,a ,,text-,,book ,,of ,,entomology ,illustration ,a ,,text-,,book ,,of ,,entomology ,,including ,,the ,,anatomy1 ,,physiology1 ,,embryology ,,and ,,metamorphoses ,,of ,,insects ,,for ,,use ,,in ,,agricultural ,,and ,,technical ,,schools ,,and ,,colleges ,,as ,,well ,,as ,,by ,,the ,,working ,,entomologist ,,by ,,alpheus ,s4 ,,packard1 ,m4,d41 ,,ph4,d4 ,,professor ,,of ,,zo,,logy ,,and ,,geology1 ,,brown ,,university ,,author ,,of 8,,guide ,,to ,,study ,,of ,,insects10 8,,entomology ,,for ,,beginners10 ,,etc4 ,new ,york ,,the ,,macmillan ,,company ,,london3 ,,macmillan ,,co41 ,,ltd4 #ahih ,all rights reserved ,,copyright1 #ahih1 ,,by ,,the ,,macmillan ,,company4 ,norwood ,press ,j4 ,s4 ,cushing ,co4--,berwick ,smith ,norwood ,mass4 ,u4,s4,a4 ,,preface ,illustration ,in preparing this book the author had in mind the wants both of the student and the teacher4 ,for the student's use the more difficult portions1 particularly that on the embryology1 may be omitted4 ,the work has grown in part out of the writer's experience in class work4 ,in instructing small classes in the anatomy and metamorphoses of insects1 it was strongly felt that the mere dissection and drawing of a few types1 comprising some of our common insects1 were by no means sufficient for broad1 thorough work4 ,plainly enough the laboratory work is all important1 being rigidly disciplinary in its methods1 and affording the foundation for any farther work4 ,but to this should be added frequent explanations or formal lectures1 and the student should be required to do collateral reading in some general work on structural and developmental entomology4 ,with this aim in view1 the present work has been prepared4 ,it might be said in explanation of the plan of this book1 that the students having previously taken a lecture course in the zology of the invertebrates1 were first instructed in the facts and conclusions bearing on the relations of insects to other ,arthropoda1 and more especially the anatomy of ,peripatus1 of the ,myriopoda1 and of ,scolopendrella4 ,then the structure of ,campodea1 ,machilis1 and ,lepisma was described1 after which a few types of winged insects1 beginning with the locust and ending with the bee1 were drawn and dissected2 the nymph of the locust1 and the larva and pupa of a moth and of a wasp and bee being drawn and examined4 ,had time permitted1 an outline of the embryology and of the internal changes in flies during their metamorphoses would have been added4 ,this book gives1 of course with much greater fulness and detail for reference and collateral reading1 what we roughly outlined in our class work4 ,the aim has been to afford a broad foundation for future more special work by any one who may want to carry on the study of some group of insects1 or to extend in any special direction our present knowledge of insect morphology and growth4 ,many of our entomologists begin their studies without any previous knowledge of the structure of animals1 taking it up as an amusement4 ,they may be mere collectors and satisfied simply to know the name of their captures1 but it is hoped that with this book in their hands they may be led to desire farther information regarding what has already been done on the structure and mode of growth of the common insects4 ,for practical details as to how to dissect1 to make microscopic slides1 and to mount and preserve insects generally1 they are referred to the author's 8,entomology for ,beginners40 ,it may also be acknowledged that even in our best and latest general treatises on zology1 or comparative anatomy1 or morphology1 the portion related to insects is scarcely so thoroughly done as those parts devoted to other phyla1 that of ,lang1 however1 his invaluable ,comparative ,anatomy1 being an exception4 ,on this account1 therefore1 it is hoped that this hiatus in our literature may be in a degree filled4 ,the author has made free use of the excellent article 8,insecta0 of ,newport1 of ,lang's comprehensive summary in his most useful ,text-book of ,comparative ,anatomy1 of ,graber's excellent ,die ,insecten1 of ,miall and ,denny's ,the ,structure and ,life-,history of the ,cockroach1 and of ,sharp's ,insecta4 ,kolbe's ,einfhrung has been most helpful4 ,but besides these helps1 liberal use has been made of the very numerous memoirs and monographic articles which adorn our entomological literature4 ,the account of the embryology of insects is based on ,korschelt and ,heider's elaborate work1 ,lehrbuch der ,vergleichenden ,entwicklungsgeschichte der ,wirbellosen ,thiere1 the illustrations of this portion being mainly taken from it1 through the ,messrs4 ,swan ,sonnenschein ,co41 ,london4 ,professor ,h4 ,s4 ,pratt has kindly read over the manuscript and also the proofs of the portion on embryology and metamorphoses1 and the author is happy to acknowledge the essential service he has rendered4 ,the bibliographical lists are arranged by dates1 so as to give an idea of the historical development of each subject4 ,the aim has been to make these lists tolerably complete and to include the earliest1 almost forgotten works and articles as well as the most recent4 ,much care has been taken to give due credit either to the original sources from which the illustrations are copied1 or to the artist2 about ninety of the simpler figures were drawn by the author1 many of them for this work4 ,for the use of certain figures acknowledgments are due to the ,boston ,society of ,natural ,history1 to the ,division of ,entomology1 ,u4 ,s4 ,department of ,agriculture1 through the kind offices of ,mr4 ,l4 ,o4 ,howard1 and to the ,illinois ,state ,laboratory of ,natural ,history1 through ,professor ,s4 ,a4 ,forbes and ,mr4 ,c4 ,a4 ,hart4 ,professor ,w4 ,m4 ,wheeler1 of the ,university of ,chicago1 has kindly loaned for reproduction several of his original drawings published in the ,journal of ,morphology4 ,a number are reproduced from figures in the reports of the ,united ,states ,entomological ,commission4 ,,providence1 ,r4 ,i41 ,march #d1 #ahih4 ,,table ,,of ,,contents ,illustration ,,part ,i4 ,,morphology ,,and ,,physiology ,,page ,,position ,,of ,,insects ,,in ,,the ,,animal ,,kingdom #a ,,relations ,,of ,,insects ,,to ,,other ,,arthropoda #b ,the ,crustacea #d ,the ,merostomata #e ,the ,trilobita #e ,the ,arachnida #f ,relations of ,peripatus to insects #i ,relation of ,myriopods to insects #aa ,relations of the ,symphyla to insects #ah ,diagnostic or essential characters of ,symphyla #bb ,,insecta 7,,hexapoda7 #bf ,diagnostic characters of insects #bf #a4 ,,external ,,anatomy a4 ,regions of the body #bg b4 ,the integument 7exoskeleton7 #bh ,chitin #bi c4 ,mechanical origin and structure of the segments 7somites1 arthromeres1 etc47 #cj d4 ,mechanical origin of the limbs and of their jointed structure #ce ,,the ,,head ,,and ,,its ,,appendages #db a4 ,the head #db ,the labrum #db ,the epipharynx and labrum-epipharynx #dc ,attachment of the head to the trunk #df ,the basal or gular region of the head #df ,the occiput #dh ,the tentorium #di ,number of segments in the head #ej ,the composition of the head in the ,hymenoptera #ee b4 ,appendages of the head #eg ,the antenn #eg ,the mandibles #ei ,the first maxill #fb ,the second maxill #fh ,the hypopharynx #gj ,does the hypopharynx represent a distinct segment8 #hb ,,the ,,thorax ,,and ,,its ,,appendages #hf a4 ,the thorax3 its external anatomy #hf ,the patagia #hi ,the tegul #hi ,the apodemes #ib ,the acetabula #id b4 ,the legs3 their structure and functions #ie ,tenent hairs #ii ,why do insects have but six legs8 #ajj ,loss of limbs by disuse #aja c4 ,locomotion 7walking1 climbing1 and swimming7 #ajc ,mechanics of walking #ajc ,locomotion on smooth surfaces #aaa ,climbing #aaf ,the mode of swimming of insects #aaf d4 ,the wings and their structure #abj ,the veins #aba ,the squam #abc ,the halteres #abd ,the thyridium #abd ,the tegmina and hemelytra #abd ,the elytra #abd e4 ,development and mode of origin of the wings #abf ,embryonic development of the wings #abf ,evagination of the wing outside of the body #acb ,extension of the wing2 drawing out of the tracheoles #acc f4 ,the primitive origin of the wings #acg ,the development and structure of the trache and veins of the wing #add g4 ,mechanism of flight #adh ,theory of insect flight #aej ,graber's views as to the mechanism of the wings1 flight1 etc4 #aec ,,the ,,abdomen ,,and ,,its ,,appendages #afb ,the median segment #afc ,the cercopoda #afd ,the ovipositor and sting #afg ,the styles and genital claspers 7,rhabdopoda7 #agf ,velum penis #aha ,the suranal plate #aha ,the podical plates or paranal lobes #ahb ,the infra-anal lobe #ahc ,the egg-guide #ahc ,,the ,,armature ,,of ,,insects3 ,,set1 ,,hairs1 ,,scales1 ,,tubercles1 ,,etc4 #ahg ,the cuticula #ahg ,set #ahh ,glandular hairs and spines #aij ,scales #aic ,development of the scales #aie ,spinules1 hair-scales1 hair-fields1 and androconia #aig ,,the ,,colors ,,of ,,insects #bja ,optical colors #bja ,natural colors #bjc ,chemical and physical nature of the pigment #bjf ,ontogenetic and phylogenetic development of colors #bjg #b4 ,,internal ,,anatomy ,,the ,,muscular ,,system #baa ,musculature of a caterpillar #bac ,musculature of a beetle #bac ,minute structure of the muscles #bae ,muscular power of insects #bag ,,the ,,nervous ,,system #bbb a4 ,the nervous system as a whole #bbb b4 ,the brain #bbf ,the optic or procerebral segment #bca ,procerebral lobes #bcb ,the mushroom or stalked bodies #bcc ,structure of the mushroom bodies #bcd ,the central body #bcg ,the antennal or olfactory lobes 7,deutocerebrum7 #bcg ,the sophageal lobes 7,tritocerebrum7 #bcg c4 ,histological elements of the brain #bch d4 ,the visceral 7sympathetic or stomatogastric7 system #bch e4 ,the supraspinal cord #bdj f4 ,modifications of the brain in different orders of insects #bdj g4 ,functions of the nerve-centres and nerves #bdc ,,the ,,sensory ,,organs #bdi a4 ,the eyes and insect vision #bdi ,the simple or single-lensed eye 7ocellus7 #bdi ,the compound or facetted eye 7ommateum7 #bej ,the facet or cornea #bej ,the crystalline lens or cone #bea ,the pigment #bec ,the basilar membrane #bec ,the optic tract #bec ,origin of the facetted eye #bee ,mode of vision by single eyes or ocelli #bee ,mode of vision by facetted eyes #bef ,the principal use of the facetted eye to perceive the movements of animals #bei ,how far can insects see8 #bfj ,relation of sight to the color of eyes #bfj ,the color sense of insects #bfj b4 ,the organs of smell #bfd ,historical sketch of our knowledge of the organs of smell #bfd ,physiological experiments #bfh ,relation of insects to smelling substances before and after the loss of their antenn #bfi ,experiments on the use of the antenn in seeking for food #bgj ,experiments testing the influence of the antenn of the males in seeking the females #bgj ,structure of the organs of smell in insects #bga c4 ,the organs of taste #bha ,structure of the taste organs #bhb ,distribution in different orders of insects #bhb ,experimental proof #bhf d4 ,the organs of hearing #bhg ,the ears or tympanal and chordotonal sense-organs of ,orthoptera and other insects #bhh ,antennal auditory hairs #bib ,special sense-organs in the wings and halteres #bic e4 ,the sounds of insects #bic ,,the ,,digestive ,,canal ,,and ,,its ,,appendages #big a4 ,the digestive canal #cjb ,the sophagus #cjc ,the crop or ingluvies #cjc ,the 8sucking stomach0 or food-reservoir #cje ,the fore-stomach or proventriculus #cjf ,the sophageal valve #caa ,proventricular valvule #cac ,the peritrophic membrane #cac ,the mid-intestine #cad ,histology of the mid-intestine #caf ,the hind-intestine #caf ,large intestine #caf ,the ileum #cag ,the gastro-ileal folds #cag ,the colon #cag ,the rectum #cah ,the vent 7anus7 #cai ,histology of the digestive canal #cbj b4 ,digestion in insects #cbd ,the mechanism of secretion #cbf ,absorbent cells #cbh ,,the ,,glandular ,,and ,,excretory ,,appendages ,,of ,,the ,,digestive ,,canal #cca a4 ,the salivary glands #cca b4 ,the silk or spinning glands1 and the spinning apparatus #cci ,the process of spinning #cdj ,how the thread is drawn out #cdc ,appendages of the silk-gland 7,filippi's glands7 #cde c4 ,the ccal appendages #cdg d4 ,the excretory system 7urinary or ,malpighian tubes7 #cdh ,primitive number of tubes #cec e4 ,poison-glands #ceg f4 ,adhesive or cement-glands #cfj g4 ,the wax-glands #cfa h4 8,honey-dew0 or wax-glands of ,aphids #cfd i4 ,dermal glands in general #cfe ,,defensive ,,or ,,repugnatorial ,,scent-,,glands #cfh ,eversible coxal glands #cfi ,ftid glands of ,orthoptera #cfi ,anal glands of beetles #cgb ,the blood as a repellent fluid #cgd ,eversible glands of caddis-worms and caterpillars #cge ,the osmeterium in ,papilio larv #cgg ,dorsal and lateral eversible metameric sacs in other larv #cgg ,distribution of repugnatorial or alluring scent-glands in insects #chb ,,the ,,alluring ,,or ,,scent-,,glands #cia ,,the ,,organs ,,of ,,circulation #cig a4 ,the heart #cig ,the propulsatory apparatus #dja ,the supraspinal vessel #djc ,the aorta #djd ,the pericardial cells #dje ,pulsatile organs of the legs #dje b4 ,the blood #djg ,the leucocytes #djg c4 ,the circulation of the blood #dji ,effects of poisons on the pulsations #dab ,,the ,,blood ,,tissue #dai a4 ,the fat-body #dai b4 ,the pericardial fat-body or pericardial cells #dbj ,leucocytes or phagocytes in connection with the pericardial cells #dba c4 ,the nocytes #dbc d4 ,the phosphorescent organs #dbd ,physiology of the phosphorescence #dbf ,,the ,,respiratory ,,system #dcj a4 ,the trache #dca ,distribution of the trache #dcb b4 ,the spiracles or stigmata #dcg ,the position and number of pairs of stigmata #dci ,the closing apparatus of the stigma #dda c4 ,morphology and homologies of the tracheal system #ddb d4 ,the spiral threads or tnidia #ddd e4 ,origin of the trache and of the 8spiral thread0 #ddg ,internal1 hair-like bodies #dea f4 ,the mechanism of respiration and the respiratory movements of insects #dea g4 ,the air-sacs #def ,the use of the air-sacs #deg h4 ,the closed or partly closed tracheal system #dei i4 ,the rectal1 tracheal gills1 and rectal respiration of larval ,odonata and other insects #dfc j4 ,tracheal gills of the larv of insects #dff ,blood-gills #dge k4 ,tracheal gills of adult insects #dgf ,,the ,,organs ,,of ,,reproduction #dhe a4 ,the male organs of reproduction #did ,the testes #die ,the seminal ducts #dif ,the ejaculatory duct #dig ,the accessory glands #dig ,the spermatozoa #dig ,formation of the spermatozon #dih b4 ,the female organs of reproduction #ejj ,the ovaries and the ovarian tubes #ejj ,origin of incipient eggs in the germ of the testes #ejd ,the bursa copulatrix #eje ,the spermatheca #ejf ,the colleterial glands #ejf ,the vagina or uterus #ejg ,signs of copulation in insects #ejg ,,part ,,ii4 ,,embryology ,,of ,,insects a4 ,the egg #eae ,mode of deposition #eah ,vitality of eggs #ebj ,appearance and structure of the ripe egg #ebj ,the egg-shell and yolk-membrane #ebj ,the micropyle #ebb ,internal structure of the egg #ebd b4 ,maturation or ripening of the egg #ebe c4 ,fertilization of the egg #ebe d4 ,division and formation of the blastoderm #ebf e4 ,formation of the first rudiments of the embryo and of the embryonic membranes #eca ,formation of the embryonic membranes #ecb ,the gastrula stage #ece ,division of the embryo or primitive band into body-segments #ecf ,differences between the invaginated and overgrown primitive band #ech ,revolution of the embryo where the primitive band is invaginated #edj f4 ,formation of the external form of the body #edb ,origin of the body-segments #edb ,the procephalic lobes #edd ,fore-intestine 7stomodum7 and hind-intestine 7proctodum71 labrum #edg ,completion of the head #edh g4 ,the appendages #edh ,the cephalic appendages #edh ,the thoracic appendages #eej ,the abdominal appendages #eej ,appendages of the first abdominal segment 7pleuropodia7 #eea ,are the abdominal legs of ,lepidoptera and phytophagous ,hymenoptera true limbs8 #eeb ,the trache #eec h4 ,nervous system #eed ,completion of the definite form of the body #eee i4 ,dorsal closure and involution of the embryonic membranes #eef j4 ,formation of the germ-layers #eeh k4 ,farther development of the mesoderm2 formation of the body-cavity #efc l4 ,formation of organs #eff ,the nervous system #eff ,development of the brain #efg ,development of the eyes #efg ,intestinal canal and glands #efi ,the salivary glands #egj ,the urinary tubes #egb ,the heart #egb ,the blood-corpuscles #egd ,musculature2 connective tissue2 fat-body #egd ,the reproductive organs #ege ,development of the male germinal glands #egi m4 ,length of embryonic life #ehb n4 ,the process of hatching #ehc ,the hatching spines #ehe ,,part ,,iii4 ,,the ,,metamorphoses ,,of ,,insects a4 ,the nymph as distinguished from the larval stage #eic b4 ,stages or stadia of metamorphosis #eid c4 ,ametabolous and metabolous stages #eid ,,the ,,larva #eii a4 ,the ,campodea-form type of larva #fjj b4 ,the eruciform type of larva #fjb c4 ,growth and increase in size of the larva #fjh d4 ,the process of moulting #fji ,the number of moults in insects of different orders #fae ,reproduction of lost limbs #fai ,formation of the cocoon #fai ,sanitary conditions observed by the honey-bee larva1 and admission of air within the cocoon #fbc ,,the ,,pupa ,,state #fbe a4 ,the pupa considered in reference to its adaptation to its surroundings and its relation to phylogeny #fca b4 ,mode of escape of the pupa from its cocoon #fcb c4 ,the cremaster #fcf ,mode of formation of the cremaster and suspension of the chrysalis in butterflies #fcg ,,formation ,,of ,,the ,,pupa ,,and ,,imago ,,in ,,the ,,holometabolous ,,insects 7,,the ,,diptera ,,excepted7 #fdj a4 ,the ,lepidoptera #fdb ,the changes in the head and mouth-parts #fdf ,the change in the internal organs #fdg ,the wings #fed ,development of the feet and of the cephalic appendages #fed ,embryonic cells and the phagocytes #fee ,formation of the femur and of the tibia2 transformation of the tarsus #fef ,the antenn #feg ,maxill and labial palpi #feh ,process of pupation #ffj b4 ,the ,hymenoptera #ffa ,ocular or oculo-cephalic buds #ffe ,the antennal buds #ffe ,the buds of the buccal appendages #ffe ,the buds of the ovipositor #ffe ,,development ,,of ,,the ,,imago ,,in ,,the ,,diptera #fff a4 ,development of the outer body-form #ffh ,formation of the imago in ,corethra #ffh ,formation of the imago in ,culex #fgj ,formation of the imago in ,chironomus #fga ,formation of the imago in ,muscid #fgc b4 ,development of the internal organs of the imago #fgh ,the hypodermis #fgh ,the muscles #fhj ,the digestive canal #fha ,the tracheal system #fhc ,the nervous system #fhd ,the fat-body #fhe ,definitive fate of the leucocytes #fhe ,the post-embryonic changes and imaginal buds in the ,pupipara 7,melophagus7 #fhf c4 ,general summary #fhg ,,hypermetamorphism #fhh ,,summary ,,of ,,the ,,facts ,,and ,,suggestions ,,as ,,to ,,the ,,causes ,,of ,,metamorphism #gje ,theoretical conclusions2 causes of metamorphosis #gjh ,,text-,,book ,,of ,,entomology ,illustration ,,part ,i4--,,morphology ,,and ,,physiology ,illustration ,,position ,,of ,,insects ,,in ,,the ,,animal ,,kingdom ,although the insects form but a single class of the animal kingdom1 they are yet so numerous in orders1 families1 genera1 and species1 their habits and transformations are so full of instruction to the biologist1 and they affect human interests in such a variety of ways1 that they have always attracted more attention from students than any other class of animals1 the number of entomologists greatly surpassing that of ornithologists1 ichthyologists1 or the special students of any other class1 while the literature has assumed immense proportions4 ,insects form about four-fifths of the animal kingdom4 ,there are about #bej1jjj species already named and contained in our museums1 while the number of living and fossil species in all is estimated to amount to between one and two millions4 ,in their structure insects are perhaps more complicated than any other animals4 ,this is partly due to the serial arrangement of the segments and the consequent segmental repetition of organs1 especially of the external appendages1 and of the muscles1 the trache1 and the nerves4 ,the brain is nearly or quite as complicated as that of the higher vertebrates1 while the sense-organs1 especially those of touch1 sight1 and smell are1 as a rule1 far more numerous and only less complex than those of vertebrates4 ,moreover1 in their psychical development1 certain insects are equal1 or even superior1 to any other animals1 except birds and mammals4 ,the animal kingdom is primarily divided into two grand divisions1 the one-celled 7,protozoa7 and many-celled animals 7,metazoa74 ,in the latter group the cells and tissues forming the body are arranged in three fundamental cell-layers2 viz4 the ectoderm or outer layer1 the mesoderm1 and endoderm4 ,the series of branches1 or phyla1 comprised under the term ,metazoa are the ,porifera1 ,clenterata1 ,vermes1 ,echinodermata1 ,mollusca1 ,arthropoda1 and ,vertebrata4 ,their approximate relationships may be provisionally expressed by the following ,,tabular ,,view ,,of ,,the ,,eight ,,branches ,,or ,,phyla ,,of ,,the ,,animal ,,kingdom4 ,,viii4 ,vertebrata4 ,ascidians and ,fishes to ,man4 ,,vii4 ,arthropoda4 ,trilobites1 ,crustacea1 ,arachnida1 ,insects1 etc4 ,,vi4 ,mollusca4 ,clams1 ,snails1 ,cuttles4 ,v4 ,echinodermata4 ,crinoids1 ,star-fish1 ,sea-urchins1 etc4 ------------------------------ --------------------------------------- ,,iv4 ,vermes4 ,flat and ,round ,worms1 ,polyzoa1 ,brachiopods1 ,annelids4 ,,iii4 ,clenterata4 ,,ii4 ,porifera4 ,hydra1 ,jelly-fishes4 ,sponges4 ------------------------------------ ,,metazoa4 ,many-celled animals with #c cell-layers4 ,i4 ,,protozoa4 ,single-celled animals4 ,,relations ,,of ,,insects ,,to ,,other ,,arthropoda ,the insects by general consent stand at the head of the ,arthropoda4 ,their bodies are quite as much complicated or specialized1 and indeed1 when we consider the winged forms1 more so1 than any other class of the branch1 and besides this they have wings1 fitting them for an arial life4 ,it is with little doubt that to their power of flight1 and thus of escaping the attacks of their creeping arthropod enemies1 insects owe1 so to speak1 their success in life2 i4e4 their numerical superiority in individuals1 species1 and genera4 ,it is also apparently their power of moving or swimming swiftly from one place to another which has led to the numerical superiority in species of fishes to other ,vertebrata4 ,among terrestrial vertebrates1 the birds1 by virtue of their ability to fly1 greatly surpass in number of species the reptiles and mammals4 ,the ,arthropoda are in general characterized by having the body composed of segments 7somites or arthromeres7 bearing jointed appendages4 ,they differ from the worms in having segmented appendages1 i4e4 antenn1 jaws1 and legs1 instead of the soft unjointed outgrowths of the annelid worms4 ,moreover1 their bodies are composed of a more or less definite number of segments or rings1 grouped either into a head-thorax 7cephalothorax7 and hind-body1 as in ,crustacea1 or into a head differentiated from the rest of the body 7trunk71 the latter not being divided into a distinct thorax and abdomen1 as in ,myriopoda2 or into three usually quite distinct regions--the head1 thorax1 and hind-body or abdomen1 as in insects4 ,in certain aberrant1 modified forms1 as the ,tardigrada1 or the ,pantopoda1 and the mites1 the body is not differentiated into such definite regions4 ,in their internal organs arthropods agree in their general relations with the higher worms1 hence most zologists agree that they have directly originated from the annelid worms4 ,the position and general shape of the digestive canal1 of the nervous and circulatory systems1 are the same in ,arthropoda as in annelid 7oligochete7 worms1 so much so that it is generally thought that the ,arthropoda are the direct descendants of the worms4 ,it is becoming evident1 however1 that there was no common ancestor of the ,arthropoda as a whole1 and that the group is a polyphyletic one4 ,hence1 though a convenient group1 it is a somewhat artificial one1 and may eventually be dismembered into at least three or four phyla or branches4 ,the following diagram may serve to show in a tentative way the relations of the classes of ,arthropoda to each other1 and also may be regarded as a provisional genealogical tree of the branch4 #i4 ,insecta4 #g4 ,chilopoda4 #d4 ,arachnida4 #f4 ,diplopoda4 #c4 ,merostomata4 #h4 ,symphyla4 #a4 ,crustacea4 #f;a4 ,pauropoda4 #b4 ,trilobita4 ------- -------------- -------------------------- -------- #e4 ,peripatus4 #d;a4 ,pantopoda4 #d;b4 ,tardigrada4 ---------------------------------------- - ,different ,annelida4 ,trochosphra4 ,we will now rapidly review the leading features of the classes of ,arthropoda4 ,the ,crustacea4--,these ,arthropoda are in many most important characteristics unlike the insects2 they have two pairs of antenn1 five pairs of buccal appendages1 and they are branchiate ,arthropoda4 ,they have evidently originated entirely independently1 and by a direct line of descent from some unknown annelid ancestor which was either a many-segmented worm1 with parapodia1 or the two groups together with the ,rotifera may have originated from a common appendigerous ,trochosphra4 ,their segments in the higher forms are definite in number 7#bc or #bd7 and arranged into two regions1 a head-thorax 7cephalothorax7 and hind-body 7abdomen74 ,nearly all the segments1 both of the cephalothorax and abdomen1 bear a pair of jointed limbs1 and to them at their base are1 in the higher forms1 appended the gills 7branchi74 ,the limbs are in the more specialized forms 7shrimps and crabs7 differentiated into eye-stalks1 two pairs of antenn1 a pair of palpus-bearing jaws 7mandibles71 two pairs of maxill and three pairs of maxillipeds2 these appendages being biramose1 and the latter bearing gills attached to their basal joints4 ,the legs are further differentiated into ambulatory thoracic legs and into swimming or abdominal legs1 and in the latter the first pair of the male is modified into copulatory organs 7gonopoda74 ,the male and female reproductive organs as a rule are in separate individuals1 hermaphrodites being very unusual1 and the glands may be paired or single4 ,the sexual outlets are generally paired1 and1 as in the male lobster and other ,macrura1 open in the basal joint of the last pair of legs1 and in the female in the third from the last2 while originally in all ,crustacea the sexual organs were most probably paired 7,fig4 #c1 ,b74 ,they are1 except a few land ,isopoda1 aquatic1 mostly marine1 and when they have a metamorphosis1 pass through a six-legged larval stage1 called the ,nauplius1 the shrimps and crabs passing through an additional stage1 the ,zoa4 ,crustacea also differ much from insects in the highly modified nature of the nephridia1 which are usually represented by the green gland of the lobster1 or the shell-glands of the ,phyllopoda1 which open out in one of the head-segments2 also in the possession of a pair of large digestive glands1 the so-called liver4 ,intermediate in some respects between the ,crustacea and insects1 but more primitive1 in respect to what are perhaps the most weighty characters1 than the ,crustacea1 are the ,trilobita1 the ,merostomata 7,limulus71 and1 finally1 the ,arachnida1 these being allied groups4 ,in the ,trilobita and ,merostomata 7,limulus71 the head-appendages are more like feet than jaws1 while they have in most respects a similar mode of embryonic development1 the larval forms being also similar4 ,illustration3 ,,fig4 #a4--,restoration of under side of a trilobite 7,triarthrus becki71 the trunk limbs bearing small triangular respiratory lobes or gills4--,after ,beecher4 ,the ,merostomata4--,the only living form1 ,limulus1 is undoubtedly a very primitive type1 as the genital glands and ducts are double1 opening wide apart on the basal pair of abdominal legs 7,fig4 #c74 ,moreover1 their head-appendages1 which are single1 with spines on the basal joint1 are very primitive and morphologically nearer in shape to those of the worms 7,syllid1 etc47 than even those of the ,crustacea4 ,besides1 their four pairs of coxal glands1 with an external opening at the base of the fifth pair of head-appendages1 and which probably are modified nephridia 7,crustacea having but a single pair in any one form1 either opening out on the second antennal1 green gland1 or second maxillary1 shell-gland1 segment71 indicate a closer approximation to the polynephrous worms4 ,limulus has other archaic features1 especially as regards the structure of the simple and compound eyes and the simple nature of the brain4 ,the ,trilobita4--,these archaic forms are still more generalized and primitive than the ,merostomata and ,crustacea1 and probably were the first ,arthropoda to be evolved from some unknown annelid worm4 ,they had jointed biramose limbs of nearly uniform shape and size on each segment of the body1 which were not1 as in ,crustacea1 differentiated into antenn1 jaws 7mandibles71 maxill1 maxillipeds1 and two kinds of legs 7thoracic and abdominal71 showing that they are a much more primitive type1 and nearer to the annelids than any other ,arthropoda4 ,their gills1 as shown by the researches of ,walcott and of ,beecher1 were attached to nearly if not every pair of limbs behind the antenn 7,figs4 #a1 #b74 ,the fact that in ,trilobita the first pair of limbs is antenniform does not prove that they are ,crustacea1 since ,eurypterus has a similar pair of appendages4 ,illustration3 ,,fig4 #b4--,restored section of ,calymene3 ,c1 carapace2 en1 endopodite2 en1 exopodite2 with the gills on the epipodal or respiratory part of the appendage4--,after ,walcott4 ,the limbs in trilobites1 as well as the abdominal ones of merostomes1 and all those of ,crustacea1 except the first antenn1 are biramose1 consisting of an outer 7exopodite7 and an inner division 7endopodite74 ,in this respect the terrestrial air-breathing tracheate forms1 ,arachnida1 ,myriopoda1 and ,insecta1 differ from the branchiate forms1 as their legs are single or undivided1 being adapted for supporting the body during locomotion upon the solid earth4 ,it is to be observed that when1 as in ,limulus1 the body is supported by cephalic ambulatory limbs1 they are single1 while the abdominal limbs1 used as they are in swimming1 are biramose1 much as in ,crustacea4 ,the ,arachnida4--,the scorpions and spiders are much less closely allied to the myriopods and insects than formerly supposed4 ,their embryology shows that they have descended from forms related to ,limulus1 possibly having had an origin in common with that animal1 or having1 as some authors claim1 directly diverged from some primitive eurypteroid merostome4 ,but they differ in essential respects1 and not only in the nature and grouping of their appendages2 the first pair instead of antenniform being like mandibles1 and the second pair like the maxill1 with the palps1 of insects1 the four succeeding segments 7thoracic7 bearing each a pair of legs4 ,they also have a brain quite unlike that of ,limulus1 the nervous cord behind the brain1 however1 being somewhat similar1 though that of ,limulus differs in being enveloped by an arterial coat4 ,arachnida respire by trache1 besides book-lungs1 which1 however1 are possibly derivatives of the book-gills of ,limulus1 while they perform the office of excretion by means of the malpighian tubes1 and like ,limulus possess two large digestive glands 78liver074 ,their embryos have1 on at least six abdominal segments1 rudiments of limbs1 three pairs of which form the spinnerets1 showing their origin from ,limulus-like or eurypteroid forms2 their coxal glands are retained from their eurypteroid ancestors4 ,the ,arachnida probably descended from marine merostomes1 and not from an independent annelid ancestry1 hence we have represented them in the diagram on p4 #c as branching off from the merostomatous phylum1 rather than from an independent one4 ,illustration3 ,,fig4 #c4--,paired genital openings of different classes of arthropods4 ,a1 the most primitive1 of ,limulus polyphemus3 gen4 p1 generative papill2 d1 duct2 vd1 vas deferens2 t1 tendinous stigmata2 stig1 stigmata2 e1 external branchial muscle2 ant1 anterior lamellar muscle4--,after ,benham1 with a few changes4 ,b1 lobster 7,homarus vulgaris71 3 oe1 genital aperture on #c;d pair of legs2 ov1 ovary2 u1 unpaired portion of the same2 od1 oviduct4 ,c1 1 scorpion3 ov1 ovary1 with a single external opening4 ,d1 3 t1 testis2 vd1 vasa deferentia2 sb1 seminal vesicle2 a1 glandular appendage2 p1 penis4--,after ,blanchard4 ,e1 a myriopod 7,glomeris marginata1 73 os1 ovarian sac1 laid open2 od1 paired oviducts4 ,f1 3 t1 testis2 gvd1 common vas deferens2 pa1 paired ducts4--,after ,favre1 from ,lang4 ,g1 ,lepisma saccharina1 young 3 vd1 vas deferens1 ed1 ejaculatory duct2 ga1 external appendages4--,after ,nassonow4 ,h1 ,ephemera1 1 showing the double outlets4--,after ,palmn4 ,the characters in which arachnids approach insects1 such as trache and malpighian tubes 7none occur1 as a rule1 in marine or branchiate arthropods71 may be comparatively recent structures acquired during a change from a marine to a terrestrial life1 and not primitive heirlooms4 ,arachnida also show their later origin than merostomes by the fact that their sexual glands are in most cases single1 and though with rare exceptions the ducts are paired1 these finally unite and open externally by a common single genital aperture in the median line of the body1 at the base of the abdomen 7,fig4 #c1 ,c1 ,d74 ,in this respect ,limulus1 with its pair of genital male or female openings1 situated each at the end of a papilla1 placed widely apart at the base of the first abdominal limbs1 is decidedly more archaic4 ,unlike ,crustacea and insects1 ,arachnida do not1 except in the mites 7,acarina71 which is a very much modified group1 undergo a metamorphosis4 ,we see1 then1 that the insects1 with the ,myriopoda1 are somewhat isolated from the other ,arthropoda4 ,the ,myriopoda have a single pair of antenn1 and as they have other characters in common with insects1 ,lang has united the two groups in a single class ,antennata2 but1 as we shall see1 this seems somewhat premature and unnecessary4 ,yet the two groups have perhaps had a common parentage1 and may prove to belong to a distinct1 common phylum4 ,not only by their structure and embryology1 as well as their metamorphosis1 do the myriopods and insects stand apart from the ,arachnida and other arthropods1 but it seems probable that they have had a different ancestry1 the arthropods being apparently polyphyletic4 ,there are two animals which appear to connect the insects with the worms1 and which indicate a separate line of descent from the worms independent of that of the other classes4 ,these are the singular ,peripatus1 which serves as a connecting link between arthropods and worms1 and ,scolopendrella 7,symphyla74 ,these two animals are guide-posts1 pointing out1 though vaguely to be sure1 the way probably trod by the forms1 now extinct1 which led up to the insects4 ,relations of ,peripatus to ,insects4--,we will first recount the characteristics of this monotypic class4 ,peripatus 7,fig4 #d7 stands alone1 with no forms intermediate between itself and the worms on the one hand1 and the true ,arthropoda on the other4 ,originally supposed to be a worm1 it is now referred to a class by itself1 the ,malacopoda of ,blainville1 or ,protracheata of ,haeckel4 ,it lives in the tropics1 in damp places under decaying wood4 ,in general appearance it somewhat resembles a caterpillar1 but the head is soft and worm-like1 though it bears a pair of antenna-like tentacles4 ,it may be said rather to superficially resemble a leech with clawed legs1 the skin and its wrinkles being like those of a leech4 ,there is a pair of horny jaws in the mouth1 but these are more like the pharyngeal teeth of worms than the jaws of arthropods4 ,the numerous legs end each in a pair of claws4 ,the ladder-like nervous system is unlike that of annelid worms or arthropods1 but rather recalls that of certain molluscs 7,chiton1 etc471 as well as that of certain flat and nemertine worms4 ,its annelid features are the large number of segmentally arranged true nephridia1 and the nature of the integument4 ,its arthropodan features1 which appear to take it out of the group of worms1 are the presence of trache1 of true salivary and slime glands1 of a pair of coxal glands 7,fig4 #d1 ,c1 cd7 as well as the claws at the end of the legs4 ,the trache1 which are by no means the only arthropodan features1 are evidently modified dermal glands4 ,the heart is arthropodan1 being a dorsal tube lying in a pericardial sinus1 with many openings4 ,this assemblage of characters is not to be found in any marine or terrestrial worm4 ,the trache 7,fig4 #d1 ,d1 tr7 are unbranched fine tubes1 without a 8spiral thread10 and are arranged in tufts1 in ,p4 edwardsii opening by simple orifices or pores 78stigmata07 scattered irregularly over the surface of the body2 but in another species 7,p4 capensis7 some of the stigmata are arranged more definitely in longitudinal rows1--on each side two1 one dorsally and one ventrally4 8,the stigmata in a longitudinal row are1 however1 more numerous than the pairs of legs40 7,lang47 ,the salivary glands1 opening by a short common duct into the under side of the mouth1 in the same general position as in insects1 are evidently1 as the embryology of the animal proves1 transformed nephridia1 and being of the arthropodan type explain the origin and morphology of those of insects4 ,it is so with the slime glands2 these1 with the coxal glands1 being transformed and very large dermal glands4 ,those of insects arose in the same manner1 and are evidently their homologues1 while those of ,peripatus were probably originally derived from the setiparous glands in the appendages 7parapodia7 of annelid worms4 ,illustration3 ,,fig4 #d4--;,a1 ,peripatus nov zealandi4--,after ,sedgwick1 from ,lang4 ,b1 ,peripatus capensis1 side view1 enlarged about twice the natural size4--,after ,moseley1 from ,balfour4 ,c1 ,anatomy of ,peripatus capensis4 ,the enteric canal behind the pharynx has been removed4 g1 brain2 a1 antenna2 op1 oral or slime papill2 sd1 slime gland2 sr1 slime reservoir1 which at the same time acts as a duct to the gland2 so#d1 so#e1 so#f1 so#i1 nephridia of the #dth1 #eth1 #fth1 and #ith pairs of limbs2 cd1 elongated coxal gland of the last pair of feet2 go1 genital aperture2 an1 anus2 ph1 pharynx2 n1 longitudinal trunk of the nervous system4--,after ,balfour1 from ,lang4 ,d1 ,portion of the body of ,peripatus capensis opened to show the scattered tufts of trache 7tr72 v1 v1 ventral nerve cords4--,after ,moseley4 ,the genital glands and ducts are paired1 but it is to be observed that the outlets are single and situated at the end of the body4 ,in the male the ejaculatory duct is single2 in its base a spermatophore is formed4 ,it will be seen1 then1 that ,peripatus is not only a composite type1 and a connecting link between worms and tracheate arthropods1 but that it may reasonably be regarded1 if not itself the ancestor1 as resembling the probable progenitor of myriopods and insects1 though of course there is a very wide gap between ,peripatus and the other antennate1 air-breathing ,arthropoda4 ,illustration3 ,,fig4 #d4--;,e1 ,peripatus edwardsii1 head from the under side3 a1 base of antenna2 op1 oral papilla2 the figure also shows the papill around the mouth1 and the four jaws4--,after ,balfour1 from ,lang4 ,f1 ,anterior end of ,peripatus capensis1 ventral side1 laid open3 a1 antenna2 z1 tongue2 k1 jaw2 sd1 salivary gland2 gs1 union of the two salivary glands2 ph1 pharynx2 1 sophagus2 l1 lip papill around the mouth2 op1 oral or slime papilla2 sld1 duct or reservoir of the slime gland4--,after ,balfour1 from ,lang4 ,relation of ,myriopods to ,insects4--,the ,myriopoda are the nearest allies of the insects4 ,they have a distinct head1 with one pair of antenn4 ,the eyes are simple1 with the exception of a single genus 7,cermatia71 in which they are aggregated or compound4 ,the trunk or body behind the head is1 as a rule1 long and slender1 and composed of a large but variable number of segments1 of equal size and shape1 bearing jointed legs1 which invariably end in a single claw4 ,the mouth-parts of the myriopods are so different in shape and general function from those of insects1 that this character1 together with the equally segmented nature of the portion of the body behind the head 7the trunk71 forbids our merging them1 as some have been inclined to do1 with the insects4 ,there are two sub-classes of myriopods1 differing in such important respects that by ,pocock#a and by ,kingsley they are regarded as independent classes1 each equivalent to the insects4 ,of these the most primitive are the ,diplopoda 7,chilognatha71 represented by the galley-worms 7,julus1 etc474 ,illustration3 ,,fig4 #e4--,mandible of ,julus3 l1 lacinia2 g1 galea2 p1 dens mandibularis2 ma1 8mala02 lt1 lamina tritoria2 st1 stipes2 c1 cardo2 m1 muscle4--,after ,latzel4 ,in the typical ,diplopoda the head consists of three segments1 a preoral or antennal1 and two postoral1 there being two pairs of jaw-like appendages1 which1 though in a broad morphological sense homologues of the mandibles and first maxill of insects1 are quite unlike them in details4 ,illustration3 ,,fig4 #f4--,under lip or deutomala of ,scoterpes copei3 hyp1 hypostoma or mentum2 lam4 lab1 lamina labialis2 stip4 e1 stipes exterior2 with the malella exterior 7mal4 e7 and malella interior 7mal4 i72 the stipes interior1 with the malulella2 and the labiella 7hypopharynx of ,vom ,rath7 with its stilus 7stil474 ,as we have previously stated1#b the so-called 8mandibles0 of diplopods are entirely different from those of insects1 since they appear to be #b- or #c-;jointed1 the terminal joint being #b-lobed1 thus resembling the maxill rather than the mandibles of insects1 which consist of but a single piece or joint1 probably the homologue of the galea or molar joint of the diplopod protomala4 ,the mandible of the ,julid 7,fig4 #e1 ,julus molybdinus71 ,lysiopetalid1 and ,polydesmid consists of three joints2 viz4 a basal piece or cardo1 a stipes1 and the mala mandibularis1 which supports two lobes analogous to the galea and lacinia of the maxilla of an insect4 ,there is an approach1 as we shall see1 in the mandible of ,copris1 to that of the ,julid1 but in insects in general the lacinia is wanting1 and the jaw consists of but a single piece4 ,the deutomal 7gnathochilarium71 or second pair of diplopod jaws1 are analogous to the labium or second maxill of insects1 forming a flattened1 plate-like under-lip1 constituting the floor of the mouth 7,fig4 #f74 ,this pair of appendages needs farther study1 especially in the late embryo1 before it can be fully understood4 ,so far as known1 judging by ,metschnikoff's work on the embryology of the diplopods1 these myriopods seem to have in the embryo but two pairs of post-antennal mouth-parts1 which he designated as the 8mandibles0 and 8labium40 ,meinert1 however1 regards as a third pair of mouth-parts or 8labium0 what in our ,fig4 #g is called the internal stipes 7stip4 i471 behind which is a triangular plate1 lamina labialis 7lam4 lab71 which he regards as the sternite of the same segment4 ,illustration3 ,,fig4 #g4--;,deutomala of ,julus1 the lettering as in ,fig4 #f4 ,illustration3 ,,fig4 #h4--;,head of ,scolopendra1 seen from beneath1 showing the 8mandible0 7protomala7 with its cardo 7card47 and stipes 7st471 also the labrum and epilabrum4 ,the hypopharynx1 our 8labiella10 7,fig4 #f71 with the supporting rods or stili linguales 7sti4 l71 of ,meinert1 are of nearly the same shape as in some insects4 ,of the clypeus of insects there is apparently no homologue in myriopods1 though in certain diplopods there is an interantennal clypeal region4 ,the labium of insects is represented by a short1 broad piece1 which1 however1 unlike that of insects1 is immovable1 and is flanked by a separate piece called the epilabrum 7,fig4 #h74 ,vom ,rath has observed an epipharynx1 which has the same general relations as in insects4 ,illustration3 ,,fig4 #i4--,larva of ,julus3 a1 the #c;d abdominal segment1 with the new limbs just budding out2 b1 new segments arising between the penultimate and the last segment4--,after ,newport4 ,the embryology of myriopods is in many respects like that of insects4 ,the larva of diplopods hatches with but few segments1 and with but three pairs of limbs2 but these are not1 as in insects1 appended to consecutive segments1 but in one species the third1 and in another1 ,julus multistriatus8 7,fig4 #aj71 the second1 segment from the head is footless1 while ,vom ,rath represents the first segment of an ,european ,blaniulus as footless1 the feet being situated consecutively on segments #b to #d4 ,the new segments arise at 8the growing point0 situated between the last and penultimate segment1 growing out in groups of sixes 7,newport7 or in our ,julus multistriatus8 in fives 7,fig4 #aj74 ,in adult life diplopods 7,julus7 have a single pair of limbs on the three first segments1 or those corresponding to the thoracic segments of insects1 the succeeding segments having two pairs to each segment4 ,illustration3 ,,fig4 #aj4--;,freshly hatched larva of ,julus multistriatus8 #c mm4 long3 a1 #e pairs of rudimentary legs1 one pair to a segment4 ,sinclair 7,heathcote7 regards each double segment in the diplopods as not two original segments fused together1 nor a single segment bearing two pairs of legs1 but as 8two complete segments perfect in all particulars1 but united by a large dorsal plate which was originally two plates which have been fused together40 7,myriopods1 #ahie1 p4 #ga47 ,that the segments were primitively separate is shown1 he adds1 by the double nature of the circulatory system1 the nerve cord1 and the first traces of segmentation in the mesoblast4 ,kenyon believes that from the conditions in pauropods1 ,lithobius1 etc41 there are indications of alternate plates 7not segments7 having disappeared1 and of the remaining plates overgrowing the segments behind them1 so as to give rise to the anomalous double segments4#c ,illustration3 ,,fig4 #aa4--,sixth pair of legs of ,polyzonium germanicum1 3 cs1 ventral sacs2 cox1 coxa2 st1 sternal plate2 sp1 spiracle4--,after ,haase4 ,diplopods are also provided with eversible coxal sacs1 in position like those of ,symphyla and ,synaptera2 ,meinert1 ,latzel1 and also ,haase having detected them in several species of ,chordeumid1 ,lysiopetalid1 and ,polyzonid 7,fig4 #aa74 ,in ,lysiopetalum anceps these blood-gills occur in both sexes between the cox of the third to sixteenth pair of limbs4 ,in the ,diplopods the blood-gills appear to be more or less permanently everted1 while in ,scolopendrella they are usually retracted within the body 7,fig4 #ae1 cg74 ,diplopods also differ externally from insects in the genital armature1 a complicated apparatus of male claspers and hooks apparently arising from the sternum of the sixth segment and being the modified seventh pair of legs4 ,in myriopods there are no pleural pieces or 8pleurites10 so characteristic of winged insects4 ,perhaps the most fundamental difference between diplopods and insects is the fact that the paired genital openings of the former are situated not far behind the head between the second and third pair of legs4 ,both the oviducts and male ejaculatory ducts are paired1 with separate openings4 ,the genital glands lie beneath1 while in chilopods they lie above the intestine2 this1 as ,korschelt and ,heider state1 being a more primitive relation1 since in ,peripatus they also lie above the digestive canal4 ,the nervous system of diplopods is not only remarkable for the lack of the tendency towards a fusion of the ganglia observable in insects1 but for the fact that the double segments are each provided with two ganglia4 ,the brain also is very small in proportion to the ventral cord1 the nervous system being in its general appearance somewhat as in caterpillars4 ,the arrangement of the trache and stigmata is much as in insects1 but in the ,diplopoda the tracheary system is more primitive than in chilopods1 a pair of stigmata and a pair of tracheal bundles occurring in each segment1 while the bundles are not connected by anastomosing branches1 branched trache only occurring in the ,glomerid4 ,the trache themselves are without spiral threads 7tnidia74 ,it is noteworthy that the trache arise much later than in insects1 not appearing until the animal is hatched2 in this respect the myriopods approximate ,peripatus4 ,in the ,chilopoda also the parts of the head1 except the epicranium1 are not homologous with those of insects1 neither are the mouth-parts1 of which there are five pairs4 ,the structure of the head of centipedes is shown in part in ,fig4 #ab1 compare also ,fig4 #h4 ,it will be seen that it differs much from that of the diplopods1 though the mandibles 7protomal7 are homologous2 they are divided into a cardo and stipes1 thus being at least two-jointed4 ,the second pair of postoral appendages is in centipedes very different from the gnathochilarium of diplopods4 ,as seen in ,fig4 #ab #b1 they are separate1 cylindrical1 fleshy1 five-jointed appendages1 the maxillary appendages of ,newport1 which are 8connected transversely at their base with a pair of soft appendages0 7c71 the lingua of ,newport4 ,the third and fourth pair are foot-jaws1 and we have called them malipedes1 as they have of course no homology with the maxillipedes of ,crustacea4 ,the second pair of these malipedes1 forming the last pair of mouth-appendages1 is the poison-fangs 7#d71 which are intermediate between the malipedes and the feet2 ,meinert does not allow that these are mouth-appendages4 ,illustration3 ,,fig4 #ab4--,structure of a chilopod4 ,a1 ,lithobius americanus1 natural size4 ,b1 under side of head and first two body-segments and legs1 enlarged3 ant1 antenna2 #a1 jaws2 #b1 first accessory jaw2 c1 lingua2 #c1 second accessory jaw and palpus2 #d1 poison-jaw4 7,kingsley del47 ,c1 side view of head 7after ,newport73 ep1 epicranium2 l1 frontal plate2 sc1 scute2 #a1 first leg2 sp1 spiracle4 ,the embryology of ,geophilus by ,metschnikoff shows plainly the four pairs of post-antennal appendages4 ,the embryo ,geophilus is hatched in the form of the adult1 having1 unlike the diplopods1 no metamorphosis1 its embryological history being condensed or abbreviated4 ,but in examining ,metschnikoff's figures certain primitive diplopod features are revealed4 ,the body of the embryo shortly before hatching is cylindrical2 the sternal region is much narrower than in the adult1 hence the insertions of the feet are nearer together1 while the first six pairs of appendages begin to grow out before the hinder ones4 ,thus the first six pairs of appendages of the embryo ,geophilus correspond to the antenn1 two pairs of jaws1 and three pairs of legs of the larval ,julus4 ,these features appear to indicate that the chilopods may be an offshoot from the diplopod stem4 ,the acquisition of a second pair of legs to a segment in diplopods1 as in the phyllopod ,crustacea1 is clearly enough a secondary character1 as shown by the figures of ,newport in his memoir on the development of the ,myriopoda 7,pl4 ,,iv474 ,thus the tendency in the ,myriopoda1 both diplopods and chilopods1 is towards the multiplication of segments and the elongation of the body1 while in insects the polypodous embryo has the three terminal segments of the abdomen well formed1 these being1 however1 before hatching1 partly atrophied1 so that the body of insects after birth tends to become shortened or condensed4 ,this indicates the descent of insects from ancestors with elongated polypodous hind-bodies like ,scolopendrella4 ,korschelt and ,heider suggest that the stem-form of myriopods was a homonomously jointed form like ,peripatus1 consisting of a rather large number of segments1 but we might1 with ,haase1 consider that the great number of segments which we now find indicates a late acquisition of this form4 ,the genital opening in chilopods is single1 and situated in the penultimate segment of the body1 as in insects4 ,while recognizing the close relationship of the ,myriopoda with the insects1 it still seems advisable not to unite them into a single group 7as ,oudemans1 ,lang1 and others would do71 but to regard them as forming an equivalent class4 ,on the other hand1 when we take into account the form and structure of the head1 antenn1 and especially the shape of the first pair of mouth-appendages1 being at least two-jointed in both groups1 we think these characters1 with the homonomously segmented body behind the head1 outweigh the difference in the position of the genital outlet1 important as that may seem4 ,it should also be taken into account that while insects are derived from polypodous ancestors1 no one supposes1 with the exception of one or two authors1 that these ancestors are the ,myriopoda1 the latter having evidently descended from a six-legged ancestor1 quite different from that of the ,campodea ancestor of insects4#d ,in regard to the sexual openings of worms1 though their position is in general in the anterior part of the body1 it is still very variable1 though1 in general1 paired4 ,in the oligochete worms the genital zone1 with the external openings1 is formed by the segments lying between the #ith and #adth rings1 though in some the genital organs are situated still nearer the head4 ,the myriopods1 which evolved from the worms earlier than insects1 appear to have in their most primitive forms 7the ,diplopoda7 retained this vermian position of the genital outlets4 ,in the later forms1 the chilopods1 the genital openings have been carried back to near the end of the body1 as in insects4 ,from observations made by three different observers on the freshly hatched larva of the ,julid1 it appears that the ancestral diplopods were six-footed1 or oligopod1 the larva of ,pauropus 7,fig4 #ac7 approaching nearest to our idea of the ancestral myriopod1 which might provisionally be named ,protopauropus4 ,relations of the ,symphyla to ,insects4--,opinions respecting the position of the ,symphyla1 represented by ,scolopendrella 7,fig4 #ad71 are very discordant4 ,by most writers since ,newport1 ,scolopendrella has been placed among the myriopods4 ,the first author1 however1 to examine its internal anatomy was ,menge 7#ahea71 who discovered among other structures 7trache1 etc47 the silk-glands situated in the last two segments1 and which open at the end of each cercus4 ,he regarded the form as 8the type of a genus or family intermediate between the hexapod ,lepismid and the ,scolopendrid40 ,illustration3 ,,fig4 #ac4--,pauropus huxleyi1 much enlarged4 ,a1 enlarged view of head1 antenn1 and first pair of legs 7original74 ,b1 young4--,after ,lubbock4 ,c1 longitudinal section of ,pauropus huxleyi1 3 a1 brain2 b1 salivary gland2 k1 mid-intestine2 g1 rectum2 h1 ventral nerve-cord2 c1 bud-like remnants of cox2 d1 penis2 e1 vesicula seminalis2 f1 ductus glandularis2 i#a1 divisions of testes4--,after ,kenyon4 ,in #ahgce the writer referred to this form as follows3 8,it may be regarded as a connecting link between the ,thysanura and ,myriopoda1 and shows the intimate relation of the myriopods and the hexapods1 perhaps not sufficiently appreciated by many zologists40 ,in #ahhj ,ryder regarded it as 8the last survival of the form from which insects may be supposed to have descended10 and referred it to 8the new ordinal group ,symphyla1 in reference to the singular combination of myriopodous1 insectean1 and thysanurous characters which it presents4#f0 ,illustration3 ,,fig4 #ad4--,scolopendrella immaculata1 from above1--after ,lang2 also from beneath1 the genital opening on the #dth trunk-segment3 sac1 eversible or coxal sac2 an1 anus2 c1 cereopod2 v1 vestigial leg4--,after ,haase1 from ,peytoureau4 ,a ,b ,c1 head and buccal appendages of ,scolopendrella immaculata3 ,a1 head seen from above2 cl1 clypeus4 ,b1 head from beneath2 l1 first pair of legs2 mx1 #ast maxilla2 mx#a1 #b;d maxilla2 t1 8labial plates0 of ,latzel1 labium of ,muhr4 ,c1 #ast maxilla2 l1 lacinia2 g1 galea2 p1 rudiment of the palpus4--,after ,latzel4 ,d1 end of the body3 p#aa1 eleventh1 p#ab1 twelfth undeveloped pair of legs2 p#ac1 modified1 vestigial legs1 bearing tactile organs 7so72 sg1 cercopod1 with duct of spinning gland1 dg2 cd1 eversible or coxal gland2 h#hs1 coxal spur of the #aath pair of legs4--,after ,latzel from ,lang4 ,wood-,mason considered it to be a myriopod1 and 8the descendant of a group of myriopods from which the ,campode1 ,thysanura1 and ,collembola may have sprung40 ,we are indebted to ,grassi for the first extended work on the morphology of ,scolopendrella 7#ahhe74 ,in #ahhf he added to our knowledge facts regarding the internal anatomy1 and gives a detailed comparison with the ,thysanura1 besides pointing out the resemblances of ,scolopendrella to ,pauropus1 diplopods1 chilopods1 as well as ,peripatus4 ,illustration3 ,,fig4 #ae4--,section of ,scolopendrella immaculata3 1 sophagus2 oe4 v1 sophageal valve entering the mid-intestine 78stomach072 i1 intestine2 r1 rectum2 br1 brain2 ns1 abdominal chain of ganglia2 ovd1 oviduct2 ov1 ovary2 s4 gl1 silk-gland1 and op1 its outer opening in cercus1 ur4 t1 urinary tube2 cg1 coxal glands or blood-gills4--,author del4 ,in #ahhh ,grassi expressed his view as to the position of the ,symphyla1 stating that it should not be included in the ,thysanura1 since it evidently has myriopod characters2 these being the supraspinal vessel1 the ventral position of the genital glands2 the situation of the genital opening in the fourth segment of the trunk1 its ganglionic chain being like that of diplopods1 its having limbs on all the segments1 etc4 ,on the other hand1 ,grassi has with much detail indicated the points of resemblance to the ,thysanura4 ,the principal ones are the thin integument1 the want of sympathetic ganglia1 the presence of a pair of cephalic stigmata1 like that said to occur in certain ,collembola1 and in the embryo of ,apis2 two endoskeletal processes situated near the ventral fascia of the head2 the epicranial suture also occurring in ,thysanura1 ,collembola1 ,orthoptera1 and other winged insects1 and being absent in diplopods and chilopods4 ,he also adds that the digestive canal both in ,symphyla and ,thysanura is divided into three portions2 the malpighian tubes in ,thysanura present very different conditions 7there being none in ,japyx71 among which may be comprised those of ,scolopendrella4 ,in both groups there is a single pair of salivary glands4 ,the cellular epithelium of the mid-intestine of ,scolopendrella is of a single form as in ,campodea and ,japyx4 ,the fat-body1 dorsal vessel1 with its valves and ostia1 are alike in the two groups1 as are the appendages of the end of the abdomen1 the anal cerci 7cercopoda7 of ,scolopendrella being the homologues of the multiarticulate appendages of ,lepisma1 etc41 and of the forceps of ,japyx4 ,in those of ,scolopendrella1 we have found the large duct leading from the voluminous silk-gland1 a single large sac extending forwards into the third segment from the end of the body 7,fig4 #ae1 s4 gl74 ,other points of resemblance1 all of which he enumerates1 are the slight differences in the number of trunk-segments1 the presence in the two groups of the abdominal 8false-legs0 7parapodia71 the dorsal plate1 and the mouth-parts4 ,as regards the latter1 ,grassi affirms that there is a perfect parallelism between those of ,scolopendrella and ,thysanura4 ,to this point we will return again in treating more especially of those of the ,symphyla4 ,finally1 ,grassi concludes that there is 8a great resemblance between the ,thysanura and ,scolopendrella40 ,he1 however1 believed that the ,symphyla are the forerunners of the myriopods1 and not of the insects1 his genealogical tree representing the symphylan and thysanuran phyla as originating from the same point1 this point also being1 rather strangely1 the point of origin of the arachnidan phylum4 ,haase 7#ahhi7 regarded ,scolopendrella as a myriopod1 and ,pocock 7#ahic7 assigned the ,symphyla to an independent class1 regarding ,scolopendrella as 8the living form that comes nearest to the hypothetical ancestor of the two great divisions of tracheates40 ,schmidt's work 7#ahie7 on the morphology of this genus is more extended and richly illustrated than ,grassi's1 his method of research being more modern4 ,he also regards this form as one of the lower myriopods4 ,in conclusion1 it appears to us that1 on the whole1 if we throw out the single characteristic of the anteriorly situated genital opening1 the ovarian tubes being directed toward the end of the body 7,fig4 #ae1 ovd1 ov71 there is not sufficient reason for placing the ,symphyla among the ,myriopoda1 either below or near the diplopods4 ,this is the only valid reason for not regarding ,scolopendrella as the representative of a group from which the insects have descended1 and which partly fills the wide abyss between ,peripatus and insects4 ,with the view of ,pocock1 that both insects and myriopods have descended from ,scolopendrella1 we do not agree1 because this form has so many insectean features1 and a single unpaired genital opening4 ,for the same reason we should not agree with ,schmidt in interpolating the ,symphyla between the ,pauropoda and ,diplopoda4 ,in these last two progoneate groups the genital openings are paired1 hence they are much more primitive types than ,scolopendrella1 in which there is but a single opening4 ,it seems most probable that the ,symphyla1 though progoneate1 are more recent forms than the progoneate myriopods1 which have retained the primitive feature of double sexual outlets4 ,it is more probable that the ,symphyla were the descendants of these polypodous forms4 ,certainly ,scolopendrella is the only extant arthropod which1 with the sole exception of the anteriorly situated genital opening1 fulfils the conditions required of an ancestor of ,thysanura1 and through them of the winged insects4 ,no one has been so bold as to suggest the derivation of insects from either diplopods or chilopods1 while their origin from a form similar to ,scolopendrella seems not improbable4 ,yet ,uzel has very recently discovered that ,campodea develops in some respects like ,geophilus1 the primitive band sinking in its middle into the yolk1 with other features as in chilopods4#g ,the retention of a double sexual opening in the diplopods is paralleled by the case of ,limulus with its double or paired sexual outlets1 opening in a pair of papill1 as compared with what are regarded as the generalized or more primitive ,crustacea1 which have an unpaired sexual opening4 ,the following summary of the structural features of the ,symphyla1 as represented by ,scolopendrella1 is based mainly on the works of ,grassi1 ,haase1 and ,schmidt1 with observations of my own4 ,diagnostic or essential characters of ,symphyla4--,head shaped as in ,thysanura 7,cinura71 with the ,y-shaped tergal suture1 which occurs commonly in insects 7,thysanura1 ,collembola1 ,dermaptera1 ,orthoptera1 ,platyptera1 ,neuroptera1 etc471 but is wanting in ,myriopoda 7,diplopoda and ,chilopoda72 antenn#h unlike those of ,myriopoda in being very long1 slender1 and moniliform4 ,clypeus distinct4 ,labrum emarginate1 with six converging teeth4 ,mandibles #b-;jointed1 consisting of a vestigial stipes and distal or molar joint1 the latter with eight teeth4 ,first maxill with an outer and inner mala situated on a well-developed stipes2 with a minute1 #a-;jointed palpus4 ,second pair of maxill3 each forming two oblong flat pieces1 median sutures distinct1 with no palpi2 these pieces are toothed in front1 and appear to be homologous with the two median pieces of the gnathochilarium of ,diplopoda4 ,hypopharynx8 ,epipharynx8 ,trunk with from fifteen to sixteen dorsal1 more or less free subequal scutes1 the first the smallest4 ,pedigerous segments twelve2 also twelve pairs of #e-;jointed legs1 which are of nearly equal length1 the first pair #d-1 the others #e-;jointed1 all ending in two claws1 as in ,synaptera and winged insects4 ,a pair of #a-;jointed anal cerci homologous with those of ,thysanura and ,orthoptera1 into each of which opens a large abdominal silk-gland4 ,abdominal segments with movable styles or 8pseudopods0 78,parapodia0 of ,latzel and of ,schmidt71 like those of ,campodea and ,machilis1 and situated on the base of the coxal joint in front of the ventral sac4 ,within the body near the base of each abdominal style is an eversible coxal sac or blood-gill 7,fig4 #ae1 cg74 ,the single genital opening is on the fourth trunk-segment in both sexes 7,fig4 #ae1 indicated by the arrow74 ,the malpighian tubes 7ur4 t7 are two in number1 opening into the digestive canal at the anterior end of the hind intestine2 they extend in front to the third or second segment from the head4 ,they are broad and straight at their origin1 becoming towards the end very slender and convoluted4 ,the three divisions of the digestive tract are as in insects1 the epithelium of the mid-gut being histologically as in ,campodea and ,japyx2 rectal glands are present4 ,a pair of very large salivary glands are situated in the first to the fourth trunk-segments1 consisting of a glandular portion with its duct1 which unite into a common duct opening on the under side of the head1 probably in the labium4 ,but a single pair of stigmata is present1 and these are situated in the front of the head1 beneath the insertion of the antenn and within the stipes of the mandibles2 the trache are very fine1 without spiral threads 7tnidia71 and mostly contained within the head1 two fine branches extending on each side into the second trunk-segment4 ,after birth the body increases in length by the addition of new segments at the growing point4 ,in respect to the nervous system1 there are no diagnostic characters2 there are1 however1 not as many as two pairs of ganglia to a segment4 ,the brain is well developed1 sending a pair of slender nerves to the small eyes4 ,the ganglia of the segment bearing the first pair of legs is fused with the subsophageal ganglion4 ,grassi was unable to detect a true sympathetic system1 but he suspects the existence of a very small frontal ganglion4 ,the slender dorsal vessel1 provided with ostia and valvules1 pulsates along the entire length of the trunk2 an aorta passes into the head4 ,the internal genital organs of both sexes are paired1 and extend along the greater part of the trunk2 in either sex they may be compared to two long1 slender1 straight cords extending from the fourth to the tenth pair of legs4 ,the two oviducts do not unite before reaching the sexual opening 7,fig4 #ae1 ovd74 ,the male sexual organs are more complicated than the feminine4 ,the paired testicular tubes lie in trunk-segments #f to #ab1 on each side1 and partly under the intestinal canal1 communicating with each other by a cross-anastomosis situated under the intestine1 and which1 like the testes1 is filled with sperm4 ,of the paired seminal ducts 7vas deferens7 in trunk-segment #d1 each unites again into a thick tube1 sending a blind tube forward into the third segment4 ,under the place of union of the two vasa deferentia arise the paired ductus ejaculatorii1 which open beneath in the uterus masculinus4 ,the anterior blind ends of the vasa deferentia form a sort of small paired vesicul seminales in which a great quantity of ripe sperm is stored4 ,the uterus masculinus is in its structure homologous with the evaginable penis of ,pauropus1 ,polyxenus1 and some diplopods1 and the sexual opening has without doubt become secondarily unpaired4 ,the sexual opening is rather long and is closed by two longitudinal folds4 8,in several respects the male sexual organs of ,scolopendrella are like those of ,pauropus2 in the last-named form we have indeed an unpaired testis1 but also in ,scolopendrella we see the beginning of such a singleness2 namely1 the presence of an anastomosis uniting the two tubes1 their communication by means of a transverse connecting canal and a glandular structure in the epithelium forming them4 ,the male sexual organs of ,pauropus differ only through a still greater complication40 7,schmidt47 ,scolopendrella in habits resembles chilopods1 being found in company with ,geophilus burrowing deep in light sand under leaves1 or living at the surface of the ground under sticks or stones4 ,it is very agile in its movements1 and is probably carnivorous4 ,it was considered by ,haase to be eyeless1 but the presence of two ocelli has been demonstrated both by ,grassi and by ,schmidt4 ,whether the pigment and corneous facet are present is not certain4 ,the embryology is entirely unknown 7although ,henshaw reports finding a hexapodous young one71 and it need not be said that a knowledge of it is a very great desideratum4 ,it is most probable that the young is hexapodous1 since the first pair of limbs are #d-;jointed1 all the rest #e-;jointed2 while ,newport1 and also ,ryder1 observed specimens with nine1 ten1 eleven1 and twelve pairs1 and ,wood-,mason confirms their observations1 8which prove that a pair of legs is added at each moult10 and he concludes that the addition of new segments 8therefore takes place in this animal by the intercalation of two at each moult between the antepenultimate and penultimate sterna1 as in the ,chilognatha1 and as also in some of the ,chilopoda40 ,there is but one family1 ,scolopendrellid1 and a single genus1 ,scolopendrella1 which seems to be1 like other archaic types1 cosmopolitan in its distribution4 ,our commonest species is ,s4 immaculata ,newport1 which occurs from ,massachusetts to ,cordova1 ,mexico1 and in ,europe from ,england to the ,mediterranean and ,russia2 ,mr4 ,o4 ,f4 ,cook tells me he has found a species in ,liberia1 ,west ,africa4 ,the other species are ,s4 notacantha ,gervais1 ,europe and ,eastern ,united ,states2 ,s4 nivea ,scopoli 7,s4 grati ,ryder71 ,europe and ,united ,states2 ,s4 latipes ,scudder1 ,massachusetts4 ,,literature ,,on ,,scolopendrella ,newport1 ,george4 ,monograph of the class ,myriopoda1 order ,chilopoda4 7,trans4 ,linn4 ,soc4 xix1 pp4 #cdi-dci1 #a ,pl41 #ahde47 ,menge1 ,a4 ,myriapoden der ,umgegend von ,danzig4 7,neuste ,schriften der naturforsch4 ,gesell4 ,danzig4 iv1 #ahea47 ,ryder1 ,john ,h4 ,scolopendrella as the type of a new order of articulates 7,symphyla74 7,amer4 ,nat41 ,may1 #ahhj1 xiv1 pp4 #cge1 #cgf47 ---- ,the structure1 affinities1 and species of ,scolopendrella4 7,proc4 ,acad4 ,nat4 ,soc4 ,phil41 pp4 #gi-hf1 #ahha1 #b ,figs47 ,packard1 ,a4 ,s4 ,scolopendrella and its position in nature4 7,amer4 ,nat41 #ahha1 pp4 #fih-gjd1 ,fig47 ,muhr1 ,jos4 ,die ,mundtheile von ,scolopendrella und ,polyzonium4 ,prag1 #ahhb1 #a ,pl4 ,mason1 ,j4 ,wood4 ,morphological notes bearing on the origin of insects4 7,trans4 ,ent4 ,soc4 ,london1 #ahgi1 pp4 #ade-afg1 ,figs47 ---- ,notes on the structure1 post-embryonic development1 and systematic position of ,scolopendrella4 7,ann4 and ,mag4 ,nat4 ,hist41 ,july1 #ahhc1 pp4 #ec-fc47 ,latzel1 ,robert4 ,die ,myriapoden der osterreichisch-ungarischen ,monarchie1 ii1 ,wien1 #ahhd1 pp4 #a-ci1 ,pls4 ,haase1 ,erich4 ,die ,abdominalanhnge der ,insekten mit ,bercksichtigung der ,myriapoden4 7,morph4 ,jahrbuch1 xv1 pp4 #cca-dce1 #b ,pls41 #ahhi47 ,schmidt1 ,peter4 ,beitrge zur ,kenntnis der niederen ,myriapoden4 7,zeits4 f4 wissen4 ,zool41 lix1 pp4 #dcf-eaj1 #b ,pls41 #ahie47 ,,insecta 7,,hexapoda7 ,we are now prepared to discuss the fundamental or essential characters of the insects1 including the wingless subclass 7,synaptera71 and the winged 7,pterygota74 ,diagnostic characters of insects4--,body consisting of not more than twenty-one segments1 which are usually heteronomous or of unequal size and shape1 arranged in three usually well-defined regions2 i4e4 a head1 thorax1 and hind-body or abdomen4 ,head small and flattened or rounded1 composed of not less than six segments1 and bearing1 besides the eyes1 at least four pairs of jointed appendages2 i4e4 one pair of antenn1 and three pairs of masticatory appendages1 the distal or molar portion of which is primarily divided into three divisions1 supported on a stipes and cardo1 and in certain orders modified into piercing or sucking structures4 ,the head is composed of an epicranium1 bearing a distinct clypeus and labrum1 with the epipharynx4 ,mandibles #a-;jointed1 without a palpus and very generally with no1 or uncertain1 traces of a lacinia and a stipes4 ,two pairs of maxill2 the first pair separate1 usually #c-lobed1 comprising a lacinia1 galea1 and palpifer1 with a palpus which is never more than #f-;jointed4 ,the second pair united to form the labium or under lip1 composed of two lacini fused together2 in the generalized forms with a rudimentary galea2 bearing a pair of palpi1 never more than #d-;jointed2 with paragloss sometimes present4 7,a third pair of mouth-appendages situated between the antenn and mandibles in the embryo of ,anurida1 and ,apis1 and adult ,campodea47 ,the epipharynx forming the roof of the mouth1 and bearing gustatory organs4 ,hypopharynx usually well developed1 lying on the under side of the mouth1 just above the labium1 and receiving the end of the salivary duct4 ,eyes of two kinds3 a pair of compound1 and from two to three simple eyes 7ocelli74 ,the thorax consisting of three segments1 the two latter segments in the winged orders highly differentiated into numerous tergal and lateral pieces and a single sternum2 in the ,synaptera the segments are undivided4 7,in the higher ,hymenoptera the basal abdominal segment coalesced with the thorax47 ,three pairs of legs1 each foot ending in a pair of claws4 ,two pairs of wings 7except in the ,synaptera71 a pair to each of the two hinder thoracic segments2 the wings occasionally reduced or wanting in certain adaptive forms1 which1 however1 had winged ancestors4 ,abdomen consisting at the most of from ten to twelve segments4 ,no functional abdominal legs except in the ,thysanura1 and in the larv of ,lepidoptera4 ,a pair of #a- or many-jointed cercopods on the tenth segment2 and in certain forms a pair of styles on the ninth segment4 ,in certain orders an ovipositor or sting formed of three pairs of styliform processes2 in ,collembola a single pair of processes forming the elater4 ,the genital openings opisthogoneate1 usually single1 but paired in ,thysanura 7,lepisma71 ,dermaptera1 and ,plectoptera 7,ephemerid74 ,the digestive canal in the winged orders is highly differentiated1 the fore-intestine being divided into an sophagus and proventriculus1 the hind-intestine into an ileum1 colon1 and rectum1 with rectal glands4 ,the nervous system consists of a well-developed brain1 in the more specialized orders highly complicated2 no more than thirteen pairs of ganglia1 which may be more or less fused in the more specialized orders4 ,three frontal ganglia1 and a well-developed1 sympathetic system present4 ,stigmata confined 7except possibly in ,sminthurus7 to the thorax and abdomen1 not more than ten pairs in all1 and usually but nine pairs4 ,tracheal system as a rule highly differentiated2 invariably with tnidia4 ,dorsal vessel with ostia and valvules2 no arteries except the cephalic aorta2 no veins4 ,after birth there is in the more specialized pterygote orders a reduction in the number of terminal segments of the abdomen4 ,development either direct 7,synaptera71 or with an incomplete 7with nymph and winged or imaginal stages71 or complete metamorphosis2 in the latter case with a larval1 pupal1 and imago stage4 ,the insects may be divided into two sub-classes1--the ,synaptera1 and the winged orders1 ,pterygota1 of ,gegenbaur 7#ahgg71 since the differences between the two groups appear on the whole to be of more than ordinal rank4 #a4 ,,external ,,anatomy a4 ,the regions of the body ,the insects differ from other arthropods in that the body is divided into three distinct regions1--the head1 thorax1 and abdomen1 the latter regions in certain generalized forms not always very distinctly differentiated4 ,the body behind the head may also conveniently be called the trunk1 and the segments composing it the trunk-segments4 ,in insects the head is larger in proportion to the trunk than in other classes1 notably the ,crustacea2 the thorax is usually slightly or somewhat larger than the head1 while the hind-body or abdomen is much the larger region1 as it consists of ten to eleven1 and perhaps in the ,dermaptera and ,orthoptera twelve1 segments1 and contains the mid- and hind-intestine1 as well as the reproductive organs4 ,when we compare the body of an insect with that of a worm1 in which the rings are distinctly developed1 we see that in insects ring distinctions have given way to regional distinctions4 ,the segments lose their individuality4 ,it is comparatively easy to trace the segments in the hind-body of an insect1 as in this region they are least modified2 so with the thorax2 but in the head of the adult insect it is impossible to discover the primitive segments1 as they are fused together into a sort