,sketch of the ,deposits
 containing extinct ,mammalia in the    
neighbourhood of the ,plata4 ,the next  
following meeting1 on ,may #agth1 was   
devoted to ,darwin's ,coral-reef paper1 
entitled ,on certain areas of elevation 
and subsidence in the ,pacific and      
,indian ,oceans1 as deduced from the    
study of ,coral ,formations4 ,neither of
 these three early papers of ,darwin    
were published in the ,transactions of  
the ,geological ,society1 but the       
minutes of the ,council show that they  
were withdrawn by the author by         
permission of the ,council4  ,darwin's  
activity during this session led to some
 rather alarming effects upon his       
health1 and he was induced to take a    

holiday in ,staffordshire and the ,isle 
of ,wight4 ,he was not idle1 however1   
for a remark of his uncle1 ,mr          
,wedgwood1 led him to make those        
interesting observations on the work    
done by earthworms1 that resulted in his
 preparing a short memoir on the        
subject1 and this paper1 ,on the        
,formation of ,mould1 was read at the   
,society on ,november #ast1 #ahcg1 being
 the first of ,darwin's papers published
 in full2 it appeared in ,vol4 ,v4 of   
the ,geological ,transactions1 pages    
#eje-eaj4  ,during this session1 ,darwin
 attended nearly all the ,council       
meetings1 and took such an active part  
in the work of the ,society that it is  
not surprising to find that he was now  
requested to accept the position of     
,secretary4 ,after some hesitation1 in  
which he urged his inexperience and want
 of knowledge of foreign languages1 he  
consented to accept the appointment4    
7,l4,l4 ,i4 page #bhe47  ,at the        
anniversary meeting on ,february #afth1 

#ahch1 the ,wollaston ,medal was given  
to ,owen in recognition of his services 
in describing the fossil mammals sent   
home by ,darwin4 ,in his address1 the   
,president1 ,professor ,whewell1 dwelt  
at length on the great value of the     
papers which ,darwin had laid before the
 ,society during the preceding session4 
,on ,march #gth1 ,darwin read before the
 ,society the most important perhaps of 
all his geological papers1 ,on the      
,connexion of certain ,volcanic         
,phenomena in ,south ,america1 and on   
the ,formation of ,mountain-,chains and 
,volcanoes as the effect of ,continental
 ,elevations4 ,in this paper he boldly  
attacked the tenets of the              
,catastrophists4 ,it is evident that    
,darwin at this time1 taking advantage  
of the temporary improvement in his     
health1 was throwing himself into the   
breach of ,uniformitarianism with the   
greatest ardour4 ,lyell wrote to        
,sedgwick on ,april #bast1 #ahcg1       
,darwin is a glorious addition to any   

society of geologists1 and is working   
hard and making way1 both in his book   
and in our discussions4 7,the ,life and 
,letters of the ,reverend ,adam         
,sedgwick1 ,vol4 ,i4 page #dhd1         
,cambridge1 #ahij47  ,we have           
unfortunately few records of the        
animated debates which took place at    
this time between the old and new       
schools of geologists4 ,i have often    
heard ,lyell tell how ,lockhart would   
bring down a party of friends from the  
,athenaeum ,club to ,somerset ,house on 
,geological nights1 not1 as he carefully
 explained1 that he cared for geology1  
but because he liked to while the       
fellows fight4 ,but it fortunately      
happens that a few days after this last 
of ,darwin's great field-days1 at the   
,geological ,society1 ,lyell1 in a      
friendly letter to his father-in-law1   
,leonard ,horner1 wrote a very lively   
account of the proceedings while his    
impressions were still fresh2 and this  
gives us an excellent idea of the       

character of these discussions4         
,neither ,sedgwick nor ,buckland were   
present on this occasion1 but we can    
imagine how they would have chastised   
their two erring pupils--more in sorrow 
than in anger--had they been there4     
,greenough1 too1 was absent--possibly   
unwilling to countenance even by his    
presence such outrageous doctrines4     
,darwin1 after describing the great     
earthquakes which he had experienced in 
,south ,america1 and the evidence of    
their connection with volcanic          
outbursts1 proceeded to show that       
earthquakes originated in fractures1    
gradually formed in the earth's crust1  
and were accompanied by movements of the
 land on either side of the fracture4   
,in conclusion he boldly advanced the   
view that continental elevations1 and   
the action of volcanoes1 are phenomena  
now in progress1 caused by some great   
but slow change in the interior of the  
earth2 and1 therefore1 that it might be 
anticipated1 that the formation of      

mountain chains is likewise in progress3
 and at a rate which may be judged of by
 either actions1 but most clearly by the
 growth of volcanoes4 7,proc4 ,geol4    
,soc4 ,vol4 ,,ii4 pages #fed-fj47       
,lyell's account 7,life1 ,letters and   
,journals of ,sir ,charles ,lyell1      
,bart41 edited by his sister-in-law1    
,mrs ,lyell1 ,vol4 ,,ii4 pages #dj1 #da 
7,letter to ,leonard ,horner1 #ahch71 #b
 vols4 ,london1 #ahha47 of the          
discussion was as follows3 ,in support  
of my heretical notions1 ,darwin opened 
upon ,de la ,beche1 ,phillips and others
 his whole battery of the earthquakes   
and volcanoes of the ,andes1 and argued 
that spaces at least a thousand miles   
long were simultaneously subject to     
earthquakes and volcanic eruptions1 and 
that the elevation of the ,pampas1      
,patagonia1 etc41 all depended on a     
common cause2 also that the greater the 
contortions of strata in a mountain     
chain1 the smaller must have been each  
separate and individual movement of that

 long series which was necessary to     
upheave the chain4 ,had they been more  
violent1 he contended that the          
subterraneous fluid matter would have   
gushed out and overflowed1 and the      
strata would have been blown up and     
annihilated4 7,it is interesting to     
compare this with what ,darwin wrote to 
,henslow seven years earlier47 ,he      
therefore introduces a cooling of one   
small underground injection1 and then   
the pumping in of other lava1 or        
porphyry1 or granite1 into the          
previously consolidated and first-formed
 mass of igneous rock4 7,ideas somewhat 
similar to this suggestion have recently
 been revived by ,dr ,see 7,proc4 ,am4  
,phil4 ,soc4 ,vol4 ,,xlvii4 #aijh1 page 
#bfb4747 ,when he had done his          
description of the reiterated strokes of
 his volcanic pump1 ,de la ,beche gave  
us a long oration about the             
impossibility of strata of the ,alps1   
etc41 remaining flexible for such a time
 as they must have done1 if they were to

 be tilted1 convoluted1 or overturned by
 gradual small shoves4 ,he never1       
however1 explained his theory of        
original flexibility1 and therefore ,i  
am as unable as ever to comprehend why  
flexiblility is a quality so limited in 
time4  ,phillips then got up and        
pronounced a panegyric upon the         
,principles of ,geology1 and although he
 still differed1 thought the actual     
cause doctrine had been so well put1    
that it had advanced the science and    
formed a date or era1 and that for      
centuries the two opposite doctrines    
would divide geologists1 some contending
 for greater pristine forces1 others    
satisfied1 like ,lyell and ,darwin1 with
 the same intensity as nature now       
employs4  ,fitton quizzed ,phillips a   
little for the warmth of his eulogy1    
saying that he 7,fitton7 and others1 who
 had ,mr ,lyell always with them1 were  
in the habit of admiring and quarrelling
 with him every day1 as one might do    
with a sister or cousin1 whom one would 

only kiss and embrace fervently after a 
long absence4 ,this seemed to be ,mr    
,phillips' case1 coming up occasionally 
from the provinces4 ,fitton then        
finished this drollery by charging me   
with not having done justice to ,hutton1
 who he said was for gradual elevation4 
,i replied1 that most of the critics had
 attacked me for overrating ,hutton1 and
 that ,playfair understood him as ,i    
did4  ,whewell concluded by considering 
,hopkins' mathematical calculations1 to 
which ,darwin had often referred4 ,he   
also said that we ought not to try and  
make out what ,hutton would have taught 
and thought1 if he had known the facts  
which we now know4  ,it may be necessary
 to point out1 in explanation of the    
above narrative1 that while it was      
perfectly clear from ,hutton's rather   
obscure and involved writings that he   
advocated slow and gradual change on the
 earth's surface1 his frequent          
references to violent action and        
earthquakes led many--including         

,playfair1 ,lyell and ,whewell--to      
believe that he held the changes going  
on in the earth's interior to be of a   
catastrophic nature4 ,fitton1 however1  
maintained that ,hutton was consistently
 uniformitarian4 ,before the idea of the
 actual flowing of solid bodies under   
intense pressure had been grasped by    
geologists1 ,de la ,beche1 like         
,playfair before him1 maintained that   
the bending and folding of rocks must   
have been effected before their complete
 consolidation4  ,in concluding his     
account of this memorable discussion1   
,lyell adds3 ,i was much struck with the
 different tone in which my gradual     
causes was treated by all1 even         
including ,de la ,beche1 from that which
 they experienced in the same room four 
years ago1 when ,buckland1 ,de la       
,beche7871 ,sedgwick1 ,whewell1 and some
 others treated them with as much       
ridicule as was consistent with         
politeness in my presence4  ,this       
important paper was1 in spite of its    

theoretical character1 published in full
 in the ,transactions of the ,geological
 ,society 7,ser4 #b1 ,vol4 ,v4 pages    
#fja-fcj74 ,it did not however appear   
till #ahdj1 and possibly some changes   
may have been made in it during the long
 interval between reading and printing4 
,during the year #ahci1 ,darwin         
continued his regular attendance at the 
,council meetings1 but there is no      
record of any discussions in which he   
may have taken part1 and he contributed 
no papers himself to the ,society4 ,at  
the beginning of #ahdj1 he was          
re-elected for the third time as        
,secretary1 but the results of failing  
health are indicated by the circumstance
 that1 only at one meeting early in the 
session1 was he able to attend the      
,council4 ,at the beginning of the next 
session 7,feb4 #ahda7 ,bunbury succeeded
 him as ,secretary1 ,darwin still       
remaining on the ,council4 ,it may be   
regarded as a striking indication of the
 esteem in which he was held by his     

fellow geologists1 that ,darwin remained
 on the ,council for #ad consecutive    
years down to #ahdi1 though his         
attendances were in some years very few4
 ,in #ahdc and #ahdd he was a           
,vice-president1 but after his          
retirement at the beginning of #ahej1 he
 never again accepted re-nomination4 ,he
 continued1 however1 to contribute      
papers to the ,society1 as we shall see1
 down to the end of #ahfb4  ,although   
,darwin early became a member of the    
,geological ,dining ,club1 it is to be  
feared that he scarcely found himself in
 a congenial atmosphere at those        
somewhat hilarious gatherings1 where the
 hardy wielders of the hammer not only  
drank port--and plenty of it--but wound 
up their meal with a mixture of ,scotch 
ale and soda water1 a drink which1 as   
reminiscent of the field1 was regarded  
as especially appropriate to geologists4
 ,even after the meetings1 which        
followed the dinners1 they reassembled  
for suppers1 at which geological        

dainties1 like pterodactyle pie figured 
in the bill of fare1 and fines of       
bumpers were inflicted on those who     
talked the ologies4  ,after being       
present at a fair number of meetings in 
#ahcg and #ahch1 ,darwin's attendances  
at the ,club fell off to two in #ahci1  
and by #ahda he had ceased to be a      
member4 ,in a letter to ,lyell on ,dec4 
#bnd1 #ahda1 ,leonard ,horner wrote that
 the day before ,at the ,council1 ,i had
 the satisfaction of seeing ,darwin     
again in his place and looking well4 ,he
 tried the last evening meeting1 but    
found it too much1 but ,i hope before   
the end of the season he will find      
himself equal to that also4 ,i hail     
,darwin's recovery as a vast gain to    
science4 ,darwin's probably last        
attendance1 this time as a guest1 was in
 #ahea1 when ,horner again wrote to     
,lyell1 ,charles ,darwin was at the     
,geological ,society's ,club yesterday1 
where he had not been for ten           
years--remarkably well1 and grown quite 

stout4 7,memoirs of ,leonard ,horner    
7privately printed71 ,vol4 ,,ii4 pages  
#ci and #aie47  ,it may be interesting  
to note that at the somewhat less lively
 dining ,club--the ,philosophical--in   
the founding of which his friends ,lyell
 and ,hooker had taken so active a part1
 ,darwin found himself more at home1 and
 he was a frequent attendant--in spite  
of his residence being at ,down--from   
#ahec to #ahfd4 ,he even made           
contributions on scientific questions   
after these dinners4 ,in a letter to    
,hooker he states that he was deeply    
interested in the reforms of the ,royal 
,society1 which the ,club was founded to
 promote4 ,he says also that he had     
arranged to come to town every ,club day
 and then my head1 ,i think1 will allow 
me on an average to go to every other   
meeting4 ,but it is grievous how often  
any change knocks me up4 7,l4,l4 ,,ii4  
pages #db1 #dc47  ,of the years #ahcg   
and #ahch ,darwin himself says they were
 the most active ones which ,i ever     

spent1 though ,i was occasionally       
unwell1 and so lost some time444 ,i also
 went a little into society4 7,l4,l4 ,i4
 pages #fg1 #fh47 ,but of the four years
 from #ahci to #ahdb he has to confess  
sadly ,i did less scientific work1      
though ,i worked as hard as ,i could1   
than during any other equal length of   
time in my life4 ,this was owing to     
frequently recurring unwellness1 and to 
one long and serious illness4 7,l4,l4   
,i4 page #fi47  ,darwin's work at the   
,geological ,society did not by any     
means engage the whole of his energies1 
during the active years #ahcg and #ahch4
 ,in ,june of the latter year1 leaving  
town in somewhat bad health1 he found   
himself at ,edinburgh again1 and engaged
 in examining the ,salisbury ,craigs1 in
 a very different spirit to that excited
 by ,jameson's discourse4 7,l4,l4 ,i4   
page #bij47 ,proceeding to the          
,highlands he then had eight days of    
hard work at the famous ,parallel ,roads
 of ,glen ,roy1 being favoured with     

glorious weather4  ,he says of the      
writing of the paper on the subject--the
 only memoir contributed by ,darwin to  
the ,royal ,society1 to which he had    
been recently elected--that it was one  
of the most difficult and instructive   
tasks ,i was ever engaged on4 ,the paper
 extends to #dj quarto pages and is     
illustrated by two plates4 ,though it is
 full of the records of careful         
observation and acute reasoning1 yet the
 theory of marine beaches which he      
propounded was1 as he candidly admitted 
in after years 7,m4,l4 ,,ii page #ahh471
 altogether wrong4 ,the alternative     
lake-theory he found himself unable to  
accept at the time1 for he could not    
understand how barriers could be formed 
at successive levels across the valleys2
 and until the following year1 when the 
existence of great glaciers in the      
district was proved by the researches of
 ,agassiz1 ,buckland and others1 the    
difficulty appeared to him an           
insuperable one4 ,although ,darwin said 

of this paper in after years that it was
 a great failure and ,i am ashamed of   
it--yet he retained his interest in the 
question ever afterwards1 and he says my
 error has been a good lesson to me     
never to trust in science to the        
principle of exclusion4 7,m4,l4 ,,ii4   
pages #aga-ic47  ,although ,darwin had  
not realised in #ahch that large parts  
of the ,british ,islands had been       
occupied by great glaciers1 he had by no
 means failed while in ,south ,america  
to recognise the importance of          
ice-action4 ,his observations1 as       
recorded in his ,journal1 on glaciers   
coming down to the sea-level1 on the    
west coast of ,south ,america1 in a     
latitude corresponding to a much lower  
one than that of the ,british ,islands1 
profoundly interested geologists2 and   
the same work contains many valuable    
notes on the boulders and unstratified  
beds in ,south ,america in which they   
were included4  ,but in #ahdj ,agassiz  
read his startling paper on the evidence

 of the former existence of glaciers in 
the ,british ,islands1 and this was     
followed by ,buckland's memoir on the   
same subject4 ,on ,april #ad1 #ahda1    
,darwin contributed to the ,geological  
,society his important paper ,on the    
,distribution of ,erratic ,boulders and 
the ,contemporaneous ,unstratified      
,deposits of ,south ,america1 a paper   
full of suggestiveness for those        
studying the glacial deposits of this   
country4 ,it was published in the       
,transactions in #ahdb4  ,the           
description of traces of glacial action 
in ,north ,wales1 by ,buckland1 appears 
to have greatly excited the interest of 
,darwin4 ,with ,sedgwick he had1 in     
#ahca1 worked at the stratigraphy of    
that district1 but neither of them had  
noticed the very interesting surface    
features4 7,l4,l4 ,i4 page #eh47 ,darwin
 was able to make a journey to ,north   
,wales in ,june1 #ahdb 7alas6 it was his
 last effort in field-geology7 and as a 
result he published his most able and   

convincing paper on the subject in the  
,september number of the ,philosophical 
,magazine for #ahdb4 ,thus the mystery  
of the bell-stone was at last solved and
 ,darwin1 writing many years afterwards1
 said ,i felt the keenest delight when  
,i first read of the action of icebergs 
in transporting boulders1 and ,i gloried
 in the progress of ,geology4 7,l4,l4   
,i4 page #da47 ,to the ,geographical    
,journal he had sent in #ahci a note ,on
 a ,rock seen on an ,iceberg in #af deg 
,s4 ,latitude4 ,for the subject of      
ice-action1 indeed1 ,darwin retained the
 greatest interest to the end of his    
life4 7,m4,l4 ,,ii4 pages #adh-ga47  ,in
 #ahdf1 ,darwin read two papers to the  
,geological ,society ,on the dust which 
falls on vessels in the ,atlantic1 and  
,on the ,geology of the ,falkland       
,islands2 in #ahdh he contributed a note
 on the transport of boulders from lower
 to higher levels2 and in #ahfb another 
note on the thickness of the ,pampean   
formation1 as shown by recent borings at

 ,buenos ,ayres4 ,an account of the     
,british ,fossil ,lepadidae read in     
#ahej1 was withdrawn by him4  ,at the   
end of #ahcf ,darwin had settled himself
 in lodgings in ,fitzwilliam ,street1   
,cambridge1 and devoted three months to 
the work of unpacking his specimens and 
studying his collection of rocks4 ,the  
pencilled notes on the ,manuscript      
,catalogue in the ,sedgwick ,museum     
enable us to realise his mode of work1  
and the diligence with which it was     
carried on4 ,the letters ,m and ,h1     
indicate the assistance he received from
 time to time from ,professor ,miller1  
the crystallographer1 and from his      
friend ,henslow4 ,miller not only       
measured many of the crystals submitted 
to him1 but evidently taught ,darwin to 
use the reflecting goniometer himself   
with considerable success4 ,the book of 
measurements in which the records were  
kept1 appears to have been lost1 but the
 pencilled notes in the catalogue show  
how thoroughly the work was done4 ,the  

letter ,r attached to some of the       
numbers in the catalogue evidently      
refers to the fact that they were       
submitted to ,mr ,trenham ,reeks 7who   
analysed some of his specimens7 at the  
,geological ,survey quarters in ,craig's
 ,court4 ,this was at a later date when 
,darwin was writing the ,volcanic       
,islands and ,south ,america4  ,it was  
about the month of ,march1 #ahcg1 that  
,darwin completed this work upon his    
rocks1 and also the unpacking and       
distribution of his fossil bones and    
other specimens4 ,we have seen that     
,november1 #ahcb1 must certainly be     
regarded as the date when he ,,first    
realised the important fact that the    
fossil mammals of the ,pampean formation
 were all closely related to the        
existing forms in ,south ,america2 while
 ,october1 #ahce1 was1 as undoubtedly1  
the date when the study of the birds and
 other forms of life in the several     
islands of the ,galapagos ,islands gave 
him his ,,second impulse towards        

abandoning the prevalent view of the    
immutability of species4 ,when then in  
his pocket-book for #ahcg ,darwin wrote 
the often quoted passage3 ,in ,july     
opened first note-book on ,transmutation
 of ,species4 ,had been greatly struck  
from about the month of previous ,march 
on character of ,south ,american        
fossils1 and species on ,galapagos      
,archipelago4 ,these facts 7especially  
latter71 origin of all my views 7,l4,l4 
,i4 page #bgf471 it is clear that he    
must refer1 not to his first inception  
of the idea of evolution1 but to the    
flood of recollections1 the reawakening 
of his interest in the subject1 which   
could not fail to result from the sight 
of his specimens and the reference to   
his notes4  ,except during the summer   
vacation1 when he was visiting his      
father and uncle1 and with the latter   
making his first observations upon the  
work of earthworms1 ,darwin was busy    
with his arrangements for the           
publication of the five volumes of the  

,zoology of the ',beagle' and in getting
 the necessary financial aid from the   
government for the preparation of the   
plates4 ,he was at the same time        
preparing his ,journal for publication4 
,during the years #ahcg to #ahdc1       
,darwin worked intermittently on the    
volumes of ,zoology1 all of which he    
edited1 while he wrote introductions to 
those by ,owen and ,waterhouse and      
supplied notes to the others4  ,although
 ,darwin says of his ,journal that the  
preparation of the book was not hard    
work1 as my ,,ms4 ,journal had been     
written with care4 ,yet from the time   
that he settled at #cf1 ,great          
,marlborough ,street in ,march1 #ahcg1  
to the following ,november he was       
occupied with this book4 ,he tells us   
that the account of his scientific      
observations was added at this time4    
,the work was not published till ,march1
 #ahci1 when it appeared as the third   
volume of the ,narrative of the         
,surveying ,voyages of ,h4,m4 ,ships    

',adventure' and ',beagle' between the  
years #ahbf and #ahcf4 ,the book was    
probably a long time in the press1 for  
there are no less than #bj pages of     
addenda in small print4 ,even in this1  
its first form1 the work is remarkable  
for its freshness and charm1 and excited
 a great amount of attention and        
interest4 ,in addition to matters       
treated of in greater detail in his     
other works1 there are many geological  
notes of extreme value in this volume1  
such as his account of lightning tubes1 
of the organisms found in dust1 and of  
the obsidian bombs of ,australia4       
,having thus got out of hand a number of
 preliminary duties1 ,darwin was ready  
to set to work upon the three volumes   
which were designed by him to constitute
 ,the ,geology of the ,voyage of the    
',beagle'4 ,the first of these was to be
 on ,the ,structure and ,distribution of
 ,coral-reefs4 ,he commenced the writing
 of the book on ,october #e1 #ahch1 and 
the last proof was corrected on ,may #f1

 #ahdb4 ,allowing for the frequent      
interruptions through illness1 ,darwin  
estimated that it cost him twenty months
 of hard work4  ,darwin has related how 
his theory of ,coral-reefs which was    
begun in a more deductive spirit than   
any of his other work1 for in #ahcd or  
#ahce it was thought out on the west    
coast of ,south ,america1 before ,i had 
seen a true coral-reef4 7,l4,l4 ,i4 page
 #gj47 ,the final chapter in ,lyell's   
second volume of the ,principles was    
devoted to the subject of ,coral-reefs1 
and a theory was suggested to account   
for the peculiar phenomena of atolls4   
,darwin at once saw the difficulty of   
accepting the view that the numerous and
 diverse atolls all represent submerged 
volcanic craters4 ,his own work had for 
two years been devoted to the evidence  
of land movements over great areas in   
,south ,america1 and thus he was led to 
announce his theory of subsidence to    
account for barrier and encircling reefs
 as well as atolls4  ,fortunately1      

during his voyage across the ,pacific   
and ,indian ,oceans1 in his visit to    
,australia and his twelve days' hard    
work at ,keeling ,island1 he had        
opportunities for putting his theory to 
the test of observation4  ,on his return
 to ,england1 ,darwin appears to have   
been greatly surprised at the amount of 
interest that his new theory excited4   
,urged by ,lyell1 he read to the        
,geological ,society a paper on the     
subject1 as we have seen1 with as little
 delay as possible1 but this paper was  
withdrawn by permission of the ,council4
 ,an abstract of three pages however    
appeared in the ,proceedings of the     
,geological ,society4 7,vol4 ,,ii4 pages
 #eeb-eed 7,may #ca1 #ahcg747 ,a full   
account of the observations and the     
theory was given in the ,journal 7#ahci7
 in the #dj pages devoted to ,keeling   
,island in particular and to ,coral     
formations generally4 7,journal 7#ast   
edition71 pages #dci-fi47  ,it will be  
readily understood what an amount of    

labour the book on ,coral reefs cost    
,darwin when we reflect on the number of
 charts1 sailing directions1 narratives 
of voyages and other works which1 with  
the friendly assistance of the          
authorities at the ,admiralty1 he had to
 consult before he could draw up his    
sketch of the nature and distribution of
 the reefs1 and this was necessary      
before the theory1 in all its important 
bearings1 could be clearly enunciated4  
,very pleasing is it to read how        
,darwin1 although arriving at a         
different conclusion to ,lyell1 shows1  
by quoting a very suggestive passage in 
the ,principles 7#ast edition ,vol4     
,,ii4 page #bif471 how the latter only  
just missed the true solution4 ,this    
passage is cited1 both in the ,journal  
and the volume on ,coral-reefs4 ,lyell1 
as we have seen1 received the new theory
 not merely ungrudgingly1 but with the  
utmost enthusiasm4  ,in #ahdi ,darwin   
was gratified by receiving the support  
of ,dana1 after his prolonged           

investigation in connection with the    
,u4,s4 ,exploring ,expedition 7,m4,l4   
,,ii4 pages #bbf-h471 and in #ahgd he   
prepared a second edition of his book1  
in which some objections which had been 
raised to the theory were answered4 ,a  
third edition1 edited by ,professor     
,bonney1 appeared in #ahhj1 and a fourth
 7a reprint of the first edition1 with  
introduction by myself7 in #ahij4       
,although ,professor ,semper1 in his    
account of the ,pelew ,islands1 had     
suggested difficulties in the acceptance
 of ,darwin's theory1 it was not till   
after the return of the ,challenger     
expedition in #ahge that a rival theory 
was propounded1 and somewhat heated     
discussions were raised as to the       
respective merits of the two theories4  
,while geologists have1 nearly without  
exception1 strongly supported ,darwin's 
views1 the notes of dissent have come   
almost entirely from zoologists4 ,at the
 height of the controversy unfounded    
charges of unfairness were made against 

,darwin's supporters and the authorities
 of the ,geological ,society1 but this  
unpleasant subject has been disposed of1
 once for all1 by ,huxley4 7,essays upon
 some ,controverted ,questions1 ,london1
 #ahib1 pages #cad-cbh and #fbc-fbe47   
,darwin's final and very characteristic 
utterance on the coral-reef controversy 
is found in a letter which he wrote to  
,professor ,alexander ,agassiz1 ,may    
#eth1 #ahha3 less than a year before his
 death3 ,if ,i am wrong1 the sooner ,i  
am knocked on the head and annihilated  
so much the better4 ,it still seems to  
me a marvellous thing that there should 
not have been much1 and long-continued1 
subsidence in the beds of the great     
oceans4 ,i wish that some doubly rich   
millionaire would take it into his head 
to have borings made in some of the     
,pacific and ,indian atolls1 and bring  
home cores for slicing from a depth of  
#ejj or #fjj feet4 7,l4,l4 ,,iii4 page  
#ahd47  ,though the doubly rich         
millionaire has not been forthcoming1   

the energy1 in ,england1 of ,professor  
,sollas1 and in ,new ,south ,wales of   
,professor ,anderson ,stuart served to  
set on foot a project1 which1 aided at  
first by the ,british ,association for  
the ,advancement of ,science1 and       
afterwards taken up jointly by the      
,royal ,society1 the ,new ,south ,wales 
,government1 and the ,admiralty1 has led
 to the most definite and conclusive    
results4  ,the ,committee appointed by  
the ,royal ,society to carry out the    
undertaking included representatives of 
all the views that had been put forward 
on the subject4 ,the place for the      
experiment was1 with the consent of     
every member of the ,committee1 selected
 by the late ,admiral ,sir ,w4,j4       
,wharton--who was not himself an        
adherent of ,darwin's views--and no one 
has ventured to suggest that his        
selection1 the splendid atoll of        
,funafuti1 was not a most judicious one4
  ,by the pluck and perseverance of     
,professor ,sollas in the preliminary   

expedition1 and of ,professor ,t4       
,edgeworth ,david and his pupils1 in    
subsequent investigations of the island1
 the rather difficult piece of work was 
brought to a highly satisfactory        
conclusion4 ,the ,new ,south ,wales     
,government lent boring apparatus and   
workmen1 and the ,admiralty carried the 
expedition to its destination in a      
surveying ship which1 under ,captain    
7now ,admiral7 ,a4 ,mostyn ,field1 made 
the most complete survey of the atoll   
and its surrounding seas that has ever  
been undertaken in the case of a coral  
formation4  ,after some failures and    
many interruptions1 the boring was      
carried to the depth of #aaad feet1 and 
the cores obtained were sent to         
,england4 ,here the examination of the  
materials was fortunately undertaken by 
a zoologist of the highest repute1 ,dr  
,g4,j4 ,hinde--who has a wide experience
 in the study of organisms by           
sections--and he was aided at all points
 by specialists in the ,british ,museum 

of ,natural ,history and by other       
naturalists4 ,nor were the chemical and 
other problems neglected4  ,the verdict 
arrived at1 after this most exhaustive  
study of a series of cores obtained from
 depths twice as great as that thought  
necessary by ,darwin1 was as            
follows3--,the whole of the cores are   
found to be built up of those organisms 
which are seen forming coral-reefs near 
the surface of the ocean--many of them  
evidently in situ2 and not the slightest
 indication could be detected1 by       
chemical or microscopic means1 which    
suggested the proximity of              
non-calcareous rocks1 even in the lowest
 portions brought up4  ,but this was not
 all4 ,professor ,david succeeded in    
obtaining the aid of a very skilful     
engineer from ,australia1 while the     
,admiralty allowed ,commander ,f4,c4,d4 
,sturdee to take a surveying ship into  
the lagoon for further investigations4  
,by very ingenious methods1 and with    
great perseverance1 two borings were put

 down in the midst of the lagoon to the 
depth of nearly #bjj feet4 ,the bottom  
of the lagoon1 at the depth of #aja     
#a_/b feet from sea-level1 was found to 
be covered with remains of the          
calcareous1 green sea-weed ,halimeda1   
mingled with many foraminifera2 but at a
 depth of #afc feet from the surface of 
the lagoon the boring tools encountered 
great masses of coral1 which were proved
 from the fragments brought up to belong
 to species that live within ,,at ,,most
 #abj feet from the surface of the      
ocean1 as admitted by all zoologists4   
7,the ,atoll of ,funafuti2 ,report of   
the ,coral ,reef ,committee of the      
,royal ,society1 ,london1 #aijd47       
,darwin's theory1 as is well known1 is  
based on the fact that the temperature  
of the ocean at any considerable depth  
does not permit of the existence and    
luxuriant growth of the organisms that  
form the reefs4 ,he himself estimated   
this limit of depth to be from #abj to  
#acj feet2 ,dana1 as an extreme1 #aej   

feet2 while the recent very prolonged   
and successful investigations of        
,professor ,alexander ,agassiz in the   
,pacific and ,indian ,oceans lead him   
also to assign a limiting depth of #aej 
feet2 the ,,effective1 ,,reef-,,forming 
,,corals1 however1 flourishing at a much
 smaller depth4 ,mr ,stanley ,gardiner  
gives for the most important            
reef-forming corals depths between #cj  
and #ij feet1 while a few are found as  
low as #abj feet or even #ahj feet4  ,it
 will thus be seen that the verdict of  
,funafuti is clearly and unmistakeably  
in favour of ,darwin's theory4 ,it is   
true that some zoologists find a        
difficulty in realising a slow sinking  
of parts of the ocean floor1 and have   
suggested new and alternative           
explanations3 but geologists generally1 
accepting the proofs of slow upheaval in
 some areas--as shown by the admirable  
researches of ,alexander                
,agassiz--consider that it is absolutely
 necessary to admit that this elevation 

is balanced by subsidence in other      
areas4 ,if atolls and barrier-reefs did 
not exist we should indeed be at a great
 loss to frame a theory to account for  
their absence4  ,after finishing his    
book on ,coral-reefs1 ,darwin made his  
summer excursion to ,north ,wales1 and  
prepared his important memoir on the    
glaciers of that district3 but by       
,october 7#ahdb7 we find him fairly     
settled at work upon the second volume  
of his ,geology of the                  
',beagle'--,geological ,observations on 
the ,volcanic ,islands1 visited during  
the ,voyage of ,h4,m4,s4 ',beagle'4 ,the
 whole of the year #ahdc was devoted to 
this work1 but he tells his friend ,fox 
that he could manage only a couple of   
hours per day1 and that not very        
regularly4 7,l4,l4 ,i4 page #cba47      
,darwin's work on the various volcanic  
islands examined by him had given him   
the most intense pleasure1 but the work 
of writing the book by the aid of his   
notes and specimens he found uphill     

work1 especially as he feared the book  
would not be read1 even by geologists4  
7,loc4 cit47  ,as a matter of fact the  
work is full of the most interesting    
observations and valuable suggestions1  
and the three editions 7or reprints7    
which have appeared have proved a most  
valuable addition to geological         
literature4 ,it is not necessary to     
refer to the novel and often very       
striking discoveries described in this  
well-known work4 ,the subsidence beneath
 volcanic vents1 the enormous denudation
 of volcanic cones reducing them to     
basal wrecks1 the effects of solfatarric
 action and the formation of various    
minerals in the cavities of rocks--all  
of these subjects find admirable        
illustration from his graphic           
descriptions4 ,one of the most important
 discussions in this volume is that     
dealing with the lamination of lavas as 
especially well seen in the rocks of    
,ascension4 ,like ,scrope1 ,darwin      
recognised the close analogy between the

 structure of these rocks and those of  
metamorphic origin--a subject which he  
followed out in the volume ,geological  
,observations on ,south ,america4  ,of  
course in these days1 since the         
application of the microscope to the    
study of rocks in thin sections1        
,darwin's nomenclature and descriptions 
of the petrological characters of the   
lavas appear to us somewhat crude4 ,but 
it happened that the ,challenger visited
 most of the volcanic islands described 
by ,darwin1 and the specimens brought   
home were examined by the eminent       
petrologist ,professor ,renard4 ,renard 
was so struck with the work done by     
,darwin1 under disadvantageous          
conditions1 that he undertook a         
translation of ,darwin's work into      
,french1 and ,i cannot better indicate  
the manner in which the book is regarded
 by geologists than by quoting a passage
 from ,renard's preface4 ,referring to  
his own work in studying the rocks      
brought home by the ,challenger         

7,renard's descriptions of these rocks  
are contained in the ,challenger        
,reports4 ,mr ,harker is supplementing  
these descriptions by a series of       
petrological memoirs on ,darwin's       
specimens1 the first of which appeared  
in the ,geological ,magazine for ,march1
 #aijg471 he says3  ,je dus1 en me      
livrant a ces recherches1 suivre ligne  
par ligne les divers chapitres des      
,observations geologiques consacrees aux
 iles de l',atlantique1 oblige que      
j'etais de comparer d'une maniere suivie
 les resultats auxquels j'etais conduit 
avec ceux de ,darwin1 qui servaient de  
controle a mes constatations4 ,je ne    
tardai pas a eprouver une vive          
admiration pour ce chercheur qui1 sans  
autre appareil que la loupe1 sans autre 
reaction que quelques essais            
pyrognostiques1 plus rarement quelques  
mesures au goniometre1 parvenait a      
discerner la nature des agregats        
mineralogiques les plue complexes et les
 plus varies4 ,ce coup d'oeil qui savait

 embrasser de si vastes horizons1       
penetre ici profondement tous les       
details lithologiques4 ,avec quelle     
surete et quelle exactitude la structure
 et la composition des roches ne        
sont'elles pas determinees1 l'origne de 
ces masses minerales deduite et         
confirmee par l'etude comparee des      
manifestations volcaniques d'autres     
regions2 avec quelle science les        
relations entre les faits qu'il decouvre
 et ceux signales ailleurs par ses      
devanciers ne sont'elles pas etablies1  
et comme voici ebranlees les hypotheses 
regnantes1 admises sans preuves1 celles1
 par exemple1 des crateres de           
soulevement et de la differenciation    
radicale des phenomenes plutoniques et  
volcaniques6 ,ce qui acheve de donner a 
ce livre un incomparable merite1 ce sont
 les idees nouvelles qui s'y trouvent en
 germe et jetees la comme au hasard     
ainsi qu'un superflu d'abondance        
intellectuelle inepuisable4             
7,observations ,geologiques sur les     

,iles ,volcaniques444 1 ,paris1 #aijb1  
pages vi41 vii47  ,while engaged in his 
study of banded lavas1 ,darwin was      
struck with the analogy of their        
structure with that of glacier ice1 and 
a note on the subject1 in the form of a 
letter addressed to ,professor ,j4,d4   
,forbes1 was published in the           
,proceedings of the ,royal ,society of  
,edinburgh4 7,vol4 ,,ii4 7#ahdd-e71     
pages #ag1 #ah47  ,from ,april1 #ahcb1  
to ,september1 #ahce1 ,darwin had been  
occupied in examining the coast or      
making inland journeys in the interior  
of the ,south ,american continent4 ,thus
 while eighteen months were devoted1 at 
the beginning and end of the voyage to  
the study of volcanic islands and       
coral-reefs1 no less than three and a   
half years were given to ,south         
,american geology4 ,the heavy task of   
dealing with the notes and specimens    
accumulated during that long period was 
left by ,darwin to the last4 ,finishing 
the ,volcanic ,islands on ,february     

#adth1 #ahdd1 he1 in ,july of the same  
year1 commenced the preparation of two  
important works which engaged him till  
near the end of the year #ahdf4 ,the    
first was his ,geological ,observations 
on ,south ,america1 the second a recast 
of his ,journal1 published under the    
short title of ,a ,naturalist's ,voyage 
round the ,world4  ,the first of these  
works contains an immense amount of     
information collected by the author     
under great difficulties and not        
unfrequently at considerable risk to    
life and health4 ,no sooner had ,darwin 
landed in ,south ,america than two sets 
of phenomena powerfully arrested his    
attention4 ,the first of these was the  
occurrence of great masses of red mud   
containing bones and shells1 which      
afforded striking evidence that the     
whole continent had shared in a series  
of slow and gradual but often           
interrupted movements4 ,the second      
related to the great masses of          
crystalline rocks which1 underlying the 

muds1 cover so great a part of the      
continent4 ,darwin1 almost as soon as he
 landed1 was struck by the circumstance 
that the direction1 as shown by his     
compass1 of the prominent features of   
these great crystalline                 
rock-masses--their cleavage1            
master-joints1 foliation and pegmatite  
veins--was the same as the orientation  
described by ,humboldt 7whose works he  
had so carefully studied7 on the west of
 the same great continent4  ,the first  
five chapters of the book on ,south     
,america were devoted to formations of  
recent date and to the evidence         
collected on the east and west coasts of
 the continent in regard to those grand 
earth-movements1 some of which could be 
shown to have been accompanied by       
earthquake-shocks4 ,the fossil bones1   
which had given him the first hint      
concerning the mutability of species1   
had by this time been studied and       
described by comparative anatomists1 and
 ,darwin was able to elaborate much more

 fully the important conclusion that the
 existing fauna of ,south ,america has a
 close analogy with that of the period  
immediately preceding our own4  ,the    
remaining three chapters of the book    
dealt with the metamorphic and plutonic 
rocks1 and in them ,darwin announced his
 important conclusions concerning the   
relations of cleavage and foliation1 and
 on the close analogy of the latter     
structure with the banding found in     
rock-masses of igneous origin4 ,with    
respect to the first of these           
conclusions1 he received the powerful   
support of ,daniel ,sharpe1 who in the  
years #aheb and #ahed published two     
papers on the structure of the ,scottish
 ,highlands1 supplying striking         
confirmation of the correctness of      
,darwin's views4 ,although ,darwin's and
 ,sharpe's conclusions were contested by
 ,murchison and other geologists1 they  
are now universally accepted4 ,in his   
theory concerning the origin of         
foliation1 ,darwin had been to some     

extent anticipated by ,scrope1 but he   
supplied many facts and illustrations   
leading to the gradual acceptance of a  
doctrine which1 when first enunciated1  
was treated with neglect1 if not with   
contempt4  ,the whole of this volume on 
,south ,american geology is crowded with
 the records of patient observations and
 suggestions of the greatest value2 but1
 as ,darwin himself saw1 it was a book  
for the working geologist and caviare to
 the general4 ,its author1 indeed1      
frequently expressed his sense of the   
dryness of the book2 he even says ,i    
long hesitated whether ,i would publish 
it or not1 and he wrote to ,leonard     
,horner ,i am astonished that you should
 have had the courage to go right       
through my book4 7,m4,l4 ,,ii4 page     
#bba47  ,fortunately the second book1 on
 which ,darwin was engaged at this time1
 was of a very different character4 ,his
 ,journal1 almost as he had written it  
on board ship1 with facts and           
observations fresh in his mind1 had been

 published in #ahci and attracted much  
attention4 ,in #ahde1 he says1 ,i took  
much pains in correcting a new edition1 
and the work which was commenced in     
,april1 #ahde1 was not finished till    
,august of that year4 ,the volume       
contains a history of the voyage with a 
sketch of those observations in ,natural
 ,history and ,geology1 which ,i think  
will possess some interest for the      
general reader4 ,it is not necessary to 
speak of the merits of this scientific  
classic4 ,it became a great favourite   
with the general public--having passed  
through many editions--it was1 moreover1
 translated into a number of different  
languages4 ,darwin was much gratified by
 these evidences of popularity1 and     
naively remarks in his ,autobiography1  
,the success of this my first literary  
child tickles my vanity more than that  
of any of my other books 7,l4,l4 ,i4    
page #hj47--;and this was written after 
the ,origin of ,species had become      
famous6  ,in ,darwin's letters there are

 many evidences that his labours during 
these ten years devoted to the working  
out of the geological results of the    
voyage often made many demands on his   
patience and indomitable courage4 ,most 
geologists have experience of the       
contrast between the pleasures felt when
 wielding the hammer in the field1 and  
the duller labour of plying the pen in  
the study4 ,but in ,darwin's case1      
innumerable interruptions from sickness 
and other causes1 and the oft-deferred  
hope of reaching the end of his task    
were not the only causes operating to   
make the work irksome4 ,the great       
project1 which was destined to become   
the crowning achievement of his life1   
was now gradually assuming more definite
 shape1 and absorbing more of his time  
and energies4  ,nevertheless1 during all
 this period1 ,darwin so far regarded   
his geological pursuits as his ,,proper 
work1 that attention to other matters   
was always spoken of by him as indulging
 in idleness4 ,if at the end of this    

period the world had sustained the great
 misfortune of losing ,darwin by death  
before the age of forty--and several    
times that event seemed only too        
probable--he might have been remembered 
only as a very able geologist of most   
advanced views1 and a traveller who had 
written a scientific narrative of more  
than ordinary excellence6  ,the         
completion of the ,geology of the       
',beagle' and the preparation of a      
revised narrative of the voyage mark the
 termination of that period of fifteen  
years of ,darwin's life during which    
geological studies were his principal   
occupation4 ,henceforth1 though his     
interest in geological questions        
remained ever keen1 biological problems 
engaged more and more of his attention  
to the partial exclusion of geology4    
,the eight years from ,october1 #ahdf1  
to ,october1 #ahed1 were mainly devoted 
to the preparation of his two important 
monographs on the recent and fossil     
,cirripedia4 ,apart from the value of   

his description of the fossil forms1    
this work of ,darwin's had an important 
influence on the progress of geological 
science4 ,up to that time a practice had
 prevailed for the student of a         
particular geological formation to take 
up the description of the plant and     
animal remains in it--often without     
having anything more than a rudimentary 
knowledge of the living forms           
corresponding to them4 ,darwin in his   
monograph gave a very admirable         
illustration of the enormous advantage  
to be gained--alike for biology and     
geology--by undertaking the study of the
 living and fossil forms of a natural   
group of organisms in connection with   
one another4 ,of the advantage of these 
eight years of work to ,darwin himself1 
in preparing for the great task lying   
before him1 ,huxley has expressed a very
 strong opinion indeed4 7,l4,l4 ,,ii4   
pages #bdg-dh47  ,but during these eight
 years of species work1 ,darwin found   
opportunities for not a few excursions  

into the field of geology4 ,he          
occasionally attended the ,geological   
,society1 and1 as we have already seen1 
read several papers there during this   
period4 ,his friend1 ,dr ,hooker1 then  
acting as botanist to the ,geological   
,survey1 was engaged in studying the    
,carboniferous flora1 and many          
discussions on ,palaezoic plants and on 
the origin of coal took place at this   
period4 ,on this last subject he felt   
the deepest interest and told ,hooker1  
,i shall never rest easy in ,down       
churchyard without the problem be solved
 by some one before ,i die4 7,m4,l4 ,i4 
pages #fc1 #fd47  ,as at all times1     
conversations and letters with ,lyell on
 every branch of geological science     
continued with unabated vigour1 and in  
spite of the absorbing character of the 
work on the ,cirripedes1 time was found 
for all4 ,in #ahdi his friend ,herschel 
induced him to supply a chapter of forty
 pages on ,geology to the ,admiralty    
,manual of ,scientific ,inquiry which he

 was editing4 ,this is ,darwin's single 
contribution to books of an educational 
kind4 ,it is remarkable for its         
clearness and simplicity and attention  
to minute details4 ,it may be read by   
the student of ,darwin's life with much 
interest1 for the directions he gives to
 an explorer are without doubt those    
which he1 as a self-taught geologist1   
proved to be serviceable during his life
 on the ,beagle4  ,on the completion of 
the ,cirripede volumes1 in #ahed1       
,darwin was able to grapple with the    
immense pile of ,,ms4 notes which he had
 accumulated on the species question4   
,the first sketch of #ce pages 7#ahdb71 
had been enlarged in #ahdd into one of  
#bcj pages 7,the first draft of the     
,origin is being prepared for ,press by 
,mr ,francis ,darwin and will be        
published by the ,cambridge ,university 
,press this year 7#aiji74 ,a4,c4,s472   
but in #ahef was commenced the work     
7never to be completed7 which was       
designed on a scale three or four times 

more extensive than that on which the   
,origin of ,species was in the end      
written4  ,in drawing up those two      
masterly chapters of the ,origin1 ,on   
the ,imperfection of the ,geological    
,record1 and ,on the ,geological        
,succession of ,organic ,beings1 ,darwin
 had need of all the experience and     
knowledge he had been gathering during  
thirty years1 the first half of which   
had been almost wholly devoted to       
geological study4 ,the most enlightened 
geologists of the day found much that   
was new1 and still more that was        
startling from the manner of its        
presentation1 in these wonderful essays4
 ,of ,darwin's own sense of the         
importance of the geological evidence in
 any presentation of his theory a       
striking proof will be found in a       
passage of the touching letter to his   
wife1 enjoining the publication of his  
sketch of #ahdd4 ,in case of my sudden  
death1 he wrote1 444 the editor must be 
a geologist as well as a naturalist4    

7,l4,l4 ,,ii4 pages #af1 #ag47  ,in     
spite of the numerous and valuable      
palaeontological discoveries made since 
the publication of ,the ,origin of      
,species1 the importance of the first of
 these two geological chapters is as    
great as ever4 ,it still remains true   
that ,those who believe that the        
geological record is in any degree      
perfect1 will at once reject the        
theory--as indeed they must reject any  
theory of evolution4 ,the striking      
passage with which ,darwin concludes    
this chapter--in which he compares the  
record of the rocks to the much         
mutilated volumes of a human            
history--remains as apt an illustration 
as it did when first written4  ,and the 
second geological chapter1 on the       
,succession of ,organic ,beings--though 
it has been strengthened in a thousand  
ways1 by the discoveries concerning the 
pedigrees of the horse1 the elephant and
 many other aberrant types1 though new  
light has been thrown even on the origin

 of great groups like the mammals1 and  
the gymnosperms1 though not a few fresh 
links have been discovered in the chains
 of evidence1 concerning the order of   
appearance of new forms of life--we     
would not wish to have re-written4 ,only
 the same line of argument could be     
adopted1 though with innumerable fresh  
illustrations4 ,those who reject the    
reasonings of this chapter1 neither     
would they be persuaded if a long and   
complete succession of ancestral forms  
could rise from the dead and pass in    
procession before them4  ,among the     
geological discussions1 which so        
frequently occupied ,darwin's attention 
during the later years of his life1     
there was one concerning which his      
attitude seemed somewhat remarkable--,i 
allude to his views on the permanence of
 ,continents and ,ocean-basins4 ,in a   
letter to ,mr ,mellard ,reade1 written  
at the end of #ahhj1 he wrote3 ,on the  
whole1 ,i lean to the side that the     
continents have since ,cambrian times   

occupied approximately their present    
positions4 ,but1 as ,i have said1 the   
question seems a difficult one1 and the 
more it is discussed the better4 7,m4,l4
 ,,ii4 page #adg47 ,since this was      
written1 the important contribution to  
the subject by the late ,dr ,w4,t4      
,blanford 7himself1 like ,darwin1 a     
naturalist and geologist7 has appeared  
in an address to the ,geological        
,society in #ahij2 and many discoveries1
 like that of ,dr ,woolnough in ,fiji1  
have led to considerable qualifications 
of the generalisation that all the      
islands in the great ocean are wholly of
 volcanic or coral origin4  ,i remember 
once expressing surprise to ,darwin     
that1 after the views which he had      
originated concerning the existence of  
areas of elevation and others of        
subsidence in the ,pacific ,ocean1 and  
in face of the admitted difficulty of   
accounting for the distribution of      
certain terrestrial animals and plants1 
if the land and sea areas had been      

permanent in position1 he still         
maintained that theory4 ,looking at me  
with a whimsical smile1 he said3 ,i have
 seen many of my old friends make fools 
of themselves1 by putting forward new   
theoretical views or revising old ones1 
,,after ,,they ,,were ,,sixty ,,years   
,,of ,,age2 so1 long ago1 ,i determined 
that on reaching that age ,i would write
 nothing more of a speculative          
character4  ,though ,darwin's letters   
and conversations on geology during     
these later years were the chief        
manifestations of the interest he       
preserved in his old love1 as he        
continued to call it1 yet in the sunset 
of that active life a gleam of the old  
enthusiasm for geology broke forth once 
more4 ,there can be no doubt that       
,darwin's inability to occupy himself   
with field-work proved an insuperable   
difficulty to any attempt on his part to
 resume active geological research4     
,but1 as is shown by the series of      
charming volumes on plant-life1 ,darwin 

had found compensation in making patient
 and persevering experiment take the    
place of enterprising and exact         
observation2 and there was one direction
 in which he could indulge the old love 
by employment of the new faculty4  ,we  
have seen that the earliest memoir      
written by ,darwin1 which was published 
in full1 was a paper ,on the ,formation 
of ,mould which was read at the         
,geological ,society on ,november #ast1 
#ahcg1 but did not appear in the        
,transactions of the ,society till      
#ahdj1 where it occupied four and a half
 quarto pages1 including some           
supplementary matter1 obtained later1   
and a woodcut4 ,this little paper was   
confined to observations made in his    
uncle's fields in ,staffordshire1 where 
burnt clay1 cinders1 and sand were found
 to be buried under a layer of black    
earth1 evidently brought from below by  
earthworms1 and to a recital of similar 
facts from ,scotland obtained through   
the agency of ,lyell4 ,the subsequent   

history of ,darwin's work on this       
question affords a striking example of  
the tenacity of purpose with which he   
continued his enquiries on any subject  
that interested him4  ,in #ahdb1 as soon
 as he was settled at ,down1 he began a 
series of observations on a foot-path   
and in his fields1 that continued with  
intermissions during his whole life1 and
 he extended his enquiries from time to 
time to the neighbouring parks of ,knole
 and ,holwood4 ,in #ahdd we find him    
making a communication to the           
,gardener's ,chronicle on the subject4  
,about #ahgj1 his attention to the      
question was stimulated by the          
circumstance that his niece 7,miss ,l4  
,wedgwood7 undertook to collect and     
weigh the worm-casts thrown up1 during a
 whole year1 on measured squares        
selected for the purpose1 at ,leith     
,hill ,place4 ,he also obtained         
information from ,professor ,ramsay     
concerning observations made by him on a
 pavement near his house in #ahga4      

,darwin at this time began to realise   
the great importance of the action of   
worms to the archaeologist4 ,at an      
earlier date he appears to have obtained
 some information concerning articles   
found buried on the battle-field of     
,shrewsbury1 and the old ,roman town of 
,uriconium1 near his early home2 between
 #ahga and #ahgh ,mr 7afterwards ,lord7 
,farrer carried on a series of          
investigations at the ,roman ,villa     
discovered on his land at ,abinger2     
,darwin's son ,william examined for his 
father the evidence at ,beaulieu ,abbey1
 ,brading1 ,stonehenge and other        
localities in the neighbourhood of his  
home2 his sons ,francis and ,horace were
 enlisted to make similar enquiries at  
,chideock and ,silchester2 while        
,francis ,galton contributed facts      
noticed in his walks in ,hyde ,park4 ,by
 correspondence with ,fritz ,muller and 
,dr ,ernst1 ,darwin obtained information
 concerning the worm-casts found in     
,south ,america2 from ,dr ,kreft those  

of ,australia2 and from ,mr ,scott and  
,dr 7afterwards ,sir ,george7 ,king1    
those of ,india2 the last-named         
correspondent also supplied him with    
much valuable information obtained in   
the ,south of ,europe4 ,help too was    
obtained from the memoirs on ,earthworms
 published by ,perrier in #ahgd and van 
,hensen in #ahgg1 while ,professor ,ray 
,lankester supplied important facts with
 regard to their anatomy4  ,when        
therefore the series of interesting     
monographs on plant-life had been       
completed1 ,darwin set to work in       
bringing the information that he had    
gradually accumulated during forty-four 
years to bear on the subject of his     
early paper4 ,he also utilised the skill
 and ingenuity he had acquired in       
botanical work to aid in the elucidation
 of many of the difficulties that       
presented themselves4 ,i well remember a
 visit which ,i paid to ,down at this   
period4 ,at the side of the little study
 stood flower-pots containing earth with

 worms1 and1 without interrupting our   
conversation1 ,darwin would from time to
 time lift the glass plate covering a   
pot to watch what was going on4         
,occasionally1 with a humorous smile1 he
 would murmur something about a book in 
another room1 and slip away2 returning  
shortly1 without the book but with      
unmistakeable signs of having visited   
the snuff-jar outside4 ,after working   
about a year at the worms1 he was able  
at the end of #ahha to publish the      
charming little book--,the ,formation of
 ,vegetable ,mould through the ,action  
of ,worms1 with ,observations on their  
,habits4 ,this was the last of his      
books1 and its reception by reviewers   
and the public alike afforded the       
patient old worker no little            
gratification4 ,darwin's scientific     
career1 which had begun with geological 
research1 most appropriately ended with 
a return to it4  ,it has been impossible
 to sketch the origin and influence of  
,darwin's geological work without1 at   

almost every step1 referring to the part
 played by ,lyell and the ,principles of
 ,geology4 ,haeckel1 in the chapters on 
,lyell and ,darwin in his ,history of   
,creation1 and ,huxley in his striking  
essay ,on the ,reception of the ,origin 
of ,species 7,l4,l4 ,,ii4 pages         
#agi-bjd47 have both strongly insisted  
on the fact that the ,origin of ,darwin 
was a necessary corollary to the        
,principles of ,lyell4  ,it is true     
that1 in an earlier essay1 ,huxley had  
spoken of the doctrine of               
,uniformitarianism as being1 in a       
certain sense1 opposed to that of       
,evolution 7,huxley's ,address to the   
,geological ,society1 #ahfi4 ,collected 
,essays1 ,vol4 ,,viii4 page #cje1       
,london1 #ahif472 but in his later years
 he took up a very different and more   
logical position1 and maintained that   
,consistent uniformitarianism postulates
 evolution as much in the organic as in 
the inorganic world4 ,the origin of a   
new species by other than ordinary      

agencies would be a vastly greater      
'catastrophe' than any of those which   
,lyell success fully eliminated from    
sober geological speculation4 7,l4,l4   
,,ii4 page #aij47  ,huxley's admiration 
for the ,principles of ,geology1 and his
 conviction of the greatness of the     
revolution of thought brought about by  
,lyell1 was almost as marked as in the  
case of ,darwin himself4 7,see his      
,essay on ,science and ,pseudo ,science4
 ,collected ,essays1 ,vol4 ,v4 page #ij1
 ,london1 #aijb47 ,he felt1 however1 as 
many others have done1 that in one      
respect the very success of ,lyell's    
masterpiece has been the reason why its 
originality and influence have not been 
so fully recognised as they deserved to 
be4 ,written as the book was before its 
author had arrived at the age of thirty1
 no less than eleven editions of the    
,principles were called for in his      
lifetime4 ,with the most scrupulous     
care1 ,lyell1 devoting all his time and 
energies to the task of collecting and  

sifting all evidence bearing on the     
subjects of his work1 revised and       
re-revised it2 and as in each edition1  
eliminations1 modifications1            
corrections1 and additions were made1   
the book1 while it increased in value as
 a storehouse of facts1 lost much of its
 freshness1 vigour and charm as a piece 
of connected reasoning4  ,darwin        
undoubtedly realised this when he wrote 
concerning the ,principles1 the first   
edition1 my old true love1 which ,i     
never deserted for the later editions4  
7,m4,l4 ,,ii4 page #bbb47 ,huxley once  
told me that when1 in later life1 he    
read the first edition1 he was both     
surprised and delighted1 feeling as if  
it were a new book to him4 7,i have     
before me a letter which illustrates    
this feeling on ,huxley's part4 ,he had 
lamented to me that he did not possess a
 copy of the first edition of the       
,principles1 when1 shortly afterwards1  
,i picked up a dilapidated copy on a    
bookstall2 this ,i had bound and sent to

 my old teacher and colleague4 ,his     
reply is characteristic3  ,october #h1  
#ahhd4  ,my ,dear ,judd1  ,you could not
 have made me a more agreeable present  
than the copy of the first edition of   
,lyell1 which ,i find on my table4 ,i   
have never been able to meet with the   
book1 and your copy is1 as the old woman
 said of her ,bible1 the best of books  
in the best of bindings4  ,ever yours   
sincerely1  ,t4,h4 ,huxley4  7,i cannot 
refrain from relating an incident which 
very strikingly exemplifies the         
affection for one another felt by ,lyell
 and ,huxley4 ,in his last illness1 when
 confined to his bed1 ,lyell heard that 
,huxley was to lecture at the ,royal    
,institution on the ,results of the     
',challenger' expedition3 he begged me  
to attend the lecture and bring him an  
account of it4 ,happening to mention    
this to ,huxley1 he at once undertook to
 go to ,lyell in my place1 and he did so
 on the morning following his lecture4  
,i shall never forget the look of       

gratitude on the face of the invalid    
when he told me1 shortly afterwards1 how
 ,huxley had sat by his bedside and     
repeated the whole lecture to him47     
,darwin's generous nature seems often to
 have made him experience a fear lest he
 should do less than justice to his dear
 old master1 and to the influence that  
the ,principles of ,geology had in      
moulding his mind4 ,in #ahde he wrote to
 ,lyell1 ,i have long wished1 not so    
much for your sake1 as for my own       
feelings of honesty1 to acknowledge more
 plainly than by mere reference1 how    
much ,i geologically owe you4 ,those    
authors1 however1 who like you1 educate 
people's minds as well as teach them    
special facts1 can never1 ,i should     
think1 have full justice done them      
except by posterity1 for the mind thus  
insensibly improved can hardly perceive 
its own upward ascent4 7,l4,l4 ,i4 pages
 #ccg-h47 ,in another letter1 to        
,leonard ,horner1 he says3 ,i always    
feel as if my books came half out of    

,lyell's brain1 and that ,i never       
acknowledge this sufficiently4 7,m4,l4  
,,ii4 page #aag47 ,darwin's own most    
favourite book1 the ,narrative of the   
,voyage1 was dedicated to ,lyell in     
glowing terms2 and in the ,origin of    
,species he wrote of ,lyell's grand work
 on the ,principles of ,geology1 which  
the future historian will recognise as  
having produced a revolution in ,natural
 ,science4 ,what glorious good that work
 has done he fervently exclaims on      
another occasion4 7,l4,l4 ,i4 page      
#cdb47  ,to the very end of his life1 as
 all who were in the habit of talking   
with ,darwin can testify1 this sense of 
his indebtedness to ,lyell remained with
 him4 ,in his ,autobiography1 written in
 #ahgf1 the year after ,lyell's death1  
he spoke in the warmest terms of the    
value to him of the ,principles while on
 the voyage and of the aid afforded to  
him by ,lyell on his return to ,england4
 7,l4,l4 ,i4 page #fb47 ,but the year   
before his own death1 ,darwin felt      

constrained to return to the subject and
 to place on record a final             
appreciation--one as honourable to the  
writer as it is to his lost friend3  ,i 
saw more of ,lyell than of any other    
man1 both before and after my marriage4 
,his mind was characterised1 as it      
appeared to me1 by clearness1 caution1  
sound judgment1 and a good deal of      
originality4 ,when ,i made any remark to
 him on ,geology1 he never rested until 
he saw the whole case clearly1 and often
 made me see it more clearly than ,i had
 done before4 ,he would advance all     
possible objections to my suggestion1   
and even after these were exhausted     
would remain long dubious4 ,a second    
characteristic was his hearty sympathy  
with the work of other scientific men444
 ,his delight in science was ardent1 and
 he felt the keenest interest in the    
future progress of mankind4 ,he was very
 kind-hearted444 ,his candour was highly
 remarkable4 ,he exhibited this by      
becoming a convert to the ,descent      

theory1 though he had gained much fame  
by opposing ,lamarck's views1 and this  
after he had grown old4  ,,the ,,science
 ,,of ,,geology ,,is ,,enormously       
,,indebted ,,to ,,lyell--,,more ,,so1   
,,as ,i ,,believe1 ,,than ,,to ,,any    
,,other ,,man ,,who ,,ever ,,lived4     
7,l4,l4 ,i4 pages #ga-b 7the italics are
 mine477  ,those who knew ,lyell        
intimately will recognise the truth of  
the portrait drawn by his dearest       
friend1 and ,i believe that posterity   
will endorse ,darwin's deliberate       
verdict concerning the value of his     
labours4  ,it was my own good fortune1  
to be brought into close contact with   
these two great men during the later    
years of their life1 and ,i may perhaps 
be permitted to put on record the       
impressions made upon me during friendly
 intercourse with both4  ,in some       
respects1 there was an extraordinary    
resemblance in their modes and habits of
 thought1 between ,lyell and ,darwin2   
and this likeness was also seen in their

 modesty1 their deference to the opinion
 of younger men1 their enthusiasm for   
science1 their freedom from petty       
jealousies and their righteous          
indignation for what was mean and       
unworthy in others4 ,but yet there was a
 difference4 ,both ,lyell and ,darwin   
were cautious1 but perhaps ,lyell       
carried his caution to the verge of     
timidity4 ,i think ,darwin possessed1   
and ,lyell lacked1 what ,i can only     
describe by the theological term1       
faith--the substance of things hoped    
for1 the evidence of things not seen4   
,both had been constrained to feel that 
the immutability of species could not be
 maintained4 ,both1 too1 recognised the 
fact that it would be useless to        
proclaim this conviction1 unless        
prepared with a satisfactory alternative
 to what ,huxley called the ,miltonic   
hypothesis4 ,but ,darwin's conviction   
was so far vital and operative that it  
sustained him while working unceasingly 
for twenty-two years in collecting      

evidence bearing on the question1 till  
at last he was in the position of being 
able to justify that conviction to      
others4  ,and yet ,lyell's attitude--and
 that of ,hooker1 which was very        
similar--proved of inestimable service  
to science1 as ,darwin often            
acknowledged4 ,one of the greatest      
merits of the ,origin of ,species is    
that so many difficulties and objections
 are anticipated and fairly met2 and    
this was to a great extent the result of
 the persistent and very candid--if     
always friendly--criticism of ,lyell and
 ,hooker4  ,i think the divergence of   
mental attitude in ,lyell and ,darwin   
must be attributed to a difference in   
temperament1 the evidence of which      
sometimes appears in a very striking    
manner in their correspondence4 ,thus in
 #ahch1 while they were in the thick of 
the fight with the ,catastrophists of   
the ,geological ,society1 ,lyell wrote  
characteristically3 ,i really find1 when
 bringing up my ,preliminary ,essays in 

,principles to the science of the       
present day1 so far as ,i know it1 that 
the great outline1 and even most of the 
details1 stand so uninjured1 and in many
 cases they are so much strengthened by 
new discoveries1 especially by yours1   
that we may begin to hope that the great
 principles there insisted on will stand
 the test of new discoveries4 7,lyell's 
,life1 ,letters and ,journals1 ,vol4    
,,ii4 page #dd47 ,to which the more     
youthful and impetuous ,darwin replies3 
,,begin ,,to ,,hope3 why the            
,,possibility of a doubt has never      
crossed my mind for many a day4 ,this   
may be very unphilosophical1 but my     
geological salvation is staked on it444 
it makes me quite indignant that you    
should talk of ,,hoping4 7,l4,l4 ,i4    
page #bif47  ,it was not only ,darwin's 
geological salvation that was at stake1 
when he surrendered himself to his      
enthusiasm for an idea4 ,to his firm    
faith in the doctrine of continuity we  
owe the ,origin of ,species2 and while  

,darwin became the ,paul of evolution1  
,lyell long remained the doubting       
,thomas4  ,many must have felt like     
,h4,c4 ,watson when he wrote3 ,how could
 ,sir ,c4 ,lyell444 for thirty years    
read1 write1 and think1 on the subject  
of species ,,and ,,their ,,succession1  
and yet constantly look down the wrong  
road6 7,l4,l4 ,,ii4 page #bbg47 ,huxley 
attributed this hesitation of ,lyell to 
his profound antipathy to the doctrine  
of the pithecoid origin of man4 7,l4,l4 
,,ii4 page #aic47 ,without denying that 
this had considerable influence 7and    
those who knew ,lyell and his great     
devotion to his wife and her memory1 are
 aware that he and she felt much        
stronger convictions concerning such    
subjects as the immortality of the soul 
than ,darwin was able to confess to7 yet
 ,i think ,darwin had divined the real  
characteristics of his friend's mind1   
when he wrote3 ,he would advance all    
possible objections444 ,,and ,,even     
,,after ,,these ,,were ,,exhausted1     

,,would ,,remain ,,long ,,dubious4      
,very touching indeed was the friendship
 maintained to the end between these two
 leaders of thought--free as their      
intercourse was from any smallest trace 
of self-seeking or jealousy4 ,when in   
#ahgd ,i spent some time with ,lyell in 
his ,forfarshire home1 a communication  
from ,darwin was always an event which  
made a red-letter day1 as ,lyell used to
 say2 and he gave me many indications in
 his conversation of how strongly he    
relied upon the opinion of ,darwin--more
 indeed than on the judgment of any     
other man--this confidence not being    
confined to questions of science1 but   
extending to those of morals1 politics1 
and religion4  ,i have heard those who  
knew ,lyell only slightly1 speak of his 
manners as cold and reserved4 ,his      
complete absorption in his scientific   
work1 coupled with extreme              
short-sightedness1 almost in the end    
amounting to blindness1 may have        
permitted those having but a casual     

acquaintance with him to accept such a  
view4 ,but those privileged to know him 
intimately recognised the nobleness of  
his character and can realise the       
justice and force of ,hooker's words    
when he heard of his death3 ,my loved1  
my best friend1 for well nigh forty     
years of my life4 ,the most generous    
sharer of my own and my family's hopes1 
joys and sorrows1 whose affection for me
 was truly that of a father and brother 
combined4  ,but the strongest of all    
testimonies to the grandeur of ,lyell's 
character is the lifelong devotion to   
him of such a man as ,darwin4 ,before   
the two met1 we find ,darwin constantly 
writing of facts and observations that  
he thinks will interest ,mr ,lyell2 and 
when they came together the mutual      
esteem rapidly ripened into the warmest 
affection4 ,both having the advantage of
 a moderate independence1 permitting of 
an entire devotion of their lives to    
scientific research1 they had much in   
common1 and the elder man--who had      

already achieved both scientific and    
literary distinction--was able to give  
good advice and friendly help to the    
younger one4 ,the warmth of their       
friendship comes out very strikingly in 
their correspondence4 ,when ,darwin     
first conceived the idea of writing a   
book on the species question1 soon after
 his return from the voyage1 it was by  
following the example of ,lyell in      
,geology that he hoped to succeed       
7,l4,l4 ,i4 page #hc472 when in #ahdd1  
,darwin had finished his first sketch of
 the work1 and1 fearing that his life   
might not be spared to complete his     
great undertaking1 committed the care of
 it in a touching letter to his wife1 it
 was his friend ,lyell whom he named as 
her adviser and the possible editor of  
the book 7,l4,l4 ,,ii4 pages #ag-ah472  
it was ,lyell who1 in #ahef1 induced    
,darwin to lay the foundations of a     
treatise 7,l4,l4 ,i4 page #hd47 for     
which the author himself selected the   
,principles as his model2 and when the  

dilemma arose from the receipt of       
,wallace's essay1 it was to ,lyell      
jointly with ,hooker that ,darwin       
turned1 not in vain1 for advice and     
help4  ,during the later years of his   
life1 ,i never heard ,darwin allude to  
his lost friend--and he did so very     
often--without coupling his name with   
some term of affection4 ,for a brief    
period1 it is true1 ,lyell's excessive  
caution when the ,origin was published1 
seemed to try even the patience of      
,darwin2 but when the master was at last
 able to declare himself fully          
convinced1 he was the occasion of more  
rejoicing on the part of ,darwin1 than  
any other convert to his views4 ,the    
latter was never tired of talking of    
,lyell's magnanimity and asserted that1 
,to have maintained in the position of a
 master1 one side of a question for     
thirty years1 and then deliberately give
 it up1 is a fact to which ,i much doubt
 whether the records of science offer a 
parallel4 7,l4,l4 ,,ii4 pages #bbi-cj47 

,of ,darwin himself1 ,i can safely      
affirm that ,i never knew anyone who had
 met him1 even for the briefest period1 
who was not charmed by his personality4 
,who could forget the hearty hand-grip  
at meeting1 the gentle and lingering    
pressure of the palm at parting1 and    
above all that winning smile which      
transformed his countenance--so as to   
make portraits1 and even photographs1   
seem ever afterwards unsatisfying6      
,looking back1 one is indeed tempted to 
forget the profoundness of the          
philosopher1 in recollection of the     
loveableness of the man4     ,,xix4     
,,darwin',s ,,work ,,on ,,the           
,,movements ,,of ,,plants4 ,by ,francis 
,darwin1  ,honorary ,fellow of ,christ's
 ,college1 ,cambridge4   ,my father's   
interest in plants was of two kinds1    
which may be roughly distinguished as   
,,evolutionary and ,,physiological4     
,thus in his purely evolutionary work1  
for instance in ,the ,origin of ,species
 and in his book on ,variation under    

,domestication1 plants as well as       
animals served as material for his      
generalisations4 ,he was largely        
dependent on the work of others for the 
facts used in the evolutionary work1 and
 despised himself for belonging to the  
blessed gang of compilers4 ,and he      
correspondingly rejoiced in the         
employment of his wonderful power of    
observation in the physiological        
problems which occupied so much of his  
later life4 ,but inasmuch as he felt    
evolution to be his life's work1 he     
regarded himself as something of an     
idler in observing climbing plants1     
insectivorous plants1 orchids1 etc4 ,in 
this physiological work he was to a     
large extent urged on by his passionate 
desire to understand the machinery of   
all living things4 ,but though it is    
true that he worked at physiological    
problems in the naturalist's spirit of  
curiosity1 yet there was always present 
to him the bearing of his facts on the  
problem of evolution4 ,his interests1   

physiological and evolutionary1 were    
indeed so interwoven that they cannot be
 sharply separated4 ,thus his original  
interest in the fertilisation of flowers
 was evolutionary4 ,i was led 7,life and
 ,letters1 ,i4 page #ij471 he says1 to  
attend to the cross-fertilisation of    
flowers by the aid of insects1 from     
having come to the conclusion in my     
speculations on the origin of species1  
that crossing played an important part  
in keeping specific forms constant4 ,in 
the same way the value of his           
experimental work on heterostyled plants
 crystalised out in his mind into the   
conclusion that the product of          
illegitimate unions are equivalent to   
hybrids--a conclusion of the greatest   
interest from an evolutionary point of  
view4 ,and again his work ,cross and    
,self ,fertilisation may be condensed to
 a point of view of great importance in 
reference to the meaning and origin of  
sexual reproduction4 7,see ,professor   
,goebel's article in the present        

volume47  ,the whole of his             
physiological work may be looked at as  
an illustration of the potency of his   
theory as an instrument for the         
extension of the realm of natural       
knowledge4 7,huxley in ,darwin's ,life  
and ,letters4 ,,ii4 page #bjd47  ,his   
doctrine of natural selection gave1 as  
is well known1 an impulse to the        
investigation of the use of organs--and 
thus created the great school of what is
 known in ,germany as ,biology--a       
department of science for which no      
,english word exists except the rather  
vague term ,natural ,history4 ,this was 
especially the case in floral biology1  
and it is interesting to see with what  
hesitation he at first expressed the    
value of his book on ,orchids 7,life and
 ,letters1 ,,iii4 page #bed471 ,it will 
perhaps serve to illustrate how ,natural
 ,history may be worked under the belief
 of the modification of species 7#ahfa74
 ,and in #ahfb he speaks 7,loc4 cit47   
more definitely of the relation of his  

work to natural selection3 ,i can show  
the meaning of some of the apparently   
meaningless ridges 7and7 horns2 who will
 now venture to say that this or that   
structure is useless8 ,it is the fashion
 now to minimise the value of this class
 of work1 and we even find it said by a 
modern writer that to inquire into the  
ends subserved by organs is not a       
scientific problem4 ,those who take this
 view surely forget that the structure  
of all living things is1 as a whole1    
adaptive1 and that a knowledge of how   
the present forms come to be what they  
are includes a knowledge of why they    
survived4 ,they forget that the         
,,summation of variations on which      
divergence depends is under the rule of 
the environment considered as a         
selective force4 ,they forget that the  
scientific study of the interdependence 
of organisms is only possible through a 
knowledge of the machinery of the units4
 ,and that1 therefore1 the investigation
 of such widely interesting subjects as 

extinction and distribution must include
 a knowledge of function4 ,it is only   
those who follow this line of work who  
get to see the importance of minute     
points of structure and understand as my
 father did even in #ahdb1 as shown in  
his sketch of the ,origin 7,now being   
prepared for publication471 that every  
grain of sand counts for something in   
the balance4 ,much that is confidently  
stated about the uselessness of         
different organs would never have been  
written if the naturalist spirit were   
commoner nowadays4 ,this spirit is      
strikingly shown in my father's work on 
the movements of plants4 ,the           
circumstance that botanists had not1 as 
a class1 realised the interest of the   
subject accounts for the fact that he   
was able to gather such a rich harvest  
of results from such a familiar object  
as a twining plant4 ,the subject had    
been investigated by ,h4 von ,mohl1     
,palm1 and ,dutrochet1 but they failed  
not only to master the problem but      

