,,the ,,story ,,of ,a ,,boulder4        
,,the ,,story ,,of ,a ,,boulder         
,,or               ,,gleanings ,,from   
,,the ,,note-,,book ,,of ,a ,,field     
,,geologist                             
,,by                                    
,,archibald ,,geikie                    
,,of ,,the ,,geological ,,survey ,,of   
,,great ,,britain4                      
,illustrated with ,woodcuts4            
,,edinburgh3 ,,thomas ,,constable ,,and 
,,co4 ,,hamilton1 ,,adams1 ,,and ,,co41 
,,london4                               
,,mdccclviii4                           
,,edinburgh3 ,t4 ,,constable1 ,,printer 
,,to ,,her ,,majesty4                   
,,to                         ,,george   
,,wilson1 ,m4,d41 ,f4,r4,s4,e4          
,,regius ,,professor ,,of ,,technology  
,,in ,,the ,,university ,,of            
,,edinburgh1                            
,,these ,,pages                         
,,are                                   
,,affectionately ,,inscribed4           
,,preface      ,the present ,volume has 

been written among the rocks which it   
seeks  to describe1 during the intervals
 of leisure of a field-geologist4  ,its 
composition has been carried on by      
snatches1 often short and far  apart1   
some of the descriptions having been    
jotted down on the spot  by streamlet   
and hill-side1 or in the quiet of old   
quarries2 others1  again1 in            
railway-carriage or stage-coach4 ,by    
much the larger portion1  however1 has  
been written by the village fireside1   
after the field-work  of the day was    
over--a season not the most favourable  
to any mental  exercise1 for weariness  
of body is apt to beget lassitude of    
mind4 ,in  short1 were ,i to say that   
these ,chapters have been as often      
thrown  aside and resumed again as they 
contain paragraphs1 the statement would 
probably not exceed the truth4 ,but the 
erratic life of an itinerant  student of
 science is attended with yet greater   
disadvantages4 ,it  entails an absence  
from all libraries1 more especially     

scientific  ones1 and the number of     
works of reference admissible into his  
parva  supellex must ever be few indeed4
 ,with these hindrances1 can the  writer
 venture to hope that what has thus been
 so disjointed and  unconnected to him1 
will not seem equally so to his readers8
 ,yet if his  descriptions1 written1 as 
it were1 face to face with ,nature1 are 
found  to have caught some tinge of     
,nature's freshness1 and please the     
reader  well enough to set him in the   
way of becoming a geologist1 he shall   
have accomplished all his design4    ,it
 cannot be too widely known1 or too     
often pressed on the attention1         
especially of the young1 that a true    
acquaintance with science1 so           
delightful to its possessors1 is not to 
be acquired at second-hand4  ,text-books
 and manuals are valuable only so far as
 they supplement  and direct our own    
observations4 ,a man whose knowledge of 
,nature is  derived solely from these   
sources1 differs about as much from one 

who  betakes himself to ,nature herself1
 as a dusty1 desiccated mummy does  from
 a living man4 ,you have the same bones 
and sinews in both2 but  in the one they
 are hard and dry1 wholly incapable of  
action2 in the  other they are instinct 
with freshness and life4 ,he who would  
know what  physical science really is1  
must go out into the fields and learn it
  for himself3 and whatever branch he   
may choose1 he will not be long in      
discovering that a forenoon             
intelligently spent there must be deemed
  of far more worth than days and weeks 
passed among books4 ,he sees the        
objects of his study with his own eyes1 
and not through the spectacles  of      
books2 facts come home to him with a    
vividness and reality they  never can   
possess in the closet2 the free buoyant 
air brightens his  spirits and          
invigorates his mind1 and he returns    
again to his desk or  his workshop with 
a store of new health and pleasure and  
knowledge4  ,geology is peculiarly rich 

in these advantages1 and lies in a      
manner  open to all4 ,no matter what may
 be the season of the year1 it offers   
always some material for observation4   
,in the depth of winter we have  the    
effects of ice and frost to fall back   
upon1 though the country  should lie    
buried in snow2 and then when the longer
 and brighter  days of spring and summer
 come round1 how easily may the hammer  
be  buckled round the waist1 and the    
student emerge from the dust of town    
into the joyous air of the country1 for 
a few delightful hours among  the rocks2
 or when autumn returns with its long   
anticipated holidays1  and preparations 
are made for a scamper in some distant  
locality1  hammer and note-book will not
 occupy much room in the portmanteau1   
and will certainly be found most        
entertaining company4 ,the following    
pages--forming a digest of the          
,carboniferous rocks--may1 perhaps1 in  
some measure1 guide the explorations of 
the observer1 by indicating  to him the 

scope of geological research1 the       
principles on which the  science rests1 
and the mode in which it is pursued4    
,but ,i repeat1 no  book1 no            
lecture-room1 no museum1 will make a    
geologist of him4 ,he must  away to the 
fields and study for himself1 and the   
more he can learn  there he will become 
the better geologist4    ,he need not   
burden himself with accoutrements4 ,a   
hammer1 pretty stout  in its dimensions1
 with a round blunt face and a flat     
sharp tail2 a  note-book and a good     
pocket-lens1 are all he needs to begin  
with4  ,having these1 let him seek to   
learn the general characters' of the    
more common rocks1 aiding himself1 where
 he can1 by a comparison with  the      
specimens of a museum1 or1 failing that1
 with the descriptions of  a text-book4 
,let him then endeavour to become       
acquainted with some of  the more       
characteristic fossils of the district  
in which he resides1  so as to be able  
to recognise them wherever they occur4  

,private  collections and local museums 
are now becoming comparatively common1  
and these1 where accessible1 will aid   
him vastly in his studies4 ,having  at  
length mastered the more abundant rocks 
and organic remains of his              
neighbourhood1 let him try to trace out 
the connexion of the different  strata  
across the country1 so as to understand 
its structure4 ,for  this purpose it    
will be necessary to examine every      
ravine and natural  exposure of the     
rocks1 along with quarries1 ditches1    
railway-cuttings1  and1 in short1 the   
whole surface of the district4 ,a       
general notion  of the geology of the   
place will1 not perhaps be of very      
difficult  attainment2 and this done1   
the observer should attempt to put down 
the connexion of the rocks on paper1 for
 till this is accomplished he  will have
 at the best but an imperfect1 and      
perhaps incorrect notion  of the        
subject4 ,the best map of the district  
should be obtained1 also  a clinometer1 

or instrument for ascertaining the angle
 at which rocks  dip with the horizon1  
and a pocket-compass with which to mark 
the  direction of the dip and strike of 
strata1 that is1 the outcrop1  or line  
which they form when they come to the   
surface4 ,thus armed1 he  may commence a
 geological survey of his neighbourhood4
 ,wherever he  sees a bed of rock       
exposed1 it should be marked down on his
 map with  an arrow pointing to the     
direction in which the stratum is       
dipping1  the angle of dip1 ascertained 
by the clinometer1 being put alongside4 
,the nature of the rock1 whether        
sandstone1 shale1 limestone1 or         
greenstone1 must be set down at the same
 place1 and1 to save room1  a system of 
marks for the different rocks may be    
conveniently used4  ,when a sufficient  
area of ground has been thus traversed1 
the student  may find1 say a row of     
arrows on his map all pointing due west1
 and  indicating a set of quarries about
 a quarter of a mile distant from one   

another1 the rock in each of them       
dipping to the west4 ,if there be at    
the one end a limestone containing      
certain fossils1 and at the other  end a
 stratum exactly similar1 containing the
 same fossils1 while the  quarries      
between display the same rock1 he will  
infer1 of course1 that  the whole is one
 limestone1 and will accordingly draw a 
line from the  last quarry on the north 
to the last on the south1 connecting    
them all  together4 ,if the bed dips    
steeply down1 the line will be          
narrower1--if  but slightly inclined1 it
 will be broader2 the breadth of such a 
line  7which may be coloured to taste7  
always varying with the thickness  of   
the stratum and the angle which it makes
 with the horizon4 ,in a  district where
 faults and curvatures along with       
trap-rocks abound1 the  mapping becomes 
more complex1 but the principle remains 
the same--a  curved stratum on the      
ground making a similarly curved band on
 the map1  and a fault or dislocation of

 a set of beds producing1 in the same   
way1  a corresponding break in the lines
 traced4 ,in short1 a geological map    
should be as far as possible a          
transcript of the surface rocks of a    
country4 ,the beginner should avoid1    
however1 attempting too much2 it  will  
be enough for him at first to have      
mastered the leading features  of the   
geology of his district2 the details    
cannot be shown save on  a map of a     
large scale1 and are better transferred 
to his note-book4  ,the use of such     
mapping is to enable us to gain a       
correct knowledge of  the geological    
structure of a country1 and of the      
relation of rocks to  each other as     
regards age1 origin1 c4 ,bacon tells us 
that writing  makes an exact man2 we may
 say with equal truth that mapping makes
  an exact geologist4 ,it is sometimes  
easy enough to obtain a notion of  the  
general character of a district by      
taking a few rambles across it2  but we 
can never know it thoroughly until we   

have mapped it4 ,and this  is done not  
as mere dry routine1 or by a series of  
hard uninteresting  rules4 ,in reading  
off the geological structure of a       
country1 we  ascertain its history      
during many thousand ages long prior to 
that  of man4 ,we become1 as it were1   
interpreters of hieroglyphics1 and      
historians of long-perished dynasties4  
,those who have had experience of       
field-geology1 know how vain it is  to  
attempt to compress into a page or two  
the results of years1 and  that a few   
vague general directions are about the  
utmost that can be  attempted4 ,the     
practice of the science cannot be taught
 in books1 far  less in prefaces1       
neither can it be learned from them4    
,and so ,i once  more repeat the advice3
 ,get away to the fields4 ,seek to      
decipher the  geological records for    
yourself1 and look with your own eyes   
into the  long series of ages whose     
annals lie inscribed among the rocks4   
,if you  can secure the co-operation of 

a few companions1 so much the better4   
,half-a-dozen hammers zealously at work 
in a richly fossiliferous  stratum will 
soon pile up a tolerable collection of  
its treasures4 ,but  whether singly or  
in company1 use your eyes and your      
hammer1 and even  though in the end you 
should never become a geologist1 you    
will in the  meantime gain health and   
vigour1 and a clearness of observation1 
that  will stand you in good stead      
through life4          ,,contents4      
,,chapter ,i4    ,,page      ,scene near
 ,colinton in midsummer--,a grey        
travelled ,boulder--,its         aspect 
and contents--,its story of the past1   
#a      ,,chapter ,,ii4      ,exterior  
of the boulder--,travelled stones a     
difficult problem--,once                
referred to the ,deluge--,other         
theories--,novelty of the true          
solution--,icebergs formed in three     
ways--,progress and scenery         of  
an iceberg--,its effects--,size of      
icebergs--,boulder clay         had a   

glacial origin--,this explanation       
confirmed by fossil                     
shells--,laws of the distribution of    
life--,deductions1                      
#f      ,,chapter ,,iii4      ,how the  
boulder came to be one--,crag and       
tail--,scenery of         central       
,scotland3 ,edinburgh--,crag and tail   
formerly         associated in its      
origin with the boulder-clay--,this     
explanation erroneous--,denudation an   
old process--,its                       
results--,illustration from the         
,mid-,lothian coal-field--,the          
three ,ross-shire hills--,the ,hebrides 
relics of an         ancient            
land--,scenery of the western           
coast--,effects of         the          
breakers--,denudation of the ,secondary 
strata of the                           
,hebrides--,preservative influence of   
trap-rocks--,lost         species of the
 ,hebrides--,illustration--,origin of   
the         general denudation of the   
country--,illustrative action         of

 streams--,denudation a very slow       
process--,many old         land-surfaces
 may have been effaced--,varied aspect  
of the         ,british ,islands during 
a period of submergence--,illustration1 
#ah      ,,chapter ,,iv4      ,interior 
of the boulder--,wide intervals of      
,geology--,illustration--,long interval 
between the         formation of the    
boulder as part of a sand-bed1          
and its striation by glacial            
action--,sketch of the                  
intervening ages--,the boulder a ,lower 
,carboniferous         rock--,cycles of 
the astronomer and the geologist        
contrasted--,illustration--,plants shown
 by the boulder once         grew green 
on land--,traces of that ancient land   
,its seas1         shores1 forests1 and 
lakes1 all productive of material       
aids to our comfort and power--,plants  
of the ,carboniferous                   
era--,ferns--,tree-ferns--,calamites--,a
sterophyllites--                        
,lepidodendron--,lepidostrobus--,stigmar

ia--,scene in a ruined                  
palace--,sigillaria--,conifer1          
,cycade--,antholites1 the oldest        
known flower--,grade of the             
,carboniferous flora--,its resemblance  
to that of ,new ,zealand1               
#cj      ,,chapter ,v4      ,scenery of 
the carboniferous forests--,contrast in 
the         appearance of coal districts
 at the present day--,abundance         
of animal life in the ,carboniferous    
era--,advantages         of palontology 
over fossil-botany--,carboniferous      
fauna--,actini--,cup-corals--,architectu
re of the present         day might be  
improved by study of the architecture of
 the         ,carboniferous             
period--,mode of propagation of         
corals--,a         forenoon on the      
beach--,various stages in the           
decomposition of                        
shells--,sea-mat--,bryozoa--,fenestella-
-,retepora--,stone-lilies--             
,popular superstitions--,structure of   
the stone-lilies--,aspect         of the

 sea-bottom on which the stone-lilies   
flourished--,sea-urchins--,crustacea1   
their high                              
antiquity--,cyprides--,architecture of  
the ,crustacea and         mollusca     
contrasted--,king-crabs1                
#ei      ,,chapter ,,vi4                
,carboniferous fauna continued--,george 
,herbert's ode on         ,man--,his    
idea of creation--,what nature teaches  
on         this subject--,molluscous    
animals--,range of species in           
time proportionate to their distribution
 in space--,two         principles of   
renovation and decay exhibited alike in 
the         physical world and the world
 of life--,their effects--,the          
mollusca--,abundantly represented in the
 carboniferous                          
rocks--,pteropods--,brachiopods--,produc
tus--,its alliance with                 
,spirifer--,spirifer--,terebratula--,lam
ellibranchs--,gastropods--              
,land-snail of ,nova                    
,scotia--,cephalopods--,structure of    

orthoceras--,habits of living nautilus1 
#hf      ,,chapter ,,vii4               
,classification of the naturalist not   
always correspondent with         the   
order of nature--,incongruous grouping  
of animals         in the invertebrate  
division--,rudimentary skeleton         
of the cephalopods--,introduction of the
 vertebrate         type into           
creation--,ichthyolites of the          
carboniferous         rocks--,their     
state of keeping--,classification of    
fossil                                  
fishes--,placoids--,ichthyodorulites--,g
anoids--,their structure                
exemplified in the megalichthys and     
holoptychius--,cranium of               
megalichthys--,its armature of          
scales--,microscopic structure of       
a scale--,skeleton of                   
megalichthys--,history of the discovery 
of the holoptychius--,confounded with   
megalichthys--,external         ornament
 of holoptychius--,its jaws and         
teeth--,microscopic         structure of

 the teeth--,paucity of terrestrial     
fauna in coal         measures--,insect 
remains--,relics of                     
reptiles--,concluding         summary of
 the characters of the ,carboniferous   
fauna--,results1                        
#aaj      ,,chapter ,,viii4      ,sand  
and gravel of the boulder--,what they   
suggested--,their         consideration 
leads us among the more mechanical      
operations         of ,nature--,an      
endless succession of mutations in the  
economy of the universe--,exhibited in  
plants ,in animals--,in         the     
action of winds and oceanic             
currents--,beautifully         shown by 
the ceaseless passage of water from land
 to         sea1 and sea to land--,this 
interchange not an isolated             
phenomenon--,how aided in its effects by
 a universal process         of decay   
going on wherever a land surface is     
exposed to         the air--,complex    
mode of ,nature's                       
operations--,interlacing         of     

different causes in the production of an
 apparently         single and simple   
effect--,decay of rocks--,chemical      
changes--,underground and surface       
decomposition--,carbonated              
springs--,the ,spar ,cave--,action of   
rain-water--,decay of                   
granite--,scene in                      
,skye--,trap-dykes--,weathered cliffs of
         sandstone--,of                 
conglomerate--,of shale--,of            
limestone--,caverns         of          
,raasay--,incident--,causes of this     
waste of calcareous                     
rocks--,tombstones1                     
#ach      ,,chapter ,,ix4               
,mechanical forces at work in the       
disintegration of                       
rocks--,rains--,landslips--,effects of  
frosts--,glaciers and                   
icebergs--,abrading power of            
rivers--,suggested volume on the        
geology of rivers--,some of its probable
 contents--,scene         in a woody    
ravine--,first idea of the origin of the

 ravine         one of primeval         
cataclysms--,proved to be               
incorrect--,love         of the         
marvellous long the bane of             
geology--,more careful                  
examination shows the operations of     
,nature to be singularly         uniform
 and gradual--,the doctrine of slow and 
gradual change         not less poetic  
than that of sudden paroxysms--,the     
origin         of the ravine may be     
sought among some of the quieter        
processes of ,nature--,features of the  
ravine ,lessons of the                  
waterfall--,course of the stream through
 level ground--,true         history of 
the ravine--,waves and currents--,what  
becomes of the         waste of the     
land--,the ,rhone and the ,leman        
,lake--,deltas on the                   
sea-margin--,reproductive effects of    
currents and waves--,usual              
belief in the stability of the land and 
the mutability of the                   
ocean--,the reverse true--,continual    

interchange of land and         sea part
 of the economy of ,nature--,the        
continuance of such a         condition 
of things in future ages rendered       
probable by its         continuance     
during the past1                        
#aeg      ,,chapter ,x4      ,the       
structure of the stratified part of the 
earth's         crust conveniently      
studied by the examination of a         
single formation--,a coal-field selected
 for this         purpose--,illustration
 of the principles necessary to such    
an investigation--,the antiquities of a 
country of value in         compiling   
its pre-historic annals--,geological    
antiquities         equally valuable and
 more satisfactorily arranged--,order   
of superposition of stratified          
formations--,each formation             
contains its own suite of organic       
remains--,the age of         the boulder
 defined by this test from              
fossils--,each         formation as a   
rule shades into the adjacent           

ones--,mineral         substances       
chiefly composing the stratified rocks  
few         in number--,not of much     
value in themselves as a test of        
age--,the ,mid-,lothian coal-basin--,its
 subdivisions--,the         limestone of
 ,burdiehouse--,its fossil remains--,its
 probable         origin--,carboniferous
 limestone series of ,mid-,lothian--,its
         relation to that of            
,england--,its organic remains totally  
different from those of                 
,burdiehouse--,structure and            
scenery of ,roman ,camp ,hill--,its     
quarries of the mountain                
limestone--,fossils of these quarries   
indicative of an ancient                
ocean-bed--,origin of the               
limestones--,similar formations still   
in progress--,coral-reefs and their     
calcareous silt--,sunset         among  
the old quarries of ,roman ,camp ,hill1 
#agh      ,,chapter ,,xi4               
,intercalation of coal seams among      
mountain limestone beds of              

,mid-,lothian--,north ,greens           
seam--,most of our coal seams           
indicate former land-surfaces--,origin  
of coal a debated                       
question--,erect fossil trees in        
coal-measures--,deductions to         be
 drawn therefrom--,difference between   
the mountain limestone         of       
,scotland and that of                   
,england--,coal-bearing character of the
         northern series--,divisions of 
the ,mid-,lothian coal-field--,the      
,edge coals--,their origin illustrated  
by the growth of modern                 
deltas--,delta of the ,nile--,of the    
,mississippi--,of the                   
,ganges--,progress of formation of the  
,edge coals--,scenery         of the    
period like that of modern              
deltas--,calculations of         the    
time required for the growth of a       
coal-field--,why of         doubtful    
value--,roslyn ,sandstone               
group--,affords proofs of         a     
general and more rapid subsidence       

beneath the sea--,its         great     
continuity--,probable origin--,flat     
coals--,similar         in origin to the
 ,edge coals below--,their series not   
now         complete--,recapitulation of
 the general changes indicated by       
the ,mid-,lothian coal-field1           
#bjd      ,,chapter ,,xii4              
,trap-pebbles of the boulder--,thickness
 of the earth's crust                   
unknown--,not of much consequence to the
 practical         geologist--,interior 
of the earth in a highly heated         
condition--,proofs of this--,granite and
 hypogene         rocks--,trap-rocks3   
their identity with lavas and           
ashes--,scenery of a trappean           
country--,subdivisions of         the   
trap-rocks--,intrusive                  
traps--,trap-dykes--,intrusive          
sheets--,salisbury ,crags--,traps of the
 neighbourhood of                       
,edinburgh--,amorphous                  
masses--,contemporaneous trap-rocks of  
two kinds--,contemporaneous melted      

rocks--,tests for their age         and 
origin--,examples from neighbourhood of 
,edinburgh--,tufas         or volcanic  
ashes--,their structure and             
origin--,example         of             
contemporaneous trap-rocks--,mode of    
interpreting         them--,volcanoes of
 ,carboniferous times--,conclusion1     
#bce          ,,the ,,story ,,of ,a     
,,boulder4          ,,chapter ,i4       
,scene near ,colinton in midsummer--,a  
grey travelled ,boulder--,its           
aspect and contents--,its story of the  
past4    ,three miles to the south-west 
of ,edinburgh1 and not many hundred     
yards  from the sequestered village of  
,colinton1 there is a ravine1 overshaded
  by a thick growth of beech and elm1   
and traversed beneath by a stream1      
which1 rising far away among the        
southern hills1 winds through the  rich 
champaign country of ,mid-,lothian4 ,it 
is1 at all seasons of the  year1 one of 
the most picturesque nooks in the       
county4 ,i have seen it  in the depth of

 winter--the leafless boughs doddered   
and dripping1 the  rocks dank and bare  
save where half-hidden by the rotting   
herbage1 and  the stream1 red and       
swollen1 roaring angrily down the glen1 
while the  families1 located along its  
banks1 fleeing in terror to the higher  
grounds1 had left their cottages to the 
mercy of the torrent4 ,the last  time ,i
 visited the place was in the heart of  
,june1 and surely never did  woodland   
scene appear more exquisitely beautiful4
 ,the beech trees were  in full leaf1   
and shot their silvery boughs in slender
 arches athwart  the dell1 intertwining 
with the broader foliage and deeper     
green of  the elm1 and the still darker 
spray of the stately fir4 ,the rocks on 
either side were tapestried with        
verdure2 festoons of ivy1 with here  and
 there a thread of honey-suckle         
interwoven1 hung gracefully from the    
cliffs overhead2 each projecting ledge  
had its tuft of harebells1 or           
speedwell1 or dog-violets1 with their   

blue flowers peeping out of the  moss   
and lichens2 the herb-robert trailed its
 red blossoms over crag  and stone2 the 
wood-sorrel nestled its bright leaves   
and pale flowerets  among the gnarled   
roots of beech and elm2 while high over 
all1 alike on  the rocks above and among
 the ferns below1 towered the gently    
drooping  stalks of the fox-glove4 ,the 
stream1 almost gone1 scarcely broke the 
stillness with a low drowsy murmur1 as  
it sauntered on among the  lapides      
adesos of its pebbly channel4 ,horace's 
beautiful lines found  again their      
realization3--        ,qua pinus ingens1
 albaque populus      ,umbram hospitalem
 consociare amant          ,ramis1 et   
obliquo laborat              ,lympha    
fugax trepidare rivo4 #a    ,footnote   
#a3        ,where the tall pine and     
poplar pale      ,delight to cast       
athwart the vale          ,a pleasing   
shade4      ,while the clear stream low 
murmuring bells4      ,and o'er its     
winding channel toils          ,adown   

the glade4--,a4 ,g4      ,it was noon1  
and the sun shone more brightly and with
 greater heat  than had been felt for   
years4 ,the air1 heavy and warm1 induced
 a  feeling of listlessness and languor1
 and the day seemed one for which  the  
only appropriate employment would have  
been to read once again  the ,castle of 
,indolence4 ,but failing that1 ,i found 
it pleasant to  watch the flickering    
light shot in fitful gleams through the 
thick  canopy of leaves1 and thus1 in   
the coolness of the shade1 to mark      
these rays--sole messengers from the    
sweltering world around--as they  danced
 from rock to stream1 now lighting up   
the ripples that curled  dreamily on1   
now chequering some huge boulder that   
lay smooth and  polished in mid-channel1
 anon glancing playfully among the      
thickets  of briar or honeysuckle and   
vanishing in the shade4 ,sometimes a    
wagtail would alight at hand1 or a bee  
drone lazily past1 while even  an       
occasional butterfly would venture down 

into this shady covert4  ,but1 with     
these exceptions1 the animal creation   
seemed to have gone to  sleep1 an       
example which it was somewhat difficult 
to avoid following4  ,while thus idly   
engaged1 my eye rested on a large       
boulder on the  opposite side4 ,it lay  
partly imbedded in a stiff clay1 and    
partly  protruding from the surface of  
the bank some way above the stream4  ,a 
thick arbour of leafage overhung it1    
through which not even the  faintest ray
 of sunshine could force its way4 ,the  
spot seemed cooler  and more picturesque
 than that which ,i occupied1 and so1   
crossing the  well-nigh empty channel1  
,i climbed the bank and was soon seated 
on the  boulder4 ,a stout hammer is a   
constant companion in my rambles1 and   
was  soon employed on this occasion in  
chipping almost unconsciously the       
newly-acquired seat4 ,the action was1   
perhaps1 deserving of the satire  of    
,wordsworth's ,solitary3--              
,you may trace him oft      ,by scars1  

which his activity has left      ,beside
 our roads and pathways1 though1 thank  
,heaven6      ,this covert nook reports 
not of his hand4      ,he1 who with     
pocket-hammer smites the edge      ,of  
luckless rock or prominent stone1       
disguised      ,in weather-stains1 or   
crusted o'er by ,nature      ,with her  
first growths1 detaching by the stroke  
,a chip or splinter to resolve his      
doubts2      ,and1 with that ready      
answer satisfied1      ,the substance   
classes by some barbarous name1         
,and hurries on2 or from the fragments  
picks      ,his specimen2 if but imply  
interveined      ,with sparkling        
mineral1 or should crystal cube         
,lurk in its cells and thinks himself   
enriched4      ,wealthier1 and doubtless
 wiser1 than before6    ,there was      
nothing in the distant aspect of the    
boulder to attract  attention4 ,it was  
just such a mass as dozens of others all
 round4 ,nor1  on closer inspection1    
might anything peculiar have been       

observed4 ,it  had an irregularly oblong
 form1 about two or three feet long1 and
 half  as high4 ,ferns and herbage were 
grouped around it1 the wood-sorrel      
clustered up its sides1 and little      
patches of moss and lichen nestled  in  
its crevices4 ,and yet1 withal1 there   
was something about it that1  ere long1 
riveted my attention4 ,i examined it    
minutely from one end to  the other1 and
 from top to bottom4 ,the more ,i looked
 the more did ,i see  to interest me2   
and when1 after a little labour1 some   
portions of its  upper surface were     
detached1 my curiosity was abundantly   
gratified4  ,that grey lichened stone1  
half hid among foliage1 and unheeded by 
any  human being1 afforded me material  
for a pleasant forenoon's thought4      
,will my reader accept an expanded      
narrative of my reverie8    ,i can      
almost anticipate a smile4 ,what can    
there be remarkable in such  a grey     
stone1 hidden in a wood1 and of which   
nobody knows anything8  ,it never formed

 part of any ancient building2 it marks 
the site of  no event in the olden time2
 it is linked with nothing in the       
history  of our country4 ,what of       
interest1 then1 can it have for us8     
,nay1 ,i  reply1 you are therein        
mistaken4 ,it is1 assuredly1 linked with
 the  history of our country--it does   
mark the passing of many a historical   
event long ere human history began2 and1
 though no tool ever came upon  it1 it  
did once form part of a building that   
rose under the finger of  the ,almighty 
during the long ages of a bygone        
eternity4 ,to change the  figure1 this  
boulder seemed like a curious volume1   
regularly paged1  with a few extracts   
from older works4 ,bacon tells us that  
some books  are to be tasted1 others to 
be swallowed1 and some few to be chewed 
and  digested4 ,of the last honour ,i   
think the boulder fully worthy1 and if  
the reader will accompany me1 ,i shall  
endeavour to show him how the  process  
was attempted by me4    ,the rock       

consisted of a hard grey sandstone      
finely laminated above1  and getting    
pebbly and conglomeritic below4 ,the    
included pebbles were  well worn1 and   
belonged to various kinds of rock4 ,the 
upper part of  the block was all        
rounded1 smoothed1 and deeply grooved1  
and1 when  split open1 displayed        
numerous stems and leaflets of plants   
converted  into a black coaly substance4
 ,these plants were easily recognisable 
as well-known organisms of the          
carboniferous strata1 and it became     
accordingly evident that the boulder was
 a block of carboniferous  sandstone4   
,the pebbles below1 however1 must have  
been derived from  more ancient rocks1  
and they were thus seen to represent    
some older  geological formation4 ,in   
this grey rock1 therefore1 there could  
at  once be detected well-marked traces 
of at least two widely-separated  ages4 
,the evidence for each was indubitable1 
and the chronology of  the whole mass   
could not be mistaken4 ,the surface     

striation bore  undoubted evidence of   
the glacial period1 the embedded plants 
as  plainly indicated the far more      
ancient era of the coal-measures1 while 
the pebbles of the base pointed1 though 
dimly1 to some still more  primeval age4
 ,i had here1 as it were1 a quaint1 old1
 black-letter  volume of the middle     
ages1 giving an account of events that  
were  taking place at the time it was   
written1 and containing on its earlier  
pages numerous quotations from authors  
of antiquity4 ,the scratched  surface1  
to complete the simile1 may be compared 
to this old work  done up in a modern   
binding4 ,let us1 then1 first of all1   
look for a  little at the exterior of   
the volume1 and inquire into the origin 
of  that strangely-striated surface1 and
 of the clay in which the boulder       
rested4          ,,chapter ,,ii4        
,exterior of the boulder--,travelled    
stones a difficult problem--,once       
referred to the ,deluge--,other         
theories--,novelty of the true          

solution--,icebergs formed in three     
ways--,progress and scenery         of  
an iceberg--,its effects--,size of      
icebergs--,boulder-clay         had a   
glacial origin--,this explanation       
confirmed by fossil                     
shells--,laws of the distribution of    
life--,deductions4    ,has the reader1  
when wandering up the course of a       
stream1 rod in hand  perhaps1 ever      
paused at some huge rounded block of    
gneiss or granite  damming up the       
channel1 and puzzled himself for a      
moment to conjecture  how it could get  
there8 ,or when rolling along in a      
railway carriage1  through some deep    
cutting of sand1 clay1 and gravel1 did  
the question  ever obtrude itself how   
such masses of water-worn material came 
into  existence8 ,did he ever wonder at 
the odd position of some huge grey      
boulder1 far away among the hills1      
arrested as it were on the steep  slope 
of a deep glen1 or perched on the edge  
of a precipitous cliff1 as  though a    

push with the hand would hurl it down   
into the ravine below8  ,or did he ever 
watch the operations of the quarryman1  
and mark1 as each  spadeful of soil was 
removed1 how the surface of the rock    
below was all  smoothed1 and striated1  
and grooved8    ,these questions1       
seemingly simple enough1 involve what   
was wont to  be one of the greatest     
problems of geology1 and not many years 
have  elapsed since it was solved4 ,the 
whole surface of the country was        
observed to be thickly covered with a   
series of clays1 gravels1 and  sands1   
often abounding in rounded masses of    
rock of all sizes up to  several yards  
in diameter4 ,these deposits were seen  
to cover all  the harder rocks1 and to  
occur in a very irregular manner1       
sometimes  heaped up into great mounds1 
and sometimes entirely wanting4 ,they   
were  evidently the results of no agency
 visible now1 either on the land  or    
around our coasts4 ,they had an         
appearance rather of tumultuous  and    

violent action1 and so it was wisely    
concluded that they must be  traces of  
the great deluge4 ,the decision had at  
least this much in its  favour1 it was  
thoroughly orthodox1 and accordingly    
received marked  approbation1 more      
especially from those who wished well to
 the young  science of geology1 but were
 not altogether sure of its tendencies4 
,but1 alas6 this promising symptom very 
soon vanished4 ,as observers            
multiplied1 and investigations were     
carried on in different countries1  the 
truth came out that these clays and     
gravels were peculiarly a  northern     
formation2 that they did not appear to  
exist in the south of  ,france1 ,italy1 
,asia ,minor1 ,syria1 and the contiguous
 countries4 ,if1  then1 they originated 
from the rushing of the diluvian waters1
 these  southern lands must have escaped
 the catastrophe1 and the site of the   
plains of ,eden would have to be sought 
somewhere between the ,alps  and the    
,north ,pole4 ,this1 of course1 shocked 

all previous ideas of  topography2 it   
was accordingly agreed1 at least among  
more thoughtful  men1 that with these   
clays and sands the deluge could have   
had nothing  to do4    ,other theories  
speedily sprang up1 endeavouring to     
account for the  phenomena by supposing 
great bodies of water rushing with      
terrific  force across whole continents1
 sweeping away the tops of hills1       
tearing up and dispersing entire        
geological formations1 and strewing  the
 ocean-bottom with scattered debris4    
,but this explanation had the           
disadvantage of being woefully          
unphilosophical and not very clearly    
orthodox4 ,such debacles did not appear 
to have ever taken place in  any        
previous geologic era1 and experience   
was against them4 ,besides1  they did   
not account for some of the most evident
 characteristics of  the phenomena1 such
 as the northern character of the       
formation1 the  long parallel striations
 of the rock surfaces1 and the perching 

of  huge boulders on lofty hills1 often 
hundreds of miles distant from the      
parent rock4 ,geologists were completely
 at fault1 and the boulder-clay         
remained a mystery for years4    ,when  
we consider the physical aspects of the 
countries where the  question was       
studied1 we cannot much wonder that the 
truth was so hard  to find4 ,in the     
midst of corn-fields and meadows1 one   
cannot readily  realize the fact that   
the spot where they stand has been the  
site of  a wide-spread sea2 and that    
where now villages and green lanes meet 
the eye1 there once swam the porpoise   
and the whale1 or monsters of  a still  
earlier creation1 unwieldy in bulk and  
uncouth in form4 ,such  changes1        
however1 must have been1 for their      
traces meet us on every  hand4 ,we have 
the sea dashing against our shores1 and 
there seems  nothing at all improbable  
in the assertion that once it dashed    
against  our hill-tops4 ,no one1        
therefore1 has any difficulty in giving 

such  statements his implicit belief4   
,but who could have dreamed that these  
fields1 so warm and sunny1 were once    
sealed in ice1 and sunk beneath  a sea  
that was cumbered with many a wandering 
iceberg8 ,who could have  imagined1 that
 down these glens1 now carpeted with    
heath and harebell1  the glacier worked 
its slow way amid the stillness of      
perpetual snow8  ,and yet strange as it 
may seem1 such is the true solution of  
the  problem4 ,the boulder-clay was     
formed during the slow submergence of   
our  country beneath an icy sea1 and the
 rock-surfaces owe their polished  and  
striated appearance to the grating      
across them of sand and stones  frozen  
into the bottom of vast icebergs1 that  
drifted drearily from the  north4 ,that 
we may the better see how these results 
have been effected1  let us glance for a
 little at the phenomena observable in  
northern  latitudes at the present day4 
,icebergs are formed in three principal 
ways3--#ast1 ,by glaciers  descending to

 the shore1 and being borne seawards by 
land-winds2 #b;d1  ,by river-ice packed 
during spring1 when the upper reaches of
 the rivers  begin to thaw2 #c;d1 ,by   
coast-ice4    ,i4 ,there is an upper    
stratum of the atmosphere characterized 
by intense  cold1 and called the region 
of perpetual snow4 ,it covers the earth 
like a great arch1 the two ends resting1
 one on the arctic1 the other  on the   
antarctic zone1 while the centre1 being 
about #af1jjj feet above  the sea1#b    
rises directly over the tropics4        
,wherever a mountain is  sufficiently   
lofty to pierce this upper stratum1 its 
summit is covered  with snow1 and1 as   
the snow never melts1 it is plain that1 
from the  accumulations of fresh        
snow-drifts1 the mountain-tops1 by      
gradually  increasing in height and     
width1 would become the supporting      
columns  of vast hills of ice1 which1   
breaking up at last from their weight   
and width1 would roll down the          
mountain-sides and cover vast areas  of 

country with a ruin and desolation more 
terrible than that of any  avalanche4   
,olympus would really be superposed upon
 ,ossa4 ,by a beautiful  arrangement    
this undue growth is prevented1 so that 
the hill-tops  never vary much in height
 above the sea4 ,the cone of ice and    
snow  which covers the higher part of   
the mountain1 sends down into each of   
the diverging valleys a long sluggish   
stream of ice1 with a motion so  slow as
 to be almost imperceptible4 ,these     
streams are called glaciers4  ,as they  
creep down the ravines and gorges1      
blocks of rock detached  by the frosts  
from the cliffs above1 fall on the      
surface of the ice1  and are slowly     
carried along with it4 ,the bottom also 
of the glaciers  is charged with sand1  
gravel1 and mud1 produced by the        
slow-crushing  movement2 large rocky    
masses become eventually worn down into 
fragments1 and the whole surface of the 
hard rock below is traversed  by long   
parallel grooves and stri in the        

direction of the glacier's  course4     
,among the ,alps1 the lowest point to   
which the glacier descends  is about    
#hejj feet4 ,there the temperature gets 
too high to allow of its  further       
progress1 and so it slowly melts away1  
choking up the valleys  with piles of   
rocky fragments called moraines1 and    
'giving rise to  numerous muddy streams 
that traverse the valleys1 uniting at   
length  into great rivers such as the   
,rhone1 which enters the ,lake of       
,geneva  turbid and discoloured with    
glacial mud4    ,footnote #b3 ,the      
average height of the snow-line within  
the tropics  is #ae1bjg feet1 but it    
varies according to the amount of land  
and sea  adjacent1 and other causes4    
,thus1 among the ,bolivian ,andes1 owing
 to  the extensive radiation1 and the   
ascending currents of air from the      
neighbouring plains and valleys1 the    
line stands at a level of #ah1jjj  feet1
 while1 on mountains near ,quito1 that  
is1 immediately on the  equatorial line1

 the lowest level is #ae1gie4--,see     
,mrs4 ,somerville's  ,physical          
,geography1 #dth edit4 p4 #cad4    ,in  
higher latitudes1 where the lower limit 
of the snow-line descends to  the level 
of the sea1 the glaciers are often seen 
protruding from the  shore1 still laden 
with blocks that have been carried down 
from valleys  far in the interior4 ,the 
action of storms and tides is sufficient
 to  detach large masses of the ice1    
which then floats off1 and is often     
wafted for hundreds of miles into       
temperate regions1 where it gradually   
melts away4 ,such floating islands are  
known as icebergs4    ,,ii4 ,in climates
 such as that of ,canada1 where the     
winters are very  severe1 the rivers    
become solidly frozen over1 and1 if the 
frost be  intense enough1 a cake of ice 
forms at the bottom4 ,in this way sand1 
mud1 and rocky fragments strewing the   
banks or the channel of the  stream1 are
 firmly enclosed4 ,when spring sets in1 
and the upper parts  of the rivers begin

 to thaw1 the swollen waters burst their
 wintry  integuments1 and the ice is    
then said to pack4 ,layer is pushed     
over layer1 and mass heaped upon mass1  
until great floes are formed4  ,these   
have often the most fantastic shapes1   
and are borne down by the  current1     
dropping1 as they go1 the mud and       
boulders1 with which they  are charged1 
until they are stranded along some coast
 line1 or melt  away in mid-ocean4      
,,iii4 ,but icebergs are also produced  
by the freezing of the water of  the    
ocean4 ,in high latitudes1 this takes   
place when the temperature  falls to    
#bhe of ,fahrenheit4 ,the surface of the
 sea then parts with its  saline        
ingredients1 and takes the form of a    
sheet of ice1 which1 by  the addition of
 successive layers1 augmented sometimes 
by snow-drifts1  often reaches a height 
of from thirty to forty feet4 ,on the   
approach of  summer these ice-fields    
break up1 crashing into fragments with a
 noise  like the thundering of cannon4  

,the disparted portions are then carried
  towards the equator by currents1 and  
may be encountered by hundreds  floating
 in open sea4 ,their first form is flat1
 but1 as they travel on1  they assume   
every variety of shape and size4    ,on 
the shores of brackish seas1 such as the
 ,baltic1 or along a coast  where the   
salt water is freshened by streams or   
snow-drifts from the  land1 sheets of   
ice also frequently form during severe  
frosts4 ,sand and  boulders are thus    
frozen in1 especially where a layer of  
ice has formed  upon the sea-bottom4#c  
,the action of gales or of tides is     
sufficient  to break up these masses1   
which are then either driven ashore and 
frozen in a fresh cake of ice1 or blown 
away to sea4 ,the bergs formed  in this 
way have originally a low flat outline1 
and many extend as  ice-fields over an  
area of many miles1 while1 at a later   
time1 they may  be seen towering        
precipitously as great hills1 some #bjj 
or #cjj feet  high4    ,footnote #c3 ,i 

was informed by the late ,mr4 ,hugh     
,miller1 that a seam  of shale abounding
 in liassic fossils1 had been found     
intercalated  among the boulder-clay    
beds in the vicinity of ,eathie4 ,he    
explained its  occurrence there by      
supposing that it had formed a reef     
along a shore  where ground-ice was     
forming2 and so having been firmly      
frozen in1 it  was torn up on the       
breaking of the ice1 and deposited at a 
distance  among the mud at the          
sea-bottom4    ,few sights in nature are
 more imposing than that of the huge1   
solitary iceberg1 as1 regardless alike  
of wind and tide1 it steers  its course 
across the face of the deep far away    
from land4 ,like one  of the            
,hrim-thursar1 or ,frost-giants of      
,scandinavian mythology1#d  it issues   
from the portals of the north armed with
 great blocks of  stone4 ,proudly it    
sails on4 ,the waves that dash in foam  
against its  sides shake not the        
strength of its crystal walls1 nor      

tarnish the  sheen of its emerald caves4
 ,sleet and snow1 storm and tempest1 are
 its  congenial elements4 ,night falls  
around1 and the stars are reflected     
tremulously from a thousand peaks1 and  
from the green depths of  caverns       
measureless to man4 ,dawn again arises1 
and the slant rays of  the rising sun   
gleam brightly on every projecting crag 
and pinnacle1  as the berg still floats 
steadily on2 yet1 as it gains more      
southern  latitudes1 what could not be  
accomplished by the united fury of the  
waves1 is slowly effected by the        
mildness of the climate4 ,the floating  
island becomes gradually shrouded in    
mist and spume1 streamlets  everywhere  
trickle down its sides1 and great crags 
ever and anon fall  with a sullen plunge
 into the deep4 ,the mass becoming      
top-heavy1  reels over1 exposing to     
light rocky fragments still firmly      
imbedded4  ,these1 as the ice around    
them gives way1 are dropped one by one  
into  the ocean1 until at last the      

iceberg itself melts away1 the mists are
  dispelled1 and sunshine once more     
rests upon the dimpled face of the      
deep4#e ,if1 however1 before this final 
dissipation1 the wandering  island      
should be stranded on some coast1       
desolation and gloom are  spread over   
the country for leagues4 ,the sun is    
obscured1 and the air  chilled2 the     
crops will not ripen2 and1 to avoid the 
horrors of famine1  the inhabitants are 
fain to seek some more genial locality  
until the  ice shall have melted away2  
and months may elapse before they can   
return again to their villages4         
,footnote #d3 ,the account of the origin
 of these giants1 as given in  the prose
 ,edda1 is very graphic1 and may be not 
inaptly quoted  here3--,when the rivers 
that are called ,elivagar had flowed far
 from  their sources1 replied ,har1 the 
venom which they rolled along2          
hardened1 as does dross that runs from a
 furnace1 and became ice4  ,when the    
rivers flowed no longer1 and the ice    

stood still1 the vapour  arising from   
the venom gathered over it and froze to 
rime2 and in this  manner were formed in
 ,ginnungagap many layers of congealed  
vapour1  piled one over the             
other4--,that part of ,ginnungagap1     
added ,jafnhar1  that lies towards the  
north1 was thus filled with heavy masses
 of  gelid vapour and ice1 whilst       
everywhere within were whirlwinds and   
fleeting mists4 ,but the southern part  
of ,ginnungagap was lighted by  the     
sparks and flakes that flew into it from
 ,muspellheim4444 ,when the  heated     
blast met the gelid vapour1 it melted   
into drops1 and1 by the  might of him   
who sent the heat1 these drops quickened
 into life1 and  took a human semblance4
 ,the being thus formed was named ,ymir1
 from whom  descend the race of the     
,frost-giants 7,hrim-thursar71 as it is 
said in  the ,vlusp1 ',from ,vidolph    
came all witches2 from ,vilmeith all    
wizards2  from ,svarthfdi all           
poison-seekers2 and all giants from     

,ymir4'--,see  ,mallet's ,northern      
,antiquities1 edit4 ,bohn1 p4 #djb4     
,footnote #e3 ,that beautiful expression
 of schylus occurs to me1 so  impossible
 adequately to clothe in ,english3   4  
,who that has spent a calm summer day   
upon the sea1 has not realized its      
force and delicate beauty8    ,the      
iceberg melts away1 but not without     
leaving well-marked traces of  its      
existence4 ,if it disappear in          
mid-ocean1 the mud and boulders1 with   
which it was charged1 are scattered     
athwart the sea-bottom4 ,blocks  of     
stone may thus be carried across        
profound abysses1 and deposited         
hundreds of miles from the parent hill2 
and it should be noticed1 that  this is 
the only way1 so far as we know1 in     
which such a thing could  be effected4  
,great currents could sweep masses of   
rock down into deep  gulfs1 but could   
not sweep them up again1 far less repeat
 this process  for hundreds of miles4   
,such blocks could only be transported  

by being  lifted up at the one place and
 set down at the other2 and the only    
agent we know of1 capable of carrying   
such a freight1 is the iceberg4  ,in    
this way1 the bed of the sea in northern
 latitudes must be covered  with a thick
 stratum of mud and sand1 plentifully   
interspersed with  boulders of all      
sizes1 and its valleys must gradually be
 filled up as  year by year the deposit 
goes on4    ,but this is not all4 ,the  
visible portion of an iceberg is only   
about  one-ninth part of the real bulk  
of the whole mass1 so that if one be    
seen #ajj feet high1 its lowest peak may
 perhaps be away down #hjj feet  below  
the waves4 ,now it is easy to see that  
such a moving island will  often grate  
across the summit and along the sides of
 submarine hills2  and when the lower   
part of the berg is roughened over with 
earth and  stones1 the surface of the   
rock over which it passes will be torn  
up  and dispersed1 or smoothed and      
striated1 while the boulders imbedded in

  the ice will be striated in turn4     
,but some icebergs have been seen rising
 #cjj feet over the sea2 and  these1 if 
their submarine portions sank to the    
maximum depth1  must have reached the   
enormous total height of #bgjj          
feet--that is1  rather higher than the  
,cheviot ,hills4#f ,by such a mass1 any 
rock or  mountain-top existing #bdjj    
feet below the surface of the ocean     
would be  polished and grooved1 and     
succeeding bergs depositing mud and     
boulders  upon it1 this smoothed surface
 might be covered up and suffer no      
change  until the ocean-bed should be   
slowly upheaved to the light of day4    
,in this way1 submarine rock surfaces at
 all depths1 from the coast  line down  
to #bjjj or #cjjj feet1 may be scratched
 and polished1 and  eventually entombed 
in mud4    ,footnote #f3 ,in the        
,american ,journal of ,science for      
#ahdc1 p4  #aee1 mention is made of an  
iceberg aground on the ,great ,bank of  
,newfoundland4 ,the average depth of the

 water was about #ejj feet1 and  the    
visible portion of the berg from #ej to 
#gj feet high1 so that its  total height
 must have been little short of #fjj    
feet1 of which only a  tenth part       
remained above water4    ,illustration3 
,fig4 #a4 ,iceberg grating along the    
sea-bottom and  depositing mud and      
boulders4    ,and such has been the     
origin of the deep clay1 which1 with its
 included  and accompanying boulders1   
covers so large a part of our country4  
,when  this arctic condition of things  
began1 the land must have been slowly   
sinking beneath the sea2 and so1 as     
years rolled past1 higher and yet       
higher zones of land were brought down  
to the sea-level1 where floating  ice1  
coming from the north-west1 stranded    
upon the rocks1 and scored  them all    
over as it grated along4 ,this period of
 submergence may have  continued until  
even the highest peak of the ,grampians 
disappeared1  and1 after suffering from 
the grinding action of ice-freighted    

rocks1  eventually lay buried in mud far
 down beneath a wide expanse of sea1    
over which there voyaged whole argosies 
of bergs4 ,when the process of          
elevation began1 the action of waves and
 currents would tend greatly to  modify 
the surface of the glacial deposit of   
mud and boulders1 as the  ocean-bed     
slowly rose to the level of the coast   
line4 ,in some places  the muddy        
envelope was removed1 and the subjacent 
rock laid bare1  all polished and       
grooved4 ,in other localities1 currents 
brought in a  continual supply of sand1 
or washed off the boulder mud and sand1 
and  then re-deposited them in irregular
 beds2 hence resulted those local       
deposits of stratified sand and gravel  
so frequently to be seen resting  over  
the boulder clay4 ,at length1 by        
degrees1 the land emerged from the  sea1
 yet glaciers still capped its hills and
 choked its valleys2 but  eventually a  
warmer and more genial climate arose1   
plants and animals1  such as those at   

present amongst us1 and some1 such as   
the wolf1 no  longer extant1 were ere   
long introduced2 and eventually1 as lord
 of the  whole1 man took his place upon 
the scene4#g    ,footnote #g3 ,the      
reader who wishes to enter more fully   
into the  geological effects of         
icebergs1 should consult the suggestive 
section  on that subject in ,de la      
,beche's ,geological ,observer2 also the
  ,principles and ,visit to the ,united 
,stales of ,sir ,charles ,lyell1  with  
the various authorities referred to by  
these writers4    ,it is pleasant to    
mark1 when once the true solution of a  
difficulty is  obtained1 how all the    
discordant elements fall one by one into
 order1  and how every new fact elicited
 tends to corroborate the conclusion4   
,in  some parts of the glacial beds1    
there occur regular deposits of shells  
which must have lived and died in the   
places where we find them4 ,from  ten to
 fifteen per cent1 of them belong to    
species which are extinct1  that is to  

say1 have not been detected living in   
any sea4 ,some of them  are still       
inhabitants of the waters around our    
coasts1 but the large  majority occur in
 the northern seas4 ,they are           
emphatically northern  shells1 and get  
smaller in size and fewer in number as  
they proceed  southward1 till they      
disappear altogether4 ,in like manner1  
the palm1  on the other hand1 is        
characteristically a tropical plant4 ,it
 attains  its fullest development in    
intertropical countries1 getting stunted
  in its progress towards either pole1  
and ceasing to grow in the open  air    
beyond the thirty-eighth parallel of    
latitude in the southern  hemisphere1   
and the forty-fifth in the northern4    
,so1 too1 the ivy1  which in our country
 hangs out its glossy festoons in every 
woodland1  and around the crumbling     
walls of abbey1 and castle1 and tower1  
is  nursed in the drawing-rooms of ,st4 
,petersburg as a delicate and  favourite
 exotic4 ,in short1 the laws which      

regulate the habitat of a  plant or an  
animal are about as constant as those   
which determine its  form4 ,there are1  
indeed1 exceptions to both4 ,we may     
sometimes find a  stray vulture from the
 shores of the ,mediterranean gorging   
itself on  sheep or lambs among the     
wolds of ,england1#h just as we often   
see                ,a double cherry     
seeming parted1      ,but yet an union  
in partition2    or as we hear of a     
sheep with five legs1 and a kid with two
 heads4  ,but these exceptions1 from    
their comparative rarity1 only make the 
laws more evident4 ,when1 therefore1 we 
find1 in various parts of our  country1 
beds of shells in such a state of       
preservation as to lead  us to believe  
that the animals must have lived and    
died where their  remains are now to be 
seen1 we justly infer that the districts
 where  they occur must at one period   
have been submerged4 ,if the shells     
belong to fresh-water species1 it is    
plain that they occur on the site  of an

 old lake4 ,if they are marine1 we      
conclude that the localities  where they
 are found no matter how high above the 
sea must formerly  have stood greatly   
lower1 so as to form the ocean bed4 ,to 
proceed one  step further4 ,if the      
shells are of a southern type1 that is1 
if they  belong to species#i which are  
known to exist only in wanner seas than 
our own1 we pronounce that at a former  
period the latitudes of ,great  ,britain
 must have enjoyed a more temperate and 
genial climate1 so as  to allow southern
 shells to have a wider range           
northwards4 ,if1 on the  other hand1    
they are of an arctic or boreal type1 we
 in the same way  infer that our        
latitudes were once marked by a severer 
temperature than  they now possess1 so  
as to permit northern shells to range   
farther  southwards4 ,this reasoning is 
strictly correct1 and the truth involved
  forms the basis of all inquiries into 
the former condition of the earth  and  
its inhabitants4    ,footnote #h3 ,two  

of these birds 7,neopron pecnopterus7   
are stated to  have been seen near      
,kilve1 in ,somersetshire1 in ,october  
#ahbe4 ,one was  shot1 the other        
escaped4    ,footnote #i3 ,there is not 
a little difficulty in reasoning        
satisfactorily as to climatal           
conditions1 from the distribution of    
kindred forms4 ,even in a single genus  
there may be a wide range of            
geographical distribution1 so that mere 
generic identity is not always  a safe  
guide4 ,thus1 the elephant now          
flourishes in tropical countries1  but  
in the glacial period a long-haired     
species was abundant in the  frozen     
north4 ,i have above restricted myself  
entirely to species  whose habits and   
geographical distribution are already   
sufficiently  known4    ,the evidence   
furnished by the northern shells in the 
boulder-clay  series is1 accordingly1 of
 the most unmistakable kind4 ,these     
organisms  tell us that at the time they
 lived our country lay sunk beneath a   

sea1  such as that of ,iceland and the  
,north ,cape1 over which many an iceberg
  must have journeyed1 and thus they    
corroborate our conclusions1 derived    
independently from the deep clay and    
boulder beds and the striated           
rock-surfaces1 as to the glacial origin 
of the boulder-clay4          ,,chapter 
,,iii4        ,how the boulder came to  
be one ,crag and tail--,scenery of      
central ,scotland3 ,edinburgh--,crag and
 tail formerly         associated in its
 origin with the boulder-clay--,this    
explanation erroneous--,denudation an   
old process--,its                       
results--,illustration from1 the        
,mid-,lothian coal-field--,the          
three ,ross-shire hills--,the ,hebrides 
relics of an         ancient            
land--,scenery of the western           
coast--,effects of         the          
breakers--,denudation of the ,secondary 
strata of the                           
,hebrides--,preservative influence of   
trap-rocks--,lost         species of the

 ,hebrides--,illustration--,origin of   
the         general denudation of the   
country--,illustrative action         of
 streams--,denudation a very slow       
process--,many old         land-surfaces
 may have been effaced--,varied aspect  
of the         ,british ,islands during 
a period of submergence--,illustration4 
,the scratched and grooved surface of   
the boulder was produced when  it was   
fast frozen in some iceberg1 and driven 
gratingly across some  submarine summit1
 or stranded on some rocky coast-line4  
,but1 from its  rounded form1 the stone 
had evidently undergone a long process  
of wear  and tear previous to its       
glacial journey4 ,probably it had       
hitherto lain  along a surf-beaten      
beach1 where in the course of ages it   
had gradually  been worn into its       
present rounded shape4 ,but how came it 
there8 ,it  must originally have formed 
part of a flat sandstone bed1 with many 
other beds piled above it4 ,by what     
agency1 then1 was this great pile       

reduced to fragments8    ,the answer to 
these questions must be a somewhat      
lengthened one1 for  the subject relates
 not to a few beds of rock hastily      
broken up and  dispersed1 but to the    
physical changes of an entire country1  
carried on  during a vast succession of 
geological periods4    ,a phenomenon1   
known familiarly as crag and tail1 has  
long been  connected in its origin with 
the drift or boulder beds4 ,has my      
reader  ever travelled through central  
,scotland8 ,if so1 he must often have   
noticed the abrupt isolated form of many
 of the hills1 presenting a  mural front
 to the west1 and a long sloping        
declivity to the east4  ,from the great 
number of isolated hard trap-rocks in   
this region1 the  phenomenon is much    
better seen than in most other parts of 
the kingdom4  ,there is1 for instance1  
the castle rock of ,stirling1 with its  
beetling  crag and castellated summit1  
which present so imposing a front to the
  west4 ,many other examples are seen   

along the line of the ,edinburgh and    
,glasgow ,railway4 ,the range of hills  
south of ,linlithgow1 the singularly    
abrupt basalt of ,binny ,craig1 the long
 rounded ridge of ,ratho1  the          
double-peaked crag of ,dalmahoy1 the    
broad undulation of woody               
,corstorphine1 are all examples more or 
less marked4 ,edinburgh itself  is an   
excellent illustration4 ,the ,calton    
,hill shows a steep front to  the town1 
while its eastern side slopes away down 
to the sea4 ,arthur's  ,seat1 in like   
manner1 has a precipitous western face1 
and a gentle  declivity eastward4 ,the  
,castle rock1 too1 shoots up            
perpendicularly  from the valley that   
girdles it on the north1 west1 and      
south1 sinking  away to the east in a   
long slope--        ,whose ridgy back   
heaves to the sky1      ,piled deep and 
massy1 close and high4    ,east-,lothian
 presents several well-marked instances2
 in particular1  ,north ,berwick ,law   
and ,traprain4 ,a phenomenon so general 

must have had  some general origin1 and 
it was accordingly attributed to the    
same  agency which produced the         
drift-clays and the striated            
rock-surfaces1  when these were believed
 to be the results of great diluvial    
action4  ,it would seem1 however1 that  
the phenomenon of crag and tail should  
not be associated with the boulder-clay4
 ,the latter is undoubtedly a  newer    
,tertiary formation1#aj but the         
denudation#aa which produced  crag and  
tail must have been going on long ere   
the ,tertiary ages had  begun4 ,there is
 satisfactory evidence that large areas 
of our country  were planed down at a   
greatly more ancient period than that of
 even the  oldest of the ,tertiary      
series4 ,thus1 the whole area of the    
county of  ,sussex suffered a very      
extensive denudation during the later   
,secondary  ages4 ,the ,hebrides had    
undergone a similar process previous to 
the  deposition of the ,lias and        
,oolite1 and the ,greywacke hills of    

south  ,scotland1 previous to the       
formation of the ,old ,red ,sandstone4  
,there  seems thus to have been a       
general and continuous process of       
degradation  at work during a long      
succession of geological ages4          
,footnote #aj3 ,the reader is referred  
to the table of the geological          
formations at the end of the volume for 
the relative position of the  beds      
described4    ,footnote #aa3 ,denudation
 is a geological term used to denote the
  removal of rock by the wasting action 
of water1 whereby the underlying        
mineral masses are denuded or laid bare4
    ,the results of this long-continued 
action are of the most startling  kind4 
,i have referred to the phenomenon of   
crag and tail as perhaps the  most      
readily observable4 ,we must not fail to
 remember that the crag  which now      
stands up so prominently above the level
 of the surrounding  country1 at one    
period lay buried beneath an            
accumulation of sandstone1  shale1 or   

other strata1 all of which have been    
carried away1 so as  to leave the harder
 rock in bold relief1 with a portion of 
the less  coherent strata sloping as a  
long tail from its eastern side4 ,the   
crag1  too1 is often breached in many   
places1 worn down at one end1 rounded   
on the summit1 and sometimes well-nigh  
ground away altogether1 whilst  in front
 there is invariably a deep hollow      
scooped out by the current  when        
arrested by the abrupt cliff4 ,in ,fig4 
#b1 a represents a crag of  greenstone  
worn away and bared of the shales which 
once covered it2  b1 the sloping tail of
 softer strata1 protected from abrasion 
by  the resistance of the trap-rock1 and
 covered by a deep layer of drift1  d2 c
 marks the hollow on the west side of   
the crag4    ,illustration3 ,fig4 #b    
,crag and tail4    ,but when we come to 
measure the actual amount of material   
that has been  carried away1 we are lost
 in conjecture as to the vastness of the
 time  which such a process must have   

occupied4 ,for instance1 the            
coal-bearing  strata of ,mid-,lothian   
must at one period have been connected  
with those  of ,linlithgow and          
,stirling4 ,at a subsequent date1 the   
western area  subsided to form the      
,stirlingshire coal-basin1 and the      
eastern area1 in  like manner1 sank down
 to form the coal-basin of              
,mid-,lothian1 while the  intermediate  
portion stretched from east to west as a
 great arch1 or1  as it is termed       
geologically1 an anticlinal axis4 ,now1 
the whole of  this arch has been worn   
away1 not a vestige of it remains1 and  
yet its  upper or coal-bearing part was 
fully #cjjj feet thick4#ab    ,footnote 
#ab3 ,this remarkable example of        
denudation was first described  by ,mr4 
,m',laren1 in his ,sketch of the        
,geology of ,fife and the  ,lothians1 a 
work in which the author showed himself 
to be in advance  of the science of his 
time4    ,let us take a small portion of
 this district1 and endeavour to        

calculate the amount of matter thus     
removed4 ,the ,pentland hills  form a   
chain stretching from near ,edinburgh   
for some fourteen miles  southward1 and 
having an average breadth of about two  
miles and a  half4 ,they are formed     
chiefly of felspathic trap-rocks1       
resting upon  and interstratified with  
conglomerate apparently of ,old ,red    
age1 which  in turn lies upon vertical  
,silurian slates4 ,before the           
,carboniferous  strata were thrown down 
by successive faults1 they must have    
covered  these hills completely to a    
depth of not less than #fjjj feet4#ac   
,from this small area1 therefore1       
stratified sandstones1 shales1          
limestones1 and coal1 must have been    
removed to the enormous extent of  one  
billion1 eight hundred and fifty-four   
thousand1 four hundred and  sixty-four  
millions of cubic feet4    ,footnote    
#ac3 ,the actual depth of the           
,mid-,lothian coal-field1 to the  base  
of the carboniferous limestone1 is      

rather more than #cjjj feet4 ,it  is1   
perhaps1 rather under than over the     
truth to allow #cjjj feet for  the total
 thickness of beds from the limestone to
 the conglomerate of  ,liberton1 though1
 owing to the curved and contorted      
position of the  strata from ,edinburgh 
to ,stirlingshire1 it is impossible to  
obtain a  measurement of their real     
thickness4 ,i have attributed the       
isolation  of the ,falkirk and          
,mid-,lothian coal-fields to the effect 
of faults  and general depressions of   
their areas4 ,this was assuredly the    
case  in the latter coal-field1 and     
probably in the former also4 ,the trap  
which occurs between them1 though in    
great abundance1 has certainly  not     
acted as an elevating agent4 ,it occurs 
in beds among the strata1  and1 judging 
from the number of associated tufas1    
appears to have been  to a considerable 
extent erupted while the lower          
carboniferous series  was forming4 ,mr4 
,m',laren1 in his excellent work1 p4    

#ajj1 states his  opinion that the traps
 may have materially contributed to push
 up the  coal strata4 ,a careful and    
extended examination of the district has
  convinced me that this view is        
incorrect4    ,but1 perhaps1 the most   
striking instances of denudation in the 
,british  ,islands are the three famous 
,ross-shire hills--,suil ,veinn1 ,coul  
,mor1  and ,coul ,bheig4 ,they are      
formed of piles of sandstone beds like  
tiers  of regular masonry1 and reach a  
height of #cjjj feet over the sea4 ,the 
sandstone of which they are composed    
must once have formed a bed or  set of  
beds fully #bjjj feet thick1 that       
covered the whole district for  many    
miles around4 ,yet of this extensive    
deposit there now exist only  a few     
isolated fragments4 ,i have watched the 
sunshine and shadow of an  autumn sky   
resting alternately on these strange    
pyramidal hills1 as  they towered in    
their giant proportions like the last   
remnants of a  mighty rampart that had  

stood the brunt of a long siege1 and1   
breached  at last in many places1 had   
been all but levelled to the ground4    
,how  long-continued and how potent must
 that agency have been which could  cut 
down and disperse the massive barrier   
that flanked the western  coast of      
,ross-shire to a height of #bjjj feet6  
,the ,hebrides are but the shattered    
relics of an old land that had its      
mountain-peaks and its glens1 its       
streams and lakes1 and may have  nursed 
in its solitude the red-deer and the    
eagle1 but was never  trodden by the    
foot of man4 ,a glance at the map is    
enough to convince  us of this4 ,we     
there see islands1 and peninsulas1 and  
promontories1  and deep bays1 and       
long-retiring inlets1 as though the     
country had  been submerged and only its
 higher points remained above water4    
,the  conviction is impressed more      
strongly upon us by a visit to these    
shores4 ,we sail through the windings of
 one of the sounds1 and can  scarcely   

believe that we are on the bosom of the 
salt sea4 ,hills rise  on all sides1 and
 the water1 smooth as a polished mirror1
 shows so  pure and limpid that in the  
sunshine we can see the white pebbles   
that  strew its bed many fathoms down4  
,the eastern shore is often abruptly    
interrupted by long-receding lochs edged
 round with lofty mountains1  and thus1 
where we had looked to see a deep heathy
 glen1 with1  perchance1 a white        
tree-shaded mansion in the far distance1
 and a few  dun smoking cottages in     
front1 we are surprised to catch a      
glimpse of  the white sails of a yacht1 
or the darker canvas of the             
herring-boats4  ,we sail on1 and soon a 
sudden turn brings us abruptly to the   
mouth of  the sound4 ,a bold headland1  
studded around with rocky islets1 rises 
perpendicularly from the sea1 bleak and 
bare1 without a bush or tree1  or the   
faintest trace of the proximity of man4 
,the broad swell of the  ,atlantic comes
 rolling in among these rocks1 and      

breaks in foam against  the grey cliffs 
overhead4 ,in tempests1 such a scene    
must be of the most  terrific kind4 ,wo 
to the hapless vessel that is sucked    
into the vortex  of these breakers1     
whose roar is sometimes heard at the    
distance of  miles6 ,even in the calmest
 weather the white surf comes surging   
in1  and a low sullen boom is ever      
reverberating along the shore4 ,we see  
the harder rocks protruding far into the
 sea1 and often pierced with  long      
twilight caves1 while the softer ones   
are worn into deep clefts1  or hollowed 
out into open bays strewed over with    
shingle4 ,the sunken  rocks and islets1 
scarcely showing their tops above water1
 were all  evidently at one time        
connected1 for1 as we recede from the   
shore1 we  can mark how the process of  
demolition goes on4 ,there is first the 
projecting ness or promontory1 well-nigh
 severed from the mainland1 but  still  
connected by a rude arch1 through which 
the swell ever gurgles  to and fro4     