of capsule1 and have almost entirely lost their individuality4 ,in general it may be said that the head contains or bears the organs of sense and of prehension and mastication of the food2 the thorax the organs of locomotion2 and the abdomen those of reproduction4 ,when we compare the body of a wasp or bee with that of a worm1 we see that there is a decided transfer of parts headward2 this process of cephalization so marked in the ,crustacea likewise obtains in insects4 ,also the two hinder regions of the body are1 in a much greater degree than in worms1 governed by the brain1 the principal seat of the intelligence1 which1 so to speak1 dominates and unifies the functions of the body1 both digestive1 locomotive1 and reproductive1 as also those of the muscles moving the different segments and regions of the body4 ,to a large extent arthropodan morphology and class distinctions are based on the regional arrangement of the somites themselves4 ,thus in the process of grouping of the segments into the three regions1 some increase in size1 while others undergo a greater or less degree of reduction2 one segment being developed at the expense of one or more adjoining ones4 ,this principle was first pointed out by ,audouin1 and is called ,audouin's law4 ,it is owing to the greater development of certain segments and the reduction of others1 both of the body-segments and of the segments of the limbs1 that we have the wonderful diversity of form in the species and genera1 and higher groups of insects1 as well as those of other arthropods4 b4 ,the integument 7exoskeleton7 ,the skin or integument of insects consists1 primarily1 as in worms and all arthropods1 of an epithelial layer of cells called the hypodermis4 ,this layer secretes the cuticle1 which is of varying thickness and flexibility1 and is usually very dense1 impermeable1 and light1 compared with the crust of the ,crustacea1 where the cuticle becomes heavy and solid by the deposition of the carbonate and phosphate of lime4 ,this is due to the presence of a substance called by ,odier chitin4#i ,the cuticle is thin1 delicate1 and flexible between the joints2 it is likewise so in such diaphanous aquatic larv as that of ,corethra1 and in the gills of aquatic insects1 also in the walls of the trache and of the salivary ducts4 ,the cuticle thus forms a more or less solid crust which is broken into joints and pieces 7sclerites71 forming supports for the attachments of the muscles and serving to protect the soft parts within4 ,chitin4--,if we allow an insect to soak for a long time in acids1 or boil it in liquid potassa or caustic potash1 the integument is not affected4 ,the muscles and the other soft parts are dissolved1 leaving the cuticle clear and transparent4 ,this insolubility of the cuticle is due to the presence of chitin1 the insoluble residue left after such treatment4 ,it also resists boiling in acids1 in any alkalies1 alcohol or ether4 ,the chemical formula is ,c#ae;,h#bf,n#b,o#aj4aj 8,chitin forms less than one-half by weight of the integument1 but it is so coherent and uniformly distributed that when isolated by chemical reagents1 and even when cautiously calcined1 it retains its original organized form4 ,the color which it frequently exhibits is not due to any essential ingredient2 it may be diminished or even destroyed by various bleaching processes40 7,miall and ,denny47 8,the chemical stability of chitin is so remarkable that we might expect it to accumulate like the inorganic constituents of animal skeletons1 and form permanent deposits4 ,schlossberger 7,ann4 d4 chem4 u4 pharm41 bd4 #ih7 has1 however1 shown that it changes slowly under the action of water4 ,chitin kept for a year under water partially dissolved1 turned into a slimy mass1 and gave off a peculiar smell4 ,this looks as if it were liable to putrefaction4 ,the minute proportion of nitrogen in its composition may explain the complete disappearance of chitin in nature40 7,miall and ,denny1 ,the ,cockroach1 p4 #bi47 ,chitin1 or a substance closely similar to it1 occurs in worms and in their tubes1 especially in the pharyngeal teeth of annelids and in their set4 ,the shell of ,lingula and the pen of cuttle-fish contain true chitin 7,krukenberg74 ,the integument of ,limulus1 of trilobites1 and of ,arachnida1 as well as ,myriopoda1 appears to consist of chitin4#aa ,the chitin is rapidly deposited at the end of embryonic life1 also during the larval and pupal stages4 ,as is well known1 insects after moulting are white1 but in a few hours turn dark1 and those which live in total darkness are white1 showing that light has a direct effect in causing the dark color of the integument4 ,moseley analyzed one pound weight of ,blatta1 and found plenty of iron with a remarkable quantity of manganese4 ,schneider regarded chitin as a hardening of the protoplasm rather than a secretion1 and the cuticle is looked upon as an exudation4 ,it is structureless1 not consisting of cells1 and consists of fine irregular lamin4 8,a cross-section of the chitinous layer or #8cuticle' examined with a high power shows extremely close and fine lines perpendicular to the lamin40 ,in the cockroach the free surface of the cuticle is divided into polygonal1 raised spaces or areas which correspond each to a chitinous cell of the hypodermis4 7,miall and ,denny47 ,numerous pore-canals pass through the cuticle of all the external parts of the body4 ,the larger canals nearly always form the way for the passage of secretions from dermal cells1 or connect with the cavities of hairs or set2 when very fine and not connected with hairs or scales1 they are either empty or filled with air1 and may possibly serve for respiration4 ,vosseler distinguishes in the cuticle two layers of different physical and chemical characters4 ,besides the external chitinous layer there is an inner layer which entirely agrees with cellulose4 7,zool4 ,centralblatt1 ii1 #ahie1 p4 #aag47 ,the reparative nature of chitin is seen in the fact that ,verhoeff finds that a wound on an adult ,carabus1 and presumably on other insects1 is speedily closed1 not merely by a clot of blood1 but by a new growth of chitin4 c4 ,mechanical origin and structure of the segments 7somites1 arthromeres1 metameres1 zonites7 ,the segments are merely thickenings of the skin connected by folds or duplications of the integument1 and not actually separate or individual rings or segments4 ,this is shown by longitudinal 7sagittal7 sections through the body1 and also by soaking or boiling the entire insect in caustic potash1 when it is seen that the integument is continuous and not actually subdivided into separate somites or arthromeres1 since they are seen to be connected by a thin intersegmental membrane 7,fig4 #af74 ,but this segmentation or metamerism of the integument is1 however1 the external indication of the segmentation of the arthropodan body most probably inherited from the worms1 being a disposition of the soft parts which is characteristic of the vermian type4 ,this segmentation of the integument is correlated with the serial repetition of the ganglia of the nervous system1 of the ostia of the dorsal vessel1 the primitive disposition of the segmental and reproductive organs1 of the soft1 muscular dissepiments which correspond to the suture between the segments1 and with the metameric arrangement of the muscles controlling the movements of the segments on each other1 and which internal segmentation or metamerism is indicated very early in embryonic life by the mesoblastic somites4 ,illustration3 ,,fig4 #af4--;,diagram of the anterior part of an insect1 showing the membranous intersegmental folds1 g4--,after ,graber4 ,in the unjointed worms1 as ,graber states1 the body forms a single but flexible lever4 ,in the earthworm the muscular tube or body-wall is enclosed by a stiffer cuticle1 divided into segments2 hence the worm can move in all required directions1 but only by sections1 as seen in ,fig4 #af1 which represents the thickened integument divided into segments1 and folded inward between each segment1 this thin portion of the skin being the intersegmental fold4 ,each segment corresponds to a special zone of the subdivided muscular tube 7m71 the fascia extending longitudinally4 ,the figure shows the mode of attachment of the fascia of the muscle-tube to the segment4 ,the anterior edge is inserted on the stiff1 unyielding1 inner surface of each segment3 the hinder edge of the muscle is attached to the thin1 flexible1 intersegmental fold1 which thus acts as a tendon on which the muscle can exert its force4 7,graber47 ,illustration3 ,,fig4 #ag4--;,diagram of the integument and arrangement of the segmental muscles3 ,a1 relaxed2 m1 muscle2 g1 membranous articulation2 r1 chitinous ring4 ,b1 the same contracted on both sides4 ,c1 on one side4--,after ,graber4 8,fig4 #ag makes this still clearer4 ,the muscles 7m7 extend between two segments immediately succeeding each other4 ,supposing the anterior one 7,a7 to be stationary1 what do we then see when the muscle contracts8 ,does it also become shorter8 ,the intersegmental fold is drawn forwards1 and hence the entire hinder segment moves forward and is shoved into the front one1 and so on with the others1 as at ,b4 ,afterwards1 if the strain of the muscle is relieved by the diminishing action of the tensely stretched1 intersegmental membrane1 it again returns to a state of rest40 7,graber47 ,illustration3 ,,fig4 #ah4--;,diagrams to demonstrate the mechanism of the motion of the segmented body in the ,arthropoda3 ,one larger segment 7cf7 and #d smaller4 ,the exoskeleton is indicated by black lines1 the interarticular membranes by dotted lines4 ,the hinges between consecutive segments are marked at1 tergal 7dorsal7 skeleton2 s1 sternal 7ventral7 skeleton2 d1 dorsal longitudinal muscles extensors 7and flexors in an upward direction72 v1 ventral longitudinal muscles flexors4 ,in ,b1 the row of segments is stretched2 in ,a1 by the contraction of the muscles 7d7 bent upward2 in ,c1 downward2 tg1 tergal2 sg1 sternal interarticular membranes4--,after ,lang4 ,while we look upon the dermal tube of worms as a single but flexible lever1 the body of the arthropods1 as ,graber states1 is a linear system of stiff levers4 ,we have here a series of stiff1 solid rings1 or hooks1 united by the intersegmental membrane into a whole4 ,when the muscles1 extending from one ring to the next behind contract1 and so on through the entire series1 the rings approximate each other4 ,the ectoskeletal segments bend to one side by the contraction of the muscles on one side1 the point of the outer segmental fold opposite the fixed point becoming converted into the turning-point 7,c74 ,the usual result of the arrangement of the locomotive system is the simple curving of the body 7,c71 and then the alternate bending of the body to right and left1 which produces the serpentine movements characteristic of the earthworms1 the centipede1 and many insect larv4 ,the most striking example of the wonderful variety of movements which can be made by an insect are those of the ,syrphus larva4 ,when feeding amid a herd of aphides1 it is seen to now raise the front part of the body erect and stiff1 then to bend it down1 or rapidly turn it to either side1 or move it in a complete circle4 7,graber1 pp4 #bc-bf47 ,the arrangement and mode of working of the muscles1 says ,lang1 is illustrated by ,fig4 #ah1 which shows us five segments1 one larger 7ct7 and four smaller1 in vertical projection4 ,the thicker portion of the integument is marked by strong outlines1 the delicate and flexible interarticular membranes 7tg1 sg7 in dotted lines4 ,the hinges between two consecutive segments are marked a4 ,a dorsal muscle 7d7 is attached to the larger segment 7ct71 and runs through the smaller segments1 being inserted in the dorsal portion of the crust 7t7 of each by means of a bundle of fibres4 ,a ventral muscle 7v7 does the same on the sternal side 7s74 8,the skeletal segments10 adds ,lang1 8may be compared to a double-armed lever1 whose fulcrum lies in the hinges4 ,if the dorsal muscle contracts1 it draws the dorsal arm of the lever 7the tergal portion of the skeleton7 in the direction of the pull towards the larger segments2 the tergal interarticular membranes become folded1 the ventral stretched1 and the four segments bend upward 7,fig4 #ah1 ,a74 ,if the ventral muscle contracts1 while at the same time the dorsal slackens1 the row of segments will be bent downwards 7,fig4 #ah1 ,c740 ,l4 ,b4 ,sharp suggests1 that in the ,crustacea the rings formed by 8the regularity and stress of muscular action0 would be hardened by the deposition of lime at the most prominent portion1 i4e4 between what we have called the intersegmental folds4 7,american ,naturalist1 #ahic1 p4 #hi47 ,cope also states that 8with the beginning of induration of the integument1 segmentation would immediately appear1 for the movements of the body and limbs would interrupt the deposit at such points as would experience the greatest flexure4 ,the muscular system would initiate the process1 since flexure depends on its contractions1 and its presence in animals prior to the induration of the integuments in the order of phylogeny1 furnishes the conditions required40 7,the ,primary ,factors of ,organic ,evolution1 p4 #bfh1 #ahie47 ,it is apparent that the jointed or metameric structure of the bodies of insects and other arthropods is an inheritance from the segmented worms4 ,in the worms the body is a continuous dermo-muscular tube1 while in arthropods this tube is divided into regions1 and the cuticle is thicker and more resistant4 ,to go back to the incipient stages in the process of segmentation of the body1 we conceive that the worms probably arose from a creeping gastrula-like form1 the gastra4 ,the act of creeping gradually induced an elongated shape of the body4 ,the movement of such an organism in a forward direction would gradually evolve a fore and aft1 dorsal and ventral1 and bilateral symmetry4 ,as soon as this was attained1 as the effect of creeping over rough irregular surfaces there would result mechanical lateral strains intermittently acting during the serpentine movements of the worm4 ,the integument would1 we can readily suppose1 tend to bend or yield1 or become permanently wrinkled1 at more or less regular intervals4 ,the arrangement of the muscles would gradually conform to this habit of creeping1 and finally the nervous system and other organs more directly connected with the creeping movements of the organism would tend to be correlated in their arrangement with that of the segments4 ,in this way the homonomous segments of the annelid body probably became developed1 and their relations and shapes were eventually fixed by inheritance4 ,after this stage was reached1 and limbs began to appear1 the segments would tend to become heteronomous1 and to be grouped into regions4 ,illustration3 ,,fig4 #ai4--;,dujardinia rotifera1 with jointed tentacles and caudal appendages4--,with some changes1 after ,quatrefages4 ,the origin of the joints or segments in the limbs of arthropods was probably due to the mechanical strains to which what were at first soft fleshy outgrowths along the sides of the body became subjected4 ,indeed1 certain annelid worms of the family ,syllid have segmented tentacles and parapodia1 as in ,dujardinia 7,fig4 #ai74 ,we do not know enough about the habits of these worms to understand how this metamerism may have arisen1 but it is possibly due to the act of pushing or repeated efforts to support the body while creeping over the bottom among broken shells1 over coarse gravel1 or among seaweeds4 ,it is obvious1 however1 that the jointed structure of the limbs of arthropods1 if we are to attempt any explanation at all of the origin of such structure1 was primarily due mainly to lateral strains and impacts resulting from the primitive endeavors of the ancestral arthropods to raise and to support the body while thus raised1 and then to push or drag it forward by means of the soft1 partially jointed1 lateral limbs which were armed with bristles1 hooks1 or finally claws4 ,on the other hand1 by adaptation1 or as the result of parasitism and consequent lack of active motion1 the original number of segments may by disuse be diminished4 ,thus in adult wasps and bees1 the last three or four abdominal segments may be nearly lost1 though the larval number is ten4 ,during metamorphosis the body is made over1 and the number1 shape1 and structure of the segments greatly modified4 ,in the female of the ,stylopid the thorax loses all traces of segments1 and is fused with the head1 and the abdominal segments are faintly marked1 losing their chitin4 ,while the maxill have several joints1 the mandibles are #a-;jointed1 but there are traces of two joints in ,campodea1 certain beetles1 etc4 ,in the antenna there is a great elasticity in respect to the number of joints1 which vary from one or two to a hundred or more4 ,it is likewise so in the thoracic legs1 where the number of tarsal joints varies from one to five2 also in the cercopoda1 the number of joints varying from one or two to twelve or more4 d4 ,mechanical origin of the limbs and of their jointed structure ,we have already hinted at the mode of origin of the limbs of arthropods4 ,like the body or trunk1 the limbs are chitinous dermo-muscular tubes1 with a dense solid cuticle1 and internal muscles1 and were it not for their division at more or less regular intervals into segments1 forming distinct sets of levers1 set up by the strains in these tubular supports1 there would be no power of varied motion4 ,even certain worms1 as already stated1 have their tentacles and parapodia1 or certain appendages of their parapodia1 more or less jointed1 but there are no indications of claws or of any other hard chitinous armature at the extremity1 and the skin is thin and soft4 ,in the most simple though not the most primitive arthropods1 such as the ,tardigrades1 whose body is not segmented1 there are four pairs of short unjointed legs1 ending each in two claws1 which have probably arisen in response to the stimulus of pushing or dragging efforts4 ,the legs of ,peripatus are unjointed1 and have a thin cuticle1 but end in a pair of claws1 which have evidently arisen as a supporting armature1 the result of the act of moving or pulling the body over the uneven surface of the ground4 ,illustration3 ,,fig4 #bj4--;,a prothoracic leg of ,chironomus larva2 and pupa4 ,illustration3 ,,fig4 #ba4--;,a1 larva of ,ephydra californica3 a1 b1 c1 pupa4 ,there is good reason to suppose that such limbs arose from dynamical causes1 similar to those exciting the formation of secondary adaptations such as are to be seen in the prop or supporting legs of certain dipterous larv1 as the single pair of ,chironomus 7,fig4 #bj7 and ,simulium1 or the series of unjointed soft tubercles of ,ephydra 7,fig4 #ba71 etc41 which are armed with hooks and claws1 and are thus adapted for dragging the insect through or over vegetation or along the ground4 ,now by frequent continuous use of such unjointed structures1 the cuticle would tend to become hard1 owing to the deposit of a greater amount of chitin between the folds of the skin1 until finally the body being elongated and homonomously segmented1 the movements of walking or running would be regular and even1 and we would have homonomously jointed legs like those of the trilobites1 or of the most generalized ,crustacea and of ,myriopoda4 ,in the most primitive arthropods1--and such we take it were on the whole the trilobites1 rather than the ,crustacea1--the limbs were of nearly the same shape1 being long and slender and evenly jointed from and including the antenn1 to the last pair of limbs of the abdominal region4 ,in these forms there appear to be1 so far as we now know1 no differentiation into mandibles1 maxill1 maxillipedes1 and thoracic legs1 or into gonopoda4 ,the same lack of diversity of structure and function of the head-appendages has survived1 with little change1 in ,limulus4 ,in the trilobites 7,fig4 #a7 none of the limbs have yet been found to end in claws or forceps2 being in this respect nearly as primitive as in the worms4 ,secondary adaptations have arisen in ,limulus1 the cephalic appendages being forcipated1 adapted as supports to the body and for pushing it onward through the sand or mud1 while the abdominal legs are broad and flat1 adapted for swimming and bearing the broad gill-leaves4 ,it is thus quite evident that we have three stages in the evolution of the arthropodan limb2 i4e4 #a1 the syllid stage1 of simple1 jointed1 soft1 yielding appendages not used as true supports 7,fig4 #ai72 #b1 the trilobite stage1 where they are more solid1 evenly jointed1 but not ending in claws2 and by their comparatively great numbers 7as in the trilobite1 ,triarthrus7 fully supporting the body on the bottom of the sea4 ,in ,limulus they are much fewer in number1 thicker1 and acting as firm supports1 the cephalic limbs of use in creeping1 and ending in solid claws4 #c1 ,the third stage is the long slender swimming head-appendages of the nauplius stage of ,crustacea4 ,as regards the evolution of limbs of terrestrial arthropods1 we have the following stages3 #a1 the soft unjointed limbs of ,tardigrades1 ending in two claws1 and those of ,peripatus1 and the pseudo- or prop-legs of certain dipterous larv2 #b1 finally the evolution of the long1 solid1 jointed limbs of ,pauropus and other primitive myriopods1 the legs forming solid1 firm supports elevating the body1 and enabling the insect to drag itself over the ground or to walk or run4 ,when the body is elongated and many-segmented1 the legs are necessarily numerous2 but when it is short1 the legs become few in number1 i4e4 six1 in the hexapodous young of myriopods and in insects1 or eight in ,arachnida4 ,whenever the legs are used for walking1 i4e4 to raise and support the body1 they end in a solid point or in a pair of forceps or claws4 ,on the other hand1 as in phyllopods1 where the legs are used mainly for swimming1 they are unarmed and are soft and membranous1 or1 as in the limbs of the nauplius or zoa stage of crustaceans1 end in a simple soft point1 which often bears tactile set4 ,the tarsal joints are more numerous in order to give greater flexibility to the limb in seizing and grasping objects1 both to drag the body forwards and to support it4 ,unlike those of the ,crustacea1 the limbs of insects are not primitively biramose1 but single1 the three-lobed first maxill1 and secondarily bilobed second maxill being the result of adaptation4 ,embryology on the whole proves the truth of this assumption2 the maxill of both pairs are at first single buds1 afterwards becoming lobed4 ,all the appendages of the body1 including the ovipositor or sting1 are modified limbs1 as shown by their embryological development4 ,it is noticeable that in the crab1 where the body is raised by the limbs above the bottom1 it is much shorter and more cephalized than in the shrimps4 ,also in the simply walking and running spiders1 the hind-body is shorter than in scorpions1 while in the running and flying insects1 such as the ,cicindelid1 and in the swiftly flying flies and bees1 there is a tendency to a shortening of the body1 especially of the abdomen4 ,the long body of the dragon-fly is an impediment to flight1 but compensated for by the action of the large wings4 ,the arthropodan limb is a compound leverage system4 ,it is1 says ,graber1 a lateral outgrowth of the trunk1 which repeats in miniature that of the main trunk1 its single series of joints or segments forming a jointed dermo-muscular tube4 ,yet the lateral appendages of an insect differ from the main trunk in two ways3 7#a7 they taper to the end which bears the two claws1 and 7#b7 their segments are in the living animal arranged not in a straight line1 but at different angles to each other4 ,the basal joint turning on the trunk acts as the first of a whole series of levers4 ,the second joint1 however1 is connected with the musculature of the first or basal joint1 and thus each succeeding joint is moved on the one preceding4 ,each lever1 from the first to the last1 is both an active and a passive instrument4 7,graber47 ,while1 however1 as ,graber states1 the limbs possess their own sets of muscles and can move by the turning of the basal joint1 the labor is very much facilitated1 as is readily seen1 by the trunk1 though the latter has to a great extent delegated its locomotive function to the appendages1 which again divide its labor among the separate joints4 ,graber then calls attention to the analogy of the mechanics of locomotion of insects to those of vertebrates4 ,an insect's and a vertebrate's legs are constructed on the same general mechanical principles1 the limbs of each forming a series of levers4 ,illustration3 ,,fig4 #bb4--;,diagram of the knee-joint of a vertebrate 7,a7 and an insect's limb 7,b73 a1 upper2 b1 lower1 shank1 united at ,a by a capsular joint1 at ,b by a folding joint2 d1 extensor or lifting muscle2 d#a1 flexor or lowering muscle of the lower joint4 ,the dotted line indicates in ,a the contour of the leg4--,after ,graber4 ,fig4 #bb1 ,a1 represents diagrammatically the knee joint of a vertebrate1 and ,b that of an insect2 a1 the femur or thigh1 and b1 the tibia or shank4 ,in the vertebrate the internally situated bones are brought into close union and bend by means of a hinge-joint2 so also in the chitinous-skinned insect4 ,the stiff dermal tube of the insect acts as a lever by means of the thin intersegmental membrane 7c7 pushed in or telescoped in to the thigh joint1 a special joint-capsule being superfluous4 ,the muscles are in general the same in both types2 they form a circle4 ,in both the shank is extended by the contraction of the upper muscles 7d7 and is bent by the contraction of the lower 7d#a74 ,the intersegmental membrane of the insect's limb is in a degree a two-armed lever1 whose pivot 7f7 lies in the middle4 ,the internal invagination of the intersegmental fold 7,b1 g-h7 affords the necessary support to the muscles acting like the tendon in the vertebrate4 7,graber47 ,illustration3 ,,fig4 #bc4--,primitive band or germ of a ,sphinx moth1 with the segments indicated1 and their rudimentary appendages3 c1 upper lip2 at1 antenn2 md1 mandibles2 mx1 mx1 first and second maxill2 l1 l1 l1 legs2 al1 abdominal legs4--,after ,kowalevsky4 ,graber also calls attention to the fact that this insect limb differs in one important respect from that of land vertebrates4 ,the leverage system in the last is divided at the end into five parallel divisions or digits4 ,in arthropods1 on the contrary1 all the joints succeed one another in a linear series4 ,in insects1 as well as in other arthropods1 modifications of the limbs usually take the form of a simple reduction in the number of segments4 ,thus while the normal number of tarsal joints is five1 we have trimerous and dimerous ,coleoptera1 and in certain ,scarabid the anterior tarsi are lost4 ,savigny was the first1 in #ahaf1 in his great work1 8,thorie des organes de la bouche des ,crustacs et des ,insectes10 to demonstrate that not only were the buccal appendages of biting insects homologous with those of bugs1 moths1 flies1 etc41 but that they were homologous with the thoracic legs1 and that thus a unity of structure prevails throughout the appendages of the body of all arthropods4 ,oken also observed that 8the maxill are only repeated feet40 ,what was modestly put forth as a theory by the ,french morphologist has been abundantly proved by the embryology of insects of different orders to be a fact4 ,as shown in ,fig4 #bc the antenn and buccal appendages arise as paired tubercles exactly as the thoracic legs4 ,the abdominal region also bears similar embryonic or temporary limbs1 all of which in those insects without an ovipositor disappear1 except the cercopoda1 after birth4 ,,literature ,,on ,,the ,,external ,,anatomy ,general ,swammerdam1 ,johann4 ,biblia natur4 7,in ,dutch1 ,german1 and ,english47 #agcg-agch1 fol41 ,london1 #ageh1 ,pls4 ,raumur1 ,rn ,antoine ,ferchault1 de4 ,mmoires pour servir l'histoire des insectes4 i-iv1 #d1 ,paris1 #agcd-agdb4 ,lyonet1 ,pieter4 ,trait anatomique de la chenille1 qui ronge le bois de saule1 etc4 #d1 pp4 xxii1 #faf4 la ,haye1 #agcb4 ,tab4 #ah4 ---- ,recherches sur l'anatomie et les metamorphoses de differentes espces d'insectes4 ,ouvrage posthume1 publi par ,m4 ,w4 de ,haan4 pp4 #ehj1 tab4 #ed1 #ahcb4 ,latreille1 ,pierre ,andr4 ,des rapports gnraux de l'organization extrieure des animaux invertbres articuls1 et comparaison des ,annelides avec les ,myriapodes4 7,mmoires du ,mus4 d',hist4 ,nat41 #ahbj1 vi1 pp4 #aaf-add47 ---- ,de quelques appendices particuliers du thorax de divers insectes4 7,mmoires du ,mus4 d',hist4 ,nat41 #ahba1 vii1 pp4 #a-ba74 ---- ,observations nouvelles sur l'organization extrieure et gnrale des animaux articuls et pieds articuls1 et application de ces connoissances la nomenclature des principales parties des mmes animaux4 7,mmoires du ,mus4 d',hist4 ,nat41 viii1 #ahbb1 pp4 #afi-bjb47 ,cuvier1 ,george ,leopold ,christian ,dagobert4 ,rapport sur les recherches anatomiques sur le thorax des animaux articuls et celui des insectes en particulier par ,m4 ,v4 ,audouin4 #d1 pp4 #ae1 tab4 #a1 ,paris1 #ahbc4 ,audouin1 ,jean ,victor4 ,recherches anatomiques sur le thorax des animaux articuls et celui des insectes hexapodes en particulier4 7,annales des ,sciences naturelles1 i1 pp4 #ig-ace1 #daf-dcb1 #ahbd47 ,kirby1 ,william1 and ,william ,spence4 ,introduction to entomology4 i-iv1 #ahaf-ahbh1 ,london4 ,straus-,durckheim1 ,hercule4 ,considrations gnrales sur l'anatomie compare des animaux articuls4 ,paris1 #ahbh1 atlas of #ai plates4 ,mac,leay1 ,william ,sharp4 ,explanation of the comparative anatomy of the thorax in winged insects1 with a review of the present state of the nomenclature of its parts4 7,zol4 ,journal1 v1 pp4 #ade-agi1 #ahcj1 #b ,pls47 ,burmeister1 ,hermann4 ,a manual of entomology4 ,trans4 by ,w4 ,e4 ,shuckard1 #h1 pp4 #fed1 ,london1 #ahcf1 #cb ,pl4 ,westwood1 ,john ,obadiah4 ,an introduction to the modern classification of insects1 i1 ii1 #h1 pp4 #dfb1 #ehg1 #aeh1 #a ,pl4 and #acc blocks of figs41 #ahci-ahdj4 ,newport1 ,george4 ,art4 ,insecta in ,todd's ,cyclopdia of ,anatomy and ,phys4 ii1 pp4 #hec-iid1 #ahci1 ,figs4 #cbi-dci4 ,erichson1 ,wilhelm ,ferdinand4 ,entomographien4 ,berlin1 #ahdj4 ,brull1 ,auguste4 ,recherches sur les transformations des appendices dans les articuls4 7,annales des ,sciences nat4 ,sr4 #c1 ii1 pp4 #bga-cgd1 tab4 #a1 #ahdd47 ,winslow1 ,a4 ,p43 son4 ,om byggnaden af thorax hos ,insekterna4 ,helsingborg1 #ahfb1 #a ,pl1 pp4 #bd4 ,packard1 ,alpheus ,spring4 ,guide to the study of insects4 #ahfi4 ---- ,systematic position of the ,orthoptera in relation to other insects4 7,third report ,u4 ,s4 ,ent4 ,commission1 pp4 #bhf-cde1 #ahhc1 ,pls4 xxiii-lxi47 ,graber1 ,vitus4 ,die ,insekten4 #ab1 pp4 #djc1 #fjc1 ,mnchen1 #ahgg1 many ,figs4 ,huxley1 ,thomas ,henry4 ,a manual of the anatomy of invertebrated animals4 #ab1 pp4 #cig-dea1 ,figs41 ,london1 #ahgg4 ,hammond1 ,arthur4 ,thorax of the blow-fly4 7,journ4 ,linn4 ,soc41 ,london1 xv4 ,zol41 #ahhj1 pp4 #ca47 ,brauer1 ,friedrich4 ,ueber das ,segment mdiaire ,latreille's4 7,sitzb4 d4 k4 ,akad4 d4 ,wissensch4 ,wien1 #ahhb1 pp4 #bah-bda1 #c tab47 ---- ,systematisch-zoologische ,studien4 7,ibid41 #ahhe1 pp4 #bcg-dac47 ,gosch1 ,c4 ,c4 ,a4 ,on ,latreille's theory of 8,le ,segment mdiaire40 7,nat4 ,tidsskrift 7#c71 xiii1 pp4 #dge-eca1 #ahhc47 ,miall1 ,l4 ,c41 and ,denny1 ,alfred4 ,the structure and life-history of the cockroach 7,periplaneta orientalis74 ,an introduction to the study of insects4 #h1 pp4 #bbd1 ,london1 #ahhf4 ,cheshire1 ,frank ,r4 ,bees and bee-keeping4 i1 ,scientific1 ,london1 #ahhf1 ,pls4 and ,figs4 ,lang1 ,arnold4 ,text-book of comparative anatomy4 i1 pp4 #dbf-ejh1 #ahia1 many ,figs4 ,kolbe1 ,h4 ,j4 ,einfhrung in die ,kenntniss der ,insekten4 #h1 pp4 #gji1 #cbd figs41 ,berlin1 #ahic4 ,sharp1 ,david4 ,the ,cambridge natural history4 ,insecta1 i1 #h1 pp4 #hc-ehd1 #ahie1 ,figs4 #dg-cga4 ,also the works of ,bos1 ,chabrier1 ,cholodkowsky1 ,comstock1 ,dewitz1 ,eaton1 ,erichson1 ,gerstaecker1 ,girard1 ,grassi1 ,hagen1 ,haase1 ,kellogg1 ,knoch1 ,lacordaire1 ,latreille1 ,leuckart1 ,lendenfeld1 ,lowne1 ,lubbock1 ,mayer1 ,meinert1 ,f4 ,mller1 ,osten-,sacken1 ,pagenstecher1 ,reinhard1 ,schaum1 ,schidte1 ,scudder1 ,j4 ,b4 ,smith1 ,spinola1 ,stein1 ,weismann1 ,wood-,mason4 ,,the ,,head ,,and ,,its ,,appendages a4 ,the head ,illustration3 ,,fig4 #bd4--,presumed larva of ,nemoptera 7,necrophilus arenarius71 ,pyramids of ,egypt4--,after ,roux1 from ,sharp4 ,while the head is originally composed of probably not less than six segments1 these are in the adult insect fused together into a capsule or hard chitinous box1 the epicranium1 with no distinct traces of the primitive segments4 ,the head contains the brain and accessory ganglia1 the mouth or buccal cavity1 also the air-sacs in many winged forms1 and gives support to the external organs of sense1 the antenn1 and to the buccal appendages1 the larger part of the interior being filled with the muscles moving these structures4 ,the solid walls of the head serve as a lever or support for the attachment of these muscles1 especially those of the mandibles4 ,thus there is a correlation between the large size of the mandibles of the soldier white ants and ants1 the head being correspondingly large to accommodate the great mandibular muscles4 ,the other extreme is seen in the larva of ,necrophilus 7,fig4 #bd71 with its long slender neck and diminutive head4 ,the clypeus4--,this is that part of the head situated in front of the epicranium1 and anterior to the eyes1 forming the roof of the posterior part of the mouth1 and is1 as embryology shows1 probably a tergal sclerite4 ,it varies greatly in shape and size in the different orders of insects4 ,it is often divided into two parts1 the clypeus posterior and clypeus anterior1 or which may be designated as the post- and ante-clypeus 7,figs4 #bi1 ,b74 ,the labrum4--,the 8upper lip0 or labrum is an unpaired flap-like piece hinged to the front edge of the clypeus1 and may be seen to move up and down when the insect moves its mandibles4 ,it forms the roof of the anterior part of the mouth 7,figs4 #fi1 #gd71 and its inner side is lined with a soft membrane1 usually provided with hairs and sense-papill or cups1 forming the epipharynx4 ,the labrum is more or less deeply bilobed1 especially in caterpillars and in adult ,staphylinid1 and has been thought by some writers 7,kowalevsky1 ,carrire1 and also ,chatin7 to represent a pair of appendages1 but ,heymons 7#ahie7 refutes this view1 stating as his reason that the labrum arises between the two halves of the nervous system 7protocerebrum71 while all the true appendages arise on each side of the nervous system4 7,see also ,fig4 #cd47 ,illustration3 ,,fig4 #be4--;,front view of the head of ,c4 spretus3 ,e1 epicranium2 ,c1 clypeus2 ,l1 labrum2 ,o1 o1 ocelli2 e1 eye2 a1 antenna2 md1 mandible2 mx1 portion of maxilla uncovered by the labrum2 p1 maxillary palpus2 p1 labial palpus4 ,in the fleas 7,siphonaptera7 both the clypeus and labrum are wanting4 ,while it apparently forms an anterior specialized portion of the procephalic lobes1 ,viallanes regarded it as belonging to the third1 or his tritocerebral1 segment1 since the labral nerves arise from the tritocerebral ganglia4 ,but since in all the early as well as late stages of embryonic life it appears to be situated in front of the mouth1 it would seem to belong to the first segment4 ,in the embryo of ,blatta it first appears as a thick crescentic fold being slightly divided anterior to the mouth1 and in ,doryphora it appears as a heart-shaped or deeply bilobed prominence situated in front of the mouth 7,wheeler74 ,the epipharynx and labrum-epipharynx4--,the epipharynx is the under surface or pharyngeal lining of the clypeus and labrum1 forming the membranous roof of the mouth4 ,as it contains the organs of taste and has been generally overlooked by entomologists1 we may dwell at some length on its structure in different orders4 ,raumur was1 so far as we have been able to ascertain1 the first author to describe and figure the epipharynx1 which he observed in the honey bee and bumble bee1 and called la langue1 remarking that it closes the opening into the sophagus1 and that it is applied against the palate4 ,according to ,kirby and ,spence1 ,de ,geer described the epipharynx of the wasp2 and ,latreille referred to it1 calling it the sous labre4 ,the name epipharynx was bestowed upon this organ by ,savigny1 who thus speaks of that of the bees3 8,ce pharynx est1 la vrit1 non seulement cach par la lvre suprieure1 mais encore exactement recouvert par un organe particulier que ,raumur a dj dcrit4 ,c'est une sorte d'appendice membraneux qui est reu entre les deux branches des mchoires4 ,cette partie ayant pour base le bord suprieur du pharynx1 peut prendre le nom d'pipharynx ou d'piglosse40 ,he also describes that of ,diptera4 ,what ,walter has lately proved to be the epipharynx of ,lepidoptera was regarded by ,savigny and all subsequent writers as the labrum4 ,the latest account of the function of this organ is that by ,cheshire1 who states that the tube made by the maxill and labial palpi cannot act as a suction pipe1 because it is open above4 8,this opening is closed by the front extension of the epipharynx1 which closes down to the maxill1 fitting exactly into the space they leave uncovered1 and thus the tube is completed from their termination to the sophagus40 ,illustration3 ,,fig4 #bf4--;,epipharynx of ,phaneroptera angustifolia3 cl1 clypeus2 lbr4 e1 labrum-epipharynx2 t c1 taste cups1 both on the clypeal and on the labral regions4 ,illustration3 ,,fig4 #bg4--;,epipharynx of ,hadencus subterraneus1 cave cricket4 ,it is singular that this organ is not mentioned in ,burmeister's ,manual of entomology1 in ,lacordaire's ,introduction l'entomologie1 or by ,newport in his admirable article ,insecta in ,todd's ,cyclopedia of anatomy4 ,neither has ,straus-,durckheim referred to or figured it in his great work on the anatomy of ,melolontha vulgaris4 ,in their excellent work on the cockroach1 ,miall and ,denny state that 8,the epipharynx1 which is a prominent part in ,coleoptera and ,diptera1 is not recognizable in ,orthoptera0 7p4 #de74 ,we have1 however1 found it to be always present in this order 7,figs4 #bf1 #bg74 ,we are not aware that any modern writers have described or referred to the epipharynx of the mandibulate orders of insects4 ,although ,dr4 ,g4 ,joseph speaks of finding taste-organs on the palate of almost every order of insects1 especially plant-feeding forms1 we are unable to find any specific references1 his detailed observations being apparently unpublished4 ,the epipharynx is so intimately associated with the elongated labium of certain ,diptera1 that1 with ,dr4 ,dimmock1 we may refer to the double organ as the labrum-epipharynx2 and where1 as in the lepidopterous ,micropteryx semipurpurella1 described and figured by ,walter1 and the ,panorpid 7,panorpa and ,boreus71 the labrum seems pieced out with a thin1 pale membranous fold which appears to be an extension of the epipharynx1 building up the dorsal end of the labrum1 this term is a convenient one to use4 ,in the lower orders of truly mandibulate insects1 from the ,thysanura to the ,coleoptera1 excluding those which suck in liquid food1 such as the ,diptera1 ,lepidoptera1 and ,hymenoptera1 and the ,mecoptera 7,panorpid7 with their elongated head and feeble1 small mandibles1 the epipharynx forms a simple membranous palatal lining of the clypeus and labrum4 ,in such insects there is no soft projecting or pendant portion1 fitted to close the throat or to complete a partially tubular arrangement of the first and second maxill4 ,in all the mandibulate insects1 then1 the epipharynx forms simply the under surface or pharyngeal lining of the clypeus and labrum1 the surface being uniformly moderately convex1 and corresponding in extent to that of the clypeus and labrum1 posteriorly merging into the palatal wall of the pharynx2 the armature of peculiar gathering-hairs sometimes spreading over its base1 being continuous with those lining the mouth and beginning of the sophagus4 ,the suture separating the labrum from the clypeus does not involve the epipharynx1 though since certain gustatory fields lie under the front edge of the clypeus1 as well as labrum1 one may in describing them refer to certain fields or groups of cups or pits as occupying a labral or clypeal region or position4 ,the lack of traces of a suture in the epipharynx corresponding to the labral suture above1 suggests that the labrum does not represent a pair of coalesced appendages1 and that it1 with the clypeus1 simply forms the solid cuticular roof of the mouth4 ,the only soft structures seen between the epipharynx and labrum1 besides the nerves of special sense1 are the elevator muscles of the labrum1 and two trache1 one on each side4 ,the structure and armature of the epipharyngeal surface even besides the taste-pits1 taste-cups and rods1 is very varied1 the set assuming very different shapes4 ,there seem to be two primary forms of set1 7#a7 the normal forms which arise from a definite cell2 and 7#b7 soft1 flattened1 often hooked hairs which are cylindrical towards the end1 but arise from a broad triangular base1 without any cell-wall4 ,these are like the 8gathering hairs0 of ,cheshire1 situated on the bees' and wasps' tongue2 they also line the walls of the pharynx and extend toward the sophagus4 ,they are also similar to the 8hooked hairs0 of ,will4 ,the first kind1 or normal set1 are either simply defensive1 often guarding the sense-cups or sensory fields on which the sense-cups are situated1 or they have a nerve extending to them and are simply tactile in function4 ,the surface of the epipharynx1 then1 appears to be highly sensitive1 and to afford the principal seat of the gustatory organs1 which are described under the head of organs of taste4 ,,literature ,,on ,,the ,,epipharynx ,raumur4 ,mmoires pour servir l'histoire des insectes1 v1 #agdj1 p4 #cah1 ,pl4 #bh1 ,figs4 #d1 #g1 #h1 #i1 #aj1 #aa l4 ,kirby and ,spence4 ,intr4 to entomology1 iii1 #ahbh1 p4 #deg4 ,de ,geer4 ii1 #aggh2 v1 #bf1 ,fig4 #aa1 ,m4 ,kirby and ,spence4 ,pl4 xii1 ,fig4 #b ,k4 ,latreille4 ,organisation extrieure des insectes1 p4 #ahd4 7,quoted from ,kirby and ,spence47 ,savigny4 ,mmoires sur les animaux sans vertbres4 ,partie ,ire1 #ahaf1 p4 #ab4 ,walter1 ,alfred4 ,beitrge zur ,morphologie der ,schmetterlinge4 ,erster ,theil4 ,zur ,morphologie des ,schmetterlingsmundtheile4 7,jena4 ,zeits41 xviii1 #ahhe1 p4 #geb47 ,cheshire1 ,f4 ,r4 ,bees and bee-keeping1 i1 ,london1 #ahhf1 p4 #ic4 ,joseph1 ,gustav4 ,zur ,morphologie des ,geschmacksorganes bei ,inseckten4 7,amtlicher ,bericht der #ej ,versammlung deutscher ,naturforscher u4 ,artzte in ,mnchen4 #ahgg1 pp4 #bbg1 #bbh47 ,dimmock1 ,george4 ,the anatomy of the mouth-parts and of the sucking apparatus of some ,diptera1 #ahha4 7,also in ,psyche1 iii1 pp4 #bca-bda1 ,pl4 #a1 #ahhb47 ,packard1 ,a4 ,s4 ,on the epipharynx of the ,panorpid4 7,psyche1 #ahhi1 v1 pp4 #aei-afd47 ---- ,notes on the epipharynx and the epipharyngeal organs of taste in mandibulate insects4 7,psyche1 v1 pp4 #aic-aii1 #bbb-bbh1 #ahhi47 ,attachment of the head to the trunk4--,the head is either firmly supported by the broad prothoracic segment in ,orthoptera1 many beetles1 etc41 into which it is more or less retracted1 or it is free and attached by a slender neck1 easily turning on the trunk1 as in dragon-flies1 flies1 etc4 ,in some insects there are several chitinous plates1 situated on an island in the membrane on the under side of the neck2 these are the 8cervical sclerites0 of ,sharp1 occurring 8in ,hymenoptera1 in many ,coleoptera1 and in ,blattid40 ,the basal or gular region of the head4--,at the hinder part of the head is the opening 7occipital foramen7 into the trunk4 ,the cheek 7gena7 is the side of the head1 and to its inner wall is attached the mandibular muscle2 it thus forms the region behind the eye and over the base of the mandibles4 ,in the ,termitid1 where the head is broad and flat1 it forms a distinct piece on the under side of the head bounding the gulo-mental region 7,fig4 #bh74 ,in the ,neuroptera 7,corydalus1 ,fig4 #bi1 and ,mantispa1 ,fig4 #cj7 it is less definitely outlined4 ,illustration3 ,,fig4 #bi4--;,head of ,corydalus cornutus1 3 ,a1 from above4 ,b1 from beneath4 ,c1 from the side4 a4 cly1 clypeus anterior2 p4 cly1 clypeus posterior2 lbr1 labrum2 md1 mandible2 mx1 base of first maxilla2 mp1 its palpus2 m1 mentum2 sm1 submentum2 plpr1 palpifer2 lig1 fused second maxill2 ant1 antenna2 occ1 occiput4 ,illustration3 ,,fig4 #bh4--;,head of ,termopsis angusticollis1 seen from beneath1 showing the gena and gula3 m1 mentum2 sm1 submentum2 labr1 under side of the labrum2 x1 hypopharyngeal chitinous support4 ,all the gulo-mental region of the head appears to represent the base of the second maxill1 and the question hence arises whether the submentum is not the homologue of the cardines of the first maxill fused1 and the mentum that of the stipites of the latter also fused together4 ,if this should prove to be the case1 the homologies between the two pairs of maxill will be still closer than before supposed4 ,where the gula is differentiated1 this represents the basal piece of the second maxill4 ,in ,figs4 #bh1 #bi1 #cj1 and #ca1 these three pieces are clearly shown to belong to the second maxillary segment4 ,it is evident that these pieces or sclerites belong to the second maxillary or labial segment of the head1 as does the occiput1 which may represent the tergo-pleural portion of the segment4 ,miall and ,denny also regarded the submentum as the basal piece of the second maxill4 ,illustration3 ,,fig4 #cj4--;,head of ,mantispa brunnea1 under side3 e1 eye2 other lettering as in ,fig4 #bi4 ,illustration3 ,,fig4 #ca4--;,head of ,limnephilus pudicus1 under side3 e1 eye2 l1 ligula2 p1 palpifer2 lp1 labial palpi4 ,the occiput 7,fig4 #bi1 ,b1 ,c71 as stated beyond1 is very rarely present as a separate piece2 in the adult insect we have only observed it in ,corydalus4 ,the occipital region may be designated as that part of the head adjoining and containing the occipital foramen4 ,newport considers the occiput as that portion of the base of the head 8which is articulated with the anterior margin of the prothorax4 ,it is perforated by a large foramen1 through which the organs of the head are connected with those of the trunk4 ,it is very distinct in ,hydros and most ,coleoptera1 and in some1 the ,staphylinid1 ,carabid1 and ,silphid is constricted and extended backwards so as to form a complete neck40 7,see also p4 #ea47 ,illustration3 ,,fig4 #cb4--;,interior and upper and under surface of the head of ,hydros piceus3 d1 clypeus2 e1 labrum2 g1 maxilla2 h1 its palpus2 i1 labium2 k1 labial palpus2 p1 sutura epicranii2 q1 cotyloid cavity2 r1 torulus2 s1 v1 lamin squamosa2 t1 lamina posteriores2 u1 tentorium2 w1 lamin orbitales2 x1 os transversum2 y1 articulating cavity for the mandible2 z1 os hypopharyngeum4--,after ,newport4 ,the tentorium4--,the walls of the head are supported or braced within by two beams or endosternites passing inwards1 and forming a solid chitinous process or loop which extends in the cockroach downwards and forwards from the lower edge of the occipital foramen4 8,in front it gives off two long crura or props1 which pass to the ginglymus1 and are reflected thence upon the inner surface of the clypeus1 ascending as high as the antennary socket1 round which they form a kind of rim40 7,miall and ,denny47 ,the sophagus passes upwards between its anterior crura1 the long flexor of the mandible lies on each side of the central plate2 the suprasophageal ganglion rests on the plate above1 and the subsophageal ganglion lies below it1 the nerve cords which unite the two passing through the circular aperture4 7,miall and ,denny47 ,in ,coleoptera 7,hydros7 it protects the nervous cord which passes under it4 7,newport1 ,fig4 #cb1 u47 ,illustration3 ,,fig4 #cc4--,posterior view of head of ,anabrus2 t1 tentorium4 ,joutel del4 ,in ,anabrus the tentorium is ,v-shaped1 the two arms originating on each side of the base of the clypeus next to the base of each mandible the origin being indicated by two small foramina partly concealed externally and passing inwards and backwards and uniting just before reaching the posterior edge of the large occipital foramen 7,fig4 #cc74 ,palmn regards the tentorium as representing a pair of trache 7with the cephalic spiracles7 which have become modified for supports or for muscular attachment1 since he finds that in ,ephemera the tentorium breaks across the middle during exuviation1 each half being drawn out of the head like the chitinous lining of a tracheal tube4 ,this view is supported by ,wheeler1 who has shown that the tentorium of ,doryphora originates from five pairs of invaginations of the longitudinal commissures1 and which are anterior to those of the second maxillary segment4 8,these invaginations grow inwards as slender tubes1 which anastomose in some places4 ,their lumina are ultimately filled with chitin40 7,jour4 ,morph41 iii1 p4 #cfh47 ,this view has also been held by ,carrire and ,cholodkowsky1 but ,heymons concludes from his embryological studies on ,forficula and ,blattid 7#ahie7 that it is unfounded4 ,that this is probably the case is proved by the fact that the apodemes of the thoracic region are evidently not modified trache1 since the stigmata and trache are present4 ,number of segments in the head4--,while it is taken for granted by many entomologists that the head of insects represents a single segment1 despite the circumstance that it bears four pairs of appendages1 the more careful1 philosophical observers have recognized the fact that it is composed of more than a single segment4 ,burmeister recognized only two segments in the head2 ,carus and ,audouin recognized three2 ,macleay and ,newman four2 ,straus-,durckheim even so many as seven4 ,huxley supposed that there are five segments bearing appendages1 remarking1 8if the eyes be taken to represent the appendages of another somite1 the insect head will contain six somites40 7,manual of ,anat4 ,invert4 ,animals1 p4 #cih47 ,these discordant views were based on the examination of the head in adult insects2 but if we confine ourselves to the imago alone1 it is impossible to arrive at a solution of the problem4 ,newport took a step in the right direction when he wrote3 8,it is only by comparing the distinctly indicated parts of the head in the perfect insect with similar ones in the larva that we can hope to ascertain the exact number of segments of which it is composed40 ,he then states that in the head of ,hydros piceus are the remains of four segments1 though still in the next paragraph1 when speaking of the head as a whole1 he considers it as the first segment1 8while10 he adds1 8the aggregation of segments of which it is composed we shall designate individually subsegments40 ,that the head of insects is composed of four segments was shown on embryological grounds by the writer 7#ahga7 and afterwards by ,graber 7#ahgi74 ,the antenn and mouth-parts are outgrowths budding out from the four primitive segments of the head2 the antenn grow out from the under side of the procephalic lobes1 and these should therefore receive the name of antennal lobes4 ,in like manner the mandibles and first and second maxill arise respectively from the three succeeding segments4 ,illustration3 ,,fig4 #cd4--;,embryo of ,anurida maritima3 tc4 ap1 minute temporary appendage of the tritocerebral segment1 the premandibular appendage2 at1 antenna2 md1 mandible2 mx#a1 first maxilla2 mx#b1 second maxilla2 p#a-p#c1 thoracic2 ap#a1 ap#b1 abdominal appendages2 an1 anus--,after ,wheeler4 ,while the postoral segments and their appendages are readily seen to be four in number1 the question arises as to whether the eyes represent the appendages of one or more preoral segments4 ,in this case embryology thus far has not afforded clear1 indubitable evidence4 ,we are therefore obliged to rely on the number of neuromeres1 or primitive ganglia4 ,in the postoral region of the head1 as also in the trunk1 a pair of neuromeres correspond to each segment4 7,see also under ,nervous ,system1 and under ,embryology47 ,we therefore turn to the primitive number of neuromeres constituting the procephalic lobes or brain4 ,from the researches of ,patten1 ,viallanes1 and of ,wheeler1 especially of ,viallanes1 it appears that the brain or suprasophageal ganglion is divided into three primitive segments4 7,see ,nervous ,system1 ,brain47 ,the antenn are innervated from the middle division or deutocerebrum4 ,hence the ocular segment1 i4e4 that bearing the compound and simple eyes1 is supposed to represent the first segment of the head4 ,this1 however1 does not involve the conclusion that the eyes are the homologues of the limbs1 however it may be in the ,crustacea4 ,the second head-segment is the antennal1 the antenn being the first pair of true jointed appendages4 ,the third segment of the head is very obscurely indicated1 and the facts in proof of its existence are scanty and need farther elucidation4 ,viallanes' tritocerebral lobes or division of the brain is situated in a segment found by ,wheeler to be intercalated between the antennal and mandibular segments4 ,he also detected in ,anurida maritima1 the rudiments of a pair of appendages1 smaller than those next to it1 and which soon disappear 7,fig4 #cd1 tc4 ap74 ,he calls this segment the intercalary4#ab ,heymons 7#ahie7 designates it as the 8,vorkiefersegment10 and it may thus be termed the premandibular segment4 ,illustration3 ,,fig4 #ce4--;,head of embryo of honey bee3 ,b1 a little later stage than ,a4 pr4m1 premandibular segment2 cl1 clypeus2 ant1 antenna2 md1 mandible2 mx1 first maxilla2 mx1 second maxilla2 sp1 spiracle4--,after ,btschli4 ,as early as #ahgj ,btschli observed in the embryo of the honey bee the rudiments of what appeared to be a pair of appendages between the antenn and mandibles1 but1 judging by his figures1 nearer to and more like the mandibles than the rudimentary antenn 7,fig4 #ce72 they seemed to him 8almost like a pair of inner antenn40 8,i find10 he says1 8in no other insects any indication of this peculiar appendage1 which at the time of its greatest development attains a larger size than the antenn1 and which1 afterwards becoming less distinct1 forms by fusion with that on the other side a sort of larval lower lip4 ,that this appendage does not belong to the category of segmental appendages is indicated by the site of its origin on the upper side of the primitive band40 7,zeitschr4 wissen4 ,zool41 xx1 p4 #ech47 ,grassi has also observed it in ,apis1 and regards it as the germ of a first1 but deciduous1 pair of jaws4 ,in the embryo of ,hylotoma ,graber 7,figs4 #acd1 #ace7 found what he calls three pairs of 8preantennal projections10 one of which he thinks corresponds to the 8inner antenn0 of ,btschli4 ,this subject needs further investigation4 ,it thus appears that the procephalic lobes of the embryo of insects1 with the rudiments of the antenn1 constitute the primitive head1 and perhaps correspond to the annelidan head1 while gradually the antennal appendages were in the phylogenetic development of the class fused with the two segments of the primary head4 ,that the second maxillary segment1 the occiput1 was the last to be added1 and at first somewhat corresponded in position to the poison-fangs of centipedes 7,chilopods71 is shown by our observations on the embryology of schna 7,fig4 #cf74 ,illustration3 ,,fig4 #cf4--schna nearly ready to hatch3 #d1 labium1 between ,t and e the occipital tergite2 #e-g1 legs4 ,illustration3 ,,fig4 #cg4--;,head of embryo ,nematus1 showing the labial segment3 occ1 forming the occiput2 cl1 clypeus2 lb1 labrum2 md1 mandible2 mdm1 muscle of same2 mx1 maxilla2 mx1 second maxilla 7labium72 oe1 sophagus4 ,the mandibular segment appears to form a large part of the post-antennal region of the epicranium on account of the great mandibular muscle which arises from so large an area of the anterior region of the head 7,fig4 #cg74 ,judging from the embryo of ,nematus 7,fig4 #cg71 the first maxillary segment is tergally aborted1 there being no tergo-pleural portion left4#ac ,the second maxillary segment tergally appears to be represented by the occipital region of the head4 ,all the gular region1 including the submentum and mentum1 probably represents the base of the labium or second maxill4#ad ,the so-called 8occiput0 forms the base of the head of ,corydalus1 a neuropterous insect1 which1 however1 is more distinct in the larva4 ,in most other adult insects the occiput is either obsolete or fused with the hinder part of the epicranium4 ,we have traced the history of this piece 7sclerite7 in the embryo of schna1 a dragon-fly1 and have found that it represents the tergal portion of the sixth or labial segment4 ,in our memoir on the development of this dragon-fly1 ,pl4 #b1 ,fig4 #i1 the head of the embryo is seen to be divided into two regions1 the anterior1 formed of the antennal1 mandibular1 and first maxillary segments1 and the posterior1 formed of the sixth or labial segment4 ,this postoral segment at first appears to be one of the thoracic segments1 but is afterwards added to the head1 though not until after birth1 as it is still separate in the freshly hatched nymph 7,fig4 #d2 see also ,kolbe1 p4 #acb1 ,fig4 #ei1 sq4 #e74 ,a4 ,brandt's figure of ,calopteryx virgo 7,pl4 #b1 ,fig4 #ai7 represents an embryo of a stage similar to ours1 in which the postoral or sixth 7labial7 segment is quite separate from the rest of the head4 ,the accompanying figure1 copied from our memoir1 also shows in a saw-fly larva 7,nematus ventricosus7 the relations of the labial or sixth segment to the rest of the head4 ,the suture between the labial segment and the preoral part of the head disappears in adult life4 ,from this sketch it would seem that the back part of the head1 i4e4 of the epicranium1 may be made up in part of the tergite or pleurites of the mandibular segment1 since the mandibular muscles are inserted on the roof of the head behind the eyes4 ,it is this labial segment which in ,corydalus evidently forms the occiput1 and of which in most other insects there is no trace in larval or adult life1 unless we except certain ,orthoptera 7,locusta71 and the larva of the ,dyticid4 ,the following table is designed to show the number and succession of the segments of the head1 with their respective segments4 ,,tabular ,,view ,,of ,,the ,,segments1 ,,pieces 7,,sclerites71 ,,and ,,appendages ,,of ,,the ,,head ,,name ,,of ,,segment ,,pieces ,,or ,,regions ,,appendages1 ,,etc4 ,,of ,,the ,,head-,,capsule #a4 ,ocellar ,epicranium1 ,compound and simple ,preoral1 7,protocerebral74 anterior region eyes 7,ocelli74 in early with the clypeus embryo4 labrum1 and epipharynx4 ,postoral1#b4 ,antennal ,epicranium1 ,antenn4 in early 7,deutocerebral74 including the embryo4 antennal sockets4 #c4 ,premandibular1 ,wanting in ,premandibular or intercalary postembryonic appendages 7in 7,tritocerebral74 life1 except in ,campodea74 ,campodea4 #d4 ,mandibular4 ,epicranium behind ,mandibles4 the antenn1 gen4 #e4 #ast ,maxillary4 ,epicranium1 hinder #ast ,maxill4 edge8 ,tentorium4 #f4 #b;d ,maxillary1 or,occiput4 #b;d ,maxill or labial4 ,labium4 ,post-gula1 gula1 submentum1 mentum1 hypopharynx 7lingua1 ligula71 paragloss1 spinneret4 ,illustration3 ,,fig4 #ch4--,larva 7a7 of a chalcid1 about to pupate1 with the head1 including the eyes and three ocelli1 in the prothoracic segment3 b1 c1 pupa4 ,the composition of the head in the ,hymenoptera4--,ratzeburg stated in #ahcb that the head in the adult ,hymenoptera 7,cynips1 ,hemiteles1 and ,formica7 does not correspond to that of the larva1 but is derived from the head and the first thoracic segment of the larva4 ,westwood and also ,goureau made less complete but similar observations1 though ,westwood afterwards changed his opinion1 and the same view was maintained by ,reinhard4 ,our own observations 7as seen in ,fig4 #ch7 led us to suppose that this was a mistaken view2 that the larval head1 being too small to contain that of the semipupa1 was simply pushed forward1 as in caterpillars4 ,bugnion1 however1 reaffirms it in such a detailed way that we reproduce his account4 ,he maintains that the views of ,ratzeburg are exact and easy to verify in the chalcid genus ,encyrtus1 except1 however1 that which concerns the ventral part and the posterior border of the prothoracic segment4 ,as the time of transformation approaches1 the head of the larva1 he says1 is depressed and soon concealed under the edge of the prothoracic segment2 the latter elongates1 becomes thicker and more convex1 and within can be seen the two oculo-cephalic imaginal buds4 ,the head of the perfect insect is derived not only from the head of the larva1 but also from the portion of the prothoracic segment which is occupied by the buds1 i4e4 almost its entire dorsolateral face4 ,but the hinder and ventral part of this segment 7which contains the imaginal buds of the first pair of legs7 takes no part in the formation of the head2 these parts1 according to ,bugnion1 towards the end of the larval period detaching themselves so as to become fused with the thorax and constitute the pronotum and the prosternum4 ,illustration3 ,,fig4 #ci4--;,anterior half of larva of ,encyrtus1 ventral face1 showing the upper 7wing7 and lower 7leg7 thoracic imaginal buds3 b1 mouth2 ch1 chitinous arch2 gl1 silk gland2 g1 brain2 n1 nervous cord2 a#a1 bud of fore1 a#b1 bud of hind1 wing2 p#a-p#c1 buds of legs2 st#a-st#c1 stigmata4 ,illustration3 ,,fig4 #dj4--;,anterior part of ,encyrtus larva1 #a4b mm4 in length2 dorsal face2 the cellular masses beginning to form the buds of the wings1 eyes1 and antenn3 o1 eye bud2 e1 stomach4 ,illustration3 ,,fig4 #da4--,older ,encyrtus larva1 lateral view1 showing the buds of the antenn 7f71 legs1 and wings2 oe1 sophagus2 q#a1 q#b1 q#c1 buds of the genital armature2 x1 rudiment of the sexual gland 7ovary or testis72 u1 urinary tube2 i1 intestine 7rectum72 a1 anus4 ,illustration3 ,,fig4 #db4--;,a still older larva1 ready to transform4 ,the imaginal buds of the antenn1 eyes1 wings1 and legs have become elongated2 lettering as in ,fig4 #da4--,this and ,figs4 #ci-da after ,bugnion4 ,this mode of formation of the head may be observed still more easily in ,rhodites1 ,hemiteles1 and ,microgaster1 from the fact that their oculo-cephalic buds are much more precocious1 and that the eyes are charged with pigment at a period when the insect still preserves its larval form4 8444 ,i believe that this mode of formation of the head occurs in all ,hymenoptera with apodous larv1 in this sense2 that a more or less considerable part of the first thoracic segment is always soldered to the head of the larva to constitute the head of the perfect insect4 ,the arrangement of the nervous system is naturally in accord with this peculiarity of development1 and the cephalic ganglia of the larva to which the ocular blastems later adapt themselves1 are found not in the head1 but in the succeeding segment 7,figs4 #ci1 #dj1 #da74 8,relying on these facts1 ,i maintain that the encroachment of the head on the prothorax is a consequence of the preponderance in size of the brain1 and indicates the superiority of the ,hymenoptera over other insects44440 ,that the pronotum is derived from the larval prothoracic segment is proved by the fact that the first pair of stigmata becomes what authors call the 8prothoracic0 stigmata of the perfect insect4 ,but ,bugnion thinks that the projection which carries it1 and which he calls the shoulder 7,figs4 #da and #db71 belongs to the mesonotum4 b4 ,appendages of the head ,the antenn4--,these are organs of tactile sense1 but also bear olfactory1 and in some cases auditory organs2 they are usually inserted between or in front of the eyes1 and moved by two small muscles at the base1 within the head4 ,in the more generalized insects the antenn are simple1 many-jointed appendages1 the joints being equal in size and shape4 ,the antenn articulate with the head by a ball and socket joint1 the part on which it moves being called the torulus 7,fig4 #cb1 r74 ,in the more specialized forms it is divided into the scape1 the pedicel1 and a flagellum 7or clavola72 but usually1 as in ants1 wasps1 and bees1 there are two parts1 the basal three-jointed one being the scape1 and the distal one1 the usually long filiform flagellum4 ,the antenn1 especially the flagellum1 vary greatly in form in insects of different families and orders1 this variation being the result of adaptation to their peculiar surroundings and habits4 ,the number of antennal joints may be one 7,articerus1 a clavigerid beetle71 or two in ,paussus and in ,adranes ccus 7,fig4 #dcab71 where they are short and club-shaped2 in flies 7,muscid1 etc471 they are very short and with few joints1 and when at rest lying in a cavity adapted for their reception4 ,in the lamellicorn beetles the flagellum is divided into several leaves1 and this condition may be approached in the serrate or flabellicorn antenn of other beetles4 ,in ,lepidoptera1 and in certain saw-flies and beetles1 they are either pectinate or bipectinate1 being in one case at least1 that of the ,australian ,hepialid 7,abantiades argenteus71 tripectinate 7,fig4 #dd71 and in the dipterous 7,tachinid7 genus ,talarocera the third joint is bipectinate 7,fig4 #de74 ,in ,xenos and in ,parnus they may be deeply forked1 while in ,otiocerus1 two long processes arise from the base1 giving it a trifid shape4 ,in dragon-flies and cicad1 they are minute and hair-like1 though jointed1 while in the larv of many metabolous insects they are reduced to minute three-jointed tubercles4 ,in aquatic beetles1 bugs1 etc41 the antenn are short1 and often1 when at rest1 bent close to the body1 as long antenn would impede their progress4 ,illustration3 ,,fig4 #dc4--;,different forms of antenn of beetles3 #a1 serrate2 #b1 pectinate2 #c1 capitate 7and also geniculate72 #d-g1 clavate2 #h1 #i1 lamellate2 #aj1 serrate 7,dorcatoma72 #aa1 irregular 7,gyrinus72 #ab1 two-jointed antenna of ,adranes ccus4--,after ,le,conte4 a1 first joint of flagellum of antenna of ,troctes silvarum2 b1 of ,t4 divinatorius4--,after ,kolbe4 ,illustration3 ,,fig4 #dd4--,tripectinate antenna of an ,australian moth4 ,while usually more or less sensorial in function1 ,graber states that the longicorn beetles in walking along a slender twig use their antenn as a rope-dancer does his balancing pole4 ,illustration3 ,,fig4 #de4--;,antenna of ,talarocera nigripennis1 4--,after ,williston4 ,recent examination of the sense-organs in the antenn of an ant1 wasp1 or bee enables us1 he says1 to realize what wonderful organs the antenn are4 ,in such insects we have a rod-like tube which can be folded up or extended out into space1 containing the antennal nerve1 which arises directly from the brain and sends a branch to each of the thousands of olfactory pits or pegs which stud its surface4 ,the antenna is thus a wonderfully complex organ1 and the insect must be far more sensitive to movements of the air1 to odors1 wave-sounds1 and light-waves1 than any of the vertebrate animals4 ,that ants appear to communicate with each other1 apparently talking with their antenn1 shows the highly sensitive nature of these appendages4 8,the honey-bee when constructing its cells ascertains their proper direction and size by means of the extremities of these organs40 7,newport47 ,how dependent insects are upon their antenn is seen when we cut them off4 ,the insect is at once seriously affected1 its central nervous system receiving a great shock1 while it gives no such sign of distress and loss of mental power when we remove the palpi or legs4 ,on depriving a bee of its antenn1 it falls helpless and partially paralyzed to the earth1 is unable at first to walk1 but on partly recovering the use of its limbs1 it still has lost the power of cordinating its movements1 nor can it sting2 in a few minutes1 however1 it becomes able to feebly walk a few steps1 but it remains over an hour nearly motionless4 ,other insects after similar treatment are not so deeply affected1 though bees1 wasps1 ants1 moths1 certain beetles1 and dragon-flies are at first more or less stunned and confused4 ,the antenn afford salient secondary sexual differences1 as seen in the broadly pectinated antenn of male bombycine moths1 certain saw-flies 7,lophyrus71 and many other insects4 ,the mouth-parts1 buccal appendages1 or trophi1 comprise1 besides the labrum1 the mandibles and maxill4 ,the mandibles4--,these are true jaws1 adapted for cutting1 tearing1 or crushing the food1 or for defence1 while in the bees they are used as tools for modelling in wax1 and in ,cetonia1 etc41 as a brush for collecting pollen4 ,they are usually opposed to each other at the tips1 but in many carnivorous forms their tips cross each other like shears4 ,they are situated below the clypeus on each side1 and are hinged to the head by a true ginglymus articulation1 consisting of two condyles or tubercles to which muscles are attached1 the principal ones being the flexor and great extensor 7,fig4 #dh74 ,they are solid1 chitinous1 of varied shapes1 and in the form of the teeth those of the same pair differ somewhat from each other 7,fig4 #df ,a74 ,in the pollen-eating beetles 7,cetoni7 and in the dung-beetles 7,aphodius1 etc47 the edge is soft and flexible4 ,in the males of ,lucanus1 etc4 7,fig4 #dg71 and of ,corydalus 7,fig4 #bi71 they are of colossal size1 and are large and sabre-shaped in the larv of water-beetles1 ant-lions1 ,chrysopa1 etc4 where they are perforated at the tips1 through which the blood of their prey is sucked4 ,while the mandibles are generally regarded as composed of a single piece1 in ,campodea and ,machilis there appears to be an additional basal piece apparently corresponding to the stipes of the first maxilla1 and separated by a faint suture from the molar or distal joint4 ,in ,campodea there is a minute movable appendage figured both by ,meinert and by ,nassonow1 which appears to represent the lacinia of the maxilla 7,fig4 #dh74 ,wood-,mason has observed in the mandibles of the embryo of a ,javanese cockroach1 ,blatta 7,panesthia7 javanica1 indications of 8the same number of joints as in that of chilognathous myriopods1 or one less than in that of ,machilis40 ,also he adds3 8,in both #8larv' and adults of ,panesthia javanica a faint groove crosses the #8back' of the mandible at the base4 ,this groove appears to be the remains of the joint between the third and apical segments of the formerly #d-segmented mandibles40 ,illustration3 ,,fig4 #df4--,various forms of mandibles4 ,a1 right and left of ,termopsis4 ,a1 showing at the shaded portion the 8molar0 of ,smith4 ,b1 ,termes flavipes1 soldier2 md1 its mandible4 ,c1 ,panorpa4 ,illustration3 ,,fig4 #dg4--;,chiasognathus grantii1 reduced4 ,male4--,after ,darwin4 ,illustration3 ,,fig4 #dh4--,mandible of ,campodea3 l1 prostheca or lacinia2 g1 galea2 f1 f1 flexor muscles2 e1 extensor2 r1 r1 retractor2 rt1 muscle retaining the mandible in its place4--,after ,meinert4 ,a1 extremity of the same4--,after ,nassonow4 ,illustration3 ,,fig4 #di4--,mandible of ,passalus cornutus with the prostheca 7l73 ,a1 that of a ,nicaraguan species2 a1 inside1 b1 outside view1 with the muscle4 ,he also refers to the prostheca of ,kirby and ,spence 7,fig4 #di71 which he thinks appears to be a mandibular lacinia homologous with it in ,staphylinid and other beetles 7,j4 ,b4 ,smith also considers it as 8homologous to the lacinia of the maxilla071 and on examining it in ,p4 cornutus and a ,nicaragua species 7,fig4 #di71 we adopt his view1 since we have found that it is freely movable and attached by a tendon and muscle to the galea4 ,in the rove beetles 7,gorius1 ,staphylinus1 etc47 and in the subaquatic ,heterocerid1 instead of a molar process1 is a membranous setose appendage not unlike the coxal appendages of ,scolopendrella1 movably articulated to the jaw1 which he thinks answers to the molar branch of the jaws in ,blatta and ,machilis4 8,it has its homologue in the diminutive ,trichopterygid in the firmly chitinized quadrant-shaped second mandibular joint1 which is used in a peculiar manner in crushing the food02 also in the movable tooth of the ,passalid1 and in the membranous inner lobe of the mandibles of the goliath-beetles1 etc4 ,j4 ,b4 ,smith has clearly shown that the mandibles are compound in certain of the lamellicorns4 ,in ,copris carolina 7,fig4 #ej71 he says1 the small membranous mandibles are divided into a basal piece 7basalis71 the homologue of the stipes in the maxilla2 another of the basal pieces he calls the molar1 and this is the equivalent of the subgalea1 while a third sclerite1 only observed in ,copris1 is the conjunctivus1 the lacinia 7prostheca7 being well developed4 ,smith therefore concludes 8that the structure of the mandible is fundamentally the same as that of the labium and maxilla1 and that we have an equally complex organ in point of origin4 ,its usual function1 however1 demands a powerful and solid structure1 and the sclerites are in most instances as thoroughly chitinized and so closely united to the others that practically there is only a single piece1 in which the homology is obscured40 7,trans4 ,amer4 ,ent4 ,soc41 xix1 pp4 #hd1 #he4 #ahib47 ,from the studies of ,smith and our observations on ,staphylinus1 ,passalus1 ,phanus1 etc4 7,fig4 #ej1 ,a1 ,b7 we fully agree with the view that the mandibles are primarily #c-lobed appendages like the maxill4 ,nymphal ,ephemerids have a lacinia-like process4 7,heymons47 ,illustration3 ,,fig4 #ej4--,mandible of ,copris carolina4--,after ,smith4 ,a,c4 anaglypticus4 ,a 7figure to right71 do4 of ,leistotrophus cingulatus2 ,b1 of ,phanus carnifex2 g1 end of galea1--g1 enlarged2 c1 conjunctivus4 ,c1 of ,melo angusticollis3 l1 lacinia2 a1 lacinia enlarged4 ,mandibles are wanting in the adults of the more specialized ,lepidoptera1 being vestigial in the most generalized forms 7certain ,tineina and ,crambus71 but well developed in that very primitive moth1 ,eriocephala 7,fig4 #ea74 ,they are also completely atrophied in the adult ,trichoptera1 though very large and functional in the pupa of these insects 7,fig4 #eb71 as also in the pupa of ,micropteryx 7,fig4 #ec74 ,they are also wanting in the imago of male ,diptera and in the females of all flies except ,culicid and ,tabanid4 ,they are said by ,dr4 ,horn to be absent in the adult ,platypsyllus castoris1 though well developed in the larva2 and functional mandibles are lacking in the ,hemiptera4 ,the first maxill4--,these highly differentiated appendages are inserted on the sides of the head just behind the mandibles and the mouth1 and are divided into three lobes1 or divisions1 which are supported upon two1 and sometimes three basal pieces1 i4e4 the basal joint or cardo1 the second joint or stipes1 with the palpifer1 the latter present in ,termitid 7,fig4 #ed1 plpgr71 but not always separately developed 7,fig4 #ee74 ,the cardo varies in shape1 but is more or less triangular and is usually wedged in between the submentum and mandible4 ,it is succeeded by the stipes1 which usually forms the support for the three lobes of the maxilla1 and is more or less square in shape4 ,illustration3 ,,fig4 #ea4--,mandible of ,eriocephala calthella3 a1 a1 inner and outer articulation2 s1 cavity of the joint 7acetabulum72 ,a1 end seen from one side of the cutting edge4--,after ,walter4 ,illustration3 ,,fig4 #eb4--;,a1 ,pupa of ,phryganea pilosa4--,after ,pictet4 ,b1 mandibles of pupa of ,molanna angustata4--,after ,sharp4 ,illustration3 ,,fig4 #ec4--,pupa of ,micropteryx purpuriella1 front view3 md1 mandibles2 mx4p1 maxillary palpus1 end drawn separately2 mx4'p1 labial palpi2 lb1 labrum2 ,a1 another view from a cast skin4 ,the three distal divisions of the maxilla are called1 respectively1 beginning with the innermost1 the lacinia1 galea1 and palpifer1 the latter being a lobe or segment bearing the palpus4 ,the lacinia is more or less jaw-like and armed on the inner edge with either flexible or stiff bristles1 spines1 or teeth1 which are very variable in shape and are of use as stiff brushes in pollen-eating beetles1 etc4 ,the galea is either single-jointed and helmet-shaped or subspatulate1 as in most ,orthoptera1 or #b-;jointed in ,gryllotalpa1 or lacinia-like in ,myrmeleon 7,fig4 #ee1 ,c72 or1 in the ,carabid 7,fig4 #ef7 and ,cicindelid1 it is #b-;jointed and in form and function like a palpus4 ,illustration3 ,,fig4 #ed4--;,a1 maxilla of ,termopsis angusticollis4 ,b1 ,termes flavipes3 c1 cardo2 sti1 stipes2 plpgr1 palpiger2 palp1 palpus2 lac1 lacinia2 g1 gal1 galea4 ,illustration3 ,,fig4 #ee4--;,a1 maxilla of ,mantispa brunnea4 ,b1 ,ascalaphus longicornis4 ,c1 ,myrmeleon diversum4 ,lettering as in ,fig4 #ed4 ,illustration3 ,,fig4 #ef4--,maxilla of a carabid1 ,anophthalmus tellkampfii3 l1 lacinia2 g1 #b-;jointed galea2 p1 palpus2 st1 stipes2 c1 cardo4 ,illustration3 ,,fig4 #eg4--,maxilla of ,nemognatha1 1 from ,montana4 ,a1 base of maxilla enlarged to show the taste-papill 7tp7 and cups 7tc71 on the galea 7ga74 ,b1 part of end