7which here concerns us7 to give the    
absorbing interest of ,darwin's book to 
what they discovered4  ,his work on     
climbing plants was his first sustained 
piece of work on the physiology of      
movement1 and he remarks in #ahfd3 ,this
 has been new sort of work for me4      
7,life and ,letters1 ,,iii4 page #cae4  
,he had1 however1 made a beginning on   
the movements of ,drosera47 ,he goes on 
to remark with something of surprise1 ,i
 have been pleased to find what a       
capital guide for observations a full   
conviction of the change of species is4 
,it was this point of view that enabled 
him to develop a broad conception of the
 power of climbing as an adaptation by  
means of which plants are enabled to    
reach the light4 ,instead of being      
compelled to construct a stem of        
sufficient strength to stand alone1 they
 succeed in the struggle by making use  
of other plants as supports4 ,he showed 
that the great class of tendril- and    
root-climbers which do not depend on    

twining round a pole1 like a            
scarlet-runner1 but on attaching        
themselves as they grow upwards1 effect 
an economy4 ,thus a ,phaseolus has to   
manufacture a stem three feet in length 
to reach a height of two feet above the 
ground1 whereas a pea which had ascended
 to the same height by the aid of its   
tendrils1 was but little longer than the
 height reached4 7,climbing ,plants     
7#bnd edition #ahge71 page #aic47  ,thus
 he was led on to the belief that       
,,twining is the more ancient form of   
climbing1 and that tendril-climbers have
 been developed from twiners4 ,in       
accordance with this view we find       
,,leaf-,,climbers1 which may be looked  
on as incipient tendril-bearers1        
occurring in the same genera with simple
 twiners4 7,loc4 cit4 page #aie47 ,he   
called attention to the case of         
,maurandia semperflorens in which the   
young flower-stalks revolve             
spontaneously and are sensitive to a    
touch1 but neither of these qualities is

 of any perceptible value to the        
species4 ,this forced him to believe    
that in other young plants the rudiments
 of the faculty needed for twining would
 be found--a prophecy which he made good
 in his ,power of ,movement many years  
later4  ,in ,climbing ,plants he did    
little more than point out the          
remarkable fact that the habit of       
climbing is widely scattered through the
 vegetable kingdom4 ,thus climbers are  
to be found in #ce out of the #ei       
,phanerogamic ,alliances of ,lindley1 so
 that the conclusion is forced on our   
minds that the capacity of revolving    
7,if a twining plant1 e4g4 a hop1 is    
observed before it has begun to ascend a
 pole1 it will be noticed that1 owing to
 the curvature of the stem1 the tip is  
not vertical but hangs over in a roughly
 horizontal position4 ,if such a shoot  
is watched it will be found that if1 for
 instance1 it points to the north at a  
given hour1 it will be found after a    
short interval pointing north-east1 then

 east1 and after about two hours it will
 once more be looking northward4 ,the   
curvature of the stem depends on one    
side growing quicker than the opposite  
side1 and the revolving movement1 i4e4  
circumnutation1 depends on the region of
 quickest growth creeping gradually     
round the stem from south through west  
to south again4 ,other plants1 e4g4     
,phaseolus1 revolve in the opposite     
direction471 on which most climbers     
depend1 is inherent1 though undeveloped1
 in almost every plant in the vegetable 
kingdom4 7,climbing ,plants1 page #bje47
  ,in the ,origin 7,edition ,i4 page    
#dbg1 ,edition ,,vi4 page #cgd47 ,darwin
 speaks of the apparent paradox1 that   
the very same characters are analogical 
when one class or order is compared with
 another1 but give true affinities when 
the members of the same class or order  
are compared one with another4 ,in this 
way we might perhaps say that the       
climbing of an ivy and a hop are        
analogical2 the resemblance depending on

 the adaptive result rather than on     
community of blood2 whereas the relation
 between a leaf-climber and a true      
tendril-bearer reveals descent4 ,this   
particular resemblance was one in which 
my father took especial delight4 ,he has
 described an interesting case occurring
 in the ,fumariaceae4 7,climbing        
,plants1 page #aie47 ,the terminal      
leaflets of the leaf-climbing ,fumaria  
officinalis are not smaller than the    
other leaflets2 those of the            
leaf-climbing ,adlumia cirrhosa are     
greatly reduced2 those of ,corydalis    
claviculata 7a plant which may be       
indifferently called a leaf-climber or a
 tendril-bearer7 are either reduced to  
microscopical dimensions or have their  
blades wholly aborted1 so that this     
plant is actually in a state of         
transition2 and finally in the ,dicentra
 the tendrils are perfectly             
characterized4  ,it is a remarkable fact
 that the quality which1 broadly        
speaking1 forms the basis of the        

climbing habit 7namely revolving        
nutation1 otherwise known as            
circumnutation7 subserves two distinct  
ends4 ,one of these is the finding of a 
support1 and this is common to twiners  
and tendrils4 ,here the value ends as   
far as tendril-climbers are concerned1  
but in twiners ,darwin believed that the
 act of climbing round a support is a   
continuation of the revolving movement  
7circumnutation74 ,if we imagine a man  
swinging a rope round his head and if we
 suppose the rope to strike a vertical  
post1 the free end will twine round it4 
,this may serve as a rough model of     
twining as explained in the ,movements  
and ,habits of ,climbing ,plants4 ,it is
 on these points--the nature of         
revolving nutation and the mechanism of 
twining--that modern physiologists      
differ from ,darwin4 7,see the          
discussion in ,pfeffer's ,the           
,physiology of ,plants ,eng4 ,tr4       
7,oxford1 #aijf71 ,,iii4 page #cd1 where
 the literature is given4 ,also ,jost1  

,vorlesungen uber ,pflanzenphysiologie1 
page #efb1 ,jena1 #aijd47  ,their       
criticism originated in observations    
made on a revolving shoot which is      
removed from the action of gravity by   
keeping the plant slowly rotating about 
a horizontal axis by means of the       
instrument known as a klinostat4 ,under 
these conditions circumnutation becomes 
irregular or ceases altogether4 ,when   
the same experiment is made with a plant
 which has twined spirally up a stick1  
the process of climbing is checked and  
the last few turns become loosened or   
actually untwisted4 ,from this it has   
been argued that ,darwin was wrong in   
his description of circumnutation as an 
automatic change in the region of       
quickest growth4 ,when the free end of a
 revolving shoot points towards the     
north there is no doubt that the south  
side has been elongating more than the  
north2 after a time it is plain from the
 shoot hanging over to the east that the
 west side of the plant has grown most1 

and so on4 ,this rhythmic change of the 
position of the region of greatest      
growth ,darwin ascribes to an unknown   
internal regulating power4 ,some modern 
physiologists1 however1 attempt to      
explain the revolving movement as due to
 a particular form of sensitiveness to  
gravitation which it is not necessary to
 discuss in detail in this place4 ,it is
 sufficient for my purpose to point out 
that ,darwin's explanation of           
circumnutation is not universally       
accepted4 ,personally ,i believe that   
circumnutation is automatic--is         
primarily due to internal stimuli4 ,it  
is however in some way connected with   
gravitational sensitiveness1 since the  
movement normally occurs round a        
vertical line4 ,it is not unnatural     
that1 when the plant has no external    
stimulus by which the vertical can be   
recognised1 the revolving movement      
should be upset4  ,very much the same   
may be said of the act of twining1      
namely that most physiologists refuse to

 accept ,darwin's view 7above referred  
to7 that twining is the direct result of
 circumnutation4 ,everyone must allow   
that the two phenomena are in some way  
connected1 since a plant which          
circumnutates clockwise1 i4e4 with the  
sun1 twines in the same direction1 and  
vice versa4 ,it must also be granted    
that geotropism has a bearing on the    
problem1 since all plants twine upwards1
 and cannot twine along a horizontal    
support4 ,but how these two factors are 
combined1 and whether any 7and if so    
what7 other factors contribute1 we      
cannot say4 ,if we give up ,darwin's    
explanation1 we must at the same time   
say with ,pfeffer that the causes of    
twining are444 unknown4 7,the           
,physiology of ,plants1 ,eng4 ,tr4      
7,oxford1 #aijf71 ,,iii4 page #cg47     
,let us leave this difficult question   
and consider some other points made out 
in the progress of the work on climbing 
plants4 ,one result of what he called   
his niggling 7,life and ,letters1 ,,iii4

 page #cab47 work on tendrils was the   
discovery of the delicacy of their sense
 of touch1 and the rapidity of their    
movement4 ,thus in a passion-flower     
tendril1 a bit of platinum wire weighing
 #a4b mg4 produced curvature 7,climbing 
,plants1 page #aga471 as did a loop of  
cotton weighing #b mg4 ,pfeffer         
7,untersuchungen a4d4 ,bot4 ,inst4 z4   
,tubingen1 ,bd4 ,i4 #ahha-he1 page      
#ejf471 however1 subsequently found much
 greater sensitiveness3 thus the tendril
 of ,sicyos angulatus reacted to        
#j4jjjbe mg41 but this only occurred    
when the delicate rider of cottonwool   
fibre was disturbed by the wind4 ,the   
same author expanded and explained in a 
most interesting way the meaning of     
,darwin's observation that tendrils are 
not stimulated to movement by drops of  
water resting on them4 ,pfeffer showed  
that ,,dirty water containing minute    
particles of clay in suspension acts as 
a stimulus4 ,he also showed that        
gelatine acts like pure water2 if a     

smooth glass rod is coated with a #aj   
per cent solution of gelatine and is    
then applied to a tendril1 no movement  
occurs in spite of the fact that the    
gelatine is solid when cold4 ,pfeffer   
7,physiology1 ,eng4 ,tr4 ,,iii4 page    
#eb4 ,pfeffer has pointed out the       
resemblance between the contact         
irritability of plants and the human    
sense of touch4 ,our skin is not        
sensitive to uniform pressure such as is
 produced when the finger is dipped into
 mercury 7,tubingen ,untersuchungen1 ,i4
 page #ejd47 generalises the result in  
the statement that the tendril has a    
special form of irritability and only   
reacts to differences of pressure or    
variations of pressure in contiguous444 
regions4 ,darwin was especially         
interested in such cases of specialised 
irritability4 ,for instance in ,may1    
#ahfd1 he wrote to ,asa ,gray 7,life and
 ,letters1 ,,iii4 page #cad47 describing
 the tendrils of ,bignonia capreolata1  
which abhor a simple stick1 do not much 

relish rough bark1 but delight in wool  
or moss4 ,he received1 from ,gray1      
information as to the natural habitat of
 the species1 and finally concluded that
 the tendrils are specially adapted to  
climb trees clothed with lichens1       
mosses1 or other such productions4      
7,climbing ,plants1 page #ajb47         
,tendrils were not the only instance    
discovered by ,darwin of delicacy of    
touch in plants4 ,in #ahfj he had       
already begun to observe ,sundew        
7,drosera71 and was full of astonishment
 at its behaviour4 ,he wrote to ,sir    
,joseph ,hooker 7,life and ,letters1    
,,iii4 page #cai473 ,i have been working
 like a madman at ,drosera4 ,here is a  
fact for you which is certain as you    
stand where you are1 though you won't   
believe it1 that a bit of hair #a_/ghjjj
 of one grain in weight placed on gland1
 will cause ,,one of the gland-bearing  
hairs of ,drosera to curve inwards4     
,here again ,pfeffer 7,pfeffer in       
,untersuchungen a4 d4 ,bot4 ,inst4 z4   

,tubingen1 ,i4 page #dia47 has1 as in so
 many cases1 added important facts to my
 father's observations4 ,he showed that 
if the leaf of ,drosera is entirely     
freed from such vibrations as would     
reach it if observed on an ordinary     
table1 it does not react to small       
weights1 so that in fact it was the     
vibration of the minute fragment of hair
 on the gland that produced movement4   
,we may fancifully see an adaptation to 
the capture of insects--to the dancing  
of a gnat's foot on the sensitive       
surface4  ,darwin was fond of telling   
how when he demonstrated the            
sensitiveness of ,drosera to ,mr ,huxley
 and 7,i think7 to ,sir ,john ,burdon   
,sanderson1 he could perceive 7in spite 
of their courtesy7 that they thought the
 whole thing a delusion4 ,and the story 
ended with his triumph when ,mr ,huxley 
cried out1 ,it ,,is moving4  ,darwin's  
work on tendrils has led to some        
interesting investigations on the       
mechanisms by which plants perceive     

stimuli4 ,thus ,pfeffer 7,tubingen      
,untersuchungen ,i4 page #ebd47 showed  
that certain epidermic cells occurring  
in tendrils are probably organs of      
touch4 ,in these cells the protoplasm   
burrows as it were into cavities in the 
thickness of the external cell-walls and
 thus comes close to the surface1 being 
separated from an object touching the   
tendril merely by a very thin layer of  
cell-wall substance4 ,haberlandt        
7,physiologische ,pflanzenanatomie1     
,edition ,,iii4 ,leipzig1 #aijd4        
,sinnesorgane im ,pflanzenreich1        
,leipzig1 #aija1 and other              
publications47 has greatly extended our 
knowledge of vegetable structure in     
relation to mechanical stimulation4 ,he 
defines a sense-organ as a contrivance  
by which the ,,deformation or forcible  
change of form in the protoplasm--on    
which mechanical stimulation depends--is
 rendered rapid and considerable in     
amplitude 7,sinnesorgane1 page #aj74 ,he
 has shown that in certain papillose and

 bristle-like contrivances1 plants      
possess such sense-organs2 and moreover 
that these contrivances show a          
remarkable similarity to corresponding  
sense-organs in animals4  ,haberlandt   
and ,nemec 7,ber4 d4 ,deutschen bot4    
,gesellschaft1 ,,xviii4 #aijj4 ,see ,f4 
,darwin1 ,presidential ,address to      
,section ,k1 ,british ,association1     
#aijd47 published independently and     
simultaneously a theory of the mechanism
 by which plants are orientated in      
relation to gravitation4 ,and here again
 we find an arrangement identical in    
principle with that by which certain    
animals recognise the vertical1 namely  
the pressure of free particles on the   
irritable wall of a cavity4 ,in the     
higher plants1 ,nemec and ,haberlandt   
believe that special loose and freely   
movable starch-grains play the part of  
the otoliths or statoliths of the       
crustacea1 while the protoplasm lining  
the cells in which they are contained   
corresponds to the sensitive membrane   

lining the otocyst of the animal4 ,what 
is of special interest in our present   
connection is that according to this    
ingenious theory 7,the original         
conception was due to ,noll 7,heterogene
 ,induction1 ,leipzig1 #ahib71 but his  
view differed in essential points from  
those here given47 the sense of         
verticality in a plant is a form of     
contact-irritability4 ,the vertical     
position is distinguished from the      
horizontal by the fact that1 in the     
latter case1 the loose starch-grains    
rest on the lateral walls of the cells  
instead of on the terminal walls as     
occurs in the normal upright position4  
,it should be added that the statolith  
theory is still sub judice2 personally  
,i cannot doubt that it is in the main a
 satisfactory explanation of the facts4 
,with regard to the ,,rapidity of the   
reaction of tendrils1 ,darwin records   
7,climbing ,plants1 page #aee4 ,others  
have observed movement after about #f47 
that a ,passion-,flower tendril moved   

distinctly within #be seconds of        
stimulation4 ,it was this fact1 more    
than any other1 that made him doubt the 
current explanation1 viz4 that the      
movement is due to unequal growth on the
 two sides of the tendril4 ,the         
interesting work of ,fitting            
7,pringsheim's ,jahrb4 ,,xxxviii4 #aijc1
 page #ede47 has shown1 however1 that   
the primary cause is not 7as ,darwin    
supposed7 contraction on the concave1   
but an astonishingly rapid increase in  
growth-rate on the convex side4  ,on the
 last page of ,climbing ,plants ,darwin 
wrote3 ,it has often been vaguely       
asserted that plants are distinguished  
from animals by not having the power of 
movement4 ,it should rather be said that
 plants acquire and display this power  
only when it is of some advantage to    
them4  ,he gradually came to realise the
 vividness and variety of vegetable     
life1 and that a plant like an animal   
has capacities of behaving in different 
ways under different circumstances1 in a

 manner that may be compared to the     
instinctive movements of animals4 ,this 
point of view is expressed in well-known
 passages in the ,power of ,movement4   
7,the ,power of ,movement in ,plants1   
#ahhj1 pages #ega-c47 ,it is impossible 
not to be struck with the resemblance   
between the444 movements of plants and  
many of the actions performed           
unconsciously by the lower animals4 ,and
 again1 ,it is hardly an exaggeration to
 say that the tip of the radicle444     
having the power of directing the       
movements of the adjoining parts1 acts  
like the brain of one of the lower      
animals2 the brain being seated within  
the anterior end of the body1 receiving 
impressions from the sense-organs1 and  
directing the several movements4  ,the  
conception of a region of perception    
distinct from a region of movement is   
perhaps the most fruitful outcome of his
 work on the movements of plants4 ,but  
many years before its publication1 viz4 
in #ahfa1 he had made out the wonderful 

fact that in the ,orchid ,catasetum     
7,life and ,letters1 ,,iii4 page #bfh47 
the projecting organs or antennae are   
sensitive to a touch1 and transmit an   
influence for more than one inch        
,,instantaneously1 which leads to the   
explosion or violent ejection of the    
pollinia4 ,and as we have already seen a
 similar transmission of a stimulus was 
discovered by him in ,sundew in #ahfj1  
so that in #ahfb he could write to      
,hooker 7,life and ,letters1 ,,iii4 page
 #cba473 ,i cannot avoid the conclusion1
 that ,drosera possesses matter at least
 in some degree analogous in            
constitution and function to nervous    
matter4 ,i propose in what follows to   
give some account of the observations on
 the transmission of stimuli given in   
the ,power of ,movement4 ,it is         
impossible within the space at my       
command to give anything like a complete
 account of the matter1 and ,i must     
necessarily omit all mention of much    
interesting work4 ,one well-known       

experiment consisted in putting opaque  
caps on the tips of seedling grasses    
7e4g4 oat and canary-grass7 and then    
exposing them to light from one side4   
,the difference1 in the amount of       
curvature towards the light1 between the
 blinded and unblinded specimens1 was so
 great that it was concluded that the   
light-sensitiveness resided exclusively 
in the tip4 ,the experiment undoubtedly 
proves that the sensitiveness is much   
greater in the tip than elsewhere1 and  
that there is a transmission of stimulus
 from the tip to the region of          
curvature4 ,but ,rothert 7,rothert1     
,cohn's ,beitrage1 ,,vii4 #ahid47 has   
conclusively proved that the basal part 
where the curvature occurs is also      
,,directly sensitive to light4 ,he has  
shown1 however1 that in other grasses   
7,setaria1 ,panicum7 the cotyledon is   
the only part which is sensitive1 while 
the hypocotyl1 where the movement       
occurs1 is not directly sensitive4  ,it 
was however the question of the         

localisation of the gravitational sense 
in the tip of the seedling root or      
radicle that aroused most attention1 and
 it was on this question that a         
controversy arose which has continued to
 the present day4  ,the experiment on   
which ,darwin's conclusion was based    
consisted simply in cutting off the tip1
 and then comparing the behaviour of    
roots so treated with that of normal    
specimens4 ,an uninjured root when      
placed horizontally regains the vertical
 by means of a sharp downward curve2 not
 so a decapitated root which continues  
to grow more or less horizontally4 ,it  
was argued that this depends on the loss
 of an organ specialised for the        
perception of gravity1 and residing in  
the tip of the root2 and the experiment 
7together with certain important        
variants7 was claimed as evidence of the
 existence of such an organ4  ,it was at
 once objected that the amputation of   
the tip might check curvature by        
interfering with longitudinal growth1 on

 the distribution of which curvature    
depends4 ,this objection was met by     
showing that an injury1 e4g4 splitting  
the root longitudinally 7,see ,f4       
,darwin1 ,linnean ,soc4 ,journal 7,bot74
 ,,xix4 #ahhb1 page #bah471 which does  
not remove the tip1 but seriously checks
 growth1 does not prevent geotropism4   
,this was of some interest in another   
and more general way1 in showing that   
curvature and longitudinal growth must  
be placed in different categories as    
regards the conditions on which they    
depend4  ,another objection of a much   
more serious kind was that the          
amputation of the tip acts as a shock4  
,it was shown by ,rothert 7,see his     
excellent summary of the subject in     
,flora #ahid 7,erganzungsband71 page    
#aii47 that the removal of a small part 
of the cotyledon of ,setaria prevents   
the plant curving towards the light1 and
 here there is no question of removing  
the sense-organ since the greater part  
of the sensitive cotyledon is intact4   

,in view of this result it was          
impossible to rely on the amputations   
performed on roots as above described4  
,at this juncture a new and brilliant   
method originated in ,pfeffer's         
laboratory4 7,see ,pfeffer1 ,annals of  
,botany1 ,,viii4 #ahid1 page #cag1 and  
,czapek1 ,pringsheim's ,jahrb4 ,,xxvii4 
#ahie1 page #bdc47 ,pfeffer and ,czapek 
showed that it is possible to bend the  
root of a lupine so that1 for instance1 
the supposed sense-organ at the tip is  
vertical while the motile region is     
horizontal4 ,if the motile region is    
directly sensitive to gravity the root  
ought to curve downwards1 but this did  
not occur3 on the contrary it continued 
to grow horizontally4 ,this is precisely
 what should happen if ,darwin's theory 
is the right one3 for if the tip is kept
 vertical1 the sense-organ is in its    
normal position and receives no stimulus
 from gravitation1 and therefore can    
obviously transmit none to the region of
 curvature4 ,unfortunately this method  

did not convince the botanical world    
because some of those who repeated      
,czapek's experiment failed to get his  
results4  ,czapek 7,berichte d4         
,deutsch4 bot4 ,ges4 ,,xv4 #ahig1 page  
#eaf1 and numerous subsequent papers4   
,english readers should consult ,czapek 
in the ,annals of ,botany1 ,,xix4 #aije1
 page #ge47 has devised another         
interesting method which throws light on
 the problem4 ,he shows that roots1     
which have been placed in a horizontal  
position and have therefore been        
geotropically stimulated1 can be        
distinguished by a chemical test from   
vertical1 i4e4 unstimulated roots4 ,the 
chemical change in the root can be      
detected before any curvature has       
occurred and must therefore be a symptom
 of stimulation1 not of movement4 ,it is
 particularly interesting to find that  
the change in the root1 on which        
,czapek's test depends1 takes place in  
the tip1 i4e4 in the region which       
,darwin held to be the centre for       

gravitational sensitiveness4  ,in #ahii 
,i devised a method 7,f4 ,darwin1       
,annals of ,botany1 ,,xiii4 #ahii1 page 
#efg47 by which ,i sought to prove that 
the cotyledon of ,setaria is not only   
the organ for light-perception1 but also
 for gravitation4 ,if a seedling is     
supported horizontally by pushing the   
apical part 7cotyledon7 into a          
horizontal tube1 the cotyledon will1    
according to my supposition1 be         
stimulated gravitationally and a        
stimulus will be transmitted to the     
basal part of the stem 7hypocotyl7      
causing it to bend4 ,but this curvature 
merely raises the basal end of the      
seedling1 the sensitive cotyledon       
remains horizontal1 imprisoned in its   
tube2 it will therefore be continually  
stimulated and will continue to transmit
 influences to the bending region1 which
 should therefore curl up into a helix  
or corkscrew-like form1--and this is    
precisely what occurred4  ,i have       
referred to this work principally       

because the same method was applied to  
roots by ,massart 7,massart1 ,mem4      
,couronnes ,acad4 ,r4 ,belg4 ,,lxii4    
#aijb47 and myself 7,f4 ,darwin1        
,linnean ,soc4 ,journ4 ,,xxxv4 #aijb1   
page #bff47 with a similar though less  
striking result4 ,although these        
researches confirmed ,darwin's work on  
roots1 much stress cannot be laid on    
them as there are several objections to 
them1 and they are not easily repeated4 
,the method which--as far as we can     
judge at present--seems likely to solve 
the problem of the root-tip is most     
ingenious and is due to ,piccard4       
7,pringsheim's ,jahrb4 ,,xl4 #aijd1 page
 #id47  ,andrew ,knight's celebrated    
experiment showed that roots react to   
centrifugal force precisely as they do  
to gravity4 ,so that if a bean root is  
fixed to a wheel revolving rapidly on a 
horizontal axis1 it tends to curve away 
from the centre in the line of a radius 
of the wheel4 ,in ordinary              
demonstrations of ,knight's experiment  

the seed is generally fixed so that the 
root is at right angles to a radius1 and
 as far as convenient from the centre of
 rotation4 ,piccard's experiment is     
arranged differently4 7,a seed is       
depicted below a horizontal dotted line 
,,aa1 projecting a root upwards47 ,the  
root is oblique to the axis of rotation1
 and the extreme tip projects beyond    
that axis4 ,line ,,aa represents the    
axis of rotation1 ,t is the tip of the  
root just above the line ,,aa1 and ,b is
 the region just below line ,,aa in     
which curvature takes place4 ,if the    
motile region ,b is directly sensitive  
to gravitation 7and is the only part    
which is sensitive7 the root will curve 
7down and away from the vertical7 away  
from the axis of rotation1 just as in   
,knight's experiment4 ,but if the tip ,t
 is alone sensitive to gravitation the  
result will be exactly reversed1 the    
stimulus originating in ,t and conveyed 
to ,b will produce curvature 7up towards
 the vertical74 ,we may think of the    

line ,,aa as a plane dividing two       
worlds4 ,in the lower one gravity is of 
the earthly type and is shown by bodies 
falling and roots curving downwards3 in 
the upper world bodies fall upwards and 
roots curve in the same direction4 ,the 
seedling is in the lower world1 but its 
tip containing the supposed sense-organ 
is in the strange world where roots     
curve upwards4 ,by observing whether the
 root bends up or down we can decide    
whether the impulse to bend originates  
in the tip or in the motile region4     
,piccard's results showed that both     
curvatures occurred and he concluded    
that the sensitive region is not        
confined to the tip4 7,czapek           
7,pringsheim's ,jahrb4 ,,xxxv4 #aijj1   
page #cfb7 had previously given reasons 
for believing that1 in the root1 there  
is no sharp line of separation between  
the regions of perception and movement47
  ,haberlandt 7,pringsheim's ,jahrb4    
,,xlv4 #aijh1 page #ege47 has recently  
repeated the experiment with the        

advantage of better apparatus and more  
experience in dealing with plants1 and  
has found as ,piccard did that both the 
tip and the curving region are sensitive
 to gravity1 but with the important     
addition that the sensitiveness of the  
tip is much greater than that of the    
motile region4 ,the case is in fact     
similar to that of the oat and          
canary-grass4 ,in both instances my     
father and ,i were wrong in assuming    
that the sensitiveness is confined to   
the tip1 yet there is a concentration of
 irritability in that region and        
transmission of stimulus is as true for 
geotropism as it is for heliotropism4   
,thus after nearly thirty years the     
controversy of the root-tip has         
apparently ended somewhat after the     
fashion of the quarrels at the ,rainbow 
in ,silas ,marner--you're both right and
 you're both wrong4 ,but the            
brain-function of the root-tip at which 
eminent people laughed in early days    
turns out to be an important part of the

 truth4 7,by using ,piccard's method ,i 
have succeeded in showing that the      
gravitational sensitiveness of the      
cotyledon of ,sorghum is certainly much 
greater than the sensitiveness of the   
hypocotyl--if indeed any such           
sensitiveness exists4 ,see ,wiesner's   
,festschrift1 ,vienna1 #aijh47  ,another
 observation of ,darwin's has given rise
 to much controversy4 7,power of        
,movement1 page #acc47 ,if a minute     
piece of card is fixed obliquely to the 
tip of a root some influence is         
transmitted to the region of curvature  
and the root bends away from the side to
 which the card was attached4 ,it was   
thought at the time that this proved the
 root-tip to be sensitive to contact1   
but this is not necessarily the case4   
,it seems possible that the curvature is
 a reaction to the injury caused by the 
alcoholic solution of shellac with which
 the cards were cemented to the tip4    
,this agrees with the fact given in the 
,power of ,movement that injuring the   

root-tip on one side1 by cutting or     
burning it1 induced a similar curvature4
 ,on the other hand it was shown that   
curvature could be produced in roots by 
cementing cards1 not to the naked       
surface of the root-tip1 but to pieces  
of gold-beaters skin applied to the     
root2 gold-beaters skin being by itself 
almost without effect4 ,but it must be  
allowed that1 as regards touch1 it is   
not clear how the addition of shellac   
and card can increase the degree of     
contact4 ,there is however some evidence
 that very close contact from a solid   
body1 such as a curved fragment of      
glass1 produces curvature3 and this may 
conceivably be the explanation of the   
effect of gold-beaters skin covered with
 shellac4 ,but on the whole it is       
perhaps safer to classify the shellac   
experiments with the results of         
undoubted injury rather than with those 
of contact4  ,another subject on which a
 good deal of labour was expended is the
 sleep of leaves1 or as ,darwin called  

it their ,,nyctitropic movement4 ,he    
showed for the first time how widely    
spread this phenomenon is1 and attempted
 to give an explanation of the use to   
the plant of the power of sleeping4 ,his
 theory was that by becoming more or    
less vertical at night the leaves escape
 the chilling effect of radiation4 ,our 
method of testing this view was to fix  
some of the leaves of a sleeping plant  
so that they remained horizontal at     
night and therefore fully exposed to    
radiation1 while their fellows were     
partly protected by assuming the        
nocturnal position4 ,the experiments    
showed clearly that the horizontal      
leaves were more injured than the       
sleeping1 i4e4 more or less vertical1   
ones4 ,it may be objected that the      
danger from cold is very slight in warm 
countries where sleeping plants abound4 
,but it is quite possible that a        
lowering of the temperature which       
produces no visible injury may          
nevertheless be hurtful by checking the 

nutritive processes 7e4g4 translocation 
of carbohydrates71 which go on at night4
 ,stahl 7,bot4 ,zeitung1 #ahig1 page    
#ha47 however has ingeniously suggested 
that the exposure of the leaves to      
radiation is not ,,directly hurtful     
because it lowers the temperature of the
 leaf1 but ,,indirectly because it leads
 to the deposition of dew on the        
leaf-surface4 ,he gives reasons for     
believing that dew-covered leaves are   
unable to transpire efficiently1 and    
that the absorption of mineral          
food-material is correspondingly        
checked4 ,stahl's theory is in no way   
destructive of ,darwin's1 and it is     
possible that nyctitropic leaves are    
adapted to avoid the indirect as well as
 the direct results of cooling by       
radiation4  ,in what has been said ,i   
have attempted to give an idea of some  
of the discoveries brought before the   
world in the ,power of ,movement 7,in   
#ahha ,professor ,wiesner published his 
,das ,bewegungsvermogen der ,pflanzen1 a

 book devoted to the criticism of ,the  
,power of ,movement in ,plants4 ,a      
letter to ,wiesner1 published in ,life  
and ,letters1 ,,iii4 page #ccf1 shows   
,darwin's warm appreciation of his      
critic's work1 and of the spirit in     
which it is written47 and of the        
subsequent history of the problems4 ,we 
must now pass on to a consideration of  
the central thesis of the book1--the    
relation of circumnutation to the       
adaptive curvatures of plants4          
,darwin's view is plainly stated on     
pages #c-d of the ,power of ,movement4  
,speaking of circumnutation he says1 ,in
 this universally present movement we   
have the basis or groundwork for the    
acquirement1 according to the           
requirements of the plant1 of the most  
diversified movements4 ,he then points  
out that curvatures such as those       
towards the light or towards the centre 
of the earth can be shown to be         
exaggerations of circumnutation in the  
given directions4 ,he finally points out

 that the difficulty of conceiving how  
the capacities of bending in definite   
directions were acquired is diminished  
by his conception4 ,we know that there  
is always movement in progress1 and its 
amplitude1 or direction1 or both1 have  
only to be modified for the good of the 
plant in relation with internal or      
external stimuli4  ,it may at once be   
allowed that the view here given has not
 been accepted by physiologists4 ,the   
bare fact that circumnutation is a      
general property of plants 7other than  
climbing species7 is not generally      
rejected4 ,but the botanical world is no
 nearer to believing in the theory of   
reaction built on it4  ,if we compare   
the movements of plants with those of   
the lower animals we find a certain     
resemblance between the two4 ,according 
to ,jennings 7,h4,s4 ,jennings1 ,the    
,behavior of the ,lower ,animals4       
,columbia ,u4 ,press1 ,n4,y4 #aijf47 a  
,paramoecium constantly tends to swerve 
towards the aboral side of its body     

owing to certain peculiarities in the   
set and power of its cilia4 ,but the    
tendency to swim in a circle1 thus      
produced1 is neutralised by the rotation
 of the creature about its longitudinal 
axis4 ,thus the direction of the swerves
 ,,in ,,relation ,,to ,,the ,,path of   
the organism is always changing1 with   
the result that the creature moves in   
what approximates to a straight line1   
being however actually a spiral about   
the general line of progress4 ,this     
method of motion is strikingly like the 
circumnutation of a plant1 the apex of  
which also describes a spiral about the 
general line of growth4 ,a rooted plant 
obviously cannot rotate on its axis1 but
 the regular series of curvatures of    
which its growth consists correspond to 
the aberrations of ,paramoecium         
distributed regularly about its course  
by means of rotation4 7,in my address to
 the ,biological ,section of the        
,british ,association at ,cardiff       
7#ahia7 ,i have attempted to show the   

connection between circumnutation and   
,,rectipetality1 i4e4 the innate        
capacity of growing in a straight line47
 ,just as a plant changes its direction 
of growth by an exaggeration of one of  
the curvature-elements of which         
circumnutation consists1 so does a      
,paramoecium change its course by the   
accentuation of one of the deviations of
 which its path is built4 ,jennings has 
shown that the infusoria1 etc41 react to
 stimuli by what is known as the method 
of trial4 ,if an organism swims into a  
region where the temperature is too high
 or where an injurious substance is     
present1 it changes its course4 ,it then
 moves forward again1 and if it is      
fortunate enough to escape the          
influence1 it continues to swim in the  
given direction4 ,if however its change 
of direction leads it further into the  
heated or poisonous region it repeats   
the movement until it emerges from its  
difficulties4 ,jennings finds in the    
movements of the lower organisms an     

analogue with what is known as pain in  
conscious organisms4 ,there is certainly
 this much resemblance that a number of 
quite different sub-injurious agencies  
produce in the lower organisms a form of
 reaction by the help of which they1 in 
a partly fortuitous way1 escape from the
 threatening element in their           
environment4 ,the higher animals are    
stimulated in a parallel manner to vague
 and originally purposeless movements1  
one of which removes the discomfort     
under which they suffer1 and the        
organism finally learns to perform the  
appropriate movement without going      
through the tentative series of actions4
  ,i am tempted to recognise in         
circumnutation a similar groundwork of  
tentative movements out of which the    
adaptive ones were originally selected  
by a process rudely representative of   
learning by experience4  ,it is1        
however1 simpler to confine ourselves to
 the assumption that those plants have  
survived which have acquired through    

unknown causes the power of reacting in 
appropriate ways to the external stimuli
 of light1 gravity1 etc4 ,it is quite   
possible to conceive this occurring in  
plants which have no power of           
circumnutating--and1 as already pointed 
out1 physiologists do as a fact neglect 
circumnutation as a factor in the       
evolution of movements4 ,whatever may be
 the fate of ,darwin's theory of        
circumnutation there is no doubt that   
the research he carried out in support  
of1 and by the light of1 this hypothesis
 has had a powerful influence in guiding
 the modern theories of the behaviour of
 plants4 ,pfeffer 7,the ,physiology of  
,plants1 ,eng4 ,tr4 ,,iii4 page #aa471  
who more than any one man has impressed 
on the world a rational view of the     
reactions of plants1 has acknowledged in
 generous words the great value of      
,darwin's work in the same direction4   
,the older view was that1 for instance1 
curvature towards the light is the      
direct mechanical result of the         

difference of illumination on the       
lighted and shaded surfaces of the      
plant4 ,this has been proved to be an   
incorrect explanation of the fact1 and  
,darwin by his work on the transmission 
of stimuli has greatly contributed to   
the current belief that stimuli act     
indirectly4 ,thus we now believe that in
 a root and a stem the mechanism for the
 perception of gravitation is identical1
 but the resulting movements are        
different because the                   
motor-irritabilities are dissimilar in  
the two cases4 ,we must come back1 in   
fact1 to ,darwin's comparison of plants 
to animals4 ,in both there is perceptive
 machinery by which they are made       
delicately alive to their environment1  
in both the existing survivors are those
 whose internal constitution has enabled
 them to respond in a beneficial way to 
the disturbance originating in their    
sense-organs4     ,,xx4 ,,the ,,biology 
,,of ,,flowers4 ,by ,k4 ,goebel1 ,ph4,d4
  ,professor of ,botany in the          

,university of ,munich4   ,there is     
scarcely any subject to which ,darwin   
devoted so much time and work as to his 
researches into the biology of flowers1 
or1 in other words1 to the consideration
 of the question to what extent the     
structural and physiological characters 
of flowers are correlated with their    
function of producing fruits and seeds4 
,we know from his own words what        
fascination these studies possessed for 
him4 ,we repeatedly find1 for example1  
in his letters expressions such as      
this3--,nothing in my life has ever     
interested me more than the             
fertilisation of such plants as ,primula
 and ,lythrum1 or again ,anacamptis or  
,listera4 7,more ,letters of ,charles   
,darwin1 ,vol4 ,,ii4 page #dai47        
,expressions of this kind coming from a 
man whose theories exerted an           
epoch-making influence1 would be        
unintelligible if his researches into   
the biology of flowers had been         
concerned only with records of isolated 

facts1 however interesting these might  
be4 ,we may at once take it for granted 
that the investigations were undertaken 
with the view of following up important 
problems of general interest1 problems  
which are briefly dealt with in this    
essay4  ,darwin published the results of
 his researches in several papers and in
 three larger works1 7i7 ,on the various
 contrivances by which ,british and     
,foreign ,orchids are fertilised by     
insects 7,first edition1 ,london1 #ahfb2
 second edition1 #ahgg2 popular edition1
 #aijd47 7ii7 ,the effects of ,cross and
 ,self fertilisation in the vegetable   
kingdom 7,first edition1 #ahgf2 second  
edition1 #ahgh74 7iii7 ,the different   
forms of ,flowers on plants of the same 
species 7,first edition1 #ahgg2 second  
edition1 #ahhj74  ,although the         
influence of his work is considered     
later1 we may here point out that it was
 almost without a parallel2 not only    
does it include a mass of purely        
scientific observations1 but it awakened

 interest in very wide circles1 as is   
shown by the fact that we find the      
results of ,darwin's investigations in  
floral biology universally quoted in    
school books2 they are even willingly   
accepted by those who1 as regards other 
questions1 are opposed to ,darwin's     
views4  ,the works which we have        
mentioned are1 however1 not only of     
special interest because of the facts   
they contribute1 but because of the     
,,manner in which the facts are         
expressed4 ,a superficial reader seeking
 merely for catch-words will1 for       
instance1 probably find the book on     
cross and self-fertilisation rather dry 
because of the numerous details which it
 contains3 it is1 indeed1 not easy to   
compress into a few words the general   
conclusions of this volume4 ,but on     
closer examination1 we cannot be        
sufficiently grateful to the author for 
the exactness and objectivity with which
 he enables us to participate in the    
scheme of his researches4 ,he never     

tries to persuade us1 but only to       
convince us that his conclusions are    
based on facts2 he always gives         
prominence to such facts as appear to be
 in opposition to his opinions1--a      
feature of his work in accordance with a
 maxim which he laid down3--,it is a    
golden rule1 which ,i try to follow1 to 
put every fact which is opposed to one's
 preconceived opinion in the strongest  
light4 7,more ,letters1 ,vol4 ,,ii4 page
 #cbd47  ,the result of this method of  
presentation is that the works mentioned
 above represent a collection of most   
valuable documents even for those who   
feel impelled to draw from the data     
other conclusions than those of the     
author4 ,each investigation is the      
outcome of a definite question1 a       
preconceived opinion1 which is either   
supported by the facts or must be       
abandoned4 ,how odd it is that anyone   
should not see that all observation must
 be for or against some view if it is to
 be of any service6 7,ibid4 ,vol4 ,i4   

page #aie47  ,the points of view which  
,darwin had before him were principally 
the following4 ,in the first place the  
proof that a large number of the        
peculiarities in the structure of       
flowers are not useless1 but of the     
greatest significance in pollination    
must be of considerable importance for  
the interpretation of adaptations2 ,the 
use of each trifling detail of structure
 is far from a barren search to those   
who believe in natural selection4       
7,fertilisation of ,orchids 7#ast       
edition71 page #cea2 7#bnd edition      
#aijd7 page #bhf47 ,further1 if these   
structural relations are shown to be    
useful1 they may have been acquired     
because from the many variations which  
have occurred along different lines1    
those have been preserved by natural    
selection which are beneficial to the   
organism under the complex and          
ever-varying conditions of life4 7,ibid4
 page #cea47 ,but in the case of flowers
 there is not only the question of      

adaptation to fertilisation to be       
considered4 ,darwin1 indeed1 soon formed
 the opinion which he has expressed in  
the following sentence1--,from my own   
observations on plants1 guided to a     
certain extent by the experience of the 
breeders of animals1 ,i became convinced
 many years ago that it is a general law
 of nature that flowers are adapted to  
be crossed1 at least occasionally1 by   
pollen from a distinct plant4 7,cross   
and ,self fertilisation 7#ast edition71 
page #f47  ,the experience of animal    
breeders pointed to the conclusion that 
continual in-breeding is injurious4 ,if 
this is correct1 it raises the question 
whether the same conclusion holds for   
plants4 ,as most flowers are            
hermaphrodite1 plants afford much more  
favourable material than animals for an 
experimental solution of the question1  
what results follow from the union of   
nearly related sexual cells as compared 
with those obtained by the introduction 
of new blood4 ,the answer to this       

question must1 moreover1 possess the    
greatest significance for the correct   
understanding of sexual reproduction in 
general4  ,we see1 therefore1 that the  
problems which ,darwin had before him in
 his researches into the biology of     
flowers were of the greatest importance1
 and at the same time that the point of 
view from which he attacked the problems
 was essentially a teleological one4    
,we may next inquire in what condition  
he found the biology of flowers at the  
time of his first researches1 which were
 undertaken about the year #ahch4 ,in   
his autobiography he writes1--,during   
the summer of #ahci1 and1 ,i believe1   
during the previous summer1 ,i was led  
to attend to the cross-fertilisation of 
flowers by the aid of insects1 from     
having come to the conclusion in my     
speculations on the origin of species1  
that crossing played an important part  
in keeping specific forms constant4     
7,the ,life and ,letters of ,charles    
,darwin1 ,vol4 ,i4 page #ij1 ,london1   

#ahhh47 ,in #ahda he became acquainted  
with ,sprengel's work3 his researches   
into the biology of flowers were thus   
continued for about forty years4  ,it is
 obvious that there could only be a     
biology of flowers after it had been    
demonstrated that the formation of seeds
 and fruit in the flower is dependent on
 pollination and subsequent             
fertilisation4 ,this proof was supplied 
at the end of the seventeenth century by
 ,r4,j4 ,camerarius 7#affe-agba74 ,he   
showed that normally seeds and fruits   
are developed only when the pollen      
reaches the stigma4 ,the manner in which
 this happens was first thoroughly      
investigated by ,j4,g4 ,kolreuter       
7#agcc-ahjf 7,kolreuter1 ,vorlaufige    
,nachricht von einigen das ,geschlecht  
der ,planzen betreffenden ,versuchen und
 ,beobachtungen1 ,leipzig1 #agfa2 with  
three supplements1 #agfc-ff4 ,also1     
,mem4 de l'acad4 ,st ,petersbourg1 ,vol4
 ,,xv4 #ahji4771 the same observer to   
whom we owe the earliest experiments in 

hybridisation of real scientific        
interest4 ,kolreuter mentioned that     
pollen may be carried from one flower to
 another partly by wind and partly by   
insects4 ,but he held the view1 and that
 was1 indeed1 the natural assumption1   
that self-fertilisation usually occurs  
in a flower1 in other words that the    
pollen of a flower reaches the stigma of
 the same flower4 ,he demonstrated1     
however1 certain cases in which         
cross-pollination occurs1 that is in    
which the pollen of another flower of   
the same species is conveyed to the     
stigma4 ,he was familiar with the       
phenomenon1 exhibited by numerous       
flowers1 to which ,sprengel afterwards  
applied the term ,dichogamy1 expressing 
the fact that the anthers and stigmas of
 a flower often ripen at different      
times1 a peculiarity which is now       
recognised as one of the commonest means
 of ensuring cross-pollination4  ,with  
far greater thoroughness and with       
astonishing power of observation ,c4,k4 

,sprengel 7#agej-ahaf7 investigated the 
conditions of pollination of flowers4   
,darwin was introduced by that eminent  
botanist ,robert ,brown to ,sprengel's  
then but little appreciated work1--,das 
entdeckte ,geheimniss der ,natur im ,bau
 und in der ,befruchtung der ,blumen    
7,berlin1 #agic72 this is by no means   
the least service to ,botany rendered by
 ,robert ,brown4  ,sprengel proceeded   
from a naive teleological point of view4
 ,he firmly believed that the wise      
,author of nature had not created a     
single hair without a definite purpose4 
,he succeeded in demonstrating a number 
of beautiful adaptations in flowers for 
ensuring pollination2 but his work      
exercised but little influence on his   
contemporaries and indeed for a long    
time after his death4 ,it was through   
,darwin that ,sprengel's work first     
achieved a well deserved though belated 
fame4 ,even such botanists as concerned 
themselves with researches into the     
biology of flowers appear to have       

formerly attached much less value to    
,sprengel's work than it has received   
since ,darwin's time4 ,in illustration  
of this we may quote ,c4,f4 ,gartner    
whose name is rightly held in the       
highest esteem as that of one of the    
most eminent hybridologists4 ,in his    
work ,versuche und ,beobachtungen uder  
die ,befruchtungsorgane der             
vollkommeneren ,gewachse und uber die   
naturliche und kunstliche ,befruchtung  
durch den eigenen ,pollen he also deals 
with flower-pollination4 ,he recognised 
the action of the wind1 but he believed1
 in spite of the fact that he both knew 
and quoted ,kolreuter and ,sprengel1    
that while insects assist pollination1  
they do so only occasionally1 and he    
held that insects are responsible for   
the conveyance of pollen2 thorough      
investigations would show that a very   
small proportion of the plants included 
in this category require this assistance
 in their native habitat4 7,gartner1    
,versucher und ,beobachtungen444 1 page 

#cce1 ,stuttgart1 #ahdd47 ,in the       
majority of plants self-pollination     
occurs4  ,seeing that even investigators
 who had worked for several decades at  
fertilisation-phenomena had not advanced
 the biology of flowers beyond the      
initial stage1 we cannot be surprised   
that other botanists followed to even a 
less extent the lines laid down by      
,kolreuter and ,sprengel4 ,this was in  
part the result of ,sprengel's          
supernatural teleology and in part due  
to the fact that his book appeared at a 
time when other lines of inquiry exerted
 a dominating influence4  ,at the hands 
of ,linnaeus systematic botany reached a
 vigorous development1 and at the       
beginning of the nineteenth century the 
anatomy and physiology of plants grew   
from small beginnings to a flourishing  
branch of science4 ,those who concerned 
themselves with flowers endeavoured to  
investigate their development and       
structure or the most minute phenomena  
connected with fertilisation and the    

formation of the embryo4 ,no room was   
left for the extension of the biology of
 flowers on the lines marked out by     
,kolreuter and ,sprengel4 ,darwin was   
the first to give new life and a deeper 
significance to this subject1 chiefly   
because he took as his starting-point   
the above-mentioned problems1 the       
importance of which is at once admitted 
by all naturalists4  ,the further       
development of floral biology by ,darwin
 is in the first place closely connected
 with the book on the fertilisation of  
,orchids4 ,it is noteworthy that the    
title includes the sentence1--and on the
 good effects of intercrossing4  ,the   
purpose of the book is clearly stated in
 the introduction3--,the object of the  
following work is to show that the      
contrivances by which ,orchids are      
fertilised1 are as varied and almost as 
perfect as any of the most beautiful    
adaptations in the animal kingdom2 and1 
secondly1 to show that these            
contrivances have for their main object 

the fertilisation of each flower by the 
pollen of another flower4               
7,fertilisation of ,orchids1 page #a47  
,orchids constituted a particularly     
suitable family for such researches4    
,their flowers exhibit a striking wealth
 of forms2 the question1 therefore1     
whether the great variety in floral     
structure bears any relation to         
fertilisation 7,in the older botanical  
literature the word fertilisation is    
usually employed in cases where         
,,pollination is really in question3 as 
,darwin used it in this sense it is so  
used here47 must in this case possess   
special interest4  ,darwin succeeded in 
showing that in most of the orchids     
examined self-fertilisation is either an
 impossibility1 or1 under natural       
conditions1 occurs only exceptionally4  
,on the other hand these plants present 
a series of extraordinarily beautiful   
and remarkable adaptations which ensure 
the transference of pollen by insects   
from one flower to another4 ,it is      

impossible to describe adequately in a  
few words the wealth of facts contained 
in the ,orchid book4 ,a few examples    
may1 however1 be quoted in illustration 
of the delicacy of the observations and 
of the perspicuity employed in          
interpreting the facts4  ,the majority  
of orchids differ from other seed plants
 7with the exception of the ,asclepiads7
 in having no dust-like pollen4 ,the    
pollen1 or more correctly1 the          
pollen-tetrads1 remain fastened together
 as club-shaped pollinia usually borne  
on a slender pedicel4 ,at the base of   
the pedicel is a small viscid disc by   
which the pollinium is attached to the  
head or proboscis of one of the insects 
which visit the flower4 ,darwin         
demonstrated that in ,orchis and other  
flowers the pedicel of the pollinium1   
after its removal from the anther1      
undergoes a curving movement4 ,if the   
pollinium was originally vertical1 after
 a time it assumed a horizontal         
position4 ,in the latter position1 if   

the insect visited another flower1 the  
pollinium would exactly hit the sticky  
stigmatic surface and thus effect       
fertilisation4 ,the relation between the
 behaviour of the viscid disc and the   
secretion of nectar by the flower is    
especially remarkable4 ,the flowers     
possess a spur which in some species    
7e4g4 ,gymnadenia conopsea1 ,platanthera
 bifolia1 etc47 contains honey 7nectar71
 which serves as an attractive bait for 
insects1 but in others 7e4g4 our native 
species of ,orchis7 the spur is empty4  
,darwin held the opinion1 confirmed by  
later investigations1 that in the case  
of flowers without honey the insects    
must penetrate the wall of the          
nectarless spurs in order to obtain a   
nectar-like substance4 ,the glands      
behave differently in the nectar-bearing
 and in the nectarless flowers4 ,in the 
former they are so sticky that they at  
once adhere to the body of the insect2  
in the nectarless flowers firm adherence
 only occurs after the viscid disc has  

hardened4 ,it is1 therefore1 adaptively 
of value that the insects should be     
detained longer in the nectarless       
flowers 7by having to bore into the     
spur71--than in flowers in which the    
nectar is freely exposed4 ,if this      
relation1 on the one hand1 between the  
viscid matter requiring some little time
 to set hard1 and the nectar being so   
lodged that moths are delayed in getting
 it2 and1 on the other hand1 between the
 viscid matter being at first as viscid 
as ever it will become1 and the nectar  
lying all ready for rapid suction1 be   
accidental1 it is a fortunate accident  
for the plant4 ,if not accidental1 and  
,i cannot believe it to be accidental1  
what a singular case of adaptation6     
7,fertilisation of ,orchids 7#ast       
edition71 page #ec47  ,among exotic     
orchids ,catasetum is particularly      
remarkable4 ,one and the same species   
bears different forms of flowers4 ,the  
species known as ,catasetum tridentatum 
has pollinia with very large viscid     

discs2 on touching one of the two       
filaments 7antennae7 which occur on the 
gynostemium of the flower the pollinia  
are shot out to a fairly long distance  
7as far as #a metre7 and in such manner 
that they alight on the back of the     
insect1 where they are held4 ,the       
antennae have1 moreover1 acquired an    
importance1 from the point of view of   
the physiology of stimulation1 as       
stimulus-perceiving organs4 ,darwin had 
shown that it is only a touch on the    
antennae that causes the explosion1     
while contact1 blows1 wounding1 etc4 on 
other places produce no effect4 ,this   
form of flower proved to be the male4   
,the second form1 formerly regarded as a
 distinct species and named             
,monachanthus viridis1 is shown to be   
the female flower4 ,the anthers have    
only rudimentary pollinia and do not    
open2 there are no antennae1 but on the 
other hand numerous seeds are produced4 
,another type of flower1 known as       
,myanthus barbatus1 was regarded by     

,darwin as a third form3 this was       
afterwards recognised by ,rolfe 7,rolfe1
 ,r4,a4 ,on the sexual forms of         
,catasetum with special reference to the
 researches of ,darwin and others1      
,journ4 ,linn4 ,soc4 ,vol4 ,,xxvii4     
7,botany71 #ahia1 pages #bjf-bbe47 as   
the male flower of another species1     
,catasetum barbatum ,link1 an           
identification in accordance with the   
discovery made by ,cruger in ,trinidad  
that it always remains sterile4  ,darwin
 had noticed that the flowers of        
,catasetum do not secrete nectar1 and he
 conjectured that in place of it the    
insects gnaw a tissue in the cavity of  
the labellum which has a slightly sweet1
 pleasant and nutritious taste4 ,this   
conjecture as well as other conclusions 
drawn by ,darwin from ,catasetum have   
been confirmed by ,cruger--assuredly the
 best proof of the acumen with which the
 wonderful floral structure of this most
 remarkable of the ,orchids was         
interpretated far from its native       

habitat4  ,as is shown by what we have  
said about ,catasetum1 other problems in
 addition to those concerned with       
fertilisation are dealt with in the     
,orchid book4 ,this is especially the   
case in regard to flower morphology4    
,the scope of flower morphology cannot  
be more clearly and better expressed    
than by these words3 ,he will see how   
curiously a flower may be moulded out of
 many separate organs--how perfect the  
cohesion of primordially distinct parts 
may become1--how organs may be used for 
purposes widely different from their    
proper function1--how other organs may  
be entirely suppressed1 or leave mere   
useless emblems of their former         
existence4 7,fertilisation of ,orchids1 
page #bhi47  ,in attempting1 from this  
point of view1 to refer the floral      
structure of orchids to their original  
form1 ,darwin employed a much more      
thorough method than that of ,robert    
,brown and others4 ,the result of this  
was the production of a considerable    

literature1 especially in ,france1 along
 the lines suggested by ,darwin's work4 
,this is the so-called anatomical       
method1 which seeks to draw conclusions 
as to the morphology of the flower from 
the course of the vascular bundles in   
the several parts4 7,he wrote in one of 
his letters1 444 the destiny of the     
whole human race is as nothing to the   
course of vessels of orchids 7,more     
,letters1 ,vol4 ,,ii4 page #bge47       
,although the interpretation of the     
orchid flower given by ,darwin has not  
proved satisfactory in one particular   
point--the composition of the           
labellum--the general results have      
received universal assent1 namely that  
all ,orchids owe what they have in      
common to descent from some             
monocotyledonous plant1 which1 like so  
many other plants of the same division1 
possessed fifteen organs arranged       
alternately three within three in five  
whorls4 7,fertilisation of ,orchids     
7#ast edition71 page #cjg47 ,the        

alterations which their original form   
has undergone have persisted so far as  
they were found to be of use4  ,we see  
also that the remarkable adaptations of 
which we have given some examples are   
directed towards cross-fertilisation4   
,in only a few of the orchids           
investigated by ,darwin--other similar  
cases have since been described--was    
self-fertilisation found to occur       
regularly or usually4 ,the former is the
 case in the ,bee ,ophrys 7,ophrys      
apifera71 the mechanism of which greatly
 surprised ,darwin4 ,he once remarked to
 a friend that one of the things that   
made him wish to live a few thousand    
years was his desire to see the         
extinction of the ,bee ,ophrys1 an end  
to which he believed its                
self-fertilising habit was leading4     
7,life and ,letters1 ,vol4 ,,iii4 page  
#bgf 7footnote747 ,but1 he wrote1 the   
safest conclusion1 as it seems to me1   
is1 that under certain unknown          
circumstances1 and perhaps at very long 

intervals of time1 one individual of the
 ,bee ,ophrys is crossed by another4    
7,fertilisation of ,orchids page #ga47  
,if1 on the one hand1 we remember how   
much more sure self-fertilisation would 
be than cross-fertilisation1 and1 on the
 other hand1 if we call to mind the     
numerous contrivances for               
cross-fertilisation1 the conclusion is  
naturally reached that it is an         
astonishing fact that self-fertilisation
 should not have been an habitual       
occurrence4 ,it apparently demonstrates 
to us that there must be something      
injurious in the process4 ,nature thus  
tells us1 in the most emphatic manner1  
that she abhors perpetual               
self-fertilisation444 ,for may we not   
further infer as probable1 in accordance
 with the belief of the vast majority of
 the breeders of our domestic           
productions1 that marriage between near 
relations is likewise in some way       
injurious1 that some unknown great good 
is derived from the union of individuals

 which have been kept distinct for many 
generations8 7,ibid41 page #cei47  ,this
 view was supported by observations on  
plants of other families1 e4g4          
,papilionaceae2 it could1 however1 in   
the absence of experimental proof1 be   
regarded only as a working hypothesis4  
,all adaptations to cross-pollination   
might also be of use simply because they
 made pollination possible when for any 
reason self-pollination had become      
difficult or impossible4                
,cross-pollination would1 therefore1 be 
of use1 not as such1 but merely as a    
means of pollination in general2 it     
would to some extent serve as a remedy  
for a method unsuitable in itself1 such 
as a modification standing in the way of
 self-pollination1 and on the other hand
 as a means of increasing the chance of 
pollination in the case of flowers in   
which self-pollination was possible1 but
 which might1 in accidental             
circumstances1 be prevented4 ,it was1   
therefore1 very important to obtain     

experimental proof of the conclusion to 
which ,darwin was led by the belief of  
the majority of breeders and by the     
evidence of the widespread occurrence of
 cross-pollination and of the remarkable
 adaptations thereto4  ,this was        
supplied by the researches which are    
described in the two other works named  
above4 ,the researches on which the     
conclusions rest had1 in part at least1 
been previously published in separate   
papers3 this is the case as regards the 
heterostyled plants4 ,the discoveries   
which ,darwin made in the course of his 
investigations of these plants belong to
 the most brilliant in biological       
science4  ,the case of ,primula is now  
well known4 ,c4,k4 ,sprengel and others 
were familiar with the remarkable fact  
that different individuals of the       
,european species of ,primula bear      
differently constructed flowers2 some   
plants possess flowers in which the     
styles project beyond the stamens       
attached to the corolla-tube            

7long-styled form71 while in others the 
stamens are inserted above the stigma   
which is borne on a short style         
7short-styled form74 ,it has been shown 
by ,breitenbach that both forms of      
flower may occur on the same plant1     
though this happens very rarely4 ,an    
analogous case is occasionally met with 
in hybrids1 which bear flowers of       
different colour on the same plant 7e4g4
 ,dianthus caryophyllus74 ,darwin showed
 that the external differences are      
correlated with others in the structure 
of the stigma and in the nature of the  
pollen4 ,the long-styled flowers have a 
spherical stigma provided with large    
stigmatic papillae2 the pollen grains   
are oblong and smaller than those of the
 short-styled flowers4 ,the number of   
the seeds produced is smaller and the   
ovules larger1 probably also fewer in   
number4 ,the short-styled flowers have a
 smooth compressed stigma and a corolla 
of somewhat different form2 they produce
 a greater number of seeds4  ,these     

different forms of flowers were regarded
 as merely a case of variation1 until   
,darwin showed that these heterostyled  
plants are adapted for reciprocal       
fertilisation2 so that the two or three 
forms1 though all are hermaphrodites1   
are related to one another almost like  
the males and females of ordinary       
unisexual animals4 7,forms of ,flowers  
7#ast edition71 page #b47 ,we have here 
an example of hermaphrodite flowers     
which are sexually different4 ,there are
 essential differences in the manner in 
which fertilisation occurs4 ,this may be
 effected in four different ways2 there 
are two legitimate and two illegitimate 
types of fertilisation4 ,the            
fertilisation is legitimate if pollen   
from the long-styled flowers reaches the
 stigma of the short-styled form or if  
pollen of the short-styled flowers is   
brought to the stigma of the long-styled
 flower1 that is the organs of the same 
length of the two different kinds of    
flower react on one another4            

,illegitimate fertilisation is          
represented by the two kinds of         
self-fertilisation1 also by             
cross-fertilisation1 in which the pollen
 of the long-styled form reaches the    
stigma of the same type of flower and1  
similarly1 by cross-pollination in the  
case of the short-styled flowers4  ,the 
applicability of the terms legitimate   
and illegitimate depends1 on the one    
hand1 upon the fact that insects which  
visit the different forms of flowers    
pollinate them in the manner suggested2 
the pollen of the short-styled flowers  
adhere to that part of the insect's body
 which touches the stigma of the        
long-styled flower and vice versa4 ,on  
the other hand1 it is based also on the 
fact that experiment shows that         
artificial pollination produces a very  
different result according as this is   
legitimate or illegitimate2 only the    
legitimate union ensures complete       
fertility1 the plants thus produced     
being stronger than those which are     

produced illegitimately4  ,if we take   
#ajj as the number of flowers which     
produce seeds as the result of          
legitimate fertilisation1 we obtain the 
following numbers from illegitimate     
fertilisation3  ,primula officinalis    
7,p4 veris7 7,cowslip7444 #fi ,primula  
elatior 7,oxlip744444444444444444444 #bg
 ,primula acaulis 7,p4 vulgaris7        
7,primrose7444 #fj  ,further1 the plants
 produced by the illegitimate method of 
fertilisation showed1 e4g4 in ,p4       
officinalis1 a decrease in fertility in 
later generations1 sterile pollen and in
 the open a feebler growth4 7,under very
 favourable conditions 7in a greenhouse7
 the fertility of the plants of the     
fourth generation increases--a point1   
which in view of various theoretical    
questions1 deserves further             
investigation47 ,they behave in fact    
precisely in the same way as hybrids    
between species of different genera4    
,this result is important1 for we thus  
learn that the difficulty in sexually   

uniting two organic forms and the       
sterility of their offspring1 afford no 
sure criterion of so-called specific    
distinctness 7,forms of ,flowers1 page  
#bdb73 the relative or absolute         
sterility of the illegitimate unions and
 that of their illegitimate descendants 
depend exclusively on the nature of the 
sexual elements and on their inability  
to combine in a particular manner4 ,this
 functional difference of sexual cells  
is characteristic of the behaviour of   
hybrids as of the illegitimate unions of
 heterostyled plants4 ,the agreement    
becomes even closer if we regard the    
,primula plants bearing different forms 
of flowers not as belonging to a        
systematic entity or species1 but as    
including several elementary species4   
,the legitimately produced plants are   
thus true hybrids 7,when ,darwin wrote  
in reference to the different forms of  
heterostyled plants1 which all belong to
 the same species as certainly as do the
 two sexes of the same species 7,cross  

and ,self fertilisation1 page #dff71 he 
adopted the term species in a           
comprehensive sense4 ,the recent        
researches of ,bateson and ,gregory 7,on
 the inheritance of ,heterostylism in   
,primula2 ,proc4 ,roy4 ,soc4 ,ser4 ,b1  
,vol4 ,,lxxvi4 #aije1 page #eha7 appear 
to me also to support the view that the 
results of illegitimate crossing of     
heterostyled ,primulas correspond with  
those of hybridisation4 ,the fact that  
legitimate pollen effects fertilisation1
 even if illegitimate pollen reaches the
 stigma a short time previously1 also   
points to this conclusion4              
,self-pollination in the case of the    
short-styled form1 for example1 is not  
excluded4 ,in spite of this1 the        
numerical proportion of the two forms   
obtained in the open remains            
approximately the same as when the      
pollination was exclusively legitimate1 
presumably because legitimate pollen is 
prepotent471 with which their behaviour 
in other respects1 as ,darwin showed1   

presents so close an agreement4 ,this   
view receives support also from the fact
 that descendants of a flower fertilised
 illegitimately by pollen from another  
plant with the same form of flower      
belong1 with few exceptions1 to the same
 type as that of their parents4 ,the two
 forms of flower1 however1 behave       
differently in this respect4 ,among #afb
 seedlings of the long-styled           
illegitimately pollinated plants of     
,primula officinalis1 including five    
generations1 there were #aef long-styled
 and only six short-styled forms1 while 
as the result of legitimate             
fertilisation nearly half of the        
offspring were long-styled and half     
short-styled4 ,the short-styled         
illegitimately pollinated form gave five
 long-styled and nine short-styled2 the 
cause of this difference requires       
further explanation4 ,the significance  
of heterostyly1 whether or not we now   
regard it as an arrangement for the     
normal production of hybrids1 is        

comprehensively expressed by ,darwin3   
,we may feel sure that plants have been 
rendered heterostyled to ensure         
cross-fertilisation1 for we now know    
that a cross between the distinct       
individuals of the same species is      
highly important for the vigour and     
fertility of the offspring4 7,forms of  
,flowers1 page #beh47 ,if we remember   
how important the interpretation of     
heterostyly has become in all general   
problems as1 for example1 those         
connected with the conditions of the    
formation of hybrids1 a fact which was  
formerly overlooked1 we can appreciate  
how ,darwin was able to say in his      
autobiography3 ,i do not think anything 
in my scientific life has given me so   
much satisfaction as making out the     
meaning of the structure of these       
plants4 7,life and ,letters1 ,vol4 ,i4  
page #ia47  ,the remarkable conditions  
represented in plants with three kinds  
of flowers1 such as ,lythrum and        
,oxalis1 agree in essentials with those 

in ,primula4 ,these cannot be considered
 in detail here2 it need only be noted  
that the investigation of these cases   
was still more laborious4 ,in order to  
establish the relative fertility of the 
different unions in ,lythrum salicaria  
#bbc different fertilisations were made1
 each flower being deprived of its male 
organs and then dusted with the         
appropriate pollen4  ,in the book       
containing the account of heterostyled  
plants other species are dealt with     
which1 in addition to flowers opening   
normally 7chasmogamous71 also possess   
flowers which remain closed but are     
capable of producing fruit4 ,these      
cleistogamous flowers afford a striking 
example of habitual self-pollination1   
and ,h4 von ,mohl drew special attention
 to them as such shortly after the      
appearance of ,darwin's ,orchid book4   
,if it were only a question of producing
 seed in the simplest way1 cleistogamous
 flowers would be the most conveniently 
constructed4 ,the corolla and frequently

 other parts of the flower are reduced2 
the development of the seed may1        
therefore1 be accomplished with a       
smaller expenditure of building material
 than in chasmogamous flowers2 there is 
also no loss of pollen1 and thus a      
smaller amount suffices for             
fertilisation4  ,almost all these       
plants1 as ,darwin pointed out1 have    
also chasmogamous flowers which render  
cross-fertilisation possible4 ,his view 
that cleistogamous flowers are derived  
from originally chasmogamous flowers has
 been confirmed by more recent          
researches4 ,conditions of nutrition in 
the broader sense are the factors which 
determine whether chasmogamous or       
cleistogamous flowers are produced1     
assuming1 of course1 that the plants in 
question have the power of developing   
both forms of flower4 ,the former may   
fail to appear for some time1 but are   
eventually developed under favourable   
conditions of nourishment4 ,the belief  
of many authors that there are plants   

with only cleistogamous flowers cannot  
therefore be accepted as authoritative  
without thorough experimental proof1 as 
we are concerned with extra-european    
plants for which it is often difficult  
to provide appropriate conditions in    
cultivation4  ,darwin sees in           
cleistogamous flowers an adaptation to a
 good supply of seeds with a small      
expenditure of material1 while          
chasmogamous flowers of the same species
 are usually cross-fertilised and their 
offspring will thus be invigorated1 as  
we may infer from a wide-spread analogy4
 7,forms of ,flowers 7#ast edition71    
page #cda47 ,direct proof in support of 
this has hitherto been supplied in a few
 cases only2 we shall often find that   
the example set by ,darwin in solving   
such problems as these by laborious     
experiment has unfortunately been little
 imitated4  ,another chapter of this    
book treats of the distribution of the  
sexes in polygamous1 dioecious1 and     
gyno-dioecious plants 7the last term1   

now in common use1 we owe to ,darwin74  
,it contains a number of important facts
 and discussions and has inspired the   
experimental researches of ,correns and 
others4  ,the most important of         
,darwin's work on floral biology is1    
however1 that on cross and              
self-fertilisation1 chiefly because it  
states the results of experimental      
investigations extending over many      
years4 ,only such experiments1 as we    
have pointed out1 could determine       
whether cross-fertilisation is in itself
 beneficial1 and self-fertilisation on  
the other hand injurious2 a conclusion  
which a merely comparative examination  
of pollination-mechanisms renders in the
 highest degree probable4 ,later floral 
biologists have unfortunately almost    
entirely confined themselves to         
observations on floral mechanisms4 ,but 
there is little more to be gained by    
this kind of work than an assumption    
long ago made by ,c4,k4 ,sprengel that  
very many flowers have the sexes        

separate and probably at least as many  
hermaphrodite flowers are dichogamous2  
it would thus appear that ,nature was   
unwilling that any flower should be     
fertilised by its own pollen4  ,it was  
an accidental observation which inspired
 ,darwin's experiments on the effect of 
cross and self-fertilisation4 ,plants of
 ,linaria vulgaris were grown in two    
adjacent beds2 in the one were plants   
produced by cross-fertilisation1 that   
is1 from seeds obtained after           
fertilisation by pollen of another plant
 of the same species2 in the other grew 
plants produced by self-fertilisation1  
that is from seed produced as the result
 of pollination of the same flower4 ,the
 first were obviously superior to the   
latter4  ,darwin was surprised by this  
observation1 as he had expected a       
prejudicial influence of                
self-fertilisation to manifest itself   
after a series of generations3 ,i always
 supposed until lately that no evil     
effects would be visible until after    

several generations of                  
self-fertilisation1 but now ,i see that 
one generation sometimes suffices and   
the existence of dimorphic plants and   
all the wonderful contrivances of       
orchids are quite intelligible to me4   
7,more ,letters1 ,vol4 ,,ii4 page #cgc47
  ,the observations on ,linaria and the 
investigations of the results of        
legitimate and illegitimate             
fertilisation in heterostyled plants    
were apparently the beginning of a long 
series of experiments4 ,these were      
concerned with plants of different      
families and led to results which are of
 fundamental importance for a true      
explanation of sexual reproduction4     
,the experiments were so arranged that  
plants were shielded from insect-visits 
by a net4 ,some flowers were then       
pollinated with their own pollen1 others
 with pollen from another plant of the  
same species4 ,the seeds were germinated
 on moist sand2 two seedlings of the    
same age1 one from a cross and the other

 from a self-fertilised flower1 were    
selected and planted on opposite sides  
of the same pot4 ,they grew therefore   
under identical external conditions2 it 
was thus possible to compare their      
peculiarities such as height1 weight1   
fruiting capacity1 etc4 ,in other cases 
the seedlings were placed near to one   
another in the open and in this way     
their capacity of resisting unfavourable
 external conditions was tested4 ,the   
experiments were in some cases continued
 to the tenth generation and the flowers
 were crossed in different ways4 ,we    
see1 therefore1 that this book also     
represents an enormous amount of most   
careful and patient original work4  ,the
 general result obtained is that plants 
produced as the result of               
cross-fertilisation are superior1 in the
 majority of cases1 to those produced as
 the result of self-fertilisation1 in   
height1 resistance to external injurious
 influences1 and in seed-production4    
,ipomoea purpurea may be quoted as an   

example4 ,if we express the result of   
cross-fertilisation by #ajj1 we obtain  
the following numbers for the fertilised
 plants4       ,generation4   ,height4  
,number of seeds4       #a              
#ajj3 #gf   #ajj3 #fd      #b           
#ajj3 #gi   -      #c             #ajj3 
#fh   #ajj3 #id      #d                 
#ajj3 #hf   #ajj3 #id      #e           
#ajj3 #ge   #ajj3 #hi      #f           
#ajj3 #gb   -      #g             #ajj3 
#ha   -      #h             #ajj3 #he   
-      #i             #ajj3 #gi   #ajj3 
#bf 7,number of capsules7      #aj      
#ajj3 #ed   -   ,taking the average1 the
 ratio as regards growth is #ajj3gg4    
,the considerable superiority of the    
crossed plants is apparent in the first 
generation and is not increased in the  
following generations2 but there is some
 fluctuation about the average ratio4   
,the numbers representing the fertility 
of crossed and self-fertilised plants   
are more difficult to compare with      
accuracy2 the superiority of the crossed

 plants is chiefly explained by the fact
 that they produce a much larger number 
of capsules1 not because there are on   
the average more seeds in each capsule4 
,the ratio of the capsules was1 e4g4 in 
the third generation1 #ajj3ch1 that of  
the seeds in the capsules #ajj3id4 ,it  
is also especially noteworthy that in   
the self-fertilised plants the anthers  
were smaller and contained a smaller    
amount of pollen1 and in the eighth     
generation the reduced fertility showed 
itself in a form which is often found in
 hybrids1 that is the first flowers were
 sterile4 7,complete sterility was not  
found in any of the plants investigated 
by ,darwin4 ,others appear to be more   
sensitive2 ,cluer found ,zea ,mais      
almost sterile after three generations  
of self-fertilisation4 7,cf4 ,fruwirth1 
,die ,zuchtung der ,landwirtschaftlichen
 ,kulturpflanzen1 ,berlin1 #aijd1 ,,ii4 
page #f477  ,the superiority of crossed 
individuals is not exhibited in the same
 way in all plants4 ,for example in     