,then1 a little farther from the shore1 
a huge isolated  crag1 washed on all    
sides by the surge1 raises its grey     
lichen-clothed  summit4 ,a short way    
beyond1 there is the well-worn islet    
whose surface  shelters neither lichen  
nor sea-weed1 but is ever wet with the  
dash of  the waves4 ,further to the sea1
 the white gleam of the breakers marks  
the site of the sunken rock4 ,thus1 in  
the space of a hundred yards1 we  may   
sometimes behold the progress of change 
from land to sea1 and see  before us a  
specimen of that action which slowly but
 yet steadily has  narrowed and breached
 the outline of our western shores4#ad  
,footnote #ad3 ,i have endeavoured to   
illustrate the process of  denudation by
 a reference to breaker-action on the   
existing coast-line  of the ,hebrides2  
but a strong current must have          
materially increased  the force of the  
ancient waves1 and produced abrasion to 
some depth  below them4    ,if we       
attempt to trace the connexions of      

strata among the ,hebrides1  we shall be
 more fully impressed with the magnitude
 of the changes  which have been        
effected4 ,thus the ,lias and ,oolite   
occur in patches  along the shores of   
,mull1 ,morven1 ,ardnamurchan1 ,eigg1   
,skye1 ,raasay1  and ,applecross4 ,but  
though now only in patches1 these       
formations must  once have extended over
 a considerable area1 for they seem to  
form the  under-rock of the whole of the
 northern part of ,skye1 and are seen in
  almost every lone island from         
,ardnamurchan ,point to the ,shiant     
,isles4  ,these scattered portions1     
often many miles distant from each      
other1  are the remnants of a great     
sheet of liassic and oolitic strata1 now
  almost entirely swept away1 and are   
extant from having been covered  over   
with hard trap-rocks4 ,but for these it 
may be doubted whether we  should ever  
have known that corals once gleamed     
white along the shores  of ,skye1 that  
the many-chambered ammonite swam over   

the site of the  ,coolin ,hills1 that   
the huge reptilian monsters of these    
ancient times1  icthyosaurs and         
plesiosaurs1 careered through the waters
 that laved  the grey hills of ,sleat1  
and that forests of zamia and cycas1 and
 many  other plants indicative of a warm
 climate1 bloomed green and luxuriant   
along the site of that strange mist-clad
 cliff-line1 that shoots up  into the   
pinnacles of the ,storr and ,quiraing4  
,it is curious to reflect1  that the    
records of these peaceful scenes have   
been preserved to us by  the devastating
 eruptions of volcanic forces2 that the 
old lava-streams  which spread death    
through the waters along whose bed they 
travelled1  have yet been the means of  
protecting the districts which they     
wasted1  while those parts where they   
did not reach have been long since swept
  away4 ,it is allowable to believe1    
that in the portions of liassic  strata 
which have been destroyed there existed 
the remains of not a  few species1      

perhaps some genera1 to be found nowhere
 else1 and of  whose former existence   
there is now1 by consequence1 no trace4 
,in the  small island of ,pabba--a relic
 of the ,scottish ,lias--,i found       
thirty-one  species1 of which ,dr4      
,wright has pronounced four to be       
new4#ae ,a  subsequent visit to the     
adjacent island of ,raasay has increased
 the  list4 ,in short1 every patch of   
these ,secondary rocks1 if thoroughly   
explored1 might be found to yield its   
peculiar organisms4 ,and in the  far    
larger area that has been carried away  
there existed1 doubtless1  many more4   
,we are accustomed to see individuals   
perish and their  remains crumble away1 
but the species still holds on4 ,in the 
stratified  portion of the earth's      
crust1 however1 we mark how not merely  
individuals have perished1 but whole    
genera and species2 but of these  the   
remains are still before us in the      
rocks2 we can study their forms1  and1  
from a comparison with recent species   

and genera1 can arrive at  some idea of 
their nature and functions4 ,in this    
way1 we are able to  picture the various
 conditions of the earth when these     
organisms lived  in succession upon its 
surface4 ,yet1 we may readily           
conjecture1 that  in ancient eras many  
tribes and genera of plants and animals 
lived  for ages1 and then passed away   
without leaving any record of their     
existence4 ,many circumstances might    
concur to prevent the preservation  of  
their remains4 ,the species of the      
,hebrides were preserved in the  usual  
manner1 but the cemetery in which their 
remains were entombed has  been washed  
away1 and they can be seen nowhere else4
 ,it is as if on  some isolated country 
there had lived a race of men1 tall     
,patagonians1  or swarthy ,hottentots1  
or diminutive ,laplanders1 with a       
civilisation of  their own2 owing to    
some change of climate the race         
gradually dwindled  down until it died  
out2 eventually1 too1 the land settled  

down beneath  the sea with all its      
ruined cities and villages1 which1 as   
they reached  in succession the level of
 the waves1 were torn up and dispersed1 
and  other races at last voyaged over   
the site of that old land1 dreaming     
not1 that in bygone years fellow-mortals
 of an extinct type had  pastured their 
herds where now there rolled a          
widespread sea4    ,footnote #ae3       
,quart4 ,jour4 ,geol4 ,soc41 vol4 xiv4  
p4 #bf4    ,but to return4 ,we have seen
 that the long-continued action of the  
sea  has been sufficient to breach and  
waste away the existing coast-line  of  
western ,scotland4 ,when1 therefore1    
such results are produced by so         
ordinary a cause1 need we go to seek the
 agency of great debacles to  explain   
the denudation of other parts of the    
country8 ,it is known that  at great    
depths currents have little effect upon 
the rocks which they  traverse1 and that
 their action is greater as it nears the
 surface4 ,to  account for the phenomena

 of crag and tail1 and the general      
denudation  of the country1 we may      
suppose the land to have been often     
submerged  and re-elevated4 ,as hill    
after hill rose towards or sank below   
the  sea-level1 it would be assailed by 
a strong current that flowed  from the  
west and north-west1 until1 in its slow 
upward or downward  progress1 it got    
beyond the reach of the denuding        
agencies4 ,in this way  the general     
contour of the land would be greatly    
though very gradually  changed4 ,hills  
of sandstone1 or other material of      
feeble resistance1  would be swept away1
 the harder trap-rocks would stand up   
bared of the  strata which once covered 
them1 deep hollows would be excavated in
  front of all the more prominent       
eminences1 and long declivities would   
be left behind them4--7,see ,fig4 #b47  
,if my reader has ever visited the      
channel of a mountain-torrent--         
,imbres      ,quern super notas aluere  
ripas--    he must have noticed an exact

 counterpart to these appearances4 ,when
  the waters have subsided1 the         
overflowed parts are seen to be covered 
in many places with sand4 ,wherever a   
pebble occurs along the surface  of this
 sand1 it has invariably a hollow before
 it on the side facing  the direction   
whence the stream is flowing1 and a long
 tail of sand  pointing down the        
channel4 ,if we watch the motion of the 
water along  its bed1 the denuding      
agency may be seen actively at work4    
,every pebble  that protrudes above the 
shallow streamlet arrests the course of 
the  current1 which is then diverted in 
three directions4 ,one part turns  off  
to the right hand of the pebble1 and    
cuts away the sand from its  flank2     
another part strikes off to the left1   
and removes the sand from  that side2   
while a middle part descends in front of
 the pebble1 and1  by a kind of circular
 or gyratory movement1 scoops out a     
hollow in the  sand in front4 ,behind   
the pebble the water is pretty still1 so

 that the  sand remains undisturbed1 and
 is further increased by the            
accumulation  above it of sediment swept
 round by the lateral currents4 ,now1 in
 place  of the supposed stream1 let us  
substitute the ocean with its westerly  
current--for the pebble1 a great        
trap-hill--for the sand1 easily  friable
 shales and sandstones1 and we have     
exactly the condition of  things which  
produced crag and tail4    ,this process
 of destruction must have been in       
progress during many  geological ages4  
,we may suppose1 that in that time the  
land often  changed level1 sometimes    
rising far above the sea1 and sometimes 
sinking deep below it4 ,we can well     
believe that the surface would  often be
 covered with vegetation2 that plants1  
widely differing from  those which are  
now indigenous1 clothed its hill-sides  
and shaded  its valleys2 and that       
animals of long extinct forms roamed    
over its  plains or prowled amid its    
forests4 ,when the country1 in the lapse

 of  centuries1 sank beneath the        
sea-level1 all trace of these scenes    
would  eventually be effaced4 ,the      
westerly currents would soon recommence 
the  process of degradation1 uprooting  
the forests1 devastating the plains1    
wearing down the hills1 and scooping out
 the valleys2 and so1 when the          
ocean-bed1 in the course of ages1 became
 again dry land1 it would arise  another
 and yet the same4 ,the little valley1  
where once1 perchance1  the mastodon    
used to rest his massive bulk amid a    
rich growth of ferns1  shaded by the    
thick umbrage of coniferous trees1 would
 emerge a deep  glen with bare and      
barren rocks on either side2 the site of
 the hill  whereon herds of the         
gazelle-like anoplothere were wont to   
browse1  might reappear a level plain2  
the low-browed rock1 under whose shadow 
the ungraceful palothere used of old to 
rest from the heat of the  noon-tide    
sun1 might emerge a beetling crag       
shooting up several hundred  feet over  

the valley4 ,it is by this repeated     
elevation and submergence1  carried on  
for many ages1 that our country has     
acquired its present  configuration4    
,we can easily picture to ourselves the 
appearance which the ,british  ,islands 
would thus at different periods present4
 ,at one time1 nearly  the whole of     
,england would be under water1 with1    
however1 a few islands  representing the
 higher peaks of ,cornwall2 others      
scattered over the  site of the ,west   
,riding of ,yorkshire2 and a hilly tract
 of land over  what is now ,wales4      
,scotland must have existed in a sorely 
mutilated  state4 ,a thick-set          
archipelago would represent the ,cheviot
 ,hills1 and  the country south of the  
,forth and the ,clyde2 north of which   
there  would intervene a broad strait1  
with a comparatively large area of      
undulating land beyond1 stretching      
across what is now the area of  the     
,grampian ,hills4 ,a narrow fiord would 
run along the site of the  ,caledonian  

,canal1 cutting the country into two    
parts1 and running  far into it on      
either side as deep lochs and bays4 ,i  
have had such a  condition of things    
vividly recalled when on the summit of a
 lofty hill  in early morning1 while the
 mists were still floating over the     
lower  grounds1 and only the higher     
hill-tops1 like so many islands1 rose   
above the sea of cloud4 ,it was not a   
little interesting to cast the eye      
athwart this changing scene1 and mark   
how each well-known peak and  eminence  
looked when deprived of its broad sweep 
of base4 ,what before  had always seemed
 an abrupt precipitous summit1 now took 
the form of a  lonely rock or deep-sea  
stack1 that might have served as a haunt
 for  the gull and the gannet4 ,the long
 swelling hill rose above the mist as  a
 low undulating island1 treeless and    
barren4 ,it was easy to think of  that  
wide expanse of mist as the veritable   
domain of ocean1 to picture  the time   
when these were veritable islands lashed

 by the surge1 and  to conjure up       
visions of ice-floes drifting through   
the narrows1 or  stranding on the rocks1
 amid a scene of wide-spread nakedness  
and  desolation4          ,,chapter     
,,iv4        ,interior of the boulder   
,wide intervals of                      
,geology--,illustration--,long interval 
between the         formation of the    
boulder as part of a sand-bed1          
and its striation by glacial            
action--,sketch of the                  
intervening ages--,the boulder a ,lower 
,carboniferous         rock--,cycles of 
the astronomer and the geologist        
contrasted--,illustration--,plants shown
 by the boulder once         grew green 
on land--,traces of that ancient        
land--,its seas1         shores1        
forests1 and lakes1 all productive of   
material         aids to our comfort and
 power--,plants of the ,carboniferous   
era--,ferns--,tree-ferns--,calamites--,a
sterophyllites--                        
,lepidodendron--,lepidostrobus--,stigmar

ia--,scene in a ruined                  
palace--,sigillaria--,conifer1          
,cycade--,antholites1 the oldest        
known flower--,grade of the             
,carboniferous flora--,its resemblance  
to that of ,new ,zealand4    ,i have    
likened the boulder to an old volume of 
the middle ages encased  in a modern    
binding4 ,we have looked a little into  
the mechanism and  history of the       
boards2 in other words1 we have gone    
over the history of  the scratched      
surface of the boulder1 of the clays and
 sands around it1  and of that still    
earlier cycle of denudation whereof the 
rock itself  is probably a relic4       
,before proceeding to open the volume   
itself1 it  will be well that we clearly
 mark the wide interval in time between 
the ages represented by the             
surface-striation and those indicated by
  the interior of the boulder4 ,when we 
proceed from the groovings on the       
outside to the plants within1 we pass1  
to be sure1 over scarcely an  inch of   

space1 but we make a leap over untold   
millenniums in point of  time4 ,it is as
 if we had laid our hands on a volume of
 history which  had by some misfortune  
found its way into the nursery4 ,the    
first page  that catches our eye relates
 the battle of the ,reform ,bill1 and1  
on  turning the previous leaf1 we find  
ourselves with ,boadicea and her        
woad-coloured soldiery4 ,now1 if one    
utterly ignorant of the chronology  of  
the country were to be told that the    
volume related solely to one  people1 he
 would at once see from the manners and 
customs delineated1  that the two pages 
referred to very different states of    
civilisation1  and consequently to      
widely-separated periods4 ,but he could 
give no  account of how long an interval
 might have elapsed between the time    
when ,london had its inhabitants        
massacred by ,boadicea1 and the time    
when another generation of them was     
excited by the tardiness of ,king       
,william iv4 ,he could form no          

conjecture as to what events might have 
happened in the meanwhile4 ,the interval
 might be a century or twenty           
centuries1 wherein the city might have  
been burnt down fifty times4  ,clearly1 
if he wished to make himself acquainted 
with the intervening  history1 he would 
have to betake himself to an unmutilated
 volume4    ,and just so is it with our 
boulder4 ,we can easily believe1 merely 
from  looking at it as it lies on its   
clayey bed1 that a long time must have  
elapsed between the time of its         
formation as part of a sandstone bed1   
and the period of its transportation and
 striation by an iceberg4 ,the  sand of 
which it is formed must have been washed
 down by currents1 and  other sediment  
would settle down over it4 ,it would    
take some time to  acquire its present  
hardness and solidity1 while1 in long   
subsequent  times1 after being broken up
 and well-rounded by breaker or current 
action1 it may have lain on some old    
coast-line for centuries before it  was 

finally frozen into an ice-floe1 and so 
freighted to a distance4  ,but the      
stone1 with all its stories of the olden
 time1 can tell us  nothing of this     
intervening period4 ,it leads us from a 
dreary frozen  sea at once into a land  
of tropical luxuriance1 and so1 if we   
desire to  know anything of the missing 
portion of the chronology1 we must seek 
it  elsewhere4    ,the ,boulder-clay is 
one of the latest of geologic           
periods4#af ,beyond  it we get into     
,tertiary times1 and learn from the     
caves of ,yorkshire  how elephants1     
hyenas1 rhinoceroses1 hippopotami1      
bears1 and wolves1  prowled over the    
rich valleys2 while1 from the quarries  
of the ,isle of  ,wight1 we see how at  
an earlier time herds of uncouth        
palotheres and  slimly-built            
anoplotheres browsed the plains of ,old 
,england4 ,beyond  the ,tertiary ages   
come those of the ,chalk1 with its ocean
 that swarmed  with sea-urchins1        
terebratul1 pectens1 sponges1 and many  

other forms4  ,then arises the era of   
the ,wealden1 with its bosky land       
haunted by the  unwieldy iguanodon2 the 
,oolite1 with its land rich in a        
coniferous  flora1 and tenanted by a    
race of small marsupial animals1 and its
 seas  abounding in corals1 encrinites  
of many a form1 cidares1 cuttle-fishes1 
and ammonites4 ,further back still1 come
 the times of the ,lias1 that  strange  
era in the history of our country1 when 
reptiles huger than  those of the ,nile 
swam the seas1 and sped on wings through
 the air4  ,then come the times of the  
,trias1 when a vegetation still further 
removed from existing types clothed the 
land1 and frogs large as oxen  waddled  
along the shores4 ,then the times of the
 ,permian1 with its deep  sea tenanted  
by a meagre list of corals and shells1  
and by a type of  fishes that was slowly
 passing away4 ,we arrive at last at the
 ,coal or  ,carboniferous period1 to the
 older ages of which our boulder        
belongs4    ,footnote #af3 ,for the     

names and succession of the rocks of    
which the  known part of the earth's    
crust is composed1 see the ,table at the
 end  of the volume4    ,these eras may 
have been some longer1 some shorter1 but
 each had a  duration which1 when tried 
by human standards1 must be regarded as 
immensely protracted4 ,the cycles of    
astronomy are very vast1 yet  ,i have   
often thought that the cycles of        
geology1 though probably  of much less  
duration1 impress us more forcibly with 
the antiquity  of our planet4 ,the      
astronomer tells us of light that has   
taken two  millions of years to reach   
our earth1 and of nebul that are        
millions  upon millions of miles        
distant1 but these numbers are so vast  
that  we cannot bring ourselves to      
realize them4 ,we know that there is a  
great difference between two millions   
and ten millions1 but we cannot  fully  
appreciate it1 and so the periods of the
 astronomer1 beyond a  certain point1   
cease adequately to impress us4 ,so long

 as they can be  easily contrasted with 
our own standards of comparison1 they   
have their  full force2 but after that1 
every additional million1 or ten        
millions1  or ten hundred millions1     
produces only a confused and bewildered 
sense  of immensity1 and the comparative
 amount of each addition fails to be    
realized4 ,will my reader forgive a     
homely illustration3--,some years  ago1 
,i stood at the pier-head of one of our 
smaller sea-port towns1 and  watched the
 sun as it sullenly sank behind the     
outline of the opposite  hills4 ,the    
breadth of the channel1 in the direction
 of sunset1 was  several miles1 but in  
the flush of evening one fancied he     
could almost  have thrown a stone       
across4 ,the water lay unruffled by a   
ripple1 and  reflected all the thousand 
varying tints that lighted up the sky4  
,the  harbour1 that had been a busy     
scene all evening1 began to grow less   
noisy1 as one by one the herring-boats  
pushed out to sea4 ,i found it  not a   

little interesting to mark1 as the boats
 gained the open firth1  how the        
opposite coast-line gradually seemed to 
recede4 ,the farther the  dark sails    
withdrew1 the more remote did the       
adjacent shores appear1  until1 as the  
last tinge of glory faded from the      
clouds1 and a cold  grey tint settled   
down over the landscape1 the hills lay  
deep in shade  and stretched away in the
 twilight as a dark and distant land    
from  whose valleys there rose troops of
 stars4 ,the coast-line1 as seen in     
early evening1 reminded me of the       
periods of the astronomer2 as seen in   
early night1 it reminded me of the      
periods of the geologist4 ,we fail to   
appreciate the real duration of         
astronomical cycles1 because they are   
presented to us each as one vast period4
 ,they are not subdivided into          
intervals1 and contain no succession of 
events1 by means of which1 as  by       
milestones1 we might estimate their     
extent2 and so their unvaried           

continuity tends to diminish the        
impression of their vastness1 just  as  
the firth1 without any islet or vessel  
on its surface1 seemed  greatly narrower
 than it really was4 ,for it is with    
time as it is with  space--the eye      
cannot abstractly estimate distance1 nor
 can the mind  estimate duration4 ,in   
either case1 the process must be        
conducted by a  comparison with known   
standards4 ,the geological periods      
exemplify the  same rule4 ,they may not 
be greater1 perhaps not so great1 as    
those  revealed by astronomy1 yet their 
vastness impresses us more1 because we  
can trace out their history1 and see how
 step by step they progressed4  ,thus1  
that the interval between the           
boulder-clay and the coal-measurer  was 
immense1 we learn from the records of   
many successive ages that  intervened1  
in the same way that one began to       
perceive the real breadth  of the firth1
 by resting his eye on the succession of
 intervening  herring-boats4 ,in the    

former case1 the mind has ever and anon 
a sure  footing on which to pause in    
gauging bygone eternity2 in the latter1 
the eye had likewise a succession of    
points on which to rest in  measuring   
distance4 ,or1 to return to a former    
illustration3 ,boadicea  lived eighteen 
hundred years ago1 but who does not feel
 that the last  nine hundred years look 
a great deal longer than the first8 ,the
 one  set has few marked incidents to   
fix the thoughts2 the other is replete  
with those of the most momentous kind4  
,in the one1 we have ,m meagre  list of 
conquerors and kings1 from ,julius ,csar
 down to ,athelstan2 in  the other1     
events crowd upon us from the waning of 
the ,saxon power down  through the      
rising glory of our country to the      
present plenitude of  its power and     
greatness4 ,the early centuries1 like   
the cycles of the  astronomer1 pass     
through our mind rather as one          
continuous period2 the  later centuries1
 like the cycles of the geologist1      

arrest our thoughts  by a succession of 
minor periods1 and hence the idea of    
duration is  more vividly suggested by  
the diversified events of the one       
series1  than by the comparatively      
unbroken continuity of the other4       
,let us now open the volume and try to  
decipher the strange legends  which it  
contains4 ,on removing some of the upper
 layers of the boulder1  ,i found1 as ,i
 have said1 well-preserved remains of   
several kinds of  plants4 ,one of them  
was ribbed longitudinally1 with         
transverse notches  every three or four 
inches1 us though a number of slender   
threads  had been stretched along a rod1
 and tied tightly to it at regular      
intervals4 ,another1 sorely mutilated1  
was pitted all over somewhat  after the 
fashion in which the confectioner       
punctures his biscuits4 ,a  third had a 
more regular pattern1 being prettily    
fretted with small  lozenge-shaped      
prominences that wound spirally round   
the stalk4 ,other  plants seemed to be  

present1 but in a very bad state of     
preservation4  ,they were all jumbled   
together and converted into a black     
coaly  substance1 in which no structure 
could be discerned4    ,these plants    
assuredly once grew green upon the land2
 but where now is  that land on which   
they flourished8 ,had it hills and      
valleys1 rivers  and lakes1 such as     
diversify our country8 ,was it tenanted 
by sentient  beings1 and1 if so1 what   
were their forms8 ,did insects hum their
 way  through the air1 and cattle browse
 on the plains1 and fish gambol in  the 
rivers8 ,was the land shaded with       
forests1 dark and rugged like  those of 
,norway1 or fragrant as the             
orange-groves of ,spain8 ,what1 in      
fine1 were its peculiar features1 and   
how far did its scenery resemble  that  
of any country of the present day8      
,that old land has not entirely         
disappeared4 ,traces of it are found    
pretty extensively in ,south ,wales1 in 
,staffordshire1 around ,newcastle1  and 

through central ,scotland4 ,strange as  
it may seem1 its forests  are still     
standing in many places4 ,the fishes    
that disported in its  lakes1 the       
insects that fluttered amid its woods1  
and the lizards that  crawled among its 
herbage1 are still in part preserved to 
us4 ,nay1  more2 we may sometimes see   
the sea-beaches of that ancient land    
pitted  with rain-drops1 and roughened  
with ripple-marks1 as freshly as if the 
shower had fallen and the tide had      
flowed only yesterday4 ,the peasants    
along the ,bay of ,naples gathered      
grapes from the flanks of ,vesuvius  for
 well-nigh seventeen centuries1 before  
it was ascertained that they  daily     
walked over the site of buried cities1  
with temples1 theatres1  and private    
houses still erect4 ,it was many more   
centuries ere the  people of ,great     
,britain discovered that not a few of   
their villages and  towns stood on the  
site of buried forests1 and lakes1 and  
seas4 ,we have  now1 however1 become    

aware of the fact1 and are making good  
use of it4  ,we dig into the earth and  
exhume these old forests to supply us   
with  light and fuel2 we quarry into the
 ripple-marked shores which fringed     
that old land1 and build our houses with
 the hardened sand2 we calcine  the     
ferruginous mud that gathered in its    
swampy hollows1 and extract  therefrom  
our most faithful ally both in peace and
 war--metallic iron2  we burn the       
delicate corals and shells and lily-like
 zoophytes which  lived in the sea of   
that far-distant era1 to enable us to   
smelt our  iron1 to build our houses1   
and manure our fields2 in short1 every  
year  we are discovering some new and   
valuable material in the productions  of
 that period1 or finding out some new   
use which can be made of the  substances
 already known4 ,a more than ordinary   
interest1 therefore1  attaches to the   
history of the land and sea which have  
furnished us  with so many aids to      
comfort as well as power2 and we shall  

find1 as we  go on1 that that history is
 a very curious one4    ,i shall        
describe some of the more common plants 
and animals of the  period1 that we may 
be able1 in some measure1 to look back  
through the  ages of the past1 and see  
how these plants would appear when they 
cast  their broad shadow over river and 
lake1 and how these animals would  have 
seemed to human eye in the twilight of  
the forest1 in the sluggish  flow of the
 river1 and in the stagnant waters of   
the lagoon4    ,the ,flora1 or          
vegetation of the ,carboniferous era1   
differed  widely from any that now      
exists4 ,with the exception of the      
highest  or exogenous class1 it         
possessed representatives of all the    
existing  classes of the botanic scale1 
but in very strange proportions4 ,the   
number of species of carboniferous      
plants already found in ,great  ,britain
 amounts to about three hundred1 amongst
 which the ferns are  especially        
abundant4 ,some of them seem to have    

been low-growing  plants1 like the      
bracken of our hillsides1 but others    
must have shot  up to the height of     
forest trees4 ,we can recognise a few   
coniferous  and cycadaceous plants1 a   
good many stems resembling the          
horse-tail  of our marshy grounds1 and  
some of large size akin to the creeping 
club-moss of our heaths2 but there are  
still many to which there exist  no     
living analogues4    ,when we examine   
the roof of a coal-pit1 or split open   
plates of shale  in a quarry of the     
coal-measures1 we are struck with the   
similarity  which the ferns in the stone
 bear to those among our woods and      
hills4  ,one of the most common1 and1 at
 the same time1 most elegant forms1  is 
the ,sphenopteris or wedge-leaved fern1 
of which a large list  of species is    
known4 ,one of them 7,s4 crenata7 had a 
strong stem1  from which there sprung   
straight tapering branches richly dight 
with  leaflets4 ,the leaflets--somewhat 
like minute oak-leaves--were ranged     

like those of our modern ferns1 along   
two sides of the stalk1 in  alternate   
order1 and tapered gently away to its   
outer extremity4 ,the  effect of the    
whole is singularly rich1 and one can   
well believe that a  garland of this    
ancient fern would have wreathed as     
gracefully around a  victor's brow as   
the parsley of ,nemea or the            
laurel-leaves of ,delphi4    ,another   
plant of the same genus 7,s4 affinis1   
,fig4 #c7 has leaflets  like the petals 
of the meadow-daisy1 arranged in        
clusters along its  slim diverging      
stalks4 ,from a collection and          
comparison of many  specimens1 the late 
lamented ,hugh ,miller was enabled to   
make a drawing  of this fern as it must 
have appeared when it waved green along 
the  old carboniferous hill-sides4 ,i   
enjoyed the privilege of going over     
these specimens with him1 and marked    
how1 under a master-hand1 piece  by     
piece fell into its proper place1 and   
yielded up its evidence4 ,his           

restoration1 which forms the            
frontispiece to his last work1 is a very
  beautiful one1 and it is as true as it
 is beautiful4    ,illustration3 ,fig4  
#c4 ,sphenopteris affinis4              
,illustration3 ,fig4 #d4 ,pecopteris4   
,illustration3 ,fig4 #e4 ,cyclopteris4  
,illustration3 ,fig4 #f4 ,neuropteris4  
,the ,pecopteris 7,fig4 #d1 ,p4         
heterophylla7 or comb-fern1 is so called
  from its stiff thick leaflets being in
 some species arranged along the  stalk 
like the teeth along the centre of a    
comb4 ,of all the plants  of the        
coal-measures this is the one that      
approaches most closely to  living      
nature4 ,it appears to be almost        
identical with the pteris1  of which one
 species is well known as the bracken of
 our hill-sides4  ,dr4 ,hooker figures  
together a frond of a ,new ,zealand     
species 7,p4  esculenta7 and a fossil   
frond from the ,newcastle pits4 ,they   
are  so similar as to be easily mistaken
 at first sight for drawings of  the    

same plant4#ag ,the ,neuropteris 7as ,n4
 gigantea1 ,fig4 #f7 or  nerve-leaved   
fern1 is remarkable for its             
strongly-defined venation4 ,it  is      
scarcely1 perhaps1 so elegant in its    
outline as the sphenopteris1  or some of
 the other ferns4 ,its leaflets are     
large and thick1 with an  oblong or     
rounded form1 and arranged either singly
 along the frond  stem1 or along        
secondary foot-stalks1 which diverge    
from the main stem4  ,of the latter     
kind1 some of the species have a good   
deal of resemblance  to our ,osmunda    
regalis or royal fern4 ,a species of the
 former class  7,n4 cordata7 might      
readily enough be mistaken for the young
 leaves  of the ,scolopendrium or       
hart's-tongue1 which hangs out its      
glossy  green amid the gloom of dank and
 dripping rocks4 ,there are1 besides1   
several other genera of ferns in the    
,carboniferous strata1 such as the      
,cyclopteris 7,c4 dilatata1 ,fig4 #e7 or
 round-leaved fern1 and the             

,odontopteris or tooth-fern4 ,most of   
these seem to have been lowly  plants1  
like the ferns of our own country4 ,but 
there was another class  to which no    
analogue can be shown in ,europe4 ,they 
rose high over their  humbler congeners 
as lofty trees1 and must be studied by a
 reference to  the existing tree-ferns  
of intertropical countries4    ,footnote
 #ag3 ,hooker1 ,mem4 ,geol4 ,surv4 vol4 
ii4 part ii4 p4 #djj4    ,illustration3 
,fig4 #g4 ,living ,tree-fern4           
,tree-ferns flourish in warm climates1  
and are met with in ,brazil1 the  ,east 
and ,west ,indies1 ,new ,zealand1 c4    
,they rise sometimes to the  height of  
fifty or sixty feet1 with a long        
tapering stem surmounted  by a dense    
crown of graceful fronds1 and might     
easily be mistaken at  a little distance
 for palms4 ,all the known species      
belong to the same  division            
7,polypodiace7 with the common          
polypodium of our road-sides4  ,in some 
genera1 as the alsophila of the ,east   

,indies1 the trunk is  ribbed by long   
creeping branches1 or rather rootlets1  
which descend to  the soil1 giving the  
tree somewhat of the appearance so often
 seen in  old woods1 where venerable    
fir-trees have been firmly encased by   
the  bearded stems of the ivy4 ,another 
genus1 the ,cyathea1 has its stem       
covered with oblong scars where leaves  
were attached1 and a circle of  rich    
outspread fronds surmounts its summit4  
,one of the coal-measure  tree-ferns    
seems to have resembled this recent     
type4 ,it is named  the ,caulopteris or 
stalk-fern1 and had a thick stem        
picturesquely  roughened by irregular   
oblong leaf-scars1 that wound spirally  
from its  base to its point4 ,no        
specimen has hitherto been found showing
 the  fronds in connexion with the stem1
 so that we are still ignorant of  the  
kind of foliage exhibited by this       
ancient tree4 ,there can be no  doubt1  
however1 that it was crowned with a     
large tuft of boughs that  cast their   

shadow over the sward below1 and we may1
 perhaps1 believe  that some of the     
numerous detached ferns found in the    
shales of the  coal-series1 once formed 
part of this lofty coronal4    ,an      
important section of the carboniferous  
plants is embraced under  the generic   
name of ,calamites4 ,they had smooth    
jointed stems1 like  reeds1 and         
terminated beneath in an obtuse curved  
point 7,fig4 #h71  from which there     
sprang broad leaflets or rather         
rootlets4 ,after many  years of research
 our knowledge of these plants is still 
very scanty4  ,some of them have        
exhibited a highly-organized internal   
structure1  from which it appears that  
they consisted--first1 of a soft central
  cellular pith2 second1 of a thick     
layer of woody tissue2 and third1 an    
external cylinder of strong bark1 ribbed
 longitudinally1 and furrowed           
transversely4 ,they have been ranked    
with the common horse-tail of our       
ponds1 but they would rather appear to  

belong to a higher family4 ,the  breadth
 of the stem is very various1 some      
specimens being a foot or  more in      
diameter1 others scarcely half an inch4 
,from the discoveries of  ,professor    
,williamson and ,mr4 ,binny of          
,manchester1 it seems not unlikely  that
 what we call calamites may be really   
the inner core of a plant not  yet      
named1 just as a set of fossils were    
long called sternbergi1  before they    
were discovered to be really the pith of
 coniferous trees4  ,with regard to the 
branches of the calamites1 ,brongniart's
 conjecture  may be true1 that they     
exist among the group of plants called  
asterophyllites4 ,it is not unlikely    
that many dissimilar plants have  been  
grouped together as calamites1 and1 on  
the other hand1 that plants  allied to  
the typical species have been thrown    
into separate genera4  ,for it requires 
but a slight acquaintance with the      
vegetable kingdom to  know how many     
forms analogous parts of the same plant 

may assume1 and  how impossible it would
 often be to guess the real relationship
 of such  varieties if they were not    
found growing together on one plant4    
,illustration3 ,fig4 #h4 ,terminal      
portion of a calamite stem4             
,illustration3 ,fig4 #i4ah    ,footnote 
#ah3 ,the fossil given in ,fig4 #i is   
named by ,lindley 7,foss4  ,flo4 t4 #ae1
 #af71 ,calamites nodosus4 ,he admits1  
however1 that it was  not found in      
actual contact with a calamite stem4 ,it
 has exactly the  contour of an         
asterophyllite1 and might1 perhaps1 be  
referred to that  genus4 ,it is inserted
 here that the reader may see the       
general form of  the asterophyllites1   
and the close relationship that subsists
 between  these plants and the          
calamites4    ,a remarkably graceful    
class of the coal-plants are known as   
asterophyllites4 ,they had slim fluted  
and jointed stalks1 apparently  of      
humble growth4 ,from each of the joints 
there sprang two thin  opposite branches

 with stellate clusters of leaflets     
arranged round  them at equal distances4
 ,if the reader will take a young       
rush-stalk1  and string along it a      
number of the flowers of the little     
star-wort1  keeping them a little       
distance apart1 he may form some idea of
 the  appearance of a single branch of  
the star-bearing asterophyllite4  ,some 
of the plants embraced under this genus 
are conjectured to have  been aquatic1  
spreading out their clusters of leaflets
 in the green  sluggish water of        
stagnant pools2 but many of them are    
evidently  related to the calamites1 and
 may possibly have formed part of these 
plants4    ,whoever has rambled much in 
a coal-country1 scrambling through      
briars  and brambles in old quarries1 or
 threading his way among the rocks  of  
river-courses1 must often have noticed1 
on the exposed surface of  sandstone    
blocks1 dark ribbon-like bands fretted  
over with little  diamond-shaped knobs4 
,they are so common in some districts1  

that you  can scarcely light upon a     
piece of sandstone which does not show  
one  or more4 ,they belong to a         
carboniferous plant known as            
lepidodendron  7,fig4 #aj7 or scaly     
tree1 from the peculiar style of        
ornamentation which  adorned its bark4  
,its structure and affinities have      
puzzled botanists  not a little4 ,a     
well-preserved specimen reminds one of  
the appearance  presented by a twig of  
the ,scotch fir1 when stripped of its   
green  spiky leaflets4 ,the scars thus  
left at the base of the leaflets are  of
 a wedge-like form1 and run spirally up 
the branch in a manner very  like those 
on the branches of lepidodendron2 and it
 was accordingly  supposed at one time  
that the latter plant belonged1 or at   
least was  allied1 to the conifers4 ,but
 the branches of lepidodendron possessed
 a  peculiarity that is shared in by    
none of our present coniferous trees4   
,they were what botanists call          
dichotomous1--that is1 they subdivided  

into two equal branches1 these again    
into other two1 and so on4 ,their       
internal texture1#ai too1 differed from 
that of any known conifer4  ,the only   
tribe of existing plants with which the 
lepidodendron seems  to bear comparison1
 are the ,lycopodiace1 or club-mosses1  
of which  we have several species in the
 moor-lands of our own country4 ,they   
are low trailing plants1 with moss-like 
scaly branches1 bearing at  their ends  
shaggy little tufts1 whence the popular 
name of the genus4  ,in warmer climates1
 they are both more numerous and attain 
a larger  size1 sometimes standing erect
 to about the height of an ordinary     
gooseberry-bush4 ,but though the        
lepidodendron appears to have been      
allied to these plants in structure1 it 
greatly differed from them in           
dimensions4 ,the club-mosses of the     
coal-measures shot up as goodly  trees1 
measuring fifty feet and upwards in     
height1 and sometimes  nearly five in   
diameter4 ,their general effect must    

have been eminently  picturesque4 ,a    
shaggy covering of green spiky leaflets 
bristled over  their multitudinous      
pendant boughs2 and where on the older  
stems these  leaflets had decayed and   
dropped off1 the outer bark was laid    
bare1  fretted over with rows of        
diamond-shaped or oval scars1 separated 
by waving lines of ridge or furrow1 that
 wound spirally round the  stem4 ,from  
not a few of the branches there sprang  
oblong hirsute  cones called            
lepidostrobi 7,fig4 #aa71 which bore the
 sporangia1 or  seed-cases4 ,these cones
 are of frequent occurrence in the      
shales of  the coal-measures1 and may be
 readily recognised4 ,they had a central
  axis round which the oblong sporangia 
were built1 the whole being  protected  
externally by a thick covering of       
pointed scales1 imbricated  like the    
cone of the ,scotch fir4 ,the leaflets  
of lepidodendron1 called  lepidophylla1 
were broader than those of the ,scotch  
fir1 and had a  stout mid-rib1 which    

must have given them a rigidity like    
that of the  araucarian pine a plant    
they may also have resembled in the dark
 glossy  green of its leaves4           
,footnote #ai3 ,see ,hooker1 ,mem4      
,geol4 ,surv4 vol4 ii4 part ii4 p4 #dcf4
    ,illustration3 ,fig #aj4            
,lepidodendron ,sternbergii4            
,illustration3 ,fig4 #aa4               
,lepidostrobus4    ,of all the common   
coal-measure plants1 there is perhaps   
none so  abundant as that known by the  
name of stigmaria1 or punctured-stem4   
,it is found spreading out its rootlets 
for several yards in beds of  shale and 
under-clay1 and sometimes even          
limestone1#bj while1 in  many           
sandstones1 fragments of its blackened  
stems lie as thickly  strewn as twigs   
among the woods in autumn4 ,i have said 
that several  of the plants above       
described have greatly puzzled          
botanists4 ,none  of them1 perhaps1 has 
given rise to so much conjecture and    
variety  of opinion as the stigmaria4   

,the history of the discussion regarding
  its nature and affinities1 would be   
not a little interesting as an          
illustration of the slow hindered       
progress often attendant on the         
researches of science1 and an instance  
of how a few simple facts are  sometimes
 enough to overturn the most plausible  
theories and probable  conjectures4     
,many thousands of specimens had been   
examined ere one was  found that        
revealed the true nature of the         
stigmaria4 ,it was by some  imagined to 
be a soft succulent marshy plant1       
consisting of a number  of long branches
 radiating from a sort of soft disk1    
like spokes from  the centre of a wheel4
 ,analogies were suggested with         
dicotyledonous  tribes1 as the cacti and
 euphorbi1 though it was at the same    
time  admitted that the ancient plant   
presented appearances which seemed very 
anomalous4    ,footnote #bj3 ,the       
fresh-water limestone of ,mid-,calder   
abounds in  long trailing stems and     

rootlets of stigmaria1 mingled with     
other  terrestrial plants1 and shells of
 cyprides4    ,illustration3 ,fig4 #ab  
,stigmaria rootlets springing from      
,sigillaria  stem4    ,in the course of 
an extensive survey of the coal-field of
 ,south  ,wales1 ,mr4 7now ,sir         
,william7 ,logan ascertained the        
important fact1  that each coal-seam is 
underlaid by a bed of clay1 in which the
 stems  of stigmaria1 branching freely  
in all directions1 may be traced to  the
 distance of many feet or even yards4   
,they were recognised as  undoubtedly   
occupying the site on which they grew1  
and consequently  each coal-seam was    
held to rest upon an ancient soil4 ,some
 years  afterwards1 in making a cutting 
for the ,lancaster and ,bolton ,railway1
  several upright massive stems         
belonging to a plant called sigillaria1 
were found to pass downwards into true  
stigmaria stems 7,fig4 #ab74  ,there    
could be no doubt that they were        
different parts of one and the  same    

plant4 ,this fact has since been        
abundantly demonstrated from the  ,nova 
,scotia coal-field4 ,many sigillari have
 been found there passing  down into the
 fire-clay below1 where they branch out 
horizontally as  true stigmati4 ,it is  
evident1 therefore1 that the stigmaria  
was the  under-ground portion of a      
plant1 which1 judging from the nature of
 the  soil1 and the free mode in which  
the tender rootlets branched off1       
appears to have lived in aquatic or     
marshy stations4    ,illustration3 ,fig4
 #ac4 ,stigmaria4    ,the stigmaria is  
too well marked to be readily confounded
 with any  other coal-measure plant4 ,it
 had a rounded stem1 seldom more than   
four or five inches across1 which was   
marked by a series of circular          
tubercules with a puncture in the       
centre1 arranged in spiral lines  round 
the stem4 ,each of these tubercules is  
surrounded1 in ordinary  specimens1 by a
 circular depression1#ba and the whole  
plant 7if  one may use the comparison7  

looks as if it had been smitten with    
small-pox4 ,from the hollow in the      
centre of each protuberance1 there  shot
 out a long round rootlet1 formerly     
thought to be a leaf1 and  since the    
tubercules are pretty thickly set1 the  
stigmaria must have  had a somewhat     
hirsute appearance as it crept through  
the mud4 ,it  would resemble a thick    
bearded stem of ivy1 save that the      
fibres1  instead of running up two      
sides1 were clustered all round it4     
,along  the centre of the root1 there   
ran a woody pith of a harder and more   
enduring texture than the surrounding   
part of the plant4 ,the space  between  
the outer tuberculed rind and the inner 
pith1 seems to have  been of a soft     
cellular nature1 and to have decayed    
first1 for the pith  is sometimes       
hollow1 and may not unfrequently be seen
 at a distance  from the centre1 and    
almost at the outer bark--a circumstance
 that  seems only explicable on the     
supposition1 that while the surrounding 

portions were decaying1 the firmer pith 
altered its position in the  hollow     
stem1 sinking to the lower side1 if the 
plant lay prostrate1 and  that it did   
not itself begin to decay until the     
interior of the stem  had been at least 
partially filled up with sand or mud1 or
 fossilized  by the infiltration of     
lime4 ,from the root of the sigillaria1 
which  has a curious cross-shaped mark  
on its base1 the stems of stigmaria     
strike out horizontally1 first as four  
great roots which subdivide as  they    
proceed4 ,their subdivisions are        
dichotomous1 each root splitting        
equally into two1 and thus they want    
that intricate interlacing of  rootlet  
which is so familiar to us4 ,the whole  
disposition of these  under-ground stems
 is singularly straight and regular1    
leading us to  believe that they shot   
out freely through a soft muddy soil4   
,footnote #ba3 ,such is the usual aspect
 of the plant4 ,but as the stems  have  
been1 for the most part1 greatly        

flattened by the pressure of  the       
superincumbent rocks1 the sharpness of  
the pattern has been much  effaced4 ,in 
some specimens described by ,dr4        
,hooker1 as having been  found in an    
upright position1 the external          
ornamentation presents an  appearance   
somewhat different4 ,what in the common 
specimens stand out  as tubercules1 are 
there seen to be deep circular cavities1
 in which  the shrunk flagon-shaped     
bases of the rootlets are still         
observable4  7,see above1 ,fig4 #ac b1  
which is taken from one of ,dr4         
,hooker's  plates4 ,for a detailed      
description of the structure of         
stigmaria1 see  the paper above referred
 to in the ,geological ,survey          
,memoirs47 ,a  very ornate species is   
mentioned by the late ,hugh ,miller1 in 
which  each tubercule formed the centre 
of a sculptured star1 and the whole     
stem seemed covered over with flowers of
 the composite order4 ,and what  is1    
perhaps1 still more curious1 the stem   

was seen to end off #g in an  obtuse    
point1 tuberculed like the rest of the  
plant4--,testimony of the  ,rocks1 p4   
#dfa4    ,some time ago ,i chanced to   
visit the remains of what had once been 
a royal residence1 and still looked     
majestic even in decay4 ,it gave  a     
saddened pleasure to thread its winding 
stairs1 and pass dreamily  from chamber 
to hall1 and chapel to closet2 to stand 
in its gloomy  kitchens1 with their huge
 fire-places1 whose blackened sides told
 of  many a roaring fagot that had      
ruddied merry faces in days long gone   
by2 to creep stealthily into the sombre 
dungeons1 so dank1 earthy1 and  cold1   
and then winding cautiously back1 to    
emerge into the light of the  summer    
sun4 ,the silent quadrangle had its     
encircling walls pierced with  many a   
window1 some of which had once been     
richly carved2 but their  mullions were 
now sorely wasted1 while others1 with   
broken lintels and  shattered walls     
above1 seemed only waiting for another  

storm to hurl  them among the roofless  
chambers below4 ,in the centre of the   
court-yard  stood a ruined fountain4 ,it
 had been grotesquely ornamented with   
heads  of lions and griffins1 and was   
said to have once run red with wine4    
,but  it was silent enough now2 the hand
 of time1 and a still surer enemy1  the 
hand of man1 had done their worst upon  
it2 its groined arches  and foliaged    
buttresses were broken and gone1 and now
 its shattered  beauty stood in meet    
harmony with the desolation that reigned
 around4  ,i employed myself for a while
 in looking over the fragments1 marking 
now the head of some fierce hippogryph1 
anon the limbs of some mimic  knight    
clad in armour of proof1 and ere long ,i
 stumbled on a delicately  sculptured   
fleur-de-lis1 that might have surmounted
 the toilet-window  of some fair one of 
old4 ,turning it over1 ,i found its     
unhewn side  exhibited a still more     
delicately sculptured stigmaria4 ,the   
incident  was certainly simple enough1  

perhaps even trifling4 ,and yet1        
occurring  in a spot that seemed        
consecrated to reverie1 it awoke a train
 of  pleasant reflection4 ,how wide the 
interval of time which was bridged      
across in that sculptured stone6 ,its   
one side carried the mind back  but a   
few generations1 the other hurried the  
fancy away over ages and  cycles far    
into the dim shadows of a past eternity4
 ,the one told of a  land of flowers1   
musical with the hum of the bee and the 
chantings of  birds1 and gladdened by   
the presence of man2 the other told of a
 land  luxuriant1 indeed1 in strange    
forms of vegetation--huge club-mosses1  
tall calamites1 and waving ferns--yet   
buried in a silence that was only       
broken fitfully by the breeze as it     
shook the spiky catkins or the  giant   
fronds of the forest4 ,the fleur-de-lis 
recalled memories of  ,france--the sunny
 land of ,france--which stood out so    
brightly in the  dreams of our          
school-days2 the stigmaria conjured up  

visions of a land  that was never gazed 
on by human eye1 but rolled its rich    
champaign  during the long ages of the  
,carboniferous era1 and sometimes rises 
up  dimly in the dreams of our maturer  
years4 ,between these two epochs  how   
many centuries1 how many cycles must    
have slowly rolled away6 ,the           
fleur-de-lis was carved but yesterday2  
the stigmaria flourished when  the earth
 was young1 and had seen scarcely a     
third part of its known  history4    ,i 
have said that the stem of the stigmaria
 is called sigillaria4  ,the name may be
 translated signet-stem1#bb and has     
reference to  one of the distinguishing 
peculiarities of the plant4 ,about      
twenty  ,british species are enumerated1
 some of them very dissimilar1 yet  they
 all agree in having long fluted stems  
with parallel rows of  prominent        
seal-like tubercules4 ,the sigillaria   
differed so widely in  its whole contour
 and ornamentation from every living    
plant1 that it  is impossible to convey 

an idea of its form by reference to     
existing  vegetation4 ,some of the      
species1 as ,s4 organum 7,fig4 #ad71 had
 their  trunks traversed longitudinally 
by broad ridges separated by narrow     
furrows4 ,along the summit of each ridge
 there ran a line of tubercules1  set   
regularly at distances varying from a   
third or a quarter of an inch  to close 
contact4 ,one may sometimes see no      
unfair representation of  the bark of   
this ancient tree1 when looking at a    
newly ploughed field  in spring-time1   
having each of its broad ridges dotted  
with a row of  potato sacks4 ,other     
species1 while exhibiting the same plan1
 differed  not a little in the details4 
,in some the tubercules are round1 in   
others angular1 and in a third set      
double or kidney-shaped4 ,in some  they 
are far apart1 in others they are strung
 together like a chain of  beads4       
,sometimes they exist as mere specks1   
while occasionally they  broaden out so 
as to equal in width the ridge that     

supports them4  ,one species 7,s4       
reniformis71 instead of the broad ridge 
and narrow  furrow1 exhibits an         
arrangement exactly the reverse4 ,it    
looks not  unlike a cast of the species 
first described1 save that its broad    
flat  furrows support rows of much      
larger tubercules4 ,the breast of a     
lady's  chemisette1 with a thick-set row
 of buttons down each plait1 would  be  
somewhat like this species of           
sigillaria1 with this difference1       
however1 that the buttons on the plant  
were of a form that does not  appear as 
yet to have come into fashion among the 
fair sex4 ,yet they  had no little      
elegance1 and like many other objects in
 the geological  storehouse1 might be a 
useful model for our students of design4
 ,they  were neither round nor quite    
oval1 but rather of a kidney-shape1 or  
like a double cherry4    ,footnote #bb3 
,the word sigillaria is really plural1  
and was used by the  ,romans to denote  
the little images which friends were    

wont to present  to each other at the   
end of the ,saturnalia4 ,they answered  
pretty nearly  to christmas-boxes and   
new year's gifts among ourselves4 ,it is
 not  uninteresting thus to find among  
the hard dry names of science1 one  that
 two thousand years ago was synonymous  
with all the kindliness of  friendship4 
,illustration3 ,fig4 #ad4 ,sigillaria1  
with black carbonized bark  partially   
removed4    ,there can be no doubt that 
these tubercules must once have         
supported  leaflets4 ,they are true     
leaf-scars1 like those on the ,scotch   
fir1 and  the lozenge-shaped knobs on   
the bark of lepidodendron4 ,but of the  
form  of these leaves we are still in   
ignorance1 for no part of the plant1    
save the stem and roots1 has yet been   
found4 ,the sigillaria must have  been a
 tree that could not long withstand     
maceration1 for not only are  its leaves
 gone1 but1 in many cases1 the outer    
bark has partially or  wholly decayed1  
leaving a scarcely distinguishable mass 

of carbonized  matter4#bc ,when this    
outer rind is peeled off1 the inner     
surface of  the stem is seen to be      
ridged1 furrowed1 and tuberculed in the 
same  way1 but the markings are much    
less distinct than on the outside4 ,the 
bark sometimes attains the thickness of 
an inch1 and is always found  as a layer
 of pure coal enveloping the stem where 
it stands erect1 or  lying as a flat    
cake without any central cylinder where 
the stem is  prostrate4 7,see ,fig4     
#ad47    ,footnote #bc3 ,another proof  
of the looseness of the texture of this 
ancient vegetable may be gathered from  
the almost invariable truncation  of    
even the largest erect stems2 they are  
snapped across at the height  of a few  
feet from their base4 ,the famous       
,torbanehill ,mineral  contains many    
such fragmentary stems1 often of        
considerable thickness4  ,their interior
 consists of the same material as the   
surrounding bed1  and displays many     
dissevered plants that may have been    

washed into  the decaying trunks4 ,for  
the internal structure of sigillaria see
 ,dr  ,hooker's ,memoir1 and the        
authorities therein cited4    ,another  
remarkable feature in this carboniferous
 plant is that it  appears to have had  
no branches along its stem4 ,trunks have
 been found  four and five feet in      
diameter1 and have been traced to a     
distance of  fifty1 sixty1 and even     
seventy feet1 without any marks of      
branches  being detected4 ,brongniart   
examined the portion of one stem1 which1
  at its thicker end1 had been broken   
across1 but still measured a  foot in   
breadth4 ,it ran for forty feet along   
the gallery of a mine1  narrowing to a  
width of not more than six inches1 when 
it divided into  two1 each branch       
measuring about four inches across4 ,the
 sigillaria  stems1 accordingly1 must   
have shot up1 slim and straight1 to a   
height  of sometimes seventy feet before
 they threw out a single branch4 ,we    
know nothing of the coronal of these    

strangely-formed trees4 ,from           
,brongniart's observations1 it would    
seem that the upper part of the  stem1  
like that of the lepidodendron1 was     
dichotomous1 that is1 it  branched out  
into two minor stems2 but how these were
 disposed is  unknown4 ,we are wholly   
ignorant1 too1 of the foliage of these  
branches1  though1 from the general     
structure of the plant1 as well as from 
the  number of fern-fronds often found  
around the base of the stems1 it has    
been conjectured that the sigillaria was
 cryptogamous1 and1 like the            
tree-ferns1 supported a group of        
sweeping fronds4 ,if so1 it differed in 
many respects from every known member of
 the cryptogamic tribes4    ,putting    
together1 then1 all that we know of the 
exterior of the  sigillaria1 we find    
that it was a tall slender tree1 with1  
palm-like1  a clump of foliaged branches
 above1 its stem bristling thickly1 in  
at  least its upper part1 with spiky    
leaves1 and its roots equally hirsute1  

shooting out to a distance of sometimes 
forty feet through the soft  muddy soil4
 ,future researches may bring us better 
acquainted with this  ancient organism4 
,in the meanwhile1 enough of it is known
 to mark it  out as one of the most     
ornate forms of vegetation that the     
world has  ever seen4    ,in addition to
 the above1 the coal strata have yielded
 many other  fragmentary remains1 to    
which names have been given1 but of     
which very  little is known4 ,it is     
pleasant1 amid such a wide sea of doubt 
and  uncertainty1 to alight upon some   
well-known form of whose affinities     
there can be no question1 since it still
 finds its representatives in  living   
nature4 ,of such a kind are the         
coniferous stems occasionally met  with 
in the sandstones of the coal-measures4 
4    ,it is now many years since the    
operations of the quarryman in the      
carboniferous sandstones of ,edinburgh  
and ,newcastle disclosed the  remains of
 huge gnarled trunks deeply imbedded in 

the rock4 ,the  neighbourhood of the    
latter town yielded1 in #ahbi1bd the    
stem of  a tree seventy-two feet long1  
without branches1 but roughened with    
numerous knobs1 indicative of the places
 whence branches had sprung4  ,at       
,craigleith1 near ,edinburgh1 a trunk   
thirty-six feet long1 and three  feet in
 diameter at the base1 was disinterred  
in the year #ahbf4 ,since  then1 several
 others have been found in the same     
neighbourhood2 some  of them sixty and  
even seventy feet in length1 and from   
two to six in  breadth4 ,they were1 for 
the most part1 stripped of roots and    
branches1  and lay at a greater or less 
angle among the white sandstone beds1   
which they cut across obliquely4 ,it was
 unknown for some time to what  division
 of the vegetable kingdom these trunks  
should be referred4  ,their irregular   
branched surface and undoubted bark     
indicated a higher  kind of structure   
than that possessed by any of the other 
carboniferous  plants2 but the          

conjecture remained unverified until an 
ingenious  and beautiful method was     
discovered of investigating their       
internal  organization4 ,two ,edinburgh 
geologists1 ,mr4 ,nichol and ,mr4       
,witham1  succeeded in obtaining slices 
of the plants sufficiently transparent  
to  be viewed under the microscope by   
transmitted light1 and in this way      
their true structure was readily        
perceived4 ,the method of preparing     
these objects was simply as follows3--,a
 thin slice of the plant to be  studied 
was cut by the lapidary1 or detached by 
the hammer4 ,one side  having been      
ground down smooth1 and polished1 was   
cemented by ,canada  balsam to a piece  
of plate-glass1 and the upper surface   
was then ground  down and polished in   
like manner1 so as to leave the slice no
 thicker  than cartridge-paper4#be ,when
 the preparation was then placed under  
a magnifying power1 the minute cells and
 woody fibre of the plant  could be     
detected as clearly as those of a recent

 tree4 ,the ,craigleith  fossils were in
 this way recognised as belonging to the
 great  coniferous family1 and to that  
ancient#bf division of it which is1 at  
the present day1 represented by the pine
 of ,norfolk ,island--a noble           
araucarian1 which rears its proud head  
from #afj to #bjj feet over the  soil1  
and exhibits a green and luxuriant      
breadth of foliage rare among  the      
conifer4#bg ,some of these plants have  
yielded faint traces of  the annual     
rings shown so markedly in the cross    
section of our common  forest-trees2    
whence it would appear1 that even as far
 back as the  times of the              
coal-measures1 there were seasons of    
alternate heat and  cold1 though        
probably less defined than now4         
,footnote #bd3 ,witham's ,foss4 ,veget4 
p4 #ca4    ,footnote #be3 ,for a more   
detailed description of the process1 see
  ,witham's ,foss4 ,veget4 p4 #de4      
,footnote #bf3 ,the solitary lignite of 
the ,lower ,old ,red ,sandstone1  seems 

to have been araucarian4 ,miller's      
,footprints of the ,creator1 p4  #bjc4  
,footnote #bg3 ,footprints of the       
,creator1 p4 #aib4    ,these coniferous 
trees do not appear to occur among the  
erect stems of  the coal-beds1 at least 
they are very rare in such a position4  
,their  more usual appearance is that of
 drifted1 branchless trunks1 imbedded   
along with other fragmentary plants in  
deep strata of sandstone4  ,they        
probably grew on higher ground than the 
swamps which supported  the sigillari   
and their allies1 and might have been   
carried down by  streams1 freighted out 
to sea1 and so deposited among the      
sediment that  was gathering at the     
bottom4    ,the remains of cycadaceous  
plants have been described among the    
vegetation of the coal-measures2 but    
only fragments have as yet been  found4 
,the modern ,cycade are low shrubs or   
trees1 with thick stems  of nearly      
uniform breadth1 crowned with a dense   
clump of spreading  fronds which        

resemble both those of the palms and the
 ferns4 ,they are  natives of the warmer
 regions of both hemispheres4    ,so    
long ago as the year #ahce1 ,dr4        
,lindley figured a flower-like  plant1  
to which he gave the name of            
,antholites1 ranking it among  the      
,bromeliace1 or pine-apple group4 ,it   
was afterwards suspected  by ,dr4       
,hooker to belong rather to the conifer2
 and he supposed that  the so-called    
flowerets might be really tufts of young
 unexpanded  leaves4 ,an examination of 
a more perfect specimen1 however1 has   
induced  that distinguished botanist to 
alter his convictions and return to  the
 original decision of ,lindley1 that the
 antholites are really  flowers4#bh ,in 
,fig4 #ae1 therefore1 which represents  
one of these  coal-measure fossils1 the 
reader beholds the oldest flower that   
has  yet been found2 and surely it is of
 no little interest to know1 that  amid 
the rank1 steaming forests of the       
,carboniferous era1 with all  their     

darkness and gloom1 there were at least 
some flowers--flowers1  too1 that were  
allied to still living forms1 and       
breathed out a rich  aromatic fragrance4
    ,footnote #bh3 ,see ,dr4 ,hooker's  
remarks in the ,supplement to the fifth 
edition of ,lyell's ,manual1 p4 #ca4    
,illustration3 ,fig4 #ae4--;,antholites4
    ,in fine1 from all the genera and   
species of plants that have been        
detected in the strata of the           
coal-measures1 it would appear that the 
flora of that ancient period was in a   
high degree acrogenous--that  is to say1
 consisted in great measure of ferns1   
club-mosses1 and other  members of the  
great group of plants known as acrogens4
 ,this word  literally means            
top-growers1 and is applied to those    
plants which  increase in height1 but   
not in width1 since they attain at first
  nearly their ultimate diameter4 ,such 
plants occupy a low position in  the    
botanical scale4 ,mingled with the      
numerous genera of carboniferous  ferns 

and club-mosses1 we find the remains of 
a much higher grade  of vegetation--that
 of the gymnogens1 or plants that bear  
naked  seeds--such as the firs and      
pines4 ,there also seem to have been a  
few endogenous flowering plants4        
,viewing1 then1 this flora on the       
whole1 it presents us with many striking
 resemblances to certain  botanical     
regions of the present day4 ,many of the
 tropical islands  abound in ferns1 and 
contain very few flowering plants4 ,but 
,new ,zealand  affords perhaps the      
closest parallel4 ,that island is in    
certain parts  highly mountainous1 its  
loftiest summits being covered with     
glaciers4  ,the hills throughout large  
districts are bare1 or covered with a   
scanty herbage1 while in other          
localities they are densely clothed     
with forests of pine1 beech1 and other  
trees4 ,these forests sweep  on to the  
lower grounds1 where they are replaced  
by a thick growth  of fern and          
flax-plant intermingled with            

dragon-trees and graceful  tree-ferns1  
while the more swampy regions support a 
rich profusion of  reeds and rushes4    
,such a condition of things affords a   
close parallel  to the probable         
vegetation of the ,carboniferous        
period--an immense  preponderance of    
ferns and arborescent acrogens1 with an 
intermixture  of large coniferous trees4
 ,from the general scantiness of a flora
  where ferns predominate1 it has been  
argued that the swamps of the           
coal-measures nourished a luxuriant     
repetition of comparatively few         
species2 and this hypothesis also       
receives confirmation from the          
vegetation of ,new ,zealand4 ,another   
deduction founded on the resemblance  of
 the ancient to the modern flora1 refers
 to the conditions of heat  and         
moisture4 ,it has been inferred that the
 climate of the coal period  was equable
 and humid1 like that of ,new           
,zealand--a supposition much  more      
natural and simple than that1 once so   

much in vogue1 of a heated  atmosphere  
densely charged with carbonic acid gas4 
,that the air of the  ,carboniferous    
period differed in no material respect  
from the air of  the present day1 seems 
at last proved by the remains of        
air-breathing  animals having been found
 among the coal-beds2 and there seems no
  reason why the higher mountain-tops of
 the same epoch may not have been       
clothed with glaciers as those of ,new  
,zealand are4 ,as yet we have no        
evidence of the fact1 but it is by no   
means beyond the possibility of         
proof4#bi    ,footnote #bi3 ,see        
,professor ,ramsay's suggestive ,memoir 
on ,permian  ,breccias in ,quarterly    
,journal of the ,geological ,society1   
vol4 xi4 p4  #ahe4          ,,chapter   
,v4        ,scenery of the carboniferous
 forests--,contrast in the              
appearance of coal districts at the     
present day--,abundance         of      
animal life in the ,carboniferous       
era--,advantages         of palontology 

over fossil-botany--,carboniferous      
fauna--,actini--,cup-corals--,architectu
re of the present         day might be  
improved by study of the architecture of
 the         ,carboniferous             
period--,mode of propagation of         
corals--,a         forenoon on the      
beach--,various stages in the           
decomposition of                        
shells--,sea-mat--,bryozoa--,fenestella-
-,retepora--,stone-lilies--             
,popular superstitions--,structure of   
the stone-lilies--,aspect         of the
 sea-bottom on which the stone-lilies   
flourished--,sea-urchins--,crustacea1   
their high                              
antiquity--,cyprides--,architecture of  
the ,crustacea and         mollusca     
contrasted--,king-crabs4    ,the forms  
of vegetation that flourished during the
 ,carboniferous era  seem to have been  
in large measure marshy plants1         
luxuriating on low  muddy delta-lands1  
like the cypress-swamps of the          
,mississippi1 or the  ,sunderbunds of   

the ,ganges4 ,we can picture but faintly
 the general  scenery of these old      
forests from the broken and carbonized  
remains  that have come down to us4 ,but
 though perhaps somewhat monotonous  on 
the whole1 it must have been eminently  
beautiful in detail4 ,the  sigillari    
raised their sculptured stems and lofty 
waving wreaths of  fronds high over the 
more swampy grounds1 while a thick      
underwood of  ferns and star-leaved     
asterophyllites clustered amid the shade
 below4  ,the lepidodendra shot forth   
their spiky branches from the margin of 
green islets1 and dropped their catkins 
into the sluggish water that  stole on  
among the dimpled shadows underneath4   
,tree-ferns spread out  their broad     
pendant fronds1 and wrapt the ground    
below in an almost  twilight gloom1     
darker and deeper far than that         
,hospitable roof      ,of branching elms
 star-proof1    which rose so often in  
the visions of ,milton2 or that graceful
 arch  so exquisitely sung by ,cowper1  

beneath which        ,the chequered     
earth seems restless as a flood         
,brushed by the wind4 ,so sportive is   
the light      ,shot2 through the       
boughs1 it dances as they dance1        
,shadow and sunshine intermingling      
quick1      ,and darkening and          
enlightening1 as the leaves      ,play  
wanton1 every moment1 every spot4       
,thickets of tall reeds rose out of the 
water1 with stems massive as  those of  
our forest-trees1 encircled at regular  
distances by wreaths of  pointed        
leaflets1 and bearing on their summits  
club-like catkins4 ,far  away1 the      
distant hills lay shaggy with           
pine-woods1 and nursed in their         
solitudes the springs and rivulets that 
worked a devious course through  forest1
 and glen1 and valley1 until1 united    
into one broad river1 they  crept       
through the rich foliage of the delta   
and finally passed away out  to sea1    
bearing with them a varied burden of    
drift-wood1 pine-trees  from the hills1 