of galea to show the imperfect segments and taste-organs3 n1 nerve2 a ganglionated nerve supplies each taste-papilla or cup2 l1 lacinia2 p1 palpifer2 s1 subgalea4 ,illustration3 ,,fig4 #eh4--,maxilla of ,panorpa4 ,illustration3 ,,fig4 #ei4--,maxilla of ,limnephilus pudicus3 mx1 stipes2 lac1 galea4 ,the palpus is in general antenniform and is composed of from #a to #f joints1 being usually #d- or #e-;jointed1 and is much longer than the galea4 ,in the maxilla of the beetle ,nemognatha 7,fig4 #eg71 the galea is greatly elongated1 the two together forming an imperfect tube or proboscis and reminding one of the tongue of a moth1 while the lacinia is reduced4 ,in the ,mecoptera the lacinia and galea are closely similar 7,fig4 #eh72 in the ,trichoptera only one of the lobes is present 7,fig4 #ei71 while in the ,lepidoptera the galea unites with its mate to form the so-called tongue 7,fig4 #fj74 ,the maxilla of the male of ,tegeticula yuccasella is normal1 though the gale are separate2 but in the female1 what ,smith regards as the palpifer 7the 8tentacle0 of ,riley7 is remarkably developed1 being nearly as long as the galea 7,fig4 #fa7 and armed with stout set1 the pair of processes being adapted for holding a large mass of pollen under the head4 ,illustration3 ,,fig4 #fj4--,tongue of ,aletia xylina1 with the end magnified4--,pergande del41 from ,riley4 ,a1 much reduced maxilla 7mx7 of ,paleacrita vernata2 mx4p1 palpus4 ,illustration3 ,,fig4 #fa4--;,a1 maxilla of ,tegeticula yuccasella1 3 g1 galea4 ,b1 3 pl1 enormously developed palpifer2 mx4p1 palpus2 c1 cardo2 st1 stipes2 sty1 stylus4 ,in coleopterous larv the maxill are #b-lobed 7,fig4 #fb71 the galea being undifferentiated1 but in those of saw-flies the galea is present 7,fig4 #fc1 gal74 ,illustration3 ,,fig4 #fb4--,larva of ,rhagium lineatum3 lat1 lateral view of head and thoracic segments2 mx1 first maxilla2 ml1 undifferentiated lacinia and galea2 v1 under side of head and pro- and meso- thoracic segments2 v4m4s41 one of the middle ventral segments1 magnified six times2 mx1 #b;d maxilla4 ,it now seems most probable that in the first maxill we have the primary form of buccal appendage of insects1 the appendage being composed of three basal pieces with three variously modified distal lobes or divisions2 and that the mandibles and second maxill are modifications of this type4 ,how wonderfully the maxill of the ,lepidoptera are modified1 and the peculiar shapes assumed in the ,diptera1 ,hymenoptera1 and other groups1 will be stated in the accounts of those orders1 but it is well to recall the fact that in the most primitive and generalized moth1 ,eriocephala1 the lacinia is well developed 7,fig4 #fd74 ,as ,newport remarks1 the office of the maxill in the mandibulate insects is of a twofold kind2 since they are adapted not only for seizing and retaining the food in the mouth1 but also as accessory jaws1 since they aid the mandibles in comminuting it before it is passed on to the pharynx and swallowed4 ,hence1 as the food varies so much in nature and situation1 it will be readily seen that the maxill1 especially their distal parts1 vary correspondingly4 ,thus far no close observations on the exact use of the first and second maxill have been published4 ,the palpi also are not only organs of touch1 but in some cases act as hands and also bear minute sense-organs1 the function of which is unknown1 but would appear to be usually that of smell4 ,illustration3 ,,fig4 #fc4--,selandria larva1 common on ,carya porcina1 with details of mouth-parts3 leg1 leg2 mx1 maxilla2 gal1 galea2 lac1 lacinia4 ,the second maxill4--,the 8under-lip0 or labium of insects is formed by the fusion at the basal portion of what in the embryo are separate appendages1 and which arise in the same manner as the first maxill4 ,they are invariably solidly united1 no cases of partial or incomplete fusion being known4 ,the so-called labium is situated in front of the gula or gular region1 and is bounded on each side by the gena1 or cheek4 ,as already observed1 the second maxill appear to be the appendages of the last or occipital segment of the head4 ,illustration3 ,,fig4 #fd4--,maxilla of ,eriocephala calthella3 l1 lacinia2 g1 galea2 mx4p1 maxillary palpus2 st1 stipes2 c1 cardo4--,after ,walter4 ,the second maxill are very much differentiated and vary greatly in the different orders1 being especially modified in the haustellate or suctorial orders1 notably the ,hymenoptera and ,diptera4 ,in the mandibulate orders1 particularly the ,orthoptera1 where they are most generalized and primitive in shape and structure1 they consist of the following parts3 the gula 7a postgula is present in ,dermaptera71 submentum 7lora of ,cheshire1 i1 p4 #ia71 mentum1 palpifer1 the latter bearing the palpi2 the lingua 7ligula7 and paragloss1 while the hypopharynx or lingua is situated on the upper side4 ,the labial palpi are of the same general shape as those of the first maxill1 but shorter1 with very rarely more than three joints1 though in ,pteronarcys there are four4 ,leon has detected vestigial labial palpi in several ,hemiptera 7,fig4 #gc74 ,as to the exact nature and limits of the gula1 we are not certain2 it is not always present1 and may be only a differentiation of the submentum1 or the latter piece may be regarded as a part of the gula4 ,we are disposed to consider the second maxill as morphologically nearly the exact equivalents of the first pair of maxill1 and if we adopt this view it will greatly simplify our conception of the real nature of this complicated organ4 ,the object of the fusion of the basal portion appears to be to form an under-lip1 in order both to prevent the food from falling backwards out of the mouth1 and1 with the aid of the first pair of maxill1 to pass it forward to be crushed between the mandibles1 the two sets of appendages acting somewhat as the tongue of vertebrates to carry and arrange or press the morsels of food between the teeth or cutting edges of the mandibles4 ,the spines often present on the free inner edges of the first and second maxill 7,figs4 #ed1 #fb7 form rude combs which seem to clean the antenn1 etc41 often aiding the tibial combs in this operation4 ,the submentum and mentum1 or the mentum when no submentum is differentiated 7with the gula1 when present71 appear to be collectively homologous with the cardines of the first pair of maxill1 together with the palpifers and the stipites4#ae ,these pieces are more or less square1 and have a slightly marked median suture in ,termitid1 the sign of primitive fusion or coalescence4 ,the most primitive form of the second maxill occurs in the ,orthoptera and in the ,termitid4 ,the palpifer is either single 7,periplaneta1 ,diapheromera1 ,gryllid7 or double 7,blatta orientalis1 ,locustid74 ,in ,prisopus the single piece in front of the palpifer is in other forms divided1 each half 7,blatta1 ,locustid1 ,acrydid7 bearing the two 8paragloss10 which appendages in reality are the homologues of the lacinia and galea of the first maxill4#af ,in the ,termitid 7,fig4 #fe7 the lingua is not differentiated from the palpifer1 and the two paragloss 7or the lamina externa and interna of some authors7 with the palpus are easily seen to be the homologues of the three lobes of the first maxill4 ,in the ,perlid 7,pteronarcys1 ,fig4 #ff7 the palpifer is divided1 while the four paragloss arise1 as in ,prisopus and ,anisomorpha1 from an undivided piece1 the lingua not being visible from without4 ,in the ,neuroptera the lingua or ligula is a large1 broad1 single lobe1 without 8paragloss10 and the palpifer is either single 7,myrmeleon1 ,fig4 #fg71 or divided 7,mantispa1 ,fig4 #fh74 ,in ,corydalus 7,fig4 #bi7 the palpifer forms a single piece1 and the lingua is undivided1 though lobed on the free edge4 ,illustration3 ,,fig4 #fe4--,second maxill of ,termopsis angusticollis3 li1 the homologue of the lacinia2 le1 galea4 ,in the metabolic orders above the ,neuroptera the lingua is variously modified1 or specialized1 with no vestiges of the lacinia or galea1 except in that very primitive moth1 ,eriocephala1 in which ,walter found a minute free galea1 me1 and an inner lobe 7,figs4 #gf1 #gg71 the lacinia4 ,illustration3 ,,fig4 #ff4--,second maxill of ,pteronarcys californica4 ,illustration3 ,,fig4 #fg4--,second maxill of ,myrmeleon diversum4 ,illustration3 ,,fig4 #fh4--,second maxill of ,mantispa brunnea4 ,the hypopharynx4--,while in its most generalized condition1 as in ,synaptera1 ,dermaptera1 ,orthoptera1 and ,neuroptera1 this anterior median fold or outgrowth of the labium forming the floor of the mouth may retain the designation of 8tongue10 lingua1 or ligula2 in its more specialized form1 particularly when used as a piercing or lapping organ1 the use of the name hypopharynx seems most desirable4 ,and this is especially the case since1 like the epipharynx1 it is morphologically a median structure1 and while the epipharynx forms the soft1 sensitive roof of the mouth1 or pharynx2 its opposite1 the hypopharynx1 rises as a fold from the floor of the mouth1 forming in its most generalized condition a specialized fold of the buccal integument4 ,in certain cases1 as in the honey-bee1 the very long slender 8tongue0 or hypopharynx is evidently1 as in the case of the epipharynx1 a highly sensitive armature of the mouth4 ,in all insects this organ--whether forming a soft1 tongue-like1 anterior portion or fold of the labium1 and 8continuous with the lower wall of the pharynx10 or a hard1 piercing1 awl-like appendage 7fleas and flies71 or a long1 slender1 hairy or setose1 trough-like structure like the 8tongue0 of the honey-bee--has a definite location at the end and on the upper side of the labium1 and serves to receive at its base the external opening of the salivary duct4 ,the hypopharynx1 as well shown in its lingua condition in ,orthoptera1 is continuous with and forms the anterior part or fold of the base of the coalesced second maxill4 ,it does not seem to be paired1 or to represent a pair of appendages4 ,opinion regarding the homology of this unpaired piercing organ is by no means settled1 and while there is a general agreement as to the nature of the paired mouth-parts1 recent observers differ very much as to the morphology of the organ in question4 ,it is the langue or lingua of ,savigny 7#ahaf71 the ligula of ,kirby and ,spence 7#ahbh71 the langue ou languette 7lancette mdiane du suoir7 of ,dugs 7#ahcb71 the lingua of ,westwood 7,class1 ins41 ii1 p4 #dhi1 #ahdj71 8the unpaired median piercing organ0 78the analogon of the epipharynx of ,diptera07 of ,karsten 7#ahfd71 the 8tongue0 of ,taschenberg 7#ahhj74 ,the name hypopharynx was first proposed by ,savigny in #ahaf1 who1 after naming the membranous plate which has for its base the upper side of the pharynx1 the epipharynx1 remarks3 8,dans quelques genres1 notamment dans les ,eucres1 le bord infrieur de ce mme pharynx donne naissance un autre appendice plus solide que le prcdent1 et qui s'embote avec lui4 ,je donnerai ce dernier le nom de langue ou d'hypopharynx4 ,voil donc la bouche des ,hymnoptres compose de quatre organes impaires1 sans y comprendre la ganache ou le menton2 savoir1 la lvre suprieure1 l'pipharynx1 l'hypopharynx1 et la lvre infrieure1 et de deux organes paires1 les mandibules et les mchoires40 ,as stated by ,dimmock3 8,the hypopharynx is usually present in ,diptera 7according to ,menzbier absent in ,sargus71 and contains a tube1 opening by a channel on its upper surface2 this channel extends back1 more or less1 from the tip1 and is the outlet for the salivary secretion4 ,the tip of the hypopharynx may be naked and used as a lance 7,hmatopota1 according to ,menzbier71 or may be hairy 7,musca74 ,the upper side of the base of the hypopharynx is continuous with the lower wall of the pharynx2 its under surface may entirely coalesce with the labium 7,culex1 male71 may join the labium more or less1 anterior to the month 7,musca71 or1 if either mandibles or maxill are present1 its base may join them 7,culex1 female740 7p4 #dc47 ,illustration3 ,,fig4 #fi4--,section of head of ,machilis maritima3 hyp1 hypopharynx2 lbr1 labrum2 t1 tentorium2 ph1 room in which the mandibles move on each other2 p1 paraglossa2 mx1 labium2 sd1 salivary duct2 s4gl1 salivary gland4 oe1 sophagus4--,after ,oudemans4 ,we will now briefly describe the lingua1 first of the mandibulate or biting insects1 and then its specialized form1 the hypopharynx of the haustellate and lapping insects4 ,the lingua 7hypopharynx7 exists in perhaps its most generalized condition in the ,thysanura 7,fig4 #fi71 where it forms a soft projection1 having the same relations as in ,anabrus and other ,orthoptera4#ag ,in the cockroach 7,fig4 #gj71 as stated by ,miall and ,denny1 the lingua is a chitinous fold of the oral integument situated in front of the labium1 and lying in the cavity of the mouth4 ,the common duct of the salivary glands enters the lingua1 and opens on its hinder surface4 ,the lingua is supported by a chitinous skeleton 7,figs4 #gj1 ,b2 #hb1 shp74 8,the thin chitinous surface of the lingua is hairy1 like other parts of the mouth1 and stiffened by special chitinous rods or bands40 7,miall and ,denny47 ,illustration3 ,,fig4 #gj4--;,hypopharynx of ,periplaneta orientalis2 the arrow points out of the opening of the salivary duct3 ,a1 origin of salivary duct4 ,b1 side view4 ,c1 front view4--,after ,miall and ,denny4 ,in the ,acrydiid 7,melanoplus femur-rubrum7 the tongue is a large1 membranous1 partly hollow expansion of the base of the labium4 ,it may be exposed by depressing the end of the labium1 when the opening of the salivary duct may be seen at the bottom or end of the space or gap between the hinder base of the tongue1 and the inner anterior base of the labium1 as shown by the arrows in ,fig4 #gj4 ,it is somewhat pyriform1 slightly keeled above1 and bearing fine stiff bristles1 which1 as they point more or less inwards1 probably aid in retaining the food within the mouth4 ,the base of the tongue is narrow1 and extends back to near the pharynx1 there being on the floor of the mouth1 behind the tongue1 two oblique1 slight ridges1 covered with stiff1 golden-yellow hairs1 like those on the tongue4 ,the opening of the salivary duct is situated on the under or hinder side of the hypopharynx1 between it and the base of the labium1 the base of the former being cleft2 the hollow thus formed is situated over the opening1 and forms the salivary receptacle4 ,illustration3 ,,fig4 #ga4--,section through the anterior part of the head of ,anabrus 7the mandibles removed71 showing the relations of the hypopharynx 7hyp7 to the opening of the salivary duct 7sd73 g1 galea2 l1 lacinia2 mt1 mentum2 oe1 sophagus2 lbr1 labrum2 cl1 clypeus4 ,in the ,locustid 7,anabrus1 ,fig4 #ga7 the tongue 7hypopharynx7 is a broad1 somewhat flattened lobe arising from the upper part of the base of the mentum and behind the palpifer4 ,this lobe is cavernous underneath1 the hollow being the salivary receptacle 7sr72 the latter is situated over the opening of the salivary duct1 which is placed between the base of both the hypopharynx and the labium4 ,the salivary fluid apparently has to pass up and around on each side of the hypopharynx in order to mix with the food4 ,these relations in the ,orthoptera are also the same in the ,perlid1 where the hypopharynx is well developed1 forming an unusually large tongue-like mass1 nearly filling the buccal cavity4 ,illustration3 ,,fig4 #gb4--,lingua of a ,may-fly1 ,heptagenia longicauda1 #af3 m1 central2 l1 lateral pieces4--,after ,vayssire from ,sharp4 ,in the ,odonata the lingua is a small1 rounded lobe1 as also in the ,ephemerid2 in the nymph1 however1 of ,heptagenia 7,fig4 #gb7 it is highly developed1 according to ,vayssire1 who seems inclined to regard it as representing a pair of appendages4 ,the tongue in ,hemiptera is said by ,lon to be present in ,benacus griseus 7,say7 and to correspond to the subgalea of ,brull or hypodactyle of ,audouin 7,fig4 #gc71 but this appears to correspond to the labium proper1 rather than a true lingua1 the latter not being differentiated in this order4 ,in the ,coleoptera the lingua is rather small4 ,in beetles1 as ,anopthalmus 7,fig4 #gd71 it forms a setose lobe2 and a well-developed nerve1 the lingual nerve1 passes to it1 dividing at the end into several branches 7n-l74 ,in ,sialis the lingua is short1 much less developed than usual1 being rounded1 and bears on the edge what appear to be numerous taste-hairs1 like those on the ends of the maxillary and labial palpi4 ,illustration3 ,,fig4 #gc4--;,a1 labium of ,zaitha anura4 ,b1 of ,z4 margineguttata4 ,c1 of ,gerris najas3 mt1 mentum2 lp1 labial palpi2 sg1 subgalea2 l1 lacinia 7 intermaxillare and prmaxillare of ,brull72 g1 galea4--,after ,lon4 ,in the adult ,panorpid the lingua is a minute1 simple lobe4 ,illustration3 ,,fig4 #gd4--,section through head of a carabid1 ,anopthalmus telkampfii3 br1 brain2 f4 g1 frontal ganglion2 soe1 subsophageal ganglion2 co1 commissure2 n4 l1 nerve sending branches to the lingua 7l72 mn1 maxillary nerve2 mx1 #ast maxilla2 mm1 maxillary muscle2 mx1 #b;d maxilla2 mt1 muscle of mentum2 le1 elevator muscle of the sophagus2 l of the clypeus1 and a third beyond raising the labrum 7lbr72 eph1 epipharynx2 g1 g1 salivary glands above2 g#b1 lingual gland below the sophagus 7oe72 m1 mouth2 pv1 proventriculus2 md1 mandible4 ,a1 section passing through lingual gland 7g#b74 ,in the larval ,trichoptera the spinneret is well developed1 and in structure substantially like that of caterpillars1 and it is plainly the homologue of the hypopharynx1 receiving as it does the end of the silk-duct4 ,in the adult ,trichoptera the hypopharynx is a very large1 tongue-like1 fleshy outgrowth1 and is1 both in situation and structure1 since it contains the opening of the silk-duct1 exactly homologous with the hypopharynx of insects of other orders1 being somewhat intermediate between the fleshy tongue or lingua of the mandibulate insects1 especially the ,neuroptera1 and the hypopharynx of the bees 7,fig4 #hf74 ,lucas describes and figures it under the name of 8haustellum10 but does not homologize it with the hypopharynx4 ,the caddis-flies have been observed to drink water and take in both fluid and fine particles of solid food1 and to use the haustellum for this purpose1 the end being provided with minute sense-organs like those on the first maxillary lacinia1 and possibly of a gustatory nature4 ,illustration3 ,,fig4 #ge4--;,head of ,anabolia furcata3 ,a1 front view1 showing the labrum removed4 ,b1 side view2 ant1 antenna2 oc1 ocellus2 ol1 labrum2 gh1 articulatory process2 cmx#a1 cardo2 stmx#a1 stipes2 lemx#a1 outer lobe 7galea72 ptmx#a1 palpus of #ast maxilla2 pl1 palpus of #b;d maxilla2 ha1 haustellum2 so1 gustatory pits2 spr1 opening of salivary duct2 chsp1 chitinous hook of the clasp2 spr1 furrow or gutter of the haustellum4--,after ,lucas4 ,illustration3 ,,fig4 #gf4--;,hypopharynx of ,eriocephala calthella3 lig1 ligula1 its membranous hinder edge2 lig1 anterior horny edge of the ligula-tube opening outwards2 hp1 contour of the hypopharynx2 mi1 mala interior 7lacinia72 me1 mala exterior 7galea71 of second maxilla2 mx p1 labial palpus4--,after ,walter4 ,the spinneret of the larv of ,lepidoptera is evidently the homologue of the hypopharynx of insects of other orders4 ,it will be seen that the homology of the different parts is identical1 the common duct of the silk-glands opening at the end of the hypopharynx1 which here forms a complete tube or proboscis extending beyond the end of the labium1 in adaptation to its use as a spinning organ4 ,walter refers to ,burgess's discovery of a hypopharynx in ,danais archippus1 remarking that this organ in the adult ,eriocephalid 7,fig4 #gf7 exhibits a great similarity to the relations observable in the lower insects1 adding3-- ,illustration3 ,,fig4 #gg4-- ,labium of ,micropteryx anderschella seen from within 7the labial palpi 7mx4 p7 removed to their basal joint74 ,lettering as in ,fig4 #gf4--;,after ,walter4 8,the furrow is here within coalesced with the inner side of the labium1 and though ,i see in the entire structure of the head the inner edge of the ligula tube extended under the epipharynx as far as the mandible1 ,i must also accept the fact that here also the hypopharynx extends to the mouth-opening as in all other sucking insects with a well-developed under-lip1 viz4 the ,diptera and ,hymenoptera40 ,he has also discovered in ,micropteryx a paired structure which he regards as the hypopharynx 7,fig4 #gg74 ,as he states3 ,illustration3 ,,fig4 #gh4--;,hypopharynx 7hph7 of ,danais3 cl1 clypeus2 sd1 salivary duct2 m1 labial palp muscles2 fm1 frontal muscle2 ph1 pharynx2 cor1 cornea4--,after ,burgess4 8,a portion of the inner surface of the tube-like ligula is covered by a furrow-like band which1 close to the inner side1 is coalesced with it1 and in position1 shape1 as well as its appendages or teeth on the edge1 may be regarded as nothing else than the hypopharynx40 ,a hypopharynx is also present in the highest ,lepidoptera1 ,burgess having detected it in ,danais archippus4 ,he states that the hypopharynx forms the floor of the pharyngeal cavity2 8it is convex on each side of a median furrow 7,fig4 #gh1 hph7 and somewhat resembles in shape the human breast4 ,the convex areas are dotted over with little papill1 which possibly may be taste-organs40 ,as a piercing organ the hypopharynx reaches its greatest development in the ,siphonaptera and ,diptera1 where the chitinous parts are greatly hypertrophied1 the fleshy tongue-like portion so developed in the mandibulate orders being greatly reduced4 ,the chitinous parts are alike on each side of the median organ1 being bilaterally symmetrical4 ,illustration3 ,,fig4 #gi4--;,a1 hypopharynx of ,pulex canis3 x1 basal portion situated within the head2 s4 d1 common duct of the four bladder-shaped salivary glands2 s4 d1 opening of the tubular salivary glands into the throat4 ,b1 end of the hypopharynx1 showing the gutter-like structure and teeth at the end4--,after ,landois4 ,illustration3 ,,fig4 #hj4--;,beak of ,vermipsylla3 hyp1 hypopharynx4--,after ,wagner4 ,in the fleas the hypopharynx is a large1 slender1 unpaired1 long1 chitinous trough1 as long as the mandibles1 and toothed at the end4 ,figures #gi and #hj show its relations to the other parts of the mouth2 in ,fig4 #gi1 x1 is seen where the salivary duct opens into the pharynx4 ,although this organ is not unanimously referred to the hypopharynx1 yet from the description of ,landois and others1 it is evident that this structure does not correspond to the labrum or epipharynx1 but belongs to or arises from the floor of the mouth1 and1 being in close relation to the labium1 and also receiving the salivary duct1 must be a true hypopharynx4 ,in the ,diptera the hypopharynx reaches its highest development as a large1 stout1 awl-like structure4 ,meinert1 in his detailed and elaborately illustrated work1 ,trophi ,dipterorum 7#ahha71 has made an advance on our knowledge of the hypopharynx and its homologies1 both by his evidently faithful descriptions and dissections1 and by his admirably clear figures4 ,illustration3 ,,fig4 #ha4--;,culex pipiens1 section of head3 oe sophagus2 sm1 upper muscle1 lm1 lower muscle of the sophagus2 ph1 pharynx2 rm1 retractor muscle of the receptacle 7r7 of the salivary duct 7s4d72 lbr1 labrum2 ep1 left style of the epipharynx2 f1 part of front of head4--,after ,meinert4 ,illustration3 ,,fig4 #hb4--,pharynx and hypopharynx of ,simulium fuscipes3 lph1 lower lamina of the pharynx2 p1 the salivary duct 7s4d7 perforating the pharynx2 o1 orifice of the duct2 shp1 styles of the hypopharynx2 mph1 membranous edge of the hypopharynx2 m1 protractor muscle of the pharynx2 gp1 gustatory papill4--,after ,meinert4 8,the hypopharynx1 a continuation of the lower edge 7lamina7 of the pharynx1 most generally free1 more or less produced1 acute anteriorly1 forms with the labrum the tube of the pump 7antli74 7,the hypopharynx when obsolete1 or coalesced with the canal of the proboscis1 is the theca2 in such a case the siphon or tube is formed by the theca and labrum47 ,meanwhile the hypopharynx1 the largest of all the trophi 7omnium trophorum maximus71 constitutes the chief piercing organ 7telum7 of ,diptera4 ,the hypopharynx is moved by protractor1 most generally quite or very powerful1 and by retractor muscles4 8,the efferent duct of the thoracic salivary glands 7ductus salivalis7 perforates the hypopharynx1 more or less near the base1 that the saliva may be ejected through the canal into the wound1 or that it may be conducted along the labella4 ,very rarely the salivary duct1 perforating the hypopharynx1 is continued in the shape of a free1 very slender tube4 8,the salivary duct behind the base of the hypopharynx forms the receptacle or receptaculum1 provided with retractor and levator muscles40 ,illustration3 ,,fig4 #hc4--,labrum-epipharynx 7lbr and eph7 and hypopharynx 7hyp7 of ,tabanus brominus3 oe1 posterior cylindrical portion of the sophagus2 a1 anterior swollen portion of the same2 ph1 pharynx2 ph4m1 pharyngeal muscle2 p4ph1 protractor muscle of the pharynx2 r4oe1 retractor muscle of the sophagus2 r4ph1 retractor muscle of the pharynx2 f4oe1 flexor muscle of the pharynx2 t4oe1 twisting muscle of the sophagus2 s4r1 receptacle of the salivary duct2 l1 its elevator muscle2 s1 its retractor muscle2 cl1 clypeus4--,after ,meinert4 ,illustration3 ,,fig4 #hd4--sophagus 7oe71 pharynx 7ph7 with epipharynx and labrum 7lbr7 of ,asilus atricapillus3 m1 ph1 pharyngeal muscle2 sr1 salivary receptacle2 t1 twisting2 r1 lr1 retractor muscles2 other lettering as in ,fig4 #hc4--;,after ,meinert4 ,it has been carefully studied by ,meinert in a species of ,culex 7,fig4 #ha71 ,simulium 7,fig4 #hb71 ,tabanus 7,fig4 #hc71 and in ,asilus 7,fig4 #hd71 where it is seen to attain enormous proportions4 ,in the ,hymenoptera1 this organ in its most specialized condition is a trough-like rod1 adapted for lapping nectar 7,fig4 #he1 #hf1 hyp74 ,the tongue or hypopharynx of the honey-bee has been elaborately described by ,cheshire in his ,bees and ,bee ,keeping4#ah ,he calls it the tongue or ligula4 ,it is situated in a tube formed by the maxill and labial palpi1 and can be partially retracted into the mentum4 ,he states that it can move up and down in the tube thus formed1 and then describes it as covered by a hairy sheath1 its great elasticity being due to a rod running through its centre enabling it to be used as a lapping tongue4 ,the sheath 8passes round the tongue to the back1 where its edges do not meet1 but are continuous with a very thin plaited membrane 7,g1 pm7 covered with minute hairs4 ,this membrane1 after passing towards the sides of the tongue1 returns to the angle of the nucleus1 or rod1 over the under surface of which it is probably continued4 ,the rod passes through the tongue from end to end1 gradually tapering towards its extremity1 and is best studied in the queen1 where ,i trace many nerve threads and cells4 ,it is undoubtedly endowed with voluntary movement1 and must be partly muscular1 although ,i have failed completely in getting any evidence of striation4 ,the rod on the underside has a gutter1 or trough-like hollow 7cd1 the central duct7 which is formed into a pseudotube 7false tube7 by intercrossing of black hairs4 ,it will also be seen that1 by the posterior meeting of the sheath1 the space between the folded membrane 7,g1 sd7 becomes two pseudotubes of larger size1 which ,i shall call the side ducts4 ,illustration3 ,,fig4 #he4--;,head of honey bee1 worker3 a1 antenna2 g1 epipharynx2 m1 mandible2 mx1 maxilla2 mxp1 maxillary palpus2 pg1 paraglossa2 lp1 labial palpus2 l1 hypopharynx2 b1 its spoon4--,after ,cheshire2 from ,bull4 ,div4 ,ent4 ,u4 ,s4 ,dept4 ,agr4 8,these central and side ducts run down to that part of the tongue where the spoon1 or bouton 7,k1 ,fig4 #hf7 is placed4 ,this is provided with very delicate split hairs 7b1 ,fig4 #hf7 capable of brushing up the most minute quantity of nectar1 which by capillarity is at once transferred by the gathering hairs 7which are here numerous1 long1 and thin7 to two side groove-like forms at the back of the bouton1 and which are really the opened-out extremity of the centre and side ducts1 assuming1 immediately above the bouton1 the form seen in ,f1 ,fig4 #hf4 ,the central duct1 which is only from #afjj inch to #aajjj inch in diameter1 because of its smaller size1 and so greater capillary attraction1 receives the nectar1 if insufficient in quantity to fill the side ducts4 ,but good honey-yielding plants would bring both centre and side ducts into requisition4 ,the nectar is sucked up until it reaches the paragloss 7pa1 ,b1 ,fig4 #hf71 which are plate-like in front1 but membranous extensions1 like small aprons1 behind2 and by these the nectar reaches the front of the tongue1 to be swallowed as before described40 ,illustration3 ,,fig4 #hf4--,tongue or ligula of the honey bee3 ,a1 under side of the tongue2 lp1 labial palpi2 r1 r1 rod2 p1 pouch2 sh1 sheath2 gh1 gathering hairs2 b1 bouton or spoon4 ,b1 under lip or labium1 with appendages1 partly dissected2 l1 lora or submentum2 a1 a1 retractor lingu longus2 sd1 salivary duct2 rb and b1 retractor lingu biceps2 mx1 maxill2 lp1 labial palpi2 pa1 paraglossa2 gr1 feeding groove2 sh1 sheath of ligula4 ,c1 ,d1 ,e1 sections of ligula2 hp1 hyaline plate of maxilla2 h1 hairs acting as stops2 mx1 maxilla2 lp1 labial palpi2 sd1 side duct4 ,f1 cross-section of extremity of tongue near the 8spoon02 th1 tactile hairs2 r1 rod2 n1 nucleus2 gh1 gathering hairs4 ,g1 cross-section of tongue without gathering hairs1 #djj times2 sh1 sheath2 b1 blood space2 t1 trachea3 ng1 gustatory nerve2 cd1 central duct2 sd1 lateral duct2 pm1 plaited membrane4 ,h1 same as ,g1 but magnified two hundred times1 and with pm1 plaited membrane1 turned outwards2 h1 closing hairs2 lp1 labial palpi2 b1 blood2 n1 nucleus2 r1 rod2 h1 closing hairs4 ,i1 small portion of the sheath2 lettering as before4 ,k1 extremity of the tongue1 with spoon2 b1 branching hairs for gathering4--,after ,cheshire4 ,cheshire then settles the question which has been in dispute since the time of ,swammerdam1 whether the bee's tongue is solid or tubular4 ,he agrees with ,wolff that the duct is a trough and not a tube1 and proves it by a satisfactory experiment4 ,he remarks3 ,illustration3 ,,fig4 #hg4--,longitudinal section through the head of the honey bee1 1 just outside of right antenna3 ant1 antenna with three muscles attached to mes1 mesocephalic pillar2 cl1 clypeus2 lbr1 labrum2 #a1 chyle-gland 7system no4 #a1 of ,siebold72 o1 opening of the same2 oc1 ocellus2 br1 brain2 n1 neck2 th1 thorax2 oe1 sophagus2 s4d#b1 s4d#c1 common salivary ducts of systems #b and #c2 v1 salivary valve2 c1 cardo2 ph1 pharynx2 mx1 labium2 mx4p1 labial palpi2 mt1 mentum2 mx1 maxilla2 hyp1 hypopharynx2 s1 bouton4--,after ,cheshire4 8,bees have the power1 by driving blood into the tongue1 of forcing the rod out from the sheath1 and distending the wrinkled membrane so that in section it appears as at ,h1 ,fig4 #hf1 the membrane assuming the form of a pouch1 given in full length at ,a4 ,it will be seen at once that this disposition of parts abolishes the side ducts1 but brings the central duct to the external surface4 ,the object of this curious capability on the part of the bee is1 in my opinion1 to permit of cleaning away any pollen grains1 or other impediment that may collect in the side ducts4 ,the membrane is greasy in nature1 and substances or fluids can be removed from it as easily as water from polished metal4 ,if1 now1 the sides of a needle1 previously dipped into clove oil in which rosanilin 7magenta7 has been dissolved1 so as to stain it strongly red1 be touched on the centre of the rod1 the oil immediately enters1 and passes rapidly upwards and downwards1 filling the trough40 ,does the hypopharynx represent a distinct segment8--,the facts which suggest that the hypopharynx may possibly represent a highly modified pair of appendages1 arising from a distinct intermaxillary segment1 are these3 ,heymons plainly shows that1 in the embryo of ,lepisma1 the hypopharynx originates as a transverse segment-like fold in front of the #b;d maxillary segment1 and larger than it1 and though he does not mention it in his text1 it appears like the rudiment of a distinct segment2 the hypopharynx of ,ephemerid2 arises and remains separate in the nymph from the labium 7see ,heymons' ,fig4 #bi1 and there are two lateral projections2 see also ,fig4 #gb1 and ,vayssiere's view that it may represent a pair of appendages2 ,kolbe also regards it as representing a third pair of maxill1 his endolabium1 p4 #bac74 ,though what is called an unpaired organ1 it is composed of1 or supported by1 two bilaterally symmetrical styles1 both in ,myriopods 7,fig4 #f1 labiella1 stil7 and in insects 7,fig4 #gg1 etc474 ,on the other hand1 in the embryo of pterygote insects1 an intermaxillary segment has not been yet detected4 ,,literature ,,of ,,the ,,mouth-,,parts ,,or ,,buccal ,,appendages a4 ,general ,savigny1 ,jules-,csar4 ,mmoires sur les animaux sans vertbres4 #are ,part4 ,description et classification des animaux invertbrs et articuls1 etc4 ,fasc4 #are4 ,mm4 #a-b4 ,thorie des organes de la bouche des crustacs et des insectes4 #ab ,pl41 ,paris1 #ahaf1 pp4 #a-aag4 ,gerstfeld1 ,georg4 ,ueber die ,mundteile der saugenden ,insekten4 ,dorpat1 #ahec4 ,olfers1 ,ernestus ,v4 ,annotationes ad anatomiam ,podurarum4 ,berolini1 #ahfb1 #d ,pls4 ,gerstaecker1 ,carl ,eduard ,adolph4 ,zur ,morphologie der ,orthoptera amphibiotica4 7,festschrift zur ,feier des hundertjhrigen ,bestehens der ,gesellschaft naturf4 ,freunde zu ,berlin4 #d1 #ahgc1 pp4 #ci-ei1 #a ,taf47 ,muhr1 ,joseph4 ,die ,mundteile der ,orthoptera4 ,ein ,beitrag zur vergleichenden ,anatomie4 7,jahrbuch 8,lotos40 ,prag1 #ahgg1 pp4 #dj-ga1 #h ,taf47 ,burgess1 ,edward4 ,the anatomy of the head and the structure of the maxilla in the ,psocid4 7,proc4 ,boston ,soc4 ,nat4 ,hist41 xix1 #ahgh1 pp4 #bia-bif1 #a ,pl47 ,meinert1 ,fr4 ,sur la conformation de la tte et sur l'interpretation des organes buccaux chez les insectes1 ainsi que sur la systmatique de cette ordre4 7,ent4 ,tidsskr41 #a4 ,arg41 #ahhj1 pp4 #adg-aej47 ---- ,tungens udskydelighed hos ,steninerne1 en slaegt af ,staphylinernes familie4 7,vidensk4 meddel4 fra den naturh4 ,foren1 #ahhd-ahhf1 pp4 #ahj-bjg1 #b ,pls4 ,also ,zool4 ,anzeiger1 #ahhg1 pp4 #acf-aci47 ,mller1 ,a4 ,vergleichend-anatomische ,darstellung der ,mundteile der ,insekten4 ,villach1 #ahha1 #c ,taf4 ,kraepelin1 ,karl4 ,ueber die ,mundwerkzeuge der saugenden ,insekten4 7,zool4 ,anzeiger1 #ahhb1 pp4 #egd-egi47 ,dewitz1 ,h4 ,ueber die fhrung an den ,krperanhangen der ,insekten4 7,berlin4 ,zeitschr4 xxvi41 #ahhb1 pp4 #ea-fh1 ,figs47 ,wolter1 ,max4 ,die ,mundbildung der ,orthopteren mit specieller ,bercksichtigung der ,ephemeriden4 #d ,taf4 ,greifswald1 #ahhc4 ,oudemans1 ,j4 ,t4 ,beitrge zur ,kenntniss der ,thysanura und ,collembola4 7,bijdragen tot de ,dierkunde1 pp4 #adi-bbf4 ,amsterdam1 #ahhh1 #c ,taf47 ,smith1 ,john ,b4 ,an essay on the development of the mouth-parts of certain insects4 7,trans4 ,amer4 ,philosophical ,soc41 xix1 pp4 #age-aih1 #c ,pls47 ,also articles by ,chatin1 ,mc,lachlan1 ,riley1 ,wood-,mason4 b4 ,thysanoptera 7,physapoda7 ,jordan1 ,karl4 ,anatomie und biologie der ,physapoda4 7,zeitschr4 f4 wissens4 ,zool41 xlvii1 pp4 #eda-fbj1 #c ,taf4 #ahhh47 ,garman1 ,h4 ,the mouth-parts of the ,thysanoptera4 7,bull4 ,essex ,inst41 xxii1 #d pp41 ,fig4 #ahij47 ---- ,the asymmetry of the mouth-parts of ,thysanoptera4 7,amer4 ,naturalist1 ,july1 #ahif1 pp4 #eia-eic1 ,fig47 ,bohls1 ,j4 ,die ,mundwerkzeuge der ,physapoden4 ,dissertation ,gttingen1 #ahia1 pp4 #a-cf4 ,uzel1 ,heinrich4 ,monographie der ,ordnung ,thysanoptera4 ,kniggrtz1 #ahie1 pp4 #dgb1 #aj ,taf41 #i ,figs4 c4 ,hemiptera ,lon1 ,n4 ,beitrge zur ,kenntniss der ,mundteile der ,hemipteren4 ,jena1 #ahhg1 pp4 #dg1 #a ,taf4 ---- ,labialtaster bei ,hemipteren4 7,zool4 ,anzeiger1 pp4 #ade-adg1 #ahib1 #a ,fig47 ---- ,beitrge zur ,kenntniss des ,labiums der ,hydrocoren4 7,zool4 ,anzeiger1 ,mrz #bi1 #ahig1 pp4 #gc-gg1 ,figs4 #a-e47 ,geise1 ,o4 ,mundteile der ,rhynchoten4 7,archiv f4 ,naturgesch41 xlix1 #ahhc1 pp4 #cae-cgc1 #a ,taf47 ,wedde1 ,hermann4 ,beitrge zur ,kenntniss des ,rhynchotenrssels4 7,archiv f4 ,naturgesch41 li ,jahrg41 #a ,bd41 #ahhe1 pp4 #aac-adh1 #b ,taf47 ,smith1 ,john ,b4 ,the structure of the hemipterous mouth4 7,science1 ,april #a1 #ahib1 pp4 #ahi-aij1 ,figs4 #a-e47 d4 ,coleoptera ,smith1 ,john ,b4 ,the mouth-parts of ,copris carolina2 with notes on the homologies of the mandibles4 7,trans4 ,amer4 ,ent4 ,soc41 xix1 ,april1 #ahib1 pp4 #hc-hg1 #b ,pls47 e4 ,lepidoptera ,kirbach1 ,p4 ,ueber die ,mundwerkzeuge der ,schmetterlinge4 7,zool4 ,anzeiger1 vi ,jahrg41 #ahhc1 pp4 #eec-eeh1 #b ,figs47 ---- ,ueber die ,mundwerkzeuge der ,schmetterlinge4 7,archiv f4 ,naturgeschichte1 #ahhd1 pp4 #gh-aai1 #b ,taf47 ,walter1 ,alfred4 ,palpus maxillaris ,lepidopterorum4 7,jenaische ,zeitschr4 f4 ,naturwiss1 xviii1 #ahhd1 pp4 #aba-agc1 ,taf47 ---- ,beitrge zur ,morphologie der ,lepidoptera4 ,i1 ,mundteile4 7,jenaische ,zeitschr4 f4 ,naturwiss1 xviii1 #ahhe1 pp4 #gea-hjg1 #b ,taf47 ,breitenbach1 ,w4 ,vorlufige ,mitteilung ber einige neue ,untersuchungen an ,schmetterlingsrsseln4 7,archiv f4 mikroskop4 ,anatomie1 xiv1 #ahgg1 pp4 #cjh-cag1 #a ,taf47 ---- ,untersuchungen an ,schmetterlingsrsseln4 7,ibid41 xv1 #ahgh1 pp4 #h-bi1 #a ,taf47 ---- ,ueber ,schmetterlingsrssel4 7,entomolog4 ,nachr4 #e ,jahrg41 #ahgi1 pp4 #bcg-bdc1 #a ,taf47 ---- ,der ,schmetterlingsrssel4 7,jenaische ,zeitschr4 f4 ,naturwiss1 #ahha47 f4 ,siphonaptera ,krpelin1 ,k4 ,ueber die systematische ,stellung der ,puliciden4 7,festschrift z4 #ej jahr4 ,jubil4 d4 ,realgymnas4 ,iohanneum1 ,hamburg1 pp4 #ag1 #a ,taf4 #ahhd47 ,kellogg1 ,v4 ,l4 ,the mouth-parts of the ,lepidoptera4 7,amer4 ,nat41 xxix1 #ahie1 pp4 #edf-eef1 #a ,pl4 and ,fig47 g4 ,diptera ,menzbier1 ,michael ,alexander4 ,ueber das ,kopfskelett und die ,mundwerkzeuge der ,zweiflgler4 7,bull4 ,soc4 ,imp4 ,natur4 de ,moscou1 lv1 #ahhj1 pp4 #h-ga1 #b ,taf47 ,dimmock1 ,george4 ,the anatomy of the mouth-parts and of the sucking apparatus of some ,diptera4 ,boston1 #ahha1 pp4 #dh1 #d ,pls4 ,meinert1 ,f4 ,fluernes ,munddele4 ,trophi ,dipterorum4 ,kjbenhavn1 #ahha1 #f ,pls4 ---- ,die ,mundteile der ,dipteren4 7,zool4 ,anz4 #ahhb1 pp4 #egj-egd1 #eii-fjc47 ,becher1 ,e4 ,zur ,kenntniss der ,mundteile der ,dipteren4 7,denkschr4 ,akad4 d4 ,wissensch4 ,wien41 xlv1 #ahhb1 pp4 #abc-afb1 #d ,taf47 ,hansen1 ,h4 ,j4 ,fabrica oris dipterorum3 ,dipterernes mund3 anatomisk og systematisk henseende4 #a ,tabanidae1 ,bombyliidae1 ,asilidae1 ,thereva1 ,mydas1 ,apiocera4 7,naturhist4 ,tidsskrift1 #ahhc1 xiv1 pp4 #a-ahf1 ,taf4 #a-e47 ,krpelin1 ,karl4 ,zur ,anatomie und ,physiologie des ,rssels von ,musca4 7,zeitschr4 f4 wissensch4 ,zool41 xxxix1 #ahhc1 pp4 #fhc-gai1 #b ,taf47 ,mc,closkie1 ,george4 ,kraepelin's ,proboscis of the house-fly4 7,american ,naturalist1 xviii1 #ahhd1 pp4 #abcd-abdd1 ,figs47 ,langhoffer1 ,august4 ,beitrge zur ,kenntniss der ,mundtheile der ,dipteren4 ,jena1 #ahhh1 pp4 #a-cb4 ,smith1 ,john ,b4 ,a contribution toward a knowledge of the mouth-parts of the ,diptera4 7,trans4 ,amer4 ,ent4 ,soc41 xvii1 ,nov4 #ahij1 pp4 #cai-cci1 ,figs4 #a-bb47 h4 ,hymenoptera ,briant1 ,travers ,j4 ,on the anatomy and functions of the tongue of the honey-bee 7worker74 7,journ4 ,linn4 ,soc41 ,london1 xvii1 #ahhd1 pp4 #djh-daf1 #b ,pls47 ,breithaupt1 ,p4 ,f4 ,ueber die ,anatomie und die ,funktionen der ,bienenzunge4 7,archiv f4 ,naturgesch41 ,jahrg4 lii1 #ahhf1 pp4 #dg-aab1 #b ,taf47 i4 ,larval stages ,brauer1 ,f4 ,die ,zweiflgler des kaiserlichen ,museums zu ,wien4 ,,iii1 ,systematische ,studien auf ,grundlage der ,dipterenlarven nebst einer ,zusammenstellung von ,beispielen aus der ,litteratur uber dieselben und ,beschreibung neuer ,formen4 7,denkschr4 math4-naturwiss4 ,cl4 k4 ,akad4 ,wiss4 ,wien1 #ahhc1 xlvii1 pp4 #ajj1 #e ,taf47 ,dewitz1 ,h4 ,ueber die ,fhrung an den ,krperanhangen der ,insekten speziell betrachtet an der ,legescheide der ,acridier1 dem ,stachel der ,meliponem und den ,mundteilen der ,larve von ,myrmeleon1 nebst ,beschreibung dieser ,organe4 7,berliner ent4 ,zeitschr41 xxvi1 #ahhb1 pp4 #ea-fh47 ---- ,die ,mundteile der ,larve von ,myrmeleon4 7,sitzungsber4 d4 ,ges4 naturforsch4 ,freunde zu ,berlin1 #ahha1 pp4 #afc-aff47 ,redtenbacher1 ,josef4 ,uebersicht der ,myrmeleonidenlarven4 7,denkschrift1 math4-naturwiss4 ,cl4 k4 ,akad4 ,wiss4 ,wien1 #ahhd1 xlviii1 pp4 #cce-cfh1 #g ,taf47 ,schidte1 ,j4 ,g4 ,de metamorphosi ,eleutheratorum4 ,bidrag til insekternes udviklingshistorie4 7,kroyer's ,naturhist4 ,tidsskrift4 ,kjbenhavn4 #ab ,teile mit #hh ,taf41 #ahfb-ahhc47 j4 ,embryonic stages ,heymons1 ,richard4 ,grundzge der ,entwicklung und des ,krpersbaues von ,odonaten und ,ephemeridem 7,anhang zu den ,abhandl4 ,k4 ,akad4 d4 ,wissens4 ,berlin1 #ahif1 p4 #bb1 #b ,taf4 ,see ,figs4 #e1 #bi47 ---- ,entwicklungsgeschichtliche ,untersuchungen an ,lepisma saccharina ,l4 7,zeitschr4 f4 ,wissens4 ,zoologie1 lxii1 #ahig1 p4 #eie1 #b ,taf4 ,see ,fig4 #aj47 ,,the ,,thorax ,,and ,,its ,,appendages a4 ,the thorax2 its external anatomy ,the middle region of the body is called the thorax1 and in general consists of three segments1 which are respectively named the prothorax1 mesothorax1 and metathorax 7,figs4 #hh1 #hi1 #ih74 ,illustration3 ,,fig4 #hh4--;,external anatomy of ,melanoplus spretus1 the head and thorax disjointed4 ,the thorax contains the muscles of flight and those of the legs1 besides the fore intestine 7sophagus and proventriculus71 as well as1 in the winged insects1 the salivary glands4 ,in the more generalized orders1 notably the ,orthoptera1 the three segments are distinct and readily identified4 ,illustration3 ,,fig4 #hi4--,locust1 ,melanoplus1 side view1 with the thorax separated from the head and abdomen1 and divided into its three segments4 ,each segment consists of the tergum1 pleurum1 and sternum4 ,in the prothorax these pieces are not subdivided1 except the pleural2 in such case the tergum is called the pronotum4 ,the prothorax is very large in the ,orthoptera and other generalized forms1 as also in the ,coleoptera1 but small and reduced in the ,diptera and ,hymenoptera4 ,in the winged forms the tergum of the mesothorax is differentiated into four pieces or plates 7sclerites74 ,these pieces were named by ,audouin1 passing from before backwards1 the prscutum1 scutum1 scutellum1 and postscutellum4 ,in the nymph stage and in the wingless adults of insects such as the ,mallophaga1 the true lice1 the wingless ,diptera1 ants1 etc41 these parts by disuse and loss of the wings are not differentiated4 ,it is therefore apparent that their development depends on that of the muscles of flight1 of which they form the base of attachment4 ,the scutum is invariably present1 as is the scutellum4 ,the former in nearly all insects constitutes the larger part of the tergum1 while the latter is1 as its name implies1 the small shield-shaped piece directly behind the scutum4 ,illustration3 ,,fig4 #ij4--,thorax of ,telea polyphemus1 side view1 pronotum not represented3 em1 epimerum of prothorax1 the narrow piece above being the prothoracic episternum2 ms1 mesoscutum2 scm1 mesoscutellum2 ms1 metascutum2 scm1 metascutellum2 pt1 a supplementary piece near the insertion of tegul2 w1 pieces situated at the insertion of the wings1 and surrounded by membrane2 epm1 episternum of the mesothorax2 em1 epimerum of the same2 epm1 episternum of the metathorax2 em epimerum of the same1 divided into two pieces2 c1 c1 c1 cox2 te1 te1 te1 trochantines2 tr1 tr1 tr1 trochanters4 ,a1 tergal view of the mesothorax of the same2 prm1 prscutum2 ms1 scutum2 scm1 scutellum2 ptm1 postscutellum2 t1 tegula4 ,the prscutum and postscutellum are usually minute and crowded down out of sight between the opposing segments4 ,as seen in ,fig4 #ij1 the prscutum of most moths 7,telea7 is a small rounded piece1 bent vertically down so as not to be seen from above4 ,in ,polystchotes and also in ,hepialus the prscutum is large1 well-developed1 triangular1 and wedged in between the two halves of the scutum4 ,the postscutellum is still smaller1 usually forming a transverse ridge1 and is rarely used in taxonomy4 ,illustration3 ,,fig4 #ia4--,thorax of the house-fly3 prn1 pronotum2 prsc1 prscutum2 sc1 mesoscutum2 sct1 mesoscutellum2 psct1 postscutellum2 al1 insertion of squama1 extending to the insertion of the wings1 which have been removed2 msphr1 mesophragma2 h1 balancer 7halter72 pt1 tegula2 mtn1 metanotum2 epis1 epis1 epis1 episternum of pro-1 meso-1 and metathorax2 epm1 epm1 meso- and meta-epimerum2 st1 st1 meso- and metasternum2 cx1 cx1 cx1 cox2 tr1 tr1 tr1 trochanters of the three pairs of legs2 sp1 sp1 sp1 sp1 sp1 first to fifth spiracles2 tg1 tg1 tergites of first and second abdominal segments2 u1 u1 urites4 ,the metathorax is usually smaller and shorter than the mesothorax1 being proportioned to the size of the wings4 ,in certain ,neuroptera and in ,hepialid and some tineoid moths1 where the hind wings are nearly as large as those of the anterior pair1 the metathorax is more than half or nearly two-thirds as large as the mesothorax4 ,in ,hepialid the prscutum is large and distinct1 while the scutum is divided into two widely separated pieces4 ,the postscutellum is nearly or quite obsolete4 ,the pleurum in each of the three thoracic segments is divided into two pieces2 the one in front is called the episternum1 since it rests upon the sternum2 the other is the epimerum4 ,to these pieces1 with the sternum in part1 the legs are articulated 7,fig4 #hi74 ,between the episterna is situated the breastplate or sternum1 which is very large in the more primitive forms1 as the ,orthoptera1 and is small in the ,diptera and ,hymenoptera4 ,illustration3 ,,fig4 #ib4--,prothorax of ,geometra papilionaria3 n1 notum2 p1 pleura2 st1 sternum2 pt1 patagia2 m1 membrane2 f1 femur2 h1 a hook bent backwards and beneath1 and connecting the pro- with the mesothorax4--,after ,cholodkowsky4 ,the episterna and epimera are in certain groups1 ,neuroptera1 etc41 further subdivided each into two pieces 7,fig4 #ajb74 ,the smaller pieces1 hinging upon each other and forming the attachments of the muscles of flight1 differ much in shape and size in insects of different orders4 ,the difference in shape and degree of differentiation of these parts of the thorax is mentioned and illustrated under each order1 and reference to the figures will obviate pages of tedious description4 ,a glance1 however1 at the thorax of a moth1 fly1 or bee1 where these numerous pieces are agglutinated into a globular mass1 will show that the spherical shape of the thorax in these insects is due to the enlargement of one part at the expense of another2 the prothoracic and metathoracic segments being more or less atrophied1 while the mesothorax is greatly enlarged to support the powerful muscles of flight1 the fore wings being much larger than those appended to the metathorax4 ,in the ,diptera1 whose hinder pair of wings are reduced to the condition of halteres1 the reduction of the metathorax as well as prothorax is especially marked 7,fig4 #ia74 ,the patagia4--,on each side of the pronotum of ,lepidoptera are two transversely oval1 movable1 concavo-convex1 erectile plates1 called patagia 7,fig4 #ib74 ,on cutting those of a dry ,catocala in two1 they will be seen to be hollow4 ,cholodkowsky#ai states that they are filled with blood and tracheal branches2 and he went so far as to regard them as rudimentary prothoracic wings1 in which view he was corrected by ,haase1#bj who compares them with the tegul1 regarding them also as secondary or accessory structures4 ,the tegul4--,on the mesothorax are the tegul of ,kirby 7pterygodes of ,latreille1 paraptera of ,mc,leay1 hypoptre or squamule71 which cover the base of the fore wings1 and are especially developed in the ,lepidoptera 7,fig4 #ij1 ,a1 t7 and in certain ,hymenoptera 7,fig4 #ie1 c74 ,the external opening of the spiracles just under the fore wings1 is situated in a little plate called by ,audouin the peritreme4 ,illustration3 ,,fig4 #ic4--,transformation of the bumble bee1 ,bombus1 showing the transfer of the #ast abdominal larval segment 7c7 to the thorax1 forming the propodeum of the pupa 7,d7 and imago2 n1 spiracle of the propodeum4 ,a1 larva2 a1 head2 b1 #ast thoracic2 c1 #ast abdominal segment4 ,b1 semipupa2 g1 antenna2 h1 maxill2 i1 #ast2 j1 #b;d leg2 k1 mesoscutum2 l1 mesoscutellum2 m1 metathorax2 d1 urite 7sternite of abdomen72 e1 pleurite2 f1 tergite2 o1 ovipositor2 r1 lingua2 q1 maxilla4 ,in the higher or aculeate ,hymenoptera1 besides the three segments normally composing the thorax1 the basal abdominal segment is during the change from the larva to the pupa transferred to this region1 making four segments4 ,this first abdominal is called 8the median segment0 7,figs4 #ic-ie74 ,in such a case the term alitrunk has been applied to this region1 i4e4 the thorax1 as thus constituted4 ,latreille wrongly stated that in the ,diptera the first abdominal segment also entered into the composition of the thorax2 but ,brauer has fully disproved that view1 as may be seen by an examination of his sketches which we have copied 7,fig4 #id74 ,illustration3 ,,fig4 #id4--g1 #h1 thorax of ,tipula gigantea2 #i1 of ,leptis2 #aj1 thorax of ,tabanus bromius after the removal of the abdomen1 in order to bring into view the inner mesophragma 7f71 and to show the extension of the metathorax g and g2 tr1 trochanter2 #aa1 hind end of the mesothorax1 the entire metathorax1 and the #ast and #b;d abdominal segments of ,volucella zonaria1 seen from the side4 ,the internal mesophragma 7f71 and the position of the muscle inserted in it1 are indicated by the two lines ,m4 p1 ,callus postalaris2 pr 7pz in #h71 callus pralaris ,osten ,sacken 7 8patagium0 of some authors72 g1 metanotum2 g1 metepimerum1 8segment mdiaire0 of ,latreille 7wrongly considered by him to be the #ast abdominal segment72 #d1 metasternum 7hypopleura of ,osten ,sacken72 #e 78 8episternum of metathorax0 7,brauer7 metapleura of ,osten ,sacken72 #f1 and also ,h1 halter2 st#a1 mesothoracic stigma2 st#b1 metathoracic stigma2 st#c1 first abdominal stigma2 1 dorsopleural2 1 sternopleural2 1 mesopleural sutures2 h1 #ast1 i1 #b;d1 abdominal segment2 al1 wing2 alul1 alula4 #ab1 the head and the three thoracic rings1 and the #ast abdominal segment of ,ephemera vulgata1 the connecting membranes are in white3 a1 prothorax2 b1 prscutum2 c1 scutum2 d1 scutellum2 e1 postscutellum2 ps1 postscutellum of mesothorax4--,after ,brauer4 ,illustration3 ,,fig4 #ie4--;,alitrunk of ,sphex chrysis3 ,a1 dorsal aspect2 a1 pronotum2 b1 mesonotum2 c1 tegula2 d1 base of fore1--e1 of hind1 wing2 f1 g1 divisions of metanotum2 h1 median 7true first abdominal7 segment2 i1 its spiracle2 k1 second abdominal segment1 usually called the petiole or first abdominal segment4 ,b1 posterior aspect of the median segment2 a1 upper part2 b1 superior1--c1 inferior1 abdominal foramen2 d1 ventral plate of median segment2 e1 coxa4--,after ,sharp4 ,the sternum is in rare cases subdivided into two halves1 as in the meso- and metathorax of the cockroach2 in ,forficula the prosternum is divided into four pieces besides the sternum proper 7,fig4 #if72 and in ,embia1 also1 the sternites1 according to ,sharp1 are complex4 ,illustration3 ,,fig4 #if4--,sternal view of pro-1 meso-1 and metathorax of ,forficula tniata3 pst1 prsternum1 divided into #d pieces2 st1 pro-1 st1 meso-1 st1 metasternum2 cx1 coxa2 not1 notum4 ,illustration3 ,,fig4 #ig4--;,a1 under surface of prothorax1 or prosternum1 of ,dyticus circumflexis3 #b4;g1 prosternum2 #b4;f1 episternum2 #b4;h1 epimerum2 #b4s1 antefurca or entothorax4 ,illustration3 ,,fig4 #ih4--,meso- 7,g#b7 and metathoracic ganglia 7,g#a71 with the apodemes of ,gryllotalpa4--,after ,graber4 ,illustration3 ,,fig4 #ii4--,parts of the mesothorax of ,dyticus3 ,a1 mesosternum2 #c4;a1 prscutum2 #c4;b1 scutum2 #c4;c1 scutellum2 #c4;d1 postscutellum2 #c4;e1 parapteron2 #c4;g1 mesosternum2 #c4;f1 episternum2 #c4;h1 epimerum2 #c4s1 medifurca or entothorax4 ,illustration3 ,,fig4 #ajj4--,parts of the metathorax of ,dyticus3 ,a1 metasternum2 #d4;a1 prscutum2 #d4;b1 scutum2 #d4;c1 scutellum2 #d4;d1 postscutellum2 #d4;e1 parapteron2 #d4;f1 episternum2 #d4;g1 metasternum2 #d4;h1 epimerum2 #d4s1 postfurca4--,this and ,figs4 #ig and #ii from ,audouin1 after ,newport4 ,the apodemes4--,the thorax is supported within by beam-like processes1 or apodemes1 which pass inward and also form attachments for the muscles4 ,those passing up from the sternum form the entothorax of ,audouin1 and the process of each thoracic segment is called respectively the antefurca1 medifurca1 and postfurca4 ,in the ,orthoptera 7,caloptenus and ,anabrus71 the antefurca is large1 thin1 flattened1 directed forward1 and bounds each side of the prothoracic ganglion4 ,in the ,coleoptera two plates 7,fig4 #ig1 #b4s7 arise from the inside of the sternum and 8form a collar or leave a circular hole between them for the passage of the nervous cord0 7,newport74 ,the medifurca is a pair of flat processes which diverge and bridge the commissure1 while the postfurca is situated under the commissure4 ,in beetles 7,dyticus7 ,newport states that it is expanded into two broad plates1 to which the muscles of the posterior legs are attached4 ,graber also notices in the mole cricket between the apodemes of the meso- and metathorax1 a flattened spine 7,fig4 #ih1 do7 with two perforations through which pass the commissures connecting the ganglia4 ,besides these processes there are large1 thin1 longitudinal partitions passing down from the tergum 7or dorsum71 called phragmas2 they are most developed in those insects which fly best1 i4e4 in ,coleoptera 7,figs4 #ig-aja71 ,lepidoptera1 ,diptera1 and ,hymenoptera1 none being developed in the prothorax4 7,the term phragma has also been applied to a partition formed by the inflexed hinder edge of this segment1 and is present only in those insects in which the prothorax is movable4--,century ,dictionary47 ,all these ingrowths may be in general termed apodemes4 ,there are similar structures in ,crustacea and also in ,limulus2 but ,sharp restricts this term to minute projections in beetles 7,goliathus7 situated at the sides of the thorax near the wings4 7,insecta1 p4 #ajc1 ,fig4 #eg47 ,the internal processes arising from the sternal region have been called endosternites4 ,illustration3 ,,fig4 #aja4--;,internal skeleton of ,lucanus cervus1 1 head3 ,a1 antenna2 f1 mandible2 d1 mentum2 #b1 #d1 tendons of mandible2 f1 u1 t1 parts of the tentorium2 #c e1 labial muscles4 ,thorax3 #b1 prothorax2 #c1 #d1 meso- and metathorax fused solidly together2 #c r1 acetabulum of prothorax1 into which the coxa is inserted2 #b s1 sternum2 #ct1 acetabulum of mesothorax1 #dr1 of metathorax2 #c s1 mesothoracic sternum fused with that of the metathorax 7#d;g72 #d s1 apodeme4--,after ,newport4 ,the acetabula4--,these are the cavities in which the legs are inserted4 ,they are situated on each side of the posterior part of the sternum1 in each of the thoracic segments4 ,they are1 in general1 formed by an approximation of the sternum and epimerum1 and sometimes1 also1 of the episternum1 as in ,dyticus 7,fig4 #ig1 ,a74 ,this consolidation of parts1 says ,newport1 gives an amazing increase of strength to the segments1 and is one of the circumstances which enables the insect to exert an astonishing degree of muscular power4 ,,tabular ,,view ,,of ,,the ,,segments1 ,,pieces1 ,,and ,,appendages ,,of ,,the ,,thorax ,,name ,,of ,,segment ,,pieces 7,,sclerites7 ,,appendages #a4 ,prothorax ,pronotum1 sometimes differentiated into ,scutum #ast pair of legs ,scutellum ,patagia ,episternum ,epimerum ,sternum ,antefurca #b4 ,mesothorax ,prscutum ,scutum #b;d pair of legs ,scutellum #ast pair of wings ,proscutellum ,tegul ,episternum ,squam 7,alul7 ,epimerum ,peritreme ,sternum ,mesofurca ,mesophragma ,apodemes #c4 ,metathorax ,prscutum ,scutum #c;d pair of legs ,scutellum #b;d pair of wings ,postscutellum 7,halteres of ,diptera7 ,episternum ,epimerum ,sternum ,postfurca ,metaphragma ,apodemes ,illustration3 ,,fig4 #ajb4--;,external anatomy of the trunk of ,hydrus piceus3 ,a1 sternal--,b1 tergal aspect2 #b1 pronotum2 #b a1 prosternum2 #b f1 episternum2 #c a1 prscutum2 #c b1 scutum2 #c c1 scutellum2 #c d1 postscutellum2 #c g1 mesosternum2 #c h1 episternum2 #c f1 epimerum2 #c i1 crest of the mesosternum2 #c a1 parapteron2 #c k1 coxa2 #d a1 metaprscutum2 #d b1 metascutum2 #d c1 metascutellum2 #d d1 postscutellum2 #d e1 tegula2 #d f1 episternum2 #d h1 epimerum2 #d g1 metasternum2 #d i1 crest of metasternum2 #d k and l1 coxa2 #d m1 trochanter2 n1 femur2 o1 tibia2 p1 tarsus2 q1 unguis2 #g-aa1 abdominal segments4--,after ,newport4 b4 ,the legs3 their structure and functions ,the mode of insertion of the legs to the thorax is seen in ,figs4 #ij1 #ig1 #aja1 and #ajc4 ,they are articulated to the episternum1 epimerum1 and sternum1 taken together1 and consist of five segments4 ,the basal segment or joint is the coxa1 situated between the episternum and trochanter4 ,the coxa usually has a posterior subdivision or projection1 the trochantine2 sometimes1 as in ,mantispa 7,fig4 #ajc71 the trochantine is obsolete4 ,we had previously supposed that the trochantine was a separate joint1 but now doubt whether it represents a distinct segment of the leg1 and regard it as only a subdivision of the coxa4 ,it is attached to the epimerum1 and is best developed in ,panorpid1 ,trichoptera1 and ,lepidoptera4 ,in the ,thysanura the trochantine is wanting1 and in the cockroach it merely forms a subdivision of the coxa1 its use being to support the latter4 ,the second segment is the trochanter1 a more or less short spherical joint on which the leg proper turns2 in the parasitic groups 7,ichneumonid1 etc41 ,fig4 #ajd7 it is usually divided into two pieces1 though there are some exceptions4 ,the trochanter is succeeded by the femur1 tibia1 and tarsus1 the latter consisting of from one to five segments1 the normal number being five4 ,tuffen ,west believed that the pulvillus is the homologue of an additional tarsal joint1 8a sixth tarsal joint40 ,the last tarsal segment ends in a pair of freely movable claws 7ungues71 which are modified set2 between the claws is a cushion-like pad or adhesive lobe1 called the empodium or pulvillus 7,fig4 #aje1 also variously called arolium1 palmula1 plantula1 onychium1 its appendage being called paronychium and also pseudonychium74 ,it is cleft or bilobate in many flies1 but in ,sargus trilobate4 ,all these parts vary greatly in shape and relative size in insects of different groups1 especially ,trichoptera1 ,lepidoptera1 ,diptera1 and ,hymenoptera4 ,in certain flies 7e4g4 ,leptogaster7 the empodium is wanting 7,kolbe74 ,by some writers the middle lobe is called the empodium and the two others pulvilli4 ,illustration3 ,,fig4 #ajc4--,side view of meso- and metathorax of ,mantispa brunnea1 showing the upper and lower divisions of the epimerum 7s4 em1 s4 em1 i4 em1 i4 em72 s4 epis1 i4 epis1 the same of the episternum4 ,illustration3 ,,fig4 #ajd4--;,divided 7ditrochous7 trochanter of an ichneumon3 cx1 coxa2 tr1 the two divisions of the trochanter2 f1 femur4--,after ,sharp4 ,the fore legs are usually directed forward to drag the body along1 while the middle and hind legs are directed outward and backward to push the body onwards4 ,while arachnids walk on the tip ends of their feet1 myriopods1 ,thysanura1 and all larval insects walk on the ends of the claws1 but insects generally1 especially the adults1 are1 so to speak1 plantigrade1 since they walk on all the tarsal joints4 ,in the aquatic forms the middle and hind tarsi are more or less flattened1 oar-like1 and edged with set4 ,in leaping insects1 as the locusts and grasshoppers1 and certain chrysomelids1 the hind femora are greatly swollen owing to the development of the muscles within4 ,the tibia1 besides bearing large1 lateral1 external spines1 occasionally bears at the end one or more spines or spurs called calcaria4 ,the fore tibia also in ants1 etc41 bear tactile hairs1 and chordotonal organs1 as well as other isolated sense-organs 7,janet71 and1 in grasshoppers1 ears4 ,in the ,carabid the legs are provided with combs for cleaning the antenn 7,fig4 #ajg71 and in the bees and ants these cleansing organs are more specialized1 the pectinated spine 7calcar7 being opposed by a tarsal comb 7,fig4 #ajf1 d2 for the wax-pincers of bees1 see g74 ,in general the insects use their more or less spiny legs for cleansing the head1 antenn1 palpi1 wings1 etc41 and the adaptations for that end are the bristles or spinules on the legs1 especially the tibi4 ,illustration3 ,,fig4 #aje4--;,foot of honey-bee1 with the pulvillus in use3 ,a1 under view of foot2 t1 t1 #c;d-#eth tarsal joints2 a n1 unguis2 f h1 tactile hairs2 p v1 pulvillus2 cr1 curved rod4 ,b1 side view of foot4 ,c1 central part of sole2 pd1 pad2 cr1 curved rod2 pv1 pulvillus unopened4--,after ,cheshire4 ,illustration3 ,,fig4 #ajf4--,modifications of the legs of different bees4 ,a1 ,apis3 a1 wax-pincer and outer view of hind leg2 b1 inner aspect of wax-pincer and leg1 with the nine pollen-brushes or rows of hairs2 c1 compound hairs holding grains of pollen2 d1 anterior leg1 showing antenna-cleaner2 e1 spur on tibia of middle leg4 ,b1 ,melipona3 f1 peculiar group of spines at apex of tibia of hind leg2 g1 inner aspect of wax-pincer and first tarsal joint4 ,c1 ,bombus3 h1 wax-pincer2 i1 inner view of the same and first tarsal joint1 all enlarged4--,from ,insect ,life1 ,u4 ,s4 ,div4 ,ent4 ,osten ,sacken states that among ,diptera the aerial forms 7,bombylid1 etc47 with their large eyes or holoptic heads1 which carry with them the power of hovering or poising1 have weak legs1 principally fit for alighting4 ,on the other hand1 the pedestrian or walking ,diptera 7,asilid1 etc47 8use the legs not for alighting only1 but for running1 and all kinds of other work1 seizing their prey1 carrying it1 climbing1 digging1 etc42 their legs are provided not only with spines and bristles1 but with still other appendages1 which may be useful1 or only ornamental1 as secondary sexual characters40 ,illustration3 ,,fig4 #ajg4--;,end of tibia and tarsal joints of ,anophthalmus2 c1 comb4 ,tenent hairs4--,projecting from the lower surface of the empodium are the numerous 8tenent hairs10 or holding hairs1 which are modified glandular set swollen at the end and which give out a minute quantity of a clear adhesive fluid 7,figs4 #ajh1 #aji1 #acj1 #acd74 ,in larval insects1 and the adults of certain beetles1 ,coccid1 ,aphid1 and ,collembola1 which have no empodium1 there are one or more of these tenent hairs present4 ,they enable the insect to adhere to smooth surfaces4 ,illustration3 ,,fig4 #ajh4--,transverse section through a tarsal joint of ,telephorus1 a beetle3 ch1 cuticula of the upper side2 m1 its matrix2 ch1 the sole2 m1 its matrix2 h1 adhesive hair2 h1 tactile hair1 supplied with a nerve 7n71 and arising from a main nerve 7n72 n1 ganglion of a tactile hair2 t1 section of main trachea1 from which arises a branch 7t72 dr1 glands which open into the adhesive hairs1 and form the sticky secretion2 e1 chitinous thickening2 s1 sinew2 b1 membrane dividing the hollow space of the tarsal joint into compartments4 ,see p4 #aaa4--;,after ,dewitz4 ,striking sexual secondary characters appear in the fore legs of the male ,hydrophilus1 the insect1 as ,tuffen ,west observes1 walking on the end of the tibia alone and dragging the tarsus after it4 ,the last tarsal joint is enlarged into the form of an irregular hollow shield4 ,the most completely suctorial feet of insects are those of the anterior pair of ,dyticus 7,fig4 #acb74 ,the under side of the three basal joints is fused together and enlarged into a single broad and nearly circular shield1 which is convex above and fringed with fine branching hairs1 and covered beneath with suckers1 of which two are exceptionally large2 by this apparatus of suckers the male is enabled to adhere to the back of its mate during copulation4 ,the line branching hairs around the edge prevent the water from penetrating and thus destroying the vacuum1 8while if the female struggle out of the water1 by retaining the fluid for some time around the sucker1 they will in like manner under these altered conditions equally tend to preserve the effectual contact40 7,tuffen ,west47 ,illustration3 ,,fig4 #aji4--;,cross-section through tarsus of a locust3 ch1 cuticula of upper side1--ch1 ch1 ch1 of sole2 ch1 tubulated layer2 ch1 lamellate layer2 ch1 inner projections of ch4 ,other lettering as in ,fig4 #aja4 ,see p4 #aac4--;,after ,dewitz4 ,in the saw-flies 7,urocerid and ,tenthredinid7 and other insects1 there are small membranous oval cushions 7arolia1 ,figs4 #aji and #aca7 beneath each or nearly each tarsal joint4 ,the triunguline larv of the ,meloid are so called from apparently having three ungues1 but in reality there is only a single claw1 with a claw-like bristle on each side4 ,why do insects have but six legs8--,embryology shows that the ancestors of insects were polypodous1 and the question arises to what cause is due the process of elimination of legs in the ancestors of existing insects1 so that at present there are no functional legs on the abdomen1 these being invariably restricted 7except in caterpillars7 to the thorax1 and the number never being more than six4 ,it is evident that the number of six legs was fixed by heredity in the ,thysanura1 before the appearance of winged insects4 ,we had thought that this restriction of legs to the thorax was in part due to the fact that this is the centre of gravity1 and also because abdominal legs are not necessary in locomotion1 since the fore legs are used in dragging the insect forwards1 while the two hinder pairs support and push the body on4 ,synchronously with this elimination by disuse of the abdominal legs1 the body became shortened1 and subdivided into three regions4 ,on the other hand1 as in caterpillars1 with their long bodies1 the abdominal legs of the embryo persist2 or if it be granted that the prop-legs are secondary structures1 then they were developed in larval life to prop up and move the abdominal region4 ,the constancy of the number of six legs is explained by ,dahl as being in relation to their function as climbing organs4 ,one leg1 he says1 will almost always be perpendicular to the plane when the animal is moving up a vertical surface2 and1 on the other hand1 we know that three is the smallest number with which stable equilibrium is possible2 an insect must therefore have twice this number1 and the great numerical superiority of the class may be associated with this mechanical advantage4 7,this numerical superiority of insects1 however1 seems to us to be rather due to the acquisition of wings1 as we have already stated on pages #b and #abj47 ,loss of limbs by disuse4--,not only are one or both claws of a single pair1 or those of all the feet atrophied by disuse1 but this process of reduction may extend to the entire limb4 ,in a few insects one of the claws of each foot is atrophied1 as in the feet of the ,pediculid1 of many ,mallophaga1 all of the ,coccid1 in ,bittacus1 ,hybusa 7,orthoptera71 several beetles of the family ,pselaphid1 and a weevil 7,brachybamus74 ,hoplia1 etc41 bear but a single claw on the hind feet1 while the allied ,gymnoloma has only a single claw on all the feet4 ,cybister has in general a single immovable claw on the hind feet1 but ,cybister scutellaris has1 according to ,sharp1 on the same feet an outer small and movable claw4 ,in the water bugs1 ,belostoma1 etc41 the fore feet end in a single claw1 while in others 7,corisa7 both claws are wanting on the fore feet4 ,corisa also has no claws on the hind feet2 ,notonecta has two claws on the anterior four feet1 but none on the hind pair4 ,in ,diplonychus1 however1 there are two small claws present4 7,kolbe47 ,illustration3 ,,fig4 #aaj4--,last tarsal joint of ,melolontha vulgaris1 drawn as if transparent to show the inner mechanism3 un1 claws2 str1 extensor plate2 s1 tendon of the flexor muscle2 vb1 elastic membrane between the extensor plate and the sliding surface u2 krh1 process of the ungual joint2 emp1 extensor spine1 and th1 its two tactile hairs4--,after ,ockler1 from ,kolbe4 ,among the ,scarabid1 the individuals of both sexes of the fossorial genus ,ateuchus 7,a4 sacer7 and eight other genera1 among them ,deltochilum gibbosum of the ,united ,states1 have no tarsi on the anterior feet in either sex4 ,the ,american genera ,phanus 7,fig4 #aaa71 ,gromphas1 and ,streblopus have no tarsal joints in the male1 but they are present in the female1 though much reduced in size1 and also wanting1 ,kolbe states1 in many species of ,phanus4 ,the peculiar genus ,stenosternus not only lacks the anterior feet1 but also those of the second and third pair of legs are each reduced to a vestige in the shape of a simple1 spur-like1 clawless joint4 ,the ungual joint is wanting in the weevil ,anoplus1 and becomes small and not easily seen in four other genera4 ,ryder states that the evidence that the absence of fore tarsi in ,ateuchus is due to the inheritance of their loss by mutilation is uncertain4 ,dr4 ,horn suggests that cases like ,ateuchus and ,deltochilum1 etc41 8might be used as an evidence of the persistence of a character gradually acquired through repeated mutilation1 that is1 a loss of the tarsus by the digging which these insects perform40 ,on the other hand1 the numerous species of ,phanus do quite as much digging1 and the anterior tarsi of the male only are wanting4 8,it is true10 he adds1 8that many females are seen which have lost their anterior tarsi by digging2 have1 in fact1 worn them off2 but in recently developed specimens the front tarsi are always absent in the males and present in the females4 ,if repeated mutilation has resulted in the entire disappearance of the tarsi in one fossorial insect1 it is reasonable to infer that the same results should follow in a related insect in both sexes1 if at all1 and not in the male only4 ,it is evident that some other cause than inherited mutilation must be sought for to explain the loss of the tarsi in these insects40 7,proc4 ,amer4 ,phil4 ,soc41 ,philadelphia1 #ahhi1 pp4 #ebi1 #edb47 ,illustration3 ,,fig4 #aaa4--;,fore tibia of ,phanus carnifex1 1 showing no trace of the tarsus4 ,illustration3 ,,fig4 #aab4--;,fore leg of the mole-cricket3 ,a1 outer1 ,b1 inner1 aspect2 e1 ear-slit4--,after ,sharp4 ,the loss of tarsi may be due to disuse rather than to the inheritance of mutilations4 ,judging by the enlarged fore tibi1 which seem admirably adapted for digging1 it would appear as if tarsi1 even more or less reduced1 would be in the way1 and thus would be useless to the beetles in digging4 ,careful observations on the habits of these beetles might throw light on this point4 ,it may be added that the fore tarsi in the more fossorial ,carabid1 such as ,clivina and ,scarites1 as well as those of the larva of ,cicada and those of the mole crickets 7,fig4 #aab71 are more or less reduced2 there is a hypertrophy of the tibi and their spines4 ,the shape of the tibia in these insects1 which are flattened with several broad triangular spines1 bears a strong resemblance to the nails or claws of the fossorial limbs of those mammals which dig in hard soil1 such as the armadillo1 manis1 aardvark1 and ,echidna4 ,the principle of modification by disuse is well illustrated in the following cases4 ,in many butterflies the fore legs are small and shortened1 and of little use1 and held pressed against the breast4 ,in the ,lycnid the fore tarsi are without claws2 in ,erycinid and ,libytheid the fore legs of the males are shortened1 but completely developed in the females1 while in the ,nymphalid the fore legs in both sexes are shortened1 consisting in the males of one or two joints1 the claws being absent in the females4 ,among moths loss of the fore tarsi is less frequent4 ,j4 ,b4 ,smith#ba notices the lack of the fore tarsi in the male of a deltoid1 ,litognatha nubilifasciata 7,fig4 #aac71 while the hind feet of ,hepialus hectus are shortened4 ,in an aphid 7,mastopoda pteridis1 ,esl47 all the tarsi are reduced to a single vestigial joint 7,fig4 #aad74 ,illustration3 ,,fig4 #aac4--,leg of ,litognatha3 cx1 coxa2 f1 femur2 t1 tibia2 ep1 its epiphysis1 and sh1 its shield-like process4 ,the tarsus entirely wanting4--,after ,smith4 ,entirely legless adult insects are rare1 and the loss is clearly seen to be an adaptation due to disuse2 such are the females of the ,psychid1 the females of several genera of ,coccid 7,mytilaspis1 etc471 and the females of the ,stylopid4 ,apodous larval insects are common1 and the loss of legs is plainly seen to be a secondary adaptive feature1 since there are annectant forms with one or two pairs of thoracic legs4 ,all dipterous and siphonapterous larv1 those of all the ,hymenoptera except the saw-flies1 a few lepidopterous larv1 some coleopterous1 as those of the ,rhyncophora1 ,buprestid1 ,eucnemid1 and other families1 and many ,cerambycid are without any legs4 ,in ,eupsalis minuta1 belonging to the ,brenthid1 the thoracic legs are minute4 ,the legs of larv end in a single claw1 upon the tips of which the insect stands in walking4 c4 ,locomotion 7walking1 climbing1 and swimming7 ,mechanics of walking4--,to ,graber we owe the best exposition of the mechanics of walking in insects4 8,the first segment of the insect leg10 he says1 8upon which the weight of the body rests first of all1 is the coxa4 ,its method of articulation is very different from that of the other joints4 ,the enarthrosis affords the most extensive play1 particularly in the ,hymenoptera and ,diptera40 ,in the former the development of their social conditions is very closely connected with the freest possible use of the legs1 which serve as hands4 ,in the beetles1 however1 which are very compactly built1 there exists a solid articulation whereby the entire hip rests in a tent-like excavation of the thorax1 and can only be turned round a single axis1 as may be seen in ,fig4 #aae1 where c represents the imaginary revolving axis and d the coxa4 ,in the case we are supposing1 therefore1 only a backward and forward movement of the coxa is possible1 the extent of the play of which depends on the size of the coxal pan1 as well as certain groin or bar-like structures which limit further rotation4 ,in the very dissimilar arrangement which draws in the fore1 middle1 and hind legs toward the body it is self-evident that their extent of action is also different4 ,this arrangement seems to be most yielding on the fore legs1 where the hips1 to confine ourselves to the stag-beetles1 can be turned backward and forward #fj from the middle or normal position1 and therefore describe on the whole a curve of #abj4 ,the angle of turning on the middle leg hardly exceeds a legitimate limit1 yet a forward as well as a backward rotation takes place4 ,the former is entirely wanting in the hind hips2 they can only be moved backward4 ,illustration3 ,,fig4 #aad4--,leg of an ,aphid1 with the tarsus 7t7 much reduced3 #a1 #b1 #c1 legs of #ast1 #b;d1 and #c;d pairs4 ,the number and strength of the muscles on which the rotation of the hips depends1 correspond with these varying movements of the individual legs4 ,thus1 according to ,straus ,durckheim1 the fore coxa of many beetles possesses five separate muscles and four forward and one backward roll2 the middle coxa a like number of muscles but only two forward rolls1 while the hind hips succeed in accomplishing each of the motions named with a single muscle4 ,one can best see how these muscles undertake their work1 and above all how they are situated1 if he lays bare the prothorax of the stag beetle 7,fig4 #aaf74 ,here may be seen first the thick muscle which turns to the front the rotating axis in its cylindrical pan1 and thus helps to extend the leg1 while two other tendons1 which take the opposite direction1 are fitted for reflex movements4 ,illustration3 ,,fig4 #aae4--,mechanics of an insect's leg3 d1 coxa1--c1 axis of revolution2 a and b1 the coxal muscles2 e1 trochanter muscle 7elevator of the femur72 f1 extensor1--g1 flexor1 of the tibia 7pn72 n1 tibial spine2 h1 flexor4--i1 extensor1 of the foot2 k1 extensor1--l1 flexor1 of the claw2 po1 place of flexure of the tibia2 p#aq1 leg after being turned back by the coxa4--p#ar1 by the simultaneous flexure of the tibia4 ,the resulting motion of the end of the tibia1 through the simultaneous movement 7no7 and revolution 7nq71 indicates the curve nr4--,after ,graber4 ,in ,fig4 #aae the muscles mentioned above1 and their modes of working1 may be distinguished by the arrows a and b4 ,in order to simplify matters1 we will imagine the second component part of the normal insect leg1 i4e4 the trochanter 7,figs4 #aaf1 #aag1 r71 as grown together with the third lever1 i4e4 the femur1 as the movement of both parts mostly takes place uniformly4 ,illustration3 ,,fig4 #aaf4--,section of the fore leg of a stag-beetle1 showing the muscles3 ,s1 extensor1--,b1 flexor1 of the leg2 s1 extensor1--b1 flexor1 of the femur2 o1 femur2 u1 tibia2 f1 tarsus2 k1 claw2 #aji1 s1 extensor1--b1 flexor1 of the femoro-tibial joint1 both enlarged4--,after ,graber4 ,the pulling of the small trochanter muscle