,eschscholzia californica the crossed   
seedlings do not exceed the             
self-fertilised in height and vigour1   
but the crossing considerably increases 
the plant's capacity for                
flower-production1 and the seedlings    
from such a mother-plant are more       
fertile4  ,the conception implied by the
 term crossing requires a closer        
analysis4 ,as in the majority of plants1
 a large number of flowers are in bloom 
at the same time on one and the same    
plant1 it follows that insects visiting 
the flowers often carry pollen from one 
flower to another of the same stock4    
,has this method1 which is spoken of as 
,geitonogamy1 the same influence as     
crossing with pollen from another plant8
 ,the results of ,darwin's experiments  
with different plants 7,ipomoea         
purpurea1 ,digitalis purpurea1 ,mimulus 
luteus1 ,pelargonium1 ,origanum7 were   
not in complete agreement2 but on the   
whole they pointed to the conclusion    
that ,geitonogamy shows no superiority  

over self-fertilisation 7,autogamy74    
7,similarly crossing in the case of     
flowers of ,pelargonium zonale1 which   
belong to plants raised from cuttings   
from the same parent1 shows no          
superiority over self-fertilisation47   
,darwin1 however1 considered it possible
 that this may sometimes be the case4   
,the sexual elements in the flowers on  
the same plant can rarely have been     
differentiated1 though this is possible1
 as flower-buds are in one sense        
distinct individuals1 sometimes varying 
and differing from one another in       
structure or constitution4 7,cross and  
,self fertilisation 7#ast edition71 page
 #ddd47  ,as regards the importance of  
this question from the point of view of 
the significance of cross-fertilisation 
in general1 it may be noted that later  
observers have definitely discovered a  
difference between the results of       
autogamy and geitonogamy4 ,gilley and   
,fruwirth found that in ,brassica       
,napus1 the length and weight of the    

fruits as also the total weight of the  
seeds in a single fruit were less in the
 case of autogamy than in geitonogamy4  
,with ,sinapis alba a better crop of    
seeds was obtained after geitonogamy1   
and in the ,sugar ,beet the average     
weight of a fruit in the case of a      
self-fertilised plant was #j4jji gr41   
from geitonogamy #j4jab gr41 and on     
cross-fertilisation #j4jac gr4  ,on the 
whole1 however1 the results of          
geitonogamy show that the favourable    
effects of cross-fertilisation do not   
depend simply on the fact that the      
pollen of one flower is conveyed to the 
stigma of another4 ,but the plants which
 are crossed must in some way be        
different4 ,if plants of ,ipomoea       
purpurea 7and ,mimulus luteus7 which    
have been self-fertilised for seven     
generations and grown under the same    
conditions of cultivation are crossed   
together1 the plants so crossed would   
not be superior to the self-fertilised2 
on the other hand crossing with a fresh 

stock at once proves very advantageous4 
,the favourable effect of crossing is   
only apparent1 therefore1 if the parent 
plants are grown under different        
conditions or if they belong to         
different varieties4 ,it is really      
wonderful what an effect pollen from a  
distinct seedling plant1 which has been 
exposed to different conditions of life1
 has on the offspring in comparison with
 pollen from the same flower or from a  
distinct individual1 but which has been 
long subjected to the same conditions4  
,the subject bears on the very principle
 of life1 which seems almost to require 
changes in the conditions4 7,more       
,letters1 ,vol4 ,,ii4 page #djf47  ,the 
fertility--measured by the number or    
weight of the seeds produced by an equal
 number of plants--noticed under        
different conditions of fertilisation   
may be quoted in illustration4          
,on crossing   ,on crossing    ,on self-
                                   with 
a fresh  plants of the  fertilisation   

stock         same stock   ,mimuleus    
luteus    7,first and ninth generation7 
#ajj             #d              #c     
,eschscholzia californica    7second    
generation7                #ajj         
#de             #dj    ,dianthus        
caryophyllus    7third and fourth       
generation7      #ajj            #de    
#cc    ,petunia violacea                
#ajj            #ed             #df     
,crossing under very similar conditions 
shows1 therefore1 that the difference   
between the sexual cells is smaller and 
thus the result of crossing is only     
slightly superior to that given by      
self-fertilisation4 ,is1 then1 the      
favourable result of crossing with a    
foreign stock to be attributed to the   
fact that this belongs to another       
systematic entity or to the fact that   
the plants1 though belonging to the same
 entity were exposed to different       
conditions8 ,this is a point on which   
further researches must be taken into   
account1 especially since the analysis  

of the systematic entities has been much
 more thorough than formerly4 7,in the  
case of garden plants1 as ,darwin to a  
large extent claimed1 it is not easy to 
say whether two individuals really      
belong to the same variety1 as they are 
usually of hybrid origin4 ,in some      
instances 7,petunia1 ,iberis7 the fresh 
stock employed by ,darwin possessed     
flowers differing in colour from those  
of the plant crossed with it47 ,we know 
that most of ,linneaus's species are    
compound species1 frequently consisting 
of a very large number of smaller or    
elementary species formerly included    
under the comprehensive term varieties4 
,hybridisation has in most cases        
affected our garden and cultivated      
plants so that they do not represent    
pure species but a mixture of species4  
,but this consideration has no essential
 bearing on ,darwin's point of view1    
according to which the nature of the    
sexual cells is influenced by external  
conditions4 ,even individuals growing   

close to one another are only apparently
 exposed to identical conditions4 ,their
 sexual cells may therefore be          
differently influenced and thus give    
favourable results on crossing1 as the  
benefits which so generally follow from 
a cross between two plants apparently   
depend on the two differing somewhat in 
constitution or character4 ,as a matter 
of fact we are familiar with a large    
number of cases in which the condition  
of the reproductive organs is influenced
 by external conditions4 ,darwin has    
himself demonstrated this for           
self-sterile plants1 that is plants in  
which self-fertilisation produces no    
result4 ,this self-sterility is affected
 by climatic conditions3 thus in ,brazil
 ,eschscholzia californica is absolutely
 sterile to the pollen of its own       
flowers2 the descendants of ,brazilian  
plants in ,darwin's cultures were       
partially self-fertile in one generation
 and in a second generation still more  
so4 ,if one has any doubt in this case  

whether it is a question of the         
condition of the style and stigma1 which
 possibly prevents the entrance of the  
pollen-tube or even its development1    
rather than that of the actual sexual   
cells1 in other cases there is no doubt 
that an influence is exerted on the     
latter4  ,janczewski 7,janczewski1 ,sur 
les antheres steriles des ,groseilliers1
 ,bull4 de l'acad4 des sciences de      
,cracovie1 ,june1 #aijh47 has recently  
shown that species of ,ribes cultivated 
under unnatural conditions frequently   
produce a mixed 7i4e4 partly useless7 or
 completely sterile pollen1 precisely as
 happens with hybrids4 ,there are1      
therefore1 substantial reasons for the  
conclusion that conditions of life exert
 an influence on the sexual cells4 ,thus
 the proposition that the benefit from  
cross-fertilisation depends on the      
plants which are crossed having been    
subjected during previous generations to
 somewhat different conditions1 or to   
their having varied from some unknown   

cause as if they had been thus          
subjected1 is securely fortified on all 
sides4 7,cross and ,self fertilisation  
7#ast edition71 page #ddd47  ,we thus   
obtain an insight into the significance 
of sexuality4 ,if an occasional and     
slight alteration in the conditions     
under which plants and animals live is  
beneficial 7,reasons for this are given 
by ,darwin in ,variation under          
,domestication 7#bnd edition71 ,vol4    
,,ii4 page #abg471 crossing between     
organisms which have been exposed to    
different conditions becomes still more 
advantageous4 ,the entire constitution  
is in this way influenced from the      
beginning1 at a time when the whole     
organisation is in a highly plastic     
state4 ,the total life-energy1 so to    
speak1 is increased1 a gain which is not
 produced by asexual reproduction or by 
the union of sexual cells of plants     
which have lived under the same or only 
slightly different conditions4 ,all the 
wonderful arrangements for              

cross-fertilisation now appear to be    
useful adaptations4 ,darwin was1        
however1 far from giving undue          
prominence to this point of view1 though
 this has been to some extent done by   
others4 ,he particularly emphasised the 
following consideration3--,but we should
 always keep in mind that two somewhat  
opposed ends have to be gained2 the     
first and more important one being the  
production of seeds by any means1 and   
the second1 cross-fertilisation4 7,cross
 and ,self fertilisation 7#ast edition71
 page #cga47 ,just as in some orchids   
and cleistogamic flowers                
self-pollination regularly occurs1 so it
 may also occur in other cases4 ,darwin 
showed that ,pisum sativum and ,lathyrus
 odoratus belong to plants in which     
self-pollination is regularly effected1 
and that this accounts for the constancy
 of certain sorts of these plants1 while
 a variety of form is produced by       
crossing4 ,indeed among his culture     
plants were some which derived no       

benefit from crossing4 ,thus in the     
sixth self-fertilised generation of his 
,ipomoea cultures the ,hero made its    
appearance1 a form slightly exceeding   
its crossed companion in height2 this   
was in the highest degree self-fertile  
and handed on its characteristics to    
both children and grandchildren4        
,similar forms were found in ,mimulus   
luteus and ,nicotiana 7,in ,pisum       
sativum also the crossing of two        
individuals of the same variety produced
 no advantage2 ,darwin attributed this  
to the fact that the plants had for     
several generations been self-fertilised
 and in each generation cultivated under
 almost the same conditions4 ,tschermak 
7,ueber kunstliche ,kreuzung an ,pisum  
sativum7 afterwards recorded the same   
result2 but he found on crossing        
different varieties that usually there  
was no superiority as regards height    
over the products of self-fertilisation1
 while ,darwin found a greater height   
represented by the ratios #ajj3ge and   

#ajj3fj471 types which1 after           
self-fertilisation1 have an enhanced    
power of seed-production and of         
attaining a greater height than the     
plants of the corresponding generation  
which are crossed together and          
self-fertilised and grown under the same
 conditions4 ,some observations made on 
other plants lead me to suspect that    
self-fertilisation is in some respects  
beneficial2 although the benefit thus   
derived is as a rule very small compared
 with that from a cross with a distinct 
plant4 7,cross and ,self fertilisation1 
page #cej47 ,we are as ignorant of the  
reason why plants behave differently    
when crossed and self-fertilised as we  
are in regard to the nature of the      
differentiation of the sexual cells1    
which determines whether a union of the 
sexual cells will prove favourable or   
unfavourable4  ,it is impossible to     
discuss the different results of        
cross-fertilisation2 one point must1    
however1 be emphasised1 because ,darwin 

attached considerable importance to it4 
,it is inevitable that pollen of        
different kinds must reach the stigma4  
,it was known that pollen of the same   
species is dominant over the pollen of  
another species1 that1 in other words1  
it is prepotent4 ,even if the pollen of 
the same species reaches the stigma     
rather later than that of another       
species1 the latter does not effect     
fertilisation4  ,darwin showed that the 
fertilising power of the pollen of      
another variety or of another individual
 is greater than that of the plant's own
 pollen4 7,cross and ,self              
fertilisation1 page #cia47 ,this has    
been demonstrated in the case of        
,mimulus luteus 7for the fixed          
white-flowering variety7 and ,iberis    
umbellata with pollen of another        
variety1 and observations on cultivated 
plants1 such as cabbage1 horseradish1   
etc4 gave similar results4 ,it is1      
however1 especially remarkable that     
pollen of another individual of the same

 variety may be prepotent over the      
plant's own pollen4 ,this results from  
the superiority of plants crossed in    
this manner over self-fertilised plants4
 ,scarcely any result from my           
experiments has surprised me so much as 
this of the prepotency of pollen from a 
distinct individual over each plant's   
own pollen1 as proved by the greater    
constitutional vigour of the crossed    
seedlings4 7,ibid4 page #cig47          
,similarly1 in self-fertile plants the  
flowers of which have not been deprived 
of the male organs1 pollen brought to   
the stigma by the wind or by insects    
from another plant effects              
fertilisation1 even if the plant's own  
pollen has reached the stigma somewhat  
earlier4  ,have the results of his      
experimental investigations modified the
 point of view from which ,darwin       
entered on his researches1 or not8 ,in  
the first place the question is1 whether
 or not the opinion expressed in the    
,orchid book that there is ,something   

injurious connected with                
self-fertilisation1 has been confirmed4 
,we can1 at all events1 affirm that     
,darwin adhered in essentials to his    
original position2 but                  
self-fertilisation afterwards assumed a 
greater importance than it formerly     
possessed4 ,darwin emphasised the fact  
that the difference between the         
self-fertilised and crossed plants      
raised by me cannot be attributed to the
 superiority of the crossed1 but to the 
inferiority of the self-fertilised      
seedlings1 due to the injurious effects 
of self-fertilisation4 7,ibid4 page     
#dcg47 ,but he had no doubt that in     
favourable circumstances self-fertilised
 plants were able to persist for several
 generations without crossing4 ,an      
occasional crossing appears to be useful
 but not indispensable in all cases2 its
 sporadic occurrence in plants in which 
self-pollination habitually occurs is   
not excluded4 ,self-fertilisation is for
 the most part relatively and not       

absolutely injurious and always better  
than no fertilisation4 ,nature abhors   
perpetual self-fertilisation 7,it is    
incorrect to say1 as a writer has lately
 said1 that the aphorism expressed by   
,darwin in #ahei and #ahfb1 ,nature     
abhors perpetual self-fertilisation1 is 
not repeated in his later works4 ,the   
sentence is repeated in ,cross and ,self
 fertilisation 7page #h71 with the      
addition1 ,if the word perpetual had    
been omitted1 the aphorism would have   
been false4 ,as it stands1 ,i believe   
that it is true1 though perhaps rather  
too strongly expressed47 is1 however1 a 
pregnant expression of the fact that    
cross-fertilisation is exceedingly      
widespread and has been shown in the    
majority of cases to be beneficial1 and 
that in those plants in which we find   
self-pollination regularly occurring    
cross-pollination may occasionally take 
place4  ,an attempt has been made to    
express in brief the main results of    
,darwin's work on the biology of        

flowers4 ,we have seen that his object  
was to elucidate important general      
questions1 particularly the question of 
the significance of sexual reproduction4
  ,it remains to consider what influence
 his work has had on botanical science4 
,that this influence has been very      
considerable1 is shown by a glance at   
the literature on the biology of flowers
 published since ,darwin wrote4 ,before 
the book on orchids was published there 
was nothing but the old and almost      
forgotten works of ,kolreuter and       
,sprengel with the exception of a few   
scattered references4 ,darwin's         
investigations gave the first stimulus  
to the development of an extensive      
literature on floral biology4 ,in       
,knuth's ,handbuch der ,blutenbiologie  
7,handbook of ,flower ,pollination1     
,oxford1 #aijf7 as many as #cgib papers 
on this subject are enumerated as having
 been published before ,january #a1     
#aijd4 ,these describe not only the     
different mechanisms of flowers1 but    

deal also with a series of remarkable   
adaptations in the pollinating insects4 
,as a fertilising rain quickly calls    
into existence the most varied          
assortment of plants on a barren steppe1
 so activity now reigns in a field which
 men formerly left deserted4 ,this      
development of the biology of flowers is
 of importance not only on theoretical  
grounds but also from a practical point 
of view4 ,the rational breeding of      
plants is possible only if the          
flower-biology of the plants in question
 7i4e4 the question of the possibility  
of self-pollination1 self-sterility1    
etc47 is accurately known4 ,and it is   
also essential for plant-breeders that  
they should have the power of fixing    
each fleeting variety of colour1 if they
 will fertilise the flowers of the      
desired kind with their own pollen for  
half-a-dozen generations1 and grow the  
seedlings under the same conditions4    
7,cross and ,self fertilisation 7#ast   
edition71 page #dfj47  ,but the         

influence of ,darwin on floral biology  
was not confined to the development of  
this branch of ,botany4 ,darwin's       
activity in this domain has brought     
about 7as ,asa ,gray correctly pointed  
out7 the revival of teleology in ,botany
 and ,zoology4 ,attempts were now made  
to determine1 not only in the case of   
flowers but also in vegetative organs1  
in what relation the form and function  
of organs stand to one another and to   
what extent their morphological         
characters exhibit adaptation to        
environment4 ,a branch of ,botany1 which
 has since been called ,ecology 7not a  
very happy term7 has been stimulated to 
vigorous growth by floral biology4      
,while the influence of the work on the 
biology of flowers was extraordinarily  
great1 it could not fail to elicit      
opinions at variance with ,darwin's     
conclusions4 ,the opposition was based  
partly on reasons valueless as          
counterarguments1 partly on problems    
which have still to be solved2 to some  

extent also on that tendency against    
teleological conceptions which has      
recently become current4 ,this opposing 
trend of thought is due to the fact that
 many biologists are content with       
teleological explanations1 unsupported  
by proof2 it is also closely connected  
with the fact that many authors estimate
 the importance of natural selection    
less highly than ,darwin did4 ,we may   
describe the objections which are based 
on the widespread occurrence of         
self-fertilisation and geitonogamy as of
 little importance4 ,darwin did not deny
 the occurrence of self-fertilisation1  
even for a long series of generations2  
his law states only that ,nature abhors 
,,perpetual self-fertilisation4 7,it is 
impossible 7as has been attempted7 to   
express ,darwin's point of view in a    
single sentence1 such as ,h4 ,muller's  
statement of the ,knight-,darwin law4   
,the conditions of life in organisms are
 so various and complex that laws1 such 
as are formulated in physics and        

chemistry1 can hardly be conceived47 ,an
 exception to this rule would therefore 
occur only in the case of plants in     
which the possibility of                
cross-pollination is excluded4 ,some of 
the plants with cleistogamous flowers   
might afford examples of such cases4 ,we
 have already seen1 however1 that such a
 case has not as yet been shown to      
occur4 ,burck believed that he had found
 an instance in certain tropical plants 
7,anonaceae1 ,myrmecodia7 of the        
complete exclusion of                   
cross-fertilisation4 ,the flowers of    
these plants1 in which1 however1--in    
contrast to the cleistogamous           
flowers--the corolla is well developed1 
remain closed and fruit is produced4    
,loew 7,e4 ,loew1 ,bemerkungen zu       
,burck444 1 ,biolog4 ,centralbl4 ,,xxvi4
 7#aijf747 has shown that cases occur in
 which cross-fertilisation may be       
effected even in these cleistopetalous  
flowers3 humming birds visit the        
permanently closed flowers of certain   

species of ,nidularium and transport the
 pollen4 ,the fact that the formation of
 hybrids may occur as the result of this
 shows that pollination may be          
accomplished4  ,the existence of plants 
for which self-pollination is of greater
 importance than it is for others is by 
no means contradictory to ,darwin's     
view4 ,self-fertilisation is1 for       
example1 of greater importance for      
annuals than for perennials as without  
it seeds might fail to be produced4     
,even in the case of annual plants with 
small inconspicuous flowers in which    
self-fertilisation usually occurs1 such 
as ,senecio vulgaris1 ,capsella         
bursa-pastoris and ,stellaria media1 ,a4
 ,bateson 7,anna ,bateson1 ,the effects 
of cross-fertilisation on inconspicuous 
flowers1 ,annals of ,botany1 ,vol4 ,i4  
#ahhh1 page #bee47 found that           
cross-fertilisation gave a beneficial   
result1 although only in a slight       
degree4 ,if the favourable effects of   
sexual reproduction1 according to       

,darwin's view1 are correlated with     
change of environment1 it is quite      
possible that this is of less importance
 in plants which die after ripening     
their seeds 7hapaxanthic7 and which in  
any case constantly change their        
situation4 ,objections which are based  
on the proof of the prevalence of       
self-fertilisation are not1 therefore1  
pertinent4 ,at first sight another point
 of view1 which has been more recently  
urged1 appears to have more weight4  ,w4
 ,burck 7,burck1 ,darwin's              
,kreuzeungsgesetz444 1 ,biol4           
,centralbl4 ,,xxviii4 #aijh1 page #agg47
 has expressed the opinion that the     
beneficial results of                   
cross-fertilisation demonstrated by     
,darwin concern only hybrid plants4     
,these alone become weaker by           
self-pollination2 while pure species    
derive no advantage from crossing and no
 disadvantage from self-fertilisation4  
,it is certain that some of the plants  
used by ,darwin were of hybrid origin4  

7,it is questionable if this was always 
the case47 ,this is evident from his    
statements1 which are models of         
clearness and precision2 he says that   
his ,ipomoea plants were probably the   
offspring of a cross4 7,cross and ,self 
fertilisation 7#ast edition71 page #ee47
 ,the fixed forms of this plant1 such as
 ,hero1 which was produced by           
self-fertilisation1 and a form of       
,mimulus with white flowers spotted with
 red probably resulted from splitting of
 the hybrids4 ,it is true that the      
phenomena observed in self-pollination1 
e4g4 in ,ipomoea1 agree with those which
 are often noticed in hybrids2 ,darwin  
himself drew attention to this4  ,let us
 next call to mind some of the          
peculiarities connected with            
hybridisation4 ,we know that hybrids are
 often characterized by their large     
size1 rapidity of growth1 earlier       
production of flowers1 wealth of        
flower-production and a longer life2    
hybrids1 if crossed with one of the two 

parent forms1 are usually more fertile  
than when they are crossed together or  
with another hybrid4 ,but the characters
 which hybrids exhibit on               
self-fertilisation are rather variable4 
,the following instance may be quoted   
from ,gartner3 ,there are many hybrids  
which retain the self-fertility of the  
first generation during the second and  
later generations1 but very often in a  
less degree2 a considerable number1     
however1 become sterile4 ,but the hybrid
 varieties may be more fertile in the   
second generation than in the first1 and
 in some hybrids the fertility with     
their own pollen increases in the       
second1 third1 and following            
generations4 7,k4,f4 ,gartner1 ,versuche
 uber die ,bastarderzeugung1 ,stuttgart1
 #ahdi1 page #adi47 ,as yet it is       
impossible to lay down rules of general 
application for the self-fertility of   
hybrids4 ,that the beneficial influence 
of crossing with a fresh stock rests on 
the same ground--a union of sexual cells

 possessing somewhat different          
characters--as the fact that many       
hybrids are distinguished by greater    
luxuriance1 wealth of flowers1 etc4     
corresponds entirely with ,darwin's     
conclusions4 ,it seems to me to follow  
clearly from his investigations that    
there is no essential difference between
 cross-fertilisation and hybridisation4 
,the heterostyled plants are normally   
dependent on a process corresponding to 
hybridisation4 ,the view that           
specifically distinct species could at  
best produce sterile hybrids was always 
opposed by ,darwin4 ,but if the good    
results of crossing were ,,exclusively  
dependent on the fact that we are       
concerned with hybrids1 there must then 
be a demonstration of two distinct      
things4 ,first1 that crossing with a    
fresh stock belonging to the same       
systematic entity or to the same hybrid1
 but cultivated for a considerable time 
under different conditions1 shows no    
superiority over self-fertilisation1 and

 that in pure species crossing gives no 
better results than self-pollination4   
,if this were the case1 we should be    
better able to understand why in one    
plant crossing is advantageous while in 
others1 such as ,darwin's ,hero and the 
forms of ,mimulus and ,nicotiana no     
advantage is gained2 these would then be
 pure species4 ,but such a proof has not
 been supplied2 the inference drawn from
 cleistogamous and cleistopetalous      
plants is not supported by evidence1 and
 the experiments on geitonogamy and on  
the advantage of cross-fertilisation in 
species which are usually               
self-fertilised are opposed to this     
view4 ,there are still but few          
researches on this point2 ,darwin found 
that in ,ononis minutissima1 which      
produces cleistogamous as well as       
self-fertile chasmogamous flowers1 the  
crossed and self-fertilised capsules    
produced seed in the proportion of      
#ajj3fe and that the average bore the   
proportion #ajj3hf4 ,facts previously   

mentioned are also applicable to this   
case4 ,further1 it is certain that the  
self-sterility exhibited by many plants 
has nothing to do with hybridisation4   
,between self-sterility and reduced     
fertility as the result of              
self-fertilisation there is probably no 
fundamental difference4  ,it is certain 
that so difficult a problem as that of  
the significance of sexual reproduction 
requires much more investigation4       
,darwin was anything but dogmatic and   
always ready to alter an opinion when it
 was not based on definite proof3 he    
wrote1 ,but the veil of secrecy is as   
yet far from lifted2 nor will it be1    
until we can say why it is beneficial   
that the sexual elements should be      
differentiated to a certain extent1 and 
why1 if the differentiation be carried  
still further1 injury follows4 ,he has  
also shown us the way along which to    
follow up this problem2 it is that of   
carefully planned and exact experimental
 research4 ,it may be that eventually   

many things will be viewed in a         
different light1 but ,darwin's          
investigations will always form the     
foundation of ,floral ,biology on which 
the future may continue to build4       
,,xxi4 ,,mental ,,factors ,,in          
,,evolution4 ,by ,c4 ,lloyd ,morgan1    
,,ll4,d41 ,f4,r4,s4  ,in developing his 
conception of organic evolution ,charles
 ,darwin was of necessity brought into  
contact with some of the problems of    
mental evolution4 ,in ,the ,origin of   
,species he devoted a chapter to the    
diversities of instinct and of the other
 mental faculties in animals of the same
 class4 7,origin of ,species 7#fth      
edition71 page #bje47 ,when he passed to
 the detailed consideration of ,the     
,descent of ,man1 it was part of his    
object to show that there is no         
fundamental difference between man and  
the higher mammals in their mental      
faculties4 7,descent of ,man 7#bnd      
edition #ahhh71 ,vol4 ,i4 page #ii2     
,popular edition page #ii47 ,if no      

organic being excepting man1 he said1   
had possessed any mental power1 or if   
his powers had been of a wholly         
different nature from those of the lower
 animals1 then we should never have been
 able to convince ourselves that our    
high faculties had been gradually       
developed4 7,ibid4 page #ii47 ,in his   
discussion of ,the ,expression of the   
,emotions it was important for his      
purpose fully to recognise that actions 
readily become associated with other    
actions and with various states of the  
mind4 7,the ,expression of the ,emotions
 7#bnd edition71 page #cb47 ,his        
hypothesis of sexual selection is       
largely dependent upon the exercise of  
choice on the part of the female and her
 preference for not only the more       
attractive but at the same time the more
 vigorous and victorious males4         
7,descent of ,man1 ,vol4 ,,ii4 page     
#dce47 ,mental processes and            
physiological processes were for ,darwin
 closely correlated2 and he accepted the

 conclusion that the nervous system not 
only regulates most of the existing     
functions of the body1 but has          
indirectly influenced the progressive   
development of various bodily structures
 and of certain mental qualities4       
7,ibid4 pages #dcg1 #dch47  ,throughout 
his treatment1 mental evolution was for 
,darwin incidental to and contributory  
to organic evolution4 ,for specialised  
research in comparative and genetic     
psychology1 as an independent field of  
investigation1 he had neither the time  
nor the requisite training4 ,none the   
less his writings and the spirit of his 
work have exercised a profound influence
 on this department of evolutionary     
thought4 ,and1 for those who follow     
,darwin's lead1 mental evolution is     
still in a measure subservient to       
organic evolution4 ,mental processes are
 the accompaniments or concomitants of  
the functional activity of specially    
differentiated parts of the organism4   
,they are in some way dependent on      

physiological and physical conditions4  
,but though they are not physical in    
their nature1 and though it is difficult
 or impossible to conceive that they are
 physical in their origin1 they are1 for
 ,darwin and his followers1 factors in  
the evolutionary process in its physical
 or organic aspect4 ,by the physiologist
 within his special and well-defined    
universe of discourse they may be       
properly regarded as epiphenomena2 but  
by the naturalist in his more catholic  
survey of nature they cannot be so      
regarded1 and were not so regarded by   
,darwin4 ,intelligence has contributed  
to evolution of which it is in a sense a
 product4  ,the facts of observation or 
of inference which ,darwin accepted are 
these3 ,conscious experience accompanies
 some of the modes of animal behaviour2 
it is concomitant with certain          
physiological processes2 these processes
 are the outcome of development in the  
individual and evolution in the race2   
the accompanying mental processes       

undergo a like development4 ,into the   
subtle philosophical questions which    
arise out of the naive acceptance of    
such a creed it was not ,darwin's       
province to enter2 ,i have nothing to   
do1 he said 7,origin of ,species 7#fth  
edition71 page #bje471 with the origin  
of the mental powers1 any more than ,i  
have with that of life itself4 ,he dealt
 with the natural history of organisms1 
including not only their structure but  
their modes of behaviour2 with the      
natural history of the states of        
consciousness which accompany some of   
their actions2 and with the relation of 
behaviour to experience4 ,we will       
endeavour to follow ,darwin in his      
modesty and candour in making no        
pretence to give ultimate explanations4 
,but we must note one of the            
implications of this self-denying       
ordinance of science4 ,development and  
evolution imply continuity4 ,for ,darwin
 and his followers the continuity is    
organic through physical heredity4      

,apart from speculative hypothesis1     
legitimate enough in its proper place   
but here out of court1 we know nothing  
of continuity of mental evolution as    
such3 consciousness appears afresh in   
each succeeding generation4 ,hence it is
 that for those who follow ,darwin's    
lead1 mental evolution is and must ever 
be1 within his universe of discourse1   
subservient to organic evolution4 ,only 
in so far as conscious experience1 or   
its neural correlate1 effects some      
changes in organic structure can it     
influence the course of heredity2 and   
conversely only in so far as changes in 
organic structure are transmitted       
through heredity1 is mental evolution   
rendered possible4 ,such is the logical 
outcome of ,darwin's teaching4  ,those  
who abide by the cardinal results of    
this teaching are bound to regard all   
behaviour as the expression of the      
functional activities of the living     
tissues of the organism1 and all        
conscious experience as correlated with 

such activities4 ,for the purposes of   
scientific treatment1 mental processes  
are one mode of expression of the same  
changes of which the physiological      
processes accompanying behaviour are    
another mode of expression4 ,this is    
simply accepted as a fact which others  
may seek to explain4 ,the behaviour     
itself is the adaptive application of   
the energies of the organism2 it is     
called forth by some form of            
presentation or stimulation brought to  
bear on the organism by the environment4
 ,this presentation is always an        
individual or personal matter4 ,but in  
order that the organism may be fitted to
 respond to the presentation of the     
environment it must have undergone in   
some way a suitable preparation4        
,according to the theory of evolution   
this preparation is primarily racial and
 is transmitted through heredity4       
,darwin's main thesis was that the      
method of preparation is predominantly  
by natural selection4 ,subordinate to   

racial preparation1 and always dependent
 thereon1 is individual or personal     
preparation through some kind of        
acquisition2 of which the guidance of   
behaviour through individually won      
experience is a typical example4 ,we    
here introduce the mental factor because
 the facts seem to justify the          
inference4 ,thus there are some modes of
 behaviour which are wholly and solely  
dependent upon inherited racial         
preparation2 there are other modes of   
behaviour which are also dependent1 in  
part at least1 on individual            
preparation4 ,in the former case the    
behaviour is adaptive on the first      
occurrence of the appropriate           
presentation2 in the latter case        
accommodation to circumstances is only  
reached after a greater or less amount  
of acquired organic modification of     
structure1 often accompanied 7as we     
assume7 in the higher animals by        
acquired experience4 ,logically and     
biologically the two classes of         

behaviour are clearly distinguishable3  
but the analysis of complex cases of    
behaviour where the two factors         
cooperate1 is difficult and requires    
careful and critical study of           
life-history4  ,the foundations of the  
mental life are laid in the conscious   
experience that accompanies those modes 
of behaviour1 dependent entirely on     
racial preparation1 which may broadly be
 described as instinctive4 ,in the      
eighth chapter of ,the ,origin of       
,species ,darwin says 7,origin of       
,species 7#fth edition71 page #bje471 ,i
 will not attempt any definition of     
instinct444 ,every one understands what 
is meant1 when it is said that instinct 
impels the cuckoo to migrate and to lay 
her eggs in other birds' nests4 ,an     
action1 which we ourselves require      
experience to enable us to perform1 when
 performed by an animal1 more especially
 by a very young one1 without           
experience1 and when performed by many  
individuals in the same way1 without    

their knowing for what purpose it is    
performed1 is usually said to be        
instinctive4 ,and in the summary at the 
close of the chapter he says 7,origin of
 ,species 7#fth edition71 page #bcc471  
,i have endeavoured briefly to show that
 the mental qualities of our domestic   
animals vary1 and that the variations   
are inherited4 ,still more briefly ,i   
have attempted to show that instincts   
vary slightly in a state of nature4 ,no 
one will dispute that instincts are of  
the highest importance to each animal4  
,therefore there is no real difficulty1 
under changing conditions of life1 in   
natural selection accumulating to any   
extent slight modifications of instinct 
which are in any way useful4 ,in many   
cases habit or use and disuse have      
probably come into play4  ,into the     
details of ,darwin's treatment there is 
neither space nor need to enter4 ,there 
are some ambiguous passages2 but it may 
be said that for him1 as for his        
followers to-day1 instinctive behaviour 

is wholly the result of racial          
preparation transmitted through organic 
heredity4 ,for the performance of the   
instinctive act no individual           
preparation under the guidance of       
personal experience is necessary4 ,it is
 true that ,darwin quotes with approval 
,huber's saying that a little dose of   
judgment or reason often comes into     
play1 even with animals low in the scale
 of nature4 7,ibid4 page #bje47 ,but we 
may fairly interpret his meaning to be  
that in behaviour1 which is commonly    
called instinctive1 some element of     
intelligent guidance is often combined4 
,if this be conceded the strictly       
instinctive performance 7or part of the 
performance7 is the outcome of heredity 
and due to the direct transmission of   
parental or ancestral aptitudes4 ,hence 
the instinctive response as such depends
 entirely on how the nervous mechanism  
has been built up through heredity2     
while intelligent behaviour1 or the     
intelligent factor in behaviour1 depends

 also on how the nervous mechanism has  
been modified and moulded by use during 
its development and concurrently with   
the growth of individual experience in  
the customary situations of daily life4 
,of course it is essential to the       
,darwinian thesis that what ,sir ,e4    
,ray ,lankester has termed educability1 
not less than instinct1 is hereditary4  
,but it is also essential to the        
understanding of this thesis that the   
differentiae of the hereditary factors  
should be clearly grasped4  ,for ,darwin
 there were two modes of racial         
preparation1 7#a7 natural selection1 and
 7#b7 the establishment of individually 
acquired habit4 ,he showed that         
instincts are subject to hereditary     
variation2 he saw that instincts are    
also subject to modification through    
acquisition in the course of individual 
life4 ,he believed that not only the    
variations but also1 to some extent1 the
 modifications are inherited4 ,he       
therefore held that some instincts 7the 

greater number7 are due to natural      
selection but that others 7less         
numerous7 are due1 or partly due1 to the
 inheritance of acquired habits4 ,the   
latter involve ,lamarckian inheritance1 
which of late years has been the centre 
of so much controversy4 ,it is          
noteworthy however that ,darwin laid    
especial emphasis on the fact that many 
of the most typical and also the most   
complex instincts--those of neuter      
insects--do not admit of such an        
interpretation4 ,i am surprised1 he says
 7,origin of ,species 7#fth edition71   
page #bcc471 that no one has hitherto   
advanced this demonstrative case of     
neuter insects1 against the well-known  
doctrine of inherited habit1 as advanced
 by ,lamarck4 ,none the less ,darwin    
admitted this doctrine as supplementary 
to that which was more distinctively his
 own--for example in the case of the    
instincts of domesticated animals4      
,still1 even in such cases1 it may be   
doubted1 he says 7,ibid4 pages #baj1    

#baa471 whether any one would have      
thought of training a dog to point1 had 
not some one dog naturally shown a      
tendency in this line444 so that habit  
and some degree of selection have       
probably concurred in civilising by     
inheritance our dogs4 ,but in the       
interpretation of the instincts of      
domesticated animals1 a more recently   
suggested hypothesis1 that of organic   
selection 7,independently suggested1 on 
somewhat different lines1 by ,profs4 ,j4
 ,mark ,baldwin1 ,henry ,f4 ,osborn and 
the writer471 may be helpful4 ,according
 to this hypothesis any intelligent     
modification of behaviour which is      
subject to selection is probably        
coincident in direction with an         
inherited tendency to behave in this    
fashion4 ,hence in such behaviour there 
are two factors3 7#a7 an incipient      
variation in the line of such behaviour1
 and 7#b7 an acquired modification by   
which the behaviour is carried further  
along the same line4 ,under natural     

selection those organisms in which the  
two factors cooperate are likely to     
survive4 ,under artificial selection    
they are deliberately chosen out from   
among the rest4  ,organic selection has 
been termed a compromise between the    
more strictly ,darwinian and the        
,lamarckian principles of               
interpretation4 ,but it is not in any   
sense a compromise4 ,the principle of   
interpretation of that which is         
instinctive and hereditary is wholly    
,darwinian4 ,it is true that some of the
 facts of observation relied upon by    
,lamarckians are introduced4 ,for       
,lamarckians however the modifications  
which are admittedly factors in         
survival1 are regarded as the parents of
 inherited variations2 for believers in 
organic selection they are only the     
foster parents or nurses4 ,it is because
 organic selection is the direct outcome
 of and a natural extension of ,darwin's
 cardinal thesis that some reference to 
it here is justifiable4 ,the matter may 

be put with the utmost brevity as       
follows4 7#a7 ,variations 7,v7 occur1   
some of which are in the direction of   
increased adaptation 771 others in the  
direction of decreased adaptation 7-74  
7#b7 ,acquired modifications 7,m7 also  
occur4 ,some of these are in the        
direction of increased accommodation to 
circumstances 771 while others are in   
the direction of diminished             
accommodation 7-74 ,four major          
combinations are       7a7   ,v with    
,m1      7b7   ,v with - ,m1      7c7  -
 ,v with  ,m1      7d7  - ,v with - ,m4 
,of these 7d7 must inevitably be        
eliminated while 7a7 are selected4 ,the 
predominant survival of 7a7 entails the 
survival of the adaptive variations     
which are inherited4 ,the contributory  
acquisitions 7,m7 are not inherited2 but
 they are none the less factors in      
determining the survival of the         
coincident variations4 ,it is surely    
abundantly clear that this is ,darwinism
 and has no tincture of ,lamarck's      

essential principle1 the inheritance of 
acquired characters4  ,whether ,darwin  
himself would have accepted this        
interpretation of some at least of the  
evidence put forward by ,lamarckians is 
unfortunately a matter of conjecture4   
,the fact remains that in his           
interpretation of instinct and in allied
 questions he accepted the inheritance  
of individually acquired modifications  
of behaviour and structure4  ,darwin was
 chiefly concerned with instinct from   
the biological rather than from the     
psychological point of view4 ,indeed it 
must be confessed that1 from the latter 
standpoint1 his conception of instinct  
as a mental faculty which impels an     
animal to the performance of certain    
actions1 scarcely affords a satisfactory
 basis for genetic treatment4 ,to carry 
out the spirit of ,darwin's teaching it 
is necessary to link more closely       
biological and psychological evolution4 
,the first step towards this is to      
interpret the phenomena of instinctive  

behaviour in terms of stimulation and   
response4 ,it may be well to take a     
particular case4 ,swimming on the part  
of a duckling is1 from the biological   
point of view1 a typical example of     
instinctive behaviour4 ,gently lower a  
recently hatched bird into water3       
coordinated movements of the limbs      
follow in rhythmical sequence4 ,the     
behaviour is new to the individual      
though it is no doubt closely related to
 that of walking1 which is no less      
instinctive4 ,there is a group of       
stimuli afforded by the presentation    
which results from partial immersion3   
upon this there follows as a complex    
response an application of the          
functional activities in swimming2 the  
sequence of adaptive application on the 
appropriate presentation is determined  
by racial preparation4 ,we know1 it is  
true1 but little of the physiological   
details of what takes place in the      
central nervous system2 but in broad    
outline the nature of the organic       

mechanism and the manner of its         
functioning may at least be             
provisionally conjectured in the present
 state of physiological knowledge4      
,similarly in the case of the pecking of
 newly-hatched chicks2 there is a visual
 presentation1 there is probably a      
cooperating group of stimuli from the   
alimentary tract in need of food1 there 
is an adaptive application of the       
activities in a definite mode of        
behaviour4 ,like data are afforded in a 
great number of cases of instinctive    
procedure1 sometimes occurring very     
early in life1 not infrequently deferred
 until the organism is more fully       
developed1 but all of them dependent    
upon racial preparation4 ,no doubt there
 is some range of variation in the      
behaviour1 just such variation as the   
theory of natural selection demands4    
,but there can be no question that the  
higher animals inherit a bodily         
organisation and a nervous system1 the  
functional working of which gives rise  

to those inherited modes of behaviour   
which are termed instinctive4  ,it is to
 be noted that the term instinctive is  
here employed in the adjectival form as 
a descriptive heading under which may be
 grouped many and various modes of      
behaviour due to racial preparation4 ,we
 speak of these as inherited2 but in    
strictness what is transmitted through  
heredity is the complex of anatomical   
and physiological conditions under      
which1 in appropriate circumstances1 the
 organism so behaves4 ,so far the term  
instinctive has a restricted biological 
connotation in terms of behaviour4 ,but 
the connecting link between biological  
evolution and psychological evolution is
 to be sought1--as ,darwin fully        
realised1--in the phenomena of instinct1
 broadly considered4 ,the term          
instinctive has also a psychological    
connotation4 ,what is that connotation8 
,let us take the case of the swimming   
duckling or the pecking chick1 and fix  
our attention on the first instinctive  

performance4 ,grant that just as there  
is1 strictly speaking1 no inherited     
behaviour1 but only the conditions which
 render such behaviour under appropriate
 circumstances possible2 so too there is
 no inherited experience1 but only the  
conditions which render such experience 
possible2 then the cerebral conditions  
in both cases are the same4 ,the        
biological behaviour-complex1 including 
the total stimulation and the total     
response with the intervening or        
resultant processes in the sensorium1 is
 accompanied by an experience-complex   
including the initial                   
stimulation-consciousness and resulting 
response-consciousness4 ,in the         
experience-complex are comprised data   
which in psychological analysis are     
grouped under the headings of cognition1
 affective tone and conation4 ,but the  
complex is probably experienced as an   
unanalysed whole4 ,if then we use the   
term instinctive so as to comprise all  
congenital modes of behaviour which     

contribute to experience1 we are in a   
position to grasp the view that the net 
result in consciousness constitutes what
 we may term the primary tissue of      
experience4 ,to the development of this 
experience each instinctive act         
contributes4 ,the nature and manner of  
organisation of this primary tissue of  
experience are dependent on inherited   
biological aptitudes2 but they are from 
the outset onwards subject to secondary 
development dependent on acquired       
aptitudes4 ,biological values are       
supplemented by psychological values in 
terms of satisfaction or the reverse4   
,in our study of instinct we have to    
select some particular phase of animal  
behaviour and isolate it so far as is   
possible from the life of which it is a 
part4 ,but the animal is a going        
concern1 restlessly active in many ways4
 ,many instinctive performances1 as     
,darwin pointed out 7,origin of ,species
 7#fth edition71 page #bjf471 are serial
 in their nature4 ,but the whole of     

active life is a serial and coordinated 
business4 ,the particular instinctive   
performance is only an episode in a     
life-history1 and every mode of         
behaviour is more or less closely       
correlated with other modes4 ,this      
coordination of behaviour is accompanied
 by a correlation of the modes of       
primary experience4 ,we may classify the
 instinctive modes of behaviour and     
their accompanying modes of instinctive 
experience under as many heads as may be
 convenient for our purposes of         
interpretation1 and label them instincts
 of self-preservation1 of pugnacity1 of 
acquisition1 the reproductive instincts1
 the parental instincts1 and so forth4  
,an instinct1 in this sense of the term 
7for example the parental instinct71 may
 be described as a specialised part of  
the primary tissue of experience        
differentiated in relation to some      
definite biological end4 ,under such an 
instinct will fall a large number of    
particular and often well-defined modes 

of behaviour1 each with its own peculiar
 mode of experience4  ,it is no doubt   
exceedingly difficult as a matter of    
observation and of inference securely   
based thereon to distinguish what is    
primary from what is in part due to     
secondary acquisition--a fact which     
,darwin fully appreciated4 ,animals are 
educable in different degrees2 but where
 they are educable they begin to profit 
by experience from the first4 ,only1    
therefore1 on the occasion of the first 
instinctive act of a given type can the 
experience gained be weighed as ,,wholly
 primary2 all subsequent performance is 
liable to be in some degree1 sometimes  
more1 sometimes less1 modified by the   
acquired disposition which the initial  
behaviour engenders4 ,but the early     
stages of acquisition are always along  
the lines predetermined by instinctive  
differentiation4 ,it is the task of     
comparative psychology to distinguish   
the primary tissue of experience from   
its secondary and acquired              

modifications4 ,we cannot follow up the 
matter in further detail4 ,it must here 
suffice to suggest that this conception 
of instinct as a primary form of        
experience lends itself better to       
natural history treatment than ,darwin's
 conception of an impelling force1 and  
that it is in line with the main trend  
of ,darwin's thought4  ,in a            
characteristic work1--characteristic in 
wealth of detail1 in closeness and      
fidelity of observation1 in breadth of  
outlook1 in candour and                 
modesty1--,darwin dealt with ,the       
,expression of the ,emotions in ,man and
 ,animals4 ,sir ,charles ,bell in his   
,anatomy of ,expression had contended   
that many of man's facial muscles had   
been specially created for the sole     
purpose of being instrumental in the    
expression of his emotions4 ,darwin     
claimed that a natural explanation1     
consistent with the doctrine of         
evolution1 could in many cases be given 
and would in other cases be afforded by 

an extension of the principles he       
advocated4 ,no doubt1 he said           
7,expression of the ,emotions1 page #ac4
 ,the passage is here somewhat          
condensed471 as long as man and all     
other animals are viewed as independent 
creations1 an effectual stop is put to  
our natural desire to investigate as far
 as possible the causes of ,expression4 
,by this doctrine1 anything and         
everything can be equally well          
explained444 ,with mankind1 some        
expressions444 can hardly be understood1
 except on the belief that man once     
existed in a much lower and animal-like 
condition4 ,the community of certain    
expressions in distinct though allied   
species444 is rendered somewhat more    
intelligible1 if we believe in their    
descent from a common progenitor4 ,he   
who admits on general grounds that the  
structure and habits of all animals have
 been gradually evolved1 will look at   
the whole subject of ,expression in a   
new and interesting light4  ,darwin     

relied on three principles of           
explanation4 ,the first of these        
principles is1 that movements which are 
serviceable in gratifying some desire1  
or in relieving some sensation1 if often
 repeated1 become so habitual that they 
are performed1 whether or not of any    
service1 whenever the same desire or    
sensation is felt1 even in a very weak  
degree4 7,ibid4 page #cfh47 ,the modes  
of expression which fall under this head
 have become instinctive through the    
hereditary transmission of acquired     
habit4 ,as far as we can judge1 only a  
few expressive movements are learnt by  
each individual2 that is1 were          
consciously and voluntarily performed   
during the early years of life for some 
definite object1 or in imitation of     
others1 and then became habitual4 ,the  
far greater number of the movements of  
expression1 and all the more important  
ones1 are innate or inherited2 and such 
cannot be said to depend on the will of 
the individual4 ,nevertheless1 all those

 included under our first principle were
 at first voluntarily performed for a   
definite object1--namely1 to escape some
 danger1 to relieve some distress1 or to
 gratify some desire4 7,ibid4 pages     
#cgc1 #cgd47  ,our second principle is  
that of antithesis4 ,the habit of       
voluntarily performing opposite         
movements under opposite impulses has   
become firmly established in us by the  
practice of our whole lives4 ,hence1 if 
certain actions have been regularly     
performed1 in accordance with our first 
principle1 under a certain frame of     
mind1 there will be a strong and        
involuntary tendency to the performance 
of directly opposite actions1 whether or
 not these are of any use1 under the    
excitement of an opposite frame of mind4
 7,expression of the ,emotions1 page    
#cfh47 ,this principle of antithesis has
 not been widely accepted4 ,nor is      
,darwin's own position easy to grasp4   
,our third principle1 he says 7,ibid4   
page #cfi471 is the direct action of the

 excited nervous system on the body1    
independently of the will1 and          
independently1 in large part1 of habit4 
,experience shows that nerve-force is   
generated and set free whenever the     
cerebro-spinal system is excited4 ,the  
direction which this nerve-force follows
 is necessarily determined by the lines 
of connection between the nerve-cells1  
with each other and with various parts  
of the body4  ,lack of space prevents   
our following up the details of         
,darwin's treatment of expression4      
,whether we accept or do not accept his 
three principles of explanation we must 
regard his work as a masterpiece of     
descriptive analysis1 packed full of    
observations possessing lasting value4  
,for a further development of the       
subject it is essential that the        
instinctive factors in expression should
 be more fully distinguished from those 
which are individually acquired--a      
difficult task--and that the instinctive
 factors should be rediscussed in the   

light of modern doctrines of heredity1  
with a view to determining whether      
,lamarckian inheritance1 on which       
,darwin so largely relied1 is necessary 
for an interpretation of the facts4     
,the whole subject as ,darwin realised  
is very complex4 ,even the term         
expression has a certain amount of      
ambiguity4 ,when the emotion is in full 
flood the animal fights1 flees1 or      
faints4 ,is this full-tide effect to be 
regarded as expression2 or are we to    
restrict the term to the premonitory or 
residual effects--the bared canine when 
the fighting mood is being roused1 the  
ruffled fur when reminiscent            
representations of the object inducing  
anger cross the mind8 ,broadly          
considered both should be included4 ,the
 activity of premonitory expression as a
 means of communication was recognised  
by ,darwin2 he might1 perhaps1 have     
emphasised it more strongly in dealing  
with the lower animals4 ,man so largely 
relies on a special means of            

communication1 that of language1 that he
 sometimes fails to realise that for    
animals with their keen powers of       
perception1 and dependent as they are on
 such means of communication1 the more  
strictly biological means of expression 
are full of subtle suggestiveness4 ,many
 modes of expression1 otherwise useless1
 are signs of behaviour that may be     
anticipated1--signs which stimulate the 
appropriate attitude of response4 ,this 
would not1 however1 serve to account for
 the utility of the organic             
accompaniments--heart-affection1        
respiratory changes1 vaso-motor effects 
and so forth1 together with heightened  
muscular tone1--on all of which ,darwin 
lays stress 7,expression of the         
,emotions1 pages #fe ff47 under his     
third principle4 ,the biological value  
of all this is1 however1 of great       
importance1 though ,darwin was hardly in
 a position to take it fully into       
account4  ,having regard to the         
instinctive and hereditary factors of   

emotional expression we may ask whether 
,darwin's third principle does not alone
 suffice as an explanation4 ,whether we 
admit or reject ,lamarckian inheritance 
it would appear that all hereditary     
expression must be due to               
pre-established connections within the  
central nervous system and to a         
transmitted provision for coordinated   
response under the appropriate          
stimulation4 ,if this be so1 ,darwin's  
first and second principles are         
subordinate and ancillary to the third1 
an expression1 so far as it is          
instinctive or hereditary1 being the    
direct result of the constitution of the
 nervous system4  ,darwin accepted the  
emotions themselves as hereditary or    
acquired states of mind and devoted his 
attention to their expression4 ,but     
these emotions themselves are genetic   
products and as such dependent on       
organic conditions4 ,it remained1       
therefore1 for psychologists who        
accepted evolution and sought to build  

on biological foundations to trace the  
genesis of these modes of animal and    
human experience4 ,the subject has been 
independently developed by ,professors  
,lange and ,james 7,cf4 ,william ,james1
 ,principles of ,psychology1 ,vol4 ,,ii4
 ,chap4 ,,xxv1 ,london1 #ahij472 and    
some modification of their view is      
regarded by many evolutionists as       
affording the best explanation of the   
facts4 ,we must fix our attention on the
 lower emotions1 such as anger or fear1 
and on their first occurrence in the    
life of the individual organism4 ,it is 
a matter of observation that if a group 
of young birds which have been hatched  
in an incubator are frightened by an    
appropriate presentation1 auditory or   
visual1 they instinctively respond in   
special ways4 ,if we speak of this      
response as the expression1 we find that
 there are many factors4 ,there are     
certain visible modes of behaviour1     
crouching at once1 scattering and then  
crouching1 remaining motionless1 the    

braced muscles sustaining an attitude of
 arrest1 and so forth4 ,there are also  
certain visceral or organic effects1    
such as affections of the heart and     
respiration4 ,these can be readily      
observed by taking the young bird in the
 hand4 ,other effects cannot be readily 
observed2 vaso-motor changes1 affections
 of the alimentary canal1 the skin and  
so forth4 ,now the essence of the       
,james-,lange view1 as applied to these 
congenital effects1 is that though we   
are justified in speaking of them as    
effects of the stimulation1 we are not  
justified1 without further evidence1 in 
speaking of them as effects of the      
emotional state4 ,may it not rather be  
that the emotion as a primary mode of   
experience is the concomitant of the net
 result of the organic situation--the   
initial presentation1 the instinctive   
mode of behaviour1 the visceral         
disturbances8 ,according to this        
interpretation the primary tissue of    
experience of the emotional order1 felt 

as an unanalysed complex1 is generated  
by the stimulation of the sensorium by  
afferent or incoming physiological      
impulses from the special senses1 from  
the organs concerned in the responsive  
behaviour1 from the viscera and         
vaso-motor system4  ,some psychologists1
 however1 contend that the emotional    
experience is generated in the sensorium
 prior to1 and not subsequent to1 the   
behaviour-response and the visceral     
disturbances4 ,it is a direct and not an
 indirect outcome of the presentation to
 the special senses4 ,be this as it may1
 there is a growing tendency to bring   
into the closest possible relation1 or  
even to identify1 instinct and emotion  
in their primary genesis4 ,the central  
core of all such interpretations is that
 instinctive behaviour and experience1  
its emotional accompaniments1 and its   
expression1 are but different aspects of
 the outcome of the same organic        
occurrences4 ,such emotions are1        
therefore1 only a distinguishable aspect

 of the primary tissue of experience and
 exhibit a like differentiation4 ,here  
again a biological foundation is laid   
for a psychological doctrine of the     
mental development of the individual4   
,the intimate relation between emotion  
as a psychological mode of experience   
and expression as a group of organic    
conditions has an important bearing on  
biological interpretation4 ,the emotion1
 as the psychological accompaniment of  
orderly disturbances in the central     
nervous system profoundly influences    
behaviour and often renders it more     
vigorous and more effective4 ,the       
utility of the emotions in the struggle 
for existence can1 therefore1 scarcely  
be over-estimated4 ,just as keenness of 
perception has survival-value2 just as  
it is obviously subject to variation2   
just as it must be enhanced under       
natural selection1 whether individually 
acquired increments are inherited or    
not2 and just as its value lies not only
 in this or that special perceptive act 

but in its importance for life as a     
whole2 so the vigorous effectiveness of 
activity has survival-value2 it is      
subject to variation2 it must be        
enhanced under natural selection2 and   
its importance lies not only in         
particular modes of behaviour but in its
 value for life as a whole4 ,if emotion 
and its expression as a congenital      
endowment are but different aspects of  
the same biological occurrence2 and if  
this is a powerful supplement to vigour 
effectiveness and persistency of        
behaviour1 it must on ,darwin's         
principles be subject to natural        
selection4  ,if we include under the    
expression of the emotions not only the 
premonitory symptoms of the initial     
phases of the organic and mental state1 
not only the signs or conditions of     
half-tide emotion1 but the full-tide    
manifestation of an emotion which       
dominates the situation1 we are         
naturally led on to the consideration of
 many of the phenomena which are        

discussed under the head of sexual      
selection4 ,the subject is difficult and
 complex1 and it was treated by ,darwin 
with all the strength he could summon to
 the task4 ,it can only be dealt with   
here from a special point of view--that 
which may serve to illustrate the       
influence of certain mental factors on  
the course of evolution4 ,from this     
point of view too much stress can       
scarcely be laid on the dominance of    
emotion during the period of courtship  
and pairing in the more highly organised
 animals4 ,it is a period of maximum    
vigour1 maximum activity1 and1          
correlated with special modes of        
behaviour and special organic and       
visceral accompaniments1 a period also  
of maximum emotional excitement4 ,the   
combats of males1 their dances and      
aerial evolutions1 their elaborate      
behaviour and display1 or the flood of  
song in birds1 are emotional expressions
 which are at any rate coincident in    
time with sexual periodicity4 ,from the 

combat of the males there follows on    
,darwin's principles the elimination of 
those which are deficient in bodily     
vigour1 deficient in special structures1
 offensive or protective1 which         
contribute to success1 deficient in the 
emotional supplement of which persistent
 and whole-hearted fighting is the      
expression1 and deficient in alertness  
and skill which are the outcome of the  
psychological development of the powers 
of perception4 ,few biologists question 
that we have here a mode of selection of
 much importance1 though its influence  
on psychological evolution often fails  
to receive its due emphasis4 ,mr        
,wallace 7,darwinism1 pages #bhb1 #bhc1 
,london1 #ahhi47 regards it as a form of
 natural selection2 to it1 he says1 we  
must impute the development of the      
exceptional strength1 size1 and activity
 of the male1 together with the         
possession of special offensive and     
defensive weapons1 and of all other     
characters which arise from the         

development of these or are correlated  
with them4 ,so far there is little      
disagreement among the followers of     
,darwin--for ,mr ,wallace1 with fine    
magnanimity1 has always preferred to be 
ranked as such1 notwithstanding his     
right1 on which a smaller man would have
 constantly insisted1 to the claim of   
independent originator of the doctrine  
of natural selection4 ,so far with      
regard to sexual selection ,darwin and  
,mr ,wallace are agreed2 so far and no  
farther4 ,for ,darwin1 says ,mr ,wallace
 7,ibid4 page #bhc471 has extended the  
principle into a totally different field
 of action1 which has none of that      
character of constancy and of inevitable
 result that attaches to natural        
selection1 including male rivalry2 for  
by far the larger portion of the        
phenomena1 which he endeavours to       
explain by the direct action of sexual  
selection1 can only be so explained on  
the hypothesis that the immediate agency
 is female choice or preference4 ,it is 

to this that he imputes the origin of   
all secondary sexual characters other   
than weapons of offence and defence444  
,in this extension of sexual selection  
to include the action of female choice  
or preference1 and in the attempt to    
give to that choice such wide-reaching  
effects1 ,i am unable to follow him more
 than a very little way4  ,into the     
details of ,mr ,wallace's criticisms it 
is impossible to enter here4 ,we cannot 
discuss either the mode of origin of the
 variations in structure which have     
rendered secondary sexual characters    
possible or the modes of selection other
 than sexual which have rendered them1  
within narrow limits1 specifically      
constant4 ,mendelism and mutation       
theories may have something to say on   
the subject when these theories have    
been more fully correlated with the     
basal principles of selection4 ,it is   
noteworthy that ,mr ,wallace says       
7,darwinism1 pages #bhc1 #bhd473        
,besides the acquisition of weapons by  

the male for the purpose of fighting    
with other males1 there are some other  
sexual characters which may have been   
produced by natural selection4 ,such are
 the various sounds and odours which are
 peculiar to the male1 and which serve  
as a call to the female or as an        
indication of his presence4 ,these are  
evidently a valuable addition to the    
means of recognition of the two sexes1  
and are a further indication that the   
pairing season has arrived2 and the     
production1 intensification1 and        
differentiation of these sounds and     
odours are clearly within the power of  
natural selection4 ,the same remark will
 apply to the peculiar calls of birds1  
and even to the singing of the males4   
,why the same remark should not apply to
 their colours and adornments is not    
obvious4 ,what is obvious is that means 
of recognition and indication that the  
pairing season has arrived are dependent
 on the perceptive powers of the female 
who recognises and for whom the         

indication has meaning4 ,the hypothesis 
of female preference1 stripped of the   
aesthetic surplusage which is           
psychologically both unnecessary and    
unproven1 is really only different in   
degree from that which ,mr ,wallace     
admits in principle when he says that it
 is probable that the female is pleased 
or excited by the display4  ,let us for 
our present purpose leave on one side   
and regard as sub judice the question   
whether the specific details of         
secondary sexual characters are the     
outcome of female choice4 ,for us the   
question is whether certain             
psychological accompaniments of the     
pairing situation have influenced the   
course of evolution and whether these   
psychological accompaniments are        
themselves the outcome of evolution4 ,as
 a matter of observation1 specially     
differentiated modes of behaviour1 often
 very elaborate1 frequently requiring   
highly developed skill1 and apparently  
highly charged with emotional tone1 are 

the precursors of pairing4 ,they are    
generally confined to the males1 whose  
fierce combats during the period of     
sexual activity are part of the         
emotional manifestation4 ,it is         
inconceivable that they have no         
biological meaning2 and it is difficult 
to conceive that they have any other    
biological end than to evoke in the     
generally more passive female the       
pairing impulse4 ,they are based on     
instinctive foundations ingrained in the
 nervous constitution through natural   
7or may we not say sexual87 selection in
 virtue of their profound utility4 ,they
 are called into play by a specialised  
presentation such as the sight or the   
scent of the female at1 or a little in  
advance of1 a critical period of the    
physiological rhythm4 ,there is no      
necessity that the male should have any 
knowledge of the end to which his       
strenuous activity leads up4 ,in        
presence of the female there is an      
elaborate application of all the        

energies of behaviour1 just because ages
 of racial preparation have made him    
biologically and emotionally what he    
is--a functionally sexual male that must
 dance or sing or go through hereditary 
movements of display1 when the          
appropriate stimulation comes4 ,of      
course after the first successful       
courtship his future behaviour will be  
in some degree modified by his previous 
experience4 ,no doubt during his first  
courtship he is gaining the primary data
 of a peculiarly rich experience1       
instinctive and emotional4 ,but the     
biological foundations of the behaviour 
of courtship are laid in the hereditary 
coordinations4 ,it would seem that in   
some cases1 not indeed in all1 but      
perhaps especially in those cases in    
which secondary sexual behaviour is most
 highly evolved1--correlative with the  
ardour of the male is a certain amount  
of reluctance in the female4 ,the       
pairing act on her part only takes place
 after prolonged stimulation1 for       

affording which the behaviour of male   
courtship is the requisite presentation4
 ,the most vigorous1 defiant and        
mettlesome male is preferred just       
because he alone affords a contributory 
stimulation adequate to evoke the       
pairing impulse with its attendant      
emotional tone4  ,it is true that this  
places female preference or choice on a 
much lower psychological plane than     
,darwin in some passages seems to       
contemplate where1 for example1 he says 
that the female appreciates the display 
of the male and places to her credit a  
taste for the beautiful4 ,but ,darwin   
himself distinctly states 7,descent of  
,man 7#bnd edition71 ,vol4 ,,ii4 pages  
#acf1 #acg2 7,popular edition71 pages   
#fdb1 #fdc47 that it is not probable    
that she consciously deliberates2 but   
she is most excited or attracted by the 
most beautiful1 or melodious1 or gallant
 males4 ,the view here put forward1     
which has been developed by ,prof4      
,groos 7,the ,play of ,animals1 page    

#bdd1 ,london1 #ahih471 therefore seems 
to have ,darwin's own sanction4 ,the    
phenomena are not only biological2 there
 are psychological elements as well4    
,one can hardly suppose that the female 
is unconscious of the male's presence2  
the final yielding must surely be       
accompanied by heightened emotional     
tone4 ,whether we call it choice or not 
is merely a matter of definition of     
terms4 ,the behaviour is in part        
determined by supplementary             
psychological values4 ,prof4 ,groos     
regards the coyness of females as a most
 efficient means of preventing the too  
early and too frequent yielding to the  
sexual impulse4 7,ibid4 page #bhc47 ,be 
that as it may1 it is1 in any case1 if  
we grant the facts1 a means through     
which male sexual behaviour with all its
 biological and psychological           
implications1 is raised to a level      
otherwise perhaps unattainable by       
natural means1 while in the female it   
affords opportunities for the           

development in the individual and       
evolution in the race of what we may    
follow ,darwin in calling appreciation1 
if we empty this word of the aesthetic  
implications which have gathered round  
it in the mental life of man4  ,regarded
 from this standpoint sexual selection1 
broadly considered1 has probably been of
 great importance4 ,the psychological   
accompaniments of the pairing situation 
have profoundly influenced the course of
 biological evolution and are themselves
 the outcome of that evolution4  ,darwin
 makes only passing reference to those  
modes of behaviour in animals which go  
by the name of play4 ,nothing1 he says  
7,descent of ,man1 ,vol4 ,,ii4 page #fj2
 7,popular edition71 page #eff471 is    
more common than for animals to take    
pleasure in practising whatever instinct
 they follow at other times for some    
real good4 ,this is one of the very     
numerous cases in which a hint of the   
master has served to stimulate research 
in his disciples4 ,it was left to ,prof4

 ,groos to develop this subject on      
evolutionary lines and to elaborate in a
 masterly manner ,darwin's suggestion4  
,the utility of play1 he says 7,the     
,play of ,animals1 page #gf471 is       
incalculable4 ,this utility consists in 
the practice and exercise it affords for
 some of the more important duties of   
life1--that is to say1 for the          
performance of activities which will in 
adult life be essential to survival4 ,he
 urges 7,ibid4 page #ge47 that the play 
of young animals has its origin in the  
fact that certain very important        
instincts appear at a time when the     
animal does not seriously need them4 ,it
 is1 however1 questionable whether any  
instincts appear at a time when they are
 not needed4 ,and it is questionable    
whether the instinctive and emotional   
attitude of the play-fight1 to take one 
example1 can be identified with those   
which accompany fighting in earnest1    
though no doubt they are closely related
 and have some common factors4 ,it is   

probable that play1 as preparatory      
behaviour1 differs in biological detail 
7as it almost certainly does in         
emotional attributes7 from the earnest  
of after-life and that it has been      
evolved through differentiation and     
integration of the primary tissue of    
experience1 as a preparation through    
which certain essential modes of skill  
may be acquired--those animals in which 
the preparatory play-propensity was not 
inherited in due force and requisite    
amount being subsequently eliminated in 
the struggle for existence4 ,in any case
 there is little question that ,prof4   
,groos is right in basing the           
play-propensity on instinctive          
foundations4 7,the ,play of ,animals    
page #bd47 ,none the less1 as he        
contends1 the essential biological value
 of play is that it is a means of       
training the educable nerve-tissue1 of  
developing that part of the brain which 
is modified by experience and which thus
 acquires new characters1 of elaborating

 the secondary tissue of experience on  
the predetermined lines of instinctive  
differentiation and thus furthering the 
psychological activities which are      
included under the comprehensive term   
intelligent4  ,in ,the ,descent of ,man 
,darwin dealt at some length with       
intelligence and the higher mental      
faculties4 7,descent of ,man 7#ast      
edition71 ,chapters ,,ii1 ,,iii1 ,v2    
7#bnd edition71 ,chapters ,,iii1 ,,iv1  
,v47 ,his object1 he says1 is to show   
that there is no fundamental difference 
between man and the higher mammals in   
their mental faculties2 that these      
faculties are variable and the          
variations tend to be inherited2 and    
that under natural selection beneficial 
variations of all kinds will have been  
preserved and injurious ones eliminated4
  ,darwin was too good an observer and  
too honest a man to minimise the        
enormous difference between the level of
 mental attainment of civilised man and 
that reached by any animal4 ,his        

contention was that the difference1     
great as it is1 is one of degree and not
 of kind4 ,he realised that1 in the     
development of the mental faculties of  
man1 new factors in evolution have      
supervened--factors which play but a    
subordinate and subsidiary part in      
animal intelligence4 ,intercommunication
 by means of language1 approbation and  
blame1 and all that arises out of       
reflective thought1 are but foreshadowed
 in the mental life of animals4 ,still  
he contends that these may be explained 
on the doctrine of evolution4 ,he urges 
7,ibid4 ,vol4 ,i4 pages #gj1 #ga2       
7,popular edition71 pages #gj1 #ga47    
that man is variable in body and mind2  
and that the variations are induced1    
either directly or indirectly1 by the   
same general causes1 and obey the same  
general laws1 as with the lower animals4
 ,he correlates mental development with 
the evolution of the brain4 7,ibid4 page
 #ha47 ,as the various mental faculties 
gradually developed themselves1 the     

brain would almost certainly become     
larger4 ,no one1 ,i presume1 doubts that
 the large proportion which the size of 
man's brain bears to his body1 compared 
to the same proportion in the gorilla or
 orang1 is closely connected with his   
higher mental powers4 ,with respect to  
the lower animals1 he says 7,descent of 
,man 7,popular edition71 page #hb471    
,m4,e4 ,lartet 7,comptes ,rendus des    
,sciences1 ,june #a1 #ahfh471 by        
comparing the crania of tertiary and    
recent mammals belonging to the same    
groups1 has come to the remarkable      
conclusion that the brain is generally  
larger and the convolutions are more    
complex in the more recent form4  ,sir  
,e4 ,ray ,lankester has sought to       
express in the simplest terms the       
implications of the increase in size of 
the cerebrum4 ,in what1 he asks1 does   
the advantage of a larger cerebral mass 
consist8 ,man1 he replies is born with  
fewer ready-made tricks of the          
nerve-centres--these performances of an 

inherited nervous mechanism so often    
called by the ill-defined term          
'instincts'--than are the monkeys or any
 other animal4 ,correlated with the     
absence of inherited ready-made         
mechanism1 man has a greater capacity of
 developing in the course of his        
individual growth similar nervous       
mechanisms 7similar to but not identical
 with those of 'instinct'7 than any     
other animal444 ,the power of being     
educated--'educability' as we may term  
it--is what man possesses in excess as  
compared with the apes4 ,i think we are 
justified in forming the hypothesis that
 it is this 'educability' which is the  
correlative of the increased size of the
 cerebrum4 ,there has been natural      
selection of the more educable animals1 
for the character which we describe as  
'educability' can be transmitted1 it is 
a congenital character4 ,but the        
,,results of education can ,,not be     
transmitted4 ,in each generation they   
have to be acquired afresh1 and with    

increased 'educability' they are more   
readily acquired and a larger variety of
 them444 ,the fact is that there is no  
community between the mechanisms of     
instinct and the mechanisms of          
intelligence1 and that the latter are   
later in the history of the evolution of
 the brain than the former and can only 
develop in proportion as the former     
become feeble and defective4 7,nature1  
,vol4 ,,lxi4 pages #fbd1 #fbe 7#aijj747 
,in this statement we have a good       
example of the further development of   
views which ,darwin foreshadowed but did
 not thoroughly work out4 ,it states the
 biological case clearly and tersely4   
,plasticity of behaviour in special     
accommodation to special circumstances  
is of survival value2 it depends upon   
acquired characters2 it is correlated   
with increase in size and complexity of 
the cerebrum2 under natural selection   
therefore the larger and more complex   
cerebrum as the organ of plastic        
behaviour has been the outcome of       

natural selection4 ,we have thus the    
biological foundations for a further    
development of genetic psychology4      
,there are diversities of opinion1 as   
,darwin showed1 with regard to the range
 of instinct in man and the higher      
animals as contrasted with lower types4 
,darwin himself said 7,descent of ,man1 
,vol4 ,i4 page #ajj47 that ,man1        
perhaps1 has somewhat fewer instincts   
than those possessed by the animals     
which come next to him in the series4   
,on the other hand1 ,prof4 ,wm4 ,james  
says 7,principles of ,psychology1 ,vol4 
,,ii4 page #bhi47 that man is probably  
the animal with most instincts4 ,the    
true position is that man and the higher
 animals have fewer complete and        
self-sufficing instincts than those     
which stand lower in the scale of mental
 evolution1 but that they have an       
equally large or perhaps larger mass of 
instinctive raw material which may      
furnish the stuff to be elaborated by   
intelligent processes4 ,there is1       

perhaps1 a greater abundance of the     
primary tissue of experience to be      
refashioned and integrated by secondary 
modification2 there is probably the same
 differentiation in relation to the     
determining biological ends1 but there  
is at the outset less differentiation of
 the particular and specific modes of   
behaviour4 ,the specialised instinctive 
performances and their concomitant      
experience-complexes are at the outset  
more indefinite4 ,only through acquired 
connections1 correlated with experience1
 do they become definitely organised4   
,the full working-out of the delicate   
and subtle relationship of instinct and 
educability--that is1 of the hereditary 
and the acquired factors in the mental  
life--is the task which lies before     
genetic and comparative psychology4     
,they interact throughout the whole of  
life1 and their interactions are very   
complex4 ,no one can read the chapters  
of ,the ,descent of ,man which ,darwin  
devotes to a consideration of the mental

 characters of man and animals without  
noticing1 on the one hand1 how sedulous 
he is in his search for hereditary      
foundations1 and1 on the other hand1 how
 fully he realises the importance of    
acquired habits of mind4 ,the fact that 
educability itself has innate           
tendencies--is in fact a partially      
differentiated educability--renders the 
unravelling of the factors of mental    
progress all the more difficult4  ,in   
his comparison of the mental powers of  
men and animals it was essential that   
,darwin should lay stress on points of  
similarity rather than on points of     
difference4 ,seeking to establish a     
doctrine of evolution1 with its basal   
concept of continuity of process and    
community of character1 he was bound to 
render clear and to emphasise the       
contention that the difference in mind  
between man and the higher animals1     
great as it is1 is one of degree and not
 of kind4 ,to this end ,darwin not only 
recorded a large number of valuable     

observations of his own1 and collected a
 considerable body of information from  
reliable sources1 he presented the whole
 subject in a new light and showed that 
a natural history of mind might be      
written and that this method of study   
offered a wide and rich field for       
investigation4 ,of course those who     
regarded the study of mind only as a    
branch of metaphysics smiled at the     
philosophical ineptitude of the mere man
 of science4 ,but the investigation1 on 
natural history lines1 has been         
prosecuted with a large measure of      
success4 ,much indeed still remains to  
be done2 for special training is        
required1 and the workers are still few4
 ,promise for the future is however     
afforded by the fact that investigation 
is prosecuted on experimental lines and 
that something like organised methods of
 research are taking form4 ,there is now
 but little reliance on casual          
observations recorded by those who have 
not undergone the necessary discipline  

in these methods4 ,there is also some   
change of emphasis in formulating       
conclusions4 ,now that the general      
evolutionary thesis is fully and freely 
accepted by those who carry on such     
researches1 more stress is laid on the  
differentiation of the stages of        
evolutionary advance than on the fact of
 their underlying community of nature4  
,the conceptual intelligence which is   
especially characteristic of the higher 
mental procedure of man is more firmly  
distinguished from the perceptual       
intelligence which he shares with the   
lower animals--distinguished now as a   
higher product of evolution1 no longer  
as differing in origin or different in  
kind4 ,some progress has been made1 on  
the one hand in rendering an account of 
intelligent profiting by experience     
under the guidance of pleasure and pain 
in the perceptual field1 on lines       
predetermined by instinctive            
differentiation for biological ends1 and
 on the other hand in elucidating the   

method of conceptual thought employed1  
for example1 by the investigator himself
 in interpreting the perceptual         
experience of the lower animals4  ,thus 
there is a growing tendency to realise  
more fully that there are two orders of 
educability--first an educability of the
 perceptual intelligence based on the   
biological foundation of instinct1 and  
secondly an educability of the          
conceptual intelligence which refashions
 and rearranges the data afforded by    
previous inheritance and acquisition4   
,it is in relation to this second and   
higher order of educability that the    
cerebrum of man shows so large an       
increase of mass and a yet larger       
increase of effective surface through   
its rich convolutions4 ,it is through   
educability of this order that the human
 child is brought intellectually and    
affectively into touch with the ideal   
constructions by means of which man has 
endeavoured1 with more or less success1 
to reach an interpretation of nature1   

and to guide the course of the further  
evolution of his race--ideal            
constructions which form part of man's  
environment4  ,it formed no part of     
,darwin's purpose to consider1 save in  
broad outline1 the methods1 or to       
discuss in any fulness of detail the    
results of the process by which a       
differentiation of the mental faculties 
of man from those of the lower animals  
has been brought about--a               
differentiation the existence of which  
he again and again acknowledges4 ,his   
purpose was rather to show that1        
notwithstanding this differentiation1   
there is basal community in kind4 ,this 
must be remembered in considering his   
treatment of the biological foundations 
on which man's systems of ethics are    
built4 ,he definitely stated that he    
approached the subject exclusively from 
the side of natural history4 7,descent  
of ,man1 ,vol4 ,i4 page #adi47 ,his     
general conclusion is that the moral    
sense is fundamentally identical with   

the social instincts1 which have been   
developed for the good of the community2
 and he suggests that the concept which 
thus enables us to interpret the        
biological ground-plan of morals also   
enables us to frame a rational ideal of 
the moral end4 ,as the social instincts1
 he says 7,ibid4 page #ahe471 both of   
man and the lower animals have no doubt 
been developed by nearly the same steps1
 it would be advisable1 if found        
practicable1 to use the same definition 
in both cases1 and to take as the       
standard of morality1 the general good  
or welfare of the community1 rather than
 the general happiness4 ,but the kind of
 community for the good of which the    
social instincts of animals and         
primitive men were biologically         
developed may be different from that    
which is the product of civilisation1 as
 ,darwin no doubt realised4 ,darwin's   
contention was that conscience is a     
social instinct and has been evolved    
because it is useful to the tribe in the

 struggle for existence against other   
tribes4 ,on the other hand1 ,j4,s4 ,mill
 urged that the moral feelings are not  
innate but acquired1 and ,bain held the 
same view1 believing that the moral     
sense is acquired by each individual    
during his life-time4 ,darwin1 who notes
 7,ibid4 page #aej 7footnote747 their   
opinion with his usual candour1 adds    
that on the general theory of evolution 
this is at least extremely improbable4  
,it is impossible to enter into the     
question here3 much turns on the exact  
connotation of the terms conscience and 
moral sense1 and on the meaning we      
attach to the statement that the moral  
sense is fundamentally identical with   
the social instincts4  ,presumably the  
majority of those who approach the      
subjects discussed in the third1 fourth 
and fifth chapters of ,the ,descent of  
,man in the full conviction that mental 
phenomena1 not less than organic        
phenomena1 have a natural genesis1      
would1 without hesitation1 admit that   

the intellectual and moral systems of   
civilised man are ideal constructions1  
the products of conceptual thought1 and 
that as such they are1 in their         
developed form1 acquired4 ,the moral    
sentiments are the emotional analogues  
of highly developed concepts4 ,this does
 not however imply that they are outside
 the range of natural history treatment4
 ,even though it may be desirable to    
differentiate the moral conduct of men  
from the social behaviour of animals 7to
 which some such term as pre-moral or   
quasi-moral may be applied71 still the  
fact remains that1 as ,darwin showed1   
there is abundant evidence of the       
occurrence of such social               
behaviour--social behaviour which1 even 
granted that it is in large part        
intelligently acquired1 and is itself so
 far a product of educability1 is of    
survival value4 ,it makes for that      
integration without which no social     
group could hold together and escape    
elimination4 ,furthermore1 even if we   

grant that such behaviour is            
intelligently acquired1 that is to say  
arises through the modification of      
hereditary instincts and emotions1 the  
fact remains that only through these    
instinctive and emotional data is       
afforded the primary tissue of the      
experience which is susceptible of such 
modification4  ,darwin sought to show1  
and succeeded in showing1 that for the  
intellectual and moral life there are   
instinctive foundations which a         
biological treatment alone can disclose4
 ,it is true that he did not in all     
cases analytically distinguish the      
foundations from the superstructure4    
,even to-day we are scarcely in a       
position to do so adequately4 ,but his  
treatment was of great value in giving  
an impetus to further research4 ,this   
value indeed can scarcely be            
overestimated4 ,and when the natural    
history of the mental operations shall  
have been written1 the cardinal fact    
will stand forth1 that the instinctive  

and emotional foundations are the       
outcome of biological evolution and have
 been ingrained in the race through     
natural selection4 ,we shall more       
clearly realise that educability itself 
is a product of natural selection1      
though the specific results acquired    
through cerebral modifications are not  
transmitted through heredity4 ,it will1 
perhaps1 also be realised that the      
instinctive foundations of social       
behaviour are1 for us1 somewhat out of  
date and have undergone but little      
change throughout the progress of       
civilisation1 because natural selection 
has long since ceased to be the dominant
 factor in human progress4 ,the history 
of human progress has been mainly the   
history of man's higher educability1 the
 products of which he has projected on  
to his environment4 ,this educability   
remains on the average what it was a    
dozen generations ago2 but the          
thought-woven tapestry of his           
surroundings is refashioned and improved

 by each succeeding generation4 ,few men
 have in greater measure enriched the   
thought-environment with which it is the
 aim of education to bring educable     
human beings into vital contact1 than   
has ,charles ,darwin4 ,his special field
 of work was the wide province of       
biology2 but he did much to help us     
realise that mental factors have        
contributed to organic evolution and    
that in man1 the highest product of     
,evolution1 they have reached a position
 of unquestioned supremacy4     ,,xxii4 
,,the ,,influence ,,of ,,the            
,,conception ,,of ,,evolution ,,on      
,,modern ,,philosophy4 ,by ,h4          
,hoffding4  ,professor of ,philosophy in
 the ,university of ,copenhagen4   ,i4  
,it is difficult to draw a sharp line   
between philosophy and natural science4 
,the naturalist who introduces a new    
principle1 or demonstrates a fact which 
throws a new light on existence1 not    
only renders an important service to    
philosophy but is himself a philosopher 

in the broader sense of the word4 ,the  
aim of philosophy in the stricter sense 
is to attain points of view from which  
the fundamental phenomena and the       
principles of the special sciences can  
be seen in their relative importance and
 connection4 ,but philosophy in this    
stricter sense has always been          
influenced by philosophy in the broader 
sense4 ,greek philosophy came under the 
influence of logic and mathematics1     
modern philosophy under the influence of
 natural science4 ,the name of ,charles 
,darwin stands with those of ,galileo1  
,newton1 and ,robert ,mayer--names which
 denote new problems and great          
alterations in our conception of the    
universe4  ,first of all we must lay    
stress on ,darwin's own personality4    
,his deep love of truth1 his            
indefatigable inquiry1 his wide horizon1
 and his steady self-criticism make him 
a scientific model1 even if his results 
and theories should eventually come to  
possess mainly an historical interest4  