and stray leaves and cones from the     
lower grounds4    ,how different such a 
scene from that now presented by the    
very same  areas of country6 ,these old 
delta lands are now our coal-fields1 and
  have exchanged the deep stillness of  
primeval nature for the din and  turmoil
 of modern mining districts4 ,in these  
ancient times1 not only  was man        
uncreated1 but the earth as yet lacked  
all the higher types of  vertebrated    
being4 ,none of the animals that we see 
around us existed  then2 there were no  
sheep1 nor oxen1 horses1 deer1 nor dogs4
 ,neither  were the quadrupeds of other 
lands represented2 the forests nourished
  no lions or tigers1 no wolves or      
bears1 no opossums or kangaroos4 ,in    
truth1 the land must have been a very   
silent one1 for we know as yet of  no   
animated existence that could break the 
stillness1 save perchance  some chirping
 grasshopper1 or droning beetle1 or     
quivering dragon-fly4  ,no bee hummed   
along on errands of industry2 it is     

doubtful1 indeed1  whether              
honey-yielding flowers formed part of   
the carboniferous flora2  no lark       
carolled blithely in the sky1 nor rook  
croaked among the  woods4 ,all was      
still2 and one might1 perhaps1 have     
stood on some of  those tree-crested    
islets1 and heard no sound but the      
rippling of the  water along the reedy  
and sedgy banks1 and the rustling of the
 gloomy  branches overhead4    ,to one  
who muses on these bygone ages it is no 
unimpressive situation  to stand in the 
midst of a large coal district and mark 
its smoking  chimneys1 clanking engines1
 and screaming locomotives1 its squalid 
villages and still more squalid         
inhabitants1 and its mingled air of     
commercial activity1 physical           
wretchedness1 and moral degradation4    
,it is from such a point of view that we
 receive the most forcible  illustration
 of those great changes whereof every   
country has been the  scene1 and which  
are so tersely expressed by one who has 

gazed on the  revelations of geology    
with the eye of a true poet--           
,there rolls the deep where grew the    
tree4        ,o earth1 what changes hast
 thou seen6        ,there where the long
 street roars1 bath been      ,the      
stillness of the central sea4    ,but   
the lifelessness of the carboniferous   
forests was amply compensated  by the   
activity that reigned in river1 lagoon1 
and sea4 ,coral groves  gleamed white   
beneath the waves1 fishes of many a     
shape disported in  stream and lake1 and
 the bulkier forms1 armed in massive    
plates of  bone1 ascended the rivers or 
haunted the deeper recesses of the open 
sea4 ,in some beds of rock the remains  
of these various animals lie  crowded   
together like drifted tangle on the     
sea-shore1 and the whole  reminds us of 
a vast cemetery or charnel-house4 ,the  
bones lie at all  angles1 many of them  
broken and disjointed as though the     
owner had died  at a distance1 and his  
remains1 sadly mutilated on the way1 had

 been  borne to their last resting-place
 by the shifting currents2 others  lie  
all in place1 covered with their        
armature of scales1 as though  the      
creature1 conscious of approaching      
dissolution1 had sought out a  sheltered
 nook and there lain down and died4 ,it 
is not uninteresting  or uninstructive  
to tract2 out in an old quarry stratum  
above stratum1  each with its groups of 
once living things4 ,i know of few      
employments  more pleasant than to sit  
there1 amid the calm stillness of a     
summer  evening1 when the shadows are   
beginning to steal along the valleys and
  creep up the hill-sides1 and in that  
dim fading light to try in fancy  to    
clothe these dry bones with life1 to    
picture the time when they  lived and   
moved in the glassy depths of lakes and 
seas1 or amid the  solitudes of jungles 
and forests1 and so to spend a pleasant 
hour in  reverie1 till roused at last by
 the vesper song of the lark1 or the low
  meanings of the night wind as it sighs

 mournfully through the woods4    ,the  
study of fossil animals embraces a much 
greater range of subject  than that of  
fossil plants4 ,the fauna of any        
particular geological  formation1 that  
is to say1 its embedded animal remains1 
for the most  part vastly exceeds in    
number its flora1 or vegetable remains1 
and is  likewise usually better         
preserved4 ,about the nature and        
affinities of  several tribes of fossil 
plants there hangs an amount of         
uncertainty  which renders them a       
dubious guide to the climatal and other 
conditions  of the period and locality  
in which they lived4 ,generic           
distinctions  among living plants often 
rest on the character of those parts    
which  are the most perishable1 such as 
flowers and seed-vessels4 ,these        
delicate structures we1 of course1 can  
hardly look to find preserved  in the   
rocks1 and we have in place of them only
 detached leaflets1  twigs1 branches1   
and stems1 often sorely mutilated in    

outward form1 and  presenting no trace  
of internal organization4 ,but the      
tribes of the  animal kingdom have1 for 
the most part1 harder frameworks4 ,the  
minute  infusoria1 which by their       
accumulated remains help to choke up the
  delta of the ,nile1 and swarm by      
millions in every ocean of the globe1   
have their silicious or calcareous      
shells so minute that ,ehrenberg  has   
estimated a cubic inch of tripoli to    
contain forty-one thousand  millions of 
them4 ,the polypi have their internal   
calcareous skeletons1  which abound in  
all the older limestones1 and form the  
coral reefs of  the present day4 ,the   
mollusca1 too1 though1 as their name    
imports1 they  have perishable bodies1  
are yet1 in most cases1 furnished with  
hard  calcareous shells1 that indicate  
by their various modifications of form  
and structure1 the character of the     
animal that lived within them4 ,they    
are found in all the formations from the
 earliest upwards1 and as they  vastly  

exceed in numbers all the other classes 
with which the geologist  has to deal1  
they form the larger part of that basis 
of evidence from  which he interprets   
the past history of organized existence4
 ,hugh  ,miller loved to talk of them as
 the shell alphabet1 out of which the   
language of palontological history      
should be compiled4 ,the vertebrata1    
too1 all have their hard skeletons1     
easily capable of preservation1  whether
 it be in the form of the massive       
exo-skeleton of bone that  characterized
 the older ganoidal fishes1 or the      
compact endo-skeleton  of the reptiles  
and mammals4 ,a greater amount of       
attention is1  therefore1 due to the    
study of fossil animals1 since they thus
 not  only far exceed fossil plants in  
number1 but possess a higher value as   
evidence of ancient physical conditions4
    ,the fauna of the ,carboniferous    
system is a very numerous one1          
exhibiting specimens of almost every    
class of animal life1 from the  tiny    

foraminifer up to the massive           
bone-covered sauroidal fish1  and even  
to occasional traces of true reptilian  
remains4 ,by far the  larger number are 
peculiar to the sea1 such as the        
molluscan tribes  and corals2 others are
 undoubtedly terrestrial organisms1 such
 as the  wings and wing-sheaths of      
several kinds of insects2 while some    
appear  to be peculiar to fresh or      
brackish water1 such as shells allied to
  our unio or river-mussel1 and minute  
crustaceous animals known as  cyprides1 
of which we have still representatives  
in our ponds and  ditches4 ,it is plain1
 then1 that if we rightly ascertain the 
class or  family to which one of these  
fossils belonged1 we shall obtain a clue
  to the history of the physical        
geography1 during ,carboniferous times1 
of the district in which the fossil     
occurs4 ,a bed of unios will tell  us of
 old rivers and lakes that spread out   
their blue waters where  now1 perchance1
 there lie waving fields of corn4 ,a bed

 of corals and  stone-lilies will lay   
before us the bottom of an ancient ocean
 that  rolled its restless waves where  
to-day1 perhaps1 the quarryman plies    
his task amid the gloom of dark         
pine-woods4 ,in short1 these organic    
remains are to the history of the earth 
what ancient monuments are to  the      
history of man4 ,they enable us to trace
 out the varied changes  of our planet  
and its inhabitants down to the human   
era1 just as the  wooden canoe1 the     
flint arrow-head1 the stone coffin1 the 
bronze sword1  the iron cuirass1 the    
ruined abbey1 and the feudal castle1    
teach us the  successive stages of      
progress in the history of our own      
country4    ,whoever has spent a few    
days on some rocky coast1 must have     
noticed  adhering to half-tide stones   
numerous solitary actini4 ,arrayed in   
all the colours of the rainbow--purple1 
green1 and gold--these little  creatures
 hang out their tentacles like so many  
flowers1 and have hence  received the   

popular name of sea-anemones4 ,their    
internal structure is  no less          
beautiful4 ,they resemble so many large 
plump gooseberries1 and  consist of a   
little sack suspended within a larger   
one4 ,the outer sack  is fringed along  
its upper edges with one or more rows of
 slim hollow  tentacles1 which diverge  
outwards like the petals of the daisy1  
and can  be contracted at pleasure so as
 somewhat to resemble the daisy when    
folded up at sunset4 ,the inner sack1   
which forms the stomach of the  animal1 
has a short opening or gullet1 at the   
upper part of which is  the mouth lying 
in the centre of the cavity surrounded  
by the fringes  of tentacles4 ,the inner
 sack is connected with the outer by    
means of  thin membranes1 like so many  
partition-walls1 which radiate inwards  
like spokes towards the axle of a wheel4
 ,the space between each of  these      
membranes1 or lamell1 forms an          
independent chamber1 but it has  a      
communication with those on either side 

by a window in each wall1  and further  
opens upwards into the hollow tentacles1
 which1 with minute  orifices at their  
outer points1 may be compared to        
chimneys4 ,these  chambers form the     
breathing apparatus of the little       
creature4 ,sea-water  passes down       
through the tentacle into the hollow    
chamber below1  whence1 by the constant 
action of minute hairlike cilia that    
line the  walls like tapestry1 it is    
driven through the window into the next 
chamber1 thence into the next1 and so   
on1 passing gradually through the       
tentacles back to the sea4    ,the      
actini are of a soft perishable         
substance1 but many of the other        
,anthozoa1 or flower-like animals1 have 
hard calcareous skeletons4 ,of  such a  
kind are the polypi that in the ,pacific
 ,ocean have raised those  stupendous   
reefs and islands of coral4 ,it does not
 appear that1 during  the ,carboniferous
 period1 there existed any reef-building
 zoophytes1  but some of the most       

abundant forms of life belonged to a    
kindred  tribe1 and are known by the    
name of ,cyathophyllid1 or cup-corals4  
,as the name imports1 the typical genus 
has a general cup-shaped form1  but this
 is liable to many aberrations in the   
cognate genera4 ,the  younger specimens 
of one species 7,cyathopsis fungites7   
have a curved  outline somewhat like the
 bowl of a tobacco-pipe1 whence the     
quarrymen  know them as pipe-heads4 ,the
 older individuals are generally more or
  less wrinkled and twisted1 sometimes  
reaching a length of eight or nine      
inches1 and have been named by the      
workmen rams'-horns4    ,illustration3  
,fig4 #af4--;,cyathopsis 7clisiophyllum 
87 fungites4    ,the annexed figure     
7,fig4 #af7 shows their general         
appearance and  structure4 ,the lower   
end was fixed to the rock like the flat 
sucker-like disc of the actinia4 ,around
 the outer margin there diverged  one or
 more rows of slim tentacles1 hollow1   
soft1 and retractile1 like  those of the

 actinia4 ,from the margin to the centre
 there radiated  more than a hundred    
lamell1 but these differed from the     
corresponding  membranes of the modern  
animal1 inasmuch as they were           
strengthened  internally by a skeleton  
of hard carbonate of lime2 and to this  
difference we owe their preservation4   
,they stand out in high relief  upon    
weathered specimens1 showing the long1  
narrow chambers that ran  between them4 
,their walls were once doubtless hung   
with countless  vibratile cilia1 and    
perhaps pierced each with its window1   
through  which the currents of water    
passed in their ceaseless progress to   
and  from the sea4 ,at the centre lay   
the mouth1 communicating by a short     
gullet with the stomach1 which occupied 
the central portion of the  animal1 and 
from the outer walls of which the lamell
 diverged like so  many buttresses4 ,in 
its youngest stages1 the animal occupied
 the whole  length of the cup1 but1 us  
it increased in size1 it gradually      

retreated  from the narrow end1 which   
was then divided off by a thin          
calcareous  membrane4 ,at each          
successive stage of its growth1 a new   
membrane was  added1 each further and   
further from the lower end1 so that     
eventually  the creature left below it a
 series of empty chambers all firmly    
built up4 ,thus1 in a specimen six or   
eight inches long1 there would  in      
reality only be a small part            
tenanted--in fact merely the upper      
floor--all the lower storeys remaining  
silent and uninhabited4 ,the  house of  
this old-world architect differed widely
 in one respect from  human dwellings4  
,man begins his basement story of the   
same dimensions  as those that are to   
succeed it1 or1 if any difference is    
made at all1  the upper floors are built
 each less than the one below it1 so    
that  the whole structure tapers upward 
to a point1 as in the ,pyramids4 ,but   
the cyathopsis reversed this latter     
process2 it inverted the cone1          

commencing the smallest chamber at the  
bottom1 and placing the widest  at the  
top4 ,indeed1 one is sometimes puzzled  
to conjecture how so bulky  a building  
could be securely poised on so narrow a 
basis1 and it is  certainly difficult to
 see how the creature could move about  
with such  a ponderous load to drag     
along4 ,the snail carries his house on  
his  back1 yet it is a slim structure at
 the best2 but the cup-coral must  not  
merely have carried his house1 but some 
dozen or two of old ones  strung one    
after another to his tail4 ,perhaps1    
though free to move  about and try      
change of residence in its youthful     
days1 the creature  gradually settled   
down in life1 and took up its permanent 
abode in some  favourite retreat1 the   
more especially as in process of time it
 became  what we should call a very     
respectable householder4    ,allied to  
the cyathopsis is another and still more
 beautiful coral1  described so long ago
 as the latter part of the seventeenth  

century  by the ,welsh antiquary and    
naturalist1 ,lhwyd1 under the name of   
,lithostrotion4 ,although many perfect  
specimens of it have been  found1 and it
 is usually as well preserved as any of 
its congeners1  men of science have been
 sadly at a loss what to call it4 ,four 
or  five synonyms may be found applied  
to it in different works on             
palontology4 ,there seems now1 however1 
a tendency to return to the  name that  
old ,lhwyd gave it two centuries ago2   
the family to which  it belongs1 and of 
which it is the type1 has accordingly   
been termed  the ,lithostrotionid1 and  
the species in question ,lithostrotion  
striatum 7,fig4 #ag74 ,it differed from 
the cyathopsis in several  respects1 but
 chiefly in this1 that it lived in      
little congregated  groups or colonies1 
whereas the cyathopsis1 like our own    
actinia1 dwelt  alone4    ,illustration3
 ,fig4 #ag4--,lithostrotion striatum4   
,each of these colonies was formed of a 
cluster of hexagonal1 or rather         

polygonal pillars1 fitting closely into 
each other1 like the basaltic  columns  
of ,fingal's ,cave1 and springing from a
 common base at the sea  bottom4#cj     
,each pillar constituted the abode of a 
single animal1  and resembled generally 
the stalk of the cyathopsis4 ,it had the
 same  minute diverging partitions      
running from the outer walls towards the
  centre1 and the same thin diaphragms1 
which1 stretching horizontally  across  
the interior of the column at short     
intervals1 marked the  successive stages
 of the animal's growth4 ,within these  
partitions1  which vary from forty to   
eighty in number1 there runs an inner   
circular  tube with thin lamell and     
diaphragms4 ,the exterior of the columns
 is  ribbed longitudinally by a set of  
long fine stri1 which give somewhat  the
 appearance of the fluting on a         
,corinthian pillar4 ,the columns1       
moreover1 are not straight1 but have an 
irregular1 wrinkled outline1  so that1  
by a slant light1 they look like some   

old pillar formed of  many layers of    
stone1 the joints of which have wasted  
away1 producing  an undulating profile  
in place of the original even one4 ,but 
in these  ancient coral columns there is
 no blunted outline1 no worn hollow2    
the sculpturing stands out as sharp and 
fresh1 and the wavy curves as  clearly  
defined1 as though the creature had died
 but yesterday4 ,they  resemble no order
 of human architecture1 save faintly1   
perhaps1 some of  the wavy outlines of  
the ,arabesque4    ,footnote #cj3 ,sir  
,roderick ,murchison figures in his     
,siluria1 p4 #bhb1  a gigantic specimen1
 which measured two feet four inches in 
width4    ,despite all the improvements 
and inventions of modern times1 classic 
architecture has made no progress since 
the days of ,pericles4 ,all that  we do 
now is but to reproduce what the ,greeks
 created #bjjj years ago1  and he is    
reckoned the best architect who         
furnishes the best imitation4  ,our     
architects might find some useful hints1

 however1 by studying the  lowlier      
orders of nature4 ,they would see there 
patterns of beauty far  more delicate   
than the ,grecian capital1 and more     
light and airy than  the ,gothic shaft4 
,and whether or not they could found a  
new order of  architecture1 they could  
not fail to discover many modifications 
and  improvements upon some of the old4 
,they could not readily light upon  a   
more graceful form than that of the     
lithostrotion1 would they but  picture  
it as it grew at the bottom of the old  
carboniferous sea4 ,a  group of         
hexagonal pillars1 firmly compacted     
together like those of  the ,giant's    
,causeway1 or ,fingal's ,cave1 rose from
 a white calcareous  pediment1 as       
columns from the marble steps of an     
,athenian temple4 ,each  side of the    
pillar had a wavy undulating surface1   
delicately fluted by  long slender stri1
 the whole being so arranged that the   
convexities  of one surface fitted into 
the sinuosities of the adhering one4    

,each  pillar was crowned above by a    
capital1 consisting of the soft         
vibratile  tentacles of the animal1 that
 hung over like so many acanthus leaves4
  ,of the form of these tentacles1 their
 design and grouping1 we know  nothing  
save what may be gathered from the      
analogy of living corals4  ,there can be
 little doubt1 however1 that1 like the  
flower-shaped buds  of the existing     
reef-building polyps1 they must have    
been eminently  beautiful1 and in strict
 keeping with the graceful column which 
they  crowned4    ,another kindred form 
was that known as the lithodendron4 ,it1
 too1  grew in colonies1 and seems to   
have closely resembled the last1 save   
that the pillars1 in place of being     
six-sided1 were round4 ,i have seen  a  
bed of these corals several yards in    
extent1 and seven or eight  inches deep1
 where the individuals were closely     
crowded together1 so  as to resemble a  
series of tobacco-pipe stems1 or slim   
pencils set on  end4 ,the tubes1        

however1 were not all quite straight2   
many being more  or less curved1 and    
sometimes crossing their neighbours     
obliquely4  ,the internal arrangement   
was on the same plan as in the two      
previous  corals4 ,the same numerous    
partitions ran from the exterior wall   
towards the central tube1 the same      
thick-set diaphragms crossed the  entire
 breadth of the column1 imparting the   
same minute honey-combed  appearance to 
a cross section4 ,the exterior of the   
column 7in ,l4  fasciculatum7 was       
likewise traversed by the same          
longitudinal stri4    ,both these corals
 seem to have been fissiparous1 that is 
to say1 they  propagated by splitting   
into two parts1 each of which formed the
 base  of a new column with a new       
animal4 ,the evidence for this statement
  rests on the fact1 that many of the   
tubes are seen to bifurcate in  their   
course1 so that two new tubes are       
produced equal in size and  completeness
 to the old one from which they proceed4

 ,another mode of  generation which1 in 
at least its earlier stages1 would      
produce a  somewhat similar appearance  
is called gemmation1 and consists in    
the protrusion of a bud or gemmule from 
the side of the animal1 which  shortly  
develops into a new and perfect         
individual4 ,it is probable1  however1  
that the ordinary mode of propagation   
among these old corals  was the usual   
one by impregnated ova4 ,these ova1 like
 those of our  sea-anemones1 were       
probably generated within the           
partitions1 between  the central stomach
 and the outer wall1 whence they passed 
down into  the stomach1 and were ejected
 by the mouth of the parent as little   
gemmules1 furnished with the power of   
locomotion by means of vibratile  cilia4
 ,some of the ,medusa family possess    
this three-fold mode of  propagation2   
but1 in all1 the last-mentioned is the  
most usual4    ,has the reader ever     
stretched himself along the shore1      
while1 perhaps1  a ,july sun blazed     

overhead1 and a fitful breeze came over 
the sea1 just  strong enough to chase   
ashore an endless series of rippling    
wavelets1  and breathe over his temples 
a delicious and refreshing coolness8    
,thus placed1 and gazing dreamily now1  
perchance1 at the distant sails  like   
white specks along the boundary line of 
sea and sky2 now at the  gulls wheeling 
in broad circles through the air1 and   
shooting swift  as arrows down into the 
blue water1 he must often have turned to
 look  for a little at the sand which1  
heaped up in little mounds around him1  
formed a couch well-nigh as soft as the 
finest down4 ,many a varied  fragment   
entered into the composition of that    
sand4 ,mingled among the  minuter       
quartzy particles lay scores of shells1 
some with the colour  not yet faded1 and
 the valves still together--the delicate
 tellina1  with its polished surface1   
and its flush of pink2 the cardium with 
its  strong white plaited sides1 and the
 turritella with its circling spire2    

some were worn down and sorely effaced1 
others broken into fragments  by the    
ceaseless grinding of the waves4 ,it was
 pleasant labour in such  a sultry noon 
to pick out the shells of one species in
 all stages of  decay4 ,the ,trochus    
lineatus1 or ,silver ,willie1 as young  
ramblers by  the sea-shore love to call 
it1 showed well the process of          
destruction4  ,the perfect shell1 cast  
ashore1 perhaps1 by the last storm1 and 
still  uninjured by the tides1 displayed
 its russet epidermis1 or outer skin1   
covered with fine brown zig-zag lines1  
running across the whorls from  the     
creature's wide pearl-lined mouth to the
 apex4 ,a second shell  exhibited a     
surface that had begun to suffer2 the   
point had been  divested of its thin    
outer skin1 and laid bare the silvery   
coating of  pearl below4 ,a third had   
undergone a still longer period of      
abrasion1  for the whole of the         
epidermis was gone1 and the surface     
gleamed with  a pearly iridescence4 ,in 

yet a fourth1 this bright exterior had  
been  in large measure worn away1 and   
the blunted1 rounded shell displayed    
the dull white calcareous substance of  
which it was mainly built up4  ,but     
there were other objects of interest in 
the sand3 bits of tangle1  crusted over 
with a fine net-work of gauze1 and      
fragments of thin  leaf-like membrane1  
consisting of a similar slender network 
known  popularly as the sea-mat1        
occasionally turned up among the pebbles
  and shells4 ,no one who met with these
 organisms for the first time  could    
fail to be struck with the extreme      
delicacy of finish1 if one  may so      
speak1 that characterizes them4 ,and yet
 he might be puzzled to  know what to   
make of them4 ,the leaf-like membrane1  
at a first glance1  looks not unlike    
some of the flat-leaved alg1 and such   
the observer  might readily take them to
 be4 ,such1 too1 they were long regarded
 by  naturalists2 but a more careful    
examination of them showed that the     

so-called plants really belonged to the 
animal kingdom1 and that the  supposed  
leaves were1 in truth1 the organic      
dwelling-places of minute  zoophytes1 of
 which many hundreds lay grouped        
together on every square  inch4 ,for    
many years these little creatures were  
called celliferous  corallines1 and     
classed among the polypi1 that great    
tribe which has  its representatives in 
every ocean1 from the coral reefs of the
 ,pacific  to the little bell-shaped    
hydra amid the tangle of our own seas4  
,but the microscope--that lamp which    
lights us into the inner recesses  of   
nature--revealed at last their true     
character4 ,fixed to one spot1  living  
in communities1 and exceedingly minute1 
in short1 with many of  the outward     
features of the true corallines1 they   
were yet found to  possess a structure  
so complex and highly organized1 as to  
entitle them  to rank among the higher  
tribes of the invertebrate animals1 and 
they  are now accordingly pretty        

generally subjoined to the mollusca1    
under  the name of ,bryozoa4    ,each   
bryozoon consists externally of a single
 horny or calcareous cell1  sometimes   
furnished with a valve-like lid that    
folds down when the  animal withdraws   
itself4 ,when danger is past1 and the   
creature begins  again to emerge1 the   
upper parts1 which were drawn in like   
the inverted  finger of a glove1 are    
pushed out until a series of tentacles1 
covered  with minute hair-like bodies1  
called cilia1 are expanded4 ,the        
vibratile  motion of these cilia causes 
a constant current in the direction of  
the mouth1 which lies in the centre of  
the hollow whence the tentacles  spring2
 animalcules are in this way brought in 
rapid succession within  reach of the   
mouth1 and form a never-failing source  
of nourishment4  ,the interior is       
greatly more complex than that of the   
polypi4 ,the  stomach is connected above
 with a cavity like the gizzard of a    
bird1  furnished with pointed sides1    

which serve to triturate the food before
  it passes into the stomach4 ,there is 
also a distinct intestine4 ,the         
muscular action for the expansion and   
retraction of the animal is  highly     
developed1 and the generative system is 
a greatly more complex  one than that of
 the polyps already referred to4 ,in    
short1 however  closely they might be   
thought to resemble the corals in       
outward form1  their internal structure 
undoubtedly links them with a much      
higher type  of organization1 and       
justifies the naturalist in subjoining  
them as a  sub-order to the mollusca4   
,the cells are grouped at short         
intervals along a horny or calcareous   
substance1 that sometimes encrusts      
sea-weed1 or spreads out as a flat      
leaf-like membrane1 or rises into       
cup-shaped or dendritic forms4 ,a       
series of cells constituting a separate 
and independent colony1 is  termed a    
polypidom4 ,the cells are further       
connected together by an  external      

jelly-like integument1 in which they are
 sunk1 and which  serves to secrete the 
calcareous particles from the sea4      
,it is interesting to know that         
creatures so minute and yet so complexly
  organized1 existed abundantly in the  
seas of the ,carboniferous period4  ,no 
less than fifty-four species are        
enumerated as having been obtained  from
 the carboniferous strata of the        
,british ,islands1 and scarcely a  year 
passes without one or two new species   
being added to the list4  ,the most     
frequent belong to the genus            
,fenestella1 or little window1  a name  
indicative of the reticulated grouping  
of the branches like the  wooden        
framework of a window4 ,each of these   
branches1 or interstices1  as they are  
called1 was more or less straight1 being
 connected with  that on either side by 
a row of transverse bars1 just as the   
central  mullion of an abbey window is  
connected with the flanking ones by     
means  of cross-bars of stone4 ,not     

unfrequently some of the branches       
subdivide  into two1 as we saw to be the
 case among the cup-corals4             
,illustration3 ,fig4 #ah4--;a1          
,fenestella oculata 7,m',coy71 nat4     
size2  b1 magnified portion of the same4
    ,fig4 #ah illustrates the relative  
disposition of these branches4 ,in a1   
the natural size of the fossil is given2
 b is a portion of the same  magnified1 
to show the form and arrangement of the 
ribs and cross-bars4  ,each rib is seen 
to have two sides separated by a rounded
 ridge4 ,along  each side there runs a  
row of circular hollows or cells1 every 
one  of which once formed the abode of a
 distinct bryozoon4 ,the back or  inner 
surface of the branch1 was ribbed and   
granulated irregularly1  without any    
cells4 ,the connecting bars or          
dissepiments have no cells1  and served 
merely to bind the interstices together 
into one firm  organically-united       
polypidom4 ,such fragments as that here 
figured  are the most usual traces to be

 found of these animals among the       
carboniferous rocks4 ,but perfect       
specimens are sometimes met with which  
show how delicate and graceful a        
structure the polypidom of some of the  
fenestell must have been4 ,all these    
bars sprung from a common point  as     
their basis1 and rose up in the form of 
a cup4 ,it was1 in short1 a  cup of     
network1 hung with waving tentacles and 
quivering cilia4 ,i have  seen some     
dissections of flowers in which all the 
softer tissue had  been removed1 so as  
to present only the harder veinings of  
the leaves  with their thousand         
ramifications bleached to a delicate    
whiteness4  ,out of these               
skeleton-leaves there were formed groups
 of lilies1  crocuses1 geraniums1 and   
roses1 like patterns of the finest      
gauze4 ,some  of the larger-stemmed     
leaves that had been artistically       
moulded into a  tulip form1 seemed not  
inaptly to represent the general contour
 of the  skeleton of the old            

carboniferous fenestella4    ,an allied 
form is called the ,retepora4 ,it       
differed from the previous  organism in 
having the ribs not straight1 but       
irregularly anastomosing1  that is1     
running into and coalescing with each   
other1 so as to form  a close network   
with oval interspaces1 like a piece of  
very minute  wire-fence4 ,each of these 
wavy libs was completely covered over on
 one  side with oval pores or cells1    
which1 as in the fenestella1 formed the 
abode of the living animals4 ,the       
differences in organization between  the
 animal of fenestella and that of       
retepora can1 of course1 only be  matter
 of speculation4 ,the general structure 
in both must1 however1  have been pretty
 much alike4 ,the former genus is now no
 longer extant1  but the latter1 which  
was ushered into the world during the   
era of the  ,old ,red ,sandstone1 still 
lives in the deeper recesses of the     
ocean1 and  manifests in its structure  
and habits the leading characteristics  

of  bryozoan life4    ,what rambler     
among old lime-quarries is not familiar 
with the  stone-lily1 so abundant an    
organism in most of the ,palozoic and   
many of the ,secondary limestones8 ,in  
some beds of the carboniferous          
limestone its abundance is almost       
incredible4 ,i have seen a weathered    
cliff in which its remains stood out in 
bold relief1 crowded together1  to use  
an expression of ,dr4 ,buckland's1 as   
thickly as straws in a  corn-rick4 ,the 
joints of this animal1 known now as     
entrochi or  wheel-stones1 forced       
themselves on the notice of men during  
even the  middle ages1 and an           
explanation was soon found for their    
existence4  ,from their occurring       
largely about the coast at ,holy        
,island1 they were  set down as the     
workmanship of ,saint ,cuthbert4        
,on a rock by ,lindisfarne1      ,st4   
,cuthbert sits and toils to frame       
,the sea-born beads which bear his name4
    ,the aged saint was represented as  

employing his nights in this highly     
intellectual task1 sitting on a lone    
rock out in the sea1 and using an       
adjacent one as his anvil4        ,such 
tales had ,whitby's fishers told1       
,and said they might his shape behold1  
,and hear his anvil sound1      ,a      
deaden'd clang1--a huge dim form        
,seen but1 and heard1 when gathering    
storm        ,and night were closing    
round4    ,but these wheel-stones were  
not the only geological curiosities  to 
which this simple mode of explanation   
was applied4 ,in the same  storied      
neighbourhood there occur in            
considerable numbers the round  whorled 
shells of the genus ,ammonites4 ,these  
were gravely set down  as petrified     
snakes wanting the head1 and their      
petrifaction and  decapitation were     
alike reverently ascribed to the power  
of the sainted  abbess of ,whitby4      
,they told      ,how of a thousand      
snakes each one      ,was changed into a
 coil of stone      ,when holy ,hilda   

prayed4    ,the stone-lily belonged to  
that large class of animals ranked      
together  as ,echinodermata1 a name     
taken from one of the leading           
subdivisions  of the group--the ,echini 
or sea-urchins4 ,it seems to have been  
one  of the earliest forms of life upon 
our planet1 its disjointed stalks       
occurring largely in some of the oldest 
,silurian limestones4 ,in the           
,secondary ages it began gradually to   
wane1 until at the present day its      
numerous genera appear to be represented
 by but the comatula and the            
pentacrinite1 two tiny forms that float 
their jointed arms in the  profounder   
depths of the sea4    ,illustration3    
,fig4 #ai4--;a1 ,cyathocrinites planus4 
b1 ,encrinal  stem1 with uniform joints4
 c1 ,single joint1 or wheelstone4    ,as
 its name imports1 the stone-lily or    
encrinite had a plant-like  form4 ,it   
consisted of a long stalk fixed by the  
lower end to the  sea-bottom1 and       
supporting above a lily-shaped cup1 in  

which were  placed the mouth and stomach
 7,fig4 #ai a74 ,the stalk consisted of 
circular plates 7some of them not so    
thick as a sixpence71 having  their flat
 sides covered with a set of minute ribs
 radiating from the  centre1 and so     
arranged that the prominent lines of one
 joint fitted  into corresponding       
depressed lines of the adhering ones4   
,the centre  of each joint was pierced  
by a small aperture1 like the axle of a 
wheel1 which1 when the stem was entire1 
formed part of the long tube  or canal  
that traversed the centre of the stem1  
and served to convey  aliment to the    
remotest part of the animal4 ,detached  
joints have thus  a wheel-like          
appearance 7,fig #ai c71 and hence their
 common name of  wheel-stones4 ,in many 
species they were not all of the same   
diameter1  but alternately larger and   
smaller1 as if the stem had been made up
 of  a tall pile of sixpences and       
threepenny pieces in alternate          
succession4  ,this variation gives a    

remarkably elegant contour to the stalk4
 ,the  flower-shaped cup consisted of a 
cavity formed of geometric calcareous   
plates1 and fringed along its upper     
margin with thick calcareous  arms1 five
 or ten in number1 that subdivided into 
still more slender  branches1 which were
 fringed along their inner side with    
minute cirri  or feelers4 ,all these    
subdivisions1 however fine1 were made up
 of  calcareous joints like the stalk1  
so that every stone-lily consisted  of  
many thousand pieces1 each perfect in   
its organization and delicate  in its   
sculpturing4 ,one species peculiar to   
the ,liassic formation  7,extracrinus   
,briareus7 has been calculated to       
contain one hundred and  fifty thousand 
joints6    ,the effect of this minute   
subdivision was to impart the most      
perfect  flexibility to even the        
smallest pinnule4 ,the flower could     
instantly  collapse1 and thus the       
animals on which the encrinite preyed   
were  seized and hurried to the central 

mouth4 ,the lower part of the cup1 or   
pelvis1 as it is called1 contained the  
stomach and other viscera1 and          
communicated with the most distant part 
of the body by the central  alimentary  
canal4    ,but while this continued the 
general type on which the encrinites    
were constructed1 it received many minor
 modifications4 ,these were  effected   
chiefly on the form and arrangement of  
the cup-shaped body  and its appendages1
 and form now the basis of our          
classification  into genera and species4
 ,thus1 in the genus known as           
,platycrinus1  the lower part of the cup
 consists of two rows of large hexagonal
 or  polygonal plates fitting closely   
into each other1 while the upper part   
rises into a dome-like elevation formed 
of smaller polygonal plates1  which have
 often a mammillated exterior4 ,the arms
 sprang from the  widest part of the    
body where the large pieces of the lower
 cup were  succeeded by the small pieces
 of the upper4 ,in an ,irish species    

7,p4  triacontadactylus71 the arms      
subdivided into thirty branches1 each   
fringed with minuter pinnules and       
folding round the central elevated      
spire1 as the petals of a crocus close  
round its central pistil4 ,in  another  
encrinite 7,poteriocrinites conicus71   
the cup was shaped like  an inverted    
cone1 the point being affixed to the    
summit of the stalk1  and the broad part
 throwing out from its edges the lateral
 arms4 ,the  ,woodocrinus macrodactylus 
had such gigantic arms as well-nigh to  
conceal the position of the cup1 which  
relatively was very small in  size4     
,they sprang from near the base of the  
cup1 five in number1 but  soon          
subdivided each into two1 the ten arms  
thus produced being closely  fringed    
with the usual jointed calcareous       
pinnules4    ,the size and arrangement  
of the joints of the stalk also differed
 in  different genera4 ,the ,woodocrinus
 and many others had them alternately   
broad and narrow1 like a string of      

buttons of unequal sizes2 others had    
all the joints of the same relative     
diameter 7,fig4 #ai b71 so that the     
stalk tapered by a uniform line from    
base to point4 ,i may add1 that  on some
 specimens of both these kinds of stems1
 we can notice small1  solitary areol1  
or scars1 which may mark the points of  
attachment  of cirri1 or little         
tentacles1 like those on the stem of the
 existing  ,pentacrinite4 ,but though   
each of these varieties of stem is      
peculiar to  a certain number of genera1
 there is often so little distinction   
among  the detached fragments1 that it  
becomes difficult1 indeed impossible1   
to assign each to its appropriate       
individual4 ,we may say1 that certain   
encrinal stalks could not have belonged 
to a poteriocrinus1 and others  could   
never have fitted on to the cup of an   
actinocrinus2 but we cannot  often say  
positively to what species they actually
 would have fitted4  ,there can1        
however1 be no doubt about their being  

encrinites1 and so  we have in them a   
safe and evident test for the origin of 
the rock in  which their remains occur4 
,but to this ,i shall afterwards revert4
    ,in the meantime1 ,i would have the 
reader to fix the stone-lily in  his    
memory as peculiarly and emphatically a 
marine animal1 dwelling  probably in the
 deeper and stiller recesses of the     
ocean1 like the  ,pentacrinite of       
existing times4 ,let him try to remember
 it1 not in the  broken and sorely      
mutilated state in which we find it     
among the blocks  of our lime-quarries1 
but as it must have lived at the bottom 
of the  carboniferous seas4 ,the oozy   
floor of these old waters lay thickly   
covered with many a graceful production 
of the deep1 submarine gardens  of      
,violet1 asphodel1 ivy1 and vine-leaves1
 roses and lilies1      ,coral and      
sea-fan1 and tangle1 the blooms and the 
palms of the ocean4    ,amid this rich  
assemblage of animated forms1 the       
stone-lilies must have  occupied a      

conspicuous place4 ,grouped in thick-set
 though diminutive  forests1 these      
little creatures raised their waving    
stems1 and spread  out their tremulous  
arms1 like beds of tulips swaying in the
 evening  air4 ,their flower like cups1 
so delicately fringed1 must have        
presented  a scene of ceaseless activity
 as they opened and closed1 coiling up  
while the animal seized its prey1 or on 
the approach of danger1 and  relaxing   
again when the food had been secured1 or
 when the symptoms  of a coming enemy   
had passed away4 ,only from this        
animated action  would one have been apt
 to conjecture these organisms to be    
other  than vegetable4 ,they lived1 too1
 not in detached patches1 like the      
tulip-beds of the florist1 but1 to judge
 from the abundance of their  remains1  
must have covered acre after acre1 and  
square mile 'after  square mile1 with a 
dense growth of living1 quivering       
flowers4 ,as one  individual died out1  
another took its place1 the decaying    

steins and  flowers meanwhile falling to
 pieces among the limy sediment that lay
  thickly athwart the sea-bottom1 and   
contributing1 by their decay and        
entombment1 to build up those enormous  
masses of rock1 known as the            
mountain-limestone1 which stretch       
through ,yorkshire and the central      
counties into ,wales4    ,in addition to
 the stone-lilies1 the carboniferous    
rocks contain the  remains of several   
other kinds of ,echinodermata4 ,some of 
them find  their nearest modern         
analogues among the sea-urchins so      
common on  our shores2 but ,i pass on to
 notice another very interesting class  
of fossils known by the name of         
,crustacea1 and still abundantly        
represented1 the crab and lobster being 
familiar examples4    ,the ,crustacea1  
so called from the hard crust or shell  
which envelops  them1 form1 with all    
their orders and genera1 a very numerous
 family4  ,they are of interest to us as
 containing among their number some of  

the oldest forms of life4 ,away down in 
the lower ,silurian rocks1 among  the   
most ancient fossiliferous strata1 we   
find the crustacean with  its armour of 
plates and its prominent sessile eyes   
set round with  lenses1 still visible on
 the stone4 ,thus1 on the first page of 
the  stony records of our planet's      
history are these primeval organisms    
engraved4 ,in some localities1 where    
oxide of iron is largely present1  they 
are coated with a bright yellow         
efflorescence1 and stand out  from the  
dull grey stone like figures embossed in
 gold4#ca ,on all  the subsequent leaves
 of this ancient chronicle1 we can      
detect the  remains of crustacean life1 
and many tribes still swarm in our seas 
and lakes4 ,it is interesting1 however1 
as marking the onward progress  of      
creation1 to notice that1 though this   
great family has continued  to live     
during all the successive geological    
ages1 its members have  ever been       
changing1 the older types waning and    

dying out1 while newer  genera rose to  
supply for a time their place1 and then 
passed away  before the advance of other
 and yet later forms4 ,the trilobites   
that  meet us on the very verge of      
creation1 swarmed by millions in the    
seas  of the ,silurian ages1 diminished 
gradually during the era of the ,old    
,red ,sandstone1 and seem to have died  
out altogether in the times of  the     
,coal4 ,in no ocean of the present day  
is a trace of any of their  many genera 
to be seen4 ,the decapods1 of which our 
common crab is a  typical form1 began to
 be after the trilobites had died out4  
,in all the  subsequent eras they       
gradually increased in numbers1 and at  
the present  day they form the most     
abundant order of crustacean life4 ,the 
history  of these two divisions1 to     
adopt ,agassiz's mode of representation1
 may  be illustrated by two long        
tapering bands like two attenuated      
pyramids4  ,the one has its broad base  
resting upon the existing now1 and      

thinning  away into the past1 till at   
last it comes to a point4 ,at a little  
interval the apex of the other begins1  
and gradually swells outward as  it     
recedes1 till the wide base terminates  
at the first beginnings of  life4       
,footnote #ca3 ,such is the aspect of   
the organisms in some of the  ,silurian 
sandstones near ,girvan4 ,i have seen   
the same bright tint  on a set of       
fossils from the ,llandeilo flags of    
,wales1 and from the  slates of         
,desertcreat1 ,ireland1 and have        
disinterred similarly gilded  shells    
from the vertical greywack slates of the
 ,pentland ,hills and  ,peeblesshire4   
,nothing can be more beautiful than the 
aspect of these  fossils when first laid
 open1 but the bright gleam eventually  
passes  away on exposure4    ,but there 
are also some orders that would be best 
illustrated by a  long line of nearly   
uniform breadth1 extending from the     
first geologic  periods to the present  
day4 ,in other words1 they seem to have 

retained  during all time pretty much   
the same amount of development4 ,i shall
  confine my notice of the carboniferous
 ,crustacea to the description of  a    
single genus belonging to a family that 
seems to have begun during  the period  
of the ,lower ,silurian1 and still      
flourishes abundantly in  existing      
waters4    ,illustration3 ,fig4 #bj4    
#a4 ,carboniferous cypris1 nat4 size1   
and magnified4    #b4 ,recent cypris1   
highly magnified4    #c4 ,carboniferous 
king-crab 7,limulus trilobitoides74     
,the genus to which ,i refer is a       
well-known fossil in some parts of  the 
,coal-measure series1 and has been named
 ,cypris4 ,the shells of  cyprides are  
very minute1 considerably less than the 
heads of small  pins 7,fig4 #bj-a74     
,they can be seen quite well1 however1  
without the  use of a magnifying power4 
,in shape they resemble beans1 and when 
seen  scattered over a slab of shale1   
look much liker seeds than the relics   
of animal life4 ,yet1 under this simple 

exterior1 they concealed a  somewhat    
complex organization4 ,the little       
bean-shaped shells1 which  are all that 
now remains to us of their structure1   
formed the crust  or outer shell in     
which their viscera were contained1 and 
answered to  the massive carapace and   
segments of the crab4 ,they consisted of
 two  valve-like cases fitting to each  
other1 so as to resemble the united     
valves of a bivalve shell4 ,from the    
upper end there were protruded  through 
the opening between the valves a pair of
 slim jointed antenn1  each furnished at
 its point with a bundle of minute      
hair-like cilia  7,fig4 #bj-b74 ,these1 
when set in rapid motion1 served to     
impel the  creature through the water4  
,the legs1 four in number1 were         
encrusted  with the same hard membrane1 
and had the same jointed structure as   
those of our common shrimps and crabs4  
,the foremost pair were pointed  like   
the antenn with fine hairs1 the         
incessant action of which  assisted the 

animal in swimming4 ,of the little1     
confluent1 sessile  eyes1 the delicate  
branchia or gills1 and all the complex  
internal  structure of the nervous1     
circulating1 and other systems1 no trace
  has survived on the stone2 but enough 
of the general external form is  left to
 show us the true affinities of these   
organisms in the animated  world of the 
present time4 ,by studying the forms and
 habits of the  cyprides that swarm in  
some of our ponds and marshes1 a just   
conception  is obtained of the structure
 and habitat of the animals that once   
occupied the minute bean-shaped shells1 
which lie by millions among the  shales 
of the ,carboniferous system4 ,from such
 a comparison we infer1  that just as   
the cyprides of to-day are fresh-water  
animals abounding  among the green slime
 of stagnant pools1 so1 in past ages1   
they must  have preserved with the same 
organization the same habits4 ,and thus 
we arrive at the important conclusion   
that the strata in which the  remains of

 cyprides abound must have been         
deposited in lakes or rivers4  ,this    
gives us a key by which to interpret    
some of the changes of a  geological    
system1 and the ancient physical        
revolutions of large tracts  of country4
    ,the shales of the coal-measures    
sometimes contain the cypris cases in   
such abundance as to derive therefrom a 
sort of fissile structure4  ,it should  
be borne in mind1 however1 that each    
animal may during its  lifetime have    
possessed in succession several of these
 cases4 ,among the  shell-bearing       
molluscous animals1 the little shell    
which contains the  creature in its     
youngest stages remains ever after as an
 integral part  of the outer calcareous 
case4 ,as the inhabitant grows1 it      
continues  to add band after band to the
 outer edge of the shell1 each of which1
  whilst preserving the general symmetry
 and proportions of the whole           
structure1 increases its dimensions in  
every way4 ,among the univalves1  such1 

for example1 as the turritella1 so      
common on our shores1 the  layers of    
growth succeed each other like the steps
 of one of those  long spiral stairs    
that our feudal forefathers loved to    
build from  the court-yard to the       
watch-tower of their castles4 ,each new 
layer  exceeding in bulk its            
predecessors1 adds a new step to the    
ascending  pile1 and thus the           
ever-widening mouth winds spirally      
upwards around  the central pillar4 ,the
 bivalves exemplify the same principle4 
,the  successive additions are made in a
 crescent form to the outer edges1  and 
form those prominent concentric ridges  
so conspicuous on many of  our commoner 
shells1 such1 for instance1 as some of  
those in the genera  ,astarte and       
,venus4    ,but the architecture of the 
,crustacea 7and1 of course1 that of the 
cyprides7 is conducted on a very        
different principle4 ,their houses      
admit of no additions or enlargements1  
and so1 when the animals find           

themselves getting somewhat straitened1 
they retire to a sheltered  spot1 and   
there1 separating the walls that hem    
them in1 crawl out like  soft lumps of  
dough4 ,the outer membrane of the       
moulted animal quickly  acquires        
strength and hardness1 and in a day or  
two the renovated  creature is as       
healthy and vigorous as ever4 ,in this  
process it is  not merely an external   
shell1 like that of a mollusc1 which is 
thrown  off1 but a veritable skin1 so   
that when the old shell is abandoned  it
 frequently could not be detected on a  
first glance to be empty1  the outer    
crust of every leg and joint1 and       
sometimes even of thin  bristles1       
remaining just as in the living animal4 
,it is not unlikely that this process of
 moulting takes place annually  in most 
of the ,crustacea1 so that if we suppose
 a fossil member of the  group to have  
lived six years1 it would have left six 
crusts to be  entombed in any deposits  
that might be forming at the time4 ,of  

course  there would be many chances     
against all the six being preserved1 but
  the possibility of at least several of
 them becoming fossilized should  be    
borne in mind when we speculate on the  
abundance of such organisms  in any     
geological formation4    ,i might refer 
to another very interesting group of    
crustacean animals  known as the        
,limuli1 or king-crabs1 of which there  
were at least  three representatives    
during the times of the ,english        
,carboniferous  system 7,fig4 #bj-c74   
,they are remarkable chiefly for their  
large  crescent-shaped shield1 their    
long sword-like tail1 and their double  
pair of eyes1 of which the outer ones   
are large1 sessile1 and compound1  like 
those of the trilobites1 while the      
middle pair are small1 simple1  and set 
close together on the forehead1 like    
those of the single-eyed  ,cyclops in   
the old mythology4 ,altogether1 with    
their shields1 swords1  watchful waking 
eyes1 strong massive armour1 and great  

size 7for some  of them measure two feet
 in length71 they form a most warlike   
genus4          ,,chapter ,,vi4         
,carboniferous fauna continued--,george 
,herbert's ode on         ,man--,his    
idea of creation--,what nature teaches  
on         this subject--,molluscous    
animals--,range of species in           
time proportionate to their distribution
 in space--,two         principles of   
renovation and decay exhibited alike in 
the         physical world and the world
 of life--,their effects--,the          
mollusca--,abundantly represented in the
 carboniferous                          
rocks--,pteropods--,brachiopods--,produc
tus--,its alliance with                 
,spirifer--,spirifer--,terebratula--,lam
ellibranchs--,gastropods--              
,land-snail of ,nova                    
,scotia--,cephalopods--,structure of    
orthoceras--         ,habits of living  
nautilus4    ,holy ,george ,herbert1 in 
one of the most remarkable odes of the  
seventeenth century1 sang quaintly1 yet 

nobly1 of the dignity of man4  ,he      
looked into the design and nature of the
 human heart1 and saw there  a palace   
that had been built for the abode of the
 ,eternal4 ,deserted  though it might   
be1 broken down and in ruins1 yet there 
still lingered  a trace of its ancient  
glory1 and the whole material world     
still  testified to its inherent        
greatness4 ,he looked abroad on the face
 of  nature1 and saw1 in all its objects
 and all its movements1 a continued     
ministration to man4                ,for
 us the windes do blow2      ,the earth 
doth rest1 heav'n move1 and fountains   
flow4          ,nothing we see1 but     
means our good1          ,as our        
delight1 or as our treasure2      ,the  
whole is1 either our cupboard of food1  
,or cabinet of pleasure4                
,the starres have us to bed2      ,night
 draws the curtain1 which the sunne     
withdraws2          ,musick and light   
attend our head4          ,all things   
unto our flesh are kinde      ,in their 

descent and being2 to our minde         
,in their ascent and cause4    ,the idea
 is a very natural one1 and is          
consequently as old as man  himself4    
,human vanity is soothed by the         
reflection that all this varied  world1 
with its countless beauties1 has been   
designed and arrayed  solely for the use
 of man4 ,and yet1 if we but think of   
it1 such a view  of creation1 however   
natural and pleasing1 is at the best but
 a narrow  and selfish one4 ,it         
assuredly finds no response in nature1  
and grows  more and more out of fashion 
the further our investigations proceed4 
,nature teaches us that long ere man    
appeared upon the earth there were      
successive generations of living things 
just as now2 that the sun  shone1 and   
the waves rolled1 and the wind blew1 as 
they do to-day2 and  that1 on as lovely 
a planet as that whereon we dwell1 there
 lay forests  and prairies nursing in   
abundance animals of long-extinct forms2
 lakes  and rivers1 haunted by creatures

 that find no representatives now2  and 
seas teeming with life1 from the minute 
infusory up to the most  unwieldy       
icthyosaur1 or the most gigantic        
cetacean4 ,and all this1 too1  ere a    
reasoning1 intelligent being had been   
numbered among terrestrial  creatures1  
and when1 perhaps1 each successive      
creation was witnessed  by none save    
those morning stars who sang together1  
and those sons  of ,god who shouted for 
joy4 ,the delight and comfort of the    
human  race formed1 doubtless1 one of   
the many reasons why this globe was so  
bountifully garnished4#cb ,but the      
workmanship of a ,being infinitely      
wise1 and good1 and powerful1 could     
hardly have been other than  complex and
 beautiful4 ,that symmetry and grace    
which we see running  as a silver thread
 through every part of creation1 forms  
one of the  characteristics of the      
,almighty's mode of working4 ,from the  
,fountain  of all ,beauty nothing       
unseemly or deformed can proceed4 ,and  

so we  find1 away back among the ages of
 the past1 that1 though the material    
world might be less complete1 it was not
 less beautiful than now4 ,nay1  those  
bygone millenniums stood higher in one  
respect1 for the eye of  ,god rested    
upon their unsullied glory1 and he      
pronounced them very  good2 but these   
last ages of creation are dimmed and    
darkened1 and  that ,eye now watches a  
world trodden down by the powers of     
evil4 ,there  is profound truth in the  
sublime allegory of ,milton that        
represents  ,sin girt round with        
clamorous hell-hounds1 and the two      
grisly forms  sitting at the farthest   
verge of purity and light1 to keep the  
gates of  darkness and chaos4 ,with the 
introduction of moral evil into our     
planet  came the elements of deformity  
and confusion4 ,the geologist can go    
back  to a time ere yet the harmony of  
nature had been broken4 ,the ,christian 
looks forward to a day when that harmony
 shall be again restored1 and  when     

guilt with all its hideous train shall  
be for ever chased away  from the abodes
 of the redeemed4    ,footnote #cb3 ,in 
connexion with this subject ,i have been
 often struck  with a passage in ,st4   
,paul's ,epistle to the ,colossians1 i4 
#aj1 ,all  things were created by him   
,christ and for --with a view to1  on   
account of him4 ,it is probable that    
these words1 in their full  meaning1    
cannot be understood by us4 ,yet they   
seem to point to ,christ  as at once the
 ,creator1 and himself the acme and     
design of creation2  and perhaps they   
may contain what hereafter shall prove  
the key to  the mystery of creation4 ,on
 this impressive and difficult subject  
the  reader should refer to the closing 
chapter of ,hugh ,miller's ,footprints  
of the ,creator4 ,see also ,m',cosh on  
,typical ,forms1 #b;d edit4 p4 #eca4    
,such thoughts as these sometimes arise 
in the mind of one who labours  much    
among organic remains4 ,by no class of  
fossils are they more  vividly suggested

 than by those which we come next to    
examine--the  various tribes of         
molluscous animals4 ,this results from  
the high  antiquity of these organisms1 
and the similarity of type which they   
have manifested in all ages4 ,in the    
very earliest geological periods  they  
exhibited the same symmetry of external 
form as now1 the same  beauty of        
structure1 and apparently the same      
delicacy of colour4 ,nay1  so closely   
did they resemble their existing        
congeners that we are  seldom at a loss 
as to their affinities1 and can refer   
them to their  places in the scale of   
creation1 and sometimes even to genera  
still  living4#cc    ,footnote #cc3 ,it 
must be admitted1 however1 that not a   
few of the  identifications already made
 are somewhat suspicious ,the natural   
tendency is to perceive resemblances--a 
tendency which even the most  rigid     
science sometimes fails to control4     
,the geological ages saw many strange   
types of creation4 ,one era1 in         

especial1 furnished reptiles which      
united in their structure the snout  of 
the porpoise1 the head of the lizard1   
the teeth of the crocodile1  the paddles
 of the whale1 and the backbone of the  
fish4 ,some displayed  the long pliant  
neck of the swan1 and others careered   
through the  air on wings like those of 
the bat4 ,but the molluscous tribes have
  never exhibited such aberrant forms4  
,the existing classes and orders  of the
 naturalist are still the same as those 
which nourished during  the successive  
geological periods4 ,hence their value  
as evidence of  physical changes in the 
ancient world4 ,hence1 too1 the         
conviction1  forced upon the mind of the
 observer1 that the conditions for the  
support of life never deviated much from
 those now in operation2 that  in place 
of all the varied beauty of the world   
having arisen for the  use of man1 it   
existed millions of years ere the breath
 of life had  been breathed into his    
nostrils2 that in fine1 man is but a    

new-comer1  a creation of yesterday4    
,there is another point suggested by the
 occurrence of mollusca in the          
,carboniferous system1 to which it may  
be well to refer1 namely1 the  curious1 
and as yet not wholly understood fact1  
that the range of  animals in time is in
 some way proportionate to their range  
in space4  ,in other words1 it often    
happens 7so often1 indeed1 as apparently
 to  indicate a law7 that the more      
widely diffused a genus is found to be  
at the present day1 the farther back can
 we trace its remains into the          
geological ages4 ,this fact probably    
depends upon causes1 many of which  are 
still unknown to us2 but the following  
remarks may help the reader  to a notion
 of the general bearings of the         
subject4#cd    ,footnote #cd3 ,the law  
is more especially exemplified by the   
mollusca1  but it may eventually be     
found to characterize other classes4    
,we1  perhaps1 see traces of it in the  
present distribution of the two most    

ancient orders of icthyic life--the     
placoids and ganoids4    ,in the        
profounder recesses of the ocean1 the   
temperature remains more  or less       
uniform all over the globe4#ce ,in these
 undisturbed regions  there occur1 along
 with corals and other humble animals1  
many kinds of  mollusca1 such as        
terebratul1 crani1 scissurell1 c4 ,these
 are very  generally found not to be    
confined to one province or limited     
district1  but to flourish in every sea 
from ,hudson's ,bay to ,hindustan4 ,one 
of  the causes of this wide distribution
 is the uniformity of temperature  that 
characterizes the depths in which they  
live4 ,they can migrate  from one ocean 
to another1 from the torrid zone to the 
polar circle1  without experiencing any 
destructive change in the thermal       
conditions  of their element4 ,and      
provided only they meet with no barrier 
in the  form of a lofty submarine       
mountain chain or profound abyss1 and   
can  secure the requisite food in their 

journey1 we know no reason why some  of 
these shells may not thus extend        
themselves over wide areas4 ,of the  two
 species of rhynconella now living1 one 
inhabits the depths of  the icy sea1 the
 other enjoys the warmer waters that    
lave ,new ,zealand4  ,the species1 in   
this case1 seem 7for the fact cannot yet
 be accepted  as fully proved7 to occupy
 a more limited area1 while the genus   
has a  larger range4    ,footnote #ce3  
,the stratum of constant temperature    
runs in a wave-like  form from pole to  
pole4 ,in the arctic and antarctic      
oceans it is found  at a depth of #dejj 
feet1 whence it slopes upwards so as to 
reach the  surf ice at the temperate    
zone on both sides of the equator4 ,it  
then  gradually sinks down in the warmer
 regions1 till at the equator it is     
#gbjj feet below the sea-level4 ,there  
are thus one tropical and two  polar    
basins separated by two wave-like       
circles1 or1 as a geologist  would say1 
three synclinal troughs separated by two

 anticlinal ridges4    ,now1 a genus    
widely diffused1 and capable of enduring
 great differences  in the temperature  
and other conditions of the ocean1 would
 probably  suffer least from any great  
physical changes4 ,if all the sea at one
  locality were converted into land1 the
 genus would be driven into other       
districts1 and thrive as abundantly as  
ever2 or1 even supposing that it  should
 become locally extinct1 it would still 
be abundantly represented  in other     
oceans of the globe4 ,in the course of  
many ages1 after many  such slow        
revolutions in the configuration of land
 and sea1 the genus  might perhaps      
become greatly reduced in numbers1 until
 at length some  final elevation of the 
sea-bed1 or other change1 might cause   
its total  extinction4 ,in the          
rhynconella1 we perhaps see one of these
 genera in  its last stage4 ,any great  
change in northern latitudes would      
probably  destroy the arctic species1   
and a similar change around ,new        

,zealand  might gradually extinguish the
 southern one4    ,looking1 then1 from  
this point of view into the past history
 of life  upon our planet1 we see that  
such extinctions have often taken place4
  ,at first1 many of these              
widely-diffused genera were created4    
,they  were represented by a large      
number of species as well as            
individuals1  and ranged over all the   
oceans of the globe2 but in tracing out 
their  history1 we mark one species     
after another passing away4 ,some of    
them  lived for but a comparatively     
short period2 others came in with the   
beginning and saw out the end of an     
entire geological system2 but of  all   
these early species there is not now a  
single one extant1 though  some of the  
genera still inhabit our seas4 ,it is   
plain1 therefore1  that but for the     
operation of another principle1 all the 
genera1 too1  would ere this have become
 extinct1 for the whole can contain no  
more  than the sum of its parts2 and if 

these parts are destroyed the whole     
must perish simultaneously4 ,as the     
species of certain genera died out1     
however1 their places were from time to 
time filled up with new ones1  yet the  
rate of increase became ever less and   
less than the rate of  decrease1 so that
 the numbers of such genera grew fewer  
with every  successive period1 and have 
reached their minimum in existing seas4 
,there are instances1 however1 in which 
this ratio was reversed1 the  list of   
added species continually outnumbering  
that of the extinct1  till the genus    
reached its maximum1 when it either     
continued at that  stage till the       
present day1 or began slowly to decline4
    ,in the physical world around us1 we
 behold a perpetual strife between  the 
two great principles of renovation and  
decay4 ,hills are insensibly  crumbling 
into valleys2 valleys are gradually cut 
down1 and their  debris transported to  
the sea4 ,our shores bear witness to the
 slow  but ever onward march of the     

ocean1 whether as shattered cliff's worn
  by the incessant lashing of the surge1
 or as sand-banks and submerged  forests
 that represent the wolds and holms of  
our forefathers4 ,we mark1  too1 how the
 sediment thus borne into the main is   
sowing        ,the dust of continents to
 be2    while the slow elevation of     
large tracts of country1 or the sudden  
upheaval of others1 shows us by how     
powerful an agency the balance of  land 
and sea is preserved1 and how sometimes 
the paroxysm of an hour  may effect a   
mightier change than the wasting and    
decay of a thousand  years4 ,we choose  
to call these two principles            
antagonistic1 because in  their effects 
they are entirely opposite2 yet there is
 no discordance1  no caprice in their   
operation4 ,each works out its end1 and 
the result  is the harmony and stability
 of the face of nature4    ,in the world
 of life1 too1 there seems to have been 
a double principle  of decline and      
renewal4 ,the natural tendency of       

species and genera1  like that of       
individuals1 has been towards           
extinction4 ,why it should be  so we    
know not1 further than that they are for
 the most part influenced  by every     
change in physical geography4 ,but they 
probably obey a still  higher law which 
governs their duration1 as the laws of  
vitality govern  the life of an         
individual ,if we are but slightly      
acquainted with the  agency by which the
 degradation of land is                 
counter-balanced1 we are  still more    
ignorant of the laws that preserve the  
balance of life4  ,creation is a        
mystery1 and such it must for ever      
remain4 ,so1 too1 are  the principles on
 which it has been conducted4 ,we can   
but mark their  results4 ,we see new    
species appear from time to time in the 
upward  series of the geological        
formations1 but they tell not whence    
they  came4 ,of two genera created      
together at the beginning1 one ere long 
died out1 but the other still lives2 yet

 here there is assuredly  nought like   
discordance or caprice4 ,nay1 these two 
principles--death  and creation--have   
been in active operation all through the
 ages1 and  the result is that varied   
and exquisitely beautiful world wherein 
we  dwell4    ,the ,mollusca are so     
named from the soft nature of their     
bodies1 and are  familiar to us as      
exemplified in the garden-snail and the 
shells of the  sea-shore4 ,the general  
type upon which they are constructed is 
that of  an external muscular bag1      
either entire or divided into two1      
called  the mantle1 in which the viscera
 are contained4 ,in most of the orders1 
they have likewise an outer hard        
calcareous shell1 consisting of one or  
more parts4 ,it is of course this shell 
alone that can be detected in  the      
rocks1 but by attending to the relations
 between the living animals  and their  
shells1 we ascertain the nature and     
affinities of the fossil  species4      
,few who ramble by the sea-shore1       

gathering limpets1 whelks1 and  cockles1
 are aware how complex an anatomy is    
concealed within one  of those brown    
discoloured shells4 ,there are elaborate
 nervous and  muscular                  
systems--sometimes several hearts with  
accompanying arteries  and veins--often 
dozens of rudimentary eyes--capsules    
which perform  the function of          
ears--jaws1 teeth1 a strongly armed     
tongue--gullet1  gizzard1 stomach1      
liver1 intestine1 and complete breathing
 apparatus4  ,the structure and grouping
 of these parts vary in the different   
genera  and orders1 and upon such       
variations is founded the classification
 of  the naturalist4 ,thus1 the mollusca
 of the highest class are called  the   
,cephalopoda1 or head-footed1 because   
their feet1 or rather  arms1 are slung  
in a belt round the head4 ,they contain1
 among their  number1 the cuttle-fish1  
with its curious internal bone that     
shadows  forth1 as it were1 the coming  
of the vertebrate type2 and the         

nautilus1  with its many-decked vessel  
of pearl4 ,the second class is termed   
the  ,gastropoda1 or belly-footed1 as   
the genera embraced under it  creep on  
the under side of the body1 which is    
expanded into a broad  retractile foot4 
,the common snail and whelk are familiar
 examples4 ,the  third class is formed  
by the ,pteropoda1 or                   
wing-footed--delicate  animals1 found   
only in the open sea1 and remarkable for
 a pair  of wing-like expansions or fins
 on the sides of the mouth4 ,the        
,lamellibranchiata form the fourth      
class1 and receive their name  from the 
laminated form of their branchia1 or    
gills4 ,they contain the  two-valved    
shells1 such as the oyster and scallop1 
and are one of the  most abundant groups
 of animals on our coasts4 ,the fifth   
class consists  of the ,brachiopoda1 or 
arm-footed molluscs a name given to them
  from their long spiral arms1 once     
thought to be the instruments of        
motion1 but now ascertained only to     

assist in bringing the food to the      
mouth4 ,the sixth1 and humblest class1  
has received the designation of         
,tunicata1 from the thick bladder-like  
tunic1 or sac1 which supplies  the place
 of an outer shell4    ,the geologist   
finds the remains of all these classes  
in the different  rock-formations of the
 crust of the earth4 ,they flourished so
  abundantly in the earliest seas1 that 
the first geological period  has        
sometimes been called the ,age of       
,molluscs2 and1 during all the          
subsequent eras1 they held a prominent  
place among the inhabitants of  the     
deep4 ,let us look for a little at their
 development in the times of  the       
,carboniferous system4    ,as the       
,carboniferous group of rocks exhibits  
the remains of ocean-bed1  lake-bottom1 
and land-surface1 so we find in it      
shells of marine1  fresh-water and      
7though rarely7 terrestrial mollusca4   
,the marine  genera greatly predominate1
 just as the shells of the sea at the   

present day vastly outnumber those      
either of lakes or of the land4 ,in     
,england they occur chiefly in the lower
 part of the formation1 giving a        
characteristic stamp to the deep series 
of beds known as the mountain           
limestone4 ,there they are associated   
with the corals and stone-lilies        
already described--all productions of   
the sea4 ,in ,northumberland1  however1 
and generally throughout ,scotland1 they
 occupy a somewhat  different position4 
,the great mountain limestone of central
 ,england  gets split up into           
subdivisions as it proceeds northward1  
and beds of  coal1 full of land plants1 
become mingled with the ordinary marine 
strata4 ,sometimes we may find a group  
of brachiopods scattered over the       
macerated stem of a stigmaria2 and the  
writer has himself collected a          
sigillaria in a limestone crowded with  
stone-lilies and producti4  ,but this   
intermingling is still further carried  
on in the upper part  of the series4    