works against the weight of the body when this is carried over on to the trochanter by means of the coxa1 as seen at the arrow e in ,fig4 #aae4 ,it may be designated as the femoral lever4 ,the plane of direction in which the femur1 as seen by the rotation just mentioned1 is moved1 exactly coincides in insects with that of the tibia and the foot1 while all can be simultaneously raised or dropped1 or1 as the case may be1 stretched out or retracted4 ,therein1 therefore1 lies an essential difference from the fully developed extremities of vertebrates among which1 even on the lever arms which are stationary at the end1 an extensive turning is possible4 ,the muscles which move the tibia1 and indirectly the femur1 also consist of an extensor muscle which is situated in the upper side of the femur 7,fig4 #aaf1 s1 ,fig4 #aae1 f71 and of a flexor 7,fig4 #aaf1 b1 ,fig4 #aae1 g71 which lies under the former4 ,the stilt-like spines on the point 7,figs4 #aae and #aah1 ,l#cn7 on which this segment is directly supported are important parts of the tibia4 7,graber47 ,illustration3 ,,fig4 #aag4--,left fore leg of a cerambycid beetle3 h1 coxa2 r1 trochanter2 o1 femur2 u1 tibia2 f1 tarsus2 k1 claw4--,after ,graber4 ,considering the respective positions of the individual levers of the leg and the nature of the materials of which they are made1 the legs of insects may be likened1 as ,graber states1 to elastic bows1 which1 when pressed down together from above1 their own indwelling elasticity is able to raise again and thus keep the body upright4 ,this is very plainly shown in certain stilt-legged bark-beetles1 in which1 as in a rubber doll1 as soon as the body is pressed down on the ground1 the organs of motion extend again without the intervention of muscles2 indeed this experiment succeeds even with dead1 but not yet wholly stiff1 insects4 ,graber then turns to the analysis of the movements of insect legs when in motion1 and the mode of walking of these insects in general4 ,this subject had been but slightly investigated until ,graber made a series of observations and experiments1 of which we can give only the most important results4 ,the locomotion of insects is an extremely complicated subject4 ,let us consider1 ,graber says1 first1 a running or carabid beetle1 when walking merely with the fore and hind legs4 ,the former will be bent forward and the latter backward4 8,let us begin with the left fore leg 7,fig4 #aah1 ,l#a74 ,let the same be extended and fixed on the ground by means of its sharp claws and its pointed heel4 ,now what happens when the tibial flexors draw together8 ,as the foot1 and therefore the tibia also1 have a firm position1 then the contraction of the muscles named must cause the femur to approach the tibia1 whereby the whole body is drawn along with it4 ,this individual act of motion may be well studied in grasshoppers when they are climbing on a twig by stretching out their long fore leg directly forward1 and then drawing up the body through the shortening of the tibial flexors until the middle leg also reaches the branch4 8,but while the fore legs advance the body by drawing the free lever to the fixed leg-segment1 the hind legs do this in exactly the opposite way4 ,the hind leg1 namely1 seeks to stretch out the tibia1 and thus to increase the angle of the knee 7,r#c71 thereby giving a push on the ground1 by means of which the body is shoved forward a bit4 8,though it might be supposed that the feet would remain stationary during the extension or retraction of the limbs1 this never occurs in actual walking4 ,not merely the upper1 but also the lower1 thigh is either drawn in or stretched out1 as the case may be4 ,the latter then describes a straight line with its point during this scraping or scratching motion 7,fig4 #aae1 no71 which is obviously the chord to that quadrant which would be drawn by the tibia or foot in a yielding medium1 as water1 for instance4 ,but even this motion results extremely rarely1 and never in actual walking4 ,if we fix our eye anew upon the fore leg at the very moment when it is again retracted1 after the resultant #8fixing1' we shall then observe that the hip also is simultaneously turned backward in a definite angle4 ,the tibia would describe the arc nq 7,fig4 #aae7 by means of the latter alone4 8,this plane1 in conjunction with the rectilinear #8movement' 7no7 obtained by the retraction of the tibia1 produces a path 7nr71 and this is what is actually described by a painted foot upon a properly prepared surface1 as a sheet of paper2#bb supposing1 however1 that the body in the meantime is not moved forward by other forces4 ,in the last case1 and this indeed always takes place in running1 the trunk is moved a bit forward1 together with the leg which is just describing its curve with a rapidity corresponding to the momentum obtained2 the result of this is that the curve of the foot from its beginning 7n7 to its end 7a7 bends round close to itself1 just as a man who1 when on board a ship in motion1 walks across it diagonally1 and yet on the whole moves forward1 because his line of march1 uniting with that of the ship1 results in a change of position in space4 8,the case is the same in the middle and hind legs1 which must make a double course also1 yet in such a way that the straight line is drawn1 not during the retraction1 but during the extension2 during which1 however1 quite as in the fore leg1 the members mentioned 7,r#c7 gradually approach the body4 8,when the legs have reached the maximum of their retraction1 or of their extension1 as the case may be1 and therefore the end of their active course for that time1 then begins the opposite or backward movement2 that is1 the fore legs are again extended1 while their levers draw the remaining legs together again4 ,illustration3 ,,fig4 #aah4--;,a ,carabus beetle in the act of walking or running3 three legs 7,l#a1 ,r#b1 ,l#c7 are directed forward1 while the others 7,r#a1 ,l#b1 ,r#c71 which are directed backward toward the tail1 have ended their activity2 ab1 cd1 and ef are curves described by the end of the tibi1 and passing back to the end of the body2 bh1 di1 and fg are curves described by the same legs during their passive change of position4--,after ,graber4 8,at the same time1 as we may see by the uniting leg1 the limb is either a little raised1 that there may be no unnecessary friction1 or it remains during the passive step also1 with its means of locomotion in slight contact with the ground4 8,the curve of two steps1 as inscribed by the end of the tibia of the left fore leg of a stag-beetle1 affords an instructive summary of the conditions of which we have been speaking 7,fig4 #aba1 ,b74 ,we see two curves4 ,the thick one 7ab71 directed toward the axis of the body1 corresponds to the effective act of a single walking function1 which brings the body a bit forward2 the thinner1 on the other hand1 or we might say the hair line 7bc71 which1 however1 is but rarely made quite clearly1 is produced by the ineffectual backward movement1 by which the insect again approaches its working posture 7c74 ,it is at first placed at some distance from the body1 in order that 7like c also7 it may draw near to the body again2 but in such a way1 naturally1 that it coincides with the starting-point of the following active curve 7cd74 ,it is evident that even the passive curve is not the imprint of the movement accomplished exclusively by the leg1 for this latter1 while struggling to reach its resting-place1 is really involuntarily carried forward with the rest of the body4 8,the scroll-like lines drawn by the swimming beetle 7,dyticus71 with the large1 sharp points of its hind tibia1 are also very instructive 7,fig4 #aai1 ,a74 ,illustration3 ,,fig4 #aai4--;,a1 trail curves described by the tibial spines of the right and left hind limb of ,dyticus4 ,b1 the same made by the right hind leg 7r#c7 alone4 ,natural size4--,after ,graber4 ,illustration3 ,,fig4 #abj4--,the same by the two hind legs of ,melolontha3 a1 the active and thickened section of the curve4 ,natural size4 ,illustration3 ,,fig4 #aba4--;,a1 track curves of two of the tibial spines of the left1 middle legs of a stag-beetle4 ,natural size4 ,b1 the same enlarged2 fg1 the longitudinal axis of the trunk2 cd and ab1 the active curve passing inward1--bc and de1 the passive going outward4 ,c1 two curves described by the left hind legs2 in this case1 the curves are not inwards or backwards1 but partly directly inward 7b71 and in part obliquely forwards 7a74 8,the diversions and modifications in the course of the active step1 as furnished by the moving factor of the remaining legs1 are already clearly illustrated by the curves shown by the joints of the hind tibia of a ,may-beetle 7,fig4 #abj7 and a stag-beetle 7,fig4 #aba1 c74 ,the actual faint line in this case does not run from the front toward the back1 as would correspond to the active leg-motion1 but either directly inward 7,fig4 #aba1 cb71 or even somewhat to the front4 ,in the ,may-beetles1 and even more in the running garden-beetle1 the curves of the hind legs present themselves as screw-like lines 7,fig4 #abb1 l#c71 while the scrawling of the remaining members 7l#a1 l#b7 is much simpler4 8,inasmuch as we now have a cursory knowledge of the movements made by each individual leg for itself1--movements1 however1 which plainly occur very differently according to the structure of these appendages1--the question now is of the combined play1 the total effect of all the legs taken together1 and therefore of the walk and measure of the united work of the foot4 8,in opposition to the caterpillars and many other crawling animals which extend their legs in pairs and really swing them by the worm-like mode of contraction of the dermo-muscular tube1 the legs of fully grown insects are moved in the contrary direction and in no sense in pairs1 but alternately--or1 more strictly speaking1 in a diagonal direction4 8,for an examination of the gait of insects1 we choose1 for obvious reasons1 those which have very long legs and which at the same time are slow walkers4 8,insects may be called #8double-three-footed1' from the manner in which they alternately place their legs4 ,there are always three legs set in motion at the same time1 or nearly so1 while in the meantime the remaining legs support the body1 after which they change places4 ,illustration3 ,,fig4 #abb4--,the same by the left fore 7l#a71 middle 7l#b71 and hind1 leg 7l#c7 of a ,carabus4 ,natural size4 ,illustration3 ,,fig4 #abc4-,tracks of a ,blaps mortisaga marked by the differently painted tibial points3 1 tracks of fore1 --1 middle1 --_/1 hind leg4 ,natural size4 ,illustration3 ,,fig4 #abd4--,tracks of ,necrophorus vespilio4 ,natural size4 8,to be more exact1 it is usually thus3 ,at first 7,fig4 #aah7 the left fore leg 7,l#a7 steps out1 then follows the right middle leg 7,r#b71 and the left hind leg 7,l#c74 ,then while the left fore leg begins to retract and thus make the backward movement1 the right fore leg is extended1 whereupon the left middle leg and the right hind leg are raised in the same order as the first three feet40 ,graber#bc painted the feet of beetles and let them run over paper1 and goes on to say3 8,let us first pursue the tracks of the ,blaps1 for example 7,fig4 #abc74 ,let the insect begin its motion4 ,the left fore leg stands at a1 the right middle leg at 1 and the left hind leg at c4 ,the corresponding number of the other set of three feet at 1 b1 4 ,at the first step the three feet first mentioned advance to ac1 the second set on the other hand to b4 ,thereby the tracks made by the successive steps fall quite1 or almost quite1 on each other1 as appear also in the tracks of a burying beetle 7,fig4 #abd74 8,as the fore legs are directed forward and the hind legs backward1 while the middle legs are placed obliquely1 the reason of the more marked impressions of the latter is evident4 8,the highest testimony to the precise exactitude and accuracy of the walking mechanism of insects is furnished by the fact that in most insects1 and particularly in those most fleet of foot1 which1 whether they are running away or chasing their prey1 must be able to rely entirely upon their means of locomotion2--the fact1 we say1 that whether they desire to move slowly or more quickly1 the distances of the steps1 measured by the length as well as by the cross-direction1 hardly differ a hair's breadth from one another1 and this is also the case when the tarsi are cut off and the insects are obliged to run on the points of their heels 7tibi74 8,thence1 inasmuch as the trunk of insects is carried by two legs and by one on each side alternately1 it may surely be concluded a priori that when walking it is inclined now to the right and now to the left1 and that the track1 too1 which is left behind by a precise point of the leg1 can in no wise be a straight line2 and in reality this is not the case4 8,a plainly marked regular curve1 which approaches a sinuous line1 as seen in ,fig4 #abe1 is often obtained by painting many insects1 for example ,trichodes1 ,melo1 etc41 which1 when running1 either bring the end of their hind body near to the ground or into contact with it4 ,illustration3 ,,fig4 #abe4--,tracks of ,trichodes2 the middle sinuous line is made by the tip of the abdomen4 ,natural size4 ,illustration3 ,,fig4 #abf4--,tracks of another insect which1 in running1 can only use three legs 7r#a1 l#d1 r#c7 which become indicated differently from normal conditions4 ,natural size4 ,illustration3 ,,fig4 #abg4--,the same of an insect crossing over a surface inclined #cj from the horizon1 whereby the placing of the feet becomes changed4 ,natural size4--,this and ,figs4 #abj-abf after ,graber4 8,the locomotive machine of insects may be called1 to a certain extent1 a double set of three feet each1 as most insects1 and particularly those provided with a broad trunk1 are able to balance themselves with one of these two sets of feet1 and indeed when walking1 as well as when standing still1 can move about even better with one set of these feet than with four legs4 ,in the latter case1 that is1 if one cuts off a pair of legs from an insect1 the trunk can balance itself only with extreme difficulty1 and there is therefore little prospect that insects will ever become four-footed4 8,but if one compels insects to run on three legs1 he will thus make the interesting discovery that to make up the deficiency they place the remaining feet and bring them to the ground somewhat differently than when the second set of feet is active4 ,figs4 #abd and #abf may be compared for this purpose4 ,the former shows the footprints of a burying beetle running with all six legs1 the latter the track of the same insect1 which1 however1 has at its disposal only the right fore leg1 the left middle leg1 and the right hind leg4 ,one may plainly see here that the track of the hind leg on the right side 7r#c7 approaches the track of the middle leg on the left side1 and then further1 that the right fore leg 7r#a7 steps out more to the right to make up for the deficiency of the middle leg4 8,a similar adaptation of the position of the legs1 which is entirely dependent on the choice of the insect1 may also be observed there1 if one compels insects which are not provided with corresponding adhesive lobes to run away over crooked surfaces4 ,fig4 #abc shows the footprints of a ,blaps when running upon a horizontal plane4 ,fig4 #abg1 on the contrary1 shows the tracks of the legs when going diagonally over a gradually inclined surface4 ,here1 also1 the insect holds on with his fore and middle legs 7r#a1 r#b7 stretched upward1 whereby also the impressions on both sides come to lie farther apart than in the normal mode of walking4 8,it will not surprise the reader who is familiar with the gait of crabs1 to hear that many insects also understand the laudable art of going backward1 wherein the hind legs simply change places with the fore legs4 8,the jumping motion of insects may be best studied in grasshoppers4 ,when these insects are preparing for a jump1 they stretch out the upper thigh horizontally1 clap the tibi together1 and also retract the foot-segment4 ,after a slight pause for rest1 during which they are getting ready for the jump1 they then jerk the tibi suddenly backward and against the ground with all their strength by means of the extensor muscles40 ,the correctness of ,graber's views has been confirmed by ,marey by instantaneous photographs 7,figs4 #abh1 #abi74 ,locomotion on smooth surfaces4--,how flies and other insects are able to walk up1 or run with the body inverted1 on hard surfaces has been lately discovered by ,dewitz1 ,dahl1 and others4 ,all authors are agreed that this power is due to the presence of the specialized empodium of each tarsus4 ,dewitz confirmed the opinion of ,blackwell1 that a glutinous liquid is exuded from the apices of the tenent hairs which fringe the empodium4 ,by fastening insects feet uppermost on the under side of a covering glass which projects from a glass slide1 the hairs which clothe the empodia of the foot of a fly 7,musca erythrocephala7 may be seen to be tipped with drops of transparent liquid4 ,on the leg being drawn back from the glass1 a transparent thread is drawn out1 and drops are found to be left on the glass4 ,in cases where these hairs are wanting1 as in the ,hemiptera1 the adhesive fluid exudes directly from pores in the foot4 ,in the beetles 7,telephorus dispar7 and other insects the tenent hairs on the foot end in sharp points1 below which are placed the openings of the canals4 ,the glands1 ,dewitz states1 are chiefly flask-shaped and unicellular1 situated in the hypodermis of the chitinous coat2 each gland opening into one of the hairs 7,fig4 #ajh72 they are each invested by a structureless tunica propria1 and contain granular protoplasm1 a nucleus placed at the inner side1 and a vesicle1 prolonged into a tube which1 traversing the neck of the gland1 is attached to the root of the hair2 the vesicle receiving the secretion4 ,each gland is connected with a fine nerve-twig1 and secretion is probably voluntary4 ,among the tenent hairs of the empodium are others which must be supplied with a nerve1 forming tactile hairs1 as they each proceed from a unicellular ganglion 7,fig4 #ajh1 n74 ,the secretion is forced out of the gland by the contraction of the protoplasm1 ,dewitz having seen the secretion driven out from the internal vesicle into its neck4 ,illustration3 ,,fig4 #abh4--,the walk of an orthopterous insect3 series to be followed from right to left4--,after ,marey4 ,illustration3 ,,fig4 #abi4--;,beetle walking3 series to be followed from left to right4--,after ,marey4 ,illustration3 ,,fig4 #acj4--;,a1 end of an adhesive hair of a weevil 7,eupolus73 i1 canal3 i1 its external opening at the end of the hair4 ,b1 end of a similar hair of ,telephorus with drops of the secretion4--,after ,dewitz4 ,in the spherical last tarsal joint of ,orthoptera 7,fig4 #aji71 which is without these tenent hairs1 nearly all the cells of the hypodermis are converted into unicellular glands1 each of which sends out a long1 fine1 chitinous tubule1 which is connected with its fellows by very fine hairs and is continuous with the chitinous coat of the foot and opens through it4 ,the sole of the foot is elastic and adapts itself to minute inequalities of surfaces1 while the anterior of each tarsal joint is almost entirely occupied by an enlargement of the trachea1 which acts on the elastic sole like an air chamber1 rendering it tense and at the same time pliant4 ,dewitz adds that the apparatus situated on the front legs of the male of ,stenobothrus sibiricus 7,fig4 #aca7 must have the function of causing the legs to adhere closely to the female by the excretion of an adhesive material4 ,the hairs of the anterior tarsi of male ,carabi also appear to possess the power of adhesion4 ,in the house-fly the empodia seem to be only called into action when the insect has to walk on vertical smooth surfaces1 as at other times they hang loosely down4 ,burmeister observed the use of a glutinous secretion for walking in dipterous larv1 and ,dewitz found that the larva of a ,musca used for this purpose a liquid ejected from the mouth4 ,the larv of another fly 7,leucopis puncticornis7 perform their loop-like walk by emitting a fluid from both mouth and anus4 ,a ,cecidomyia larva is able to leap by fixing its anterior end by means of an adhesive fluid4 ,the larva of the leaf-beetle1 ,galeruca1 moves by drawing up its hinder end1 fixing it thus1 and carrying the anterior part of the body forward with its feet until fully extended1 when it breaks the glutinous adhesion4 ,the abdominal legs of some saw-fly larv have the same power4 ,dahl could not detect in the foot of the hornet 7,vespa crabro7 any space which could be considered as a vacuum4 ,illustration3 ,,fig4 #aca4--,stenobothrus sibiricus pairing3 ,a4 the 1 fore tarsus 7t7 greatly enlarged2 ar1 arolia2 p1 pulvillus4--,after ,pagenstecher4 ,simmermacher states that in most cases of climbing beetles the tubular tenent hairs pour out a secretion 7,figs4 #acc1 #acd71 8and it is probable that we have here to do with the phenomena not of actual attachment by1 as it were1 gluing1 but of adhesion2 the orifice of the tubes is divided obliquely1 and the tubes are1 at this point1 extremely delicate and flexible1 so as to adhere by their lower surface2 in this adhesion they are aided by the secreted fluid40 ,in the case of the ,diptera he does not accept the theory by which the movement of the fly along smooth surfaces is ascribed to an alternate fixation and separation1 but believes in a process of adhesion1 aided by a secretion1 as in many ,coleoptera4 7,in the ,cerambycid there is no secretion1 and the tubules are merely sucking organs1 like those observed in the male ,silphid47 8,the attaching lobes1 closely beset with chitinous hairs1 are enabled1 in consequence of the pressure of the foot1 to completely lie along any smooth surface2 this expels the air beneath the lobes1 which are then acted on by the pressure of the outer air40 7,journ4 ,roy4 ,micr4 ,soc41 #ahhd1 p4 #gcf47 ,another writer 7,rombouts7 thinks this power is due to capillary adhesion4 ,illustration3 ,,fig4 #acb4--;,fore leg of ,dyticus1 under side1 with sucker1 formed of #c enlarged tarsal joints3 with a small cupule highly magnified4 #abj4--;,after ,miall4 ,the action of the pulvillus and claws when at rest or in use by the honey-bee is well shown by ,cheshire 7,fig4 #ace1 ,b74 ,in ascending a rough surface1 8the points of the claws catch 7as at ,b7 and the pulvillus is saved from any contact1 but if the surface be smooth1 so that the claws get no grip1 they slide back and are drawn beneath the foot 7as at ,a71 which change of position applies the pulvillus1 so that it immediately clings4 ,it is the character of the surface1 then1 and not the will of the bee1 that determines whether claw or pulvillus shall be used in sustaining it4 ,but another contrivance1 equally beautiful1 remains to be noticed4 ,the pulvillus is carried folded in the middle 7as at ,c1 ,fig4 #aje71 but opens out when applied to a surface2 for it has at its upper part an elastic and curved rod 7cr1 ,figs4 #aje and #ace71 which straightens as the pulvillus is pressed down2 ,c and ,d1 ,fig4 #ace1 making this clear4 ,the flattened-out pulvillus thus holds strongly while pulled1 by the weight of the bee1 along the surface1 to which it adheres1 but comes up at once if lifted and rolled off from its opposite sides1 just as we should pull a wet postage stamp from an envelope4 ,the bee1 then1 is held securely till it attempts to lift the leg1 when it is freed at once2 and1 by this exquisite yet simple plan1 it can fix and release each foot at least twenty times per second40 7,bees and ,bee-keeping1 p4 #abg47 ,illustration3 ,,fig4 #acc4--;,cross-section through a tarsal joint of fore leg of ,dyticus1 1 showing the stalked chitinous suckers 7s71 with a marginal bristle on each side3 t1 trachea2 a1 an isolated tubule or sucker of ,loricera1--b1 of ,chlnius1--c1 of ,cicindela2 d1 two views of one of ,necrophorus germanicus1 4 ,illustration3 ,,fig4 #acd4--,section through the tarsus of a ,staphylinid beetle2 the glandular or tenent hairs arising from chitinous processes4 ,a1 section through the tarsal joint of the pine weevil1 ,hylobius abietis1 showing the crowded1 bulbous1 glandular1 or tenent hairs arising from unicellular glands4--,this and ,fig4 #acc after ,simmermacher4 ,ockler divides the normal two-clawed foot into three subtypes3 7#a7 with an unpaired median empodium2 7#b7 with two outer lateral adhesive lobes2 7#c7 with two adhesive lobes below the claws2 the latter is the chief type and forms either a climbing or a clasping foot4 ,the amount of movement possessed by the claws is limited1 and what there is1 is effected by means of an elastic membrane and the extensor plate 7,fig4 #aaj74 ,the 8extensor sole0 which is always present in insects with an unpaired median fixing or adhesive organ 7empodium7 is to be regarded as a modification of the extensor seta4 ,the extensor plate is peculiar to an insect's foot4 ,ockler states that the so-called 8pressure plate0 of ,dahl is only a movably articulated1 skeletal1 supporting plate for the median fixing lobule4 ,illustration3 ,,fig4 #ace4--;,honey-bee's foot in the act of climbing1 showing the automatic action of the pulvillus1 #cj3 ,a1 position of foot in climbing on a slippery surface1 or glass2 pv1 pulvillus2 fh1 tactile hairs2 un1 unguis2 t1 last tarsal joint4 ,b1 position of foot in climbing rough surface4 ,c1 section of pulvillus just touching flat surface2 cr1 curved rod4 ,d1 the same applied to the surface4--,after ,cheshire4 ,climbing4--,in certain respects the power of climbing supplies the want of wings1 and even exists often in house-flies among which there is shown a many-sided motion that is quite unheard of in other groups of insects4 ,the best climbers are obviously those insects which live on trees and bushes1 as1 for example1 longicorn beetles and grasshoppers4 ,these may be accurately called the monkeys of the insect kind1 even if their movements take place less gracefully1 and indeed rather stiffly and woodenly4 ,we already know what are the proper climbing organs2 that is1 the sharp easily movable claws on the foot4 ,with the help of these claws certain insects1 ,may-beetles for example1 can hang upon one another like a chain2 indeed1 bees and ants in this manner bind themselves together into living garlands and bridges4 ,there are still added to the chitinous hooks flaps and balls of a sticky nature1 by help of which likewise the insects glue themselves together4 ,to facilitate the spanning of still thicker twigs1 the climbing foot of insects has a greater movability even than when it only serves as a sole4 7,graber47 ,the mode of swimming of insects4--,to study the swimming movements of insects1 let us examine a ,dyticus4 ,it will appear1 as ,graber states1 to be wonderfully adapted to its element4 8,the body resembles a boat4 ,there is nowhere a projecting point or a sharp corner which would offer unnecessary resistance to motion2 bulging out in the middle and pointed at the end1 it cuts through the resistance of the water like a wedge4 ,the movable parts1 the oars1 seem to be as well fitted for their purpose as the burden to be moved by them4 ,that the hind legs must bear the brunt of this follows from their position exactly in the middle of the body1 where it is widest4 ,in other insects also these legs are used for the same purpose as soon as the insects are put in the water4 ,but the swimming legs of water-beetles are oars of quite peculiar construction4 ,they are not turned about in the cox1 as are other legs1 but at the foot-joint4 ,the coxa1 namely1 has grown entirely together with the thoracic partition4 ,the muscles we have mentioned1 exceeding in strength all the soft parts taken together1 take hold directly of the large wing-shaped tendons of the upper thigh1 and extend and retract the leg in one of the planes lying close to the abdominal partition4 ,the foot forms the oar1 however4 ,it is very much lengthened and still more widened1 and can be turned and bent in by separate muscles in such a way that in the passive movement1 that is1 the retraction1 the narrow edge is turned to the fore1 and therefore to the medium to be dislodged2 however1 as soon as the active push is to be performed and the leg is extended with greater force1 it cuts down through the water with its whole width4 ,these effective oar-blades are still considerably enlarged by the hairs arising on the side of the foot1 which spread out at the decisive moment4 8,every one knows that the oar-blades of swimming beetles always go up and down simultaneously and in regular time4 ,on the other hand1 as soon as one puts a ,dyticus on the dry land1 i4e4 on an unyielding medium1 it uses its hind legs entirely after the manner of other land insects2 that is1 they are drawn in and extended again alternately1 as takes place clearly enough from the footsteps in ,fig4 #aai1 ,a4 ,we learn from this that water insects have not yet1 from want of practice1 forgotten the mode of walking of land insects4 8,the forcing up of the water as a propelling power is added to the repulsion produced by the strong strokes of the oars4 ,if the beetle stood up horizontally in the water1 he would be lifted up4 8,as the trunk1 however1 assumes an oblique position when the insect wishes to swim1 one can then imagine the driving up of the water as being divided into two forces1 one of which drives the body forward in a horizontal direction1 while the other1 that is1 the vertical component1 is supplied by the moving of the oars4 ,the swimming insect is thus1 as it were1 a snake flying in the water4 8,the long streamer-like hind legs of many water-bugs1 for example ,notonecta1 approach more nearly our artificial oars4 ,these legs are turned out from the bottom4 8,there is no doubt but that the legs of insects1 as regards the many-sidedness and exactitude of their locomotive actions1 place the similar contrivances of other animals far in the shade4 ,we shall be forced to admire these ingenious levers still more1 however1 when we take into consideration their energy and strength4 ,that the force with which the locomotive muscles of insects is drawn together is enormous compared with that of vertebrates1 we may learn if we try to subdue the rhythmical movements of the thorax of a large butterfly by the pressure of our finger or to open against the insect's will the closed jumping leg of a grasshopper1 or the fossorial shovel of a mole-cricket40 ,,literature ,,on ,,legs ,,and ,,feet ,mac,leay1 ,w4 ,s4 ,on the structure of the tarsus in the tetramerous ,coleoptera of the ,french entomologists4 7,trans4 ,linn4 ,soc4 ,london1 xv1 #ahbe1 pp4 #fc-gc47 ,speyer1 ,o4 ,untersuchung der ,beine der ,schmetterlinge4 7,isis1 #ahdc1 pp4 #afa-bjg1 #bdc-bfd47 ,pokorsky ,joravko1 ,a4 von4 ,quelques remarques sur le dernier article du tarse des ,hymnoptres4 7,bull4 ,soc4 imp4 ,natur4 ,moscou1 #ahdd1 xvii1 pp4 #adj-aei4 ,ref4 in ,isis1 #ahdh1 v1 p4 #cdg47 ,rossmassler1 ,e4 ,a4 ,das ,bein der ,insekten4 7,aus der ,heimath1 #ahfj1 #c kap41 pp4 #cbg-ccd1 ,fig47 ,west1 ,tuffen4 ,the foot of the fly2 its structure and action2 elucidated by comparison with the feet of other insects1 etc4 ,part ,i4 7,trans4 ,linn4 ,soc4 ,london1 xxiii1 #ahfa1 pp4 #cic-dba1 #a ,pl47 ,sundevall1 ,c4 ,on insektenas extremiteter samt deras hufoud och munddelar4 7,kongl4 ,vetenskaps ,akad4 ,handlingar4 iii1 ,nr4 #i1 #ahfa47 ,lindemann1 ,c4 ,notizen zur ,lehre vom ausseren ,skelete der ,insekten 7,gelenke und ,muskeln der ,fsse74 #a ,taf4 7,bull4 ,soc4 imp4 d4 ,natur4 ,moscou1 xxxvii1 #ahfd1 pp4 #dbf-dcb47 ,liebe1 ,o4 ,die ,gelenke der ,insekten4 ,chemnitz1 #ahgc4 #d4 #a ,taf4 ,canestrini1 ,j4 ,ueber ein sonderbares ,organ der ,hymenopteren4 7,zool4 ,anzeiger1 #ahhj1 pp4 #dba1 #dbb47 ,dahl1 ,f4 ,beitrge zur ,kenntnis des ,baues und der ,funktionen der ,insektenbeine4 7,archiv f4 ,naturgesch4 #a ,jahrg41 #ahhd1 pp4 #adf-aic1 #c ,taf4 ,sep41 #dh pp4 ,vorlauf4 ,mitteil1 in ,zool4 ,anz41 #ahhd1 pp4 #ch-da47 ,langer1 ,k4 ,ueber den ,gelenkbau bei den ,arthrozoen4 ,vierter ,beitrag zur vergleichenden ,anatomie und ,mechanik der ,gelenke4 7,denkschriften der ,akad4 d4 ,wissensch4 ,wien1 xviii1 ,bd4 ,physikal4-mathem4 ,classe1 pp4 #ii-adj4 #c ,taf47 ,graber1 ,vitus4 ,ueber die ,mechanik des ,insektenkrpers4 7,biolog4 ,centralbl41 iv1 #ahhd1 pp4 #efj-egj47 ---- ,die ausseren mechanischen ,werkzeuge der ,tiere1 ii ,teil4 ,wirbellose ,tiere1 #ahhf1 pp4 #age-ahb1 #bjh-baj4 ,dewitz1 ,h4 ,ueber die ,fortbewegung der ,tiere an senkrechten glatten ,flchen vermittelst eines ,sekretes4 #c ,taf4 7,pflger's ,archiv f4 d4 ges4 ,physiologie1 xxxiii1 #ahhd1 pp4 #ddj-dha47 ,ockler1 ,a4 ,das ,krallenglied am ,insektenfuss4 7,archiv f4 ,naturgesch41 #ahij1 pp4 #bba-bfb1 #b ,taf47 ,,literature ,,of ,,locomotion 7,,walking1 ,,etc47 ,carlet1 ,g4 ,sur le mode de locomotion des chenilles4 7,compt1 rend4 ,acad4 ,paris1 #ahhh1 cvii1 pp4 #aca-acd4 ,naturwiss4 ,rundschau1 iii ,jahrg41 #ahhh1 ,no4 #db1 p4 #edc47 ---- ,de la marche d'un insecte rendu tetrapode par la suppression d'une paire de pattes4 7,ibid41 pp4 #efe1 #eff47 ---- ,sur la locomotion des insectes et des arachnides4 7,ibid41 #ahgi1 ,t4 #hi1 pp4 #aabd1 #aabe47 ---- ,ueber den ,gang eines vierfssig gemachten ,insekts4 7,naturwiss4 ,rundschau1 viii ,jahrg41 #ahhh1 pp4 #fff-ffg2 ,compt4 rend4 #ahhh1 cvii47 ,demoor1 ,j4 ,recherches sur la marche des insectes et des arachnides4 tude experimentale d',anatomie et de ,physiologie compares4 7,archiv de ,biologie1 ,lige1 #ahhj1 #db pp4 #c ,pls47 ---- ,ueber das ,gehen der ,arthropoden mit ,bercksichtigung der ,schwankungen des ,krpers4 7,compt4 rend4 ,acad4 d4 ,sc4 ,paris1 #ahij1 cxi1 pp4 #hci-hdj47 ,osten-,sacken1 ,c4 ,r4 von4 ,ueber das ,betragen des kalifornischen flgellosen ,bittacus 7apterus ,mc,lachl474 7,wiener ,ent4 ,zeit41 #ahhb1 pp4 #abc47 ,dixon1 ,h4 ,h4 ,preliminary note on the walking of some of the ,arthropoda4 7,proc4 ,r4 ,dublin ,soc4 vii1 pp4 #egd-egh1 #ahib4 ,also ,nature1 #ahig47 ,also the works of ,graber1 ,marey1 ,cheshire1 etc4 ,,literature ,,of ,,walking ,,on ,,smooth ,,surfaces ,blackwell1 ,j4 ,remarks on the pulvilli of insects4 7,trans4 ,linn4 ,soc4 ,london1 xvi1 #ahca1 pp4 #dhg-dib1 #gfg-ggj47 ,lowne1 ,b4 ,t4 ,on the so-called suckers of ,dytiscus and the pulvilli of insects4 7,trans4 ,roy4 ,micr4 ,soc41 pp4 #bfg-bga1 #ahga1 #a ,pl47 ,west1 ,tuffen4 ,on certain appendages to the feet of insects subservient to holding or climbing4 7,journ4 of the ,proceed4 ,linn4 ,soc4 ,london1 ,zology1 vi1 #ahfb1 pp4 #bf-hh47 ,dewitz1 ,h4 ,ueber die ,fortbewegung der ,tiere an senkrechten1 glatten ,flchen vermittelst eines ,sekrets4 7,pflger's ,archiv f4 d4 ges4 ,physiologie1 xxxiii1 #ahhd1 pp4 #ddj-dha4 #c ,taf4 ,also ,zool4 ,anzeiger1 #ahhd1 pp4 #djj-dje47 ---- ,wie ist es den ,stubenfliegen und anderen ,insekten mglich1 an senkrechten ,glaswanden emporzulaufen4 7,sitzungsb4 ,ges4 naturf4 ,freunde zu ,berlin1 #ahhb1 pp4 #e-g47 ---- ,weitere ,mitteilungen ber den ,klettern der ,insekten 7,ibid41 #ahhb1 pp4 #aji-aac74 ---- ,die ,befestigung durch einen klebenden schleim beim springen gegen senkrechte ,flchen4 7,zool4 ,anzeiger1 #ahhc1 pp4 #bgc1 #bgd47 ---- ,ueber die ,wirkung der ,haftlappchen toter ,fliegen4 7,ent4 ,nachr41 x ,jahrg41 #ahhd1 pp4 #bhf1 #bhg47 ---- ,weitere ,mitteilungen ber das ,klettern der ,insekten an glatten senkrechten ,flchen4 7,zoolog4 ,anzeiger1 #ahhe4 viii ,jahrg41 pp4 #aeg-aei47 ---- ,richtigstellung der behauptungen des ,herrn ,f4 ,dahl4 7,archiv f4 mikroskop4 ,anat41 #ahhe1 xxvi1 pp4 #abe-abh47 ,rombouts1 ,j4 ,e4 ,ueber die ,fortbewegung der ,fliegen an glatten ,flchen4 7,zool4 ,anzeiger1 #ahhd1 pp4 #fai-fbc47 ---- ,de la facult qu'out les mouches de se mouvoir sur le verre et sur les autres corps polis4 7,archiv ,museum ,teyler 7#b71 #d ,part1 pp4 #af4 ,fig47 ,simmermacher1 ,g4 ,untersuchungen ber ,haftapparate an ,tarsalgliedern von ,insekten4 7,zeitschr4 f4 wissensch4 ,zool4 xl1 #ahhd1 pp4 #dha-eef4 #c ,taf41 #b ,figs4 ,also ,zoolog4 ,anzeiger1 vii ,jahrg41 #ahhd1 pp4 #bbe-bbh47 ---- ,antwort an ,herrn ,dr4 ,h4 ,dewitz4 7,ibid41 pp4 #eac-eag47 ,dahl1 ,f4 ,die ,fussdrsen der ,insekten4 7,archiv f4 mikroskop4 ,anat41 #ahhe1 xxv1 pp4 #bcf-bfc4 #b ,taf4 ,see also p4 #aah47 ,emery1 ,c4 ,fortbewegung von ,tieren an senkrechten und berhangenden glatten ,flchen4 7,biolog4 ,centralbl41 #ahhd1 #d ,bd41 pp4 #dch-ddc47 ,lon1 ,n4 ,disposition anatomique des organes de succion chez les ,hydrocores et les ,gocores4 7,bull4 ,soc4 des ,medec4 et ,natur1 de ,jassy41 #ahhh47 d4 ,the wings and their structure ,the insects differ from all other animals except birds in possessing wings1 and as we at the outset have claimed1 it is evidently owing to them that insects are numerically so superior to any other class of animals1 since their power of flight enables them to live in the air out of reach of many of their enemies1 the greatest destruction to insect life occurring in the wingless larval and pupal stages4 ,the presence of wings has exerted a profound influence on the shape and structure of the body1 and it is apparently due to their existence that the body is so distinctly triregional1 since this feature is least marked in the synapterous insects4 ,the wings are thin1 broad leaf-like folds of the integument1 attached to the thorax and moved by powerful muscles which occupy the greater part of the thoracic cavity4 ,the two pairs of wings are outgrowths of the middle and hinder part of the thorax1 the anterior pair being attached to the mesothoracic and the hinder pair to the metathoracic segment4 ,the larger pair is developed from the middle segment of the thorax4 ,the differentiation of the tergites into scutum1 scutellum1 etc41 is the result of the appearance of wings1 because these sclerites are more or less reduced or effaced in wingless insects1 such as apterous ,orthoptera and moths1 ants1 etc4 ,the size of the hinder thoracic segments is closely related to that of the wings they bear4 ,in those ,orthoptera which have hind wings larger than those of the fore pair1 the metathorax is larger than the mesothorax4 ,in such ,neuroptera as have the hind wings nearly or quite as large as the anterior pair1 or in the ,trichoptera and in the ,hepialid1 the metathorax is nearly as large as the mesothorax1 while in ,coleoptera the metathorax is as large and often much larger4 ,in the ,ephemerid1 ,diptera1 and ,hymenoptera1 which have either only rudimentary 7halteres7 or small hind wings1 the metathorax is correspondingly reduced in size4 ,the wings morphologically1 as their development shows1 are simple sac-like outgrowths of the integument1 i4e4 of the free hinder edge of the tergal plates1 their place of origin being apparently above the upper edge of the epimera or pleural sclerites4 ,calvert#bd however1 regards the upper lamina of the wing as tergal1 and the lower1 pleural4 ,the wings in most insects are attached to the thorax by a membrane containing several little plates of chitin called by ,audouin articulatory epidemes4 ,the wings1 then1 are simple1 very thin chitinous lamellate expansions of the integument1 which are supported and strengthened by an internal framework of hollow chitinous tubes4 ,the veins4--,the so-called 8veins0 or 8nervures10 which are situated between the upper and under layers of the wing are so disposed as to give the greatest lightness and strength to the wings4 ,hagen has shown that in the freshly formed wings these two layers can be separated1 when it can be seen that the veins pass through each layer4 ,these veins are in reality quite complex1 consisting of a minute central trachea enclosed within a larger tube which at the instant the insect emerges from the nymph1 or pupa1 as the case may be1 is filled with blood 7,fig4 #acf74 ,since these tubes at first contain blood1 which has been observed to circulate through them1 and since the heart can be most easily injected through them1 they may more properly be called veins than nervures4 ,the shape and venation of the wings afford excellent ordinal as well as family and generic characters1 while they also enable the systematist to exactly locate the spots and other markings of the wings4 ,the spaces enclosed by the veins and their cross-branches are called cells1 and their shape often affords valuable generic and specific characters4 ,illustration3 ,,fig4 #acf4--;,cross-section of wing of ,pronuba4--,after ,spuler4 ,illustration3 ,,fig4 #acg4--;,cross-section of wing of ,pieris3 s1 insertions of scales4-,after ,spuler4 ,the structure of a complete vein is described by ,spuler4 ,in a cross-section of a noctuid moth 7,triphna pronuba1 ,fig4 #acf7 the chitinous walls are seen to consist of two layers1 an outer 7,u7 and inner 7c71 the latter of which takes a stain and lies next to the hypodermis 7hy74 ,in the cavity of the vein is the trachea 7tr71 which shows more or less distinctly the so-called spiral thread2 within the cavity are also ,semper's 8rib0 7r7 and blood-corpuscles 7bc71 which proves that the blood circulates in the veins of the completely formed wing1 though this does not apply to all ,lepidoptera with hard mature wings4 ,we have been able to observe the same structure in sections of the wing of ,zygna4 ,a cross-section of a vein of ,pieris brassic shows that the large trachea is first formed1 and that it extends along the track between the protoplasmic threads connecting the two hypodermal layers4 ,the main trache throw off on both sides a number of secondary branches showing at their end a cell with an intracellular tracheal structure2 these accessory trache afterwards branch out4 ,the accessory or transverse trache often disappear1 though in some moths they remain permanently4 ,fig4 #acg tr#b represents these secondary veins in the edge of the fore wing of ,laverna vanella1 arising from a main trachea 7tr7 passing through vein ,i 7v71 two of the twigs extending to the centre1 showing that the latter has no homology with a true vein4 ,only rarely and in strongly developed thick folds are the transverse trache provided with a chitinous thickening1 as for example in ,cossus ligniperda4 ,since from such accessory trache the transverse veins in lepidopterous wings are developed1 we can recognize in them the homologies of the net-veins in reticulated venations4 ,there is no sharply defined difference between reticulated and non-reticulated venations2 no genetic difference exists between the two kinds of venation1 since there occur true ,blattid both with and without a reticulated venation 7,spuler74 ,in the fore wings of ,odonata1 ,psocina1 ,mantispid1 and most ,hymenoptera is an usually opaque colored area between the costal edge and the median vein1 called the pterostigma4 ,in shape the wings are either triangular or linear oval1 and at the front edge the main veins are closer together than elsewhere1 thus strengthening the wings and affording the greatest resistance to the air in making the downward stroke during flight4 ,it is noticeable that when the veins are in part aborted from partial disuse of the wings1 they disappear first from the hinder and middle edge1 those on the costal region persisting4 ,this is seen in the wings of ,embiid 7,oligotoma71 ,cynipid1 ,proctotrupid1 ,chalcids1 ants1 etc4 ,the front edge of the wing is called the costal1 its termination in the outer angle of the wing is called the apex2 the outer edge 7termen7 is situated between the apex and the inner or anal angle1 between which and the base of the wing is the inner or internal edge4 ,while in ,orthoptera1 dragon-flies1 ,termitid1 and ,neuroptera the wings are not attached to each other1 in many ,lepidoptera they are loosely connected by the loop and frenulum1 or in ,hymenoptera by a series of strong hooks4 ,these hooks are arranged1 says ,newport1 8in a slightly twisted or spiral direction along the margin of the wing1 so as to resemble a screw1 and when the wings are expanded attach themselves to a little fold on the posterior margin of the anterior wing1 along which they play very freely when the wings are in motion1 slipping to and fro like the rings on the rod of a window curtain40 ,at the base of the hind wings of ,trichoptera and in the lepidopterous ,micropteryx there is an angular fold 7jugum7 at the base of each wing 7,fig4 #ach72 that of the anterior wings is retained in ,eriocephala and ,hepialid4 ,illustration3 ,,fig4 #ach4--,venation of fore and hind wings of ,micropteryx purpurella3 j1 jugum1 on each wing2 d1 discal vein2 the ,roman numerals indicate veins ,i4-,,viii4 and their branches4 ,in the wings of ,orthoptera as well as other insects1 the fore wings1 especially1 are divided into three well-marked areas1 the costal1 median1 and internal2 of these the median area is the largest1 and in grasshoppers and crickets is more or less modified to form the musical apparatus1 consisting of the drum-like resonant area1 with the file or bow4 ,the squam4--,in the calyptrate ,muscid1 a large scale-like membranous broad orbicular whitish process is situated beneath the base of the wing1 above the halter2 7,fig4 #id1 #aj sq47 it is either small or wanting in the acalyptrate muscids4 ,kirby and ,spence state that when the insect is at rest the two divisions of this double lobe are folded over each other1 but are extended during flight4 ,their exact use is unknown4 ,kolbe1 following other ,german authors1 considers the term squama as applicable to the whole structure1 restricting the term alula to the other lobe-like division4 ,more recently 7#ahij and #ahig7 ,osten-,sacken recommends 8squam2 in the plural1 as a designation for both of these organs taken together2 squama1 in the singular1 would mean the posterior squama alone1 and antisquama the anterior squama alone20 the strip of membrane running in some cases between them1 or connecting the squama with the scutellum1 should be called the post-alar membrane4 ,by a mistake ,loew1 and others following him1 used the word tegula for squama1 but this term should be restricted to the sclerite of the mesothorax previously so designated 7,fig4 #ij1 ,a1 t74 ,the squama or its two subdivisions has also by various authors been termed alula1 calypta1 squamula1 lobulus1 axillary lobe1 aileron1 cuilleron1 schuppen1 and scale4 7,berlin ,ent4 ,zeitschrift1 xli1 #ahif1 pp4 #bhe-bhh1 #cbh1 #cch47 ,the halteres4--,in the ,diptera the hind wings are modified to form the halteres or balancers1 which are present in all the species1 even in ,nycteribia1 but are absent in ,braula4 ,meinert finds structures in the ,lepidoptera which he considers as the homologues of the halteres of ,diptera4 8,in the ,noctuid10 he remarks1 8,i find arising from the fourth thoracic segment 7segment mdiaire71 but covered by hair1 an organ like the halter of ,diptera40 7,ent4 ,tidskrift41 i1 #ahhj1 p4 #afh47 ,he gives no details4 ,in the ,stylopid1 on the contrary1 the fore wings are reduced to little narrow pads1 while the hind wings are of great size4 ,the thyridium is a whitish spot marking a break in the cubital vein of the fore wing of ,trichoptera2 these minute thyridia occur in the fore wings of the saw-flies2 there is also an intercostal thyridium on the costal part of the wings of ,dermaptera4 ,the fore wings of ,orthoptera are thicker than the hinder ones1 and serve to protect the hind-body when the wings are folded2 they are sometimes called tegmina4 ,it is noteworthy1 that1 according to ,scudder1 in all the paleozoic cockroaches the fore wings 7tegmina7 were as distinctly veined as the hinder pair1 8and could not in any sense be called coriaceous40 7,pretertiary ,insects of ,n4 ,a41 p4 #ci47 ,scudder also observes that in the paleozoic insects as a rule the fore and hind wings were similar in shape and venation1 8heterogeneity making its appearance in mesozoic times40 ,in the heteropterous ,hemiptera1 also1 the basal half of the fore wings is thick and coriaceous or parchment-like1 and also protects the body when they are folded2 these wings are called hemelytra4 ,in the ,dermaptera the small short fore wings are thickened and elytriform4 ,the elytra4--,this thickening of the fore wings is carried out to its fullest extent in the fore wings of beetles1 where they form the sheaths1 shards1 or elytra1 under which the hind wings are folded4 ,the indexed costal edge is called the epipleurum1 being wide in the ,tenebrionid4 ,during flight 8the elytra are opened so as to form an angle with the body and admit of the free play of the wings0 7,kirby and ,spence74 ,in the running beetles 7,carabid71 also in the weevils and in many ,ptinidae1 the hind wings are wanting1 through disuse1 and often the elytra are firmly united1 forming a single hard shell or case4 ,the firmness of the elytra is due both to the thickness of the chitinous deposit and to the presence of minute chitinous rods or pillars connecting the upper and lower chitinous surfaces4 ,illustration3 ,,fig4 #aci4--,longitudinal section through the edge of the elytrum of ,lina nea3 gl1 glands2 r1 reservoir2 fb1 fat-body2 m1 matrix2 u1 upper1--l1 lower1 lamella4--,after ,hoffbauer4 ,hoffbauer finds that in the elytra of beetles of different families the venation characteristic of the hind wings is wanting1 the main trache being irregular or arranged in closely parallel longitudinal lines1 and nerve-fibres pass along near them1 sense-organs being also present4 ,the fat-bodies in the cavity of the elytra1 which is lined with a matrix layer1 besides nerves1 trache1 and blood1 contain secretory vesicles filled with uric-acid concretions such as occur in the fat-body of ,lampyris4 ,there are also a great many glands varying much in structure and position1 such occurring also in the pronotum 7,fig4 #aci74 ,meinert considers the elytra of ,coleoptera to be the homologues of the tegul of ,lepidoptera and of ,hymenoptera4 ,he also calls attention to the alula observed in ,dyticus1 situated at the base of the elytra1 but which is totally covered by the latter4 ,the alul of these beetles he regards as the homologues of the anterior wings of ,hymenoptera and ,diptera4 ,no details are given in support of these views4 7,ent4 ,tidskrift1 i1 #ahhj1 p4 #afh47 ,hoffbauer 7#ahib7 also has suggested that the elytra are not the homologues of the fore wings of other insects1 but of the tegul4 ,kolbe describes the alula of ,dyticus as a delicate1 membranous lobe at the base of the elytra1 but not visible when they are closed3 its fringed edge in ,dyticus is bordered by a thickening forming a tube which contains a fluid4 ,the alula is united with the inner basal portion and articulation of the wing-cover1 forming a continuation of them4 ,dufour considered that the humming noise made by these beetles is produced by the alulets4 ,hoffbauer finds no structural resemblances in the alul of ,dyticus to the elytra4 ,he does not find 8the least trace of veins40 ,they are more like appendages of the elytra4 ,lacordaire considered that their function is to prevent the disarticulation of the elytra1 but ,hoffbauer thinks that they serve as contrivances to retain the air which the beetle carries down with it under the surface1 since he almost always found a bubble of air concealed under it2 besides1 their folded and fringed edge seems especially fitted for taking in and retaining air4 ,hoffbauer then describes the tegul of the hornet and finds them to be1 not as ,cholodkowsky states1 hard1 solid1 chitinous plates1 but hollow4 ,they are inserted immediately over the base or insertion of the fore wings1 being articulated by a hinge-joint1 the upper lamella extending into a cavity of the side of the mesothorax1 and connected by a hinge-like1 articulating membrane with the lower projection of the bag or cavity4 ,the lower lamella becomes thinner towards the place of insertion1 is slightly folded1 and merges without any articulation into the thin1 thoracic wall at a point situated over the insertion of the fore wing4 ,the tegul also differ from the wings in having no muscles to move them1 the actual movements being of a passive nature1 and due to the upward and downward strokes of the wings4 ,comstock adopts ,meinert's view that the elytra are not true fore wings1 but gives no reasons4 7,manual1 p4 #die47 ,dr4 ,sharp1#be however1 after examining ,dyticus and ,cybister1 affirms that this structure is only a part of the elytron1 to which it is extensively attached1 and that it corresponds with the angle at the base of the wing seen in so many insects that fold their front wings against the body4 ,he does not think that the alula affords any support to the view that the elytra of beetles correspond with the tegul of ,hymenoptera rather than with the fore wings4 ,that the elytra are modified paraptera 7tegul7 is negatived by the fact that the latter have no muscles1 and that the elytra contain trache whose irregular arrangement may be part of the modified degenerate structure of the elytra4 ,kolbe finds evidences of veins4 ,the question may also be settled by an examination of the structure of the pupal wings4 ,a study of a series of sections of both pairs of wings of the pupa of ,doryphora and of a ,clytus convinces us that the elytra are the homologues of the fore wings of other insects4 e4 ,development and mode of origin of the wings ,embryonic development of the wings4--,the wings of insects are essentially simple dorsal outgrowths of the integument1 being evaginations of the hypodermis4 ,they begin to form in the embryo before hatching1 first appearing as folds1 buds1 or evaginations1 of the hypodermis1 which lie in pouches1 called peripodal cavities4 ,they are not visible externally until rather late in larval life1 after the insect1 such as a grasshopper1 has moulted twice or more times2 while in holometabolous insects they are not seen externally until the pupa state is attained4 ,the subject of their origin is in a less satisfactory state than desirable from the fact that at the outset the development of the wings of the most generalized insects1 such as ,orthoptera1 ,termes1 etc41 was not first examined1 that of the most highly modified of any insects1 i4e4 the ,muscid1 having actually been first studied4 ,in the course of his embryological studies on the ,muscid 7,musca comitoria and ,sarcophaga carnaria7 ,weismann 7#ahfd7 in examining the larv of these flies just before pupation1 found that the wings1 as well as the legs and mouth-appendages1 developed from microscopic masses of indifferent cells1 which he called 8imaginal discs40 ,from the six imaginal discs or buds in the lower part of the thorax arise the legs1 while from four dorsal discs1 two in the meso- and two in the metathoracic segment1 arise the fore and hind wings 7,fig4 #ada47 ,these imaginal buds1 as we prefer to call these germs1 usually appear at the close of embryonic life1 being found in freshly hatched larv4 ,illustration3 ,,fig4 #adj4--;,imaginal buds in ,musca1--,a1 in ,corethra1--,b1 in ,melophagus1--,c1 in embryo of ,melophagus2 dorsal view of the head2 b1 bud2 p1 peripodal membrane2 c1 cord2 hy1 hypodermis2 cl1 cuticula2 st1 stomodum2 v1 ventral cephalic1 behind are the two dorsal cephalic buds4--,after ,pratt4 ,as first observed by ,weismann1 the buds are1 like those of the appendages1 simply attached to trache and sometimes to nerves1 in the former case appearing as minute folds or swellings of the peritoneal membrane of certain of the trache4 ,in ,volucella the imaginal buds were1 however1 found by ,knckel d',herculais to be in union with the hypodermis4 ,dewitz detected a delicate thread-like stalk connecting the peripodal membrane with the hypodermis1 and ,van ,rees has since proved in ,musca1 and ,pratt in ,melophagus1 the connection of the imaginal buds with the hypodermis 7,fig4 #adj74 ,these tracheal enlargements increase in size1 and become differentiated into a solid mass which corresponds to the upper part of the mesothorax1 while a tongue-shaped continuation becomes the rudiment of the wing4 ,during larval life the rudiments of the wings crumple1 thus forming a cavity4 ,while the larva is transforming into the pupa1 the sheath or peripodal membranes of the rudimentary wings are drawn back1 the blood presses in1 and thus the wings are everted out of the peripodal cavities4 ,due credit1 however1 should be given to ,herold1 as the pioneer in these studies1 who first described in his excellent work on the development of ,pieris brassic 7#ahae7 the wing-germs in the caterpillar after the third moult4 ,this discovery has been overlooked by recent writers1 with the exception of ,gonin1 whose statement of ,herold's views we have verified4 ,herold states that the germs of the wings appear on the inside of the second and third thoracic segments1 and are recognized by their attachment to the 8protoplasmic network0 7schleimnetz71 which we take to be the hypodermis1 the net-like appearance of this structure being due to the cell-walls of the elements of the hypodermal membrane4 ,these germs are1 says ,herold1 also distinguished from the flakes of the fat-body by their regular symmetrical form4 ,fine trache are attached to the wing-germs1 in the same way as to the flakes of the fat-body4 ,it thus appears that ,herold in a vague way attributes the origin of these wing-germs1 and also the germs of the leg1 to the hypodermis1 since his schleimnetz is the membrane which builds up the new skin4 ,herold also studied the later development of the wings1 and discovered the mode of origin of the veins1 and in a vague way traced the origin of the scales and hairs of the body1 as well as that of the colors of the butterfly4 ,herold also says that as the caterpillar grows larger1 and also the wing-germs1 8the larval skin in the region under which they lie hidden is spotted and swollen10 and he adds in a footnote3 8,this is the case with all smooth caterpillars marked with bright colors4 ,in dark and hairy caterpillars the swelling of the skin through the growth of the underlying wing-germs is less distinct or not visible at all0 7pp4 #bi1 #cj74 ,it should be added that ,malpighi1 ,swammerdam1 and also ,raumur had detected the rudiments of the wings in the caterpillar just before pupation under the old larval skin4 ,lyonet 7#agfj7 also describes and figures the four wing-germs situated in the second and third thoracic segments1 but was uncertain as to their nature4 ,each of these masses1 he says1 is 8situated in the fatty body without being united to it1 and is attached to the skin in a deep fold which it makes there40 ,he could throw no certain light on their nature1 but says3 8their number and situation leads to the supposition that they may be the rudiments of the wings of the moth0 7pp4 #ddi1 #dej74 ,during the transformation into the pupa the imaginal buds unite and grow out or extend along their edges1 while the enveloping membrane disappears4 ,the rudimentary wings are now like little sacs1 and soon show a fusion of the two wing-membranes or lamin with the veins1 while the trache disappear1 the places occupied by the trache becoming the veins4 8,very early1 as soon as the scales are indicated1 begin in a very peculiar way the fusion of the wing-lamin4 ,there occur openings in the hypodermis into which the cells extend longitudinally and then laterally give way to each other4 ,hence no complete opening is found1 but the epithelium appears by sections through a straight line sharply bordered along the wingcavity4 ,it is a continuous membrane formed of plasma which ,i will call the ground membrane of the epithelium4 ,through this ground membrane pass blood-corpuscles as well as blood-lymph40 7,schaeffer47 ,illustration3 ,,fig4 #ada4--;,anterior part of young larva of ,simulium sericea1 showing the thoracic imaginal buds3 p1 prothoracic bud 7only one not embryonic72 w1 w1 fore and hind wing-buds2 l1 l1 l1 leg-buds2 n1 nervous system2 br1 brain2 e1 eye2 sd1 salivary duct2 p1 prothoracic foot4--,after ,weismann4 ,afterwards 7#ahff7 ,weismann studied the development of the wings in ,corethra plumicornis1 which is a much more primitive and generalized form than ,musca1 and in which the process of development of the wings is much simpler1 and1 as since discovered1 more as in other holometabolous insects4 ,he also examined those of ,simulium 7,fig4 #ada74 ,in ,corethra1 after the fourth and last larval moulting1 there arises at first by evagination and afterwards by invagination a cup-shaped depression on each side in the upper part of the mesothoracic segment within which the rudiment of the wings lies like a plug4 ,the wings without other change simply increase in size until1 in the transformation into the pupa by the withdrawal of the hypodermis1 the wings project out and become filled with blood1 the trache now being wholly wanting1 and other tissues being sparingly present4 ,illustration3 ,,fig4 #adb4--,section through thorax of a ,tineid larva on sycamore1 passing through the #ast pair of wings 7w73 ht1 heart2 i1 sophagus2 s1 salivary gland3 ut1 urinary tube2 nc1 nervous cord2 m1 recti muscles2 a part of the fat body overlies the heart4 ,a1 right wing-germ enlarged4 ,these observations on two widely separate groups of ,diptera were confirmed by ,landois1 and afterwards by ,pancritius1 for the ,lepidoptera1 by ,ganin for the ,hymenoptera1 by ,dewitz for ,hymenoptera 7ants7 and ,trichoptera2 also for the ,neuroptera by ,pancritius4 ,in the ant-lion 7,myrmeleon formicarius7 ,pancritius found no rudiments of the wings in larv a year old1 but they were detected in the second year of larval life1 and do not differ much histologically or in shape from those of ,lepidoptera4 ,in the ,coleoptera and ,hymenoptera the imaginal buds appear rather late in larval life1 yet their structure is like that of ,lepidoptera4 ,in ,cimbex the rudiments of the wings are not found in the young larva1 but are seen in the semipupa1 which stage lasts over six weeks4 ,illustration3 ,,fig4 #adc4--,section of the same specimen as in ,fig4 #adb1 but cut through the second pair of wings 7w73 i1 mid-intestine2 h1 heart2 fb1 fat-body2 l1 leg2 n1 nervous cord4 ,the general relation of the rudiments 7imaginal buds7 of the wings of a tineid moth to the rest of the body near the end of larval life may be seen in ,figs4 #adb1 #adc 7,tinea871 the sections not1 however1 showing their connection with the hypodermis1 which has been torn away during the process of cutting4 ,that the wing is but a fold of the hypodermis is well seen in ,fig4 #add1 of ,datana1 which represents a much later stage of development than in ,figs4 #adb and #adc1 the larva just entering on the semipupa stage4 ,in caterpillars of stage ,i1 #c to #d mm4 in length1 ,gonin found the wing-germs as in ,fig4 #ade1 ,a being a thickening of the hypodermis1 with the embryonic cells1 i4e4 of ,verson1 on the convex border4 ,the two leaves1 or sides of the wing1 begin to differentiate in stage ,,ii 7,c1 ,d71 and in stage ,,iii the envelope is formed 7,e71 while the trache begin to proliferate1 and the capillary trache or tracheoles at this time arise 7,fig4 #ade1 tc74 ,the wall of the principal trachea appears to be resolved into filaments1 and all the secondary branches assume the appearance of bundles of twine4 ,landois regarded them as the product of a transformation of the nuclei1 but ,gonin thinks they arise from the entire cells1 stating that from each cell arises a ball 7peloton7 of small twisted tubes4 ,illustration3 ,,fig4 #add4--,section through mesothoracic segment of ,datana ministra1 passing through the wings 7w73 c1 cuticula2 hyp1 hypodermis3 ap1 apodeme2 dm1 dorsal longitudinal4--vm1 ventral longitudinal4 muscles2 dmt1 depressor muscle of tergum2 t1 trachea2 n1 nerve cords2 i1 intestine2 u1 urinary tubes2 l1 insertion of legs4 ,as the large branches penetrate into the wing1 the balls 7pelotons7 of fine tracheal threads tend to unroll1 and each of the new ramifications of the secondary tracheal system is accompanied in its course by a bundle of capillary tubes4 ,this secondary system of wing-trache1 then1 arises from the mother trachea at the end of the third stage1 when we find already formed the chitinous tunic1 which will persist through the fourth stage up to pupation4 ,it differs from the tracheoles in not communicating with the air-passage2 it possesses no spiral membrane at the origin1 and takes no part in respiration4 ,gonin thus sums up the nature of the two tracheal systems in the rudimentary wing1 which he calls the provisional and permanent systems4 8,the first1 appearing in the second stage of the larva1 comprises all the capillary tubes1 and arising from numerous branches passes off from the lateral trunk of the thorax before reaching the wing2 the second is formed a little later by the direct ramification of the principal branch4 8,these two systems are absolutely independent of each other within the wing4 ,their existence is simultaneous but not conjoint4 ,one is functionally active after the third moult2 the other waits the final transformation before becoming active40 ,illustration3 ,,fig4 #ade4--;,a1 section of wing-bud of larva of ,pieris brassic of stage ,i1 in front of the invagination pit4 ,b1 section passing through the invagination pit4 ,c1 section of same in stage ,,ii1 through the invagination pit2--,d1 behind it1 making the bud appear independent of the thoracic wall4 ,e1 wing-bud at the beginning of the #c;d larval stage1 section passing almost through the pedicel or hypodermic insertion1 the traces of which appear at hi2 h1 hypodermis2 t or tr1 trachea2 i1 opening of invagination2 ec1 embryonic cells2 l1 external layer or envelope2 in1 internal wall of the wing2 ex1 external wall2 s1 cell of a tactile hair2 tc1 capillary tubes2 c1 cavity of invagination4--,after ,gonin4 ,evagination of the wing outside of the body4--,we have seen that the alary germs arise as invaginations of the hypodermis2 we will now1 with the aid of ,gonin's account1 briefly describe1 so far as is known1 the mode of evagination of the wings4 ,during the fourth and last stage of the caterpillar of ,pieris1 the wings grow very rapidly1 and undergo important changes4 ,six or seven days after the last larval moult the chitinous wall is formed1 the wing remaining transparent4 ,it grows rapidly and its lower edge extends near the legs4 ,it is now much crumpled on the edge1 owing to its rapid growth within the limits of its own segment4 ,partly from being somewhat retracted1 and partly owing to the irregularity of its surface1 the wing gradually separates from its envelope1 and the cavity of invagination 7,fig4 #ade1 c7 becomes more like a distinct or real space4 ,the outer opening of the alary sac enlarges quite plainly1 though without reaching the level of the edge of the wing4 ,this condition of things does not still exactly explain how the wing passes to the outside of the body4 ,gonin compares these conditions to those exhibited by a series of sections of the larva1 made forty-eight hours later1 on a caterpillar which had just spun its girdle of silk4 ,at this time the wings have become entirely external1 but1 says ,gonin1 we do not see the why or the how4 ,the partition of the sac has disappeared1 and with it the cavity and the leaf of the envelope4 ,it appears probable that the partition has been destroyed1 because the space between the two teguments is strewn with numerous bits1 many of which adhere to the chitinous integument1 while others are scattered along the edges of the wings1 in their folds1 or between the wings and the wall of the thorax4 ,another series of sections showed that the exit of the fore wings had been accomplished1 while the hinder pair was undergoing the process of eversion4 ,in this case the partition showed signs of degeneration3 deformation of the nuclei1 indistinct cellular limits1 pigmentation1 granular leucocytes1 and fatty globules4 ,after the destruction of the partition1 what remains of the layer of the envelope is destined to make a part of the thoracic wall and undergoes for this purpose a superficial desquamation4 ,the layer of flattened cells is removed and replaced by a firmer epithelium like that covering the other regions4 ,it is this renewed hypodermis which conceals the wing within1 serves to separate it from the cavity of the body1 and gives the illusion of a complete change in its situation4 ,other changes occur1 all forming a complete regeneration1 but which does not accord with the description of ,van ,rees for the ,muscid4 ,finally1 ,gonin concludes that the dbris scattered about the wing comes from the two layers of the partition of the sac1 from the flattened hypodermis of the renewed envelope1 from the chitinous cuticle of the wing1 and from the inner surface of the chitinous integument4 ,he thinks that the metamorphosis of ,pieris is intermediate between the two types of ,corethra and of ,musca1 established by ,weismann1 as follows3 ,corethra4--,the wing is formed in a simple depression of the hypodermic wall4 ,no destruction4 ,pieris4--,the rudiment is concealed in a sac attached to the hypodermis by a short pedicel4 ,destruction of the partition and its replacement by a part of the thoracic wall by means of the imaginal epithelium4 ,musca4--,the pedicel is represented by a cord of variable length1 whose cavity may be obliterated 7,van ,rees74 ,the imaginal hypodermis is substituted for the larval hypodermis1 which has completely disappeared1 either by desquamation 7,viallanes71 or by histolytic resorption 7,van ,rees74 ,extension of the wing2 drawing out of the tracheoles4--,when it is disengaged from the cavity1 the wing greatly elongates and the creases on its surface are smoothed out2 the blood penetrates between the two walls1 and the cellular fibres1 before relaxed and sinuous1 are now firmly extended4 ,of the two tracheal systems1 the large branches are sinuous1 and they are rendered more distinct by the presence of a spiral membrane2 but the two tunics are not separated as in the other trache of the thorax2 moreover1 the mouth choked up with dbris does not yet communicate with that of the principal trunk4 ,the bundles of tracheoles on their part form straight lines1 as if the folds of the organ had had no influence on them4 ,as they have remained bound together1 apart from the chitinous membrane of the tracheal trunk1 they become drawn out with this membrane1 at the time of exuviation1 i4e4 of pupation1 and are drawn out of the neighboring spiracle4 ,illustration3 ,,fig4 #adf4--;,full-grown larva of ,pieris brassic1 opened along the dorsal line3 d1 digestive canal2 s1 silk-gland2 g1 brain2 st ,i1 prothoracic stigma2 st ,,iv1 #ast abdominal stigma2 a1 a1 germs 7buds7 of fore and hind wings2 p1 bud of prothoracic segment2--those of the third pair are concealed under the silk-glands2 ,i-,,iii1 thoracic rings4--,after ,gonin4 8,this is a very curious phenomenon1 which can be verified experimentally3 if we cut off the wing1 while sparing the larval integument around the thoracic spiracles1 we preserve the two tracheal systems2 the same operation performed after complete removal of the larval skin does not give the secondary tracheal system40 7,gonin47 ,deceived by the appearance of the tracheoles while still undeveloped1 ,landois and ,pancritius1 who have not mentioned the drawing out of the capillaries of the larva1 affirm that they are destroyed by resorption in the chrysalis4 8,the study of the trache is closely connected with that of the veins 7nervures74 ,it is well to guard against the error of ,verson1 who mistakes for these last the large tracheal branches of the wing4 ,this confusion is easily explained2 it proves that ,verson had1 with us1 recognized that the secondary system is1 in the larva1 exempt from all respiratory function4 ,landois thought that the pupal period was the time of formation of the veins4 ,it seems to me probable that they are derived from the sheath of the peritracheal spaces40 7,gonin1 pp4 #cj-cc47 ,illustration3 ,,fig4 #adg4--,left anterior wing of a larva #c days before pupation4 ,the posterior part is rolled up3 st1 prothoracic stigma2 tr4 i41 internal tracheal trunk2 tr4 e41 tr4 e41 external tracheal trunk2 p1 cavity of a thoracic leg1 with the imaginal bud b4--,after ,gonin4 ,the appearance of the wing-germs in the fully grown caterpillar1 as revealed by simple dissection1 is shown at ,fig4 #adf2 ,fig4 #adg represents a wing of a larva three days before pupation1 with the germ of a thoracic leg4 ,illustration3 ,,fig4 #adh4--;,graber's diagrams for explaining the origin and primary invagination of the hypodermis to form the germs of the leg 7b71 and wings 7f1 ,a-,c71 and afterwards their evagination ,d1 so that they lie on the outside of the body4 ,e1 stage ,b1 showing the hypodermal cavities 7f7 and stalks connecting the germs with the hypodermis 7z74--,after ,graber4 ,illustration3 ,,fig4 #adi4--,section lengthwise through the left wing of mature larva in ,pieris rap3 t1 trachea2 hyp1 hypodermis2 c1 cuticula4--,after ,mayer4 ,a4 ,g4 ,mayer has examined the late development of the wings in ,pieris rap4 ,fig4 #adi represents a frontal section through the left wing of a mature larva and shows the rudiment of the wing1 lying in its hypodermal pocket or peripodal cavity4 ,how the trachea passes into the rudimentary wing1 and eventually becomes divided into the branches1 around which the main veins afterwards form1 is seen in ,figs4 #add1 #adg1 #aei4 ,the histological condition of the wing at this time is represented by ,fig4 #aea1 the spindle-like hypodermal cells forming the two walls being separated by the ground-membrane of ,semper4 8,while in the pupa state10 says ,mayer1 8the wing-membrane is thrown into a very regular series of closely compressed folds1 a single scale being inserted upon the crest of each fold4 ,when the butterfly issues from the chrysalis1 these folds in the pupal wings flatten out1 and it is this flattening which causes the expansion of the wings4444 ,it is evident that the wings after emergence undergo a great stretching and flattening4 ,the mechanics of the operation appears to be as follows4 ,the hmolymph1 or blood1 within the wings is under considerable pressure1 and this pressure would naturally tend to enlarge the freshly emerged wing into a balloon-shaped bag2 but the hypodermal fibres 7h7 hold the upper and lower walls of the wing-membrane closely together1 and so1 instead of becoming a swollen bag1 the wing becomes a thin flat one4 ,and thus it is that the little thick corrugated sac-like wings of the freshly emerged insect become the large1 thin1 flat wings of the imago4444 ,the area of the wing of the imago of ,danais plexippus is #h4f times that of the pupa4 ,now1 as the wing of the young pupa has about #fj times the area of the wing in the mature larva1 it is evident that in passing from the larval state to maturity the area of the wings increases more than #ejj times40 ,illustration3 ,,fig4 #aej4--;,diagrammatic reproduction of ,fig4 #adi showing the wing-germ in its peripodal cavity 7p73 h'drm1 hypodermis2 tr1 trachea2 cta1 cuticula2 a1 anterior end4--,after ,mayer4 ,illustration3 ,,fig4 #aea4--,section of the wing-germ1 the upper and lower sides connected by spindle-like hypodermic cells 7h71 forming the rods of the adult wing2 mbr1 ground-membrane of ,semper4--,after ,mayer4 f4 ,the primitive origin of the wings ,farther observations are needed to connect the mode of formation of the wings in the holometabolous insects with the more primitive mode of origin seen in the hemimetabolous orders1 but the former mode is evidently inherited from the latter4 ,pancritius remarks that the development of the rudiments of the wing in a hypodermal cavity is in the holometabolic insects to be regarded as a later inherited character1 the external conditions causing it being unknown4 ,fritz ,mller was the first to investigate the mode of development of the wings of the hemimetabolic insects1 examining the young nymphs of ,termites4 ,he regards the wings as evaginations of the hypodermis1 which externally appear as thoracic scale-like projections1 into which enter rather late in nymphal life trache which correspond to the veins which afterward arise4 ,illustration3 ,,fig4 #aeb4--,rudimentary wing of young nymph of ,blatta1 with the five principal veins developed4 ,the primitive mode of origin of the wings may1 therefore1 be best understood by observing the early stages of those insects1 such as the ,orthoptera and ,hemiptera1 which have an incomplete metamorphosis4 ,if the student will examine the nymphs of any locust in their successive stages1 he will see that the wings arise as simple expansions downward and backward of the lateral edges of the meso- and metanotum4 ,in the second nymphal stage this change begins to take place1 but it does not become marked until the succeeding stage1 when the indications of veins begin to appear1 and the lobe-like expansion of the notum is plainly enough a rudimentary wing4 ,graber#bf thus describes the mode of development of the wings in the nymph of the cockroach3 8,if one is looking only at the exterior of the process1 he will perceive sooner or later on the sides of the meso- and metathorax pouch-like sacs1 which increase in extent with the dorsal integument and at the same time are more and more