,in the intellectual domain the primary 
object is to reach high summits from    
which wide surveys are possible1 to     
reach them toiling honestly upwards by  
way of experience1 and then not to turn 
dizzy when a summit is gained4          
,darwinians have sometimes turned dizzy1
 but ,darwin never4 ,he saw from the    
first the great importance of his       
hypothesis1 not only because of its     
solution of the old problem as to the   
value of the concept of species1 not    
only because of the grand picture of    
natural evolution which it unrolls1 but 
also because of the life and inspiration
 its method would impart to the study of
 comparative anatomy1 of instinct and of
 heredity1 and finally because of the   
influence it would exert on the whole   
conception of existence4 ,he wrote in   
his note-book in the year #ahcg3 ,my    
theory would give zest to recent and    
fossil comparative anatomy2 it would    
lead to the study of instinct1 heredity1
 and mind-heredity1 whole 7of7          

metaphysics4 7,life and ,letters of     
,charles ,darwin1 ,vol4 ,i4 page #h47   
,we can distinguish four main points in 
which ,darwin's investigations possess  
philosophical importance4  ,the         
evolution hypothesis is much older than 
,darwin2 it is1 indeed1 one of the      
oldest guessings of human thought4 ,in  
the eighteenth century it was put       
forward by ,diderot and ,lamettrie and  
suggested by ,kant 7#aghf74 ,as we shall
 see later1 it was held also by several 
philosophers in the first half of the   
nineteenth century4 ,in his preface to  
,the ,origin of ,species1 ,darwin       
mentions the naturalists who were his   
forerunners4 ,but he has set forth the  
hypothesis of evolution in so energetic 
and thorough a manner that it perforce  
attracts the attention of all thoughtful
 men in a much higher degree than it did
 before the publication of the ,origin4 
,and further1 the importance of his     
teaching rests on the fact that he1 much
 more than his predecessors1 even than  

,lamarck1 sought a foundation for his   
hypothesis in definite facts4 ,modern   
science began by demanding--with ,kepler
 and ,newton--evidence of verae causae2 
this demand ,darwin industriously set   
himself to satisfy--hence the wealth of 
material which he collected by his      
observations and his experiments4 ,he   
not only revived an old hypothesis1 but 
he saw the necessity of verifying it by 
facts4 ,whether the special cause on    
which he founded the explanation of the 
origin of species--,natural             
,selection--is sufficient1 is now a     
subject of discussion4 ,he himself had  
some doubt in regard to this question1  
and the criticisms which are directed   
against his hypothesis hit ,darwinism   
rather than ,darwin4 ,in his            
indefatigable search for empirical      
evidence he is a model even for his     
antagonists3 he has compelled them to   
approach the problems of life along     
other lines than those which were       
formerly followed4  ,whether the special

 cause to which ,darwin appealed is     
sufficient or not1 at least to it is    
probably due the greater part of the    
influence which he has exerted on the   
general trend of thought4 ,struggle for 
existence and natural selection are     
principles which have been applied1 more
 or less1 in every department of        
thought4 ,recent research1 it is true1  
has discovered greater empirical        
discontinuity--leaps1 mutations--whereas
 ,darwin believed in the importance of  
small variations slowly accumulated4 ,it
 has also been shown by the experimental
 method1 which in recent biological work
 has succeeded ,darwin's more historical
 method1 that types once constituted    
possess great permanence1 the           
fluctuations being restricted within    
clearly defined boundaries4 ,the problem
 has become more precise1 both as to    
variation and as to heredity4 ,the inner
 conditions of life have in both        
respects shown a greater independence   
than ,darwin had supposed in his theory1

 though he always admitted that the     
cause of variation was to him a great   
enigma1 a most perplexing problem1 and  
that the struggle for life could only   
occur where variation existed4 ,but1 at 
any rate1 it was of the greatest        
importance that ,darwin gave a living   
impression of the struggle for life     
which is everywhere going on1 and to    
which even the highest forms of         
existence must be amenable4 ,the        
philosophical importance of these ideas 
does not stand or fall with the answer  
to the question1 whether natural        
selection is a sufficient explanation of
 the origin of species or not3 it has an
 independent1 positive value for        
everyone who will observe life and      
reality with an unbiassed mind4  ,in    
accentuating the struggle for life      
,darwin stands as a characteristically  
,english thinker3 he continues a train  
of ideas which ,hobbes and ,malthus had 
already begun4 ,moreover in his critical
 views as to the conception of species  

he had ,english forerunners2 in the     
middle ages ,occam and ,duns ,scotus1 in
 the eighteenth century ,berkeley and   
,hume4 ,in his moral philosophy1 as we  
shall see later1 he is an adherent of   
the school which is represented by      
,hutcheson1 ,hume and ,adam ,smith4     
,because he is no philosopher in the    
stricter sense of the term1 it is of    
great interest to see that his attitude 
of mind is that of the great thinkers of
 his nation4  ,in considering ,darwin's 
influence on philosophy we will begin   
with an examination of the attitude of  
philosophy to the conception of         
evolution at the time when ,the ,origin 
of ,species appeared4 ,we will then     
examine the effects which the theory of 
evolution1 and especially the idea of   
the struggle for life1 has had1 and     
naturally must have1 on the discussion  
of philosophical problems4  ,,ii4  ,when
 ,the ,origin of ,species appeared fifty
 years ago ,romantic speculation1       
,schelling's and ,hegel's philosophy1   

still reigned on the continent1 while in
 ,england ,positivism1 the philosophy of
 ,comte and ,stuart ,mill1 represented  
the most important trend of thought4    
,german speculation had much to say on  
evolution1 it even pretended to be a    
philosophy of evolution4 ,but then the  
word evolution was to be taken in an    
ideal1 not in a real1 sense4 ,to        
speculative thought the forms and types 
of nature formed a system of ideas1     
within which any form could lead us by  
continuous transitions to any other4 ,it
 was a classificatory system which was  
regarded as a divine world of thought or
 images1 within which metamorphoses     
could go on--a condition comparable with
 that in the mind of the poet when one  
image follows another with imperceptible
 changes4 ,goethe's ideas of evolution1 
as expressed in his ,metamorphosen der  
,pflanzen und der ,thiere1 belong to    
this category2 it is1 therefore1        
incorrect to call him a forerunner of   
,darwin4 ,schelling and ,hegel held the 

same idea2 ,hegel expressly rejected the
 conception of a real evolution in time 
as coarse and materialistic4 ,nature1 he
 says1 is to be considered as a ,,system
 ,,of ,,stages1 the one necessarily     
arising from the other1 and being the   
nearest truth of that from which it     
proceeds2 but not in such a way that the
 one is ,,naturally generated by the    
other2 on the contrary 7their connection
 lies7 in the inner idea which is the   
ground of nature4 ,the ,,metamorphosis  
can be ascribed only to the notion as   
such1 because it alone is evolution444  
,it has been a clumsy idea in the older 
as well as in the newer philosophy of   
nature1 to regard the transformation and
 the transition from one natural form   
and sphere to a higher as an outward and
 actual production4 7,encyclopaedie der 
philosophischen ,wissenschaften 7#dth   
edition71 ,berlin1 #ahde1 paragraph     
#bdi47  ,the only one of the            
philosophers of ,romanticism who        
believed in a real1 historical          

evolution1 a real production of new     
species1 was ,oken4 7,lehrbuch der      
,naturphilosophie1 ,jena1 #ahji47       
,danish philosophers1 such as ,treschow 
7#ahab7 and ,sibbern 7#ahdf71 have also 
broached the idea of an historical      
evolution of all living beings from the 
lowest to the highest4 ,schopenhauer's  
philosophy has a more realistic         
character than that of ,schelling's and 
,hegel's1 his diametrical opposites1    
though he also belongs to the romantic  
school of thought4 ,his philosophical   
and psychological views were greatly    
influenced by ,french naturalists and   
philosophers1 especially by ,cabanis and
 ,lamarck4 ,he praises the ever         
memorable ,lamarck1 because he laid so  
much stress on the will to live4 ,but he
 repudiates as a wonderful error the    
idea that the organs of animals should  
have reached their present perfection   
through a development in time1 during   
the course of innumerable generations4  
,it was1 he said1 a consequence of the  

low standard of contemporary ,french    
philosophy1 that ,lamarck came to the   
idea of the construction of living      
beings in time through succession6      
7,ueber den ,willen in der ,natur 7#bnd 
edition71 ,frankfurt a4 ,m41 #ahed1     
pages #da-dc47  ,the positivistic stream
 of thought was not more in favour of a 
real evolution than was the ,romantic   
school4 ,its aim was to adhere to       
positive facts3 it looked with suspicion
 on far-reaching speculation4 ,comte    
laid great stress on the discontinuity  
found between the different kingdoms of 
nature1 as well as within each single   
kingdom4 ,as he regarded as unscientific
 every attempt to reduce the number of  
physical forces1 so he rejected entirely
 the hypothesis of ,lamarck concerning  
the evolution of species2 the idea of   
species would in his eyes absolutely    
lose its importance if a transition from
 species to species under the influence 
of conditions of life were admitted4    
,his disciples 7,littre1 ,robin7        

continued to direct against ,darwin the 
polemics which their master had employed
 against ,lamarck4 ,stuart ,mill1 who1  
in the theory of knowledge1 represented 
the empirical or positivistic movement  
in philosophy--like his ,english        
forerunners from ,locke to              
,hume--founded his theory of knowledge  
and morals on the experience of the     
single individual4 ,he sympathised with 
the theory of the original likeness of  
all individuals and derived their       
differences1 on which he practically and
 theoretically laid much stress1 from   
the influence both of experience and    
education1 and1 generally1 of physical  
and social causes4 ,he admitted an      
individual evolution1 and1 in the human 
species1 an evolution based on social   
progress2 but no physiological evolution
 of species4 ,he was afraid that the    
hypothesis of heredity would carry us   
back to the old theory of innate ideas4 
,darwin was more empirical than ,comte  
and ,mill2 experience disclosed to him a

 deeper continuity than they could find2
 closer than before the nature and fate 
of the single individual were shown to  
be interwoven in the great web binding  
the life of the species with nature as a
 whole4 ,and the continuity which so    
many idealistic philosophers could find 
only in the world of thought1 he showed 
to be present in the world of reality4  
,,iii4  ,darwin's energetic renewal of  
the old idea of evolution had its chief 
importance in strengthening the         
conviction of this real continuity in   
the world1 of continuity in the series  
of form and events4 ,it was a great     
support for all those who were prepared 
to base their conception of life on     
scientific grounds4 ,together with the  
recently discovered law of the          
conservation of energy1 it helped to    
produce the great realistic movement    
which characterises the last third of   
the nineteenth century4 ,after the      
decline of the ,romantic movement people
 wished to have firmer ground under     

their feet and reality now asserted     
itself in a more emphatic manner than in
 the period of ,romanticism4 ,it was    
easy for ,hegel to proclaim that the    
real was the rational1 and that the     
rational was the real3 reality itself   
existed for him only in the             
interpretation of ideal reason1 and if  
there was anything which could not be   
merged in the higher unity of thought1  
then it was only an example of the      
impotence of nature to hold to the idea4
 ,but now concepts are to be founded on 
nature and not on any system of         
categories too confidently deduced a    
priori4 ,the new devotion to nature had 
its recompense in itself1 because the   
new points of view made us see that     
nature could indeed hold to ideas1      
though perhaps not to those which we had
 cogitated beforehand4  ,a most         
important question for philosophers to  
answer was whether the new views were   
compatible with an idealistic conception
 of life and existence4 ,some proclaimed

 that we have now no need of any        
philosophy beyond the principles of the 
conservation of matter and energy and   
the principle of natural evolution3     
existence should and could be definitely
 and completely explained by the laws of
 material nature4 ,but abler thinkers   
saw that the thing was not so simple4   
,they were prepared to give the new     
views their just place and to examine   
what alterations the old views must     
undergo in order to be brought into     
harmony with the new data4  ,the        
realistic character of ,darwin's theory 
was shown not only in the idea of       
natural continuity1 but also1 and not   
least1 in the idea of the cause whereby 
organic life advances step by step4     
,this idea--the idea of the struggle for
 life--implied that nothing could       
persist1 if it had no power to maintain 
itself under the given conditions4      
,inner value alone does not decide4     
,idealism was here put to its hardest   
trial4 ,in continuous evolution it could

 perhaps still find an analogy to the   
inner evolution of ideas in the mind2   
but in the demand for power in order to 
struggle with outward conditions        
,realism seemed to announce itself in   
its most brutal form4 ,every form of    
,idealism had to ask itself seriously   
how it was going to struggle for life   
with this new ,realism4  ,we will now   
give a short account of the position    
which leading thinkers in different     
countries have taken up in regard to    
this question4  ,i4 ,herbert ,spencer   
was the philosopher whose mind was best 
prepared by his own previous thinking to
 admit the theory of ,darwin to a place 
in his conception of the world4 ,his    
criticism of the arguments which had    
been put forward against the hypothesis 
of ,lamarck1 showed that ,spencer1 as a 
young man1 was an adherent to the       
evolution idea4 ,in his ,social ,statics
 7#ahej7 he applied this idea to human  
life and moral civilisation4 ,in #aheb  
he wrote an essay on ,the ,development  

,hypothesis1 in which he definitely     
stated his belief that the              
differentiation of species1 like the    
differentiation within a single         
organism1 was the result of development4
 ,in the first edition of his           
,psychology 7#ahee7 he took a step which
 put him in opposition to the older     
,english school 7from ,locke to ,mill73 
he acknowledged innate ideas so far as  
to admit the tendency of acquired habits
 to be inherited in the course of       
generations1 so that the nature and     
functions of the individual are only to 
be understood through its connection    
with the life of the species4 ,in #aheg1
 in his essay on ,progress1 he          
propounded the law of differentiation as
 a general law of evolution1 verified by
 examples from all regions of           
experience1 the evolution of species    
being only one of these examples4 ,on   
the effect which the appearance of ,the 
,origin of ,species had on his mind he  
writes in his ,autobiography3 ,up to    

that time444 ,i held that the sole cause
 of organic evolution is the inheritance
 of functionally-produced modifications4
 ,the ,origin of ,species made it clear 
to me that ,i was wrong1 and that the   
larger part of the facts cannot be due  
to any such cause444 ,to have the theory
 of organic evolution justified was of  
course to get further support for that  
theory of evolution at large with       
which444 all my conceptions were bound  
up4 7,spencer1 ,autobiography1 ,vol4    
,,ii4 page #ej1 ,london1 #aijd47        
,instead of the metaphorical expression 
natural selection1 ,spencer introduced  
the term survival of the fittest1 which 
found favour with ,darwin as well as    
with ,wallace4  ,in working out his     
ideas of evolution1 ,spencer found that 
differentiation was not the only form of
 evolution4 ,in its simplest form       
evolution is mainly a concentration1    
previously scattered elements being     
integrated and losing independent       
movement4 ,differentiation is only      

forthcoming when minor wholes arise     
within a greater whole4 ,and the highest
 form of evolution is reached when there
 is a harmony between concentration and 
differentiation1 a harmony which        
,spencer calls equilibration and which  
he defines as a moving equilibrium4 ,at 
the same time this definition enables   
him to illustrate the expression        
survival of the fittest4 ,every living  
organism exhibits such a moving         
equilibrium--a balanced set of functions
 constituting its life2 and the         
overthrow of this balanced set of       
functions or moving equilibrium is what 
we call death4 ,some individuals in a   
species are so constituted that their   
moving equilibria are less easily       
overthrown than those of other          
individuals2 and these are the fittest  
which survive1 or1 in ,mr ,darwin's     
language1 they are the select which     
nature preserves4 7,ibid4 page #ajj47   
,not only in the domain of organic life1
 but in all domains1 the summit of      

evolution is1 according to ,spencer1    
characterised by such a harmony--by a   
moving equilibrium4  ,spencer's analysis
 of the concept of evolution1 based on a
 great variety of examples1 has made    
this concept clearer and more definite  
than before4 ,it contains the three     
elements2 integration1 differentiation  
and equilibration4 ,it is true that a   
concept which is to be valid for all    
domains of experience must have an      
abstract character1 and between the     
several domains there is1 strictly      
speaking1 only a relation of analogy4   
,so there is only analogy between       
psychical and physical evolution4 ,but  
this is no serious objection1 because   
general concepts do not express more    
than analogies between the phenomena    
which they represent4 ,spencer takes his
 leading terms from the material world  
in defining evolution 7in the simplest  
form7 as integration of matter and      
dissipation of movement2 but as he--not 
always quite consistently 7,cf4 my      

letter to him1 #ahgf1 now printed in    
,duncan's ,life and ,letters of ,herbert
 ,spencer1 page #agh1 ,london1          
#aijh47--;assumed a correspondence of   
mind and matter1 he could very well give
 these terms an indirect importance for 
psychical evolution4 ,spencer has       
always1 in my opinion with full right1  
repudiated the ascription of            
materialism4 ,he is no more a           
materialist than ,spinoza4 ,in his      
,principles of ,psychology 7paragraph   
#fc7 he expressed himself very clearly3 
,though it seems easier to translate    
so-called matter into so-called spirit1 
than to translate so-called spirit into 
so-called matter--which latter is indeed
 wholly impossible--yet no translation  
can carry us beyond our symbols4 ,these 
words lead us naturally to a group of   
thinkers whose starting-point was       
psychical evolution4 ,but we have still 
one aspect of ,spencer's philosophy to  
mention4  ,spencer founded his laws of  
evolution on an inductive basis1 but he 

was convinced that they could be deduced
 from the law of the conservation of    
energy4 ,such a deduction is1 perhaps1  
possible for the more elementary forms  
of evolution1 integration and           
differentiation2 but it is not possible 
for the highest form1 the equilibration1
 which is a harmony of integration and  
differentiation4 ,spencer can no more   
deduce the necessity for the eventual   
appearance of moving equilibria of      
harmonious totalities than ,hegel could 
guarantee the higher unities in which   
all contradictions should be reconciled4
 ,in ,spencer's hands the theory of     
evolution acquired a more decidedly     
optimistic character than in ,darwin's2 
but ,i shall deal later with the        
relation of ,darwin's hypothesis to the 
opposition of optimism and pessimism4   
,,ii4 ,while the starting-point of      
,spencer was biological or cosmological1
 psychical evolution being conceived as 
in analogy with physical1 a group of    
eminent thinkers--in ,germany ,wundt1 in

 ,france ,fouillee1 in ,italy           
,ardigo--took1 each in his own manner1  
their starting-point in psychical       
evolution as an original fact and as a  
type of all evolution1 the hypothesis of
 ,darwin coming in as a corroboration   
and as a special example4 ,they maintain
 the continuity of evolution2 they find 
this character most prominent in        
psychical evolution1 and this is for    
them a motive to demand a corresponding 
continuity in the material1 especially  
in the organic domain4  ,to ,wundt and  
,fouillee the concept of will is        
prominent4 ,they see the type of all    
evolution in the transformation of the  
life of will from blind impulse to      
conscious choice2 the theories of       
,lamarck and ,darwin are used to support
 the view that there is in nature a     
tendency to evolution in steady         
reciprocity with external conditions4   
,the struggle for life is here only a   
secondary fact4 ,its apparent prominence
 is explained by the circumstance that  

the influence of external conditions is 
easily made out1 while inner conditions 
can be verified only through their      
effects4 ,for ,ardigo the evolution of  
thought was the starting-point and the  
type3 in the evolution of a scientific  
hypothesis we see a progress from the   
indefinite 7indistinto7 to the definite 
7distinto71 and this is a characteristic
 of all evolution1 as ,ardigo has       
pointed out in a series of works4 ,the  
opposition between indistinto and       
distinto corresponds to ,spencer's      
opposition between homogeneity and      
heterogeneity4 ,the hypothesis of the   
origin of differences of species from   
more simple forms is a special example  
of the general law of evolution4  ,in   
the views of ,wundt and ,fouillee we    
find the fundamental idea of idealism3  
psychical phenomena as expressions of   
the innermost nature of existence4 ,they
 differ from the older ,idealism in the 
great stress which they lay on evolution
 as a real1 historical process which is 

going on through steady conflict with   
external conditions4 ,the ,romantic     
dread of reality is broken4 ,it is      
beyond doubt that ,darwin's emphasis on 
the struggle for life as a necessary    
condition of evolution has been a very  
important factor in carrying philosophy 
back to reality from the heaven of pure 
ideas4 ,the philosophy of ,ardigo1 on   
the other side1 appears more as a       
continuation and deepening of           
positivism1 though the ,italian thinker 
arrived at his point of view            
independently of ,french-,english       
positivism4 ,the idea of continuous     
evolution is here maintained in         
opposition to ,comte's and ,mill's      
philosophy of discontinuity4 ,from      
,wundt and ,fouillee ,ardigo differs in 
conceiving psychical evolution not as an
 immediate revelation of the innermost  
nature of existence1 but only as a      
single1 though the most accessible      
example1 of evolution4  ,,iii4 ,to the  
,french philosophers ,boutroux and      

,bergson1 evolution proper is continuous
 and qualitative1 while outer experience
 and physical science give us fragments 
only1 sporadic processes and mechanical 
combinations4 ,to ,bergson1 in his      
recent work ,l',evolution ,creatrice1   
evolution consists in an elan de vie    
which to our fragmentary observation and
 analytic reflexion appears as broken   
into a manifold of elements and         
processes4 ,the concept of matter in its
 scientific form is the result of this  
breaking asunder1 essential for all     
scientific reflexion4 ,in these         
conceptions the strongest opposition    
between inner and outer conditions of   
evolution is expressed3 in the domain of
 internal conditions spontaneous        
development of qualitative forms--in the
 domain of external conditions          
discontinuity and mechanical            
combination4  ,we see1 then1 that the   
theory of evolution has influenced      
philosophy in a variety of forms4 ,it   
has made idealistic thinkers revise     

their relation to the real world2 it has
 led positivistic thinkers to find a    
closer connection between the facts on  
which they based their views2 it has    
made us all open our eyes for new       
possibilities to arise through the prima
 facie inexplicable spontaneous         
variations which are the condition of   
all evolution4 ,this last point is one  
of peculiar interest4 ,deeper than      
speculative philosophy and mechanical   
science saw in the days of their        
triumph1 we catch sight of new streams1 
whose sources and laws we have still to 
discover4 ,most sharply does this appear
 in the theory of mutation1 which is    
only a stronger accentuation of a main  
point in ,darwinism4 ,it is interesting 
to see that an analogous problem comes  
into the foreground in physics through  
the discovery of radioactive phenomena1 
and in psychology through the assumption
 of psychical new formations 7as held by
 ,boutroux1 ,william ,james and         
,bergson74 ,from this side1 ,darwin's   

ideas1 as well as the analogous ideas in
 other domains1 incite us to renewed    
examination of our first principles1    
their rationality and their value4 ,on  
the other hand1 his theory of the       
struggle for existence challenges us to 
examine the conditions and discuss the  
outlook as to the persistence of human  
life and society and of the values that 
belong to them4 ,it is not enough to    
hope 7or fear87 the rising of new forms2
 we have also to investigate the        
possibility of upholding the forms and  
ideals which have hitherto been the     
bases of human life4 ,darwin has here   
given his age the most earnest and most 
impressive lesson4 ,this side of        
,darwin's theory is of peculiar interest
 to some special philosophical problems 
to which ,i now pass4  ,,iv4  ,among    
philosophical problems the problem of   
knowledge has in the last century       
occupied a foremost place4 ,it is       
natural1 then1 to ask how ,darwin and   
the hypothesis whose most eminent       

representative he is1 stand to this     
problem4  ,darwin started an hypothesis4
 ,but every hypothesis is won by        
inference from certain presuppositions1 
and every inference is based on the     
general principles of human thought4    
,the evolution hypothesis presupposes1  
then1 human thought and its principles4 
,and not only the abstract logical      
principles are thus presupposed4 ,the   
evolution hypothesis purports to be not 
only a formal arrangement of phenomena1 
but to express also the law of a real   
process4 ,it supposes1 then1 that the   
real data--all that in our knowledge    
which we do not produce ourselves1 but  
which we in the main simply receive--are
 subjected to laws which are at least   
analogous to the logical relations of   
our thoughts2 in other words1 it assumes
 the validity of the principle of       
causality4 ,if organic species could    
arise without cause there would be no   
use in framing hypotheses4 ,only if we  
assume the principle of causality1 is   

there a problem to solve4  ,though      
,darwinism has had a great influence on 
philosophy considered as a striving     
after a scientific view of the world1   
yet here is a point of view--the        
epistemological--where philosophy is not
 only independent but reaches beyond any
 result of natural science4 ,perhaps it 
will be said3 the powers and functions  
of organic beings only persist 7perhaps 
also only arise7 when they correspond   
sufficiently to the conditions under    
which the struggle of life is to go on4 
,human thought itself is1 then1 a       
variation 7or a mutation7 which has been
 able to persist and to survive4 ,is    
not1 then1 the problem of knowledge     
solved by the evolution hypothesis8     
,spencer had given an affirmative answer
 to this question before the appearance 
of ,the ,origin of ,species4 ,for the   
individual1 he said1 there is an a      
priori1 original1 basis 7or ,anlage7 for
 all mental life2 but in the species all
 powers have developed in reciprocity   

with external conditions4 ,knowledge is 
here considered from the practical point
 of view1 as a weapon in the struggle   
for life1 as an organon which has been  
continuously in use for generations4 ,in
 recent years the economic or pragmatic 
epistemology1 as developed by ,avenarius
 and ,mach in ,germany1 and by ,james in
 ,america1 points in the same direction4
 ,science1 it is said1 only maintains   
those principles and presuppositions    
which are necessary to the simplest and 
clearest orientation in the world of    
experience4 ,all assumptions which      
cannot be applied to experience and to  
practical work1 will successively be    
eliminated4  ,in these views a striking 
and important application is made of the
 idea of struggle for life to the       
development of human thought4 ,thought  
must1 as all other things in the world1 
struggle for life4 ,but this whole      
consideration belongs to psychology1 not
 to the theory of knowledge             
7epistemology71 which is concerned only 

with the validity of knowledge1 not with
 its historical origin4 ,every          
hypothesis to explain the origin of     
knowledge must submit to                
cross-examination by the theory of      
knowledge1 because it works with the    
fundamental forms and principles of     
human thought4 ,we cannot go further    
back than these forms and principles1   
which it is the aim of epistemology to  
ascertain and for which no further      
reason can be given4 7,the present      
writer1 many years ago1 in his          
,psychology 7,copenhagen1 #ahhb2        
,english translation ,london1 #ahia71   
criticised the evolutionistic treatment 
of the problem of knowledge from the    
,kantian point of view47  ,but there is 
another side of the problem which is1   
perhaps1 of more importance and which   
epistemology generally overlooks4 ,if   
new variations can arise1 not only in   
organic but perhaps also in inorganic   
nature1 new tasks are placed before the 
human mind4 ,the question is1 then1 if  

it has forms in which there is room for 
the new matter8 ,we are here touching a 
possibility which the great master of   
epistemology did not bring to light4    
,kant supposed confidently that no other
 matter of knowledge could stream forth 
from the dark source which he called the
 thing-in-itself1 than such as could be 
synthesised in our existing forms of    
knowledge4 ,he mentions the possibility 
of other forms than the human1 and warns
 us against the dogmatic assumption that
 the human conception of existence      
should be absolutely adequate4 ,but he  
seems to be quite sure that the         
thing-in-itself works constantly1 and   
consequently always gives us only what  
our powers can master4 ,this assumption 
was a consequence of ,kant's            
rationalistic tendency1 but one for     
which no warrant can be given4          
,evolutionism and systematism are       
opposing tendencies which can never be  
absolutely harmonised one with the      
other4 ,evolution may at any time break 

some form which the system-monger       
regards as finally established4 ,darwin 
himself felt a great difference in      
looking at variation as an evolutionist 
and as a systematist4 ,when he was      
working at his evolution theory1 he was 
very glad to find variations2 but they  
were a hindrance to him when he worked  
as a systematist1 in preparing his work 
on ,cirripedia4 ,he says in a letter3 ,i
 had thought the same parts of the same 
species more resemble 7than they do     
anyhow in ,cirripedia7 objects cast in  
the same mould4 ,systematic work would  
be easy were it not for this confounded 
variation1 which1 however1 is pleasant  
to me as a speculatist1 though odious to
 me as a systematist4 7,life and        
,letters1 ,vol4 ,,ii4 page #cg47 ,he    
could indeed be angry with variations   
even as an evolutionist2 but then only  
because he could not explain them1 not  
because he could not classify them4 ,if1
 as ,i must think1 external conditions  
produce little ,,direct effect1 what the

 devil determines each particular       
variation8 7,ibid4 page #bcb47 ,what    
,darwin experienced in his particular   
domain holds good of all knowledge4 ,all
 knowledge is systematic1 in so far as  
it strives to put phenomena in quite    
definite relations1 one to another4 ,but
 the systematisation can never be       
complete4 ,and here ,darwin has         
contributed much to widen the world for 
us4 ,he has shown us forces and         
tendencies in nature which make absolute
 systems impossible1 at the same time   
that they give us new objects and       
problems4 ,there is still a place for   
what ,lessing called the unceasing      
striving after truth1 while absolute    
truth 7in the sense of a closed system7 
is unattainable so long as life and     
experience are going on4  ,there is here
 a special remark to be made4 ,as we    
have seen above1 recent research has    
shown that natural selection or struggle
 for life is no explanation of          
variations4 ,hugo de ,vries             

distinguishes between partial and       
embryonal variations1 or between        
variations and mutations1 only the      
last-named being heritable1 and         
therefore of importance for the origin  
of new species4 ,but the existence of   
variations is not only of interest for  
the problem of the origin of species2 it
 has also a more general interest4 ,an  
individual does not lose its importance 
for knowledge1 because its qualities are
 not heritable4 ,on the contrary1 in    
higher beings at least1 individual      
peculiarities will become more and more 
independent objects of interest4        
,knowledge takes account of the         
biographies not only of species1 but    
also of individuals3 it seeks to find   
the law of development of the single    
individual4 7,the new science of        
,ecology occupies an intermediate       
position between the biography of       
species and the biography of            
individuals4 ,compare ,congress of ,arts
 and ,science1 ,st ,louis1 ,vol4 ,v4    

#aijf 7the ,reports of ,drude and       
,robinson7 and the work of my colleague 
,e4 ,warming47 ,as ,leibniz said long   
ago1 individuality consists in the law  
of the changes of a being4 ,la loi du   
changement fait l'individualite de      
chaque substance4 ,here is a world which
 is almost new for science1 which till  
now has mainly occupied itself with     
general laws and forms4 ,but these are  
ultimately only means to understand the 
individual phenomena1 in whose nature   
and history a manifold of laws and forms
 always cooperate4 ,the importance of   
this remark will appear in the sequel4  
,v4  ,to many people the ,darwinian     
theory of natural selection or struggle 
for existence seemed to change the whole
 conception of life1 and particularly   
all the conditions on which the validity
 of ethical ideas depends4 ,if only that
 has persistence which can be adapted to
 a given condition1 what will then be   
the fate of our ideals1 of our standards
 of good and evil8 ,blind force seems to

 reign1 and the only thing that counts  
seems to be the most heedless use of    
power4 ,darwinism1 it was said1 has     
proclaimed brutality4 ,no other         
difference seems permanent save that    
between the sound1 powerful and happy on
 the one side1 the sick1 feeble and     
unhappy on the other2 and every attempt 
to alleviate this difference seems to   
lead to general enervation4 ,some of    
those who interpreted ,darwinism in this
 manner felt an aesthetic delight in    
contemplating the heedlessness and      
energy of the great struggle for        
existence and anticipated the           
realisation of a higher human type as   
the outcome of it3 so ,nietzsche and his
 followers4 ,others recognising the same
 consequences in ,darwinism regarded    
these as one of the strongest objections
 against it2 so ,duhring and ,kropotkin 
7in his earlier works74  ,this          
interpretation of ,darwinism was        
frequent in the interval between the two
 main works of ,darwin--,the ,origin of 

,species and ,the ,descent of ,man4 ,but
 even during this interval it was       
evident to an attentive reader that     
,darwin himself did not found his       
standard of good and evil on the        
features of the life of nature he had   
emphasised so strongly4 ,he did not     
justify the ways along which nature     
reached its ends2 he only pointed them  
out4 ,the real was not to him1 as to    
,hegel1 one with the rational4 ,darwin  
has1 indeed1 by his whole conception of 
nature1 rendered a great service to     
ethics in making the difference between 
the life of nature and the ethical life 
appear in so strong a light4 ,the       
ethical problem could now be stated in a
 sharper form than before4 ,but this was
 not the first time that the idea of the
 struggle for life was put in relation  
to the ethical problem4 ,in the         
seventeenth century ,thomas ,hobbes gave
 the first impulse to the whole modern  
discussion of ethical principles in his 
theory of bellum omnium contra omnes4   

,men1 he taught1 are in the state of    
nature enemies one of another1 and they 
live either in fright or in the glory of
 power4 ,but it was not the opinion of  
,hobbes that this made ethics           
impossible4 ,on the contrary1 he found a
 standard for virtue and vice in the    
fact that some qualities and actions    
have a tendency to bring us out of the  
state of war and to secure peace1 while 
other qualities have a contrary         
tendency4 ,in the eighteenth century    
even ,immanuel ,kant's ideal ethics     
had--so far as can be seen--a similar   
origin4 ,shortly before the foundation  
of his definitive ethics1 ,kant wrote   
his ,idee zu einer allgemeinen          
,weltgeschichte 7#aghd71 where--in a way
 which reminds us of ,hobbes1 and is    
prophetic of ,darwin--he describes the  
forward-driving power of struggle in the
 human world4 ,it is here as with the   
struggle of the trees for light and air1
 through which they compete with one    
another in height4 ,anxiety about war   

can only be allayed by an ordinance     
which gives everyone his full liberty   
under acknowledgment of the equal       
liberty of others4 ,and such ordinance  
and acknowledgment are also attributes  
of the content of the moral law1 as     
,kant proclaimed it in the year after   
the publication of his essay 7#aghe7    
7,cf4 my ,history of ,modern ,philosophy
 7,english translation ,london1 #aijj71 
,i4 pages #gf-gi47 ,kant really came to 
his ethics by the way of evolution1     
though he afterwards disavowed it4      
,similarly the same line of thought may 
be traced in ,hegel though it has been  
disguised in the form of speculative    
dialectics4 7,herrschaft und            
,knechtschaft1 ,phanomenologie des      
,geistes1 ,,iv4 ,a41 ,leiden1 #aijg47   
,and in ,schopenhauer's theory of the   
blind will to live and its abrogation by
 the ethical feeling1 which is founded  
on universal sympathy1 we have a more   
individualistic form of the same idea4  
,it was1 then1 not entirely a foreign   

point of view which ,darwin introduced  
into ethical thought1 even if we take no
 account of the poetical character of   
the word struggle and of the more direct
 adaptation1 through the use and non-use
 of power1 which ,darwin also           
emphasised4 ,in ,the ,descent of ,man he
 has devoted a special chapter 7,the    
,descent of ,man1 ,vol4 ,i4 ,ch4 iii47  
to a discussion of the origin of the    
ethical consciousness4 ,the             
characteristic expression of this       
consciousness he found1 just as ,kant   
did1 in the idea of ought2 it was the   
origin of this new idea which should be 
explained4 ,his hypothesis was that the 
ethical ought has its origin in the     
social and parental instincts1 which1 as
 well as other instincts 7e4g4 the      
instinct of self-preservation71 lie     
deeper than pleasure and pain4 ,in many 
species1 not least in the human species1
 these instincts are fostered by natural
 selection2 and when the powers of      
memory and comparison are developed1 so 

that single acts can be valued according
 to the claims of the deep social       
instinct1 then consciousness of duty and
 remorse are possible4 ,blind instinct  
has developed to conscious ethical will4
  ,as already stated1 ,darwin1 as a     
moral philosopher belongs to the school 
that was founded by ,shaftesbury1 and   
was afterwards represented by           
,hutcheson1 ,hume1 ,adam ,smith1 ,comte 
and ,spencer4 ,his merit is1 first1 that
 he has given this tendency of thought a
 biological foundation1 and that he has 
stamped on it a doughty character in    
showing that ethical ideas and          
sentiments1 rightly conceived1 are      
forces which are at work in the struggle
 for life4  ,there are still many       
questions to solve4 ,not only does the  
ethical development within the human    
species contain features still          
unexplained 7,the works of ,westermarck 
and ,hobhouse throw new light on many of
 these features472 but we are confronted
 by the great problem whether after all 

a genetic historical theory can be of   
decisive importance here4 ,to every     
consequent ethical consciousness there  
is a standard of value1 a primordial    
value which determines the single       
ethical judgments as their last         
presupposition1 and the rightness of    
this basis1 the value of this value can 
as little be discussed as the           
rationality of our logical principles4  
,there is here revealed a possibility of
 ethical scepticism which evolutionistic
 ethics 7as well as intuitive or        
rationalistic ethics7 has overlooked4   
,no demonstration can show that the     
results of the ethical development are  
definitive and universal4 ,we meet here 
again with the important opposition of  
systematisation and evolution4 ,there   
will1 ,i think1 always be an open       
question here1 though comparative       
ethics1 of which we have so far only the
 first attempts1 can do much to throw   
light on it4  ,it would carry us too far
 to discuss all the philosophical works 

on ethics1 which have been influenced   
directly or indirectly by evolutionism4 
,i may1 however1 here refer to the book 
of ,c4,m4 ,williams1 ,a ,review of the  
,systems of ,ethics founded on the      
,theory of ,evolution 7,new ,york and   
,london1 #ahic471 in which1 besides     
,darwin1 the following authors are      
reviewed3 ,wallace1 ,haeckel1 ,spencer1 
,fiske1 ,rolph1 ,barratt1 ,stephen1     
,carneri1 ,hoffding1 ,gizycki1          
,alexander1 ,ree4 ,as works which       
criticise evolutionistic ethics from an 
intuitive point of view and in an       
instructive way1 may be cited3 ,guyau   
,la morale anglaise contemporaine       
7,paris1 #ahgi471 and ,sorley1 ,ethics  
of ,naturalism4 ,i will only mention    
some interesting contributions to       
ethical discussion which can be found in
 ,darwinism besides the idea of struggle
 for life4  ,the attention which ,darwin
 has directed to variations has opened  
our eyes to the differences in human    
nature as well as in nature generally4  

,there is here a fact of great          
importance for ethical thought1 no      
matter from what ultimate premiss it    
starts4 ,only from a very abstract point
 of view can different individuals be   
treated in the same manner4 ,the most   
eminent ethical thinkers1 men such as   
,jeremy ,bentham and ,immanuel ,kant1   
who discussed ethical questions from    
very opposite standpoints1 agreed in    
regarding all men as equal in respect of
 ethical endowment4 ,in regard to       
,bentham1 ,leslie ,stephen remarks3 ,he 
is determined to be thoroughly          
empirical1 to take men as he found them4
 ,but his utilitarianism supposed that  
men's views of happiness and utility    
were uniform and clear1 and that all    
that was wanted was to show them the    
means by which their ends could be      
reached4 7,english literature and       
society in the eighteenth century1      
,london1 #aijd1 page #ahg47 ,and ,kant  
supposed that every man would find the  
categorical imperative in his           

consciousness1 when he came to sober    
reflexion1 and that all would have the  
same qualifications to follow it4 ,but  
if continual variations1 great or small1
 are going on in human nature1 it is the
 duty of ethics to make allowance for   
them1 both in making claims1 and in     
valuing what is done4 ,a new set of     
ethical problems have their origin here4
 7,cf4 my paper1 ,the law of relativity 
in ,ethics1 ,international ,journal of  
,ethics1 ,vol4 ,i4 #ahia1 pages #cg-fb47
 ,it is an interesting fact that ,stuart
 ,mill's book ,on ,liberty appeared in  
the same year as ,the ,origin of        
,species4 ,though ,mill agreed with     
,bentham about the original equality of 
all men's endowments1 he regarded       
individual differences as a necessary   
result of physical and social           
influences1 and he claimed that free    
play shall be allowed to differences of 
character so far as is possible without 
injury to other men4 ,it is a condition 
of individual and social progress that a

 man's mode of action should be         
determined by his own character and not 
by tradition and custom1 nor by abstract
 rules4 ,this view was to be            
corroborated by the theory of ,darwin4  
,but here we have reached a point of    
view from which the criticism1 which in 
recent years has often been directed    
against ,darwin--that small variations  
are of no importance in the struggle for
 life--is of no weight4 ,from an ethical
 standpoint1 and particularly from the  
ethical standpoint of ,darwin himself1  
it is a duty to foster individual       
differences that can be valuable1 even  
though they can neither be of service   
for physical preservation nor be        
physically inherited4 ,the distinction  
between variation and mutation is here  
without importance4 ,it is quite natural
 that biologists should be particularly 
interested in such variations as can be 
inherited and produce new species4 ,but 
in the human world there is not only a  
physical1 but also a mental and social  

heredity4 ,when an ideal human character
 has taken form1 then there is shaped a 
type1 which through imitation and       
influence can become an important factor
 in subsequent development1 even if it  
cannot form a species in the biological 
sense of the word4 ,spiritually strong  
men often succumb in the physical       
struggle for life2 but they can         
nevertheless be victorious through the  
typical influence they exert1 perhaps on
 very distant generations1 if the       
remembrance of them is kept alive1 be it
 in legendary or in historical form4    
,their very failure can show that a type
 has taken form which is maintained at  
all risks1 a standard of life which is  
adhered to in spite of the strongest    
opposition4 ,the question to be or not  
to be can be put from very different    
levels of being3 it has too often been  
considered a consequence of ,darwinism  
that this question is only to be put    
from the lowest level4 ,when a stage is 
reached1 where ideal 7ethical1          

intellectual1 aesthetic7 interests are  
concerned1 the struggle for life is a   
struggle for the preservation of this   
stage4 ,the giving up of a higher       
standard of life is a sort of death2 for
 there is not only a physical1 there is 
also a spiritual1 death4  ,,vi4  ,the   
,socratic character of ,darwin's mind   
appears in his wariness in drawing the  
last consequences of his doctrine1 in   
contrast both with the audacious        
theories of so many of his followers and
 with the consequences which his        
antagonists were busy in drawing4       
,though he1 as we have seen1 saw from   
the beginning that his hypothesis would 
occasion a whole of metaphysics1 he was 
himself very reserved as to the ultimate
 questions1 and his answers to such     
questions were extorted from him4  ,as  
to the question of optimism and         
pessimism1 ,darwin held that though pain
 and suffering were very often the ways 
by which animals were led to pursue that
 course of action which is most         

beneficial to the species1 yet          
pleasurable feelings were the most      
habitual guides4 ,we see this in the    
pleasure from exertion1 even            
occasionally from great exertion of the 
body or mind1 in the pleasure of our    
daily meals1 and especially in the      
pleasure derived from sociability1 and  
from loving our families4 ,but there was
 to him so much suffering in the world  
that it was a strong argument against   
the existence of an intelligent ,first  
,cause4 7,life and ,letters ,vol4 ,i4   
page #caj47  ,it seems to me that       
,darwin was not so clear on another     
question1 that of the relation between  
improvement and adaptation4 ,he wrote to
 ,lyell3 ,when you contrast natural     
selection and 'improvement1' you seem   
always to overlook444 that every step in
 the natural selection of each species  
implies improvement in that species ,,in
 ,,relation ,,to ,,its ,,condition ,,of 
,,life444 ,improvement implies1 ,i      
suppose1 ,,each ,,form ,,obtaining      

,,many ,,parts ,,or ,,organs1 all       
excellently adapted for their functions4
 ,all this1 he adds1 seems to me quite  
compatible with certain forms fitted for
 simple conditions1 remaining unaltered1
 or being degraded4 7,ibid4 ,vol4 ,,ii4 
page #agg47 ,but the great question is1 
if the conditions of life will in the   
long run favour improvement in the sense
 of differentiation 7or harmony of      
differentiation and integration74 ,many 
beings are best adapted to their        
conditions of life if they have few     
organs and few necessities4 ,pessimism  
would not only be the consequence1 if   
suffering outweighed happiness1 but also
 if the most elementary forms of        
happiness were predominant1 or if there 
were a tendency to reduce the standard  
of life to the simplest possible1 the   
contentment of inertia or stable        
equilibrium4 ,there are animals which   
are very highly differentiated and      
active in their young state1 but later  
lose their complex organisation and     

concentrate themselves on the one       
function of nutrition4 ,in the human    
world analogies to this sort of         
adaptation are not wanting4 ,young      
idealists very often end as old         
,philistines4 ,adaptation and progress  
are not the same4  ,another question of 
great importance in respect to human    
evolution is1 whether there will be     
always a possibility for the existence  
of an impulse to progress1 an impulse to
 make great claims on life1 to be active
 and to alter the conditions of life    
instead of adapting to them in a passive
 manner4 ,many people do not develop    
because they have too few necessities1  
and because they have no power to       
imagine other conditions of life than   
those under which they live4 ,in his    
remarks on the pleasure from exertion   
,darwin has a point of contact with the 
practical idealism of former times--with
 the ideas of ,lessing and ,goethe1 of  
,condorcet and ,fichte4 ,the continual  
striving which was the condition of     

salvation to ,faust's soul1 is also the 
condition of salvation to mankind4      
,there is a holy fire which we ought to 
keep burning1 if adaptation is really to
 be improvement4 ,if1 as ,i have tried  
to show in my ,philosophy of ,religion1 
the innermost core of all religion is   
faith in the persistence of value in the
 world1 and if the highest values       
express themselves in the cry           
,excelsior6 then the capital point is1  
that this cry should always be heard and
 followed4 ,we have here a corollary of 
the theory of evolution in its          
application to human life4  ,darwin     
declared himself an agnostic1 not only  
because he could not harmonise the large
 amount of suffering in the world with  
the idea of a ,god as its first cause1  
but also because he was aware that if we
 admit a first cause1 the mind still    
craves to know whence it came and how it
 arose4 7,life and ,letters1 ,vol4 ,i4  
page #cjf47 ,he saw1 as ,kant had seen  
before him and expressed in his ,kritik 

der ,urtheilskraft1 that we cannot      
accept either of the only two           
possibilities which we are able to      
conceive3 chance 7or brute force7 and   
design4 ,neither mechanism nor teleology
 can give an absolute answer to ultimate
 questions4 ,the universe1 and          
especially the organic life in it1 can  
neither be explained as a mere          
combination of absolute elements nor as 
the effect of a constructing thought4   
,darwin concluded1 as ,kant1 and before 
him ,spinoza1 that the oppositions and  
distinctions which our experience       
presents1 cannot safely be regarded as  
valid for existence in itself4 ,and1    
with ,kant and ,fichte1 he found his    
stronghold in the conviction that man   
has something to do1 even if he cannot  
solve all enigmas4 ,the safest          
conclusion seems to me that the whole   
subject is beyond the scope of man's    
intellect2 but man can do his duty4     
7,ibid4 page #cjg47  ,is this the last  
word of human thought8 ,does not the    

possibility1 that man can do his duty1  
suppose that the conditions of life     
allow of continuous ethical striving1 so
 that there is a certain harmony between
 cosmic order and human ideals8 ,darwin 
himself has shown how the consciousness 
of duty can arise as a natural result of
 evolution4 ,moreover there are lines of
 evolution which have their end in      
ethical idealism1 in a kingdom of       
values1 which must struggle for life as 
all things in the world must do1 but a  
kingdom which has its firm foundation in
 reality4     ,,xxiii4 ,,darwinism ,,and
 ,,sociology4 ,by ,c4 ,bougle4          
,professor of ,social ,philosophy in the
 ,university of ,toulouse and           
,deputy-,professor at the ,sorbonne1    
,paris4   ,how has our conception of    
social phenomena1 and of their history1 
been affected by ,darwin's conception of
 ,nature and the laws of its            
transformations8 ,to what extent and in 
what particular respects have the       
discoveries and hypotheses of the author

 of ,the ,origin of ,species aided the  
efforts of those who have sought to     
construct a science of society8  ,to    
such a question it is certainly not easy
 to give any brief or precise answer4   
,we find traces of ,darwinism almost    
everywhere4 ,sociological systems       
differing widely from each other have   
laid claim to its authority2 while1 on  
the other hand1 its influence has often 
made itself felt only in combination    
with other influences4 ,the ,darwinian  
thread is worked into a hundred patterns
 along with other threads4  ,to deal    
with the problem1 we must1 it seems1    
first of all distinguish the more       
general conclusions in regard to the    
evolution of living beings1 which are   
the outcome of ,darwinism1 from the     
particular explanations it offers of the
 ways and means by which that evolution 
is effected4 ,that is to say1 we must1  
as far as possible1 estimate separately 
the influence of ,darwin as an          
evolutionist and ,darwin as a           

selectionist4  ,the nineteenth century1 
said ,cournot1 has witnessed a mighty   
effort to reintegrer l'homme dans la    
nature4 ,from divers quarters there has 
been a methodical reaction against the  
persistent dualism of the ,cartesian    
tradition1 which was itself the         
unconscious heir of the ,christian      
tradition4 ,even the philosophy of the  
eighteenth century1 materialistic as    
were for the most part the tendencies of
 its leaders1 seemed to revere man as a 
being apart1 concerning whom laws might 
be formulated a priori4 ,to bring him   
down from his pedestal there was needed 
the marked predominance of positive     
researches wherein no account was taken 
of the pride of man4 ,there can be no   
doubt that ,darwin has done much to     
familiarise us with this attitude4 ,take
 for instance the first part of ,the    
,descent of ,man3 it is an accumulation 
of typical facts1 all tending to        
diminish the distance between us and our
 brothers1 the lower animals4 ,one might

 say that the naturalist had here taken 
as his motto1 ,whosoever shall exalt    
himself shall be abased2 and he that    
shall humble himself shall be exalted4  
,homologous structures1 the survival in 
man of certain organs of animals1 the   
rudiments in the animal of certain human
 faculties1 a multitude of facts of this
 sort1 led ,darwin to the conclusion    
that there is no ground for supposing   
that the king of the universe is exempt 
from universal laws4 ,thus belief in the
 imperium in imperio has been1 as it    
were1 whittled away by the progress of  
the naturalistic spirit1 itself         
continually strengthened by the         
conquests of the natural sciences4 ,the 
tendency may1 indeed1 drag the social   
sciences into overstrained analogies1   
such1 for instance1 as the assimilation 
of societies to organisms4 ,but it will1
 at least1 have had the merit of helping
 sociology to shake off the             
pre-conception that the groups formed by
 men are artificial1 and that history is

 completely at the mercy of chance4     
,some years before the appearance of    
,the ,origin of ,species1 ,auguste      
,comte had pointed out the importance1  
as regards the unification of positive  
knowledge1 of the conviction that the   
social world1 the last refuge of        
spiritualism1 is itself subject to      
determininism4 ,it cannot be doubted    
that the movement of thought which      
,darwin's discoveries promoted          
contributed to the spread of this       
conviction1 by breaking down the        
traditional barrier which cut man off   
from ,nature4  ,but ,nature1 according  
to modern naturalists1 is no immutable  
thing3 it is rather perpetual movement1 
continual progression4 ,their           
discoveries batter a breach directly    
into the ,aristotelian notion of        
species2 they refuse to see in the      
animal world a collection of immutable  
types1 distinct from all eternity1 and  
corresponding1 as ,cuvier said1 to so   
many particular thoughts of the         

,creator4 ,darwin especially            
congratulated himself upon having been  
able to deal this doctrine the coup de  
grace3 immutability is1 he says1 his    
chief enemy2 and he is concerned to     
show--therein following up ,lyell's     
work--that everything in the organic    
world1 as in the inorganic1 is explained
 by insensible but incessant            
transformations4 ,nature makes no       
leaps--,nature knows no gaps3 these two 
dicta form1 as it were1 the two         
landmarks between which ,darwin's idea  
of transformation is worked out4 ,that  
is to say1 the development of ,darwinism
 is calculated to further the           
application of the philosophy of        
,becoming to the study of human         
institutions4  ,the progress of the     
natural sciences thus brings unexpected 
reinforcements to the revolution which  
the progress of historical discipline   
had begun4 ,the first attempt to        
constitute an actual science of social  
phenomena--that1 namely1 of the         

economists--had resulted in laws which  
were called natural1 and which were     
believed to be eternal and universal1   
valid for all times and all places4 ,but
 this perpetuality1 brother1 as ,knies  
said1 of the immutability of the old    
zoology1 did not long hold out against  
the ever swelling tide of the historical
 movement4 ,knowledge of the            
transformations that had taken place in 
language1 of the early phases of the    
family1 of religion1 of property1 had   
all favoured the revival of the         
,heraclitean view3 panta rei4 ,as to the
 categories of political economy1 it was
 soon to be recognised1 as by ,lassalle1
 that they too are only historical4 ,the
 philosophy of history1 moreover1 gave  
expression under various forms to the   
same tendency4 ,hegel declares that all 
that is real is rational1 but at the    
same time he shows that all that is real
 is ephemeral1 and that for history     
there is nothing fixed beneath the sun4 
,it is this sense of universal evolution

 that ,darwin came with fresh authority 
to enlarge4 ,it was in the name of      
biological facts themselves that he     
taught us to see only slow metamorphoses
 in the history of institutions1 and to 
be always on the outlook for survivals  
side by side with rudimentary forms4    
,anyone who reads ,primitive ,culture1  
by ,tylor1--a writer closely connected  
with ,darwin--will be able to estimate  
the services which these cardinal ideas 
were to render to the social sciences   
when the age of comparative research had
 succeeded to that of a priori          
construction4  ,let us note1 moreover1  
that the philosophy of ,becoming in     
passing through the ,darwinian biology  
became1 as it were1 filtered3 it got rid
 of those traces of finalism1 which1    
under different forms1 it had preserved 
through all the systems of ,german      
,romanticism4 ,even in ,herbert         
,spencer1 it has been plausibly argued1 
one can detect something of that sort of
 mystic confidence in forces            

spontaneously directing life1 which     
forms the very essence of those systems4
 ,but ,darwin's observations were       
precisely calculated to render such an  
hypothesis futile4 ,at first people may 
have failed to see this2 and we call to 
mind the ponderous sarcasms of ,flourens
 when he objected to the theory of      
,natural ,selection that it attributed  
to nature a power of free choice4       
,nature endowed with will6 ,that was the
 final error of last century2 but the   
nineteenth no longer deals in           
personifications4 7,p4 ,flourens1       
,examen du ,livre de ,m4 ,darwin sur    
l',origine des ,especes1 page #ec1      
,paris1 #ahfd4 ,see also ,huxley1       
,criticisms on the ',origin of          
,species'1 ,collected ,essays1 ,vol4    
,,ii1 page #ajb1 ,london1 #aijb47 ,in   
fact ,darwin himself put his readers on 
their guard against the metaphors he was
 obliged to use4 ,the processes by which
 he explains the survival of the fittest
 are far from affording any indication  

of the design of some transcendent      
breeder4 ,nor1 if we look closely1 do   
they even imply immanent effort in the  
animal2 the sorting out can be brought  
about mechanically1 simply by the action
 of the environment4 ,in this connection
 ,huxley could with good reason maintain
 that ,darwin's originality consisted in
 showing how harmonies which hitherto   
had been taken to imply the agency of   
intelligence and will could be explained
 without any such intervention4 ,so1    
when later on1 objective sociology      
declares that1 even when social         
phenomena are in question1 all finalist 
preconceptions must be distrusted if a  
science is to be constituted1 it is to  
,darwin that its thanks are due2 he had 
long been clearing paths for it which   
lay well away from the old familiar road
 trodden by so many theories of         
evolution4  ,this anti-finalist         
doctrine1 when fully worked out1 was1   
moreover1 calculated to aid in the      
needful dissociation of two notions3    

that of evolution and that of progress4 
,in application to society these had    
long been confounded2 and1 as a         
consequence1 the general idea seemed to 
be that only one type of evolution was  
here possible4 ,do we not detect such a 
view in ,comte's sociology1 and perhaps 
even in ,herbert ,spencer's8 ,whoever1  
indeed1 assumes an end for evolution is 
naturally inclined to think that only   
one road leads to that end4 ,but those  
whose minds the ,darwinian theory has   
enlightened are aware that the          
transformations of living beings depend 
primarily upon their conditions1 and    
that it is these conditions which are   
the agents of selection from among      
individual variations4 ,hence1 it       
immediately follows that transformations
 are not necessarily improvements4      
,here1 ,darwin's thought hesitated4     
,logically his theory proves1 as ,ray   
,lankester pointed out1 that the        
struggle for existence may have as its  
outcome degeneration as well as         

amelioration3 evolution may be          
regressive as well as progressive4      
,then1 too--and this is especially to be
 borne in mind--each species takes its  
good where it finds it1 seeks its own   
path and survives as best it can4 ,apply
 this notion to society and you arrive  
at the theory of multilinear evolution4 
,divergencies will no longer surprise   
you4 ,you will be forewarned not to     
apply to all civilisations the same     
measure of progress1 and you will       
recognise that types of evolution may   
differ just as social species themselves
 differ4 ,have we not here one of the   
conceptions which mark off sociology    
proper from the old philosophy of       
history8  ,but if we are to estimate the
 influence of ,darwinism upon           
sociological conceptions1 we must not   
dwell only upon the way in which ,darwin
 impressed the general notion of        
evolution upon the minds of thinkers4   
,we must go into details4 ,we must      
consider the influence of the particular

 theories by which he explained the     
mechanism of this evolution4 ,the name  
of the author of ,the ,origin of        
,species has been especially attached1  
as everyone knows1 to the doctrines of  
natural selection and of struggle for   
existence1 completed by the notion of   
individual variation4 ,these doctrines  
were turned to account by very different
 schools of social philosophy4          
,pessimistic and optimistic1            
aristocratic and democratic1            
individualistic and socialistic systems 
were to war with each other for years by
 casting scraps of ,darwinism at each   
other's heads4  ,it was the spectacle of
 human contrivance that suggested to    
,darwin his conception of natural       
selection4 ,it was in studying the      
methods of pigeon breeders that he      
divined the processes by which nature1  
in the absence of design1 obtains       
analogous results in the differentiation
 of types4 ,as soon as the importance of
 artificial selection in the            

transformation of species of animals was
 understood1 reflection naturally turned
 to the human species1 and the question 
arose1 ,how far do men observe1 in      
connection with themselves1 those laws  
of which they make practical application
 in the case of animals8 ,here we come  
upon one of the ideas which guided the  
researches of ,galton1 ,darwin's cousin4
 ,the author of ,inquiries into ,human  
,faculty and its ,development           
7,inquiries into ,human ,faculty1 pages 
#a1 #b1 #c sq41 ,london1 #ahhc471 has   
often expressed his surprise that1      
considering all the precautions taken1  
for example1 in the breeding of horses1 
none whatever are taken in the breeding 
of the human species4 ,it seems to be   
forgotten that the species suffers when 
the fittest are not able to perpetuate  
their type4 ,ritchie1 in his ,darwinism 
and ,politics 7,darwinism and ,politics 
pages #i1 #bb1 ,london1 #ahhi47 reminds 
us of ,darwin's remark that the         
institution of the peerage might be     

defended on the ground that peers1 owing
 to the prestige they enjoy1 are enabled
 to select as wives the most beautiful  
and charming women out of the lower     
ranks4 7,life and ,letters of ,charles  
,darwin1 ,,ii4 page #che47 ,but1 says   
,galton1 it is as often as not heiresses
 that they pick out1 and birth          
statistics seem to show that these are  
either less robust or less fecund than  
others4 ,the truth is that              
considerations continue to preside over 
marriage which are entirely foreign to  
the improvement of type1 much as this is
 a condition of general progress4 ,hence
 the importance of completing ,odin's   
and ,de ,candolle's statistics which are
 designed to show how characters are    
incorporated in organisms1 how they are 
transmitted1 how lost1 and according to 
what law eugenic elements depart from   
the mean or return to it4  ,but thinkers
 do not always content themselves with  
undertaking merely the minute researches
 which the idea of ,selection suggests4 

,they are eager to defend this or that  
thesis4 ,in the name of this idea       
certain social anthropologists have     
recast the conception of the process of 
civilisation1 and have affirmed that    
,social ,selection generally works      
against the trend of ,natural           
,selection4 ,vacher de                  
,lapouge--following up an observation by
 ,broca on the point--enumerates the    
various institutions1 or customs1 such  
as the celibacy of priests and military 
conscription1 which cause elimination or
 sterilisation of the bearers of certain
 superior qualities1 intellectual or    
physical4 ,in a more general way he     
attacks the democratic movement1 a      
movement1 as ,p4 ,bourget says1 which is
 anti-physical and contrary to the      
natural laws of progress2 though it has 
been inspired by the dreams of that most
 visionary of all centuries1 the        
eighteenth4 7,v4 de ,lapouge1 ,les      
,selections sociales1 page #bei1 ,paris1
 #ahif47 ,the ,equality which levels    

down and mixes 7justly condemned1 he    
holds1 by the ,comte de ,gobineau71     
prevents the aristocracy of the blond   
dolichocephales from holding the        
position and playing the part which1 in 
the interests of all1 should belong to  
them4 ,otto ,ammon1 in his ,natural     
,selection in ,man1 and in ,the ,social 
,order and its ,natural ,bases 7,die    
naturliche ,auslese beim ,menschen1     
,jena1 #ahic2 ,die ,gesellschaftsordnung
 und ihre naturlichen ,grundlagen4      
,entwurf einer ,sozialanthropologie1    
,jena1 #ahif471 defended analogous      
doctrines in ,germany2 setting the curve
 representing frequency of talent over  
against that of income1 he attempted to 
show that all democratic measures which 
aim at promoting the rise in the social 
scale of the talented are useless1 if   
not dangerous2 that they only increase  
the panmixia1 to the great detriment of 
the species and of society4  ,among the 
aristocratic theories which ,darwinism  
has thus inspired we must reckon that of

 ,nietzsche4 ,it is well known that in  
order to complete his philosophy he     
added biological studies to his         
philological2 and more than once in his 
remarks upon the ,wille zur ,macht he   
definitely alludes to ,darwin2 though it
 must be confessed that it is generally 
in order to proclaim the in sufficiency 
of the processes by which ,darwin seeks 
to explain the genesis of species4      
,nevertheless1 ,nietzsche's mind is     
completely possessed by an ideal of     
,selection4 ,he1 too1 has a horror of   
panmixia4 ,the naturalists' conception  
of the fittest is joined by him to that 
of the hero of romance to furnish a     
basis for his doctrine of the ,superman4
 ,let us hasten to add1 moreover1 that  
at the very moment when support was     
being sought in the theory of ,selection
 for the various forms of the           
aristocratic doctrine1 those same forms 
were being battered down on another side
 by means of that very theory4          
,attention was drawn to the fact that by

 virtue of the laws which ,darwin       
himself had discovered isolation leads  
to etiolation4 ,there is a risk that the
 privilege which withdraws the          
privileged elements of ,society from    
competition will cause them to          
degenerate4 ,in fact1 ,jacoby in his    
,studies in ,selection1 in connexion    
with ,heredity in ,man1 7,etudes sur la 
,selection dans ses rapports avec       
l'heredite chez l'homme1 ,paris1 page   
#dha1 #ahha471 concludes that sterility1
 mental debility1 premature death and1  
finally1 the extinction of the stock    
were not specially and exclusively the  
fate of sovereign dynasties2 all        
privileged classes1 all families in     
exclusively elevated positions share the
 fate of reigning families1 although in 
a minor degree and in direct proportion 
to the loftiness of their social        
standing4 ,from the mass of human beings
 spring individuals1 families1 races1   
which tend to raise themselves above the
 common level2 painfully they climb the 

rugged heights1 attain the summits of   
power1 of wealth1 of intelligence1 of   
talent1 and then1 no sooner are they    
there than they topple down and         
disappear in gulfs of mental and        
physical degeneracy4 ,the demographical 
researches of ,hansen 7,die drei        
,bevolkerungsstufen1 ,munich1 #ahhi47   
7following up and completing ,dumont's7 
tended1 indeed1 to show that urban as   
well as feudal aristocracies1 burgher   
classes as well as noble castes1 were   
liable to become effete4 ,hence it might
 well be concluded that the democratic  
movement1 operating as it does to break 
down class barriers1 was promoting      
instead of impeding human selection4    
,so we see that1 according to the point 
of view1 very different conclusions have
 been drawn from the application of the 
,darwinian idea of ,selection to human  
society4 ,darwin's other central idea1  
closely bound up with this1 that1       
namely1 of the struggle for existence   
also has been diversely utilised4 ,but  

discussion has chiefly centered upon its
 signification4 ,and while some         
endeavour to extend its application to  
everything1 we find others trying to    
limit its range4 ,the conception of a   
struggle for existence has in the       
present day been taken up into the      
social sciences from natural science1   
and adopted4 ,but originally it         
descended from social science to        
natural4 ,darwin's law is1 as he himself
 said1 only ,malthus' law generalised   
and extended to the animal world3 a     
growing disproportion between the supply
 of food and the number of the living is
 the fatal order whence arises the      
necessity of universal struggle1 a      
struggle which1 to the great advantage  
of the species1 allows only the best    
equipped individuals to survive4 ,nature
 is regarded by ,huxley as an immense   
arena where all living beings are       
gladiators4 7,evolution and ,ethics1    
page #bjj2 ,collected ,essays1 ,vol4    
,,ix1 ,london1 #ahid47  ,such a         

generalisation was well adapted to feed 
the stream of pessimistic thought2 and  
it furnished to the apologists of war1  
in particular1 new arguments1 weighted  
with all the authority which in these   
days attaches to scientific             
deliverances4 ,if people no longer say1 
as ,bonald did1 and ,moltke after him1  
that war is a providential fact1 they   
yet lay stress on the point that it is a
 natural fact4 ,to the peace party      
,dragomirov's objection is urged that   
its attempts are contrary to the        
fundamental laws of nature1 and that no 
sea wall can hold against breakers that 
come with such gathered force4  ,but in 
yet another quarter ,darwinism was      
represented as opposed to philanthropic 
intervention4 ,the defenders of the     
orthodox political economy found in it  
support for their tenets4 ,since in the 
organic world universal struggle is the 
condition of progress1 it seemed obvious
 that free competition must be allowed  
to reign unchecked in the economic      

world4 ,attempts to curb it were in the 
highest degree imprudent4 ,the spirit of
 ,liberalism here seemed in conformity  
with the trend of nature3 in this       
respect1 at least1 contemporary         
naturalism1 offspring of the discoveries
 of the nineteenth century1 brought     
reinforcements to the individualist     
doctrine1 begotten of the speculations  
of the eighteenth3 but only1 it         
appeared1 to turn mankind away for ever 
from humanitarian dreams4 ,would those  
whom such conclusions repelled be       
content to oppose to nature's           
imperatives only the protests of the    
heart8 ,there were some who declared1   
like ,brunetiere1 that the laws in      
question1 valid though they might be for
 the animal kingdom1 were not applicable
 to the human4 ,and so a return was made
 to the classic dualism4 ,this indeed   
seems to be the line that ,huxley took1 
when1 for instance1 he opposed to the   
cosmic process an ethical process which 
was its reverse4  ,but the number of    

thinkers whom this antithesis does not  
satisfy grows daily4 ,although the      
pessimism which claims authorisation    
from ,darwin's doctrines is repugnant to
 them1 they still are unable to accept  
the dualism which leaves a gulf between 
man and nature4 ,and their endeavour is 
to link the two by showing that while   
,darwin's laws obtain in both kingdoms1 
the conditions of their application are 
not the same3 their forms1 and1         
consequently1 their results1 vary with  
the varying mediums in which the        
struggle of living beings takes place1  
with the means these beings have at     
disposal1 with the ends even which they 
propose to themselves4  ,here we have   
the explanation of the fact that among  
determined opponents of war partisans of
 the struggle for existence can be      
found3 there are disciples of ,darwin in
 the peace party4 ,novicow1 for example1
 admits the combat universel of which   
,le ,dantec 7,les ,luttes entre         
,societies humaines et leurs phases     

successives1 ,paris1 #ahic17 speaks2 but
 he remarks that at different stages of 
evolution1 at different stages of life  
the same weapons are not necessarily    
employed4 ,struggles of brute force1    
armed hand to hand conflicts1 may have  
been a necessity in the early phases of 
human societies4 ,nowadays1 although    
competition may remain inevitable and   
indispensable1 it can assume milder     
forms4 ,economic rivalries1 struggles   
between intellectual influences1 suffice
 to stimulate progress3 the processes   
which these admit are1 in the actual    
state of civilisation1 the only ones    
which attain their end without waste1   
the only ones logical4 ,from one end to 
the other of the ladder of life1        
struggle is the order of the day2 but   
more and more as the higher rungs are   
reached1 it takes on characters which   
are proportionately more humane4        
,reflections of this kind permit the    
introduction into the economic order of 
limitations to the doctrine of laisser  

faire1 laisser passer4 ,this appeals1 it
 is said1 to the example of nature where
 creatures1 left to themselves1 struggle
 without truce and without mercy2 but   
the fact is forgotten that upon         
industrial battlefields the conditions  
are different4 ,the competitors here are
 not left simply to their natural       
energies3 they are variously            
handicapped4 ,a rich store of artificial
 resources exists in which some         
participate and others do not4 ,the     
sides then are unequal2 and as a        
consequence the result of the struggle  
is falsified4 ,in the animal world1 said
 ,de ,laveleye 7,le socialisme          
contemporain1 page #chd 7#fth edition71 
,paris1 #ahia471 criticising ,spencer1  
the fate of each creature is determined 
by its individual qualities2 whereas in 
civilised societies a man may obtain the
 highest position and the most beautiful
 wife because he is rich and well-born1 
although he may be ugly1 idle or        
improvident2 and then it is he who will 

perpetuate the species4 ,the wealthy    
man1 ill constituted1 incapable1 sickly1
 enjoys his riches and establishes his  
stock under the protection of the laws4 
,haycraft in ,england and ,jentsch in   
,germany have strongly emphasised these 
anomalies1 which nevertheless are the   
rule4 ,that is to say that even from a  
,darwinian point of view all social     
reforms can readily be justified which  
aim at diminishing1 as ,wallace said1   
inequalities at the start4  ,but we can 
go further still4 ,whence comes the idea
 that all measures inspired by the      
sentiment of solidarity are contrary to 
,nature's trend8 ,observe her carefully1
 and she will not give lessons only in  
individualism4 ,side by side with the   
struggle for existence do we not find in
 operation what ,lanessan calls         
association for existence4 ,long ago1   
,espinas had drawn attention to         
societies of animals1 temporary or      
permanent1 and to the kind of morality  
that arose in them4 ,since then1        

naturalists have often insisted upon the
 importance of various forms of         
symbiosis4 ,kropotkin in ,mutual ,aid   
has chosen to enumerate many examples of
 altruism furnished by animals to       
mankind4 ,geddes and ,thomson went so   
far as to maintain that ,each of the    
greater steps of progress is in fact    
associated with an increased measure of 
subordination of individual competition 
to reproductive or social ends1 and of  
interspecific competition to            
co-operative association4 7,geddes and  
,thomson1 ,the ,evolution of ,sex1 page 
#caa1 ,london1 #ahhi47 ,experience      
shows1 according to ,geddes1 that the   
types which are fittest to surmount     
great obstacles are not so much those   
who engage in the fiercest competitive  
struggle for existence1 as those who    
contrive to temper it4 ,from all these  
observations there resulted1 along with 
a limitation of ,darwinian pessimism1   
some encouragement for the aspirations  
of the collectivists4  ,and ,darwin     

himself would1 doubtless1 have          
subscribed to these rectifications4 ,he 
never insisted1 like his rival1         
,wallace1 upon the necessity of the     
solitary struggle of creatures in a     
state of nature1 each for himself and   
against all4 ,on the contrary1 in ,the  
,descent of ,man1 he pointed out the    
serviceableness of the social instincts1
 and corroborated ,bagehot's statements 
when the latter1 applying laws of       
physics to politics1 showed the great   
advantage societies derived from        
intercourse and communion4 ,again1 the  
theory of sexual evolution which makes  
the evolution of types depend           
increasingly upon preferences1          
judgments1 mental factors1 surely offers
 something to qualify what seems hard   
and brutal in the theory of natural     
selection4  ,but1 as often happens with 
disciples1 the ,darwinians had          
out-,darwined ,darwin4 ,the             
extravagancies of social ,darwinism     
provoked a useful reaction2 and thus    

people were led to seek1 even in the    
animal kingdom1 for facts of solidarity 
which would serve to justify humane     
effort4  ,on quite another line1        
however1 an attempt has been made to    
connect socialist tendencies with       
,darwinian principles4 ,marx and ,darwin
 have been confronted2 and writers have 
undertaken to show that the work of the 
,german philosopher fell readily into   
line with that of the ,english          
naturalist and was a development of it4 
,such has been the endeavour of ,ferri  
in ,italy and of ,woltmann in ,germany1 
not to mention others4 ,the founders of 
scientific socialism had1 moreover1     
themselves thought of this              
reconciliation4 ,they make more than one
 allusion to ,darwin in works which     
appeared after #ahei4 ,and sometimes    
they use his theory to define by        
contrast their own ideal4 ,they remark  
that the capitalist system1 by giving   
free course to individual competition1  
ends indeed in a bellum omnium contra   

omnes2 and they make it clear that      
,darwinism1 thus understood1 is as      
repugnant to them as to ,duhring4  ,but 
it is at the scientific and not at the  
moral point of view that they place     
themselves when they connect their      
economic history with ,darwin's work4   
,thanks to this unifying hypothesis1    
they claim to have constructed--as ,marx
 does in his preface to ,das ,kapital--a
 veritable natural history of social    
evolution4 ,engels speaks in praise of  
his friend ,marx as having discovered   
the true mainspring of history hidden   
under the veil of idealism and          
sentimentalism1 and as having proclaimed
 in the primum vivere the inevitableness
 of the struggle for existence4 ,marx   
himself1 in ,das ,kapital1 indicated    
another analogy when he dwelt upon the  
importance of a general technology for  
the explanation of this psychology3--a  
history of tools which would be to      
social organs what ,darwinism is to the 
organs of animal species4 ,and the very 

importance they attach to tools1 to     
apparatus1 to machines1 abundantly      
proves that neither ,marx nor ,engels   
were likely to forget the special       
characters which mark off the human     
world from the animal4 ,the former      
always remains to a great extent an     
artificial world4 ,inventions change the
 face of its institutions4 ,new modes of
 production revolutionise not only modes
 of government1 but modes even of       
collective thought4 ,therefore it is    
that the evolution of society is        
controlled by laws special to it1 of    
which the spectacle of nature offers no 
suggestion4  ,if1 however1 even in this 
special sphere1 it can still be urged   
that the evolution of the material      
conditions of society is in accord with 
,darwin's theory1 it is because the     
influence of the methods of production  
is itself to be explained by the        
incessant strife of the various classes 
with each other4 ,so that in the end    
,marx1 like ,darwin1 finds the source of

 all progress in struggle4 ,both are    
grandsons of ,heraclitus3--polemos pater
 panton4 ,it sometimes happens1 in these
 days1 that the doctrine of             
revolutionary socialism is contrasted as
 rude and healthy with what may seem to 
be the enervating tendency of solidarist
 philanthropy3 the apologists of the    
doctrine then pride themselves above all
 upon their faithfulness to ,darwinian  
principles4  ,so far we have been mainly
 concerned to show the use that social  
philosophies have made of the ,darwinian
 laws for practical purposes3 in order  
to orientate society towards their      
ideals each school tries to show that   
the authority of natural science is on  
its side4 ,but even in the most         
objective of theories1 those which      
systematically make abstraction of all  
political tendencies in order to study  
the social reality in itself1 traces of 
,darwinism are readily to be found4     
,let us take for example ,durkheim's    
theory of ,division of ,labour 7,de la  