,the coal-beds1 with their underclays   
and stigmaria  rootlets1 evidently      
representing ancient vegetation with the
 soils  on which it grew1 are succeeded 
by beds of limestone1 full of marine    
mollusca2 and these1 again1 are erelong 
replaced by sandstones1  shales1 and    
ironstones1 charged with land-plants and
 fresh-water  shells4 ,to this curious  
blending of very different organic      
remains1 ,i  shall have occasion to     
refer more at large in a subsequent     
chapter4 ,i  mention it now as a sort of
 apology for the dryness of details     
which  it is necessary to give1 in order
 to complete our picture of the         
carboniferous fauna1 and to understand  
the principles upon which the  ancient  
history of the earth is deciphered4     
,illustration3 ,fig4 #ba4    ,of the    
,pteropoda1 we have1 as yet1 but one    
carboniferous genus1  the conularia     
7,fig4 #ba74 ,it was a slim delicate    
shell1 in shape an  oblong cone1 having 
four sides1 finely striated with a sort 

of zig-zag  moulding like that of the   
,norman arch4 ,each of the four angles  
was  traversed along its whole extent by
 a narrow gutter-like depression1  and  
this style of fluting1 combined with the
 markings on the sides1  imparted no    
little elegance to the shell4 ,the      
conularia is not a  common fossil4 ,it  
has been found among the coal-bearing   
strata of  ,coalbrook-,dale1 and was    
noticed long ago by ,dr4 ,ure in his    
,history of  ,rutherglen4    ,the       
,brachiopoda are bivalve molluscs1 but  
unlike most other molluscs  they are    
rooted to one spot1 and destitute of any
 power of locomotion4  ,their shells are
 unequal1 the dorsal1 or upper valve1   
being smaller  and usually more bulged  
out than the under or ventral valve1    
which  in most species is prolonged at  
its narrow end into a kind of beak4  ,in
 the terebratula this beak has a little 
circular hole1 from which  there emerges
 a short peduncle or stalk1 that fixes  
itself firmly to a  rock or other       

substance at the sea-bottom1 and serves 
the purpose of  an anchor and cable to  
keep the little vessel safely moored4   
,when the  shells are detached1 these   
perforated ventral valves have so       
exactly  the form of the old ,roman     
lamps1 that they were called ,lampades1 
or lamp-shells1 by the old              
naturalists4#cf ,other species1 as the  
lingul1 have no beak1 and the long      
peduncle passes out between the  valves1
 which are of nearly equal size1 and    
have been compared to the  shape of a   
duck's bill4 ,in yet another genus1 the 
crania1 there is  no peduncle1 but the  
animal adheres by its lower valve1 much 
like  the oyster1 and may often be seen 
clustered in groups on decayed sea      
urchins or other organisms1 particularly
 in the chalk formation4    ,footnote   
#cf3 ,see the excellent ,manual of      
,mollusca1 by ,woodward1 p4  #bji4      
,the internal structure of these animals
 is singularly beautiful4 ,the  inner   
surface of each valve is lined with a   

soft membranous substance1  called the  
pallial lobe1 the margin of which is set
 round with stiff  hair-like bristles1  
that prevent the ingress of any foreign 
body likely  to interfere with the play 
of the delicate filaments of the arms4  
,these  two soft lobes are furnished    
with veins1 and supply the place of a   
breathing apparatus4 ,the body of the   
animal occupies not quite a third  part 
of the interior of its valves1 and is   
situated at the narrow end4  ,there are 
thus two distinct regions within the    
shell1 separated from  each other by a  
strong membrane1 through the centre of  
which is the  opening of the mouth4 ,the
 smaller cavity next the hinge contains 
the  viscera1 and the outer larger one1 
the folded and ciliated arms4 ,these    
arms form one of the most characteristic
 features of the brachiopods4  ,they are
 two in number1 and proceeding from the 
margin of the mouth1  advance into the  
outer empty chamber of the shell1 and   
return upon  themselves in spiral curves

 and folds4 ,they are fringed with slim1
  flat1 narrow filaments1 set along the 
arm like teeth along the back of  a fine
 comb4 ,though called arms1 these long  
ciliated appendages are  rather         
enormously protruded lips4 ,the         
vibratory action of the fringes  causes 
currents to set inwards towards the     
mouth1 which is placed at  the inner end
 or base of the arms4 ,to support these 
long convoluted  arms1 many of the      
genera are furnished with slender hoops 
of hard  calcareous matter1 which are   
hung from the dorsal valve1 and are     
still  found within the shells of some  
of the most ancient fossil brachiopods4 
,the little visceral cavity contains the
 complex groups of muscles for  opening 
and closing the valves1 a simple        
stomach1 a large granular  liver1 a     
short intestine1 two hearts1 and the    
centre of the nervous  system4 ,without 
going into the details of these various 
structures1  the reader will see that   
the brachiopoda are really a highly     

organized  tribe2 and ,i am thus        
particular in the enumeration1 partly   
that he may  the better understand the  
mechanism of the carboniferous shells of
  that type1 and partly that he may mark
 how the oldest forms of life1  those   
that meet us on the very threshold of   
animated existence1 were  not low in    
organization1 but possessed an anatomy  
as complex as it was  beautiful4    ,who
 that has ever wielded an enthusiastic  
hammer among the richly  fossiliferous  
beds of the mountain limestone1 does not
 remember with  delight the hosts of    
delicately fluted shells that the labour
 of an  hour could pile up before him8  
,there was the striated productus1  with
 its slim spines scattered over the     
stone4 ,there1 too1 lay the  spirifer   
with its broader plications1 its toothed
 margin1 and its  deeply indented valve4
 ,less common1 and so more highly       
prized1 was the  slimly-ribbed          
rhynconella1 with its sharp1 prominent  
beak1 or perhaps  the smooth1 thin      

terebratula1 with its colour-bands not  
yet effaced4  ,these were pleasant      
hours1 and their memory must dwell      
gratefully  among the recollections of  
one whose avocations immure him         
throughout  well-nigh the livelong year 
amid the din and dust of town--the fumum
  et opes strepitumque ,rom4            
,illustration3 ,fig4 #bb4--,productus   
giganteus4    ,in the productus the     
dorsal valve is sometimes quite flat1   
while  the ventral is prominently       
arched1 and the shell resembles a little
  cup with a flat plate of the same     
diameter placed over it4 ,usually1      
however1 both the valves are            
concavo-convex1 or arched in the same   
direction like two saucers placed within
 each other4 ,the exterior  surface of  
each valve is differently ornamented in 
the various species4  ,a very common    
style of sculpturing is by a set of fine
 hair-like  longitudinal ribs1 diverging
 more or less regularly from the hinge  
line  to the outer margin4 ,in some     

species these ribs are wider1 and are   
furnished with little prominent scars4  
,in others 7as ,p4 punctatus7  a set of 
semicircular ridges runs round the      
shell1 narrowing as they  converge from 
the outer lips to the centre of the     
hinge line1 and  bearing each an        
irregular row of small scars or         
tubercules4 ,some of  the species are   
very irregularly ornamented into a sort 
of wrinkled  surface1 in which the stri 
seem1 as it were1 thrown over the valves
 in  bundles at random4    ,the         
productus was furnished with slender    
hollow spines1 which rose up  from the  
surface of either valve1 chiefly1       
however1 about the hinge4 ,in  ,p4      
spinosus they were long and stout1 like 
thin rush stalks1 while in  the smaller 
species they rather resembled stiff     
bristles4 ,the use of  these spines is  
not very well made out4 ,as most of the 
producti appear  to have been free1 that
 is1 without any peduncle fixing them to
 the  sea-bottom1 it has been           

conjectured that the spines1 by sinking 
deep  into the mud1 may have served the 
place of a peduncle to moor the shell4  
,as regards size1 the productus is very 
variable4 ,you may gather some  species 
in the young form1 not larger than peas1
 while others may  reward your search1  
having a breadth of six or eight inches 
7,p4  giganteus74 ,but however much they
 may vary in dimensions1 they usually   
remain pretty constant in their         
abundance1 being among the most common  
fossils of the mountain limestone1 and  
even of some limestones in the  true    
,coal-measures2#cg and that must be a   
poor stratum indeed which  cannot yield 
you a bagful of producti4    ,footnote  
#cg3 ,see the table given below in      
,chap4 ,x4    ,the productus no longer  
ranks among living forms4 ,it began     
during the  times of the ,upper         
,silurian system1 lived all through the 
,old ,red  ,sandstone1 and attained its 
maximum of development in the seas of   
the  ,lower ,carboniferous group4 ,as   

the coal forests began to flourish1 the 
productus seems to have waned2 but it is
 still sometimes found in  considerable 
numbers in the ironstones and limestones
 intercalated  among the coal seams of  
northern ,england and central ,scotland4
 ,in the  period which succeeded the    
coal1 that1 namely1 of the ,permian1 it 
seems  to have died out altogether1 at  
least no trace of its remains have as   
yet been detected in strata of a later  
age4 ,but whilst it lived1 the          
productus must have enjoyed a wide range
 of climate1 for its valves  have been  
found by thousands both in the old world
 and in the new4 ,i  have seen several  
that were brought from the hills of     
,china1 and they  occur likewise in     
,thibet4 ,specimens have been brought1  
too1 from the  warm plains of           
,australia1 and from the snows of       
,spitzbergen4    ,in looking over the   
fossils that lie grouped along beds of  
the  mountain limestone1 there are two  
forms that we find almost invariably    

side by side--the productus and the     
spirifer4 ,they seem to have  begun life
 together1 or rather1 perhaps1 the      
spirifer is somewhat  the older brother4
 ,they voyaged through the same seas1   
and anchored  themselves to the same    
ocean-bed1 sometimes among mud and ooze1
 and  often among bowers of corals and  
stone-lilies4 ,they visited together    
the most distant parts of the world1    
from ,china to ,chili1 and from         
,hudson's ,bay to ,new ,zealand4 ,i have
 sometimes laid open fragments of       
limestone where they lay thickly        
clustered as though they had ended  a   
life of friendship by dying very        
lovingly together4 ,but after all  the  
varieties of the productus had died out1
 some species of the  spirifer still    
lived on1 and it was not until the      
period of the lias  that they finally   
disappeared4 ,i remember meeting with   
one of these  latest spirifers in the   
course of a ramble in early morning     
along the  shores of ,pabba1 one of the 

lone sea-girt islands of the ,hebrides1 
where the ,scottish secondary rocks are 
represented4 ,the beach was  formed of  
low shelving reefs of a dark-brown      
micaceous shale1 richly  charged with   
the characteristic fossils of the       
,lias--ammonites1  belemnites1 gryph1   
pectines1 c4 ,in the course of the walk 
,i came to  a lighter coloured band1    
with many reddish-brown nodules of      
ironstone1  but with no observable      
fossils4 ,a search1 however1 of a few   
minutes  disclosed a weathered specimen1
 near which a limpet had made good its  
resting-place2 and this solitary        
specimen proved to be one of the last   
lingering spirifers 7,s4 ,walcottii74   
,the form struck me at once as a        
familiar one1 and recalled the fossils  
of the mountain limestone4 ,it  may seem
 a puerile fancy1 but to one who had    
lately been working among  palozoic     
rocks1 and remembered the history of the
 spirifer1 there  was something         
suggestive in the loneliness of the     

specimen4 ,with the  exception of one or
 two other organisms 7as rhynconella71  
it was by  far the most ancient form of 
the deposit4 ,its family had come into  
the  world thousands of years before    
that of the large pinn that lay among   
the neighbouring shales1 and perhaps    
millions of years before that of  the   
gracefully curved ammonites4 ,but the   
family was nearly extinct  when these   
shales were being thrown down as sandy  
mud1 and this wasted  specimen1 worn by 
the dash of the waves1 seemed in its    
solitariness no  inapt representative of
 an ancient genus that was passing away4
    ,the spirifer received its name from
 the two highly developed spiral        
processes in the interior of the shell  
attached to the dorsal valve4  ,they    
were hard1 like the substance of the    
shell1 and sprang from  near the hinge1 
each diverging outwards to near the     
border of the  valve4 ,they resembled   
two cork-screws1 but the loops were much
 closer  together4 ,these coiled        

calcareous wires almost filled the      
hollow of the  shell 7,fig4 #bc71 and   
ample support was thus afforded to the  
filamentous  arms4 ,in recent           
brachiopods1 these arms do not always   
strictly follow  the course of the      
calcareous loops4 ,among palozoic genera
 the case may  have been similar1 so    
that the complex calcareous coil of the 
spirifer  may not perhaps indicate a    
corresponding complexity of the arms4   
,but  none of the few recent forms      
exhibit anything like the coiled        
processes  of the spirifer4    ,the     
,carboniferous system of ,great ,britain
 and ,ireland is stated to  have yielded
 between fifty and sixty species of     
spirifers4 ,of course1  in such a long  
list the gradations are sometimes very  
nice1 and to an  ordinary eye           
imperceptible1 but there exist many     
marked differences  notwithstanding4    
,the general type of the spirifers is   
tolerably well  defined4 ,they had both 
valves arched outwards1 not             

concavo-convex as  in the productus4    
,their hinge-line1 like that of the     
latter shell1  ran in a straight line1  
and their dorsal valve was raised along 
its  centre from hinge to outer margin1 
into a prominent ridge1 while in the    
ventral valve there was a furrow exactly
 to correspond4 ,most of the  species   
were traversed by sharp ribs radiating  
from the centre of the  hinge-line like 
those on the surface of the common      
cockle4 ,but some  were quite smooth1   
retaining only the high lobe in the     
centre1 such as  ,s4 glaber4 ,in a noble
 specimen figured by ,m',coy#ch under   
the name  of ,s4 princeps1 the valves   
are covered with broad plaits that sweep
  gracefully outward from the centre of 
the hinge-line4    ,footnote #ch3 ,carb4
 ,limest4 ,foss4 of ,ireland1 pl4 #ba1  
fig4 #a4    ,illustration3 ,fig4        
#bc4--,spirifer hystericus4 b1 ,interior
 of the  same1 showing the arrangement  
of the spiral arms4    ,the spirifers   
vary more in form than in external      

ornament4 ,some are  triangular1 others 
nearly semicircular1 others long and    
attenuated4 ,in  some species 7as the   
,s4 glaber71 the central ridge is very  
prominent1  taking up about a third of  
the entire area of the shell1 and thus  
giving it a trilobed appearance4 ,in    
others 7as ,s4 symmetricus7 it is  less 
marked1 and bears a minor furrow down   
its centre2 while in yet a  third class 
7as in some specimens of ,s4 trigonalis7
 the median fold  scarcely rises above  
the ribs that are ranged on each side4  
,these old shells probably anchored     
themselves to the sea-bottom by  means  
of a thin peduncle1 and lived by the    
vigorous action of those  complex       
fringed arms1 whose screw-like skeleton 
still occasionally  remains1 and which  
conveyed to the mouth the animal        
substances that  served as food4        
,illustration3 ,fig4 #bd4--,terebratula 
hastata4    ,i shall refer to but one   
other brachiopod of the carboniferous   
rocks1  interesting both as one of the  

forms of life still living in our  seas1
 and as exhibiting1 after the lapse of  
such a vast interval1 the  form of the  
coloured bands which adorned it when    
alive4 ,it is called  ,terebratula      
hastata2 a slim delicate shell like its 
representatives  of the present day1    
narrow at the beak1 and bulging out     
towards the  outer margin1 which is     
slightly curved4 ,the surface is smooth1
 and  in the older specimens has        
numerous concentric layers of growth1   
especially marked near the margin4 ,the 
stripes of colour radiate from  the     
beak1 outwards1 and though the tint     
which once brightened them is  no longer
 visible1 it may be that the vessel of  
the little terebratula1  which lay      
anchored perhaps fifty fathoms down1 was
 well-nigh as  gaily decked as a felucca
 of the ,levant4 ,but the existence of  
these  colour-bands is not merely       
interesting2 the geologist can turn it  
to account in investigating the physical
 conditions of an ancient  ocean4 ,the  

late ,professor ,edward ,forbes1 after a
 careful series of  investigations in   
the ,mediterranean1 brought to light the
 fact1 that  below a depth of fifty     
fathoms shells are but dimly coloured1  
and hence  he inferred1 from the        
numerous coloured shells of the         
carboniferous  limestone1 that the ocean
 in which they lived was not much more  
than  fifty fathoms deep4#ci            
,footnote #ci3 ,similar coloured bands  
are found even in the ,lower  ,silurian1
 e4g41 on turbo rupestris 7,murchison's 
,siluria1 p4 #aid71 while  on many of   
the carboniferous gastropods and        
lamellibranchiate bivalves1  they are of
 frequent occurrence4    ,the           
lamellibranchiate bivalve shells of the 
,british ,carboniferous  system1 so far 
as yet discovered1 number about #cjj    
species1 belonging  to genera some of   
which are still familiar to us4 ,there  
were the  pectens or scallops1 the      
pinnas with their beards of byssus1  the
 cardiums or cockles1 the mytili and    

modiol or mussels1  all sea-shells4     
,then among the fresh-water bivalves we 
can detect  several species of the unio 
or river mussel1 that perhaps displayed 
valves as silvery in their lining as    
those of our own pearl-mussels4  ,but   
with these well-known forms there       
co-existed some that no longer  survive4
 ,such was the conocardium1 a curious   
form that looks like a  cardium cut     
through the middle1 with a long slender 
tube added to  the dismembered side     
7,fig4 #be74 ,the aviculopecten1 a shell
 allied to  our common scallop1 and     
sometimes showing still its colour-bands
 7,fig4  #be71 and the cardinia or      
anthracosia1 a small bivalve that       
abounds  in the shales and ironstones of
 our coal-fields1 along with nautili1   
producti1 and conulari at ,coalbrook    
,dale1 and with a thin leaf-like        
lingula at ,borrowstounness4            
,illustration3 ,fig4                    
#be4--;,carboniferous ,lamellibranchs4  
#a4 ,aviculopecten sublobatus 7showing  

colour-bands74 #b4 ,conocardium         
aliformis4    ,the ,gastropods of the   
carboniferous rocks in the ,british     
,islands  embrace from twenty-five to   
thirty genera1 with upwards of #bjj     
species4 ,here1 too1 we can detect some 
forms that have not yet passed  away4   
,the trochus1 so universally diffused   
over the globe at the  present day1 also
 lived in the palozoic seas4 ,its       
companions1 the  natica1 the turritella1
 and the turbo1 likewise flourished in  
these ancient waters4 ,among the genera 
now extinct we may notice the           
euomphalus1 with its whorls coiled in a 
flat discoidal form2 and the            
bellerophon1 with its simple coiled     
shell1 resembling in general form  the  
nautilus4 ,the gastropods are numerously
 represented in our gardens  and woods1 
by the various species of the snails1   
animals that have a  most extensive     
distribution over the world1 and number 
probably not  much under two thousand   
species4    ,illustration3 ,fig4        

#bf4--;,carboniferous ,gastropods4      
#a4 ,euomphalus peatangulatus4 #b4      
,pleurotomaria carinata 7showing        
colour-bands74    ,for a long time it   
was matter of surprise that no such land
 shells  had ever been detected in the  
carboniferous rocks4 ,trees and forests 
had been turned up by the hundred1 but  
never a trace was found of  any         
air-breathing creature4 ,from this fact1
 and from the enormous  amount of       
vegetable matter preserved1 it was once 
hastily inferred  that the atmosphere of
 that ancient period must have been     
uncongenial  to air-breathers2 that1 in 
short1 it was a dense heated medium  of 
noxious carbonic-acid gas1 wrapt round  
the earth like a vast  mephitic         
exhalation1 favourable in the highest   
degree to the growth  of vegetation1 yet
 deadly as the air of ,avernus to all   
terrestrial  animals4 ,but this notion1 
like most other bold deductions from    
merely  negative evidence1 has had to be
 abandoned1 for traces of air-breathers 

have at last been found4 ,among these1  
not the least interesting is  the shell 
of a pupa1 a sort of land-snail1 which  
,sir ,charles ,lyell  detected1 along   
with the bones of a small reptile1      
embedded in the  heart of an upright    
sigillaria stem in the carboniferous    
rocks of ,nova  ,scotia4 ,small as was  
the organism1 the evidence furnished by 
it proved  scarcely less valuable than  
if it had been a large mammal that might
  have afforded material for weeks of   
study4 ,the similarity of the shell  to 
existing forms1 showed that the ancient 
carboniferous forests had  at least one 
race of air-breathing creatures among   
their foliage1 and  that the atmosphere 
of the period could have differed in no 
material  point from that of the present
 day1 for as the snails breathe by      
lungs1  and require1 consequently1 a    
continual supply of oxygen to support   
respiration1 they could not have existed
 in an atmosphere charged with  carbonic
 acid4    ,illustration3 ,fig           

#bg4--;,carboniferous ,cephalopods4     
#a4 ,nautilus ,koninckii4 #b4           
,goniatites crenistria4 #c4 ,orthoceras 
laterale  7fragment74    ,the           
,cephalopods1 or highest class of       
mollusca1 are represented among  the    
,british carboniferous strata by seven  
genera4 ,of these the most              
characteristic is the orthoceras1 so    
named from its shell being  like a long 
straight horn4 ,when the animal was     
young it inhabited a  single-chambered  
shell like that of many of the          
gastropods1 but as  it increased in size
 and prolonged its shell in a straight  
line1 it  withdrew from the first       
occupied chamber4 ,this was partitioned 
off by a  thin wall called a septum1    
through the centre of which a tube ran  
to  the narrow end of the shell 7,fig4  
#bg74 ,as the creature grew1 chamber    
after chamber was in this way formed1   
each of them quite air-tight1 and       
traversed by the central tube4 ,suppose 
a graduated series of diminutive        

watch-glasses to be pierced by a long   
tapering glass-tube in such a  way that 
they should have their convex faces     
towards the narrow end of  the tube1 and
 be arranged at short intervals1 the    
smallest one placed  near the point of  
the tube1 and the largest a little below
 the wider  end4 ,suppose1 further1 that
 this piece of mechanism were placed    
within  another tube tapering to an     
obtuse point1 and that the edges of the 
watch-glasses fitted tightly to the     
inner surface of this larger tube4      
,such would be a rough model of the     
structure of the orthoceras4    ,the    
inner tube that traverses the centre of 
the chambers from end  to end of the    
shell is called the syphon1 but its uses
 are very  problematical4 ,at one time  
naturalists inclined to regard it as    
intended to be filled with fluid1 which1
 by expanding the membrane  of the tube1
 would compress the air in the chambers1
 and thus1  increasing the specific     
gravity of the animal1 enable it to sink

 to  the bottom4 ,in this way1 by       
emptying or filling the syphonal tube1  
the orthoceras might have risen rapidly 
to the surface of the deep1  or sunk as 
swiftly to the bottom4 ,but this view1  
so pretty that one  wishes it were      
confirmed1 must be regarded as at least 
doubtful4 ,the  orthoceras more probably
 owed its power of progression to the   
action of  a funnel connected with the  
breathing apparatus1 whereby jets of    
water  were squirted out that drove the 
shell rapidly along4 ,the use of the    
air-tight chambers was1 perhaps1 to give
 buoyancy to the shell so as to  make it
 nearly of the same specific gravity as 
water4 ,such a provision  must have been
 amply needed1 for ,professor ,owen     
mentions an orthoceras  from            
,dumfries-shire that measured six feet  
in length1 and similar  gigantic        
specimens have been found in ,america4  
,unless the chambers in  these shells   
had been air-tight1 the animals that    
inhabited them would  have been held    

down about as firmly to one spot as if  
they had been  tied to a sheet-anchor4  
,no mollusc could have possessed much   
locomotion  with so ponderous a tail1   
six feet or more in length1 to drag     
after it4  ,but this inconvenience was  
obviated by the simple plan of having   
the  chambers close1 and filled with    
nitrogen or other gas evolved by the    
chemistry of the inmate4 ,the shell1 in 
this way1 acquired no little  buoyancy1 
and probably stood up like a church     
spire1 the animal keeping  close to the 
bottom to lie in wait for any hapless   
mollusc or trilobite  that might chance 
to come in its way4    ,the nautilus    
7,fig4 #bg71 which still lives in our   
seas1 occurred  likewise in those of the
 ,carboniferous period4 ,it was a coiled
 shell2  in truth1 just an orthoceras   
rolled up in one plane like a coil of   
watch-spring4 ,an allied form1 called   
the goniatite 7,fig4 #bg71 had  the     
margins of its septa of a zig-zag form1 
like the angles of the  wall round a    

fortified town4 ,when the thin outer    
coating of the  shell is removed1 the   
ends of these partition-walls are seen  
to form  strongly-marked angulated      
sutures or joints1 where they come in   
contact  with the shell4 ,hence the name
 of the genus--angled shell4    ,all    
these animals were predaceous4 ,they did
 not confine themselves to  the lower   
forms of life1 polyps and medus1 nor    
even to the humbler  tribes of their own
 sub-kingdom1 but hesitated not to wage 
war with  creatures greatly higher in   
the scale of creation than themselves1  
such  as the smaller fishes4 ,they      
swarmed in the palozoic seas1 and well  
merited the title of scavengers of the  
deep1 that has been bestowed  on the    
sharks of our own day4 ,they seem to    
have performed a function  now divided  
partly among the fishes and partly among
 the higher  gastropodous molluscs4 ,and
 accordingly we find that as these      
latter  tribes increased1 the           
orthoceratites1 and goniatites1 and     

ammonites  waned4 ,at the present day1  
of all the palozoic cephalopods there   
remains but one--the nautilus#dj2 a and 
so rare is it1 that up to  the year     
#ahcb1 all sorts of fanciful notions    
existed as to its nature  and functions4
 ,in fact1 the nautilus was a sort of   
myth which any  naturalist could dress  
up as he chose1 much as the old poets   
used to  picture the ship ,argo4 ,a     
specimen was at length procured and     
intrusted  to the examination of        
,professor ,owen1 by whom its anatomy   
was studied1  and afterwards            
philosophically described in an         
elaborate monograph4  ,then1 for the    
first time1 did geologists obtain a true
 notion of the  nature of those         
siphonated shells1 which lie grouped by 
hundreds in the  palozoic and secondary 
formations4 ,yet we still want an       
account of the  habits of the nautilus4 
,the older naturalists alleged that it  
could  at pleasure rise to the surface  
or sink into the depths of the ocean2   

that it could spread out its fleshy arms
 and float across the waves or  draw    
them in1 capsize the little vessel1 and 
so return to a creeping  posture among  
the sea-weed at the bottom4 ,these      
statements may to some  extent be true1 
for the chambers of the nautilus shell  
must impart  great buoyancy to it4 ,but 
in the meantime the story of the sailing
  propensities of the animal is derived 
from a sort of mythic age1 and  must be 
viewed with some little suspicion4      
,until further observations  are made1  
we shall neither fully understand the   
economy of the nautilus  nor the habits 
of the cephalopods of the palozoic seas4
 ,but the day  is probably not far      
distant when such doubts will be set at 
rest1 and  we shall know whether the    
nautili and orthoceratites swam in      
argosies  over the surface of the ocean1
 or1 keeping ever at the bottom1 left   
the  waves to roll far above them1      
unvaried save perchance by some floating
  sea-weed or drifted tree4    ,footnote

 #dj3 ,and perhaps even that is         
doubtful1 for it is not unlikely  that  
after all1 the palozoic nautili may     
belong in reality to another  genus4    
,twenty years hence will probably see no
 little change on our  present          
identifications4          ,,chapter     
,,vii4        ,classification of the    
naturalist not always correspondent with
         the order of                   
nature--,incongruous grouping of animals
         in the invertebrate            
division--,rudimentary skeleton         
of the cephalopods--,introduction of the
 vertebrate         type into           
creation--,ichthyolites of the          
carboniferous         rocks--,their     
state of keeping--,classification of    
fossil                                  
fishes--,placoids--,ichthyodorulites--,g
anoids--,their structure                
exemplified in the megalichthys and     
holoptychius--,cranium of               
megalichthys--,its armature of          
scales--,microscopic structure of       

a scale--,skeleton of                   
megalichthys--,history of the discovery 
of the holoptychius--,confounded with   
megalichthys--,external         ornament
 of holoptychius--,its jaws and         
teeth--,microscopic         structure of
 the teeth--,paucity of terrestrial     
fauna in coal         measures--,insect 
remains--,relics of                     
reptiles--,concluding         summary of
 the characters of the carboniferous    
fauna--,results4    ,the organic remains
 hitherto described belong to that large
 division  of the animal kingdom        
instituted by ,lamarck1 to comprehend   
all those  whose internal structure is  
supported by no vertebral column1 and   
which are hence termed invertebrate4    
,they are for the most part  protected  
by a hard outer covering1 or            
exo-skeleton1 which assumes  many       
different modifications4 ,we have seen  
it in the calcareous  cells of the      
little net-like fenestella1 in the      
geometric cup of  the stone-lily1 in the

 double case of the cypris1 and in the  
shells  of the mollusca4 ,but the order 
of nature does not always exactly       
correspond with the classification of   
the naturalist4 ,his system  must       
necessarily be precise1 formal1 and     
defined4 ,one tribe ends off  abruptly1 
and is immediately succeeded by another1
 with different  functions and          
structure1 and dignified with a separate
 name4 ,but in  the order of creation1  
such abrupt demarcations are few1 for if
 they  exist in the present economy1    
they can not unfrequently be filled up  
from the existences of the past4 ,there 
is usually a shading off of  one class  
into another1 like the blending of the  
tints of sunset1  and it often baffles  
all the skill of the profoundest        
anatomist1 by  drawing a distinct line1 
to pronounce where the one division     
actually  ends and the other begins4    
,any name1 therefore1 which is intended 
to  embrace a large section of the      
animal kingdom1 must ever be more or    

less arbitrary4 ,it will extend too far 
in one direction1 and embrace  organisms
 which might be classed in a different  
section4 ,it will  probably not extend  
far enough in another1 and thus leave   
beyond its  pale animals possessing     
strong affinities to the majority of    
those  included under it4 ,more         
especially is this true of every system 
of  classification that proceeds upon   
the modifications of a single  feature1 
or upon mere negative resemblances4     
,suppose1 for instance1  that it were   
proposed by some highly systematic      
individual to divide  the inhabitants of
 our country into two great classes--the
 bearded  and the beardless4 ,in the    
latter category he would arrange all the
  more quiet and orderly portion of the 
community1 with perchance a  tolerable  
intermixture of rogues4 ,the bearded    
group would present a  most motley      
array--from the fierce-visaged heroes of
 the ,crimea to the  peaceable          
stone-mason or begrimed pitman--all     

brought into one list1  and yet agreeing
 in no single feature save that of being
 like ,bully  ,bottom the weaver1       
marvellous hairy about the face4 ,but   
,lamarck's  invertebrate division of the
 animal kingdom presents a grouping of  
yet  more diverse characteristics1 as   
cannot fail to be confessed when we     
recollect that it embraces among its    
members the microscopic monad1  the     
coral polyp1 the lobster1 the butterfly1
 the limpet1 the nautilus1  and the     
cuttle-fish4 ,cuvier's three-fold       
grouping of the division  into mollusca1
 articulata1 and radiata1 has now       
supplanted the  old name1 though the    
latter is still retained as a sort of   
convenient  designation for all the     
animals below the vertebrate type4      
,the most highly developed of the recent
 cephalopods exhibit a true  internal   
skeleton1 in the form of a strong oblong
 bone1 on which the  body is hung4 ,in  
this respect they occupy a sort of      
intermediate place  between the lower   

molluscs on the one hand1 and the lower 
fishes on  the other4 ,theirs is not a  
vertebral column1 but rather1 as it     
were1  a foreshadowing of it2 not1      
however1 as a link in some process of   
self-development from mollusc to fish1  
for these higher cephalopods do  not    
appear to have been created until fishes
 and reptiles had lived  for ages4 ,the 
vertebrate type has been traced         
well-nigh as far back  into the past as 
we have yet been able to penetrate4     
,once introduced1  it has never ceased  
to exist1 but in the successive         
geological ages  has been ever receiving
 newer and higher modifications1        
reaching its  perfection at length in   
man4 ,the vertebrate form of structure  
fulfils  the highest adaptations of     
which terrestrial beings seem capable4  
,we  can hardly conceive of corporeal   
existence reaching a more elevated      
stage of development1 save in thereby   
becoming less material1 and  receiving  
an impartation of some higher element4  

,the vertebrate  animals display not    
merely the most complexly organized     
structures1  but manifest in their      
habits the workings of the higher       
instincts  and affections4 ,among the   
invertebrate tribes the propagation of  
the  species is1 in the vast majority of
 cases1 a mere mechanical function1     
like that of feeding or respiration1 and
 the eggs once deposited1 the  parent   
has no further care of her young4 ,but  
among the vertebrated  animals1 on the  
other hand1 the perpetuation of the race
 forms the  central pillar round which  
the natural affections are entwined4 ,it
  parcels out every species into pairs1 
in each of which the mates are  bound   
together by the strongest ties of       
attachment4 ,it gives birth1  too1 to   
that noble instinct which leads the     
mother to expose her own  life rather   
than suffer harm to come to her         
offspring4 ,it produces1 at  least in   
man1 that reciprocal attachment of      
offspring to parent1 from  which springs

 no small part of all that is holiest   
and best in this  world4 ,these         
attributes1 to a greater or less extent1
 belong to all  the vertebrate animals1 
from the fish up to man4 ,in looking    
over the  relics of animal life in the  
earlier geological formations1 we are   
apt1  as we gaze on the massive jaws and
 teeth1 the strong bony armour1 and  the
 sharp1 barbed spines1 to think only of 
a time of war and carnage1  when the    
larger forms preyed upon the smaller1 or
 ruthlessly sought  to exterminate each 
other4 ,yet should we not remember1 that
 with all  these weapons and instincts  
of self-preservation there were linked  
attributes of a nobler kind2 that the   
earliest vertebrate remains point  to   
the introduction--though perhaps in but 
a rudimentary form--of  self-sacrificing
 love into our planet8 ,the march of    
creation from  the first dawn of life   
has ever been an onward one1 as regards 
the  development not only of organic    
structure but of the social relations2  

and if it be true that physical         
organization finds its archetype in     
man1 it is assuredly no less so that in 
him too we meet with the  highest       
manifestation of those instincts which1 
by linking individual  to individual1   
have ever marked out the vertebrate     
tribes of animals  from the more        
machine-like characteristics of the     
invertebrate4    ,we pass now to the    
vertebrate animals1 and shall look for a
 little into  the general grade and     
organization of the fishes that         
characterized the  carboniferous rivers 
and seas4    ,a collection of the       
ichthyolites of the carboniferous rocks 
presents  almost every variety in the   
mode of preservation4 ,the smaller      
species  are frequently found entire1   
and show their shining scales still     
regularly imbricated as when the        
creatures were alive4 ,the larger forms 
seldom occur in other than a very       
fragmentary condition4 ,the limestones  
yield dark-brown or black1 oblong1      

leech-like teeth1 which are found  on   
examination to be those of an ancient   
family of sharks4 ,the shales  are often
 sprinkled over with glittering scales  
and enamelled bones4  ,some of the coals
 and ironstones yield in abundance long 
sculptured  spines1 huge jaws bristling 
with sharp conical teeth1 and detached  
tusks1 sometimes five or six inches     
long4 ,in short1 the naturalist who     
would decipher the ichthyology of the   
,coal formation1 finds before  him1 in  
the rocks1 not a suite of correctly     
arranged1 and carefully  preserved      
skeletons1 but a set of disjointed1     
unconnected bones2 here  a tooth1 there 
a scale1 now a jaw1 now a dermal plate1 
all mingled at  random4 ,and yet1 though
 the evidence lie in this fragmentary   
state1 our  knowledge of these ancient  
fishes is far from being correspondingly
  meagre4 ,to such precision has the    
science of comparative anatomy  arrived1
 that a mere scale or tooth is often    
enough to indicate the  nature and      

functions of the individual to which it 
belonged1 and to  establish the         
existence in former times of a          
particular class or order  of animals4  
,thus the smooth rounded teeth of the   
mountain limestone are  found to present
 both externally and internally a close 
resemblance to  the hinder flat teeth of
 the sole living cestraciont 7,c4       
,philippi72  and we hence learn that a  
family of sharks1 now all but extinct1  
abounded in the palozoic seas4 ,the     
occurrence of a set of dark1  rounded   
little objects1 which by the unpractised
 eye would be apt to be  mistaken for   
pebbles1 is in this way sufficient at   
once to augment our  knowledge of the   
various animals of the ,carboniferous   
period1 and to  establish an important  
fact in the history of creation4    ,of 
the four great ,orders into which       
,agassiz#da subdivided the class        
,pisces1 the ,placoids and ,ganoids1    
agreeing on the whole with the          
cartilaginous fishes of ,cuvier1 occur  

abundantly in the palozoic  rocks1 while
 the ,cycloids and ,ctenoids1 answering 
to ,cuvier's  osseous fishes1 began in  
the ,secondary formations1 and are found
 in  all subsequent deposits4 ,the two  
former reached their maximum in the     
earlier geological ages1 and have been  
gradually dwindling down ever  since1   
till now they are represented by        
comparatively few genera2 the  two      
latter are emphatically modern orders2  
they have been constantly  increasing in
 numbers since their creation1 and swarm
 in every sea at  the present day4 ,the 
carboniferous ichthyolites belong1 of   
course1 only  to the two first-mentioned
 orders the placoids and ganoids4       
,footnote #da3 ,the classification of   
,agassiz1 which is certainly not  a     
little arbitrary and artificial1 has    
been altered by ,mller1 a  distinguished
 ,german anatomist1 whose arrangement   
has been modified  again by ,professor  
,owen4 ,see ,owen's ,lectures on        
,comparative ,anatomy1  vol4 ii4 p4 #dg4

 ,there is far from anything like       
unanimity on the  subject4 ,every       
naturalist thinks himself at liberty to 
modify and  restrict the groupings of   
his predecessors or contemporaries1     
sometimes  without condescending to give
 synonyms or any clue by which one may  
compare the rival classifications4 ,the 
geological student cannot engage  in a  
more sickening task than that of ranging
 through these various  arrangements1   
and he must possess some self-command   
who can refrain  from throwing up the   
search in disgust4 ,the best way of     
progressing is  to select some standard 
work and keep to it1 until the          
characteristics  of the genera and      
families have been mastered1 and as far 
as possible1  verified from actual      
observation4 ,after such preliminary    
training1 the  student will be more able
 to grope his way through the chaos and 
dark  night of synonyms and systems4    
,the ,placoid1 or ,plagiostome fishes1  
are familiar to us all as  exemplified  

in the common thornback and skate of our
 markets4 ,they are  covered with a     
tough skin1 which either supports a set 
of tuberculed  plates as in the         
thornback1 or a thick crop of small     
rounded bony  points or plates1 as in   
the shagreen of the sharks4 ,the head   
consists  of a single cartilaginous box4
 ,the spinal column is likewise formed  
of cartilage1 built up in the higher    
genera of partially ossified  vertebr4  
,the tail is heterocercal or unequally  
lobed1 inasmuch as  the spinal column1  
instead of ending off abruptly as it    
does in the  herring1 trout1 and all our
 commoner fishes1 passes on to the      
extreme  point of the upper half of the 
tail4 ,this is a noticeable feature1 for
  it has been found to characterize all 
the fishes that lived in the  earlier   
geological periods4 ,the fins are often 
strengthened by strong  spines of bone1 
which stand up in front of them and     
serve the double  purpose of organs of  
progression and weapons of defence4 ,the

 teeth vary  a good deal in form4 ,in   
the larger number of existing placoids  
they  are of a sharp cutting shape1     
often with saw-like edges4 ,among the   
sharks they run along the jaws in       
numerous rows1 of which1 however1  only 
the outer one is used1 those behind     
lying in reserve to fill up  the        
successive gaps in the front rank4 ,the 
teeth do not sink into the  jaw1 as in  
the ganoids1 but are merely bound       
together by the tough  integument which 
forms the lips4 ,another form of tooth1 
abundant among  the ancient placoids1   
and visible on some of those at the     
present  day1 shows a smooth rounded    
surface1 the teeth being closely grouped
  together into a sort of tessellated   
pavement which1 in the recent  species1 
runs round the inner part of the jaws1  
while a row of conical  teeth guards the
 entrance of the mouth4                 
,illustration3 ,fig4                    
#bh4--;,ctenacanthus hybodoides4        
7,edgerton47    ,the animals which      

possess these characteristics include   
the various  tribes of the sharks and   
rays1 and form the highest group of     
fishes4  ,they are all active and       
predaceous1 frequenting every part of   
the ocean  where their prey is to be    
found4 ,the formidable spines and       
hideous  chasm of teeth belonging to the
 bulkier forms1 render them more than  a
 match for any other denizens of the    
deep1 and thus they reign in  undisputed
 supremacy--the scourge of their        
congeners1 and a terror to  man4    ,the
 seas of the ,carboniferous era abounded
 with similar predaceous  fishes1 some  
of which must have been of enormous     
size4 ,an entire  specimen has never    
been obtained2 nor1 from the            
destructible nature  of the animal      
framework1 can we expect to meet with   
one4 ,but the hard  bony parts of the   
animals1 those capable in short of      
preservation  in mineral accumulations1 
are of common occurrence in the mountain
  limestone beds and even among the coal

 seams4 ,the dorsal spines or           
ichthyodorulites1 are especially        
conspicuous 7,fig4 #bh74 ,they stood  up
 along the creature's back like masts1  
the fin which was attached to  the      
hinder margin of each1 representing the 
sail4 ,the spine could be  raised or    
depressed at pleasure1 its movements    
regulating those of the  fin1 much as   
the raising or lowering of the mast in a
 boat influences  the lug-sail that is  
attached to it4 ,the general form of    
these spines  was long1 tapering1 and   
more or less rounded4 ,but they assumed 
many  varieties of surface ornament4    
,some species were ribbed               
longitudinally1  and had along their    
posterior concave side a set of little  
hooks  somewhat like the thorns of a    
rose4 ,others seem to have been quite   
smooth1 and of a flattened shape1 with a
 thick-set row of sharp hooks  down both
 of the edges1 like the spine on the    
tail of the sting-ray  of the           
,mediterranean4 ,such weapons have      

considerable resemblance to  the barbed 
spear-heads of savage tribes1 and it is 
certain they were  intended to act in a 
similar way1 as at once offensive and   
defensive  arms4 ,the toothed spines of 
the sting-rays are still used in some   
parts of the world to point the         
warrior's spear and arrow4 ,is there    
not something suggestive in the fact    
that these stings1 after having         
accomplished their appointed purpose as 
weapons of war in the great  deep1      
should come to be employed over again in
 a like capacity on the  land2 and that 
an instrument1 which was designed by the
 ,creator as a  means of protecting its 
possessor1 should be turned by man into 
an  implement for gratifying his        
cupidity and satiating his revenge8     
,other  ichthyodorulites are elegantly  
ornamented by long rows of tuberculed   
lines arranged in a zig-zag fashion1 or 
in straight rows tapering from  base to 
point4 ,in all there was a blunt        
unornamented base1 which sank  into the 

back and served as a point of attachment
 for the muscles  employed in raising or
 depressing the spine4 ,in some         
specimens the  outer point appears      
rounded and worn1 the characteristic    
ornament being  effaced for some        
distance--a circumstance which probably 
indicates that  these fishes frequented 
the more rocky parts of the sea4#db     
,footnote #db3 ,see ,egerton1 ,quart4   
,jour4 ,geol4 ,soc41 vol4 ix4 p4 #bha4  
,the placoid teeth of the carboniferous 
rocks show the usual forms  of the      
order4 ,some of them are sharp and      
pointed1 as those of the  hybodonts2    
others have a smooth1 rounded1 or       
plate-like form1 as in the              
cestracionts4 ,the latter often show a  
dark brilliant surface1 and might  be   
readily enough mistaken for well-worn   
pebbles4 ,in the oblong rounded  teeth  
of psammodus the surface is densely     
covered with minute points  like grains 
of sand1 whence the name of the genus4  
,these teeth1 when  sliced and viewed   

under the microscope by transmitted     
light1 exhibit a  complex reticulated   
internal structure4    ,agassiz' second 
great ,order of fishes is named ,ganoid1
 from a ,greek  word signifying         
brightness1 in allusion to the brightly 
enamelled  surface of their dermal      
covering4 ,they differ from the placoids
 in  having their outer surface cased in
 a strong armature of bone1 which  is   
disposed either in the form of large    
overlapping plates1 as among  the       
strange tortoise-like fishes of the ,old
 ,red ,sandstone1 or as thick  scales1  
which are either placed at intervals1 as
 along the back and  sides of the       
sturgeon1 or closely imbricated1 as in  
the stony-gar  7lepidosteus7 of the     
,american rivers4 ,this strong1 massive 
skeleton  constitutes in many genera the
 sole support of the animal framework1  
the inner skeleton being of a gristly   
cartilaginous kind1 like that  of the   
skate4 ,on this account traces of the   
vertebral column are by  no means       

abundant among the older formations4    
,but as the ganoids form  a sort of     
intermediate link between the placoid or
 gristly fishes  on the one hand1 and   
the bony fishes on the other1 they are  
found  to present in their different    
genera examples of both these kinds  of 
structure4 ,thus1 the skeleton of the   
sturgeon consists of a firm  cartilage1 
out of which the vertebr are moulded1 so
 that this fish  was at one time ranked 
with the sharks in the cartilaginous    
tribe of  ,cuvier4 ,the skeletons of    
some of the older ganoids 7as           
holoptychius71  on the other hand1      
manifest such a decidedly osseous       
structure1 with  sometimes so much of a 
reptilian cast1 that the bones were at  
first  referred to some huge extinct    
saurians4 ,the head of the ganoid fishes
  is encased in a set of large massive  
plates of bone1 and the jaws  are       
furnished with several rows of small    
sharp teeth1 intermingled  with a less  
numerous but larger-sized and more      

formidable kind4 ,the  interior of the  
mouth likewise displayed in many ancient
 genera groups  of palatal teeth1 so    
that the dental apparatus of these      
animals  must have been very complex and
 complete4 ,the tail in all the older   
ganoids was heterocercal1 like that of  
the sharks1 the lobes being  not        
unfrequently densely covered with minute
 overlapping scales of  bone--a         
peculiarity which also extended to the  
fins4 ,but the fins  were sometimes     
strengthened in another way by having   
the foremost ray  greatly thickened and 
enlarged1 so as to form a stiff spine   
like the  ichthyodorulites of the       
placoids4 ,the whole of the external    
surface  of these ganoidal fishes       
glittered with enamel1 and was usually  
sculptured in the most graceful patterns
 or ornamented with fine  lines and     
punctures so minute as to be almost     
invisible to the naked  eye4 ,every     
plate1 scale1 fin-ray1 nay1 the very    
lips exhibited the  characteristic      

enamel mottled over with the style of   
ornament peculiar  to the species4 ,and 
when we think we have exhausted the     
contemplation  of these beauties1 it    
needs but a glance through an ordinary  
microscope  to assure us that the       
unassisted eye catches only a           
superficial glimpse  of them4 ,the more 
highly we magnify any portion of these  
old-world  mummies1 the more exquisite  
does its structure appear4    ,in the   
carboniferous rocks of ,great ,britain1 
upwards of forty species  of ganoids    
have been detected4 ,they have a wide   
range in size1 the  smallest measuring  
scarce two or three inches1 while the   
largest1 to  judge at least from the    
bones which they have left behind1 must 
have  reached a length of twenty1 or    
perhaps even thirty feet ,the lesser    
genera 7,fig4 #bi7 were characterized by
 small1 angular1 glossy scales1  usually
 ornamented either with a very minute   
punctulation1 or with  fine hair-like   
lines which sometimes exhibited the most

 complicated  patterns4 ,the scales were
 likewise occasionally serrated along   
the  exposed edges--a style of ornament 
which gives no little richness to  the  
aspect of the dermal covering4 ,the     
fins1 closely imbricated with  small    
angular scales of bone1 sometimes       
displayed a striated ray in  front1 but 
this neither possessed the strength nor 
the formidable  aspect of the           
corresponding spine among the placoids4 
,the head was  encased in a set of bony 
plates fitting tightly into each other1 
and  ornamented with various patterns   
according to the species4 ,the teeth    
were very small and fine1 resembling the
 bristles of a brush1 but in  at least  
some species intermingled with teeth of 
a larger size4 ,the  minute style of    
dentition in these smaller fishes has   
been thought to  indicate their habit of
 keeping to the bottom of the water and 
feeding  on the soft decaying substances
 lying there4 ,nowhere have ,i seen the 
small rhomboidal scales of the          

paloniscus so abundant as among dark    
shales charged with cypris cases and    
fragments of terrestrial plants1  and on
 such occasions the idea has often      
occurred that these graceful  little    
fishes1 like the amia of the ,american  
rivers1 may have fed on  the cyprides   
that swarmed along the bottom of the    
estuary4    ,illustration3 ,fig4        
#bi4--;,amblypterus macropterus 7a      
,carboniferous  ganoid74    ,scattered  
over the fresh-water limestones1        
ironstones1 and shales1 or  crowded     
together along the upper surface of some
 of the coal-seams1  there occur the    
remains of two very remarkable ganoidal 
fishes4 ,they  deserve our attention for
 their great size1 their complex        
organization1  and the important place  
in the scale of animal life which they  
occupied  during a former period4 ,one  
of them has been called megalichthys  or
 great fish--an unhappy name1 since the 
animal did not reach the  dimensions    
attained by not a few of the other      

ganoids1 and was even  surpassed by at  
least one of its contemporary congeners4
 ,the other  is known as the            
holoptychius or wrinkled scale4 ,a more 
detailed  examination of these two      
animals will perhaps best enable us to  
understand the character of the ganoid  
fishes that lived in the waters  of the 
,carboniferous period4    ,the          
megalichthys had an average length of   
about three feet4 ,like  the other      
members of the ganoid order it had a    
glittering exterior1  every scale and   
plate being formed of strong bone1 and  
coated with a  bright layer of enamel4  
,wherever this polished surface extends1
 it is  found to be ornamented with a   
minute punctulation1 the pores of which 
lie thickly together like the finer dots
 of a stippled engraving4  ,the cranial 
plates are further varied by a scattered
 and irregular  series of larger        
punctures that look as if they had been 
formed by the  insertion of a pin-point 
into a soft yielding surface4 ,the      

examination  of the head of the         
megalichthys as depicted in ,fig4 #cj1  
will convey an  adequate conception of  
the structure of a ganoidal cranium4    
,illustration3 ,fig4 #cj4--;,head of    
,megalichthys ,hibberti1 one-sixth of   
natural size 7,agass4 ,poiss4 ,foss4    
,tab4 #fc74    ,a ,upper side4 ,b4      
,under side4 ,c ,profile4    ,the snout 
is formed of an elegantly curved bone   
7c7 fringed along  its under edge with  
minute thick-set teeth4 ,on either side 
it is  flanked by two triangular plates1
 which occupy the space between the     
intermaxillary bone 7c7 and the upper   
jaws 7q q74 ,the eye orbits  seem to    
have been at the corners of the         
intermaxillary1 circumscribed  by the   
sub-orbitals 7f g h7 and the ethmoids   
7b74 ,the massive  intermaxillary bone  
had its posterior margin of an angular  
form1 and  into the notch thus formed   
there was wedged the anterior end of a  
long  strip of plates1 which expanded as
 they approached the occipital part  of 

the cranium1 and terminated in three    
irregular plates that may  represent the
 place of the parietal and occipital    
bones4 ,the space  between this belt and
 the upper jaws was occupied by three   
large plates  7i k l7 which in other    
ganoids1 as the osteolepis of the ,old  
,red  ,sandstone1 were united into a    
single pre-opercular bone of            
considerable  size4 ,the operculum or   
gill cover 7m7 was relatively large1 and
  had an elegantly curved anterior      
margin4 ,the upper jaws 7q7 were        
comparatively small1 and had a fringe of
 small conical teeth4 ,the under  jaws  
7r r7 reached to nearly double the      
length of the upper1 and were  similarly
 set round with teeth4 ,the teeth of the
 megalichthys1 like  those of the living
 lepidosteus1 consisted of two kinds1 of
 which the  one bristled thickly along  
the outer edge of the jaw as sharp      
minute  points1 averaging about a line  
in length1 while behind this outer row  
lay a scattered series of much larger   

teeth that sometimes rose nearly  an    
inch above the jaw4 ,the external       
surface of these more formidable  tusks 
is smooth1 glittering1 and minutely     
striated with fine lines from  base to  
point1 while the root of each is farther
 marked by a circle of  short1 deep1    
longitudinal furrows4 ,the internal     
structure displays a  close ivory1 which
 when viewed under a microscope is seen 
to be made up  of fine tubes radiating  
from the outer surface to the hollow    
central  cavity4 ,some of the bones in  
the interior of the mouth seem to have  
been also furnished with an apparatus of
 teeth4 ,the under surface of  the      
cranium between the arch of the under   
jaws consists of two oblong  central    
plates 7t7 surrounded by a row of       
sixteen irregular ones1  eight on each  
side1 and terminated in front by a large
 lozenge-shaped  scale 7u7 which fits   
into their angle of junction on the one 
side1  and into the symphysis of the    
jaws on the other4 ,in the osteolepis   

there were likewise two large plates    
terminating in a similar  lozenge-shaped
 one1 but without the flanking rows4 ,in
 the famous ,old  ,red holoptychius of  
,clashbennie1 the under surface of the  
head had  but two plates1 and in the    
still older and more gigantic           
asterolepis1  there was but one4 ,it is 
the delightful task of the              
paleontologist  to compare and contrast 
these various pieces of mechanism1 to   
mark  how what seems lacking in one     
comes to be supplied in another1 and to 
trace out the various modes in which1   
during the ages of the past1  ,nature   
has wrought out the same leading plan1  
sounding1 as it were1 an  ever-changing 
series of modulations upon one key-note4
 ,in comparing  together the ganoids of 
the ,old ,red ,sandstone and the        
,carboniferous  rocks1 he finds that in 
the asterolepis--a fish belonging to the
 lower  part of the former              
formation--the pointed arch formed by   
the sweep of  the lower jaws is filled  

up by a single plate like some          
abbey-window  with its mullions knocked 
away1 and built up with rude stone and  
lime4  ,higher in the same group of     
rocks he meets with the cranium of the  
holoptychius1 where there is one        
straight central mullion running  in an 
unbroken line from the angle of the arch
 to its base4 ,in the  osteolepis#dc he 
sees this mullion branching into two at 
its upper  end1 so that the window      
consists of three divisions1 as in the  
simplest  style of ,gothic4 ,passing    
upwards into the ,carboniferous system1 
he  encounters a still more ornate      
arrangement in the cranium of the       
megalichthys4 ,the central mullion with 
its two upper branches still  remains1  
but it is flanked by an additional one  
on each side1 from  which there spring  
six cross bars that diverge obliquely   
with a slight  curve1 so as to join the 
outer arch and subdivide the window into
  nineteen compartments4 ,so varied are 
the plans of the ,divine ,architect  in 

what to man may seem such a little      
matter as the piecing together of  a    
fish's skull4    ,footnote #dc3 ,hugh   
,miller's ,footprints of the ,creator1  
p4 #ia4    ,the body of the megalichthys
 was cased in an armature of as solid   
and  glittering bone as that which      
defended its head4 ,where the plates of 
the cranium ended off they were         
succeeded by large rhomboidal scales    
that crossed the body obliquely1 and    
overlapped each other like the  metal   
plates in the antique scale-armour4     
,each scale consisted of  two parts1 of 
which one had a rhomboid form and was   
covered over with  enamel1 while the    
other ran round the two inner sides of  
the rhomb  as a broad unenamelled       
selvage deeply indented along its       
centre4 ,it  was the enamelled portion  
alone that formed the outer surface1 the
  rough unpolished border being covered 
by the overlapping edges of  the        
adjoining scales4 ,the scales had not a 
uniform thickness1 but  were strongest  

at the covered part from which each     
thinned off to  the outer edges4 ,in    
this way the thin edge of one scale     
pressed down  on the thick part of the  
subjacent one1 and a covering of uniform
  strength and smoothness was produced4 
,looking at a set of these scales  as   
they still occupy their original        
position on the creature's body1  it is 
scarcely more than a half of each which 
meets our eye2 for the  unenamelled     
border occupied about a third of the    
entire surface1 and  a fourth of the    
remainder was covered by the overlapping
 scales4 ,the  effect of this           
arrangement must have been to combine   
great strength  with the most perfect   
flexibility4 ,notwithstanding the bulk  
of his  helmet and the weight of his    
scale-armour1 we cannot conceive the    
megalichthys to have been other than a  
lithe1 active1 predaceous fish1  dealing
 death and destruction among the        
herring-like shoals of little  palonisci
 and amblypteri1 though able to maintain

 perhaps but a  doubtful warfare with   
his more bulky contemporary1 the        
holoptychius4  ,the internal structure  
of the scales of the megalichthys       
exhibits the  same provision for        
combining strength with the least       
possible amount  of material4 ,viewed in
 a transverse section under a magnifying
 power  of about eight diameters1 they  
are seen to consist of three layers of  
bone2 each possessing a peculiar        
structure4 ,the outermost is formed  of 
a tessellated pavement of minute round  
ocelli1 having a fine brown  colour1 and
 placed close together with considerable
 regularity4 ,they  somewhat resemble   
little wheels1 the axle being either a  
dark solid  nucleus or a small circular 
aperture1 whence there radiates to the  
outer rim a set of exceedingly minute   
fibres which were originally  hollow1   
and served as canals to carry on the    
growth of the scale4 ,the  vacant space 
left where four wheels impinge on each  
other1 forms one  of the pores that     

cover the enamelled surface of the      
scale4 ,the whole  structure of this    
outer layer very closely resembles that 
presented by  the internal part of the  
base of the teeth1 save that the        
confluent  lobes shown in the teeth     
become in the scale detached into       
separate and  independent circles4 ,the 
central stratum of each scale is        
composed of  a loose open network of    
cancellated bone that passes into the   
layer on  either side1 and resembles in 
its general texture the osseous vertebr 
of the same fish4 ,the under layer1 one 
end of which rested immediately  on the 
skin1 approaches more to the firmness   
and solidity of the outer  one1 but1 in 
place of a tessellated1 ivory-like      
pavement1 it had a  close fibrous       
texture1 with here and there a scattered
 cavity1 and the  fibres were matted    
together so as to resemble the more     
solid structure  of the cranial bones4  
,the effect of this triple arrangement  
must have  been to impart great strength

 and lightness to the external armature 
of the fish2 the middle spongy layer    
serving1 by its porosity1 at once  to   
deaden the effect of any blow aimed at  
the outside1 and to give  buoyancy and  
lightness to what would otherwise have  
been a coat of  mail well-nigh1 as      
ponderous as that of a feudal chief4    
,one can hardly  conceive any implement 
of warfare in use among the lower       
animals of  strength enough to pierce   
this massive covering4 ,but we shall    
find  as we go on that if the           
megalichthys had a strong defensive     
armour1  a bulkier neighbour had a still
 stronger offensive one1 and that the   
enamelled plates of the one fish were   
scarcely a match for the huge  pointed  
tusks of the other4    ,the megalichthys
 had an osseous skeleton1 with vertebr  
of a discoidal  form4 ,these internal   
bones when viewed under the microscope  
are found  to display an open           
cancellated structure1 resembling that  
of the  central layer in the scales4 ,it

 thus appears that this ancient fish    
was not merely defended by a hard       
external armour1 but possessed an       
equally solid framework of bone within4 
,mingled with the scales and bones of   
the megalichthys1 there are found  the  
remains of a still larger fish1 to which
 the name of ,holoptychius  has been    
given4 ,its external ornament differed  
entirely from that of  the animal last  
described4 ,it possessed teeth sometimes
 six or seven  times larger1 and jaws1  
plates1 and bones of a form and         
dimensions  totally distinct4 ,strange  
as it may seem1 however1 these two      
fishes  have been constantly and        
systematically confounded from the time 
when  they were first discovered4 ,two  
or three years ago1 there might be  seen
 in the ,british ,museum several        
specimens of the holoptychius1  of which
 some bore the correct name1 while the  
rest were labelled  ,megalichthys2 and a
 similar error prevailed in several of  
the other  museums4#dd ,the confusion   

can be traced very distinctly in the    
memoir  of ,dr4 ,hibbert1 who for the   
first time described the remains of     
these  fishes1 and wrote according to   
information received from ,agassiz4     
,footnote #dd3 ,the mistake was noticed 
in #ahde by ,hugh ,miller1 who1 in a    
foot-note to his ,first ,impressions of 
,england and its ,people1 p4 #ga1  well 
defines the distinctions between the two
 ichthyolites4    ,in the autumn of     
#ahcb1 the attention of the scientific  
public of  ,edinburgh was directed to   
the extraordinary character of some     
fossil  remains obtained from the       
lime-quarries of ,burdiehouse1 a village
 about  four miles to the south of the  
town4 ,dr4 ,hibbert visited the         
locality1  and soon saw enough to excite
 his lively interest in its thorough    
investigation4 ,the ,royal ,society of  
,edinburgh warmly supported his         
exertions1 and by their means a large   
suite of specimens was eventually       
obtained1 which the ,doctor from time to

 time described as they were            
successively received4 ,at the          
meeting#de of the ,british ,association 
in  ,edinburgh1 in #ahcd1 the specimens 
were exhibited before the ,geological   
,section1 and a memoir upon them read by
 their successful discoverer4  ,on the  
conclusion of the paper1 a lively       
discussion ensued upon the  nature of   
the animal to which the scales and teeth
 had belonged4  ,dr4 ,hibbert argued1   
from the deeply-furrowed teeth1 and the 
strong1  massive cranial plates1 that   
the animal must have been a reptile1 and
  supported his assertion by no small   
amount of anatomical skill4 ,in the     
midst of the discussion1 a message was  
sent to the great ichthyologist  of     
,neufchatel1 who happened to be at that 
time busily engaged in the  ,zoological 
,section4 ,passing over the fossils as  
they lay grouped  upon the table1 with  
that quick perception for which he is so
 justly  celebrated1 ,agassiz at once   
decided that the bones must have been   

those of some large and hitherto        
undescribed fish4 ,such a decision  from
 such an authority produced of course no
 little sensation1 and the  naturalist  
was told with some surprise that the    
remains had just been  elaborately      
described as those of extinct reptiles4 
,reptiles6 thought  ,agassiz1 and again 
his quick eye darted over the table2 but
 the fossils  would yield no other      
answer than what they had already given4
 ,despite  their seeming reptilian      
character1 they were undoubtedly        
ichthyic1  though belonging to an animal
 up to that time unknown4 ,in the       
completed  memoir which ,dr4 ,hibbert   
subsequently submitted to the ,royal    
,society1  his mistake was freely       
acknowledged1 and the remains there     
flourish as  those of a true fish4 ,but 
with this amendment a grave error of    
another  kind was committed1 though in  
this the ,doctor seems to have been     
supported by the authority of ,agassiz  
himself4 ,the large bones1 scales1  and 

teeth of the ,burdiehouse limestone1    
were all indiscriminately  thrown into  
one genus1 to which ,agassiz gave the   
name of ,megalichthys2  and in the      
memoir we find the different kinds of   
scales and teeth  described and figured 
without the slightest intimation or     
suspicion  that they might possibly have
 belonged to different animals4 ,the    
novelty of the discoveries soon         
attracted general attention to  ,dr4    
,hibbert's paper4 ,it was quoted or     
referred to in almost every  scientific 
work treating of general geology1 while 
in some instances  7as in ,dr4          
,buckland's ,bridgewater ,treatise7 the 
erroneously-named  bones were           
re-engraved4 ,a tooth from the ,fife    
coal-field1 drawn  for one of the       
woodcuts in a popular elementary manual1
 was also  named megalichthys2 an error 
perpetuated through every edition till  
the last1 where the tooth has been      
restored to its true owner--the         
holoptychius4 ,in truth1 no two         

organisms have ever been so maltreated2 
and if the reader will kindly bear with 
me a little further1 it will  not be    
difficult to show him that the          
holoptychius had peculiarities  of its  
own quite as distinct as those that have
 come before us in the  megalichthys1   
and that each animal has a full and     
legitimate claim to a  separate and     
independent niche in the gallery of     
fossil fishes4    ,footnote #de3 ,see   
,agassiz1 ,poiss4 ,foss41 tom4 ii4 ,part
 #b1 p4 #hi et  seq4    ,the word       
holoptychius means1 as ,i have said1    
wrinkled or folded  all over1--a name   
truly expressive of the peculiar style  
of ornament  displayed by every part of 
the exterior of the animal's body4 ,the 
head-plates1 which are of great size1   
exhibit a fine corrugated  shagreen-like
 surface1 roughened into knobs1 and wavy
 lines of  confluent tubercules1 that   
remind one disposed to be fanciful1 of a
  frosty ,december moon with its        
isolated peaks1 and confluent mountain  

chains4 ,the scales are of a rounded or 
oval form1 and vary from less  than half
 an inch to fully four or even five     
inches in diameter4  ,their upper side  
consists of two parts1 one of which with
 a crescent  shape lay beneath1 the     
over-lapping scales1 while the other    
passed  outwards to form a portion of   
the outer visible surface4 ,the part    
that was hidden by the overlapping scale
 was smooth1 with a finely  striated    
surface4 ,the exposed portion displayed 
the usual corrugated  sculpturing1 many 
of the little tubercules having striated
 sides1 and  showing1 in consequence1 no
 little resemblance to the star-like    
knobs  on the dermal covering of the    
,old ,red ,sandstone asterolepis4 ,the  
inner  surface of the scales was        
concave1 with a central prominent oblong
  point surrounded by encircling scaly  
ridges1 and forming what is called  the 
centre of ossification4#df    ,footnote 
#df3 ,the above descriptions of the     
scales and teeth of these  two fishes1  

are taken from specimens in my own      
collection4 ,none of my  holoptychian   
scales show incontestable the proportion
 of the covered to  the exposed part4   
,judging from the aspect of one of them1
 the wrinkled  portion occupied perhaps 
about three-fifths of the entire scale1 
the remaining part being covered by the 
overlapping edges of those  adjacent2   
for the characteristic corrugated       
surface was essentially  an external    
ornament1 and ceased at the point where 
the external  bone passed into the      
interior4 ,i may remark1 that the upper 
side of  the scales is not very         
frequently seen in the ,burdiehouse     
limestone1  the rough surface usually   
adhering to the rock1 and leaving only  
the  smooth inner side exposed4 ,out of 
seven specimens from that locality1     
only one shows the upper side1 and that 
by no means in a perfect state  of      
keeping4 ,the structure alike of scales 
and bones can be seen to  much greater  
advantage in the shales1 ironstones1 and