separated from the body4 ,these wing-covers either keep the same position as in the flat-bodied ,blattid1 or in insects with bodies more compressed the first rudiments hang down over the sides of the thorax4 ,as soon as they have exceeded a certain length1 these wing-covers are laid over on the back4 ,however1 if we study the process of development of the wings with a microscope1 by means of sections made obliquely through the thorax1 the process appears still more simple4 ,the chief force of all evolution is and remains the power of growth in a definite direction4 ,in regard to the skin this growth is possible in insects only in this way2 namely1 that the outer layer of cells is increased by the folds which are forced into the superficial chitinous skin4 ,these folds naturally grow from one moult to another in proportion to the multiplication of the cells1 and are not smoothed out until after the moulting1 when the outer resistance is overcome4 ,illustration3 ,,fig4 #aec4--,partial metamorphosis of ,melanoplus femur-rubrum1 showing the five nymph stages1 and the gradual growth of the wings1 which are first visible externally in #c1 #c;b1 #c;c4--,emerton del4 8,as1 however1 the first wing-layers depend upon the wrinkling of the general integument of the body through the increase in the upper layer1 the further growth of the wings depends in the later stages upon the wrinkling of the epidermis of the wing-membrane even1 which fact we also observe under the microscope when the new wings drawn forth from the old covers appear at first to be quite creased together4 ,these wing-like wrinkles in the skin are not empty pouches1 but contain tissues and organs within1 which are connected with the skin1 as the fat of the body1 the network of trache1 muscles1 etc4 ,alongside the trache1 running through the former wing-pouches and accompanied by the nerves1 there are canals through which the blood flows in and out4 ,illustration3 ,,fig4 #aed4--,stages in the growth of the wings of the nymph of ,termes flavipes3 ,a1 young2 a1 a wing enlarged4 ,b1 older nymph2 b1 fore wing2 n1 a vein4 ,c1 wings more advanced2--,d1 mature4 ,illustration3 ,,fig4 #aee4--,wings of nymph of ,psocus4 8,after the last moult1 however1 when the supply of moisture is very much reduced in the wing-pouches1 which are contracted at the bottom1 their two layers become closely united1 and afterward grow into one single1 solid wing-membrane4 8,these thick-walled blood-tubes arising above and beneath the upper and lower membrane of the wing are the veins of the wings2 the development of the creased wings in the pupa of butterflies is exactly like that of cockroaches and bugs4 ,the difference is only that the folds of integument furnishing the wings with an ample store of material for their construction reach in a relatively shorter time1 that is the space of time between two moults1 the same extent that they would otherwise attain only in the course of several periods of growth in the ametabolous insects40 ,illustration3 ,,fig4 #aef4--,nymph of ,aphrophora permutata1 with enlarged view of the wings and the veins3 pro1 pronotum2 sc1 mesoscutum2 #a;ab1 #ast abdominal segment4 ,ignorant of ,graber's paper1 we had arrived at the same result1 after an examination of the early nymph-stages of the cockroach1 as well as the locusts1 ,termites1 and various ,hemiptera4 ,in all these forms it is plainly to be seen that the wings are simply expansions1 either horizontal or partly vertical 7where1 as in locusts1 etc41 the body is compressed1 and the meso- and metanota are rounded downwards71 of the hinder and outer edge of the meso- and metanotum4 ,as will be seen by reference to the accompanying figures1 the wings are notal 7tergal7 outgrowths from the dorsal arch of the two hinder segments of the thorax4 ,at first1 as seen in the young pupal cockroach 7,fig4 #aeb7 and locust 7,fig4 #aec1 also ,figs4 #aed and #aef7 the rudiments of the wings are continuous with the notum4 ,late in nymphal life a suture and a hinge-joint appear at the base of the wing1 and thus there is some movement of the wing upon the notum2 finally1 the trache are well developed in the wings1 and numerous small sclerites are differentiated at the base of the wing1 to which the special muscles of flight are attached1 and thus the wings1 after the last nymphal moult1 have the power of flapping1 and of sustaining the insect in the air2 they thus become true organs of flight4 ,it is to be observed1 then1 that the wings in all hemimetabolous insects are outgrowths from the notum1 and not from the flanks or pleurum of the thorax4 ,there is1 then1 no structure in any other part of the body with which they are homologous4 ,illustration3 ,,fig4 #aeg4--;,development of wings of ,trichoptera3 ,a1 portion of body-wall of young larva of ,trichostegia2 ch1 cuticula1 forming at r a projection into the hypodermis1 m2 r1 and d1 forming thus the first rudiment of the wing4 ,b1 the parts in a larva of nearly full size2 a1 c1 d1 b1 the well-developed hypodermis of the wing-germ separated into two parts by r1 the penetrating extension of the cuticula2 v1 mesoderm1 ,c1 wing-pad of another ,phryganeid freed from its case at its change to the pupa3 b1 d1 outer layer of the hypodermis 7m7 of the body-wall2 v1 inner layer within nuclei4--,after ,dewitz1 from ,sharp4 ,the same may be said of the true ,neuroptera1 ,trichoptera 7,fig4 #aeg71 the ,coleoptera1 and the ,diptera1 ,lepidoptera1 and ,hymenoptera4 ,as we have observed in the house fly1#bg the wings are evidently outgrowths of the meso- and metanotum2 we have also observed this to be most probably the case in the ,lepidoptera1 from observations on a ,tortrix in different stages of metamorphosis4 ,it is also the case with the ,hymenoptera1 as we have observed in bees and wasps2#bh and in these forms1 and probably all ,hymenoptera1 the wings are outgrowths of the scutal region of the notum4 ,with these facts before us we may speculate as to the probable origin of the wings of insects4 ,the views held by some are those of ,gegenbaur1 also adopted by ,lubbock1 and originally by myself4#bi ,according to ,gegenbaur3 8,the wings must be regarded as homologous with the lamellar tracheal gills1 for they do not only agree with them in origin1 but also in their connection with the body1 and in structure4 ,in being limited to the second and third thoracic segments they point to a reduction in the number of the tracheal gills4 ,it is quite clear that we must suppose that the wings did not arise as such1 but were developed from organs which had another function1 such as the tracheal gills2 ,i mean to say that such a supposition is necessary1 for we cannot imagine that the wings functioned as such in the lower stages of their development1 and that they could have been developed by having such a function40 ,illustration3 ,,fig4 #aeh4--;,changes in external form of the young larva of ,calotermes rugosus1 showing1 in ,a and ,b1 the mode of origin of the wing-pads3 ,a1 newly hatched1 with #i antennal joints1 #h4 ,b1 older larva1 with #aj joints1 #h4 ,c1 next stage1 with #aa joints1 #h4 ,d1 larva1 with twelve joints2 the position of the parts of the alimentary canal are shown3 v1 crop2 m1 stomach2 b1 8paunch02 e1 intestine2 r1 heart1 #afc4--;,after ,fritz ,mller1 from ,sharp4 ,if we examine the tracheal gills of the smaller dragon-fly 7,agrion71 or the ,may-flies1 or ,sialid1 or ,perlid1 or ,phryganeid1 we see that they are developed in a very arbitrary way1 either at the end of the abdomen1 or on the sternum1 or from the pleurum2 moreover1 in structure they invariably have but a single trachea1 from which minute twigs branch out2#cj in the wings there are five or six main trache1 which give rise to the veins4 ,thus1 in themselves1 irrespective of their position1 they are not the homologues of the gills4 ,the latter are only developed in the aquatic representatives of the ,neuroptera and ,pseudoneuroptera1 and are evidently adaptive1 secondary1 temporary organs1 and are in no sense ancestral1 primitive structures from which the wings were developed4 ,there is no good reason to suppose that the aquatic ,odonata or ,ephemerids or ,neuroptera were not descendants of terrestrial forms4 ,to these results we had arrived by a review of the above-mentioned facts1 before meeting with ,fritz ,mller's opinions1 derived from a study of the development of the wings of ,calotermes 7,fig4 #aeh74 ,mller#ca states that 87#a7 ,the wings of insects have not originated from #8tracheal gills4' ,the wing-shaped continuations of the youngest larv are in fact the only parts in which air tubes are completely wanting1 while trache are richly developed in all other parts of the body4#cb 7#b7 ,the wings of insects have arisen from lateral continuations of the dorsal plates of the body-segments with which they are connected40 ,now1 speculating on the primary origin of wings1 we need not suppose that they originated in any aquatic form1 but in some ancestral land insect related to existing cockroaches and ,termes4 ,we may imagine that the tergites 7or notum7 of the two hinder segments of the thorax grew out laterally in some leaping and running insect2 that the expansion became of use in aiding to support the body in its longer leaps1 somewhat as the lateral expansions of the body aid the flying squirrel or certain lizards in supporting the body during their leaps4 ,by natural selection these structures would be transmitted in an improved condition until they became flexible1 i4e4 attached by a rude hinge-joint to the tergal plates of the meso- and metathorax4 ,then by continued use and attempts at flight they would grow larger1 until they would become permanent organs1 though still rudimentary1 as in many existing ,orthoptera1 such as certain ,blattari and ,pezotettix4 ,by this time a fold or hinge having been established1 small chitinous pieces enclosed in membrane would appear1 until we should have a hinge flexible enough to allow the wing to be folded on the back1 and also to have a flapping motion4 ,a stray tracheal twig would naturally press or grow into the base of the new structure4 ,after the trachea running towards the base of the wing had begun to send off branches into the rudimentary structure1 the number and direction of the future veins would become determined on simple mechanical principles4 ,the rudimentary structures beating the air would need to be strengthened on the front or costal edge4 ,here1 then1 would be developed the larger number of main veins1 two or three close together1 and parallel4 ,these would be the costal1 subcostal1 and median veins4 ,they would throw out branches to strengthen the costal edge1 while the branches sent out to the outer and hinder edges of the wings might be less numerous and farther apart4 ,the net-veined wings of ,orthoptera and ,pseudoneuroptera1 as compared with the wings of ,hymenoptera1 show that the wings of net-veined insects were largely used for respiration as well as for flight1 while in beetles and bees the leading function is flight1 that of respiration being quite subordinate4 ,the blood would then supply the parts1 and thus respiration or aration of the blood would be demanded4 ,as soon as such expansions would be of even slight use to the insect as breathing organs1 the question as to their permanency would be settled4 ,organs so useful both for flight and aration of the blood would be still further developed1 until they would become permanent structures1 genuine wings4 ,they would thus be readily transmitted1 and being of more use in adult life during the season of reproduction1 they would be still further developed1 and thus those insects which could fly the best1 i4e4 which had the strongest wings1 would be most successful in the struggle for existence4 ,thus also1 not being so much needed in larval life before the reproductive organs are developed1 they would not be transmitted except in a very rudimentary way1 as perhaps masses of internal indifferent cells 7imaginal discs71 to the larva1 being the rather destined to develop late in larval and in pupal life4 ,thus the development of the wings and of the generative organs would go hand in hand1 and become organs of adult life4#cc ,the development and structure of the trache and veins of the wing4--,the so-called veins 78nervures07 originate from fine tracheal twigs which pass into the imaginal discs4 ,a single longitudinal trachea grows down into the wing-germ 7,fig4 #adg71 this branch arising through simple budding of the large body-trachea passing under the rudiment of the wing4 ,illustration3 ,,fig4 #aei4--;,germ of a hind wing detached from its insertion1 and examined in glycerine3 i1 pedicel of insertion to the hypodermis2 tr1 trachea2 b1 semicircular pad2 e1 enveloping membrane2 c1 bundle of capillary tracheoles2 the large trache of the wing not visible2 they follow the course of the bundles of tracheoles4--,after ,gonin4 ,gonin states that before the trache reach the wing they divide into a great number of capillary tubes united into bundles and often tangled4 ,this mass of trache does not penetrate into the wing-germ by one of its free ends1 but spreading over about a third of the surface of the wing1 separates into a dozen bundles which spread out fan-like in the interior of the wing4 7,fig4 #aei74 ,these ramifications1 as seen under the microscope1 are very irregular2 they form here and there knots and anastomoses4 ,they end abruptly in tufts at a little distance from the edge of the wing4 ,a raised semicircular ridge 7b7 surrounds the base of the wing1 and within this the capillaries are formed1 while on the other side they are covered by a cellular layer4 ,landois1 he says1 noticed neither the pedicel of the insertion of the wing 7i7 nor the ridge 7b74 ,herold only states that the trache pass like roots into the wing4 ,landois believed that they formed an integral part of it4 ,dewitz and ,pancritius used sections to determine their situation4 ,fig4 #afj will illustrate ,landois' views as to the origin of the trache and veins4 ,a represents the germ of a hind wing attached to a trachea2 c the elongated cells1 in which1 as seen at ,b1 c1 a fine tangled tracheal thread 7t7 appears1 seen to be magnified at ,c4 ,the cell walls break down1 and the threads become those which pass through the centre of the veins4 ,illustration3 ,,fig4 #afj4--,origin of the wings and their veins4--,after ,landois4 ,illustration3 ,,fig4 #afa4-,section of the 8rib0 of a vein3 c1 cord2 b1 twig4--,after ,schaeffer4 ,the wing-rods4--,semper discovered in transverse sections of the wings1 what he called ,flgelrippen2 one such rib accompanying the trachea in each vein4 ,he did not discover its origin1 and his description of it is said to be somewhat erroneous4 ,schaeffer has recently examined the structure1 remarking3 8,i have surely observed the connection of this cellular tube with the trache4 ,it is found in the base of the wing where the lumen of the trache is much widened4 ,i only describe the fully formed rib 7rippe74 ,in a cross-section it forms a usually cylindrical tube which is covered by a very thin chitinous intima which bears delicate twigs 7,fig4 #afa74 ,these twigs are analogous to the thickened ridge of the tracheal intima4 ,i can see no connection between the branches of the different twigs4 ,through the ribs 7rippen7 extend a central cord 7c7 which shows in longitudinal section a clear longitudinal streaking4 ,semper regarded it as a nerve4 ,but the connection of the tube with the trachea contradicts this view4 ,i can only regard the cord as a separation-product of the cells of the walls40 ,illustration3 ,,fig4 #afb4--,parts of a vein of the cockroach1 showing the nerve 7n7 by the side of the trachea 7tr72 c1 blood-corpuscles4--,after ,moseley4 ,other histological elements4--,these are the blood-lymph1 corpuscles1 blood-building masses1 and nerves4 ,schaeffer states that in the immature pupal wings we find besides the large trache1 which are more or less branched1 and in the wing-veins at a later period1 blood-corpuscles which are more or less gorged with nutritive material1 and also the 8balls of granules0 of ,weismann1 which are perhaps the 8single fat-body cells0 detected by ,semper4 ,schaeffer also states that into the hypodermal fold of the rudiments of the wings pass peculiar formations of the fat-body and tracheal system1 and connected with the fat-body are masses of small cells which by ,schaeffer are regarded as blood-building masses4 ,fine nerves have also been detected within the veins1 ,moseley stating that a nerve-fibre accompanies the trachea in all the larger veins in the insects he has examined 7,fig4 #afb71 while it is present in ,melolontha1 where the trachea is absent4 ,,literature ,,on ,,the ,,wings ,jurine1 ,l4 ,nouvelle mthode de classer les ,hymnoptres et les ,dipters4 ,genve1 #ahjg1 #d pp4 #cai1 #ad ,pls4 ---- ,observations sur les ailes des ,hymnoptres4 7,mm4 acad4 ,turin1 #ahbj1 xxiv1 pp4 #agg-bad47 ,latreille1 ,p4 ,a4 ,de la formation des ailes des ,insectes4 7,mm4 sur divers sujets de l'histoire naturelle des ,insectes1 etc4 ,paris1 #ahai4 ,fasc4 #h47 ---- ,de quelques appendices particuliers du thorax de divers ,insectes4 7,mm4 du ,mus4 d',hist4 nat41 #ahba1 vii1 pp4 #a-ba1 #ced-cfc47 ,chabrier1 ,j4 ,essai sur le vol des insectes4 7,mm4 du ,mus4 d',hist4 nat41 #ahbj1 vi1 pp4 #daj-dgf2 #ahba1 vii1 pp4 #big-cgb2 #ahbb1 viii1 pp4 #dg-ii1 #cdi-djc47 ,separate1 pp4 #cbh1 #ac ,pls4 ,burmeister1 ,hermann4 ,handbuch der entomologie1 i1 #ahcb1 pp4 #if-ajf1 #bfc-bfg1 #did-eje4 ---- ,untersuchungen ber die ,flgeltypen der ,coleopteren4 7,abhandl4 d4 naturf4 ,ges4 ,halle1 #ahed1 ii1 pp4 #abe-adj1 #a ,taf47 ,romand1 ,b4 ,e4 de4 ,tableau de l'aile suprieure des ,hymnoptres1 #a ,pl4 ,paris1 #ahci4 7,revue ,zool41 ii1 pp4 #cci2 ,bericht von ,erichson fr #ahci1 pp4 #ed-ef47 ,lefebure1 ,a4 ,communication verbale sur la ptrologie des ,lpidoptres4 7,annal4 ,soc4 ,ent4 ,france1 #ahdb1 i1 pp4 #e-ce1 #c ,pls4 ,also ,revue ,zool4 ,paris1 #ahdb1 pp4 #eb-eh1 #a ,pl47 ,deschamps1 ,b4 ,recherches microscopiques sur l'organisation des lytres des ,coloptres4 7,ann4 sc4 nat41 sr4 #c1 iii1 #ahde1 pp4 #ced-cfc47 ,heer1 ,oswald4 ,die ,insektenfauna der ,tertirgebilde von ,oeningen und ,radaboj41 #ahdg1 #a4 ,teil1 pp4 #ge-id4 ,newman1 ,e4 ,memorandum on the wing-rays of insects4 7,trans4 ,ent4 ,soc4 ,london1 ser4 #b1 iii1 #ahee1 pp4 #bbe-bca47 ,westwood1 ,j4 ,o4 ,notes on the wing-veins of insects4 7,trans4 ,ent4 ,soc4 ,london1 ser4 #b1 iv1 #aheg1 pp4 #fj-fd47 ,loew1 ,h4 ,die ,schwinger der ,dipteren4 7,berlin1 ,entom4 ,zeitschr41 #aheh1 pp4 #bbe-bcj47 ,saussure1 ,h4 de4 tudes sur l'aile des ,orthoptres4 7,ann4 scienc4 nat41 #e sr4 x1 p4 #afa47 ,schiner1 ,j4 ,r4 ,ueber das ,flgelgeder der ,dipteren4 7,verhdl4 k4 k4 ,zool4-bot41 ,ges4 ,wien1 #ahfd1 pp4 #aic-bjj1 #a ,taf47 ,hagen1 ,h4 ,a4 ,ueber rationelle ,benennung des ,geders in den ,flgeln der ,insekten4 7,stettin4 ,ent4 ,zeitung1 #ahgj1 xxxi1 pp4 #caf-cbj1 #a ,taf47 ---- ,kurze ,bemerkungen ber das ,flgelgeder der ,insekten4 7,wiener ,entom4 ,zeit41 #ahhf1 v1 pp4 #caa1 #cab47 ,plateau1 ,f4 ,qu'est-ce que l'aile d'un insecte8 7,stett4 ,ent4 ,zeit4 ,jahrg4 #cb1 #ahga1 pp4 #cc-db1 #a ,taf4 ,journal d4 ,zool41 ii1 #ahgc1 pp4 #abf-acg47 ,moseley1 ,h4 ,n4 ,on the circulation in the wing of ,blatta orientalis and other insects1 etc4 7,quart4 ,journ4 ,micr4 ,sc4 #ahga1 xi1 pp4 #chi-cie1 #a ,pl47 ,roger1 ,otto4 ,das ,flgelgeder der ,kafer4 ,erlangen1 #ahge1 #ij p4 ,rade1 ,e4 ,die westfalischen ,donacien und ihre nachsten ,verwandten4 #c ,taf4 7,vierter ,jahresber4 d4 ,westfal ,prov4-,vereins f4 ,wiss4 u4 ,kunst1 #ahgf1 pp4 #eb-hg2 ,flgel1 pp4 #fa-fh47 ,katter1 ,f4 ,ueber ,inseckten1 speziell ,schmetterlingsflgel4 7,entom4 ,nachr41 iv1 #ahgh1 pp4 #bgi-bha1 #bic-bih1 #cjd-cji1 #cba-cbc47 ,hofmann1 ,georg v4 ,ueber die morphologische ,deutung der ,insektenflgel4 7,jahresber4 d4 akad4-naturwiss4 ,vereins1 ,graz1 v ,jahrg41 #ahgi1 pp4 #fc-fh47 ,kolbe1 ,h4 ,j4 ,das ,flgelgeder der ,psociden und seine systematische ,bedeutung4 7,stettin4 ,entom4 ,zeitung1 #ahhj1 pp4 #agi-ahf1 #a ,taf47 ---- ,die ,zwischenraume zwischen den ,punktstreifen der punktiertgestreiften ,flgeldecken der ,coleoptera als rudimentare ,rippen aufgefasst4 7,jahresber4 zool4 ,sektion d4 ,westfal4 ,prov4-,ver4 f4 ,wiss4 u4 ,kunst4 ,mnster1 #ahhf1 pp4 #eg-ei1 #a ,taf47 ,lee1 ,a4 ,bolles4 ,les balanciers des ,diptres1 leurs organes sensifres et leurs histologie4 7,recueil ,zool4 ,suisse1 i1 #ahhe1 pp4 #cfc-cib1 #a ,pl47 ,poppius1 ,alfred4 ,ueber das ,flgelgeder der finnischen ,dendrometriden4 #a ,taf4 7,berl4 ,entom4 ,zeitschr41 #ahhh1 pp4 #ag-bh47 ,comstock1 ,j4 ,h4 ,on the homologies of the wing-veins of insects4 7,american ,naturalist1 xxi1 #ahhg1 pp4 #icb-icd47 ,brauer1 ,f4 ,ansichten ber die palozoischen ,insekten und deren ,deutung4 7,annal4 d4 k4 k4 naturhist4 ,mus4 ,wien1 ,bd4 i1 #ahhf1 pp4 #hf-abf1 #b ,taf47 ,brauer1 ,f41 und ,j4 ,redtenbacher4 ,ein ,beitrag zur ,entwicklung des ,flgelgeders der ,insekten4 7,zool4 ,anz4 #ahhh1 pp4 #ddc-ddg47 ,redtenbacher1 ,j4 ,vergleichende ,studien ber das ,flgelgeder der ,insekten4 #ab ,taf4 7,annalen d4 k4 k4 naturhist4 ,hofmuseums zu ,wien1 #ahhf1 i1 pp4 #aec-bca47 ,schoch1 ,g4 ,miscellanea entomologica4 ,i4 ,das ,geder des ,insektenflgels2 ,,ii4 ,prolegomena zur ,fauna dipterorum ,helvetiae1 ,wissenschaftl4 7,beilage z4 ,programm d4 ,kantonsschule ,zurich1 #ahhi1 #d1 #dj p47 ,bondsdorff1 ,a4 von4 ,ueber die ,ableitung der ,skulpturverhltnisse bei den ,deckflgeln der ,coleopteren4 7,zool4 ,anz41 #ahij1 xiii ,jahrg41 pp4 #cdb-cdf47 ,spuler1 ,arnold4 ,zur ,phylogenie und ,ontogenie des ,flgelgeders der ,schmetterlinge4 7,zeitschr4 wissens4 ,zool41 liii1 #eig-fdf1 #b ,taf41 #ahib47 ,also the writings of ,adolph1 ,bugnion1 ,calvert1 ,comstock1 ,diez1 ,giraud1 ,gonin1 ,graber1 ,kellogg1 ,packard1 ,pratt1 ,scudder1 ,walsh4 g4 ,mechanism of flight ,marey's views on the flight of insects4--,as we owe more to ,marey than to any one else for what exact knowledge we have of the theory of flight of insects1 the following account is condensed from his work entitled 8,movement40 ,the exceedingly complicated movements of the wings would lead us1 he says1 to suppose that there exists in insects a very complex set of muscles of flight1 but in reality1 he claims1 there are only the two elevator and depressor muscles of each wing4#cd ,and ,marey says that when we examine more closely the mechanical conditions of the flight of insects1 we see that an upward and downward motion given by the muscles is sufficient to produce all these successive acts1 so well coordinated with each other2 the resistance of the air effecting all the other movements4 ,he also refers to the experiments of ,giraud which prove that the insect needs for flight a rigid main-rib and a flexible membrane4 ,illustration3 ,,fig4 #afc4--,the two upper lines are produced by the contacts of a drone's wing on a smoked cylinder4 ,in the middle are recorded the vibrations of a tuning-fork 7#bej vibrations per second7 for comparison with the frequency of the wing movements4 ,below are seen the movements of the wing of a bee4--,after ,marey4 ,if we take off the wing of an insect1 and holding it by the small joint which connects it with the thorax1 expose it to a current of air1 we see that the plane of the wing is inclined more and more as it is subjected to a more powerful impulse of the wind4 ,the anterior nervure resists1 but the membranous portion which is prolonged behind bends on account of its greater pliancy4 ,the wings of insects may be regarded simply as vibrating wires1 and hence the frequency of their movements can be calculated by the note produced4 ,their movements can be recorded directly on a revolving cylinder1 previously blackened with smoke1 the slightest touch of the tip of the wing removing the black and exposing the white paper beneath2 ,fig4 #afc was obtained in this way4 ,by this method it was calculated that in the common fly the wings made #ccj strokes per second1 the bee #aij1 the ,macroglossus #gb1 the dragon-fly #bh1 and the butterfly 7,pieris rap7 #i4 ,thus the smaller the species1 the more rapid are the movements of the wings4 ,illustration3 ,,fig4 #afd4--;,appearance of a wasp flying in the sun3 the extremity of the wing is gilded4--,after ,marey4 ,the path or trajectory made by the tip of the wing is like a figure #h4 ,marey obtained this by fastening a spangle of gold-leaf to the extremity of a wasp's wing4 ,the insect was then seized with a pair of forceps and held in the sun in front of a dark background1 the luminous trajectory shaping itself in the form of a lemniscate 7,fig4 #afd74 ,to determine with accuracy the direction taken by the wing at different stages of the trajectory1 a small piece of capillary glass tubing was blackened in the smoke of a candle1 so that the slightest touch on the glass was sufficient to remove the black coating and show the direction of movement in each limb of the lemniscate4 ,this experiment was arranged as shown in ,fig4 #afe4 ,different points on the path of movement were tested by the smoked rod1 and from the track along which the black had been removed the direction of movement was deduced4 ,this direction is represented in the figure by means of arrows4 ,illustration3 ,,fig4 #afe4--;,experiment to test the direction of movement of an insect's wing3 a1 a1 b1 b1 different positions of the smoked rod4 ,theory of insect flight4--8,the theory of insect flight10 says ,marey1 8may be completely explained from the preceding experiments4 ,the wing1 in its to-and-fro movement1 is bent in various directions by the resistance of the air4 ,its action is always that of an inclined plane striking against a fluid and utilizing that part of the resistance which is favorable to its onward progression4 8,this mechanism is the same as that of a waterman's scull1 which as it moves backwards and forwards is obliquely inclined in opposite directions1 each time communicating an impulse to the boat40 ,the mechanism in the case of the insect's wing is far simpler1 however1 than in the process of sculling1 since 8the flexible membrane which constitutes the anterior part of the wing presents a rigid border1 which enables the wing to incline itself at the most favorable angle40 8,the muscles only maintain the to-and-fro movement1 the resistance of the air does the rest1 namely1 effects those changes in surface obliquity which determine the formation of an #h-shaped trajectory by the extremity of the wing40 ,illustration3 ,,fig4 #aff4--;,bee flying about in the chamber of the apparatus4--,after ,marey4 ,lendenfeld has applied photography to determine the position of the wings of a dragon-fly1 and ,marey has carried chronophotography farther to indicate the normal trajectory of the wing1 and to show the position in flight4 ,fig4 #aff shows a bee in various phases of flight4 8,the insect sometimes assumes almost a horizontal position1 in which case the lower part of its body is much nearer the object-glass than is its head1 and yet both extremities are equally well defined in the photograph4 ,the successive images are separated by an interval of #abj of a second 7a long time when compared to the total time occupied by a complete wing movement1 i4e4 #aaij of a second74 ,and hence it is useless to attempt to gain a knowledge of the successive phases of movement by examining the successive photographs of a consecutive series representing an insect in flight4 ,nevertheless an examination of isolated images affords information of extreme interest with regard to the mechanism of flight4 8,we have seen that owing to the resistance of the air the expanse of wing is distorted in various directions by atmospheric resistance4 ,now1 as the oscillations during flight are executed in a horizontal plane1 the obliquity of the wing-surface ought to diminish the apparent breadth of the wing4 ,this appearance can be seen in ,fig4 #afg4 ,there is here a comparison between two ,tipul3 the one in the act of flight1 the other perfectly motionless and resting against the glass window4 ,illustration3 ,,fig4 #afg4--;,illustration to show two ,tipul1 one of them remaining motionless on the glass1 and the other moving its limbs in different directions1 and setting its body at various inclinations3 the illustration only represents a small part of a long series4--,after ,marey4 8,the motionless insect maintains its wings in a position of vertical extension2 the plane is therefore at right angles to the axis of the object-glass4 ,the breadth of the wing can be seen in its entirety2 the nervures can be counted1 and the rounding off of the extremities of the wings is perfectly obvious4 ,on the other hand1 the flying insect moves its wings in a horizontal direction1 and owing to the resistance of the air the expanse of the wings is obliquely disposed1 and only the projection of its surface can be seen in the photograph4 ,this is why the extremity of the wings appears as if it were pointed1 while the other parts look much narrower than normal4 ,the extent of the obliquity can be measured from the apparent alteration in width1 for the projection of this plane with the vertical is the sine of the angle4 ,from this it may be gathered that the right wing 7,fig4 #afh1 third image7 was inclined at an angle of about #ej with the vertical1 say #dj with the horizontal4 ,this inclination necessarily varies at different points of the trajectory and must augment with the rapidity of movement2 the obliquity reaching its maximum in those portions of the wings which move with the greatest velocity1 namely1 towards the extremities4 ,the result is that the wing becomes twisted at certain periods of the movement40 7,see the fourth image in ,fig4 #afh47 ,the position of the balancers seems to vary according to that of the wings4 7,marey's ,movement1 pp4 #bec-beg47 ,illustration3 ,,fig4 #afh4--,tipula in the act of flying1 showing the various attitudes of the wings and the position of the balancers4 ,graber's views as to the mechanism of the wings1 flight1 etc4--,although in reality insects possess but four wings1 nature1 says ,graber1 evidently endeavors to make them dipteral4 ,this end is attained in a twofold manner4 ,in the butterflies1 bees1 and cicadas1 the four wings never act independently of each other1 as two individual pairs1 but they are always joined to a single flying plate by means of peculiar hooks1 rows of claws1 grooved clamps1 and similar contrivances proceeding from the modified edges of the wings2 indeed1 this connection is usually carried so far that the hind wings are entirely taken in tow by the front1 and consequently possess a relatively weak mechanism of motion4 ,the other mode of wing reduction consists in the fact that one pair is thrown entirely out of employment4 ,we observe this for instance in bugs1 beetles1 grasshoppers1 etc4 ,in the meantime1 then1 we may not trust to appearances4 ,as their development indeed teaches us1 the wings as well as the additional members must be regarded as actual evaginations of the common sockets of the body1 and in order especially to refute the prevalent opinion that these wing-membranes are void of sensation1 it should be remembered that ,leydig has proved the existence1 as well as one can be convinced by experiment1 of a nerve-end apparatus in certain basal or radical veins of the wing-membrane1 which is very extensive and complicated1 and therefore indicates the performance of an important function1 perhaps of a kind of balancing sense1 and also that these same insect wings1 with their delicate membrane1 are very easily affected by different outside agents1 as1 for instance1 warmth1 currents of air1 etc4 ,usually in their inactive or passive state the wings are held off horizontally from the body during flight1 and are laid upon the back again when the insect alights2 but an exception occurs in most butterflies and ,neuroptera1 among which the wing-joint allows only one movement round the oblique and long axis of the wings4 ,from this cause1 too1 the insects just mentioned can unfold their wings suddenly4 ,illustration3 ,,fig4 #afi4--;,anterior part of a ,cicada for demonstrating the mechanism of the articulation of the fore wing3 a1 articular head2 b1 articular pan1 frog1 or cotyla2 g1 elastic band2 c1 d1 e1 system of elastic rods2 r#a1 r#b1 #ast and #b;d abdominal segments4 ,,hf1 hind wings4--,after ,graber4 ,the transition of the wings from the active to the resting condition seems to be by way of a purely passive process1 which1 therefore1 usually gives no trouble to the insect4 ,the wing being extended by the tractive power of the muscles1 flies back1 when this ceases1 to its former or resting posture by means of its natural elasticity1 like a spiral spring disturbed from its balance4 ,the structure of this spring joint is very different1 however4 ,it usually consists 7,fig4 #afi7 of two parts4 ,the wing can move itself up and down in a vertical plane by means of the forward joint1 and at the same time can rotate somewhat round its long axis1 because the chitinous part mentioned above is ground off after the fashion of a mandrel4 ,the hinder joint1 at a greater distance from the body1 virtually consists of a rounded piece 7a7 capitate towards the outside1 and of a prettily hollowed socket 7b7 formed by the union of the thick ribs of the hind wings1 which slides round the head joint when the wings snap back upon the back4 ,the mechanism which causes this turning is1 however1 of a somewhat complicated nature4 ,the most instrumental part of it is the powerful elastic band 7g7 which is stretched over from the hinder edge of the mesothorax 7,r#b7 towards that of the wings4 ,this membrane is extended by the expansion of the wings1 and draws them towards the body as soon as the contraction of the muscles relaxes4 ,this closing band of the wings is assisted by a leverage system consisting of three little chitinous rods 7c1 d1 e71 which at its joining presses inwards on the body on one side1 and on the hinder edge and head-joint of the wing on the other4 ,we must1 however1 lay great stress on a few more kinds of wing support4 ,illustration3 ,,fig4 #agj4--,mesothoracic skeleton of a stag beetle3 schi1 scutellum1 on each side of which is the articulation of the fore wing 7,v71 consisting of two small styliform processes 7v1 h7 of the base of the wing2 za1 tooth which fits into the cavity of the wing-lock 7gr72 l1 edge of the right wing1 passing into the corresponding groove 7fa7 of the left2 ,di1 diaphragm for the attachment of the tergal muscle of the metasternum2 ,di#a 7not explained by author72 ,ka1 acetabulum of the coxa 7,h72 ,se1 chitinous process for the attachment of the coxal muscle2 ,fe1 femur2 ,sch1 tibia2 ,b#b1 sternum4--,after ,graber4 ,the wing-cases of beetles at their return from flight are joined together like the shells of a mussel on the inside as well as to the wedge-shaped plate 7,fig4 #agj1 schi7 between their bases4 ,there is even a kind of clasp at hand for this purpose4 ,the base of the wing1 that is1 bears a pair of tooth-like projections 7za71 which fit into the corresponding hollows of the little plate4 ,the commissure arising from the joining of the inner edges is characteristic4 ,usually the wings on both sides interlock by means of a groove1 as in stag-beetles1 but sometimes even1 as in ,chlamys1 after the manner of two cog-wheels1 so that we have here also an imitation of the two most prevalent methods which the cabinet-maker uses in joining boards together4 ,the act of folding the broad hind wings among beetles is not less significant than the arrangement of the fore wing4 ,if we forcibly spread out the former in a beetle which has just been killed and then leave it to its own resources again1 we observe the following result3 ,according to its peculiar mode of joining1 the costal vein on the fore edge approaches the mid or discoidal vein of the basal half as well as the distal half of the wing1 whence arises a longitudinal fold which curves in underneath4 ,then the distal half snaps under like the blade of a pocket knife and lies on the plane of the costal edge of the wing1 while it also draws after it the neighboring wing-area4 ,the soft hinder-edge portion turns in simultaneously when this wing-area remains fixed to the body while the costal portion is moving towards the middle line of the body4 ,the wing-membranes of almost all insects have1 moreover1 the capability of folding themselves somewhat1 and this power of extending or contracting the wing-membrane at will is of great importance in flight4 ,yes1 but how is the folded wing spread out again8 ,the fact may be shown more simply and easily than one might suppose1 and may be most plainly demonstrated even to a larger public by making an artificial wing exactly after the pattern of the natural one1 in which bits of whalebone may take the place of veins and a piece of india rubber the membrane spread out between them4 ,the reader will be patient while we just explain to him the act of unfolding of the membranous wing of the beetle4 ,the actual impulse for this unfolding is due to the flexor muscles which pull on1 and at the same time somewhat raise the vein on the costal edge4 ,by this means the membranous fold lying directly behind the costal vein is first spread out4 ,but since this fold is connected with the longitudinal fold of the distal end of the wing which closes like a blade1 the wing-area last mentioned which is attached to the middle fold of the wing by the elastic spring-like diagonal vein becomes stretched out4 ,the hinder rayed portion adjacent to the body is1 on the other hand1 simply drawn along when the wing stands off from the body4 ,in order to properly grasp the mechanism of the insect wing we must again examine its mode of articulation to the body somewhat more accurately4 ,illustration3 ,,fig4 #aga4--,longitudinal section through a ,tipula3 a1 mouth2 an1 antenna2 k#c1 maxillary palpus2 ol1 labrum2 o,g1 brain2 u,g1 subsophageal ganglion2 ,,bg1 thoracic ganglion2 schl1 sophagus2 m,d1 digestive canal2 ,ov1 ovary2 v,f1 fore wing2 sch1 halter2 lm1 longitudinal--b-r1 lateral muscles4--,after ,graber4 ,if we select the halteres of a garden gnat 7,tipula7 at the moment of extension1 we shall find them to be formed almost exactly after the pattern of our oars1 since the oblong oar-blade passes into a longitudinal handle4 ,the pedicel of the balancer is formed by the thick longitudinal primary veins of the wing-membrane4 ,this pedicel 7,fig4 #aga7 is implanted in the side of the thorax in such a manner that the wing may be compared to the top of a ninepin4 ,one may think1 and on the whole it is actually the fact1 that the stiff pedicel of the wing is inserted in the thoracic wall1 and that a short portion of it 7,fig4 #agb71 projects into the cavity of the thorax4 ,it is true there is no actual hole to be found in the thoracic wall1 as the intermediate space between the base or pedicel of the wing and the aperture in the thorax is lined with a thin yielding membrane1 on which the wing is suspended as on an axle-tree4 ,according to this1 therefore1 the insect wing1 as well as any other appendage of arthropods1 acts as a lever with two arms4 ,the reader can then conjecture what may be the further mechanism of the wing machine4 ,we only need now two muscles diametrically opposed to each other and seizing on the power arm of the wing1 one of which pulls down the short wing arm1 thereby raising the oar1 while the other pulls up the power arm4 ,and indeed the raising of the wing follows in the manner indicated1 since a muscle 7hi7 is attached to the end of the wing-handle 7a7 which projects freely into the breast cavity by the contraction of which the power arm is drawn down4 ,illustration3 ,,fig4 #agb4--,scheme of the flying apparatus of an insect3 mnl1 thoracic walls2 ab1 wings2 c1 pivot2 d1 point of insertion of the depressor muscle of the wing 7kd72--a1 that of the elevator of the wing 7ai72 rs1 muscle for expanding1--ml1 for contracting1 the walls of the thorax4--,after ,graber4 ,illustration3 ,,fig4 #agc4--,muscles of the fore wing of a dragon-fly 7an1 ax71 exposed by removing the thoracic walls3 h#a1 h#b1 elevators1--s#a-s#e1 depressors1 of the wings 7s#a1 s#b1 rotators74--,after ,graber4 ,on the other hand1 we have been entirely mistaken in reference to the mechanism which lowers the wings4 ,the muscle concerned1 that is kd1 is not at all the antagonist of the elevator muscle of the wing1 since it is placed close by this latter1 but nearer to the thoracic wall4 ,but then1 how does it come to be the counterpart of its neighbor8 ,in fact1 the lever of the wing is situated in the projecting piece alone4 ,the extensor muscle of the wing does not pull on the power arm1 but on the resistant arm on the other side of the fulcrum 7c74 ,the illustration shows1 however1 how such a case is possible4 ,the membrane of the joint fastening the wing-stalk to the thorax is turned up outwards below the stalk like a pouch4 ,the tendon of the flexor of the wing passes through this pouch to its point of attachment 7c7 lying on the other side of the fulcrum 7d74 ,thus it is very simply explained how two muscles which act in the same direction can nevertheless have an entirely contrary working power4 ,this is in a way the bare physical scheme of the flying machine by the help of which we shall more easily become acquainted with its further details4 ,dragon-flies are unquestionably the most suitable objects for the study of the muscles pulling directly on the wing itself4 ,if the lateral thoracic wall 7,fig4 #agc7 be removed or the thorax opened lengthwise there appears a whole storehouse of muscular cords which are spread out in an oblique direction between the base of the wing and the side of the thoracic plate4 ,there is first to be ascertained1 by the experiment of pulling the individual muscles in the line with a pincers1 which ones serve for the lifting and which for the lowering of the wings4 ,in dragon-flies the muscles are arranged in two rows and in such a way that the flexors or depressors 7s1 #a bis7 cling directly to the thoracic wall 7compare also the muscle dk in ,fig4 #agb and se in ,fig4 #agd71 while the raiser or extensor 7h #a1 to h #b1 ,fig4 #agb1 hi and ,fig4 #agd he7 lie farther in4 ,the form of the wing-muscles is sometimes cylindrical1 sometimes like a prism1 or even ribbon-like4 ,however1 the contracted bundles of fibres do not come directly upon the joint-process we have described1 but pass over often indeed at a very considerable distance from them1 into peculiar chitinous tendons4 ,these have the form of a cap-like plate1 often serrate on the edge1 which is prolonged into a thread1 which should be considered as the direct continuation of the base of the wings4 ,the wings1 therefore1 sink down into the thoracic cavity as if they were a row of cords ending in handles where the strain of the muscles is applied4 ,illustration3 ,,fig4 #agd4--,transverse section through the thorax of a locust 7,stenobothrus73 b#a1 leg2 h1 heart2 ga1 ventral cord2 se1 depressor1--he1 elevator1 of the wing 7fl72 b-r1 lateral muscles which expand the thoracic walls2--lm1 longitudinal muscles which contract them2 shm1 uhm1 muscles to the legs2 bg1 apodemes4--,after ,graber4 ,illustration3 ,,fig4 #age4--;,inner view of a portion of the left side of body of ,libellula depressa1 showing a part of the mechanism of flight1 viz41 some of the chitinous ridges at base of the upper wing1 and some of the insertions of the tendons of muscles3 ,a1 line of section through the base of the upper wing1 the wing being supposed to be directed backwards4 ,c1 upper portion of mechanism of the lower wing2 b1 lever extending between the pieces connected with the two wings4--,after von ,lendenfeld1 from ,sharp4 ,as may be seen in ,fig4 #agc1 the contractile section of several of the muscles of the wing 7s#e7 is extraordinarily reduced1 while its thread-like tendon is proportionately longer4 ,this gradation being almost like that of the pipes of an organ in the length of the wing-muscles1 as may so easily be observed in the large dragon-flies1 plainly indicates that the strain of the individual muscles is quite different in strength1 since1 as the phenomenon of flight demands it1 the different parts of the base of the wing become respectively relaxed in very dissimilar measure4 ,we have thus far discussed only the elevator and depressor muscles4 ,other groups 7s#as#c7 are yet to be added1 however1 crossing under the first at acute angles1 which when pulling the wing sidewise1 bring about in union with the other muscles a screw-like turning of the wings4 ,while in dragon-flies all the muscles which are principally influential in moving the wing are directly attached to it1 and thus evidently assert their strength most advantageously1 the case is essentially different with all other insects4 ,here1 as has already been superficially mentioned above1 the entire set of muscles affecting the wing is analyzed into two parts of which the smaller only is usually directly joined to the wings1 while the movement is indirectly influenced by the remainder 7,graber74 ,in the dragon-fly the two wings are 8brought into correlative action by means of a lever of unusual length existing amongst the chitinous pieces in the body wall at the base of the wings 7,fig4 #age1 b74 ,the wing-muscles are large2 according to von ,lendenfeld there are three elevator1 five depressor1 and one abductor muscles to each wing4 ,he describes the wing-movements as the results of the correlative action of numerous muscles and ligaments1 and of a great number of chitinous pieces connected in a jointed manner0 7,sharp74 ,if again we take the longitudinal section of the thoracic cavity of gnats in ,fig4 #aga1 we shall perceive a compactly closed system of muscular bars intersecting each other almost at right angles and interlaced with a tangled mass of trache1 some of which muscles extend 7lm7 longitudinally1 that is from the front to the back1 while others 7b-r7 stretch out in a vertical direction1 that is between the plates of the abdomen and back4 ,in order that we may more easily comprehend this important muscular apparatus we will illustrate the thoracic cavity of insects by an elastic steel ring 7,fig4 #agb71 to which we may affix artificial wings4 ,if this ring be pressed together from above downward1 along the line rs1 thus imitating the pulling of the vertical or lateral thoracic muscles1 then the wings on both sides spring up4 ,this is to be explained by the fact that through this manipulation a pressure is exerted on the lifting power arm of the wings4 ,if1 on the other hand1 the ring be compressed on the sides 7ml71 which is the same thing as if the longitudinal muscles contracted the thorax from before backward1 and thus arched it more1 then the wings are lowered4 ,agrionin1 according to ,kolbe1 can fly with the fore pair of wings or with the hind pair almost as well as with both pairs together4 ,also the wings of these insects can be cut off before the middle of their length without injuring their power of flight4 ,butterflies1 ,catocal1 and ,bombycid fly after the removal of the hind wings4 ,also the balancers of the ,diptera must be useful in flying1 since their removal lessens the power of flight4 ,chabrier regarded the under sides of the shell-like extended wing-covers of the beetles as wind-catchers1 which1 seized by wind currents1 carry the insect through the air4 ,we may also consider the wing-covers as regulators of the centre of gravity of flight4 ,the observations of insects made by ,poujade 7,ann4 ,soc4 ,ent41 ,france1 #ahhg1 p4 #aig7 during flight teaches us1 says ,kolbe1 that in respect to the movement during flight of both pairs of wings1 they may be divided into two categories3-- #a4 ,into those where both pairs of wings 7together71 either united1 and also when separated from each other1 perform flight4 ,such are the ,libellulid1 ,perlid1 ,sialid1 ,hemerobiid1 ,mymeleonid1 ,acridiid1 ,locustid1 ,blattid1 ,termitid1 etc4 #b4 ,into those whose fore and hind wings act together like one wing1 since they are connected by hooks 7hamuli71 as in certain ,hymenoptera1 or are attached in other ways4 ,here belong ,hymenoptera1 ,lepidoptera1 ,trichoptera1 ,cicadid1 ,psocid1 etc4 ,the musculature of the mesothorax and metathorax is similar in those insects both of whose pairs of wings are like each other1 and act independently during flight1 viz4 in the ,libellulid4 ,on the other hand1 in the second category1 where the fore and hind wings act as a single pair and the fore wings are mostly larger than the hinder 7except in most of the ,trichoptera71 the musculature of the mesothorax is more developed than that of the metathorax4 ,to neither category belong the beetles1 whose wing-covers are peculiar organs of flight1 and not for direct use1 and the ,diptera1 which possess but a single pair of wings4 ,in the beetles the hind wings1 in the ,diptera the fore wings1 serve especially as organs of flight4 ,it may be observed that the ,diptera are the best fliers1 and that those insects which use both pairs of wings as a single pair fly better than those insects whose two pairs of wings work independently of each other4 ,an exception are the swift-flying ,libellulid1 whose specially formed muscles of flight explain their unusual capabilities for flying 7,kolbe74 ,,literature ,,on ,,flight ,marey1 ,e4 ,j4 ,la machine animale4 ,locomotion terrestre et arienne4 ,paris1 #ahgd4 ---- ,mmoire sur le vol des insectes et des oiseaux4 7,annal4 ,scienc4 natur41 #e sr41 ,zool4 xii1 #ahfi1 pp4 #di-aej2 #e sr41 ,zool4 xv1 #ahgb1 #db ,figs47 ---- ,note sur le vol des insectes4 7,compt4 rend4 et ,mm4 ,soc4 d4 ,biol4 ,paris1 #d sr41 v1 #ahfi1 ,c4 ,r4 pp4 #acf-aci47 ---- ,recherches sur le mcanisme du vol des insectes4 7,journal de l',anatomie et de la ,physiologie1 #f ,anne1 #ahfi1 pp4 #ai-cf1 #ccg-cdh47 ---- ,animal mechanism4 ,new ,york1 #ahgi1 pp4 #ahj-bji4 ---- ,movement4 ,new ,york1 #ahie1 pp4 #bci-bgd4 ,hartings4 ,ueber den ,flug4 7,niederland4 ,archiv f4 ,zoologie1 iv1 ,leiden1 #ahgg-gh47 ,lucy4 ,le vol des oiseaux1 chauvesouris et insectes4 ,paris4 ,tatin1 ,v4 ,expriences physiologiques et synthtiques sur le mcanisme du vol4 7,ecole prat4 d4 haut4 tud4 ,physiol4 exprim4 ,trav4 du laborat4 de ,marey1 #ahgg1 pp4 #bic-cjb47 ---- ,expriences sur le vol mcanique4 7,ibid41 #ahgf1 pp4 #hg-ajh47 ,bellesme1 ,jousset de4 ,recherches exprimentales sur les fonctions du balancier chez les insectes ,diptres1 ,paris1 #ahgh1 #if pp41 ,figs4 ---- ,sur une fonction de direction dans le vol des insectes4 7,compt4 rend41 lxxxix1 #ahgi1 pp4 #ihj-ihc47 ,pettigrew1 ,j4 ,bell4 ,on the mechanical appliances by which flight is attained in the animal kingdom4 7,trans4 ,linn4 ,soc41 #ahfh1 xxvi1 ,pt4 ,i1 pp4 #aig-bgg1 #d ,pl47 ---- ,on the physiology of wings4 7,trans4 ,roy4 ,soc4 ,edinburgh1 #ahga1 xxvi1 pp4 #cba-ddf47 ,krarup-hansen1 ,c4 ,j4 ,l4 ,beitrag zu einer ,theorie des ,fluges der ,vogel1 ,insekten und ,fledermause4 7,copenhagen u4 ,leipzig1 ,fritsch1 #ahfi1 #dh pp47 ,lendenfeld1 ,r4 ,v4 ,der ,flug der ,libellen4 7,sitzungsber4 d4 kais4 ,akad4 d4 ,wiss4 ,wien1 lxxxiii1 #ahha1 pp4 #bhi-cgf1 #g ,taf42 ,zool4 ,anz41 #ahhj1 p4 #hb47 ,girard1 ,m4 ,note sur diverses expriences relatives la fonction des ailes chez les insectes4 7,ann4 ,soc4 ,ent4 ,france1 #d sr41 ii1 #ahfb1 pp4 #aed-afb47 ,mhlhuser1 ,f4 ,a4 ,ueber das ,fliegen der ,insekten4 7#bb4 bis #bd41 ,jahresb4 d4 ,pollichia1 ,drkheim1 #ahff1 pp4 #cg-db47 ,plateau1 ,flix4 ,recherches exprimentales sur la position du centre de gravit chez les insectes4 7,archiv d4 ,scienc4 phys4 et natur4 d4 ,genve1 ,nouv4 priode1 xliii1 #ahgb1 pp4 #e-cg47 ,plateau1 ,flix4 ,ueber die ,lage des ,schwerpunktes bei den ,insekten4 ,auszug4 7,naturforscher v4 ,sklarek1 v4 ,jahrg41 #ahgb1 pp4 #aab-aac47 ---- ,recherches physico-chimiques sur les articuls aquatiques4 7,bull4 d4 l',acad4 ,roy4 ,belg41 xxxiv1 #ahgb1 pp4 #a-ej1 ,fig47 ---- ,qu'est-ce que l'aile d'un insecte8 7,stett4 ,ent4 ,zeit41 #ahga1 pp4 #cc-db1 ,pl47 ---- ,l'aile des insectes4 7,journ4 d4 ,zool41 ii1 #ahgc1 pp4 #abf-acg47 ,perez1 ,j4 ,sur les causes de bourdonnement chez les insectes4 7,comptes rend41 lxxxvii1 p4 #ece1 ,paris1 #ahgh47 ,strasser1 ,hans4 ,mechanik des ,fluges4 7,archiv f4 ,anat4 u4 ,phys41 #ahgh1 p4 #caj-cej1 #a ,taf47 ---- ,ueber die ,grundbedingungen der aktiven ,locomotion4 7,abhandl4 d4 naturf4 ,gesellsch41 ,halle1 #ahhj1 xv1 pp4 #aba-aif1 ,figs47 ,moleyre1 ,l4 ,recherches sur les organes du vol chez les insectes de l'ordre des ,hemiptres4 7,compt4 rend4 de l',acad4 d4 ,scienc4 de ,paris1 #ahhb1 xcv1 pp4 #cdi-ceb47 ,amans1 ,p4 ,essai sur le vol des insectes4 7,revue d4 ,sc4 ,nat4 ,montpellier1 #c sr41 ii1 #ahhc1 pp4 #dfi-dij1 #b ,pl42 iii1 #ahhd1 pp4 #aba-aci1 #c ,pl47 ---- tude de l'organe du vol chez les ,hymnoptres4 7,ibid41 iii1 pp4 #dhe-ebb1 #b ,pl47 ---- ,comparaisons des organes du vol dans la srie animale4 ,des organes du vol chez les insectes4 7,annal4 d4 ,scienc4 nat4 ,zool41 #f sr41 xix1 pp4 #a-bbb1 #h ,pl47 ,mullenhoff1 ,k4 ,die ,grosse der ,flugflchen4 7,pflger's ,archiv f4 d4 ges4 ,physiologie1 #ahhd1 xxxv1 pp4 #djg-dec47 ---- ,die ,ortsbewegungen der ,tiere4 7,wissensch4 ,beil4 z4 ,programm d4 ,andreas-,realgymnas4 ,berlin1 #ahhe1 #ai pp47 ,poujade1 ,g4 ,a4 ,note sur les attitudes des insectes pendant le vol4 7,ann4 ,soc4 ,ent4 ,france1 #ahhd1 #f sr41 iv1 pp4 #aig-bjj1 #a ,pl47 ,krancher1 ,o4 ,die ,tne der ,flgelschwingungen unserer ,honigbiene4 7,deutscher ,bienenfreund1 #ahhb1 #ah4 ,jahrg41 pp4 #aig-bjd47 ,landois1 ,h4 ,ueber das ,flugvermgen der ,insekten4 7,natur4 und ,offenbarung1 vi1 #ahfj1 pp4 #ebi-edj47 ,ungern-,sternberg1 von4 ,betrachtungen ber die ,gesetze des ,fluges4 7,zeitschr4 d4 ,deutschen ,vereins z4 ,frderung d4 ,luftschiffahrt-,naturwissensch4 ,wochenschrift v4 ,potonie1 iv1 #ahhi1 p4 #aeh47 ,baudelot1 ,e4 ,du mecanisme suivant lequel s'effectue chez les ,coloptres le retract des ailes infrieures sous les lytres au moment du passage a l'tat de repos4 7,bull4 ,soc4 d4 ,scienc4 nat41 ,strasbourg1 #a ,anne1 #ahfh1 pp4 #acg-ach47 ,ris1 ,fr4 ,die schweizerischen ,libellen4 ,schaffhausen1 #ahhe4 7,beiheft der ,mitteil4 d4 ,schweiz4 ,ent4 ,ges41 vii1 pp4 #ce-hd47 ,,the ,,abdomen ,,and ,,its ,,appendages ,illustration3 ,,fig4 #agf4--;,abdomen of ,termes flavipes3 #a-aj1 the ten tergites2 #a-i1 the nine urites2 c1 cercopod4 ,illustration3 ,,fig4 #agg4--;,end of abdomen of ,panorpa debilis drawn out1 the chitinous pieces shaded3 ,l1 lateral1 ,d1 dorsal view2 c1 jointed cercopoda4--,gissler del4 ,in the abdomen the segments are more equally developed than elsewhere1 retaining the simple annular shape of embryonic life1 and from their generalized nature their number can be readily distinguished 7,fig4 #agf74 ,the tergal and sternal pieces of each segment are of nearly the same size1 the tergal often overlapping the sternal 7though in the ,coleoptera the sternites are larger than the tergites71 while there are no pleural pieces1 the lateral region being membranous when visible and bearing the stigmata 7,fig4 #agg1 ,l74 ,in the terminal segments beyond the genital outlet1 however1 there is a reduction in and loss of segments1 especially in the adults of the metabolous orders1 notably the ,panorpid 7,fig4 #agg71 ,diptera1 and aculeate ,hymenoptera2 in the ,chrysidid only three or four being usually visible1 the distal segments being reduced and telescoped inward4 ,the typical number of abdominal segments 7uromeres71 i4e4 that occurring in each order of insects1 is ten2 and in certain families of ,orthoptera1 eleven4 ,in the embryos1 however1 of the most generalized winged orders1 ,orthoptera 7,fig4 #aii71 ,dermaptera1 and ,odonata1 eleven can be seen1 while ,heymons has recently detected twelve in blattid and ,forficula embryos1 and he claims that in the nymphs of certain ,odonata there are twelve segments1 the twelfth being represented by the anal or lateral plates4 ,it thus appears that even in the embryo condition of the more generalized winged insects1 the number of uromeres is slightly variable4 ,we have designated the abdomen as the urosome2 the abdominal segments of insects and other ,arthropods as uromeres1 and the sternal sclerites as urosternites1 farther condensed into urites4 7,see ,third ,report ,u4 ,s4 ,entomological ,commission1 #ahhc1 pp4 #cjg1 #cbd1 #dce1 etc47 ,illustration3 ,,fig4 #agh4--,nymph of the pear tree ,psylla1 with its glandular hairs4--,after ,slingerland4 ,bull4 ,div4 ,ent4 ,u4 ,s4 ,dep4 ,agr4 ,the reduction takes place at the end of the abdomen1 and is usually correlated with the presence or absence of the ovipositor4 ,in the more generalized insects1 as the cockroaches1 the tenth segment is1 in the female1 completely aborted1 the ventral plate being atrophied1 while the dorsal plate is fused during embryonic life1 as ,cholodkowsky has shown1 with the ninth tergite1 thus forming the suranal plate4 ,in the advanced nymph of ,psylla the hinder segments of the abdomen appear to be fused together1 the traces of segmentation being obliterated1 though the segments are free in the first stage and in the imago 7,fig4 #agh74 ,it thus recalls the abdomen of spiders1 of ,limulus1 and the pygidium of trilobites4 ,the median segment4--,there has been in the past much discussion as to the nature of the first abdominal segment1 which1 in those ,hymenoptera exclusive of the phytophagous families1 forms a part of the thorax1 so that the latter in reality consists of four segments1 what appearing to be the first abdominal segment being in reality the second4 ,latreille and also ,audouin considered it as the basal segment of the abdomen1 the former calling it the 8segment mdiaire10 while ,newman termed it the 8propodeum40 ,this view was afterward held by ,newport1 ,schidte1 ,reinhard1 and by the writer1 as well as ,osten-,sacken1 ,brauer1 and others4 ,the first author to attempt to prove this by a study of the transformations was ,newport in #ahci 7article 8,insecta074 ,he states that while the body of the larva is in general composed of thirteen distinct segments1 counting the head as the first1 8the second1 third1 fourth1 and1 as we shall hereafter see1 in part also the fifth1 together form the thorax of the future imago0 7p4 #hgj74 ,although at first inclined to ,audouin's opinion1 he does not appear to fully accept it1 yet farther on 7p4 #iba7 he concludes that in the ,hymenoptera the 8fifth0 segment 7first abdominal7 is not in reality a part of the true thorax1 8but is sometimes connected more or less with that region1 or with the abdomen1 being intermediate between the two4 ,hence we have ventured to designate it the thoracico-abdominal segment40 ,had he considered the higher ,hymenoptera alone1 he would undoubtedly have adopted ,latreille's view1 but he saw that in the saw-flies and ,lepidoptera the first abdominal segment is not entirely united with the thorax1 being still connected with the abdomen as well as the thorax4 ,reinhard in #ahfe reaffirmed ,latreille's view4 ,in #ahff we stated from observations on the larv made three years earlier1 that during the semipupa stage of ,bombus the entire first abdominal segment is 8transferred from the abdomen to the thorax with which it is intimately united in the ,hymenoptera10 and we added that we deemed this to be 8the most essential zological character separating the ,hymenoptera from all other insects40 7,see ,fig4 #ic1 showing the gradual transfer and fusion of this segment with the thorax47 ,in the saw-flies the fusion is incomplete1 as also in the ,lepidoptera1 while in the ,diptera and all other orders the thorax consists of but three segments4 7,see also pp4 #ij-ib47 ,illustration3 ,,fig4 #agi4--;,abdomen of ,machilis maritima1 1 seen from beneath3 the left half of the #hth ventral plate removed2 ,i-,,ix1 abdominal segments2 c1 cercopoda2 cb1 coxal glands2 hs1 coxal stylets2 lr1 ovipositor4--,after ,oudemans1 from ,lang4 ,the cercopoda4--,we have applied this name to the pair of anal cerci appended to the tenth abdominal segment1 and which are generally regarded as true abdominal legs4 ,as is now well known1 the embryos of insects of different orders have numerous temporary pairs of abdominal appendages which arise in the same manner1 have the same embryonic structure1 and are placed in a position homologous with those of the thorax4 ,in the embryo of canthus rudimentary legs appear1 as shown by ,ayers1 on the first to tenth abdominal segment1 the last or tenth pair becoming the cercopoda2 and similar rudimentary appendages have been detected in the embryos of ,coleoptera1 ,lepidoptera1 and ,hymenoptera 7,apid74 ,cholodkowsky has observed eleven pairs of abdominal appendages in ,phyllodromia4 ,they are very long and multiarticulate in the ,thysanura 7,fig4 #agi74 ,in the ,dermaptera they are not jointed and are forcep-like4 ,it should also be observed that in the larva or ,sisyra 7,fig4 #aha7 there are seven pairs of #e-;jointed abdominal appendages1 though these may be secondary structures or tracheal gills4 ,in the ,perlid and the ,plectoptera 7,ephemerid71 they are very long1 sometimes over twice as long as the body1 and composed of upward of #ee joints2 they also occur in the ,panorpid 7,fig4 #agg74 ,in the dragon-flies the cerci are large1 but not articulated1 and serve as claspers or are leaf-like#ce 7,fig4 #ahj74 ,in a few ,coleoptera1 as the palm-weevil 7,rhynchophorus phnicis71 ,cerambyx1 ,drilus1 etc41 the so-called ovipositor ends in a hairy1 #a-;jointed1 palpiform cercus4 ,short #be-;jointed cercopoda are present in ,termitid1 and #b-;jointed ones in ,embiid4 ,illustration3 ,,fig4 #ahj4--;,end of abdomen of schna heros1 3 ur1 urosternite2 or1 outer1 ir1 inner styles of the ovipositor2 #aa1 #aath abdominal segment2 c1 cercopod4 ,illustration3 ,,fig4 #aha4--,larva of ,sisyra1 from beneath4 ,b1 an abdominal appendage4--,after ,westwood1 from ,sharp4 ,illustration3 ,,fig4 #ahb4--;,cercopoda 7,p7 of ,mantis4--,after ,lacaze-,duthiers4 ,the anal cerci are present in the ,orthoptera and1 when multiarticulate1 function as abdominal antenn4 ,they are longest in the ,mantid 7,fig4 #ahb72 they also occur in the larva of the saw-fly1 ,lyda 7,fig4 #ahc74 ,dr4 ,a4 ,dohrn has stated that the cerci of ,gryllotalpa are true sensory organs1 and we have called those of the cockroach abdominal antenn1 having detected about ninety sacs on the upper side of each joint of the stylets1 which are supposed to be olfactory in nature1 and which are larger and more numerous than similar sacs or pits in the antenn of the same insect4#cf ,from his experiments upon decapitated cockroaches1 ,graber concluded that these cerci were organs of smell4 ,illustration3 ,,fig4 #ahc4--,lyda larva3 a1 head2 b1 end of body seen from above2 c1 from side1 with cercopod4 ,haase regarded these appendages1 from their late development and frequent reduction1 as old inherited appendages which are approaching atrophy through disuse4 ,cholodkowsky states that ,tridactylus1 a form allied to ,gryllotalpa1 bears on the tenth abdominal segment two pairs of cerci 7ventral and dorsal71 and that the ventral pair may correspond to the atrophied appendages of the tenth embryonic segment of ,phyllodromia1 with which afterward the eleventh segment becomes fused4 ,the cercopods are not necessarily confined to the eleventh or to the tenth segment1 for when there are only nine segments1 with the vestige of a tenth1 as in ,xiphidium1 they arise from the ninth uromere1 and in the more modern cockroaches1 as ,panesthia1 in which there are but seven entire segments1 they are appended to the last or eighth uromere4 ,illustration3 ,,fig4 #ahd4--;,anabrus1 1 side-view1 dissected2 showing the relative size of the ovipositor3 c1 the minute cercopod4--,kingsley del4 ,as to the homology and continuity of these cercopods with the ventral outgrowths of the embryo1 several embryologists1 notably ,wheeler1 are emphatic in regarding them as such4 ,it thus appears that either the embryonic appendages of the seventh or eighth1 ninth or tenth uromere may persist1 and form the cercopoda of the adult4 ,the ovipositor4--,the end of the oviduct is guarded by three pairs of chitinous1 unjointed styles closely fitted together1 forming a strong1 powerful apparatus for boring into the ground or into leaves1 stems of plants1 the bodies of insects1 or even into solid wood1 so that the eggs may be deposited in a place of safety4 ,in the ants1 wasps1 and bees the ovipositor also functions as a sting1 which is further provided with a poison-sac4 ,morphologically1 the ovipositor is composed of three pairs of unjointed styles 7rhabdites of ,lacaze-,duthiers1 gonapophyses of ,huxley71 which are closely appressed to or sheathed within each other1 the eggs passing out from the end of the oviduct1 which lies1 as ,dewitz states1 between the two styles of the lowest or innermost pair1 and under the cross-bars or at the base of the stylets mentioned2 the styles or blades spreading apart to allow of the passage of the egg4 ,illustration3 ,,fig4 #ahe4--,saw of ,hylotoma3 a1 lateral scale2 i1 saw2 f1 gorget2 #gt1 #gth tergite2 #fs1 #fth sternite2 ov1 oviduct2 in1 intestine4--,after ,lacaze-,duthiers4 ,the ovipositor is best developed in the ,thysanura 7,fig4 #agi1 ,campodea excepted71 in ,orthoptera 7,fig4 #ahd71 in the ,odonata1 ,hemiptera1 certain ,physapoda1 ,rhaphiid1 and in the phytophagous ,hymenoptera1 where it is curiously modified to form a rather complicated saw for cutting slits in wood or leaves 7,fig4 #ahe74 ,it is wanting or quite imperfect in ,coleoptera1 ,diptera1 and ,lepidoptera4 ,morphologically1 the ovipositor appears to be formed out of the abdominal appendages of the seventh1 eighth1 and ninth segments of the female1 which1 instead of disappearing in the orders first mentioned1 persist as permanent styles4 ,wheeler asserts from his study of the embryonic development of ,xiphidium 8there can be no doubt concerning the direct continuity of the embryonic appendages with the gonapophyses40 ,he goes on to say3-- 8,one embryo1 which had just completed katatrepis1 still showed traces of all the abdominal appendages4 ,the pairs on the eighth1 ninth1 and tenth segments were somewhat enlarged4 ,in immediately succeeding stages the appendages of the second to sixth segments disappear2 the pair on the seventh disappear somewhat later4 ,up to the time of hatching the gonapophyses could be continuously traced1 since in ,xiphidium there is no flexure of the abdomen1 as in other forms1 to obscure the ventral view of the terminal segments4 ,from the time of hatching ,dewitz has traced the development of the ovipositor in another locustid 7,locusta viridissima71 so that now we have the complete history of the organ40 ,heymons1 however1 is inclined to believe that they are simply hypodermal outgrowths4 ,illustration3 ,,fig4 #ahf4--;,ideal plan of the structure of the ovipositor to illustrate ,lacaze-,duthiers' view3 b1 #hth tergite2 c1 epimerum2 a1 a1 two pieces forming the outer pair of rhabdites2 i1 the #b;d pair1 or stylets2 and f1 the inner pair1 or sting2 d1 support of sting2 e1 piece supporting the stylet2 ,r1 anus2 o1 outlet of oviduct4 ,the #gth1 #hth1 and #ith sternites are aborted4--,after ,lacaze-,duthiers4 ,the first to study the morphology of the ovipositor was ,lacaze-,duthiers1 who referred their origin to the partially atrophied dorsal or ventral sclerites of one of the last abdominal segments2 a view accepted by ,gerstaecker#cg 7,figs4 #ahf1 #ahg74 ,the present writer 7#ahff71 however1 showed that the sting of ,bombus was not formed of the reduced pieces of the segments themselves1 but arose from special outgrowths on the ventral side of the eighth and ninth abdominal segments4 ,these appendages he did not at first regard as the homologues of the limbs1 until in #ahga1 after studying the origin of the spring of the ,podurans 7,isotoma71 he found that it was a true jointed appendage and therefore a homologue of a pair of the styles forming the ovipositor of the winged insects1 and that the three pairs of styles of the latter were homologues of the thoracic legs and cephalic appendages4 ,the view was stated in the ,guide to the ,study of ,insects4 7,see also ,amer4 ,nat41 ,march1 #ahga1 p4 #f47 ,kraepelin also affirms that the styles of the ovipositor are segmental appendages and homologues of the antenn1 wings 7sic71 and legs4 ,illustration3 ,,fig4 #ahg4--a1 abdomen of ,cynips1 showing the great dorsal segment1 the peduncle1 and the position of the ovipositor within2 #b1 the entire ovipositor2 a1 lateral scale2 a1 its valve2 b1 anal scale2 b1 stylet2 c1 support of the stylet2 e1 base or support of sting 7fi72 #c1 profile showing the relation of the genital armature to the rest of the abdomen1 the #fth sternite having been drawn to show its full size2 #d1 anal scale 7b7 and stylet2 e1 i1 supports and body of the stylet2 c1 piece uniting the two scales2 #e1 lateral scale 7a71 and a sheath2 d1 support of the sting 7f72 #f1 transverse section of the body through the sting 7diagrammatic72 ,r1 internal armature2 o1 oviduct2 a1 lateral scale2 a its valve2 e1 support of the stylets 7i72 b1 anal scale2 c1 piece uniting two scales2 f1 sting2 d1 its support2 #g1 a second section simpler and more theoretical than the first2 #h1 diagrammatic1 all the elements of the sting have been reduced to pieces of the same form4--,after ,lacaze-,duthiers4 ,an objection to this view is the fact that the posterior pairs of styles appear to arise both from one and the same segment1--the ninth4 ,dewitz questions whether the four appendages of the ninth segment represent two pairs of limbs1 or one pair split into two branches1 and prefers the latter view1 but leaves it as a point to be settled by future investigations4 ,as will be seen below1 both ,kraepelin and ,bugnion observed a pair of rudiments to each of the three penultimate segments1 those of the middle pair splitting in two4 ,wheeler maintains1 erroneously we think1 that the inner of the two pairs on the ninth segment represents the tenth pair of abdominal appendages2 but in reality this latter pair become the cercopods4 ,that there are probably originally in insects of all the orders provided with an ovipositor three distinct pairs of appendages1 one to each segment1 is proved1 or at least strongly suggested1 by ,ganin's researches on the three pairs of abdominal imaginal discs of the third larva of ,platygaster and ,polynema 7,fig4 #ahh71 which are transformed into the ovipositor4 ,he remarks that these imaginal discs have the same origin and pass through the same changes as those in front1 i4e4 those destined to form the thoracic legs4 ,dewitz has shown that the germs of the ovipositor of the honey-bee arise as buds on the two segments before the last 7,fig4 #ahi74 ,illustration3 ,,fig4 #ahh4--,third larva of ,polynema3 at1 antenna2 fl1 imaginal buds of the wing2 l1 of the legs2 tg1 buds of the middle pair of stylets of the ovipositor2 fk1 fat-body2 eg1 ear-like process4--,after ,ganin4 ,illustration3 ,,fig4 #ahi4--;,imaginal buds and papill of the ovipositor of the honey-bee attached to trache2 at different stages3 b1 #ast2 b1 #b;d or middle2 and c1 #c;d pair of papill4--,after ,dewitz4 ,kraepelin also detected in the larva of the honey-bee a pair of what he regarded as genuine imaginal buds on abdominal segments eight1 nine1 and ten2 the buds on the tenth segment are divided each in two2 of these four appendages the two median ones form the barbed sting 7gorgeret or stachelrinne71 and the two lateral stylets1 the valves 7stachelscheiden74 ,the two buds of the ninth segment give rise to the vagina and to the oviducts1 and these unite secondarily with the posterior end of the ovaries4 ,the genital appendages of the male correspond to those of the female1 and arise from four imaginal buds situated on the under side of the tenth abdominal segment4 ,illustration3 ,,fig4 #aij4--a1 sting and poison sac of the honey-bee3 ,,gd1 poison gland2 ,gb1 poison reservoir2 ,d1 accessory gland2 sh1 sheathing style or sting-8feeler02 ,str sting2 ,ba1 sheath2 ,q1 quadrate plate2 ,o1 oblong piece2 ,w1 angular piece2 ,b1 base of the sting and stylets2 ,stb1 ,stb1 the two barbed stylets or darts4 #b1 sting seen from the ventral face3 lettering as in the other figure4--,after ,kraepelin1 from ,perrier4 ,in the ants1 according to ,dewitz1 the genital armature is derived from imaginal buds situated on the under side of the seventh1 eighth1 and ninth abdominal segments4 ,bugnion has observed the formation of six imaginal buds of the genital armature in the larva of a chalcid 7,encyrtus1 ,figs4 #da1 #db1 #aia1 q#a1 q#b1 q#c71 the transformation of the central part of these structures into small digitiform pads1 then the division of the two intermediate buds into four 787 7,fig4 #aia1 ,b1 q#b71 but was unable to trace their farther development4 ,the subject still needs farther investigation1 since certain observers1 as ,haase1 and1 more recently1 ,heymons1 do not believe that they are homologues of the legs1 but integumental structures1 though of somewhat higher value than the style of the base of the legs of ,scolopendrella and ,thysanura2 but it is to be observed that as yet we know but little of the embryological history of these styles4 ,those authors who have examined the elements of the ovipositor1 and regard them as homologues 7homodynamous7 of the limbs1 are ,weismann 7#ahff71 ,ganin 7#ahfi71 ,packard 7#ahga71 ,ouljanin 7#ahgb71 ,kraepelin1 ,kowalevsky 7#ahgc71 ,dewitz 7#ahge71 ,huxley 7#ahgg71 ,cholodkowsky1 ,bugnion 7#ahia71 and ,wheeler 7#ahib74 ,as shown1 then1 by our observations and those of ,dewitz 7,figs4 #ahi and #aib71 the rudiments of the ovipositor consist of three pairs of tubercles1 arising1 as ,kraepelin and also ,bugnion 7,fig4 #aia7 have shown1 from three pairs of imaginal discs1 situated respectively on the seventh1 eighth1 and ninth uromeres1 or at least on the three penultimate segments of the abdomen4 ,with the growth of the semipupa1 the end of the abdomen decreases in size1 and is gradually incurved toward the base 7,fig4 #aic71 and the three pairs of appendages approach each other so closely that the two outer ones completely ensheath the inner pair1 until a complete extensible tube is formed1 which1 by the changes in form of the muscles within1 is gradually withdrawn entirely within the body4 ,illustration3 ,,fig4 #aia4--;,a1 end of larva of ,encyrtus of #b;d stage1 showing the three pairs of imaginal buds of the ovipositor q#a1 q#b1 q#c4 ,b1 the same in an older larva ready to transform2 i1 intestine2 x1 genital gland2 a1 anus4--,after ,bugnion4 ,an excellent account of the honey-bee's sting is given by ,cheshire 7,figs4 #aid1 #aie74 ,the outermost of the three pairs of stylets forming the apparatus is the two thick1 hairy 8palpi0 or feelers 7,p71 these being freer from the sting proper than in the ovipositor of ,orthoptera4 ,the sting itself is composed of the two inner pairs of stylets2 one of these pairs is united to form the sheath 7sh71 while the other pair form the two barbed darts4 ,the sheath has three uses3 first1 to open the wound2 second1 to act as an intermediate conduit for the poison2 and third1 to hold in accurate position the long barbed darts4 ,the sheath does not enclose the darts as a scabbard1 but is cleft down the side presented in ,fig4 #aid1 which is below when the sting points backward4 ,but1 says ,cheshire1 as the darts move up and down1 they would immediately slip from their position1 unless prevented by a mechanical device1 exhibited by ,b and ,c1 giving in cross-section sheath and darts near the end1 and at the middle of the former4 8,the darts 7d7 are each grooved through their entire length1 while upon the sheath 7sh7 are fixed two guide rails1 each like a prolonged dovetail1 which1 fitted into the groove1 permits of no other movement than that directly up and down40 ,the darts are terminated by ten barbs of ugly form 7,d1 ,fig4 #aid71 and much larger than those of the sheath1 and as soon as the latter has established a hold1 first one dart and then the other is driven forward by successive blows4 ,these in turn are followed by the sheath1 when the darts again more deeply plunge1 until the murderous little tool is buried to the hilt4 ,but these movements are the result of a muscular apparatus yet to be examined1 and which has been dissected away to bring the rigid pieces into view4 ,the dovetail guides of the sheath are continued far above its bulbous portion1 as we see by ,e1 ,fig4 #aie2 and along with these the darts are also prolonged upward1 still held to the guides by the grooved arrangement before explained2 but both guides and darts1 in the upper part of their length1 curve from each other somewhat like the arms of a ,y1 to the points c1 c 7,a1 ,fig4 #aid71 where the darts make attachment to two levers 7i1 i74 ,the levers 7k1 l and k1 l7 are provided with broad muscles1 which terminate by attachment to the lower segments of the abdomen4 ,these1 by contraction1 revolve the levers aforesaid round the points f1 f1 so that1 without relative movement of rod and groove1 the points c1 c approach each other4 ,the arms of the ,y straighten and shorten1 so that the sheath and darts are driven from their hiding-place