,division du ,travail social1 ,paris1   
#ahic47 ,the conclusions he derives from
 it are that whenever professional      
specialisation causes multiplication of 
distinct branches of activity1 we get   
organic solidarity--implying            
differences--substituted for mechanical 
solidarity1 based upon likenesses4 ,the 
umbilical cord1 as ,marx said1 which    
connects the individual consciousness   
with the collective consciousness is    
cut4 ,the personality becomes more and  
more emancipated4 ,but on what does this
 phenomenon1 so big with consequences1  
itself depend8 ,the author goes to      
social morphology for the answer3 it is1
 he says1 the growing density of        
population which brings with it this    
increasing differentiation of           
activities4 ,but1 again1 why8 ,because  
the greater density1 in thrusting men up
 against each other1 augments the       
intensity of their competition for the  
means of existence2 and for the problems
 which society thus has to face         

differentiation of functions presents   
itself as the gentlest solution4  ,here 
one sees that the writer borrows        
directly from ,darwin4 ,competition is  
at its maximum between similars1 ,darwin
 had declared2 different species1 not   
laying claim to the same food1 could    
more easily coexist4 ,here lay the      
explanation of the fact that upon the   
same oak hundreds of different insects  
might be found4 ,other things being     
equal1 the same applies to society4 ,he 
who finds some unadopted speciality     
possesses a means of his own for getting
 a living4 ,it is by this division of   
their manifold tasks that men contrive  
not to crush each other4 ,here we       
obviously have a ,darwinian law serving 
as intermediary in the explanation of   
that progress of division of labour     
which itself explains so much in the    
social evolution4  ,and we might take   
another example1 at the other end of the
 series of sociological systems4 ,g4    
,tarde is a sociologist with the most   

pronounced anti-naturalistic views4 ,he 
has attempted to show that all          
application of the laws of natural      
science to society is misleading4 ,in   
his ,opposition ,universelle he has     
directly combatted all forms of         
sociological ,darwinism4 ,according to  
him the idea that the evolution of      
society can be traced on the same plan  
as the evolution of species is          
chimerical4 ,social evolution is at the 
mercy of all kinds of inventions1 which 
by virtue of the laws of imitation      
modify1 through individual to           
individual1 through neighbourhood to    
neighbourhood1 the general state of     
those beliefs and desires which are the 
only quantities whose variation matters 
to the sociologist4 ,but1 it may be     
rejoined1 that however psychical the    
forces may be1 they are none the less   
subject to ,darwinian laws4 ,they       
compete with each other2 they struggle  
for the mastery of minds4 ,between types
 of ideas1 as between organic forms1    

selection operates4 ,and though it may  
be that these types are ushered into the
 arena by unexpected discoveries1 we yet
 recognise in the psychological         
accidents1 which ,tarde places at the   
base of everything1 near relatives of   
those small accidental variations upon  
which ,darwin builds4 ,thus1 accepting  
,tarde's own representations1 it is     
quite possible to express in ,darwinian 
terms1 with the necessary               
transpositions1 one of the most         
idealistic sociologies that have ever   
been constructed4  ,these few examples  
suffice4 ,they enable us to estimate the
 extent of the field of influence of    
,darwinism4 ,it affects sociology not   
only through the agency of its advocates
 but through that of its opponents4 ,the
 questionings to which it has given rise
 have proved no less fruitful than the  
solutions it has suggested4 ,in short1  
few doctrines1 in the history of social 
philosophy1 will have produced on their 
passage a finer outcrop of ideas4       

,,xxiv4 ,,the ,,influence ,,of ,,darwin 
,,upon ,,religious ,,thought4 ,by ,p4,n4
 ,waggett1 ,m4,a41 ,s4,s4,j4,e4   ,i4   
,the object of this paper is first to   
point out certain elements of the       
,darwinian influence upon ,religious    
thought1 and then to show reason for the
 conclusion that it has been1 from a    
,christian point of view1 satisfactory4 
,i shall not proceed further to urge    
that the ,christian apologetic in       
relation to biology has been successful4
 ,a variety of opinions may be held on  
this question1 without disturbing the   
conclusion that the movements of        
readjustment have been beneficial to    
those who remain ,christians1 and this  
by making them more ,christian and not  
only more liberal4 ,the theologians may 
sometimes have retreated1 but there has 
been an advance of theology4 ,i know    
that this account incurs the charge of  
optimism4 ,it is not the worst that     
could be made4 ,the influence has been  
limited in personal range1 unequal1 even

 divergent1 in operation1 and           
accompanied by the appearance of waste  
and mischievous products4 ,the estimate 
which follows requires for due balance a
 full development of many qualifying    
considerations4 ,for this ,i lack space1
 but ,i must at least distinguish my    
view from the popular one that our      
difficulties about religion and natural 
science have come to an end4            
,concerning the older questions about   
origins--the origin of the world1 of    
species1 of man1 of reason1 conscience1 
religion--a large measure of            
understanding has been reached by some  
thoughtful men4 ,but meanwhile new      
questions have arisen1 questions about  
conduct1 regarding both the reality of  
morals and the rule of right action for 
individuals and societies4 ,and these   
problems1 still far from solution1 may  
also be traced to the influence of      
,darwin4 ,for they arise from the       
renewed attention to heredity1 brought  
about by the search for the causes of   

variation1 without which the study of   
the selection of variations has no      
sufficient basis4  ,even the existing   
understanding about origins is very far 
from universal4 ,on these points there  
were always thoughtful men who denied   
the necessity of conflict1 and there are
 still thoughtful men who deny the      
possibility of a truce4  ,it must       
further be remembered that the earlier  
discussion now1 as ,i hope to show1     
producing favourable results1 created   
also for a time grave damage1 not only  
in the disturbance of faith and the loss
 of men--a loss not repaired by a change
 in the currents of debate--but in what 
,i believe to be a still more serious   
respect4 ,i mean the introduction of a  
habit of facile and untested hypothesis 
in religious as in other departments of 
thought4  ,darwin is not responsible for
 this1 but he is in part the cause of   
it4 ,great ideas are dangerous guests in
 narrow minds2 and thus it has happened 
that ,darwin--the most patient of       

scientific workers1 in whom hypothesis  
waited upon research1 or if it          
provisionally outstepped it did so only 
with the most scrupulously careful      
acknowledgment--has led smaller and less
 conscientious men in natural science1  
in history1 and in theology to an       
over-eager confidence in probable       
conjecture and a loose grip upon the    
facts of experience4 ,it is not too much
 to say that in many quarters the age of
 materialism was the least              
matter-of-fact age conceivable1 and the 
age of science the age which showed     
least of the patient temper of inquiry4 
,i have indicated1 as shortly as ,i     
could1 some losses and dangers which in 
a balanced account of ,darwin's         
influence would be discussed at length4 
,one other loss must be mentioned4 ,it  
is a defect in our thought which1 in    
some quarters1 has by itself almost     
cancelled all the advantages secured4 ,i
 mean the exaggerated emphasis on       
uniformity or continuity2 the           

unwillingness to rest any part of faith 
or of our practical expectation upon    
anything that from any point of view can
 be called exceptional4 ,the high degree
 of success reached by naturalists in   
tracing1 or reasonably conjecturing1 the
 small beginnings of great differences1 
has led the inconsiderate to believe    
that anything may in time become        
anything else4  ,it is true that this   
exaggeration of the belief in uniformity
 has produced in turn its own perilous  
reaction4 ,from refusing to believe     
whatever can be called exceptional1 some
 have come to believe whatever can be   
called wonderful4  ,but1 on the whole1  
the discontinuous or highly various     
character of experience received for    
many years too little deliberate        
attention4 ,the conception of uniformity
 which is a necessity of scientific     
description has been taken for the      
substance of history4 ,we have accepted 
a postulate of scientific method as if  
it were a conclusion of scientific      

demonstration4 ,in the name of a        
generalisation which1 however just on   
the lines of a particular method1 is the
 prize of a difficult exploit of        
reflexion1 we have discarded the direct 
impressions of experience2 or1 perhaps  
it is more true to say1 we have used for
 the criticism of alleged experiences a 
doctrine of uniformity which is only    
valid in the region of abstract science4
 ,for every science depends for its     
advance upon limitation of attention1   
upon the selection out of the whole     
content of consciousness of that part or
 aspect which is measurable by the      
method of the science4 ,accordingly     
there is a science of life which rightly
 displays the unity underlying all its  
manifestations4 ,but there is another   
view of life1 equally valid1 and        
practically sometimes more important1   
which recognises the immediate and      
lasting effect of crisis1 difference1   
and revolution4 ,our ardour for the     
demonstration of uniformity of process  

and of minute continuous change needs to
 be balanced by a recognition of the    
catastrophic element in experience1 and 
also by a recognition of the exceptional
 significance for us of events which may
 be perfectly regular from an impersonal
 point of view4  ,an exorbitant jealousy
 of miracle1 revelation1 and ultimate   
moral distinctions has been imported    
from evolutionary science into religious
 thought4 ,and it has been a damaging   
influence1 because it has taken men's   
attention from facts1 and fixed them    
upon theories4  ,,ii4  ,with this       
acknowledgment of important drawbacks1  
requiring many words for their proper   
description1 ,i proceed to indicate     
certain results of ,darwin's doctrine   
which ,i believe to be in the long run  
wholly beneficial to ,christian thought4
 ,these are3  ,the encouragement in     
theology of that evolutionary method of 
observation and study1 which has shaped 
all modern research3  ,the recoil of    
,christian apologetics towards the      

ground of religious experience1 a recoil
 produced by the pressure of scientific 
criticism upon other supports of faith3 
,the restatement1 or the recovery of    
ancient forms of statement1 of the      
doctrines of ,creation and of divine    
,design in ,nature1 consequent upon the 
discussion of evolution and of natural  
selection as its guiding factor4  7#a7  
,the first of these is quite possibly   
the most important of all4 ,it was well 
defined in a notable paper read by ,dr  
,gore1 now ,bishop of ,birmingham1 to   
the ,church ,congress at ,shrewsbury in 
#ahif4 ,we have learnt a new caution    
both in ascribing and in denying        
significance to items of evidence1 in   
utterance or in event4 ,there has been1 
as in art1 a study of values1 which     
secures perspective and solidity in our 
representation of facts4 ,on the one    
hand1 a given utterance or event cannot 
be drawn into evidence as if all items  
were of equal consequence1 like         
sovereigns in a bag4 ,the question      

whence and whither must be asked1 and   
the particular thing measured as part of
 a series4 ,thus measured it is not less
 truly important1 but it may be         
important in a lower degree4 ,on the    
other hand1 and for exactly the same    
reason1 nothing that is real is         
unimportant4 ,the failures are not mere 
mistakes4 ,we see them1 in ,st          
,augustine's words1 as scholar's faults 
which men praise in hope of fruit4  ,we 
cannot safely trace the origin of the   
evolutionistic method to the influence  
of natural science4 ,the view is tenable
 that theology led the way4 ,probably   
this is a case of alternate and         
reciprocal debt4 ,quite certainly the   
evolutionist method in theology1 in     
,christian history1 and in the estimate 
of scripture1 has received vast         
reinforcement from biology1 in which    
evolution has been the ever present and 
ever victorious conception4  7#b7 ,the  
second effect named is the new          
willingness of ,christian thinkers to   

take definite account of religious      
experience4 ,this is related to ,darwin 
through the general pressure upon       
religious faith of scientific criticism4
 ,the great advance of our knowledge of 
organisms has been an important element 
in the general advance of science4 ,it  
has acted1 by the varied requirements of
 the theory of organisms1 upon all other
 branches of natural inquiry1 and it    
held for a long time that leading place 
in public attention which is now        
occupied by speculative physics4        
,consequently it contributed largely to 
our present estimation of science as the
 supreme judge in all matters of inquiry
 7,f4,r4 ,tennant3 ,the ,being of ,god  
in the light of ,physical ,science1 in  
,essays on some theological questions of
 the day4 ,london1 #aije471 to the      
supposed destruction of mystery and the 
disparagement of metaphysic which marked
 the last age1 as well as to the just   
recommendation of scientific method in  
branches of learning where the direct   

acquisitions of natural science had no  
place4  ,besides this1 the new          
application of the idea of law and      
mechanical regularity to the organic    
world seemed to rob faith of a kind of  
refuge4 ,the romantics had1 as          
,berthelot 7,evolutionisme et           
,platonisme1 pages #de1 #df1 #dg4       
,paris1 #aijh47 shows1 appealed to life 
to redress the judgments drawn from     
mechanism4 ,now1 in ,spencer1 evolution 
gave us a vitalist mechanic or          
mechanical vitalism1 and the appeal     
seemed cut off4 ,we may return to this  
point later when we consider evolution2 
at present ,i only endeavour to indicate
 that general pressure of scientific    
criticism which drove men of faith to   
seek the grounds of reassurance in a    
science of their own2 in a method of    
experiment1 of observation1 of          
hypothesis checked by known facts4 ,it  
is impossible for me to do more than    
glance across the threshold of this     
subject4 ,but it is necessary to say    

that the method is in an elementary     
stage of revival4 ,the imposing success 
that belongs to natural science is      
absent3 we fall short of the            
unchallengeable unanimity of the        
,biologists on fundamentals4 ,the       
experimental method with its sure       
repetitions cannot be applied to our    
subject-matter4 ,but we have something  
like the observational method of        
palaeontology and geographical          
distribution2 and in biology there are  
still men who think that the large      
examination of varieties by way of      
geography and the search of strata is as
 truly scientific1 uses as genuinely the
 logical method of difference1 and is as
 fruitful in sure conclusions as the    
quasi-chemical analysis of ,mendelian   
laboratory work1 of which last ,i desire
 to express my humble admiration4       
,religion also has its observational    
work in the larger and possibly more    
arduous manner4  ,but the scientific    
work in religion makes its way through  

difficulties and dangers4 ,we are far   
from having found the formula of its    
combination with the historical elements
 of our apologetic4 ,it is exposed1     
therefore1 to a damaging fire not only  
from unspiritualist psychology and      
pathology but also from the side of     
scholastic dogma4 ,it is hard to admit  
on equal terms a partner to the old     
undivided rule of books and learning4   
,with ,charles ,lamb1 we cry in some    
distress1 must knowledge come to me1 if 
it come at all1 by some awkward         
experiment of intuition1 and no longer  
by this familiar process of reading8    
7,essays of ,elia1 ,new ,year's ,eve1   
page #da2 ,ainger's edition4 ,london1   
#ahii47 and we are answered that the old
 process has an imperishable value1 only
 we have not yet made clear its         
connection with other contributions4    
,and all the work is young1 liable to be
 drawn into unprofitable excursions1    
side-tracked by self-deceit and         
pretence2 and it fatally attracts1 like 

the older mysticism1 the curiosity and  
the expository powers of those least in 
sympathy with it1 ready writers who1    
with all the air of extended research1  
have been content with narrow grounds   
for induction4 ,there is a danger1      
besides1 which accompanies even the most
 genuine work of this science and must  
be provided against by all its serious  
students4 ,i mean the danger of         
unbalanced introspection both for       
individuals and for societies2 of a     
preoccupation comparable to our modern  
social preoccupation with bodily health2
 of reflection upon mental states not   
accompanied by exercise and growth of   
the mental powers2 the danger of        
contemplating will and neglecting work1 
of analysing conviction and not         
criticising evidence4  ,still1 in spite 
of dangers and mistakes1 the work       
remains full of hopeful indications1    
and1 in the best examples 7,such an     
example is given in ,baron ,f4 von      
,hugel's recently finished book1 the    

result of thirty years' research3 ,the  
,mystical ,element of ,religion1 as     
studied in ,saint ,catherine of ,genoa  
and her ,friends4 ,london1 #aijh471 it  
is truly scientific in its determination
 to know the very truth1 to tell what we
 think1 not what we think we ought to   
think4 7,g4 ,tyrrell1 in ,mediaevalism1 
has a chapter which is full of the      
important ,,moral element in a          
scientific attitude4 ,the only          
infallible guardian of truth is the     
spirit of truthfulness4 ,mediaevalism   
page #ahb1 ,london1 #aijh471 truly      
scientific in its employment of         
hypothesis and verification1 and in     
growing conviction of the reality of its
 subject-matter through the repeated    
victories of a mastery which advances1  
like science1 in the ,baconian road of  
obedience4 ,it is reasonable to hope    
that progress in this respect will be   
more rapid and sure when religious study
 enlists more men affected by scientific
 desire and endowed with scientific     

capacity4  ,the class of investigating  
minds is a small one1 possibly even     
smaller than that of reflecting minds4  
,very few persons at any period are able
 to find out anything whatever4 ,there  
are few observers1 few discoverers1 few 
who even wish to discover truth4 ,in how
 many societies the problems of         
philology which face every person who   
speaks ,english are left unattempted6   
,and if the inquiring or the            
successfully inquiring class of minds is
 small1 much smaller1 of course1 is the 
class of those possessing the scientific
 aptitude in an eminent degree4 ,during 
the last age this most distinguished    
class was to a very great extent        
absorbed in the study of phenomena1 a   
study which had fallen into arrears4    
,for we stood possessed1 in rudiment1 of
 means of observation1 means for        
travelling and acquisition1 qualifying  
men for a larger knowledge than had yet 
been attempted4 ,these were now to be   
directed with new accuracy and ardour   

upon the fabric and behaviour of the    
world of sense4 ,our debt to the great  
masters in physical science who overtook
 and almost out-stripped the task cannot
 be measured2 and1 under the honourable 
leadership of ,ruskin1 we may all well  
do penance if we have failed in the     
respect due to their great powers of    
thought1 or in the admiration due to the
 far scope of their discovery4 7,queen  
of the ,air1 ,preface1 page vii4        
,london1 #aijf47 ,with what miraculous  
mental energy and divine good           
fortune--as ,romans said of their       
soldiers--did our men of curiosity face 
the apparently impenetrable mysteries of
 nature6 ,and how natural it was that   
immense accessions of knowledge1        
unrelated to the spiritual facts of     
life1 should discredit ,christian faith1
 by the apparent superiority of the new 
work to the feeble and unprogressive    
knowledge of ,christian believers6 ,the 
day is coming when men of this mental   
character and rank1 of this curiosity1  

this energy and this good fortune in    
investigation1 will be employed in      
opening mysteries of a spiritual nature4
 ,they will silence with masterful      
witness the over-confident denials of   
naturalism4 ,they will be in danger of  
the widespread recognition which thirty 
years ago accompanied every utterance of
 ,huxley1 ,tyndall1 ,spencer4 ,they will
 contribute1 in spite of adulation1 to  
the advance of sober religious and moral
 science4  ,and this result will be due 
to ,darwin1 first because by raising the
 dignity of natural science1 he         
encouraged the development of the       
scientific mind2 secondly because he    
gave to religious students the example  
of patient and ardent investigation2 and
 thirdly because by the pressure of     
naturalistic criticism the religious    
have been driven to ascertain the causes
 of their own convictions1 a work in    
which they were not without the sympathy
 of men of science4 7,the scientific    
rank of its writer justifies the        

insertion of the following letter from  
the late ,sir ,john ,burdon-,sanderson  
to me4 ,in the lecture referred to ,i   
had described the methods of ,professor 
,moseley in teaching ,biology as        
affording a suggestion of the scientific
 treatment of religion47  ,oxford1      
,april #cj1 #aijb4  ,dear ,sir1  ,i feel
 that ,i must express to you my thanks  
for the discourse which ,i had the      
pleasure of listening to yesterday      
afternoon4  ,i do not mean to say that  
,i was able to follow all that you said 
as to the identity of ,method in the two
 fields of ,science and ,religion1 but  
,i recognise that the mysticism of which
 you spoke gives us the only way by     
which the two fields can be brought into
 relation4  ,among much that was        
memorable1 nothing interested me more   
than what you said of ,moseley4  ,no    
one1 ,i am sure1 knew better than you   
the value of his teaching and in what   
that value consisted4  ,yours faithfully
  ,j4 ,burdon-,sanderson4 #ca-b47  ,in  

leaving the subject of scientific       
religious inquiry1 ,i will only add that
 ,i do not believe it receives any      
important help--and certainly it suffers
 incidentally much damaging             
interruption--from the study of abnormal
 manifestations or abnormal conditions  
of personality4  7#c7 ,both of the above
 effects seem to me of high1 perhaps the
 very highest1 importance to faith and  
to thought4 ,but1 under the third head1 
,i name two which are more directly     
traceable to the personal work of       
,darwin1 and more definitely            
characteristic of the age in which his  
influence was paramount3 viz4 the       
influence of the two conceptions of     
evolution and natural selection upon the
 doctrine of creation and of design     
respectively4  ,it is impossible here1  
though it is necessary for a complete   
sketch of the matter1 to distinguish the
 different elements and channels of this
 ,darwinian influence2 in ,darwin's own 
writings1 in the vigorous polemic of    

,huxley1 and strangely enough1 but very 
actually for popular thought1 in the    
teaching of the definitely              
anti-,darwinian evolutionist ,spencer4  
,under the head of the directly and     
purely ,darwinian elements ,i should    
class as preeminent the work of ,wallace
 and of ,bates2 for no two sets of facts
 have done more to fix in ordinary      
intelligent minds a belief in organic   
evolution and in natural selection as   
its guiding factor than the facts of    
geographical distribution and of        
protective colour and mimicry4 ,the     
facts of geology were difficult to grasp
 and the public and theologians heard   
more often of the imperfection than of  
the extent of the geological record4    
,the witness of embryology1 depending to
 a great extent upon microscopic work1  
was and is beyond the appreciation of   
persons occupied in fields of work other
 than biology4  ,,iii4  ,from the       
influence in religion of scientific     
modes of thought we pass to the         

influence of particular biological      
conceptions4 ,the former effect comes by
 way of analogy1 example1 encouragement 
and challenge2 inspiring or provoking   
kindred or similar modes of thought in  
the field of theology2 the latter by a  
collision of opinions upon matters of   
fact or conjecture which seem to concern
 both science and religion4  ,in the    
case of ,darwinism the story of this    
collision is familiar1 and falls under  
the heads of evolution and natural      
selection1 the doctrine of descent with 
modification1 and the doctrine of its   
guidance or determination by the        
struggle for existence between related  
varieties4 ,these doctrines1 though     
associated and interdependent1 and in   
popular thought not only combined but   
confused1 must be considered separately4
 ,it is true that the ancient doctrine  
of ,evolution1 in spite of the ingenuity
 and ardour of ,lamarck1 remained a     
dream tantalising the intellectual      
ambition of naturalists1 until the day  

when ,darwin made it conceivable by     
suggesting the machinery of its         
guidance4 ,and1 further1 the idea of    
natural selection has so effectively    
opened the door of research and         
stimulated observation in a score of    
principal directions that1 even if the  
,darwinian explanation became one day   
much less convincing than1 in spite of  
recent criticism1 it now is1 yet its    
passing1 supposing it to pass1 would    
leave the doctrine of ,evolution        
immeasurably and permanently            
strengthened4 ,for in the interests of  
the theory of selection1 ,fur ,darwin1  
as ,muller wrote1 facts have been       
collected which remain in any case      
evidence of the reality of descent with 
modification4  ,but still1 though thus  
united in the modern history of         
convictions1 though united and confused 
in the collision of biological and      
traditional opinion1 yet evolution and  
natural selection must be separated in  
theological no less than in biological  

estimation4 ,evolution seemed           
inconsistent with ,creation2 natural    
selection with ,providence and ,divine  
design4  ,discussion was maintained     
about these points for many years and   
with much dark heat4 ,it ranged over    
many particular topics and engaged minds
 different in tone1 in quality1 and in  
accomplishment4 ,there was at most times
 a degree of misconception4 ,some       
naturalists attributed to theologians in
 general a poverty of thought which     
belonged really to men of a particular  
temper or training4 ,the timid theism   
discerned in ,darwin by so cautious a   
theologian as ,liddon 7,h4,p4 ,liddon1  
,the ,recovery of ,s4 ,thomas2 a sermon 
preached in ,st ,paul's1 ,london1 on    
,april #bcrd1 #ahhb 7the ,sunday after  
,darwin's death747 was supposed by many 
biologists to be the necessary          
foundation of an honest ,christianity4  
,it was really more characteristic of   
devout ,,naturalists like ,philip ,henry
 ,gosse1 than of religious believers as 

such4 7,dr ,pusey 7,unscience not       
,science adverse to ,faith #ahgh7       
writes3 ,the questions as to 'species1' 
of what variations the animal world is  
capable1 whether the species be more or 
fewer1 whether accidental variations may
 become hereditary444 and the like1     
naturally fall under the province of    
science4 ,in all these questions ,mr    
,darwin's careful observations gained   
for him a deserved approbation and      
confidence47 ,the study of theologians  
more considerable and even more         
typically conservative than ,liddon does
 not confirm the description of         
religious intolerance given in good     
faith1 but in serious ignorance1 by a   
disputant so acute1 so observant and so 
candid as ,huxley4 ,something hid from  
each other's knowledge the devoted      
pilgrims in two great ways of thought4  
,the truth may be1 that naturalists took
 their view of what creation was from   
,christian men of science who naturally 
looked in their own special studies for 

the supports and illustrations of their 
religious belief4 ,of almost every      
laborious student it may be said ,hic ab
 arte sua non recessit4 ,and both the   
believing and the denying naturalists1  
confining habitual attention to a part  
of experience1 are apt to affirm and    
deny with trenchant vigour and something
 of a narrow clearness ,qui respiciunt  
ad pauca1 de facili pronunciant4        
7,aristotle1 in ,bacon1 quoted by       
,newman in his ,idea of a ,university1  
page #gh4 ,london1 #ahgc47  ,newman says
 of some secular teachers that they     
persuade the world of what is false by  
urging upon it what is true4 ,of some   
early opponents of ,darwin it might be  
said by a candid friend that1 in all    
sincerity of devotion to truth1 they    
tried to persuade the world of what is  
true by urging upon it what is false4   
,if naturalists took their version of   
orthodoxy from amateurs in theology1    
some conservative ,christians1 instead  
of learning what evolution meant to its 

regular exponents1 took their view of it
 from celebrated persons1 not of the    
front rank in theology or in thought1   
but eager to take account of public     
movements and able to arrest public     
attention4  ,cleverness and eloquence on
 both sides certainly had their share in
 producing the very great and general   
disturbance of men's minds in the early 
days of ,darwinian teaching4 ,but by far
 the greater part of that disturbance   
was due to the practical novelty and the
 profound importance of the teaching    
itself1 and to the fact that the        
controversy about evolution quickly     
became much more public than any        
controversy of equal seriousness had    
been for many generations4  ,we must not
 think lightly of that great disturbance
 because it has1 in some real sense1    
done its work1 and because it is        
impossible in days of more coolness and 
light1 to recover a full sense of its   
very real difficulties4  ,those who     
would know them better should add to the

 calm records of ,darwin 7,life and     
,letters and ,more ,letters of ,charles 
,darwin47 and to the story of ,huxley's 
impassioned championship1 all that they 
can learn of ,george ,romanes4 7,life   
and ,letters1 ,london1 #ahif4 ,thoughts 
on ,religion1 ,london1 #ahie4 ,candid   
,examination of ,theism1 ,london1       
#ahgh47 ,for his life was absorbed in   
this very struggle and reproduced its   
stages4 ,it began in a certain assured  
simplicity of biblical interpretation2  
it went on1 through the glories and     
adventures of a paladin in ,darwin's    
train1 to the darkness and dismay of a  
man who saw all his most cherished      
beliefs rendered1 as he thought1        
incredible4 7,never in the history of   
man has so terrific a calamity befallen 
the race as that which all who look may 
now 7viz4 in consequence of the         
scientific victory of ,darwin7 behold   
advancing as a deluge1 black with       
destruction1 resistless in might1       
uprooting our most cherished hopes1     

engulphing our most precious creed1 and 
burying our highest life in mindless    
destruction4--,a ,candid ,examination of
 ,theism1 page #ea47 ,he lived to find  
the freer faith for which process and   
purpose are not irreconcilable1 but     
necessary to one another4 ,his          
development1 scientific1 intellectual   
and moral1 was itself of high           
significance2 and its record is of      
unique value to our own generation1 so  
near the age of that doubt and yet so   
far from it2 certainly still much in    
need of the caution and courage by which
 past endurance prepares men for new    
emergencies4 ,we have little enough     
reason to be sure that in the           
discussions awaiting us we shall do as  
well as our predecessors in theirs4     
,remembering their endurance of mental  
pain1 their ardour in mental labour1 the
 heroic temper and the high sincerity of
 controversialists on either side1 we   
may well speak of our fathers in such   
words of modesty and self-judgment as   

,drayton used when he sang the victors  
of ,agincourt4 ,the progress of biblical
 study1 in the departments of           
,introduction and ,exegesis1 resulting  
in the recovery of a point of view      
anciently tolerated if not prevalent1   
has altered some of the conditions of   
that discussion4 ,in the years near     
#aheh1 the witness of ,scripture was    
adduced both by ,christian advocates and
 their critics as if unmistakeably      
irreconcilable with ,evolution4  ,huxley
 7,science and ,christian ,tradition4   
,london1 #aijd47 found the path of the  
blameless naturalist everywhere blocked 
by ,moses3 the believer in revelation   
was generally held to be forced to a    
choice between revealed cosmogony and   
the scientific account of origins4 ,it  
is not clear how far the change in      
,biblical interpretation is due to      
natural science1 and how far to the     
vital movements of theological study    
which have been quite independent of the
 controversy about species4 ,it belongs 

to a general renewal of ,christian      
movement1 the recovery of a heritage4   
,special ,creation--really a biological 
rather than a theological               
conception1--seems in its rigid form to 
have been a recent element even in      
,english biblical orthodoxy4  ,the      
,middle ,ages had no suspicion that     
religious faith forbad inquiry into the 
natural origination of the different    
forms of life4 ,bartholomaeus ,anglicus1
 an ,english ,franciscan of the         
thirteenth century1 was a mutationist in
 his way1 as ,aristotle1 the            
,philosopher of the ,christian          
,schoolmen1 had been in his4 ,so late as
 the seventeenth century1 as we learn   
not only from early proceedings of the  
,royal ,society1 but from a writer so   
homely and so regularly pious as        
,walton1 the variation of species and   
spontaneous generations had no          
theological bearing1 except as instances
 of that various wonder of the world    
which in devout minds is food for       

devotion4  ,it was in the eighteenth    
century that the harder statement took  
shape4 ,something in the preciseness of 
that age1 its exaltation of law1 its    
cold passion for a stable and measured  
universe1 its cold denial1 its cold     
affirmation of the power of ,god1 a ,god
 of ice1 is the occasion of that        
rigidity of religious thought about the 
living world which ,darwin by accident  
challenged1 or rather by one of those   
movements of genius which1 ,goethe 7,no 
productiveness of the highest kind444 is
 in the power of anyone4--,conversations
 of ,goethe with ,eckermann and ,soret4 
,london1 #ahej47 declares1 are elevated 
above all earthly control4  ,if         
religious thought in the eighteenth     
century was aimed at a fixed and nearly 
finite world of spirit1 it followed in  
all these respects the secular and      
critical lead4 7,la philosophie         
reformatrice du ,x,v,i,i,ie siecle      
7,berthelot1 ,evolutionisme et          
,platonisme1 ,paris1 #aijh1 page #de47  

ramenait la nature et la societe a des  
mecanismes que la pensee reflechie peut 
concevoir et recomposer4 ,in fact1      
religion in a mechanical age is         
condemned if it takes any but a         
mechanical tone4 ,butler's thought was  
too moving1 too vital1 too evolutionary1
 for the sceptics of his time4 ,in a    
rationalist1 encyclopaedic period1      
religion also must give hard outline to 
its facts1 it must be able to display   
its secret to any sensible man in the   
language used by all sensible men4      
,milton's prophetic genius furnished the
 eighteenth century1 out of the depth of
 the passionate age before it1 with the 
theological tone it was to need4 ,in    
spite of the austere magnificence of his
 devotion1 he gives to smaller souls a  
dangerous lead4 ,the rigidity of        
,scripture exegesis belonged to this    
stately but imperfectly sensitive mode  
of thought4 ,it passed away with the    
influence of the older rationalists     
whose precise denials matched the       

precise and limited affirmations of the 
static orthodoxy4  ,i shall1 then1 leave
 the specially biblical aspect of the   
debate--interesting as it is and even   
useful1 as in ,huxley's correspondence  
with the ,duke of ,argyll and others in 
#ahib 7,times1 #ahib1 passim47--in order
 to consider without complication the   
permanent elements of ,christian thought
 brought into question by the teaching  
of evolution4  ,such permanent elements 
are the doctrine of ,god as ,creator of 
the universe1 and the doctrine of man as
 spiritual and unique4 ,upon both the   
doctrine of evolution seemed to fall    
with crushing force4  ,with regard to   
,man ,i leave out1 acknowledging a grave
 omission1 the doctrine of the ,fall and
 of ,sin4 ,and ,i do so because these   
have not yet1 as ,i believe1 been       
adequately treated3 here the fruitful   
reaction to the stimulus of evolution is
 yet to come4 ,the doctrine of sin1     
indeed1 falls principally within the    
scope of that discussion which has      

followed or displaced the ,darwinian2   
and without it the ,fall cannot be      
usefully considered4 ,for the question  
about the ,fall is a question not merely
 of origins1 but of the interpretation  
of moral facts whose moral reality must 
first be established4  ,i confine myself
 therefore to ,creation and the dignity 
of man4  ,the meaning of evolution1 in  
the most general terms1 is that the     
differentiation of forms is not         
essentially separate from their         
behaviour and use2 that if these are    
within the scope of study1 that is also2
 that the world has taken the form we   
see by movements not unlike those we now
 see in progress2 that what may be      
called proximate origins are continuous 
in the way of force and matter1         
continuous in the way of life1 with     
actual occurrences and actual           
characteristics4 ,all this has no       
revolutionary bearing upon the question 
of ultimate origins4 ,the whole is a    
statement about process4 ,it says       

nothing to metaphysicians about cause4  
,it simply brings within the scope of   
observation or conjecture that series of
 changes which has given their special  
characters to the different parts of the
 world we see4 ,in particular1          
evolutionary science aspires to the     
discovery of the process or order of the
 appearance of life itself3 if it were  
to achieve its aim it could say nothing 
of the cause of this or indeed of the   
most familiar occurrences4 ,we should   
have become spectators or convinced     
historians of an event which1 in respect
 of its cause and ultimate meaning1     
would be still impenetrable4  ,with     
regard to the origin of species1        
supposing life already established1     
biological science has the well founded 
hopes and the measure of success with   
which we are all familiar4 ,all this    
has1 it would seem1 little chance of    
collision with a consistent theism1 a   
doctrine which has its own difficulties 
unconnected with any particular view of 

order or process4 ,but when it was      
stated that species had arisen by       
processes through which new species were
 still being made1 evolutionism came    
into collision with a statement1        
traditionally religious1 that species   
were formed and fixed once for all and  
long ago4  ,what is the theological     
import of such a statement when it is   
regarded as essential to belief in ,god8
 ,simply that ,god's activity1 with     
respect to the formation of living      
creatures1 ceased at some point in past 
time4  ,god rested is made the          
touchstone of orthodoxy4 ,and when1     
under the pressure of the evidences1 we 
found ourselves obliged to acknowledge  
and assert the present and persistent   
power of ,god1 in the maintenance and in
 the continued formation of types1 what 
happened was the abolition of a         
time-limit4 ,we were forced only to a   
bolder claim1 to a theistic language    
less halting1 more consistent1 more     
thorough in its own line1 as well as    

better qualified to assimilate and      
modify such schemes as ,von ,hartmann's 
philosophy of the unconscious--a        
philosophy1 by the way1 quite intolerant
 of a merely mechanical evolution4 7,see
 ,von ,hartmann's ,wahrheit und ,irrthum
 in ,darwinismus4 ,berlin1 #ahge47      
,here was not the retrenchment of an    
extravagant assertion1 but the expansion
 of one which was faltering and         
inadequate4 ,the traditional statement  
did not need paring down so as to pass  
the meshes of a new and exacting        
criticism4 ,it was itself a net meant to
 surround and enclose experience2 and we
 must increase its size and close its   
mesh to hold newly disclosed facts of   
life4 ,the world1 which had seemed a    
fixed picture or model1 gained first    
perspective and then solidity and       
movement4 ,we had a glimpse of organic  
,,history2 and ,christian thought became
 more living and more assured as it met 
the larger view of life4  ,however      
unsatisfactory the new attitude might be

 to our critics1 to ,christians the     
reform was positive4 ,what was discarded
 was a limitation1 a negation4 ,the     
movement was essentially conservative1  
even actually reconstructive4 ,for the  
language disused was a language         
inconsistent with the definitions of    
orthodoxy2 it set bounds to the         
infinite1 and by implication withdrew   
from the creative rule all such         
processes as could be brought within the
 descriptions of research4 ,it ascribed 
fixity and finality to that creature in 
which an apostle taught us to recognise 
the birth-struggles of an unexhausted   
progress4 ,it tended to banish mystery  
from the world we see1 and to confine it
 to a remote first age4  ,in the        
reformed1 the restored1 language of     
religion1 ,creation became again not a  
link in a rational series to complete a 
circle of the sciences1 but the         
mysterious and permanent relation       
between the infinite and the finite1    
between the moving changes we know in   

part1 and the ,power1 after the fashion 
of that observation1 unknown1 which is  
itself unmoved all motion's source4     
7,hymn of the ,church-- ,rerum ,deus    
tenax vigor1  ,immotus in te permanens47
  ,with regard to man it is hardly      
necessary1 even were it possible1 to    
illustrate the application of this      
bolder faith4 ,when the record of his   
high extraction fell under dispute1 we  
were driven to a contemplation of the   
whole of his life1 rather than of a part
 and that part out of sight4 ,we        
remembered again1 out of ,aristotle1    
that the result of a process interprets 
its beginnings4 ,we were obliged to read
 the title of such dignity as we may    
claim1 in results and still more in     
aspirations4  ,some men still measure   
the value of great present facts in     
life--reason and virtue and             
sacrifice--by what a self-disparaged    
reason can collect of the meaner        
rudiments of these noble gifts4 ,mr     
,balfour has admirably displayed the    

discrepancy1 in this view1 between the  
alleged origin and the alleged authority
 of reason4 ,such an argument ought to  
be used not to discredit the confident  
reason1 but to illuminate and dignify   
its dark beginnings1 and to show that at
 every step in the long course of growth
 a ,power was at work which is not      
included in any term or in all the terms
 of the series4  ,i submit that the more
 men know of actual ,christian teaching1
 its fidelity to the past1 and its      
sincerity in face of discovery1 the more
 certainly they will judge that the     
stimulus of the doctrine of evolution   
has produced in the long run vigour as  
well as flexibility in the doctrine of  
,creation and of man4  ,i pass from     
,evolution in general to ,natural       
,selection4  ,the character in religious
 language which ,i have for short called
 mechanical was not absent in the       
argument from design as stated before   
,darwin4 ,it seemed to have reference to
 a world conceived as fixed4 ,it        

pointed1 not to the plastic capacity and
 energy of living matter1 but to the    
fixed adaptation of this and that organ 
to an unchanging place or function4  ,mr
 ,hobhouse has given us the valuable    
phrase a niche of organic opportunity4  
,such a phrase would have borne a       
different sense in non-evolutionary     
thought4 ,in that thought1 the          
opportunity was an opportunity for the  
,creative ,power1 and ,design appeared  
in the preparation of the organism to   
fit the niche4 ,the idea of the niche   
and its occupant growing together from  
simpler to more complex mutual          
adjustment was unwelcome to this        
teleology4 ,if the adaptation was traced
 to the influence1 through competition1 
of the environment1 the old teleology   
lost an illustration and a proof4 ,for  
the cogency of the proof in every       
instance depended upon the absence of   
explanation4 ,where the process of      
adaptation was discerned1 the evidence  
of ,purpose or ,design was weak4 ,it was

 strong only when the natural           
antecedents were not discovered1        
strongest when they could be declared   
undiscoverable4  ,paley's favourite word
 is ,contrivance2 and for him           
contrivance is most certain where       
production is most obscure4 ,he points  
out the physiological advantage of the  
valvulae conniventes to man1 and the    
advantage for teleology of the fact that
 they cannot have been formed by action 
and pressure4 ,what is not due to       
pressure may be attributed to design1   
and when a mechanical process more      
subtle than pressure was suggested1 the 
case for design was so far weakened4    
,the cumulative proof from the multitude
 of instances began to disappear when1  
in selection1 a natural sequence was    
suggested in which all the adaptations  
might be reached by the motive power of 
life1 and especially when1 as in        
,darwin's teaching1 there was full      
recognition of the reactions of life to 
the stimulus of circumstance4 ,the      

organism fits the niche1 said the       
teleologist1 because the ,creator formed
 it so as to fit4 ,the organism fits the
 niche1 said the naturalist1 because    
unless it fitted it could not exist4 ,it
 was fitted to survive1 said the        
theologian4 ,it survives because it     
fits1 said the selectionist4 ,the two   
forms of statement are not incompatible2
 but the new statement1 by provision of 
an ideally universal explanation of     
process1 was hostile to a doctrine of   
purpose which relied upon evidences     
always exceptional however numerous4    
,science persistently presses on to find
 the universal machinery of adaptation  
in this planet2 and whether this be     
found in selection1 or in direct-effect1
 or in vital reactions resulting in     
large changes1 or in a combination of   
these and other factors1 it must always 
be opposed to the conception of a       
,divine ,power here and there but not   
everywhere active4  ,for science1 the   
,divine must be constant1 operative     

everywhere and in every quality and     
power1 in environment and in organism1  
in stimulus and in reaction1 in         
variation and in struggle1 in hereditary
 equilibrium1 and in the unstable state 
of species2 equally present on both     
sides of every strain1 in all pressures 
and in all resistances1 in short in the 
general wonder of life and the world4   
,and this is exactly what the ,divine   
,power must be for religious faith4     
,the point ,i wish once more to make is 
that the necessary readjustment of      
teleology1 so as to make it depend upon 
the contemplation of the whole instead  
of a part1 is advantageous quite as much
 to theology as to science4 ,for the    
older view failed in courage4 ,here     
again our theism was not sufficiently   
theistic4  ,where results seemed        
inevitable1 it dared not claim them as  
,god-given4 ,in the argument from       
,design it spoke not of ,god in the     
sense of theology1 but of a ,contriver1 
immensely1 not infinitely wise and good1

 working within a world1 the scene1     
rather than the ever dependent outcome1 
of ,his ,wisdom2 working in such        
emergencies and opportunities as        
occurred1 by forces not altogether      
within ,his control1 towards an end     
beyond ,himself4 ,it gave us1 instead of
 the awful reverence due to the ,cause  
of all substance and form1 all love and 
wisdom1 a dangerously detached          
appreciation of an ingenuity and        
benevolence meritorious in aim and often
 surprisingly successful in contrivance4
  ,the old teleology was more useful to 
science than to religion1 and the       
design-naturalists ought to be          
gratefully remembered by ,biologists4   
,their search for evidences led them to 
an eager study of adaptations and of    
minute forms1 a study such as we have   
now an incentive to in the theory of    
,natural ,selection4 ,one hardly meets  
with the same ardour in microscopical   
research until we come to modern        
workers4 ,but the argument from ,design 

was never of great importance to faith4 
,still1 to rid it of this character was 
worth all the stress and anxiety of the 
gallant old war4 ,if ,darwin had done   
nothing else for us1 we are to-day      
deeply in his debt for this4 ,the world 
is not less venerable to us now1 not    
less eloquent of the causing mind1      
rather much more eloquent and sacred4   
,but our wonder is not that the underjaw
 of the swine works under the ground or 
in any or all of those particular       
adaptations which ,paley collected with 
so much skill1 but that a purpose       
transcending1 though resembling1 our own
 purposes1 is everywhere manifest2 that 
what we live in is a whole1 mutually    
sustaining1 eventful and beautiful1     
where the dead forces feed the energies 
of life1 and life sustains a stranger   
existence1 able in some real measure to 
contemplate the whole1 of which1        
mechanically considered1 it is a minor  
product and a rare ingredient4 ,here1   
again1 the change was altogether        

positive4 ,it was not the escape of a   
vessel in a storm with loss of spars and
 rigging1 not a shortening of sail to   
save the masts and make a port of       
refuge4 ,it was rather the emergence    
from narrow channels to an open sea4 ,we
 had propelled the great ship1 finding  
purchase here and there for slow and    
uncertain movement4 ,now1 in deep water1
 we spread large canvas to a favouring  
breeze4  ,the scattered traces of design
 might be forgotten or obliterated4 ,but
 the broad impression of ,order became  
plainer when seen at due distance and in
 sufficient range of effect1 and the    
evidence of love and wisdom in the      
universe could be trusted more securely 
for the loss of the particular          
calculation of their machinery4  ,many  
other topics of faith are affected by   
modern biology4 ,in some of these we    
have learnt at present only a wise      
caution1 a wise uncertainty4 ,we stand  
before the newly unfolded spectacle of  
suffering1 silenced2 with faith not     

scientifically reassured but still      
holding fast certain other clues of     
conviction4 ,in many important topics we
 are at a loss4 ,but in others1 and     
among them those ,i have mentioned1 we  
have passed beyond this negative state  
and find faith positively strengthened  
and more fully expressed4  ,we have     
gained also a language and a habit of   
thought more fit for the great and dark 
problems that remain1 less liable to    
damaging conflicts1 equipped for more   
rapid assimilation of knowledge4 ,and by
 this change biology itself is a gainer4
 ,for1 relieved of fruitless encounters 
with popular religion1 it may advance   
with surer aim along the path of really 
scientific life-study which was reopened
 for modern men by the publication of   
,the ,origin of ,species4  ,charles     
,darwin regretted that1 in following    
science1 he had not done more direct    
good 7,life and ,letters1 ,vol4 ,,iii4  
page #cei47 to his fellow-creatures4 ,he
 has1 in fact1 rendered substantial     

service to interests bound up with the  
daily conduct and hopes of common men2  
for his work has led to improvements in 
the preaching of the ,christian faith4  
,,xxv4 ,,the ,,influence ,,of           
,,darwinism ,,on ,,the ,,study ,,of     
,,religions4 ,by ,jane ,ellen ,harrison4
  ,hon4 ,d4,litt4 7,durham71 ,hon4      
,,ll4,d4 7,aberdeen71 ,staff ,lecturer  
and sometime ,fellow of ,newnham        
,college1 ,cambridge4  ,corresponding   
member of the ,german ,archaeological   
,institute4  ,the title of my paper     
might well have been the creation by    
,darwinism of the scientific study of   
,religions1 but that ,i feared to mar my
 tribute to a great name by any shadow  
of exaggeration4 ,before the publication
 of ,the ,origin of ,species and ,the   
,descent of ,man1 even in the eighteenth
 century1 isolated thinkers1 notably    
,hume and ,herder1 had conjectured that 
the orthodox beliefs of their own day   
were developments from the cruder       
superstitions of the past4 ,these were  

however only particular speculations of 
individual sceptics4 ,religion was not  
yet generally regarded as a proper      
subject for scientific study1 with facts
 to be collected and theories to be     
deduced4 ,a ,congress of ,religions such
 as that recently held at ,oxford would 
have savoured of impiety4  ,in the brief
 space allotted me ,i can attempt only  
two things2 first1 and very briefly1 ,i 
shall try to indicate the normal        
attitude towards religion in the early  
part of the last century2 second1 and in
 more detail1 ,i shall try to make clear
 what is the outlook of advanced        
thinkers to-day4 7,to be accurate ,i    
ought to add in ,europe4 ,i advisedly   
omit from consideration the whole       
immense field of ,oriental mysticism1   
because it has remained practically     
untouched by the influence of           
,darwinism47 ,from this second inquiry  
it will1 ,i hope1 be abundantly manifest
 that it is the doctrine of evolution   
that has made this outlook possible and 

even necessary4  ,the ultimate and      
unchallenged presupposition of the old  
view was that religion was a ,,doctrine1
 a body of supposed truths4 ,it was in  
fact what we should now call ,theology1 
and what the ancients called ,mythology4
 ,ritual was scarcely considered at all1
 and1 when considered1 it was held to be
 a form in which beliefs1 already       
defined and fixed as dogma1 found a     
natural mode of expression4 ,this1 it   
will be later shown1 is a profound error
 or rather a most misleading half-truth4
 ,creeds1 doctrines1 theology and the   
like are only a part1 and at first the  
least important part1 of religion4      
,further1 and the fact is important1    
this ,,dogma1 thus supposed to be the   
essential content of the true religion1 
was a teleological scheme complete and  
unalterable1 which had been revealed to 
man once and for all by a highly        
anthropomorphic ,god1 whose existence   
was assumed4 ,the duty of man towards   
this revelation was to accept its       

doctrines and obey its precepts4 ,the   
notion that this revelation had grown   
bit by bit out of man's consciousness   
and that his business was to better it  
would have seemed rank blasphemy4       
,religion1 so conceived1 left no place  
for development4 ,the ,truth might be   
learnt1 but never critically examined2  
being thus avowedly complete and final1 
it was doomed to stagnation4  ,the      
details of this supposed revelation seem
 almost too naive for enumeration4 ,as  
,hume observed1 popular theology has a  
positive appetite for absurdity4 ,it is 
sufficient to recall that revelation    
included such items as the ,creation    
7,it is interesting to note that the    
very word ,creator has nowadays almost  
passed into the region of mythology4    
,instead we have ,l',evolution          
,creatrice47 of the world out of nothing
 in six days2 the making of ,eve from   
one of ,adam's ribs2 the ,temptation by 
a talking snake2 the confusion of       
tongues at the tower of ,babel2 the     

doctrine of ,original ,sin2 a scheme of 
salvation which demanded the ,virgin    
,birth1 ,vicarious ,atonement1 and the  
,resurrection of the material body4 ,the
 scheme was unfolded in an infallible   
,book1 or1 for one section of           
,christians1 guarded by the tradition of
 an infallible ,church1 and on the      
acceptance or refusal of this scheme    
depended an eternity of weal or woe4    
,there is not one of these doctrines    
that has not now been recast1 softened  
down1 mysticised1 allegorised into      
something more conformable with modern  
thinking4 ,it is hard for the present   
generation1 unless their breeding has   
been singularly archaic1 to realise that
 these amazing doctrines were literally 
held and believed to constitute the very
 essence of religion2 to doubt them was 
a moral delinquency4  ,it had not1      
however1 escaped the notice of          
travellers and missionaries that savages
 carried on some sort of practices that 
seemed to be religious1 and believed in 

some sort of spirits or demons4 ,hence1 
beyond the confines illuminated by      
revealed truth1 a vague region was      
assigned to ,,natural ,religion4 ,the   
original revelation had been kept intact
 only by one chosen people1 the ,jews1  
by them to be handed on to              
,christianity4 ,outside the borders of  
this ,goshen the world had sunk into the
 darkness of ,egypt4 ,where analogies   
between savage cults and the ,christian 
religions were observed1 they were      
explained as degradations2 the heathen  
had somehow wilfully lost the light4    
,our business was not to study but1     
exclusively1 to convert them1 to root   
out superstition and carry the torch of 
revelation to ,souls in heathen darkness
 lying4 ,to us nowadays it is a         
commonplace of anthropological research 
that we must seek for the beginnings of 
religion in the religions of primitive  
peoples1 but in the last century the    
orthodox mind was convinced that it     
possessed a complete and luminous       

ready-made revelation2 the study of what
 was held to be a mere degradation      
seemed idle and superfluous4  ,but1 it  
may be asked1 if1 to the orthodox1      
revealed religion was sacrosanct and    
savage religion a thing beneath         
consideration1 why did not the sceptics 
show a more liberal spirit1 and pursue  
to their logical issue the conjectures  
they had individually hazarded8 ,the    
reason is simple and significant4 ,the  
sceptics too had not worked free from   
the presupposition that the essence of  
religion is dogma4 ,their               
intellectualism1 expressive of the whole
 eighteenth century1 was probably in    
,england strengthened by the ,protestant
 doctrine of an infallible ,book4 ,hume 
undoubtedly confused religion with      
dogmatic theology4 ,the attention of    
orthodox and sceptics alike was focussed
 on the truth or falsity of certain     
propositions4 ,only a few minds of rare 
quality were able dimly to conceive that
 religion might be a necessary step in  

the evolution of human thought4  ,it is 
not a little interesting to note that   
,darwin1 who was leader and intellectual
 king of his generation1 was also in    
this matter to some extent its child4   
,his attitude towards religion is stated
 clearly1 in ,chapter ,,viii4 of the    
,life and ,letters4 7,vol4 ,i4 page     
#cjd4 ,for ,darwin's religious views see
 also ,descent of ,man1 #ahga1 ,vol4 ,i4
 page #fe2 #bnd edition4 ,vol4 ,i4 page 
#adb47 ,on board the ,beagle he was     
simply orthodox and was laughed at by   
several of the officers for quoting the 
,bible as an unanswerable authority on  
some point of morality4 ,by #ahci he had
 come to see that the ,old ,testament   
was no more to be trusted than the      
sacred books of the ,hindoos4 ,next went
 the belief in miracles1 and next       
,paley's argument from design broke down
 before the law of natural selection2   
the suffering so manifest in nature is  
seen to be compatible rather with       
,natural ,selection than with the       

goodness and omnipotence of ,god4       
,darwin felt to the full all the        
ignorance that lay hidden under specious
 phrases like the plan of creation and  
,unity of design4 ,finally1 he tells us 
the mystery of the beginning of all     
things is insoluble by us2 and ,i for   
one must be content to remain an        
,agnostic4  ,the word ,agnostic is      
significant not only of the humility of 
the man himself but also of the attitude
 of his age4 ,religion1 it is clear1 is 
still conceived as something to be      
,,known1 a matter of true or false      
,,opinion4 ,orthodox religion was to    
,darwin a series of erroneous hypotheses
 to be bit by bit discarded when shown  
to be untenable4 ,the ,,acts of religion
 which may result from such convictions1
 i4e4 devotion in all its forms1 prayer1
 praise1 sacraments1 are left           
unmentioned4 ,it is clear that they are 
not1 as now to us1 sociological         
survivals of great interest and         
importance1 but rather matters too      

private1 too personal1 for discussion4  
,huxley1 writing in the ,contemporary   
,review 7#ahga471 says1 ,in a dozen     
years ,the ,origin of ,species has      
worked as complete a revolution in      
biological science as the ,principia did
 in astronomy4 ,it has done so because1 
in the words of ,helmholtz1 it contained
 an essentially new creative thought1   
that of the continuity of life1 the     
absence of breaks4 ,in the two most     
conservative subjects1 ,religion and    
,classics1 this creative ferment was    
slow indeed to work4 ,darwin himself    
felt strongly that a man should not     
publish on a subject to which he has not
 given special and continuous thought1  
and hence wrote little on religion and  
with manifest reluctance1 though1 as    
already seen1 in answer to pertinacious 
inquiry he gave an outline of his own   
views4 ,but none the less he foresaw    
that his doctrine must have1 for the    
history of man's mental evolution1      
issues wider than those with which he   

was prepared personally to deal4 ,he    
writes1 in ,the ,origin of ,species     
7#fth edition1 page #dbh471 ,in the     
future ,i see open fields for far more  
important researches4 ,psychology will  
be securely based on the foundation     
already well laid by ,mr ,herbert       
,spencer1 that of the necessary         
acquirement of each mental power and    
capacity by gradation4  ,nowhere1 it is 
true1 does ,darwin definitely say that  
he regarded religion as a set of        
phenomena1 the development of which may 
be studied from the psychological       
standpoint4 ,rather we infer from his   
,,piety--in the beautiful ,roman        
sense--towards tradition and            
association1 that religion was to him in
 some way sacrosanct4 ,but it is        
delightful to see how his heart went out
 towards the new method in religious    
study which he had himself1 if          
half-unconsciously1 inaugurated4        
,writing in #ahga to ,dr ,tylor1 on the 
publication of his ,primitive ,culture1 

he says 7,life and ,letters1 ,vol4      
,,iii4 page #aea471 ,it is wonderful how
 you trace animism from the lower races 
up the religious belief of the highest  
races4 ,it will make me for the future  
look at religion--a belief in the soul1 
etc4--from a new point of view4         
,psychology was henceforth to be based  
on the necessary acquirement of each    
mental capacity by gradation4 ,with     
these memorable words the door closes on
 the old and opens on the new horizon4  
,the mental focus henceforth is not on  
the maintaining or refuting of an       
orthodoxy but on the genesis and        
evolution of a capacity1 not on         
perfection but on process4 ,continuous  
evolution leaves no gap for revelation  
sudden and complete4 ,we have henceforth
 to ask1 not when was religion revealed 
or what was the revelation1 but how did 
religious phenomena arise and develop4  
,for an answer to this we turn with new 
and reverent eyes to study the heathen  
in his blindness and the child born in  

sin4 ,we still indeed send out          
missionaries to convert the heathen1 but
 here at least in ,cambridge before they
 start they attend lectures on          
anthropology and comparative religion4  
,the decadence theory is dead and should
 be buried4  ,the study of primitive    
religions then has been made possible   
and even inevitable by the theory of    
,evolution4 ,we have now to ask what new
 facts and theories have resulted from  
that study4 ,this brings us to our      
second point1 the advanced outlook on   
religion to-day4  ,the view ,i am about 
to state is no mere personal opinion of 
my own4 ,to my present standpoint ,i    
have been led by the investigations of  
such masters as ,drs ,wundt1 ,lehmann1  
,preuss1 ,bergson1 ,beck and in our own 
country ,drs ,tylor and ,frazer4 7,i can
 only name here the books that have     
specially influenced my own views4 ,they
 are ,w4 ,wundt1 ,volkerpsychologie1    
,leipzig1 #aijj1 ,p4 ,beck1 ,die        
,nachahmung1 ,leipzig1 #aijd1 and       

,erkenntnisstheorie des primitiven      
,denkens in ,zeitschrift f4 ,philos4 und
 ,philos4 ,kritik1 #aijc1 page #agb1 and
 #aijd1 page #i4 ,henri ,bergson1       
,l',evolution ,creatrice and ,matiere et
 ,memoire1 #aijh1 ,k4 ,th4 ,preuss1     
various articles published in the       
,globus 7see page #ejg1 note #a71 and in
 the ,archiv4 f4 ,religionswissenschaft1
 and for the subject of magic1 ,,mm4    
,hubert et ,mauss1 ,theorie generale de 
la ,magie1 in ,l',annee ,sociologique1  
,,vii47  ,religion always contains two  
factors4 ,first1 a theoretical factor1  
what a man ,,thinks about the           
unseen--his theology1 or1 if we prefer  
so to call it1 his mythology4 ,second1  
what he ,,does in relation to this      
unseen--his ritual4 ,these factors      
rarely if ever occur in complete        
separation2 they are blended in very    
varying proportions4 ,religion we have  
seen was in the last century regarded   
mainly in its theoretical aspect as a   
doctrine4 ,greek religion for example   

meant to most educated persons ,greek   
mythology4 ,yet even a cursory          
examination shows that neither ,greek   
nor ,roman had any creed or dogma1 any  
hard and fast formulation of belief4 ,in
 the ,greek ,mysteries 7,see my         
,prolegomena to the ,study of ,greek    
,religion1 page #aee1 ,cambridge1       
#aijc47 only we find what we should call
 a ,confiteor2 and this is not a        
confession of faith1 but an avowal of   
rites performed4 ,when the religion of  
primitive peoples came to be examined it
 was speedily seen that though vague    
beliefs necessarily abound1 definite    
creeds are practically non-existent4    
,ritual is dominant and imperative4     
,this predominance and priority of      
ritual over definite creed was first    
forced upon our notice by the study of  
savages1 but it promptly and happily    
joined hands with modern psychology4    
,popular belief says1 ,i think1         
therefore ,i act2 modern scientific     
psychology says1 ,i act 7or rather1     

,r,eact to outside stimulus71 and so ,i 
come to think4 ,thus there is set going 
a recurrent series3 act and thought     
become in their turn stimuli to fresh   
acts and thoughts4 ,in examining        
religion as envisaged to-day it would   
therefore be more correct to begin with 
the practice of religion1 i4e4 ritual1  
and then pass to its theory1 theology or
 mythology4 ,but it will be more        
convenient to adopt the reverse method4 
,the theoretical content of religion is 
to those of us who are ,protestants far 
more familiar and we shall thus proceed 
from the known to the comparatively     
unknown4  ,i shall avoid all attempt at 
rigid definition4 ,the problem before   
the modern investigator is1 not to      
determine the essence and definition of 
religion but to inquire how religious   
phenomena1 religious ideas and practices
 arose4 ,now the theoretical content of 
religion1 the domain of theology or     
mythology1 is broadly familiar to all4  
,it is the world of the unseen1 the     

supersensuous2 it is the world of what  
we call the soul and the supposed       
objects of the soul's perception1       
sprites1 demons1 ghosts and gods4 ,how  
did this world grow up8  ,we turn to our
 savages4 ,intelligent missionaries of  
bygone days used to ply savages with    
questions such as these3 ,had they any  
belief in ,god8 ,did they believe in the
 immortality of the soul8 ,taking their 
own clear-cut conceptions1 discriminated
 by a developed terminology1 these      
missionaries tried to translate them    
into languages that had neither the     
words nor the thoughts1 only a vague1   
inchoate1 tangled substratum1 out of    
which these thoughts and words later    
differentiated themselves4 ,let us      
examine this substratum4  ,nowadays we  
popularly distinguish between objective 
and subjective2 and further1 we regard  
the two worlds as in some sense opposed4
 ,to the objective world we commonly    
attribute some reality independent of   
consciousness1 while we think of the    

subjective as dependent for its         
existence on the mind4 ,the objective   
world consists of perceptible things1 or
 of the ultimate constituents to which  
matter is reduced by physical           
speculation4 ,the subjective world is   
the world of beliefs1 hallucinations1   
dreams1 abstract ideas1 imaginations and
 the like4 ,psychology of course knows  
that the objective and subjective worlds
 are interdependent1 inextricably       
intertwined1 but for practical purposes 
the distinction is convenient4  ,but    
primitive man has not yet drawn the     
distinction between objective and       
subjective4 ,nay1 more1 it is foreign to
 almost the whole of ancient philosophy4
 ,plato's ,ideas 7,i owe this           
psychological analysis of the elements  
of the primitive supersensuous world    
mainly to ,dr ,beck1 ,erkenntnisstheorie
 des primitiven ,denkens1 see page #dih1
 note #a471 his ,goodness1 ,truth1      
,beauty1 his class-names1 horse1 table1 
are it is true dematerialised as far as 

possible1 but they have outside         
existence1 apart from the mind of the   
thinker1 they have in some shadowy way  
spatial extension4 ,yet ancient         
philosophies and primitive man alike    
needed and possessed for practical      
purposes a distinction which served as  
well as our subjective and objective4   
,to the primitive savage all his        
thoughts1 every object of which he was  
conscious1 whether by perception or     
conception1 had reality1 that is1 it had
 existence outside himself1 but it might
 have reality of various kinds or       
different degrees4  ,it is not hard to  
see how this would happen4 ,a man's     
senses may mislead him4 ,he sees the    
reflection of a bird in a pond4 ,to his 
eyes it is a real bird4 ,he touches it1 
,,he ,,puts ,,it ,,to ,,the ,,touch1 and
 to his touch it is not a bird at all4  
,it is real then1 but surely not quite  
so real as a bird that you can touch4   
,again1 he sees smoke4 ,it is real to   
his eyes4 ,he tries to grasp it1 it     

vanishes4 ,the wind touches him1 but he 
cannot see it1 which makes him feel     
uncanny4 ,the most real thing is that   
which affects most senses and especially
 what affects the sense of touch4       
,apparently touch is the deepest down1  
most primitive1 of senses4 ,the rest are
 specialisations and complications4     
,primitive man has no formal rubric     
optical delusion1 but he learns         
practically to distinguish between      
things that affect only one sense and   
things that affect two or more--if he   
did not he would not survive4 ,but both 
classes of things are real to him4      
,percipi est esse4  ,so far1 primitive  
man has made a real observation2 there  
are things that appeal to one sense     
only4 ,but very soon creeps in confusion
 fraught with disaster4 ,he passes      
naturally enough1 being economical of   
any mental effort1 from what he really  
sees but cannot feel to what he thinks  
he sees1 and gives to it the same       
secondary reality4 ,he has dreams1      

visions1 hallucinations1 nightmares4 ,he
 dreams that an enemy is beating him1   
and he wakes rubbing his head4 ,then    
further he remembers things2 that is1   
for him1 he sees them4 ,a great chief   
died the other day and they buried him1 
but he sees him still in his mind1 sees 
him in his war-paint1 splendid1         
victorious4 ,so the image of the past   
goes together with his dreams and       
visions to the making of this other less
 real1 but still real world1 his        
other-world of the supersensuous1 the   
supernatural1 a world1 the outside      
existence of which1 independent of      
himself1 he never questions4  ,and1     
naturally enough1 the future joins the  
past in this supersensuous world4 ,he   
can hope1 he can imagine1 he can        
prophesy4 ,and again the images of his  
hope are real2 he sees them with that   
mind's eye which as yet he has not      
distinguished from his bodily eye4 ,and 
so the supersensuous world grows and    
grows big with the invisible present1   

and big also with the past and the      
future1 crowded with the ghosts of the  
dead and shadowed with oracles and      
portents4 ,it is this supersensuous1    
supernatural world which is the         
eternity1 the other-world1 of primitive 
religion1 not an endlessness of time1   
but a state removed from full sensuous  
reality1 a world in which anything and  
everything may happen1 a world peopled  
by demonic ancestors and liable to a    
splendid vagueness1 to a once upon a    
time-ness denied to the present4 ,it not
 unfrequently happens that people who   
know that the world nowadays obeys fixed
 laws have no difficulty in believing   
that six thousand years ago man was made
 direct from a lump of clay1 and woman  
was made from one of man's superfluous  
ribs4  ,the fashioning of the           
supersensuous world comes out very      
clearly in primitive man's views about  
the soul and life after death4 ,herbert 
,spencer noted long ago the influence of
 dreams in forming a belief in          

immortality1 but being very rational    
himself1 he extended to primitive man a 
quite alien quality of rationality4     
,herbert ,spencer argued that when a    
savage has a dream he seeks to account  
for it1 and in so doing invents a spirit
 world4 ,the mistake here lies in the   
seeks to account for it4 7,primitive    
man1 as ,dr ,beck observes1 is not      
impelled by an ,erkenntnisstrieb4 ,dr   
,beck says he has counted upwards of #cj
 of these mythological ,triebe          
7tendencies7 with which primitive man   
has been endowed47 ,man is at first too 
busy ,,living to have any time for      
disinterested ,,thinking4 ,he dreams a  
dream and it is real for him4 ,he does  
not seek to account for it any more than
 for his hands and feet4 ,he cannot     
distinguish between a ,c,o,nception and 
a ,p,e,rception1 that is all4 ,he       
remembers his ancestors or they appear  
to him in a dream2 therefore they are   
alive still1 but only as a rule to about
 the third generation4 ,then he         

remembers them no more and they cease to
 be4  ,next as regards his own soul4 ,he
 feels something within him1 his        
life-power1 his will to live1 his power 
to act1 his personality--whatever we    
like to call it4 ,he cannot touch this  
thing that is himself1 but it is real4  
,his friend too is alive and one day he 
is dead2 he cannot move1 he cannot act4 
,well1 something has gone that was his  
friend's self4 ,he has stopped          
breathing4 ,was it his breath8 or he is 
bleeding2 is it his blood8 ,this        
life-power ,,is something2 does it live 
in his heart or his lungs or his        
midriff8 ,he did not see it go2 perhaps 
it is like wind1 an anima1 a ,geist1 a  
ghost4 ,but again it comes back in a    
dream1 only looking shadowy2 it is not  
the man's life1 it is a thin copy of the
 man2 it is an image 7eidolon74 ,it is  
like that shifting distorted thing that 
dogs the living man's footsteps in the  
sunshine2 it is a shade 7skia74 7,the   
two conceptions of the soul1 as a       

life-essence1 inseparable from the body1
 and as a separable phantom seem to     
occur in most primitive systems4 ,they  
are distinct conceptions but are        
inextricably blended in savage thought4 
,the two notions ,korperseele and       
,psyche have been very fully discussed  
in ,wundt's ,volkerpsychologie ,,ii4    
pages #a-adb1 ,leipzig1 #aijj47  ,ghosts
 and sprites1 ancestor worship1 the     
soul1 oracles1 prophecy2 all these      
elements of the primitive supersensuous 
world we willingly admit to be the      
proper material of religion2 but other  
elements are more surprising2 such are  
class-names1 abstract ideas1 numbers1   
geometrical figures4 ,we do not nowadays
 think of these as of religious content1
 but to primitive men they were all part
 of the furniture of his supernatural   
world4  ,with respect to class-names1   
,dr ,tylor 7,primitive ,culture1 ,vol4  
,,ii4 page #bde 7#dth edition71 #aijc47 
has shown how instructive are the first 
attempts of the savage to get at the    

idea of a class4 ,things in which       
similarity is observed1 things indeed   
which can be related at all are to the  
savage ,,kindred4 ,a species is a family
 or a number of individuals with a      
common god to look after them4 ,such for
 example is the ,finn doctrine of the   
haltia4 ,every object has its haltia1   
but the haltiat were not tied to the    
individual1 they interested themselves  
in every member of the species4 ,each   
stone had its haltia1 but that haltia   
was interested in other stones2 the     
individuals disappeared1 the haltia     
remained4  ,nor was it only class-names 
that belonged to the supersensuous      
world4 ,a man's own proper-name is a    
sort of spiritual essence of him1 a kind
 of soul to be carefully concealed4 ,by 
pronouncing a name you bring the thing  
itself into being4 ,when ,elohim would  
create ,day he called out to the ,light 
',day1' and to the ,darkness he called  
out ',night'2 the great magician        
pronounced the magic ,names and the     

,things came into being4 ,in the        
beginning was the ,word is literally    
true1 and this reflects the fact that   
our ,,conceptual world comes into being 
by the mental process of naming4 7,for a
 full discussion of this point see      
,beck1 ,nachahmung page #da1 ,die       
,sprache47 ,in old times people went    
further2 they thought that by naming    
events they could bring them to be1 and 
custom even to-day keeps up the         
inveterate magical habit of wishing     
people ,good ,morning and a ,happy      
,christmas4  ,number1 too1 is part of   
the supersensuous world that is         
thoroughly religious4 ,we can see and   
touch seven apples1 but seven itself1   
that wonderful thing that shifts from   
object to object1 giving it its         
,s,e,v,e,nness1 that living thing1 for  
it begets itself anew in                
multiplication--surely seven is a fit   
denizen of the upper-world4 ,originally 
all numbers dwelt there1 and a certain  
supersensuous sanctity still clings to  

seven and three4 ,we still say ,holy1   
,holy1 ,holy1 and in some mystic way    
feel the holier4  ,the soul and the     
supersensuous world get thinner and     
thinner1 rarer and more rarified1 but   
they always trail behind them clouds of 
smoke and vapour from the world of sense
 and space whence they have come4 ,it is
 difficult for us even nowadays to use  
the word soul without lapsing into a    
sensuous mythology4 ,the ,cartesians'   
sharp distinction between res extensa   
non cogitans and res cogitans non       
extansa is remote4  ,so far then man1   
through the processes of his thinking1  
has provided himself with a             
supersensuous world1 the world of       
sense-delusion1 of smoke and cloud1 of  
dream and phantom1 of imagination1 of   
name and number and image4 ,the natural 
course would now seem to be that this   
supersensuous world should develop into 
the religious world as we know it1 that 
out of a vague animism with ghosts of   
ancestors1 demons1 and the like1 there  

should develop in due order momentary   
gods 7,augenblicks-,gotter71 tribal     
gods1 polytheism1 and finally a pure    
monotheism4  ,this course of development
 is usually assumed1 but it is not ,i   
think quite what really happens4 ,the   
supersensuous world as we have got it so
 far is too theoretic to be complete    
material of religion4 ,it is indeed only
 one factor1 or rather it is as it were 
a lifeless body that waits for a living 
spirit to possess and inform it4 ,had   
the theoretic factor remained uninformed
 it would eventually have separated off 
into its constituent elements of error  
and truth1 the error dying down as a    
belated metaphysic1 the truth developing
 into a correct and scientific          
psychology of the subjective4 ,but man  
has ritual as well as mythology2 that   
is1 he feels and acts as well as thinks2
 nay more he probably feels and acts    
long before he definitely thinks4 ,this 
contradicts all our preconceived notions
 of theology4 ,man1 we imagine1 believes

 in a god or gods and then worships4    
,the real order seems to be that1 in a  
sense presently to be explained1 he     
worships1 he feels and acts1 and out of 
his feeling and action1 projected into  
his confused thinking1 he develops a    
god4 ,we pass therefore to our second   
factor in religion3--ritual4  ,the word 
ritual brings to our modern minds the   
notion of a church with a priesthood and
 organised services4 ,instinctively we  
think of a congregation meeting to      
confess sins1 to receive absolution1 to 
pray1 to praise1 to listen to sermons1  
and possibly to partake of sacraments4  
,were we to examine these fully         
developed phenomena we should hardly get
 further in the analysis of our         
religious conceptions than the notion of
 a highly anthropomorphic god approached
 by purely human methods of personal    
entreaty and adulation4  ,further1 when 
we first come to the study of primitive 
religions we expect a priori to find the
 same elements1 though in a ruder form4 