 coals of the  coal-fields1 where1 owing
 to the soft nature of their matrix1 the
  fossils can be readily cleared and    
exposed4    ,but perhaps the most       
remarkable and characteristic parts of  
the  carboniferous holoptychius were its
 jaws and teeth4 ,as we might  readily  
conjecture from the great size and      
strength of the scales and  cranial     
plates of this fish1 its dentition was  
of a correspondingly  massive type4 ,the
 under jaw1 with the usual corrugated   
ornament1  frequently exceeded a foot in
 length1 and displayed along its upper  
edge a thick-set group of teeth4 ,of    
these there were two kinds one  of a    
smaller size and more blunted form1 with
 short indented furrows  at their base2 
the other of a greatly more formidable  
size1 grouped  at intervals among the   
smaller ones4 ,the front end of each    
under jaw  bore one of these long       
conical tusks1 serving as it were to    
guard the  entrance of the mouth4 ,each 
of the larger teeth had a base strongly 

marked with longitudinal furrows1 and   
sank deep into the jaw1 with  the bone  
of which it sometimes anchylosed4#dg    
,the part of the tooth  above this      
socket had an oval form1 so flattened as
 to present two  cutting edges1 one     
facing the front1 the other the back of 
the mouth1  and meeting at the upper end
 of the tooth which was sharp and       
pointed4  ,such large conical tusks may 
frequently be obtained1 having a length 
of two or three inches1 while           
occasionally they range as high as six  
or seven1 the smaller teeth seldom      
reaching so much as an inch4 ,it  is    
difficult to see how1 with such a       
formidable dentition1 the jaws  could   
readily close4 ,in some specimens ,i    
have seen deep hollows beside  the bases
 of the teeth1 which may possibly have  
received those of the  opposite jaw1 but
 the gigantic tusks at the entrance of  
the mouth seem  to have stood high over 
the jaw1 passing outside like those of  
the  wild-boar4 ,if this be correct1 the

 jaw of the holoptychius would unite    
the mechanism of both the alligator and 
the crocodile--its recipient  hollows   
being analogous to the tooth-pits in the
 former tribe1 and its  protruded teeth 
to the similarly exposed teeth of the   
latter4    ,footnote #dg3 ,i have seen  
detached teeth1 wherein the length of   
the root1 or part imbedded in the jaw1  
tripled that of the exposed  part1      
sinking four or five inches into the    
bone without any trace of  anchylosis4  
,whether these huge tusks belonged to   
the upper or under  maxillary1 ,i do not
 pretend to say1 though no specimen of  
the under  jaw1 which has ever come     
under my notice1 would accommodate half 
of  such a deep-sunk base4              
,illustration3 ,fig4 #ca4--;,jaw of     
,holoptychius 7,rhizodus4--,owen7 from  
,gilmerton1 one-fourth nat4 size2 the   
large teeth along the middle part  of   
the jaw are here wanting4    ,when we   
bring the microscope to bear upon the   
elucidation of the  structure of these  

ancient teeth1 it seems as if our labour
 had but  just begun2 and that so far   
from having by an external scrutiny     
exhausted all that they have to show us1
 our knowledge of them can be  but      
scanty and superficial until we have    
studied them carefully under  a         
magnifying power4 ,microscopic sections 
of such organic remains are  prepared in
 the same way as those of the fossil    
woods already noticed2  and a more      
interesting or beautiful series of      
objects cannot be  conceived than a set 
of slices of these fossil-teeth4        
,viewed1 then1 in longitudinal section  
from base to point1 the part  above the 
fluted root of one of the large teeth of
 the holoptychius is  seen to consist of
 minute hair-like fibres of extreme     
tenuity1 which  proceed in straight     
lines from the outer surface to the     
interior4 ,at  right angles to these1   
and parallel with the outer edges1 there
 is  a set of dark widely-placed lines  
conforming to the outline of the  tooth1

 like so many long sugar-loaf shaped    
caps1 placed within each  other4 ,when  
this part is cut across1 and viewed in  
transverse section1  the tooth is       
observed to be of a flattened oval form1
 with the same  fine fibres or tubes    
radiating from the centre1 and traversed
 by the  same dark bands which now      
assume the form of concentric rings4    
,the  appearance thus presented reminds 
one at once of a cross section  of some 
dicotyledonous tree1 the dark bands     
resembling the annual  layers of growth1
 and like these resulting from a similar
 thickening  of the internal tissue4    
,the upper part of the tooth is solid   
and the  concentric rings few2 the      
middle exhibits an increase of the      
rings1 and  possesses1 moreover1 a      
hollow centre or pulp-cavity1#dh with   
the usual  diverging fibres4 ,here the  
oval form is well shown1 and the        
encircling  rings are considerably      
flattened at the ends of the long axis4 
,footnote #dh3 ,this hollow centre may  

be seen occasionally filled up by  a    
sharp conical tooth like the phragmocone
 of a belemnite4    ,the lower portion  
of the tooth exhibits a much more       
complicated  texture4 ,externally it is 
marked by deep longitudinal furrows1    
that  run down the enamelled sides and  
sink into the jaw4 ,when cut across  at 
this ribbed part1 the tooth is found to 
present the most complex  and graceful  
internal structure4 ,the prominent      
ridges between the  furrows are seen to 
be produced by crumpled folds of the    
substance of  the tooth1 which roll     
inwards towards the centre1 coalescing  
with each  other1 and forming intricate 
groups of circling knots and folds4 ,in 
some places they seem all but separated 
from each other into little  circles1   
pierced with a central aperture1 and    
recall the aspect of  the upper layer in
 the scale of megalichthys4 ,each of    
these loops and  folds presents a       
texture exactly similar to that of the  
upper part of  the tooth4 ,the same     

minute hair-like tubes1 darkened and    
thickened in  the long axis1 radiate    
towards the centre2 the same concentric 
bands  run from centre to circumference2
 so that the lower part of the tooth    
seems1 as it were1 made up of a bundle  
of smaller teeth partially  melted into 
each other4 ,between these loops and    
folds circular meshes  frequently occur1
 and add to the complexity as well as   
the beauty of  the whole structure4 ,one
 of these sections1 with all its        
twisting  crumples1 and folds1 and      
knots1 and coloured meshes1 and         
encircled  rings1 bears no small        
resemblance to an antique polished table
 that  has been cut out of the gnarled  
roots of a venerable oak4 ,this complex 
structure arose from the mode of growth 
of the tooth2 each prominent  external  
ridge continually turning inwards down  
the furrow on either  side1 and mingling
 in freakish knots with the folds that  
had gone  before4#di    ,footnote #di3  
,for an acquaintance with the remarkable

 teeth of this  ancient fish1 more      
minute than it had been my good fortune 
to possess  before1 ,i am indebted to a 
most interesting series of microscopical
  preparations kindly lent me from his  
extensive collection by my friend  ,mr4 
,alexander ,bryson of ,edinburgh4       
,the internal bones of the holoptychius 
were of great size and strength1  as    
befitted such a bulky ganoid4 ,some of  
them had a singular style of  surface   
ornament1 that somewhat resembled a     
frosted widow on a ,december  morning4  
,their internal structure was loose and 
cancellated2 the endo-  being usually of
 a less compact texture than the        
exo-skeleton4 ,judging  from the size of
 such bones1 the carboniferous          
holoptychius must have  been one of the 
bulkiest and most formidable denizens of
 the deep1  reaching sometimes to a     
length of twenty feet or even more4     
,such an  animal would have been1       
perhaps1 quite a match for our hugest   
crocodile  or alligator1 for it must    

have swum about with a litheness and    
agility  possessed by none of the       
saurian reptiles4 ,like that leviathan  
chosen  by the ,almighty1 in an age long
 subsequent1 as an illustration of ,his 
power and greatness1 the holoptychius   
must have been king over all  the       
inhabitants of the sea1 and the         
magnificent language of ,job1           
descriptive of the living animal1       
applies not less graphically to  the    
extinct one3 ,who can open the doors of 
his face8 his teeth are  terrible round 
about4 ,his scales are his pride1 shut  
up together as  with a close seal4 ,one 
is so near to another1 that no air can  
come  between them4 ,he maketh the deep 
to boil like a pot3 he maketh the sea   
like a pot of ointment4 ,he maketh a    
path to shine after him2 one would      
think the deep to be hoary4    ,our     
survey has hitherto been directed to the
 denizens of carboniferous  lake1 river1
 and sea1 and we have found them to be  
alike important in  numbers and         

interesting in organization4 ,it is     
otherwise1 however1  when we turn in    
search of the denizens of the           
carboniferous lands4  ,the crowded trees
 and shrubs of the coal strata recalling
 as they do  old forest-covered swamps1 
might seem to indicate the probability  
of  a pretty numerous terrestrial fauna4
 ,where are we to look for the          
fossilized relics of land animals1 if   
not in the remains of a submerged       
land-surface8 ,and yet1 strange as it   
may seem1 of the inhabitants of  the    
land during the ,coal-measure period we 
know almost nothing4 ,we  have ransacked
 hundreds of soils replete with the     
fossil roots of  trees1--have dug out   
hundreds of erect trunks and stumps1    
which stood  in the position in which   
they grew1--have broken up myriads of   
cubic  feet of fuel1 still retaining its
 vegetable structure1--and1 after  all1 
we continue almost as much in the dark  
regarding the invertebrate              
air-breathers of this epoch1 as if the  

coal had been thrown down in            
mid-ocean4#ej    ,footnote #ej3 ,sir    
,charles ,lyell's ,elements1 fifth      
edition1 p4 #djf4    ,the little        
land-shell already noticed as having    
been detected by ,sir  ,charles ,lyell  
in the carboniferous rocks of ,nova     
,scotia1 seems to be  as yet the only   
air-breathing mollusc obtained from     
rocks of such  high antiquity4 ,insect  
remains have been detected in the       
,english  coal-fields belonging to two  
or three species of beetles2 while on   
the  ,continent1 wing-sheaths and other 
fragments of cockroaches1 scorpions1    
grasshoppers1 locusts1 crickets1 c41    
have been detected4 ,but the most       
remarkable traces of air-breathers      
consist in various indications of  the  
existence of reptiles during the        
,carboniferous era4 ,fragmentary        
skeletons1 with detached bones and      
plates1 have been found in ,bavaria  and
 ,america1 together with long tracks of 
footprints1 from which it  appears that 

during the time our coal-seams were     
forming1 there swam  through the        
sluggish deltas1 or crept amid the dank 
luxuriant foliage1  strange lizard-like 
forms1 large enough to leave behind them
 on the  soft yielding mud or sand the  
impress of their double pair of toed    
feet4 ,but of these animals we have much
 to learn4 ,some of them have           
bequeathed to us merely their           
dismembered broken bones2 others have   
left but the imprints of their toes4    
,yet even these remains1 trifling  as   
they may seem1 become of importance when
 we remember that they  demonstrate     
fishes not to have been the highest     
types of being during  the epoch of the 
,coal1 and show that while the bulky    
holoptychius held  the supremacy of the 
waters1 lizard-like forms of a less     
formidable  type seem1 so far as we     
know1 to have ruled it over the land4   
,in fine1 then1 no one can glance at a  
list of the carboniferous fauna  without
 perceiving either that the animated    

world of that ancient  epoch must have  
had a very different proportioning from 
what now  obtains1 or that we have only 
a meagre and fragmentary record of it4  
,that the latter conclusion is the more 
philosophical will appear if we  reflect
 upon the many chances that exist       
against the entombment and  preservation
 of animal remains1 especially of those 
peculiar to the  land4 ,how very small a
 proportion of the remains of animals   
living in  our own country could be     
gathered from the surface-soil of any   
given  locality1 and how very inadequate
 would be the meagre list of species    
thus obtained1 as representing the      
varied and extensive fauna of ,great    
,britain6 ,in contrasting1 then1 the    
rich abundance of marine organisms  with
 the extreme paucity of terrestrial     
animals among the carboniferous  rocks1 
it would be too hasty to infer a        
corresponding disproportion  originally4
 ,it must be admitted that the rarity of
 air-breathers1  after such             

long-continued and extensive            
explorations among terrestrial  and     
lacustrine beds1 presents a difficult   
problem1 only 7if at all7  to be cleared
 away by patient and persevering        
investigation4 ,with  this preliminary  
caution1 we may regard the carboniferous
 fauna as  peculiarly rich in marine    
species4 ,the sea-bottoms swarmed with  
stone-lilies1 cup-corals1 and net-like  
bryozoa1 mingled with the  various      
tribes of molluscan life--the           
brachiopods with their long  ciliated   
arms2 the bivalves and gastropods with  
their coloured shells  that recall some 
of the most familiar objects of our     
shores2 and the  cephalopods with their 
groups of siphonated chambers1 straight 
as in  the orthoceras1 or gracefully    
coiled as in the goniatite4 ,the seas   
swarmed1 too1 with fishes belonging to  
the two great orders of ganoids  and    
placoids1 the latter represented now by 
our sharks and rays1  though the exact  
type of the ancient genera is retained  

only by the  cestracion or              
,port-,jackson shark2 the ganoids1 with 
their strong armour  of bone1           
represented by but two genera1 the      
lepidosteus of the ,american  rivers1   
and the polypterus of the ,nile1--two   
fishes that seem but as  dwarfs when    
placed side by side with the gigantic   
holoptychius of the  coal-measures4 ,the
 rivers and estuaries of the same period
 seem to have  been frequented by       
immense shoals of the smaller ganoidal  
fishes that  fed on decaying matter     
brought down from the land1 and perhaps1
 too1  on the minute ,crustacea that lay
 strewed by myriads along the bottom4   
,into these busy scenes the bulkier     
monsters from the sea made frequent     
migrations1 perhaps in some cases       
ascending the rivers for leagues to     
spawn1 and returning again to their     
places at the mouth of the estuary  or  
in open sea4 ,the rivers and lakes      
swarmed with small crustaceous  animals1
 and nourished1 too1 shells like those  

of our pearl-mussels4  ,the land--so    
luxuriantly clothed with vegetable      
forms--was hummed over  by beetles1     
chirupped over by grasshoppers and      
crickets1 and crawled  over by          
four-footed reptiles1 that united in    
their structure the lizard  and the     
frog4 ,but of the general grade and     
proportions of its denizens  we still   
remain in ignorance4 ,from all that yet 
appears1 the scenery  of these forests  
must have been dark1 silent1 and gloomy1
 buried in a  solitude that was startled
 by no tiger's roar1 no cattle's low1   
and  neither cheered with the melody of 
birds nor gladdened by the presence  of 
man4    ,we have lingered1 perhaps1 too 
long over the remains of these old      
carboniferous animals4 ,but the delay   
may be not without its use if1 by  thus 
bringing before us some of the more     
marked points in the structure  of      
creatures that for ages peopled our     
planet1 it broaden our view of          
creation2 and by lifting the curtain    

from off a dim1 distant period of  our  
world's long history1 it show1 amid all 
diversities of arrangement1  and all    
varieties of form1 still the same grand 
principles of design1  and the same     
modes of working as those which we can  
see and compare  among the living forms 
around us4 ,it is something to be       
assured that  the race of man has been  
preceded by many other races1 lower     
indeed  in the scale of being1 but      
manifesting1 throughout the long        
centuries  of their existence1 ideas of 
mechanism and contrivance still familiar
  to us1 and serving in this way to link
 the human era with those that  have    
gone before1 as parts of one grand      
scheme carried on by one great          
,creator4          ,,chapter ,,viii4    
,sand and gravel of the boulder--,what  
they suggested--,their                  
consideration leads us among the more   
mechanical operations         of        
,nature--,an endless succession of      
mutations in the economy         of the 

universe--,exhibited in plants--,in     
animals--,in         the action of winds
 and oceanic currents--,beautifully     
shown by the ceaseless passage of water 
from land to         sea1 and sea to    
land--,this interchange not an isolated 
phenomenon--,how aided in its effects by
 a universal process         of decay   
going on wherever a land surface is     
exposed to         the air--,complex    
mode of ,nature's                       
operations--,interlacing         of     
different causes in the production of an
 apparently         single and simple   
effect--,decay of rocks--,chemical      
changes--,underground and surface       
decomposition--,carbonated              
springs--,the ,spar ,cave--,action of   
rain-water--,decay of                   
granite--,scene in                      
,skye--,trap-dykes--,weathered cliffs of
         sandstone--,of                 
conglomerate--,of shale--,of            
limestone--,caverns         of          
,raasay--,incident--,causes of this     

waste of calcareous                     
rocks--,tombstones4    ,from the        
blackened plants that darkened the upper
 layers of the  boulder1 the transition 
was natural to the matrix in which they 
lay4  ,the whole rock consisted of a    
fine quartzy sand more or less          
distinctly  laminated1 and showing in   
its lower parts well-rounded pebbles of 
quartz1 green grit1 and felspathic trap4
 ,the contemplation of these  features  
suggested the existence of some old land
 with elevated ranges  of hills1 and    
wide verdant valleys traversed by       
rivulets and rivers  which bore a       
ceaseless burden of mud1 sand1 and      
gravel1 onwards to  the sea4 ,the       
pebbles afforded some indication of the 
kind of rocks  that formed the          
hill-sides4 ,perhaps the higher grounds 
exhibited that  grey wrinkled appearance
 peculiar to the quartz districts of the
  north-western ,highlands1 with here   
and there a bluff crag of felspathic    
trap shooting up from among the         

fern-brakes of the valley1 or cutting   
across the channel of some mountain     
stream that tumbled over the pale  rock 
in a sheet of foam4 ,and there may have 
been among these uplands  smooth        
undulating districts1 dotted over with  
dark araucarian pines1  and densely     
clothed with a brushwood of rolling     
fern1 but which showed  in all their    
ravines the green grit that formed the  
framework of the  country1--its beds    
twisted and contorted1 jointed and      
cleaved1 like  the grits and slates     
along the banks of many a stream1       
beloved by  the angler1 in the classic  
ground of the ,ettrick and the ,yarrow4 
,but  whatever may have been the special
 features of its scenery1 there can  be 
no doubt of the land's existence4 ,the  
carbonized plants stand up to  tell us  
of its strange and luxuriant vegetation4
 ,we have listened to  their story1 and 
suffered them to lead us away into      
forest1 and lake1  and sea1 to look on  
the various forms of life1 vegetable and

 animal1  which abounded in that        
far-distant age4 ,we return again to the
 boulder1  and shall now seek to learn  
the lessons which the sand and pebbles  
have  to teach us4 ,their subject       
belongs to what is called physical      
geology1  and will bring before us some 
of the more mechanical operations of    
nature1 such as the slow but constant   
action of air1 rain1 and rivers1  upon  
hard rock1 the grinding action of the   
waves1 and the consequent  accumulation 
of new masses of sedimentary rock4      
,in all the departments of nature that  
come under the cognizance of man1  there
 is seen to be an endless succession of 
mutations4 ,according to  the ,samian   
philosopher--        ,turn wheresoe'er  
we may by land or sea1      ,there's    
nought around us that doth cease to be4 
,each object varies but in form and hue1
      ,its parts exchange2 hence        
combinations new4      ,and thus is     
,nature through her mighty frame        
,for ever varying1 and yet still the    

same4    ,in the world of life we see   
how animals are sustained by a constant 
series of chemical changes in their     
blood1 every respiration of air  adding1
 as it were1 fresh fuel to the flame of 
life within4 ,in plants1  too1 there is 
an analogous process4 ,the atmospheric  
air is by them  decomposed1 part of it  
being given off again1 and part retained
 to  build up the organic structure4    
,plants withdraw mineral matter from the
  soil1 animals feed upon plants1 and   
thus the earthy substances1 after       
having formed a part1 first of rock     
masses1 then of vegetable1 and          
subsequently of animal organizations1   
are returned again to the soil1  whence 
to be once more withdrawn and undergo   
new cycles of mutation4  ,but this      
perpetual interchange is not confined to
 the vital world4 ,we  see it in the    
action of winds1 when heated air rises  
and moves in one  direction1 and the    
colder parts sink and travel the        
opposite way4 ,the  same principle is   

exhibited by the oceanic currents1 the  
removal of a  body of water1 from       
whatever cause1 always necessitating the
 ingress of  a corresponding quantity to
 supply its place4 ,but perhaps one of  
the  most beautiful instances of these  
interchanges in the whole inorganic     
world is the ceaseless passage of water 
from the land to the sea1 and  from the 
sea to the land4 ,the countless         
thousands of rivulets1 and  streams1 and
 gigantic rivers1 that are ever pouring 
their waters into  the great deep1 do   
not in the least raise its level or     
diminish its  saltness4 ,and why8       
,simply because the sea gives off by    
evaporation  as much water as it        
receives from rain and rivers4 ,the     
vapour thus  exhaled ascends to the     
upper regions of the atmosphere1 where  
it forms  clouds1 and whence it         
eventually descends as rain4 ,the larger
 part of  the rain probably falls upon  
the ocean1 but a considerable amount is 
nevertheless driven by winds across the 

land4 ,this finds its way into  the     
streams1 and so back again to the sea1  
only1 however1 to be anew  evaporated   
and sent as drizzling rain across the   
face of land and sea4  ,this interchange
 is constantly in progress1 and seems to
 have been as  unvarying during past    
ages4    ,but the ceaseless passage of  
water between land and sea is not a mere
  isolated and independent phenomenon4  
,like all the rest of ,nature's         
processes1 even the simplest1 it        
produces important and complicated      
effects4 ,and the reader may1 perhaps1  
think it worth looking at for a  little1
 when he reflects that to this seemingly
 feeble cause we owe no  small part of  
our solid lands1 whether as islands     
wasted by the sea1  or as part of vast  
and variegated continents1 wide rolling 
prairies  covered with verdure and      
roamed over by herds of cattle1 or      
wintry  ,alpine hills lifeless and bare4
    ,the truth of this will appear when 
we reflect that the moisture which      

rises from the sea and falls on the land
 as rain1 is free from any  admixture of
 impurities2 but by the time it again   
reaches the sea1  after a circuit of    
perhaps many miles down valley and      
plain1 it has  grown turbid and         
discoloured1 carrying with it a quantity
 of mud1 sand1  and drift-wood4 ,the    
sediment thus transported soon sinks to 
the bottom1  where it eventually hardens
 into rock1 and in course of time is    
raised  above the waves as part of a new
 land4 ,such ,i conceive to have been   
the  origin of the sand1 gravel1 and    
imbedded plants of our boulder4 ,it may 
be well1 however1 in going into the     
details of the subject1 to take a  wider
 view of this interesting branch of     
geology1 and look for a little  at the  
forms and modes of the decomposition of 
rocks1 and the varied  manner in which  
new sedimentary accumulations are       
formed4    ,all over the world1 wherever
 a land surface spreads out beneath the 
sky1 there goes on a process of         

degradation and decay4 ,hills are       
insensibly crumbling into the valleys1  
valleys are silently eroded1  and crags 
that ever since the birth of man have   
been the landmarks of  the race1 are yet
 slowly but surely melting away4 ,it    
matters not where  the hill or plain may
 lie1 the highest mountains of the      
tropics and  the frozen soil of the     
poles1 yield each in its measure and    
degree  to the influence of the general 
law4 ,it might seem that so universal  a
 process should be the result of some   
equally prevalent and simple  cause4    
,but when we set ourselves to examine   
the matter1 we find it far  otherwise4  
,the waste of the solid lands1 in place 
of arising from some  single general    
action1 is found to result from a       
multiform chain of  causes1 often local 
in their operation and variable in their
 effects4  ,such an investigation       
affords a good illustration of the      
general mode  and fashion in which      
,nature delights to work4 ,it shows us  

that what  may seem a very simple       
process may be in reality a very        
complicated  one2 that in truth there   
exist in the world around us few if any 
simple1 single processes1 which stand   
out by themselves unconnected  with any 
other2 that1 on the contrary1 all become
 intimately linked  together1 the       
effects of one often forming part of the
 chain of causes  in another1 and       
producing by their combined action that 
complex yet  strikingly harmonious order
 that pervades all the operations of    
,nature4  ,to an extent of which ,cicero
 never dreamed1 there runs through all  
the world such an admirable succession  
of things that each seems  entwined with
 the other1 and all are thus intimately 
linked and bound  together4#ea ,man     
separates out these various processes1  
classifies  and arranges them1 because  
from the imperfection of his mental     
powers  he cannot otherwise understand  
their effects2 all would seem but  chaos
 and confusion4 ,but the formal         

precision and the sharp lines of        
demarcation exist only in his mind4     
,they have no place in the outer  world4
 ,there we see process dove-tailing with
 process1 and spreading  out over the   
material world in an endless network of 
cause and effect4  ,we feebly try to    
trace out these interlacing threads1 but
 we can follow  them far in no          
direction4 ,proteus-like1 they seem to  
change their  aspect1 blending now into 
one form1 now into another1 and so      
eluding  our keenest pursuit4           
,footnote #ea3 ,cicero1 ,de ,nat4 ,deor4
 lib4 i4 #d4 ,so1 in ,bacon's ,wisdom   
of the ,ancients1 under the fable ,pan  
or ,nature3--,the chain of  natural     
causes links together the rise1         
duration1 and corruption2 the           
exaltation1 degeneration1 and workings2 
the processes1 the effects1  and        
changes1 of all that can any way happen 
to things4 ,such is the  philosopher's  
explanation of the ,destinies as sisters
 of ,pan4 ,in no  part of his writings  

can the thorough practical character of 
,bacon's  philosophy be more            
conspicuously seen than in his treatment
 of these  ancient fables4 ,glancing    
over the titles of the different papers1
 you  are tempted to wonder what an     
intellect which could only appreciate   
poetry as a mode of narrating history or
 as a vehicle for the teaching  of      
truth1 will make of such fairy tales as 
those of ,pan1 ,orpheus1  ,proteus1     
,cupid1 and many others4 ,they seem like
 so many airy ,naiads  crushed within   
the iron grasp of a hundred-banded      
,briareus4 ,but a  perusal of those     
delightful pages will show that the     
giant has really  no malevolent         
intentions towards his fair prisoners2  
nay1 that he only  wishes1 by stripping 
them of their paint and finery1 to show 
that1  with all their lightness and     
grace1 they are nevertheless strong     
buxom  dames1 of the same doughty race  
with himself4    ,as an instance1       
therefore1 of this remarkable           

interlacing of different  causes in what
 we call a single process1 the          
disintegration of rocks  deserves our   
attention4 ,in ordinary language1 we say
 a stone rots  away1 and its debris is  
washed down by the rains and streamlets1
 and  the process does not at first     
sight seem at all more complex than the 
expression used to describe it2 yet if  
we examine the subject1 we shall  ere   
long find that there are in nature many 
simpler things than the  rotting away of
 a stone4 ,to effect such a result1     
there come into play  a whole category  
of agencies1 chemical and mechanical1 so
 combined in  their operation1 and so   
intimately blended in their effects1    
that it  becomes no easy task to tell   
where one set ends and another begins4  
,a rock is said to undergo a chemical   
change1 when one or more of its         
component parts passes from one state of
 combination to another--as1  for       
instance1 when a mineral absorbs oxygen1
 and1 from the condition  of a          

protoxide1 changes into that of a       
peroxide2 or when1 parting with  its    
silicic acid1 it takes an equivalent    
amount of carbonic acid1 and  in place  
of a silicate becomes a carbonate4 ,now 
these1 and similar  metamorphisms1 are  
chiefly produced by water permeating    
through the  rocky mass1 and thus no    
sooner does the old combination cease1  
than the  new one which replaces it is  
dissolved by the slowly filtering water1
  and carried away either to greater    
depths1 or to the surface4 ,every  drop 
of water1 therefore1 that finds its way 
through the rock1 carries  away an      
infinitesimal portion of the mineral    
matter1 and the stone is  consequently  
undergoing a continual decay4 ,this     
condition of things may  go on either at
 some depth in the earth's crust1 or on 
the surface4  ,in the former case1      
springs and percolating water are the   
agents in  effecting the change2 in the 
latter1 it is produced chiefly by rain  
and  streams4 ,but wherever the process 

goes on1 the results1 unless where      
counteracted by some opposite agency1   
are ultimately the same4 ,it may  be of 
use to look at some examples of these   
changes1 and1 by dividing  them in a    
rough way1 into underground and surface 
actions1 we shall be  enabled to mark   
more clearly their effects4    ,a common
 source of the decay of rocks arises    
from the percolation  through them of   
water charged with carbonic acid4       
,decomposing  vegetation gives off a    
large amount of this gas1 which is      
readily  absorbed by rain-water4 ,the   
water sinks into the ground filtering   
through cracks and fissures in the      
rocks1 whence it afterwards  re-emerges 
in the form of springs4 ,now wherever1  
in its passage through  these           
subterranean rocks1 the water meets with
 any carbonate1 the  carbonic acid      
contained in the liquid immediately     
begins to dissolve  out the mineral     
matter1 and carries it eventually to the
 surface4 ,there  the amount of         

evaporation is often sufficient to cause
 a re-deposit of  the mineral in        
solution4 ,if it be lime1 a white crust 
gathers along  the sides of the stream1 
delicately enveloping grass-stalks1     
leaves1  twigs1 snail-shells1 and other 
objects1 which it may meet with in its  
progress4 ,such petrifying springs1 as  
they are popularly termed1  occur       
abundantly in our limestone districts4  
,it should be borne in  mind1 however1  
that they only produce an incrustation  
round the organic  nucleus1 and do not  
petrify it4 ,that alone is a true       
petrifaction  where the substance is    
literally fossilized1 or turned into    
stone4  ,a familiar instance of a       
similar chemical process may be seen    
under  many a bridge1 and along the     
vaulted roofs of many an old castle4    
,numerous tapering stalactites hang down
 from between the joints of the         
masonry1 resembling1 so to speak1       
icicles of stone1 often of a dazzling   
whiteness4 ,they are formed by the      

percolation of carbonated water  through
 the mortar of the joints1 the carbonate
 of lime thus withdrawn  being          
re-deposited where the water reaches the
 air and evaporates4 ,a  little pellicle
 of lime first gathers on the roof1 and 
every succeeding  drop adds to the      
length of the column4 ,in some cases1   
where the supply  of water is too great 
for the amount of evaporation1 part     
falls on the  floor1 and1 being there   
dissipated1 leaves behind a             
slowly-gathering  pile of lime called   
stalagmite4 ,in some of the ,eastern    
grottos1 the  pillars from the roof have
 become united to those on the floor1   
forming  the most exquisite and         
fairy-like combinations of arch and     
pillar4  ,an example of a calcareous    
grotto has now become pretty familiar to
  our summer tourists1 under the name of
 the ,spar ,cave4 ,it lies on an        
exposed cliff-line along the western    
shores of ,skye1 against which  the     
surge of the ,atlantic is ever breaking4

 ,you approach it from the  sea1 and    
enter a narrow recess between two       
precipitous walls of rock1  open above  
to the sky1 and washed below by the     
gurgling tide4 ,crossing  the narrow1   
shingly beach1 you find the ground      
thickly covered with  herbage1 while1   
grouped along the dark walls1 are large 
bunches of  spleenwort1 hart's-tongue   
fern1 and other plants that love the    
shade4  ,soon after entering the cave1  
all becomes sombre and cold2 and the few
  candles1 with which the party have    
furnished themselves1 only serve  to    
heighten the gloom4 ,after scrambling on
 for a time across dank1  dripping      
rocks1 and over a high bank of smooth   
marble1 on which it is  difficult to    
creep1 almost impossible to stand1 you  
arrive at a deep  pool of clear1 limpid 
water1 which extends across the cave    
from side to  side1 barring all farther 
passage4 ,the scenery at this point will
 not  readily be forgotten4 ,the roof   
towers so high that the lights are too  

feeble to show it1 while the walls1     
roughened into every form of cusp  and  
pinnacle1 pillar and cornice1 all       
glittering in the light1 resemble  the  
grotto of some fairy dream4 ,on         
returning again to the light of day1  if
 you ask the cause that has given rise  
to all this beauty1 it will  be found a 
very simple one4 ,the cleft occupied by 
the cave has been  once filled by a wall
 of igneous rock called a trap-dyke4    
,atmospheric  influences1 aided probably
 by the waves1 have caused the          
decomposition  and removal of this      
intruded rock1 and the calcareous       
sandstone on  either side 'now stands up
 in a wall-like form4 ,the upper part of
  the dyke remains as a roof to the     
cave1 but it has become completely      
covered over with the calcareous        
deposits left by the carbonated water   
that filters through the adjacent limy  
sandstone4 ,the amount of water  is     
considerable1 and consequently every    
part of the cavern--roof1  walls1 and   

floor--has been incrusted with a white  
crystalline carbonate  of lime4 ,in     
volcanic countries1 where the springs   
often come to the  ,surface in a highly 
heated state1 charged1 too1 with various
 chemical  ingredients1 they produce no 
slight amount of physical change on the 
surrounding districts1 and must be      
regarded as important geological        
agents4    ,but perhaps the most common 
and widely-diffused form of             
decomposition1  is that produced on the 
surface of the earth by the action of   
rain-water1 in slowly dissolving out the
 soluble parts of rocks1 and  washing   
away the loose1 incoherent grains that  
remain behind4 ,it is  hard to say      
whether this process is more chemical or
 mechanical4  ,the solution of the      
mineral matter belongs to the former    
class of  changes1 while the removal of 
debris must be ranked among the latter4 
,the results of these combined forces   
form one of the most important  branches
 of investigation which can occupy the  

attention of the  physical geologist1   
and in contemplating them1 we are at a  
loss whether  most to admire their      
magnitude1 or the immense lapse of time 
which  they must have occupied4 ,it may 
be worth while to look at the progress  
of this kind of disintegration1 that we 
may see how wide-spread and  constant is
 the waste that goes on over the world1 
and how materially  the effects of      
running water are by this means         
increased4 ,a volume  might be written  
about the decay of rocks1 and a most    
interesting one  it would be1 but its   
authorship would devolve rather on the  
chemist  than the geologist4#eb ,we can 
do no more here than merely glance at   
one or two illustrative examples4       
,footnote #eb3 ,a ,german chemist1      
,bischoff by name1 has written two      
learned volumes in which this subject is
 discussed 7translated into  ,english1  
and published by the ,cavendish         
,society71 valuable for their  facts1   
but not always very safe in their       

deductions4    ,among the mineral       
substances that most readily yield to   
the action of  the weather1 are the     
silicates and the carbonates4 ,the rocks
 containing  the former belong in large 
measure to what we call the igneous     
class1  such as the granites and traps2 
while those containing the latter  form 
the bulk of our useful stones1 such as  
limestone and sandstone4  ,the removal  
of alkaline silicates is due to their   
conversion into  carbonates1 which are  
readily soluble in water4 ,rain falling 
on a rock  in which they are largely    
present1 dissolves a small portion1 and 
carries it into the soil or into        
streams1 and thence to the ocean4       
,every shower in this way withdraws a   
minute amount of mineral matter1  and   
tends to leave the harder insoluble     
grains of the rock standing out  on the 
surface in the form of a loose          
pulverulent crust1 easily washed  away4 
,the debris thus formed1 where allowed  
to accumulate1 makes an  excellent kind 

of soil known to the ,scottish farmers  
as rotten rock4    ,the tourist who has 
visited any of our granitic districts1  
such as the  south-western parts of     
,cornwall1 the rugged scenery of ,arran1
 or the  hills of the ,aberdeenshire    
,highlands1 must be familiar with some  
of the  forms of waste which the rocks  
of these regions display4 ,mouldering   
blocks1 poised sometimes on but a       
slender base1 and eaten away into the   
most fantastic shapes1 abound in some   
localities1 while in other parts1  as   
for instance at the summit of ,goatfell 
in ,arran1 the rock weathers  into a    
sort of rude masonry1 and stands out in 
its nakedness and ruin  like some       
crumbling relic of ,cyclopean art4 ,in  
other districts1 as in  ,skye and in the
 adjoining island of ,raasay1 the       
granitic hills are  of a still more     
mouldering material4 ,their summits1    
white and bald1  sometimes rise to a    
height of fully two thousand feet above 
the sea1  while down their sides are    

spread long reddish-yellow tracks of    
debris  intermingled with patches of    
stunted herbage4 ,every winter adds to  
the  waste1 and lengthens the lines of  
rubbish4 ,some of these hills form a    
good field wherein to study the         
disintegration of granitic rocks1 such1 
for instance1 as ,beinn na ,cailleaich1 
that rises from the shores of           
,broadford ,bay4 ,around the eastern    
base of that mountain there stretches  a
 flat moory district1 with a few        
protruding blocks that have rolled  down
 into the plain4 ,the earlier part of   
the ascent lies over a region  of       
metamorphic limestone1 where the grey   
weathered masses of the  calcareous     
rock1 often like groups of mouldering   
tombstones1 are seen  protruding in     
considerable numbers through the rich   
soft grass and the  scanty brushwood of 
hazel and fern4 ,leaving this more      
verdant zone1 we  enter a district of   
brown heath that slowly grows in        
desolation as we  ascend4 ,huge blocks  

of syenite--a granitic rock of which the
 upper part  of the mountain entirely   
consists--cumber the soil in every      
direction1  and gradually increase in   
numbers till the furze can scarcely find
 a  nestling-place1 and is at last      
choked altogether4 ,then comes a scene  
of utter desolation4 ,grey masses of    
rock of every form and size are  piled  
upon each other in endless confusion4   
,some of them lie buried in  debris1    
others tower above each other in a rude 
sort of masonry1 while  not a few       
perched on the merest point seem but to 
await the storms of  another winter to  
hurl them down into the plain4 ,the     
ascent of such a  region is no easy     
task1 and must not unfrequently be      
performed on hands  and knees4 ,but once
 at the top1 the view is enough to      
compensate a  tenfold greater exertion4 
,far away to the west1 half sunk in the 
ocean1  lie the isles of ,eigg1 ,coll1  
and ,tiree1 with the nearer mountains of
  ,rum4 ,north-west1 are the black      

serrated peaks of the ,coolins1 that    
stand out by themselves in strange      
contrast with every other feature  of   
the landscape4 ,northward1 stretches the
 great range of syenitic  hills1 with   
the sea and the northern ,hebrides      
beyond4 ,away to the east1  across the  
intervening strait1 lie the hills of the
 mainland1 with  all their variety of   
form and outline1 and all their changing
 tints1  as the chequered light and     
shade glide athwart the scene4          
,southward1  the eye rests on the grey  
wrinkled hills of ,sleat1 and far over  
along  the line where earth and sky     
commingle1 are the mountains of ,morven1
  stretching westwards till they end in 
the bold weather-beaten headland  of    
,ardnamurchan1 beyond which lies the    
blue boundless ocean4 ,the top of       
,beinn na ,cailleaich is flat and       
smooth1 surmounted in the centre by a   
cairn4 ,tradition tells that beneath    
these stones there rest the bones  of   
the nurse of a ,norwegian princess4 ,she

 had accompanied her mistress  to the   
misty hills of ,skye1 and eventually    
died there4 ,but the love  of home      
continued strong with her to the end1   
for it was her last  request that she   
might be buried on the top of ,beinn na 
,cailleaich1  that the clear northern   
breezes1 coming fresh from the land of  
her  childhood1 might blow over her     
grave4    ,i have already alluded to the
 wasting away of a trap-dyke4 ,this     
decomposition arises from the same cause
 as among the granites--the  solution1  
and removal of the silicates4 ,all these
 trap-rocks are  igneous1 and seem to   
have risen from below through open      
fissures and  rents4 ,as they contain a 
large percentage of felspar--the same   
mineral  that gives to many granites    
their mouldering character--they may be 
seen exhibiting every form and stage of 
decay4 ,often they stand out in         
prominent relief from some cliff of soft
 shale1 with a brown surface1           
picturesquely roughened into spherical  

masses of all sizes1 that give  to the  
rock somewhat the appearance of a       
hardened pile of ammunition  in which   
ponderous shells lie intermingled with  
round shot1 grape1 and  canister4 ,each 
of the concretionary balls when examined
 is found to  exfoliate in concentric   
pellicles like the coats of an onion1   
and you  may sometimes peal off a       
considerable number before arriving at  
the  central core1 which consists of the
 hard rock still undecomposed4 ,in  this
 case the process of degradation is     
aided by the decay of another  mineral  
called augite1 which contains a variable
 percentage of iron1  and imparts the   
peculiar yellowish-brown tint to the    
weathered rock4  ,trap-dykes may also be
 seen in a still more wasted condition1 
where1  in place of protruding from a   
cliff-line1 they recede to some depth   
and give rise to deep clefts and        
fissures4 ,an instance of this kind  has
 been referred to in the case of the    
,spar ,cave1 and many others may  be    

seen along the same coast-line4 ,the    
shore there for miles is formed  of a   
low cliff of white calcareous sandstone1
 fissured by innumerable  perpendicular 
clefts of greater or less width1 and    
sometimes only a  yard or two apart4    
,each of these has once been filled by a
 dyke of  trap1 which originally rose up
 in a melted state1 and after having    
solidified into a compact stony mass1   
began to yield to the process of  decay4
 ,in all these and similar cases1 the   
primary cause of the waste  lies in the 
decomposition of the felspar4           
,rain-water acts in removing  the       
soluble portions1 and the harder grains 
that remain1 deprived of  the cementing 
matrix1 ere long crumble down and are   
washed off by the  rains4 ,in this way  
the rock insensibly moulders away1 every
 frost  loosening its structure1 and    
every shower carrying away part of its  
substance4    ,among the many objects of
 interest along a rocky coast some of   
the more  striking are certainly to be  

found in the curious and often grotesque
  forms assumed by the weathered cliffs4
 ,above high-water mark and thus  away  
from the dash of the waves1 we can often
 trace the progress of  decay among such
 sedimentary rocks as sandstones and    
conglomerates4  ,worn into holes and    
scars1 projecting cusps and tapering    
pinnacles1 or  eaten away into the rude 
semblance of a human form1 headless     
perchance1  or into the shape of a huge 
table poised on a narrow pedestal1 the  
rock affords an endless variety of      
aspects and a continual source of       
pleasure4 ,if we chance to light upon   
any building constructed out of  the    
sandstone of such cliffs1 it is worth   
noting that the removal of  the stone   
has not deprived it of its mouldering   
qualities2 nay1 that  houses erected    
within the memory of people still living
 already begin  to wear an aspect of    
venerable antiquity4 ,i remember meeting
 with an  interesting example in the    
case of an old castle built on a similar

  rocky coast-line4 ,it stood on a      
little ness or promontory of dull red   
stone1 washed on all sides save one by  
the wild sea4 ,the walls1 of  which but 
a fragment remained1 were built of a    
dark red sandstone2 but  the lapse of   
centuries had told sadly on their       
masonry4 ,the stones  rose over each    
other tier upon tier1 corroded sometimes
 into holes  and hollows1 sometimes into
 a close honey-combed surface1 but the  
mortar that had been used to cement them
 together still stood firm and          
protruded from between the tiers to     
show1 by no doubtful or ambiguous  sign1
 how silently yet how surely the wasting
 forces had been at  work4 ,the         
scutcheon over the only remaining       
gateway had been carved  out of another 
kind of stone of a lighter colour and   
harder texture1  and so its grim lions  
looked nearly as fresh and formidable as
 when  first raised to the place of     
honour which they still occupied4 ,in   
this case1 as before1 the decomposition 

was owing to the presence of  a         
considerable proportion of soluble      
matter1 which the rains of four         
centuries had carried away along with   
the loosened incoherent sandy  grains4  
,conglomerate or pudding-stone has often
 a picturesque outline in its  decay1   
more especially if its included         
fragments have a considerable  range of 
size4 ,large tracts ,of this rock exist 
in various parts of  ,britain1          
particularly in ,scotland1 where the    
basement beds of the ,old  ,red         
,sandstone consist of a coarse          
conglomerate1 sometimes several         
thousand feet in thickness4 ,such       
enormous masses form the scenery of a   
large part of ,east ,lothian1 and are   
found in detached patches across  into  
,peeblesshire and ,lanark4 ,in the      
north1 too1 the neighbourhood of        
,inverness and other parts of the same  
district display conspicuous            
conglomerate hills4 ,unless where laid  
bare by streams or by the action  of    

breakers1 the contour of these hills is 
rounded and tame1 with a  scanty        
covering of short scrubby grass and very
 few protruding bosses  of rock4 ,but   
where a mountain torrent has cut its way
 down the hill  side1 the ravine thus   
formed exhibits broken walls and pillars
 of  rock made up of rounded balls of   
every shade and size1 cemented by a     
dark-red or green paste4 ,the cementing 
material is sometimes clay1  sometimes  
lime1 and its variable nature gives rise
 to a corresponding  inequality in the  
amount and form of decomposition4 ,where
 the rounded  pebbles are bound together
 by clay1 rains act with rapidity in    
washing  away the cement1 and the       
component balls fall out by degrees1    
leaving  a cliff strangely roughened by 
protruding knobs1 and eaten away into   
clefts and hollows4 ,when the pebbles   
are held in a crystallized matrix  of   
lime1 they usually remain longer        
together1 and may sometimes be  seen    
standing up in the form of detached     

rugged pillars that defy  all regularity
 of size or outline1 and remind one of a
 sort of rude  grotto-work4 ,such       
irregularities become still more marked 
where to the  action of the rains there 
has been added the spray of the ocean4  
,a  coast-line of conglomerate1 where   
the rock rises into cliffs1 is always  a
 romantic one2 caves1 pillars1 and      
ruined walls1 all in the same rough     
grotto style1 meet us at every step4    
,here1 too1 we can mark the varying     
effect of the waves upon the lower      
portions of the rock1 eating it into    
cavernous holes and leaving rugged      
projecting pinnacles to which the       
mottled colours of the included pebbles 
give an additional and peculiar  effect4
    ,a cliff of shale seldom shows much 
of the picturesque1 though often a  good
 deal of the ruinous4 ,the rock is      
easily undermined by streams1  and a    
shale ravine usually exhibits in        
consequence either heaps of  crumbling  
rubbish1 or1 where the stream comes past

 with a more rapid  current1            
perpendicular walls1 jointed and        
laminated1 but without much  variety of 
outline4 ,such cliffs1 however1 merit   
the careful attention  of the observer1 
for from their friability they are most 
easily  decomposed and washed down by   
streams1 to form new accumulations of   
similar soft argillaceous matter4 ,a    
shale coast-line sometimes shows  cliffs
 of considerable altitude1 as in some   
parts of ,skye and ,pabba1  where the   
,lias shales may be seen piled over each
 other often to a  height of seventy or 
eighty feet1 and spreading out along the
 shore as  low flat reefs and skerries1 
brown with alg at their seaward ends1   
and showing on the higher slopes of the 
beach the characteristic  fossils of the
 ,lias--ammonites1 belemnites1 and      
gryph--crowded  together by hundreds4   
,the action of the decomposing forces   
has operated  more effectually on the   
soft material of the shale than on the  
hard  crystalline lime of the included  

shells1 so that the latter stand out  in
 relief from the dull-brown surface of  
the rock1 and from their  numbers and   
prominence form one of the most marked  
features of the  coast-line4            
,probably few have ever visited a       
limestone district without marking  the 
manner in which that rock yields to the 
action of the elements1  whether in an  
inland part of the country where rivers 
have cut deep  gullies through the rock1
 or along some exposed shore where the  
stone  has been wasted by a still ruder 
assailant4 ,an exposed cliff of hard    
homogeneous limestone weathers into deep
 clefts and holes2 the entire  surface  
assumes a pitted appearance1 somewhat   
like a sandy beach after  a showier of  
rain1 and the planes of stratification1 
or lines formed  by the parallel        
junction of the beds are often worn away
 until the  rock looks not unlike a     
piece of old masonry1 in which the      
mortar has  decayed and dropped out1    
leaving the angles of the stones to get 

wasted  and rounded by the action of the
 weather4 ,in many districts1 too1 where
  the rock is richly fossiliferous1 the 
broken joints of encrinites along  with 
corals and shells may be seen crowded   
together by myriads1 their  hard        
skeletons protruding from the wasted    
rock in such a way as to show  that the 
stone can contain very little else4 ,by 
this means we often  learn that a       
limestone bed is nothing but an old     
sea-bottom1 where  the calcareous       
sediment was mainly derived from broken 
stone-lilies1  corals1 and shells1      
though if we break off a piece of the   
rock the  internal fracture may show    
very little or no trace of any organic  
structure4 ,and hence if the geologist  
would form an accurate conception  of   
the origin and structure of many of the 
stratified rocks1 he must  study them   
not in hand specimens neatly trimmed and
 arranged along the  shelves and drawers
 of a cabinet1 nor even in the ponderous
 blocks  daily exhumed by the quarryman1

 but along some surf-beaten cliff-line  
or down some precipitous ravine where   
the rock for centuries has been  exposed
 to the wear and tear of the elements4  
,limestones and other calcareous        
formations are liable to more than      
ordinary decay1 for1 as we have seen    
above1 percolating rain-water           
constantly carries away mineral matter  
from their subterranean  portions4      
,accordingly1 in some parts of the      
country1 as for instance in  ,yorkshire1
 the interior of such rocks has been    
eaten away into great  caverns by this  
form of decomposition4    ,some         
remarkable examples occur in the island 
of ,raasay1 one of the  north-eastern   
,hebrides4 ,its eastern margin shoots up
 from the sea to a  height of over #ijj 
feet1 the cliff-line being formed of a  
calcareous  grit as perpendicular as a  
wall1 and fissured by deep chasms and   
rents4  ,the narrow table-land between  
the edges of this cliff and an abrupt   
ridge that rises behind1 is perforated  

by innumerable holes and clefts1  into  
which if a stone be thrown it may be    
heard for several seconds  rumbling far 
below4 ,the edges of these pitfalls are 
often fringed  with ferns1 rushes1 and  
long grass1 so as to be nearly hidden1  
and it  requires no little caution to   
traverse this elevated region in safety4
  ,innumerable sheep have been lost by  
falling into the subterranean  abysses1 
and even the wary natives seem to have  
sometimes lost their  footing4 ,a story 
is told of a woman who had crossed to   
the other side  of the island for the   
purchase of some commodities1 and       
returning  by the high grounds had got  
nearly within sight of her own cottage1 
when by some unlucky accident she took a
 false step and instantly  disappeared4 
,unfortunately her errand had been      
performed alone1 so that  some time     
elapsed ere she was missed4 ,the search 
continued unremitting  for two days1 but
 no trace of the missing traveller could
 be found4 ,at  last on the third day   

her figure was seen creeping slowly     
along the  road not many hundred yards  
from her own door4 ,it appeared that she
 had  first slid down a sheer height of 
about fifty feet1 when her further      
passage was intercepted by the sides of 
the fissure4 ,during the earlier  part  
of her confinement she strove hard to   
re-ascend the chasm1 and it  was not    
until1 the effort seeming fruitless1 she
 had begun to resign  herself to        
despair1 that a glimmering of light from
 below induced her  to attempt a        
descent4 ,this proved no easy matter1   
and occupied many  weary hours of labour
 and suspense2 but at length she        
succeeded in  worming herself to the    
bottom1 and crawled out more dead than  
alive  only a little way from her home4 
,there still stand perched on some of   
these precipitous cliffs the remains of 
a few villages1 the inhabitants  of     
which were accustomed to tether their   
children to the soil1 whence  one of the
 hamlets received in ,gaelic the        

soubriquet of ,tethertown4  ,many a     
valuable commodity disappeared by       
rolling over the cliff1 and  ,i have    
been assured that it was no unfrequent  
occurrence for a pot of  potatoes       
capsized at the doorway to tumble down  
the slope and make no  stop until safely
 esconced at the sea-bottom4    ,the    
process whereby these fissures and      
caverns originate is the same as  that  
noticed already in the ,spar ,cave4     
,water containing an impregnation  of   
carbonic acid filters down through      
cracks and fissures of the  calcareous  
rock1 dissolving out in its passage a   
portion of the lime  which it eventually
 carries back to the surface1 and either
 deposits  there or transports into     
streams1 and thence to the sea4 ,thus   
atom  by atom is removed wherever the   
percolating water reaches1 until in  the
 course of ages an irregular cavern of  
greater or less extent is  produced4    
,the decomposition of limestone at the  
surface results from  the same kind of  

action1 that of carbonated water4 ,every
 shower of  rain insensibly carries away
 a fraction of the constituent parts of 
the rock1 so that the size and form of  
detached blocks as well as of  exposed  
cliffs is constantly changing4 ,how     
often do we see the same  decay going on
 with a melancholy rapidity among the   
exposed marble  tombstones of our       
churchyards4 ,in a few years the tablet 
gets worn  and furrowed as though it had
 stood there for centuries4 ,eventually1
  too1 the inscription becomes effaced1 
and perhaps ere the bones of the        
deceased have mouldered away and mingled
 with their kindred dust1 the  epitaph  
that recorded for the admiration of     
posterity his many virtues  and his     
vigorous talents1 has faded from the    
stone--often1 alas6 only  too fit an    
emblem of how speedily the memory of the
 dead may fade away  out of the land of 
the living4          ,,chapter ,,ix4    
,mechanical forces at work in the       
disintegration of rocks--,rains         

,landslips--,effects of                 
frosts--,glaciers and                   
icebergs--,abrading         power of    
rivers--,suggested volume on the geology
 of         rivers--,some of its        
probable contents--,scene in a woody    
ravine--,first idea of the origin of the
 ravine one of primeval                 
cataclysms--,proved to be               
incorrect--,love of the marvellous      
long the bane of geology--,more careful 
examination shows the         operations
 of ,nature to be singularly uniform and
 gradual--,the         doctrine of slow 
and gradual change not less poetic than 
that         of sudden paroxysms--,the  
origin of the ravine may be sought      
among some of the quieter processes of  
,nature--,features of         the       
ravine--,lessons of the                 
waterfall--,course of the stream        
through level ground--,true history of  
the ravine--,waves and                  
currents--,what becomes of the waste of 
the land--,the ,rhone         and the   

,leman ,lake--,deltas on the            
sea-margin--,reproductive               
effects of currents and waves--,usual   
belief in the stability         of the  
land and the mutability of the          
ocean--,the reverse                     
true--,continual interchange of land and
 sea part of the         economy of     
,nature--,the continuance of such a     
condition of         things in future   
ages rendered probable by its           
continuance         during the past4    
,the forms of decomposition noticed in  
the last chapter were chiefly  of a     
chemical kind4 ,their effects were      
observable alike on the  surface of the 
earth and below ground2 in the latter   
case we saw them  excavating caverns and
 long irregular chasms1 in the former we
 noted  the production of debris which  
if undisturbed went to the formation  of
 soils4 ,it must be borne in mind       
however1 that in these operations  other
 forces than simply those of a chemical 
kind come into play4 ,the  percolation  

of water and the removal of insoluble   
particles on the  exposed parts of rocks
 rank as mechanical processes4 ,so also 
do those  by which new surfaces of      
mineral masses are brought within the   
sphere  of the chemical agencies1 such  
as the action of frosts1 rains1 rivers1 
and waves4 ,in short1 as already        
noticed1 any subdivision of the forces  
at work in effecting the decomposition  
of rocks must ever be more or  less     
arbitrary2 but it remains nevertheless  
useful1 if we bear in  mind that the    
exactly defined boundary lines are of   
our making1 not  ,nature's4 ,with this  
caution we may proceed to examine what  
are termed  the mechanical agencies in  
the disintegration of mineral masses1   
and in  so doing1 we shall find that the
 chemical forces are not less helpful   
to the mechanical than the latter to the
 former4    ,first1 we may notice the   
effect of rains in washing away the     
disintegrated particles to lower levels 
or into river-courses whereby  fresh    

portions of rock become exposed to the  
decomposing forces4 ,rains  also act    
powerfully in altering the form of      
cliff-lines and steep  declivities1     
especially where these consist more or  
less of friable  earthy matter4 ,after a
 long continuance of wet weather1 ,i    
have seen  the abrupt sides of a        
river-channel that were formed of a     
stiff blue  clay completely cut up by   
rents of various dimensions1 whereby    
large  masses had subsided many feet1   
while others had rolled down altogether 
and lay in the bed of the stream where  
they were undergoing a rapid  abrasion4 
,the cause of this alteration was       
obvious4 ,the rains pouring  down from  
the sloping grounds on either side of   
the river had excavated  deep channels  
on the abrupt face of the cliffs1 while 
a considerable  quantity of water       
finding its way through the soil1 had   
permeated  through joints and crevices  
in the clay some feet from the edge of  
the  bank4 ,by the combined operation of

 these causes1 masses of clay several   
yards in extent lost their cohesion and 
either settled down a few  feet1 or     
found their way to the bottom4 ,such    
landslips are of frequent  occurrence   
where large masses of rock of a hard    
compact nature rest  upon loose shales  
and clays more or less inclined4 ,whole 
hills have  been known to be hurled in  
this way into the valleys below4    ,but
 these results become perhaps still more
 marked where to the  ordinary          
operations of water there are added     
those of intense frost4  ,the effects of
 a severe winter 7such1 for instance1 as
 a ,canadian one71  in loosening the    
particles of rocks and facilitating the 
breaking-up  of large masses1 must be   
ranked among the most powerful agencies 
of  nature4 ,in such a season1 the      
percolating water with which nearly     
every  surface-rock is charged becomes  
frozen1 and in the act of congelation   
expands4 ,the result of this dilatation 
is to exert great pressure on  the      

particles of the rock1 and thereby      
loosen their cohesion4 ,when thaw  comes
 the frozen liquid contracts again1 but 
the loosened particles  have no such    
elastic power1 and so1 having lost hold 
of each other1  crumble down4 ,if the   
season be a changeable one1 frost and   
thaw quickly  alternating1 the amount of
 waste produced becomes very great4 ,not
 only  is the outer surface of the stone
 decomposed1 but the water filtering    
through the joints of the rock freezes  
there1 and thus on the arrival  of      
milder weather vast masses become       
detached from the cliffs1 and  roll     
down1 to be worn by the grinding action 
either of waves or of  rivers1 as the   
case may be4 ,spring at last sets in    
with its warmth and  its showers2 the   
snow rapidly melts away2 the whole      
country streams  with water2 every      
valley and hollow has its red turbid    
rivulet1 that  bears a burden of muddy  
sediment into the nearest river2 and    
thus the  loosened portions of the rocks

 get washed away down to sea1 leaving a 
new surface for the action of next      
winter4 ,we can easily understand1      
therefore1 that in certain regions the  
combined effects of frost and  thaw may 
work in the course of ages changes of   
almost inconceivable  extent1 and that  
the agency of ice must be not less      
varied and  important on the land than1 
in the case of the boulder clay1 we     
found  it to be in the ocean4           
,besides this action in winter1 which   
goes on more or less in every  country  
wherever the temperature sinks          
sufficiently low to permit of  the      
freezing of water1 ice effects many     
changes on the surfaces of  rocks when  
it takes the form of glaciers and       
icebergs4 ,we have already  noted the   
operation of a glacier during its slow  
progress in crushing  down large        
fragments of stone1 scratching and      
abrading the rocks over  which it       
passes1 and eventually producing a vast 
quantity of mud1 which  is carried down 

by streams to form new accumulations    
either in lakes  or seas4 ,we have also 
marked the effects of the drifting      
iceberg in  materially modifying the    
contour of submarine hills1 and         
depositing  over the ocean-bottom mud1  
gravel1 and boulders4 ,nothing further1 
therefore1 need be done here than simply
 to keep these agencies in  view1 as    
playing an important part in the        
disintegration of rocks4    ,another    
highly interesting aqueous action is    
that of streams and  rivers1 in scooping
 out for themselves channels through    
sometimes  the hardest and most solid   
rock4 ,such effects may be seen all over
  the globe1 in the old world and in the
 new1 in the bed of the  tiniest        
rivulet1 as well as in the course of the
 mightiest river4  ,and accordingly1 in 
all the long list of geological agents1 
we find  none so well known and so often
 described alike by poets1 historians1  
and scientific writers1 as well in      
ancient as in modern times4 ,what  a    

delightful volume might be written about
 the geology of rivers6 ,it  would1     
perhaps1 begin with that great river1   
the ,euphrates1 along  whose green banks
 lay the birthplace of the human race1  
tracing out the  features of its        
progress from the ravines and cataracts 
of ,armenia1  with all their surrounding
 relics of ancient art1 down into the   
plains  of ,assyria1 amid date-palms and
 ,arab villages1 onwards to the mounds  
of ,nineveh and ,babylon1 and thence to 
the waters of the ,persian ,gulf4       
,well-nigh as remote1 and perhaps still 
more interesting in its human  history1 
would be the story of the ,nile4 ,we    
should have to follow that  river from  
the mystic region of its birth1#ec      
marking the character  of the rocks     
through which winds its earlier channel1
 and the effects  upon them of the      
floods of untold centuries2 it would be 
needful1 too1  to note the influence of 
the waters on the lower grounds1 from   
where  the stream flows over the        

cataracts of ,syene1 down through the   
alluvial  plains of ,egypt2 and lastly1 
the concluding and perhaps most onerous 
part of our labour would be the         
investigation of the delta1 marking its 
origin and progress1 its features in    
ancient times1 as made known to us  in  
the graphic chapters of ,herodotus1 and 
the changes which the lapse  of more    
than twenty centuries has since wrought 
in its configuration4  ,the rivers of   
,europe would detain us long1 not less  
perhaps by their  historic interest than
 by the variety and attractiveness of   
their  physical phenomena4 ,one could   
scarce help lingering over the ,rhine1  
with its source among ,alpine glaciers1 
its lakes and gorges1 its  castles and  
antique towns2 and when once the        
narrative entered the  classic ground of
 ,italy1 it would perhaps become more   
antiquarian than  geological4 ,the      
ravine of ,tivoli1 for instance1 would  
certainly lay  claim to a whole chapter 
for itself1 with its long-continued     

river  action1 its ancient travertin1   
its beautiful calcareous incrustations1 
and above all its exquisite scenery4    
,footnote #ec3 ,fontium qui celat       
origines ,nilus a description not less  
true now than in the days of the ,sabine
 bard4               ,domus ,albune     
resonantis1      ,et prceps ,anio1 ac   
,tiburni lucus1 et uda        ,mobilibus
 pomaria rivis4#ed    ,footnote #ed3    
,albuna's grey re-echoing home1         
,and ,anio1 headlong in his foam1       
,and grove of ,tivoli1      ,and        
orchards with their golden gleam1       
,whose boughs are dipping in the stream 
,that hurries to the sea4    ,hor4      
,carm4 ,l vii4 #ab4    ,and when could  
we exhaust all1 that might be said about
 the rivers of  our own land8           
,of utmost ,tweed1 or ,ouse1 or gulfy   
,dun1      ,or ,trent1 who1 like some   
,earth-born giant1 spreads      ,his    
thirty arms along the indented meads    
,or sullen ,mole1 that runneth          
underneath2      ,or ,severn swift1     

guilty of maidens' death2      ,or rocky
 ,avon1 or of sedgy ,lee2      ,or coaly
 ,tyne1 or ancient hallow'd ,dee2       
,or ,humber loud1 that keeps the        
,scythian's name2      ,or ,medway      
smooth1 or royal-towered ,thame4        
,passing to the new world1 a vast field 
would spread out before us3 the         
,mississippi1 the ,atchafalaya1 the     
,ohio1 the ,st4 ,lawrence1 the ,amazon1 
and many other rivers that in some cases
 rise high among the regions  of        
perpetual snow1 and after traversing    
large areas of country in the  temperate
 zone1 fall into the waters of tropical 
seas4 ,by studying such  examples of    
river-action and delta-formation as are 
presented by these  gigantic streams1 we
 should arrive at some conception of the
 conditions  anciently at work in       
producing our present coal-fields4 ,nor 
would our  researches assume aught like 
completion until after a scrutiny of all
  the larger and more important rivers  
of the globe4 ,such a work could  be    

undertaken1 perhaps1 only by another    
,humboldt4 ,its successful              
accomplishment would certainly insure   
the highest renown to its author1  and  
incalculable benefits to science4       
,from what we have seen of the wide     
waste and decay everywhere in  progress 
on the solid lands of our planet1 it    
becomes no difficult  matter to perceive
 what a number of agencies must be at   
work in the  formation of a river       
channel4 ,let the reader take his stand 
in some  wooded ravine1 where the       
shelving rocks on either side are hung  
all  over with verdure1 and a tiny      
streamlet murmurs on beneath with a     
flow so quiet and gentle as scarcely to 
shake the long pendant willow  branches 
that dip into its surface1 while the    
polished pebbles that  strew its bed lie
 unmoved by the rippling current that   
glides over  them4 ,if in the midst of  
such a scene the question were to arise 
in  his mind1 ,how came this deep1      
narrow ravine into existence8 what      

answer would in all likelihood be the   
first to suggest itself8 ,his eye  would
 scan the precipitous walls of the dell1
 with their rocks cleft  through to a   
depth of perchance fifty feet4 ,it would
 require no great  scrutiny to assure   
him that the beds on the one side formed
 the onward  prolongations of those on  
the other1 and that consequently there  
must  have been a time ere yet the      
ravine existed1 when these beds         
stretched  along unbroken4 ,satisfied   
with these results1 his first impulse   
might  be to bethink him of some        
primeval earthquake1 when the solid land
  rocked to and fro like a tempested    
sea1 and broke up into great rents  and 
yawning chasms4 ,into one of these      
clefts he might suppose the  little     
streamlet had eventually found its way1 
moistening the bare and  barren rocks1  
until at length their surface put on a  
livery of moss1 or  lichen1 or          
liver-wort1 and the birch1 the alder1   
and the willow1 found  a nestling-place 

in their crevices4 ,such a view of the  
origin of the  woody dell would be      
certainly a very natural one1 and in    
some instances  might be sufficiently   
correct1 but in the present case it will
 not  explain the phenomena4 ,if the    
reader will kindly permit me to visit   
the  locality in his company1 perhaps we
 may be able to light upon the true     
explanation1 and see a few appearances  
worthy our attention4    ,first1 then1  
how can we make sure that no convulsion 
of nature has  produced a rent in the   
rocks1 and so helped the streamlet to a 
channel8  a simple question that may be 
well-nigh as simply answered4 ,we stand 
in the centre of the dell on a broad    
ledge of stone1 round whose  well-worn  
sides the rivulet is ever eddying       
onwards4 ,the block consists  of a pale 
sandstone lying in a bed about three    
feet thick1 that dips  gently down the  
stream and underlies a seam of dull1    
soft1 blue shale1  full of small shells4
 ,we trace the edge of this sandstone   