together and the thrust is made by which the sheath produces its incision and fixture4 ,the sides being symmetrical1 we may1 for simplicity's sake1 concentrate our attention on one1 say the left in the figure4 ,a muscular contraction of a broad strap joining k and d 7the dart protractor7 now revolves k on l1 so that a is raised1 by which clearly c is made to approach d2 i4e4 the dart is sent forward1 so that the barbs extend beyond the sheath and deepen the puncture4 ,the other dart1 and then the sheath1 follow1 in a sequence already explained1 and which ,g1 ,fig4 #aie1 is intended to make intelligible1 a representing the entrance of the sheath1 b the advance of the barbs1 and c the sheath in its second position4 ,the barb retractor muscle is attached to the outer side of i1 and by it a is depressed and the barbs lifted4 ,these movements1 following one another with remarkable rapidity1 are entirely reflex1 and may be continued long after the sting has been torn1 as is usual1 from the insect4 ,by taking a piece of wash-leather1 placing it over the end of the finger1 and applying it to a bee held by the wings1 we may get the fullest opportunity of observing the sting movements1 which the microscope will show to be kept up by continued impulses from the fifth abdominal ganglion and its multitudinous nerves 7n1 ,fig4 #aid1 ,a71 which penetrate every part of the sting mechanism1 and may be traced even into the darts4 ,these facts1 together with the explanation at page #di1 will show why an abdomen separated many hours may be able to sting severely1 as ,i have more than once experienced4 ,illustration3 ,,fig4 #aib4--;,base of the ovipositor of ,locusta viridissima seen from beneath3 c1 sheath1 or outer and lower pair of stylets turned to one side to show the others2 b1 upper and inner pair2 b1 third or innermost1 smallest pair of stylets4 ,a1 the same on one side1 in section4 ,the shaded parts show the muscular attachments4 ,the muscles which extend the apparatus and are attached to 1 1 and 1 as also the membranes which unite the pieces from 2 to with each other and the body1 are removed1 so that only the chitinous parts remain4--,after ,dewitz4 ,illustration3 ,,fig4 #aic4--;,development of the sting in ,bombus3 ,a1 a1 #ast pair on #hth sternite2 b1 #b;d inner pair forming the darts2 c1 outer pair4 ,b-,e1 more advanced stages4 ,f1 x1 y1 z1 three pairs of tubercles1 the germs of the male organs4 ,illustration3 ,,fig4 #aid4--,sting of bee #cj times3 ,a1 sting separated from its muscles2 ps1 poison sac2 pg1 poison gland2 #eth g1 #eth abdominal ganglion2 n1 n1 nerves2 e1 external thin membrane joining sting to last abdominal segment2 i1 k1 l1 and i1 k1 l1 levers to move the darts2 sh1 sheath2 v1 vulva2 p1 sting-palpus or feeler1 with tactile hairs and nerves4 ,b and ,c1 sections through the darts and sheath1 #cjj times3 sh1 sheath2 d1 darts2 b1 barbs2 p1 poison-channel4 ,d1 end of a dart1 #bjj3 o1 o1 openings for poison to escape into the wound4--,after ,cheshire4 ,illustration3 ,,fig4 #aie4--;,details of sting of bee3 ,e1 darts1 sheath1 and valves2 pb1 poison-bag duct2 fo1 fork2 s1 slide piece2 va1 valve2 b1 barbs4 ,f1 terminal abdominal segments2 w1 worker's sting2 q1 queen's sting2 r1 r1 anal plate2 ,g1 sting entering skin2 sh1 sheath2 a1 b1 c1 positions in first1 second1 and third thrusts with the sting4 ,h1 portion of poison gland1 #cjj2 cn1 cell nucleus2 n1 nerve2 g1 ganglionic cell4 ,i1 portion of the poison gland1 cells removed2 cd1 central duct2 d1 individual small ducts2 pr1 tunica propria4 ,k1 gland of ,formica rufa2 cd1 central duct2 d1 small ducts2 sc1 secreting cells4 ,l1 valve and support2 t1 trachea2 va1 valve2 tr1 truss or valve-prop4--,after ,cheshire4 ,illustration3 ,,fig4 #aif4--;,a1 rudimentary ovipositor of nymph of schna4 ,b1 the corresponding structures2 a1 enlarged4 ,c1 ovipositor of nymph of ,agrion2 d1 gill4 ,the male genital armature in the bees is originally composed of three pairs of tubercles1 homologous with those of the female1 all originally arising from three abdominal segments1 two afterward being anterior1 and the third pair nearer the base of the abdomen4 ,the ovipositor of the dragon-flies 7,odonata7 is essentially like that of the ,orthoptera and ,hymenoptera4 ,thus in schna 7,fig4 #aif71 ,agrion 7,fig4 #aif1 ,c71 and also in ,cicada it consists of a pair of closely appressed ensiform processes which grow out from under the posterior edge of the eighth uromere and are embraced between two pairs of thin lamelliform pieces of similar form and structure4 ,the styles and genital claspers 7,rhabdopoda74--,other appendages of the end of the abdomen of pterygote insects1 and generally1 if not always1 arising from the ninth segment1 are the clasping organs1 or rhabdopoda as we may call them1 of ,ephemerid 7,fig4 #aig71 ,neuroptera 7,corydalus ,fig4 #aih1 ,myrmeleon1 ,rhaphidia71 ,trichoptera1 ,lepidoptera1 ,diptera1 and certain phytophagous ,hymenoptera4 ,they do not appear to occur in insects which are provided with an ovipositor4 ,in ,thysanura the styles are present on segments #a-i 7,fig4 #agi74 ,those of the male ,ephemerid1 of which there are two pairs arising from the ninth segment1 are remarkable1 since they are jointed1 and they serve to represent or may be the homologues of two of the pairs of stylets composing the ovipositor of insects of other orders4 ,the lower pair 7,fig4 #aig1 rh7 are either #b-1 #c-1 or #d-;jointed 7in ,oniscigaster #e-;jointed71 while those of the upper pair are #b-;jointed 7rh74 ,these rhabdopods in the ephemerids are evidently very primitive structures1 since they approach nearest in shape and in being jointed to the abdominal legs of ,scolopendrella and the ,myriopoda4 ,the styles of the ,orthoptera are survivals of the embryonic appendages of the ninth segment 7,wheeler1 etc474 ,in ,mantis they are seen to have the same relations as the cerci1 as shown by ,heymons 7,fig4 #bjj74 ,illustration3 ,,fig4 #aig4--;,abdomen of ,ephemera 7,leptophlebia7 cupida1 3 c1 base of cercopoda2 rh1 outer #c-;jointed claspers or rhabdopods2 rh1 inner pair4 ,a1 side view4 ,illustration3 ,,fig4 #aih4--;,end of abdomen of ,corydalus cornutus1 3 vh1 rhabdopod2 c1 cercopod4 ,in the ,phasmid1 in ,anabrus1 and in the ,odonata the cercopods1 which are not jointed1 are converted into claspers1 and in the ,odonata the claspers are spiny within1 so as to give a firmer hold4 ,the suranal plate is apparently so modified as to aid in grasping the female4 ,in nearly all the ,trichoptera there are1 besides the suranal plate1 which is sometimes forked 7,nosopus71 a pair of superior and of inferior claspers1 and in certain genera 7,ascalaphomerus1 ,macronema1 ,rhyacophila1 ,hydropsyche1 ,amphipsyche1 ,smicridea1 and ,ganonema7 the lower pair are #b-;jointed like those of ,ephemerid4 ,the number of abdominal segments in the adult ,trichoptera is nine1 and ,mc,lachlan states that the genital armature consists of three pairs of appendages1 i4e4 a superior1 inferior1 and intermediate pair1 besides the suranal plate 7vestige of a tenth segment7 and the penis4 ,judging by his figures1 these three pairs of appendages arise from the last or ninth uromere1 and the upper pair seem to be the homologue of the cercopoda of ephemerids4 ,it needs still to be ascertained whether the intermediate pair is a separate set1 or merely subdivisions of the upper or lower1 and whether one of the latter may not arise from the penultimate segment1 because we should not expect that the last segment should bear more than one pair of appendages1 as we find to be the case in arthropods in general1 and in the ,neuroptera1 from which the ,trichoptera may have originated4 ,illustration3 ,,fig4 #aii4--;,end of abdomen of embryo of ,mantis3 r1 rhabdopod2 c1 cercopod2 sp1 suranal plate2 st1 stigma on #hth segment4--,after ,heymons4 ,illustration3 ,,fig4 #bjj4--;,end of abdomen of ,periplaneta americana1 1 side view3 c1 cercopod2 st1 stilus2 p1 penis2 t1 titillator2 d1 8bird's head0 7clasper872 i1 8oblong plate02 ,,ix-,,xi1 terminal segments2 ,x1 suranal plate2 ,,xi1 #aath sternite4--,after ,peytoureau4 ,in most larv of the ,trichoptera1 especially the ,rhyacophilid and ,hydropsychid1 the last abdominal segment bears a pair of #b-;jointed legs 7cercopoda71 ending in either one or two claws1 which under various forms1 sometimes forming long processes1 persist in the pupa2 and there appears to be a suranal plate1 the vestige of the tenth uromere4 ,in the pupa1 judging by ,klaplek's figure of ,leptocerus 7#bdh1i1 #be71 a pair of lateral spines arise which may in the imago form one of the pairs of appendages or styles4 ,in the pupa of cetis furva his figure #bhi shows two pairs of #a-;jointed appendages arising from the last segment2 whether the long dorsal or upper styles arise from the vestige of a more distal segment is not distinctly shown in ,klaplek's sketch4 ,the origin of these elements of the genital armature evidently needs further study4 ,whether the abdominal legs or so-called false or prop-legs of lepidopterous larv are genuine legs1 homologous with those of the thorax and with the cephalic appendages1 or whether they are secondary adaptive structures1 is a matter still under discussion4 ,that1 however1 they are true legs is shown by the embryology of the ,lepidoptera1 where there is a pair to each abdominal segment4 ,it may also be asked whether the anal legs of lepidopterous larv are not the homologues of the #b-;jointed anal appendages of caddis-worms4 ,illustration3 ,,fig4 #bja4--;,eriocephala calthella1 1 side view3 t1 palpiform suranal plate2 cl1 claspers2 s1 inferior claspers2 mxp1 maxillary palpi2 cx4 coxa2 tr1 trochanter2 sc1 scutum2 sc1 scutellum4 ,in ,lepidoptera1 notably the male of the very generalized ,eriocephala calthella 7,fig4 #bja71 besides the broad unjointed claspers1 which are curved upward and provided with a brush of stiff hooked set 7this upper pair being perhaps modified cercopods71 there is an accessory lower slenderer pair1 while the suranal plate 7t7 is palpiform or clavate and also adapted to aid in the action of the claspers4 ,the examination of the cercopods and rhabdopods in the ,trichoptera and in a generalized lepidopterous form like this enables one to understand the morphology of the genital armature1 since it consists1 besides the suranal plate1 which is often deeply forked 7in ,sphingid1 ,smith71 of a pair of modified hook-like cercopoda1 and in some cases 7,eriocephala7 of an additional pair of claspers which may be the homologues of the ephemerid rhabdopods4 ,a pair of hooks1 often strong and claw-like 7harpes71 are situated1 one near the base on the inside of each clasper2 they are especially developed in the ,noctuid 7,smith71 and appear to be present in certain ,trichoptera1 but this remains to be proved4 ,this complicated apparatus of claspers and hooks is utilized by those insects which pair while on the wing1 and is wanting in such forms as ,coleoptera and ,hemiptera4 ,besides the forceps of ,panorpa1 there are two pairs of slender filiform appendages which need farther examination4 ,in the ,diptera1 especially ,tipulid1 there is a pair of #b-;jointed appendages or forceps1 as in ,limnophila 7,osten ,sacken74 ,the male genital armature of ,diptera appears to be on the same general plan as in ,lepidoptera1 but more complicated4 ,illustration3 ,,fig4 #bjb4--,male organs of generation of ,athalia4--,after ,newport4 ,notice should also be taken of the paired uncinate hooks which are modifications of the penis-sheath of the male of cockroaches 7,phyllodromia71 which ,haase states appear to originate on the tenth ventral plate1 and which probably 8serve to open and dilate the vagina of the female1 especially as a perforated penis1 which is highly developed in ,machilis1 seems to be wanting in the ,blattid40 7,haase47 ,the penis4--,this is a single or double median style-like structure either hollow and perforated1 or solid1 very variable in shape1 receiving the end of the ejaculatory duct4 ,it is usually enclosed between two lateral plates1 the homologues perhaps of the inner pair of sheaths of the ovipositor4 ,in the ,coleoptera1 as in ,carabid and ,melolonthid1 the penis is a long chitinous tube1 8retractile within the abdomen on the under surface as far as the anterior segments40 7,newport47 ,in the ,hymenoptera1 of which that of the saw-flies is a type1 ,newport states that it 8consists of a short valvular projectile organ1 covered externally by two pointed horny plates 7i7 clothed with soft hairs40 ,above these are two other irregular double-jointed plates 7,fig4 #bjb1 l7 surrounded at their base by a chitinous ring 7k72 they are edged with prehensile hooked spines 7i74 ,between these in the middle line are two elongated muscular parts 7m7 which enclose the penis 7h71 and which1 like those in beetles1 perhaps aid in dilating the vulva of the female4 ,an examination of ,figs4 #bjc-bjg will aid in understanding the various modifications in beetles1 etc41 of this organ4 ,a general study of the anatomy and homologies of the male genital armature1 from a developmental point of view1 together with a comparison of them with the corresponding female organs1 is still needed4 ,illustration3 ,,fig4 #bjc4--;,end of abdomen situated under the anal lobes of ,hydrophilus piceus1 drawn out1 seen from the ventral side3 #f1 sternal region of #fth segment2 #g1 #h1 #i1 segments telescoped1 when retracted1 in #fth segment2 zw1 membrane connecting #fth and #gth segments2 ,g1 intromittent apparatus2 vl1 external lobes2 vlu1 inner lobes2 pn1 penis4 ,illustration3 ,,fig4 #bjd4--,the same as in ,fig4 #bjc1 seen from the side3 #f1 the free #fth segment2 #g-aj1 the four last1 when at rest1 retracted and telescoped within the #fth segment1 with the copulatory apparatus 7g72 vl1 outer1 vlu1 inner lobe2 #ajs1 tergite of #ajth segment2 #aj;i1 sternite of the same2 an1 anal opening4 ,illustration3 ,,fig4 #bje4--,terminal parts of the male copulatory apparatus of ,hydrophilus piceus1 torn apart3 vlu1 the two inner lodes2 pn1 penis2 x1 membrane torn from under side of penis2 ej1 ejaculatory duct2 os1 its opening on the under side of the penis1 directly under its tip4 ,the muscles1 trache1 and nerves are not drawn4 ,velum penis4--,in the locusts 7,acrydiid7 the penis is concealed by a convex plate1 flap1 or hood1 free anteriorly and attached posteriorly and on the sides to the ridge forming the upper edge of the tenth sternite4 ,when about to unite sexually1 the tip of the abdomen is depressed1 the hood is drawn backward1 uncovering the chitinous penis4 ,the suranal plate4--,this is a triangular1 often thick1 solid plate or area1 the remnant of the tergum of the last1 usually tenth1 segment of the abdomen1 the supra-anal or suranal plate1 or anal operculum 7lamina supra-analis7 of ,haase4 ,in most lepidopterous larv this plate is well marked2 in those of the ,platypterid it is remarkably elongated1 forming an approach to a flagellum-like terrifying appendage1 and in that of ,aglia tau it forms a long1 prominent1 sharp spine4 ,in the cockroach1 both ,cholodkowsky and ,haase maintain that the tenth abdominal segment is suppressed in the female1 the tergal portion being fused with the suranal plate 7the latter in this case1 as we understand it1 being the remnant of the eleventh segment of the embryo74 ,as to the nature of the middle jointed caudal appendage in ,thysanura and ,may-flies ,heymons has satisfactorily shown that it is a hypertrophied portion of the suranal plate1 being in ,lepisma but a filamental elongation of the small eleventh abdominal tergite4 ,illustration3 ,,fig4 #bjf4--;,copulatory organ of a weevil1 ,rhychophorus phnicis1 seen from above4 ,a1 vl1 the lobes united into a capsule2 pp1 torn membrane which connects the capsule with the #ith abdominal segment2 ej1 ejaculatory duct4 ,b1 the same seen from the side2 mu1 end of the muscle of the penis4 ,c1 the same as ,b1 without the capsule2 os1 opening of the ejaculatory duct 7ej74 ,other letters as in ,a4 ,illustration3 ,,fig4 #bjg4--;,a1 penis 7pn7 of ,carabus hortensis3 bl1 wrinkled membranous vesicle2 vlu1 the valves2 g1 part of #ith segment4 ,b1 end of penis of the same1 enlarged2 os1 cleft-like opening2 also a wrinkled vesicle1 as at bl4--,this and ,figs4 #bjc-bje after ,kolbe4 ,at the base of the suranal plate of locusts 7,acrydiid7 is the suranal fork or suranal furcula 7furcula supra-analis1 as we have called it7 7,fig4 #hh1 #hi1 f74 ,the podical plates or paranal lobes4--,in the cockroach and other insects1 also in the nymphs of ,odonata1 the anus is bounded on each side by a more or less triangular plate1 the two valves being noticeable in lepidopterous larv4 ,they are the valvul of ,burmeister1 and podical plates of ,huxley1 who also regarded them as the tergites of an eleventh abdominal segment2#ch and the subanal lamin of ,heymons4 ,they are wanting in ,ephemerid4 ,the infra-anal lobe4--,our attention was first called to this lobe or flap1 while examining some geometrid larv4 ,it is a thick1 conical1 fleshy lobe1 often ending in a hard1 chitinous point1 and situated directly beneath the vent4 ,its use is evidently to aid in tossing the pellets of excrement away so as to prevent their contact with the body4 ,the end may be sharp and hard or bear a bristle4 ,whether this lobe is the modified ventral plate of the ninth urite1 we will not undertake at present to say4 ,the egg-guide4--,in the ,acrydiid the external opening of the oviduct is bounded on the ventral side by a movable1 triangular1 acute flap1 the egg-guide 7,fig4 #hh1 ,b1 eg74 ,whether this occurs in other orders needs to be ascertained4 ,,literature ,,on ,,the ,,abdomen ,,and ,,its ,,appendages a4 ,general 7including the cerci1 stili1 etc47 ,cornelius1 ,c4 ,beitrge zur naheren ,kenntnis von ,palingenia longicauda4 7,programm d4 ,real- u4 ,gewerbeschule zu ,elberfeld1 #ahdh1 pp4 #a-ch1 #d ,taf47 ,schidte1 ,j4 ,g4 ,bemerkungen ber ,myrmecophilen4 ,ueber den ,bau des hinterleibes bei einigen ,kfergattungen4 7,germar's ,zeits4 f4 ,ent41 #ahdd47 ---- ,de metamorphosi ,eleutheratorum observationes4 7,naturhist4 ,tidsskr4 i-xiii1 #ahfa-ahhc47 ,meinert1 ,f4 ,anatomia ,forficularum4 ,anatomisk undersogelse af de ,danske ,orentviste1 i4 7,naturhist4 ,tidsskr4 #c raekke1 ii1 #ahfc1 pp4 #dbg-dhb1 #a ,pl47 ---- ,om dobbelte ,saedgange hos insecter4 7,naturhist4 ,tidsskrift1 #c raekke1 v1 #ahfh47 ,tullberg1 ,tycho4 ,sveriges ,podurider4 7,svenska ,vetensk4-,akad4 ,handl41 #ahgb1 x1 ,nr4 #aj1 #ab ,pls47 ,davis1 ,h4 ,notes on the pygidia and cerci of insects4 7,journ4 ,r4 ,micr4 ,soc41 #ahgi1 ii47 ,westhoff1 ,f4 ,ueber den ,bau des ,hypopygiums der ,gattung ,tipula ,meig4 7,mnster1 #ahhb1 pp4 #a-fb1 #f ,taf47 ,saunders1 ,edward4 ,further notes on the terminal segments of aculeate ,hymenoptera4 7,trans4 ,entom4 ,soc4 ,london1 #ahhd1 pp4 #bea-bfg1 #a ,pl47 ,palmn1 ,j4 ,a4 ,ueber paarige ,ausfhrungsgange der ,geschlechtsorgane bei ,insekten4 7,helsingfors1 #ahhd1 #e ,taf47 ,haase1 ,e4 ,die ,abdominalanhnge der ,insekten mit ,bercksichtigung der ,myriopoden4 7,morpholog4 ,jahrbuch1 #ahhi1 xv1 pp4 #cca-dce1 #b ,taf47 ---- ,abdominalanhnge bei ,hexapoden4 7,sitzungsber4 d4 ,gesellsch4 naturforsch4 ,freunde1 #ahhi1 pp4 #ai-bi47 ,wheeler1 ,william ,m4 ,on the appendages of the first abdominal segment of embryo insects4 7,trans4 ,wis4 ,acad4 ,sc41 viii1 #ahij1 pp4 #hg-adj1 #c ,pls47 ,janet1 ,charles4 tudes sur les fourmis1 #e;e note1 sur la morphologie du squelette des segments post-thoraciques chez les ,myrmicides4 7,mm4 ,soc4 ,acad1 de l',oise1 xv1 pp4 #eia-faa1 ,figs4 #a-e1 #ahid47 ,heymons1 ,richard4 ,die ,segmentirung des ,insektenkrpers4 7,anh4 ,abh4 ,akad4 ,berlin1 ,phys4 ,abh41 pp4 #ci1 ,taf41 #ahie4 ,see also ,die ,embryonalent1 von ,dermapteren und ,orthopteren1 under ,embryology47 ---- ,grundzge der ,entwicklung und des ,krperbaues von ,odonaten und ,ephemeriden4 7,abhandl4 k4 ,preuss4 ,akad4 d4 ,wissens4 ,berlin1 #ahif1 #b ,taf41 pp4 #a-ff47 ---- ,zur ,morphologie der ,abdominalanhnge bei den ,insecten4 7,morphol4 ,jahrb41 iv1 #ahif1 pp4 #agh-bjc1 #b ,taf47 ,peytoureau1 ,s4 ,a4 ,contribution l'tude de la morphologie de l'armure gnital des insectes4 7,bordeaux1 #ahie1 pp4 #bdh1 #bb ,pls41 #dc ,figs4 in text47 ,verhoeff1 ,c4 ,cerci und styli der ,tracheaten4 7,ent4 ,nachr41 xxi1 pp4 #aff-afh1 #ahie47 ,also the writings of ,oudemans1 ,packard1 etc4 b4 ,the ovipositor ,lacaze-,duthiers1 ,henri4 ,recherches sur l'armure gnitale femelle des insectes4 7,ann4 d4 sc4 natur41 #ahdi1 xii1 pp4 #cec-cgd1 #a ,pl42 #ahej1 xiv1 pp4 #ag-eb1 #a ,pl4 7,hymnoptres72 #aheb1 xvii1 pp4 #bjf-bea1 #a ,pl4 7,orthoptres72 #ahec1 xix1 pp4 #be-hh1 #d ,pl4 7,neuroptres1 ,thysanures1 ,coloptres1 ,diptres72 pp4 #bjc-bcg 7,lpidoptres1 ,aphaniptres en general4 ,also separate477 ,sollmann1 ,a4 ,der ,bienenstachel4 7,zeitschr4 f4 ,wissens4 ,zool41 xiii1 #ahfc1 pp4 #ebh-edj1 #a ,taf47 ,fengger1 ,h4 ,anatomie und ,physiologie des ,giftapparates bei den ,hymenopteren4 7,archiv f4 ,naturgesch41 #ahfc1 pp4 #aci-agh1 #a ,taf47 ,eaton1 ,a4 ,e4 ,remarks upon the homologies of the ovipositor4 7,trans4 ,ent4 ,soc4 ,london1 #ahfh1 pp4 #ada-add47 ,packard1 ,a4 ,s4 ,on the structure of the ovipositor and homologous parts in the male insects4 7,proc4 ,boston ,soc4 ,nat4 ,hist41 xi1 #ahfh1 pp4 #cic-cii1 ,figs4 #a-aa47 ,lambrecht1 ,a4 ,samtliche ,teile des ,stechapparates in ,bienenkrper und ihre ,verwendung zu technischen und vitalen ,zwecken4 7,bienemwirtsch4 ,centralbl41 #g ,jahrg41 #ahga1 pp4 #e-aa47 ,kraepelin1 ,k4 ,untersuchungen ber den ,bau1 ,mechanismus und die ,entwicklung des ,stachels der bienenartigen ,tiere4 7,zeitschr4 f4 wiss4 ,zoologie1 xxiii1 #ahgc47 ,dewitz1 ,h4 ,vergleichende ,untersuchungen ber ,bau und ,entwicklung des ,stachels der ,honigbiene und der ,legescheide der grnen ,heuschrecke4 7,knigsberg1 #ahgd47 ---- ,ueber ,bau und ,entwicklung des ,stachels und der ,legescheide einiger ,hymenopteren und der grnen ,heuschrecke4 7,zeitschr4 f4 wissen4 ,zoologie1 xxv1 #ahgd1 pp4 #agd-bjj1 #b ,taf47 ---- ,ueber ,bau und ,entwicklung des ,stachels der ,ameisen4 7,zeitschr4 f4 wiss4 ,zoologie1 #ahgg1 xxviii1 pp4 #ebg-eef1 #a ,taf47 ,adler1 ,h4 ,legeapparat und ,eierlegen der ,gallwespen4 7,deutsche ,entom4 ,zeitschr41 #ahgg1 xxi ,jahrg41 pp4 #cje-ccb1 #a ,taf47 ,cholodkowsky1 ,n4 ,ueber den ,hummelstachel und seine ,bedeutung fr die ,systematik4 7,zool4 ,anzeiger1 vii1 #ahhd1 pp4 #cab-caf47 ,ihering1 ,h4 von4 ,der ,stachel der ,meliponen4 7,ent4 ,nachr41 #ahhf1 xii1 ,jahrg41 pp4 #agg-ahh1 #a ,taf47 ,meinert1 ,f4 ,bidrag til de danske ,myrers ,naturhistorie4 7,kjbenhavn1 #ahij1 #fh s4u4 ,danske ,vidensk4 ,selsk4 ,skrifter1 #e ,raek1 v1 #c ,pls47 ,beyer1 ,o4 ,w4 ,der ,giftapparat von ,formica rufa ein reduziertes ,organ4 7,jena4 ,zeitschr4 ,naturw41 #ahij1 xxv1 pp4 #bf-aab1 #b ,taf47 ,carlet1 ,g4 ,mmoire sur le venin et l'aiguillon de l'abeille4 7,ann4 d4 sc4 nat4 ,zool41 #g sr41 ix1 #ahij1 pp4 #a-ag1 #a ,pl47 ,knckel d',herculais1 ,j4 ,mchanisme physiologique de la ponte chez les insectes orthoptres de la famille des ,acridides4--,rle de l'air comme agent mcanique et fonctions multiples de l'armure gnitale4 7,compt4 ,rend41 cxix1 pp4 #bdd-bdg1 #ahid47 ,also the writings of ,verhoeff1 ,heymons4 c4 ,the external genital armature ,klug1 ,johann ,c4 ,f4 ,versuch einer ,berichtigung der ,fabriciusschen ,gattungen ,scolia u4 ,tiphia4 7,ueber u4 ,mohr ,beitrge zur ,naturkunde1 i1 pp4 #h-dj1 #ahje1 #a ,taf47 ,audouin1 ,j4 ,v41 and ,lachat4 ,observations sur les organes copulateurs males des ,bourdons4 7,annal4 gnral1 d4 sc4 phys41 #ahba1 viii1 pp4 #bhe-bhi47 ,audouin1 ,j4 ,v4 ,lettre sur la gnration des insectes4 7,ann4 des sc4 nat41 sr4 #a1 ii1 #ahbd47 ,suckow1 ,f4 ,w4 ,l4 ,geschlechtsorgane der ,insekten4 7,heusinger1 ,zeitschr4 organ4 ,physik41 #ahbh1 ii1 pp4 #bca-bfd1 #a ,taf47 ,rathke1 ,h4 ,de ,libellularum partibus genitalibus4 ,regiomonti1 #ahcb1 pp4 #f #ch1 #c ,pls4 ,siebold1 ,c4 ,th4 ,e4 von4 ,ueber die ,fortpflanzungsweise der ,libellulinen4 7,germar's ,zeitschr4 f4 ,ent41 #ahdj1 ii1 pp4 #dba-dch47 ,selys-,longchamps1 ,e4 de4 ,monographie des ,libellulidees d',europe4 #d ,pls41 #ahdj4 ,bassi1 ,c4 ,a4 ,studi sulle funzioni degli organi genitali degl' insetti da lui osservati piu specialmente nella ,bombyx mori4 7,atti della #e ,riun4 d4 ,scienz4 ,ital4 ,lucca1 #ahdd1 pp4 #ci-id47 ,stein1 ,f4 ,vergleichende ,anatomie und ,physiologie der ,insekten1 i4 ,die weiblich4 ,geschlechtsorgane der ,kfer4 ,berlin1 #ahdg1 #i ,taf4 ,ormancey1 ,p4 ,recherches sur l'tui penial considr comme limite de l'espce dans les coloptres4 7,ann4 sc4 nat41 #ahdi1 #c sr41 ,zool41 xii1 pp4 #bbg-bdb47 ,roussel1 ,c4 ,recherches sur les organes gnitaux des insectes coloptres de la famille des ,scarabides4 7,compt4 rend4 ,acad4 d4 sc4 ,paris1 #ahfj1 l1 pp4 #aeh-afa47 ,mac,lachlan1 ,r4 ,a monographic revision and synopsis of the ,trichoptera of the ,european fauna4 ,london1 #ahgd-hj1 #ei ,pls4 ---- ,on the sexual apparatus of the male ,acentropus4 7,trans4 ,ent4 ,soc4 ,london1 #ahgb1 pp4 #aeg-afb47 ,thomson1 ,c4 ,g4 ,nagra anmarkningar ofver arterna af slagtet ,carabus4 7,thomson's ,opuscula ,entomologica1 vii1 #aheg1 pp4 #fae-gbi1 #a ,pl47 ,dufour1 ,l4 ,sur l'appareil gnital male du ,corbus bifasciatus4 7,thomson1 ,archiv ent41 #aheg1 i1 pp4 #cgh-cha47 ,white1 ,f4 ,buchanan4 ,on the male genital armature in the ,rhopalocera4 7,trans4 ,linn4 ,soc41 ser4 #a1 ,zool41 i1 pp4 #ceg-cfi1 #ahgf1 #c ,pls47 ,graber1 ,v4 ,die ,aehnlichkeit im ,baue der ausseren weiblichen ,geschlechtsorgane bei den ,lokustiden und ,akridiern auf ,grund ihrer ,entwicklungsgeschichte4 7,sitzber4 k4 ,akad4 d4 ,wissensch4 ,wien41 #ahgj1 lxi1 pp4 #a-bj1 #a ,taf47 ,scudder1 ,samuel ,h41 and ,edward ,burgess4 ,on asymmetry in the appendages of hexapod insects1 especially as illustrated in the lepidopterous genus ,nisoniades4 7,proc4 ,boston ,soc4 ,nat4 ,hist41 #ahga1 xiii1 pp4 #bhb-cjf47 ,chadima1 ,j4 ,ueber die ,homologie zwischen den mnnlichen und weiblichen ausseren ,sexualorganen der ,orthoptera ,saltatoria ,latr4 7,mitteil4 d4 naturwiss4 ,vereins f4 ,steiermark1 #ahgb1 pp4 #be-cc1 #a ,taf47 ,hagens1 von4 ,ueber die ,genitalien der mnnlichen ,bienen1 besonders der ,gattung ,sphecodes4 7,berlin ,ent4 ,zeitschr41 #ahgd1 pp4 #be-dc47 ---- ,ueber die mnnlichen ,genitalien der ,bienengattung ,sphecodes4 7,deutschen ,entom4 ,zeitschr41 #ahhb1 pp4 #bji-bbh1 #b ,taf47 ,lindenman1 ,c4 ,vergleichend-anatomische ,untersuchung ueber das mnnliche ,begattungsglied der ,borkenkfer4 7,bull4 ,soc4 ,imp4 d4 ,natural4 ,moscou1 #ahge-gg47 ,forel1 ,a4 ,der ,giftapparat und die ,analdrsen der ,ameisen4 7,zeitschr4 f4 wiss4 ,zoologie1 xxx1 suppl41 #ahgh47 ,kraatz1 ,g4 ,ueber die ,wichtigkeit der ,untersuchung des mnnlichen ,begattungsgliedes der ,kfer fr die ,systematik und ,artunterscheidung4 7,deutschen ,entom4 ,zeitschr41 #ahha1 xxv1 pp4 #aac-abf47 ---- ,ueber das mnnliche ,begattungsglied der europaischen ,cetoniiden und seine ,verwendbarkeit fr deren scharfe spezifische ,unterscheidung4 7,ibid41 pp4 #abi-adi47 ,gosse1 ,ph4 ,h4 ,on the clasping-organs ancillary to generation in certain groups of the ,lepidoptera4 7,trans4 ,linn4 ,soc41 #ahhb1 ,ser4 #b1 ,zool41 ii1 pp4 #bfe-cde1 #h ,pls47 ---- ,the prehensors of male butterflies of the genera ,ornithoptera and ,papilio4 7,proc4 ,roy4 ,soc4 ,london1 #ahha1 xxxiii1 pp4 #bc-bg47 ,radoszkowski1 ,o4 ,revision des armures copulatrices des males du genre ,bombus4 7,bull4 ,soc4 ,natur4 ,moscou1 #ahhd1 xlix1 pp4 #ea-ib1 #d ,pls47 ---- ,revision des armures copulatrices des males de la tribu ,philrmides4 7,ibid41 #ahhe1 lxi1 pp4 #cei-cgj1 #b ,pls47 ---- ,revision des armures copulatrices des males de la famille des ,mutillid4 7,hor ,soc4 ,ent4 ,ross41 #ahhe1 xix1 pp4 #c-di1 #i ,pls47 ---- ,revision des armures copulatrices des males de la tribu des ,chrysides4 7,hor ,soc4 ,ent4 ,ross1 xxiii1 #ahij1 pp4 #c-dj1 #f ,pls47 ,hofmann1 ,o4 ,beitrge zur ,kenntnis der ,butaliden4 7,stett4 ,ent4 ,zeit41 #ahhh1 pp4 #cce-cdg1 #a ,taf47 ,driedzichi1 ,h4 ,revue des espces europennes du genre ,phronia ,winn4 7,hor ,soc4 ,ent4 ,ross41 #ahhi1 xxiii1 pp4 #djd-ecb1 #aj ,pls47 ,sharp1 ,david4 ,on the structure of the terminal segment in some male ,hemiptera4 7,trans4 ,ent4 ,soc4 ,london1 #ahij1 pp4 #cii-dbg1 #c ,pls47 ,escherich1 ,k4 ,die biologische bedeutung der ,genitalanhnge der ,insekten4 7,verhandl4 d4 zool4 bot4 ,ges4 ,wien41 #ahib47 ---- ,anatomische ,studien ber das mnnliche ,genitalsystem der ,coleopteren4 7,zeits4 f4 wissens4 ,zool41 lvii1 pp4 #fbj-fda1 #a ,taf41 #c figs47 ,verhoeff1 ,c4 ,zur vergleichenden ,morphologie der 8,abdominalanhnge0 der ,coleopteren4 7,ent4 ,nachr41 xx1 pp4 #ic-if1 #ahid4 ,compare also ,o4 ,schwarz and ,j4 ,weise's criticisms in ,d4 ,ent4 ,zeit41 pp4 #aec-aeg2 also pp4 #aja-aji1 #aee-aeg4 ,zool4 ,anzeiger1 pp4 #ajj-ajf1 #ahid47 ---- ,vergleichende--morphologische ,untersuchungen ueber das ,abdomen der ,endomychiden1 etc41 und ber die ,musculature des ,copulationsapparates von ,triplax4 7,archiv f4 ,naturg41 lxi1 pp4 #bac-bhg1 #b ,taf41 #ahie47 ---- ,vergleichende ,untersuchungen ber die abdominal ,segmente der weiblichen ,hemiptera-,heteroptera und ,homoptera4 7,verh4 ,nat4 ,ver4 ,bonn1 l1 pp4 #cjg-cgd1 #ahid47 ,verhoeff1 ,c4 ,beitrge zur vergleichenden ,morphologie des ,abdomens der ,coccinelliden1 etc4 7,archiv f4 ,naturg41 lxi1 pp4 #a-hj1 #f figs41 #ahie47 ,boas1 ,j4 ,e4 ,v4 ,organe copulateur et accouplement der hanneton4 7,oversigt over det ,k4 ,danske ,vidensk4 ,selskab ,forhand1 #ahib1 ,copenhagen1 #ahic1 #a ,pl41 pp4 #bci-bfa47 ,prez1 ,j4 ,de l'organe copulateur mle des ,hymnoptres et de sa valeur taxonomique4 7,ann4 ,soc4 ,ent4 ,france1 lxiii1 pp4 #gd-ha1 ,figs41 #ahid47 ,goddard1 ,martha ,freeman4 ,on the second abdominal segment in a few ,libellulid4 7,proc4 ,amer4 ,philos4 ,soc41 xxxv1 pp4 #bje-bab1 ,january #aa1 #ahig1 #b ,pls47 ,also the writings of ,eaton1 ,emery1 ,fischer1 ,forel1 ,ghin1 ,godart1 ,hagen1 ,joly1 ,koletani1 ,loew1 ,meinert1 ,mik1 ,nicolet1 ,osten ,sacken1 ,pictet1 ,roussel1 ,schaeffer 7#aged71 ,schaum1 ,schenk1 ,j4 ,b4 ,smith1 ,thompson1 ,buchanan-,white1 ,brunner von ,wattle-,wyll1 ,weise1 ,wyenbergh4 ,the subject of copulation has been treated by ,hoffer1 ,hartig1 ,schiedeknecht1 ,verhoeff1 etc4 ,,the ,,armature ,,of ,,insects3 ,,set1 ,,hairs1 ,,scales1 ,,tubercles1 ,,etc4 ,illustration3 ,,fig4 #bjh4--,larva of ,dryocampa rubicunda1 stage ,,ii4--,bridgham del4 ,the cuticula4--,the integument is externally either smooth and shining or variously punctured1 granulated1 tuberculated1 striated1 or hairy4 ,in certain orders the skin is clothed with flattened set or scales1 while many forms1 as some caterpillars 7,figs4 #bjh1 #bji71 beetles 7,fig4 #baj71 etc41 are protected by spines1 horns1 etc41 these in adult insects often forming secondary sexual characters1 usually being more developed in the males than in the females4 ,illustration3 ,,fig4 #bji4--,larva of ,hyperchiria io1 on hatching4 ,the cuticula is not always smooth1 but is often finely granulated or even minutely spinulated4 ,on the abdominal segments of ,anabrus1 as observed by ,minot1 the cuticula is armed with microscopic conical nodules scattered irregularly over it4 ,they do not correspond1 he says1 in any way to hairs2 for they do not rest over pores1 nor did he see any specially modified cells underlying them4 8,as far as ,i have observed1 they are mere local irregularities1 each nodule being apparently supported by some four or six unmodified epidermal cells40 ,minot adds that the whole of the cuticula1 except the cones just described and the hairs1 is divided into numerous minute fields1 each of which corresponds to a single cell of the underlying hypodermis4 ,each field is bounded by a distinct polygonal outline1 and its surface is either covered by a large number of extremely minute projecting points1 as on the dorsal arch of the segment1 or is smooth1 as upon the articular membrane and ventral arch4 ,upon the sides of the dorsal arch and upon the spiracular membrane each field has a projecting spine or sometimes two or even three4 7,see also pp4 #bh1 #cj47 ,illustration3 ,,fig4 #baj4--,phanus pegasus1 1 from ,mexico4--,after ,graber4 ,illustration3 ,,fig4 #baa4--,section of integument of ,datana ministra3 c1 cuticula2 hyp1 hypodermis2 p1 outer pigmented nodulated layer4 ,the cuticle of lepidopterous larv has also been described and figured by ,minot4 ,in the caterpillars of different groups investigated by him1 the cuticle was found to be rough with microscopic teeth or spinules1 erect or flattened and scale-like1 and either densely crowded or scattered1 and affording excellent generic and specific characters4 ,in the slug-worms 7,limacodids7 we have observed that the cuticula is unusually rough1 especially on the spiniferous tubercle of ,empretia1 ,parasa1 etc4 7,fig4 #bac1 c74 ,the skin of the body between the tubercles is seen to be finely shagreened1 due to the presence of fine teeth1 which are more or less curved and bent1 these teeth arising from a very finely granulated surface 7d74 ,the cuticle of neuropterous1 trichopterous1 and tenthredinid larv will probably afford similar cases4 ,the integument of the larva of ,datana is1 on the black bands1 rough and nodulated1 the irregular nodules being filled with a black pigment1 and forming a layer 7p7 external to the true cuticula 7,fig4 #baa74 ,illustration3 ,,fig4 #bab4--;,hairs of ,datana3 f1 formative hair-cell2 c1 cuticula2 p1 pigmented layer2 hy1 hypodermis4 ,the integument of many insects contains fine canals passing through the chitinous layers and opening externally in minute pores4 ,certain of the pore-canals communicate with hollow set which sit directly over the pores2 other pores form the external openings of dermal glands1 but in many cases they are empty or only filled with air1 and do not have any hairs connected with them4 ,each of these pores communicates with a hair-forming hypodermal cell1 called by ,graber a trichogen4 ,set 78hairs0 and bristles74--,the set of insects are1 as in worms1 processes of the cuticle originating from certain of the hypodermal cells4 ,they arise either from a ring-like pit1 or from a minute tubercle1 and are usually situated at the outlet of a pore-canal1 which connects with an underlying cell of the hypodermis 7,fig4 #bab74 ,they are1 then1 bristle or hair-like processes arising from the hypodermis4 ,where the hairs or set are rubbed off1 their site is indicated by a minute ring like a follicle in the chitinous integument4 ,the cuticular hair1 says ,leydig1 is in its first condition the secretion of the cellular element of the skin1 and a thread-like continuation of the cell-body may rise up through the pore-canal into the centre of the hair1 remaining there permanently4 ,while the set are usually simple1 they are often branched1 plumose1 or spinulose1 as in larval ,hemerobiid1 ,anthrenus1 and ,dermestes1 the larv of certain coccinellid beetles1 notably ,epilachna1 and of ,cassida1 the larv of arctians1 etc41 and in bees 7,anthophila1 ,megachile1 ,osmia1 ,colletes1 ,apis1 etc474 ,the use of these spinulose1 plumose1 and twisted hairs in the bees is clearly shown by ,j4 ,b4 ,smith1 who states that as these insects walk over flowers1 the pollen grains adhere to the vestiture1 8and this also accounts for the fact1 probably noticed by every observant fruit-grower1 that bees frequently bury themselves completely in the blossoms1 or roll over every part of them4 ,such insects are after pollen1 not honey1 and by so rolling about1 the pollen grains are brought into contact with and adhere to the surface of the insect40 ,the syrphid flies also pollenize flowers1 the pollenizing of chrysanthemums being effected1 as ,smith states1 by ,eristalis tenax1 and he adds that the body vestiture of the syrphids 8is often composed of spurred and branched hairs40 7,for reference to gathering hairs1 see p4 #de47 ,illustration3 ,,fig4 #bac4--;,cuticular spinules of larva of ,adoneta3 a1 b1 c1 d1 different forms2 e1 e1 caltrops4 ,certain remarkable spines occur in limacodid larv1 notably ,empretia and ,adoneta4 ,these we have called caltrops spines1 from their resemblance to the caltrops formerly used in repelling the attacks of cavalry4 ,they are largely concerned in producing the poisonous and irritating effects resulting from contact with the caterpillars of these moths1 and are situated in scattered groups near the end of the tubercles4 ,a group of three is represented at ,fig4 #bac1 e4 ,they are not firmly embedded in the cuticle1 but on the contrary appear to become very easily loosened and detached1 and they probably1 when brought into contact with the skin of any aggressor1 burrow underneath1 and are probably in part the cause of the continual itching and annoyance occasioned by these creatures4 ,it will be seen by reference to ,fig4 #bac1 e1 that the body of the spine is spherical1 with one large1 elongated1 conical spine arising from it1 the spherical base being beset with a number of minute1 somewhat obtuse spinules4 ,illustration3 ,,fig4 #bad4--;,glandular hairs of caterpillars4 ,a1 ,dasylophia anguina3 a1 of body2 b1 of head2 c1 of prothoracic shield4 ,b1 ,ceratosia tricolor3 a1 on body2 b1 on abdominal legs4 ,c1 ,schizura ipome3 a1 from third thoracic segment2 b1 from larva stage ,,ii2 c1 simple set from minute warts4 ,glandular hairs and spines4--,in some insects occur fine1 minute1 hollow set from which exude1 perhaps through pore-canals of extreme fineness1 droplets of a clear watery or plasma-like sticky fluid4 ,the club-shaped tenent hairs of the feet of ,collembola1 and the hairs fringing the feet of ,diptera1 are modified glandular hairs4 ,here they serve to give out a sticky fluid enabling the insect to walk on smooth surfaces2 they end in a vesicle-like bulbous expansion1 which may contain numerous pore-canals4 ,those of caterpillars were first noticed by ,zeller1 and ,dimmock has particularly described those of the larv of ,pterophorid4 ,they are either club-shaped1 or variously forked at the end 7,fig4 #bad1 ,b1 a74 ,they are usually replaced after the first larval moult by ordinary1 simple1 solid1 pointed set1 and their use in caterpillars is as yet unknown4 ,whether these hairs1 as seems most probable1 arise from a specialized glandular hypodermal cell1 or not1 has not yet been discovered4 ,illustration3 ,,fig4 #bae4--;,a1 group of set arising from a subdorsal tubercle3 cut1 the cuticle2 hy1 the hypodermis2 sc1 the enlarged and specialized cells of the hypodermis which secrete the spines themselves2 pglc1 the nuclei which secrete the venomous fluid which fills the cavity of the seta 7s71 seen at p in a broken spine4 ,b1 a short entire1 and a long broken seta 7s-p72 pgle1 four poison cells2 p1 the poison in the hollow of the spine4 ,these temporary fine glandular hairs are probably the homologues of the larger true glandular bristles and spines of the later stages of certain lepidopterous larv1 which are brightly colored and lead an exposed life1 living through a large part of the summer4 ,in these structures the bristles or spines are hollow1 filled with a poisonous secretion formed in a single large1 or several smaller specialized hypodermal cells situated under the base of the spine4 ,in the venomous spines of ,lagoa crispata the poisonous fluid in the larger spines 7,figs4 #bae1 ,c1 #baf1 b7 is secreted in several large cells situated at the base of the spine1 and this is the usual form4 ,in the finer spines of a large tubercle 7,figs4 #bae1 ,a1 #baf7 there appears to be a differentiation of the hypodermal cells into two kinds1 the large1 basal deep-seated1 setigenous cells 7#baf1 sc7 and the poison-secreting nuclei 7#baf1 pglc7 situated nearer the base of the set4 ,the spines being filled with poison and breaking into bits in the skin of the hands or neck1 cause great irritation and smarting4 ,these nettling or poisonous hairs or spines are especially venomous in the larva of ,orgyia1 ,empretia stimulea1 ,hyperchiria io1 the larv of the saturnians 7,fig4 #bag7 and lasiocampids1 etc4 ,they rarely occur in insects of other orders1 though the skin of ,telephorus is said by ,leydig to bear glandular hairs4 ,illustration3 ,,fig4 #baf4--,section of a subdorsal tubercle from a larva in stage #a3 sc1 the setigenous cells1 one for each seta2 pglc1 nuclei by which the poison is secreted2 s1 seta2 p1 poison in middle of a broken spine2 cut1 cuticle2 sd1 tub1 spinulated surface of the subdorsal tubercle4 ,leydig states that in the stout bristles of ,saturnia there is1 as in the integument of the body1 a homogeneous cuticula1 under which is the cellular matrix 7hypodermis71 and the clear contents 7hyaloplasma7 are secreted from the blood4 ,the cell-structure of the hairs consist1 as in the cells of the body1 of spongioplasma and hyaloplasma4 ,leydig has observed the droplets of the secretion of the caterpillar of ,saturnia carpini oozing through distinctly observable pores1 and states that there are similar openings in the hairs and scales4 ,dewitz found easily observable openings at the end of the hair of a large exotic weevil 7,fig4 #acj74 ,the advanced nymph of ,psylla is also armed with clavate glandular hairs 7,fig4 #agh74 ,illustration3 ,,fig4 #bag4--;,armature of last four segments of ,callosamia promethea3 a1 a dorsal seta2 b1 one showing the poison 7p7 within4 ,the tubercles are outgrowths of the body-walls2 they are either smooth1 warty1 or spiny1 as in many caterpillars4 ,while the armature of insects is of little morphological importance1 it is evidently of great biological importance1 the welfare or even the life of the insect depending upon it2 and it varies in each species of insect1 especially in ,diptera1 where the position of even a single seta characterizes the species4 ,illustration3 ,,fig4 #bah4--,section through an antennal pectination of ,saturnia carpini3 a1 hypodermis1 formative cells of the hairs 7c72 d1 cuticula2 e1 trachea4--,after ,semper4 ,illustration3 ,,fig4 #bai4--;,flattened hairs from the lateral tufts of larva of ,gastropacha americana3 ,a1 three from the lateral tuft of ,heteropacha rileyana4 ,the mode of development of the hairs was first described by ,semper4 ,in the pectination of the antenna of ,saturnia carpini he observed that the hairs arise1 like the scales of the wings1 from large round formative-cells lying in the cavity1 which send out through the hypodermis and cuticle a long slender process which finally becomes the hair 7,fig4 #bah74 ,tactile hairs are those set arising over nerve cells or nerve terminations and will be discussed under the organs of sense4 ,illustration3 ,,fig4 #bbj4--,the same in ,g4 quercifolia3 a1 a small hair ending in two minute processes4 ,scales4--,in very rare cases the hairs of caterpillars 7,fig4 #bai7 are flattened and scale-like1 and this passage in the same insect of cylindrical hairs into flattened scale-like ones1 shows that the scales are only modified hairs4 ,also1 as we shall see farther on1 ,semper has proved that their mode of origin is identical4 ,while true scales are characteristic of ,synaptera 7,thysanura and ,colembola71 as well as ,lepidoptera and ,trichoptera1 they also occur in the ,psocid 7,amphientomum71 in many ,coleoptera 7,curculionid1 ,clerid1 ,ptinid1 ,dermestid1 ,byrrhid1 ,scarabid1 ,elaterid1 and ,cerambycid71 and in the ,culicid1 and a few other ,diptera1 though they are especially characteristic of the ,lepidoptera1 not a species of this great order being known to be entirely destitute of them4 ,illustration3 ,,fig4 #bba4--;,flattened and spinulated hairs of tufts of larva of ,acronycta hastulifera4 ,illustration3 ,,fig4 #bbb4--,scales from dorsal tuft1 on second thoracic segment of larva of ,gastropacha quercifolia4 ,the scales vary much in shape1 but are more or less tile-like1 attached to the surface of the body or wing by a short slender pedicel1 and are more loosely connected with the integument than the hairs1 which are thicker at the base or insertion than beyond4 ,the markings of the scales1 both of ,synaptera and ,lepidoptera1 are very elaborate1 consisting of raised lines1 ridges1 or stri with transverse ridges between4 8,the stri of the transparent scales of ,micropteryx are from about #ejj to #cjj to the millimetre1 varying in different species4 ,the opaque scales of ,morpho1 which show metallic reflections1 have about #adjj stri to the millimetre40 7,kellogg47 ,the primary use of scales1 as observed by ,kellogg1 is to protect the body1 as seen in ,synaptera and ,lepidoptera4 ,a nearly as important use is the production of colors and patterns of colors and markings1 while in certain butterflies certain scales function as the external openings of dermal scent-glands1 and they afford in some cases 7as first claimed by ,kettelhoit in #ahfj7 generic and specific characters4 ,spuler has shown that the scales are strengthened by internal chitinous pillars4 ,burgess has observed in the scales of ,danais plexippus that the under surface of the scales is usually smooth1 or provided with few and poorly developed ridges1 and this has been confirmed by ,spuler and by ,mayer 7,fig4 #bbf74 ,in the irised and metallic scales the ridges1 says ,spuler1 are not divided into teeth1 and they converge at the base to the pedicel and also toward the end of the scale 7,micropteryx71 or end in a single process beyond the middle 7the brass-colored scales of ,plusia chrysitis74 ,the arrangement of the scales on the wings is1 in the generalized moths1 irregular2 in the more specialized forms they are arranged in bands forming groups1 and in the most specialized ,lepidoptera they are more thickly crowded1 overlapping each other and inserted in regular rows crossing the wings1 these rows either uniting with each other or running parallel4 7,spuler47 ,the scattered irregular arrangement seen in ,micropteryx is also characteristic of the ,trichoptera and of ,amphientomum4 ,illustration3 ,,fig4 #bbc4--,portion of a longitudinal section through one of the young pupal wings of a summer pupa of ,vanessa antiopa3 s1 young scale2 leu4 cy41 leucocyte2 mbr4 pr41 ground membrane2 prc1 hypodermis-cells4 ,illustration3 ,,fig4 #bbd4--,portion of a longitudinal section through one wall only of the pupal wing of a specimen slightly older than that of ,fig4 #bbc2 s1 older scale4 ,development of the scales4--,the mode of origin of the scales was first worked out by ,semper in #ahhf1 who stated that in the wing of the pupal ,sphinx and ,saturnia they are seen1 in sections1 to arise from large roundish cells just under the hypodermis and which have a projection which passes out between the hypodermis 7his 8epidermis07 cells1 expanding into a more or less spherical vesicle1 the latter being the first indication of the future scale4 ,he observed that the scales are not all formed at once1 but arise one after another1 so that on one and the same wing the scales are in different stages of development4 ,illustration3 ,,fig4 #bbe4--,portion of a longitudinal section through a pupal wing about eight days before emergence3 s1 formative scale-cell2 upper s1 a scale4 ,more recently ,schaeffer has stated that the scales and also the hairs are evaginations of greatly enlarged hypodermis cells1 and still more complete evidence has been afforded by ,a4 ,g4 ,mayer 7#ahif74 ,in the wings of ,lepidoptera1 about three weeks before the imago emerges1 certain of the hypodermis cells1 which occur at regular intervals1 begin to increase in size and to project slightly above the level of the hypodermis2 these are ,semper's 8formative cells10 and are destined to secrete the scales4 ,they increase in length1 and appear as in ,fig4 #bbc4 ,in the next stage observed1 the projections are much longer 7,fig4 #bbd74 ,the hypodermis is now thrown up into a regular series of ridges1 which run across the wing4 ,each ridge1 says ,mayer1 corresponds in position with a row of formative cells1 and each furrow with the interval between two adjacent rows4 ,the scales always project from the tops of these ridges4 ,the ground or basal membrane has not participated in this folding1 and the deep processes of the hypodermis 7prc7 that once extended to this membrane have largely disappeared4 ,figure #bbe represents a more advanced stage almost eight days before the emergence of the imago4 ,the scales are originally filled with protoplasm1 which gradually withdraws1 leaving behind it little chitinous bars or pillars which serve to bind together the upper and lower surfaces of the scales1 and finally the scales become 8merely little flattened hollow sacs containing only air40 ,as ,mayer shows 7,figs4 #bbf1 #bbg71 from the study of scales examined four days before emergence of the butterfly 7,danais71 8the striations upon the upper surface of the scale are due to a series of parallel longitudinal ridges10 while the under side is usually smooth4 ,the mode of insertion is seen in ,fig4 #bbg4 ,the narrow cylindrical pedicel of the scale is merely1 according to ,semper1 inserted into a minute close-fitting socket1 which perforates the wing-membrane1 and not into a tube1 as ,landois supposed4 ,spuler describes a sort of double sac structure or follicle 7,schuppenbalg7 which receives the hollow pedicel of the scale4 ,this was originally 7#ahfj7 observed by ,f4 ,j4 ,carl ,mayer1 but more fully examined by ,spuler 7,fig4 #bbh7 though not detected by ,a4 ,g4 ,mayer4 ,illustration3 ,,fig4 #bbf4--,portion of a cross-section through the pupal wing of ,danais plexippus1 about six days before emergence3 sg1 scale2 cta4al1 wing-membrane2 cl4frm1 formative cell of the scale2 mbr4pr1 ground-membrane2 fbr4hdrm1 hypodermal fibres of pupal wings4 ,a1 portion of a longitudinal section through the pupal wing1 eight or nine days before emergence2 prc1 processes of young hypodermis scales4--,this and ,figs4 #bbc-bbe after ,mayer4 ,spinules1 hair-scales1 hair-fields1 and androconia4--,besides the scales1 fine spinules occur on the thickened veins of the wings of the ,blattid1 where they resemble fir-cones2 also in the ,perlid1 in the ,trichoptera1 and in the more generalized ,lepidoptera 7,micropterygid and ,hepialid71 occur1 as indicated by ,spuler1 delicate chitinous hollow spinules scarcely one-tenth as long as1 and more numerous than1 the scales1 which sometimes form what he calls 8,haftfelds10 or holding areas4 ,these spinules have also been noticed by ,kellogg1 and by myself in ,micropteryx2 ,kellogg1 and also ,spuler1 have observed them in certain ,trichoptera 7,hydropsyche74 ,these also occur on the veins1 and detached ones near large one-jointed hairs1 or hair-scales1 said by ,kellogg to be striated4 ,kellogg has detected these scale-hairs1 as he calls them1 in ,panorpa4 ,illustration3 ,,fig4 #bbg4--,view looking down upon the upper 7i4e4 exposed7 surface of one of the large scales situated on the veins of ,danais plexippus1 about four days before emergence3 clm1 chitinous pillars found in scales4 ,a1 a smaller scale1 a1 a1 sections of the scales4 ,b1 leucocyte found in the larger scale4--,after ,mayer4 ,illustration3 ,,fig4 #bbh4--,scale-follicles3 ,a1 of a scale of ,galleria mellonella3 r1 neck-ring4 ,b1 the same of ,polyommatus phlas4 ,c1 the same of a hair on inner edge of hind wing of ,lycna alexis 4--,after ,spuler4 ,illustration3 ,,fig4 #bbi4--;,a1 portion of wing of a caddis-fly 7,mystacides74 ,b1 enlarged1 showing the androconia and hair-scales4 ,c1 a separate androconium4--,after ,kellogg4 ,the 8hair-scales0 of the phylogenetically older ,trichoptera correspond to certain scales of ,lepidoptera1 especially the ,psychid 7,spuler71 variously called 8plumules0 7,deschamps71 8battledore scales10 also certain minute cylindrical hairs4 ,to these scent-scales is applied the term androconia4 ,they are found1 almost without exception1 on the upper side of the fore wings1 occurring in limited areas1 such as the discal spots1 or on folds of the wings4 ,fritz ,mller has shown that they function as scent-scales1 and are confined to the males4 ,kellogg has detected androconia-like scales on the wings of a caddis-fly1 ,mystacides punctata 7,fig4 #bbi74 ,illustration3 ,,fig4 #bhj4--;,cross-section of androconia surface on wing of ,thecla calanus2 a1 androconia2 gl1 gland of base2 s1 ordinary scales2 w1 wing in section4--,after ,thomas4 ,thomas has proved by sections of the wing of ,danais1 etc41 that the androconia arise from glands situated in a fold of the wing 7,fig4 #bcj71 and he states that the material elaborated by the local glands1 and distributed upon the surface of the wing by the androconia1 is that which gives to many of the ,lepidoptera their characteristic odor4 ,on comparing these 8glands10 it is evident that they are groups of specialized formative cells of ,semper 7trichogens71 which secrete an odorous fluid1 issuing perhaps from extremely fine pore-canals at the ends of the androconia4 ,they thus correspond to the glandular hairs1 poison-hairs1 and spines of caterpillars1 the formative cells of which contain either a clear lymph or poison4 ,,literature a4 ,hairs1 bristles1 cleaning spines1 calcaria1 combs1 etc4 ,leydig1 ,franz4 ,zum feineren ,bau der ,arthropoden4 7,mller's ,archiv f4 ,anat4 und ,phys41 #ahee1 pp4 #cgf-dhj47 ,fobel1 ,auguste4 ,les fourmis de la ,suisse4 ,ble1 #ahgd4 ,saunders1 ,edward4 ,remarks on the hairs of some of our ,british ,hymenoptera4 7,trans4 ,ent4 ,soc4 ,london1 #ahgh1 pp4 #afi-aga47 ,perez1 ,j4 ,notes d'apiculture4 7,bull4 ,soc4 d',apic4 de la ,gironde1 ,bordeaux1 #ahhb47 ,osten ,sacken1 ,c4 ,r4 von4 ,an essay on comparative chtotaxy1 or the arrangement of characteristic bristles of ,diptera4 7,trans4 ,ent4 ,soc4 ,london1 #ahhd1 pp4 #dig-eag47 ---- ,preliminary notice of a subdivision of the suborder ,orthorrhapha ,brachycera 7,diptera7 on chtotactic principles4 7,berlin ,ent4 ,zeitschr41 #ahif1 pp4 #cfe-cgc47 ,janet1 ,charles4 tudes sur les fourmis4 #h;e ,note4 ,sur l'organe de nettoyage tibio-tarsien de ,myrmica rubra4 7,ann4 ,soc4 ,ent4 ,france1 #ahie1 pp4 #fia-gjd1 #f ,figs47 ,see also ,j4 ,b4 ,smith's ,economic ,entomology1 #ahif1 hairs of bees4 ,also the writings of ,de ,geer1 ,huber1 ,fenger1 ,mayr1 ,forel1 ,canestrini1 and ,berlese 7#ahhj72 ,dahl1 ,cheshire1 etc4 b4 ,glandular and poisonous set and spines ,ratzeburg1 ,j4 ,th4 ,ch4 ,ueber entomologische ,krankheiten4 7,stettin ,ent4 ,zeit41 #ahdf1 vii1 pp4 #ce-da47 ,zeller1 ,p4 ,c4 ,revision der ,pterophoriden4 7,linna ,ent41 vi1 pp4 #cai-daf1 #aheb1 at p4 #cef speaks of 8,drsenhrchen407 ,dimmock1 ,george4 ,on some glands which open externally on insects4 7,psyche1 iii1 pp4 #chg-dja1 #ahhb47 ,goossens1 ,th4 ,des chenilles urticants4 7,ann4 ,soc4 ,ent4 ,france1 #ahha1 pp4 #bca-bcf47 ,des chenilles vsicants4 7,ibid41 #ahhf1 pp4 #dfa-dfd47 ,packard1 ,a4 ,s4 ,notes on some points in the external structure and phylogeny of insects4 7,proc4 ,boston ,soc4 ,nat4 ,hist41 xxv1 #ahij1 pp4 #hc-aad1 #b ,pls47 ---- ,a study of the transformations and anatomy of ,lagoa crispata1 a bombycine moth4 7,proc4 ,amer4 ,phil4 ,soc41 xxxii1 pp4 #bge-bib1 #g ,pls41 #ahid47 ,holmgren1 ,emil4 ,studier fner hudens och de krtelartade hudorganens morfologi hos ,skandinaviska macrolepidopterlarver4 7,k4 ,svenska ,vetenskaps-,akad4 ,handl41 xxvii1 pp4 #a-hc1 ,stockholm1 #ahie1 #i ,pls47 ,also the writings of ,leydig1 ,keller1 ,bach1 ,karsten1 ,scribner1 ,riley1 etc4 7,see also ,literature of repugnatorial glands47 c4 ,androconia ,deschamps1 ,bernard4 ,rcherches microscopiques sur l'organisation des ailes der ,lpidoptres4 7,ann4 des ,sc4 nat4 81 iii1 pp4 #aaa-aeg1 #ahce47 ,waufor1 ,t4 ,w4 ,on certain butterfly scales characteristic of sex4 7,london1 #ahfg-fh47 ,mc,intire1 ,s4 ,j4 ,notes on the minute structure of the scales of certain insects4 7,london1 #ahga47 ,anthony1 ,j4 ,the markings on the battledore scales of some of the ,lepidoptera4 7,london1 #ahgb47 ,scudder1 ,s4 ,h4 ,antigeny or sexual dimorphism in butterflies4 7,proc4 ,amer4 ,acad4 ,arts and ,sc41 xii1 #ahgg1 pp4 #aej-aeh47 ,also ,butterflies1 etc4 7,new ,york1 #ahha1 pp4 #aib-bjf1 figs47 ,mller1 ,fritz4 ,a prega costal das ,hesperideas4 7,archivas do ,museo nac4 do ,rio de ,janeiro1 iii1 pp4 #da-ej1 #b ,pls41 #ahgh47 ,thomas1 ,m4 ,b4 ,the androconia of ,lepidoptera4 7,amer4 ,nat41 xxvii1 pp4 #ajah-ajba1 #b ,pls41 #ahic47 d4 ,scales ,leydig1 ,franz4 ,zum feineren ,bau der ,arthropoden4 7,archiv f4 ,anat4 und ,phys41 #ahee1 pp4 #cgf-dhj1 #a ,taf47 ,semper1 ,carl4 ,beobachtungen ber die ,bildung der ,flgel1 ,schuppen1 und ,haare bei den ,lepidopteren4 7,zeitschrift f4 wissensch4 ,zoologie1 #aheg1 pp4 #cbf-cci1 #a ,taf47 ,mayer1 ,f4 ,t4 ,karl4 ,ueber den ,staub der ,schmetterlingsflgel4 7,allgem4 mediz4 ,centralzeitung1 #ahfj1 pp4 #ggb-ggd47 ,landois1 ,h4 ,beitrge zur ,entwicklungsgeschichte der ,schmetterlingsflgel in der ,raupe und ,puppe4 7,zeitschr4 f4 wissensch4 ,zoologie1 xxi1 #ahga1 pp4 #cje-caf1 #a ,taf47 ,weismann1 ,august4 ,ueber ,duftschuppen4 7,zool4 ,anzeiger1 i1 #ahgh1 pp4 #ih-ii47 ,dimmock1 ,george4 ,scales of ,coleoptera4 7,psyche1 iv1 pp4 #a-aa1 #bc-bg1 #dc-dg1 #fc-ga1 #ahhc47 ,schaeffer1 ,csar4 ,beitrge zur ,histologie der ,insekten4 7,zool4 ,jahrbcher1 ,abth4 f4 ,anat4 u4 ,ontog41 iii1 pp4 #faa-feb1 #b ,pls41 #ahhi47 ,kellogg1 ,vernon ,l4 ,the taxonomic value of the scales of the ,lepidoptera4 7,kansas ,univ4 ,quart41 iii1 pp4 #de-hi1 figs4 #a-ag1 #i ,taf41 #ahid47 ,mayer1 ,alfred ,g4 ,the development of the wing-scales and their pigment in butterflies and moths4 7,bull4 ,mus4 ,comp4 ,zool41 xxix41 #ahif1 pp4 #bji-bcf1 #g ,pls47 ,spuler1 ,arnold4 ,beitrge zur ,kenntniss des feineren ,baues und der ,phylogenie der ,flgeltedeckung der ,schmetterlings4 7,zool4 ,jahrb4 ,abth4 f4 ,anat4 u4 ,ontog41 viii1 pp4 #ebj-edc1 #a ,taf41 #ahie47 ---- ,ueber das ,vorhandensein von ,schuppenbalg bei den ,schmetterlingen4 7,biol4 ,centralblatt1 xvi1 ,sept4 #ae1 #ahif1 pp4 #fgg-fgi1 #c figs47 ,,the ,,colors ,,of ,,insects ,the colors and bright markings of insects1 especially those of butterflies1 render them the most brilliant and beautiful creatures in existence1 rivalling and even excelling the gay hues of our most splendidly colored birds4 ,the subject has been but recently taken up and is in a somewhat crude condition1 but the leading features have been roughly sketched out by the work of a few observers from a physical1 chemical1 and biological point of view4 ,the colors of insects1 as of all other animals1 are primarily due to the action of light and air2 other factors are1 as ,hagen observes1 heat and cold1 moisture and dryness1 as recently shown by the experiments on butterflies by ,dorfmeister1 ,weismann1 ,w4 ,h4 ,edwards1 and later observers4 ,they have their seat in the integument4 ,hagen divides colors into optical and natural4 ,optical colors4--8,these10 says ,hagen1 8are produced by the interference of light1 and are by no means rare among insects1 but they are solely optical phenomena4 ,colors by the interference of light are produced in two different ways3 either by thin superposed lamell1 or by many very fine lines or small impressions in very close juxtaposition4 8#a4 ,there must be present at least two superposed lamell to produce colors by interference4 ,the naked wings of ,diptera1 of dragon-flies1 and of certain ,neuroptera often show beautiful interference colors4 ,the wings of ,chrysopa and ,agrion show interference colors only for a certain time1 viz41 as long as the membranes of the wings are soft and not firmly glued together4 ,afterwards such wings become simply hyaline4 8,the scales of ,entimus and other ,curculionid are well known for their brilliancy1 and it is interesting to remark that when dry scales are examined with the microscope1 many are found partly injured1 which give in different places different colors1 according to the number of layers which remain4 ,the elytra of some ,chrysomelina and other beetles with iridescent colors probably belong to the same category4 8#b4 ,when there are scales with many fine lines or small impressions close to each other1 we have the second mode of producing colors4 8,the fine longitudinal and transversal lines of lepidopterous scales seem to serve admirably well to produce the brilliant effect of color-changing butterflies4 ,but there must be something more present1 as most of the scales of ,lepidoptera are provided with similarly fine lines1 and only comparatively few species change colors4 ,i remark purposely that the lines in the color-changing scales are not in nearer juxtaposition40 7,hagen47 8,the colors of butterflies change mostly from purple to blue1 sometimes to yellow4 ,the splendid violet color at the end of the wings of ,callosune ione is brought out by a combination of the natural with interference colors4 ,originally the scales are colored lake-red2 but a blue interference color is mixed with it2 hence the violet hue results4 ,the blue tones1 i4e4 the splendid varying blue of the ,morpho butterflies1 ,schatz claims1 owe their hue less to the interference of light than to a clouded layer of scales situated over the dark ground1 through which the light becomes reflected on the same4 ,the scales of the ,morphids are in reality brown1 as we see by transmitted light2 moreover1 only the upper side of the scales sends off blue reflections--the under side is simply brown4 ,but the blue scales of ,urvilliana are also shining blue beneath2 by transmitted light they appear as if clear yellow4 ,the smaragd-green scales of ,priamus show by transmitted light a bright red-orange1 and the orange-yellow of ,crsus a deep grass-green40 7,schatz in ,kolbe47 8,krukenberg presumes the golden-green color of ,carabus auratus to be an interference color4 ,it is not changed by the interference of light1 nor was he able to extract from the elytra any green pigment with ether1 benzol1 carbon of sulphur1 chloroform1 or alcohol1 even after having previously submitted the elytra to the influence of muriatic acid or ammonia4 ,chlorophyll is not present1 whether free or combined with an acid40 7,hagen47 ,leydig has shown that the interference colors of the hairs of certain worms 7,aphrodite and ,eunice7 may be produced by very small impressions in juxtaposition1 which bring about the same effect as stri4 ,such an arrangement occurs on the feathers of birds1 i4e4 on the necks of pigeons and elsewhere1 and ,hagen suggests that this kind of interference colors occurs more frequently among insects than is commonly known4 ,at least the limbs of certain forms appear yellow1 but when held in a certain position change to brown or blackish4 8,i know of no other explanation of this not uncommon fact on the legs of ,diptera1 of ,hymenoptera1 and of ,phryganid40 ,interference colors1 he adds1 may occur in the same place together with natural colors4 8,the mirror spots of ,saturnia pernyi show besides the interference colors a white substance in the cells of the matrix1 which ,leydig believes to be guanin4 ,but this fact is denied by ,krukenberg for the same species and also for ,attacus mylitta and ,plusia chrysitis40 ,natural colors4--,these are divided by ,hagen into dermal 7cuticular7 and hypodermal4 ,the dermal colors are due to pigment deposited in the form of very small nuclei in the cuticula4 ,hagen considers them as 8produced mostly by oxidation or carbonization1 in consequence of a chemical process originating and accompanying the development and the transformations of insects40 8,to a certain extent the dermal colors may have been derived from hypodermal colors1 as the cuticula is secreted by the hypodermis1 and the colors may have been changed by oxidation and air-tight seclusion4 ,the cuticula is in certain cases entirely colorless1--so in the green caterpillar of ,sphinx ocellata2 but the intensely red and black spots of the caterpillar of ,papilio machaon belong to the cuticula1 and only the main yellow color of the body to the hypodermis40 7,leydig1 ,histiol41 p4 #aad47 8,the dermal colors are red1 brown1 black1 and all intermediate shades1 and all metallic colors1 blue1 green1 bronze1 copper1 silver1 and gold4 ,the dermal colors are easily to be recognized as such1 because they are persistent1 never becoming obliterated or changed after death40 7,hagen47 ,minot and ,burgess refer to the cuticular colors of the cotton-worm 7,aletia71 the dark brown color belonging to the cuticula or crust4 8,upon the outside of the crust is a very thin but distinct layer1 which in certain parts rises up into a great number of minute1 pointed spines that look like so many dots in a surface view4 ,each spine is pigmented diffusely1 and together they produce the brown markings4 ,the spines are clustered in little groups1 one group over each underlying hypodermal cell40 7,u4 ,s4 ,ent4 ,comm41 #dth ,report1 p4 #df47 ,minot also shows that in caterpillars generally a part of the coloration is caused by pigmentation of the cuticula4 ,in a dull-colored insect1 such as the ,mormon cricket 7,anabrus71 the coloration1 as ,minot states1 depends principally upon the pigment of the hypodermis shining through the cuticula4 8,most of the cells contain dull1 reddish-brown granules1 but scattered in among them are patches of cells bright green in color4 ,i have observed no cells intermediate in color2 on the contrary1 the passage is abrupt1 a brown or red cell lying next a green one4 ,indeed1 ,i have never seen any microscopic object more bizarre than a piece of the epidermis of ,anabrus spread out and viewed from the surface40 7#b;d ,report ,u4 ,s4 ,ent4 ,comm41 p4 #ahi47 ,the pigment may extend through the entire cuticula1 but it is usually confined to the outermost layers1 and occurs there in union with a peculiar modelling of the upper surface into microscopic figures which are of interest not only from their delicacy1 but because they vary with each species4 7,see p4 #ahd47 ,the hypodermal colors1 situated in the hypodermis1 are1 according to ,hagen1 the result of a chemical process1 generating color out of substances contained in the body4 ,they are easily recognized1 since they fade1 change1 and disappear after death4 ,but where these colors are preserved after death and enclosed in air-tight sacs1 as in the elytra and scales and hairs of the body1 they persist1 though1 as we well know1 they may fade after exposure to light4 ,the hypodermal colors are mostly brighter and lighter than the dermal ones1 being light blue or green in different shades1 yellow to orange1 and the numerous shades of these colors combined with white2 exceptionally they are metallic1 as in ,cassida1 and are then obliterated after death4 8,the fact that such metallic colors can be retained in dead specimens by putting a drop of glycerine under the elytra1 leads us to conclude that those colors are based upon fat substances4 ,the hypodermal colors are never glossy1 as far as ,i know2 the dermal colors frequently4 8,as the wings1 elytra1 and hairs all possess a cuticula1 dermal colors are frequently to be found1 together with hypodermal ones1 chiefly in metallic colors4 ,in the same place both colors may be present1 or one of them alone4 ,so we find hypodermal colors in the elytra of ,lampyrid4 ,in the elytra of the ,cicindelid the main metallic color is dermal1 the white lines or spots are hypodermal1 by which arrangement the variability in size and shape of those spots is explained4 8,there occur in a number of insects external colors1 that is1 colors upon the cuticula1 which ,i consider to be in fact displaced hypodermal colors3 the mealy pale blue or white upon the abdomen of some ,odonata1 the white on many ,hemiptera1 the pale gray on the elytra and on the thorax of the ,goliath beetle1 and the yellowish powder on ,lixus4 ,some of these colors dissolve easily by ether or melt in heat1 and some of them are a kind of wax4 ,i believe that those colors are produced in the hypodermis1 and are exuded through the pore-canals40 7,hagen47 ,the white colors are simply for the most part due to the inclusion of air in scales4 ,the white mother-of-pearl spots of ,argynnis are produced by a system of fine transverse pore-canals filled with air2 in ,hydrometra the white ventral marks have the same origin4 7,leydig47 ,the further statements and criticisms of ,hagen regarding the relation of color to mimicry1 sexual selection1 and the origin of patterns are of much weight and will be referred to under those heads4 ,indeed1 these subjects cannot well be discussed without reference to the fundamental facts stated in the masterly papers of ,leydig and of ,hagen1 and much of the theorizing of these latter days is ill-founded1 because the colors of insects and animals are attributed to natural selection1 when they seem really the result of the action of the primary factors of organic evolution1 such as changes of light1 heat1 cold1 and chemical processes dependent on the former4 ,as to the chemical nature of color1 ,hagen1 after quoting the results of ,krukenberg and others1 thinks that the colors of insects are chemically produced by a combination of fats or fat-acids with other acids or alkalis under the influence of air1 light1 and heat4 ,he concludes3-- #a4 ,that some colors of insects can be changed or obliterated by acids4 #b4 ,that two natural colors1 madder-lake and indigo1 can be produced artificially by the influence of acid on fat-bodies4 #c4 ,as protein bodies in insects are changed into fat-bodies1 and may be changed by acids contained in insects into fat-acids1 the formation of colors in the same manner seems probable4 #d4 ,that colors can be changed by different temperatures4 #e4 ,that the pattern is originated probably by a combination of oxygen with the integument4 #f4 ,that mimicry of the hypodermal colors may be effected by a kind of photographic process4 #g4 ,finally1 color and pattern are produced by physiological processes in the interior of the bodies of insects4 ,krukenberg concludes that change of color 7in perfectly developed insects7 is a consequence of the change of food1 and can be explained by the alteration of the pigment through heat and light4 ,his experiments were made in order to ascertain the cause of the turning of green grasshoppers in autumn into yellow and pink4 ,he tried to answer two questions3 ,first1 does the pigment of grasshoppers originate directly out of the food1 and does it consist of pure chlorophyll or of a substance containing chlorophyll1 or is it to be accepted as a peculiar product of the organism8 ,second1 is the color the consequence of only one pigment1 or of several8 ,special analysis proves that the green color has no connection with chlorophyll4 ,he concludes3 8,it is evident that the green color of the grasshopper is the consequence of several different pigments which can be separated by a chemical process40 ,krukenberg believes that light has a marked influence on the color of insects and that light turns to red or pink the insects which were green during the summer4 ,it would seem1 however1 more probable that cold was the agent1 the change being due to the colder autumn weather4 ,here we might refer to the results of the studies of ,buckton and ,sorby1 on the changes in color of ,aphides3-- 8#a4 ,the purple coloring matter appears to be a quasi-living principle1 and not a product of a subsequent chemical oxidizing process4 ,mounted in balsam or other preserving fluids1 the darker species stain the fluid a fine violet4 8#b4 ,as autumn approaches and cold weather reduces the activity of the ,aphides1 the lively greens and yellows commonly become converted into ferruginous red1 and even dark brown1 which last hue in reality partakes more or less of intense violet or purple4 ,these changes have some analogy with the brilliant hues assumed by maple and other leaves during the process of slow decay4 8#c4 ,aqueous solutions of crushed dark brown and yellow-green varieties of ,aphides originate different colors with acids and alkalies4 8#d4 ,in the generality of cases coloring-matters1 such as indigo1 ,indian yellow1 madder-lake1 and the like1 do not separately exist in the substance of vegetables1 but the pigments are disengaged through fermentation or oxygenation4 ,again1 alizarin itself is reddish yellow1 but alkaline solutions strike it a rich violet just as we find them to act towards the substance which ,mr4 ,sorby calls aphidilutein4 8#e4 ,mr4 ,sorby's four stages of the changes effected by the oxidation of aphideine produce four different substances40 ,chemical and physical nature of the pigment4--,researches in this difficult field of inquiry have been made by ,landois 7#ahfd71 ,sorby 7#ahga71 ,meldola 7#ahga71 by ,krukenberg 7#ahhd71 and more recently by ,coste1 ,urech1 ,hopkins1 and ,mayer1 and the subject is of fundamental importance in dealing with mimicry and protective coloration1 the primary causes of which appear to be due to the action of physical and chemical agents4 ,over twenty years ago ,meldola observed that the yellow pigment of the sulphur-yellow butterfly 7,gonopteryx rhamni7 was soluble in water1 and showed that its aqueous solution had an acid reaction4 ,besides the yellow uranidin found by ,krukenberg in different beetles and lepidopterous pup1 still other coloring-matters1 which are very constant in different species are readily recognized by the spectroscope4 8,thus there appear in the brownish yellow lymph of ,attacus pernyi1 ,callosamia promethea and ,telea polyphemus1 after saponification of the precipitated soap readily effected by ether1 or incompletely or not removed by benzine1 a chlorophane-like lipochrome2 and in the yellowish green lymph of ,saturnia pyri and of ,platysamia cecropia besides this pigment still another whose spectrum shows a broad band on ,d1 but which disappears with the addition of acetic acid or ammonia1 as also after a long heating of the lymph up to #ff ,c40 ,coste1 and more especially ,urech1 have shown that many of the pigments may be dissolved out of the scales by means of chemical reagents1 giving colored solutions1 and leaving the scales white or colorless4 ,they have also shown that some of these pigments may be changed in color by the action of reagents1 and then restored to their original color by other reagents4 ,they have proved that reds1 yellows1 browns1 and blacks are always due to pigments1 and in a few cases greens1 blues1 violets1 purples1 and whites1 and not1 as is usually the case1 to structural conditions1 such as stri on the scales 7,mayer74 ,they confined themselves solely to the chemical side of the problem1 not considering the structure of the scales themselves4 ,urech has also discovered a beautiful smaragd-green coloring-matter in the wings 7not in the scales7 of the pupa of ,pieris brassic4 ,it is not chlorophyll1 and ,urech suggests that it may be either the germinal substance of the pigments of the scales or its bearer4 ,it is not the pigment of the blood4 ,urech has also demonstrated that in many ,lepidoptera the color of the urine which is voided upon emergence from the chrysalis is similar to the principal color of the scales4 ,hopkins has worked on the pigments within the scales of butterflies4 ,the yellow pigment in ,gonopteryx rhamni is a derivation of uric acid1 and he calls it lepidotic acid4 ,its aqueous solution is strongly acid to litmus1 and must be bad-tasting to birds4 ,hopkins has dissolved the red pigment from the border of the hind wing of ,delias eucharis1 an ,indian butterfly1 in pure water1 finding as the result a yellow solution2 but if the solution be evaporated to dryness1 the solid residue of pigment is red once more4 ,he has obtained from this pigment of eucharis a silver compound which contains a percentage of metals exactly equal to that from the pigment of ,g4 rhamni4 7,nature1 ,april #b1 #ahib47 8,the scales of the wings of the white butterflies 7,pierid7 are also shown by ,hopkins to contain uric acid1 this substance practically acting as a white pigment in these insects4 ,a yellow pigment1 widely distributed in the same family1 is shown to be a derivative of uric acid1 and its artificial production as a by-product of the hydrolysis of uric acid is demonstrated4 ,that this yellow pigment is an ordinary excretory product of the butterfly is indicated by the fact that an identical substance is voided from the rectum on emergence from the pupa4 ,these excretory pigments1 which have well-marked reactions1 are apparently confined to the ,pierid1 and are not found in other ,rhopalocera4 ,this fact shows that when a ,pierid mimics an insect belonging to another group1 the pigments of the mimicked and mimicking insects1 respectively1 are chemically quite distinct4 ,other pigments existing1 not in the scales1 but between the wing-membranes1 are shown to be of use for ornament40 7,proc4 ,royal ,soc41 ,london1 #ahid47 ,griffiths 7#ahib7 claims that the green pigment found in several species of ,papilio1 ,hesperia1 and ,limenitis1 also in ,noctuid1 ,geometrid1 and ,sphingid likewise consists of a derivative of uric acid1 which he calls lepidopteric acid4 ,by prolonged boiling in ,h,cl it is converted into uric acid4 ,spuler1 however1 finds that green does not depend on pigmentation1 but is an optical color4 ,as remarked by ,spuler1 either the chitin of the scales itself is colored reddish 7yellow grayish71 or the pigment is secreted in the nuclei4 ,a4 ,g4 ,mayer believes that the pigments of the scales are derived from the hmolymph or blood of the pupa1 for the following reasons3 7#a7 ,he is unable to find