,we expect to see ,the heathen in his   
blindness bow down to wood and stone1   
but the facts that actually confront us 
are startlingly dissimilar4 ,bowing down
 to wood and stone is an occupation that
 exists mainly in the minds of          
hymn-writers4 ,the real savage is more  
actively engaged4 ,instead of asking a  
god to do what he wants done1 he does it
 or tries to do it himself2 instead of  
prayers he utters spells4 ,in a word he 
is busy practising magic1 and above all 
he is strenuously engaged in dancing    
magical dances4 ,when the savage wants  
rain or wind or sunshine1 he does not go
 to church2 he summons his tribe and    
they dance a rain-dance or wind-dance or
 sun-dance4 ,when a savage goes to war  
we must not picture his wife on her     
knees at home praying for the absent2   
instead we must picture her dancing the 
whole night long2 not for mere joy of   
heart or to pass the weary hours2 she is
 dancing his war-dance to bring him     
victory4  ,magic is nowadays condemned  

alike by science and by religion2 it is 
both useless and impious4 ,it is        
obsolete1 and only practised by malign  
sorcerers in obscure holes and corners4 
,undoubtedly magic is neither religion  
nor science1 but in all probability it  
is the spiritual protoplasm from which  
religion and science ultimately         
differentiated4 ,as such the doctrine of
 evolution bids us scan it closely4     
,magic may be malign and private2       
nowadays it is apt to be both4 ,but in  
early days magic was as much for good as
 for evil2 it was publicly practised for
 the common weal4  ,the gist of magic   
comes out most clearly in magical       
dances4 ,we think of dancing as a light 
form of recreation1 practised by the    
young from sheer joie de vivre and      
unsuitable for the mature4 ,but among   
the ,tarahumares 7,carl ,lumholtz1      
,unknown ,mexico1 page #ccj1 ,london1   
#aijc47 in ,mexico the word for dancing1
 nolavoa1 means to work4 ,old men will  
reproach young men saying ,why do you   

not go to work8 meaning why do you not  
dance instead of only looking on4 ,the  
chief religious sin of which the        
,tarahumare is conscious is that he has 
not danced enough and not made enough   
tesvino1 his cereal intoxicant4         
,dancing then is to the savage          
,,working1 ,,doing1 and the dance is in 
its origin an imitation or perhaps      
rather an intensification of processes  
of work4 7,karl ,bucher1 ,arbeit und    
,rhythmus1 ,leipzig 7#crd edition71     
#aijb1 passim47 ,repetition1 regular and
 frequent1 constitutes rhythm and rhythm
 heightens the sense of will power in   
action4 ,rhythmical action may even1 as 
seen in the dances of ,dervishes1       
produce a condition of ecstasy4 ,ecstasy
 among primitive peoples is a condition 
much valued2 it is often1 though not    
always1 enhanced by the use of          
intoxicants4 ,psychologically the savage
 starts from the sense of his own will  
power1 he stimulates it by every means  
at his command4 ,feeling his will       

strongly and knowing nothing of natural 
law he recognises no limits to his own  
power2 he feels himself a magician1 a   
god2 he does not pray1 he ,,wills4      
,moreover he wills collectively 7,the   
subject of collective hallucination as  
an element in magic has been fully      
worked out by ,,mm4 ,hubert and ,mauss4 
,theorie generale de la ,magie1 ,in     
,l',annee ,sociologique1 #aijb--c1 page 
#adj471 reinforced by the will and      
action of his whole tribe4 ,truly of him
 it may be said ,la vie deborde         
l'intelligence1 l'intelligence c'est un 
retrecissement4 7,henri ,bergson1       
,l',evolution ,creatrice1 page #ej47    
,the magical extension and heightening  
of personality come out very clearly in 
what are rather unfortunately known as  
,,mimetic dances4 ,animal dances occur  
very frequently among primitive peoples4
 ,the dancers dress up as birds1 beasts1
 or fishes1 and reproduce the           
characteristic movements and habits of  
the animals impersonated4 7,so          

characteristic is this impersonation in 
magical dancing that among the ,mexicans
 the word for magic1 navali1 means      
disguise4 ,k4 ,th4 ,preuss1 ,archiv f4  
,religionswissenschaft1 #aijf1 page     
#ig47 ,a very common animal dance is the
 frog-dance4 ,when it rains the frogs   
croak4 ,if you desire rain you dress up 
like a frog and croak and jump4 ,we     
think of such a performance as a        
conscious imitation4 ,the man1 we think1
 is more or less ,,like a frog4 ,that is
 not how primitive man thinks2 indeed1  
he scarcely thinks at all2 what ,,he    
wants done the frog can do by croaking  
and jumping1 so he croaks and jumps and1
 for all he can1 ,,becomes a frog4      
,l'intelligence animale ,,joue sans     
doute les representations plutot qu'elle
 ne les pense4 7,bergson1 ,l',evolution 
,creatrice1 page #bje47  ,we shall best 
understand this primitive state of mind 
if we study the child born in sin4 ,if a
 child is playing at lions he does not  
,,imitate a lion1 i4e4 he does not      

consciously try to be a thing more or   
less like a lion1 he ,,becomes one4 ,his
 reaction1 his terror1 is the same as if
 the real lion were there4 ,it is this  
childlike power of utter impersonation1 
of ,,being the thing we act or even see 
acted1 this extension and               
intensification of our own personality  
that lives deep down in all of us and is
 the very seat and secret of our joy in 
the drama4  ,a child's mind is indeed   
throughout the best clue to the         
understanding of savage magic4 ,a young 
and vital child knows no limit to his   
own will1 and it is the only reality to 
him4 ,it is not that he wants at the    
outset to fight other wills1 but that   
they simply do not exist for him4 ,like 
the artist he goes forth to the work of 
creation1 gloriously alone4 ,his        
attitude towards other recalcitrant     
wills is they simply must4 ,let even a  
grown man be intoxicated1 be in love1 or
 subject to an intense excitement1 the  
limitations of personality again fall   

away4 ,like the omnipotent child he is  
again a god1 and to him all things are  
possible4 ,only when he is old and weary
 does he cease to command fate4  ,the   
,iroquois 7,hewitt1 ,american           
,anthropologist1 ,,iv4 ,i4 page #cb1    
#aijb1 ,n4,s47 of ,north ,america have a
 word1 orenda1 the meaning of which is  
easier to describe than to define1 but  
it seems to express the very soul of    
magic4 ,this orenda is your power to do 
things1 your force1 sometimes almost    
your personality4 ,a man who hunts well 
has much and good orenda2 the shy bird  
who escapes his snares has a fine       
orenda4 ,the orenda of the rabbit       
controls the snow and fixes the depth to
 which it will fall4 ,when a storm is   
brewing the magician is said to be      
making its orenda4 ,when you yourself   
are in a rage1 great is your orenda4    
,the notes of birds are utterances of   
their orenda4 ,when the maize is        
ripening1 the ,iroquois know it is the  
sun's heat that ripens it1 but they know

 more2 it is the cigala makes the sun to
 shine and he does it by chirping1 by   
uttering his orenda4 ,this orenda is    
sometimes very like the ,greek thumos1  
your bodily life1 your vigour1 your     
passion1 your power1 the virtue that is 
in you to feel and do4 ,this notion of  
orenda1 a sort of pan-vitalism1 is more 
fluid than animism1 and probably        
precedes it4 ,it is the projection of   
man's inner experience1 vague and       
unanalysed1 into the outer world4  ,the 
mana of the ,melanesians 7,codrington1  
,the ,melanesians1 pages #aah1 #aai1    
#aib1 ,oxford1 #ahia47 is somewhat more 
specialised--all men do not possess     
mana--but substantially it is the same  
idea4 ,mana is not only a force1 it is  
also an action1 a quality1 a state1 at  
once a substantive1 an adjective1 and a 
verb4 ,it is very closely neighboured by
 the idea of sanctity4 ,things that have
 mana are tabu4 ,like orenda it         
manifests itself in noises1 but         
specially mysterious ones1 it is mana   

that is rustling in the trees4 ,mana is 
highly contagious1 it can pass from a   
holy stone to a man or even to his      
shadow if it cross the stone4 ,all      
,melanesian religion1 ,dr ,codrington   
says1 consists in getting mana for      
oneself or getting it used for one's    
benefit4 7,codrington1 ,the             
,melanesians1 page #abj1 ,oxford1       
#ahia47  ,specially instructive is a    
word in use among the ,omaka 7,see      
,prof4 ,haddon1 ,magic and ,fetishism1  
page #fj1 ,london1 #aijf4 ,dr ,vierkandt
 7,globus1 ,july1 #aijg1 page #da7      
thinks that ,fernzauber is a later      
development from ,nahzauber471          
wazhin-dhedhe1 directive energy1 to     
send4 ,this word means roughly what we  
should call telepathy1 sending out your 
thought or will-power to influence      
another and affect his action4 ,here we 
seem to get light on what has always    
been a puzzle1 the belief in magic      
exercised at a distance4 ,for the savage
 will1 distance is practically          

non-existent1 his intense desire feels  
itself as non-spatial4 7,this notion of 
mana1 orenda1 wazhin-dhedhe and the like
 lives on among civilised peoples in    
such words as the ,vedic brahman in the 
neuter1 familiar to us in its masculine 
form ,brahman4 ,the neuter1 brahman1    
means magic power of a rite1 a rite     
itself1 formula1 charm1 also first      
principle1 essence of the universe4 ,it 
is own cousin to the ,greek dunamis and 
phusis4 ,see ,,mm4 ,hubert et ,mauss1   
,theorie generale de la ,magie1 page    
#aag1 in ,l',annee ,sociologique1       
,,vii47  ,through the examination of    
primitive ritual we have at last got at 
one tangible1 substantial factor in     
religion1 a real live experience1 the   
sense1 that is1 of will1 desire1 power  
actually experienced in person by the   
individual1 and by him projected1       
extended into the rest of the world4    
,at this stage it may fairly be asked1  
though the question cannot with any     
certainty be answered1 at what point in 

the evolution of man does this religious
 experience come in8  ,so long as an    
organism reacts immediately to outside  
stimulus1 with a certainty and          
conformity that is almost chemical1     
there is1 it would seem1 no place1 no   
possibility for magical experience4 ,but
 when the germ appears of an intellect  
that can foresee an end not immediately 
realised1 or rather when a desire arises
 that we feel and recognise as not      
satisfied1 then comes in the sense of   
will and the impulse magically to       
intensify that will4 ,the animal it     
would seem is preserved by instinct from
 drawing into his horizon things which  
do not immediately subserve the         
conservation of his species4 ,but the   
moment man's life-power began to make on
 the outside world demands not          
immediately and inevitably realised in  
action 7,i owe this observation to ,dr  
,k4 ,th4 ,preuss4 ,he writes 7,archiv f4
 ,relig4 #aijf1 page #ih71 ,die         
,betonung des ,willens in den           

,zauberakten ist der richtige ,kern4 ,in
 der ,tat muss der ,mensch den ,willen  
haben1 sich selbst und seiner ,umgebung 
besondere ,fahigkeiten zuzuschreiben1   
und den ,willen hat er1 sobald sein     
,verstand ihn befahigt1 ,,eine ,,uber   
,,den ,,instinkt ,,hinausgehen ,,der    
,,fursorge fur sich zu zeigen4 ,,so     
,,lange ,,ihn ,,der ,,instinkt ,,allein 
,,leitet1 ,,konnen ,,zauberhandlungen   
,,nicht ,,enstehen4 ,for more detailed  
analysis of the origin of magic1 see ,dr
 ,preuss ,ursprung der ,religion und    
,kunst1 ,globus1 ,,lxxxvi4 and          
,,lxxxvii471 then a door was opened to  
magic1 and in the train of magic        
followed errors innumerable1 but also   
religion1 philosophy1 science and art4  
,the world of mana1 orenda1 brahman is a
 world of feeling1 desiring1 willing1   
acting4 ,what element of thinking there 
may be in it is not yet differentiated  
out4 ,but we have already seen that a   
supersensuous world of thought grew up  
very early in answer to other needs1 a  

world of sense-illusions1 shadows1      
dreams1 souls1 ghosts1 ancestors1 names1
 numbers1 images1 a world only wanting  
as it were the impulse of mana to live  
as a religion4 ,which of the two worlds1
 the world of thinking or the world of  
doing1 developed first it is probably   
idle to inquire4 7,if external stimuli  
leave on organisms a trace or record    
such as is known as an ,engram1 this    
physical basis of memory and hence of   
thought is almost coincident with       
reaction of the most elementary kind4   
,see ,mr ,francis ,darwin's             
,presidential ,address to the ,british  
,association1 ,dublin1 #aijh1 page #h1  
and again ,bergson places memory at the 
very root of conscious existence1 see   
,l',evolution ,creatrice1 page #ah1 le  
fond meme de notre existence consciente 
est memoire1 c'est a dire prolongation  
du passee dans le present1 and again la 
duree mord dans le temps et y laisse    
l'enpreint de son dent1 and again1      
l',evolution implique une continuation  

reelle du passee par le present47  ,it  
is more important to ask1 ,why do these 
two worlds join8 ,because1 it would     
seem1 mana1 the egomaniac or            
megalomaniac element1 cannot get        
satisfied with real things1 and         
therefore goes eagerly out to a false   
world1 the supersensuous other-world    
whose growth we have sketched4 ,this    
junction of the two is fact1 not fancy4 
,among all primitive peoples dead men1  
ghosts1 spirits of all kinds1 become the
 chosen vehicle of mana4 ,even to this  
day it is sometimes urged that religion1
 i4e4 belief in the immortality of the  
soul1 is true because it satisfies the  
deepest craving of human nature4 ,the   
two worlds1 of mana and magic on the one
 hand1 of ghosts and other-world on the 
other1 combine so easily because they   
have the same laws1 or rather the same  
comparative absence of law4 ,as in the  
world of dreams and ghosts1 so in the   
world of mana1 space and time offer no  
obstacles2 with magic all things are    

possible4 ,in the one world what you    
imagine is real2 in the other what you  
desire is ipso facto accomplished4 ,both
 worlds are egocentric1 megalomaniac1   
filled to the full with unbridled human 
will and desire4  ,we are all of us born
 in sin1 in that sin which is to science
 the seventh and deadliest1             
anthropomorphism1 we are egocentric1    
ego-projective4 ,hence necessarily we   
make our gods in our own image4         
,anthropomorphism is often spoken of in 
books on religion and mythology as if it
 were a last climax1 a splendid final   
achievement in religious thought4       
,first1 we are told1 we have the        
lifeless object as god 7fetichism71 then
 the plant or animal 7phytomorphism1    
theriomorphism71 and last ,god is       
incarnate in the human form divine4     
,this way of putting things is          
misleading4 ,anthropomorphism lies at   
the very beginning of our consciousness4
 ,man's first achievement in thought is 
to realise that there is anything at all

 not himself1 any object to his subject4
 ,when he has achieved however dimly    
this distinction1 still for long1 for   
very long he can only think of those    
other things in terms of himself2 plants
 and animals are people with ways of    
their own1 stronger or weaker than      
himself but to all intents and purposes 
human4  ,again the child helps us to    
understand our own primitive selves4 ,to
 children animals are always people4    
,you promise to take a child for a      
drive4 ,the child comes up beaming with 
a furry bear in her arms4 ,you say the  
bear cannot go4 ,the child bursts into  
tears4 ,you think it is because the     
child cannot endure to be separated from
 a toy4 ,it is no such thing4 ,it is the
 intolerable hurt done to the bear's    
human heart--a hurt not to be healed by 
any proffer of buns4 ,he wanted to go1  
but he was a shy1 proud bear1 and he    
would not say so4  ,the relation of     
magic to religion has been much         
disputed4 ,according to one school      

religion develops out of magic1         
according to another1 though they       
ultimately blend1 they are at the outset
 diametrically opposed1 magic being a   
sort of rudimentary and mistaken science
 7,this view held by ,dr ,frazer is     
fully set forth in his ,golden ,bough   
7#bnd edition71 pages #gc-gi1 ,london1  
#aijj4 ,it is criticised by ,mr ,r4,r4  
,marett in ,from ,spell to ,prayer1     
,folk-,lore ,,xi4 #aijj1 page #acb1 also
 very fully by ,,mm4 ,hubert and ,mauss1
 ,theorie generale de la ,magie1 in     
,l',annee ,sociologique1 ,,vii4 page #a1
 with ,mr ,marett's view and with that  
of ,,mm4 ,hubert and ,mauss ,i am in    
substantial agreement471 religion having
 to do from the outset with spirits4    
,but1 setting controversy aside1 at the 
present stage of our inquiry their      
relation becomes1 ,i think1 fairly      
clear4 ,magic is1 if my view 7,this view
 as explained above is1 ,i believe1 my  
own most serious contribution to the    
subject4 ,in thinking it out ,i was much

 helped by ,prof4 ,gilbert ,murray47 be 
correct1 the active element which       
informs a supersensuous world fashioned 
to meet other needs4 ,this blend of     
theory and practice it is convenient to 
call religion4 ,in practice the         
transition from magic to religion1 from 
,spell to ,prayer1 has always been found
 easy4 ,so long as mana remains         
impersonal you order it about2 when it  
is personified and bulks to the shape of
 an overgrown man1 you drop the         
imperative and cringe before it4 ,my    
will be done is magic1 ,thy ,will be    
done is the last word in religion4 ,the 
moral discipline involved in the second 
is momentous1 the intellectual advance  
not striking4  ,i have spoken of magical
 ritual as though it were the informing 
life-spirit without which religion was  
left as an empty shell4 ,yet the word   
ritual does not1 as normally used1      
convey to our minds this notion of      
intense vitalism4 ,rather we associate  
ritual with something cut and dried1 a  

matter of prescribed form and monotonous
 repetition4 ,the association is        
correct2 ritual tends to become less and
 less informed by the life-impulse1 more
 and more externalised4 ,dr ,beck 7,die 
,nachahmung und ihre ,bedeutung fur     
,psychologie und ,volkerkunde1 ,leipzig1
 #aijd47 in his brilliant monograph on  
,imitation has laid stress on the almost
 boundless influence of the imitation of
 one man by another in the evolution of 
civilisation4 ,imitation is one of the  
chief spurs to action4 ,imitation begets
 custom1 custom begets sanctity4 ,at    
first all custom is sacred4 ,to the     
savage it is as much a religious duty to
 tattoo himself as to sacrifice to his  
gods4 ,but certain customs naturally    
survive1 because they are really useful2
 they actually have good effects1 and so
 need no social sanction4 ,others are   
really useless2 but man is too          
conservative and imitative to abandon   
them4 ,these become ritual4 ,custom is  
cautious1 but la vie est aleatoire4     

7,bergson1 op4 cit4 page #adc47  ,dr    
,beck's remarks on ritual are ,i think  
profoundly true and suggestive1 but with
 this reservation--they are true of     
ritual only when uninformed by personal 
experience4 ,the very elements in ritual
 on which ,dr ,beck lays such stress1   
imitation1 repetition1 uniformity and   
social collectivity1 have been found by 
the experience of all time to have a    
twofold influence--they inhibit the     
intellect1 they stimulate and suggest   
emotion1 ecstasy1 trance4 ,the ,church  
of ,rome knows what she is about when   
she prescribes the telling of the       
rosary4 ,mystery-cults and sacraments1  
the lineal descendants of magic1 all    
contain rites charged with suggestion1  
with symbols1 with gestures1 with       
half-understood formularies1 with all   
the apparatus of appeal to emotion and  
will--the more unintelligible they are  
the better they serve their purpose of  
inhibiting thought4 ,thus ritual deadens
 the intellect and stimulates will1     

desire1 emotion4 ,les operations        
magiques444 sont le resultat d'une      
science et d'une habitude qui exaltent  
la volonte humaine au-dessus de ses     
limites habituelles4 7,eliphas ,levi1   
,dogme et ,rituel de la haute ,magie1   
,,ii4 page #cb1 ,paris1 #ahfa1 and ,a   
defence of ,magic1 by ,evelyn           
,underhill1 ,fortnightly ,review1       
#aijg47 ,it is this personal            
,,experience1 this exaltation1 this     
sense of immediate1 non-intellectual    
revelation1 of mystical oneness with all
 things1 that again and again           
rehabilitates a ritual otherwise        
moribund4  ,to resume4 ,the outcome of  
our examination of ,,origines seems to  
be that religious phenomena result from 
two delusive processes--a delusion of   
the non-critical intellect1 a delusion  
of the over-confident will4 ,is religion
 then entirely a delusion8 ,i think not4
 7,i am deeply conscious that what ,i   
say here is a merely personal opinion or
 sentiment1 unsupported and perhaps     

unsupportable by reason1 and very       
possibly quite worthless1 but for fear  
of misunderstanding ,i prefer to state  
it47 ,every dogma religion has hitherto 
produced is probably false1 but for all 
that the religious or mystical spirit   
may be the only way of apprehending some
 things and these of enormous           
importance4 ,it may also be that the    
contents of this mystical apprehension  
cannot be put into language without     
being falsified and misstated1 that they
 have rather to be felt and lived than  
uttered and intellectually analysed1 and
 thus do not properly fall under the    
category of true or false1 in the sense 
in which these words are applied to     
propositions2 yet they may be something 
for which true is our nearest existing  
word and are often1 if not necessary at 
least highly advantageous to life4 ,that
 is why man through a series of more or 
less grossly anthropomorphic mythologies
 and theologies with their concomitant  
rituals tries to restate them4 ,meantime

 we need not despair4 ,serious          
psychology is yet young and has only    
just joined hands with physiology4      
,religious students are still hampered  
by mediaevalisms such as ,body and      
,soul1 and by the perhaps scarcely less 
mythological segregations of ,intellect1
 ,emotion1 ,will4 ,but new facts 7,see  
the ,proceedings of the ,society for    
,psychical ,research1 ,london1 passim1  
and especially ,vols4 ,,vii4-,,xv4 ,for 
a valuable collection of the phenomena  
of mysticism1 see ,william ,james1      
,varieties of ,religious ,experience1   
,edinburgh1 #aija-b47 are accumulating1 
facts about the formation and flux of   
personality1 and the relations between  
the conscious and the sub-conscious4    
,any moment some great imagination may  
leap out into the dark1 touch the secret
 places of life1 lay bare the cardinal  
mystery of the marriage of the spatial  
with the non-spatial4 ,it is1 ,i venture
 to think1 towards the apprehension of  
such mysteries1 not by reason only1 but 

by man's whole personality1 that the    
religious spirit in the course of its   
evolution through ancient magic and     
modern mysticism is ever blindly yet    
persistently moving4  ,be this as it    
may1 it is by thinking of religion in   
the light of evolution1 not as a        
revelation given1 not as a realite faite
 but as a process1 and it is so only1 ,i
 think1 that we attain to a spirit of   
real patience and tolerance4 ,we have   
ourselves perhaps learnt laboriously    
something of the working of natural law1
 something of the limitations of our    
human will1 and we have therefore       
renounced the practice of magic4 ,yet we
 are bidden by those in high places to  
pray ,sanctify this water to the        
mystical washing away of sin4 ,mystical 
in this connection spells magical1 and  
we have no place for a god-magician3 the
 prayer is to us unmeaning1 irreverent4 
,or again1 after much toil we have      
ceased1 or hope we have ceased1 to think
 anthropomorphically4 ,yet we are       

invited to offer formal thanks to ,god  
for a meal of flesh whose sanctity is   
the last survival of that sacrifice of  
bulls and goats he has renounced4 ,such 
a ritual confuses our intellect and     
fails to stir our emotion4 ,but to      
others this ritual1 magical or          
anthropomorphic as it is1 is charged    
with emotional impulse1 and others1 a   
still larger number1 think that they act
 by reason when really they are         
hypnotised by suggestion and tradition2 
their fathers did this or that and at   
all costs they must do it4 ,it was good 
that primitive man in his youth should  
bear the yoke of conservative custom2   
from each man's neck that yoke will     
fall1 when and because he has outgrown  
it4 ,science teaches us to await that   
moment with her own inward and abiding  
patience4 ,such a patience1 such a      
gentleness we may well seek to practise 
in the spirit and in the memory of      
,darwin4     ,,xxvi4 ,,evolution ,,and  
,,the ,,science ,,of ,,language4 ,by ,p4

 ,giles1 ,m4,a41 ,,ll4,d4 7,aberdeen71  
,reader in ,comparative ,philology in   
the ,university of ,cambridge4   ,in no 
study has the historical method had a   
more salutary influence than in the     
,science of ,language4 ,even the        
earliest records show that the meaning  
of the names of persons1 places1 and    
common objects was then1 as it has      
always been since1 a matter of interest 
to mankind4 ,and in every age the common
 man has regarded himself as competent  
without special training to explain by  
inspection 7if one may use a            
mathematical phrase7 the meaning of any 
words that attracted his attention4 ,out
 of this amateur etymologising has      
sprung a great amount of false history1 
a kind of historical mythology invented 
to explain familiar names4 ,a single    
example will illustrate the tendency4   
,according to the local legend the      
ancestor of the ,earl of ,erroll--a     
husbandman who stayed the flight of his 
countrymen in the battle of ,luncarty   

and won the victory over the ,danes by  
the help of the yoke of his             
oxen--exhausted with the fray uttered   
the exclamation ,hoch heigh6 ,the       
grateful king about to ennoble the      
victorious ploughman at once replied3   
,hoch heigh6 said ye      ,and ,hay     
shall ye be4  ,the ,norman origin of the
 name ,hay is well-known1 and the battle
 of ,luncarty long preceded the         
appearance of ,normans in ,scotland1 but
 the legend nevertheless persists4      
,though the earliest ,european treatise 
on philological questions which is now  
extant--the ,cratylus of ,plato1--as    
might be expected from its authorship1  
contains some acute thinking and some   
shrewd guesses1 yet the work as a whole 
is infantine in its handling of         
language1 and it has been doubted       
whether ,plato was more than half       
serious in some of the suggestions which
 he puts forward4 7,for an account of   
the ,cratylus with references to other  
literature see ,sandys' ,history of     

,classical ,scholarship1 ,i4 page #ib   
ff41 ,cambridge1 #aijc47 ,in the hands  
of the ,romans things were worse even   
than they had been in the hands of      
,plato and his ,greek successors4 ,the  
lack of success on the part of ,varro   
and later ,roman writers may have been  
partly due to the fact that1 from the   
etymological point of view1 ,latin is a 
much more difficult language than       
,greek2 it is by no means so closely    
connected with ,greek as the ancients   
imagined1 and they had no knowledge of  
the ,celtic languages from which1 on    
some sides at least1 much greater light 
on the history of the ,latin language   
might have been obtained4 ,roman        
civilisation was a late development     
compared with ,greek1 and its records   
dating earlier than #cjj ,b4,c4--a      
period when the best of ,greek          
literature was already in existence--are
 very few and scanty4 ,varro it is true 
was much more of an antiquary than      
,plato1 but his extant works seem to    

show that he was rather a dungeon of    
learning than an original thinker4  ,a  
scientific knowledge of language can be 
obtained only by comparison of different
 languages of the same family and the   
contrasting of their characteristics    
with those of another family or other   
families4 ,it never occurred to the     
,greeks that any foreign language was   
worthy of serious study4 ,herodotus and 
other travellers and antiquaries indeed 
picked up individual words from various 
languages1 either as being necessary in 
communication with the inhabitants of   
the countries where they sojourned1 or  
because of some point which interested  
them personally4 ,plato and others      
noticed the similarity of some ,phrygian
 words to ,greek1 but no systematic     
comparison seems ever to have been      
instituted4  ,in the ,middle ,ages the  
treatment of language was in a sense    
more historical4 ,the ,middle ,ages     
started with the hypothesis1 derived    
from the book of ,genesis1 that in the  

early world all men were of one language
 and of one speech4 ,though on the same 
authority they believed that the plain  
of ,shinar has seen that confusion of   
tongues whence sprang all the languages 
upon earth1 they seem to have considered
 that the words of each separate        
language were nevertheless derived from 
this original tongue4 ,and as ,hebrew   
was the language of the ,chosen ,people1
 it was naturally assumed that this     
original tongue was ,hebrew4 ,hence we  
find ,dante declaring in his treatise on
 the ,vulgar ,tongue 7,dante de ,vulgari
 ,eloquio1 ,i4 #d47 that the first word 
man uttered in ,paradise must have been 
,el1 the ,hebrew name of his ,maker1    
while as a result of the fall of ,adam1 
the first utterance of every child now  
born into this world of sin and misery  
is heu1 ,alas6 ,after the splendidly    
engraved bronze plates containing1 as we
 now know1 ritual regulations for       
certain cults1 were discovered in #addd 
at the town of ,gubbio1 in ,umbria1 they

 were declared1 by some authorities1 to 
be written in excellent ,hebrew4 ,the   
study of them has been the fascination  
and the despair of many a philologist4  
,thanks to the devoted labours of       
numerous scholars1 mainly in the last   
sixty years1 the general drift of these 
inscriptions is now known4 ,they are the
 only important records of the ancient  
,umbrian language1 which was related    
closely to that of the ,samnites and1   
though not so closely1 to that of the   
,romans on the other side of the        
,apennines4 ,yet less than twenty years 
ago a book was published in ,germany1   
which boasts itself the home of         
,comparative ,philology1 wherein the    
,german origin of the ,umbrian language 
was no less solemnly demonstrated than  
had been its ,celtic origin by ,sir     
,william ,betham in #ahdb4  ,it is good 
that the study of language should be    
historical1 but the first requisite is  
that the history should be sound4 ,how  
little had been learnt of the true      

history of language a century ago may be
 seen from a little book by ,stephen    
,weston first published in #ahjb and    
several times reprinted1 where          
accidental assonance is considered      
sufficient to establish connection4 ,is 
there not a word bad in ,english and a  
word bad in ,persian which mean the same
 thing8 ,clearly therefore ,persian and 
,english must be connected4 ,the        
conclusion is true1 but it is drawn from
 erroneous premises4 ,as stated1 this   
identity has no more value than the     
similar assonance between the ,english  
cover and the ,hebrew kophar1 where the 
history of cover as coming through      
,french from a ,latin co-operire was    
even in #ahjb well-known to many4 ,to   
this day1 in spite of recent elaborate  
attempts 7,most recently in ,h4         
,moller's ,semitisch und                
,indogermanisch1 ,erster ,teil1         
,kopenhagen1 #aijg47 to establish       
connection between the ,indo-,germanic  
and the ,semitic families of languages1 

there is no satisfactory evidence of    
such relation between these families4   
,this is not to deny the possibility of 
such a connection at a very early       
period2 it is merely to say that through
 the lapse of long ages all trustworthy 
record of such relationship1 if it ever 
existed1 has been1 so far as present    
knowledge extends1 obliterated4  ,but   
while ,stephen ,weston was publishing1  
with much public approval1 his          
collection of amusing similarities      
between languages--similarities which   
proved nothing--the key to the          
historical study of at least one family 
of languages had already been found by a
 learned ,englishman in a distant land4 
,in #aghc ,sir ,william ,jones had been 
sent out as a judge in the supreme court
 of judicature in ,bengal4 ,while still 
a young man at ,oxford he was noted as a
 linguist2 his reputation as a ,persian 
scholar had preceded him to the ,east4  
,in the intervals of his professional   
duties he made a careful study of the   

language which was held sacred by the   
natives of the country in which he was  
living4 ,he was mainly instrumental in  
establishing a society for the          
investigation of language and related   
subjects4 ,he was himself the first     
president of the society1 and in the    
third anniversary discourse delivered on
 ,february #b1 #aghf1 he made the       
following observations3 ,the ,sanscrit  
language1 whatever be its antiquity1 is 
of a wonderful structure2 more perfect  
than the ,,greek1 more copious than the 
,,latin1 and more exquisitely refined   
than either1 yet bearing to both of them
 a stronger affinity1 both in the roots 
of verbs and in the forms of grammar1   
than could possibly have been produced  
by accident2 so strong indeed1 that no  
philologer could examine them all three1
 without believing them to have sprung  
from some common source1 which1 perhaps1
 no longer exists3 there is a similar   
reason1 though not quite so forcible1   
for supposing that both the ,gothick and

 the ,celtick1 though blended with a    
very different idiom1 had the same      
origin with the ,sanscrit2 and the old  
,persian might be added to the same     
family1 if this was the place for       
discussing any question concerning the  
antiquities of ,persia4 7,asiatic       
,researches1 ,i4 page #dbb1 ,works of   
,sir ,w4 ,jones1 ,i4 page #bf1 ,london1 
#agii47  ,no such epoch-making discovery
 was probably ever announced with less  
flourish of trumpets4 ,though ,sir      
,william ,jones lived for eight years   
more and delivered other anniversary    
discourses1 he added nothing of         
importance to this utterance4 ,he had   
neither the time nor the health that was
 needed for the prosecution of so       
arduous an undertaking4  ,but the good  
seed did not fall upon stony ground4    
,the news was speedily conveyed to      
,europe4 ,by a happy chance1 the sudden 
renewal of war between ,france and      
,england in #ahjc gave ,friedrich       
,schlegel the opportunity of learning   

,sanscrit from ,alexander ,hamilton1 an 
,englishman who1 like many others1 was  
confined in ,paris during the long      
struggle with ,napoleon4 ,the influence 
of ,schlegel was not altogether for good
 in the history of this research1 but he
 was inspiring4 ,not upon him but upon  
,franz ,bopp1 a struggling ,german      
student who spent some time in ,paris   
and ,london a dozen years later1 fell   
the mantle of ,sir ,william ,jones4 ,in 
,bopp's ,comparative ,grammar of the    
,indo-,germanic languages which appeared
 in #ahcc1 three-quarters of a century  
ago1 the foundations of ,comparative    
,philology were laid4 ,since that day   
the literature of the subject has grown 
till it is almost1 if not altogether1   
beyond the power of any single man to   
cope with it4 ,but long as the discourse
 may be1 it is but the elaboration of   
the text that ,sir ,william ,jones      
supplied4  ,with the publication of     
,bopp's ,comparative ,grammar the       
historical study of language was put    

upon a stable footing4 ,needless to say 
much remained to be done1 much still    
remains to be done4 ,more than once     
there has been danger of the study      
following erroneous paths4 ,its         
terminology and its point of view have  
in some degree changed4 ,but nothing can
 shake the truth of the statement that  
the ,indo-,germanic languages constitute
 in themselves a family sprung from the 
same source1 marked by the same         
characteristics1 and differentiated from
 all other languages by formation1 by   
vocabulary1 and by syntax4 ,the         
historical method was applied to        
language long before it reached biology4
 ,nearly a quarter of a century before  
,charles ,darwin was born1 ,sir ,william
 ,jones had made the first suggestion of
 a comparative study of languages4      
,bopp's ,comparative ,grammar began to  
be published nine years before the first
 draft of ,darwin's treatise on the     
,origin of ,species was put on paper in 
#ahdb4  ,it is not therefore on the     

history of ,comparative ,philology in   
general that the ideas of ,darwin have  
had most influence4 ,unfortunately1 as  
,jowett has said in the introduction to 
his translation of ,plato's ,republic1  
most men live in a corner4 ,the         
specialisation of knowledge has many    
advantages1 but it has also             
disadvantages1 none worse perhaps than  
that it tends to narrow the specialist's
 horizon and to make it more difficult  
for one worker to follow the advances   
that are being made by workers in other 
departments4 ,no longer is it possible  
as in earlier days for an intellectual  
prophet to survey from a ,pisgah height 
all the ,promised ,land4 ,and the case  
of linguistic research has been         
specially hard4 ,this study has1 if the 
metaphor may be allowed1 a very extended
 frontier4 ,on one side it touches the  
domain of literature1 on other sides it 
is conterminous with history1 with      
ethnology and anthropology1 with        
physiology in so far as language is the 

production of the brain and tissues of a
 living being1 with physics in questions
 of pitch and stress accent1 with mental
 science in so far as the principles of 
similarity1 contrast1 and contiguity    
affect the forms and the meanings of    
words through association of ideas4 ,the
 territory of linguistic study is       
immense1 and it has much to supply which
 might be useful to the neighbours who  
border on that territory4 ,but they have
 not regarded her even with that        
interest which is called benevolent     
because it is not actively maleficent4  
,as ,horne ,tooke remarked a century    
ago1 ,locke had found a whole philosophy
 in language4 ,what have the            
philosophers done for language since8   
,the disciples of ,kant and of ,wilhelm 
von ,humboldt supplied her plentifully  
with the sour grapes of metaphysics2    
otherwise her neighbours have left her  
severely alone save for an occasional   
,ausflug1 on which it was clear they had
 sadly lost their bearings4 ,some       

articles in ,psychological ,journals1   
,wundt's great work on                  
,volkerpsychologie 7,erster ,band3 ,die 
,sprache1 ,leipzig1 #aijj4 ,new edition1
 #aijd4 ,this work has been fertile in  
producing both opponents and supporters4
 ,delbruck1 ,grundfragen der            
,sprachforschung1 ,strassburg1 #aija1   
with a rejoinder by ,wundt1             
,sprachgeschichte and                   
,sprachpsychologie1 ,leipzig1 #aija2 ,l4
 ,sutterlin1 ,das ,wesen der            
,sprachgebilde1 ,heidelberg1 #aijb2 von 
,rozwadowski1 ,wortbildung und          
,wortbedeutung1 ,heidelberg1 #aijd2 ,o4 
,dittrich1 ,grundzuge der               
,sprachpsychologie1 ,halle1 #aijd1 ,ch4 
,a4 ,sechehaye1 ,programme et methodes  
de la linguistique theorique1 ,paris1   
#aijh471 and ,mauthner's brilliantly    
written ,beitrage zu einer ,kritik der  
,sprache 7,in three parts3 7i7 ,sprache 
und ,psychologie1 7ii7 ,zur             
,sprachwissenschaft1 both ,stuttgart    
#aija1 7iii7 ,zur ,grammatic und ,logik 

7with index to all three volumes71      
,stuttgart and ,berlin1 #aijb47 give    
some reason to hope that1 on one side at
 least1 the future may be better than   
the past4  ,where ,charles ,darwin's    
special studies came in contact with the
 ,science of ,language was over the     
problem of the origin and development of
 language4 ,it is curious to observe    
that1 where so many fields of linguistic
 research have still to be              
reclaimed--many as yet can hardly be    
said to be mapped out1--the least       
accessible field of all--that of the    
,origin of ,language--has never wanted  
assiduous tillers4 ,unfortunately it is 
a field beyond most others where it may 
be said that  ,wilding oats and luckless
 darnel grow4  ,if ,comparative         
,philology is to work to purpose here1  
it must be on results derived from      
careful study of individual languages   
and groups of languages4 ,but as yet the
 group which ,sir ,william ,jones first 
mapped out and which ,bopp organised is 

the only one where much has been        
achieved4 ,investigation of the ,semitic
 group1 in some respects of no less     
moment in the history of civilisation   
and religion1 where perhaps the labour  
of comparison is not so difficult1 as   
the languages differ less among         
themselves1 has for some reason         
strangely lagged behind4 ,some years ago
 in the ,american ,journal of ,philology
 ,paul ,haupt pointed out that if       
advance was to be made1 it must be made 
according to the principles which had   
guided the investigation of the         
,indo-,germanic languages to success1   
and at last a ,comparative ,grammar of  
an elaborate kind is in progress also   
for the ,semitic languages4             
7,brockelmann1 ,vergleichende ,grammatik
 der semitischen ,sprachen1 ,berlin1    
#aijg ff4 ,brockelmann and ,zimmern had 
earlier produced two small hand-books4  
,the only large work was ,william       
,wright's ,lectures on the ,comparative 
,grammar of the ,semitic ,languages1    

,cambridge1 #ahij47 ,for the great group
 which includes ,finnish1 ,hungarian1   
,turkish and many languages of northern 
,asia1 a beginning1 but only a beginning
 has been made4 ,it may be presumed from
 the great discoveries which are in     
progress in ,turkestan that presently   
much more will be achieved in this      
field4 ,but for a certain utterance to  
be given by ,comparative ,philology on  
the question of the origin of language  
it is necessary that not merely for     
these languages but also for those in   
other quarters of the globe1 the facts  
should be collected1 sifted and         
tabulated4 ,england rules an empire     
which contains a greater variety of     
languages by far than were ever held    
under one sway before4 ,the ,government 
of ,india is engaged in producing1 under
 the editorship of ,dr ,grierson1 a     
linguistic survey of ,india1 a          
remarkable undertaking and1 so far as it
 has gone1 a remarkable achievement4 ,is
 it too much to ask that1 with the      

support of the self-governing colonies1 
a similar survey should be undertaken   
for the whole of the ,british ,empire8  
,notwithstanding the great number of    
books that have been written on the     
origin of language in the last three and
 twenty centuries1 the results of the   
investigation which can be described as 
certain are very meagre4 ,the question  
originally raised was whether language  
came into being thesei or phusei1 by    
convention or by nature4 ,the first     
alternative1 in its baldest form at     
least1 has passed from out the field of 
controversy4 ,no one now claims that    
names were given to living things or    
objects or activities by formal         
agreement among the members of an early 
community1 or that the first father of  
mankind passed in review every living   
thing and gave it its name4 ,even if the
 record of ,adam's action were to be    
taken literally there would still remain
 the question1 whence had he this power8
 ,did he develop it himself or was it a 

miraculous gift with which he was       
endowed at his creation8 ,if the latter1
 then as ,wundt says                    
7,volkerpsychologie1 ,i4 #b1 page       
#ehe471 the miracle of language is      
subsumed in the miracle of creation4 ,if
 ,adam developed language of himself1 we
 are carried over to the alternative    
origin of phusei4 ,on this hypothesis we
 must assume that the natural growth    
which modern theories of development    
regard as the painful progress of       
multitudinous generations was contracted
 into the experience of a single        
individual4  ,but even if the origin of 
language is admitted to be ,,natural    
there may still be much variety of      
signification attached to the word3     
,,nature1 like most words which are used
 by philosophers1 has accumulated many  
meanings1 and as research into the      
natural world proceeds1 is accumulating 
more4  ,forty years ago an animated     
controversy raged among the supporters  
of the theories which were named for    

short the bow-wow1 the pooh-pooh and the
 ding-dong theories of the origin of    
language4 ,the third1 which was the     
least tenacious of life1 was made known 
to the ,english-speaking world by the   
late ,professor ,max ,muller who1       
however1 when questioned1 repudiated it 
as his own belief4 7,science of         
,thought1 ,london1 #ahhg1 page #baa47   
,it was taken by him from ,heyse's      
lectures on language which were         
published posthumously by ,steinthal4   
,put shortly the theory is that         
everything which is struck1 rings4 ,each
 substance has its peculiar ring4 ,we   
can tell the more or less perfect       
structure of metals by their vibrations1
 by the answer which they give4 ,gold   
rings differently from tin1 wood rings  
differently from stone2 and different   
sounds are produced according to the    
nature of each percussion4 ,it may be   
the same with man1 the most highly      
organised of nature's work4 7,max       
,muller as above1 translating from      

,heyse47 ,max ,muller's repudiation of  
this theory was1 however1 not very      
whole-hearted for he proceeds later in  
the same argument3 ,heyse's theory1     
which ,i neither adopted nor rejected1  
but which1 as will be seen1 is by no    
means incompatible with that which for  
many years has been gaining on me1 and  
which of late has been so clearly       
formulated by ,professor ,noire1 has    
been assailed with ridicule and torn to 
pieces1 often by persons who did not    
even suspect how much truth was hidden  
behind its paradoxical appearance4 ,we  
are still very far from being able to   
identify roots with nervous vibrations1 
but if it should appear hereafter that  
sensuous vibrations supply at least the 
raw material of roots1 it is quite      
possible that the theory1 proposed by   
,oken and ,heyse1 will retain its place 
in the history of the various attempts  
at solving the problem of the origin of 
language1 when other theories1 which in 
our own days were received with popular 

applause1 will be completely forgotten4 
7,science of ,thought1 page #bab47      
,like a good deal else that has been    
written on the origin of language1 this 
statement perhaps is not likely to be   
altogether clear to the plain man1 who  
may feel that even the raw material of  
roots is some distance removed from     
nervous vibrations1 though obviously    
without the existence of afferent and   
efferent nerves articulate speech would 
be impossible4 ,but ,heyse's theory     
undoubtedly was that every thought or   
idea which occurred to the mind of man  
for the first time had its own special  
phonetic expression1 and that this      
responsive faculty1 when its object was 
thus fulfilled1 became extinct4 ,apart  
from the philosophical question whether 
the mind acts without external stimulus1
 into which it is not necessary to enter
 here1 it is clear that this theory can 
neither be proved nor disproved1 because
 it postulates that this faculty existed
 only when language first began1 and    

later altogether disappeared4 ,as we    
have already seen1 it is impossible for 
us to know what happened at the first   
beginnings of language1 because we have 
no information from any period even     
approximately so remote2 nor are we     
likely to attain it4 ,even in their     
earliest stages the great families of   
language which possess a history        
extending over many centuries--the      
,indo-,germanic and the ,semitic--have  
very little in common4 ,with the        
exception of ,chinese1 the languages    
which are apparently of a simpler or    
more primitive formation have either a  
history which1 compared with that of the
 families mentioned1 is very short1 or1 
as in the case of the vast majority1    
have no history beyond the time         
extending only over a few years or1 at  
most1 a few centuries when they have    
been observed by competent scholars of  
,european origin4 ,but1 if we may judge 
by the history of geology and other     
studies1 it is well to be cautious in   

assuming for the first stages of        
development forces which do not operate 
in the later1 unless we have direct     
evidence of their existence4  ,it is    
unnecessary here to enter into a        
prolonged discussion of the other views 
christened by ,max ,muller1 not without 
energetic protest from their supporters1
 the bow-wow and pooh-pooh theories of  
language4 ,suffice it to say that the   
former recognises as a source of        
language the imitation of the sounds    
made by animals1 the fall of bodies into
 water or on to solid substances and the
 like1 while the latter1 also called the
 interjectional theory1 looks to the    
natural ejaculations produced by        
particular forms of effort for the first
 beginnings of speech4 ,it would be     
futile to deny that some words in most  
languages come from imitation1 and that 
others1 probably fewer in number1 can be
 traced to ejaculations4 ,but if either 
of these sources alone or both in       
combination gave rise to primitive      

speech1 it clearly must have been a     
simple form of language and very limited
 in amount4 ,there is no reason to think
 that it was otherwise4 ,presumably in  
its earliest stages language only       
indicated the most elementary ideas1    
demands for food or the gratification of
 other appetites1 indications of danger1
 useful animals and plants4 ,some of    
these1 such as animals or indications of
 danger1 could often be easily          
represented by imitative sounds3 the    
need for food and the like could be     
indicated by gesture and natural cries4 
,both sources are verae causae2 to them 
,noire1 supported by ,max ,muller1 has  
added another which has sometimes been  
called the ,yo-heave-ho theory4 ,noire  
contends that the real crux in the early
 stages of language is for primitive man
 to make other primitive men understand 
what he means4 ,the vocal signs which   
commend themselves to one may not have  
occurred to another1 and may therefore  
be unintelligible4 ,it may be admitted  

that this difficulty exists1 but it is  
not insuperable4 ,the old story of the  
,european in ,china who1 sitting down to
 a meal and being doubtful what the meat
 in the dish might be1 addressed an     
interrogative ,quack-quack8 to the      
waiter and was promptly answered by     
,bow-wow1 illustrates a simple situation
 where mutual understanding was easy4   
,but obviously many situations would be 
more complex than this1 and to grapple  
with them ,noire has introduced his     
theory of communal action4 ,it was      
common effort directed to a common      
object1 it was the most primitive       
7uralteste7 labour of our ancestors1    
from which sprang language and the life 
of reason4 7,noire ,der ,ursprung der   
,sprache1 page #cca1 ,mainz1 #ahgg47 ,as
 illustrations of such common effort he 
cites battle cries1 the rescue of a ship
 running on shore 7a situation not      
likely to occur very early in the       
history of man71 and others4 ,like ,max 
,muller he holds that language is the   

utterance and the organ of thought for  
mankind1 the one characteristic which   
separates man from the brute4 ,in common
 action the word was first produced2 for
 long it was inseparably connected with 
action2 through long-continued          
connection it gradually became the firm1
 intelligible symbol of action1 and then
 in its development indicated also      
things of the external world in so far  
as the action affected them and finally 
the sound began to enter into a         
connexion with them also4 7,op4 cit4    
page #cci47 ,in so far as this theory   
recognises language as a social         
institution it is undoubtedly correct4  
,darwin some years before ,noire had    
pointed to the same social origin of    
language in the fourth chapter of his   
work on ,the ,expression of the         
,emotions in ,man and ,animals4         
,naturalists have remarked1 ,i believe  
with truth1 that social animals1 from   
habitually using their vocal organs as a
 means of intercommunication1 use them  

on other occasions much more freely than
 other animals444 ,the principle1 also1 
of association1 which is so widely      
extended in its power1 has likewise     
played its part4 ,hence it allows that  
the voice1 from having been employed as 
a serviceable aid under certain         
conditions1 inducing pleasure1 pain1    
rage1 etc41 is commonly used whenever   
the same sensations or emotions are     
excited1 under quite different          
conditions1 or in a lesser degree4 7,the
 ,expression of the ,emotions1 page #hd 
7,popular ,edition1 #aijd74  ,darwin's  
own views on language which are set     
forth most fully in ,the ,descent of    
,man 7page #aca ff4 7,popular ,edition1 
#aijf747 are characterised by great     
modesty and caution4 ,he did not profess
 to be a philologist and the facts are  
naturally taken from the best known     
works of the day 7#ahga74 ,in the notes 
added to the second edition he remarks  
on ,max ,muller's denial of thought     
without words1 what a strange definition

 must here be given to the word thought6
 7,op4 cit4 page #ace1 footnote #fc47   
,he naturally finds the origin of       
language in the imitation and           
modification of various natural sounds1 
the voices of other animals1 and man's  
own instinctive cries aided by signs and
 gestures 7op4 cit4 page #acb47444 ,as  
the voice was used more and more1 the   
vocal organs would have been            
strengthened and perfected through the  
principle of the inherited effects of   
use2 and this would have reacted on the 
power of speech4 7,op4 cit4 page #acc47 
,on man's own instinctive cries1 he has 
more to say in ,the ,expression of the  
,emotions4 7,page #ic 7,popular         
,edition1 #aijd7 and elsewhere47 ,these 
remarks have been utilised by ,prof4    
,jespersen of ,copenhagen in propounding
 an ingenious theory of his own to the  
effect that speech develops out of      
singing4 7,progress in ,language1 page  
#cfa1 ,london1 #ahid47  ,for many years 
and in many books ,max ,muller argued   

against ,darwin's views on evolution on 
the one ground that thought is          
impossible without speech2 consequently 
as speech is confined to the human race1
 there is a gulf which cannot be bridged
 between man and all other creatures4   
7,some interesting comments on the      
theory will be found in a lecture on    
,thought and ,language in ,samuel       
,butler's ,essays on ,life1 ,art and    
,science1 ,london1 #aijh47 ,on the      
title-page of his ,science of ,thought  
he put the two sentences ,no ,reason    
without ,language3 ,no ,language without
 ,reason4 ,it may be readily admitted   
that the second dictum is true1 that no 
language properly so-called can exist   
without reason4 ,various birds can learn
 to repeat words or sentences used by   
their masters or mistresses4 ,in most   
cases probably the birds do not attach  
their proper meaning to the words they  
have learnt2 they repeat them in season 
and out of season1 sometimes apparently 
for their own amusement1 generally in   

the expectation1 raised by past         
experience1 of being rewarded for their 
proficiency4 ,but even here it is       
difficult to prove a universal negative1
 and most possessors of such pets would 
repudiate indignantly the statement that
 the bird did not understand what was   
said to it1 and would also contend that 
in many cases the words which it used   
were employed in their ordinary meaning4
 ,the first dictum seems to be          
inconsistent with fact4 ,the case of    
deaf mutes1 such as ,laura ,bridgeman1  
who became well educated1 or the still  
more extraordinary case of ,helen       
,keller1 deaf1 dumb1 and blind1 who in  
spite of these disadvantages has learnt 
not only to reason but to reason better 
than the average of persons possessed of
 all their senses1 goes to show that    
language and reason are not necessarily 
always in combination4 ,reason is but   
the conscious adaptation of means to    
ends1 and so defined is a faculty which 
cannot be denied to many of the lower   

animals4 ,in these days when so many    
books on ,animal ,intelligence are      
issued from the press1 it seems         
unnecessary to labour the point4 ,yet   
none of these animals1 except by        
parrot-imitation1 makes use of speech1  
because man alone possesses in a        
sufficient degree of development the    
centres of nervous energy which are     
required for the working of articulation
 in speech4 ,on this subject much       
investigation was carried on during the 
last years of ,darwin's life and much   
more in the period since his death4 ,as 
early as #ahfa ,broca1 following up     
observations made by earlier ,french    
writers1 located the centre of          
articulate speech in the third left     
frontal convolution of the brain4 ,in   
#ahgf he more definitely fixed the organ
 of speech in the posterior two-fifths  
of the third frontal convolution        
7,macnamara1 ,human ,speech1 page #aig1 
,london1 #aijh471 both sides and not    
merely the left being concerned in      

speech production4 ,owing however to the
 greater use by most human beings of the
 right side of the body1 the left side  
of the brain1 which is the motor centre 
for the right side of the body1 is more 
highly developed than its right side1   
which moves the left side of the body4  
,the investigations of ,professors      
,ferrier1 ,sherrington and ,grunbaum    
have still more precisely defined the   
relations between brain areas and       
certain groups of muscles4 ,one form of 
aphasia is the result of injury to or   
disease in the third frontal convolution
 because the motor centre is no longer  
equal to the task of setting the        
necessary muscles in motion4 ,in the    
brain of idiots who are unable to speak1
 the centre for speech is not developed4
 7,op4 cit4 page #bbf47 ,in the         
anthropoid apes the brain is similarly  
defective1 though it has been           
demonstrated by ,professors ,cunningham 
and ,marchand that there is a tendency1 
especially in the gorilla's brain1 for  

the third frontal convolution to assume 
the human form444 ,but if they possessed
 a centre for speech1 those parts of the
 hemispheres of their brains which form 
the mechanism by which intelligence is  
elaborated are so ill-developed1 as     
compared with the rest of their bodies1 
that we can not conceive1 even with more
 perfect frontal convolutions1 that     
these animals could formulate ideas     
expressible in intelligent speech4 7,op4
 cit4 page #bbc47  ,while ,max ,muller's
 theory is ,shelley's  ,he gave man     
speech1 and speech created thought1     
,which is the measure of the universe   
7,prometheus ,unbound ,,ii4 #d471  it   
seems more probable that the development
 was just the opposite--that the        
development of new activities originated
 new thoughts which required new symbols
 to express them1 symbols which may at  
first have been1 even to a greater      
extent than with some of the lower races
 at present1 sign language as much as   
articulation4 ,when once the faculty of 

articulation was developed1 which1      
though we cannot trace the process1 was 
probably a very gradual growth1 there is
 no reason to suppose that words        
developed in any other way then they do 
at present4 ,an erroneous notion of the 
development of language has become      
widely spread through the adoption of   
the metaphorical term roots for the     
irreducible elements of human speech4   
,men never talked in roots2 they talked 
in words4 ,many words of kindred meaning
 have a part in common1 and a root is   
nothing but that common part stripped of
 all additions4 ,in some cases it is    
obvious that one word is derived from   
another by the addition of a fresh      
element2 in other cases it is impossible
 to say which of two kindred words is   
the more primitive4 ,a root is merely a 
convenient term for an abstraction4 ,the
 simplest word may be called a root1 but
 it is nevertheless a word4 ,how are new
 words added to a language in the       
present day8 ,some communities1 like the

 ,germans1 prefer to construct new words
 for new ideas out of the old material  
existing in the language2 others1 like  
the ,english1 prefer to go to the       
ancient languages of ,greece and ,rome  
for terms to express new ideas4 ,the    
same chemical element is described in   
the two languages as sour stuff         
7,sauerstoff7 and as oxygen4 ,both terms
 mean the same thing etymologically as  
well as in fact4 ,on behalf of the      
,german method1 it may be contended that
 the new idea is more closely attached  
to already existing ideas1 by being     
expressed in elements of the language   
which are intelligible even to the      
meanest capacity4 ,for the ,english     
practice it may be argued that1 if we   
coin a new word which means one thing1  
and one thing only1 the idea which it   
expresses is more clearly defined than  
if it were expressed in popularly       
intelligible elements like sour stuff4  
,if the etymological value of words were
 always present in the minds of their   

users1 oxygen would undoubtedly have an 
advantage over sour stuff as a technical
 term4 ,but the tendency in language is 
to put two words of this kind which     
express but one idea under a single     
accent1 and when this has taken place1  
no one but the student of language any  
longer observes what the elements really
 mean4 ,when the ordinary man talks of a
 blackbird it is certainly not present  
to his consciousness that he is talking 
of a black bird1 unless for some reason 
conversation has been dwelling upon the 
colour rather than other characteristics
 of the species4  ,but1 it may be said1 
words like oxygen are introduced by     
learned men1 and do not represent the   
action of the man in the street1 who1   
after all1 is the author of most        
additions to the stock of human         
language4 ,we may go back therefore some
 four centuries to a period1 when       
scientific study was only in its        
infancy1 and see what process was       
followed4 ,with the discovery of        

,america new products never seen before 
reached ,europe1 and these required     
names4 ,three of the most characteristic
 were tobacco1 the potato1 and the      
turkey4 ,how did these come to be so    
named8 ,the first people to import these
 products into ,europe were naturally   
the ,spanish discoverers4 ,the first of 
these words--tobacco--appears in forms  
which differ only slightly in the       
languages of all civilised countries3   
,spanish tabaco1 ,italian tabacco1      
,french tabac1 ,dutch and ,german tabak1
 ,swedish tobak1 etc4 ,the word in the  
native dialect of ,hayti is said to have
 been tabaco1 but to have meant not the 
plant 7,according to ,william ,barclay1 
,nepenthes1 or the ,virtue of ,tobacco1 
,edinburgh1 #afad1 the countrey which   
,god hath honoured and blessed with this
 happie and holy herbe doth call it in  
their native language ',petum'47 but the
 pipe in which it was smoked4 ,it thus  
illustrates a frequent feature of       
borrowing--that the word is not borrowed

 in its proper signification1 but in    
some sense closely allied thereto1 which
 a foreigner1 understanding the language
 with difficulty1 might readily mistake 
for the real meaning4 ,thus the ,hindu  
practice of burning a wife upon the     
funeral pyre of her husband is called in
 ,english suttee1 this word being in    
fact but the phonetic spelling of the   
,sanskrit sati1 a virtuous woman1 and   
passing into its ,english meaning       
because formerly the practice of        
self-immolation by a wife was regarded  
as the highest virtue4  ,the name of the
 potato exhibits greater variety4 ,the  
,english name was borrowed from the     
,spanish patata1 which was itself       
borrowed from a native word for the yam 
in the dialect of ,hayti4 ,the potato   
appeared early in ,italy1 for the       
mariners of ,genoa actively followed the
 footsteps of their countryman ,columbus
 in exploring ,america4 ,in ,italian    
generally the form patata has survived4 
,the tubers1 however1 also suggested a  

resemblance to truffles1 so that the    
,italian word tartufolo1 a diminutive of
 the ,italian modification of the ,latin
 terrae tuber was applied to them4 ,in  
the language of the ,rhaetian ,alps this
 word appears as tartufel4 ,from there  
it seems to have passed into ,germany   
where potatoes were not cultivated      
extensively till the eighteenth century1
 and tartufel has in later times through
 some popular etymology been            
metamorphosed into ,kartoffel4 ,in      
,france the shape of the tubers         
suggested the name of earth-apple 7pomme
 de terre71 a name also adopted in      
,dutch 7aard-appel71 while dialectically
 in ,german a form ,grumbire appears1   
which is a corruption of ,grund-birne1  
ground pear4 7,kluge ,etymologisches    
,worterbuch der deutschen ,sprache      
7,strassburg71 s4v4 ,kartoffel47 ,here  
half the languages have adopted the     
original ,american word for an allied   
plant1 while others have adopted a name 
originating in some more or less        

fanciful resemblance discovered in the  
tubers2 the ,germans alone in ,western  
,europe1 failing to see any meaning in  
their borrowed name1 have modified it   
almost beyond recognition4 ,to this     
,english supplies an exact parallel in  
parsnep which1 though representing the  
,latin pastinaca through the ,old       
,french pastenaque1 was first           
assimilated in the last syllable to the 
nep of turnep 7pasneppe in ,elizabethan 
,english71 and later had an r introduced
 into the first syllable1 apparently on 
the analogy of parsley4  ,the turkey on 
the other hand seems never to be found  
with its original ,american name4 ,in   
,england1 as the name implies1 the      
turkey cock was regarded as having come 
from the land of the ,turks4 ,the bird  
no doubt spread over ,europe from the   
,italian seaports4 ,the mistake1        
therefore1 was not unnatural1 seeing    
that these towns conducted a great trade
 with the ,levant1 while the fact that  
,america when first discovered was      

identified with ,india helped to        
increase the confusion4 ,thus in ,french
 the coq d',inde was abbreviated to     
d',inde much as turkey cock was to      
turkey2 the next stage was to identify  
dinde as a feminine word and create a   
new dindon on the analogy of chapon as  
the masculine4 ,in ,italian the name    
gallo d',india besides survives1 while  
in ,german the name ,truthahn seems to  
be derived onomatopoetically from the   
bird's cry1 though a dialectic          
,calecutischer ,hahn specifies          
erroneously an origin for the bird from 
the ,indian ,calicut4 ,in the ,spanish  
pavo1 on the other hand1 there is a     
curious confusion with the peacock4     
,thus in these names for objects of     
common knowledge1 the introduction of   
which into ,europe can be dated with    
tolerable definiteness1 we see evinced  
the methods by which in remoter ages    
objects were named4 ,the words were     
borrowed from the community whence came 
the new object1 or the real or fancied  

resemblance to some known object gave   
the name1 or again popular etymology    
might convert the unknown term into     
something that at least approached in   
sound a well-known word4  ,the ,origin  
of ,species had not long been published 
when the parallelism of development in  
natural species and in languages struck 
investigators4 ,at the time1 one of the 
foremost ,german philologists was       
,august ,schleicher1 ,professor at      
,jena4 ,he was himself keenly interested
 in the natural sciences1 and amongst   
his colleagues was ,ernst ,haeckel1 the 
protagonist in ,germany of the          
,darwinian theory4 ,how the new ideas   
struck ,schleicher may be seen from the 
following sentences by his colleague    
,haeckel4 ,speech is a physiological    
function of the human organism1 and has 
been developed simultaneously with its  
organs1 the larynx and tongue1 and with 
the functions of the brain4 ,hence it   
will be quite natural to find in the    
evolution and classification of         

languages the same features as in the   
evolution and classification of organic 
species4 ,the various groups of         
languages that are distinguished in     
philology as primitive1 fundamental1    
parent1 and daughter languages1         
dialects1 etc41 correspond entirely in  
their development to the different      
categories which we classify in zoology 
and botany as stems1 classes1 orders1   
families1 genera1 species and varieties4
 ,the relation of these groups1 partly  
coordinate and partly subordinate1 in   
the general scheme is just the same in  
both cases2 and the evolution follows   
the same lines in both4 7,haeckel1 ,the 
,evolution of ,man1 page #dhe1 ,london1 
#aije4 ,this represents ,schleicher's   
own words3 ,was die ,naturforscher als  
,gattung bezeichnen wurden1 heisst bei  
den ,glottikern ,sprachstamm1 auch      
,sprachsippe2 naher verwandte ,gattungen
 bezeichnen sie wohl auch als           
,sprachfamilien einer ,sippe oder eines 
,sprachstammes444 ,die ,arten einer     

,gattung nennen wir ,sprachen eines     
,stammes2 die ,unterarten einer ,art    
sind bei uns die ,dialekte oder         
,mundarten einer ,sprache2 den          
,varietaten und ,spielarten entsprechen 
die ,untermundarten oder ,nebenmundarten
 und endlich den einzelnen ,individuen  
die ,sprechweise der einzelnen die      
,sprachen redenden ,menschen4 ,die      
,darwinische ,theorie und die           
,sprachwissenschaft1 ,weimar1 #ahfc1    
page #ab f4 ,darwin makes a more        
cautious statement about the            
classification of languages in ,the     
,origin of ,species1 page #egh1         
7,popular ,edition1 #aijj747 ,these     
views were set forth in an open letter  
addressed to ,haeckel in #ahfc by       
,schleicher entitled1 ,the ,darwinian   
theory and the science of language4     
,unfortunately ,schleicher's views went 
a good deal farther than is indicated in
 the extract given above4 ,he appended  
to the pamphlet a genealogical tree of  
the ,indo-,germanic languages which1    

though to a large extent confirmed by   
later research1 by the dichotomy of each
 branch into two other branches1 led the
 unwary reader to suppose their         
phylogeny 7to use ,professor ,haeckel's 
term7 was more regular than our evidence
 warrants4  ,without qualification      
,schleicher declared languages to be    
natural organisms which originated      
unconditioned by the human will1        
developed according to definite laws1   
grow old and die2 they also are         
characterised by that series of         
phenomena which we designate by the term
 ',life4' ,consequently ,glottic1 the   
science of language1 is a natural       
science2 its method is in general the   
same as that of the other natural       
sciences4 7,die ,darwinische ,theorie1  
page #f f47 ,in accordance with this    
view he declared 7op4 cit4 page #bc47   
that the root in language might be      
compared with the simple cell in        
physiology1 the linguistic simple cell  
or root being as yet not differentiated 

into special organs for the function of 
noun1 verb1 etc4  ,in this probably all 
recent philologists admit that          
,schleicher went too far4 ,one of the   
most fertile theories in the modern     
science of language originated with him1
 and was further developed by his pupil1
 ,august ,leskien 7,die ,declination im 
,slavisch-litanischen und ,germanischen1
 ,leipzig1 #ahgf2 ,osthoff and          
,brugmann1 ,morphologische              
,untersuchungen1 ,i4 7,introduction71   
#ahgh4 ,the general principles of this  
school were formulated 7#ahhj7 in a     
fuller form in ,h4 ,paul's ,prinzipien  
der ,sprachgeschichte1 ,halle 7#crd     
edition1 #ahih74 ,paul and ,wundt 7in   
his ,volkerpsychologie7 deal largely    
with the same matter1 but begin their   
investigations from different points of 
view1 ,paul being a philologist with    
leanings to philosophy and ,wundt a     
philosopher interested in language471   
and by ,leskien's colleagues and        
friends1 ,brugmann and ,osthoff4 ,this  

was the principle that phonetic laws    
have no exceptions4 ,under the influence
 of this generalisation much greater    
precision in etymology was insisted     
upon1 and a new and remarkably active   
period in the study of language began4  
,stated broadly in the fashion given    
above the principle is not true4 ,a more
 accurate statement would be that an    
original sound is represented in a given
 dialect at a given time and in a given 
environment only in one way2 provided   
that the development of the original    
sound into its representation in the    
given dialect has not been influenced by
 the working of analogy4  ,it is this   
proviso that is most important for the  
characterisation of the science of      
language4 ,as ,i have said elsewhere1 it
 is at this point that this science     
parts company with the natural sciences4
 ,if the chemist compounds two pure     
simple elements1 there can be but one   
result1 and no power of the chemist can 
prevent it4 ,but the minds of men do act

 upon the sounds which they produce4    
,the result is that1 when this happens1 
the phonetic law which would have acted 
in the case is stopped1 and this        
particular form enters on the same      
course of development as other forms to 
which it does not belong4 7,p4 ,giles1  
,short ,manual of ,comparative          
,philology1 #bnd edition1 page #eg1     
,london1 #aija47  ,schleicher was wrong 
in defining a language to be an organism
 in the sense in which a living being is
 an organism4 ,regarded physiologically1
 language is a function or potentiality 
of certain human organs2 regarded from  
the point of view of the community it is
 of the nature of an institution4 7,this
 view of language is worked out at some 
length by ,prof4 ,w4,d4 ,whitney in an  
article in the ,contemporary ,review for
 #ahge1 page #gac ff4 ,this article     
forms part of a controversy with ,max   
,muller1 which is partly concerned with 
,darwin's views on language4 ,he        
criticises ,schleicher's views severely 

in his ,oriental and ,linguistic        
,studies1 page #bih ff41 ,new ,york1    
#ahgc4 ,in this volume will be found    
criticisms of various other views       
mentioned in this essay47 ,more than    
most influences it conduces to the      
binding together of the elements that   
form a state4 ,that geographical or     
other causes may effectively counteract 
the influence of identity of language is
 obvious4 ,one need only read the       
history of ancient ,greece1 or observe  
the existing political separation of    
,germany and ,austria1 of ,great        
,britain and the ,united ,states of     
,america4 ,but however analogous to an  
organism1 language is not an organism4  
,in a less degree ,schleicher1 by       
defining languages as such1 committed   
the same mistake which ,bluntschli made 
regarding the ,state1 and which led him 
to declare that the ,state is by nature 
masculine and the ,church feminine4     
7,bluntschli1 ,theory of the ,state1    
page #bd1 ,second ,english ,edition1    

,oxford1 #ahib47 ,the views of          
,schleicher were to some extent         
injurious to the proper methods of      
linguistic study4 ,but this misfortune  
was much more than fully compensated by 
the inspiration which his ideas1        
collected and modified by his disciples1
 had upon the science4 ,in spite of the 
difference which the psychological      
element represented by analogy makes    
between the science of language and the 
natural sciences1 we are entitled to say
 of it as ,schleicher said of ,darwin's 
theory of the origin of species1 it     
depends upon observation1 and is        
essentially an attempt at a history of  
development4  ,other questions there are
 in connection with language and        
evolution which require                 
investigation--the survival of one      
amongst several competing words 7e4g4   
why ,german keeps only as a high poetic 
word ross1 which is identical in origin 
with the ,english work-a-day horse1 and 
replaces it by pferd1 whose congener the

 ,english palfrey is almost confined to 
poetry and romance71 the persistence of 
evolution till it becomes revolution in 
languages like ,english or ,persian     
which have practically ceased to be     
inflectional languages1 and many other  
problems4 ,into these ,darwin did not   
enter1 and they require a fuller        
investigation than is possible within   
the limits of the present paper4        
,,xxvii4 ,,darwinism ,,and ,,history4   
,by ,j4,b4 ,bury1 ,litt4,d41 ,,ll4,d4   
,regius ,professor of ,modern ,history  
in the ,university of ,cambridge4   #a4 
,evolution1 and the principles          
associated with the ,darwinian theory1  
could not fail to exert a considerable  
influence on the studies connected with 
the history of civilised man4 ,the      
speculations which are known as         
philosophy of history1 as well as the   
sciences of anthropology1 ethnography1  
and sociology 7sciences which though    
they stand on their own feet are for the
 historian auxiliary71 have been deeply 

affected by these principles4           
,historiographers1 indeed1 have with few
 exceptions made little attempt to apply
 them2 but the growth of historical     
study in the nineteenth century has been
 determined and characterised by the    
same general principle which has        
underlain the simultaneous developments 
of the study of nature1 namely the      
,,genetic idea4 ,the historical         
conception of nature1 which has produced
 the history of the solar system1 the   
story of the earth1 the genealogies of  
telluric organisms1 and has             
revolutionised natural science1 belongs 
to the same order of thought as the     
conception of human history as a        
continuous1 genetic1 causal process--a  
conception which has revolutionised     
historical research and made it         
scientific4 ,before proceeding to       
consider the application of evolutional 
principles1 it will be pertinent to     
notice the rise of this new view4  #b4  
,with the ,greeks and ,romans history   

had been either a descriptive record or 
had been written in practical interests4
 ,the most eminent of the ancient       
historians were pragmatical2 that is1   
they regarded history as an instructress
 in statesmanship1 or in the art of war1
 or in morals4 ,their records reached   
back such a short way1 their experience 
was so brief1 that they never attained  
to the conception of continuous process1
 or realised the significance of time2  
and they never viewed the history of    
human societies as a phenomenon to be   
investigated for its own sake4 ,in the  
middle ages there was still less chance 
of the emergence of the ideas of        
progress and development4 ,such notions 
were excluded by the fundamental        
doctrines of the dominant religion which
 bounded and bound men's minds4 ,as the 
course of history was held to be        
determined from hour to hour by the     
arbitrary will of an extra-cosmic       
person1 there could be no self-contained
 causal development1 only a dispensation

 imposed from without4 ,and as it was   
believed that the world was within no   
great distance from the end of this     
dispensation1 there was no motive to    
take much interest in understanding the 
temporal1 which was to be only          
temporary4  ,the intellectual movements 
of the fifteenth and sixteenth centuries
 prepared the way for a new conception1 
but it did not emerge immediately4 ,the 
historians of the ,renaissance period   
simply reverted to the ancient          
pragmatical view4 ,for ,machiavelli1    
exactly as for ,thucydides and          
,polybius1 the use of studying history  
was instruction in the art of politics4 
,the ,renaissance itself was the        
appearance of a new culture1 different  
from anything that had gone before2 but 
at the time men were not conscious of   
this2 they saw clearly that the         
traditions of classical antiquity had   
been lost for a long period1 and they   
were seeking to revive them1 but        
otherwise they did not perceive that the

 world had moved1 and that their own    
spirit1 culture1 and conditions were    
entirely unlike those of the thirteenth 
century4 ,it was hardly till the        
seventeenth century that the presence of
 a new age1 as different from the middle
 ages as from the ages of ,greece and   
,rome1 was fully realised4 ,it was then 
that the triple division of ancient1    
medieval1 and modern was first applied  
to the history of western civilisation4 
,whatever objections may be urged       
against this division1 which has now    
become almost a category of thought1 it 
marks a most significant advance in     
man's view of his own past4 ,he has     
become conscious of the immense changes 
in civilisation which have come about   
slowly in the course of time1 and       
history confronts him with a new aspect4
 ,he has to explain how those changes   
have been produced1 how the             
transformations were effected4 ,the     
appearance of this problem was almost   
simultaneous with the rise of           

rationalism1 and the great historians   
and thinkers of the eighteenth century1 
such as ,montesquieu1 ,voltaire1        
,gibbon1 attempted to explain the       
movement of civilisation by purely      
natural causes4 ,these brilliant writers
 prepared the way for the genetic       
history of the following century4 ,but  
in the spirit of the ,aufklarung1 that  
eighteenth-century ,enlightenment to    
which they belonged1 they were concerned
 to judge all phenomena before the      
tribunal of reason2 and the apotheosis  
of reason tended to foster a certain    
superior a priori attitude1 which was   
not favourable to objective treatment   
and was incompatible with a historical  
sense4 ,moreover the traditions of      
pragmatical historiography had by no    
means disappeared4  #c4 ,in the first   
quarter of the nineteenth century the   
meaning of genetic history was fully    
realised4 ,genetic perhaps is as good a 
word as can be found for the conception 
which in this century was applied to so 

many branches of knowledge in the       
spheres both of nature and of mind4 ,it 
does not commit us to the doctrine      
proper of evolution1 nor yet to any     
teleological hypothesis such as is      
implied in progress4 ,for history it    
meant that the present condition of the 
human race is simply and strictly the   
result of a causal series 7or set of    
causal series7--a continuous succession 
of changes1 where each state arises     
causally out of the preceding2 and that 
the business of historians is to trace  
this genetic process1 to explain each   
change1 and ultimately to grasp the     
complete development of the life of     
humanity4 ,three influential writers1   
who appeared at this stage and helped to
 initiate a new period of research1 may 
specially be mentioned4 ,ranke in #ahbd 
definitely repudiated the pragmatical   
view which ascribes to history the      
duties of an instructress1 and with no  
less decision renounced the function1   
assumed by the historians of the        

,aufklarung1 to judge the past2 it was  
his business1 he said1 merely to show   
how things really happened4 ,niebuhr was
 already working in the same spirit and 
did more than any other writer to       
establish the principle that historical 
transactions must be related to the     
ideas and conditions of their age4      
,savigny about the same time founded the
 historical school of law4 ,he sought to
 show that law was not the creation of  
an enlightened will1 but grew out of    
custom and was developed by a series of 
adaptations and rejections1 thus        
applying the conception of evolution4   
,he helped to diffuse the notion that   
all the institutions of a society or a  
notion are as closely interconnected as 
the parts of a living organism4  #d4    
,the conception of the history of man as
 a causal development meant the         
elevation of historical inquiry to the  
dignity of a science4 ,just as the study
 of bees cannot become scientific so    
long as the student's interest in them  

is only to procure honey or to derive   
moral lessons from the labours of the   
little busy bee1 so the history of human
 societies cannot become the object of  
pure scientific investigation so long as
 man estimates its value in pragmatical 
scales4 ,nor can it become a science    
until it is conceived as lying entirely 
within a sphere in which the law of     
cause and effect has unreserved and     
unrestricted dominion4 ,on the other    
hand1 once history is envisaged as a    
causal process1 which contains within   
itself the explanation of the           
development of man from his primitive   
state to the point which he has reached1
 such a process necessarily becomes the 
object of scientific investigation and  
the interest in it is scientific        
curiosity4  ,at the same time1 the      
instruments were sharpened and refined4 
,here ,wolf1 a philologist with         
historical instinct1 was a pioneer4 ,his
 ,prolegomena to ,homer 7#agie7         
announced new modes of attack4          