bed across  to the left-hand side of the
 ravine1 and away up into the           
precipitous  cliff1 till it is lost amid
 the ferns and brushwood4 ,there can be 
no  doubt1 therefore1 that the ledge on 
which we were but now standing is a     
continuous portion of the rocks that    
form the left side of the ravine4       
,returning again to the centre of the   
stream1 we proceed to trace out  the    
course of the other end of the same bed1
 and find that it1 too1  strikes across 
to the rocks on the right-hand side     
without a break  or fissure1 and passes 
up into the cliff1 of which it forms a  
part4  ,clearly1 then1 the sandstone bed
 runs in an unbroken1 unfissured line1  
from the one side to the other1 and the 
rocks of either cliff form  one         
continuous series4 ,there occurs no     
break or dislocation1 which1  of course1
 there must have been had the ravine    
owed its origin to any  subterranean    
agency4 ,and so we come to conclude that
 no great cataclysm  in primeval times1 

no yawning abyss1 or gaping chasm1 has  
had anything  whatever to do with the   
formation of our deep sequestered dell4 
,what  then8 ,whither shall we turn1 you
 ask1 to find another agency equally    
grand and powerful in its operation and 
mighty in its results8    ,stay1 gentle 
reader4 ,that craving for the grand and 
the sublime1 that  hungering after      
cataclysms and convulsions1 that        
insatiable appetite  for upheavals1 and 
,titanic earth-throes1 and all the      
mightier machinery  of ,nature1 has done
 no little mischief to geology4 ,men    
have reasoned  that gigantic results in 
the physical structure of the earth must
  have had equally gigantic causes      
operating in sublime conflict and  in   
periodic paroxysms1 now heaving a       
mountain chain to the clouds  of heaven1
 now swallowing up a continent in the   
depths of the sea4  ,happily such       
extreme notions are fast passing away1  
though the old  tendency in a modified  
form still abounds4 ,a closer scrutiny  

of ,nature  as she actually shows       
herself1 not as theorists fancy she     
should be1  has revealed to us that her 
operations are for the most part slow1  
gradual1 and uniform1 and that she      
oftentimes produces the mightiest       
results by combinations of forces that  
to us might seem the very  emblems of   
feebleness and inactivity4 ,in place of 
sudden paroxysms  she demands only an   
unlimited duration of time1 and with the
 aid of  but a few of these simple1     
tardy agents1 she will eventually effect
  results perchance yet more gigantic   
than could be accomplished even  by the 
grandest catastrophe4 ,nor in thus      
seeking to explain the past  by defining
 what seems the usual mode of ,nature's 
operations in the  present1 do we1 as is
 sometimes alleged1 deprive them of     
their high  poetic element4 ,assuredly  
there is something thrilling to even the
  calmest imagination in contemplating  
the results of vast and sudden          
upheavals1 in picturing the solid crust 

of the earth heaving like a             
ground-swell upon the ocean1 in tracing 
amid        ,crags1 knolls1 and mounds1 
confusedly hurl'd1      ,the fragments  
of an earlier world2    and in conjuring
 up visions of earthquakes1 and         
frightful abysses from  which there ever
 rose a lurid glare as hill after hill  
of molten rock  came belching up from   
the fires below4 ,but while far from    
denying that  such appearances may have 
been sometimes seen during the long     
lapse  of the geological ages1 and that 
they give no little vividness and       
sublimity to a geological picture1 we   
claim for the doctrine of the  tranquil 
and uniform operation during past time  
of existing laws and  forces1 an element
 not less poetic4 ,in the former case   
the pervading  idea is that of unlimited
 expenditure of power1 in the latter    
that of  unlimited lapse of time4 ,in   
the one case the action is ,titanic but 
transient1 in the other it is tranquil  
but immensely protracted4 ,the  two     

doctrines in this way counterbalance    
each other2 yet ,i cannot but  think    
that however impressive it may be to    
stand in some lone glen1 and  while     
gazing at its dark jagged precipitous   
cliffs1 to dream about the  paroxysmal  
convulsions of some hour far back in the
 distant past1 the  scene becomes yet   
more impressive when we look on its     
nakedness and  sublimity not as the     
sudden and capricious creation of a day1
 but as  the gradual result of a        
thousand centuries4 ,these cliffs may   
once have  been low-browed rocks rising 
but a little way out of a broad grassy  
plain1 and serving as a noon-tide haunt 
for animals of long extinct  races4     
,thousands of years pass away and we see
 these same rocks higher  and steeper in
 their outline1 brown with alg and ever 
wet with surf1  while around them       
stretches a shoreless sea4 ,ages again  
roll on1 and  we mark still the same    
rocks shooting up as bleak crags covered
 with  ice and snow4 ,another interval  

of untold extent elapses1 and rock1     
snow1 and ice have all disappeared      
beneath a broad ocean cumbered  with    
ice-floes and wandering bergs4 ,again   
the curtain drops upon the  scene1 and  
when once more it rises1 the cliffs     
stand out in much the  same abrupt      
precipitous aspect with that which they 
now present1 save  that their bald      
foreheads look less seamed and scarred  
than now1 and  their dark sides show no 
trace of bush or tree4 ,the white       
cascades that  to-day pour down from    
their summits and sides--seeming in the 
distance  like the white hairs of       
age--are insensibly deepening the scars 
and  furrows on these ancient hills1 and
 thus slowly but yet surely carrying  on
 the process of degradation and decay4  
,musing on all this long  series of     
stages in the formation of one single   
cliff-line1 is there  not something more
 sublime1 something yet more impressive 
than if we  pictured but the chance     
random result of the gigantic paroxysm  

of an  hour8    ,let us not be deterred 
then from seeking an explanation of the 
origin  of the ravine among some of the 
quieter and more unobtrusive forces  of 
,nature4 ,give them but an unlimited    
period to work in and they will         
abundantly satisfy all our demands4     
,we return again to the rocky ledge in  
mid-channel1 and proceed to  ascend the 
course of the stream1 marking as we go  
the changes in the  character and       
features of the stone that forms the    
cliff on either  hand4 ,we come to a    
bare part of the ravine where brushwood 
and herbage  find but a scanty footing  
and where accordingly the rocks can be  
attentively studied4 ,the face of the   
escarpment shows a number of beds  of   
pale grey sandstone alternating with    
courses of a dark crumbly  shale4 ,the  
sandstones being harder and firmer in   
texture stand out  in prominent relief  
while the shales between have been      
wasted away1  covering the bottom of the
 slope with loose debris4 ,we can mark  

too  that1 as this decay goes on1 the   
harder beds continually lose their      
support1 cracking across chiefly along  
the lines of joint1 and rolling  down in
 huge angular blocks into the stream4   
,in truth we cannot doubt  that every   
year adds to this decay and thus slowly 
widens the dell1 for  the broken        
fragments do not form in heaps over the 
solid rock below  so as to protect it   
from the weather1 but are evidently     
carried away  by the stream and hurried 
down the ravine onwards to the sea4     
,from  what has been said above relative
 to the disintegration of rocks by      
percolating water1 frosts1 and other    
causes1 the reader will easily  see how 
this rotting away of the sides of the   
ravine must be carried  on2 and he will 
not fail to mark that here we have at   
work an agency  not yet considered1 that
 of running water4 ,the effects of the  
weather  are seen in the crumbling1     
ruinous cliffs overhead2 the effects of 
the streamlet are observable in the     

continual removal of the rubbish        
whereby a fresh surface is ever exposed 
to the decomposing forces1  while at    
some points we can mark the water       
actually undermining an  overhanging    
part of the cliff from which there are  
ever and anon vast  masses precipitated 
into the channel where eventually they  
get worn  down and carried away out to  
sea4 ,still1 you may remark1 these      
forces are at work only in widening a   
channel already made4 ,how was the      
ravine formed at first8    ,we continue 
our ascent4 ,a scrambling walk through  
briars and  hazel-bushes1 sometimes on  
rocky ledges high among the cliffs1     
sometimes among the prostrate blocks    
that dam up the stream1 brings  us at   
last full in front of a sparkling       
waterfall that dashes over  a           
precipitous face of rock some twenty    
feet high4 ,the appearances  observable 
here deserve a careful attention4 ,our  
eyes have not been  long employed noting
 the more picturesque features of the   

scene ere  they discover that the       
dark-brown band of rock forming the     
summit of  the ledge over which the     
water tumbles is continuous all round   
the  sides of the dell4 ,there is       
consequently no break or dislocation    
here4  ,approaching the cascade we note 
the rock behind it so hollowed out that 
its upper bars project several feet     
beyond the under ones4 ,in this  way the
 body of water is shot clear over the   
top of the cliff without  touching rock 
till it comes splashing down among the  
blocks in the  channel4 ,and yet this   
hollowed surface is never dry2 the spray
 of the  fall constantly striking on it 
keeps it always dank and dripping4 ,in  
some parts the rock stands out bare and 
worn1 while on the less exposed         
portions there gathers a thick green    
scum which is replaced on the  drier    
ledges by the soft cellular leaves of   
the liver-wort4 ,now our  examination of
 the influence of percolating water upon
 even the hardest  rocks teaches us that

 this moist soaked surface is just the  
very best  condition for favouring the  
decay of the rock4 ,nay more1 the green 
vegetation that mantles over the stone  
serves to prevent the water from        
running off too rapidly1 and keeps the  
rock in a still more moist state  than  
would otherwise happen4 ,so that the    
portion of sandstone behind  the cascade
 comes to be in a still more favourable 
situation for speedy  decay than the    
ledge over which the water is rapidly   
driven4 ,we can  see1 therefore1 how in 
the lapse of years the corrosion may go 
on until  the upper projecting part of  
the cliff loses its support and falls   
with  a crash into the rocky pool below1
 while the form of the waterfall        
becomes thus greatly altered1 and new   
surfaces are exposed to the wear  and   
tear of the stream4    ,but we have not 
yet exhausted all that the rocks at the 
cascade can  teach us4 ,by dint of some 
exertion we climb the cliff and gain the
  upper edge of the fall4 ,the rocks    

that form the bed of the stream are  now
 seen to be deeply grooved and worn1    
every exposed surface having  a smoothed
 blunted aspect4 ,we can mark how the   
stone has split up  along the natural   
lines of joint1 whereby great facility  
is given to  the removing power of the  
current1 and how large irregular        
angulated  blocks become detached and   
are swept down the stream4 ,in not a few
  parts1 too1 we may notice circular    
holes of greater or less depth1 in  the 
bottom of each of which lie perhaps a   
pebble or two1 that with a  constant    
gyratory movement1 caused by the eddying
 water1 have eaten  their way downwards 
into the solid rock4 ,when the stream is
 in flood  and comes roaring down the   
rocky gorge bearing along with it a vast
  amount of mud1 gravel1 and stones1 one
 can easily see how the friction  of the
 transported material must wear down the
 hard bed and sides of  the channel1 and
 how this process repeated month after  
month and year  after year1 must aid the

 decomposing forces in scooping out a   
deep  ravine4 ,from the cascade the     
ascent of the stream becomes steeper and
  the run of water is consequently more 
rapid4 ,soon however we emerge  from the
 woody copse1 and find ourselves on a   
flat alluvial cultivated  plain through 
which the rivulet winds in a tortuous   
meandering course1  bending back upon   
itself into loops that almost meet and  
well-nigh  form broad flat islets4      
,strolling along this winding route we  
can mark  the effects of the stream in  
eating away the soft clay and sand at   
one  part of the bend and piling them up
 at another4 ,such loose material  can  
present but little resistance to a      
stream swollen with rains1 and          
consequently a large quantity of the mud
 and gravel along with the  interspersed
 boulders must be swept away down into  
the dell at every  season of flood4 ,the
 matter thus removed will of course be  
still  further comminuted in its        
passage1 and at the same time will help 

to  grind down the hard rock surfaces   
over which it is driven4    ,here then  
may be found the whole history of the   
ravine4 ,originally the  streamlet wound
 its devious course through a flat      
alluvial country with  a channel sunk   
but a foot or two below the level of the
 plain4 ,such  continued its character  
till it reached a low bluff1 down which 
the  water flowed more rapidly to gain a
 second level undulating region4  ,the  
part of this bluff crossed by the stream
 was ere long bared of  its covering of 
soil and clay1 and the rock below came  
to be washed  by a group of little      
cascades4 ,once exposed to the          
decomposing and  disintegrating forces1 
the stone soon began to decay and the   
cascades  ere long merged into one4 ,by 
slow degrees the rock gave way and the  
waterfall retreated from the bluff4 ,for
 perchance thousands of years  the same 
process has been going on1 now with     
greater1 now with less  rapidity1       
according to the nature of the rocks    

encountered and other  modifying causes1
 until the fall has eaten its way back  
for well-nigh  three miles and scooped  
out a wild rocky gorge some fifty or    
sixty feet  deep4 ,this is but a        
solitary and insignificant instance of  
what may be  seen all over the world1   
for the process remains the same whether
 we  stand beside a tiny rivulet in some
 lone ,highland glen or listen to the   
roar of the falls of ,niagara4    ,there
 is but one other principal agency at   
work in the demolition of  rock-masses1 
the waves and currents of the ocean4    
,but we have already  noted the effects 
thus produced1 and need not now retrace 
our steps  further than to recall the   
vast amount of devastation which can be 
shown to have been effected in our own  
country by marine causes1 both  in      
breaching the existing shores and in    
scooping out valleys and  grinding down 
hills at former periods when the land   
was either rising  above or sinking     
below the level of the sea4    ,having  

now satisfied ourselves that there goes 
on all over the world an  incessant     
waste of the solid lands1 that the      
disintegrated debris is  washed down by 
rains and transported seawards by       
rivers1 and that the  waves are ever    
eating their way into the iron-bound    
coast-line as well  as into the low     
alluvial shore1 we naturally come to ask
 the result  and end of all this decay4 
,what becomes of that vast amount of    
mineral  matter annually removed from   
the land8 ,to be able to answer this    
question clearly and distinctly1 let us 
look for a little at what takes  place  
in lakes1 at river-mouths1 and in open  
sea4    ,the river ,rhone rises among   
the ,bernese ,alps1 and after a course  
of  about #ajj miles through the ,canton
 of ,valais1 it enters the upper end  of
 the ,lake of ,geneva4 ,its waters1     
where they mingle with those of the     
lake1 are muddy and discoloured1 but    
where they pass out at the town of      
,geneva are limpid and clear4 ,the mud1 

therefore1 which they bring into  the   
lake must be deposited there1 and as the
 stream may have continued  to flow for 
thousands of years1 we may reasonably   
expect to find some  trace of the large 
amount of sediment necessarily deposited
 during the  whole or part of that long 
period4 ,accordingly1 careful           
examination of  the ,lake of ,geneva has
 shown that such accumulations have     
really been  formed1 and that their     
progress and amount during part of the  
historic  period can be approximately   
calculated4 ,where the turbid current of
 the  ,rhone enters the still water of  
the lake1 the mud slowly sinks to the   
bottom4 ,in the lapse of centuries layer
 after layer has been thrown  down1     
rendering the lake at this part sensibly
 shallower1 until a large  area or delta
 has been filled up and converted into a
 flat alluvial  plain4 ,thus1 a town    
which in the time of the ,romans formed 
a harbour  on the water's edge1 now     
stands more than a mile and a half      

inland4  ,this new-formed land is       
entirely the work of the stream1 and if 
we  could obtain a complete section of  
it from the surface to the bottom1  we  
should see a great series of strata1    
probably from #fjj to #ijj feet  thick  
7the supposed original depth of the head
 of the lake71 and nearly  two miles in 
length1 inclined at a very slight angle4
 ,these strata1  which are said to have 
taken about eight centuries to form1    
probably  consist of alternations of    
finer and coarser particles2 for1 during
 the  hotter months1 from ,april to     
,august1 when the snows melt1 the volume
  and velocity of the river are         
greatest1 and large quantities of sand1 
mud1 vegetable matter1 and drift-wood1  
are introduced2 but1 during the  rest of
 the year1 the influx is comparatively  
feeble1 so much so that  the whole lake1
 according to ,saussure1 stands six feet
 lower4#ee ,if  the present conditions  
continue for a sufficient length of     
time1 the  lake may be eventually filled

 up with mud1 sand1 and gravel1 deposits
  that would eventually harden by       
pressure into shale and sandstone4 ,so  
that the day may yet arrive when the    
blue waters of the ,leman lake  shall   
have passed away1 when the ,rhone       
perchance may have ceased to  flow or   
found its way by some other channel1    
when the peasant may guide  the plough  
where now the boatman plies the oar1 and
 when the geologist  shall trace out in 
quarries and excavations the successive 
deposits of  hardened sediment with     
their lacustrine shells and drift-wood1 
and1  musing on the changes of which    
they are the silent yet impressive      
witnesses1 may sit down to pen a record 
of the gradual extinction of  the ,leman
 lake on that classic ground where an   
immortal historian  described the       
decline and fall of the empire of ,rome4
    ,footnote #ee3 ,lyell's ,principles 
of ,geology4 ,ninth edition1 p4 #beb4   
,the alluvial matter deposited by the   
,rhone at its entrance into the  ,lake  

of ,geneva suffers perhaps no change    
when it once reaches the  bottom4 ,layer
 after layer accumulates tranquilly1    
without disturbance  from surface       
currents or other causes1 so that the   
renovating effects  of the stream have  
here every advantage4 ,it is otherwise1 
however1  where a delta gathers at the  
mouth of a river upon the sea-margin4   
,there tides and currents are ever      
demolishing what the stream has  piled  
up4 ,often1 too1 owing to the prevalence
 of high winds from  seawards1 the river
 is dammed up for leagues1 and the      
waters of  the ocean encroach far on the
 delta1 mingling in this way marine     
remains with those that are fluviatile  
or terrestrial4 ,but with these         
modifications the process of            
delta-formation remains essentially the 
same1 both in lakes and at the sea4 ,the
 vast quantities of sand and  gravel    
transported by rivers during the        
flood-season sink to the bottom  as soon
 as the motion of the water will permit4

 ,this takes place at  the shore1 where 
eventually wide tracts of low alluvial  
land encroach  upon the sea1 covered    
with marshes and overgrown with         
vegetation4 ,a  section of any of these 
deltas1 obtained in boring for water1   
shows a  succession of sands and clays1 
with occasionally a few calcareous beds 
and quantities of peaty matter formed of
 vegetation either drifted  or that grew
 on the spot4#ef ,if1 now1 a sufficient 
amount of matter  were piled over these 
loose incoherent strata1 they would     
eventually  become as hard and compact  
as any of our ordinary building stones4 
,the  sand would subside into a firm    
compact sandstone2 the clay1 in like    
manner1 would consolidate into fissile  
shale2 the peat would become  chemically
 altered into coal2 the calcareous seams
 would take the form  of layers of      
limestone2 while the leaves1 twigs1     
branches1 and trunks1  dispersed through
 all the beds1 would get black and      
carbonized1 so as  precisely to resemble

 the lepidodendra1 calamites1 stigmari1 
c41 of  the carboniferous rocks4 ,and   
thus might a mass of fossiliferous      
strata1  thousands of feet deep and     
thousands of square miles in extent1 be 
amassed by the prolonged operation of a 
single river4    ,footnote #ef3 ,the    
structure of maritime deltas1 especially
 their  relation to the growth and      
entombment of forests1 will be more     
fully  alluded to in a subsequent       
chapter1 when we come to inquire into   
the  origin of a coal-field4    ,it     
often happens that a delta is prevented 
from extending further  seawards owing  
to the prevalence of some marine current
 that comes  sweeping along the         
coast-line and cuts away the            
accumulations thrown  down by the river4
 ,the sediment thus removed is often    
carried to great  distances1 and        
eventually settles down as a fine mud   
along the floor of  the sea1 entombing  
any fucoids1 infusoria1 shells1 corals1 
fish-bones1  or other relics that may   

lie at the bottom4    ,he who has       
witnessed a storm along a rocky         
coast-line1 has marked the  breakers    
battering against the weather-bleached  
cliffs1 and heard the  thunder-like     
rattle of the shingle at the recoil of  
every wave1 needs  not to be told how   
vast an amount of sediment must in this 
way be  formed4 ,the pebbles of the     
beach are ground down still smaller1 the
  sand produced by their friction finds 
its way to a lower level1 while  the    
finer particles taken up by the water   
are borne out to sea1 and if  a current 
traverse the locality may be transported
 for leagues1 till  they at last settle 
to the bottom4 ,the floor of the sea is 
consequently  always receiving additions
 in the form of fine mud--the waste of  
the  land--derived either from          
breaker-action1 rivers1 or icebergs1 so 
that a series of marine deposits exactly
 similar to those we find  among the    
rocks of our hills and valleys1 must be 
constantly in the  course of formation4 

,if circumstances be favourable1 the    
shingle of  the beach may eventually    
either be covered over or reach a part  
of  the sea undisturbed by currents or  
waves1 and then consolidate into  what  
we call conglomerate or pudding-stone4  
,the sand1 as before1  becomes          
sandstone1 and the mud laminated shale  
or hardened clay4 ,these  deposits may  
go on forming for thousands of years1   
until at last some  slow elevation or   
some sudden upheaval of the ocean bed   
brings them to  the light of day as part
 of a new continent4 ,thus exposed they 
would  differ in no respect from rocks  
of a similar kind now visible1 and  the 
geologist1 in tracing out their origin  
and history1 would have no  hesitation  
in ranking them among the ordinary      
marine formations of the  globe4    ,in 
fine1 we cannot quit the subject without
 being convinced that  these ceaseless  
changes afford one of the grandest      
examples of that  continuous series of  
mutations--cycle and epicycle--which has

 been  already alluded to as a          
distinguishing feature in all the       
operations  of ,nature4 ,we are         
accustomed to think and speak of the    
everlasting  hills4 ,we look on the     
solid lands whereon we dwell as the     
emblem of  all that is stable and       
steadfast1 and on the boundless ocean as
 the  type of all that is unsteady and  
changeful4 ,the traveller who stands  on
 those plains where the human race was  
cradled1 marks still the same  valleys  
with their winding rivers1 still the    
same rocks and hills1  still the same   
blue sky overhead4 ,the dust of         
centuries has gathered  over the graves 
and the dwellings of the early races1   
yet the covering  is but thin1 and if we
 could conjure from their resting-place 
some  of these venerable patriarchs1    
they might perhaps see little or no     
change on the haunts of their boyhood4  
,we feel it otherwise1 however1  when we
 contemplate the ocean4 ,in sunshine and
 in storm its surface  never rests4 ,the

 wave that now breaks against some bald 
headland of  our western shores may have
 come sweeping across from the coast of 
,america1 and the broad swell that rolls
 into surf along the shores  of         
,newfoundland may have travelled from   
the frozen seas of the ,north  ,pole4   
,and so it has ever been2 the far       
resounding sea of ,homer is the  far    
resounding sea still2 and the countless 
dimpling of the waves1  invoked in his  
agony by the chained ,prometheus1       
remains restless and  playful as ever4  
,firm as a rock1 and fickle as the sea1 
have therefore become  proverbs of      
universal acceptance4 ,yet when we      
investigate the matter  as we have done 
in this and the preceding chapter1 it   
appears that an  exactly opposite       
arrangement would be nearer the truth4  
,it is the sea  that remains constant-- 
,time writes no wrinkle on its azure    
brow2    while the land undergoes a     
continual change4 ,hills are insensibly 
mouldering away1 valleys are ever being 

widened and deepened1 rocky  coasts and 
low alluvial shores suffer a constant   
abrasion1 while  even within the bowels 
of the earth the process of             
decomposition  uninterruptedly proceeds4
 ,and thus1 in place of remaining       
unchanged  from the beginning1 we know  
of nothing more mutable than the land on
  which we dwell1 so that if the waste  
everywhere so apparent were to  go on   
unchecked or unmodified1 island and     
continent would eventually  disappear   
beneath the waves4 ,here1 however1      
another principle comes  into operation4
 ,the debris removed from the land1 as  
we have seen1  is not annihilated4      
,slowly borne seawards1 it settles down 
at river  mouths or on the floor of the 
ocean as an ever-thickening deposit1    
which eventually hardens into rock1 as  
solid and enduring as that  whence it   
was derived4 ,but it does not always    
remain there4 ,owing to  the action of  
subterranean agencies with which we are 
but slightly  acquainted1 different     

parts of the sea-bottom are continually 
rising4  ,sometimes this process goes on
 very slowly1 as along the shores  of   
,sweden1 where the coast has been       
ascertained to emerge in some           
localities at the rate of about thirty  
inches in a century2 sometimes  with    
prodigious rapidity1 as on the coast of 
,chili1 where the land  was upheaved    
from two to seven feet in a single      
night4 ,there can thus  be no doubt that
 the mysterious agency which produces   
earthquakes and  volcanoes on the land  
affects equally that portion of the     
earth's crust  covered by the waters of 
the ocean1 and must be ceaselessly      
employed  in elevating large areas of   
sea-bottom into new continents1 that    
will  ere long become clothed with      
vegetation and peopled with animals4    
,in contemplating1 therefore1 the       
constant decay in progress on the       
surface of the land1 we see not a mere  
isolated process of waste1 but a        
provision for future renovation4 ,the   

sandstone cliffs of the shore are       
battered down and their debris carried  
out to sea1 but when sea-bottom  comes  
to be land-surface1 they may be         
sandstone cliffs again1 lashed  once    
more by the breakers1 and once more     
borne as sediment to the  depths of the 
sea4 ,and thus1 in what may seem to us  
sublime antagonism1  land is ever rising
 in the domain of ocean1 and ocean ever 
encroaching  on the regions of land4 ,no
 sooner does a new island1 or mountain  
peak1  or wide area of continent1 appear
 above the waves1 than the abrading     
agencies are at work again4 ,rain1 air1 
frost1 rivers1 currents1  breakers1 all 
begin anew the process of destruction1  
and cease not  until the land has       
utterly disappeared1 and its worn debris
 has sunk  in mid-ocean to be in process
 of time once more dry land1 and suffer 
another slow process of obliteration4   
,such is the economy of nature around us
 now1 and that such will  continue to   
remain the condition of things in the   

future1 we can affirm  with probability 
from a consideration of the history of  
the past4 ,the  geologist can point to  
masses of rock several miles in         
thickness1 and  occupying a large area  
of the globe1 formed entirely of the    
worn debris  of pre-existing formations4
 ,the very oldest rocks with which he is
  acquainted are made up of hardened    
sediment1 pointing to the existence  of 
some land1 even at that early period1   
worn down by rivers or  wasted by the   
sea4 ,during all the subsequent ages the
 same principles  were at work1 and now 
well-nigh the only evidence of the      
geological  periods is to be gathered   
from the layers of sediment that        
successively  settled down at the       
sea-bottom4 ,the records which it is the
 task of  the geologist to decipher1 are
 for the most part written in sand and  
mud--the deposits of the ocean1 for in  
by far the larger number of  formations 
into which the stratified part of the   
earth's crust has been  divided1 and    

which form his only guide to the history
 of the past1 he  can detect no trace of
 land4 ,hill and valley have alike      
disappeared1  and the character of their
 scenery and inhabitants he can often   
but  dimly conjecture from the nature of
 the sediment and of the drifted        
terrestrial relics that may chance to be
 found among strata wholly  marine4     
,,chapter ,x4        ,the structure of  
the stratified part of the earth's      
crust conveniently studied by the       
examination of a         single         
formation--,a coal-field selected for   
this         purpose--,illustration of  
the principles necessary to such        
an investigation--,the antiquities of a 
country of value in         compiling   
its pre-historic annals--,geological    
antiquities         equally valuable and
 more satisfactorily arranged--,order   
of superposition of stratified          
formations--,each formation             
contains its own suite of organic       
remains--,the age of         the boulder

 defined by this test from              
fossils--,each         formation as a   
rule shades into the adjacent           
ones--,mineral         substances       
chiefly composing the stratified rocks  
few         in number--,not of much     
value in themselves as a test of        
age--,the ,mid-,lothian coal-basin--,its
 subdivisions--,the         limestone of
 ,burdiehouse--,its fossil remains--,its
 probable         origin--,carboniferous
 limestone series of ,mid-,lothian--,its
         relation to that of            
,england--,its organic remains totally  
different from those of                 
,burdiehouse--,structure and            
scenery of ,roman ,camp ,hill--,its     
quarries of the mountain                
limestone--,fossils of these quarries   
indicative of an ancient                
ocean-bed--,origin of the               
limestones--,similar formations still   
in progress--,coral-reefs and their     
calcareous silt--,sunset         among  
the old quarries of ,roman ,camp ,hill4 

,among the standard jokes of ancient    
,athens was that of the simpleton  who1 
with the intent of selling his house1   
carried about a brick as a  specimen4   
,in this and the following chapter ,i   
propose to follow his  example1 and1 for
 the purpose of giving my reader a      
correct notion of  the structure        
displayed in the stratified portion of  
the earth's crust1  to select therefrom 
a single formation whose details will   
connect  together the subjects discussed
 in the previous pages4 ,and in so doing
  it will1 ,i trust1 be found that what 
was ludicrous in the hands of  the      
,greek becomes sober sense in those of  
the geologist4 ,the brick1  then1 which 
,i would humbly present to the          
thoughtful consideration of  the reader 
as really a specimen of the house of    
which it forms a part1  has been termed 
the ,carboniferous ,system1 and consists
 of a series  of stratified rocks       
sometimes nearly #ae1jjj feet thick4    
,the plants  and animals found in these 

strata have been already described      
somewhat  in detail1 and we have turned 
aside to look at the processes whereby  
such masses of sedimentary rock came to 
be accumulated4 ,but we shall  probably 
better understand the habits of the     
animals and the general  aspect of the  
vegetation1 as well as the agencies at  
work in depositing  vast beds of mineral
 matter1 if we take a coal-field and    
analyse it  stratum by stratum1 marking 
as we go their varied and ever-changing 
character1 and the corresponding        
diversity of the included organic       
remains4 ,such an examination will bring
 before us some of the more  striking   
and important laws of geological        
research1 and while of use  to the young
 observer1 may be not without some share
 of interest  to the general reader4    
,before beginning1 however1 let me      
endeavour  to illustrate the principles 
that will guide us by a simple though   
hypothetical story4    ,suppose the bed 
of the ,firth of ,forth were raised     

above the level of  the sea and covered 
over with verdure1 and that1 in         
ignorance of the  previous topography of
 the locality1 a mason were to excavate 
on the  lately-born land the foundation 
for a dwelling-house4 ,immediately      
below the grass he would com8 upon      
layers of hardened mud containing       
oyster-beds1 with detached valves of    
cockles1 mussels1 fish-bones1 and       
perhaps the tooth of an anchor or the   
timber of some old herring-boat4  ,now1 
if he were gifted with but ordinary     
intelligence1 what would he at  once    
conclude from these remains8 ,plainly1  
that the spot on which he  stood had    
once been the bed of the sea4 ,and if in
 place of appearing  as dry mud and sand
 these deposits had got hardened into   
shale and  sandstone1 and the shells1   
too1 had become hard and stony1 this    
would  not alter his convictions4 ,he   
would still assert positively that he   
stood upon an old sea-bottom4 ,and      
suppose further1 that all this were  far

 away from any sea1 still such a        
circumstance could make no change  in   
his opinion2 he would rightly assert    
that the place of sea and  land might   
vary1 and that the ocean's being now    
many miles distant  could be no argument
 against the waves having once rolled   
over the  site of the intended          
dwelling-house4 ,let us further imagine 
that he  continues his trench1 and in   
sinking deeper comes to a bed of dark   
peat with snail-shells and bones of     
sheep1 deer1 and oxen4 ,what will  he   
infer from these8 ,clearly that they    
represent an old land-surface1  once    
covered with vegetation and browsed over
 by ruminant animals1 and  that this old
 land-surface has at some distant period
 been submerged  beneath the sea4       
,suppose1 moreover1 that below the peat 
there were a  thin bed of reeds and     
rushes intermingled with the mouldering 
remains  of fresh-water shells4 ,he     
would in that case infer that before the
  formation of the peat the locality was

 occupied by a lake4    ,putting now all
 these deductions together1 our mason   
would have evolved  a very interesting  
history4 ,he would have ascertained that
 in a bygone  age the spot on which he  
stood was the site of a lake1 tenanted  
by  delicate shells and fringed with    
reeds and rushes1 where the coot and    
the mallard may have reared their young2
 that in process of time the  vegetation
 gained upon the water1 choking up the  
lake1 so as gradually  to form a soil   
firm enough to support sheep1 deer1 and 
oxen1 and  yielding shady coverts       
whither the antlered stag could retire  
and lay  him down to die2 that in after 
years the sea had encroached upon the   
peat-moss1 and oyster-beds begun to form
 where cattle had been wont to  browse2 
that again the ocean receded1 and the   
land emerged to assume  new verdure and 
receive new inhabitants4    ,now1 in all
 this reasoning there is no hypothesis  
or speculation4 ,the  mason proves      
himself an intelligent1 honest fellow1  

and uses his eyes  and his head where   
many other men would perchance see very 
little need  for the use of either4     
,there can be no setting aside of his   
story2  he can appeal to facts4 ,there1 
says he1 is a layer of peat with  the   
rush-stalks and moss-fibres matted      
together in the soft brown  mouldering  
substance1 exactly as ,i have seen them 
a hundred times in  the peat-cuttings on
 the moors1 and ,i cannot but believe   
that they  must both have had the same  
origin1 that is1 that they grew in      
swampy  hollows of the land4 ,there1    
too1 lies a stratum of fresh-water      
shells  identical with those that occur 
in our ponds and marshes4 ,although     
mouldering now1 they are evidently not  
fragmentary1 but entire and  unbroken2  
some of them are young1 others          
full-grown1 and they lie  grouped       
together as in our present lakes4 ,such 
shells could only live  in fresh water1 
therefore the spot where ,i stand must  
have been at one  time a fresh-water    

lake4 ,there1 again1 he continues1 is a 
bed of  oysters which cannot have been  
transported hither1 for their valves are
  together1 lying just as they do in our
 present oyster-beds4 ,this green       
field1 therefore1 must have been at one 
period a muddy sea-bottom4    ,after    
this manner and upon this kind of       
evidence must all inquiries  into the   
past changes of the earth's surface be  
conducted4 ,and provided  only we       
proceed cautiously1 reasoning from      
positive facts1 and  striving as far as 
possible to exhaust what ,bacon calls   
the negative  instances1 our deductions 
possess all the certainty of truth4 ,for
 in  much the same fashion do we derive 
no small part of our acquaintance  with 
the early history of our own land1 as   
well as with the arts  and customs of   
other nations4 ,the scattered relics    
turned up by the  operations of the     
farmer--wooden canoes1 flint hatchets1  
gold torques1  bronze pots1 fragments of
 pottery1 and rusty coins--all have     

their  bearing upon the annals of the   
country1 and so clear is the evidence   
which they read out that an eminent     
antiquary has divided the early  ages of
 ,scotland into three periods1          
distinguished1 from the character  of   
their relics1 as the ,stone ,period1 the
 ,bronze ,period1 and the  ,iron        
,period4#eg ,but in such a              
classification the historian has  little
 to guide him save the nature of the    
relics themselves4 ,he places  the      
rudest first1 and groups the rest in    
succession1 according to the  degree of 
advancement in civilisation which they  
respectively indicate4  ,and the        
grouping seems just1 though in some     
cases objects belonging  to two of these
 periods may have been to some extent   
contemporaneous1  just as thatched roofs
 gave way to tiles1 tiles to slates1 and
 slates  partly to lead1 though at the  
present day a walk of half an hour in   
some localities will bring before us    
specimens of all these styles  still in 

use4 ,if1 however1 the relics of        
geological history lay  scattered about 
like those of early ,scottish history1  
all hope of  ever attaining to anything 
like a correct chronology and           
arrangement  would have to be abandoned 
in despair4 ,in truth1 it would then be 
impossible to conjecture whether any    
succession of ages preceded man1  during
 which other tribes of plants and       
animals lived and died1 or  whether the 
whole mass of fossiliferous rocks had   
been accumulated  since the human era1  
or perhaps created just as we find them4
 ,but all  this uncertainty and         
confusion has been obviated simply by   
the fossils  being ranged in beds       
vertically above each other1 the oldest 
at the  bottom and the latest at the    
top4 ,so that if we find in a low cliff 
along the shore blown sand and broken   
whelks immediately beneath the          
vegetable mould1 and oyster-valves in a 
clayey bed three feet below1 we         
pronounce the oysters to have lived     

before the whelks1 and that between     
their respective lifetimes a sufficient 
interval must have elapsed to  allow    
three feet of sand1 clay1 and gravel1 to
 accumulate4 ,what is thus  true on the 
small scale holds equally so on the     
large4 ,the stratified  formations in   
which organic remains occur are found to
 be grouped  regularly over each other  
in a settled invariable order4 ,if ,a be
 below  ,b in ,england it will be below 
,b all over the world1 and if ,c be     
above  ,d at the ,north ,pole it will be
 so at the ,south ,pole too1 and at     
every  locality where the two rocks lie 
together4 ,this order of superposition  
forms one of the grand tests for the age
 of different rock masses4 ,by  means of
 this simple rule the geologist has been
 enabled to arrange  the different      
stratified formations1 supplying the    
missing portions of  one locality from  
the more complete series of another1 so 
as to form a  chronological table of no 
small part of our planet's primeval     

history4    ,footnote #eg3 ,see ,dr4    
,daniel ,wilson's deeply interesting    
work ,the  ,pre-historic ,annals of     
,scotland4    ,but this is not all4 ,we 
must attend to the character of the     
organisms  as well as to their order of 
occurrence4 ,we must distinguish the    
animal  from the vegetable1 the         
terrestrial from the marine1 and        
scrupulously  examine the peculiarities 
of each so as to recognise them again in
  other strata4 ,by such careful        
scrutiny we may trace out the successive
  changes in the physical aspect of a   
district during past times1  viewing in 
terrestrial plants 7when clearly        
occupying their original  site7 evidence
 of an old land-surface2 in cyprides1   
unios1 and  paludin1 traces of a former 
lake2 and in corals and marine shells1  
unmistakable proofs of an ancient       
sea-bottom4 ,still further1 by marking  
the specific character of such fossils  
we obtain a key to the age of  many     
rocks that otherwise would be           

unintelligible1 for it is found that    
each of the stratified formations1 from 
the oldest upwards1 has its own         
peculiar and characteristic organisms   
recognisable all over the world4  ,this 
test of the geological position and age 
of any fossiliferous rock  has a        
peculiar value1 for it can be applied   
with infallible success  where every    
other fails4 ,the order of superposition
 is often obscured  by dislocations and 
other causes1 and the mineralogical     
texture of a  formation may change      
entirely in a short space2 but if the   
imbedded  fossils remain1 we can be at  
no loss as to the relationship of the   
rock  which contains them4 ,and hence1  
if in some lone island of the ,hebrides1
  haunted only by the screaming         
sea-fowl1 we find a patch of shale      
containing ammonites1 belemnites1 and a 
host of other shells in large  measure  
identical with those occurring among the
 clays and limestones  of               
,gloucestershire1 we infer that they    

must all belong to one series  and be of
 the same age2 that1 as we know the     
,english beds to form part  of a        
formation called ,lias1 of which1 the   
exact place in the geological  scale has
 been ascertained1 so in like manner the
 ,scottish beds must  occupy a position 
in the same series2 and that            
consequently there was  a time when the 
site of ,cheltenham and part of the     
,hebrides lay each  beneath a sea which 
teemed with ammonites1 belemnites1 and  
many other  mollusca1 along1 too1 with  
the bulky saurians of the ,lias4 ,and   
yet  no study of the surrounding rocks  
in the northern locality1 even if       
carried on for a thousand years1 could  
ever have thrown one ray of  light upon 
the subject4 ,in an earlier page our    
grey rounded boulder  was introduced to 
the reader as a mass of sandstone       
belonging to the  ,carboniferous group  
of rocks4 ,how could one be sure of the 
precise  geological age of a loose      
water-worn block that might have        

journeyed  all round the world8 ,simply 
by its included fossils4 ,the calamite1 
lepidodendron1 and stigmaria1 revealed  
the date of the stone as clearly  and   
unmistakably as if we had seen it lifted
 from its original bed  by the lever and
 crane of the quarryman4 ,these plants  
are peculiarly  characteristic of the   
,carboniferous strata1 and they         
consequently  stamp as undoubtedly of   
carboniferous age the rock which        
contains  them1 whether it be sandstone 
or conglomerate1 limestone or shale1 and
  whether we meet with it among the     
newly-raised blocks of the quarry1  or  
among the pebbles of the sea-shore4     
,each geological formation1 ,i  repeat1 
beginning at the oldest known to us1 and
 ending with those that  are still      
forming in our lakes and seas1 has its  
own set of organic  remains whereby we  
can detect it wherever it may chance to 
occur1 from  the equator to the poles4  
,each has its style1 so to speak1 just  
as  we can at once tell whether a       

drawing represents a ,hindoo1 ,egyptian1
  ,assyrian1 ,greek1 or ,gothic temple1 
simply from the general style of  the   
architecture4    ,could we but voyage   
back in time as we can sail forward in  
space1  we should find each of the      
geological formations not less clearly  
defined than are the different nations  
and countries of the present  day4#eh   
,were the reader suddenly set down in an
 out-of-the-way street  of ,paris1 he   
would probably not be long in           
discovering that he stood  on ,french   
ground4 ,or if spirited away in his     
sleep he should awake on  the banks of  
the ,nile1 he would soon ascertain      
himself to be in the  land of the       
,ptolemies4 ,and so if you transported a
 geologist blindfold  into a quarry     
where ammonites and belemnites abounded1
 mingled here  and there with bones of  
ichthyosaurs and plesiosaurs1 he would  
tell  you at once that the quarry lay   
among liassic strata4 ,or if he were    
placed in a ravine where the rocks on   

either hand displayed fern-stems1       
lepidodendra1 stigmari1 and sigillari1  
he would tell you that the  surrounding 
district was one of carboniferous rocks1
 and that probably  at no great distance
 there might be found smoking engines   
and dozens  of coal-pits4 ,or could you 
set him down in some dark night upon a  
wild coast-line1 and show him1 perchance
 by the flare of torch-light1  bones and
 scales of osteolepis1 pterichthys1 and 
dipterus1 lying on  the rocks around1 he
 would tell you that the grim crags     
which shot up  into the gloom were as   
ancient as the era of the ,old ,red     
,sandstone4 ,in  any case the character 
of the rock would signify nothing1 nor  
would  he care about the general        
features of the landscape1 though these 
too  become important characteristics in
 certain cases4 ,show him but a few     
recognisable fossils1 and you give him1 
as it were1 an ,open ,sesame to  which  
the rocks unfold their gates and reveal 
a store of wonders yet  more varied than

 those in the cave of ,ali ,baba4       
,footnote #eh3 ,see ante1 pp4 #ca1 #cb1 
and the ,table of ,rocks at the end  of 
the volume4    ,but though the          
geological systems stand thus strongly  
marked off from  each other when viewed 
as a whole1 their boundary lines can    
often be  only approximately drawn1     
thereby reminding us that the divisions 
are  of man's device1 and can have had  
no place in the plans of ,him who  needs
 not to chronicle ,his working by years 
and ages1 but with whom  there is no    
past and no future4 ,one formation      
insensibly passes into  another just as 
one nation merges into those around it4 
,there are  sometimes gaps1 however1    
between the formations1 serving to mark 
out  strongly the limits of each1#ei    
precisely as intervening seas and       
mountain-chains serve to mark put the   
boundaries of different peoples  and    
tribes4    ,footnote #ei3 ,such cases1  
however1 are probably merely local1 and 
may  have originated from some features 

in the ancient physical geography  of   
the districts where they occur4 ,for    
instance1 it has always been  thought   
that palozoic ages were marked off by a 
strong line of  demarcation from        
succeeding secondary times4 ,but the gap
 which occurs  in ,england1 ,france1 and
 ,germany1 is being slowly filled up    
from the  evidence furnished by other   
countries1 and we shall probably find in
  the end that the ,permian dovetailed  
with the ,trias as closely as the       
,silurian with the ,old ,red1 or the    
,lias with the ,oolite4 ,in truth1 the  
longer we study the past history of our 
planet the less do we see of  hiatus and
 chasm and sharp clearly defined        
boundary line2 while the  doctrine of a 
uniform system of laws and arrangements 
in the physical  world1 first           
philosophically propounded in the       
immortal ,principles of  ,sir ,charles  
,lyell1 is ever receiving fresh         
confirmation4    ,the mineral substances
 of which these formations consist are  

comparatively few in number1 being      
chiefly varieties of sandstone1  shale1 
conglomerate1 and limestone4 ,one       
sandstone can often be scarcely         
distinguished from another1 and so also 
with the other rocks2 hence  such tests 
as mineralogical texture supplies can   
seldom be relied  on to determine the   
age of rocks4 ,we can prove1 for        
example1 that a  series of limestones in
 ,england may be identical in age with a
 set of  sandstones in ,sweden1 and with
 a group of shales in ,america1 because 
they all contain the same or            
representative genera and species of    
organic remains4 ,they occupy the same  
position in the geological scale2  that 
is1 the animals whose fossilized remains
 lie buried in these rocks  were all    
living at the same time1 while lime was 
gathering at the  sea-bottom over the   
site of part of ,england1 and sand was  
being thrown  down upon a portion of    
what is now ,sweden1 and mud was        
accumulating  over a submerged area of  

,america4 ,in such cases the differences
 of  mineralogical character go for     
nothing in determining the age of the   
rocks2 we have to rely solely on the    
embedded fossils1 and on the order  of  
superposition4    ,keeping in view1     
then1 that the formations into which the
 geologist  has grouped the stratified  
portion of the earth's crust have a     
settled  and invariable order of        
occurrence1 that each of them contains  
its own  peculiar and characteristic    
group of organic remains whereby it can 
be recognised in any part of the world1 
and that such remains form  often the   
sole test at once of the geologic age   
and of the origin of  the rocks wherein 
they lie1 we may return to the plan     
above proposed  and endeavour to        
understand the structure of a           
coal-field4 ,for this  purpose it may be
 well to select one of the northern     
coal-fields of  ,britain1 since these   
perhaps display a greater variety in    
their organic  contents1 and bear       

evidence of more diversified changes in 
their mode  of formation than can be    
seen in those of the south4 ,the strata 
that  compose the coal-basin of         
,mid-,lothian will probably best suit   
our  purpose1 as they are free from the 
disturbing effects of those igneous     
intrusions which play so important a    
part among similar rocks to the  north  
and west4    ,the ,mid-,lothian         
coal-field comprises a mass of          
stratified beds of  sandstone1 shale1   
coal1 ironstone1 and limestone1 the     
united depth of  the whole being above  
#cjjj feet4 ,by reference to the annexed
 ,table it  will be seen that the lowest
 beds of the section are chiefly        
sandstones  and shales1 extending       
downwards to an unknown depth1 without  
any coal  that can be profitably worked4
 ,these under-strata form the ,lower    
,carboniferous group4 ,above them comes 
a middle zone in which the              
characteristic beds are of limestone1   
comprising the middle portion or        

,mountain ,limestone of the ,scottish   
,carboniferous rocks4 ,the third and    
highest subdivision forms the ,upper    
,carboniferous group or true ,coal      
,measures1 and constitutes the whole of 
what is properly the ,mid-,lothian      
coal-field4 ,for the sake of noting some
 of the remarkable changes  exhibited in
 the character of the rocks1 it may be  
well to begin our  survey among the     
upper beds of the under group4 ,let us  
take as our base  the famous limestone  
of ,burdiehouse1 and work our way upward
 through  the four thousand feet of     
strata that lie piled above it4         
,,vertical ,,section ,,of ,,the         
,,mid-,,lothian ,,coal-,,field4         
,,upper ,,carboniferous      ,,or       
,,coal-,,measures4      _/              
_/           ,a series of sandstones1   
shales1                                 
and fire-clays1 with interbedded        
,flat ,coal ,group4  _/                 
seams of coal occupying the             
7,above #ajjj feet47                    

central area of ,mid-,lothian           
coal-field4                             
------------------                      
_/                                      
,a great series of sandstones           
and shales with three seams of     _/   
,roslyn ,sandstone   _/                 
marine limestone 7marked here           
,group4             by dotted lines71   
,with the       7,about #aejj feet47    
exception of one or two thin seams      
it contains no coal1 and serves in      
this way to mark off the coal-          
bearing beds above from the still       
richer coal-bearing beds below4         
------------------                      
_/                                      
,a group of sandstones and       ,edge  
,coal ,group4  _/             shales    
similar to those at the        7#hjj-ijj
 feet47                 top1 and like   
them abounding in                       
coal seams1 some of which are           
thick and valuable4                     
----------------------------------------

----------------------------------------
----------------------------------------
------------------------                
,,carboniferous ,,limestones4           
_/   ,roman ,camp        _/           ,a
 set of marine limestones               
,limestones4                            
intercalated with sandstones1           
7#aej-bjj feet47                 shales1
 and a few seams of coal4               
----------------------------------------
----------------------------------------
----------------------------------------
------------------------    ,,lower     
,,carboniferous4                     _/ 
,burdiehouse      _/                    
,sandstones and shales extending        
,limestone4        to an unknown depth1 
often            7#bg feet47            
with seams of dull-grey compact     _/  
limestone1 rarely of coal4 ,the         
,thickness of ,lower                beds
 become very red towards                
,carboniferous ,rocks              the  
base1 and wholly devoid of              

unknown1 but                            
fossils4        probably greater        
than that of the                        
upper4                             ,the 
,burdiehouse limestone is twenty-seven  
feet thick1 of a yellowish  or          
bluish-grey colour1 very compact1       
splintery1 and often fissile  in        
structure1 with a finely striped and    
laminated appearance1 which  probably   
indicates a slow and tranquil origin4   
,it is ,crowded with  fossils1 every    
fragment when taken up showing its      
seed-cone1 fern-stem1  fish-scale1 or   
minute cyprides4 ,all the plants seem to
 belong to  terrestrial species1 and    
have a broken and often a macerated     
look4  ,manifestly they never grew where
 we now find their remains2 they must   
have come drifting down from swamp1 or  
jungle1 or hill-side4 ,and so  we come  
to know that during the later ages of   
the ,lower ,carboniferous  period1 there
 lay somewhere in the neighbourhood of  
,burdiehouse a land  clothed with ferns 

and club-mosses1 and through whose      
swampy hollows  there spread a network  
of stigmari1 while sigillari waved their
  fronds high overhead4 ,from what has  
been said on a previous page we may     
infer that the climate of the old land  
was moist and equable like that  of ,new
 ,zealand1 nourishing a prolific growth 
of ferns and other plants  comparatively
 low in the botanical scale4 ,the       
scenery of the vegetation  displayed    
perhaps no great variety of outline1 but
 exhibited rather an  endless succession
 of the same graceful forms4    ,but the
 limestone presents us with other       
remains than merely those of            
terrestrial plants4 ,it displays in     
abundance the minute dissevered  cases  
of cypris1 the small crustaceous animal 
described above4  ,recent species of    
this genus inhabit stagnant ponds or the
 bottoms of  gently-flowing rivers1 and 
we hence infer that the ancient species 
must  in like manner have possessed a   
similar habitat1 and consequently that  

the rocks which preserve their remains  
must have been deposited in  fresh 7or1 
perhaps1 brackish7 water4 ,tried by this
 test the ,burdiehouse  limestone must  
be regarded as a lacustrine1 or more    
probably a  fluviatile formation1 which 
gathered slowly on an undisturbed bottom
  swarming with crustaceans and         
plentifully covered with leaves1        
branches1 rootlets1 and other fragments 
of terrestrial plants brought  down by  
streams from the adjoining land4 ,thus  
the inferences drawn from  the numerous 
plants1 and from the countless multitude
 of cypris-cases1  come to be mutually  
corroborative4 ,the former tell us of   
some  neighbouring forest-covered       
country2 the latter lead us1 as it were1
  into its river-mouths1 whence we can  
descry the waving woods on either  side4
    ,still we have not exhausted all the
 fossil remains of the ,burdiehouse     
rocks4 ,mingled among the stems of ferns
 and lepidodendra1 and the  scattered   
valves of the cyprides1 lie the scales1 

teeth1 and bones1  of several large     
ganoidal fishes1 along with entire      
specimens of the  smaller genera4 ,the  
scales of holoptychius are especially   
abundant1  often crowded together by    
dozens1 and probably not far out of the 
arrangement they had when grouped on the
 body of the living animal4  ,detached  
teeth of the same fish also frequently  
occur along with  disjointed internal   
bones4 ,the remains of the contemporary 
megalichthys  likewise abound1 more     
particularly the scales1 which have a   
fine  nut-brown colour1 and dot the     
surface of the rock with their bright   
glittering enamel4 ,several other       
smaller ganoids may be met with1        
especially a small and elegant species  
of ,paloniscus 7,p4 ,robisoni71  and one
 of ,eurynotus1 a fish remarkable for   
the great size of its  dorsal fin4 ,not 
uncommon1 too1 are the ichthyodoralites 
of a gigantic  placoid--the ,gyracanthus
 formosus--with all their               
delicately-fretted  ornament and a      

peculiar crystalline glistening surface 
when broken  across1 whereby the        
smallest fragment can be easily         
distinguished from  any other bone in   
the limestone4 ,such are the ichthyic   
remains of the  ,burdiehouse beds2 what 
deductions can be legitimately drawn    
from them8    ,as before1 we must have  
recourse to the analogy of living       
nature4 ,the  existing ganoidal fishes  
chiefly inhabit lakes and rivers1       
especially  near the confluence of the  
latter with the ocean4 ,they feed on    
the decaying matter brought down from   
the land1 or on the minute  ,crustacea  
that swarm upon the river-bottom4 ,if1  
as seems probable1  the ancient ganoids 
had habits similar to those of their    
present  representatives1 then the rocks
 wherein their remains occur abundantly 
may have originated on river-bottoms1   
and such may have been the case  at     
,burdiehouse4 ,so that here again we    
have corroborative evidence  of the     
fluviatile origin of the limestone in   

question4 ,but besides  the remains of  
ganoidal fishes there occur the         
defensive spines of  placoids4 ,now1 the
 placoids are emphatically marine       
fishes1 and the  sole living            
representative of the most ancient      
genera of this order  is the            
,port-,jackson shark1 that haunts the   
seas round ,australia4 ,the             
ichthyodorulites of ,burdiehouse1       
therefore1 if we would apply analogy    
consistently1 must be regarded as the   
relics of marine species4 ,and  this    
conclusion1 too1 will be found in entire
 harmony with those  already obtained1  
for if we are right in assuming the     
,burdiehouse  strata to have originated 
at a river-bottom1 particularly near the
 sea1  we may expect to find the remains
 of marine predaceous fishes imbedded   
in the sediment that gathered there1    
just as the teeth of the shark may  be  
preserved among the mud forming in the  
upper reaches of many ,british          
estuaries1 seeing that not a few        

instances are known where that fish  has
 been stranded on such shores as those  
of the higher parts of the  ,firth of   
,forth4 ,these ,burdiehouse             
ichthyodorulites give positive proof    
that the limestone could not have       
originated in a lake1 and the only      
explanation left is that of a           
river-bottom4    ,but it may perhaps be 
objected that1 after all1 these         
fish-remains  are for the most part     
fragmentary1 and may consequently be    
drifted  specimens1 so that no          
conclusion as to the source of the rock 
can be  based on their occurrence there4
 ,the imbedded land-plants confessedly  
came from some distance1 why may not the
 same have been the case with  the bones
 and scales of the river-haunting ganoid
 fishes8 ,and1 indeed1  did we regard   
these fish-bones and scales merely in   
themselves1 the  argument might not     
perhaps be very easily answered1        
although the great  numbers and perfect 
outline of the bones1 teeth1 and scales1

 afford  pretty strong evidence that the
 owners lived and died in the locality  
where their remains are found4 ,but     
there is a curious kind of evidence  to 
be gleaned from the rocks around them   
whereby this objection can be  at once  
set aside4 ,in the limestone itself1 and
 especially in some of  the shales      
above1 there occur vast numbers of small
 oblong coprolitic  concretions of a    
dirty yellow or brown colour1 full of   
scales and  fragments of bone4 ,there   
can be no doubt that these are the      
excremental  remains of predaceous      
animals1 while their great number and   
perfect  preservation assure us that    
they could not have been drifted from a 
distance1 but must rather have been     
deposited on the spot where we now  find
 them4 ,and thus we conclude that the   
site of ,burdiehouse must have  been a  
favourite haunt of these bone-covered   
fishes2 that the bulkier  forms1 armed  
with pointed teeth or barbed-spines1    
preyed upon their  humbler congeners1   

while these in turn may have fed on the 
cyprides  that swarmed by millions at   
the bottom of the estuary4 ,i have often
  detected in these coprolites the      
peculiarly-sculptured scales of the     
paloniscus4 ,these graceful little      
animals must1 therefore1 have died  that
 their lordlier brethren might dine4    
,on a survey1 then1 of the whole        
evidence from fossils1 we are led to    
conclude that the ,burdiehouse limestone
 was slowly elaborated at the  bottom of
 an estuary1 into which the remains of  
terrestrial plants were  drifted from   
the land1 while bone-covered fishes     
haunted the waters1  and into these busy
 scenes huge sharks ascended from the   
sea to share  in the decaying putrescent
 matter ever brought down from the      
interior4    ,the upper part of the     
limestone is shaly and argillaceous1 and
 rests  below a series of shales and    
thin sandstones4 ,if the question were  
asked1 what caused the change from      
limestone to shale1 from the  deposition

 of a calcareous to that of a muddy     
sediment1 several  answers might be     
given4 ,the most probable seems to be   
the following4  ,the limestone on       
weathered surfaces displays the         
mouldering casts of  cypris-cases       
sometimes in such abundance as to show  
that the rock must  be largely made up  
of them4 ,the cyprides of the present   
day probably  cast their shells         
annually2 the integuments thus thrown   
off forming  under favourable           
circumstances a thin mouldering         
calcareous marl at  the bottom of the   
pond or marsh1 along with the decaying  
shells of  paludina1 planorbis1 limnea1 
or other fresh-water molluscs4 ,we  may 
conceive the ,burdiehouse limestone to  
have had a similar origin4  ,the        
cyprides1 inhabiting water that         
contained little argillaceous  matter1  
must have propagated by myriads1 and    
during a long period of  repose1 in     
which the conditions of land and sea1   
and the directions of  tidal currents   

and river-courses1 appear not to have   
greatly varied  in the neighbourhood of 
,burdiehouse1 the calcareous exuvi of   
these  minute animals1 along perhaps    
with the remains of other estuarine or  
fluviatile organisms1#fj would form each
 year a scarce appreciable  stratum1    
until by slow aggregation a bed         
twenty-seven feet deep was  elaborated4 
,each successive annual layer would     
hardly settle down more  perceptibly or 
more rapidly than the flickering dust   
that mottles the  floor of some old     
haunted chamber4    ,footnote #fj3      
,though ,i have never observed molluscan
 remains in the  limestone of           
,burdiehouse1 they are abundant twelve  
miles to the west1  in the equivalent   
strata around ,mid-,calder1 one little  
gastropod  being especially plentiful   
near the base of the calcareous rock in 
a  seam known to the quarrymen as the   
,buckie fake4 ,i have not met with      
specimens sufficiently perfect for      
identification1 the hard splintery      

nature of the rock seldom allowing      
anything but a cross-section to be  seen
 save on weathered specimens1 where the 
general contour of the  shells has      
sometimes reminded me of ,paludina      
multiformis grouped  together in a      
recent fresh-water marl4 ,in the shales 
above the  ,burdiehouse limestone1 ,dr  
,hibbert states he found a unio 7871    
called  by him ,u4 nuciformis4 ,trans4  
,roy4 ,soc4 ,edin4 vol4 xiii4 p4 #bde4  
,at last1 however1 this condition of    
things came to be modified4 ,the        
direction of the river channel along    
some part of its course had  varied1 or 
some analogous change had taken place1  
so that muddy  sediment transported from
 the land sank down amid the cyprides at
  the bottom4 ,in circumstances so      
uncongenial these tiny denizens  of the 
estuary diminished in numbers until the 
silt and sand came  down so rapidly and 
in such abundance that they eventually  
died out4  ,alluvial matter still       
darkened the water and covered the      

river-bottom1  enveloping now the fronds
 of a delicate fern that had waved along
  the margin of some sequestered lake   
far inland1 anon a seed-cone  that had  
been shaken by the breeze from the spiky
 branches of some  tall club-moss4      
,among these muddy beds occur numerous  
coprolites and  fish-scales1 along with 
cypriscases and a few shells of unio    
7871  showing that though the cyprides  
were decreasing1 the water still        
presented the old estuary conditions and
 still swarmed with life4    ,eventually
 there came other changes in the        
direction or rapidity of  river         
currents1 and the accumulations of mud  
and silt were succeeded by  a long      
protracted deposition of yellow sand1   
now forming the sandstone  of ,straiton4
 ,it enclosed many stems of stigmaria1  
lepidodendron1 c41  and in certain      
limited areas these plants matted       
together in such  quantities that their 
remains now form thin irregular seams of
 coal4  ,it would appear1 therefore1    

that notwithstanding these changes in   
the  matter transported and deposited at
 the locality in question1 the  estuary 
character of the locality remained      
essentially the same4 ,the  sand was at 
length replaced by fresh accumulations  
of mud and sandy  silt1 which went to   
form the beds of shale and shaly        
sandstone now  found above the ,straiton
 rock4    ,when in the course of many   
long centuries a depth of strata        
amounting  to fully #cjj feet had been  
amassed1 the area of ,mid-,lothian      
underwent  a total change4 ,owing to a  
depression of the earth's crust1 that   
seems  to have been general over the    
whole of central ,scotland1 the estuary 
in which the ,burdiehouse limestone and 
superincumbent strata were  deposited   
became open sea4 ,as the evidence of    
this change rests solely  on the        
character of the imbedded organic       
remains1 we shall pursue our  induction 
by examining the beds somewhat in       
detail4    ,rather more than #cjj feet  

above the limestone of ,burdiehouse     
there  occurs in the ,mid-,lothian      
coal-field a series of shales and seams 
of limestone4 ,the former are sometimes 
black and hard1 sometimes  bluish-grey1 
soft1 and frequently imbedding the      
remains of several  genera of mollusca  
and other organic remains4 ,the         
limestones vary  considerably in the    
thickness and general aspect of their   
several  seams1 some being highly       
crystallized and about two or three feet
 in  depth1 others dull1 compact1 and   
ranging up to twenty and thirty feet    
thick4 ,the shales and limestones are   
intercalated with and sometimes  pass   
into each other1 through the gradations 
of shaly limestone and  calcareous      
shales4 ,the whole series may measure   
#aej to #bjj feet1  resting on the      
,straiton sandstone below1 and passing  
upwards into  the under part of the     
coal-bearing strata of ,mid-,lothian    
known as  the ,edge series4 ,these      
limestones form the northern marine     

equivalents of the mountain limestone of
 ,england1 while the sandstones  and    
shales on which they rest1 including the
 ,burdiehouse beds and  all the ,lower  
,carboniferous group1 must probably be  
regarded as  estuarine equivalents of   
the same formation4 ,that is to say1    
while  marine limestones were           
accumulating over the site of central   
,england1  sandstone1 shale1 and drifted
 plants1 were slowly gathering in a wide
  estuary over what is now central      
,scotland1 and only at the close of the 
period did marine limestones form       
simultaneously at both localities4      
,in examining these ,mid-,lothian beds  
we are struck at once with the  great   
dissimilarity that obtains between their
 organic remains and  those of the      
underlying strata4 ,all the land-plants 
disappear--ferns1  lepidodendra1        
sigillari1 and stigmari4 ,the cyprides1 
too1 no longer  occur1 though the shales
 seem1 at a first glance1 to differ in  
no  respect from those underneath1 in   

some of which the cypris-cases were     
seen to abound4 ,neither can we detect  
the glittering scales and teeth  that   
stood out in such strong relief upon the
 rocks below4 ,yet the  fossils are     
scarcely less numerous than they were in
 the lower beds4  ,nay1 in some of the  
limestones they lie so crowded together 
that the  rock seems entirely made up of
 them4 ,plainly such a total renovation 
of organic life points to some equally  
extensive change of a physical  kind4   
,let us examine for a little some of the
 fossil remains occurring  in the       
mountain limestone series of            
,mid-,lothian1 and read off1 if we  can1
 the revolutions which they chronicle4  
,illustration3 ,fig4 #cb4--,section from
 ,gilmerton to ,crichton2 a1 ,lower     
,carboniferous2 b1 ,mountain ,limestone2
 c1 ,edge ,series2 d1 ,roslyn           
,sandstone ,group2 e1 ,flat ,coals2 y1  
,drift4    ,the neighbourhood of        
,edinburgh affords many facilities for  
the study of  these rocks4 ,they can be 

seen1 for instance1 at many points along
 the  ridge of the ,roman ,camp ,hill1  
near ,dalkeith1 exposed in the          
operations  of quarrying4 ,that ridge is
 formed by what is known technically as 
an anticlinal axis 7,fig4 #cb72 in other
 words1 the lower beds of the           
coal-measures rise up here into a sort  
of broad wave-like undulation1  round   
the sides of which the higher parts of  
the series are folded4 ,the  elevated   
area has either been pushed up from     
below1 or the more level  country around
 has subsided into two trough-like      
hollows1 so that now  the strata1 which 
geologically speaking are lowest1 come  
to occupy the  highest ground in the    
district4 ,seated on some of the opener 
spots  of this woody eminence the       
observer has a noble prospect on which  
to  expatiate4 ,the ground around him is
 rich in historic associations1  and    
links itself to many a varied page in   
the annals of ,scotland4 ,the  hill on  
which he rests is crowned by the        

mouldering mounds of what  tradition    
reports to have been a ,roman station1  
but which may perhaps  belong to a still
 earlier era4 ,a few hundred yards north
 rise the  wooded slopes of ,carberry   
,hill1 where the hapless ,mary          
surrendered to  her rebel lords1 and    
whence she was led into her own capital 
amid the  insults of an infuriate       
rabble4 ,northward1 too1 lies the fatal 
field  of ,pinkie1 and eastward the less
 deadly but not less decisive field  of 
,prestonpans4 ,to the west the eye can  
mark the grey smoke of the  ,scottish   
metropolis1 with its dusky towers and   
its lion-shaped hill1  and then the blue
 waving outline of the ,pentlands that  
sweep away  south and lose themselves   
among the distant hills which girdle in 
the  coal-basin of ,edinburgh and       
,haddington4 ,the course of the         
,esk--that  fabulosus amnis--passes by  
many a time-honoured spot1 from         
,habbie's  ,howe and the scene of the   
,gentle ,shepherd down by the haunted   