anything but blood within the scales during the time when the pigment is formed4 7#b7 ,in ,lepidoptera generally the first color to appear upon the pupal wings is a dull ochre-yellow1 or drab1 and this is also the color assumed by the blood when it is removed from the pupa and exposed to the air4 7#c7 ,he has succeeded by artificial means in manufacturing several pigments from the blood which are similar in color to various markings upon the wing of the imago2 chemical reagents have the same effect upon these manufactured pigments that they do upon the similarly colored pigments of the wings4 8,it should be here noted10 he says1 8that in #ahff ,landois pointed out the fact that the color of the dried blood of many caterpillars is similar to the ground color of the wings of the mature insect40 ,ontogenetic and phylogenetic development of colors4--,the colors of the wings of ,lepidoptera1 as is well known1 are acquired at the end of the pupal state4 ,the order of development of the colors in the pupal wings has been observed by ,schaeffer1 ,van ,bemmelen1 ,urech1 ,haase1 ,dixey1 ,spuler1 and ,a4 ,g4 ,mayer4 ,the immature wings are at first transparent and full of protoplasm4 ,the transparent condition of the wings corresponds to the period before the scales are formed1 and when they are full of protoplasm2 they then become whitish as the scales develop2 the latter are at first filled with protoplasm1 and afterwards turn whitish1 being little hollow sacks filled with air4 ,after the protoplasm has completely withdrawn from the scales1 the blood of the pupa enters them1 and then the coloring-matter forms4 7,mayer47 ,he adds that 8about twenty-four hours after the appearance of the dull yellow suffusion the mature colors begin to show themselves4 ,they arise1 faint at first1 in places near the centre of the wings1 and are distinguished by the fact that they first appear upon areas between the nervures1 never upon the nervures themselves4 ,indeed1 the last place to acquire the mature coloration are the outer and costal edges of the wings1 and the nervures40 ,the faint color of the scales gradually increases in intensity4 8,for example1 if a scale be destined to become black1 it first becomes pale grayish brown1 and this color gradually deepens into black40 ,urech states that in ,vanessa io first a white1 and in ,v4 urtic a pale reddish hue1 are spread over the entire wings1 and then successively arise other colors in the following order3 yellow1 yellow to brown1 red1 brown and black4 ,spuler1 however1 claims that the differentiation of colors and markings do not follow one another1 but arise simultaneously1 and that his view is confirmed by ,fischer4 ,this may be the case with the highly specialized and diversely marked butterflies1 but certainly taking the ,lepidoptera as a whole the yellows and drabs must have been the primitive hues1 the other colors being gradually added in the later more specialized forms4 ,it is noticeable that the most generalized moths1 such as the species of ,micropteryx1 ,tinea1 ,psychid1 ,hepialid 7in general71 etc41 are dull brown or yellow-drab without bars1 stripes1 or spots of bright hues4 ,these shades prevail in others of the more primitive ,lepidoptera1 such as many bombycine moths1 and they even appear to a slight extent in certain caddis-flies4 ,the authors mentioned1 especially ,mayer1 whom we quote1 claim that 8dull ochre-yellows and drabs are1 phylogenetically speaking1 the oldest pigmental colors in the ,lepidoptera2 for these are the colors that are assumed by the hmolymph upon mere exposure to the air4 ,the more brilliant pigmental colors1 such as bright yellow1 reds1 greens1 etc41 are derived by more complex chemical processes4 ,we find that dull ochre-yellow and drabs are at the present day the prevalent colors among the less differentiated nocturnal moths4 ,the diurnal forms of ,lepidoptera have almost a monopoly of the brilliant colorations1 but even in these diurnal forms one finds that dull yellow or drab colors are still quite common upon those parts of their wings that are hidden from view40 ,the more primitive moths being more or less uniformly yellowish or drab1 the next step was the formation of bars1 stripes1 finally spots1 and eyed spots1 these markings in the later forms appearing simultaneously in one and the same species of certain highly specialized moths and butterflies4 ,all that has been said will prepare the reader for the consideration of the subject of insect coloration4 ,the origin of such markings has been discussed by ,weismann1 ,eimer1 ,haase1 ,dixey1 ,fischer1 and others4 ,,literature ,heer1 ,o4 ,einfluss des ,alpenklimas auf die ,farbe der ,insecten4 7,froebel u4 ,heer1 ,mitth4 aus dem ,gebiete der theoret4 ,erdkunde1 #ahcf1 i1 pp4 #afa-agj47 ,goureau4 ,mmoire sur l'irisation des ailes des insectes4 7,ann4 ,soc4 ,ent4 ,france1 #b sr41 i1 #ahdh1 pp4 #bja-bae47 ,laboulbne1 ,a41 et ,m4 ,follin4 ,note sur la matire pulvrulente qui recouvre la surface du corps des ,lixus et de quelques autres insectes4 7,ann4 ,soc4 ,ent4 de ,france1 #ahdh1 vi1 pp4 #cja-cje1 ,fig47 ,coquerel1 ,ch4 ,note sur la prtendue poussire cryptogamique qui recouvre le corps de certains insectes4 7,ann4 ,soc4 ,ent4 ,france1 #ahej1 viii1 pp4 #ac-ae47 ,brauer1 ,f4 ,beobachtungen in ,bezug auf den ,farbenwechsel bei ,chrysopa vulgaris4 7,verhandl4 k4 k4 zool4-botan4 ,gesellsch4 ,wien41 #aheb1 pp4 #ab-ad47 ,prittwitz1 ,o4 ,f4 ,w4 v4 ,bemerkungen ber die geographische ,farbenverteilung unter den ,lepidopteren4 7,stett4 ,ent4 ,zeit41 #ahee1 xvi1 pp4 #age-ahe47 ,latham1 ,a4 ,g4 ,the causes of the metallic lustre of the scales on the wings of certain moths4 7,proc4 ,lit4 and ,phil4 ,soc4 ,manchester1 iii1 #ahfd1 pp4 #aih-aii4 ,quart4 ,journ4 ,micr4 ,sc41 new ser41 iv1 #ahfd1 pp4 #dh-di47 ,sorby1 ,h4 ,c4 ,on the coloring matter of some ,aphides4 7,quart4 ,journ4 ,micr4 ,sc41 new ser41 xi1 #ahga1 pp4 #ceb-cfa47 ,leydig1 ,franz4 ,bemerkungen ber ,farben der ,hautdecke und ,nerven der ,drsen bei ,insekten4 7,archiv f4 mikr4 ,anatomie1 xii1 #ahgf1 pp4 #ecf-eej1 #a ,taf47 ,weismann1 ,a4 ,studien zur ,descendenz-,theorie1 ii1 #ahgf4 ,hemmerling1 ,hermann4 ,ueber die ,hautfarbe der ,insecten4 7,bonn1 #ahgh1 p4 #bg47 ,buckton1 ,c4 ,b4 ,monograph of the ,british ,aphides4 7,london1 #ahgi1 ii1 p4 #afg47 ,cameron1 ,p4 ,notes on the coloration and development of insects4 7,trans4 ,ent4 ,soc4 ,london1 #ahhj1 pp4 #fi-gi47 ,hagen1 ,hermann ,a4 ,on the color and pattern of insects4 7,proc4 ,amer4 ,acad4 ,arts and ,sc41 #ahhb1 pp4 #bcd-bfg47 ,poulton1 ,edward ,bagnall4 ,the essential nature of the colouring of phytophagous larv 7and their pup71 etc4 7,proc4 ,roy4 ,soc4 ,london1 xxxviii1 pp4 #bfi-cae1 #ahhd-ahhe47 ---- ,an inquiry into the cause and extent of a special colour-relation between certain exposed lepidopterous pup and the surfaces which immediately surround them4 7,phil4 ,trans4 ,roy4 ,soc4 ,london1 clxxviii1 pp4 #caa-dda1 #a ,pl41 #ahhg47 ,krukenberg1 ,c4 ,fr4 ,w4 ,grundzge einer vergleichenden ,physiologie der ,farbstoffe und der ,farben4 7,heidelberg1 #ahhd1 pp4 #ajb47 ,mc,munn1 ,c4 ,a4 ,krukenberg's chromatological speculation4 7,nature1 xxxi1 p4 #bag1 #ahhe47 ,mller1 ,fritz1 and ,dr4 ,h4 ,a4 ,hagen4 ,the color and pattern of insects4 7,kosmos1 xiii1 #ahhf1 pp4 #dff-dfi47 ,slater1 ,j4 ,w4 ,on the presence of tannin in insects and its influence on their colors4 7,trans4 ,ent4 ,soc4 ,london1 #ahhg1 iii1 ,proceed41 pp4 #cb-cd47 ,bemmelen1 ,j4 ,f4 van4 ,ueber die ,entwicklung der ,farben und ,adern auf den ,schmetterlingsflgeln4 7,tijdschrift der nederland4 ,dierkundige ,vereeniging1 ser4 #b1 pp4 #bce-bdg1 #ahhi47 ,hopkins1 ,f4 ,g4 ,uric acid derivatives functioning as pigments in butterflies4 7,proc4 ,chem4 ,soc4 ,london1 #ahhi1 p4 #aag2 also ,nature1 xl1 p4 #cce47 ---- ,pigment in yellow butterflies4 7,nature1 xlv1 p4 #aig1 #ahia47 ---- ,the pigments of the ,pierid4 7,proc4 ,roy4 ,soc4 ,london1 lvii1 ,no4 #cdj1 pp4 #e1 #f1 #ahid4 ,phil4 ,trans4 ,roy4 ,soc4 ,london1 clxxxvi1 pp4 #ffa-fhb1 #ahif47 ,coste1 ,f4 ,h4 ,p4 ,contributions to the chemistry of insect colors4 7,the ,entomologist1 xxiii1 #ahij2 xxiv1 #ahia1 pp4 #i-ae1 etc4 ,nature1 xlv41 pp4 #eac-eag1 #eda-edb1 #fje47 ,urech1 ,f4 ,beobachtungen ber die verschiedenen ,schuppenfarben und die zeitliche ,succession ihres ,auftretens4 7,zool4 ,anzeiger1 xiv1 pp4 #dff-dgc1 #ahia2 ,ibid41 ,august #a1 #ahib47 ---- ,beitrge zur ,kenntniss der ,farbe von ,insektenschuppen4 7,zeits4 f4 ,wissens4 ,zool41 lvii1 pp4 #cjf-chd1 #ahic47 ,griffiths1 ,a4 ,b4 ,recherches sur les couleurs de quelques insectes4 7,c4 ,r4 ,acad4 ,sc4 ,paris1 cxv1 pp4 #ieh1 #iei47 ,mayer1 ,alfred ,goldsborough4 ,on the color and color-patterns of moths and butterflies4 7,proc4 ,bost4 ,soc4 ,nat4 ,hist41 xxvii41 ,march1 #ahig1 pp4 #bdc-ccj1 #aj ,pls4 ,see also p4 #bja under ,mayer47 ,also the writings of ,bates1 ,beddard1 ,belt1 ,butler1 ,darwin1 ,dimmock1 ,dixey1 ,eimer1 ,haase1 ,higgins1 ,mller1 ,poulton1 ,seitz1 ,wallace1 ,weismann4 #b4 ,,internal ,,anatomy ,,the ,,muscular ,,system ,in its general arrangement the muscular system of insects corresponds to the segmented structure of the body4 ,of the muscles belonging to a single segment1 some extend from the front edge of one segment to that of the next behind it1 and others to the hinder edge2 there are also sets of dorsal and ventral muscles passing in an oblique or vertical course 7,figs4 #af-ah74 ,as ,lang observes1 8the greater part of the muscles of the body can be traced back to a paired system of dorsal and ventral intersegmental longitudinal muscles40 ,the muscular system is simplest in larval insects1 such as caterpillars1 where the musculature is serially repeated in each segment4 ,in the larva of ,cossus ,lyonet found on one side of the body #bag dorsal1 #aed lateral1 #cfi ventral1 and in the thoracic legs #fc1 or #hjc muscles in all4 8,adding to this number the #ab small muscles of the second segment1 and #h others of the third1 which he did not describe1 there would be for all the muscles on one side of the caterpillar #hbc4 ,this would make for the entire body #afdf1 without counting a small single muscle which occurs in the subdivision of the last segment10 and also those of the internal organs as well as those of the head1 so that the total number probably amounts to about #bjjj1 not #cjjj1 as usually stated in the books4 ,lubbock admits that ,lyonet was right in his mode of estimating the number4 ,in the larva of ,pygrci bucephala he found that 8the large muscles scarcely vary at all10 though certain smaller ones are very variable4 ,lubbock observed that certain of the longitudinal muscles in the caterpillar of ,diloba split up into numerous1 not less than ten1 separate fascicles4 8,this separation of the fibres composing a muscle into separate fascicles is carried on to a much greater extent in the larv of ,coleoptera4 ,of course in the imago the number of thoracic muscles is greatly increased1 or at least in ,dyticus and the wood-feeding ,lamellicorns1 which alone ,i have examined4 ,in these two groups each of the larger muscles is represented by at least twenty separate fascicles1 which makes it far more difficult to distinguish the arrangement of the muscles40 ,the muscles are whitish or colorless and transparent1 those in the thorax being yellowish or pale brown2 and of a soft1 almost gelatinous consistence4 ,in form they are simply flat and thin1 straight1 band-like1 or in rare cases pyramidal1 barrel or feather shaped4 ,they act variously as rotators1 elevators1 depressors1 retractors1 protractors1 flexors1 and extensors4 ,illustration3 ,,fig4 #bca4--;,diagram of the muscles and nerves of the ventral surface of the segments in the larva of ,sphinx ligustri3 ,a1 ,a1 recti muscles2 #a1 #b1 ventral recti muscles 7#a1 recti majores2 #b1 recti minores72 #c1 ridge giving origin to recti muscles of one segment1 and insertion to the same of the adjoining segment2 #d1 ridge for attachment of muscle2 #e1 retractor ventriculi1 connecting the mid-intestine with the outer integument of the body4 ,b1 #f1 first oblique1--#g1 second oblique1--#i1 #aj1 third oblique1 muscles2 #aa1 fourth oblique1--#ab4 third rectus1--#ac1 fifth oblique1--#ad1 triangularis1 muscle2 #ae1 transversus medius2 #af1 transverse ridge2 #ag1 transversi abdominales2 #ah1 abdominales anteriores2 #ai1 #bj1 abdominales laterales1 some 7#bj7 longer than others2 #ba1 obliquus posterior2 #bb1 postero-laterales obliqui2 #bc1 transversus lateralis2 #bd1 second transversus lateralis2 #be1 retractor spiraculi1 or constrictor of the spiracles1 attached by a long tendon 7#bf72 #bg1 retractor valvul4 ,nerves3 a1 ganglion1--c1 transverse nerves1 of which p is the first1 q the second1 r the third1 and s the fourth branch2 t1 the main trunk1 which crosses the great longitudinal trachea1 receives a filament from the transverse nerve 7n71 and divides into two branches 7t72--some of these branches form a small plexus 7u72 the nerve t divides in two divisions 7p and v74 ,the second division ends in w and x2 the branch q divides into y and z4 ,for other explanations1 see ,newport1 art4 ,insecta4--,after ,newport4 ,illustration3 ,,fig4 #bcb4--,musculature of the ,european cockchafer1 ,melolontha vulgaris3 a1 a1 levatores capitis2 b1 depressores capitis2 c1 rotatores capitis2 d1 depressors externi2 e1 retractor or flexor of the jugular plate2 f1 oblique extensor of the jugular plate2 g1 the other retractor of the jugular plate2 h1 retractor prothoracis superior2 i1 inferior retractor1 the proper depressor of the prothorax2 k1 elevator prothoracis2 l1 one of the rotatores prothoracis2 m1 n1 o1 flexors of the coxa2 x1 great depressor muscle of the wing2 y1 y1 elevators and protractors attached to the metaphragma and base of the postfurca2 z1 second flexor of hind leg2 a1 a1 extensors of hind leg2 c1 c1 dorsal recti of abdomen4 ,q1 ejaculatory duct2 ,r1 penis2 ,s1 its prepuce4 ,m1 rectum4--,after ,straus-,durckheim1 from ,newport4 ,our knowledge of the muscular system of insects is still very imperfect4 ,to work it out thoroughly one should begin first with that of ,scolopendrella1 then some generalized synapterous form1 as ,japyx or ,lepisma1 then passing to that of a caterpillar1 and ending with some of the more highly specialized forms1 such as a beetle1 etc4 ,thus far our knowledge is confined to that of the caterpillars 7,lyonet1 ,newport1 and ,lubbock7 and the beetle 7,straus-,durckheim7 and ants 7,forel1 ,lubbock1 and ,janet74 ,musculature of a caterpillar4--,newport's account of that of the larva of ,sphinx ligustri is the most useful 7,fig4 #bca74 ,the muscles here present1 he says1 great uniformity of size and distribution in every segment1 the motions of each of these divisions of the body being almost precisely similar1 especially in the #dth to #ith trunk segments4 ,in these segments the first layer seen on removing the fat and viscera are the flat straight recti muscles4 ,they are the most powerful of all the trunk muscles1 and are those which are most concerned in shortening the body1 in effecting the duplicature of the external teguments during the changes of the insect1 and which during the larval state mainly assist in locomotion4 ,there are four sets1 two dorsal and two ventral 7,fig4 #bca1 ,a1 ,a74 ,without entering into farther details1 the reader is referred to the works of ,newport and to ,fig4 #bca4 ,musculature of a beetle4--,the best general account of the musculature of a perfect insect is that of ,straus-,durckheim in his famous work on the ,melolontha4 ,we will copy the summary of ,newport1 who adopted the nomenclature applied to these parts by ,burmeister3-- 8,the muscles that connect the head with the thorax are contained within the prothorax 7,fig4 #bcb1 #b71 and are of three kinds1 extensors1 flexors1 and retractors4 ,the extensors1 levatores capitis 7a1 a71 consist of two pairs1 one of which arises from the middle line of the pronotum1 and diverging laterally from its fellow of the opposite side1 passes directly forwards1 and is inserted by a narrow tendon into the anterior superior margin of the occipital foramen4 ,the other arises further back from the prophragma4 ,it is a long1 narrow muscle that passes directly forwards through the prothorax1 and is inserted by a tendon near the superior median line of the foramen2 so that1 while this muscle and its fellow of the opposite side elevate the head almost in a straight line1 the one first described1 when acting alone or singly1 draws the head a little on one side2 but when the whole of these muscles act in unison1 they simply elevate the head upon the prothorax4 ,the depressors or flexors1 depressores capitis 7b71 are exceedingly short muscles1 which arise from the jugular plate1 or1 when that part does not exist1 from the border of the prosternum1 and are attached to the inferior margin of the occipital foramen4 ,they simply flex the head on the prothorax4 ,the lateral flexors1 depressores externi 7d71 are two little muscles that arise from the same point as the preceding1 and are attached to the lateral inferior margin of the occipital foramen4 ,the rotatory muscles1 rotatores capitis 7c71 are two flat muscles like the elevators1 which arise1 one at the side of the antefurca and the other from the posterior jugular plate1 and passing upwards and outwards are attached to the lateral margin of the occipital foramen4 ,the retractor or flexor of the jugular plate is a small muscle 7e7 that arises from the margin of the antefurca1 and passing directly forwards is inserted by a small tendon into the middle of the jugular piece4 ,the oblique extensor of the jugular plate is a long1 slender muscle 7f7 that arises from the external margin of the pronotum1 and passing obliquely downwards and forwards traverses the prothorax and is inserted by a narrow tendon to the jugular plate immediately before the retractor4 ,the other retractor 7g7 arises from the anterior superior boundary of the pronotum1 and passing downwards is inserted into the jugular plate between the larger levator and flexor capitis4 8,the muscles proper to the prothorax consist of four pairs1 by which it is united to the succeeding segments4 ,the first of these1 the superior retractor1 retractor prothoracis superior 7h71 arises by a broad1 fleshy head from the anterior external margin of the pronotum1 and passing directly backwards is inserted by a tendon into the prophragma1 a little on one side of the median line4 ,the next muscle of importance1 the inferior retractor 7i71 arises from the anterior border of the medifurca1 and is united to the posterior of the antefurca1 thus forming with that muscle part of the great recti of the larva4 ,this muscle must be considered as the proper depressor of the prothorax4 ,the elevator prothoracis 7k7 is narrow1 pyramidal1 and arises fleshy from the lateral surface of the prophragma4 ,it passes downwards and is attached by a narrow tendon to the superior portion of the antefurca4 ,the rotatores prothoracis are the largest of all the muscles of this segment4 ,they arise1 one on each side 7l71 by a narrow head from the posterior part of the pronotum1 and passing beneath the prophragma are considerably enlarged and attached to the tegument between the two segments1 and also to the anterior portion of the mesothorax4 ,the remaining muscle proper to the prothorax is the closer of the spiracle1 an exceedingly small muscle not shown in the drawing4 8,the other muscles of this segment are those of the legs1 which are of considerable size4 ,there are three distinct flexors of the coxa 7m1 n1 o74 ,the first of these arises from the superior lateral border of the pronotum1 the second from the superior posterior border1 the third from the sides of the prothorax1 and the fourth a little nearer posteriorly1 and the whole of them are attached by narrow tendons to the sides of the coxa4 ,but there is only one extensor muscle to this part4 ,in like manner1 the extensor of the trochanter is formed of three portions 7,fig4 #bcc1 a1 b1 c72 but there is only one flexor 7d71 and one abductor 7e74 ,in the femur1 there is one extensor 7f71--a long penniform muscle that occupies the superior part of the thigh1 and is attached by a tendon to the anterior-posterior margin of the joint formed by the end of the tibia4 ,there is also but one flexor 7g7 in the femur1 which1 like the preceding muscle1 is penniform1 and occupies the inferior portion of the femur1 and its tendon is attached to the inferior border of the tibia4 ,in the tibia itself there is also one flexor and one extensor4 ,the flexor 7i7 occupies the superior portion of the limb1 and ends in a long tendon 7l7 that passes directly through the joints of the tarsus1 on their inferior surface1 and is attached to the inferior margin of the claw 7g74 ,the extensor 7h7 occupies the inferior portion of the tibia1 and is shorter than the preceding muscle1 like which it ends in a long tendon that is attached to the upper margin of the claw4 ,besides these muscles1 which are common to the joints of the tarsus1 there are two others belonging to the claw1 situated in the last joint4 ,the first of these1 the extensor 7m71 is short1 and occupies the superior portion of the last phalanx of the tarsus1 and the other1 the flexor 7n71 is a much longer penniform muscle1 which occupies nearly the whole of the upper and under surface of the posterior part of the phalanx1 and is attached1 like the long flexor of the tarsus1 to the inferior part of the claw40 ,illustration3 ,,fig4 #bcc4--,muscles of the fore leg of ,melolontha vulgaris3 a1 b1 c1 three divisions of the extensor of the trochanter2 d1 flexor1--e1 abductor1 of the trochanter2 f1 extensor of the femur2 g1 flexor of the femur2 h1 extensor of the tibia2 i1 flexor of the tibia2 l1 tendon attached to the lower edge of the claw 7g72 m1 extensor1--n1 flexor1 of the claw4--,after ,straus-,durckheim1 from ,newport4 ,these are the muscles of the prothorax1 and its organs of locomotion4 ,the reader is referred for a further account of the muscles of the hinder thoracic and of the abdominal segments to ,straus-,durckheim's original work4 ,minute structure of the muscles4--,the muscular fibres of insects are striated 7,figs4 #bce-bch71 even those of the alimentary canal2 the only notable exception being the alary muscles of the pericardial septum1 while ,lowne states that certain of the thoracic muscles of the blow-fly are not striated 7,miall and ,denny74 ,illustration3 ,,fig4 #bcd4-,section through the prothorax of ,diapheromera femoratum3 prov1 proventriculus2 tr1 trachea2 n4 c1 nervous cord2 s4 gl1 salivary gland2 hyp1 hypodermis2 ur4 t1 urinary tube2 ht1 heart2 m1 m1 m1 muscles for lowering and raising the tergum2 m1 another muscle1 its use unknown4 ,illustration3 ,,fig4 #bce4--,striated muscular fibre of ,hydrophilus3 ,a and ,b1 two fibrill in a state of extension2 a1 thick disk2 b1 thin disk2 c1 intermediate space4 ,c1 ,d1 portion of the same fibrill seen by moving the objective farther away and using a small diaphragm2 n1 thick2 c1 thin disk4 #bjjj diam4--,after ,ranvier1 from ,perrier4 ,e after ,gehuchten1 from ,lang4 ,in describing the minute structure of the muscles of ants1 wasps1 and bees1 ,c4 ,janet states that each consists of a group of fibres diverging from a tendon1 which is an integumentary invagination 7,fig4 #bcf74 ,each fibre may be regarded as a multinucleate cell2 the sarcolemma represents the cell-membrane4 ,it forms a resistant and extremely elastic tube4 ,the longitudinal 7,fig4 #bcf1 ,e7 and radiating filaments or reticulum 7spongioplasm of ,gehuchten7 lie in a nutritive filling substance 7the hyaloplasm of ,gehuchten74 ,the radiating filaments are formed of an exceedingly elastic substance1 and serve to sustain the longitudinal filaments1 to transmit the nervous stimulus to them1 and to bring them back into position after contraction4 ,janet's account agrees on the whole with that of ,gehuchten4 ,illustration3 ,,fig4 #bcf4--,preparations from the adductor muscle of the mandible of ,vespa crabro1 worker1 fixed by heat and alcohol several hours after leaving its cell4 ,a to ,e #dbe2 ,f #bab3 ,a1 terminal cupule of the tendon of a fibre4 ,b1 ,c1 union of the fibres with their tendon4 ,d1 branch of the tendon of a muscle sending out tendons of some of the fibres2 this branch is accompanied with numerous nervous ramifications 7,n74 ,e1 fragment of a nerve which furnishes the ramifications of ,fig4 ,d4 ,f1 fragment of the tendon of the adductor muscle of the mandible2 at the left are seen the terminal cupules of the fibres 7td1 c72 on the right1 on the body of the tendons1 some sessile cupules1 each of which forms the attachment of a fibre2 td1 b1 tendons of the fibres4--,after ,janet4 ,the muscles of flight are said to be penetrated by fine tracheal branches1 probably to supply a greater amount of oxygen1 as the most energetic movements of the insect are made in moving the wings during flight2 while the other muscles of the body are only surrounded by the air-tubes4 7,sharp47 ,without entering into tedious details1 the reader is referred to figures or references to the more important systems of muscles1 such as those of the legs and other appendages1 of the wings1 of respiration1 etc41 to the sections treating of those organs or functions2 also to ,figs4 #af1 #ag1 #ah1 #bb1 #dh1 #gd1 #ha1 #hc1 #hd1 #aae1 #aaf1 #agb1 #agc1 #agd1 etc4 ,muscular power of insects4--,the most detailed and careful experiments are those of ,plateau4 ,his experiments prove that even the weakest insects pull at least five times their own weight2 many of them1 however1 get the better of a burden twelve to twenty fold as heavy as themselves1 while a strong man or a draught horse1 for example1 is not even able to pull a burden which is equal to the weight of his body4 ,plateau came to the following results as to the relation of the weight of the body to the load drawn 7#a and #b are to be compared with each other1 #a being the larger1 and #b the smaller insect2 it will be seen that the smaller insect is the stronger74 ,illustration3 ,,fig4 #bcg4--,vespa crabro1 worker1 fixed by heat and alcohol some hours after leaving its cell4 ,a #dbe2 ,b to ,d #hej times3 ,a1 muscular fibre of the motor muscles of the mandibles treated1 for ten minutes1 by #a per cent potassium to bring out the reticulum2 the nodes of union of the rayed filaments with the longitudinal filaments are indicated by distinct granulations 7l4d71 and these longitudinal filaments present accessory thickenings 7d4a72 ,t1 trachea2 ,n1 junction of a nervous filament with the muscular fibres4 ,b1 fibre of the same muscle1 not treated with potassium1 stained by hmatoxylin2 ,c1 transverse section of a disk at the level of a layer of rayed filaments2 ,sarc1 sarcolemma4 ,d1 transverse section of a disk at the level of the rods2 nuc1 nucleus4--,after ,janet4 #a4 ,carabus auratus #ag4d4 #b4 ,nebria brevicollis #be4c4 #a4 ,cetonia aurata #ae4 #b4 ,trichius fasciatus #da4c4 #a4 ,melolontha vulgaris #ad4c4 #b4 ,anomala frischii #bd4c4 #a4 ,oryctes nasicornis #d4g4 #b4 ,geotrupes stercorarius #i4h4 #c4 ,onthophagus nuchicornis #ad4d4 #a4 ,necrophorus vespillo #ae4a4 #b4 ,silpha livida #bd4d4 #a4 ,ocypus morio #ag4 #b4 ,quedeus fulgidus #bi4f4 #a4 ,donacia nymph1 #db4g4 #b4 ,crioceris merdigera #ci4b4 #a4 ,bombus terrestris #af4a4 #b4 ,bombus rupestris #ad4e4 #c4 ,apis mellifica #bj4b4 ,as regards the pushing power1 the relation of the load to the size of the body in different large beetles1 gave the following figures3-- ,oryctes nasicornis #c4b4 ,geotrupes stercorarius #bh4d4 ,onthophagus nuchicornis #ib4i4 ,the leaping force of locusts was found by ,straus-,drckheim to be in dipoda grossa as #a4f1 in 4 parallela as #c4c of their weight4 ,illustration3 ,,fig4 #bch4--,vespa crabro1 fixed and stained as in the subjects of the other figures4 ,i1 ,n1 ,p #agjj2 ,h1 ,j1 ,m #hej2 the others #dbe times3 ,a-,c1 motor muscles of the antennal scape4 ,d-,p1 motor muscles of the #c;d coxa4 ,a1 ,b1 the two ends1 in very different states of contraction1 of the same fibre2 on one side the transverse stri are near together1 on the other very far apart4 ,c1 a crushed and split fibre showing a fibrous appearance1 owing to the rupture of the radiated filaments1 and the separation of the longitudinal filaments4 ,d1 muscular disk seen in section1 with two rows of nuclei4 ,e1 a muscular fibre with three rows of nuclei4 ,f1 a nucleus1 accompanied with coagulated protoplasm1 oozing from a previous break of the muscular fibre4 ,g1 nerve-terminations very near each other on the same muscular fibre4 ,h1 longitudinal filaments1 evenly covered with the coagulated substance1 and forming1 throughout the mass of the fibre1 continuous filaments4 ,i1 filaments widely separated4 ,j1 longitudinal filaments showing the beginning of one of the transverse breaks which isolate some of the disks4 ,k1 oblique view of a disk obtained by such a break1 and of a fibre in circular section1 with an axial row of nuclei2 this piece comprises three stages of radiated filaments4 ,l1 muscular fibre with a row of nuclei2 at the lower part1 the nuclei have issued from a longitudinal fissure in the fibre1 and have remained attached in a chain4 ,m1 edge of fibre in which there is quite a large1 clear space between the sarcolemma and the rods4 ,n1 passage of the trachea1 with the spiral thread1 into three capillaries with a smooth cuticula4 ,o1 elliptical disk from a fibre1 with two rows of nuclei1 and showing a layer of radiated filaments4 ,p1 fragment 7highly magnified7 of the edge of a disk seen in section4--,after ,janet4 ,a humble bee 7,bombus terrestris7 can carry while flying a load #j4fc of its own weight1 and a honey bee #j4gh2 here1 as usual1 the smaller insect is the stronger4#ci ,,literature ,,on ,,the ,,muscles a4 ,general ,lyonet1 ,p4 ,trait anatomique de la chenille4 ,la ,haye1 #agfb4 ,cornalia1 ,e4 ,monographia del ,bombyce del gelso4 7,mem4 ,r4 ,instituto ,lombardo ,sc4 ,lett4 ed ,arte1 #ahef47 ,basch1 ,s4 ,skelett und ,muskeln des ,kopfes von ,termes4 7,zeitschr4 f4 wissens4 ,zool41 xv1 #ahfe1 pp4 #ee-ge1 #a ,taf47 ,lubbock1 ,john4 ,arrangement of the cutaneous muscles of the larva of ,pygra bucephala4 ,london1 #aheh4 #b ,pls4 ---- ,on some points in the anatomy of ants4 7,month4 ,micr4 ,journ41 xviii1 pp4 #aba-adb1 #ahgg1 #d ,pls47 ---- ,on the anatomy of ants4 7,trans4 ,linn4 ,soc41 ,ser4 #b2 ,zool41 ii1 #ahgi1 pp4 #ada-aed1 #b ,pls47 ,poletajeff1 ,n4 ,du dveloppement des muscles d'ailes chez les ,odonates4 7,hor ,soc4 ,ent4 ,ross41 xvi1 #ahgi1 pp4 #aj-cg1 #e ,pls47 ---- ,die ,flugmuskeln der ,lepidopteren und ,libelluliden4 7,zool4 ,anzeiger1 #ahhj1 pp4 #bab1 #bac47 ---- ,ueber die ,flugmuskeln der ,rhopaloceren4 7,arbeiten d4 ,russ4 ,ent4 ,ges41 #ahha1 xiii1 p4 #i1 #a ,taf41 in ,russian47 ,lendenfeld1 ,r4 von4 ,der ,flug der ,libellen4 7,sitzb4 k4 ,akad4 ,wissens41 #a ,abth4 ,wien1 #ahha1 lxxxiii1 pp4 #bhi-cgf1 #g ,taf47 ,luks1 ,constantine4 ,ueber die ,brustmuskulature der ,insekten4 7,jena4 ,zeitschr4 f4 ,naturwissen41 xvi1 ,n4 ,folge ,,ix1 #ahhc1 pp4 #ebj-eeb1 #b ,taf47 ,carlet1 ,g4 ,sur les muscles de l'abdomen de l'abeille4 7,comptes rend41 #ahhd1 xcviii1 pp4 #geh1 #gei47 ,janet1 ,charles4 ,sur les muscles des fourmis1 des gupes et des abeilles4 7,comptes rend41 cxxi1 p4 #faj1 #a ,fig41 #ahie47 ,also the writings of ,straus-,durckheim1 ,newport1 ,graber1 ,burgess1 ,leydig1 ,dahl1 ,ockler1 ,dogiel1 ,dimmock1 ,kraepelin1 ,becher1 ,langer1 ,kolbe4 b4 ,histology ,aubert1 ,h4 ,ueber die eigenthmliche ,struktur der ,thoraxmuskeln der ,insekten4 7,zeitschr4 f4 wissens4 ,zool41 iv1 #ahec1 pp4 #chh-cii1 #a ,taf47 ,verson1 ,e4 ,zur ,insertionsweise der ,muskeln4 7,sitzsb4 ,akad4 d4 wiss4 math4 naturw4 ,cl4 ,wien41 lvii1 #a ,abth41 pp4 #fc-ff1 #ahfh47 ,knckel d',herculais4 ,sur le dveloppement des fibres musculaires stries chez les insectes4 7,compt4 rend4 de l',acad4 ,sc4 ,paris1 lxxv1 #ahgb47 ,grunmach1 ,emil4 ,ueber die ,structur der quergestreiften ,muskelfaser bei den ,insekten4 ,berlin1 #ahgb4 pp4 #dg4 ,fredericq1 ,l4 ,note sur la contraction des muscles stris de l',hydrophile4 7,bull4 ,acad4 ,roy4 ,belgique1 xli1 p4 #ehc1 #b ,pls47 ,gehuchten1 ,a4 van4 tude sur la structure intime de la cellule musculaire strie4 7,la ,cellule1 ii1 pp4 #bhi1 #bic-dec1 #ahhf1 #f ,pls47 ,janet1 ,charles4 tudes sur les fourmis1 les gupes et les abeilles4 #ab;e note4 7,structure des membranes articulaires des tendons et des muscles1 ,limoges1 #ahie1 pp4 #be1 #aa ,figs47 ,also the writings of ,burmeister1 ,chabrier1 ,leydig1 ,meckel1 ,lebert1 ,wagner1 ,wagener1 ,amici1 ,krause1 ,heppner1 ,retzius1 ,rollet1 ,g4 ,elias ,mller1 ,f4 ,merkel1 ,hensen1 ,klliker1 ,dogiel1 ,dnitz1 ,hagen1 ,vosseler1 ,btschli u4 ,schewiakoff1 ,lowne1 ,ciaccio1 ,biedermann1 ,cohnbeim1 ,brcke1 ,haycraft1 ,melland1 ,bowman4 c4 ,muscular power of insects ,plateau1 ,flix4 ,sur la force musculaire des insectes4 7,bull4 ,acad4 ,roy4 ,belgique1 #b ,sr4 xx1 #ahfe1 pp4 #gcb-geg2 xxii1 #ahff1 pp4 #bhc-cjh47 ---- ,recherches sur la force absolue des muscles des invertbrs4 #ahhd4 ,radan1 ,r4 ,la force musculaire des insectes4 7,revue de deux mondes1 #b ,sr41 lxiv1 #ahff1 pp4 #ggj-ggg47 ,bibiakoff1 ,paul von4 ,zur ,muskelkraft der ,insekten4 7,natur1 xvii1 #ahfh1 p4 #cii47 ,delbuf4 ,nains et gants1 tude comparative de la force des petits et des grands animaux4 ,bruxelles4 7,also in ,kosmos1 xiii1 #ahhc1 pp4 #eh-fb47 ,camerano4 ,mem4 ,acc4 ,torino 7#b71 xliii1 #ahic1 p4 #bbi4 ,also ,newport1 ,art4 ,insecta1 p4 #gf4 ,kirby and ,spence1 ,burmeister1 ,graber1 ,kolbe1 pp4 #cge1 #cgf4 ,,the ,,nervous ,,system a4 ,the nervous system as a whole ,illustration3 ,,fig4 #bci4--;,central nervous system of ,machilis maritima3 au1 eye2 lo1 optic tract2 g1 brain2 an1 antennal nerve2 oe1 sophagus passing between the sophageal commissures2 usg1 infrasophageal ganglion2 ,i-,,iii1 thoracic ganglia2 #a-h1 abdominal ganglia1 the last 7,sabc7 consisting of three fused ganglia2 s1 sympathetic nervous system of the ventral cord4--,after ,oudemans1 from ,lang4 ,the nervous system of insects consists of a double series or chain of ganglia connected by nervous cords or commissures4 ,the first of these is the brain or suprasophageal ganglion2 it is situated in the upper part of the head1 above the gullet or sophagus1 while the rest of the system1 called the ventral cord1 lies on the floor of the body1 under the digestive canal4 ,a ganglion or nerve-centre consists of a mass of ganglion-cells1 from each of which a process or fibre passes off1 uniting with others to form a nerve2 by means of these nerves the ganglia are connected with other ganglia1 and with the sensory cells and muscle-fibres4 ,the ganglia may be simple1 and arranged in pairs1 corresponding to each segment of the body1 or they may be compound1 the result of the fusion of several pairs of ganglia1 which in the early stages of the embryo are separate4 ,thus the brain of insects is a compound ganglion1 or ganglionic mass4 ,the nerves are of two kinds3 #a4 ,sensory1 which transmit sensations from the peripheral sense-cells to the ganglion1 or brain2 #b4 ,motor1 which send stimuli from the brain or any other ganglion to the muscles4 ,of ganglion cells1 some are tactile1 and others give rise to nerves of special sense1 being distributed to the eyes1 or to the organs of hearing1 smell1 taste1 or touch4 ,illustration3 ,,fig4 #bdj4--,nervous system of ,melanoplus spretus3 sp1 suprasophageal ganglion1 sending off the large optic nerve 7op7 to the eyes1 and an ocellar nerve to each ocellus 7the dotted line oc stops short of the left ocellus72 if1 infrasophageal ganglion2 #a1 #b1 #c1 thoracic ganglia2 #a-e1 five abdominal ganglia 7the fifth the largest1 and sending branches to the ovipositor1 etc47 ,the sympathetic nerve and ganglia are represented by the two main nerves which arise from the medio-cephalic 7as7 resting on and above the sophagus1 and two ganglia 7ps7 on the under side of the crop4 ,from each of these ganglia1 two nerves are sent under the crop1 and a larger nerve on each side to as far as the stomachal cca1 ending the figure at the dotted line #b1 near the second thoracic ganglion4 u1 a round1 shining body1 connected by a nerve with the medio-cephalic ganglion1 its nature unknown4 ,illustration3 ,,fig4 #bda4--,section through the head of ,machilis1 showing the brain 7br71 and subsophageal ganglion 7soe4 g72 cl1 clypeus2 lbr1 labrum2 oc1 ocellus4 ,while the suprasophageal ganglion1 or 8brain10 of the insect is much more complex than any other ganglion1 consisting more exclusively both of sensory as well as motor ganglia and their nerves1 it should be borne in mind that the subsophageal ganglion also receives nerves of special sense1 situated on the palpi and on the tongue1 as in the bee and other insects2 hence this ganglion is probably complex1 consisting of sensory and motor cells4 ,the third thoracic ganglion is also1 without doubt1 a complex one1 as in the locusts the auditory nerves pass into it from the ears1 which are situated at the base of the abdomen1 while in the green grasshoppers1 such as the katydids and their allies1 whose ears are situated in their fore legs1 the first thoracic ganglion is a complex one4 ,in the cockroach and in ,leptis 7,chrysopila71 a common fly1 the caudal appendages bear what are probably olfactory organs1 and as these parts are undoubtedly supplied from the last abdominal ganglion1 this is probably composed of sensory and motor ganglia2 so that we have in the ganglionated cord of insects a series of brains1 as it were1 running from head to tail1 and thus in a still stronger sense than in vertebrates the entire nervous system1 and not the brain alone1 is the organ of the mind of insects4 ,the simplest1 most primitive form of the nervous system of insects is seen in that of the ,thysanura4 ,that of ,campodea has not yet been fully examined1 but in that of the more complicated genus1 ,machilis 7,fig4 #bci71 we see that there is a pair of ganglia to nearly each segment1 while the brain 7,fig4 #bda7 is composed of three lobes1 viz4 the optic1 the cerebral 7,fig4 #bci1 g71 behind which is the antennal lobe1 from which the antennal nerve takes its origin4 ,behind the opening for the throat 7oe7 is situated the first ganglion of the ventral cord1 the subsophageal ganglion1 which gives rise to the nerves supplying the jaws and other mouth-parts4 ,illustration3 ,,fig4 #bdb1 ,a-,d4--,the nervous systems of #d genera of ,diptera1 to demonstrate their various degrees of fusion of ganglia3 ,a1 non-concentrated more primitive nervous system of ,chironomus plumosus1 with #c thoracic and #f abdominal ganglionic masses4 ,b1 nervous system of ,empis stercorea1 with #b thoracic and #e abdominal ganglionic masses4 ,c1 nervous system of ,tabanus bovinus1 with #a thoracic ganglionic mass1 and the abdominal ganglia closely approximated4 ,d1 highly modified nervous system of ,sarcophaga carnaria1 in which all the ganglia of the ventral cord behind the subsophageal ganglion are fused into a single ganglionic mass4--,after ,brandt1 from ,lang4 ,in the ,collembola1 which are retrograde ,thysanura1 there are from one 7,smynthurus71 to three or four ventral ganglia4 ,in the winged insects1 where the ganglia are more or less fused1 the fusion taking place in the head and at the end of the abdomen2 there are in the more simple and generalized forms1 such as ,ephemera1 the grasshopper1 locusts 7,fig4 #bdj71 etc41 thirteen ganglia besides the two pairs of compound ganglia in the head1 three pairs of thoracic ganglia1 and usually from five to eight pairs of ganglia in the abdomen4 ,illustration3 ,,fig4 #bdc4--,nervous system of the ,may beetle1 ,lachnosterna fusca3 w#a1 nerve to #ast1--w#b1 nerve to #b;d1 pair of wings2 ig1 infrasophageal ganglion4 ,illustration3 ,,fig4 #bdd4--,the same of the stag-beetle1 ,lucanus dama1 where there are #c thoracic1 and #c separate abdominal ganglia4 ,in certain winged insects the process of fusion or degeneration is carried to such an extreme that there are either no abdominal ganglia 7,fig4 #bdb1 ,d71 or their vestiges are situated in the thorax and partially fused with the thoracic ones1 as in the ,may beetle1 in which the prothoracic pair of ganglia is separate1 while the two other thoracic ganglia are fused with the abdominal1 the latter being situated in the thorax2 this fusion is carried to a further extent than in any other ,coleoptera yet examined4 ,in many ,diptera and ,hemiptera the abdominal ganglia are either absent or the vestiges are fused with the thoracic ganglia4 ,rhizotrogus1 which is allied to our ,may beetle1 as also ,hydrometra and the ,stylopid are said to lack the subsophageal ganglion 7,brandt74 ,in numerous ,coleoptera 7,acilius1 ,gyrinus1 ,necrophorus1 ,melolontha1 ,bostrichus1 ,rhynchnus72 in many ,diptera 7,culex1 ,tipula1 ,asilus1 ,xylophaga1 and ,phora72 and in the higher ,hymenoptera 7,crabronid1 ,vespid1 and ,apid71 as well as in many ,lepidoptera 7,vanessa1 ,argynnis1 and ,pontia71 two of the thoracic ganglia are fused together1 while all three are partially fused into a single mass in many brachycerous ,diptera 7,conops1 ,syrphus1 ,pangonia1 and the ,muscid72 in certain ,hemiptera 7,pentatoma1 ,nepa1 and ,acanthia72 also in a beetle 7,serica brunnea74 ,sometimes the subsophageal ganglion is fused with the first thoracic1 as in ,acanthia1 ,nepa1 and ,notonecta4 ,the greatest amount of variation is seen in the number of abdominal ganglia1 all being fused into a single one or from one to eight4 ,the fusion is usually greatest where the abdomen is shortened1 due to the partial atrophy and modification of the terminal segments which bear the ovipositor1 where present1 and the genital armature4 ,there is only one pair of abdominal ganglia in ,gyrinus and in certain flies 7,conops1 ,trypeta1 ,ortalis1 and ,phora72 two in ,rhynchnus1 a weevil1 and in the flies1 ,syrphus and ,volucella2 three in ,crabro and ,eucera2 four in ,sargus1 ,stratiomys and in butterflies1 five in the beetle1 ,silpha1 and in the fly1 ,sciara1 and the moth1 ,hepialus4 ,the nervous system in the larv of the metabolous orders is not concentrated1 though in that of the neuropterous ,myrmeleo it has undergone fusion from adaptation to the short compressed form of this insect4 b4 ,the brain ,the brain of insects appears to be nearly1 if not quite1 as complex as that of the lower vertebrates4 ,as in the latter1 the pair of suprasophageal ganglia1 or brain1 is the principal seat of the senses1 the chief organ of the insect's mind4 ,it is composed of a larger number of pairs of primitive ganglia than any of the succeeding nerve-centres1 and is1 structurally1 entirely different from and far more complicated than the other ganglia of the nervous system4 ,it possesses a central body in each hemisphere1 a 8mushroom body10 optic lobes and optic ganglia and olfactory lobe1 with their connecting and commissural nerve-fibres1 and a number of other parts not found in the other ganglia4 ,in the succeeding ganglia the lobes are in general motor2 the fibres composing the sophageal commissures1 and which arise from the sophageal commissural lobes1 extend not only to the subsophageal ganglion1 but pass along through the succeeding ganglia to the last pair of abdominal nerve-centres4#dj ,since1 then1 there is a direct continuity in the fibres forming the two main longitudinal commissures of the nervous cord1 and which originate in the brain1 it seems to follow that the movements of the body are in large part directed or cordinated by the brain4#da ,still1 however1 a second brain1 so to speak1 is found in the third thoracic ganglion of the locust1 which receives the auditory nerves from the ears situated in the base of the abdomen2 or in the first thoracic ganglion of the green grasshoppers 7katydids1 etc471 whose ears are situated in their fore legs2 while even the last pair of abdominal ganglia in the cockroach and mole cricket1 is1 so to speak1 a secondary brain1 since it distributes sensory nerves to the caudal stylets1 which are provided with organs probably olfactory in nature4 ,it is impossible to understand the morphology of the brain unless we examine the mode of origin of the nervous system in the early life of the embryo4 ,the head of an embryo insect consists of six segments1 i4e4 the ocular1 antennal1 premandibular1 mandibular1 and the #ast and #b;d maxillary segments1 so named from the appendages they bear4 ,of these the first three in the larva and adult are preoral1 and the last three are postoral4 ,the antennal segment was probably either postoral in the progenitors of insects1 or the antenn were inserted on the side of the mouth1 the latter finally moving back4#db ,the nervous system in the early embryonic condition1 as shown by ,wheeler 7,fig4 #bde71 at first consists of nineteen pairs of primitive ganglia1 called neuromeres4 ,those of the head1 which later in embryonic life fuse together to form the brain1 are the first three1 corresponding to the protocerebrum1 deutocerebrum1 and tritocerebrum of ,viallanes4 ,the first pair of primitive ganglia1 and which is situated in front of the mouth1 is divided into three lobes4 ,illustration3 ,,fig4 #bde1 ,a-,d4--,diagrams of four consecutive stages in the development of the brain and nerve-chain of the embryo of ,xiphidium3 ,i1 cephalic1--,,ii1 thoracic1--,,iii1 abdominal1 region2 st1 stomodum or primitive mouth2 an1 anus2 e1 optic plate2 pc7og71 #ast protocerebral lobe1 or optic ganglion2 pc#b1 pc#c1 #b;d and #c;d protocerebral lobes2 dc1 deutocerebrum2 tc1 tritocerebrum2 #a-af1 the #af postoral ganglia2 po4 c1 postoral commissure2 fp1 furcal pit2 ac1 anterior1--pc1 posterior1 ganglionic commissure2 ag1 anterior1--pg1 posterior1--cg1 central1--lg1 lateral gangliomeres4--,after ,wheeler4 ,the first or outermost lobe1 according to ,wheeler1 forms the optic ganglion of the larva and imago1 while the second and third lobes4 7pc#b1 pc#c7 ultimately form the bulk of the brain proper1 or the protocerebral lobes4 ,the second 7primitively postoral7 brain-segment or pair of ganglia gives origin to the antenn1 while the third brain1 or premandibular 7intercalary7 segment1 gives origin to a temporary embryonic pair of appendages found in ,anurida and ,campodea 7the premandibular ganglia71 and also to the nerves supplying the labrum4 ,these three pairs of ganglia later on in embryonic life become preoral1 the mouth moving backwards4 ,the three pairs of primitive ganglia1 behind1 i4e4 the mandibular and #ast and #b;d maxillary ganglia1 become fused together to form the subsophageal ganglion1 and which in larval and adult life is postoral4 ,if the tongue 7ligula1 or hypopharynx7 represents a distinct pair of appendages1 then there are seven segments in the head4 ,illustration3 ,,fig4 #bdf4--,section through head of a carabid1 ,anopthalmus telkampfii3 br1 brain2 fg1 frontal ganglion2 soe1 subsophageal ganglion2 co1 commissure2 n4 l1 nerve sending branches to the lingua 7l72 mn1 maxillary nerve2 mx1 #ast maxilla2 mm1 maxillary muscle2 mx #b;d maxilla2 mt1 muscle of mentum2 le1 elevator muscle of the sophagus2 l of the clypeus1 and a third beyond raising the labrum 7lbr72 eph1 epipharynx2 g4 g1 salivary glands above2 g#b1 lingual gland below the sophagus 772 m1 mouth2 pv1 proventriculus2 md1 mandible4 ,the brain1 then1 supplies nerves to the compound and simple eyes1 and to the antenn1 and gives origin to the sympathetic nerves2 it is thus the seat of the senses1 also of the insect's mind1 and cordinates the general movements of the body4 ,illustration3 ,,fig4 #bdg4--,median longitudinal section through the head of ,blatta orientalis4 ,the nervous system of the head is drawn entire4 hyp1 hypopharynx2 os4 oral cavity2 lbr1 upper lip2 gf1 frontal ganglion2 g1 brain2 na1 root of the antennal nerve2 no1 root of the optic nerve2 ga1 anterior1--gp1 posterior ganglion of the paired visceral nervous system2 1 sophagus2 c1 sophageal commissure2 usg1 infrasophageal ganglia2 cc1 longitudinal commissure between this and the first thoracic ganglion2 sg1 common duct of the salivary glands2 lb1 labium 7#b;d maxill72 nr1 recurrent nerve2 d1 nerve uniting the frontal ganglion with the sophageal commissure2 e1 nerve from this commissure to the labrum2 f1 nerve from the infrasophageal ganglion to the mandible1 --g1 to the #ast maxill1 --h1 to the lower lip 7#b;d maxill74--,after ,hofer1 from ,lang4 ,illustration3 ,,fig4 #bdh4--a1 front view of the brain of ,melanoplus femur-rubrum3 opt4 gang1 optic ganglion2 oc1 ocelli and nerves leading to them from the two hemispheres1 each ocellar nerve arising from the region containing the calices2 m4 oc1 median ocellar nerve2 opt4 l1 optic lobe sending off the optic nerve to the optic ganglion2 ant4 l1 antennal or olfactory lobe2 ant4 n1 antennal nerve2 f4 g1 frontal ganglion of sympathetic nerve2 lbr4 n1 nerve to labrum2 x1 cross-nerve or commissure between the two hemispheres2 4 c1 sophageal commissure to subsophageal ganglion4 #b1 side view of the brain and subsophageal ganglion 7lettering of brain as in #a73 s4 g1 stomatogastric or sympathetic nerve2 a4 s4 g1 anterior1 and p4 s4 g1 posterior1 sympathetic ganglia2 g#b1 subsophageal ganglion2 md1 nerve to mandible2 mx1 maxillary nerve2 ln1 labial nerve2 nl1 unknown nerve1--perhaps salivary4 #c1 interior view of the right half of the head1 showing the brain in its natural position3 an1 antenna2 cl1 clypeus2 lbr1 labrum2 m1 mouth-cavity2 md1 mandible2 t1 tongue2 1 sophagus2 c1 crop2 en1 right half of the endocranium or ,x-shaped bone1 through the anterior angle of which the sophagus passes1 while the great mandibular muscles play in the lateral angles4 ,the moon-shaped edge is that made by the knife passing through the centre of the ,x4 #d1 view of brain from above 7letters as before74 #e1 subsophageal ganglion from above3 t4 c1 commissure to the succeeding thoracic ganglion 7other letters as before74 ,fig4 #c is enlarged #h times2 all the rest #be times4--,drawn from original dissections1 by ,mr4 ,edward ,burgess1 for the ,second ,report of the ,u4 ,s4 ,entomological ,commission4 ,the pair of subsophageal ganglia distributes nerves to the mandibles1 to the #ast and #b;d maxill1 and to the salivary glands 7,fig4 #bdh74 ,its general shape and relations to the walls and to the outer organs of the head is seen in ,figs4 #bdg1 #bdh4 ,in all the winged insects 7,pterygota7 its plane is situated more or less at right angles to the horizontal plane of the ventral cord4 ,on the dorsal and anterior sides are situated the ocular lobes1 and below these the antennal lobes4 ,viallanes first1 independently of embryonic data1 divided the brain of adult insects into three regions or segments2 i4e4 the 8protocerebron10 8deutocerebron0 and 8tritocerebron10 which he afterwards found to correspond with the three primitive elements 7neuromeres7 of the brain and with the segments of the head of the embryo4 ,the brain of the locusts 7,melanoplus and dipoda7 being best known will serve as the basis of the following description1 taken mainly from ,viallanes1 with minor changes in the name of the three segments1 and other modifications4 ,i4 ,the optic or procerebral segment is composed of a median portion1 i4e4 two fused procerebral lobes 7median protocerebrum71 and of two lateral masses1 the optic ganglia 7protocerebrum71 and comprises the following regions fused together and forming the median procerebral mass 7,viallanes73-- #a4 ,procerebral lobes4 #b4 ,optic ganglia4 #c4 ,layer of postretinal fibres4 #d4 ,ganglionic plate4 7,periopticon of ,hickson47 #e4 ,external chiasma4 #f4 ,external medullary mass4 7,epiopticon of ,hickson47 #g4 ,internal chiasma4 #h4 ,internal medullary mass4 7,opticon of ,hickson47 #i4 ,optic ganglia and nerves4 #aj4 ,pedunculated or stalked body4 7,mushroom body of ,dujardin47 #aa4 ,bridge of the procerebral lobes4 #ab4 ,central body4 ,illustration3 ,,fig4 #bdi4--;,diagram of an insect's brain3 cc1 central body2 cg1 ganglionic cells2 che1 external1 chi1 internal chiasma2 c1 sophageal commissure2 cp1 mushroom body2 ctc1 tritocerebral commissure2 fpr1 postretinal fibres2 goc1 ocellar ganglion2 goc#a1 sophageal ganglion1 the dotted ring the sophagus2 gv#a1 gc#b1 gv#c1 #ast1 #b;d1 #c;d1 unpaired visceral ganglion2 gvl1 lateral visceral ganglion2 ld1 dorsal lobe of the deutocerebrum2 lg1 ganglionic plate2 lo1 olfactory lobe2 lpc1 protocerebral lobe2 me1 external1 mi1 internal medullary mass2 na1 olfactory or antennal nerve2 nl1 nerve to labrum2 no1 ocular nerve2 nt1 tegumentary nerve2 1 sophagus2 plp1 bridge of the protocerebral lobes2 rvd1 visceral root arising from the deutocerebrum2 rvt1 visceral root arising from the tritocerebrum2 tr1 tritocerebrum2 to1 optic nerve or tract4--,after ,viallanes4 ,optic ganglia4--,each of the two optic ganglia is formed of a series of three ganglionic masses situated between the compound eyes and the median procerebral mass1 i4e4 the ganglionic plate 7,fig4 #bdi1 lg71 the external medullary mass 7me71 and the internal medullary mass 7mi74 ,the postretinal fibres 7fpr7 arising from the facets or single eyes of the compound eye 7ommatidia7 pass into the ganglionic plate 7lg71 which is united within by the chiasmatic fibres 7che1 external chiasma7 of the external medullary mass 7me74 ,the last is attached to the internal medullary mass 7mi7 by fibres 7chi71 some of which are chiasmatic1 and others direct4 ,finally1 the internal medullary mass connects with the median part of the protocerebrum by direct fibres forming the optic nerve or tract 7to74 ,procerebral lobes4--,the median procerebral lobes are fused together on the median line1 forming a single central mass4 ,from each side or lobe arises the mushroom or stalked body4 ,in the middle of the mass is the central body1 and directly in front is the procerebral bridge 7plp74 ,the latter is a band uniting the two halves of the brain4 ,the procerebral lobes also give origin to the nerves to the ocelli 7no74 ,illustration3 ,,fig4 #bej4--,transverse section through the brain of the locust 7dipoda and ,caloptenus73 c1 lower part of the wall of c1 calyx2--st1 stalk of the same2 bpcl1 bridge of the protocerebral lobes2 mo1 nerve of median ocellus2 ch1 transverse fascia of the optico-olfactory chiasma2 fcb1 fibrous region of the central body2 lcb1 tubercle of the central body2 fch1 descending fascia of the optico-olfactory chiasma2 choo1 superior fascia of the optico-olfactory chiasma2 pt1 protocerebral lobes2 ld1 dorsal lobe of the deutocerebrum2 lt1 tritocerebral lobe2 gcld1 gc1 ganglion cells4--,after ,viallanes4 ,the mushroom or stalked bodies4--,these remarkable organs were first discovered by ,dujardin1 who compared them to mushrooms1 and observed that they were more highly developed in ants1 wasps1 and bees than in the lower insects1 and thus inferred that the higher intelligence of these insects was in direct relation to the development of these bodies4 ,we will call them the mushroom bodies4 ,these two bodies consist of a rounded lobular mass 7the trabecula7 of the procerebral lobe1 from which arises a double stalk 7,fig4 #bec71 the larger called the cauliculus1 the smaller the peduncle 7or pedicel72 these support the cap or calyx4 ,the calices of the bee were compared by ,dujardin to a pair of disks on each side of the brain as seen from above1 8each disk being folded together and bent downwards before and behind1 its border being thickened1 and the inner portion radiated40 ,in the locust there are but two divisions of the calyx2 in the cockroach1 ants1 wasps1 and bees1 four4 ,the shape and relation of the mushroom bodies are represented in ,figs4 #beb and #bec4 ,the bodies are connected by commissural fibres1 and are connected with the optic ganglion of the same side1 and with the central body2 while they are connected with the antennal lobes by the optico-olfactory chiasma4 ,illustration3 ,,fig4 #bea4--,sagittal section through the brain of the locust3 l4 oc4 n1 lateral ocellus nerve2 a4 t1 anterior tubercle of the mushroom body2 i4 t1 internal tubercle of the mushroom body2 c4 l1 cerebral lobes2 l4 l1 lateral lobe of the middle protocerebrum2 com1 commissural cord2 c4 mol1 central mass of the olfactory lobe2 ac4 an4 l1 fibres uniting the median lobe of the middle protocerebrum with dorsal lobes of the deutocerebrum2 gc4 trit4 l1 ganglionated cortex of the tritocerebral lobe2 c4 an4 l1 cortex of antennal 7olfactory7 lobe2 lab4 fr1 labrofrontal nerve2 oe4 com1 sophageal commissure2 tr4 com1 transverse commissure of sophageal ring2 other letters as in ,fig4 #bej4--;,after ,viallanes4 ,the stalked bodies are enveloped by the cortical layers of ganglion-cells1 those filling the hollow of the calyx having little or no protoplasm around the nucleus4 ,structure of the mushroom bodies4--,by staining the brain of the honey bee with bichromate of silver1 ,kenyon has worked out the structure of the mushroom bodies1 with their cells4 ,the cup-shaped bodies or calyces are composed of fibrillar substance 7punktsubstanz74 ,each of these cups1 he says1 is 8filled to overflowing with cells having large nuclei and very little cytoplasm40 ,from the under surface of each of these cups there descends into the general fibrillar substance of the brain 8a column of fibrillar substance1 which unites with its fellow of the same side to send a large branch obliquely downward to the median line of the brain1 and an equally large or larger branch straight forwards to the anterior cerebral surface40 ,the cells of the mushroom bodies1 observes ,kenyon1 8stand out in sharp contrast to all other nerve cells known1 though they recall to some extent the cells of ,purkinje in the higher mammals4 ,each of the cells contained within the fibrillar cup sends a nerve-process into the latter1 where it breaks up into a profusely arborescent system of branchlets1 which often appear with fine1 short1 lateral processes1 such as are characteristic of the dendrites of some mammalian nerve-cells40 ,just before entering the fibrillar substance1 a fine branch is given off that travels along the inner surface of the cup along with others of the same nature1 forming a small bundle to the stalk of the mushroom body1 down which it continues until it reaches the origin of the anterior and the inner roots above mentioned4 8,here it branches1 one branch continuing straight on to the end of the anterior root1 while the other passes to the end of the inner root4 ,throughout its whole course the fibre and its two branches are very fine4 ,nearly the whole stalk and nearly the whole of each root is made up of these straight1 parallel fibres coming from the cells within the cup of the mushroom bodies4 ,what other fibres there are enter these bodies from the side1 and branch between the straight fibres very much as the dendrites of the cells of ,purkinje branch among the parallel fine fibres from the cells of the granular layer in the mammalian cerebellum4 ,these fibres are of the nature of association fibres40 ,viallanes showed that from the olfactory or antennal lobes1 as well as from the optic ganglia1 there are tracts of fibres which finally enter the cups of the mushroom bodies1 and ,kenyon has confirmed this observation4 ,kenyon has also1 by the ,golgi method1 detected another tract1 before unknown1 8passing down the hinder side of the brain1 from the cups to the region above the sophagus1 where it bends forward and comes in contact with fibres from the ventral cord1 which exists1 although ,binet was unable to discover any growth of fibres connecting the cord with the brain4 8,the fibres entering the cups from the antennal lobe1 the optic ganglia1 and the ventral region1 spread out and branch among the arborescent endings of the mushroom-body cells4 ,the fibres branching among the parallel fibres of the roots and the stalk lead off to lower parts of the brain1 connecting with efferent or motor-fibres1 or with secondary association fibres1 that in their turn make such connections4 ,this portion of the circuit has not been perfectly made out1 though there seems to be sufficient data to warrant the assumption just made4 ,illustration3 ,,fig4 #beb4--,section #ag1 showing the central body 7centr4 b7 and mushroom body1 optic and antennal lobes 7a4 l71 and procerebral lobes 7pc4 l72 o4 cal1 outer division of the calyx2 op4 n1 optic nerve2 trab1 trabeculum2 tc4 n1 transverse nerve4 8,such fibres existing as described1 there is then a complete circuit for sensory stimuli from the various parts of the body to the cells of the mushroom bodies4 ,the dendritic or arborescent branches of these cells take them up and pass them on out along the parallel fibres or neurites in the roots of the mushroom bodies as motor or other efferent impulses4 8,this1 however1 is not all4 ,for there are numerous fibres evident in my preparations1 the full courses of which ,i have not been thus far able to determine1 but which are so situated as to warrant the inference that they may act as association fibres between the afferent fibres from the antenn1 optic ganglia1 and ventral system1 and the efferent fibres4 ,there is then a possibility of a stimulus entering the brain and passing out as a motor impulse without going into the circuit of the fibres of the mushroom bodies2 or1 in other words1 a possibility of what may be compared to reflex action in higher animals40 ,illustration3 ,,fig4 #bec4--;,enlarged view of the trabeculum 7the dotted lines tcn and obt4 n pass through it7 and its nerves1 of the mushroom body1--its calices and stalk1 and the origin of the optic nerve #bbe diameters3 atn1 ascending trabecular nerve2 obt4 n1 oblique trabecular nerve2 tcn1 transverse nerve2 lat4 n1 lateral nerve2 cent4 n1 central nerve4 ,the mushroom bodies have not yet been found to be present in the ,synaptera1 but occur in the larv1 at least of those of most metamorphic insects 7,lepidoptera and ,hymenoptera71 though not yet found in the larv of ,diptera4 ,the writer has found these bodies in the nymphs of the locust 7,melanoplus spretus71 but not in the embryo just before hatching4 ,they occur in the third larval or nymph stage of this insect4 ,it is evident that by the end of the first larval stage the brain attains the development seen in the third larval state of the two-banded species 7,c4 bivittatus74 ,illustration3 ,,fig4 #bed4--,section through the brain of ,caloptenus bivittatus in the third larval stage1 showing the two hemispheres or sides of the brain1 and the ocelli and ocellar nerves1 which are seen to arise from the top of the hemispheres directly over the calices 7compare ,fig4 #bea73 o4 cal1 outer division of calyx of left mushroom body4 ,the result of our studies on the brain of the embryo locust was that from the embryonic cerebral lobes are eventually developed the central body and the two mushroom bodies4 ,fig4 #bed shows the early condition of the mushroom bodies and their undoubted origin from the cerebral ganglia4 ,hence these bodies appear to be differentiations of the cerebral ganglia or lobes1 having no connection with the optic or antennal lobes4 ,the central body 7,fig4 #beb1 centr4 b74--,this is the only single or unpaired organ in the brain4 ,dietl characterizes it as a median commissural system4 ,viallanes describes it as formed entirely of a very fine and close fibrillar web1 like a thick hemispherical skull-cap1 situated on the median line and united with the cerebral lobes4 8,it is like a central post towards which converge fibres passing from all points of the brain2 being bound to the cerebral lobes1 to the stalked bodies1 to the optic ganglia1 and to the olfactory lobes by distinct fibrous bundles40 ,the antennal or olfactory lobes 7,deutocerebrum74--,this portion of the brain consists of two hemispherical lobes1 highly differentiated for special sensorial perceptions1 and connected by a slightly differentiated medullary mass1 the dorsal lobe 7,figs4 #bdh1 #bdi lo71 from which arise the motor fibres and those of general sensibility4 ,the antennal lobes are in part attached to the optic ganglia1 and partly to the stalked body on the same side1 by the optic olfactory chiasma 7,fig4 #bej fch1 choo71 a system of fibres partially intercrossed on the median line4 ,the sophageal lobes 7,tritocerebrum7 7,figs4 #bdi1 #bej74--;,from this region the labrum and viscera are innervated1 the nerves to the latter being called the visceral1 sympathetic1 or stomatogastric system4 ,as ,viallanes remarks1 though plainly situated in front of the mouth1 they are in fact post-sophageal centres4 ,the two lobes are situated far apart1 and are connected by a bundle of fibres passing behind the sophagus1 called the transverse commissure of the sophageal ring 7,lienard74 ,the sophageal ganglia1 besides giving rise to the labral nerves1 also give origin to the root of the frontal ganglion4 c4 ,histological elements of the brain ,the brain and other ganglia are composed of two kinds of tissue4 #a4 ,the outer slightly darker1 usually pale grayish white portion consists of cortical or ganglion-cells differing in size4 ,this portion is stained red by carmine1 the cells composing it readily taking the stain4 ,the large ganglion cells 7represented in ,figs4 #beb and #bec7 are oval1 and send off usually a single nerve-fibre2 they have a thin fibrous cell-wall1 and the contents are finely granular4 ,the nucleus is very large1 often one-half the diameter of the entire cell1 and is composed of large round refractive granules1 usually concealing the nucleolus4 #b4 ,the medullary or inner part of the brain consists of matter which remains white or unstained after the preparation has remained thoroughly exposed to the action of the carmine4 ,it consists of minute granules and interlacing fibres4 ,the latter often forms a fine irregular network inclosing masses of finely granulated nerve matter4 ,this is called by ,dietl 8marksubstanz40 ,leydig1 in his ,vom ,bau des thierischen ,krpers1 p4 #hi1 thus refers to it3-- 8,in the brain and ventral ganglia of the leech1 of insects1 and in the brain of the gastropods 7,schnecken7 ,i observe that the stalks 7stiele7 of the ganglion-cells in nowise immediately arise as nerve-fibres1 but are planted in a molecular mass or punktsubstanz1 situated in the centre of the ganglion1 and merged with this substance4 ,it follows1 from what ,i have seen1 that there is no doubt that the origin of the nerve-fibres first takes place from this central punktsubstanz40 8,this relation is the rule4 ,but there also occur in the nerve-centres of the invertebrates single1 definitely situated ganglion-cells1 whose continuations become nerve-fibres without the intervention of a superadded punktsubstanz40 ,we may1 with ,kenyon1 call it the fibrillar substance4 ,leydig subsequently 7p4 #ia7 further describes this fibrillar substance1 stating that the granules composing it form a reticulated mass of fibrill1 or1 in other words1 a tangled web of very fine fibres3-- 8,we at present consider that by the passage of the continuation of the ganglion-cells into the punktsubstanz this continuation becomes lost in the fine threads1 and on the other side of the punktsubstanz the similar fibrillar substance forms the origin of the axis-cylinders arranged parallel to one another2 so it is quite certain that the single axis-cylinder derives its fibrillar substance as a mixture from the most diverse ganglion-cells40 d4 ,the visceral 7sympathetic or stomatogastric7 system ,this system in insects is composed 7#a7 of a series of three unpaired ganglia 7,fig4 #bdi1 gv#a1 gv#b1 gv#c71 situated over the dorso-median line of the sophagus1 and connected by a median nervous cord or recurrent nerve 7nr1 vagus of ,newport74 ,the first of these ganglia is the frontal ganglion1 which is connected with the sophageal ganglia by a pair of roots 7rvt71 which have an origin primitively common with that of the labral nerves 7,fig4 #bdh1 fg and lbr74 ,illustration3 ,,fig4 #bee4--;,anterior portion of the paired and unpaired visceral nervous system of ,blatta orientalis seen from above4 ,the outlines of the brain 7g7 and the roots of the antennal nerve 7na71 which cover a portion of the sympathetic nervous system1 are given by dotted lines4 ,lettering as in ,fig4 #bdg4 nsd1 nerve to salivary gland4 ,the nervus recurrens 7nr7 enters an unpaired stomach ganglion farther back4--,after ,hofer1 from ,lang4 #b4 ,of two pairs of lateral ganglia 7,fig4 #bee1 ga1 gp7 situated two on each side of the sophagus4 ,they are connected both with the antennal lobes by a nerve 7rvd71 and to the chain of unpaired ganglia by a special connective4 ,the first pair of these ganglia sends nerves to the heart and aorta2 the second pair to the trache of the head4 ,the unpaired median or recurrent nerve 7nr7 extends back from under the brain along the upper side of the sophagus1 and 7in ,blatta71 behind the origin of the nerves to the salivary glands1 enters an unpaired ganglion1 called the stomachic ganglion 7ganglion ventriculare71 situated in front of the proventriculus4 ,the number of these stomachic ganglia varies in different orders of insects4 ,in ,blatta1 ,kpffer and also ,hofer have shown 7,fig4 #bee7 7,mller1 ,brandt1 ex ,kolbe7 that the nerve to each salivary gland arises from three different centres3 the anterior end situated under the sophagus is innervated by the paired visceral nerves from the hinder paired ganglia2 the remaining part by nerves arising from each side of the recurrent nerve2 and thirdly by a pair of nerves arising from the subsophageal ganglion which accompanies the common salivary duct1 and ends in branches which partly innervate the salivary glands and in part their muscles4 ,hofer considers that the function of this complex system of paired and unpaired ganglia1 with their nerves1 is a double one1 viz4 serving both as a centre for the peristaltic action of the sophagus1 and as innervating the salivary glands4 ,besides these a second portion of the visceral system arises from the thoracic and abdominal ventral cord4 ,it may be seen in the simplest condition yet known in the nervous system of ,machilis 7,fig4 #bci s74 ,it consists of a fine1 slender nerve1 which extends along the surface of the ventral chain of ganglia1 and sending off a pair of branches 7accessory transverse nerves7 in front of each ganglion4 ,these accessory nerves receive nerve-twigs from the upper cord of the ventral chain1 dilating near their origins into a minute elongated ganglion1 and then passing partly outwards to the branches of the trache and the muscles of the spiracles1 uniting in the middle line of each segment of the body behind the head1 i4e4 of those segments containing a pair of ganglia4 e4 ,the supraspinal cord ,in the adult ,lepidoptera has been detected1 continuous with and on the upper side of the abdominal portions of the ventral cord1 a longitudinal cord of connective tissue forming a white or yellowish band1 and which seems to be an outgrowth of the dorsal portion of the neurilemma of the ventral cord4 ,muscles pass from it to the neighboring ventral portions of the integument4 ,its use is unknown1 and attention was first called to it by ,treviranus1 who called it 8an unknown ventral vessel0 7,bauchgefss74 ,afterwards it was re-discovered by ,newport1 who described it as 8a distinct vascular canal40 ,but ,burger has proved by cross-sections that it is not tubular1 but a comparatively solid cord composed1 however1 of loose connective tissue4 ,newport found it in the larva of ,sphinx ligustri1 but ,cattie states that it is not present in that of ,acherontia atropos4 ,it has not yet been observed in insects of other orders1 but its homologue exists in the scorpion and in the centipede1 and it may prove to correspond with the far more complete arterial coat which1 with the exception of the brain1 envelops the nervous system of ,limulus4 f4 ,modifications of the brain in different orders of insects ,there are different grades of cerebral development in insects1 and ,viallanes claimed that it was no exaggeration to say that the brain of the locust 7,melanoplus7 differs as much from that of the wasp as that of the frog differs from that of man4 ,he insists that the physiological conditions which determine the anatomical modifications of the brain are correlated with #a1 the food2 #b1 the perfection of the senses2 and #c1 with the perfection of the psychic faculties4 ,for example1 in those which feed on solid food and whose sophagus is large 7,orthoptera and ,coleoptera71 the connectives are elongated1 the subsophageal commissure free in all its extent1 and the tritocerebrum is situated quite far from the preceding segment of the brain4 ,on the other hand1 in insects which feed on fluid food 7,hymenoptera1 ,lepidoptera1 ,diptera1 ,hemiptera71 the sophagus is slender and the nervous centres which surround them are very much condensed2 the connectives are short1 and the tritocerebrum is closely fused1 partly to a portion of the antennal lobes 7deutocerebrum7 and partly to the mandibular ganglion4 ,as regards the perfection of the senses1 where1 as in dragon-flies1 the eyes are very large1 the optic ganglia are correspondingly so1 and in the same insects the antenn being very small1 the antennal lobes are almost rudimentary4 ,the ants exhibit inverse conditions2 in their brain the antennal lobes are well developed1 while the optic ganglia are reduced1 and where1 as in ,typhlopone1 the eyes are wanting1 they are completely atrophied4 ,illustration3 ,,fig4 #bef4--;,head of ,anophthalmus tellkampfii1 showing the brain1--the optic ganglia1 nerves1 and eyes totally atrophied4 ,illustration3 ,,fig4 #beg4--;,head of another ,carabid1 with the brain and eyes normal3 op1 optic ganglion2 pcl1 brain4 ,in certain cave insects where the eyes are wanting1 the optic ganglia are also absent4 ,in the eyeless cave species of ,anophthalmus the optic ganglia and nerves are entirely atrophied1 as they are in ,adelops1 which1 however1 has vestiges of the facets 7ommatidia74 ,fig4 #beg represents the brain of ,chlnius pennsylvanicus1 a ,carabid beetle1 with its eyes and optic ganglia 7op7 which may be compared with ,anopthalmus1 in which these parts are totally atrophied4 ,dujardin claimed that the degree of complication of the stalked body of the ,hymenoptera was in direct relation with their mental powers4 ,this has been proved by ,forel1 who has shown that in the honey bee and ants the mushroom bodies are much more developed in the workers than in the males or females and ,viallanes adds that these bodies are almost rudimentary in the dragon-flies1 whose eyes are so large2 while on the contrary in the blind ants 7,typhlopone71 these bodies are as perfect and voluminous as in the ants with eyes4 ,illustration3 ,,fig4 #beh4--;,diagrammatic outlines of sections of the upper part of the brain of a cockroach4 ,only one side of the brain is here represented4 ,the numbers indicate the position in the series of #cd sections into which this brain was cut4 mb1 mushroom bodies1 with their cellular covering 7c7 and their stems 7st72 a1 anterior nervous mass2 m1 median nervous mass4--,after ,newton4 ,within the limits of the same order the stalked bodies are most perfect in the most intelligent forms4 ,thus in the ,orthoptera1 says ,viallanes1 the ,blatt1 ,forficul1 and the crickets1 the mushroom bodies are more perfect than in the locusts1 which have simpler herbivorous habits4 ,this perfection of the mushroom bodies is seen not only in the increase in size1 but also in the complication of its structures4 ,thus in the groups with lower instincts 7,tabanus1 schna7 the stalk does not end in a calyx projecting from the surface of the brain1 but its end1 simply truncated1 is indicated externally only by an accumulation of the ganglionic nuclei which cover it4#dc ,in types which ,viallanes regards as more advanced1 i4e4 dipoda and ,melanoplus1 the end of the stalk projects and is folded into a calyx4 ,the brain of the cockroach 7,periplaneta1 ,fig4 #beh7 is a step higher than that of the locusts1 each calyx being divided into two adjacent calices1 although the cockroaches are an older and more generalized type than locusts4 ,the stalked bodies of cockroaches are thus complex1 like those of the higher ,hymenoptera1 the calices in ,xylocopa1 ,bombus1 and ,apis being double and so large as to cover almost the entire surface of the brain4 ,finally1 in what ,viallanes regards as the most perfect type 7,vespa71 the sides of the calices are folded and become sinuous1 so as to increase the surface1 thus assuming an appearance which1 he claims1 strongly recalls that of the convolutions of the brain of the mammals4 ,cheshire also calls attention to a progression in the size of these appendages1 as well as in mental powers as we rise from the cockchafer 7,melolontha vulgaris7 to the cricket1 up to the ichneumon1 then to the carpenter bee1 and finally to the social hive bee1 8where the pedunculated bodies form the part of the volume of the cerebral mass1 and the #ahgj of the volume of the entire creature1 while in the cockchafer they are less than #abcjj the part4 ,the size of the brain is also a gauge of intelligence4 ,in the worker bee the brain is #aagd of the body2 in the red ant1 #abif2 in the ,melolontha1 #acejj2 in the ,dyticus beetle1 #addjj40 7,bees and bee-keeping1 p4 #ed47 g4 ,functions of the nerve-centres and nerves ,as we have seen1 the