,historical investigation was soon      
transformed by the elaboration of new   
methods4  #e4 ,progress involves a      
judgment of value1 which is not involved
 in the conception of history as a      
genetic process4 ,it is also an idea    
distinct from that of evolution4        
,nevertheless it is closely related to  
the ideas which revolutionised history  
at the beginning of the last century2 it
 swam into men's ken simultaneously2 and
 it helped effectively to establish the 
notion of history as a continuous       
process and to emphasise the            
significance of time4 ,passing over     
earlier anticipations1 ,i may point to a
 ,discours of ,turgot 7#agej71 where    
history is presented as a process in    
which the total mass of the human race  
marches continually though sometimes    
slowly to an ever increasing perfection4
 ,that is a clear statement of the      
conception which ,turgot's friend       
,condorcet elaborated in the famous     
work1 published in #agie1 ,esquisse d'un

 tableau historique des progres de      
l'esprit humain4 ,this work first       
treated with explicit fulness the idea  
to which a leading role was to fall in  
the ideology of the nineteenth century4 
,condorcet's book reflects the triumphs 
of the ,tiers etat1 whose growing       
importance had also inspired ,turgot2 it
 was the political changes in the       
eighteenth century which led to the     
doctrine1 emphatically formulated by    
,condorcet1 that the masses are the most
 important element in the historical    
process4 ,i dwell on this because1      
though ,condorcet had no idea of        
evolution1 the pre-dominant importance  
of the masses was the assumption which  
made it possible to apply evolutional   
principles to history4 ,and it enabled  
,condorcet himself to maintain that the 
history of civilisation1 a progress     
still far from being complete1 was a    
development conditioned by general laws4
  #f4 ,the assimilation of society to an
 organism1 which was a governing notion 

in the school of ,savigny1 and the      
conception of progress1 combined to     
produce the idea of an organic          
development1 in which the historian has 
to determine the central principle or   
leading character4 ,this is illustrated 
by the apotheosis of democracy in       
,tocqueville's ,democratie en ,amerique1
 where the theory is maintained that the
 gradual and progressive development of 
equality is at once the past and the    
future of the history of men4 ,the same 
two principles are combined in the      
doctrine of ,spencer 7who held that     
society is an organism1 though he also  
contemplated its being what he calls a  
super-organic aggregate7 7,a society    
presents suggestive analogies with an   
organism1 but it certainly is not an    
organism1 and sociologists who draw     
inferences from the assumption of its   
organic nature must fall into error4 ,a 
vital organism and a society are        
radically distinguished by the fact that
 the individual components of the       

former1 namely the cells1 are           
morphologically as well as functionally 
differentiated1 whereas the individuals 
which compose a society are             
morphologically homogeneous and only    
functionally differentiated4 ,the       
resemblances and the differences are    
worked out in ,e4 de ,majewski's        
striking book ,la ,science de la        
,civilisation1 ,paris1 #aijh471 that    
social evolution is a progressive change
 from militarism to industrialism4  #g4 
the idea of development assumed another 
form in the speculations of ,german     
idealism4 ,hegel conceived the          
successive periods of history as        
corresponding to the ascending phases or
 ideas in the self-evolution of his     
,absolute ,being4 ,his ,lectures on the 
,philosophy of ,history were published  
in #ahcg after his death4 ,his          
philosophy had a considerable effect1   
direct and indirect1 on the treatment of
 history by historians1 and although he 
was superficial and unscientific himself

 in dealing with historical phenomena1  
he contributed much towards making the  
idea of historical development familiar4
 ,ranke was influenced1 if not by ,hegel
 himself1 at least by the ,idealistic   
philosophies of which ,hegel's was the  
greatest4 ,he was inclined to conceive  
the stages in the process of history as 
marked by incarnations1 as it were1 of  
ideas1 and sometimes speaks as if the   
ideas were independent forces1 with     
hands and feet4 ,but while ,hegel       
determined his ideas by a priori logic1 
,ranke obtained his by induction--by a  
strict investigation of the phenomena2  
so that he was scientific in his method 
and work1 and was influenced by         
,hegelian prepossessions only in the    
kind of significance which he was       
disposed to ascribe to his results4 ,it 
is to be noted that the theory of ,hegel
 implied a judgment of value2 the       
movement was a progress towards         
perfection4  #h4 ,in ,france1 ,comte    
approached the subject from a different 

side1 and exercised1 outside ,germany1 a
 far wider influence than ,hegel4 ,the  
#dth volume of his ,cours de philosophie
 positive1 which appeared in #ahci1     
created sociology and treated history as
 a part of this new science1 namely as  
social dynamics4 ,comte sought the key  
for unfolding historical development1 in
 what he called the social-psychological
 point of view1 and he worked out the   
two ideas which had been enunciated by  
,condorcet3 that the historian's        
attention should be directed not1 as    
hitherto1 principally to eminent        
individuals1 but to the collective      
behaviour of the masses1 as being the   
most important element in the process2  
and that1 as in nature1 so in history1  
there are general laws1 necessary and   
constant1 which condition the           
development4 ,the two points are        
intimately connected1 for it is only    
when the masses are moved into the      
foreground that regularity1 uniformity1 
and law can be conceived as applicable4 

,to determine the social-psychological  
laws which have controlled the          
development is1 according to ,comte1 the
 task of sociologists and historians4   
#i4 ,the hypothesis of general laws     
operative in history was carried further
 in a book which appeared in ,england   
twenty years later and exercised an     
influence in ,europe far beyond its     
intrinsic merit1 ,buckle's ,history of  
,civilisation in ,england 7#aheg-fa74   
,buckle owed much to ,comte1 and        
followed him1 or rather outdid him1 in  
regarding intellect as the most         
important factor conditioning the upward
 development of man1 so that progress1  
according to him1 consisted in the      
victory of the intellectual over the    
moral laws4  #aj4 ,the tendency of      
,comte and ,buckle to assimilate history
 to the sciences of nature by reducing  
it to general laws1 derived stimulus and
 plausibility from the vista offered by 
the study of statistics1 in which the   
,belgian ,quetelet1 whose book ,sur     

l'homme appeared in #ahce1 discerned    
endless possibilities4 ,the astonishing 
uniformities which statistical inquiry  
disclosed led to the belief that it was 
only a question of collecting a         
sufficient amount of statistical        
material1 to enable us to predict how a 
given social group will act in a        
particular case4 ,bourdeau1 a disciple  
of this school1 looks forward to the    
time when historical science will become
 entirely quantitative4 ,the actions of 
prominent individuals1 which are        
generally considered to have altered or 
determined the course of things1 are    
obviously not amenable to statistical   
computation or explicable by general    
laws4 ,thinkers like ,buckle sought to  
minimise their importance or explain    
them away4  #aa4 ,these indications may 
suffice to show that the new efforts to 
interpret history which marked the first
 half of the nineteenth century were    
governed by conceptions closely related 
to those which were current in the field

 of natural science and which resulted  
in the doctrine of evolution4 ,the      
genetic principle1 progressive          
development1 general laws1 the          
significance of time1 the conception of 
society as an organic aggregate1 the    
metaphysical theory of history as the   
self-evolution of spirit1--all these    
ideas show that historical inquiry had  
been advancing independently on somewhat
 parallel lines to the sciences of      
nature4 ,it was necessary to bring this 
out in order to appreciate the influence
 of ,darwinism4  #ab4 ,in the course of 
the dozen years which elapsed between   
the appearances of ,the ,origin of      
,species 7observe that the first volume 
of ,buckle's work was published just two
 years before7 and of ,the ,descent of  
,man 7#ahga71 the hypothesis of ,lamarck
 that man is the co-descendant with     
other species of some lower extinct form
 was admitted to have been raised to the
 rank of an established fact by most    
thinkers whose brains were not working  

under the constraint of theological     
authority4  ,one important effect of the
 discovery of this fact 7,i am not      
speaking now of the ,darwinian          
explanation7 was to assign to history a 
definite place in the coordinated whole 
of knowledge1 and relate it more closely
 to other sciences4 ,it had indeed a    
defined logical place in systems such as
 ,hegel's and ,comte's2 but ,darwinism  
certified its standing convincingly and 
without more ado4 ,the prevailing       
doctrine that man was created ex abrupto
 had placed history in an isolated      
position1 disconnected with the sciences
 of nature4 ,anthropology1 which deals  
with the animal anthropos1 now comes    
into line with zoology1 and brings it   
into relation with history4 7,it is to  
be observed that history is not only    
different in scope but7 not coextensive 
with anthropology ,,in ,,time4 ,for it  
deals only with the development of man  
in societies1 whereas anthropology      
includes in its definition the          

proto-anthropic period when anthropos   
was still non-social1 whether he lived  
in herds like the chimpanzee1 or alone  
like the male ourang-outang4 7,it has   
been well shown by ,majewski that       
congregations--herds1 flocks1 packs1    
etc4--of animals are not ,,societies2   
the characteristic of a society is      
differentiation of function4 ,bee hives1
 ant hills1 may be called               
quasi-societies2 but in their case the  
classes which perform distinct functions
 are morphologically different47 ,man's 
condition at the present day is the     
result of a series of transformations1  
going back to the most primitive phase  
of society1 which is the ideal          
7unattainable7 beginning of history4    
,but that beginning had emerged without 
any breach of continuity from a         
development which carries us back to a  
quadrimane ancestor1 still further back 
7according to ,darwin's conjecture7 to a
 marine animal of the ascidian type1 and
 then through remoter periods to the    

lowest form of organism4 ,it is         
essential in this theory that though    
links have been lost there was no break 
in the gradual development2 and this    
conception of a continuous progress in  
the evolution of life1 resulting in the 
appearance of uncivilised ,anthropos1   
helped to reinforce1 and increase a     
belief in1 the conception of the history
 of civilised ,anthropos as itself also 
a continuous progressive development4   
#ac4 ,thus the diffusion of the         
,darwinian theory of the origin of man1 
by emphasising the idea of continuity   
and breaking down the barriers between  
the human and animal kingdoms1 has had  
an important effect in establishing the 
position of history among the sciences  
which deal with telluric development4   
,the perspective of history is merged in
 a larger perspective of development4   
,as one of the objects of biology is to 
find the exact steps in the genealogy of
 man from the lowest organic form1 so   
the scope of history is to determine the

 stages in the unique causal series from
 the most rudimentary to the present    
state of human civilisation4  ,it is to 
be observed that the interest in        
historical research implied by this     
conception need not be that of ,comte4  
,in the ,positive ,philosophy history is
 part of sociology2 the interest in it  
is to discover the sociological laws4   
,in the view of which ,i have just      
spoken1 history is permitted to be an   
end in itself2 the reconstruction of the
 genetic process is an independent      
interest4 ,for the purpose of the       
reconstruction1 sociology1 as well as   
physical geography1 biology1 psychology1
 is necessary2 the sociologist and the  
historian play into each other's hands2 
but the object of the former is to      
establish generalisations2 the aim of   
the latter is to trace in detail a      
singular causal sequence4  #ad4 ,the    
success of the evolutional theory helped
 to discredit the assumption or at least
 the invocation of transcendent causes4 

,philosophically of course it is        
compatible with theism1 but historians  
have for the most part desisted from    
invoking the naive conception of a god  
in history to explain historical        
movements4 ,a historian may be a theist2
 but1 so far as his work is concerned1  
this particular belief is otiose4       
,otherwise indeed 7as was remarked      
above7 history could not be a science2  
for with a deus ex machina who can be   
brought on the stage to solve           
difficulties scientific treatment is a  
farce4 ,the transcendent element had    
appeared in a more subtle form through  
the influence of ,german philosophy4 ,i 
noticed how ,ranke is prone to refer to 
ideas as if they were transcendent      
existences manifesting themselves in the
 successive movements of history4 ,it is
 intelligible to speak of certain ideas 
as controlling1 in a given period1--for 
instance1 the idea of nationality2 but  
from the scientific point of view1 such 
ideas have no existence outside the     

minds of individuals and are purely     
psychical forces2 and a historical idea1
 if it does not exist in this form1 is  
merely a way of expressing a synthesis  
of the historian himself4  #ae4 ,from   
the more general influence of ,darwinism
 on the place of history in the system  
of human knowledge1 we may turn to the  
influence of the principles and methods 
by which ,darwin explained development4 
,it had been recognised even by ancient 
writers 7such as ,aristotle and         
,polybius7 that physical circumstances  
7geography1 climate7 were factors       
conditioning the character and history  
of a race or society4 ,in the sixteenth 
century ,bodin emphasised these factors1
 and many subsequent writers took them  
into account4 ,the investigations of    
,darwin1 which brought them into the    
foreground1 naturally promoted attempts 
to discover in them the chief key to the
 growth of civilisation4 ,comte had     
expressly denounced the notion that the 
biological methods of ,lamarck could be 

applied to social man4 ,buckle had taken
 account of natural influences1 but had 
relegated them to a secondary plane1    
compared with psychological factors4    
,but the ,darwinian theory made it      
tempting to explain the development of  
civilisation in terms of adaptation to  
environment1 struggle for existence1    
natural selection1 survival of the      
fittest1 etc4 7,recently ,o4 ,seeck has 
applied these principles to the decline 
of ,graeco-,roman civilisation in his   
,untergang der antiken ,welt1 #b        
volumes1 ,berlin1 #ahie1 #aija47  ,the  
operation of these principles cannot be 
denied4 ,man is still an animal1 subject
 to zoological as well as mechanical    
laws4 ,the dark influence of heredity   
continues to be effective2 and psychical
 development had begun in lower organic 
forms1--perhaps with life itself4 ,the  
organic and the social struggles for    
existence are manifestations of the same
 principle4 ,environment and climatic   
influence must be called in to explain  

not only the differentiation of the     
great racial sections of humanity1 but  
also the varieties within these         
sub-species and1 it may be1 the         
assimilation of distinct varieties4     
,ritter's ,anthropogeography has opened 
a useful line of research4 ,but on the  
other hand1 it is urged that1 in        
explaining the course of history1 these 
principles do not take us very far1 and 
that it is chiefly for the primitive    
ultra-prehistoric period that they can  
account for human development4 ,it may  
be said that1 so far as concerns the    
actions and movements of men which are  
the subject of recorded history1        
physical environment has ceased to act  
mechanically1 and in order to affect    
their actions must affect their wills   
first2 and that this psychical character
 of the causal relations substantially  
alters the problem4 ,the development of 
human societies1 it may be argued1      
derives a completely new character from 
the dominance of the conscious psychical

 element1 creating as it does new       
conditions 7inventions1 social          
institutions1 etc47 which limit and     
counteract the operation of natural     
selection1 and control and modify the   
influence of physical environment4 ,most
 thinkers agree now that the chief clews
 to the growth of civilisation must be  
sought in the psychological sphere4     
,imitation1 for instance1 is a principle
 which is probably more significant for 
the explanation of human development    
than natural selection4 ,darwin himself 
was conscious that his principles had   
only a very restricted application in   
this sphere1 as is evident from his     
cautious and tentative remarks in the   
#eth chapter of his ,descent of ,man4   
,he applied natural selection to the    
growth of the intellectual faculties and
 of the fundamental social instincts1   
and also to the differentiation of the  
great races or sub-species 7,caucasian1 
,african1 etc47 which differ in         
anthropological character4 7,darwinian  

formulae may be suggestive by way of    
analogy4 ,for instance1 it is           
characteristic of social advance that a 
multitude of inventions1 schemes and    
plans are framed which are never carried
 out1 similar to1 or designed for the   
same end as1 an invention or plan which 
is actually adopted because it has      
chanced to suit better the particular   
conditions of the hour 7just as the     
works accomplished by an individual     
statesman1 artist or savant are usually 
only a residue of the numerous projects 
conceived by his brain74 ,this process  
in which so much abortive production    
occurs is analogous to elimination by   
natural selection47  #af4 ,but if it is 
admitted that the governing factors     
which concern the student of social     
development are of the psychical order1 
the preliminary success of natural      
science in explaining organic evolution 
by general principles encouraged        
sociologists to hope that social        
evolution could be explained on general 

principles also4 ,the idea of           
,condorcet1 ,buckle1 and others1 that   
history could be assimilated to the     
natural sciences was powerfully         
reinforced1 and the notion that the     
actual historical process1 and every    
social movement involved in it1 can be  
accounted for by sociological           
generalisations1 so-called laws1 is     
still entertained by many1 in one form  
or another4 ,dissentients from this view
 do not deny that the generalisations at
 which the sociologist arrives by the   
comparative method1 by the analysis of  
social factors1 and by psychological    
deduction may be an aid to the          
historian2 but they deny that such      
uniformities are laws or contain an     
explanation of the phenomena4 ,they can 
point to the element of chance          
coincidence4 ,this element must have    
played a part in the events of organic  
evolution1 but it has probably in a     
larger measure helped to determine      
events in social evolution4 ,the        

collision of two unconnected sequences  
may be fraught with great results4 ,the 
sudden death of a leader or a marriage  
without issue1 to take simple cases1 has
 again and again led to permanent       
political consequences4 ,more emphasis  
is laid on the decisive actions of      
individuals1 which cannot be reduced    
under generalisations and which deflect 
the course of events4 ,if the           
significance of the individual will had 
been exaggerated to the neglect of the  
collective activity of the social       
aggregate before ,condorcet1 his        
doctrine tended to eliminate as         
unimportant the roles of prominent men1 
and by means of this elimination it was 
possible to found sociology4 ,but it may
 be urged that it is patent on the face 
of history that its course has          
constantly been shaped and modified by  
the wills of individuals 7,we can ignore
 here the metaphysical question of      
freewill and determinism4 ,for the      
character of the individual's brain     

depends in any case on ante-natal       
accidents and coincidences1 and so it   
may be said that the role of individuals
 ultimately depends on chance1--the     
accidental coincidence of independent   
sequences471 which are by no means      
always the expression of the collective 
will2 and that the appearance of such   
personalities at the given moments is   
not a necessary outcome of the          
conditions and cannot be deduced4 ,nor  
is there any proof that1 if such and    
such an individual had not been born1   
some one else would have arisen to do   
what he did4 ,in some cases there is no 
reason to think that what happened need 
ever have come to pass4 ,in other cases1
 it seems evident that the actual change
 was inevitable1 but in default of the  
man who initiated and guided it1 it     
might have been postponed1 and1         
postponed or not1 might have borne a    
different cachet4 ,i may illustrate by  
an instance which has just come under my
 notice4 ,modern painting was founded by

 ,giotto1 and the ,italian expedition of
 ,charles ,,viii1 near the close of the 
sixteenth century1 introduced into      
,france the fashion of imitating        
,italian painters4 ,but for ,giotto and 
,charles ,,viii1 ,french painting might 
have been very different4 ,it may be    
said that if ,giotto had not appeared1  
some other great initiator would have   
played a role analogous to his1 and that
 without ,charles ,,viii there would    
have been the commerce with ,italy1     
which in the long run would have        
sufficed to place ,france in relation   
with ,italian artists4 ,but the         
equivalent of ,giotto might have been   
deferred for a century and probably     
would have been different2 and          
commercial relations would have required
 ages to produce the rayonnement        
imitatif of ,italian art in ,france1    
which the expedition of the royal       
adventurer provoked in a few years4 7,i 
have taken this example from ,g4        
,tarde's ,la logique sociale #b 7page   

#djc71 ,paris1 #aijd1 where it is used  
for quite a different purpose47         
,instances furnished by political       
history are simply endless4 ,can we     
conjecture how events would have moved  
if the son of ,philip of ,macedon had   
been an incompetent8 ,the aggressive    
action of ,prussia which astonished     
,europe in #agdj determined the         
subsequent history of ,germany2 but that
 action was anything but inevitable2 it 
depended entirely on the personality of 
,frederick the ,great4  ,hence it may be
 argued that the action of individual   
wills is a determining and disturbing   
factor1 too significant and effective to
 allow history to be grasped by         
sociological formulae4 ,the types and   
general forms of development which the  
sociologist attempts to disengage can   
only assist the historian in            
understanding the actual course of      
events4 ,it is in the special domains of
 economic history and ,culturgeschichte 
which have come to the front in modern  

times that generalisation is most       
fruitful1 but even in these it may be   
contended that it furnishes only partial
 explanations4  #ag4 ,the truth is that 
,darwinism itself offers the best       
illustration of the insufficiency of    
general laws to account for historical  
development4 ,the part played by        
coincidence1 and the part played by     
individuals--limited by1 and related to1
 general social conditions--render it   
impossible to deduce the course of the  
past history of man or to predict the   
future4 ,but it is just the same with   
organic development4 ,darwin 7or any    
other zoologist7 could not deduce the   
actual course of evolution from general 
principles4 ,given an organism and its  
environment1 he could not show that it  
must evolve into a more complex organism
 of a definite pre-determined type2     
knowing what it has evolved into1 he    
could attempt to discover and assign the
 determining causes4 ,general principles
 do not account for a particular        

sequence2 they embody necessary         
conditions2 but there is a chapter of   
accidents too4 ,it is the same in the   
case of history4  #ah4 ,among the       
evolutional attempts to subsume the     
course of history under general         
syntheses1 perhaps the most important is
 that of ,lamprecht1 whose              
kulturhistorische ,methode1 which he has
 deduced from and applied to ,german    
history1 exhibits the 7indirect7        
influence of the ,comtist school4 ,it is
 based upon psychology1 which1 in his   
view1 holds among the sciences of mind  
7,geisteswissenschaften7 the same place 
7that of a ,grundwissenschaft7 which    
mechanics holds among the sciences of   
nature4 ,history1 by the same           
comparison1 corresponds to biology1 and1
 according to him1 it can only become   
scientific if it is reduced to general  
concepts 7,begriffe74 ,historical       
movements and events are of a psychical 
character1 and ,lamprecht conceives a   
given phase of civilisation as a        

collective psychical condition          
7seelischer ,gesamtzustand7 controlling 
the period1 a diapason which penetrates 
all psychical phenomena and thereby all 
historical events of the time4 7,die    
kulturhistorische ,methode1 ,berlin1    
#aijj1 page #bf47 ,he has worked out a  
series of such phases1 ages of changing 
psychical diapason1 in his ,deutsche    
,geschichte with the aim of showing that
 all the feelings and actions of each   
age can be explained by the diapason2   
and has attempted to prove that these   
diapasons are exhibited in other social 
developments1 and are consequently not  
singular but typical4 ,he maintains     
further that these ages succeed each    
other in a definite order2 the principle
 being that the collective psychical    
development begins with the homogeneity 
of all the individual members of a      
society and1 through heightened         
psychical activity1 advances in the form
 of a continually increasing            
differentiation of the individuals 7this

 is akin to the ,spencerian formula74   
,this process1 evolving psychical       
freedom from psychical constraint1      
exhibits a series of psychical phenomena
 which define successive periods of     
civilisation4 ,the process depends on   
two simple principles1 that no idea can 
disappear without leaving behind it an  
effect or influence1 and that all       
psychical life1 whether in a person or a
 society1 means change1 the acquisition 
of new mental contents4 ,it follows that
 the new have to come to terms with the 
old1 and this leads to a synthesis which
 determines the character of a new age4 
,hence the ages of civilisation are     
defined as the highest concepts for     
subsuming without exception all         
psychical phenomena of the development  
of human societies1 that is1 of all     
historical events4 7,ibid4 pages #bh1   
#bi47 ,lamprecht deduces the idea of a  
special historical science1 which might 
be called historical ethnology1 dealing 
with the ages of civilisation1 and      

bearing the same relation to            
7descriptive or narrative7 history as   
ethnology to ethnography4 ,such a       
science obviously corresponds to        
,comte's social dynamics1 and the       
comparative method1 on which ,comte laid
 so much emphasis1 is the principal     
instrument of ,lamprecht4  #ai4 ,i have 
dwelt on the fundamental ideas of       
,lamprecht1 because they are not yet    
widely known in ,england1 and because   
his system is the ablest product of the 
sociological school of historians4 ,it  
carries the more weight as its author   
himself is a historical specialist1 and 
his historical syntheses deserve the    
most careful consideration4 ,but there  
is much in the process of development   
which on such assumptions is not        
explained1 especially the initiative of 
individuals4 ,historical development    
does not proceed in a right line1       
without the choice of diverging4 ,again 
and again1 several roads are open to it1
 of which it chooses one--why8 ,on      

,lamprecht's method1 we may be able to  
assign the conditions which limit the   
psychical activity of men at a          
particular stage of evolution1 but      
within those limits the individual has  
so many options1 such a wide room for   
moving1 that the definition of those    
conditions1 the psychical diapasons1 is 
only part of the explanation of the     
particular development4 ,the heel of    
,achilles in all historical speculations
 of this class has been the role of the 
individual4  ,the increasing prominence 
of economic history has tended to       
encourage the view that history can be  
explained in terms of general concepts  
or types4 ,marx and his school based    
their theory of human development on the
 conditions of production1 by which1    
according to them1 all social movements 
and historical changes are entirely     
controlled4 ,the leading part which     
economic factors play in ,lamprecht's   
system is significant1 illustrating the 
fact that economic changes admit most   

readily this kind of treatment1 because 
they have been less subject to direction
 or interference by individual pioneers4
  ,perhaps it may be thought that the   
conception of ,,social ,,environment    
7essentially psychical71 on which       
,lamprecht's psychical diapasons depend1
 is the most valuable and fertile       
conception that the historian owes to   
the suggestion of the science of        
biology--the conception of all          
particular historical actions and       
movements as 7#a7 related to and        
conditioned by the social environment1  
and 7#b7 gradually bringing about a     
transformation of that environment4 ,but
 no given transformation can be proved  
to be necessary 7pre-determined74 ,and  
types of development do not represent   
laws2 their meaning and value lie in the
 help they may give to the historian1 in
 investigating a certain period of      
civilisation1 to enable him to discover 
the interrelations among the diverse    
features which it presents4 ,they are1  

as some one has said1 an instrument of  
heuretic method4  #bj4 ,the men engaged 
in special historical researches--which 
have been pursued unremittingly for a   
century past1 according to scientific   
methods of investigating evidence       
7initiated by ,wolf1 ,niebuhr1          
,ranke7--have for the most part worked  
on the assumptions of genetic history or
 at least followed in the footsteps of  
those who fully grasped the genetic     
point of view4 ,but their aim has been  
to collect and sift evidence1 and       
determine particular facts2             
comparatively few have given serious    
thought to the lines of research and the
 speculations which have been considered
 in this paper4 ,they have been         
reasonably shy of compromising their    
work by applying theories which are     
still much debated and immature4 ,but   
historiography cannot permanently evade 
the questions raised by these theories4 
,one may venture to say that no         
historical change or transformation will

 be fully understood until it is        
explained how social environment acted  
on the individual components of the     
society 7both immediately and by        
heredity71 and how the individuals      
reacted upon their environment4 ,the    
problem is psychical1 but it is         
analogous to the main problem of the    
biologist4     ,,xxviii4 ,,the ,,genesis
 ,,of ,,double ,,stars4 ,by ,sir ,george
 ,darwin1 ,k4,c4,b41 ,f4,r4,s4  ,plumian
 ,professor of ,astronomy and           
,experimental ,philosophy in the        
,university of ,cambridge4  ,in ordinary
 speech a system of any sort is said to 
be stable when it cannot be upset       
easily1 but the meaning attached to the 
word is usually somewhat vague4 ,it is  
hardly surprising that this should be   
the case1 when it is only within the    
last thirty years1 and principally      
through the investigations of ,m4       
,poincare1 that the conception of       
stability has1 even for physicists1     
assumed a definiteness and clearness in 

which it was previously lacking4 ,the   
laws which govern stability hold good in
 regions of the greatest diversity2 they
 apply to the motion of planets round   
the sun1 to the internal arrangement of 
those minute corpuscles of which each   
chemical atom is constructed1 and to the
 forms of celestial bodies4 ,in the     
present essay ,i shall attempt to       
consider the laws of stability as       
relating to the last case1 and shall    
discuss the succession of shapes which  
may be assumed by celestial bodies in   
the course of their evolution4 ,i       
believe further that homologous         
conceptions are applicable in the       
consideration of the transmutations of  
the various forms of animal and of      
vegetable life and in other regions of  
thought4 ,even if some of my readers    
should think that what ,i shall say on  
this head is fanciful1 yet at least the 
exposition will serve to illustrate the 
meaning to be attached to the laws of   
stability in the physical universe4  ,i 

propose1 therefore1 to begin this essay 
by a sketch of the principles of        
stability as they are now formulated by 
physicists4  ,i4  ,if a slight impulse  
be imparted to a system in equilibrium  
one of two consequences must ensue2     
either small oscillations of the system 
will be started1 or the disturbance will
 increase without limit and the         
arrangement of the system will be       
completely changed4 ,thus a stick may be
 in equilibrium either when it hangs    
from a peg or when it is balanced on its
 point4 ,if in the first case the stick 
is touched it will swing to and fro1 but
 in the second case it will topple over4
 ,the first position is a stable one1   
the second is unstable4 ,but this case  
is too simple to illustrate all that is 
implied by stability1 and we must       
consider cases of stable and of unstable
 motion4 ,imagine a satellite and its   
planet1 and consider each of them to be 
of indefinitely small size1 in fact     
particles2 then the satellite revolves  

round its planet in an ellipse4 ,a small
 disturbance imparted to the satellite  
will only change the ellipse to a small 
amount1 and so the motion is said to be 
stable4 ,if1 on the other hand1 the     
disturbance were to make the satellite  
depart from its initial elliptic orbit  
in ever widening circuits1 the motion   
would be unstable4 ,this case affords an
 example of stable motion1 but ,i have  
adduced it principally with the object  
of illustrating another point not       
immediately connected with stability1   
but important to a proper comprehension 
of the theory of stability4  ,the motion
 of a satellite about its planet is one 
of revolution or rotation4 ,when the    
satellite moves in an ellipse of any    
given degree of eccentricity1 there is a
 certain amount of rotation in the      
system1 technically called rotational   
momentum1 and it is always the same at  
every part of the orbit4 7,moment of    
momentum or rotational momentum is      
measured by the momentum of the         

satellite multiplied by the             
perpendicular from the planet on to the 
direction of the path of the satellite  
at any instant47  ,now if we consider   
all the possible elliptic orbits of a   
satellite about its planet which have   
the same amount of rotational momentum1 
we find that the major axis of the      
ellipse described will be different     
according to the amount of flattening   
7or the eccentricity7 of the ellipse    
described4 ,a figure titled ,a 'family' 
of elliptic orbits with constant        
rotational momentum 7,fig4 #a7          
illustrates for a given planet and      
satellite all such orbits with constant 
rotational momentum1 and with all the   
major axes in the same direction4 ,it   
will be observed that there is a        
continuous transformation from one orbit
 to the next1 and that the whole forms a
 consecutive group1 called by           
mathematicians a family of orbits4 ,in  
this case the rotational momentum is    
constant and the position of any orbit  

in the family is determined by the      
length of the major axis of the ellipse2
 the classification is according to the 
major axis1 but it might have been made 
according to anything else which would  
cause the orbit to be exactly           
determinate4  ,i shall come later to the
 classification of all possible forms of
 ideal liquid stars1 which have the same
 amount of rotational momentum1 and the 
classification will then be made        
according to their densities1 but the   
idea of orderly arrangement in a family 
is just the same4  ,we thus arrive at   
the conception of a definite type of    
motion1 with a constant amount of       
rotational momentum1 and a              
classification of all members of the    
family1 formed by all possible motions  
of that type1 according to the value of 
some measurable quantity 7this will     
hereafter be density7 which determines  
the motion exactly4 ,in the particular  
case of the elliptic motion used for    
illustration the motion was stable1 but 

other cases of motion might be adduced  
in which the motion would be unstable1  
and it would be found that              
classification in a family and          
specification by some measurable        
quantity would be equally applicable4   
,a complex mechanical system may be     
capable of motion in several distinct   
modes or types1 and the motions         
corresponding to each such type may be  
arranged as before in families4 ,for the
 sake of simplicity ,i will suppose that
 only two types are possible1 so that   
there will only be two families2 and the
 rotational momentum is to be constant4 
,the two types of motion will have      
certain features in common which we     
denote in a sort of shorthand by the    
letter ,a4 ,similarly the two types may 
be described as ,a  a and ,a  b1 so that
 a and b denote the specific differences
 which discriminate the families from   
one another4 ,now following in          
imagination the family of the type ,a   
a1 let us begin with the case where the 

specific difference a is well marked4   
,as we cast our eyes along the series   
forming the family1 we find the         
difference a becoming less conspicuous4 
,it gradually dwindles until it         
disappears2 beyond this point it either 
becomes reversed1 or else the type has  
ceased to be a possible one4 ,in our    
shorthand we have started with ,a  a1   
and have watched the characteristic a   
dwindling to zero4 ,when it vanishes we 
have reached a type which may be        
specified as ,a2 beyond this point the  
type would be ,a - a or would be        
impossible4  ,following the ,a  b type  
in the same way1 b is at first well     
marked1 it dwindles to zero1 and finally
 may become negative4 ,hence in         
shorthand this second family may be     
described as ,a  b1444 ,a1444 ,a - b4   
,in each family there is one single     
member which is indistinguishable from a
 member of the other family2 it is      
called by ,poincare a form of           
bifurcation4 ,it is this conception of a

 form of bifurcation which forms the    
important consideration in problems     
dealing with the forms of liquid or     
gaseous bodies in rotation4  ,but to    
return to the general question1--thus   
far the stability of these families has 
not been considered1 and it is the      
stability which renders this way of     
looking at the matter so valuable4 ,it  
may be proved that if before the point  
of bifurcation the type ,a  a was       
stable1 then ,a  b must have been       
unstable4 ,further as a and b each      
diminish ,a  a becomes less pronouncedly
 stable1 and ,a  b less unstable4 ,on   
reaching the point of bifurcation ,a  a 
has just ceased to be stable1 or what   
amounts to the same thing is just       
becoming unstable1 and the converse is  
true of the ,a  b family4 ,after passing
 the point of bifurcation ,a  a has     
become definitely unstable and ,a  b has
 become stable4 ,hence the point of     
bifurcation is also a point of exchange 
of stabilities between the two types4   

7,in order not to complicate            
unnecessarily this explanation of a     
general principle ,i have not stated    
fully all the cases that may occur4     
,thus3 firstly1 after bifurcation ,a  a 
may be an impossible type and ,a  a will
 then stop at this point2 or secondly1  
,a  b may have been an impossible type  
before bifurcation1 and will only begin 
to be a real one after it2 or thirdly1  
both ,a  a and ,a  b may be impossible  
after the point of bifurcation1 in which
 case they coalesce and disappear4 ,this
 last case shows that types arise and   
disappear in pairs1 and that on         
appearance or before disappearance one  
must be stable and the other unstable47 
,in nature it is of course only the     
stable types of motion which can persist
 for more than a short time4 ,thus the  
task of the physical evolutionist is to 
determine the forms of bifurcation1 at  
which he must1 as it were1 change       
carriages in the evolutionary journey so
 as always to follow the stable route4  

,he must besides be able to indicate    
some natural process which shall        
correspond in effect to the ideal       
arrangement of the several types of     
motion in families with gradually       
changing specific differences4          
,although1 as we shall see hereafter1 it
 may frequently or even generally be    
impossible to specify with exactness the
 forms of bifurcation in the process of 
evolution1 yet the conception is one of 
fundamental importance4  ,the ideas     
involved in this sketch are no doubt    
somewhat recondite1 but ,i hope to      
render them clearer to the              
non-mathematical reader by homologous   
considerations in other fields of       
thought 7,i considered this subject in  
my ,presidential address to the ,british
 ,association in #aije1 ,report of the  
#geth ,meeting of the ,british ,assoc4  
7,s4 ,africa1 #aije71 ,london1 #aijf1   
page #c4 ,some reviewers treated my     
speculations as fanciful1 but as ,i     
believe that this was due generally to  

misapprehension1 and as ,i hold that    
homologous considerations as to         
stability and instability are really    
applicable to evolution of all sorts1 ,i
 have thought it well to return to the  
subject in the present paper471 and ,i  
shall pass on thence to illustrations   
which will teach us something of the    
evolution of stellar systems4  ,states  
or governments are organised schemes of 
action amongst groups of men1 and they  
belong to various types to which generic
 names1 such as autocracy1 aristocracy  
or democracy1 are somewhat loosely      
applied4 ,a definite type of government 
corresponds to one of our types of      
motion1 and while retaining its type it 
undergoes a slow change as the          
civilisation and character of the people
 change1 and as the relationship of the 
nation to other nations changes4 ,in the
 language used before1 the government   
belongs to a family1 and as time        
advances we proceed through the         
successive members of the family4 ,a    

government possesses a certain degree of
 stability--hardly measurable in numbers
 however--to resist disintegrating      
influences such as may arise from wars1 
famines1 and internal dissensions4 ,this
 stability gradually rises to a maximum 
and gradually declines4 ,the degree of  
stability at any epoch will depend on   
the fitness of some leading feature of  
the government to suit the slowly       
altering circumstances1 and that feature
 corresponds to the characteristic      
denoted by a in the physical problem4 ,a
 time at length arrives when the        
stability vanishes1 and the slightest   
shock will overturn the government4 ,at 
this stage we have reached the crisis of
 a point of bifurcation1 and there will 
then be some circumstance1 apparently   
quite insignificant and almost          
unnoticed1 which is such as to prevent  
the occurrence of anarchy4 ,this        
circumstance or condition is what we    
typified as b4 ,insignificant although  
it may seem1 it has started the         

government on a new career of stability 
by imparting to it a new type4 ,it grows
 in importance1 the form of government  
becomes obviously different1 and its    
stability increases4 ,then in its turn  
this newly acquired stability declines1 
and we pass on to a new crisis or       
revolution4 ,there is thus a series of  
points of bifurcation in history at     
which the continuity of political       
history is maintained by means of       
changes in the type of government4      
,these ideas seem1 to me at least1 to   
give a true account of the history of   
states1 and ,i contend that it is no    
mere fanciful analogy but a true        
homology1 when in both realms of        
thought--the physical and the           
political--we perceive the existence of 
forms of bifurcation and of exchanges of
 stability4  ,further than this1 ,i     
would ask whether the same train of     
ideas does not also apply to the        
evolution of animals8 ,a species is well
 adapted to its environment when the    

individual can withstand the shocks of  
famine or the attacks and competition of
 other animals2 it then possesses a high
 degree of stability4 ,most of the      
casual variations of individuals are    
indifferent1 for they do not tell much  
either for or against success in life2  
they are small oscillations which leave 
the type unchanged4 ,as circumstances   
change1 the stability of the species may
 gradually dwindle through the          
insufficiency of some definite quality1 
on which in earlier times no such       
insistent demands were made4 ,the       
individual animals will then tend to    
fail in the struggle for life1 the      
numbers will dwindle and extinction may 
ensue4 ,but it may be that some new     
variation1 at first of insignificant    
importance1 may just serve to turn the  
scale4 ,a new type may be formed in     
which the variation in question is      
preserved and augmented2 its stability  
may increase and in time a new species  
may be produced4  ,at the risk of       

condemnation as a wanderer beyond my    
province into the region of biological  
evolution1 ,i would say that this view  
accords with what ,i understand to be   
the views of some naturalists1 who      
recognise the existence of critical     
periods in biological history at which  
extinction occurs or which form the     
starting-point for the formation of new 
species4 ,ought we not then to expect   
that long periods will elapse during    
which a type of animal will remain      
almost constant1 followed by other      
periods1 enormously long no doubt as    
measured in the life of man1 of acute   
struggle for existence when the type    
will change more rapidly8 ,this at least
 is the view suggested by the theory of 
stability in the physical universe4 7,i 
make no claim to extensive reading on   
this subject1 but refer the reader for  
example to a paper by ,professor        
,a4,a4,w4 ,hubrecht on ,de ,vries's     
theory of ,mutations1 ,popular ,science 
,monthly1 ,july #aijd1 especially to    

page #bac47  ,and now ,i propose to     
apply these ideas of stability to the   
theory of stellar evolution1 and finally
 to illustrate them by certain recent   
observations of a very remarkable       
character4  ,stars and planets are      
formed of materials which yield to the  
enormous forces called into play by     
gravity and rotation4 ,this is obviously
 true if they are gaseous or fluid1 and 
even solid matter becomes plastic under 
sufficiently great stresses4 ,nothing   
approaching a complete study of the     
equilibrium of a heterogeneous star has 
yet been found possible1 and we are     
driven to consider only bodies of       
simpler construction4 ,i shall begin    
therefore by explaining what is known   
about the shapes which may be assumed by
 a mass of incompressible liquid of     
uniform density under the influences of 
gravity and of rotation4 ,such a liquid 
mass may be regarded as an ideal star1  
which resembles a real star in the fact 
that it is formed of gravitating and    

rotating matter1 and because its shape  
results from the forces to which it is  
subject4 ,it is unlike a star in that it
 possesses the attributes of            
incompressibility and of uniform        
density4 ,the difference between the    
real and the ideal is doubtless great1  
yet the similarity is great enough to   
allow us to extend many of the          
conclusions as to ideal liquid stars to 
the conditions which must hold good in  
reality4 ,thus with the object of       
obtaining some insight into actuality1  
it is justifiable to discuss an avowedly
 ideal problem at some length4  ,the    
attraction of gravity alone tends to    
make a mass of liquid assume the shape  
of a sphere1 and the effects of         
rotation1 summarised under the name of  
centrifugal force1 are such that the    
liquid seeks to spread itself outwards  
from the axis of rotation4 ,it is a     
singular fact that it is unnecessary to 
take any account of the size of the mass
 of liquid under consideration1 because 

the shape assumed is exactly the same   
whether the mass be small or large1 and 
this renders the statement of results   
much easier than would otherwise be the 
case4  ,a mass of liquid at rest will   
obviously assume the shape of a sphere1 
under the influence of gravitation1 and 
it is a stable form1 because any        
oscillation of the liquid which might be
 started would gradually die away under 
the influence of friction1 however      
small4 ,if now we impart to the whole   
mass of liquid a small speed of rotation
 about some axis1 which may be called   
the polar axis1 in such a way that there
 are no internal currents and so that it
 spins in the same way as if it were    
solid1 the shape will become slightly   
flattened like an orange4 ,although the 
earth and the other planets are not     
homogeneous they behave in the same way1
 and are flattened at the poles and     
protuberant at the equator4 ,this shape 
may therefore conveniently be described 
as planetary4  ,if the planetary body be

 slightly deformed the forces of        
restitution are slightly less than they 
were for the sphere2 the shape is stable
 but somewhat less so than the sphere4  
,we have then a planetary spheroid1     
rotating slowly1 slightly flattened at  
the poles1 with a high degree of        
stability1 and possessing a certain     
amount of rotational momentum4 ,let us  
suppose this ideal liquid star to be    
somewhere in stellar space far removed  
from all other bodies2 then it is       
subject to no external forces1 and any  
change which ensues must come from      
inside4 ,now the amount of rotational   
momentum existing in a system in motion 
can neither be created nor destroyed by 
any internal causes1 and therefore1     
whatever happens1 the amount of         
rotational momentum possessed by the    
star must remain absolutely constant4   
,a real star radiates heat1 and as it   
cools it shrinks4 ,let us suppose then  
that our ideal star also radiates and   
shrinks1 but let the process proceed so 

slowly that any internal currents       
generated in the liquid by the cooling  
are annulled so quickly by fluid        
friction as to be insignificant2 further
 let the liquid always remain at any    
instant incompressible and homogeneous4 
,all that we are concerned with is that1
 as time passes1 the liquid star        
shrinks1 rotates in one piece as if it  
were solid1 and remains incompressible  
and homogeneous4 ,the condition is of   
course artificial1 but it represents the
 actual processes of nature as well as  
may be1 consistently with the postulated
 incompressibility and homogeneity4     
7,mathematicians are accustomed to      
regard the density as constant and the  
rotational momentum as increasing4 ,but 
the way of looking at the matter1 which 
,i have adopted1 is easier of           
comprehension1 and it comes to the same 
in the end47  ,the shrinkage of a       
constant mass of matter involves an     
increase of its density1 and we have    
therefore to trace the changes which    

supervene as the star shrinks1 and as   
the liquid of which it is composed      
increases in density4 ,the shrinkage    
will1 in ordinary parlance1 bring the   
weights nearer to the axis of rotation4 
,hence in order to keep up the          
rotational momentum1 which as we have   
seen must remain constant1 the mass must
 rotate quicker4 ,the greater speed of  
rotation augments the importance of     
centrifugal force compared with that of 
gravity1 and as the flattening of the   
planetary spheroid was due to           
centrifugal force1 that flattening is   
increased2 in other words the           
ellipticity of the planetary spheroid   
increases4  ,as the shrinkage and       
corresponding increase of density       
proceed1 the planetary spheroid becomes 
more and more elliptic1 and the         
succession of forms constitutes a family
 classified according to the density of 
the liquid4 ,the specific mark of this  
family is the flattening or ellipticity4
  ,now consider the stability of the    

system1 we have seen that the spheroid  
with a slow rotation1 which forms our   
starting-point1 was slightly less stable
 than the sphere1 and as we proceed     
through the family of ever flatter      
ellipsoids the stability continues to   
diminish4 ,at length when it has assumed
 the shape shown in a figure titled     
,planetary spheroid just becoming       
unstable 7,fig4 #b47 where the          
equatorial and polar axes are           
proportional to the numbers #ajjj and   
#ehc1 the stability has just            
disappeared4 ,according to the general  
principle explained above this is a form
 of bifurcation1 and corresponds to the 
form denoted ,a4 ,the specific          
difference a of this family must be     
regarded as the excess of the           
ellipticity of this figure above that of
 all the earlier ones1 beginning with   
the slightly flattened planetary        
spheroid4 ,accordingly the specific     
difference a of the family has gradually
 diminished from the beginning and      

vanishes at this stage4  ,according to  
,poincare's principle the vanishing of  
the stability serves us with notice that
 we have reached a figure of            
bifurcation1 and it becomes necessary to
 inquire what is the nature of the      
specific difference of the new family of
 figures which must be coalescent with  
the old one at this stage4 ,this        
difference is found to reside in the    
fact that the equator1 which in the     
planetary family has hitherto been      
circular in section1 tends to become    
elliptic4 ,hitherto the rotational      
momentum has been kept up to its        
constant value partly by greater speed  
of rotation and partly by a symmetrical 
bulging of the equator4 ,but now while  
the speed of rotation still increases   
7,the mathematician familiar with       
,jacobi's ellipsoid will find that this 
is correct1 although in the usual mode  
of exposition1 alluded to above in a    
footnote1 the speed diminishes471 the   
equator tends to bulge outwards at two  

diametrically opposite points and to be 
flattened midway between these          
protuberances4 ,the specific difference 
in the new family1 denoted in the       
general sketch by b1 is this ellipticity
 of the equator4 ,if we had traced the  
planetary figures with circular equators
 beyond this stage ,a1 we should have   
found them to have become unstable1 and 
the stability has been shunted off along
 the ,a  b family of forms with elliptic
 equators4  ,this new series of figures1
 generally named after the great        
mathematician ,jacobi1 is at first only 
just stable1 but as the density         
increases the stability increases1      
reaches a maximum and then declines4 ,as
 this goes on the equator of these      
,jacobian figures becomes more and more 
elliptic1 so that the shape is          
considerably elongated in a direction at
 right angles to the axis of rotation4  
,at length when the longest axis of the 
three has become about three times as   
long as the shortest 7,the three axes of

 the ellipsoid are then proportional to 
#ajjj1 #dcb1 #cdc471 the stability of   
this family of figures vanishes1 and we 
have reached a new form of bifurcation  
and must look for a new type of figure  
along which the stable development will 
presumably extend4 ,two sections of this
 critical ,jacobian figure1 which is a  
figure of bifurcation1 are shown by the 
dotted lines in a figure titled ,the    
'pear-shaped figure' and the ,jocobian  
figure from which it is derived 7,fig4  
#c47 comprising two figures1 one above  
the other3 the upper figure is the      
equatorial section at right angles to   
the axis of rotation1 the lower figure  
is a section through the axis4  ,now    
,poincare has proved that the new type  
of figure is to be derived from the     
figure of bifurcation by causing one of 
the ends to be prolonged into a snout   
and by bluntening the other end4 ,the   
snout forms a sort of stalk1 and between
 the stalk and the axis of rotation the 
surface is somewhat flattened4 ,these   

are the characteristics of a pear1 and  
the figure has therefore been called the
 pear-shaped figure of equilibrium4 ,the
 firm line shows this new type of       
figure1 whilst1 as already explained1   
the dotted line shows the form of       
bifurcation from which it is derived4   
,the specific mark of this new family is
 the protrusion of the stalk together   
with the other corresponding smaller    
differences4 ,if we denote this         
difference by c1 while ,a  b denotes the
 ,jacobian figure of bifurcation from   
which it is derived1 the new family may 
be called ,a  b  c1 and c is zero       
initially4 ,according to my calculations
 this series of figures is stable 7,m4  
,liapounoff contends that for constant  
density the new series of figures1 which
 ,m4 ,poincare discovered1 has less     
rotational momentum than that of the    
figure of bifurcation4 ,if he is        
correct1 the figure of bifurcation is a 
limit of stable figures1 and none can   
exist with stability for greater        

rotational momentum4 ,my own work seems 
to indicate that the opposite is true1  
and1 notwithstanding ,m4 ,liapounoff's  
deservedly great authority1 ,i venture  
to state the conclusions in accordance  
with my own work471 but ,i do not know  
at what stage of its development it     
becomes unstable4  ,professor ,jeans has
 solved a problem which is of interest  
as throwing light on the future         
development of the pear-shaped figure1  
although it is of a still more ideal    
character than the one which has been   
discussed4 ,he imagines an ,,infinitely 
long circular cylinder of liquid to be  
in rotation about its central axis4 ,the
 existence is virtually postulated of a 
demon who is always occupied in keeping 
the axis of the cylinder straight1 so   
that ,jeans has only to concern himself 
with the stability of the form of the   
section of the cylinder1 which as ,i    
have said is a circle with the axis of  
rotation at the centre4 ,he then        
supposes the liquid forming the cylinder

 to shrink in diameter1 just as we have 
done1 and finds that the speed of       
rotation must increase so as to keep up 
the constancy of the rotational         
momentum4 ,the circularity of section is
 at first stable1 but as the shrinkage  
proceeds the stability diminishes and at
 length vanishes4 ,this stage in the    
process is a form of bifurcation1 and   
the stability passes over to a new      
series consisting of cylinders which are
 elliptic in section4 ,the circular     
cylinders are exactly analogous with our
 planetary spheroids1 and the elliptic  
ones with the ,jacobian ellipsoids4     
,with further shrinkage the elliptic    
cylinders become unstable1 a new form of
 bifurcation is reached1 and the        
stability passes over to a series of    
cylinders whose section is pear-shaped4 
,thus far the analogy is complete       
between our problem and ,jeans's1 and in
 consequence of the greater simplicity  
of the conditions1 he is able to carry  
his investigation further4 ,he finds    

that the stalk end of the pear-like     
section continues to protrude more and  
more1 and the flattening between it and 
the axis of rotation becomes a          
constriction4 ,finally the neck breaks  
and a satellite cylinder is born4       
,jeans's figure for an advanced stage of
 development is shown in a figure titled
 ,section of a rotating cylinder of     
liquid 7,fig4 #d471 but his calculations
 do not enable him actually to draw the 
state of affairs after the rupture of   
the neck4  ,there are certain           
difficulties in admitting the exact     
parallelism between this problem and    
ours1 and thus the final development of 
our pear-shaped figure and the end of   
its stability in a form of bifurcation  
remain hidden from our view1 but the    
successive changes as far as they have  
been definitely traced are very         
suggestive in the study of stellar      
evolution4  ,attempts have been made to 
attack this problem from the other end4 
,if we begin with a liquid satellite    

revolving about a liquid planet and     
proceed backwards in time1 we must make 
the two masses expand so that their     
density will be diminished4 ,various    
figures have been drawn exhibiting the  
shapes of two masses until their        
surfaces approach close to one another  
and even until they just coalesce1 but  
the discussion of their stability is not
 easy4 ,at present it would seem to be  
impossible to reach coalescence by any  
series of stable transformations1 and if
 this is so ,professor ,jeans's         
investigation has ceased to be truly    
analogous to our problem at some        
undetermined stage4 ,however this may be
 this line of research throws an        
instructive light on what we may expect 
to find in the evolution of real stellar
 systems4  ,in the second part of this  
paper ,i shall point out the bearing    
which this investigation of the         
evolution of an ideal liquid star may   
have on the genesis of double stars4    
,,ii4  ,there are in the heavens many   

stars which shine with a variable       
brilliancy4 ,amongst these there is a   
class which exhibits special            
peculiarities2 the members of this class
 are generally known as ,algol          
,variables1 because the variability of  
the star ,beta ,persei or ,algol was the
 first of such cases to attract the     
attention of astronomers1 and because it
 is perhaps still the most remarkable of
 the whole class4 ,but the circumstances
 which led to this discovery were so    
extraordinary that it seems worth while 
to pause a moment before entering on the
 subject4  ,john ,goodricke1 a          
deaf-mute1 was born in #agfd2 he was    
grandson and heir of ,sir ,john         
,goodricke of ,ribston ,hall1           
,yorkshire4 ,in ,november #aghb1 he     
noted that the brilliancy of ,algol     
waxed and waned 7,it is said that ,georg
 ,palitzch1 a farmer of ,prohlis near   
,dresden1 had about #ageh already noted 
the variability of ,algol with the naked
 eye4 ,journ4 ,brit4 ,astron4 ,assoc4   

,vol4 ,,xv4 7#aijd-e71 page #bjc471 and 
devoted himself to observing it on every
 fine night from the #bhth ,december    
#aghb to the #abth ,may #aghc4 ,he      
communicated his observations to the    
,royal ,society1 and suggested that the 
variation in brilliancy was due to      
periodic eclipses by a dark companion   
star1 a theory now universally accepted 
as correct4 ,the ,royal ,society        
recognised the importance of the        
discovery by awarding to ,goodricke1    
then only #ai years of age1 their       
highest honour1 the ,copley medal4 ,his 
later observations of ,beta ,lyrae and  
of ,delta ,cephei were almost as        
remarkable as those of ,algol1 but      
unfortunately a career of such          
extraordinary promise was cut short by  
death1 only a fortnight after his       
election to the ,royal ,society4 7,dict4
 of ,national ,biography2 article       
,goodricke 7,john74 ,the article is by  
,miss ,agnes ,clerke4 ,it is strange    
that she did not then seem to be aware  

that he was a deaf-mute1 but she notes  
the fact in her ,problems of            
,astrophysics1 page #ccg1 ,london1      
#aijc47  ,it was not until #ahhi that   
,goodricke's theory was verified1 when  
it was proved by ,vogel that the star   
was moving in an orbit1 and in such a   
manner that it was only possible to     
explain the rise and fall in the        
luminosity by the partial eclipse of a  
bright star by a dark companion4  ,the  
whole mass of the system of ,algol is   
found to be half as great again as that 
of our sun1 yet the two bodies complete 
their orbit in the short period of #b;d 
#bj;h #dhm #ees4 ,the light remains     
constant during each period1 except for 
#i;h #bjm when it exhibits a            
considerable fall in brightness         
7,clerke1 ,problems of ,astrophysics    
page #cjb and chapter ,,xviii472 the    
curve which represents the variation in 
the light is shown in a figure titled   
,the light-curve and system of ,beta    
,lyrae 7,fig4 #g474  ,the spectroscope  

has enabled astronomers to prove that   
many stars1 although apparently single1 
really consist of two stars circling    
around one another 7,if a source of     
light is approaching with a great       
velocity the waves of light are crowded 
together1 and conversely they are spaced
 out when the source is receding4 ,thus 
motion in the line of sight virtually   
produces an infinitesimal change of     
colour4 ,the position of certain dark   
lines in the spectrum affords an        
exceedingly accurate measurement of     
colour4 ,thus displacements of these    
spectral lines enables us to measure the
 velocity of the source of light towards
 or away from the observer472 they are  
known as spectroscopic binaries4        
,campbell of the ,lick ,observatory     
believes that about one star in six is a
 binary 7,astrophysical ,journ4 ,vol4   
,,xiii4 page #hi1 #aija4 ,see also ,a4  
,roberts1 ,nature1 ,sept4 #ab1 #aija1   
page #dfh472 thus there must be many    
thousand such stars within the reach of 

our spectroscopes4  ,the orientation of 
the planes of the orbits of binary stars
 appears to be quite arbitrary1 and in  
general the star does not vary in       
brightness4 ,amongst all such orbits    
there must be some whose planes pass    
nearly through the sun1 and in these    
cases the eclipse of one of the stars by
 the other becomes inevitable1 and in   
each circuit there will occur two       
eclipses of unequal intensities4  ,it is
 easy to see that in the majority of    
such cases the two components must move 
very close to one another4  ,the        
coincidence between the spectroscopic   
and the photometric evidence permits us 
to feel complete confidence in the      
theory of eclipses4 ,when then we find a
 star with a light-curve of perfect     
regularity and with a characteristics of
 that of ,algol1 we are justified in    
extending the theory of eclipses to it1 
although it may be too faint to permit  
of adequate spectroscopic examination4  
,this extension of the theory secures a 

considerable multiplication of the      
examples available for observation1 and 
some #cj have already been discovered4  
,dr ,alexander ,roberts1 of ,lovedale in
 ,cape ,colony1 truly remarks that the  
study of ,algol variables brings us to  
the very threshold of the question of   
stellar evolution4 7,proc4 ,roy4 ,soc4  
,edinburgh1 ,,xxiv4 ,part ,,ii4 7#aijb71
 page #gc47 ,it is on this account that 
,i propose to explain in some detail the
 conclusion to which he and some other  
observers have been led4  ,although     
these variable stars are mere points of 
light1 it has been proved by means of   
the spectroscope that the law of        
gravitation holds good in the remotest  
regions of stellar space1 and further it
 seems now to have become possible even 
to examine the shapes of stars by       
indirect methods1 and thus to begin the 
study of their evolution4 ,the chain of 
reasoning which ,i shall explain must of
 necessity be open to criticism1 yet the
 explanation of the facts by the theory 

is so perfect that it is not easy to    
resist the conviction that we are       
travelling along the path of truth4     
,the brightness of a star is specified  
by what is called its magnitude4 ,the   
average brightness of all the stars     
which can just be seen with the naked   
eye defines the sixth magnitude4 ,a star
 which only gives two-fifths as much    
light is said to be of the seventh      
magnitude2 while one which gives #b     
#a_/b times as much light is of the     
fifth magnitude1 and successive         
multiplications or divisions by #b #a_/b
 define the lower or higher magnitudes4 
,negative magnitudes have clearly to be 
contemplated2 thus ,sirius is of        
magnitude minus #a4d1 and the sun is of 
magnitude minus #bf4  ,the definition of
 magnitude is also extended to          
fractions2 for example1 the lights given
 by two candles which are placed at #ajj
 feet and #ajj feet #f inches from the  
observer differ in brightness by        
one-hundredth of a magnitude4  ,a great 

deal of thought has been devoted to the 
measurement of the brightness of stars1 
but ,i will only describe one of the    
methods used1 that of the great         
astronomer ,argelander4 ,in the         
neighbourhood of the star under         
observation some half dozen standard    
stars are selected of known invariable  
magnitudes1 some being brighter and some
 fainter than the star to be measured2  
so that these stars afford a visible    
scale of brightness4 ,suppose we number 
them in order of increasing brightness  
from #a to #f2 then the observer        
estimates that on a given night his star
 falls between stars #b and #c1 on the  
next night1 say between #c and #d1 and  
then again perhaps it may return to     
between #b and #c1 and so forth4 ,with  
practice he learns to evaluate the      
brightness down to small fractions of a 
magnitude1 even a hundredth part of a   
magnitude is not quite negligible4  ,for
 example1 in observing the star ,,rr    
,centauri five stars were in general    

used for comparison by ,dr ,roberts1 and
 in course of three months he secured   
thereby #cjj complete observations4     
,when the period of the cycle had been  
ascertained exactly1 these #cjj values  
were reduced to mean values which       
appertained to certain mean places in   
the cycle1 and a mean light-curve was   
obtained in this way4 ,figures titled   
,light curve of ,,rr ,centauri 7,fig4   
#e7 and ,the light-curve and system of  
,beta ,lyrae 7,fig4 #g7 show examples of
 light curves4  ,i shall now follow out 
the results of the observation of ,,rr  
,centauri not only because it affords   
the easiest way of explaining these     
investigations1 but also because it is  
one of the stars which furnishes the    
most striking results in connection with
 the object of this essay4 7,see        
,monthly notices ,r4,a4,s4 ,vol4 #fc1   
#aijc1 page #ebg47 ,this star has a mean
 magnitude of about #g #a_/b1 and it is 
therefore invisible to the naked eye4   
,its period of variability is #ad;h #cbm

 #ajs4#gf1 the last refinement of       
precision being of course only attained 
in the final stages of reduction4       
,twenty-nine mean values of the         
magnitude were determined1 and they were
 nearly equally spaced over the whole   
cycle of changes4 ,the black dots in    
,fig4 #e exhibit the mean values        
determined by ,dr ,roberts4 ,the last   
three dots on the extreme right are     
merely the same as the first three on   
the extreme left1 and are repeated to   
show how the next cycle would begin4    
,the smooth dotted curve will be        
explained hereafter1 but1 by reference  
to the scale of magnitudes on the       
margins of the figure1 it may be used to
 note that the dots might be brought    
into a perfectly smooth curve by        
shifting some few of the dots by about a
 hundredth of a magnitude4  ,this       
light-curve presents those              
characteristics which are due to        
successive eclipses1 but the exact form 
of the curve must depend on the nature  

of the two mutually eclipsing stars4 ,if
 we are to interpret the curve with all 
possible completeness1 it is necessary  
to make certain assumptions as to the   
stars4 ,it is assumed then that the     
stars are equally bright all over their 
disks1 and secondly that they are not   
surrounded by an extensive absorptive   
atmosphere4 ,this last appears to me to 
be the most dangerous assumption        
involved in the whole theory4  ,making  
these assumptions1 however1 it is found 
that if each of the eclipsing stars were
 spherical it would not be possible to  
generate such a curve with the closest  
accuracy4 ,the two stars are certainly  
close together1 and it is obvious that  
in such a case the tidal forces         
exercised by each on the other must be  
such as to elongate the figure of each  
towards the other4 ,accordingly it is   
reasonable to adopt the hypothesis that 
the system consists of a pair of        
elongated ellipsoids1 with their longest
 axes pointed towards one another4 ,no  

supposition is adopted a priori as to   
the ratio of the two masses1 or as to   
their relative size or brightness1 and  
the orbit may have any degree of        
eccentricity4 ,these last are all to be 
determined from the nature of the       
light-curve4  ,in the case of ,,rr      
,centauri1 however1 ,dr ,roberts finds  
the conditions are best satisfied by    
supposing the orbit to be circular1 and 
the sizes and masses of the components  
to be equal1 while their luminosities   
are to one another in the ratio of #d to
 #c4 ,as to their shapes he finds them  
to be so much elongated that they       
overlap1 as exhibited in his figure     
titled ,the shape of the star ,,rr      
,centauri 7,fig4 #f474 ,the dotted curve
 shows a form of equilibrium of rotating
 liquid as computed by me some years    
before1 and it was added for the sake of
 comparison4  ,on turning back to ,fig4 
#e the reader will see in the smooth    
dotted curve the light variation which  
would be exhibited by such a binary     

system as this4 ,the curve is the result
 of computation and it is impossible not
 to be struck by the closeness of the   
coincidence with the series of black    
dots which denote the observations4  ,it
 is virtually certain that ,,rr         
,centauri is a case of an eclipsing     
binary system1 and that the two stars   
are close together4 ,it is not of course
 proved that the figures of the stars   
are ellipsoids1 but gravitation must    
deform them into a pair of elongated    
bodies1 and1 on the assumptions that    
they are not enveloped in an absorptive 
atmosphere and that they are            
ellipsoidal1 their shapes must be as    
shown in the figure4  ,this light-curve 
gives an excellent illustration of what 
we have reason to believe to be a stage 
in the evolution of stars1 when a single
 star is proceeding to separate into a  
binary one4  ,as the star is faint1     
there is as yet no direct spectroscopic 
evidence of orbital motion4 ,let us turn
 therefore to the case of another star1 

namely ,v ,puppis1 in which such        
evidence does already exist4 ,i give an 
account of it1 because it presents a    
peculiarly interesting confirmation of  
the correctness of the theory4  ,in     
#ahie ,pickering announced in the       
,harvard ,circular ,no4 #ad that the    
spectroscopic observations at ,arequipa 
proved ,v ,puppis to be a double star   
with a period of #c;d #b;h #dfm4 ,now   
when ,roberts discussed its light-curve 
he found that the period was #a;d #aj;h 
#edm #bgs1 and on account of this       
serious discrepancy he effected the     
reduction only on the simple assumption 
that the two stars were spherical1 and  
thus obtained a fairly good             
representation of the light-curve4 ,it  
appeared that the orbit was circular and
 that the two spheres were not quite in 
contact4 ,obviously if the stars had    
been assumed to be ellipsoids they would
 have been found to overlap1 as was the 
case for ,,rr ,centauri4 7,astrophysical
 ,journ4 ,vol4 ,,xiii4 7#aija71 page    

#agg47 ,the matter rested thus for some 
months until the spectroscopic evidence 
was re-examined by ,miss ,cannon on     
behalf of ,professor ,pickering1 and we 
find in the notes on page #agg of ,vol4 
,,xxviii4 of the ,annals of the ,harvard
 ,observatory the following3 ,a4,g4,c4  
#ajecd4 ,this star1 which is the ,algol 
variable ,v ,puppis1 has been found to  
be a spectroscopic binary4 ,the period  
#a;d4#ded 7i4e4 #a;d #aj;h #edm7        
satisfies the observations of the       
changes in light1 and of the varying    
separation of the lines of the spectrum4
 ,the spectrum has been examined on #fa 
plates1 on #bc of which the lines are   
double4 ,thus we have valuable evidence 
in confirmation of the correctness of   
the conclusions drawn from the          
light-curve4 ,in the circumstances1     
however1 ,i have not thought it worth   
while to reproduce ,dr ,roberts's       
provisional figure4  ,i now turn to the 
conclusions drawn a few years previously
 by another observer1 where we shall    

find the component stars not quite in   
contact4 ,this is the star ,beta ,lyrae 
which was observed by ,goodricke1       
,argelander1 ,belopolsky1 ,schur1       
,markwick and by many others4 ,the      
spectroscopic method has been           
successfully applied in this case1 and  
the component stars are proved to move  
in an orbit about one another4 ,in      
#ahig1 ,mr4 ,g4,w4 ,myers applied the   
theory of eclipses to the light-curve1  
on the hypothesis that the stars are    
elongated ellipsoids1 and he obtained   
the interesting results exhibited in    
,fig4 #g4 7,astrophysical ,journ4 ,vol4 
,,vii4 7#ahih71 page #a47  ,the period  
of ,beta ,lyrae is relatively long1     
being #ab;d #ba;h #dgm1 the orbit is    
sensibly eccentric1 and the two         
spheroids are not so much elongated as  
was the case with ,,rr ,centauri4 ,the  
mass of the system is enormous1 one of  
the two stars being #aj times and the   
other #ba times as heavy as our sun4    
,further illustrations of this subject  

might be given1 but enough has been said
 to explain the nature of the           
conclusions which have been drawn from  
this class of observation4  ,in my      
account of these remarkable systems the 
consideration of one very important     
conclusion has been purposely deferred4 
,since the light-curve is explicable by 
eclipses1 it follows that the sizes of  
the two stars are determinable          
relatively to the distance between them4
 ,the period of their orbital motion is 
known1 being identical with the complete
 period of the variability of their     
light1 and an easy application of       
,kepler's law of periodic times enables 
us to compute the sum of the masses of  
the two stars divided by the cube of the
 distance between their centres4 ,now   
the sizes of the bodies being known1 the
 mean density of the whole system may be
 calculated4 ,in every case that density
 has been found to be much less than the
 sun's1 and indeed the average of a     
number of mean densities which have been

 determined only amounts to one-eighth  
of that of the sun4 ,in some cases the  
density is extremely small1 and in no   
case is it quite so great as half the   
solar density4  ,it would be absurd to  
suppose that these stars can be uniform 
in density throughout1 and from all that
 is known of celestial bodies it is     
probable that they are gaseous in their 
external parts with great condensation  
towards their centres4 ,this conclusion 
is confirmed by arguments drawn from the
 theory of rotating masses of liquid4   
7,see ,j4,h4 ,jeans1 ,on the density of 
,algol variables1 ,astrophysical ,journ4
 ,vol4 ,,xxii4 7#aije71 page #ig47      
,although1 as already explained1 a good 
deal is known about the shapes and the  
stability of figures consisting of      
homogeneous incompressible liquid in    
rotation1 yet comparatively little has  
hitherto been discovered about the      
equilibrium of rotating gaseous stars4  
,the figures calculated for homogeneous 
liquid can obviously only be taken to   

afford a general indication of the kind 
of figure which we might expect to find 
in the stellar universe4 ,thus the      
dotted curve in ,fig4 #e1 which exhibits
 one of the figures which ,i calculated1
 has some interest when placed alongside
 the figures of the stars in ,,rr       
,centauri1 as computed from the         
observations1 but it must not be        
accepted as the calculated form of such 
a system4 ,i have moreover proved more  
recently that such a figure of          
homogeneous liquid is unstable4         
,notwithstanding this instability it    
does not necessarily follow that the    
analogous figure for compressible fluid 
is also unstable1 as will be pointed out
 more fully hereafter4  ,professor      
,jeans has discussed in a paper of great
 ability the difficult problems offered 
by the conditions of equilibrium and of 
stability of a spherical nebula4 7,phil4
 ,trans4 ,r4,s4 ,vol4 ,,cxcix4 ,a       
7#aijb71 page #a4 ,see also ,a4         
,roberts1 ,s4 ,african ,assoc4 ,adv4    