scenery  of ,roslyn1 the cliffs of      
,hawthornden1 the grounds of ,newbattle1
 and  the old ,roman station of         
,inveresk4 ,east1 west1 and south1 the  
broad  expanse of green field and       
clustering wood swells upward to the    
distant  hills that encircle the        
landscape with a wavy line of softest   
blue4  ,northward the eye rests on the  
,firth of ,forth with its solitary      
sails1  bounded by the bosky heights of 
,fife1 and opening outwards by the ,may 
,island and the ,bass ,rock into the    
far-off hazy ocean4 ,on every side      
objects of historic interest lie crowded
 together1 about which many  pleasant   
volumes have been and might still be    
written4 ,if the observer  be a lover of
 geological science he will find an     
examination of the  structure of the    
hill to impart an additional interest to
 the scene4  ,from the wide panorama of 
hill and dale1 river and sea1 with all  
its  battle-fields1 castles1 and abbeys1
 and all its memories of the olden      

time1 let him turn into one of the      
quarries that indent the flanks  of the 
hill1 and try to decipher there the     
records of a still older  history4 ,an  
hour or two thus spent will pass swiftly
 and pleasantly  away1 and on quitting  
the quarry he will have gained a new    
light in  which to look on the landscape
 that lies spread out below4    ,the    
mountain limestone of ,mid-,lothian     
consists1 as has been mentioned1  of    
several seams interbedded with black and
 calcareous shales4 ,the  quarries on   
,roman ,camp ,hill have been opened in  
several of the thickest  of these seams4
 ,let us enter one of the excavations4  
,a vertical face  of rock forms the     
background1 overhung above by long      
dangling tufts of  withered grass1 and  
washed below by a pool of water having  
that milky  green tint peculiar to old  
lime-quarries4 ,the lowest rock visible 
is  a dull grey limestone with a        
yellowish weathered surface4 ,above it  
rests a mass of hard yellow calcareous  

shale1 known to the workmen  as bands4  
,this rock is worthless as a source of  
lime1 nor from its  irregular           
laminations and shivery structure has it
 much value in any  other way4 ,a few   
inches of surface-soil form the upper   
part of the  section4 ,it requires but a
 glance over the weathered surface of   
the  limestone to mark that the rock    
abounds in fossils4 ,of these by far    
the most numerous are the joints of the 
stone-lily1 for the most part  of small 
size1 and when broken across1 with their
 minute central  apertures1 looking like
 so many fractured stems of             
tobacco-pipes4 ,other  organisms also   
occur1 such as a small                  
delicately-plaited productus1  a larger 
and more boldly-ribbed spirifer1 a small
 cyathophyllum or  cup-coral1 and the   
fragile interlacing meshes of one of the
 net-like  bryozoa--the fenestella4 ,of 
rarer occurrence are the whorled shells 
called bellerophon1 the long chambered  
shells of orthoceratites1 and  the      

grooved tapering shells of pinn4 ,many  
of the same fossils can be  detected in 
the beds above1 which thus evidently all
 form part of one  series with the rock 
below4 ,what1 then1 were the            
circumstances under  which these strata 
originated8    ,the answer to such a    
question is not far to seek4 ,the corals
 and  crinoids are exclusively marine   
families1 and so any stratum in which   
their remains occur must have had a     
submarine origin4 ,it matters not  in   
this case though the specimens be       
fragmentary1 showing a broken and       
drifted appearance4 ,for even supposing 
that they did not live at the  spot     
where their petrified relics are now    
exhumed by the operations of  the       
quarryman1 granting that they were      
drifted from a distance1 still  they    
could only have been drifted from one   
part of the sea-bottom to  another4 ,the
 state of keeping of the specimen often 
tells vastly on the  value of its       
evidence when it belongs to a land or   

fresh-water tribe4  ,thus1 in one of the
 limestones of ,west-,lothian ,i have   
found a black  carbonized stem of       
sigillaria4 ,now1 the sigillaria was a  
land-plant  as much as any of our hazels
 or willows1 and where the evidence from
  the associated organisms coincides1   
furnishes its own testimony as  to the  
origin of the rock which imbeds its     
remains4 ,but the stem in  question was 
a mere fragment1 and showed moreover a  
worn macerated  surface4 ,such a fossil 
had evidently no value as a test of the 
origin  of the limestone1 which might   
have been elaborated either in an inland
  lake or in open sea4 ,that it had     
really a marine origin1 and that the    
sigillaria actually was1 as it seemed to
 have been1 a drifted plant1  ,i        
ascertained beyond a doubt by detecting 
on the same slab hundreds  of encrinal  
stems along with the shells1 and thin1  
delicate1 silvery  spines of productus4 
,thus1 then1 the organisms of the land  
may be  carried into the sea1 and in    

dealing with their fossilized remains   
in the deposits of former ages we must  
be very careful in the use of  evidence 
derived from fragmentary and drifted    
specimens4 ,but no such  caution is     
needed in regard to the productions of  
the sea4 ,if they be  fragmentary and   
drifted1 we may believe they were rolled
 about by tides  and currents previous  
to their final entombment2 but still    
they remain  as good a test as ever of  
the marine character of the rock in     
which  they occur4#fa    ,footnote #fa3 
,the exceptional instance1 of the       
accumulation on the land  of blown sand 
imbedding the broken remains of marine  
shells1 needs only  to be noticed here4 
,the fossils of ,roman ,camp ,hill are  
not drifted specimens4 ,they must  have 
lived and died where the quarryman now  
finds them4 ,we recognise  them as all  
unequivocally marine2 corals1 crinoids1 
and brachiopodous  molluscs1 are all    
clearly the denizens of the sea1 and    
hence we  conclude that they mark the   

site of an ancient ocean4 ,the          
snail-shells  that swarm about the      
fruit-trees of our orchards not more    
unmistakably  indicate a land-surface   
than do these petrified relics evidence 
an old  sea-bottom4 ,we can argue1 too1 
from the crowded way in which they lie  
grouped together1 that life must have   
been prolific in these primeval  waters4
 ,every fragment of the rock shows its  
dozens1 nay1 hundreds1  of stone-lily   
joints1 disjointed indeed1 yet easily   
recognisable4  ,they must have swarmed  
as thickly along the floor of the sea as
 the  strong-stemmed tangle that darkens
 the bottom of many a picturesque  bay  
along our western coasts1 yet with a    
gracefulness of outline such  as none of
 our larger sea-weeds can boast4 ,less  
numerous but not less  markedly in situ 
are the shells of productus and         
spirifer1 the former  with its          
finely-striated surface fresh as if the 
creature had died but  yesterday1 while 
the slender spines with which it was    

armed lie strewed  around4 ,in short1   
the whole suite of organisms points to a
 period of  tranquil deposition in a sea
 of probably no great depth1 where the  
lower forms of the animal kingdom       
flourished in abundance1 contributing   
by their calcareous secretions to form  
continuous layers of limestone4    ,such
 a condition of things finds a parallel 
in many parts of the globe  at the      
present day4 ,thus1 the shores of the   
islands of the ,pacific  are white with 
fine calcareous mud1 that results from  
the action  of breakers on the          
surrounding coral-reefs4 ,this mud1     
enveloping  fragments of coral1 shells1 
sea-weed1 drift-wood1 and other         
extraneous  substances1 hardens on      
exposure1 and becomes eventually a      
limestone1  travertine1 or calc-sinter4 
,we may believe that the same process   
goes  on out at sea1 around the edges of
 atolls or circular coral-reefs1  and   
that the sediment thus thrown down will 
enclose any zoophytes  or molluscan     

remains that may lie at the sea-bottom1 
along perhaps  with fuci1 and occasional
 water-logged fragments of wood that    
have  been drifted from land4 ,along the
 shores of ,guadaloupe a bed of this    
calcareous silt has formed since        
,america was colonized by man1 for it   
has been found to contain fragments of  
pottery1 arrow-heads1 and other         
articles of human workmanship4#fb ,the  
same rock has yielded1 besides1  the    
partially-petrified bones of several    
human skeletons1 one of which1  though  
without the head1 forms a prominent     
object among the fossil  treasures of   
the ,british ,museum4 ,the rock in which
 these remains are  embedded is         
described as harder than statuary       
marble1 notwithstanding  its recent     
origin4 ,by supposing the same process  
to be carried on over  a large area and 
for a long period1 we may see how a     
continuous stratum  of limestone could  
be elaborated1 full of fossil relics of 
corals1  molluscs1 and other marine     

productions4 ,and in some such way1 we  
may  be permitted to believe1 the seams 
of limestone on ,roman ,camp ,hill  were
 accumulated4 ,the billows of that old  
carboniferous ocean may not  have sent  
up their white surf against the margin  
of snowy coral-reefs1  but the currents 
below did their work of demolition as   
effectually1  and by sweeping through   
the submarine groves of stone-lilies and
  cup-corals1 as the night winds of     
autumn sweep athwart the heavy-laden    
fields1 would prostrate many a          
full-grown stem and scatter its         
loosened joints among the thickening    
lime that covered the bottom4           
,stone-lily1 cup-coral1 net-coral1      
productus1 spirifer1 pinna1 nautilus1   
orthoceratite1 all would eventually be  
entombed amid the decaying  remains of  
their congeners1 and thus produce a     
slowly-increasing seam  of limestone4   
,footnote #fb3 ,lyell's ,manual of      
,elementary ,geology1 p4 #aba4 ,fifth   
edition4    ,we still linger in the old 

quarry on ,roman ,camp ,hill1 but the   
day  draws rapidly to a close1 and the  
long level beams of the setting sun     
lighten up the higher grounds with a    
golden flush1 while the valley  below   
lies deep in shade4 ,the rays fall      
brightly on the abrupt face of          
limestone at the further end of the     
quarry1 every prominence standing  out  
in bold relief1 and casting its shadow  
far behind4 ,our eye1 in  passing over  
the sunlit rock1 can detect the         
fractured joint of many an  encrinite   
glancing in the light2 along1 too1 with 
the strongly defined  outlines of some  
of the lesser and more abundant         
molluscs--spirifers  or producti4 ,some 
of them1 sorely effaced by the rains1   
have begun  to yield a scanty nestling  
place for creeping fibres of moss2      
others  yet bare1 afford a rest to the  
,vanessa whereon to spread its wings  in
 the mellow sunset ere flitting         
homewards among the dewy herbage4  ,the 
bushes overhead scarcely rustle in the  

light-breathing air that  comes fitfully
 across the land1 and the long grass    
nods dreamily on  the margin of the pool
 below4 ,there rests a calm stillness on
 all the  nearer landscape1 and the     
distant ground blends away into the     
shades  of evening4 ,the scene1 in      
short1 has about it that solemn         
impressive  repose which irresistibly   
arrests the fancy1 and sets it to dress 
up  into fantastic shapes the massive   
clouds that float in the western  sky1  
to picture grim forms amid the misty    
shadows of the valley1 or to  dwell half
 dreaming upon the memories of the past1
 that come crowding  through the mind in
 quick succession4 ,our labours among   
the fossils of  the old quarry1 however1
 enable fancy to draw her stores from   
another  source4 ,we muse on these      
petrified relics1 gilded by the last    
rays  of the setting sun1 when slowly1  
like a dissolving view1 sunset and      
herbage melt away1 and the bottom of the
 old carboniferous ocean lies  before us

 with its corals and shells and         
stone-lilies1 stretching out  their     
quivering arms1 or expanding and        
contracting their flower-like  petals   
amid a scene of ceaseless animation and 
activity4 ,geology  delights in         
contrasts1 and assuredly the contrast   
presented to us this  evening between   
the present and the past of ,roman ,camp
 ,hill1 will not  rank among the least  
striking of those which she has to      
reveal4 ,there  is now spread over us   
the blue sky1 richly hung with tinted   
clouds1  and melodious with the evening 
songs of the lark1 the blackbird1 and   
the thrush4 ,not less surely did a wide 
expanse of sea during the               
,carboniferous era roll over the hill on
 which we stand4 ,and yonder  silvery   
moon that mounts up amid the violet     
twilight of the east1 has  witnessed    
each scene and all the countless changes
 that have intervened  between them4    
,the same pale light that now begins to 
steal through the  woods and athwart the

 fields1 must have streamed down upon   
that old  sea and illumined its green   
depths4 ,oceans and continents1 islands 
and  lakes1 hills and valleys1 have come
 and gone with all their successive     
races of living things1 and that same   
planet has marked them all4 ,she  has   
seen1 too1 as but a thing of yesterday1 
the appearance of man upon  the scene1  
with all the successive centuries that  
have elapsed since  then4 ,truly the    
goddess of the silver bow would have a  
strange story  to tell us could we      
interrogate her about the past4 ,but the
 days of  ,endymion have gone by1 and   
she now no longer visits in a personal  
form  the seat of beings who gaze at her
 crescent orb and daringly pronounce  it
 a scene of blasted ruin and desolation4
          ,,chapter ,,xi4               
,intercalation of coal seams among      
mountain limestone beds of              
,mid-,loihian--,north ,greens           
seam--,most of our coal seams           
indicate former land-surfaces--,origin  

of coal a debated                       
question--,erect fossil trees in        
coal-measures--,deductions to         be
 drawn therefrom--,difference between   
the mountain limestone         of       
,scotland and that of                   
,england--,coal-bearing character of the
         northern series--,divisions of 
the ,mid-,lothian coal-field--,the      
,edge coals--,their origin illustrated  
by the growth of modern                 
deltas--,delta of the ,nile--,of the    
,mississippi--,of the                   
,ganges--,progress of formation of the  
,edge coals--,scenery         of the    
period like that of modern              
deltas--,calculations of         the    
time required for the growth of a       
coal-field--,why of         doubtful    
value--,roslyn ,sandstone               
group--,affords proofs of         a     
general and more rapid subsidence       
beneath the sea--,its         great     
continuity--,probable origin--,flat     
coals--,similar         in origin to the

 ,edge coals below--,their series not   
now         complete--,recapitulation of
 the general changes indicated by       
the ,mid-,lothian coal-field4    ,among 
the old quarries of ,roman ,camp ,hill  
and down the course of  several streams 
in the same county1 the limestone beds  
of the mountain  limestone series are   
seen to be associated with strata of    
shale1 some  of which are highly        
calcareous1 and charged with the same   
organic  remains that occur in the      
limestones4 ,such shaly intercalations  
mark  as before the transport and       
deposition of muddy sediment around and 
above the corals and stone-lilies of the
 sea-bottom4 ,all these beds  must      
undoubtedly be regarded as marine4 ,but 
there occur1 besides1  seams of         
sandstone and black partially-bituminous
 shale1 with layers  of coal and        
fire-clay4 ,to this singular            
intermixture it may be well  to advert  
more particularly1 since it forms one of
 the distinguishing  features of these  

northern rocks1 as contrasted with those
 of central  and south-western ,england1
 and more especially since it will lead 
us  to mark again the value of fossil   
remains as evidence of the ancient      
changes of land and sea4    ,the        
southern part of ,mid-,lothian consists 
of a broad heathy moorland1  that slopes
 northward into the more cultivated     
country1 and swells  upward to the south
 into the series of undulating ridges   
that form the  ,moorfoot ,hills4 ,it is 
traversed by several streams which rise 
high  among the pasture grounds of the  
south1 and flow some into the valley  of
 the ,esk1 and thence into the sea at   
,musselburgh2 others past the  ancient  
fortalices of ,borthwick and ,crichton1 
and so by the valley of  the ,tyne into 
the sea at ,tyningham4 ,in their upper  
course they traverse  a broad belt of   
the mountain limestone that stretches   
across this  part of the country from   
east to west1 and dips away north under 
the  coal-field4 ,where the streams have

 been able to cut through the thick     
mantle of heath1 sand1 gravel1 and clay1
 by which these higher grounds  are     
covered1 we sometimes obtain a complete 
section of the strata  displayed in     
regular sequence along the bottom of the
 channels4 ,thus1  one of the rivulets  
that trickles slowly through the swampy 
ground of  ,middleton ,muir1 on         
approaching the line of limestone begins
 to descend  more rapidly1 and has      
excavated its course through several    
feet of the  rock below4 ,the limestones
 are well exposed along each side of the
  stream1 forming in some places steep  
walls tapestried with moss and  overhung
 with scraggy furze1 and offering to the
 student an instructive  series of      
sections4 ,near the farm of ,esperston1 
where the stream flows  through a narrow
 secluded valley1 the limestones form a 
floor which the  water in the course of 
centuries has worn smooth1 so that the  
rock with  its included encrinal stems  
and shells1 polished by the ceaseless   

flow  of the current1 shows like a sheet
 of variegated marble4 ,at one point  on
 the side of the water-course the       
observer may notice a low ledge  of rock
 jutting out for a short way along the  
edge of the stream4 ,the  upper part is 
a hard compact limestone1 full of small 
crinoidal joints4  ,the bed underneath  
it has been greatly eroded by the       
rivulet1 but  enough remains to show    
that the stratum is one of coal4 ,it    
rests upon  the series of limestones and
 sandstones seen in the upper part of   
the  water-course1 and is surmounted by 
the thick limestones of ,arniston and   
,middleton4 ,a similar seam nineteen    
inches thick has been worked among  the 
limestone about three miles to the west 
at ,fountain4 ,the same bed  occurs     
among the quarries on ,roman ,camp ,hill
 already mentioned1 and ,i  have seen an
 equivalent stratum intercalated among  
sheets of cup-corals  and stone-lilies  
on the shore at ,aberlady1 where the    
waves have laid  open perhaps the finest

 section of ,carboniferous limestone    
strata in  ,scotland4 ,in               
,west-,lothian1 too1 the same           
intercalation of coal-seams  among the  
mountain limestone beds can be seen in  
many places4 ,thus1 in  the bed of the  
,river ,almond1 near ,blackburn1 the    
following section is  laid bare3--      
,calcareous shale4    ,limestone        
7marine71 eight feet4    ,calcareous    
shale1 with spirifers1 c4    ,coal1 six 
to eight inches4    ,fire-clay4         
,sandstone4    ,a short way further down
 the stream another bed of limestone    
occurs  with several seams of coal below
 it1 one of them attaining a thickness  
of six feet4    ,in addition to the thin
 seam at ,esperston1 the ,mid-,lothian  
field  contains several others4 ,of     
these by much the most important is that
  known as the ,north ,greens ,seam4 ,it
 varies in thickness from only a  few   
inches to fully #e feet1 and has been   
extensively worked for the  parrot or   
gas-coal which it contains4 ,it rests   

upon a pavement of  shale1 sometimes of 
fire-clay1 and occurs about midway      
between two  thick marine limestones1   
being from #hj to #ij feet distant from 
each4  ,i have laid open many a block of
 the parrot-coal at the pit mouth1  and 
marked the well-defined outlines of the 
stigmaria covered with a  yellowish     
efflorescence of iron pyrites1 like     
gilded figures upon  a black velvet     
ground4 ,the plants lie with their      
divergent rootlets  spread out regularly
 along the stem like teeth on the back  
of a comb1  thus seeming to indicate no 
hurried agglomeration by some tidal wave
 or  turbid river1 but rather a slow and
 tranquil deposition4    ,the fossils of
 the coal-seams consist for the most    
part of the  plants above described1    
which we saw to belong to terrestrial   
species4 ,but the reader will now       
understand that in dealing with  organic
 remains we cannot infer1 because a     
certain stratum contains  nothing but   
land-plants1 that it must necessarily by

 consequence be a  land-formation4 ,for 
we have seen that the plants of the     
,burdiehouse  limestone1 though all     
terrestrial1 gave no support to the idea
 that the  rock had originated on land4 
,in all such cases regard must be had   
not  only to the nature of the imbedded 
organisms1 but their condition and  mode
 of occurrence1 and to the character of 
those associated with them4  ,especial  
care must be taken to distinguish what  
has been transported  from what is in   
situ1 otherwise1 by attending only to   
one part of  the evidence1 we shall miss
 the import of the whole1 and altogether
  misinterpret the records which we seek
 to decipher4    ,for years the subject 
of the origin of coal formed one of the 
many  battle-fields on which geologists 
delighted to break lances4 ,they  ranged
 themselves under two banners1 the      
drift-theory men and the  growth-theory 
men1 the former maintaining strenuously 
that coal  was simply vegetation        
transported from the land and deposited 

in  large troughs at river-mouths or    
sea-bottoms1 the latter as eagerly      
contending that the vegetation had not  
been drifted1 but grew on  the very     
locality where its remains are now      
exhumed4 ,neither party  lacked         
plausible arguments in support of its   
doctrines4 ,the drift  combatants       
stoutly affirmed it to be contrary to   
all experience that  a land-surface     
should be so oscillating as their       
opponents required1  that in short it   
was absurd to hold each coal-seam as    
marking a period  of elevation1 for     
there were often dozens of seams in as  
many yards  of strata1 some of them     
scarcely an inch thick1 and yet1        
according to  the growth theory1 each   
would have required for its accumulation
  a special uplifting of the land above 
the sea-level4 ,these and many  other   
difficulties were thought to be         
triumphantly overcome by the  hypothesis
 of transport and deposition4 ,the      
vegetation borne down  by some ancient  

,mississippi would collect in vast      
rafts1 and these  becoming water-logged 
would sink to the bottom1 where1 by     
getting  eventually covered over with   
silt and sand1 they would in process of 
time be chemically altered into coal4   
,this explanation was1 however1         
vigorously resisted by the opposite     
side4 ,they alleged that the drift      
theory could account neither for the    
wide extent of coal-seams nor  for their
 remarkable persistency in thickness4   
,if the vegetation had  really been     
hurried out to sea by river-action1 it  
seemed natural to  expect that the      
coal-seams should occur in sporadic     
patches of very  unequal thicknesses1   
according as the drifted plants had been
 more  densely or more loosely packed4  
,but this was found not to be the case  
in point of fact4 ,the coal-seams were  
ascertained to be generally  singularly 
continuous1 and to retain for the most  
part a pretty uniform  thickness over   
considerable areas4 ,and what was still 

more worthy of  note1 they were1 as a   
whole1 markedly free from extraneous    
matter1  such as sand and mud4 ,where   
these impurities did occur1 it was      
usually  in the form of intercalated    
seams or partings1 often quite as       
regular  and extensive as the coal      
itself4 ,had the vegetation1 therefore1 
been  transported into the sea1 it could
 hardly fail to get mixed up with  the  
fine impalpable mud which1 like that of 
the ,ganges or ,mississippi1  might have
 discoloured the ocean for leagues from 
the river-mouth1  and settled down as a 
thickening stratum at the sea-bottom4   
,and many  other arguments1 derived from
 the nature and arrangement of the      
strata  interbedded among the           
coal-seams1 were urged to prove that the
 latter  had originated from vegetation 
which grew on the spot4                 
,illustration3 ,fig4 #cc4--,section from
 ,cape ,breton coal-field1 showing  four
 planes of vertical stems1 and seven    
ancient soils with their  covering of   

vegetation4    a1 sandstones2 b1 shales2
 c1 coal2 d1 fire-clays2 e1  arenaceous 
shales4    ,the warfare seems now pretty
 nearly at an end1 and as often happens 
in  such cases1 it has been found that  
each party was to some extent in the    
right and to some extent in the wrong4  
,it has been ascertained that  some     
coal-seams must have originated from the
 deposition of drift-wood  in the mud   
and ooze of the sea-bottom1 while others
 undoubtedly arose  from the decay and  
entombment of vegetation in swampy      
plains of the  land4 ,that the latter   
mode of formation has been the usual one
 in most  of our coal-fields has been   
generally acknowledged since ,sir       
,william  ,logan's announcement that    
each coal-seam1 for the most part1 rests
  upon a bed of fire-clay1 which1 with  
its embedded roots1 marks the  site of  
an ancient soil4 ,this fact has been    
abundantly confirmed in  every part of  
this country1 and indeed wherever an    
extended series of  coal-seams has been 

examined4 ,not only have the underlying 
fire-clays  been found1 but in not a few
 instances erect stems of trees1 passing
  down through the coal-seam and        
spreading out their divergent roots in  
the clay below1 exactly as they must    
have done when they flourished  green   
and luxuriant in the times of the       
,carboniferous system4 ,this was        
especially the case in the ,parkfield   
,colliery1 ,wolverhampton1 where        
seventy-three trunks were laid bare in  
the space of about a quarter of  an     
acre1 each with its roots attached4 ,the
 same appearance was observed  some     
years ago in the ,dalkeith coal-field1  
where a group of erect  trees was       
encountered covering a space of several 
square yards4 ,some  instructive        
sections of such fossil-forests are     
given by ,mr4 ,brown from  the ,cape    
,breton coal-field4#fc ,in one of them  
7,fig4 #cc7 no fewer than  four planes  
occur1 each supporting its group of     
erect steins4 ,now1 no  one can glance  

over this and the other sections        
illustrative of the  same paper1 or the 
descriptions given by ,sir ,charles     
,lyell and others  of the ,nova ,scotian
 coal-field1 without being compelled to 
admit that  the trees in question grew  
just where their upright stems can still
 be  seen1 and consequently that the    
accompanying coal-seams originated not  
from vegetation drifted by river-action1
 but from vegetation that grew  upon the
 spot4 ,and though erect stems do not   
exist in every coal-field1  we seldom   
fail to detect the not less important   
occurrence of the  fire-clays and       
hardened shales that support the        
coal-seams and prove  by their embedded 
rootlets their identity with ancient    
soils4 ,thus we  arrive at the inference
 that while in certain localities       
coal-seams  have resulted from drifted  
vegetable matter1 they have nevertheless
 for  the most part been formed from    
plants that flourished where the collier
  now excavates1 amid damp and dripping 

caverns1 their carbonized remains4      
,footnote #fc3 ,quart4 ,jour4 ,geol4    
,soc4 vol4 vi4 pp4 #abj1 #acj4 ,the cut 
given above 7,fig4 #cc7 is taken from   
one of these sections as modified  by   
the late ,sir ,henry de la ,beche       
7,geological ,observer1 p4 #ehb74 ,in   
the original the beds are inclined at a 
considerable angle1 but for the  sake of
 clearness they are here reduced to     
horizontality4    ,applying1 then1 this 
deduction to the strata occurring on the
 horizon  of the mountain limestone in  
,mid-,lothian1 we are led to believe    
that  the ,north ,greens coal-seam marks
 the site of a former land-surface4  ,it
 shows no vertical stems1 but has all   
the other accompaniments of  an ordinary
 seam1 such as the underlying fire-clay 
and shale1 with  their included         
stigmari4 ,and this conclusion has more 
than ordinary  interest1 for if it be   
true1 we have evidence of a terrestrial 
formation among strata unequivocally    
marine2 in other words1 we see  proofs  

either of an elevation or a             
filling-up#fd of the sea-bottom  carried
 slowly on until land-plants grew up in 
matted swamps where  once there swarmed 
corals and encrinites1 and then of a    
gradual  subsidence1 so that marine     
organisms flourished again in abundance 
over the site of the submerged          
vegetation4 ,it is not insisted that    
each of the thin coal-seams among the   
limestone strata marks a former         
terrestrial area4 ,some of them may     
possibly have resulted from the         
transport and deposition of plants borne
 from the land4 ,yet there are  others  
of wide extent resting upon beds of     
fire-clay which contains  stigmaria     
rootlets1 c4 ,these ,i cannot but regard
 as the remains of  plants that grew    
upon the spot4 ,and so1 while we        
recognise in the beds  of limestone     
undoubted evidence of a former          
sea-bottom1 ,i am persuaded  we must    
equally admit that at least several of  
the coal-seams bear fair  evidence of a 

former land-surface1 scarcely raised    
above the sea-level  indeed1 but        
nourishing nevertheless a thickly matted
 vegetation4 ,in  this way we shall see 
the mountain limestone series of the    
,lothians  to be not a purely marine    
formation1 but one partly marine and    
partly  deltoid1 showing in the         
succession of its strata proofs of a    
gradual  submergence1 interrupted by    
movements of elevation1 so that the area
  which at one period formed the        
ocean-bed became at a later time low    
delta-land1 and after continuing perhaps
 for ages to stretch out its  verdant   
surface beneath the open sky1 sank again
 amid the corals of a  wide-spread sea4 
,footnote #fd3 ,if it be correct to set 
down the ,north ,greens coal-seam  as   
really representing a terrestrial       
surface1 that is1 of course1 a  flat    
delta or plain scarcely raised above the
 sea-level1 we must1 ,i  suspect1 call  
in the aid of a slight elevatory        
process1 or else hold  that the depth of

 the sea at the locality where the lower
 limestone was  forming did not exceed  
#hj or #ij feet1 and may have been      
considerably  less1 and that this space 
came to be eventually filled up by the  
detritus of the river4 ,but the wide    
extent and sometimes the great          
thickness of the limestone beds seem to 
indicate a greater depth1 and  thus     
favour the idea of an elevation of the  
sea-bottom to form the  ,north ,greens  
coal-seam4    ,now this condition of    
things differs entirely from what is    
presented  by the ,mountain ,limestone  
group of ,england4 ,that formation1 when
  typically developed1 attains a        
thickness of from #ajjj to #bjjj feet1  
and  gives rise to that green hilly kind
 of scenery whence it has derived  its  
name4 ,it is unequivocally a marine     
deposit1 since it abounds in  corals1   
echinoderms1 brachiopodous molluscs1 and
 other productions of  the deep4        
,northward1 however1 it undergoes a     
gradual change1 getting  greatly        

thinner1 and split up by a series of    
intercalations of shale  and sandstone4 
,this alteration goes on until1 on the  
border-land  between the two countries1 
the massive limestone of ,derbyshire has
  dwindled down into a series of thin   
beds1 often widely separated by         
intervening strata1 which contain many  
seams of coal4 ,after crossing  the     
,silurian district1 and descending the  
northern slopes of the  ,lammermuir     
,hills1 we get into the ,carboniferous  
system again1 and find  its limestone   
series still farther diminished4 ,with  
this decrease  of marine formations1 we 
can detect an augmentation of           
coal-bearing  strata4 ,thus the         
,berwickshire coal-field lies in this   
lower set of  beds1 far under the       
coal-measures of ,newcastle4 ,in the    
,lothians1 too1  as has been shown1 coal
 is extensively worked in the same      
series1 and  these seams also find their
 representatives in ,fife and           
,lanarkshire4  ,the gradual change from 

the kind of strata found on the horizon 
of  the ,burdiehouse limestone1 to those
 occurring on the horizon of the        
,mountain limestone1 indicates1 as we   
saw1 a gradual change of the  conditions
 of deposition2 and the nature of this  
alteration is shown by  the difference  
in the character of the imbedded        
fossils4 ,the passage  of the massive   
,derbyshire limestone into the thin     
limestones and  coal-bearing sandstones 
of the north1 as decidedly marks another
 change  in the relative position of sea
 and land4 ,the former was a succession 
in time1 the latter was one in space1   
but the mode of reasoning remains  the  
same for both4 ,in the former case1 we  
saw estuarine strata passing  upward    
into others wholly marine1 and the order
 of superposition told  us that the     
locality was first an estuary1 and then 
slowly became open  sea4 ,in the latter 
case1 we see marine beds not succeeded  
by estuarine  strata1 but becoming      
estuarine strata themselves4 ,the thick 

limestones  gradually thin out          
horizontally into a great series of     
sandstones and  shales1 with interbedded
 coal-seams1 so that what bears evidence
 of a  deep sea at the one end1 gives   
proof of a muddy and sandy delta at the 
other4 ,in other words1 during the ages 
represented by what we call the         
,mountain ,limestone1 the central and   
south-western portions of ,england  lay 
far below a wide breadth of ocean1 and  
nourished a luxuriant crop  of          
stone-lilies1 mingled with the other    
denizens of the deep1 while the  ,border
 district1 and the whole of central     
,scotland1 exhibited all the  conditions
 of a vast delta1 sometimes spreading   
out as broad verdant  jungles1 anon     
showing only scattered irregular groups 
of low1 bare  mud-banks and sand-spits1 
which at other times disappeared        
altogether  beneath the dun discoloured 
waves4 ,now the reader will not fail to 
mark that this curious and interesting  
fact in the past history of our         

country1 is ascertained solely from a   
comparison of fossil remains4  ,the     
stone-lilies and shells of ,derbyshire1 
and the lepidodendra and  land-plants of
 the ,lothians1 form our sole basis of  
evidence1 and we  may rest on them with 
as perfect certainty as if they were so 
many duly  attested documents deposited 
among the archives of our ,state-,paper 
,office4    ,in our survey of the       
coal-field of ,mid-,lothian1 we have    
passed from  the ,lower ,carboniferous  
estuary beds of ,burdiehouse to the     
,middle  ,carboniferous marine beds of  
,roman ,camp ,hill1 and their associated
  terrestrial strata1--the coal-seams   
and fire-clays4 ,we come now1 in our    
upward progress1 to the ,upper          
,carboniferous group1 or ,coal-measures 
proper4#fe ,these strata rest           
immediately upon the limestones1 and    
attain a depth here of over three       
thousand feet4 ,they consist of a  great
 series of sandstones1 shales1 coals1   
and fire-clays1 that vary  in thickness 

from less than an inch to many feet1 or 
even yards4 ,the  coal-seams are        
especially variable1 many of them       
existing as mere films  of carbonaceous 
matter2 others varying up to a depth of 
fourteen feet4  ,there are from fifty to
 sixty that exceed a foot1 but the      
average  thickness throughout the whole 
series is about three and a half        
feet4#ff ,they are nearly all underlaid 
by fire-clay or shale1 and very         
generally have a roof of the latter     
material4    ,footnote #fe3 ,these      
terms--,lower1 ,middle1 and ,upper      
,carboniferous1 are  used for want of   
others1 and for the sake of clearness4  
,they must not  be regarded1 however1 as
 equivalent to similar groupings of the 
,english  carboniferous rocks1 for the  
,scottish series is probably much older 
than the greater part of the ,english1  
and coeval1 to a considerable  extent1  
with the mountain limestone and         
millstone grit of the latter  country4  
,footnote #ff3 ,see ,milne on           

,mid-,lothian ,coal-field4 ,trans4      
,royal ,soc4  ,edin4 vol4 xiv4 p4 #bef1 
whence the above details are taken4     
,by referring to the diagram of this    
coal-field1 given above at p4  #aif1 the
 reader will notice that the series is  
divisible into three  groups3--#ast1 and
 undermost1 a considerable depth of coal
 bearing  strata known as the edge      
series1 because they lie along the      
western  limits of the coal-basin at a  
high angle1 and sometimes even on  edge2
 #b;d1 ,a great thickness of sandstones 
nearly barren of coal1  but containing  
at least three beds of limestone this   
may be termed  the ,roslyn sandstone    
group2 #c;d1 and highest1 another series
 of  coal-bearing strata1 commonly      
called the flat coals1 because they     
occupy the centre of the basin where the
 beds repose at a low angle1  and are in
 places quite flat4 ,it will be         
convenient to keep in mind  this        
three-fold division1 for it will point  
us to some important  changes in the    

ancient conditions of this coal-field4  
,the edge series1 which forms the       
lowest1 and of course oldest of the     
above groups1 averages from #hjj to #ijj
 feet in thickness4 ,it contains  about 
thirty seams of coal above a foot thick1
 and many more of less  size4 ,they     
occur irregularly1 some lying only a few
 inches apart1  others from eighty to   
ninety feet1 the intervening space being
 occupied  by sandstone or shale4       
,now as each coal-seam1 with its        
associated under-clay1 appears to mark  
a former land surface1 it will follow   
that there must be as many old  land    
surfaces in this series of strata as    
there are such coal-seams1  and that for
 every intervening mass of sandstone or 
shale1 the area  of vegetation must have
 been submerged4 ,this conclusion would 
have  been violently resisted by the    
supporters of the drift theory4 ,they   
would have roundly asserted that such an
 unsteady surface was a mere            
supposition to suit a hypothesis1       

unsupported by fact1 and contrary  to   
the analogy of existing nature2 and they
 would not perhaps have  hesitated to   
maintain1 that such an oscillating land 
could be little  fitted to nourish so   
rich and luxuriant a vegetation as that 
of the  ,carboniferous period4 ,but it  
will not be difficult to show that our  
conclusion1 so far from being contrary  
to analogy1 is amply borne  out by the  
processes of existing nature1 and that  
its opponents1 and  even its original   
asserters1 failed to perceive that what 
it demands  is not a rapidly oscillating
 crust1 but one as steady and uniform as
  that of many of the least disturbed   
countries at the present day2  and that 
we do not require to call in the aid of 
a special elevation  and submergence for
 every coal-seam1 but that for the most 
part the  hypothesis of a steady sinking
 of the area of a coal-field1           
interrupted  perhaps by occasional      
elevatory movements1 along with an      
active and  constant deposition of      

sediment by the varying currents of a   
large  river1 is sufficient1 if not     
thoroughly to explain1 at least to      
throw great light upon the origin of    
those enormous masses of strata         
composing our present coal-basins4 ,the 
oft-recurring variations in  the nature 
of the strata that form our             
coal-measures1 sandstones  alternating  
with shales1 these again with coals and 
fire-clays1  together also with the     
terrestrial origin of the coal-seams1   
and the  occasional presence of true    
marine organisms1 make it evident that1 
to obtain any modern analogue to such a 
condition of things1 we must  examine   
those localities where large bodies of  
fresh water1 carrying  sediment and     
vegetation from the land1 mingle with   
the sea4 ,let us then  look for a little
 at the operations now in progress at   
the mouths of  the larger rivers1 and   
mark how far they elucidate the         
structure and  history of a coal-field4 
,egypt is the gift of the ,nile4 ,such  

was the conclusion arrived at by  one of
 the most diligent observers of ancient 
,greece--the venerable  ,herodotus4#fg  
,he sailed up the river marking all the 
leading features  in its scenery1 and   
noting the more apparent evidences of   
ancient  physical changes4 ,his remarks 
on these subjects form one of the       
earliest specimens of scientific        
reasoning that have come down to us1    
and are remarkable for their correctness
 and the truly inductive mode  of       
thought which they evince4 ,modern      
travellers have amply confirmed  the    
opinions of the father of history1 and  
we now know that but for its  central   
river1 ,egypt would be a vast dreary    
expanse of arid sand like  the          
neighbouring deserts of ,lybia4 ,the    
,nile1 by annually inundating  the      
country1 deposits over it a stratum of  
rich loam1 and thus not  only waters the
 land1 but continually renews the soil4 
,the sediment  in this way brought down 
has gradually encroached upon the waters

 of  the ,mediterranean1 being heaped up
 at the river mouth into shifting       
sand-banks1 islets1 and great tracts of 
low1 swampy ground1 slightly  raised    
above the sea-level4 ,through this      
series of silting deposits1  the river  
sends a number of branches1 often       
winding in labyrinthine  convolutions1  
and ever changing their course1 by      
wearing away the silt  at one place1 and
 throwing it down at another4 ,the area 
traversed by  the mouths of the ,nile   
was called by the ,greeks the ,delta1   
from its  similarity in form to the     
,greek letter1 and the name has since   
been  given to all such fluviatile      
deposits1 whether they have this general
  form or not4    ,footnote #fg3        
,euterpe1 #e4--;,his words are very     
emphatic4 ,to one of  ordinary          
intelligence1 who has not heard of it   
before1 but sees it1  ,egypt is         
manifestly land acquired by the         
inhabitants1 and a gift from  the       
river--  4 ,the #ajth and #abth chapters

 of the same  book deserve especial     
study for the admirable inductive style 
in which  the historian compares the    
phenomena observable in ,egypt with what
 were  well known as the results of     
river action in other lands4 ,the       
passages  might be quoted word for word 
in the most rigid scientific argument of
  any modern geologist4    ,the sediment
 annually deposited by the ,nile varies 
in thickness in  different years4 ,the  
mean thickness of the annual layers at  
,cairo has  been calculated not to      
exceed that of a sheet of thin          
pasteboard1 so  that a stratum of two or
 three feet must represent the          
accumulation  of a thousand years4#fh   
,such thin lamin must resemble greatly  
some  of the more fissile shales in the 
,carboniferous system1 which were1      
perhaps1 formed by as slow a process1   
and in their aggregate depth  probably  
took many thousand years to accumulate4 
,but those fluviatile  depositions of   
the ,nile vary little in kind1 for when 

cut through they  are found regularly   
stratified down to their base1 which    
rests upon the  great underlying sand4  
,they show us how the argillaceous seams
 of the  coal-measures may have         
originated2 but the diversity of        
character in  these ,carboniferous rocks
 indicates a more varied kind of        
sediment1 and  probably more rapid and  
active transporting currents4 ,a closer 
analogy  to such a condition of things  
meets us on the shores of the ,new      
,world4    ,footnote #fh3 ,lyell's      
,principles1 p4 #bfb4    ,the           
,mississippi1 so magnificent in all its 
proportions1 has raised  a delta which  
covers a tract of about #ad1jjj square  
miles1 equal to  almost half the area of
 ,ireland4 ,the lower parts of this     
delta are  formed of low1 shifting      
banks1 traversed by innumerable streams 
that  diverge from the main river1 and  
alternately throw down and remove vast  
quantities of earthy sediment1          
intermingled with rafts of drift-wood4  

,these swamps are covered with a rank   
growth of long grass and reeds1  and for
 about six months of the year are more  
or less submerged below  the waters of  
the river1 while liable at the same time
 to continual  inundation and           
encroachment from the sea4 ,the higher  
parts of the  delta1 though also subject
 to a similar periodical submergence1   
nourish a more luxuriant vegetation4    
,vast tracts of level sandy soil  are   
densely overgrown with pine1 which is   
used extensively for making  pitch4     
,large districts of the swampy ground   
are covered with willows1  poplars1 and 
thickets of the deciduous cypress1 an   
elegant tree that  rises more than #ajj 
feet above the soil4 ,when in hot       
seasons these  swamps get dried up1 pits
 are burnt into the ground many feet    
deep1  or as far down as the fire can   
descend without meeting with water1  and
 it is then found that scarcely any     
residuum or earthy matter is  left4 ,at 
the bottom of all these 'cypress swamps'

 a bed of clay is  found1 with roots of 
the tall cypress1 just as the underclays
 of the  coal are filled with           
stigmaria4#fi ,in this way a thick      
accumulation  of vegetable matter goes  
on forming for years1 until either the  
river  changes its course1 and          
inundating the swamp gradually covers it
 over  with sand and mud1 or until1     
owing to oscillations of the earth's    
crust1 the district is either           
permanently submerged1 so as to be      
silted  over1 or elevated to nourish a  
new and different kind of vegetation4   
,footnote #fi3 ,lyell's ,elements1 p4   
#chf4    ,that such changes have taken  
place in the past history of the river  
we  have several interesting proofs4    
,thus1 owing to the great earthquakes   
of #ahaa1 #ahab1 an area of more than   
#bjjj square miles was permanently      
submerged4#gj ,since then it has gone   
under the name of the ,sunk  ,country2  
and ,sir ,charles ,lyell1 who visited   
the locality in #ahdf1 that  is1        

thirty-four years afterwards1 tells us  
that he saw innumerable  submerged      
trees1 some erect1 others prostrate4    
,now1 it is easy to see  how such an    
area may1 when the climate suits1 become
 the receptacle of  vast accumulations  
of peat1 which1 by pressure and chemical
 action1  will ultimately pass into     
coal4 ,if we suppose the submergence    
carried  on more rapidly at some        
periods1 the plants might have been     
unable to  keep pace with the           
ever-increasing inroads of sand and mud4
 ,in such  cases the layer of vegetation
 would become eventually entombed       
beneath  succeeding deposits of earthy  
matter4 ,were the amount of sediment    
thus  thrown down sufficient in the end 
to counteract the downward motion of    
the earth's crust1 and so raise the     
bottom of the river or lake to the      
level of the water1 vegetation would    
spring up afresh and clothe the  new    
raised surface as densely as in former  
years4 ,this alternation1  according as 

the amount of sinking or the amount of  
sediment  predominated1 might go on for 
thousands of years1 until a series of   
strata many thousand feet thick were    
accumulated1 and tranquilly  carried    
down bed after bed below the level of   
the waters4    ,footnote #gj3 ,see ,sir 
,charles ,lyell's ,second ,visit to     
,united ,stales1  chap1 xxxiii4    ,it  
is interesting to know that the case    
supposed here has actually  been        
realized in the delta of the ,ganges4   
,some years ago an ,artesian  well was  
attempted to be made near ,calcutta1 and
 the auger was sunk  to a depth of #dha 
feet4#ga ,the material passed through   
consisted of  sand1 clay1 and nodules of
 argillaceous limestone1 and at various 
depths1 from #ej to #chj feet1 several  
seams of decaying wood and peat  were   
found1 along with bones of various      
animals1 such as deer and  fresh-water  
tortoises1 and fragments of lacustrine  
shells4 ,each of  these vegetable layers
 evidently formed at one time a         

forest-covered  swamp like those of the 
surrounding delta at the present day2   
and  hence it follows1 that during the  
accumulation of the ,gangetic delta1    
the ground in that locality must have   
undergone a depression of more  than    
#cjj feet1 and that this sinking has    
been interrupted by slight  elevations1 
or by periods when the ground remained  
stationary1 so as  to admit of a dense  
and prolonged growth of vegetation1 at  
successive  intervals1 upon the swampy  
flats and shifting islands4 ,the general
  appearance of these old forests is    
pretty well shown by the mangrove       
swamps along the mouths of the river4   
,these trees flourish in dense  jungles 
on the banks1 and extend even below high
 water mark1 being  covered in places by
 shell fish4 ,so that were these        
maritime parts  of the delta inundated  
by the ocean1 and buried beneath a mass 
of mud  and silt1 the peaty layer that  
would be formed would display trunks of 
trees still occupying their original    

erect position1 and spreading out  their
 roots in the clay below1 exactly as the
 sigillaria is found to do  in the      
coal-seams of the carboniferous rocks1  
while clustered round the  carbonized   
stems1 or scattered among the decayed   
leaves and branches1  there might be    
detected limpets and barnacles 7as      
lingul and pectens  occur in the        
coal-seams71 showing1 by their mode of  
occurrence1 that  they lived and died   
upon the spot4    ,footnote #ga3 ,see   
,lyell's ,principles1 p4 #bhj4    ,if my
 reader will now suppose this sand of   
the ,indian river to be  hardened into  
sandstone1 the mud in like manner       
compressed into  shale1 and the peat    
beds chemically altered into coal1 can  
he fail to  perceive the striking       
analogy between the section thus        
displayed and  those already given from 
the ,mid-,lothian and ,cape ,breton     
coal-fields8  ,the differences between  
the ancient and modern strata are not in
 kind  but in degree4 ,the ,scottish    

series reaches to more than six times   
the  thickness of the ,indian one1 and  
the coal-seams in the one exceed in     
individual thickness the peat-beds in   
the other4 ,we must remember1  however1 
that the climate of ,hindustan is not   
remarkably favourable to  the           
accumulation of vegetable matter1 the   
heat being so great that the  plants    
decay almost as rapidly as they grow4   
,and it should likewise  be borne in    
mind1 that were the conditions of       
subsidence and of the  gradual          
accumulation of sedimentary matter to   
continue even in the same  ratio as     
heretofore1 the ,ganges might1 in the   
course of ages1 heap up  a series of    
stratified sands1 clays1 and peat-beds1 
many thousand feet  in thickness1 and   
many thousand square miles in extent1   
rivalling1  or perhaps surpassing in    
depth1 the largest coal-field in the    
world4  ,the parallelism between this   
delta and an ordinary coal-field holds  
singularly close1 not merely as regards 

the nature of the stratified  deposits4 
,the alluvial plain of ,bengal has      
undergone a process of  subsidence to an
 unknown depth1 whereby successive areas
 of terrestrial  vegetation have been   
carried down to be entombed beneath     
fluviatile  sand and mud4 ,it is        
likewise subject to the more sudden     
operation  of earthquakes1 whereby large
 tracts of country become permanently   
altered1 and changes are effected on the
 direction1 rapidity1 and  detritus of  
the streams4 ,it is1 moreover1 liable to
 wide-spread  inroads of the sea1 which 
sometimes covers cultivated districts to
  a depth of several feet1 laying waste 
the fields and destroying the           
inhabitants4 ,these and other features  
help us to understand the origin  of    
such vast masses of sedimentary strata  
as those of our coal-fields1  where     
terrestrial1 fluviatile1 and marine     
remains alternate in rapid  sequence1 or
 sometimes occur together4    ,the      
origin of the constant succession of    

coal seams1 sandstones1 and  shales1 of 
the ,edge series may be thus accounted  
for4 ,the area of  ,mid-,lothian formed 
part of a great delta1 which1 like that 
of the  ,ganges1 was undergoing a       
gradual subsidence during the           
,carboniferous  era4 ,the rate of this  
movement probably varied at different   
times1 and  might even be occasionally  
interrupted by short periods of         
elevation4  ,when the ever-increasing   
accumulations of silt brought down by   
the  river reached or nearly reached the
 surface of the water1 they would       
become the site of wide tracts of swampy
 vegetation that flourished  for        
hundreds or thousands of years4         
,eventually1 however1 these  jungles1   
invaded by the changing currents of the 
river1 were buried  beneath a thick     
deposit of fluviatile sediment1 or more 
probably the  vegetation might become   
unable to keep pace with an accelerated 
rate  of submergence1 and the forests   
would then be tranquilly carried  down  

beneath the water1 and soon covered over
 with sand and mud4 ,the  detrital      
matter might in like manner continue to 
be deposited over the  sunk forest for  
many years1 perhaps centuries1 until the
 muddy bottom  again reached the        
surface1 and once more waved green with 
sigillari1  calamites1 and lepidodendra4
 ,another long interval might here      
elapse1  in which a thick bed of        
vegetable matter might accumulate1 much 
after  the manner of the formation of   
peat among the bogs and mosses of our   
own country4 ,the periodical inundations
 of the river probably gave  rise to    
wide marshes and lagoons1 often tenanted
 by lacustrine shells1  and thickly     
overgrown with aquatic vegetation4 ,the 
decaying plants  decomposed the red     
ochreous matter with which the water was
 charged1  and re-deposited it among the
 mud and rotting leaves at the bottom as
  a carbonate of iron4 ,such ferruginous
 accumulations1 often entombing         
fern-stems and other plants1 with scales

 and teeth of ganoidal fishes1          
sometimes conulari and lingul1 and1 in  
certain localities1 whole  acres and    
miles of fresh-water shells1 are known  
now as our clay-band  and black-band    
ironstones4 ,we can easily conceive     
that1 in shallower  parts of the        
lagoons1 a dense growth of marshy plants
 might spring  up1 preventing any       
deposition of iron1 and when the whole  
came to be  covered over with later     
accumulations of sand or mud1 the deeper
 parts  of the old lake would be covered
 with a seam of ironstone1 and the      
shallower portions would display a bed  
of coal4 ,in some such way we  may      
account for the frequent passage of     
ironstone into coal1 and coal  into     
ironstone in many of our coal-fields4   
,if undisturbed by the ever  changing   
currents of the river1 these wide       
expanses of marsh and lake  might       
continue for many long years1 the       
constant evaporation being              
counterbalanced by continual supplies of

 water from the main stream4            
,eventually1 however1 owing perhaps to  
another period of more rapid            
submergence1 the water gained the       
ascendency1 and once more rolled over   
prostrate stems and matted thickets of  
ferns1 that sank slowly down  beneath a 
deepening sheet of sand and mud4 ,often1
 too1 the sea must  have flooded1       
perhaps for years1 the flat delta-lands1
 carrying with it  its own productions1 
such as the lingul and cardini1 which we
 find  among the coal seams4 ,and thus  
the process went on during the long ages
  of the ,carboniferous system4 ,forest 
after forest spread its continuous      
mantle of green athwart the low swampy  
lands of that old delta1 and  each in   
succession foundered amid the muddy     
waters1 now of the ocean  and now of the
 river1 that strewed over its site a    
rich detritus which  went to form the   
soil of new jungles and forests4    ,the
 ,edge series measures from #hjj to #ijj
 feet in depth1 so that the  depression 

must have been carried on till the      
forest that once grew  nearly on the    
sea-level had sunk #hjj feet below it   
,this process was  undoubtedly a very   
slow and tranquil one4 ,yet geologists  
used to regard  these frequent changes  
of sedimentary matter as so many proofs 
of  repeated catastrophic submergences1 
when the ocean came rolling over  the   
land1 prostrating forests1 uprooting the
 hugest trees1 and leaving  the         
scattered bones and scales of fishes    
amid vast accumulations of mud  and     
sand1 where but lately there had bloomed
 a luxuriant vegetation4  ,but the sober
 and diligent student of geologic fact  
will read in these  rocks no such record
 of cataclysms4 ,he will see in them    
evidences of  the same gradual and sure 
operation which marks the processes of  
,nature  at the present day4 ,he will   
note how during a tranquil and probably 
imperceptible submergence of the        
river-bottom1 forest after forest       
sprang up1 flourished perhaps for ages1 

and eventually settled down  beneath the
 waters of the river and sometimes of   
the ocean1 amid ever  increasing        
accumulations of mud and sand4 ,musing  
on these ancient  changes he will be    
lost in wonder at the immense duration  
of the period  during which they were in
 progress2 and he will try in some      
measure  to realize the features of     
their scenery4 ,he will picture the     
delta  with its ever-varying islets and 
sand-banks1 its lakes and submerged     
forests1 its leafless trunks peering    
above the water and sticking along  the 
shoaling mud1 and its crowded jungles   
that cover every drier spot4  ,he will  
cast his eyes to where the delta opens  
out into the ocean1 and  mark how the   
waves encroach upon the mud-banks1      
cutting away what the  river has piled  
up1 and washing the roots of gigantic   
trees that wave  their green coronal of 
fronds above1 and overshadow the        
rippling of  the green sea below4 ,he   
will try to thread the windings of the  

stately  river through brakes of ferns  
and calamites1 and banks richly hung    
with tree-ferns and sigillari1 and then 
upward through dark shaggy  pine-woods1 
silent and gloomy1 with the water       
creeping lazily through  the shade or   
dashing in white cascades over dripping 
rocks1 and onward  still1 far away among
 the distant hills till the fountainhead
 of the  great stream is reached1       
gushing from the splintered sides of    
some  lone rock1 or pouring perchance   
out of the glimmering caverns of some   
massive glacier high amid the regions of
 perpetual snow4    ,many attempts have 
been made to estimate the amount of time
 which  some of our coal-fields may have
 required for their accumulation4  ,but 
so large a number of conjectural        
elements must necessarily enter  into   
such calculations1 that the results come
 to be of very doubtful  value4 ,by     
estimating the amount of sediment       
annually transported by  such rivers as 
the ,ganges or ,mississippi1 we may     

ascertain how long a  mass of similar   
sedimentary strata would take to form   
under similar  conditions4 ,and if our  
calculation had to do merely with such  
detrital  accumulations1 we might hope  
to arrive at some approach to accuracy4 
,but besides these sedimentary strata1  
the formation of which must have  been  
wholly analogous to that of similar     
deposits at the present day1  we have to
 deal with the problems suggested by the
 coal-seams4 ,we know  nothing of the   
climate of the ,carboniferous period    
save what may be  conjectured from the  
analogy of existing climates2 and in a  
question  regarding the accumulation of 
decaying vegetable matter climate is a  
subject of the first importance4 ,we are
 ignorant1 too1 of the rate of  growth  
peculiar to the carboniferous flora2 and
 even if we hold that  it was probably  
rapid1 the process of decay may have    
been equally  speedy1 and so a forest   
might go on shooting up fresh trees as  
the old  ones rotted away1 yet at the   

end of a thousand years there might be a
  scarcely greater thickness of         
vegetable matter on the ground than at  
the commencement4 ,a seam of coal two   
feet thick might thus represent1  say   
the accumulation of a hundred years1 and
 another of exactly the  same thickness 
might stand as the accumulation of a    
thousand years4  ,until we know more of 
the vegetation and climate of the coal  
period1  the thickness of a coal-seam   
can hardly be held as a certain guide to
  the lapse of time required for its    
formation4    ,for the sake of          
illustration1 let me take the following 
fragment of a  coal-measure section3--  
,shale1      #bj feet4    ,coal1        
#d       ,fire-clay1   #f               
,sandstone1  #dj       ,beginning at the
 bottom1 we may compute the period of   
the forty feet  of sandstone variously1 
according to the river selected as the  
type  of a transporting agent4 ,tried by
 the standard of the ,nile1 all other   
conditions being similar1 such a deposit

 would require perhaps not  less than   
#ad1jjj years2 by that of the           
,mississippi1 #ejjj2 and by that  of the
 ,ganges1 nearly #bjjj4gb ,we come1     
then1 to the superincumbent  fire-clay  
and coal1 representing an ancient soil  
and the forest that  grew on it4 ,the   
occurrence of these seams shows us that 
the river-bed  had become a swampy tract
 clothed with vegetation2 but who shall 
say how long it may have continued so8  
,like the sunk country of the           
,mississippi1 it may have been          
submerged1 and to some extent cut off   
from the sediment-transporting channels 
of the river1 and thus1 as  a vast lake1
 have nourished a prolific growth of    
marshy and aquatic  plants4 ,if the     
temperature resembled that of our own   
country1 the  growth of peaty matter1   
other circumstances being favourable1   
might  be comparatively rapid4 ,if1     
however1 as seems probable1 the climate 
were more warm and humid1 giving rise to
 a more luxuriant vegetation1  and at   

the same time to a more rapid decay1 a  
long interval might have  elapsed       
without adding materially to the        
thickness of the vegetable              
accumulations1 and the eventual         
entombment of peaty matter sufficient   
to consolidate into four feet of coal1  
might be owing in some measure  to the  
submergence of the swamp beneath the    
waters of the river1  whereby a quantity
 of detrital matter was deposited that  
arrested the  process of putrefaction1  
and entombed the thickly matted plants  
which  were growing on the spot at the  
time4 ,hence1 until we know more of  the
 conditions under which vegetation may  
accumulate at river-mouths  in such a   
climate as the coal plants are          
conjectured to have enjoyed1            
calculations of the amount of time      
required for the formation of a  great  
series of coal-bearing strata must be   
regarded as premature4  ,in the present 
instance1 we can but affirm that the    
growth of the  four-foot coal-seam      

probably occupied many long years1 even 
at the most  rapid rate of accumulation 
known to us4 ,the forest-covered swamp  
on  which the plants grew was eventually
 invaded by muddy detritus brought  down
 by the river2 and during another period
 of indefinite extent--five  hundred    
years or five thousand years--fine mud  
continued to settle down  over the      
foundered forest1 hardening eventually  
into twenty feet of  shale4    ,footnote
 #gb3 ,some observers have pointed to   
the occurrence of vertical  and inclined
 trunks of trees in the ,carboniferous  
sandstones1 and  deduced therefrom what 
has seemed to them a triumphant argument
 in  favour of the rapidity wherewith   
our coal-fields must have formed4 ,a    
foundered tree1 they say1 sank with its 
heavy-laden roots among the  sand at the
 bottom1 its stem pointing up into the  
water like the snags  of the            
,mississippi1 so that the sand must have
 come rapidly down to  entomb the whole 
before it had time to decay1 and thus   

thirty or forty  feet of sediment must  
have been deposited in a few years1     
perhaps even  months4 ,but this is      
somewhat like a begging of the question4
 ,we have  yet to learn how long a      
water-logged trunk will resist          
decomposition4    ,the ,edge coals of   
the ,mid-,lothian coal-field are        
succeeded by a group  of sandstones and 
thin shales1 with three or more seams of
 limestone4  ,this group of strata1     
which we may call the ,roslyn ,sandstone
 ,series1  reaches a thickness of from  
#abjj to #aejj feet1 and serves as a    
middle  zone to divide the ,edge coals  
below from the ,flat coals above4 ,it   
contains only a few thin laminations of 
coal1 and these chiefly at its  upper   
and under portions4 ,such a great       
intercalation of beds1 without          
coal-seams1 points1 we might readily    
conjecture1 to some change in the       
physical conditions of the ancient      
delta4 ,the nature of this change can   
be easily made out from an examination  

of the rocks1 and the reader  will see  
that here again we are indebted to      
fossil remains for the most  conclusive 
and satisfactory evidence of these old  
physical revolutions4    ,the absence of
 coal-seams suffices to indicate that   
during the  formation of the middle     
group that part of the delta occupying  
the  site of ,mid-,lothian was          
continually submerged1 and never rose to
 the  surface so as to allow a covering 
of vegetation to form upon it4#gc  ,the 
large beds of sandstone prove a         
continued transport and deposition  of  
detritus during undisturbed periods of  
considerable length4 ,the               
intercalations of shale1 pointing to    
local changes in the currents or  other 
modifying causes1 are usually of small  
thickness and extent1  while the        
sandstone beds sometimes attain a depth 
of #aej or #bjj feet1  and extend over  
wide areas of country4 ,so far these    
mechanical rocks  indicate the          
deposition of sand and mud under water1 

but whether at  river-mouth or          
sea-bottom is left uncertain4 ,from the 
fossil remains1  however1 we learn that 
the deposition took place in the sea1   
but at  no great distance from land2 in 
other words1 the area of ,mid-,lothian1 
which1 during the accumulation of the   
edge coals1 had been alternately        
clothed with vegetation and inundated by
 the river1 sank down many  fathoms1 so 
that the sea rolled over it and all its 
submerged forests4  ,the proof is       
two-fold1 first1 from the character of  
the organic remains  in the limestones2 
and second1 from that of those in the   
sandstones and  shales4    ,footnote    
#gc3 ,of course1 this deduction is      
founded1 as the reader  will notice1 on 
the assumption that we have now the     
series1 as it was  deposited1 and that  
no peaty swamp or forest was denuded    
away1 and its  site occupied by sand and
 silt4 ,but the assumption is rendered  
probable  from the conditions of        
formation indicated by the ,roslyn      

group4    ,in some of the streamlets    
that flow into the beautifully wooded   
vale  of the ,esk1 south of ,penicuik1  
these limestones can be well seen1  worn
 in the water-channel1 or crusted over  
with moss along the banks4  ,their      
organisms are singularly abundant1 and  
consist of cyathophylla1  encrinites1   
spirifers1 producti1 c41 all exclusively
 marine4 ,in a  picturesque brook that  
falls into the ,esk near a saw-mill in  
the  grounds of ,penicuik ,house1 ,i    
have seen the little cup-corals         
clustered  by dozens on the weathered   
rock1 showing their delicate striated   
wrinkles in high relief among the       
scattered valves of productus and       
innumerable joints of the stone-lily4   
,they were all well preserved1 and  in  
their grouping and general appearance   
differed in no respect from  similar    
organisms in the mountain limestone of  
,roman ,camp ,hill4 ,the  inference to  
be drawn from them must accordingly     
correspond with what  has been deduced  

from the mountain limestone fossils1    
viz41 that they  mark the site of a     
sea-bottom which remained free from mud 
and sand for  considerable periods1     
during each of which there abounded     
corals and  shells1 whose exuvi went to 
form several seams of limestone4 ,but   
that  this sea-bottom was at no period  
very far distant from land1 is proved   
by the drifted plants that occur in the 
sandstones and shales both  below and   
above1 and which often show so little   
trace of maceration1  that we can hardly
 believe they were carried far1 or      
floated for a long  while previous to   
being enveloped in the sand or mud at   
the bottom4 ,i  have never detected     
vegetable remains in the limestones     
themselves1 but  there seems no reason  
why they should not be found there4     
,one of the most remarkable and         
difficult phenomena presented by these  
limestones is their great persistency4  
,i have traced them over a  large part  
of ,mid-,lothian1 from the highly       

inclined beds at ,joppa to  the         
contorted and faulted strata near       
,carlops4 ,i have found them1  too1 in  
many parts of ,west-,lothian and        
,stirlingshire1 from the sea at         
,borrowstounness southwards into        
,lanarkshire4 ,they likewise occur in   
,fife1 and seem to sweep away through   
,lanark and ,ayrshire4 ,the area  in    
which ,i have found them cannot be much 
under #gjj square miles1  yet they are  
probably spread over a much greater     
extent of country4  ,throughout this    
region they appear to continue on the   
whole at pretty  much the same vertical 
distance from each other1 and average   
three or  four feet thick each4 ,they   
vary in number1 three being found in    
parts  of ,mid-,lothian1 in other parts 
only two4 ,throughout ,west-,lothian    
there  seem to be but two seams in the  
middle or moor-rock series1 and the     
same two seams are found passing over   
into ,perth near ,culross4 ,there  are  
differences1 too1 in the structure and  

composition of the seams1  one running  
sometimes as a single bed of dull blue  
limestone1 and  then gradually splitting
 up into three layers of a greyer and   
more  earthy texture1 with soft shale   
between them4 ,but making all these     
abatements1 the observer cannot fail to 
be struck with the general  regularity  
and continuity of these limestones4 ,and
 the fact becomes  all the more         
remarkable when we consider the great   
irregularity1 and  continual            
intercalations1 and repetitions of the  
strata1 both above and  below4 ,marine  
beds are usually persistent over large  
areas1 especially  where extensively    
developed4 ,as they decrease in         
thickness1 their  continuity for the    
most part lessens1 so that the rule is1 
on the  whole1 a safe one1 the thinner  
any particular stratum1 the less likely 
are we to trace it to a considerable    
distance4 ,yet1 not only are these      
,mid-,lothian limestones thin1 but they 
occur in regular sequence among  a set  

of continually alternating and very     
irregular beds1 and extend  over several
 hundred square miles of country4 ,and  
this1 too1 not in a  single seam1 but in
 two1 three1 or even more1 so that the  
difficulty of  accounting for such      
intercalations is proportionately       
increased4    ,we have seen above that  
the area of a delta is often partially  
submerged below the sea1 and that such  
changes may become of the most  marked  
kind where the country is liable to be  
depressed by earthquakes4  ,there can   
accordingly be no difficulty in         
understanding how the ancient           
carboniferous delta of ,mid-,lothian may
 have likewise subsided4 ,but the       
limestones are unmistakable evidence    
that not only was the area of  the delta
 submerged1 but that for a while no     
sediment was deposited  over it1 and    
hence marine animals peculiar to clear  
water flourished  so long and so        
abundantly as to form by their remains  
several beds of  limestone4 ,had these  

beds been merely local we might have    
regarded them  as having been deposited 
in lagoon-like portions of the delta1   
shut out  from the detrital matter of   
the river on the one side and open to   
the  sea on the other4 ,but their wide  
extent and nearly uniform thickness     
preclude such a supposition4 ,the       
following explanation appears to me  the
 most probable3--    ,after the series  
of the ,edge coals had been brought to a
 close1 the  coal-fields of ,scotland   
underwent a complete submergence below  
the sea4  ,this depression was probably 
very gradual1 yet more rapid than that  
long-continued one which had been going 
on during the earlier part of  the      
,carboniferous series1 and the          
consequence of this greater rapidity    
was to prevent the growth of stigmaria  
swamps or reedy jungles1 by  keeping the
 alluvial surface continually sunk to   
some depth below the  water4 ,the amount
 of subsidence until the deposition of  
the lowest  limestone may not have been 

great1 but even a slight depression     
would  tell vastly on an area of flat   
delta land4 ,mud banks would be brought 
down into the region of waves and       
surface-currents1 and speedily be       
spread out over the floor of the sea4   
,forest-covered islands would in  like  
manner be levelled down1 and their trees
 sent drifting seaward  or submerged    
amid the re-formed silt4 ,thus altered1 
the delta would  sink below the sea1 and
 the sediment borne down by the river   
would  be scattered out over the older  
deposits as a slowly-forming sheet4  ,by
 degrees this detrital matter must have 
been carried less and less  farther out 
to sea2 in other words1 the area of     
deposit or delta must  have crept       
gradually nearer to the land--a result  
owing partly to the  recession of the   
ancient coast-line1 and partly perhaps  
to a greater  amount of depression      
inland than at the coast1 which would of
 course  lessen the velocity of the     
streams and cause them to deposit their 

burden of sediment at higher levels than
 before4 ,the consequence  of this      
retreat of the delta from the sea would 
be to purify the  water over the site of
 the old swamps1 and render it fitted   
for the  habitation of corals1 molluscs1
 and other marine animals4 ,a medium    
thus  prepared would not be allowed to  
remain long untenanted1 and so we find  
that it came to be densely peopled with 
the organisms peculiar to such  a       
station4 ,stone-lilies1 cup-corals1     
net-like bryozoa1 molluscs of many      
kinds1 and large predatory fish1 swarmed
 in these old waters1 and their         
calcareous shells and skeletons are now 
broken up by the quarryman and  the     
collier as hard compact limestone4      
,after these animals had lived and died 
in successive generations1  perhaps for 
thousands of years1 the downward        
movement of the earth's  crust seems to 
have ceased for a while or to have      
become greatly less4  ,the effect of    
this would be just to reverse what had  

been previously  done1 especially if a  
slight elevatory movement took place4   
,the streams  would in such             
circumstances descend from the uplifted 
ground with  renewed velocity and       
transport their detritus to gradually   
increasing  distances4 ,the muddy and   
sandy sediment thus borne seawards would
  slowly silt over the coral-banks at   
the bottom1 and in conditions so        
ungenial the organisms would dwindle    
down and finally die out4 ,a great      
thickness of sand and mud would be      
spread out over their remains so  long  
as the currents from the land continued 
to carry sediment out to  sea1 and thus 
probably originated the sandstones and  
shales superposed  above the lowest     
limestone4    ,eventually the old steady
 downward movement returned1 and with it
 the  corals and stone-lilies4 ,the     
detritus again sank to the bottom much  
nearer the land1 forming great banks and
 shoals that choked up the  river-mouth4
 ,seaward the water regained its purity1

 and the bottom  once more swarmed with 
living things4 ,another lapse of many   
thousand  years may have here intervened
 during which the marine exuvi gathered 
into another seam of limestone1 until   
again the process of subsidence  either 
ceased for a time1 or what is perhaps   
more probable1 became  considerably     
feebler4 ,detrital matter began to creep
 seaward as  before1 and eventually     
entombed the corallines and crinoids to 
a great  depth4 ,the calcareous bed thus
 formed is the second limestone1 and the
  superincumbent silt-beds represent the
 sandstones and shales that rest  above 
it4    ,in some such way as this does   
the ,roslyn sandstone series appear to  
have originated4 ,i have indicated what 
seems to have been the main  features in
 the process1 but it was probably a very
 complex one4 ,there  may have been a   
great many oscillations of level of     
variable effects1  some of them raising 
the disturbed area to a much greater    
height at  one point than at another4   

,this inequality would of course produce
  marked effects along a low flat       
country such as that at the mouth of a  
great river4 ,new currents would be     
produced and the direction of old  ones 
changed2 great shoals and banks of silt 
would be worn down only  to be thrown up
 again at some new point1 where another 
oscillatory  movement would expose them 
afresh to destructive denudation4 ,the  
variations in the amount of elevation   
and depression would likewise  modify   
the transport of detritus to the sea1   
and give rise to a varied  and          
ever-changing sea-bottom4 ,in short1 the
 alternations and variations  must have 
been endless1 for to the ordinary       
multiplied interchanges of  a delta we  
must add those induced by a constant and
 unequal oscillation  of the earth's    
crust4    ,the ,roslyn sandstone series 
comes to a close1 and passing onward in 
ascending scale we meet with another    
great group of coal-bearing  strata4    
,they occupy the central area of the    

,mid-,lothian coal-field1  and from     
their gentle inclination as compared    
with the lower strata  that rise up from
 under them on either side of the basin1
 are known as  the ,flat ,coals4 ,their 
total thickness--that is to say1 all    
that has  escaped denudation--amounts to
 a thousand feet or more4 ,they consist 
chiefly of sandstones1 shales1          
ironstones1 and fire-clays1 with from   
twenty to twenty-five seams of coal1 of 
which sixteen are thick enough  to be   
worked4 ,their similarity to the ,edge  
coals below points to a  similarity in  
the conditions of formation4 ,the       
frequent alternations  of sandstone and 
shale show how the delta gradually      
pushed outwards  again and re-occupied  
its ancient site above the successive   
forests of  the ,edge series and the    
successive coral-beds of the ,roslyn    
group4 ,the  coal-seams indicate the    
further progress of the detrital        
accumulations1  and the eventual        
formation of vast swampy flats that     

nourished a rank  growth of stigmari1   
and tracts of drier ground waving with  
ferns1 and  shadowed by the spiky       
foliage of the club-moss and the broader
 fronds  of the tree-fern4    ,the ,flat
 coals are not succeeded by any other   
palozoic strata4 ,above  them stretches 
the drift already described3 sometimes  
in the form  of a stiff blue clay       
resting on a striated rock-surface2     
sometimes  as a coarse gravel containing
 fragments of all the rocks in the      
neighbourhood2 and sometimes as a fine  
white sand diagonally laminated1  and   
often showing dark partings of          
coal-fragments4 ,from the section  given
 above 7,fig4 #cb7 at p4 #aif1 the      
reader1 will see that as the  upper     
limit of the ,flat coals is formed by   
the drift1 a large part of  that series 
may have been borne away by denuding    
agencies4 ,had there  been even a seam  
of limestone above them1 it would have  
sufficed to  show their true thickness1 
for we should then have seen1 that how  

much soever had been removed in later   
times from above the limestone1  nothing
 had been removed from below it2 and so 
it would mark the true  original limit  
of the series4 ,we cannot now tell how  
much thicker the  upper part of the     
,mid-,lothian carboniferous system may  
have been4  ,probably1 during the long  
ages that intervened between palozoic   
and  post-tertiary times1 many hundred  
feet were borne away and carried to     
other sites1 there to grow up into new  
islands and continents1 clothed  with   
other types of verdure1 and peopled by  
other races of animals1 and  fitted to  
become1 in a long subsequent period1 the
 dwelling-place of  man4    ,in fine1   
the evidence of these ancient changes in
 the history of the  ,mid-,lothian      
coal-field is derived1 as we have seen1 
from two sets of  facts2 first1 those of
 a mechanical1 and1 second1 those of an 
organic  kind--the one class explaining 
and confirming the other4 ,beginning our
  investigation at the horizon of the   

,burdiehouse limestone1 we saw the      
curtain rise slowly from off a wide     
estuary1 in which there gambolled  large
 bone-covered fishes1 while huge        
pine-trees--branchless and bare1        
seed-cones1 fern-fronds1 and twigs of   
club-moss1 floated slowly away  out to  
sea4 ,the panorama moved on1 and brought
 before us the ocean-bed  of the ,roman 
,camp limestone1 with its groves of     
stone-lilies and  bunches of coral2 its 
tiny shells moored to the bottom1 or    
creeping  slowly athwart the limy floor1
 or spreading out their many arms1 and  
rising or sinking at will4 ,this picture
 passed slowly away1 and then  came the 
delta of the ,edge coals1 with its      
sand-banks and ever-shifting  currents1 
its stigmaria swamps1 and its           
forest-covered islets4 ,we saw  the     
delta gradually sink beneath the sea1   
and corals and stone-lilies  cluster    
thick over its submerged area1 to form  
the limestones of the  ,roslyn group4   
,again1 the mud-bars of the river crept 

out to sea1 and  tangled forests waved  
green as of old1 washed by the sea or   
inundated  by the river4 ,how this last 
period came to a close1 we shall        
probably  never know1 and have no       
possible means of conjecturing4 ,we pass
 at one  step from the ancient era of   
the coal to the comparatively modern one
  of the drift--from a verdant palozoic 
land1 to an icy post-tertiary  sea4 ,it 
is like a leap in history from the days 
of ,pericles and ,aspasia  to those of  
,king ,otho1 or from the tents of       
,runnymede to the ,crystal  ,palace of  
,sydenham4          ,,chapter ,,xii4    
,trap-pebbles of the boulder--,thickness
 of the earth's crust                   
unknown--,not of much consequence to the
 practical         geologist--,interior 
of the earth in a highly heated         
condition--,proofs of this--,granite and
 hypogene         rocks--,trap-rocks2   
their identity with lavas and           
ashes--,scenery of a trappean           
country--,subdivisions of         the   

trap-rocks--,intrusive                  
traps--,trap-dykes-intrusive            
sheets--,salisbury ,crags--,traps of the
 neighbourhood of                       
,edinburgh--,amorphous                  
masses--,contemporaneous trap-rocks of  
two kinds--,contemporaneous melted      
rocks--,tests for their age         and 
origin--,examples from neighbourhood of 
,edinburgh--,tufas         or volcanic  
ashes--,their structure and             
origin--,example         of             
contemporaneous trap-rocks--,mode of    
interpreting         them--,volcanoes of
 ,carboniferous times--,conclusion4     
,in the previous pages1 allusion has    
been made to the trap-pebbles  imbedded 
in the boulder1 to the various forms of 
decay exhibited by  granitic and        
trappean rocks1 and to the elevation and
 depression of the  solid crust of the  
earth4 ,will the reader bear with me for
 but a few  pages more1 while ,i seek to
 indicate one or two points of interest 
in  a branch of geology that would      

abundantly reward a diligent observer8  
,since the days of ,hutton1 the         
investigation of what are called        
igneous rocks has fallen somewhat into  
the background1 and geologists  have    
given themselves1 perhaps too           
exclusively1 to the study of organic    
remains1 so that while the palontology  
of the ,british islands has  enjoyed an 
extensive exploration1 but little has   
been done towards the  elucidation of   
our igneous formations and their        
accompanying phenomena4  ,much remains  
to be accomplished1 even in those       
districts usually  regarded as in a     
manner thread-bare1 and he must be but  
an indifferent  observer who cannot add 
a few gleanings to the general stock of 
information upon this branch of ,british
 geology4    ,many conjectures have been
 formed1 and many theories propounded1  
as  to the nature of the internal parts 
of our globe4 ,some have supposed  that 
there is an outer solid film or crust1  
some ten or twenty miles  thick1        

enveloping a vast ball of intensely     
heated matter2 others have  attempted to
 show that the interior must be nearly  
solid throughout1  with1 however1 great 
lakes1 or vesicles of gas and melted    
rock1  somewhat after the fashion1 we   
may suppose1 of the oil-holes in a      
,gruyre cheese4 ,but whether the heated 
material occupy the whole or  only parts
 of the internal area1 is not of much   
consequence to the  practical geologist2
 he is content to believe that it       
exists1 and in  sufficient quantity1    
too1 to produce the most momentous      
changes on  the surface of the earth4   
,we see the effects of this             
subterraneous  agent in earthquakes and 
volcanoes1 and the geologist can tell us
  of similar1 as well as of other       
changes1 effected by it during past     
ages4 ,granite hills1 and mountainous   
districts of mica-slate and  gneiss1    
bear evidence of what is termed         
metamorphism--a change in  the mineral  
structure of rocks1 believed to have    

taken place through  the agency of heat 
deep in the interior of the earth2 for  
no analogous  appearances have been     
detected in progress at the surface4    
,such rocks1  known as metamorphic1 or  
hypogene1 still form a difficult        
problem1  not likely to be              
satisfactorily solved until the chemist 
shall have  thoroughly investigated the 
subject2 for it seems likely to be      
found1  after all1 that long-continued  
chemical action1 without a very alarming
  degree of heat1 may have produced even
 the most intense metamorphism4  ,but   
dropping this part of the subject1 in   
which so much yet remains  to be        
discovered1 let us look for a little at 
another branch of the  geologist's      
evidence1 where we meet with no such    
hampering hypotheses  and doubtful      
conjectures1 namely1 the trap-rocks4    
,every one knows that basalt1 lava1     
pumice1 scori1 and ashes1 are  the      
various matters ejected from volcanoes4 
,when these materials are  found        

interstratified among the various       
geological formations1 they  are termed 
trap-rocks1--a name derived from the    
,swedish trappa1 a  stair1 in allusion  
to the step-like or terraced appearance 
which they  often present4 ,they are of 
all ages1 having been detected in the   
lower  ,silurians of ,wales1 and in the 
deposits of all subsequent periods up   
to the volcanic eruptions of the present
 day2 thus evidencing1 that  from the   
remotest times there have been tnas and 
,vesuvii slumbering  perhaps for ages1  
and then awakening to lay the           
surrounding districts  in ruins4 ,i have
 already said that the rocks from which 
the geologist  has to compile his       
history1 are mostly relics of the sea2  
hence most of  the trap-rocks which he  
meets with in his explorations are the  
products  of submarine eruptions4 ,far  
away down among the ,silurian rocks1 he 
can  trace the floor of a primeval ocean
 thickly covered with stone-lilies1     
trilobites1 and molluscs1 and in        

following it out he marks how ashes  and
 lapilli1 ejected from some submarine   
orifice1 settled down amid the          
organisms and well-nigh destroyed them1 
while at other times streams of  molten 
matter were poured out along the        
sea-bottom1 and hardened into  masses of
 solid rock4 ,he sometimes even         
encounters what seems the vent  whence  
these eruptions proceeded1 filled up now
 by a boss or plug of  hardened trap1   
but he never can detect any trace of    
land4 ,some of these  oceanic volcanoes 
may1 like ,graham's ,island in the      
,mediterranean1 have  raised their tops 
above water1 sending clouds of steam and
 cinders far  and wide through the air1 
but the waves would eventually wear down
 the  new-born land1 and scatter its    
broken fragments along the floor of the 
sea4 ,among the carboniferous rocks of  
,scotland1 however1 we meet with a      
different condition of things4 ,there1  
too1 we can trace out submarine         
lava-streams1 and mark how showers of   

ashes destroyed the delicate  organisms 
of the deep2 but we encounter1 besides1 
undoubted traces  of a land1 not parched
 and ruinous as though the igneous      
forces had  laid it waste for ever1 but 
thickly clothed with vegetation of a    
more  luxuriant type than that which    
clusters over ,vesuvius and ,calabria1  
or  lies spread out across the level    
plains of fruit-teeming ,sicily4#gd  ,we
 have looked at the plants and animals  
of the ,carboniferous era2 its  rivers  
and deltas2 its slow elevations and     
depressions of the ground4  ,it may1    
perhaps1 complete the picture of that   
ancient period1 if we  examine1 though  
but briefly1 its igneous eruptions1 the 
more especially  since these may be     
regarded as1 to a considerable extent1  
typical of  trap-rocks belonging to     
every age and every country4            
,footnote #gd3     4 sch4 ,prom4        
,vinct4 #cfi--;a passage graphically    
descriptive of an ancient eruption  of  
tna4    ,unless when deeply buried      

beneath drift-sand and clay1 trappean   
regions  usually possess scenery of a   
marked kind4 ,a green undulating country
  stretches out as far as the eye can   
reach1 diversified here and there  with 
bold abrupt crags and conical hills4    
,the lower grounds show in the  winter  
season their rich brown loam1 that waxes
 green as the spring  comes on1 and ere 
summer's close spreads out its heavy    
crops of golden  grain4 ,the higher     
ridges are for the most part thickly    
wooded1 yet  the soil is often scanty1  
and1 among the white stems of the beech1
 or  the matted roots of the fir and the
 elm1 we may not unfrequently see  the  
rock protruding its lichen-crusted face1
 mottled with mosses and  liverworts1   
while some sluggish runnel collects in  
stagnant pools1  or trickles over the   
blocks with a thick green scum4         
,sometimes the  hill has never been     
planted1 but stands up now1 as it has   
done for  centuries2 its western face   
craggy and precipitous1 with bushes of  

sloe-thorn and furze1 and stray saplings
 of mountain-ash clinging to  the       
crevices1 while its eastern slope sinks 
down into the rolling  country around   
with a green lumpy surface1 through     
which1 at many a  point1 the grey       
time-stained rock may be seen4 ,the     
whole district  suggests to the fancy a 
billowy sea1 and1 as one casts his eye  
from  some commanding hill-top athwart  
the wide expanse of hill and valley1    
sweeping away in endless undulations1 he
 is apt to bethink him of  some day far 
back in the past1 when the verdant      
landscape around lay  barren and        
desolate1 while the solid earth rocked  
and heaved in vast  ground-swells like a
 wide tempested ocean4 ,such is the     
aspect presented  by some of the more   
trappean regions of ,scotland4 ,but the 
origin of  this kind of scenery must be 
ascribed to the effects of denuding     
currents in scooping out the softer     
strata into clefts and valleys1 and     
leaving the harder trap-rocks in        

prominent relief1 rather than to any    
great inequality of surface produced by 
the eruption of igneous matter2  for we 
shall find that the throwing out of     
sheets of lava and showers  of volcanic 
ashes was often a very quiet process    
after all4    ,trap-rocks generally may 
be variously classified according to the
  aspect under which we view them4      
,mineralogically they are augitic1  when
 the mineral augite enters largely into 
their composition2  hornblendic1 when   
the augite is replaced by hornblende2   
and  felspathic1 where felspar forms the
 most marked constituent4  ,the first   
class includes all the dark homogeneous 
compounds called  basalts2 the second1  
the hornblendic greenstones1 or         
diorites2  and the third1 the felstones1
 porphyries1 and tufas4  ,geologically1 
they are beds when they are             
interstratified with the  contiguous    
rocks2 and dykes or veins when they     
penetrate them like  walls1 or in an    
irregular manner4 ,the former class may 

be either of  the same age with the     
rocks among which they lie1 or of a     
later date1  just as in a pile of books 
the centre one may either have been     
placed  there originally with the rest1 
or thrust in long afterwards4 ,the      
latter class must always be later than  
the rocks which they traverse1  for it  
is plain the rocks must have been in    
existence before trap-dykes  and veins  
could be shot through them4 ,hence      
geologists are accustomed  to speak of  
contemporaneous and subsequent          
trap-rocks3 the one list  including all 
the tufas1 and those melted rocks which 
can be shown to  have been erupted      
during the time when the limestones1    
sandstones1 or  shales around them were 
forming2 the other embracing all the    
dykes and  veins along with those beds  
of melted rock which have been intruded 
between the strata4 ,these and other    
distinctions will be better  understood 
from a few examples collected chiefly   
from the carboniferous  district of     

central ,scotland4    ,the trap-rocks   
seen there exhibit a wide range of      
structure1 texture1  colour1 and general
 aspect4 ,there are two pretty marked   
kinds--the  augitic or hornblendic1 and 
the felspathic2 the former being usually
  of a more or less crystalline aspect2 
the latter1 commonly dull1 and  often   
without any crystals4#ge ,in the augitic
 traps1 the crystals  are sometimes of  
large size and well-defined1 so that the
 rock could  hardly be distinguished at 
first sight from an ordinary grey       
granite1  while at other times1 and not 
unfrequently even in other portions of  
the same mass1 the stone assumes a black
 appearance without distinct  crystals4 
,the former variety would be called a   
greenstone1 the  latter a basalt2 the   
chief components in either case being   
felspar  and hornblende1 or felspar and 
augite1 with a variable admixture  of   
other minerals1 the shade of colour     
varying from a pale blue or  leek-green1
 through the different hues of grey1 to 

a deep velvet black4  ,there are other  
traps1 however1 consisting entirely1 or 
nearly so1  of felspar1 whence they are 
known as felstones4 ,such rocks enjoy  a
 wide range of colour1 some of them     
being pure white1 others of a  bluish   
grey or dingy brown2 and they may be    
seen graduating from a  pale yellow1 or 
flesh-colour1 to a brick-red or deep    
purple4 ,when a  trap displays distinct 
disseminated crystals1 usually of       
felspar1 it  becomes a porphyry2 when it
 shows rounded cavities1 like those of  
furnace-slag1 it is said to be          
vesicular2 and when these globular or   
almond-shaped cavities are filled with  
carbonate of lime1 chalcedony1  or other
 minerals1 the rock forms an amygdaloid4
 ,such peculiarities  of structure      
indicate to some extent the origin of   
the mass1 and may  be found in any kind 
of trap4 ,thus we have porphyritic      
greenstones1  basalts1 or felstones1 and
 the same rocks may be likewise         
vesicular  or amygdaloidal4 ,some of    

them1 such as many greenstones1 display 
on  weathered surfaces that curious     
spheroidal structure already alluded    
to2 others are built up into geometric  
columns4    ,footnote #ge3 ,this        
distinction1 though a sufficiently safe 
one in  some localities1 must not be    
held as by any means universal in its   
application1 the felspathic traps being 
often as crystalline in aspect  as the  
augitic1 and the augitic1 on the other  
hand1 as dull as the  felspathic4       
,such peculiarities of composition and  
structure form the basis of  a          
mineralogical classification of the     
igneous rocks1 which is of  use in      
working out the geology of a district4  
,the most convenient  subdivision for   
our present purpose1 however1 is that   
which proceeds  upon the origin and mode
 of occurrence of the trap-rocks4       
,viewed  thus1 they resolve themselves  
into two great groups1 the intrusive    
and contemporaneous1 both of which      
contain greenstones1 basalts1  c41--the 

sole distinction between those of the   
one class and those of  the other1 being
 the relation of age and mode of        
occurrence which they  bear to the      
surrounding rocks4    ,i4 ,the intrusive
 traps occur in the form of walls and   
veins1  sometimes in that of flat       
parallel beds1 and often as huge        
amorphous  masses1 to which no definite 
name can be given4 ,but whatever shape  
they  may assume1 they generally agree  
in presenting well-marked features1     
whereby their origin can be readily     
ascertained4 ,the rocks through  which  
they pass are more or less hardened1    
often contorted1 and  sometimes         
traversed by innumerable cracks and     
rents1 into some of which  the trap has 
penetrated in the form of veins4    ,a  
trap-dyke is a long wall of igneous     
matter1 cutting more or less            
perpendicularly through the surrounding 
rocks4 ,sometimes these dykes  attain a 
breadth of many yards1 and may not      
unfrequently be traced for  miles       

running in a nearly straight line over  
hill and valley1 easily  recognisable by
 a long smooth ridge1 with the rock     
protruding here and  there from below   
where the soil is thin4 ,it is          
interesting to follow  out one of these 
long ramparts from its beginning to its 
close1 and  mark how undeviatingly it   
cuts through the rocks4 ,no matter what 
may  be the nature of the stone         
encountered1 hard conglomerate1 friable 
shale1 compact limestone1 or jointed    
fissile sandstone1 all are broken       
across1 and the right line preserved    
throughout4 ,nay1 ,i have seen a  still 
more curious instance of this           
persistency1 where the dyke ran for     
four miles through a set of mountain    
limestone and lower coal-measure        
strata1 and several enormous sheets of  
greenstone and basalt4 ,even  when      
passing through these traps the dyke    
remained perfectly distinct1  its       
crystalline structure and external      
configuration presenting a  well-marked 

contrast with those of the surrounding  
eminences4 ,of  course it must have been
 formed after all the rocks through     
which  it passed4 ,the sandstones and   
shales must have settled down long      
previously on some estuary bed or       
sea-bottom2 the corals and shells  of   
the limestones1 and the matted plants of
 the successive coal-seams  must have   
lived and died1 perhaps thousands or    
millions of years  before1 and their    
remains have hardened into stone1 ere   
the continuity  of the strata was broken
 across by the long deep wall of        
greenstone4  ,trap-dykes are accordingly
 appropriately termed intrusive4 ,they  
have been intruded among and must always
 be later than the rocks in  which they 
occur4 ,in tracing out their character1 
more especially in a  trappean district1
 such as that of ,linlithgowshire1 where
 they abound1  we soon find other       
evidence of their intrusive nature4     
,where they pass  through limestone1    
they sometimes convert it into a white  

saccharine  marble2 shales they bake    
into a sort of porcelain or burnt       
pottery2 and  sandstones become         
semi-fused into a hard homogeneous      
quartz-rock4 ,nor  are the changes      
confined to the rocks traversed2 the    
dykes themselves1  along their sides1   
become fine grained and hardened2       
occasionally1 too1  the colour alters   
from the usual bluish or greenish-grey  
to black1 or  to a brick-red1 or        
dull-brown1 similar to that of the      
altered shale  and sandstone1 of which  
detached portions may be found adhering 
to  the outer walls of the dyke1 or even
 embedded in its substance4  ,the       
central portion of the dyke may thus be 
markedly crystalline1  forming what we  
should call a greenstone1 while the     
outside parts1  where the trap comes in 
contact with the adjacent rocks1 are    
fine  grained and homogeneous1 so as to 
become a true basalt4 ,sometimes1  too1 
these exterior edges are highly         
vesicular and amygdaloidal1  detached   

fragments closely resembling the slag of
 an iron-furnace1 and  occasionally the 
dyke presents a columnar arrangement1   
the ends of  the hexagonal or polygonal 
columns abutting against the sandstone  
or  other rock on either side1 and      
losing themselves towards the centre in 
the general mass of the trap4 ,where the
 strata traversed are broken  and       
jointed1 the dykes which cut them       
through may be seen in some  places     
throwing out lateral veins that         
accommodate themselves to all  the      
irregularities of the fissures4 ,these  
minor portions exhibit for  the most    
part the same leading features with the 
parent mass1 and the  result of the     
whole is a general baking of the beds1  
with sometimes not  a little contortion1
 and an amount of irregularity and      
disturbance1  apparent at once to the   
most inexperienced observer4 7,see ,fig4
 #cd47    ,if the reader will verify    
these statements by actual exploration  
in  the field1 he will probably not be  

long in arriving at the following       
conclusions3 trap-dykes must once have  
been in a melted state1 as is  shown by 
their vesicular cavities and divergent  
veins2 this liquid  condition must have 
been attended with the most intense     
heat1 as may be  gathered from the burnt
 and baked appearance of the contiguous 
rocks2  they have1 for the most part1   
especially where of large size1 risen   
from below along previously-formed      
dislocations--a circumstance which  may 
be inferred from their persistency in a 
straight line through beds  of very     
different resisting power1 for had the  
liquid matter forced  a way for itself1 
it would have squirted between the beds 
along the  lines of least resistance1   
and not directly and for miles across   
them2  and hence1 trap-dykes must be    
regarded not as themselves the agents   
in dislocating and contorting a         
district1 but merely as signs of the    
parent force at work below4    ,all the 
features of these trap-dykes here stated

 may be observed in the  central        
district of ,scotland1 among rocks of   
,carboniferous age4 ,but he  who would  
study trap-dykes on the great scale     
without quitting ,britain1  should visit
 some of the more trappean islands of   
the ,hebrides4 ,he  will there find them
 intersecting glen and hill-side1 in an 
intricate  network1 standing up through 
the heather like ruined walls1 and      
running  often for considerable         
distances up bald cliff-line1 and across
  precipitous ravine4 ,in some          
localities1 among such limestone        
districts  as that of ,strath1 detached 
eminences may be seen with congregated  
dykes coursing their sides and summits1 
while the heathy interspaces  are       
cumbered with grey and white protruding 
blocks of marble1 that give  to these   
green knolls the aspect of old          
time-wasted abbeys with their           
clustering tombstones4 ,the magnificent 
sections laid open in these  localities 
by the action of mountain streams1 and  

by the waves of the  ,atlantic1 leave   
the student of igneous rocks nothing to 
desire save a  long lease of leisure4   
,another form frequently assumed by the 
intrusive traps1 is that of  wide beds  
or sheets intercalated with greater or  
less regularity among  stratified rocks 
7,fig4 #cd b74 ,they may be regarded as 
horizontal  dykes1 the igneous matter1  
in place of cutting across the strata1  
having forced a way for itself between  
them4 ,viewed in this light they  will  
be found exactly to correspond with     
ordinary dykes2 the rocks on  which they
 rest1 and those which lie above them   
being both altered like  those on either
 side of a dyke or vein4 ,a well-known  
example of this  form of trap is that of
 ,salisbury ,crags1 where a bed of      
greenstone  twenty to eighty feet thick 
is intercalated among sandstones1       
shales1  and coarse limestones1         
belonging to the ,lower ,carboniferous  
series4 ,its  under surface presents a  
remarkably even line1 broken at         

intervals1  however1 where the truncated
 ends of sandstone beds protrude up     
into the greenstone1 or where the latter
 cuts into the sandstone  below1        
occasionally enveloping detached        
fragments1 and sending veins  through   
them4 ,along the line of contact both   
rocks undergo a change4  ,the greenstone
 becomes reddened1 finer grained1 and of
 a dull earthy  aspect4 ,the sandstones 
and shales are also red1 and excessively
 hard1  the former resembling a quartz  
rock1 and the latter passing into a sort
  of flinty chert or chalcedony4 ,the   
sandstones above the trap1 where  they  
can be examined1 are also found to      
present the same hardened1  baked       
appearance1 the most intense            
metamorphism being observable  in those 
parts which are completely surrounded by
 igneous matter4  ,these points were    
noted many years ago during the famous  
controversy  between the disciples of   
,hutton and ,werner1 the former viewing 
them  as demonstrative evidence of the  

igneous origin of the trap-rock1 the    
latter1 on the other hand1 professing to
 see nothing in the section  of the     
,crags at all militating against the    
theory that the rocks had  originated   
from deposition in water4 ,many a battle
 was fought in this  locality1 and not a
 few of the trap-dykes and hills possess
 to the  geologist a classic interest1  
from having been the examples whence    
some of the best established geological 
opinions were first deduced4  ,the      
contest between the ,huttonians and     
,wernerians terminated long ago  in the 
acknowledged victory of the former2     
,hutton's doctrines are now  recognised 
all over the world4 ,it is interesting1 
however1 to walk  over the scenes of the
 warfare1 and mark the very rocks among 
which it  raged1 and from the           
peculiarities of which it took its rise4
 ,basalts  and greenstones1 sandstones  
and shales1 with all their crumplings   
and  contortions1 still stand up as     
memorials of powerful igneous action1   

and of physical changes in the primeval 
past2 and they have become to  the      
geologist memorials1 too1 of changes in 
the onward progress of his  science1    
where1 out of conflicts perhaps yet more
 tumultuous than those  of ancient      
,nature1 there emerged at last the clear
 demonstrable truth4    ,illustration3  
,fig4 #cd4--;,intrusive ,trap4    ,in   
the accompanying section 7,fig4 #cd71   
the more marked characters of  intrusive
 traps are exhibited4 ,the main mass of 
igneous rock is the  dyke 7d71 rising   
through a dislocation or fault1 which   
has thrown  down the beds on one side   
several feet below those on the other1  
as  is shown by the interruption of the 
shale and ironstone beds 7sh74  ,the    
dyke gives off two ramifications1 one of
 them cutting across the  beds obliquely
 as a vein 7v72 the other passing along 
the planes  of the shaly layers as a    
horizontal bed 7b74 ,the vein1 it will  
be  noticed1 produces considerable      
alteration in its progress1 carrying up 

and baking a portion of the shale 7sh71 
and turning up the edges of  the beds on
 both sides1 which get cracked and      
hardened along the line  of contact4    
,the bed runs with some regularity for a
 short distance  through the shales1    
which show marks of great alteration at 
their  junction with the trap4 ,its     
under surface at one point is seen to   
have  involved a portion of the shale   
which has become in consequence highly  
metamorphosed1 while along the upper    
surface the bed has sent out a  short   
irregular vein that twists and otherwise
 alters the shales  above4 ,these       
circumstances would suffice to show that
 even though we  did not find this bed  
in connexion with a mass of intrusive   
trap1 it  must1 nevertheless1 have been 
thrust among previously-formed strata1  
and could not have been contemporaneous1
 that is1 poured out along the          
sea-bottom before the shales above it   
were deposited4    ,but one other form  
needs to be mentioned here as           

characteristic of the  ,carboniferous   
intrusive trap-rocks--that of great     
amorphous masses  which cut through the 
strata irregularly4 ,they have not the  
wall-like  form of dykes1 nor do they   
conform to the line of bedding of the   
rocks  among which they occur4 ,they are
 sometimes irregular lumps1 lying  above
 or among the strata1 and probably      
connected with some vein or  dyke below4
 ,in other localities they look like the
 upper ends of vast  pillars which may  
descend into the very depths of         
,tartarus1 as though a  great hole had  
been blown through the crust of the     
earth1 and a column  of melted matter   
had risen to fill the cavity4 ,such     
masses are often  called bosses1 and    
seem not unfrequently to have been the  
craters  of eruption whence great sheets
 of lava and showers of ashes were      
ejected far and wide over the           
neighbourhood4 ,they serve to connect   
the intrusive traps1 whose age is always
 more or less uncertain1 with  the      

bedded traps properly so called1 the    
geological date of which can  usually be
 sufficiently ascertained4    ,,ii4 ,the
 bedded or contemporaneous trap-rocks   
consist of two well-marked  kinds4      
,there are1 #ast1 the melted rocks1 such
 as greenstones and  basalts and #b;d1  
the tufas and volcanic ashes4    ,those 
of the first-named class differ in no   
respect from the traps  already noticed1
 so far as regards mineralogical        
texture1 general  structure1 and        
appearance4 ,in hand specimens the      
intrusive and bedded  greenstones and   
basalts cannot be distinguished1 nor    
even when examined  in the field and in 
masses extending over considerable areas
 is it  always possible to say to which 
division any particular hill or crag    
should be assigned4 ,the reason of this 
resemblance is obvious4 ,where a  trap  
has either cut through or insinuated    
itself among rocks of earlier  date it  
is called intrusive1 in relation to the 
rocks so traversed1  and of course we   

cannot be sure to what geological period
 it should be  referred1 nor how long an
 interval may have elapsed between the  
time  when these rocks were forming and 
the time when the trap was intruded     
among them4 ,if1 however1 the igneous   
rock passed upward through these  same  
strata and then spread out as a flat    
sheet along the sea-bottom1  the part   
that came to the top would be termed    
contemporaneous  with the deposits going
 on at the time4 ,hence it follows that 
all  contemporaneous lava-form          
trap-rocks are at the same time         
intrusive as  regards the strata passed 
through in their progress to the        
surface4 ,if  the sheet of melted matter
 that spread out below the water were in
 the  course of ages worn completely    
away1 along with the strata subsequently
  piled above it1 so as to leave merely 
a neck or dyke filling up the  cavity   
through which the lava rose1 we should  
pronounce the remnant  intrusive1 and   
could form no certain conclusion as to  

its age or  as to whether its site had  
ever been a crater actively at work in  
throwing out lava and ashes4 ,the sole  
difference1 therefore1 between a        
contemporaneous and an intrusive        
greenstone is simply this3 the former   
rose through a fissure until it reached 
the surface1 and then rolled  out as a  
flat parallel sheet2 the latter may have
 been erupted from  below at the same   
time1 yet1 owing to different           
circumstances1 never  reached the       
surface1 but spread out among or cut    
through the strata  underneath4 ,and so1
 when we come to examine in quarries1   
ravines1 and  other exposures1 the      
remains of two such eruptions1 we soon  
ascertain  the relative age of the      
former from that of the strata among    
which it  occurs1 but as to the date of 
the latter we are wholly at a loss1 for 
it gives us no clue by which we can show
 whether it was erupted before  or after
 the other4 ,we can but compare the     
mineralogical character  of the intruded

 with that of the contemporaneous masses
 in the same  district1 and1 from the   
resemblance which may be traced between 
them1  draw at the best but a doubtful  
inference as to their relative dates4   
,the contemporaneous traps always assume
 a bedded form1 the intrusive           
occasionally do so2 and the question    
naturally arises here1 what are  the    
tests whereby a bed of trap may be known
 to be contemporaneous and  not         
intrusive8 ,the answer is happily a     
simple one4 ,an intrusive mass  is found
 to alter to a greater or less extent   
the rocks in contact  with it2 if it    
occur as a dyke1 then the beds on either
 side have  been cut through and        
probably otherwise affected2 if it take 
the form  of a bed or sheet1 the strata 
lying above and below it will be found  
to be both altered1 showing evidently   
that a heated mass has been  interposed 
between them1 and consequently that the 
igneous rock is of  later date than any 
of the strata among which it occurs4 ,in

 the case  of a contemporaneous melted  
trap1 however1 the appearances presented
  are different2 it always takes the    
form of a flat bed corresponding  to all
 the inclinations and curvatures of the 
sandstones1 shales1  limestones1 or     
other strata among which it lies4 ,if   
examined carefully1  it may be found not
 unfrequently baking and contorting the 
bed that  forms its pavement1 but       
producing no change whatever on that    
which  composes its roof4 ,it may be    
capped and underlaid by layers of shale1
  and in such a case we might not       
improbably find the shale below it      
highly baked1 so as to resemble a sort  
of rude pottery1 while the shale  above 
would present no sign of such           
metamorphism1 but on the contrary  might
 display its delicate plants or shells  
down to the very surface  of the trap1  
and were the latter concealed from view 
we should never  suspect1 from the      
aspect of this shale1 that any igneous  
rock existed  in the neighbourhood4 ,the

 inference to be drawn from such        
appearances  seems very obvious4 ,had   
the upper shale been in existence when  
the  greenstone or basalt was erupted1  
it would have suffered an alteration    
similar to that produced on the shale   
below2 and the fact1 plain and          
palpable1 that it has undergone no such 
change1 shows pretty clearly  that it   
was deposited at the bottom of the water
 after the trap had  cooled and         
consolidated1 and that consequently the 
trap must be  intermediate in age       
between the beds on which it rests and  
those which  lie above it2 in other     
words1 that it is a contemporaneous     
rock4  ,hence1 if we know the exact     
geological position and age of the      
shales1  we know also those of the      
associated trap1 and can thus ascertain 
that at a certain definite period in the
 past history of our planet a           
particular district was the scene of    
volcanic action4    ,examples of such   
contemporaneous traps abound among the  

carboniferous  rocks of central         
,scotland1 especially in ,fife and the  
,lothians 7,fig4  #ce74 ,i may refer    
again to the vicinity of ,edinburgh as  
affording some  excellent illustrations4
 ,the eastern part of ,arthur's ,seat   
displays  a series of basalts and       
greenstones which can be proved to have 
been  thrown out during the times of the
 ,lower ,carboniferous rocks1 at a      
period long anterior to that of the     
,burdiehouse limestone4 ,the ,pentland  
,hills exhibit on a much greater scale  
vast sheets of felspathic traps1  such  
as felstones and tufas1 traceable in    
some cases for six or seven  miles1     
which were erupted at a still earlier   
period4#gf ,the trap  pebbles in our    
boulder consisted of light yellow and   
pink felstone1  and were derived1 ,i    
make no doubt1 from these ,pentland     
,hill beds1 when  what forms now the    
cone of ,carnethy1 rising well-nigh     
#aijj feet above  the sea1 existed as   
one of a scattered archipelago of       

islets1 or as a  sunken rock battered by
 the waves that scattered its shingle   
along the  floor of what may have been  
either a shallow sea or a shoaling      
estuary1  where eventually the sand and 
pebbles hardened into that bed of coarse
  grey sandstone whence our boulder was 
derived4    ,footnote #gf3 ,the geology 
of ,arthur's ,seat and ,pentland ,hills 
was  admirably worked out more than     
quarter of a century ago by ,mr4        
,m',laren4  ,his work 7already referred 
to7 is unfortunately now out of print4  
,the second class of contemporaneous    
trap-rocks are the tufas or  volcanic   
ashes4 ,they differ entirely in their   
aspect and origin from  any of the rocks
 already described4 ,greenstones1       
basalts1 felstones1  and such like1 were
 all melted rocks1 thrust up from below 
as we see  lava thrown out by a modern  
volcano1 being styled contemporaneous   
when  poured out along the sea-bottom or
 the land1 and intrusive when they      
never reached the surface but cut       

through the strata below4 ,the tufas1   
however1 point to a totally different   
origin4 ,they are of various  shades of 
colour1 according to their chemical     
composition4 ,in ,east  ,lothian they   
assume a deep red hue2 among the        
,pentland ,hills they  are often        
flesh-coloured1 while in                
,linlithgowshire they range from a      
dull-brown to a pale leek-green1 green  
being the prevailing tint4 ,they  always
 show a dull uncrystalline surface1     
irregularly roughened by  included      
fragments of various rocks1 such as     
trap1 sandstone1 shale1  and many       
others4 ,these fragments or lapilli vary
 in size from less  than a pin-head up  
to large bombs of several hundredweight1
 and from  being generally abundant give
 to the tufas one of their best-marked  
characteristics4 ,the smaller pieces are
 usually more or less angular1  and     
throughout the carboniferous series of  
,linlithgowshire consist  chiefly of a  
pale felspathic matter1 lighter in shade

 and commonly  harder in texture than   
the matrix or paste in which they lie4  
,in  some localities1 where the included
 pieces are larger1 they have a  rounded
 form1 and often show a honey-combed    
vesicular surface1 like  balls of       
hardened slag4 ,fragments of sandstone  
have not unfrequently  a semi-fused     
appearance1 and plates of shale         
sometimes look like the  broken debris  
from a tile-work1 although in many      
instances these  fragments may be found 
showing no trace whatever of alteration1
 being  undistinguishable from the      
neighbouring sandstones and shales from 
which they probably came4 ,i have seen  
in some of the coarser tufas1 or  rather
 volcanic conglomerates1 enormous masses
 of basalt and greenstone  buried deep  
in the surrounding green or red         
felspathic paste1 and  showing on their 
more prominent edges the usual vesicular
 cavities4  ,in such conglomerates there
 is usually no division into beds2 the  
whole mass1 indeed1 forms a bed between 

lower and higher strata1 but  internally
 it shows for the most part no trace of 
stratification4 ,in  these confused     
assemblages one may occasionally light  
upon detached  crystals of augite or    
other mineral scattered irregularly     
through  the tufa4 ,their angles will be
 found often blunted1 and the crystals  
themselves broken1 appearances which    
have likewise been noticed among  the   
ash of modern volcanoes4 ,when the tufas
 are finer grained they  usually exhibit
 a well-marked stratification1 and can  
often be split  up into lamin like an   
ordinary fissile sandstone4 ,organic    
remains not  unfrequently abound in such
 laminated beds1 and vary in their      
character  as widely as in any other    
stratified rock1 being sometimes        
land-plants1  sometimes sea-shells4     
,such are some of the more obvious      
characters of the volcanic ashes or     
tufas1 as developed among the           
carboniferous rocks of central          
,scotland4  ,their great varieties of   

composition and general aspect render   
them  a somewhat difficult set of rocks 
to master1 but when fairly and  fully   
understood they soon prove themselves to
 be by far the most  interesting section
 of the traps1 for one needs seldom to  
hesitate a  moment as to their origin or
 date1 while their fossil contents      
impart  to them an interest all their   
own4 ,by comparing such rocks with the  
consolidated ash or fine dust and       
lapilli of a modern volcano1 a          
remarkable resemblance of external      
characters is found to subsist2 and     
this likeness holds sufficiently close1 
when pursued into details1 to  show that
 the ancient and the modern rocks have  
resulted from the same  source1 that1   
namely1 of volcanic eruption4 ,the ash  
of active burning  mountains falls down 
their sides loosely and incoherently1   
every  successive shower of dust or     
scori settling without much regularity  
on those that have gone before4 ,the ash
 of the old carboniferous  eruptions1   

however1 was showered for the most part 
over the sea or  across wide shoaling   
estuaries1 at least it is only such     
portions of  it as fell there that have 
come down to our day4 ,settling down    
among  the mud and sand at the bottom1  
the volcanic matter accumulated in  wide
 horizontal beds1 every marked          
inequality being smoothed down by  the  
currents until a series of regularly    
stratified layers came to be  formed1   
entombing any organisms that might find 
their way to the bottom  or be lying    
there at the time4 ,the ash of          
terrestrial volcanoes has no  marked    
stratification because thrown out in    
open air1 while that of  the            
carboniferous rocks of central ,scotland
 is distinctly bedded from  having been 
deposited under water4    ,tufas and    
contemporaneous melted traps are very   
generally found  together               
interstratified regularly with each     
other1 and the inference  to be drawn   
from their juxtaposition is of course   

simply this1 that  at one time liquid   
lava rolled along the bottom of the     
water1 while  at another showers of     
volcanic dust and cinders settled down  
in  successive beds4 ,this active play  
of the igneous forces took place  at the
 mouths of estuaries or farther to sea2 
and it is accordingly  sometimes not a  
little interesting to trace1 amid the   
sediment that  accumulated below the    
water during the pauses between the     
eruptions1  well-preserved remains now  
of plants that had come drifting from   
the  land1 anon of slim spirifers1 and  
producti that swarmed upon the  hardened
 lava-streams1 and amid the thickening  
volcanic mud that  slowly sank to the   
sea-bottom4 ,such a sequence of events  
will be made  plain from the following  
section1 the materials of which are     
derived  from different parts of the    
trappean region of ,linlithgowshire4    
,the  undermost bed here shown 7#a7 is  
one of marine limestone1 abounding  with
 encrinal joints1 corals1 spirifers1 and

 other undoubtedly marine  organisms4   
,above it comes a layer of tufa or      
volcanic ash 7#b7 of a  dull green      
aspect1 the boundary line between the   
two rocks lying as  clear as if the     
quarryman had marked it off with his    
foot-rule4 ,the  upper part of the ash1 
however1 does not show an equally clear 
line  of demarcation with the stratum   
above4 ,on the contrary1 it gradually   
changes its character1 becomes more     
calcareous as it goes up1 with  here and
 there a stone-lily joint or a stray    
productus1 until these  organisms       
increase so much in number that the rock
 insensibly passes  into an ordinary    
limestone 7#c7 like that below4 ,next   
succeeds a thin  seam of ash 7#d7       
resting sharply on the limestone and    
overlaid by a bed  of shale 7#e7        
containing the same marine organisms4   
,another stratum of  ash 7#f7 resembling
 those below follows the shale1 and is  
surmounted by  a close compact          
greenstone 7#g7 that hardens the ash on 

which it rests1  but produces no        
apparent alteration on the soft fissile 
shale 7#h7  above it4 ,next is a fourth 
seam of volcanic ash 7#i7 resembling    
those  below it1 but without any shells 
or crinoidal joints1 the only fossils   
observable being a few carbonized stems 
apparently of calamites and             
lepidodendra4 ,above it comes a bed of  
white quartzy sandstone 7#aj7 with      
similar vegetable remains1 and then a   
layer of white stiff fire-clay  7#aa7   
with rootlets of stigmaria1 above which 
lies a seam of coal 7#ab74  ,a thin     
layer of soft blue shale 7#ac7 here     
intervenes1 somewhat baked  along its   
upper portions by another bed of compact
 vesicular greenstone  7#ad71 which     
displays in places a well-marked        
columnar structure4 ,it is  surmounted  
by a highly characteristic ash 7#ae7 in 
which there occur  numerous large bombs 
chiefly of trap of different kinds1 some
 of them  highly vesicular4 ,fragments  
of shale also occur1 mingled here and   

there  with black carbonized fragments  
of coal-measure plants1 but without any 
of the shells and other marine organisms
 so abundant below4 ,the topmost  bed is
 a grey carbonaceous sandstone 7#af71   
underlying a thin covering  of vegetable
 mould4    ,illustration3 ,fig4         
#ce4--;,contemporaneous ,trap4    ,such 
is the skeleton1 as it were1 of the     
section2 the mere dry bones  which      
remain to the geologist1 and which he   
must study closely to  be able to give  
them life again4 ,the lowest bed        
visible1 with its  stone-lilies and     
molluscs1 we readily recognise as       
marking an old  ocean-bed1 so that the  
little episode in the primeval records  
of  our planet here presented to us     
opens1 like the two great epics of      
antiquity1 within sound of the          
wide-roaring sea4 ,the seam of ash which
  follows shows1 from the sharpness of  
its line of demarcation with the        
limestone1 how the denizens of the      
sea-bottom were suddenly destroyed  by a

 thick shower of volcanic dust that     
settled down over their  remains4 ,the  
waters1 however1 soon cleared1 and ere  
long stone-lilies  and producti were    
plentiful as ever1 mingling their       
remains among the  upper layers of the  
soft muddy ash1 and giving rise         
therefrom to a  sort of calcareous ash  
or ashy limestone1 until in the course  
of time  the volcanic matter became     
wholly covered over by a seam of        
ordinary  limestone4 ,the corals and    
stone-lilies were1 however1 anew        
destroyed  by the deposition of volcanic
 dust that settled over them as a seam  
of ash1 after which the water was again 
rendered turbid and muddy by  the inroad
 of foreign matter1 which1 brought down 
by rivers or by the  changing currents  
of the ocean1 sank to the bottom and    
eventually  consolidated into a seam of 
shale4 ,thereafter the volcanic forces  
began once more to eject a quantity of  
dust and scori that fell into  the water
 and spread along the bottom as a       

stratum of ash1 and to  pour out a      
current of lava which hardened into a   
great sheet visible  now as the         
undermost greenstone of the section4    
,the emission of the  lava seems to have
 terminated the eruption1 for the next  
stratum is  one of shale like that below
 the ash1 so that the muddy sediment1   
the deposition of which was interrupted 
for a while by the volcanic  products1  
began afresh to settle down along the   
sea-bottom4 ,this  last condition of    
things seems to have continued for a    
considerable  period1 seeing that the   
shale bed is relatively thick1 and from 
its  fissile laminated structure        
indicates a slow and tranquil           
deposition4  ,another eruption of       
volcanic dust and ashes again           
interrupted the  detrital deposits1 and 
gave rise to another seam of tufa4 ,this
 last  subterranean movement seems to   
have considerably altered the general   
contour of the sea-bottom1 and so       
elevated it1 at least at one part1  that

 a thick accumulation of sand1 and      
subsequently of clay1 filled  it up to  
the level of the water or nearly so1    
giving rise to a dense  growth of the   
stigmaria and other coal-measure plants 
whose roots are  still seen imbedded in 
the fire-clay on which1 as a soft muddy 
soil1  they originally grew4 ,it is     
probable1 however1 that1 notwithstanding
  such elevations of the sea-bed1 there 
was a general subsidence of the  ground 
during the accumulation of these strata1
 for we see that the  peaty morass1     
represented now by the coal-seam1 ere   
long sank beneath  the waters1 with the 
inroads of which it was unable to keep  
pace1 while  there slowly silted over it
 a muddy sediment that hardened at      
length  into what is now a seam of      
shale4 ,but this order of things had    
been in  existence for but a            
comparatively short period when the     
igneous forces  broke out again1        
ejecting a stream1 of molten lava that  
spread along  the bottom of the shallow 

waters and hardened as before into a    
sheet  of greenstone4 ,this was followed
 by an abundant shower of dust and      
lapilli1 along with numerous large      
masses of greenstone and basalt4  ,these
 falling into the water accumulated on  
the upper surface of the  lava-stream1  
then somewhat cooled1 and formed in the 
end a stratum of  ash of a rubbly       
conglomeritic aspect4 ,that the sheet of
 greenstone  really spread out along the
 sea-bottom before the ejection of the  
ash1  and was not intruded among the    
beds at a later period1--that1 in short1
  it must be regarded as a              
contemporaneous and not as an intrusive 
rock1  seems sufficiently shown by its  
great regularity and evenness1 and by   
the unaltered condition of the fine soft
 felspathic matter which covers  its    
upper surface4 ,it was assuredly in a   
highly-heated condition when  poured    
out1 as may be gathered from the baked  
aspect of the mud over  which it rolled2
 but it had cooled and solidified1 at   

least along its  upper surface1 ere     
buried beneath the shower of ashes4 ,the
 last bed  exhibited in the section is a
 grey sandstone1 with many carbonaceous 
streaks and traces of land-plants1      
showing a pause in the volcanic         
activity of the district1 during which  
the streams from the land  brought down 
sandy sediment1 with an abundant        
admixture of macerated  leaves1         
branches1 and other drift-wood4    ,it  
thus appears that not only were the     
plains and hills of the  ,carboniferous 
era richly clothed with vegetation1 and 
its waters  crowded with animals1 but   
that then1 as now1 subterranean forces  
were  at work1 sometimes elevating1     
sometimes depressing the area alike of  
the land and of the sea2 while1 not     
unfrequently1 melted lava rose  from    
below1 rolling along the bottom of the  
waters1 and showers of  ashes were flung
 far and wide through the air1 settling 
at last as a  thickening sediment along 
the floor of the sea1 or athwart the    

marshy  swamps of the delta4 ,whether   
the interior of the land had burning    
cones  among its pine-covered hills we  
know not yet4 ,such1 however1 probably  
existed2 nay1 there may have been among 
the higher peaks some snowy  pillar of  
heaven1 like the tna of ,pindar1 raising
 its smoking summit  among everlasting  
crags of ice in solitudes lifeless and  
bare4#gg    ,footnote #gg3 ,the highest 
points of ,new ,zealand1 nearly #aj1jjj 
feet  above the sea1 are said to be     
clothed for two-thirds of their height  
with ice and snow4 ,if1 therefore1      
during ,carboniferous times1 there      
existed somewhere to the west of what is
 now central ,scotland1 a chain  cf     
hills #ejjj or #fjjj feet high1 their   
summits might perhaps have been  as     
wintry us that of ,mont ,blanc4    ,our 
boulder has served us like the minstrels
 in modern ,gothic  poetry1 who appear  
between the cantos1 and give an air of  
unity and  completeness to what would   
otherwise be often rambling and         

unconnected4  ,and now1 at the close1 it
 comes again before us1 lying in its bed
 of  clay1 clustered with mosses of     
brightest green1 and overshadowed by its
  flickering canopy of beechen leaves4  
,silent and senseless1 the emblem1      
seemingly1 of calm repose and unchanging
 durability1 what could we have         
conceived it should have to chronicle1  
save the passing1 perchance1 of  many a 
wintry ,december and many a sultry      
,june4 ,such1 indeed1 would be  the     
character of its records of the         
centuries that have passed away  since  
the birth of man1 did any such record   
survive in its keeping4  ,but it rests  
there as the memorial of far earlier    
centuries1 and of  an older creation2   
and though now surrounded with all that 
is lovely  or picturesque--the twinkling
 flowers on every side1 the wide arch of
  boughs overhead1 and the murmuring    
streamlet in the dell below--and  though
 forming itself no unimpressive object  
in the scene1 the boulder  looks out    

upon us unconnected with anything       
around4 ,like a sculptured  obelisk     
transported from the plains of ,assyria 
to the streets of  ,london1 it offers no
 link of association with the order of  
things  around it2 its inscriptions are 
written in hieroglyphics long since     
extinct1 but of which the key yet       
remains to show us that the rocks of    
our planet are not masses of dead1      
shapeless matter1 but chronicles of  the
 past2 and that all the varied beauty of
 green field and waving wood  is but a  
thin veil of gossamer spread out over   
the countless monuments  of the dead4   
,we have raised one little corner of    
this gauze-like  covering1 and tried to 
decipher the memorials of bygone        
creations1  traced in clear and legible 
characters on the boulder4 ,first1 there
  lies spread out before us a wide      
arctic sea1 studded with icebergs  that 
come drifting from the north4 ,here and 
there a bare barren islet  rises above  
the waste of waters1 and the packed     

ice-floes often strand  along its       
shores1 while at other parts great      
towering bergs1 aground  in mid-ocean1  
keep rising and falling with the        
heavings of the surge1  and seem ever on
 the verge of toppling into the deep4   
,but this scene1  so bleak and lifeless1
 erelong fades away1 and we can descry a
 wide  archipelago of islands1 green    
well-nigh to the water's edge1 and      
looking like the higher hill-tops of    
some foundered continent4 ,the  waves   
are actively at work wearing down the   
shores1 which present for  the most part
 an abrupt cliff-line to the west4 ,this
 picture1 too1  gets gradually dim1 and 
when the darkness and haze have cleared 
away1  the scene is wholly new4 ,for    
miles around there spreads out an       
expanse  of water1 like a wide lake1    
thickly dotted with islets of every form
  and size1 clothed with a rich         
vegetation4 ,here a jungle of tall reeds
  shoots out of the water1 clustering   
with star-like leaves2 there a  group of

 graceful trees1 fluted like the columns
 of an ancient temple1  and crowned by a
 coronal of sweeping fronds1 spread out 
their roots  amid the soft mud4 ,yonder 
lies a drier islet1 rolling with ferns  
of  every shape and size1 with here and 
there a lofty tree-fern1 waving its     
massive boughs high overhead4 ,the      
vegetation1 rank and luxuriant in the   
extreme1 strikes us as different from   
anything visible at the present  day1   
though1 as our eyes rest on the muddy   
discoloured current1 we  can mark1 now  
and then1 huge trunks1 branchless and   
bare1 that recall  some of the living   
pine-trees4 ,the denizens of the water  
seem to be  equally strange4            
,occasionally a massive head1 with sharp
 formidable  tusks1 peers above the     
surface1 and then the gleam of fins and 
scales  reveals a creature some twenty  
or thirty feet long4 ,glancing down into
  the clearer spots1 we can detect many 
other forms of the finny tribes1  all   
cased in a strong glistening armature of

 scales1 and darting  about with        
ceaseless activity4 ,beyond this scene  
of almost tropical  luxuriance1 on the  
one side1 lies the blue ocean1 with its 
countless  shells and corals1 its       
stone-lilies and sea-urchins1 and its   
large  predaceous fish2 on the other    
side stretches a far-off chain of hills1
  whose nether slopes1 dark with        
pine-woods1 sweep down into the rich    
alluvial plains4 ,and then this         
landscape1 too1 fades slowly away1 and  
thick darkness descends upon us4 ,yet   
through the gloom we feel ever  and anon
 the rambling earthquake1 and see in the
 distance the glare  of some active     
volcano that throws a ruddy gleam amid  
the pumice and  ashes1 ever dancing     
along the surface of the sea4 ,and now  
this last  scene melts away like the    
rest1 and dark night comes down in which
 we  can detect no ray of light1 and    
beyond which we cannot go4 ,the record  
of the boulder can conduct us no further
 into the history of the past4    ,the  

same principles which have been pursued 
in the previous pages in  elucidating   
the history of the ,carboniferous       
system1 will conduct  the reader to the 
true origin and age of any group of     
rocks he may  encounter1 whatever its   
nature1 and wheresoever its locality4   
,let  him1 therefore1 in his country    
rambles1 seek to verify them in valley  
and hill-side1 by lake and cataract1 and
 along river-course and  sea-shore4 ,let
 him not be content with simply admiring
 the picturesque  grouping of           
rock-masses1 but rather seek to         
interpret their origin  and history1    
tracing them step by step into the past1
 amid ages long  prior to man4 ,such a  
process will give him a yet keener      
relish for  the beauties of their       
scenery1 by ever calling up to his mind 
some of  those striking contrasts with  
which geology abounds4 ,in the stillness
  of the mountain-glen1 he will see on  
every side traces of the waves of       
ocean1 and when dipping his oars into   

the unruffled sea among groups  of      
wasted rocks1 miles from shore1 he will 
bethink him1 perchance1  of some old    
forest-covered land1 of which these     
battered islets are  the sole memorials4
 ,his enjoyment of the scenery of nature
 is thus  increased manifold1 and he    
carries about with him a power of making
  even the tamest landscape interesting4
 ,cowper1 in one of his exquisite       
letters1 remarks1--,everything ,i see in
 the fields1 is to me an object2  and ,i
 can look at the same rivulet or at a   
handsome tree1 every day of  my life1   
with new pleasure4 ,had the sweet singer
 of ,olney lived to  witness the results
 obtained by the geologists whom he     
satirized1 he  would perhaps have       
sauntered along the ,ouse with a new    
pleasure1 and  have felt a yet more     
intense delight in casting his eyes     
athwart the  breadth of landscape that  
spreads out around-the ,peasant's nest4 
,such1 however1 are after all only      
secondary incentives to the study of    

the rocks4 ,as a mental exercise1       
geology certainly yields to none of  the
 other sciences1 for it addresses itself
 at once to the reasoning  powers and to
 the imagination1 and may thus be made a
 source both  of intellectual training  
and of delightful recreation4 ,of none  
of  the sciences is it so easy to get a 
general smatter1 yet none is so         
difficult thoroughly to master1 for     
geology embraces all the sciences4  ,in 
so wide a field1 the student will       
therefore find ample room to  expatiate4
 ,in beginning the study1 he may perhaps
 think it1 as ,milton  pictured the     
other paths of learning1 laborious1     
indeed1 at the first  ascent2 but else  
so smooth1 so green1 so full of goodly  
prospects and  melodious sounds on every
 side1 that the harp of ,orpheus was not
 more  charming4 ,if time and taste     
disincline him to travel over the whole 
of the broad field1 there are delightful
 nooks to which he may betake  himself1 
replete with objects of beauty and      

interest1 where he may  spend his       
leisure1 and by so doing not merely     
delight himself1 but  enlarge the bounds
 of human knowledge4 ,no part of the    
domain can be too  obscure or remote to 
reward his attention2 no object too     
trifling or  insignificant3 for the     
march of science1 though a stately one1 
proceeds  not by strides1 but by steps  
often toilsome and slow2 and she stands 
mainly indebted for her progress not to 
the genius of a few gigantic            
intellects1 but to the united efforts of
 many hundred labourers1 each  working  
quietly in his own limited sphere4      
,but the highest inducement to this     
study must ever be that so quaintly  put
 by old ,sir ,thomas ,browne3 ,the world
 was made to be inhabited by  beasts1   
but studied and contemplated by man3    
'tis the debt of our  reason we owe unto
 ,god1 and the homage we pay for not    
being beasts2  without this the world is
 still as though it had not been1 or as 
it  was before the sixth day1 when as   

yet there was not a creature that  could
 conceive or say there was a world4     
,geology lifts off for us the  veil that
 shrouds the past1 and lays bare the    
monuments of successive  creations that 
had come and gone long ere the human    
race began4 ,she  traces out the plan of
 the ,divine working during a vast cycle
 of ages-1  and points out how the past 
dovetails with the present1 and how the 
existing condition of things comes in as
 but the last and archetypal  economy in
 a long progressive series4 ,by thus    
revealing what has gone  before1 she    
enables us more fully to understand what
 we see around us  now4 ,much that is   
incomplete she restores2 much that is   
enigmatical  she explains4 ,she teaches 
us more fully man's true position in the
  created universe1 by showing that in  
him all the geologic ages meet  that he 
is the point towards which creation has 
ever been tending4 ,how  far the facts  
brought to light by geology may bear    
upon the future1  will not1 perhaps1 be 

solved until that future shall have     
come4 ,there  is1 nevertheless1 in the  
meanwhile1 material enough for solemn   
and  earnest reflection1 and as years go
 by the amount will probably be  always 
increasing4 ,for we must ever be only   
learners here1 and when all  earthly    
titles and distinctions have passed     
away1 and we enter amid the  realities  
of another world1 we shall carry with us
 this one common name  alone4 ,it will1 
perhaps1 be then as now1 that only      
,in contemplation of created things     
,by steps we may ascend to ,god4    ,and
 it can surely be no unmeet preparation 
for such a scene1 in humble  faith to   
read the records of ,his doings which   
the ,almighty has graven  on the rocks  
around us4 ,many problems meet us on    
every hand problems  which it seems     
impossible for us now to solve and as   
the circle of  science ever widens1 its 
enveloping circumference of difficulty  
and  darkness widens in proportion4 ,it 
is1 doubtless1 well that it should be   

so2 for we are thus taught to regard our
 present state as imperfect and         
incomplete1 and to long for that higher 
and happier one promised by the         
,redeemer to those that love ,him1 when 
we shall know thoroughly even as  we are
 thoroughly known4      ,,table ,,of    
,,fossiliferous ,,rocks4    ,,lyell',s  
,elements1 p4 #aji4       #a4 ,,recent4 
,,post-,,tertiary4     #b4              
,,post-,,pliocene4                      
#c4 ,,newer ,,pliocene4                 
,,pliocene4               #d4 ,,older   
,,pliocene4                             
,,tertiary     #e4 ,,upper ,,miocene4   
,,miocene4               or     #f4     
,,lower ,,miocene4                      
,,cainozoic4                            
#g4 a ,,upper ,,eocene4      ,,eocene4  
#g4 b ,,middle ,,eocene4                
#h4 ,,lower ,,eocene4                   
#i4 ,,maestricht ,,beds4          #aj4  
,,upper ,,white ,,chalk4        #aa4    
,,lower ,,white ,,chalk4        #ab4    
,,upper ,,greensand4       ,,cretaceous4

            #ac4 ,,gault4               
#ad4 ,,lower ,,greensand4               
#ae4 ,,wealden4                         
#af4 ,,purbeck ,,beds4                  
#ag4 ,,portland ,,stone4                
,,secondary    #ah4 ,,kimmeridge ,,clay4
                              or    #ai4
 ,,coral ,,rag4             ,,jurassic  
,,mesozoic4    #bj4 ,,oxford ,,clay4    
#ba4 ,,great or ,,bath ,,oolite4        
#bb4 ,,inferior ,,oolite4               
#bc4 ,,lias4                            
#bd4 ,,upper ,,trias4                   
#be4 ,,middle ,,trias1                  
or                 ,,triassic4          
,,muschelkalk4                          
#bf4 ,,lower ,,trias4                   
#bg4 ,,permian1                         
or                   ,,permian4         
,,magnesian ,,limestone4                
#bh4 ,,coal-,,measures4                 
#bi4 ,,carboniferous                    
,,carboniferous4                        
,,limestone4                            
,,primary    #cj4 ,,upper ,,devonian4   

,,devonian1 or            or    #ca4    
,,lower                 ,,old ,,red     
,,sandstone4  ,,pal,,ozoic4             
#cb4 ,,upper ,,silurian4                
,,silurian4              #cc4 ,,lower   
#cd4 ,,upper ,,cambrian4                
,,cambrian4              #ce4 ,,lower   
99       99       99       99       99  
,transcriber ,note    ,minor typos      
corrected4 ,some images moved to nearest
 paragraph break4 ,a  paragraph break   
was added to page #gd and #aje to       
accommodate placement  of ,figures #ag  
and #bf respectively4 ,the missing      
anchor for the footnote  on page #aii   
was added4