,sci4 ,vol4 ,i4 7#aijc71 page #f47 ,in a
 later paper 7,astrophysical ,journ4    
,vol4 ,,xxii4 7#aije71 page #ig471 in   
contrasting the conditions which must   
govern the fission of a star into two   
parts when the star is gaseous and      
compressible with the corresponding     
conditions in the case of incompressible
 liquid1 he points out that for a       
gaseous star 7the agency which effects  
the separation will no longer be        
rotation alone2 gravitation also will   
tend towards separation444 ,from        
numerical results obtained in the       
various papers of my own1444 ,i have    
been led to the conclusion that a       
gravitational instability of the kind   
described must be regarded as the       
primary agent at work in the actual     
evolution of the universe1 ,laplace's   
rotation playing only the secondary part
 of separating the primary and satellite
 after the birth of the satellite47  ,it
 is desirable to add a word in          
explanation of the expression           

gravitational instability in this       
passage4 ,it means that when the        
concentration of a gaseous nebula       
7without rotation7 has proceeded to a   
certain stage1 the arrangement in       
spherical layers of equal density       
becomes unstable1 and a form of         
bifurcation has been reached4 ,for      
further concentration concentric        
spherical layers become unstable1 and   
the new stable form involves a          
concentration about two centres4 ,the   
first sign of this change is that the   
spherical layers cease to be quite      
concentric and then the layers of equal 
density begin to assume a somewhat      
pear-shaped form analogous to that which
 we found to occur under rotation for an
 incompressible liquid4 ,accordingly it 
appears that while a sphere of liquid is
 stable a sphere of gas may become      
unstable4 ,thus the conditions of       
stability are different in these two    
simple cases1 and it is likely that     
while certain forms of rotating liquid  

are unstable the analogous forms for gas
 may be stable4 ,this furnishes a reason
 why it is worth while to consider the  
unstable forms of rotating liquid4      
,there can ,i think be little doubt but 
that ,jeans is right in looking to      
gravitational instability as the primary
 cause of fission1 but when we consider 
that a binary system1 with a mass larger
 than the sun's1 is found to rotate in a
 few hours1 there seems reason to look  
to rotation as a contributory cause     
scarcely less important than the primary
 one4  ,with the present extent of our  
knowledge it is only possible to        
reconstruct the processes of the        
evolution of stars by means of          
inferences drawn from several sources4  
,we have first to rely on the general   
principles of stability1 according to   
which we are to look for a series of    
families of forms1 each terminating in  
an unstable form1 which itself becomes  
the starting-point of the next family of
 stable forms4 ,secondly we have as a   

guide the analogy of the successive     
changes in the evolution of ideal liquid
 stars2 and thirdly we already possess  
some slender knowledge as to the        
equilibrium of gaseous stars4  ,from    
these data it is possible to build up in
 outline the probable history of binary 
stars4 ,originally the star must have   
been single1 it must have been widely   
diffused1 and must have been endowed    
with a slow rotation4 ,in this condition
 the strata of equal density must have  
been of the planetary form4 ,as it      
cooled and contracted the symmetry round
 the axis of rotation must have become  
unstable1 through the effects of        
gravitation1 assisted perhaps by the    
increasing speed of rotation4 7,i learn 
from ,professor ,jeans that he now      
7,december #aijh7 believes that he can  
prove that some small amount of rotation
 is necessary to induce instability in  
the symmetrical arrangement47 ,the      
strata of equal density must then become
 somewhat pear-shaped1 and afterwards   

like an hour-glass1 with the            
constriction more pronounced in the     
internal than in the external strata4   
,the constrictions of the successive    
strata then begin to rupture from the   
inside progressively outwards1 and when 
at length all are ruptured we have the  
twin stars portrayed by ,roberts and by 
others4  ,as we have seen1 the study of 
the forms of equilibrium of rotating    
liquid is almost complete1 and ,jeans   
has made a good beginning in the        
investigation of the equilibrium of     
gaseous stars1 but much more remains to 
be discovered4 ,the field for the       
mathematician is a wide one1 and in     
proportion as the very arduous          
exploration of that field is attained so
 will our knowledge of the processes of 
cosmical evolution increase4  ,from the 
point of view of observation1 improved  
methods in the use of the spectroscope  
and increase of accuracy in photometry  
will certainly lead to a great increase 
in our knowledge within the next few    

years4 ,probably the observational      
advance will be more rapid than that of 
theory1 for we know how extraordinary   
has been the success attained within the
 last few years1 and the theory is one  
of extreme difficulty2 but the two ought
 to proceed together hand in hand4      
,human life is too short to permit us to
 watch the leisurely procedure of       
cosmical evolution1 but the celestial   
museum contains so many exhibits that it
 may become possible1 by the aid of     
theory1 to piece together bit by bit the
 processes through which stars pass in  
the course of their evolution4  ,in the 
sketch which ,i have endeavoured to give
 of this fascinating subject1 ,i have   
led my reader to the very confines of   
our present knowledge4 ,it is not much  
more than a quarter of a century since  
this class of observation has claimed   
the close attention of astronomers2     
something considerable has been         
discovered already and there seems      
scarcely a discernible limit to what    

will be known in this field a century   
from now4 ,some of the results which ,i 
have set forth may then be shown to be  
false1 but it seems profoundly          
improbable that we are being led astray 
by a ,will-of-the-,wisp4     ,,xxix4    
,,the ,,evolution ,,of ,,matter4 ,by    
,w4,c4,d4 ,whetham1 ,m4,a41 ,f4,r4,s4   
,trinity ,college1 ,cambridge4   ,the   
idea of evolution in the organic world1 
made intelligible by the work of        
,charles ,darwin1 has little in common  
with the recent conception of change in 
certain types of matter4 ,the discovery 
that a process of disintegration may    
take place in some at least of the      
chemical atoms1 previously believed to  
be indestructible and unalterable1 has  
modified our view of the physical       
universe1 even as ,darwin's scheme of   
the mode of evolution changed the trend 
of thought concerning the organic world4
 ,both conceptions have in common the   
idea of change throughout extended      
realms of space and time1 and1          

therefore1 it is perhaps not unfitting  
that some account of the most recent    
physical discoveries should be included 
in the present volume4  ,the earliest   
conception of the evolution of matter is
 found in the speculation of the        
,greeks4 ,leucippus and ,democritus     
imagined unchanging eternal atoms1      
,heracleitus held that all things were  
in a continual state of flux--,panta    
rei4  ,but no one in the ,ancient       
,world--no one till quite modern        
times--could appreciate the strength of 
the position which the theory of the    
evolution of matter must carry before it
 wins the day4 ,vague speculation1 even 
by the acute minds of philosophers1 is  
of little use in physical science before
 experimental facts are available4 ,the 
true problems at issue cannot even be   
formulated1 much less solved1 till the  
humble task of the observer and         
experimenter has given us a knowledge of
 the phenomena to be explained4  ,it was
 only through the atomic theory1 at     

first apparently diametrically opposed  
to it1 that the conception of evolution 
in the physical world was to gain an    
established place4 ,for a century the   
atomic theory1 when put into a modern   
form by ,dalton1 led farther and farther
 away from the idea of change in matter4
 ,the chemical elements seemed quite    
unalterable1 and the atoms1 of which    
each element in modern view is composed1
 bore to ,clerk ,maxwell1 writing about 
#ahgj1 the stamp of manufactured        
articles exactly similar in kind1       
unchanging1 eternal4  ,nevertheless     
throughout these years1 on the whole so 
unfavourable to its existence1 there    
persisted the idea of a common origin of
 the distinct kinds of matter known to  
chemists4 ,indeed1 this idea of unity in
 substance in nature seems to accord    
with some innate desire or intimate     
structure of the human mind4 ,as ,mr    
,arthur ,balfour well puts it1 ,there is
 no a priori reason that ,i know of for 
expecting that the material world should

 be a modification of a single medium1  
rather than a composite structure built 
out of sixty or seventy elementary      
substances1 eternal and eternally       
different4 ,why then should we feel     
content with the first hypothesis and   
not with the second8 ,yet so it is4 ,men
 of science have always been restive    
under the multiplication of entities4   
,they have eagerly watched for any sign 
that the different chemical elements own
 a common origin1 and are all compounded
 out of some primordial substance4 ,nor1
 for my part1 do ,i think that such     
instincts should be ignored444 that they
 exist is certain2 that they modify the 
indifferent impartiality of pure        
empiricism can hardly be denied4        
7,report of the #gdth ,meeting of the   
,british ,association 7,presidential    
,address1 ,cambridge #aijd71 page #i1   
,london1 #aije47  ,when ,dalton's atomic
 theory had been in existence some half 
century1 it was noted that certain      
numerical relations held good between   

the atomic weights of elements          
chemically similar to one another4 ,thus
 the weight 7#hh7 of an atom of         
strontium compared with that of hydrogen
 as unity1 is about the mean of those of
 calcium 7#dj7 and barium 7#acg74 ,such 
relations1 in this and other chemical   
groups1 were illustrated by ,beguyer de 
,chancourtois in #ahfb by the           
construction of a spiral diagram in     
which the atomic weights are placed in  
order round a cylinder and elements     
chemically similar are found to fall on 
vertical lines4  ,newlands seems to have
 been the first to see the significance 
of such a diagram4 ,in his law of       
octaves1 formulated in #ahfd1 he        
advanced the hypothesis that1 if        
arranged in order of rising atomic      
weight1 the elements fell into groups1  
so that each eighth element was         
chemically similar4 ,stated thus1 the   
law was too definite2 no room was left  
for newly-discovered elements1 and some 
dissimilar elements were perforce       

grouped together4  ,but in #ahfi        
,mendeleeff developed ,newland's        
hypothesis in a form that attracted at  
once general attention4 ,placing the    
elements in order of rising atomic      
weight1 but leaving a gap where         
necessary to bring similar elements into
 vertical columns1 he obtained a        
periodic table with natural vacancies to
 be filled as new elements were         
discovered1 and with a certain amount of
 flexibility at the ends of the         
horizontal lines4 ,from the position of 
the vacancies1 the general chemical and 
physical properties of undiscovered     
elements could be predicted1 and the    
success of such predictions gave a      
striking proof of the usefulness of     
,mendeleeff's generalisation4  ,when the
 chemical and physical properties of the
 elements were known to be periodic     
functions of their atomic weights1 the  
idea of a common origin and common      
substance became much more credible4    
,differences in atomic weight and       

differences in properties alike might   
reasonably be explained by the          
differences in the amount of the        
primordial substance present in the     
various atoms2 an atom of oxygen being  
supposed to be composed of sixteen times
 as much stuff as the atom of hydrogen1 
but to be made of the same ultimate     
material4 ,speculations about the mode  
of origin of the elements now began to  
appear1 and put on a certain air of     
reality4 ,of these speculations perhaps 
the most detailed was that of ,crookes1 
who imagined an initial chaos of a      
primordial medium he named protyle1 and 
a process of periodic change in which   
the chemical elements successively were 
precipitated4  ,from another side too1  
suggestions were put forward by ,sir    
,norman ,lockyer and others that the    
differences in spectra observed in      
different classes of stars1 and produced
 by different conditions in the         
laboratory1 were to be explained by     
changes in the structure of the         

vibrating atoms4  ,the next step in     
advance gave a theoretical basis for the
 idea of a common structure of matter1  
and was taken in an unexpected          
direction4 ,clerk ,maxwell's            
electromagnetic theory of light1        
accepted in ,england1 was driven home to
 continental minds by the confirmatory  
experiments of ,hertz1 who in #ahhh     
detected and measured the               
electromagnetic waves that ,maxwell had 
described twenty years earlier4 ,but1 if
 light be an electromagnetic phenomenon1
 the light waves radiated by hot bodies 
must take their origin in the vibrations
 of electric systems4 ,hence within the 
atoms must exist electric charges       
capable of vibration4 ,on these lines   
,lorentz and ,larmor have developed an  
electronic theory of matter1 which is   
imagined in its essence to be a         
conglomerate of electric charges1 with  
electro-magnetic inertia to explain     
mechanical inertia4 7,larmor1 ,aether   
and ,matter1 ,cambridge1 #aijj47 ,the   

movement of electric charges would be   
affected by a magnetic field1 and hence 
the discovery by ,zeeman that the       
spectral lines of sodium were doubled by
 a strong magnetic force gave           
confirmatory evidence to the theory of  
electrons4  ,then came ,j4,j4 ,thomson's
 great discovery of minute particles1   
much smaller than any chemical atom1    
forming a common constituent of many    
different kinds of matter4 7,thomson1   
,conduction of ,electricity through     
,gases 7#bnd edition71 ,cambridge1      
#aijf47 ,if an electric discharge be    
passed between metallic terminals       
through a glass vessel containing air at
 very low pressure1 it is found that    
rectilinear rays1 known as cathode rays1
 proceed from the surface of the cathode
 or negative terminal4 ,where these rays
 strike solid objects1 they give rise to
 the ,rontgen rays now so well known2   
but it is with the cathode rays         
themselves that we are concerned4 ,when 
they strike an insulated conductor1 they

 impart to it a negative charge1 and    
,thomson found that they were deflected 
from their path both by magnetic and    
electric forces in the direction in     
which negatively electrified particles  
would be deflected4 ,cathode rays then  
were accepted as flights of negatively  
charged particles1 moving with high     
velocities4 ,the electric and magnetic  
deflections give two independent        
measurements which may be made on a     
cathode ray1 and both the deflections   
involve theoretically three unknown     
quantities1 the mass of the particles1  
their electric charge and their         
velocity4 ,there is strong cumulative   
evidence that all such particles possess
 the same charge1 which is identical    
with that associated with a univalent   
atom in electrolytic liquids4 ,the      
number of unknown quantities was thus   
reduced to two--the mass and the        
velocity4 ,the measurement of the       
magnetic and electric deflections gave  
two independent relations between the   

unknowns1 which could therefore be      
determined4 ,the velocities of the      
cathode ray particles were found to vary
 round a value about one-tenth that of  
light1 but the mass was found always to 
be the same within the limits of error1 
whatever the nature of the terminals1 of
 the residual gas in the vessel1 and of 
the conditions of the experiment4 ,the  
mass of a cathode ray particle1 or      
corpuscle1 as ,thomson1 adopting        
,newton's name1 called it1 is about the 
eight-hundredth part of the mass of a   
hydrogen atom4  ,these corpuscles1 found
 in so many different kinds of          
substance1 are inevitably regarded as a 
common constituent of matter4 ,they are 
associated each with a unit of negative 
electricity4 ,now electricity in motion 
possesses electromagnetic energy1 and   
produces effects like those of          
mechanical inertia4 ,in other words1 an 
electric charge possesses mass1 and     
there is evidence to show that the      
effective mass of a corpuscle increases 

as its velocity approaches that of light
 in the way it would do if all its mass 
were electromagnetic4 ,we are led       
therefore to regard the corpuscle from  
one aspect as a disembodied charge of   
electricity1 and to identify it with the
 electron of ,lorentz and ,larmor4      
,thus1 on this theory1 matter and       
electricity are identified2 and a great 
simplification of our conception of the 
physical structure of ,nature is        
reached4 ,moreover1 from our present    
point of view1 a common basis for matter
 suggests or implies a common origin1   
and a process of development possibly   
intelligible to our minds4 ,the idea of 
the evolution of matter becomes much    
more probable4  ,the question of the    
nature and physical meaning of a        
corpuscle or electron remains for       
consideration4 ,on the hypothesis of a  
universal luminiferous aether1 ,larmor  
has suggested a centre of aethereal     
strain a place where the continuity of  
the medium has been broken and cemented 

together again 7to use a crude but      
effective image7 without accurately     
fitting the parts1 so that there is a   
residual strain all round the place4    
7,larmor1 loc4 cit47 ,thus he explains  
in quasi-mechanical terms the properties
 of an electron4 ,but whether we remain 
content for the time with our           
identification of matter and            
electricity1 or attempt to express both 
of them in terms of hypothetical aether1
 we have made a great step in advance on
 the view that matter is made up of     
chemical atoms fundamentally distinct   
and eternally isolated4  ,such was the  
position when the phenomena of          
radio-activity threw a new light on the 
problem1 and1 for the first time in the 
history of science1 gave definite       
experimental evidence of the            
transmutation of matter from one        
chemical element to another4  ,in #ahif 
,h4 ,becquerel discovered that compounds
 of the metal uranium continually       
emitted rays capable of penetrating     

opaque screens and affecting            
photographic plates4 ,like cathode and  
,rontgen rays1 the rays from uranium    
make the air through which they pass a  
conductor of electricity1 and this      
property gives the most convenient      
method of detecting the rays and of     
measuring their intensity4 ,an          
electroscope may be made of a strip of  
gold-leaf attached to an insulated brass
 plate and confined in a brass vessel   
with glass windows4 ,when the gold-leaf 
is electrified1 it is repelled from the 
similarly electrified brass plate1 and  
the angle at which it stands out        
measures the electrification4 ,such a   
system1 if well insulated1 holds its    
charge for hours1 the leakage of        
electricity through the air being very  
slow4 ,but1 if radio-active radiation   
reach the air within1 the gold-leaf     
falls1 and the rate of its fall1 as     
watched through a microscope with a     
scale in the eye-piece1 measures the    
intensity of the radiation4 ,with some  

form of this simple instrument1 or with 
the more complicated quadrant           
electrometer1 most radio-active         
measurements have been made4  ,it was   
soon discovered that the activity of    
uranium compounds was proportional to   
the amount of uranium present in them4  
,thus radio-activity is an atomic       
property dependent on the amount of an  
element and independent of its state of 
chemical combination4  ,in a search for 
radio-activity in different minerals1   
,m4 and ,mme ,curie found a greater     
effect in pitch-blende than its contents
 of uranium warranted1 and1 led by the  
radio-active property alone1 they       
succeeded1 by a long series of chemical 
separations1 in isolating compounds of a
 new and intensely radio-active         
substance which they named radium4      
,radium resembles barium in its chemical
 properties1 and is precipitated with   
barium in the ordinary course of        
chemical analysis4 ,it is separated by a
 prolonged course of successive         

crystallisation1 the chloride of radium 
being less soluble than that of barium1 
and therefore sooner separated from an  
evaporating solution4 ,when isolated1   
radium chloride has a composition1      
which1 on the assumption that one atom  
of metal combines with two of chlorine  
as in barium chloride1 indicates that   
the relative weight of the atom of      
radium is about #bbe4 ,as thus prepared1
 radium is a well-marked chemical       
element1 forming a series of compounds  
analogous to those of barium and showing
 a characteristic line spectrum4 ,but1  
unlike most other chemical elements1 it 
is intensely radio-active1 and produces 
effects some two million times greater  
than those of uranium4  ,in #ahii ,e4   
,rutherford1 then of ,montreal1         
discovered that the radiation from      
uranium1 thorium and radium was complex4
 7,rutherford1 ,radio-activity 7#bnd    
edition71 ,cambridge1 #aije47 ,three    
types of rays were soon distinguished4  
,the first1 named by ,rutherford        

alpha-rays1 are absorbed by thin metal  
foil or a few centimetres of air4 ,when 
examined by measurements of the         
deflections caused by magnetic and      
electric fields1 the alpha-rays are     
found to behave as would positively     
electrified particles of the magnitude  
of helium atoms possessing a double     
ionic charge and travelling with a      
velocity about one-tenth that of light4 
,the second or beta type of radiation is
 much more penetrating4 ,it will pass   
through a considerable thickness of     
metallic foil1 or many centimetres of   
air1 and still affect photographic      
plates or discharge electroscopes4      
,magnetic and electric forces deflect   
beta-rays much more than alpha-rays1    
indicating that1 although the speed is  
greater1 approaching in some cases      
within five per cent4 that of light1 the
 mass is very much less4 ,the beta-rays 
must be streams of particles1 identical 
with those of cathode rays1 possessing  
the minute mass of ,j4,j4 ,thomson's    

corpuscle1 some eight-hundredth part of 
that of a hydrogen atom4 ,a third or    
gamma type of radiation was also        
detected4 ,more penetrating even than   
beta-rays1 the gamma-rays have never    
been deflected by any magnetic or       
electric force yet applied4 ,like       
,rontgen rays1 it is probable that      
gamma-rays are wave-pulses in the       
luminiferous aether1 though the         
possibility of explaining them as       
flights of non-electrified particles is 
before the minds of some physicists4    
,still another kind of radiation has    
been discovered more recently by        
,thomson1 who has found that in high    
vacua1 rays become apparent which are   
absorbed at once by air at any ordinary 
pressure4  ,the emission of all these   
different types of radiation involves a 
continual drain of energy from the      
radio-active body4 ,when ,m4 and ,mme   
,curie had prepared as much as a gramme 
of radium chloride1 the energy of the   
radiation became apparent as an         

evolution of heat4 ,the radium salt     
itself1 and the case containing it1     
absorbed the major part of the          
radiation1 and were thus maintained at a
 temperature measurably higher than that
 of the surroundings4 ,the rate of      
thermal evolution was such that it      
appeared that one gramme of pure radium 
must emit about #ajj gramme-calories of 
heat in an hour4 ,this observation1     
naturally as it follows from the        
phenomena previously discovered1 first  
called attention to the question of the 
source of the energy which maintains    
indefinitely and without apparent       
diminution the wonderful stream of      
radiation proceeding from a radio-active
 substance4 ,in the solution of this    
problem lies the point of the present   
essay4  ,in order to appreciate the     
evidence which bears on the question we 
must now describe two other series of   
phenomena4  ,it is a remarkable fact    
that the intensity of the radiation from
 a radio-active body is independent of  

the external conditions of temperature1 
pressure1 etc4 which modify so          
profoundly almost all other physical and
 chemical processes4 ,exposure to the   
extreme cold of liquid air1 or to the   
great heat of a furnace1 leaves the     
radio-activity of a substance unchanged1
 apparent exceptions to this statement  
having been traced to secondary causes4 
,then1 it is found that radio-activity  
is always accompanied by some chemical  
change2 a new substance always appears  
as the parent substance emits these     
radiations4 ,thus by chemical reactions 
it is possible to separate from uranium 
and thorium minute quantities of        
radio-active materials to which the     
names of uranium-,x and thorium-,x have 
been given4 ,these bodies behave        
differently from their parents uranium  
and thorium1 and show all the signs of  
distinct chemical individuality4 ,they  
are strongly radio-active1 while1 after 
the separation1 the parents uranium and 
thorium are found to have lost some of  

their radio-activity4 ,if the           
,x-substances be kept1 their            
radio-activity decays1 while that of the
 uranium or thorium from which they were
 obtained gradually rises to the initial
 value it had before the separation4 ,at
 any moment1 the sum of the             
radio-activity is constant1 the activity
 lost by the product being equal to that
 gained by the parent substance4 ,these 
phenomena are explained if we suppose   
that the ,x-product is slowly produced  
in the substance of the parent1 and     
decays at a constant rate4 ,uranium1 as 
usually seen1 contains a certain amount 
of uranium-,x1 and its radio-activity   
consists of two parts--that of the      
uranium itself1 and that of the ,x      
product4 ,when the latter is separated  
by means of its chemical reactions1 its 
radio-activity is separated also1 and   
the rates of decay and recovery may be  
examined4  ,radium and thorium1 but not 
uranium1 give rise to radio-active gases
 which have been called emanations4     

,rutherford has shown that their        
radio-activity1 like that of the ,x     
products1 suffers decay1 while the walls
 of the vessel in which the emanation is
 confined1 become themselves            
radio-active4 ,if washed with certain   
acids1 however1 the walls lose their    
activity1 which is transferred to the   
acid1 and can be deposited by           
evaporation from it on to a solid       
surface4 ,here again it is clear that   
the emanation gives rise to a           
radio-active substance which clings to  
the walls of the vessel1 and is soluble 
in certain liquids1 but not in others4  
,we shall return to this point1 and     
trace farther the history of the        
radio-active matter4 ,at present we wish
 to emphasise the fact that1 as in other
 cases1 the radio-activity of the       
emanation is accompanied by the         
appearance of a new kind of substance   
with distinct chemical properties4  ,we 
are now in a position to consider as a  
whole the evidence on the question of   

the source of radio-active energy4  7#a7
 ,radio-activity is accompanied by the  
appearance of new chemical substances4  
,the energy liberated is therefore      
probably due to the associated chemical 
change4 7#b7 ,the activity of a series  
of compounds is found to accompany the  
presence of a radio-active element1 the 
activity of each compound depends only  
on the contents of the element1 and is  
independent of the nature of its        
combination4 ,thus radio-activity is a  
property of the element1 and is not     
affected by its state of isolation or   
chemical combination4 7#c7 ,the         
radio-activity of a simple transient    
product decays in a geometrical         
progression1 the loss per second being  
proportional to the mass of substance   
still left at the moment1 and           
independent of its state of             
concentration or dilution4 ,this type of
 reaction is well known in chemistry to 
mark a mono-molecular change1 where each
 molecule is dissociated or altered in  

structure independently4 ,if two or more
 molecules were concerned               
simultaneously1 the rate of reaction    
would depend on the nearness of the     
molecules to each other1 that is1 to the
 concentration of the material4 7#d7    
,the amount of energy liberated by the  
change of a given mass of material far  
transcends the amount set free by any   
known ordinary chemical action4 ,the    
activity of radium decays so slowly that
 it would not sink to half its initial  
value in less than some two thousand    
years1 and yet one gramme of radium     
emits about #ajj calories of heat during
 each hour of its existence4  ,the      
energy of radio-activity is due to      
chemical change1 but clearly to no      
chemical change hitherto familiar to    
science4 ,it is an atomic property1     
characteristic of a given element1 and  
the atoms undergo the change            
individually1 not by means of           
interaction among each other4 ,the      
conclusion is irresistible that we are  

dealing with a fundamental change in the
 structure of the individual atoms1     
which1 one by one1 are dissociating into
 simpler parts4 ,we are watching the    
disintegration of the atoms of the      
chemist1 hitherto believed              
indestructible and eternal1 and         
measuring the liberation of some of the 
long-suspected store of internal atomic 
energy4 ,we have stumbled on the        
transmutation dreamed by the alchemist1 
and discovered the process of a         
veritable evolution of matter4  ,the    
transmutation theory of radio-activity  
was formulated by ,rutherford           
7,rutherford1 ,radio-activity 7#bnd     
edition71 ,cambridge1 #aije1 page #cjg47
 and ,soddy in #aijc4 ,by its light1 all
 recent work on the subject has been    
guided2 it has stood the supreme test of
 a hypothesis1 and shown power to       
suggest new investigations and to       
co-ordinate and explain them1 when      
carried out4 ,we have summarised the    
evidence which led to the conception of 

the theory2 we have now to consider the 
progress which has been made in tracing 
the successive disintegration of        
radio-active atoms4  ,soon after the    
statement of the transmutation theory1 a
 striking verification of one of its    
consequences appeared4 ,the measurement 
of the magnetic and electric deflection 
of the alpha-rays suggested to          
,rutherford the idea that the stream of 
projectiles of which they consisted was 
a flight of helium atoms4 ,ramsay and   
,soddy1 confining a minute bubble of    
radium emanation in a fine glass tube1  
were able to watch the development of   
the helium spectrum as1 day by day1 the 
emanation decayed4 ,by isolating a very 
narrow pencil of alpha-rays1 and        
watching through a microscope their     
impact on a fluorescent screen1         
,rutherford has lately counted the      
individual alpha-projectiles1 and       
confirmed his original conclusion that  
their mass corresponded to that of      
helium atoms and their charge to double 

that on a univalent atom4 7,proc4 ,roy4 
,soc4 ,a1 page #ada1 #aijh47 ,still more
 recently1 he has collected the         
alpha-particles shot through an         
extremely thin wall of glass1 and       
demonstrated by direct spectroscopic    
evidence the presence of helium4 7,phil4
 ,mag4 ,february #aiji47  ,but the most 
thorough investigation of a radio-active
 pedigree is found in ,rutherford's     
classical researches on the successive  
disintegration products of radium1 in   
order to follow the evidence on which   
his results are founded1 we must        
describe more fully the process of decay
 of the activity of a simple            
radio-active substance4 ,the decay of   
activity of the body known as uranium-,x
 is shown in a falling curve 7,fig4     
#a474 ,it will be seen that1 in each    
successive #bb days1 the activity falls 
to half the value it possessed at the   
beginning4  ,this change in a           
geometrical progression is              
characteristic of simple radio-active   

processes1 and can be expressed         
mathematically by a simple exponential  
formula4  ,as we have said above1 solid 
bodies exposed to the emanations of     
radium or thorium become coated with a  
radio-active deposit4 ,the rate of decay
 of this activity depends on the time of
 exposure to the emanation1 and does not
 always show the usual simple type of   
curve4 ,thus the activity of a rod      
exposed to radium emanation for #a      
minute decays in accordance with a curve
 7,fig4 #b7 which represents the        
activity as measured by the alpha-rays4 
,if the electroscope be screened from   
the alpha-rays1 it is found that the    
activity of the rod in beta- an         
gamma-rays increases for some #ce       
minutes and then diminishes 7,fig4 #c474
  ,these complicated relations have been
 explained satisfactorily and completely
 by ,rutherford on the hypothesis of    
successive changes of the radio-active  
matter into one new body after another4 
7,rutherford1 ,radio-activity 7#bnd     

edition71 ,cambridge1 #aije1 page #cgi47
 ,the experimental curve represents the 
resultant activity of all the matter    
present at a given moment1 and the      
process of disentangling the component  
effects consists in finding a number of 
curves1 which express the rise and fall 
of activity of each kind of matter as it
 is produced and decays1 and1 fitted    
together1 give the curve of the         
experiments4  ,other methods of         
investigation also are open4 ,they have 
enabled ,rutherford to complete the     
life-history of radium and its products1
 and to clear up doubtful points left by
 the analysis of the curves4 ,by the    
removal of the emanation1 the activity  
of radium itself has been shown to      
consist solely of alpha-rays4 ,this     
removal can be effected by passing air  
through the solution of a radium salt4  
,the emanation comes away1 and the      
activity of the deposit which it leaves 
behind decays rapidly to a small        
fraction of its initial value4 ,again1  

some of the active deposits of the      
emanation are more volatile than others1
 and can be separated from them by the  
agency of heat4  ,from such evidence    
,rutherford has traced a long series of 
disintegration products of radium1 all  
but the first of which exist in much too
 minute quantities to be detected       
otherwise than by their                 
radio-activities4 ,moreover1 two of     
these products are not themselves       
appreciably radio-active1 though they   
are born from radio-active parents1 and 
give rise to a series of radio-active   
descendants4 ,their presence is inferred
 from such evidence as the rise of beta 
and gamma radio-activity in the solid   
newly deposited by the emanation2 this  
rise measuring the growth of the first  
radio-active offspring of one of the    
non-active bodies4 ,some of the radium  
products give out alpha-rays only1 one  
beta- and gamma-rays1 while one yields  
all three types of radiation4 ,the      
pedigree of the radium family may be    

expressed in the following table1 the   
time noted in the second column being   
the time required for a given quantity  
to be half transformed into its next    
derivative4                ,time of half
      ,radio-       ,properties         
decay             activity    ,radium   
,about #bfjj years  alpha rays          
,element chemically analogous           
to barium4    ,emanation  #c4h days     
alpha rays   ,chemically inert gas2     
condenses at -#aej deg ,c4    ,radium-,a
   #c minutes         alpha rays        
,behaves as a solid deposited on        
surfaces2 concentrated on a             
negative electrode4    ,radium-,b   #ba 
minutes        no rays      ,soluble in 
strong acids2                           
volatile at a white heat2 more          
volatile than ,a or ,c4    ,radium-,c   
#bh minutes        alpha1 beta1 ,soluble
 in strong acids2 less                  
gamma rays    volatile than ,b4         
,radium-,d   about #dj years    no rays 
,soluble in strong acids2 volatile      

below #ajjj deg ,c4    ,radium-,e   #f  
days            beta1 gamma             
,non-volatile at #ajjj deg ,c4          
rays    ,radium-,f   #adc days          
alpha rays   ,volatile at #ajjj deg ,c4 
,deposited from solution on a           
bismuth plate4   ,of these products1 ,a1
 ,b1 and ,c constitute that part of the 
active deposit of the emanation which   
suffers rapid decay and nearly          
disappears in a few hours4 ,radium-,d1  
continually producing its short-lived   
descendants ,e and ,f1 remains for years
 on surfaces once exposed to the        
emanation1 and makes delicate           
radio-active researches impossible in   
laboratories which have been            
contaminated by an escape of radium     
emanation4  ,a somewhat similar pedigree
 has been made out in the case of       
thorium4 ,here thorium-,x is interposed 
between thorium and its short-lived     
emanation1 which decays to half its     
initial quantity in #ed seconds4 ,two   
active deposits1 thorium ,a and ,b1     

arise successively from the emanation4  
,in uranium1 we have the one obvious    
derivative uranium-,x1 and the question 
remains whether this one descent can be 
connected with any other individual or  
family4 ,uranium is long-lived1 and     
emits only alpha-rays4 ,uranium-,x      
decays to half value in #bb days1 giving
 out beta- and gamma-rays4 ,since our   
evidence goes to show that              
radio-activity is generally accompanied 
by the production of new elements1 it is
 natural to search for the substance of 
uranium-,x in other forms1 and perhaps  
under other names1 rather than to       
surrender immediately our belief in the 
conservation of matter4  ,with this idea
 in mind we see at once the significance
 of the constitution of uranium         
minerals4 ,formed in the remote         
antiquity of past geological ages1 these
 minerals must become store-houses of   
all the products of uranium except those
 which may have escaped as gases or     
possibly liquids4 ,even gases may be    

expected to some extent to be retained  
by occlusion4 ,among the contents of    
uranium minerals1 then1 we may look for 
the descendants of the parent uranium4  
,if the descendants are permanent or    
more long-lived than uranium1 they will 
accumulate continually4 ,if they are    
short-lived1 they will accumulate at a  
steady rate till enough is formed for   
the quantity disintegrating to be equal 
to the quantity developed4 ,a state of  
mobile equilibrium will then be reached1
 and the amount of the product will     
remain constant4 ,this constant amount  
of substance will depend only on the    
amount of uranium which is its source1  
and1 for different minerals1 if all the 
product is retained1 the quantity of the
 product will be proportional to the    
quantity of uranium4 ,in a series of    
analyses of uranium minerals1 therefore1
 we ought to be able to pick out its    
more short-lived descendants by seeking 
for instances of such proportionality4  
,now radium itself is a constituent of  

uranium minerals1 and two series of     
experiments by ,r4,j4 ,strutt and ,b4,b4
 ,boltwood have shown that the content  
of radium1 as measured by the           
radio-activity of the emanation1 is     
directly proportional to the content of 
uranium4 7,strutt1 ,proc4 ,roy4 ,soc4   
,a1 ,february #aije2 ,boltwood1 ,phil4  
,mag4 ,april1 #aije47 ,in ,boltwood's   
investigation1 some twenty minerals1    
with amounts of uranium varying from    
that in a specimen of uraninite with    
#gd4fe per cent41 to that in a monazite 
with #j4cj per cent41 gave a ratio of   
uranium to radium1 constant within about
 one part in ten4  ,the conclusion is   
irresistible that radium is a descendant
 of uranium1 though whether uranium is  
its parent or a more remote ancestor    
requires further investigation by the   
radio-active genealogist4 ,on the       
hypothesis of direct parentage1 it is   
easy to calculate that the amount of    
radium produced in a month by a         
kilogramme of a uranium salt would be   

enough to be detected easily by the     
radio-activity of its emanation4 ,the   
investigation has been attempted by     
several observers1 and the results1     
especially those of a careful experiment
 of ,boltwood1 show that from purified  
uranium salts the growth of radium1 if  
appreciable at all1 is much less than   
would be found if the radium was the    
first product of change of the uranium4 
,it is necessary1 therefore1 to look for
 one or more intermediate substances4   
,while working in #ahii with the uranium
 residues used by ,m4 and ,mme ,curie   
for the preparation of radium1 ,debierne
 discovered and partially separated     
another radio-active element which he   
called actinium4 ,it gives rise to an   
intermediate product actinium-,x1 which 
yields an emanation with the short      
half-life of #c4i seconds4 ,the         
emanation deposits two successive       
disintegration products actinium-,a and 
actinium-,b4  ,evidence gradually       
accumulated that the amounts of actinium

 in radio-active minerals were1 roughly 
at any rate1 proportional to the amounts
 of uranium4 ,this result pointed to a  
lineal connection between them1 and led 
,boltwood to undertake a direct attack  
on the problem4 ,separating a quantity  
of actinium from a kilogramme of ore1   
,boltwood observed a growth of #h4e x   
7#aj to the power -#i7 gramme of radium 
in #aic days1 agreeing with that        
indicated by theory within the limits of
 experimental error4 7,american ,journal
 of ,science1 ,december1 #aijf47 ,we may
 therefore insert provisionally actinium
 and its series of derivatives between  
uranium and radium in the radio-active  
pedigree4  ,turning to the other end of 
the radium series we are led to ask what
 becomes of radium-,f when in turn it   
disintegrates8 ,what is the final       
non-active product of the series of     
changes we have traced from uranium     
through actinium and radium8  ,one such 
product has been indicated above4 ,the  
alpha-ray particles appear to possess   

the mass of helium atoms1 and the growth
 of helium has been detected by its     
spectrum in a tube of radium emanation4 
,moreover1 helium is found occluded in  
most if not all radio-active minerals in
 amount which approaches1 but never     
exceeds1 the quantity suggested by      
theory4 ,we may safely regard such      
helium as formed by the accumulation of 
alpha-ray particles given out by        
successive radio-active changes4  ,in   
considering the nature of the residue   
left after the expulsion of the five    
alpha-particles1 and the consequent     
passage of radium to radium-,f we are   
faced by the fact that lead is a general
 constituent of uranium minerals4 ,five 
alpha-particles1 each of atomic weight  
#d1 taken from the atomic weight 7about 
#bbe7 of radium gives #bje--;a number   
agreeing fairly well with the #bjg of   
lead4 ,since lead is more permanent than
 uranium1 it must steadily accumulate1  
no radio-active equilibrium will be     
reached1 and the amount of lead will    

depend on the age of the mineral as well
 as on the quantity of uranium present  
in it4 ,in primary minerals from the    
same locality1 ,boltwood has shown that 
the contents of lead are proportional to
 the amounts of uranium1 while1         
accepting this theory1 the age of       
minerals with a given content of uranium
 may be calculated from the amount of   
lead they contain4 ,the results vary    
from #djj to #bjjj million years4       
7,american ,journal of ,science1        
,october1 #aije1 and ,february1 #aijg47 
,we can now exhibit in tabular form the 
amazing pedigree of radio-active change 
shown by this one family of elements4   
,an immediate descent is indicated by 1 
while one which may either be immediate 
or involve an intermediate step is shown
 by4444 ,no place is found in this      
pedigree for thorium and its            
derivatives4 ,they seem to form a       
separate and independent radio-active   
family4                          ,atomic
 ,weight  ,time of half                 

,radio-,activity                        
decay     ,uranium               #bch4e 
alpha     ,uranium-,x             8     
#bb days          beta1 gamma    444    
,actinium              8            8   
no rays     ,actinium-,x            8   
#aj4b days        alpha 7beta1 gamma7   
,actinium ,emanation    8               
#c4i seconds      alpha     ,actinium-,a
            8            #ce4g minutes  
no rays     ,actinium-,b            8   
#b4ae minutes      alpha1 beta1 gamma   
444    ,radium                #bbe      
about #bfjj years  alpha     ,radium    
,emanation      8            #c4h days  
alpha     ,radium-,a              8     
#c minutes         alpha     ,radium-,b 
8            #ba minutes        no rays 
,radium-,c              8            #bh
 minutes        alpha1 beta1 gamma      
,radium-,d              8               
about #dj years    no rays              
,radium-,e              8            #f 
days            beta 7gamma7            
,radium-,f              8               

#adc days          alpha    444    ,lead
                  #bjg          8       
no rays   ,as soon as the transmutation 
theory of radio-activity was accepted1  
it became natural to speculate about the
 intimate structure of the radio-active 
atoms1 and the mode in which they broke 
up with the liberation of some of their 
store of internal energy4 ,how could we 
imagine an atomic structure which would 
persist unchanged for long periods of   
time1 and yet eventually spontaneously  
explode1 as here an atom and there an   
atom reached a condition of instability8
  ,the atomic theory of corpuscles or   
electrons fortunately was ready to be   
applied to this new problem4 ,of the    
resulting speculations the most detailed
 and suggestive is that of ,j4,j4       
,thomson4 7,phil4 ,mag4 ,march1 #aijd47 
,thomson regards the atom as composed of
 a number of mutually repelling negative
 corpuscles or electrons held together  
by some central attractive force which  
he represents by supposing them immersed

 in a uniform sphere of positive        
electricity4 ,under the action of the   
two forces1 the electrons space         
themselves in symmetrical patterns1     
which depend on the number of electrons4
 ,three place themselves at the corner  
of an equilateral triangle1 four at     
those of a square1 and five form a      
pentagon4 ,with six1 however1 the single
 ring becomes unstable1 one corpuscle   
moves to the middle and five lie round  
it4 ,but if we imagine the system       
rapidly to rotate1 the centrifugal force
 would enable the six corpuscles to     
remain in a single ring4 ,thus internal 
kinetic energy would maintain a         
configuration which would become        
unstable as the energy drained away4    
,now in a system of electrons1          
electromagnetic radiation would result  
in a loss of energy1 and at one point of
 instability we might well have a sudden
 spontaneous redistribution of the      
constituents1 taking place with an      
explosive violence1 and accompanied by  

the ejection of a corpuscle as a        
beta-ray1 or of a large fragment of the 
atom as an alpha-ray4  ,the discovery of
 the new property of radio-activity in a
 small number of chemical elements led  
physicists to ask whether the property  
might not be found in other elements1   
though in a much less striking form4    
,are ordinary materials slightly        
radio-active8 ,does the feeble electric 
conductivity always observed in the air 
contained within the walls of an        
electroscope depend on ionizing         
radiations from the material of the     
walls themselves8 ,the question is very 
difficult1 owing to the wide            
distribution of slight traces of radium4
 ,contact with radium emanation results 
in a deposit of the fatal radium-,d1    
which in #dj years is but half removed4 
,is the natural leak of a brass         
electroscope due to an intrinsic        
radio-activity of brass1 or to traces of
 a radio-active impurity on its surface8
 ,long and laborious researches have    

succeeded in establishing the existence 
of slight intrinsic radio-activity in a 
few metals such as potassium1 and have  
left the wider problem still unsolved4  
,it should be noted1 however1 that1 even
 if ordinary elements are not           
radio-active1 they may still be         
undergoing spontaneous disintegration4  
,the detection of ray-less changes by   
,rutherford1 when those changes are     
interposed between two radio-active     
transformations which can be followed1  
show that spontaneous transmutation is  
possible without measureable            
radio-activity4 ,and1 indeed1 any theory
 of disintegration1 such as ,thomson's  
corpuscular hypothesis1 would suggest   
that atomic rearrangements are of much  
more general occurrence than would be   
apparent to one who could observe them  
only by the effect of the projectiles1  
which1 in special cases1 owing to some  
peculiarity of atomic configuration1    
happened to be shot out with the        
enormous velocity needed to ionize the  

surrounding gas4 ,no evidence for such  
ray-less changes in ordinary elements is
 yet known1 perhaps none may ever be    
obtained2 but the possibility should not
 be forgotten4  ,in the strict sense of 
the word1 the process of atomic         
disintegration revealed to us by the new
 science of radio-activity can hardly be
 called evolution4 ,in each case        
radio-active change involves the        
breaking up of a heavier1 more complex  
atom into lighter and simpler fragments4
 ,are we to regard this process as      
characteristic of the tendencies in     
accord with which the universe has      
reached its present state1 and is       
passing to its unknown future8 ,or have 
we chanced upon an eddy in a backwater1 
opposed to the main stream of advance8  
,in the chaos from which the present    
universe developed1 was matter composed 
of large highly complex atoms1 which    
have formed the simpler elements by     
radio-active or ray-less disintegration8
 ,or did the primaeval substance consist

 of isolated electrons1 which have      
slowly come together to form the        
elements1 and yet have left here and    
there an anomaly such as that           
illustrated by the unstable family of   
uranium and radium1 or by some such     
course are returning to their state of  
primaeval simplicity8     ,,index4      
,abraxas grossulariata4  ,acquired      
characters1 transmission of4  ,acraea   
johnstoni4  ,adaptation4  ,adloff4      
,adlumia cirrhosa4  ,agassiz1 ,a4       
,agassiz1 ,l4  ,alexander4  ,allen1     
,c4,a4  ,alternation of generations4    
,ameghino4  ,ammon1 ,o41 ,works of4     
,ammonites1 ,descent of4  ,amphidesmus  
analis4  ,anaea divina4  ,andrews1      
,c4,w4  ,angiosperms1 evolution of4     
,anglicus1 ,bartholomaeus4              
,ankyroderma4  ,anomma4  ,antedon       
rosacea4  ,antennularia antennina4      
,anthropops4  ,ants1 modifications of4  
,arber1 ,e4,a4,n41--and ,j4 ,parkin1 on 
the origin of ,angiosperms4             
,archaeopteryx4  ,arctic regions1       

velocity of development of life in4     
,ardigo4  ,argelander4  ,argyll1 ,huxley
 and the ,duke of4  ,aristotle4         
,arrhenius4  ,asterias1 ,loeb on        
hybridisation of4  ,autogamy4  ,avena   
fatua4  ,avenarius4  ,bacon1 on         
mutability of species4  ,baehr1 von1 on 
,cytology4  ,baer1 law of von4  ,bain4  
,baldwin1 ,j4,m4  ,balfour1 ,a4,j4      
,ball1 ,j4  ,barber1 ,mrs ,m4,e41 on    
,papilio nireus4  ,barclay1 ,w4         
,barratt4  ,bary1 de4  ,bates1 ,h4,w41  
on ,mimicry4--,letters from ,darwin     
to4--elsewhere4  ,bateson1 ,a4          
,,bateson1 ,w41 on ,heredity and        
,variation in ,modern lights4--on       
discontinuous evolution4--on            
hybridisation4  ,bateson1 ,w4 and ,r4,p4
 ,gregory4  ,bathmism4  ,beche1 de la4  
,beck1 ,p4  ,becquerel1 ,h4  ,beebe1    
,c4,w41 on the plumage of birds4--on    
sexual selection4  ,beguyer de          
,chancourtois4  ,bell's 7,sir ,charles7 
,anatomy of ,expression4  ,belopolsky4  
,belt1 ,t41 on ,mimicry4  ,beneden1 ,e4 

van4  ,benson1 ,m4  ,bentham1 ,g41 on   
,darwin's species-theory4--on           
geographical distribution4  ,bentham1   
,jeremy4  ,bergson1 ,h4  ,berkeley4     
,berthelot4  ,betham1 ,sir ,w4          
,bickford1 ,e41 experiments on          
degeneration by4  ,bignonia capreolata4 
,biophores4  ,birds1 geological history 
of4  ,blanford1 ,w4,t4  ,blaringhem1 on 
wounding4  ,blumenbach4  ,bodin4        
,boltwood1 ,b4,b4  ,bonald1 on war4     
,bonnet4  ,bonney1 ,t4,g4  ,bonnier1 ,g4
  ,bopp1 ,f41 on language4  ,,bougle    
,c41 on ,darwinism and ,sociology4      
,bourdeau4  ,bourget1 ,p4  ,boutroux4   
,boveri1 ,t4  ,brachiopods1 history of4 
,brassica1 hybrids of4  ,brassica       
,napus4  ,broca4  ,brock1 on ,kant4     
,brown1 ,robert4  ,brugmann and         
,osthoff4  ,brugmann4  ,brunetiere4     
,bruno1 on ,evolution4  ,buch1 von4     
,bucher1 ,k4  ,buckland4  ,buckle4      
,buffon4  ,burchell1 ,w4,j4  ,burck1 ,w4
  ,burdon-,sanderson1 ,j41 letter from4 
,,bury1 ,j4,b41 on ,darwinism and       

,history4  ,butler1 ,a4,g4  ,butler1    
,samuel4  ,butschli1 ,o4  ,butterflies1 
mimicry in4--sexual characters in4      
,cabanis4  ,campbell4  ,camels1         
geological history of4  ,camerarius1    
,r4,j4  ,candolle1 ,a4 de4  ,cannon and 
,davenport1 experiments on ,daphniae by4
  ,capsella bursapastoris4  ,carneri4   
,castnia linus4  ,catasetum barbatum4   
,catasetum tridentatum4  ,caterpillars1 
variation in4  ,celosia1 variability of4
  ,cereals1 variability in4  ,cesnola1  
experiments on ,mantis by4              
,chaerocampa1 colouring of4  ,chambers1 
,r41 ,the ,vestiges of ,creation by4    
,chromosomes and ,chromomeres4  ,chun4  
,cieslar1 experiments by4               
,circumnutation1 ,darwin on4  ,claus4   
,cleistogamy4  ,clerke1 ,miss ,a4       
,clodd1 ,e4  ,cluer4  ,clytus arietis4  
,coadaptation4  ,codrington4  ,cohen and
 ,peter4  ,collingwood4  ,colobopsis    
truncata4  ,colour1 ,e4,b4 ,poulton on  
,the ,value in the ,struggle for life   
of4--influence and temperature on       

changes in4--in relation to ,sexual     
,selection4  ,colours1                  
incidental4--warning4  ,comte1 ,a4      
,condorcet4  ,cope4  ,coral reefs1      
,darwin's work on4  ,correlation of     
organisms1 ,darwin's idea of the4       
,correlation of parts4  ,corydalis      
claviculata4  ,cournot4  ,couteur1 ,col4
 ,le4  ,crooks1 ,sir ,william4  ,cruger1
 on ,orchids4  ,cunningham and          
,marchand1 on the brain4  ,curie1 ,m4   
and ,mme4  ,cuvier4  ,cycadeoidea       
dacotensis4  ,cycads1 geological history
 of4  ,cystidea1 an ancient group4      
,cytology and heredity4  ,cytolysis and 
fertilisation4  ,czapek4  ,dalton's     
atomic theory4  ,dana1 ,j4,d41 on marine
 faunas4  ,danaida chrysippus4  ,danaida
 genutia4  ,danaida plexippus4  ,dante4 
,dantec1 ,le1  ,darwin1 ,charles1 as an 
,anthropologist4--on ants4--and the     
,beagle ,voyage4--on the ,biology of    
,flowers4--as a ,botanist4--his         
influence on ,botany4--and ,s4          
,butler4--at ,cambridge4--on            

,cirripedia4--on climbing plants4--on   
colour4--on coral reefs4--on the        
,descent of ,man4--his work on          
,drosera4--at ,edinburgh4--his influence
 on ,animal ,embryology4--on            
,geographical ,distribution4--his work  
on ,earthworms4--evolutionist authors   
referred to in the ,origin by4--and ,e4 
,forbes4--on the geological record4--and
 ,geology4--his early love for          
geology4--his connection with the       
,geological ,society of ,london4--and   
,haeckel4--and ,henslow4--and           
,history4--and ,hooker4--and            
,huxley4--on ice-action4--on igneous    
rocks4--on ,lamarck4--on ,language4--his
 ,scientific ,library4--and the ,linnean
 ,society4--and ,lyell4--and            
,malthus4--on ,patrick ,matthew4--on    
mental evolution4--on ,mimicry4--a      
,monistic ,philosopher4--on the         
movements of plants4--on ,natural       
,selection4--a ,naturalist for          
,naturalists4--on ,paley4  ,darwin1     
,charles1 his ,pangenesis               

hypothesis4--on the permanence of       
continents4--his personality4--his      
influence on ,philosophy4--predecessors 
of4--his views on religion1 etc4--his   
influence on religious thought4--his    
influence on the study of               
religions4--his methods of              
research4--and ,sedgwick4--on ,sexual   
,selection4--the first germ of his      
species theory4--on ,h4                 
,spencer4--causes of his success4--on   
,variation4--on the ,vestiges of        
,creation4--on volcanic islands4--and   
,wallace4--letter to ,wallace           
from4--letter to ,e4,b4 ,wilson from4   
,darwin1 ,e41 on the colour of          
animals4--,charles ,darwin's reference  
to4--on evolution4  ,,darwin1 ,f41 on   
,darwin's work on the ,movements of     
,plants4--on ,darwin as a               
botanist4--observations on ,earthworms  
by4--on ,lamarckism4--on ,memory4--on   
,prichard's ,anticipations4--various4   
,,darwin1 ,,sir ,g41 on ,the ,genesis of
 ,double ,stars4--on the earth's mass4  

,darwin1 ,h4  ,darwin1 ,w4  ,darwinism1 
,sociology1 ,evolution and4  ,davenport 
and ,cannon1 experiments on ,daphniae   
by4  ,david1 ,t4,e41 his work on        
,funafuti4  ,death1 cause of natural4   
,debey1 on ,cretaceous plants4          
,debierne4  ,degeneration4  ,delage1    
experiments on parthenogenesis by4      
,delbruck4  ,democritus4  ,deniker4     
,descartes4  ,descent1 history of       
doctrine of4  ,descent of ,man1 ,g4     
,schwalbe on ,the4--,darwin on ,sexual  
,selection in ,the4--rejection in       
,germany of ,the4  ,desmatippus4        
,desmoulins1 ,a41 on ,geographical      
,distribution4  ,detto4  ,development1  
effect of environment on4  ,dianthus    
caryophyllus4  ,diderot4  ,digitalis    
purpurea4  ,dimorphism1 seasonal4       
,dismorphia astynome4  ,dismorphia      
orise4  ,distribution1 ,h4 ,gadow on    
,geographical4--,sir ,w4                
,thiselton-,dyer on4  ,dittrick1 ,o4    
,dixey1 ,f4,a41 on the scent of         
,butterflies4  ,dolichonyx oryzivorus4  

,dorfmeister4  ,down1 ,darwin at4       
,draba verna4  ,dragomirov4  ,driesch1  
experiments by4--elsewhere4  ,drosera1  
,darwin's work on4  ,dryopithecus4      
,dubois1 ,e41 on ,pithecanthropus4      
,duhring4  ,duhamel4  ,duncan1 ,j4,s4   
,duncan1 ,p4,b4  ,duns ,scotus4  ,duret1
 ,c4  ,durkheim1 on division of labour4 
,dutrochet4  ,echinoderms1 ancestry of4 
,ecology4  ,eimer4  ,ekstam4            
,elephants1 geological history of4      
,elymnias phegea4  ,e4 undularis4       
,embleton1 ,a4,l4  ,embryology1 ,a4     
,sedgwick on the influence of ,darwin   
on4  ,embryology1 as a clue to          
,phylogeny4--the ,origin of ,species    
and4  ,empedocles4  ,engles4            
,environment1 action of4--,klebs on the 
influence on plants of4--,loeb on       
experimental study in relation to4      
,eohippus4  ,epicurus1 a poet of        
,evolution4  ,eristalis4  ,ernst4       
,ernst1 ,a41 on the ,flora of ,krakatau4
  ,eschscholzia californica4  ,espinas4 
,eudendrium racemosum4  ,evolution1 in  

relation to ,astronomy4--and            
creation4--conception                   
of4--discontinuous4--experimental4--fact
ors of4--fossil plants as evidence      
of4--and language4--of matter1 ,w4,c4,d4
 ,whetham on4--mental4--,lloyd ,morgan  
on mental factors in4--,darwinism and   
,social4--,saltatory4--,herbert ,spencer
 on4--,uniformitarian4--,philosophers   
and modern methods of studying4         
,expression of the ,emotions4           
,fabricius1 ,j4,c41 on geographical     
distribution4  ,farmer1 ,j4,b4  ,farrer1
 ,lord4  ,fearnsides1 ,w4,g4  ,felton1  
,s41 on protective resemblance4  ,ferri4
  ,ferrier1 his work on the brain4      
,fertilisation1 experimental work on    
animal-4  ,fertilisation of ,flowers4   
,fichte4  ,field1 ,admiral ,a4,m4       
,fischer1 experiments on ,butterflies   
by4  ,fitting4  ,flemming1 ,w4          
,flourens4  ,flowering plants1 ancestry 
of4  ,flowers1 ,k4 ,goebel on the       
,biology of4  ,flowers and ,insects4    
,flowers1 relation of external          

influences to the production of4  ,fol1 
,h4  ,forbes1 ,e4--and ,c4 ,darwin4     
,ford1 ,s4,o4 and ,a4,c4 ,seward1 on the
 ,araucarieae4  ,fossil ,animals1 ,w4,b4
 ,scott on their bearing on evolution4  
,fossil ,plants1 ,d4,h4 ,scott on their 
bearing on evolution4  ,fouillee4       
,fraipont1 on skulls from ,spy4         
,,frazer1 ,j4,g41 on ,some ,primitive   
,theories of the ,origin of             
,man4--various4  ,fruwirth4  ,fumaria   
officinalis4  ,funafuti1 coral atoll of4
  ,fundulus4  ,f4 heteroclitus4         
,,gadow1 ,h41 on ,geographical          
,distribution of ,animals4--elsewhere4  
,gartner1 ,k4,f4  ,gallus bankiva4      
,galton1 ,f4  ,gamble1 ,f4,w4 and ,f4,w4
 ,keeble4  ,gasca1 ,la4  ,geddes1 ,p4   
,geddes1 ,p4 and ,a4,w4 ,thomson4       
,gegenbauer4  ,geikie1 ,sir ,a4         
,geitonogamy4  ,genetics4  ,geographical
 ,distribution of ,animals4--of         
,plants4--influence of ,the ,origin of  
,species on4--,wallace's contribution   
to4  ,geography of former periods1      

reconstruction of4  ,geology1 ,darwin   
and4  ,geranium spinosum4  ,germ-plasm1 
continuity of4--,weismann on4  ,germinal
 ,selection4  ,gibbon4  ,gilbert4       
,,giles1 ,p41 on ,evolution and the     
,science of ,language4                  
,giuffrida-,ruggeri4  ,giotto4          
,gizycki4  ,glossopteris ,flora4        
,gmelin4  ,godlewski1 on hybridisation4 
,,goebel1 ,k41 on ,the ,biology of      
,flowers4--his work on ,morphology4     
,goethe and ,evolution4--on the relation
 between ,man and ,mammals4--elsewhere4 
,goldfarb4  ,gondwana ,land4            
,goodricke1 ,j4  ,gore1 ,dr4            
,gorjanovic-,kramberger4  ,gosse1 ,p4,h4
  ,grabau1 ,a4,w41 on ,fusus4           
,grand',eury1 ,f4,c41 on fossil plants4 
,grapta ,c4 album4  ,gravitation1 effect
 on life-phenomena of4  ,gray1 ,asa4    
,gregoire1 ,v4  ,groom1 ,t4,t41 on      
heliotropism4  ,groos4  ,grunbaum1 on   
the brain4  ,guignard1 ,l4  ,gulick4    
,guppy1 on plant-distribution4  ,guyau4 
,gwynne-,vaughan1 ,d4,t41 on            

,osmundaceae4  ,gymnadenia conopsea4    
,haberlandt1 ,g4  ,haddon1 ,a4,c4       
,,haeckel1 ,e41 on ,charles ,darwin as  
an ,anthropologist4--on ,colour4--and   
,darwin4--on the ,descent of            
,man4--contributions to ,evolution by4  
,haeckel1 ,e41 on ,lamarck4--on         
,language4--a leader in the ,darwinian  
controversy4--on ,lyell's influence on  
,darwin4--various4  ,hacker4            
,hagedoorn1 on hybridisation4  ,hales1  
,s4  ,hansen4  ,harker1 ,a4  ,,harrison1
 ,j4,e41 on ,the ,influence of          
,darwinism on the ,study of ,religions4 
,hartmann1 von4  ,harvey4  ,haupt1 ,p41 
on ,language4  ,haycraft4  ,hays1 ,w4,m4
  ,hegel4  ,heliconius narcaea4         
,heliotropism in animals4  ,henslow1    
,rev4 ,j4,s4 and ,darwin4  ,hensen1     
,van4  ,herbst1 his experiments on sea  
urchins4  ,heracleitus4  ,herder4       
,heredity and ,cytology4--,haeckel      
on4--and ,variation4--various4  ,hering1
 ,e41 on ,memory4  ,herschel1 ,j4       
,hertwig1 ,r4  ,hertwig1 ,o4  ,hertz4   

,heteromorphosis4  ,heterostylism4      
,heuser1 ,e4  ,hewitt4  ,heyse's theory 
of language4  ,hinde1 ,g4,j41 his work  
on ,funafuti4  ,hipparion4  ,hippolyte  
cranchii4  ,hirase4  ,history1 ,darwin  
and4  ,hobbes1 ,t4  ,hobhouse4          
,,hoffding1 ,h41 on ,the ,influence of  
the ,conception of ,evolution on ,modern
 ,philosophy4  ,hofmeister1 ,w4         
,holmes1 ,s4,j41 on ,arthropods4        
,holothurians1 calcareous bodies in skin
 of4  ,homo heidelbergensis4  ,homo     
neandertalensis4  ,homo pampaeus4  ,homo
 primigenius4  ,homunculus4  ,hooker1   
,sir ,j4,d41 and ,darwin4--on           
,distribution of ,plants4--on           
,ferns4--,letter to the ,editor from4   
,horner1 ,l4  ,horse1 ,geological       
history of the4  ,huber4  ,hubert and   
,mauss4  ,hubrecht1 ,a4,r4,w4  ,hugel1  
,f4 von4  ,humboldt1 ,a4 von4           
,humboldt1 ,w4 von4  ,hume4  ,hutcheson4
  ,hutton4  ,huxley1 ,t4,h41 and        
,darwin4--and the ,duke of ,argyll4--on 
,embryology4--on ,geographical          

,distribution4--on ,lamarck4--,letter to
 ,j4,w4 ,judd from4--on ,lyell4--on     
,man4--on ,the ,origin of ,species4--on 
,selection4--on ,teleology4--on         
transmission of acquired                
characters4--various4  ,hybridisation4  
,hybrids1 ,sterility of4  ,hyracodon4   
,iberis umbellata4  ,ikeno4             
,imperfection of the ,geological        
,record4  ,ingenhousz1 on plant         
physiology4  ,inheritance of acquired   
characters4  ,insects and ,flowers4     
,instinct4  ,instincts1 experimental    
control of animal4  ,ipomaea purpurea4  
,irish ,elk1 an example of              
co-adaptation4  ,jacobian figures4      
,jacoby1 ,studies in ,selection by4     
,james1 ,w4  ,janczewski4  ,jeans1      
,j4,h4  ,jennings1 ,h4,s41 on           
,paramoecium4  ,jentsch4  ,jespersen1   
,prof41 ,theory of4  ,johannsen1 on     
,species4  ,jones1 ,sir ,william1 on    
,language4  ,jordan4  ,,judd1 ,j4,w41 on
 ,darwin and ,geology4  ,kallima1       
protective colouring of4  ,kallima      

inachis4  ,kammerer's experiments on    
,salamanders4  ,kant1 ,i4  ,keane1 on   
the ,primates4  ,keeble1 ,f4,w4 and     
,f4,w4 ,gamble1 on ,colour-change4      
,keith1 on ,anthropoid ,apes4  ,kellogg1
 ,v41 on heliotropism4  ,kepler4        
,kerguelen ,island4  ,kidd4  ,kidston1  
,r41 on fossil plants4  ,killmann1 on   
origin of human races4  ,king1 ,sir     
,george4  ,klaatsch1 on ,ancestry of    
,man4  ,klaatsch and ,hauser4  ,,klebs1 
,g41 on ,the influence of ,environment  
on the forms of plants4  ,kniep4        
,knies4  ,knight1 ,a41 experiments on   
plants by4--on ,geotropism4             
,knight-,darwin law4  ,knuth4           
,kolliker1 his views on ,evolution4     
,kolreuter1 ,j4,g4  ,kohl4              
,korschinsky4  ,kowalevsky1 on fossil   
horses4  ,krakatau1 ,ernst on the ,flora
 of4  ,krause1 ,e4  ,kreft1 ,dr4        
,kropotkin4  ,kupelwieser1 on           
hybridisation4  ,lagopus hyperboreus4   
,lamarck1 his division of the ,animal   
,kingdom4--,darwin's opinion of4--on    

,evolution4--on ,man4--various4         
,lamarckian principle4  ,lamb1 ,c4      
,lamettrie4  ,lamprecht4  ,lanessan1    
,j4,l4 de4  ,lang4  ,lange4  ,language1 
,darwin on4--,evolution and the ,science
 of4--various4  ,lankester1 ,sir ,e4    
,ray1 on degeneration4--on              
educability4--on the germ-plasm         
theory4--elsewhere4  ,lapouge1 ,vacher  
de4  ,larmor1 ,j4  ,lartet1 ,m4,e4      
,lassalle4  ,lathyrus odoratus4         
,lavelaye1 de4  ,lawrence1 ,w4          
,lehmann4  ,lehmann-,nitsche4           
,leibnitz4  ,lepidium ,draba4           
,lepidoptera1 variation in4  ,leskien1  
,a41 on language4  ,lessing4            
,leucippus4  ,levi1 ,e4  ,lewes1 ,g4,h4 
,lewin1 ,capt4  ,liapounoff4  ,liddon1  
,h4,p4  ,light1 effect on organisms of4 
,limenitis archippus4--arthemis4        
,linnaeus4  ,livingstone1 on            
plant-forms4  ,llamas1 geological       
history of4  ,lockyer1 ,sir ,n4  ,locy1 
,w4,a4  ,,loeb1 ,j41 on ,the            
,experimental ,study of the influence of

 environment on ,animals4  ,loew1 ,e4   
,longstaff1 ,g4,b41 on the ,scents of   
,butterflies4  ,lorentz4  ,lotsy1 ,j4,p4
  ,love1 ,a4,e4,w4  ,lovejoy4  ,lubbock4
  ,lucas1 ,k4  ,lucretius1 a poet of    
,evolution4  ,lumholtz1 ,c4  ,luteva    
macrophthalma4  ,lycorea halia4  ,lyell1
 ,sir ,charles1 and ,darwin4--the       
influence of4--on geographical          
distribution4--on ,the ,origin of       
,species4--on the permanence of         
,ocean-basins4--publication of the      
,principles by4--the uniformitarian     
teaching of4  ,lythrum salicaria4       
,macacus1 ear of4  ,mac,dougal1 on      
wounding4  ,mach1 ,e4  ,macromytis      
flexuosa1 colour-change in4  ,magic and 
religion4  ,mahoudeau4  ,maillet1 de4   
,majewski4  ,malthus1 his influence on  
,darwin4--various4  ,mammalia1 history  
of4  ,man1 ,descent of4--,j4,g4 ,frazer 
on some primitive theories of the origin
 of4--mental and moral qualities of     
animals and4--pre-,darwinian views on   
the ,descent of4--religious views of    

primitive4--,tertiary flints worked by4 
,man1 ,g4 ,schwalbe on ,darwin's        
,descent of4  ,manouvrier4  ,mantis     
religiosa1 colour experiments on4       
,marett1 ,r4,r4  ,markwick4  ,marshall1 
,g4,a4,k4  ,marx4  ,massart4  ,masters1 
,m4  ,matonia pectinata4  ,matthew1 ,p41
 and ,natural ,selection4  ,maupertuis4 
,maurandia semperflorens4  ,mauss and   
,herbert4  ,mauthner4  ,maxwell4        
,maxwell1 ,clerk4  ,mayer1 ,r4          
,mechanitis lysimnia4  ,meehan1 ,t4     
,meldola1 ,r41 ,letters from ,darwin to4
  ,melinaea ethra4  ,mendel4            
,mendeleeff4  ,merrifield4  ,merz1      
,j4,t4  ,mesembryanthemum truncatum4    
,mesohippus4  ,mesopithecus4            
,metschnikoff4  ,mill1 ,j4,s4           
,mimicry4--,h4,w4 ,bates on4--,f4       
,muller on4  ,mimulus luteus4  ,miquel1 
,f4,w4,a4  ,mobius4  ,mohl1 ,h4 von4    
,moltke1 on war4  ,monachanthus viridis4
  ,monkeys1 fossil4  ,montesquieu4      
,montgomery1 ,t4,h4  ,monstrosoties4    
,monticelli4  ,moore1 ,j4,e4,s4         

,,morgan1 ,c4 ,,lloyd1 on ,mental       
,factors in ,evolution4--on ,organic    
,selection4  ,morgan1 ,t4,h4  ,morse1   
,e4,s41 on colour4  ,morselli4          
,mortillet4  ,moseley4  ,mottier1 ,m4   
,muller1 ,fritz1 ,fur ,darwin by4--on   
,mimicry4  ,muller1 ,fritz4  ,muller1   
,j4  ,muller1 ,max1 on language4        
,murray1 ,a41 on geographical           
distribution4  ,murray1 ,g4             
,mutability4  ,mutation4  ,myanthus     
barbatus4  ,myers1 ,g4,w41 on ,eclipses4
  ,nageli4  ,nathorst1 ,a4,g4           
,nathusius4  ,natural ,selection1 and   
adaptation4--,darwin's views            
on4--,darwin and ,wallace on4--and      
design4--and educability4--,fossil      
plants in relation to4--and human       
development4--and ,mimicry4--and        
,mutability4--various4  ,naudin4        
,neandertal skulls4  ,nemec4  ,neoclytus
 curvatus4  ,neodarwinism4  ,neumayr1   
,m4  ,newton1 ,a4  ,newton1 ,i4         
,niebuhr4  ,nietzsche4  ,nilsson1 on    
cereals4  ,nitsche4  ,noire4  ,noll4    

,novicow4  ,nuclear division4           
,nussbaum1 ,m4  ,nuttall1 ,g4,h4,f4     
,occam4  ,odin4  ,oecology1 see         
,ecology4  ,oenothera biennis4          
,oenothera gigas4  ,oenothera           
,lamarckiana4  ,oenothera muricata4     
,oenothera nanella4  ,oestergren1 on    
,holothurians4  ,oken1 ,l4  ,oliver1    
,f4,w41 on ,palaeozoic ,seeds4  ,ononis 
minutissima4  ,ophyrs apifera4          
,orchids1 ,darwin's work on the         
fertilisation of4  ,organic ,selection4 
,origin of ,species1 first draft of     
the4--geological chapter in the4        
,orthogenesis4  ,ortmann1 ,a4,e4        
,osborn1 ,h4,f4--,from the ,greeks to   
,darwin by4  ,osthoff and ,brugmann4    
,ostwald1 ,w4  ,ovibos moschatus4       
,owen1 ,sir ,richard4  ,oxford1         
,ashmolean ,museum at4  ,packard1 ,a4,s4
  ,palaeontological ,record1 ,d4,h4     
,scott on the4--,w4,b4 ,scott on the4   
,palaeopithecus4  ,paley4  ,palitzch1   
,g4  ,palm4  ,pangenesis4  ,panmixia1   
,weismann's principle of4  ,papilio     

dardanus4  ,papilio meriones4  ,papilio 
merope4  ,papilio nireus4  ,paramoecium1
 ,jennings on4  ,parker1 ,g4,h41 on     
,butterflies4  ,parkin1 ,j4 and         
,e4,a4,n4 ,arber1 on the origin of      
,angiosperms4  ,parthenogenesis1        
artificial4  ,paul1 ,h4 and ,wundt4     
,pearson1 ,k4  ,peckham1 ,dr and ,mrs1  
on the ,attidae4  ,penck4  ,penzig4     
,peripatus1 distribution of4            
,peridineae4  ,permanence of continents4
  ,perrier1 ,e4  ,perrhybris pyrrha4    
,perthes1 ,b4 de4  ,peter1 on sea       
urchin's eggs4  ,petunia violacea4      
,pfeffer1 ,w4  ,pfitzner1 ,w4           
,pflueger4  ,phillips4  ,philosophy1    
influence of the conception of evolution
 on modern4  ,phryniscus nigricans4     
,phylogeny1 embryology as a clue        
to4--,palaeontological evidence on4     
,physiology of plants1 development of4  
,piccard1 on ,geotropism4  ,pickering1  
spectroscopic observations by4  ,piranga
 erythromelas4  ,pisum sativum4         
,pithecanthropus4  ,pitheculites4       

,planema epaea4  ,plants1 ,darwin's work
 on the movements of4--geographical     
distribution of4--,palaeontological     
record of fossil4  ,platanthera bifolia4
  ,plate4  ,plato4  ,playfair4          
,pliopithecus4  ,pocock1 ,r4,i4         
,poincare4  ,polarity1 ,vochting on4    
,polymorphic species4--variability in   
cereals4  ,polypodium incanum4          
,porthesia chrysorrhoea4  ,potonie1 ,r4 
,pouchet1 ,g4  ,,poulton1 ,e4,b41 on    
,the ,value of ,colour in the ,struggle 
for ,life4--experiments on ,butterflies 
by4--on ,j4,c4 ,prichard4--on           
,mimicry4--various4  ,pratt4  ,pratz1   
du4  ,premutation4  ,preuss1 ,k4 ,th4   
,prichard1 ,j4,c4  ,primula1            
heterostylism in4  ,primula acaulis4    
,primula elatior4  ,primula officinalis4
  ,promeces viridis4  ,pronuba          
yuccasella4  ,protective resemblance4   
,protocetus4  ,protohippus4             
,psychology4  ,pteridophytes1 history   
of4  ,pteridospermeae4  ,pucheran4      
,pusey4  ,quatrefages1 ,a4 de4          

,quetelet1 statistical investigations   
by4  ,rabl1 ,c4  ,radio-activity4       
,radiolarians4  ,raimannia odorata4     
,ramsay1 ,sir ,w4 and ,soddy4  ,ranke4  
,rau1 ,a4  ,ray1 ,j4  ,reade1 ,mellard4 
,recapitulation1 the theory of4         
,reduction4  ,regeneration4  ,reid1 ,c4 
,reinke4  ,religion1 ,darwin's attitude 
towards4--,darwin's influence on the    
study of4--and ,magic4  ,religious      
thought1 ,darwin's influence on4        
,renard1 on ,darwin's work on volcanic  
islands4  ,reproduction1 effect of      
environment on4  ,reptiles1 history of4 
,reversion4  ,rhinoceros1 the history of
 the4  ,ridley1 ,h4,n4  ,riley1 ,c4,v4  
,ritchie4  ,ritual4  ,roberts1 ,a4      
,robertson1 ,t4,b4  ,robinet4  ,rolfe1  
,r4,a4  ,rolph4  ,romanes1 ,g4,j4       
,rothert4  ,roux4  ,rozwadowski1 von4   
,ruskin4  ,rutherford1 ,e4  ,rutot4     
,sachs1 ,j4  ,st ,hilaire1 ,e4,g4 de4   
,salamandra atra4  ,salamandra maculosa4
  ,saltatory ,evolution1 7see also      
,mutations74  ,sanders1 experiments on  

,vanessa by4  ,saporta1 on the          
,evolution of ,angiosperms4  ,sargant1  
,ethel1 on the ,evolution of            
,angiosperms4  ,savigny4  ,scardafella  
inca4  ,scent1 in relation to ,sexual   
,selection4  ,scharff1 ,r4,f4           
,schelling4  ,schlegel4  ,schleicher1   
,a41 on language4  ,schleiden and       
,schwann1 ,cell-theory of4  ,schmarda1  
,l4,k41 on geographical distribution4   
,schoetensack1 on ,homo heidelbergensis4
  ,schreiner1 ,k4,e4  ,schubler1 on     
cereals4  ,schultze1 ,o41 experiments on
 ,frogs4  ,schur4  ,schutt4  ,,schwalbe1
 ,g41 on ,the ,descent of ,man4         
,sclater1 ,p4,l41 on geographical       
distribution4  ,,scott1 ,d4,h41 on ,the 
,palaeontological ,record               
7,plants74--elsewhere4  ,,scott1 ,w4,b41
 on ,the ,palaeontological ,record      
7,animals74  ,scrope4  ,scyllaea4       
,sechehaye1 ,c4,a4  ,,sedgwick1 ,a41 on 
,the ,influence of ,darwin on ,animal   
,embryology4  ,sedgwick1 ,a41 ,darwin's 
,geological ,expedition with4  ,seeck1  

,o4  ,seed-plants1 origin of4           
,segregation4  ,selection1              
artificial4--germinal4  ,selection1     
natural 7see ,natural                   
,selection74--organic4--sexual4--social 
and natural4--various4  ,selenka4       
,semnopithecus4  ,semon1 ,r4  ,semper4  
,senebier4  ,senecio vulgaris4  ,sergi4 
,seward1 ,a4,c4--and ,s4,o4 ,ford4--and 
,j4 ,gowan4  ,sex1 recent investigations
 on4  ,sharpe1 ,d4  ,sherrington1 ,c4,s4
  ,shirreff1 ,p4  ,shrewsbury1 ,darwin's
 recollections of4  ,sibbern4  ,sinapis 
alba4  ,smerinthus ocellata4            
,smerinthus populi4  ,smerinthus tiliae4
  ,smith1 ,a4  ,smith1 ,w4  ,snyder4    
,sociology1 ,darwinism and4--,history   
and4  ,soddy4  ,sollas1 ,w4,j4  ,sorley1
 ,w4,r4  ,species1 ,darwin's early work 
on transmutation of4--geographical      
distribution and origin                 
of4--immutability of4--influence on     
environment on4--,lamarck on4--multiple 
origin of4--the nature of               
a4--polymorphic4--production by         

physico-chemical means of4--and         
varieties4--de ,vries's work on4        
,spencer1 ,h41 on evolution4--on        
,lyell's ,principles4--on the nature of 
the living cell4--on primitive man4--on 
the theory of ,selection4--on           
,sociology4  ,spencer1 ,h41 on the      
transmission of acquired characters4--on
 ,weismann4--various4  ,sphingidae1     
variation in4  ,spinoza4  ,sports4      
,sprengel1 ,c4,k4  ,stability1 principle
 of4  ,stahl4  ,standfuss4  ,stars1     
evolution of double4  ,stellaria media4 
,stephen1 ,l4  ,sterility in hybrids4   
,sterne1 ,c4  ,stockard1 his experiments
 on fish embryos4  ,,strasburber1 ,e41  
on ,the ,minute ,structure of ,cells in 
relation to ,heredity4                  
,strongylocentrotus franciscanus4       
,strongylocentrotus purpuratus4         
,struggle for existence4  ,strutt1      
,r4,j4  ,stuart1 ,a4  ,sturdee1         
,f4,c4,d4  ,sutterlin1 ,l4  ,sully4     
,sutton1 ,a4,w4  ,sutton1 ,w4,s4        
,svalof1 agricultural station of4       

,swainson1 ,w4  ,synapta1 calcareous    
bodies in skin of4  ,s4 lappa4          
,syrphus4  ,tarde1 ,g4  ,teleology and  
adaptation4  ,tennant1 ,f4,r4           
,teratology4  ,tetraprothomo4           
,,thiselton-,,dyer1 ,,sir ,,william1 on 
,geographical distribution of           
,plants4--on ,burchell4--on protective  
resemblance4--elsewhere4  ,,thomson1    
,j4,a41 on ,darwin's                    
,predecessors4--elsewhere4--and ,p4     
,geddes4  ,thomson1 ,sir ,j4,j4         
,theology1 ,darwin and4  ,tiedemann1 ,f4
  ,tooke1 ,horne4  ,totemism4           
,treschow4  ,treviranus4  ,trifolium    
pratense quinquefolium4  ,trigonias4    
,trilobites1 phylogeny of4  ,tschermack4
  ,turgot4  ,turner1 ,sir ,w4  ,twins1  
artificial production of4  ,tylor4      
,tyndall1 ,w4  ,tyrrell1 ,g4            
,uhlenhuth1 on blood reactions4         
,underhill1 ,e4  ,use and disuse4       
,vanessa4  ,vanessa antiope4  ,vanessa  
levana4  ,vanessa polychloros4  ,vanessa
 urticae4  ,van 't ,hoff4  ,varanus     

,salvator4  ,variability1 ,darwin's     
attention directed to4--,w4 ,bateson    
on4--and cultivation4--causes           
of4--polymorphic4  ,variation1          
continuous and discontinuous4--,darwin's
 views as an evolutionist1 and as a     
systematist1 on4--definite and          
indefinite4--environment and4--and      
heredity4--as seen in the life-history  
of an organism4--minute4--mutability    
and4--in relation to species4--,h4 de   
,vries on4  ,varigny1 ,h4 de4  ,varro1  
on language4  ,veronica chamaedrys4     
,verworn4  ,vestiges of ,creation1      
,darwin on ,the4  ,vierkandt4           
,vilmorin1 ,l4 de4  ,virchow1 his       
opposition to ,darwin4  ,virchow1 on the
 transmission of acquired characters4   
,vochting4  ,vogt1 ,c4  ,voltaire4      
,volvox4  ,,vries1 ,h4 de1 on           
,variation--the ,mutation theory of4    
,,waggett1 ,,rev4 ,p4,n41 on ,the       
,influence of ,darwin upon religious    
thought4  ,wagner4  ,waldeyer1 ,w4      
,wallace1 ,a4,r41 on ,malayan           

,butterflies4--on ,colour4--and         
,darwin4--on the ,descent of ,man4--on  
distribution4--on ,malthus4--on ,natural
 ,selection4--on the permanence of      
continents4--on social reforms4--on     
,sexual ,selection4  ,waller1 ,a4,d4    
,walton4  ,watson1 ,h4,c4  ,watson1 ,s4 
,watt1 ,j41 and ,natural ,selection4    
,watts1 ,w4,w4  ,wedgwood1 ,l4  ,weir1  
,j4,j4  ,,weismann1 ,a41 on ,the        
,selection ,theory4--on ,amphimixis4    
,weismann1 ,a41 his germ-plasm          
theory4--on ontogeny4--and              
,prichard4--and ,spencer4--on the       
transmission of acquired                
characters4--various4  ,wells1 ,w4,c41  
and ,natural ,selection4  ,weston1 ,s41 
on language4  ,,whetham1 ,w4,c4,d41 on  
,the ,evolution of ,matter4  ,whewell4  
,white1 ,g4  ,wichmann4  ,wieland1      
,g4,r41 on fossil ,cycads4  ,wiesner1 on
 ,darwin's work on plant movements4     
,williams1 ,c4,m4  ,williamson1 ,w4,c4  
,wilson1 ,e4,b41 on cytology4--letter   
from ,darwin to4  ,wolf4  ,wollaston's1 

,t4,v4 ,variation of ,species4          
,woltmann4  ,woolner4  ,wundt1 on       
language4  ,xylina vetusta4  ,yucca1    
fertilisation of4  ,zeiller1 ,r41 on    
,fossil ,plants4  ,zeller1 ,e4          
,zimmermann1 ,e4,a4,w4  ,zittel1 on     
palaeontological research4  ,zoonomia1  
,erasmus ,darwin's4