central seat of the functions of the nervous system is not the brain alone 7suprasophageal ganglion71 but each ganglion is more or less the seat of vital movements1 those of the abdomen being each a distinct motor and respiratory centre4 ,the two halves of a ganglion are independent of each other4 ,according to ,faivre1 the brain is the seat of the will and of the power of cordinating the movements of the body1 while the infrasophageal ganglion is the seat of the motive power and also of the will4 ,the physiological experiments of ,binet1 which are in the line of those of ,faivre1 but more thorough1 demonstrate that an insect may live for months without a brain1 if the subsophageal ganglion is left intact1 just as a vertebrate may exist without its cerebrum4 ,as ,kenyon says3 8,faivre long ago showed that the subsophageal ganglion is the seat of the power of cordination of the muscular movements of the body4 ,binet has shown that the brain is the seat of the power directing these movements4 #8,a debrained hexapod will eat when food is placed beneath its palpi1 but it cannot go to its food even though the latter be but a very small space removed from its course or position4 ,whether the insect would be able to do so if the mushroom bodies only were destroyed1 and the antennal lobes1 optic lobes1 and the rest of the brain were left intact1 is a question that yet remains to be answered'0 7,kenyon74 ,in insects which are beheaded1 however readily they respond to stimulation of the nerves1 they are almost completely wanting in will power4 ,yet insects which have been decapitated can still walk and fly4 ,hymenoptera will live one or two days after decapitation1 beetles from one to three days1 and moths 7,agrotis7 will show signs of life five days after the loss of their head4 ,that the loss of will power is gradual was proved by decapitating ,polistes pallipes4 ,a day after the operation she was standing on her legs and opening and closing her wings2 #da hours after the operation she was still alive1 moving her legs1 and thrusting out her sting when irritated4 ,ichneumon otiosus1 after the removal of its head1 remained very lively1 and cleaned its wings and legs1 the power of cordination in its wings and legs remaining4 ,a horse-fly1 a day after decapitation1 was lively and flew about in a natural manner4#dd ,when the abdomen is cut off1 respiration in that region is not at first interrupted4 ,the seat of respiratory movements was referred by ,faivre to the hinder thoracic ganglion1 but ,plateau says that this view must be entirely abandoned1 remarking3 8,all carefully performed experiments on the nervous system of ,arthropoda have shown that each ganglion of the ventral chain is a motor centre1 and in insects a respiratory centre1 for the somite to which it belongs0 7,miall and ,denny's ,the ,cockroach1 p4 #afd74 ,the last pair of abdominal ganglia serve as the nervous centre of the nerves sent to the genital organs4 ,the recurrent or stomatogastric nerve1 which1 through the medium of the frontal ganglion1 regulates digestion1 has only a slight degree of sensibility2 the insect remains quiet even when a powerful allurement is presented to the digestive tract 7,kolbe74 ,faivre states that the destruction of the frontal ganglion1 or a section of the commissures connecting it with the brain1 puts an end to swallowing movements2 on the other hand1 stimulation results in energetic movements of this nature4 ,yersin1 by cutting through the commissure in different places1 and thus isolating the ganglia of the nervous cord of ,gryllus campestris1 arrived at the following results3-- #a4 ,the section of a nerve near its origin rendered the organ supplied by this nerve incapable of performing its functions4 #b4 ,if the connectives between two ganglia1 i4e4 the second and third thoracic ganglia1 are cut through1 the fore as well as hinder parts of the body retain their power of motion and sensation2 but a stimulus applied to the anterior part of the body does not pass to the hinder portion4 #c4 ,insects with an incomplete metamorphosis after section of the connectives are not in every case unable to moult and to farther develop4 #d4 ,if only one of the two connectives be cut through1 the appendages of the side cut through which take their origin between the place injured and the hinder end of the body1 often lose sensation and freedom of motion1 or the power of cordination of movements becomes irregular4 ,sometimes this is shown by an unsteadiness in the gait1 so that the insect walks around in a circle2 after a while these irregularities cease1 and the movements of the limbs on the injured side are only slightly restrained4 ,by a section of both connectives in any one place the power of cordination of movements is not injured4 #e4 ,the section of the connectives appear to have no influence on nutrition1 but affects reproduction1 the attempt at fertilization on the part of the male producing no result1 and the impregnated female laying no eggs4 #f4 ,injury to the brain1 or to the subsophageal1 or one of the thoracic ganglia1 is followed by a momentary enfeeblement of the ganglion affected4 ,afterwards there results a convulsive trembling1 which either pervades the whole body or only the appendages innervated by the injured ganglion4 #g4 ,as a result of an injury to the brain there is such a lack of steadiness in the movements that the insect walks or flies in a circle2 for instance1 a fly or dragon-fly thus injured in flying describes a circle or spiral4 ,steiner1 in making this experiment1 observed that the insect circled on its uninjured side4 ,the brain is thus a motor centre4 #h4 ,by injuring a thoracic ganglion1 one or all the organs which receive nerves from the ganglion are momentarily weakened4 ,afterwards the functions become restored4 ,sometimes1 however1 the insect walks in a circle4 ,faivre observed that after the destruction of the metathoracic ganglion of ,dyticus marginalis the hind wings and hind legs were partially paralyzed 7,kolbe1 ex ,yersin74 ,,literature ,,on ,,the ,,nervous ,,system a4 ,general ,newport1 ,george4 ,on the nervous system of the ,sphinx ligustri ,l41 and on the changes which it undergoes during a part of the metamorphoses of the insect4 7,phil4 ,trans4 ,roy4 ,soc41 ,london1 #ahcb1 pp4 #chc-cih2 #ahcd1 pp4 #chi-dbc1 ,pls47 ,helmholtz1 ,h4 ,l4 ,f4 ,de fabrica systematis nervosi evertebratorum4 ,diss4 in aug4 ,berolini1 #ahdb4 ,blanchard1 ,e4 ,recherches anatomiques et zoologiques sur le systme nerveux des animaux sans vertbres4 ,du systme nerveux des insectes4 7,annales des ,sciences nat41 ,sr4 #c1 v1 #ahdf1 pp4 #bgc-cgi1 #h ,pls47 ---- ,du systme nerveux chez les invertbres dans ses rapports avec la classification de ces animaux4 ,paris1 #ahdi4 ---- in ,cuvier's ,rgne animal4 7,edition accompagne de planches graves4 ,insectes4 ,pl4 #c1 #c;a1 and #d47 ,leidy1 ,joseph4 ,history and anatomy of the hemipterous genus ,belostoma4 7,memoirs ,amer4 ,acad4 ,arts and ,sc41 ,n4 ,s4 iv1 #ahdi1 pp4 #eg-fg1 #a ,pl47 ,scheiber1 ,s4 ,h4 ,vergleichende ,anatomie und ,physiologie der stridenlarven4 7,sitzungsb4 k4 ,akad4 wiss4 ,wien4 ,math4-,naturwiss4 ,cl41 xli1 #ahfj1 pp4 #dci-dif2 xlv1 #ahfb1 pp4 #g-fh2 #e ,taf47 ,tullberg1 ,tycho4 ,sveriges ,podurider4 7,k4 ,svenska vet4 ,akad4 ,handl4 x1 #ahgb1 pp4 #a-gj1 #ab ,taf47 ,berlese1 ,a4 ,osservazione sulla anatomia descrittiva del ,gryllus campestris ,l4 7,atti della soc4 ,veneto-,trentina1 #ahhj1 vii1 pp4 #bjj-bii47 ,baudelot1 ,e4 ,contributions la physiologie der systme nerveux des insectes4 7,revue d4 sc4 nat41 i1 pp4 #bfi-bhj1 #ahgb47 ,studer1 ,th4 ,ueber ,nervenendigung bei ,insekten4 ,kleine ,beitrge zur ,histologie der ,insekten4 7,mitt4 ,naturf4 ,ges41 ,bern1 #ahgd1 pp4 #ig-ajd1 #a ,taf47 ,brandt1 ,e4 ,recherches anatomiques et morphologiques sur le systme nerveux des insectes ,hymnoptres4 7,compt4 rendus de l',acad4 ,sc41 ,paris1 #ahge47 ---- ,ueber das ,nervensystem der ,apiden4 7,sitzungsb4 d4 naturf4 ,ges41 in ,petersbourg1 vii1 #ahgf47 ---- ,ueber das ,nervensystem der ,schmetterlingsraupen4 7,verhandl4 der ,russ4 ,ent4 ,gesellsch41 x1 #ahgg4 ,also #af other articles with plates1 in ,hor ,soc4 ,ent4 ,ross41 #ahgh-ahhb47 ,mark1 ,e4 ,l4 ,the nervous system of ,phylloxera4 7,psyche1 ii1 pp4 #bja-bjg1 #ahgi47 ,riley1 ,charles ,valentine4 ,the nervous system and salivary glands of ,phylloxera4 7,psyche1 ii1 pp4 #bbe1 #bbf1 #ahgi47 ,cholodkowsky1 ,n4 ,zur ,frage ber den ,baue und ber die ,innervation der ,speicheldrsen der ,blattiden4 7,hor ,soc4 ,ent4 ,ross41 #ahha1 xvi1 pp4 #f-i1 #b ,taf47 ,linard1 ,v4 ,constitution de l'anneau sophagien4 7,archives de ,biologie1 i1 pp4 #cha-cia1 #ahhj1 #a ,taf47 ,michaels1 ,h4 ,nervensystem von ,oryctes nasicornis im ,larven-1 ,puppen-1 und ,kferzustande4 7,zeits4 f4 wissens4 ,zool41 xxxiv1 #ahhj1 pp4 #fda-gjb1 #d ,taf47 ,rossi1 ,a4 ,sul modo di terminare dei nervi nei muscoli dell' organo sonoro della ,cicala commune 7,cicada plebeja74 7,mem4 accad4 sc4 ,bologna1 #ahhj1 #d ,ser41 i1 pp4 #ffa-ffe47 ,foettinger1 ,a4 ,sur le termination des nerfs dans les muscles des insectes4 7,archiv de ,biologie1 i1 #ahhj47 ,binet4 ,contribution l'tude der system nerveux sous intestinal des insectes4 7,journ4 l'anat4 et phys41 xxx1 pp4 #ddi-ehj1 #ahid47 ,paulowa4 ,zum ,bau des ,eingeweide ,nervensystems der ,insekten4 7,zool4 ,anzeiger41 xviii1 ,feb4 #be1 #ahie1 pp4 #he-hg47 ,also the writings of ,lyonet1 ,cuvier1 ,rolando1 ,straus-,durckheim1 ,leydig1 ,newport1 ,graber1 ,viallanes1 ,grassi1 ,oudemans4 b4 ,the brain ,dujardin1 ,f4 ,mmoires sur le systme nerveux des insectes4 7,annales des ,sciences nat1 ,sr4 #c1 #ahej1 xiv1 pp4 #aie-bjf1 ,pl4 #a1 #ahej47 ,rabl-,rckhard4 ,studien ber ,insectengehirne4 7,archiv fr ,anatomie1 ,physiologie1 etc41 herausg4 von ,reichert u4 ,r4 du ,bois-,raymond1 #ahgf1 p4 #dhj1 ,taf4 i47 ,dietl1 ,m4 ,j4 ,die ,organization des ,arthropodengehirns4 7,zeitschr4 wissens4 ,zool41 xxvii1 #ahgf1 p4 #dhh1 ,taf4 xxxvi4-xxxviii47 ,flogel1 ,t4 ,h4 ,l4 ,ueber den einheitlichen ,bau des ,gehirns in den verschiedenen ,insectenordnungen4 7,zeitschr4 wissens4 ,zool41 xxx1 ,suppl41 #ahgh1 p4 #eef1 ,taf4 xxiii1 xxiv47 ,newton1 ,e4 ,t4 ,on a new method of constructing models of the brains of insects1 etc4 7,journ4 ,quekett ,microscopical ,club1 pp4 #aej-aeh1 #ahgi47 ---- ,on the brain of the cockroach1 ,blatta orientalis4 7,quart4 ,journ4 ,microscopical ,science1 ,july1 #ahgi1 p4 #cdj1 ,pl4 xv1 xvi47 ,packard1 ,a4 ,s4 ,the brain of the locust4 7,chapter xi1 ,second ,report of the ,u4 ,s4 ,entomological ,commission1 pp4 #bbc-bdb1 ,pls4 ix-xv1 #ahhj47 ,cuccati1 ,giovanni4 ,sulla stuttura del ganglio sopraesofageo di alcuni ortotteri4 7,acrydium lineola1 ,locusta viridissima1 ,locusta 7species871 ,gryllotalpa vulgaris1 ,bologna1 #ahhg1 #d1 pp4 #a-bg1 ,pl4 i-iv47 ---- ,intorno alla struttura del cervello della ,sonomya erythrocephala1 nota preventiva4 ,bologna1 #ahhg4 ---- ,ueber die ,organization des ,gehirns des ,sonomya erythrocephala4 7,zeitschr4 f4 wissens4 ,zool41 #ahhh1 xlvi1 pp4 #bdj-bfi1 #b ,taf47 ,viallanes1 ,h4 tudes histologiques et organologiques sur les centres nerveux et les organes des sens des animaux articuls4 #a4 ,mmoire4 ,le ganglion optique de la langouste 7,palinurus vulgaris74 7,annal4 d4 ,sc4 ,nat4 ,zool41 #ahhd1 #f;e ,sr41 xvii1 ,art4 #c1 pp4 #a-gd1 #e ,pls47 #b4 ,mmoire4 ,le ganglion optique de la ,libellule 7schna maculatissima74 7,ibid41 #ahhe1 #f;e ,sr41 xviii1 ,art4 #d1 pp4 #a-cd1 #c ,pls47 #c4 ,mmoire4 ,le ganglion optique de quelques larves de ,diptres 7,musca1 ,eristalis1 ,stratiomys74 7,ibid41 #ahhf1 #f;e ,sr41 xix1 ,art4 ,m4 #d1 pp4 #cd1 #b ,pls47 #d4 ,mmoire4 ,le cerveau de la gupe 7,vespa crabro et vulgaris74 7,ibid41 #ahhg1 #g;e ,sr41 ii1 pp4 #e-ajj1 #f ,pls47 #e4 ,mmoire4 #a4 ,le cerveau du criquet 7dipoda crulescens et ,caloptenus italicus74 #b4 ,comparaison du cerveau des ,crustacs et des ,insectes4 #c4 ,le cerveau et la morphologie du squelette cphalique4 7,ibid41 #ahhh1 #g;e ,sr41 iv1 pp4 #a-abj1 #f ,pls47 ---- ,sur la structure interne du ganglion optique de quelques larves de ,diptres4 7,bull4 ,soc4 ,phil41 ,paris1 #ahhe1 #g;e ,sr41 ix1 pp4 #ge-gh47 ---- ,la structure du cerveau des ,hymnoptres4 7,bull4 ,soc4 ,philomat41 ,paris1 #ahhf1 #g;e ,sr41 x1 pp4 #hb1 #hc47 ---- ,la structure du cerveau des ,orthoptres4 7,bull4 ,soc4 ,philomat41 ,paris1 #ahhf1 #g;e ,sr41 xi1 pp4 #aai-abf47 ---- ,sur la morphologie compare du cerveau des ,insectes et des ,crustacs4 7,compt4 rend4 ,acad4 ,sc4 ,paris1 #ahhg1 civ1 pp4 #ddd-ddg47 ,kenyon1 ,f4 ,c4 ,the meaning and structure of the so-called 8mushroom bodies0 of the hexapod brain4 7,amer4 ,naturalist1 xxx1 #ahif1 pp4 #fdc-fej1 #a fig47 ---- ,the brain of the bee4 7,journ4 ,comp4 ,neurology1 vi1 fasc4 #c1 #ahif1 pp4 #acc-baj47 ---- ,the optic lobes of the bee's brain in the light of recent neurological methods4 7,amer4 ,nat41 xxxi1 #ahig1 pp4 #cfi-cgf1 #a ,pl47 ,with the embryological works of ,graber1 ,heider1 ,korscheldt1 ,patten1 ,wheeler1 etc4 c4 ,histology of the nervous ,system ,helmholtz4 ,de fabrica systematis nervosi evertebratorum4 ,diss4 ,berolini1 #ahdb4 ,remak4 ,ueber d4 ,inhalt d4 ,nervenprimitivrhren4 7,archiv f4 ,anat4 u4 ,phys41 #ahdc47 ,leydig4 ,lehrbuch der ,histologie der ,menschen und der ,thiere4 #aheg4 ---- ,vom ,bau des thierischen ,krpers4 i4 #ahfd4 ---- ,tafeln zur vergleichenden ,anatomie4 i4 ,tbingen1 #ahfd4 ---- ,zelle und ,gewebe1 neue ,beitrge zur ,histologie des ,tier-,krpers4 ,bonn1 #ahhe1 pp4 #bai1 #f ,taf4 ,walter4 ,mikroscopische ,studien ber das ,centralnervensystem wirbelloser ,thiere4 #ahfc4 ,dietl1 ,m4 ,j4 ,die ,gewebselemente des ,centralnervensystems bei wirbellosen ,thieren4 7,aus den ,berichten des naturw4-medic4 ,vereins in ,innsbruck47 ,innsbruck1 #ahgh4 ,berger4 ,untersuchungen ber den ,bau des ,gehirns und der ,retina der ,arthropoden4 7,arbeiten des zool4 ,instituts zu ,wien1 ,heft #b1 p4 #agc1 #ahgh47 ---- ,nachtrag zu den ,untersuchungen ber den ,bau des ,gehirns und der ,retina der ,arthropoden4 7,ibid41 ,heft #c47 ,viallanes1 ,h4 ,recherches sur l'histologie des insectes1 etc4 ,paris1 #ahhb4 7,annales des ,sciences nat41 pp4 #a-cdh1 ,pls4 #a-ah47 ---- ,sur la structure de la substance ponctue des insectes4 ,paris1 #ahhe4 ,haller1 ,b4 ,ueber die sogenannte ,leydig'sche ,punktsubstantz im ,centralnervensystem4 7,morp4 ,jahrb41 xi1 #ahhf47 ,nansen1 ,f4 ,the structure and combination of the histological elements of the central nervous system4 7,bergen's ,museum ,aarsberetning for #ahhf4 ,bergen1 #ahhg47 ,also the writings of ,benedicenti1 ,holmgren4 ,,the ,,sensory ,,organs a4 ,the eyes and insect vision ,illustration3 ,,fig4 #bei4--;,different forms of compound eyes4 ,a1 a bug 7,pyrrhocoris74 ,b1 worker bee4 ,c1 drone4 ,d1 male ,bibio1 a holoptic insect4--,from ,judeich and ,nitsche4 ,of the eyes of insects there are two kinds1 the simple and the compound4 ,of the former there are usually three1 arranged in a triangle near the top of the head1 between the compound eyes 7,fig4 #bei1 ,b74 ,the compound or facetted eyes1 which are usually round and prominent1 differ much in size and in the number of facets4 ,the number of facets varies from #ab in ,lepisma1--though in a ,brazilian beetle 7,lathridius7 there are only seven unequal facets1--to #ej in the ant1 and up to #djjj in the house-fly1 #ab1jjj in ,acherontia atropos1 #ag1jjj in ,papilio1 #bj1jjj in the dragon-fly 7schna71 #be1jjj in a beetle 7,mordella71 while in ,sphinx convolvuli1 the number reaches #bg1jjj4 ,the size of the facets seems to bear some relation to that of the insect1 but even in the smallest species none have been observed less than #abjjj of an inch in diameter4 ,day-flying ,lepidoptera have smaller facets than moths 7,lubbock74 ,illustration3 ,,fig4 #bfj4--,section through the ocellus of a young ,dyticus larva3 ct1 cuticula2 l1 corneal lens2 gh1 cells of the vitreous body1 being modified hypodermal cells 7hy72 st1 rods2 re1 retinal cells2 no1 optic nerve4--,after ,grenacher1 from ,lang4 ,the simple1 or single-lensed eye 7ocellus74--,morphologically the simple eye is a modified portion of the ectoderm1 the pigment enclosing the retinal cells arising from specialized hypodermal cells1 and covered by a specialized transparent portion of the cuticula1 forming the corneal lens4 ,the apparatus is supplied with a nerve1 the fibres of which end in a rod or solid nerve-ending1 as in other sensory organs4 ,as seen in the ocellus of ,dyticus 7,fig4 #bfj71 under the corneal lens the hypodermis forms a sort of pit1 and the cells are modified to form the vitreous body 7vitrella7 and retina4 ,each retinal cell 7re7 is connected with a fibre from the optic nerve1 contains pigment1 and ends in a rod directed outwards towards the lens4 ,the cells at the end of the pit or depression are1 next to the lens1 without pigment1 and1 growing in between the retina and the lens1 fill it up1 and thus form a sort of vitreous body4 ,the ocellus appears to be a direct heirloom from the eyes of worms1 while the many-facetted compound eye of the crustaceans and of insects is peculiar to these classes4 ,the compound eye of the myriopod ,scutigera differs structurally in many respects from the compound eye of insects1 and that of ,limulus still more so4 ,it should be observed that in the young nymph of ,ephemera1 as well as in the semipupa of ,bombus1 each of the three ocelli are situated on separate sclerites4 ,in ,bombus the anterior ocellus has a double shape1 being broad1 transversely ovate1 and not round like the two others1 as if resulting from the fusion of what were originally two distinct ocelli4 ,the ocelli are not infrequently wanting1 as in adult ,dermaptera1 in the ,locustid1 and in certain ,hemiptera 7,hydrocora74 ,in ,lepidoptera there are but two ocelli2 in geometrid moths they are often atrophied1 and they are absent in butterflies 7except ,pamphila74 ,the compound or facetted eye 7ommateum74--,the facetted arthropod eye is wonderfully complex and most delicately organized1 being far more so than that of vertebrates or molluscs4 ,the simplest or most primitive facetted eye appears to be that of ,lepisma4 ,as stated by ,watase1 the compound eye of arthropods is morphologically 8a collection of ectodermic pits whose outer open ends face towards the sources of light1 and whose inner ends are connected with the central nervous system by the optic nerve fibres40 ,the facetted eye is composed of numerous simple eyes called ommatidia1 each of which is complicated in structure4 ,the elements which make up an ommatidium are the following3 7#a7 ,the facet or cornea1 which is a specialized portion of the cuticula2 and 7#b71 the crystalline lens or cone2 7#c71 the nerve-ending or retinula1 which is formed out of the retinula cells and the rhabdom or rod lying in its axis2 and 7#d7 of the pigment enclosing the lens and rod2 the last three elements are derived from the hypodermis4 ,the single eyes are separated from each other by pigment cells4 ,the facet or cornea4--,this is biconvex1 clear1 transparent1 usually hexagonal in outline1 and refracts the light4 ,the corneal lenses are cast in moulting4 ,the corneal lenses are circular in most cases where they are very convex1 as in ,lathridius and ,batocera4 ,the hexagonal ones are very irregular4 ,when they are very convex the eye has a granular appearance1 but when not greater than the convexity of the eye itself1 the eye appears perfectly smooth 7,bolbocerus1 etc474 ,the facets in the lower part of the eye of ,dineutes are a trifle larger than in the upper part 7about nine to ten74 ,in many insects the reverse is the case1 the upper facets being larger than the lower1 a notable instance being ,anax4 ,the intervening lines between the facets are often beset with hairs1 sometimes very long and dense1 as in the drone bee and ,trichophthalmus2 and the modifications of the hairs into scales which takes place on the body occurs on the eyes also1 the scales on the eyes of some beetles of the family ,colydiid being very large1 arranged in lines over the eyes like tombstones 7,trachypholis74#de ,illustration3 ,,fig4 #bfa4--,section through the eye of a fly 7,musca vomitoria73 c1 cornea1 or facet2 pc1 pseudocone2 r1 retinula2 ,rh1 rhabdom2 pg#a1 pg#b1 pg#c1 pigment cells2 b4m1 basilar membrane2 ,t1 ,tt#a1 ,tt#b1 trachea2 tv1 tracheal vesicle2 t4a1 terminal anastomosis2 op1 opticon2 c4op1 epiopticon2 p4op1 periopticon2 n4c1 nuclei2 n4c4s1 nerve-cell sheath2 ,n4f1 decussating nerve-fibres4--,after ,hickson1 from ,lubbock4 ,the crystalline lens or cone4--,behind or within the facets is a layer composed of the cones1 behind which are the layers of retinul and rhabdoms1 and which correspond to the layer of rods and cones1 but not the retina as a whole1 of vertebrate animals4 ,the crystalline lens is1 when present1 usually more or less conical1 and consists of four or more hypodermis-cells4 ,the cones are of various shapes and sizes in insects of different groups1 or are entirely wanting1 and ,grenacher has divided the eyes of insects into eucone1 pseudocone1 and acone4 ,as the pseudocone seems1 however1 to be rather a modification of the eucone eye1 the following division may be made3-- #a4 ,eucone eyes1 comprising those with a well-developed cone4 ,they occur in ,lepisma1 ,blatta 7,fig4 #bfb71 and other ,orthoptera1 in ,neuroptera1 in ,cicadid1 in those ,coleoptera with five tarsal joints1 in the dipterous genus ,corethra1 and in the ,lepidoptera and ,hymenoptera 7,fig4 #bfc74 ,illustration3 ,,fig4 #bfb4--,ommatidium of cockroach 7,periplaneta73 lf1 cornea2 kk1 crystalline cone2 pg pigment cell2 rl1 retinula2 rm1 rhabdom4--,after ,grenacher1 from ,lubbock4 ,illustration3 ,,fig4 #bfc4--,two separate elements of the eucone eye of a bee2 ,lf1 cornea2 n1 nucleus of ,semper2 ,kk1 crystalline cone2 ,pg1 pigment cells2 ,rl1 retinula2 ,rm1 rhabdom4--,after ,grenacher1 from ,lubbock4 ,illustration3 ,,fig4 #bfd4--,three ommatidia of a pseudocone eye1 diagrammatic3 ,a1 a separate ommatidium of ,musca vomitoria1 semi-diagrammatic3 c1 cornea2 p4c1 pseudocone2 pg1 pigmented cells surrounding the pseudocone2 p4g#b1 additional pigment cells2 p4g#c1 basal pigment cells2 n4p4c1 nuclei of pseudocone2 r1 retinul2 n4r1 n4r1 nucleus of retinul2 ,r1 rhabdom2 b4m1 basal membrane2 t4a1 terminal anastomosis sending nerve-fibrils to the retinul4 ,b1 section through a retinula and rhabdom near the basal membrane1 the six retinul 7r7 fused into a tube ensheathing the rhabdom 7,r74--,after ,hickson4 a4 ,pseudocone eyes2 in which1 instead of the crystalline lens or cone1 there are four cells filled with a transparent fluid medium1 and a smaller protoplasmic portion containing a nucleus 7,muscid1 ,fig4 #bfd1 pc74 ,hickson states that the difference between the eucone and pseudocone eyes lies in the fact that in the pseudocone eye 8the refracting body formed by the cone-cell lies behind the nuclei10 and in the eucone eye in front of it4 #b4 ,acone eyes1 where the cone or refracting body is wanting1 but is represented by the four primitive cone-cells4 ,acone eyes occur in ,forficulid1 ,hemiptera 7except ,cicadid71 the nematocerous ,diptera 7,tipula1 etc471 and those ,coleoptera which have less than five tarsal joints4 ,the retinula and rod4--,the retinula is morphologically a nerve-end cell1 situated at the end of a nerve-fibril arising from the optic nerve4 ,the elements of the retinula of ,musca are six in number and surround the rhabdom 7,fig4 #bfd71 which consists of a bundle of six long1 delicate chitinous rods1 more or less firmly united together 7,fig4 #bfd1 ,r74 ,the six elements of the retinula of ,musca are in their outer or distal portion free from one another1 but towards their base are fused into a sheath 7,fig4 #bfd1 r74 ,they are true nerve-end cells1 as shown by ,mller and by ,max ,schultze1 their views having been confirmed by ,grenacher and by ,hickson4 ,the relations of the nerves to the rods after passing through the basal membrane is seen in ,fig4 #bff4 ,the pigment4--,the cones or pseudocones are mostly buried in pigment1 as well as the rods2 and the pigment forms two layers4 ,the outer of the two layers is called the iris pigment 7,fig4 #bfe1 e1 iris tapetum71 and the inner 7f7 the retinal pigment4 ,between the ommatidia internally there occur1 according to ,hickson1 pigment cells 7,fig4 #bfd1 p4g#c71 each of which stands on the basilar membrane and sends a fine process outwards towards the internal process of the external pigment-cell 7p4g#b74 ,a long1 slender tracheal vesicle also passes in between the retinul4 ,illustration3 ,,fig4 #bfe4--,two ommatidia from the eye of ,colymbetes fuscus1 #afj3 a1 cornea2 b1 cone2 c1 rhabdom2 d1 basal membrane1 with nerve filaments below it3 e1 iris pigment2 f1 retina pigment4--,after ,exner1 from ,sharp4 ,the basilar membrane4--,this is a thin fenestrate membrane 7,fig4 #bfa7 separating the cones and rods from the optic tract 7,fig4 #bfd1 b4m74 ,it is perforated for the passage of tracheal diverticula and of the optic nerve fibrils4 ,it separates the dioptric or instrumental portion of the eye from the percipient portion1 i4e4 the optic tract4 ,the optic tract4--,this is the optic ganglion of earlier writers1 and appears to be the percipient portion of the eye1 as opposed to the dioptric portion4 ,if the reader will examine ,figs4 #bdi and #bfa1 he will see that it consists of three distinct ganglionic swellings1 i4e4 the opticon1 epiopticon1 and periopticon1 whose structure is very complicated4 ,in ,musca 7,fig4 #bfa7 the first ganglionic swelling 7opticon7 is separated from the brain by a slight constriction1 which ,berger regards as the homologue of the optic nerve of the other arthropods4 ,it consists of a very fine granular matrix traversed throughout by a fine meshwork of minute fibrill1 the neurospongium of ,hickson4 ,in the young cockroach 7,periplaneta7 the optic nerve separating the cerebral ganglion from the opticon is much longer in proportion than it is in the adult blow-fly4 ,illustration3 ,,fig4 #bff4--,periopticon and terminal anastomosis of ,agrion1 showing the character of the elements of the periopticon 7p4op7 and the structure of the terminal anastomosis 7t4a74 #a4 ,the first layer of the terminal anastomosis1 consisting of a plexus of fibrils and nerve-cells 7n4c74 #b4 ,the second layer1 in which the fibrils are collected together in bundles4 #c4 ,the final optic plexus and nerve-cells4 #d4 ,the layer in which the optic fibrils are collected in bundles to be distributed to the retinul 7r72 b4m1 basal membrane4--,after ,hickson4 ,the second ganglionic swelling 7epiopticon1 ,fig4 #bfa1 c4op7 is separated from the opticon by a tract of fine nerve-fibrils1 which partially decussate2 at the decussation two or three larger nerve-cells may be seen4 ,it also contains a few scattered nerve-cells 7n4c74 ,the third ganglionic swelling 7periopticon1 p4op7 is separated from the others by a bundle of long optic nerve-fibrils1 which cross one another4 ,it is composed of a number of cylindrical masses of neurospongium arranged side by side 7,fig4 #bfa1 p4op74 ,between these elements of the periopticon1 which do not seem to bear any relation to the number of ommatidia1 a single nerve-cell is very frequently seen4 ,the periopticon does not occur in ,periplaneta and ,nepa 7,hickson74 ,the three optic ganglia thus described1 together with the cerebral ganglia1 are surrounded by a sheath of densely packed nerve-cells4 ,bearing in mind the fact that the retinul are the nerve-end cells of the fibres passing through the periopticon1 it will be well to read the following account1 by ,hickson1 of the terminal anastomosis of the optic fibrils in the periopticon of ,agrion bifurcatum1 and to examine his sketch 7,fig4 #bff73 8,the terminal anastomosis of ,agrion may be conveniently divided into four regions4 ,first the region 7#a7 lying nearest to the periopticon in which the nerve-cells are numerous1 and the fibrils leaving the periopticon form a complicated plexus2 the region 7#b7 next to this1 in which the fibrils have collected into bundles separated by spaces occupied by very thin-walled trache in which there are no spiral markings1 and lymph-spaces2 next1 the region 7#c7 in which the fibrils form a final plexus1 and in which there are again a considerable number of nerve-cells2 and1 lastly1 the region 7#d7 in which the fibrils are again collected into bundles1 separated by spaces containing trache1 which perforate the basement membrane to supply the retinul40 ,it would seem as if the decussation of the optic nerve-fibrils were a matter of primary importance1 as it so generally occurs1 but in the young of that most generalized of all pterygote insects1 the cockroach 7,periplaneta71 ,hickson states that the optic nerve-fibrils which leave the periopticon pass without decussating to the ommateum1 and in the adult there is only a partial decussation4 ,in ,nepa there is no decussation1 but the anastomosis is complicated by the presence of looped and transverse anastomoses4 ,looking at the eye as a whole1 ,hickson regards all the nerve structure of the eye lying between the crystalline cone-layer and the true optic nerve to be analogous with the retina of other animals4 ,with ,ciaccio1 ,berger1 and others1 he does not regard the layer composed of the retinul and rhabdoms as the equivalent of the retina of vertebrates1 etc4 ,origin of the facetted eye4--,the two kinds of eye1 the simple and the compound1 are supposed to have been derived from a primitive type1 resembling the single eye 7ommatidium7 of the acone eye of ,tipula4 ,as stated by ,lang1 8an increase of the elements of this primitive eye led to the formation of the ocellus2 an increase in number of the primitive eyes1 and their approximation1 led to the formation of the compound facet eye40 ,this view is suggested1 he says1 by the groups of closely contiguous single eyes of the myriopods1 considered in connection with the compound eye of ,scutigera4 ,grenacher looks upon simple 7ocelli7 and compound eyes as 8sisters10 not derived from one another1 but from a common parentage4 ,immature insects rarely possess compound eyes2 they are only known to occur in the nymphs of ,odonata and ,ephemerid1 and in the larv and pupa of ,corethra4 ,mode of vision by single eyes or ocelli4--,in their simplest condition1 the eyes of worms and other of the lower invertebrates1 probably only enable those animals to distinguish light from darkness4 ,the ocelli of spiders and of many insects1 however1 probably enable them1 as ,lubbock remarks1 to see as our eyes do4 ,the simple lens throws on the retina an image1 which is perceived by the fine terminations of the optic nerve4 ,the ocelli of different arthropods differ1 however1 very much in degree of complexity4 ,mller considered that the power of vision of ocelli 8is probably confined to the perception of very near objects40 8,this may be inferred10 ,mller states1 8partly from their existing principally in larv and apterous insects1 and partly from several observations which ,i have made relative to the position of these simple eyes4 ,in the genus ,empusa the head is so prolonged over the middle inferior eye that1 in the locomotion of the animal1 the nearest objects can only come within the range4 ,in ,locusta cornuta1 also1 the same eye lies beneath the prolongation of the head4444 ,in the ,orthoptera generally1 also1 the simple eyes are1 in consequence of the depressed position of the head1 directed downwards towards the surface upon which the insects are moving40#df ,lowne considers that in the ocellus of ,eristalis1 the great convexity of the lens must give it a very short focus1 and the comparatively small number of rods render the picture of even very near objects quite imperfect and practically useless for purposes of vision1 and that the function of the ocelli is 8the perception of the intensity and the direction of light1 rather than of vision1 in the ordinary acceptation of the term40 ,raumur1 ,marcel de ,serres1 ,dugs1 and ,forel have shown by experiment1 that in insects which possess both ocelli and compound eyes1 the former may be covered over without materially affecting the movements of the animals1 while if the facetted eyes are covered1 they act as if in the dark 7,lubbock74 ,while ,plateau regards the ocelli as of scarcely any use to the insect1 and ,forel claims that wasps1 humble bees1 ants1 etc41 walk or fly almost equally well without as with the aid of their ocelli1 ,lubbock demurs to this view1 and says the same experiments of ,forel's might almost be quoted to prove the same with reference to the compound eyes4 ,indeed1 the writer has observed that in caves1 eyeless beetles apparently run about as freely and with as much purpose1 as their eyed relatives in the open air4 ,plateau has recently shown that caterpillars which have ocelli alone are very short-sighted1 not seeing objects at a distance beyond one or two centimetres1 and it has been fully proved by ,plateau and others1 that spiders1 with their well-formed ocelli1 are myopic1 and have little power of making out distinctly the shape of the objects they see4 ,on the whole1 we are rather inclined to agree with ,lubbock and ,forel1 that the ocelli are useful in dark places and for near vision4 ,they are1 as ,lubbock states1 especially developed in insects1 such as ants1 bees1 and wasps1 which live partly in the open light and partly in the dark recesses of nests4 ,moreover1 the night-flying moths nearly all possess ocelli1 while with one known exception 7,pamphila7 they are wanting in butterflies4 ,finally1 remarks ,lubbock1 8,whatever the special function of ocelli may be1 it seems clear that they must see in the same manner as our eyes do--that is to say1 the image must be reversed4 ,on the other hand1 in the case of compound eyes1 it seems probable that the vision is direct1 and the difficulty of accounting for the existence in the same animal of two such different kinds of eyes is certainly enhanced by the fact that1 as it would seem1 the image given by the medial eyes is reversed1 while that of the lateral ones is direct0 7p4 #aha74 ,mode of vision by facetted eyes4--,the complexity of the facetted eyes of insects is amazing1 and difficult to account for unless we accept the mosaic theory of ,mller1 who maintained that the distinctness of the image formed by such an eye will be greater in proportion to the number of separate cones4 ,his famous theory is thus stated3 8,an image formed by several thousand separate points1 of which each corresponds to a distinct field of vision in the external world1 will resemble a piece of mosaic work1 and a better idea cannot be conceived of the image of external objects which will be depicted on the retina of beings endowed with such organs of vision1 than by comparing it with perfect work of that kind40 ,illustration3 ,,fig4 #bfg4--;,from ,lubbock4 ,how vision is effected by a many-facetted eye is thus explained by ,lubbock3 8,let a number of transparent tubes1 or cones with opaque walls1 be ranged side by side in front of the retina1 and separated from one another by black pigment4 ,in this case the only light which can reach the optic nerve will be that which falls on any given tube in the direction of its axis40 ,for instance1 in ,fig4 #bfg1 the light from a will pass to a1 that from b to b1 that from c to c1 and so on4 ,the light from c1 which falls on the other tubes1 will not reach the nerve1 but will impinge on the sides and be absorbed by the pigment4 ,thus1 though the light from c will illuminate the whole surface of the eye1 it will only affect the nerve at c4 ,according to this view those rays of light only which pass directly through the crystalline cones1 or are reflected from their sides1 can reach the corresponding nerve-fibres4 ,the others fall on1 and are absorbed by1 the pigment which separates the different facets4 ,hence each cone receives light only from a very small portion of the field of vision1 and the rays so received are collected into one spot of light4 ,it follows from this theory that the larger and more convex the eye1 the wider will be its field of vision1 while the smaller and more numerous are the facets1 the more distinct will be the vision 7,lubbock74 ,the theory is certainly supported by the shape and size and the immense number of facets of the eye of the dragon-fly1 which all concede to see better1 and at a longer range1 than probably any other insect4 ,mller's mosaic theory was generally received1 until doubted and criticised by ,gottsche 7#aheb71 ,dor 7#ahfa71 ,plateau1 and others4 ,as ,lubbock in his excellent summary states1 ,gottsche's observation 7previously made by ,leeuwenhoek7 that each separate cornea gives a separate and distinct image1 was made on the eye of the blow-fly1 which does not possess a true crystalline cone4 ,plateau's objection loses its force1 since he seems to have had in his mind1 as ,lubbock states1 ,gottsche's1 rather than ,mller's1 theory4 ,mller's theory is supported by ,boll1 ,grenacher1 ,lubbock1 ,watase1 and especially by ,exner1 who has given much attention to the subject of the vision of insects1 and is the weightiest authority on the subject4 ,gottsche's view that each of the facetted eyes makes a distinct image which partially overlaps and is combined with all the images made by the other facets1 was shown by ,grenacher to be untenable1 after repeating ,gottsche's experiments with the eyes of moths1 in which the crystalline cones are firm and attached to the cornea4 ,he was thus able to remove the soft parts1 and to look through the cones and the cornea4 ,when the microscope was focussed at the inner end of the cone1 a spot of light was visible1 but no image4 ,as the object-glass was moved forward1 the image gradually came into view1 and then disappeared again4 ,here1 then1 the image is formed in the interior of the cone itself4 ,exner attempted to make this experiment with the eye of ,hydrophilus1 but in that insect the crystalline cones always came away from the cornea4 8,he1 however1 calculated the focal length1 refraction1 etc41 of the cornea1 and concluded that1 even if1 in spite of the crystalline cone1 an image could be formed1 it would fall much behind the retinula40 8,in these cases1 then10 adds ,lubbock1 8an image is out of the question4 ,moreover1 as the cone tapers to a point1 there would1 in fact1 be no room for an image1 which must be received on an appropriate surface4 ,in many insect eyes1 indeed1 as in those of the cockchafer1 the crystalline cone is drawn out into a thread1 which expands again before reaching the retinula4 ,such an arrangement seems fatal to any idea of an image40 ,lubbock thus sums up the reasons which seem to favor ,mller's theory of mosaic vision1 and to oppose ,gottsche's view3 87#a7 ,in certain cases1 as in ,hyperia1 there are no lenses1 and consequently there can be no image2 7#b7 the image would generally be destroyed by the crystalline cone2 7#c7 in some cases it would seem that the image would be formed completely behind the eye1 while in others1 again1 it would be too near the cornea2 7#d7 a pointed retina seems incompatible with a clear image2 7#e7 any true projection of an image would in certain species be precluded by the presence of impenetrable pigment1 which only leaves a minute central passage for the light-rays2 7#f7 even the clearest image would be useless1 from the absence of a suitable receptive surface1 since both the small number and mode of combination of the elements composing that surface seem to preclude it from receiving more than a single impression2 7#g7 no system of accommodation has yet been discovered2 finally 7#h71 a combination of many thousand relatively complete eyes seems quite useless and incomprehensible40 ,in his most recent work 7#ahij7 on the eyes of crustacea and insects1 ,exner states that the numerous simple eyes which make up the compound eye have each a cornea1 but it is more or less flat1 and the crystalline part of the eye has not the shape of a lens1 but of a 8lens cylinder10 that is1 of a cylinder which is composed of sheets of transparent tissue1 the refracting powers of which decrease toward the periphery of the cylinder4 ,if an eye of this kind is removed and freed of the pigment which surrounds it1 objects may be looked at through it from behind2 but its field of vision is very small1 and the direct images received from each separate eye are either produced close to one another on the retina 7or rather the retinul of all the eyes7 or superposed4 ,in this last case no less than thirty separate images may be superposed1 which is supposed to be of great use to night-flying insects4 ,exner claims that many other advantages result from the compound nature of an insect's eye4 ,thus the mobile pigment1 which corresponds to our iris1 can take different positions1 either between the separate eyes or behind the lens cylinders1 in which case it acts as so many screens to intercept the over-abundance of light4 ,exner finds that with its compound eyes the common glow-worm 7,lampyris7 is capable of distinguishing large signboard letters at a distance of ten or more feet1 as well as extremely fine lines engraved one-hundredth of an inch apart1 if they are at a distance of less than half an inch from the eye4 ,exner substantiates the truth of the results of ,plateau's experiments1 and claims that while the compound eye is inferior to the vertebrate eye for making out the forms of objects1 it is superior to the latter in distinguishing the smallest movements of objects in the total field of vision4 ,more recently ,mallock has given some optical reasons to show that ,mller's view is the true one4 ,he concludes1 and thus agrees with ,plateau1 that insects do not see well1 at any rate as regards their power of defining distant objects1 and their behavior certainly favors this view4 ,it might be asked1 ,what advantage1 then1 have insects with compound eyes over those with simple eyes8 ,mallock answers1 that the advantage over simple-eyed animals lies in the fact that there is hardly any practical limit to the nearness of the objects they can examine4 8,with the composite eye1 indeed1 the closer the object the better the sight1 for the greater will be the number of lenses employed to produce the impression2 whereas1 in the simple eye the focal length of the lens limits the distance at which a distinct view can be obtained40 ,he gives a table containing measures of the diameters and angles between the axes of the lenses of various insect eyes1 and states that the best of the eyes would give a picture about as good as if executed in rather coarse woodwork and viewed at a distance of a foot1 8and although a distant landscape could only be indifferently represented on such a coarse-grained structure1 it would do very well for things near enough to occupy a considerable part of the field of view40 ,the principal use of the facetted eye to perceive the movements of animals4--,plateau adopts ,exner's views as to the use of the facetted eye in perceiving the movements of other animals4 ,he therefore concludes that insects and other arthropods with compound eyes do not distinguish the form of objects2 but with ,exner he believes that their vision consists mainly in the perception of moving bodies4 ,most animals seem but little impressed by the form of their enemies or of their victims1 though their attention is immediately excited by the slightest displacement4 ,hunters1 fishermen1 and entomologists have made in confirmation of this view numerous and demonstrative observations4 ,though the production of an image in the facetted eye of the insect seems impossible1 we can easily conceive1 says ,plateau1 how it can ascertain the existence of a movement4 ,indeed1 if a luminous object is placed before a compound eye1 it will illuminate a whole group of simple eyes or facets2 moreover1 the centre of this group will be clearer than the rest4 ,every movement of the luminous body will displace the centre of clearness2 some of the facets not illuminated will first receive the light1 and others will renter into the shade2 some nervous terminations will be excited anew1 while those which were so formerly will cease to be4 ,hence the facetted eyes are not complete visual organs1 but mainly organs of orientation4 ,plateau experimented in the following way3 ,in a darkened room1 with two differently shaped but nearly equal light-openings1 one square and open1 the other subdivided into a number of small holes1 and therefore of more difficult egress1 he observed the choices of opening made by insects flying from the other end of the room4 ,careful practical provisions were made to eliminate error2 the light-intensity of the two openings was as far as possible equalized or else noted1 and no trees or other external objects were in view4 ,the room was not darkened beyond the limit at which ordinary type ceases to be readable1 otherwise the insects refused to fly 7it is well known that during the passage of a thick cloud insects usually cease to fly74 ,these observations were made on insects both with or without ocelli1 in addition to the compound eyes1 and with the same results4 ,from repeated experiments on flies1 bees1 etc41 butterflies and moths1 dragon-flies and beetles1 ,plateau concludes that insects with compound eyes do not notice differences in form of openings in a half-darkened room1 but fly with equal readiness to the apparently easy and apparently difficult way of escape2 that they are attracted to the more intensely lighted opening1 or to one with apparently greater surface2 hence he concludes that they cannot distinguish the form of objects1 at least only to a very slight extent1 though they readily perceive objects in motion4 ,one result of his experiments is that insects only utilize their eyes to choose between a white luminous orifice in a dark chamber1 or another orifice1 or group of orifices1 equally white4 ,they are guided neither by odorous emanations nor by differences of color4 ,he thinks that bees have as bad sight and act almost exactly as flies4 ,from numerous experiments on ,odonata1 ,coleoptera1 ,lepidoptera1 ,diptera1 and ,hymenoptera ,plateau arrives provisionally at the following conclusions3 #a4 ,diurnal insects have need of a quick strong light1 and cannot direct their movements in partial obscurity4 #b4 ,insects with compound eyes do not notice differences of form existing between two light orifices1 and are deceived by an excess of luminous intensity as well as by the apparent excess of surface4 ,in short1 they do not distinguish the form of objects1 or if they do1 distinguish them very badly4 ,lubbock1 however1 does not fully accept ,plateau's experiments with the windows1 and thinks they discern the form of bodies better than ,plateau supposes4 ,how far can insects see8--,it is now supposed that no insects can perceive objects at a greater distance than about six feet4 ,on an average ,lepidoptera can see the movements of rather large bodies #a4ej meters1 but ,hymenoptera only #eh cm41 and ,diptera #fh cm42 while the firefly 7,lampyris7 can see tolerably well the form of large objects at a distance of over two meters4 ,until further experiments are made1 it seems probable1 then1 that few if any insects have acute sight1 that they see objects best when moving1 and on the whole--except dragon-flies and other predaceous1 swiftly flying insects1 such as certain flies1 wasps1 and bees1 which have very large rounded eyes--insects are guided mainly rather by the sense of smell than of sight4 ,relation of sight to the color of eyes4--,it appears from the observations of ,girschner that those ,diptera with eyes of a uniform color see better than those with brightly banded or spotted eyes4 ,thus those flies 7,asilid1 ,empid1 ,leptid1 ,dolichopid7 whose predaceous habits requires good or quick sight have uniformly dark eyes1 as have also such flies as live constantly on the wing1 i4e41 the holoptic ,bombyliid1 ,syrphid1 ,pipunculid1 etc41 whose eyes are also very large4 ,those flies whose larv are parasitic on other animals have eyes of a uniform color that they may readily detect the most suitable host for their young2 such are the ,bombyliid1 ,conopid1 ,pipunculid1 and ,tachinid4 ,certain flies which live in the clear sunlight1 as many ,dolichopid1 some ,bombyliid1 and certain ,tabanid 7,tabanus1 ,chrysops1 ,hmatopota71 and which are often easily caught with the hand1 have eyes spotted or banded with bright or metallic colors4 ,this is also a sexual trait1 as the males of some horse-flies visiting flowers have eyes of a single color1 the spots and bands surviving only on the lower and hinder parts of the eye1 while their voracious blood-sucking females have the entire eye spotted or banded 7,kolbe74 ,the color-sense of insects4--,insects1 as ,spengel first suggested1 appear to be able to distinguish the color of objects4 ,lubbock has experimentally proved that bees1 wasps1 and ants have this power1 blue being the favorite color of the honey-bee1 and violet of ants1 which are sensitive to ultra-violet rays4 ,it is well known that butterflies will descend from a position high in the air1 mistaking white bits of paper for white flowers2 while1 as we have observed1 white butterflies 7,pieris7 prefer white flowers1 and yellow butterflies 7,colias7 appear to alight on yellow flowers in preference to white ones4 ,the late ,mr4 ,s4 ,l4 ,elliott once informed us that on a red barn with white trimmings he observed that white moths 7,spilosoma1 ,hyphantria1 and ,acronycta oblinita7 rested on the white parts1 while on the darker1 reddish portions sat ,catocal and other dark or reddish moths4 ,gross observed that house-flies would frequent a bluish green ring on the ceiling of his chamber2 but if it were covered by white paper1 the flies would leave the spot1 though they would return as soon as the paper ring was removed 7,kolbe74 ,we have observed that house-flies prefer green paper to the yellowish wall of a kitchen1 but were not attracted to sheets of a ,prussian blue paper1 attached to the same wall and ceiling4 ,it is generally supposed that the shape and high colors of flowers attract insects2 but ,plateau has made a number of ingenious experiments which tend to disprove this view4 ,he used in his investigations the dahlia1 with its central head of flowerets1 which contrast so strongly with the corolla4 ,he finds 7#a7 that insects frequent flowers which have not undergone any mutilation1 but whose form and colors are hidden by green leaves4 7#b7 ,neither the shape nor lively colors of the central head 7capitulum7 seem to attract them4 7#c7 ,the gayly colored peripheral flowerets of simple dahlias and1 consequently1 of the heads of other composite flowers1 do not play the rle of signals1 such as has been attributed to them4 7#d7 ,the insects are evidently guided by another sense than that of sight1 and this sense is probably that of smell4 ,,literature ,,on ,,the ,,eyes ,,and ,,vision a4 ,general ,serres1 ,marcel de4 ,mmoires sur les yeux composs et les yeux lisses des insectes4 ,montpellier1 #ahac4 ,mller1 ,johannes4 ,zur vergleichenden ,physiologie des ,gesichtssinnes der ,menschen und der ,tiere4 #h ,taf4 ,leipzig1 #ahbf4 ---- ,ueber die ,augen des ,maikfers4 7,meckel's ,archiv f4 ,anat4 u4 ,phys41 #ahbi1 pp4 #agg-aha2 ,ann4 d4 ,sc4 nat41 #ahbi1 sr4 #a1 xviii1 pp4 #ajh-aab47 ,dujardin1 ,f4 ,sur les yeux simples ou stemmates des animaux articuls4 7,c4 ,r4 ,acad4 ,sci41 ,paris1 #ahdg1 xxv1 pp4 #gaa-gad47 ,gottsche1 ,c4 ,m4 ,beitrag zur ,anatomie und ,physiologie des ,auges der ,krebse und ,fliegen4 7,mller's ,archiv fr ,anat4 u4 ,phys41 #aheb1 pp4 #dhc-dib4 ,figs47 ,murray1 ,andrew4 ,on insect vision and blind insects4 7,edinburgh ,new ,phil4 ,jour41 new ser4 vi1 #aheg1 pp4 #abj-ach47 ,claparde1 douard4 ,zur ,morphologie der zusammengesetzten ,augen bei den ,arthropoden4 7,zeitschr4 f4 wissensch4 ,zool41 #ahei1 x1 pp4 #aia-bad1 #c ,taf47 ,dor1 ,h4 ,de la vision chez les ,arthropodes4 7,archives ,sci4 ,phys1 et ,nat41 #ahfa1 xii1 p4 #bb1 #a ,pl47 ,landois1 ,h4 ,die ,raupenaugen 7,ocelli compositi mihi74 7,zeitschr4 f4 wissensch4 ,zool41 xvi1 #ahff1 pp4 #bg-dd1 #a ,taf47 ---- und ,w4 ,thelen4 ,zur ,entwicklungsgeschichte der fasettierten ,augen von ,tenebrio molitor ,l4 7,zeitschr4 f4 wissensch4 ,zool41 xvii1 #ahfg1 pp4 #cd-dc1 #a ,taf47 ,schultze1 ,max4 ,untersuchungen ber die zusammengesetzten ,augen der ,krebsen und ,insecten4 ,bonn1 #ahfh4 ,schmidt1 ,oscar4 ,die ,form der ,krystallkegel in ,arthropodenauge4 7,zeitschr4 f4 wissensch4 ,zool41 xxx1 ,suppl41 #ahgh1 pp4 #a-ab1 #a ,taf47 ,grenacher1 ,h4 ,untersuchungen ueber das ,sehorgan der ,arthropoden1 insbesondere ,spinnen1 ,insecten und ,crustaceen4 7,gttingen1 #ahgi1 #d1 pp4 #a-ahh1 #aa ,taf47 ,reichenbach1 ,h4 ,wie die ,insekten sehen4 ,fig4 7,daheim1 xvi ,jahrg41 #ahhj1 pp4 #bhd-bhf47 ,poletajew1 ,n4 ,ueber die ,ozellen und ihr ,sehvermgen bei den ,phryganiden4 7,hor ,soc4 ,ent4 ,ross41 #ahhd1 xviii1 p4 #bc1 #a ,taf4 ,in ,russian47 ,hickson1 ,s4 ,j4 ,the eye and optic tract of insects4 7,quart4 ,journ4 ,micr4 ,sc41 ser4 #b1 xxv1 #ahhe1 pp4 #bae-bba1 #c ,pls47 ,notthaft1 ,jul4 ,ueber die ,gesichtswahrnehmungen vermittelst des ,fazettenauges4 7,abhandl4 ,senckenberg4 naturf4 ,ges41 xii41 #ahhj1 pp4 #ce-abd1 #e ,taf47 ---- ,die physiologische ,bedeutung des fazettierten ,insektenauges4 7,kosmos1 #ahhf1 xviii1 pp4 #ddb-dej1 ,fig47 ,mark1 ,e4 ,l4 ,simple eyes in arthropods4 7,bull4 ,mus4 ,comp4 ,zool41 #ahhg1 xiii1 pp4 #di-aje1 #e ,pls47 ,girschner1 ,e4 ,einiges ber die ,frbung der ,dipterenaugen4 7,berlin4 ,ent4 ,zeitschr41 #ahhh1 xxxi1 pp4 #aee-afb1 #a ,taf47 ,graber1 ,v4 ,das unicorneale ,tracheatenauge4 7,archiv f4 ,mikroskop4 ,anat41 xvii1 #ahgi1 pp4 #eh-ic1 #c ,taf42 ,nachtrag1 p4 #id47 ---- ,fundamentalversuche ber die ,helligkeits- und ,farbenempfindlichkeit augenloser und geblendeter ,tiere4 7,sitzgs4-,ber4 ,akad4 ,wissensch41 ,wien1 #ahhc1 lxxxvii1 pp4 #bja-bcf47 ,dahl1 ,fr4 ,die ,insekten knnen ,formen unterscheiden4 7,zool4 ,anz41 xii1 #ahhi1 pp4 #bdc-bdg47 ,ciaccio1 ,g4 ,v4 ,figure dichiarative della minuta fabbrica degli occhi de' ,ditteri4 ,bologna1 #ahhd1 #ab ,taf41 #cj pp4 ---- ,della minuta fabbrica degli occhi de' ,ditteri4 7,mem4 ,accad4 ,bologna1 #ahhf1 ser4 #d1 vi1 pp4 #fje-ffj47 ---- ,sur la forme et la structure des facettes de la corne et sur les milieux refringents des yeux composs des ,muscids4 7,journ4 ,micr41 ,paris1 #ahhi1 xiii ,anne1 pp4 #hj-hd47 ,carrire1 ,j4 ,on the eyes of some invertebrata4 7,quart4 ,journ4 ,micr4 ,sc4 #ahhd1 ser4 #b1 xxiv1 pp4 #fgc-fha1 #a ,pl47 ---- ,ueber die ,arbeiten von ,viallanes1 ,ciaccio und ,hickson4 7,biolog4 ,centralblatt1 v1 #ahhe1 pp4 #ehi-eig47 ---- ,die ,sehorgane der ,tiere vergleichend anatomisch dargestellt4 ,mnchen u4 ,leipzig1 #ahhe1 #bje pp41 #adg ,figs41 #a ,taf4 ---- ,kurze ,mitteilungen aus fortgesetzten ,untersuchungen ber die ,sehorgane4 7,zool4 ,anz41 ix ,jarhg41 #ahhf1 pp4 #ada-adg1 #dgi-dha1 #dif-ejj47 ,forel1 ,a4 ,les fourmis de la ,suisse4 7,neue ,denkschriften der schweiz4 naturforsch4 ,gesellsch4 xxvi4 #ahgd1 pp4 #dhj1 #b ,pls47 ,separate4 pp4 iv u4 #deg4 ,genve4 ---- ,beitrag zur ,kenntnis der ,sinnesempfindungen der ,insekten4 7,mitteil4 d4 ,mnchener ,ent4 ,vereins1 ii ,jahrg41 #ahgh1 pp4 #a-ba47 ---- ,sensations des insectes4 7,recueil ,zool4 ,suisse1 iv1 #ahhf et #ahhg47 ,plateau1 ,f4 ,l'instinct chez les insectes mis en dfaut par les fleurs artificielles8 7,assoc4 franaise avancement des sciences4 ,congrs de ,clermont4 ,ferrand1 #ahgf47 ,plateau1 ,f4 ,recherches exprimentales sur la vision chez les insectes4 ,les insectes distinguent-ils la forme des objets8 7,bull4 ,acad4 ,belg4 #c ,sr4 x1 #ahhe1 pp4 #bca-bej47 ---- ,recherches exprimentales sur la vision chez les insectes4 #a4 ,part1 a4 ,rsum des travaux effectus jusqu'en #ahhg sur la structure et le fonctionnement des yeux simples4 b4 ,vision chez les ,myriapodes4 7,ibid4 ,sr4 #c1 xiv1 #ahhg1 pp4 #djg-ddh1 #a ,pl47 #c4 ,part1 a4 ,vision chez les chenilles1 b4 ,rle des ocelles frontaux chez les insectes parfaits4 7,ibid4 ,sr4 #c1 xv1 #ahhh1 pp4 #bh-ia47 #d4 ,part4 ,vision l'aide des yeux composs4 a4 ,rsum anatomo-physiologique4 b4 ,expriences comparatives sur les insectes et sur les vertbrs4 7,mm4 cour4 et autres ,mm4 ,acad4 ,belg4 #ahhh1 xliii1 pp4 #a-ia1 #b ,pls47 #e4 ,part1 a4 ,perception des mouvements chez les insectes4 b4 ,addition aux recherches sur le vol des insectes avengls4 c4 ,rsum gnral4 7,bull4 ,acad4 ,belg4 #ahhh1 sr4 #c1 xvi1 pp4 #cie-deg1 #a ,pl47 ---- ,recherches exprimentales sur la vision chez les ,arthropodes1 #b ,pls4 7,mm4 couronn4 et autres ,mm4 publ4 p4 l',acad4 ,roy4 d4 ,sciences1 etc41 de ,belgique1 xliii1 ,bruxelles1 #ahhi47 ,watase1 ,s4 ,on the morphology of the compound eyes in the ,arthropoda4 7,studies from biol4 laborat4 ,johns-,hopkins ,univ41 #ahij1 pp4 #bhg-ccd1 #d ,pls47 ,stefanowska1 ,m4 ,la disposition histologique du pigment dans les yeux des ,arthropodes4 7,recueil ,zool4 ,suisse1 #ahij1 pp4 #aea-bjj1 #b ,pls47 ,pankrath1 ,o4 ,das ,auge der ,raupen und ,phryganiden larven4 7,zeitschr4 f4 wissensch4 ,zool41 #ahij1 xlix1 pp4 #fij-gjh1 #b ,taf47 ,lowne1 ,b4 ,th4 ,on the modifications of the simple and compound eyes of insects4 7,philos4 ,trans4 ,roy4 ,soc41 ,london1 clxix1 #ahgh1 pp4 #egg-fjb1 #c ,pls47 ---- ,on the structure and functions of the eyes of ,arthropoda4 7,proc4 ,roy4 ,soc41 ,london1 #ahhc1 xxxv1 pp4 #adj-ade47 ---- ,on the compound vision and the morphology of the eye in insects4 7,trans4 ,linn4 ,soc41 ,london1 #ahhd1 ii1 pp4 #chi-dbj1 #d ,pls47 ---- ,on the structure of the retina of the blow-fly 7,calliphora erythrocephala74 7,jour4 ,linn4 ,soc41 ,london1 #ahij1 xx1 pp4 #djf-dag1 #a ,pl47 ,patten1 ,w4 ,eyes of molluscs and arthropods4 7,journal of ,morphol41 ,boston1 #ahhg1 i1 pp4 #fg-ib1 #a ,pl42 ,mitteil4 ,zool4 ,stat4 ,neapel1 vi1 #ahhf1 pp4 #edb-gef1 #e ,taf47 ---- ,studies on the eyes of arthropods4--#a4 ,development of the eyes of ,vespa1 with observations on the ocelli of some insects4 7,ibid41 pp4 #aic-bbf1 #a ,pl47--#b4 ,eyes of ,acilius4 7,ibid41 #ahhh1 ii41 pp4 #aij-ig1 #g ,pls47 ---- ,on the eyes of molluscs and arthropods4 7,zool4 ,anzeiger1 #ahhg1 x ,jahrg41 pp4 #bef-bfa47 ---- ,is the ommatidium a hair-bearing sense-bud8 7,anatom4 ,anzeiger1 #ahij1 v1 pp4 #cec-cei1 #d ,figs47 ,exner1 ,s4 ,ueber das ,sehen von ,bewegungen und die ,theorie des zusammengesetzten ,auges4 7,sitzgsber4 d4 math4 naturwiss4 ,cl4 kais4 ,akad4 d4 ,wissens4 ,wien1 lxxii ,jahrg41 #ahge1 #c ,abt4 ,physiologie1 pp4 #aef-aij1 #a ,taf47 ---- ,die ,frage von der ,funktionsweise der ,fazettenauges4 7,biolog4 ,centralblatt1 i1 #ahha1 pp4 #bgb-bha47 ---- ,das ,netzhautbild des ,insektenauges4 7,sitzgsber4 kais4 ,akad4 d4 ,wissensch4 ,wien1 #ahhi1 xcviii1 #c ,abt41 pp4 #ac-fe1 #b ,taf4 u4 #g ,figs47 ---- ,durch ,licht bedingte ,verschiebungen des ,pigmentes im ,insektenauge und deren physiologische ,bedeutung4 7,ibid41 pp4 #adc-aea1 #a ,taf47 ,exner1 ,s4 ,die ,physiologie der fazettierten ,augen von ,krebsen und ,insekten1 #g ,taf41 #a1 ,lichtdruck u4 #bc ,holzschn4 pp4 #bjf4 ,wien1 ,f4 ,deuticke1 #ahia4 ,lubbock1 ,john4 ,on the senses1 instincts1 and intelligence of animals1 with special reference to insects4 ,london1 #ahhh1 pp4 #bib4 ,mallock1 ,a4 ,insect sight and the defining power of composite eyes4 7,proc4 ,roy4 ,soc41 ,london1 #ahid1 lv1 pp4 #he-ij1 #c ,figs47 b4 ,the color-sense ,nussli1 ,j4 ,ueber den ,farbensinn der ,bienen4 7,schweiz4 ,bienenzeitung1 ,n4 ,f41 ii ,jahrg41 #ahgi1 pp4 #bch-bdj47 ,kramer4 ,der ,farbensinn der ,bienen4 7,ibid41 iii ,jahrg41 #ahhj1 pp4 #agi-aih47 ,gross1 ,wilhelm4 ,ueber den ,farbensinn der ,tiere1 insbesondere der ,insekten4 7,isis v4 ,russ41 v ,jahrg41 #ahhj1 pp4 #bib-bid1 #cjj-cjb1 #cjh-cji47 ,lubbock1 ,john4 ,ants1 bees1 and wasps4 ,london1 #ahhb1 pp4 #ddh4 ,also ,on the senses1 etc41 of animals1 #ahhi4 ,graber1 ,vitus4 ,grundlinien zur ,erforschung des ,helligkeits und ,farbensinnes der ,tiere4 ,prag u4 ,leipzig1 #ahhd1 pp4 #cbb4 7,see also p4 #bfb47 ,forel1 ,auguste4 ,les ,fourmis peroisent-elles l'ultra-violet avec leurs yeux ou avec leur peau8 7,arch4 ,sci4 ,phys4 ,nat4 ,genve1 #ahhf1 #c sr41 xvi1 pp4 #cdf-cej47 ,also the works of ,darwin1 ,wallace1 ,f4 ,mller1 ,grant ,allen's ,the ,color ,sense 7#ahgi71 ,beddard's ,animal ,coloration1 etc4 b4 ,the organs of smell ,the seat of the organs of smell is mainly in the antenn1 and they may be regarded as the principal olfactory organs4 ,for our present knowledge of the anatomy and physiology of the olfactory organs of insects we are mainly indebted to the recent investigations of ,hauser and of ,kraepelin4 ,the following historical and critical remarks are translated from ,kraepelin's able treatise3 ,historical sketch of our knowledge of the organs of smell4--,in the first half of the last century began the inquiries as to the seat of the sense of smell in the arthropods4 ,thus ,raumur1 in his ,mmoires 7i1 p4 #bhc2 ii1 #bbd71 expressed the view that in the antenn was situated a special organ which might be an organ of smell4 ,lesser1 ,roesel1 ,lyonet1 ,bonnet1 and others expressed the same opinion4 ,before this ,sulzer suggested that an 8unknown sense0 might exist in the antenn2 others regarded the stigmata as organs of smell1 as these were considered the natural passages for the olfactory currents4 ,dumril1 in two special treatises as well as in his ,considrations gnrales1 sought to prove the theory as to the seat of the organs of smell in the stigmata4 ,against both of these leading views as to the seat of the sense of smell were expressed1 in the last century1 different opinions4 ,thus ,comparetti thought that the sense of smell might be localized in very different points of the head1 in the antennal club of lamellicorns1 in the sucking-tube of ,lepidoptera1 in special frontal holes of flies and ,orthoptera1 etc41 while ,bonsdorf considered the palpi as organs of smell4 ,thus four different views1 confused1 were held at the opening of this century2 the ,hamburg zologist1 ,m4 ,c4 ,s4 ,lehrman1 in three different treatises1 brought together all the hitherto known observations and arguments1 treated them critically1 and completed them by his own extended studies4 ,lehrman adopted the opinions of ,reimarus1 ,baster1 ,dumril1 and ,schelver1 that the stigmata presented the most convenient place for the site of the organs of smell4 ,cuvier followed throughout the lead of ,lehrman1 but ,latreille returned to the view of the perception of smell by the antenn1 while ,treviranus considered the mouth of arthropods as the probable site of the sense of smell1 an opinion which1 before his time1 ,huber1 in his experiments on bees1 had thought to be correct4 ,marcel de ,serres 7#ahaa7 returned again to the palpi1 and asserted--at least in the ,orthoptera--their functions to be olfactory1 while ,blainville1 ten years later1 again expressed anew the old opinion that the antenn1 or at least their terminations1 were organs of smell4 ,up to that date there was an uncertainty as to the seat of the organs both of smell and hearing4 ,fabricius1 indeed1 had already1 in #aghc1 thought he had found an organ of hearing at the base of the outer antenna4 ,in #ahbf ,j4 ,mller mentioned an already well-known organ in the abdomen of crickets as an organ of hearing4 ,mller1 however1 was doubtful1 from the fact that the nerve passing to this organ arose1 not from the brain1 but from the third thoracic ganglion2 but1 notwithstanding1 he remarks3 8,perhaps we have not found the organ of hearing in insects because we sought for it in the head40 ,this discovery was afterwards considerably broadened and extended by ,siebold's work1 for the views of these naturalists on the seat of both organs had a definite influence1 especially in ,germany4 ,for awhile1 indeed1 ,mller's hypothesis stood in complete contradiction1 so that during the following decennial was presented anew the picture of opposing observations and opinions as to the nature of the organs of smell4 ,while ,robineau-,desvoidy1 at the end of the twentieth year1 and also later1 in different writings1 strove energetically for the olfactory nature of the antenn1 ,straus-,drckheim held fast to the view that the trache possessed the function under discussion4 ,at the same period ,kirby and ,spence1 in their valuable ,introduction to ,entomology1 maintained that 8two white cushions on the under side of the upper lip0 in the mouth of biting insects formed a nose or 8rhinarium0 peculiar to insects4 ,this opinion was afterwards adopted by ,lacordaire 7,introduction ,entomologie71 and also by ,oken in his ,lehrbuch der ,naturphilosophie1 while ,burmeister1 rejecting all the views previously held1 believed that insects might perhaps smell 8with the inner upper surface of the skin40 ,mller's locust's ear he regarded as a vocal organ4 ,besides these occasional expressions of opinion1 the ,french literature of the thirtieth and fortieth years of this century recorded a long series of special works1 with weighty experimental and physiological contents1 on this subject4 ,thus ,lefebre1 in #ahch1 described the experiments which he made on bees1 and which seemed to assign the seat of the sense of smell to the antenn4 ,dugs reported similar researches on the ,scolopendr1 and ,pierret thought that the great development of the antenn in the male ,bombycid might be similarly interpreted4 ,driesch sought to give currency to the views of ,bonsdorf1 ,lamarck1 and ,marcel de ,serres1 that the sense of smell was localized in the palpi1 though ,duponchel went back to the old assertion of roscepsis of ,lehrman1 i4e4 of the air-test through the antenn1 and ,goureau again referred the seat of the sense of smell to the mouth4 ,in ,england1 ,newport at this period put forth a work in which he considered the antenn as organs of touch and hearing1 and the palpi as organs of smell--a view which1 as regards the antenn1 was opposed by ,newman4 ,thus the contention as to the use of the antenn and the seat of the organs of smell and hearing fluctuated from one side to the other1 and when in #ahdd ,kster1 by reason of his experiments on numerous insects1 again claimed that 8the antenn are the smelling organs of insects10 he argued on a scientific basis2 yet v4 ,siebold and ,stannius 7#ahdh71 in their valuable ,lehrbuch der vergleichenden ,anatomie 7p4 #eha71 remarked that 8organs of smell have not yet with certainty been discovered in these animals40 ,the following decennial was of marked importance in the judgment of many disputed questions4 ,almost contemporaneously with ,siebold and ,stannius' ,lehrbuch appeared an opportune treatise by ,erichson1 in which this naturalist first brought forward certain anatomical data as to the structure of the antenn of insects4 ,in a great number of insects ,erichson described on the upper surface of the antenn peculiar minute pits1 8pori10 which1 according to him1 were covered by a thin membrane1 and to which he ascribed the perception of smell4 ,a still more thorough work on this subject was published in the following year by ,burmeister1 who recognized in the pits of lamellicorns many small tubercles and hairs2 and about the same time ,slater1 as also ,pierret and ,erichson before him had done1 out of the differences of the antennal development in the males and females in flesh and plant-eating insects1 brought together the proof of the olfactory function of the antenn4 ,but the most valuable work of this period is that of ,perris1 who1 after a review of previous opinions1 by exact observations and experiments1 a model of their kind1 sought to discover the seat of the sense of smell4 ,he comes to the conclusion that the antenn1 and perhaps also the palpi1 may claim this sense1 and finds full confirmation of ,dufour's views1 and adopts as new the physiological possibility expressed by ,hill and ,bonnet1 that the antenn might be the seat of both senses--those of smell and hearing4 ,the beautiful works of ,erichson1 ,burmeister1 and ,perris could not remain long unnoticed4 ,in #aheg ,hicks published complete researches on the peculiar nerve-endings which he had found in the antenn1 also in the halteres of flies and the wings of all the other groups of insects1 and which he judged to be for the perception of smell4 ,but ,erichson's and ,burmeister's 8pori0 were by ,lesps1 in #aheh1 explained to be so many auditory vesicles with otoliths4 ,this view was refuted by ,claparde and ,claus without their deciding on any definite sense4 ,leydig first made a decided step in advance4 ,in different writings this naturalist had busied himself with the integumental structures of arthropods1 and declared ,erichson's view as to the olfactory nature of the antennal pits as the truest1 before he1 in his careful work on the olfactory and auditory organs of crabs and insects1 had given excellent representations of the numerous anatomical details which he had selected from his extensive researches in all groups of arthropods4 ,besides the pits which were found to exist in ,crustacea1 ,scolopendr1 beetles1 ,hymenoptera1 ,diptera1 ,orthoptera1 ,neuroptera1 and ,hemiptera1 and which had only thus far been regarded as sense-organs1 ,leydig first calls attention to the widely distributed pegs and teeth1 also considering them as sense-organs4 8,olfactory teeth10 occurring as pale rods1 perforated at the end1 on the surface of the antenn of ,crustacea1 ,myriopoda1 ,hymenoptera1 ,lepidoptera1 ,coleoptera1 are easily distinguished1 and besides the 8olfactory pegs0 of the palpi1 may be claimed as organs of smell4 ,the nerve-end apparatus first discovered by ,hicks in the halteres and wings1 ,leydig thinks should be ranked as organs of hearing4 ,there was still some opposition to ,leydig's opinion that in the insects the sense of smell is localized in the antenn 7teeth and pits71 and here the work of ,hensen might be mentioned1 which in #ahfj had a decided influence upon the conclusion of some inquiries4 ,thus ,landois denied that the antenn had the sense of smell1 and declared that the pits in the antenn of the stag beetle were auditory organs4 ,so1 also1 ,paasch rejected ,leydig's conclusion1 while he sought to again reinstate the old opinion of ,rosenthal as to the olfactory nature of the frontal cavity of the ,diptera4 ,in spite of the exact observations and interesting anatomical discoveries of ,forel in ants1 made in #ahgd1 there appeared the great work of ,wolff on the olfactory organs of bees1 in which this observer1 with much skill and acuteness1 sought to give a basis for the hypothesis of ,kirby and ,spence that the seat of the sense of smell lay in the soft palatine skin of the labrum within the mouth 7i4e4 the epipharynx74 ,joseph1 two years later1 drew attention to the stigmata as olfactory organs1 referring to the olfactory girdle1 and ,forel sought by an occasional criticism of ,wolff's conclusions to prove experimentally the olfactory function of the antenna2 but ,graber1 in his widely read book on insects1 defended the ,wolffian 8nose0 in the most determined way1 and denied to the antenn their so often indicated faculty of smell4 ,in #ahgi ,bert thought he had observed in the antenna of the flea a distinct auditory organ1 and ,lubbock considered the organs of ,forel in the antenn of ants as a 8microscopic stethoscope40 ,in #ahgi ,graber described a new otocyst-like sense-organ in the antenn of flies1 which was accompanied by a complete list of all the conceivable forms of auditory organs in arthropods4 ,in this work ,graber described in ,musca and other ,diptera closed otocysts with otoliths and auditory hairs1 as ,lesps had previously done4 ,but ,paul ,mayer1 in two essays1 refuted this view in a criticism of the opinion of ,bert1 referring the 8otocysts with otoliths0 to the well-known antennal pits into which trache might pass4 ,mayer did not decide on the function of the hairs which extend to the bottom of the pits2 while in the most recent research1 that of ,hauser1 the author again energetically contended for the olfactory function of the antenn4 ,both through physiological experiments and detailed anatomical investigations ,hauser sought to prove his hypothesis1 as ,pierrot1 ,erichson1 ,slater1 and others had done before him1 besides working from an evolutional point of view4 ,in a purely anatomical aspect1 especially prominent are his discovery of the singularly formed nerve-rods in the pits and peg-like teeth of the ,hymenoptera and their development1 as well as the assertion that numerous hairs in the pits described by ,leydig1 ,meyer1 etc41 should be considered as direct terminations of nervous fibres passing into the pits4 ,in the pits he farther1 with ,erichson1 notices a serous fluid1 which may serve as a medium for the perception of smells4 ,among the latest articles on this subject are those of ,knckel and ,gazagnaire1 which are entirely anatomical1 while the latest treatise of ,graber on the organs of hearing in insects opposes ,hicks's theory of the olfactory function of the nerve-end apparatus in the halteres1 wings1 etc41 and argues for the auditory nature of these structures4 ,finally1 according to ,voges1 the sense of smell is not localized1 but spread over the whole body4 ,my own observations on different groups of insects agree1 in general1 with those of ,perris1 ,forel1 and ,hauser1 without being in a position to confirm or deny the varying relations of the ,hemiptera4 ,that irritating odorous substances 7chloroform1 acetic acid7 cause the limbs to move in sympathy with the stimulus1 ,i have seen several times in ,acanthosoma2 still it may be a gustatory rather than olfactory stimulus4 ,turning now from speculation and simple observation to exact anatomical and histological data1 the nerve-end apparatus seems to have a distinct reference to the perception of odors4 ,it comprises a structure composed of nervous substances which are enclosed in a chitinous tube1 and either only stand in relation to the surrounding bodies by the perforated point1 or pass to the surface as free nerve-fibrill4 ,in insects there is a remarkable and fundamental difference in the structures of the parts supposed to be the organs of smell4 ,erichson was acquainted only with the 8pori0 covered by a thin membrane2 but ,burmeister1 in his careful work on the antenn of the lamellicorns1 distinguished pits at the bottom of which hairs rise from a cup-like tubercle1 from those which were free from hairs4 ,leydig afterwards was the first to regard as olfactory organs the so-called pegs 7kegel71 a short1 thick1 hair-like structure distinctly perforated at the tip1 which had already1 by ,lesps in ,cercopis1 etc41 been described as a kind of tactile papilla4 ,other very peculiar olfactory organs of different form1 ,forel 7,fourmis de la ,suisse7 discovered in the antenn of ants1 which ,lubbock incorrectly associated with the nerve-end apparatus found by ,hicks in other insects4 ,as the final result of his researches ,kraepelin states that the great variety of antennal structures previously described may be referred to a single common fundamental type of a more or less developed free or sunken hair-like body which stands in connection by means of a wide pore-canal with a many-nucleated ganglion-cell4 ,the latter sends only a relatively slender nerve-fibre 7axial cord7 through the pore-canal into the hair2 but the same is enclosed by epithelial cells which surround the pore-canal4 ,hauser's researches on the organs of smell in insects were so carefully made and conclusive that our readers will1 we feel sure1 be glad to have laid before them in detail the facts which prove so satisfactorily that the antenn of most insects are olfactory rather than auditory in their functions4 ,physiological experiments4--,first of all one should observe as exactly as possible the normal animal in its relation to certain odorous substances1 whose fumes possess no corrosive power or peculiarities interfering with respiration2 then remove the antenn and try after several days to ascertain what changes have taken place in the relation of the animal to the substance4 ,in order to come to no false results it is often necessary to let the insects operated upon rest one or two days1 for immediately after the operation they are generally so restless that a careful experiment is impossible4 ,the extirpation of the antenn is borne by different insects in different ways2 many bear it very easily1 and can live for months after the operation1 while others die in the course of a few days after the loss of these appendages4 ,the animals seem to be least injured if the operation is performed at a time when they are hibernating4 ,pyrrhocoris apterus1 and many other insects1 afforded a very striking proof of this relation4 ,experiments made by placing the antenn in liquid paraffine so as to cover them with a layer of paraffine1 thus excluding the air1 gave the same result as if the antenn had been removed4 ,the experiments may be divided1 according to their object1 into three groups4 ,experiments of the first kind were made on insects in their relation to strong-smelling substances1 as turpentine1 carbolic acid1 etc41 before and after extirpation of the antenn4 ,the second group embraces experiments on the relation of animals as regards their search for food2 and finally the third group embraces experiments on the relation of the sexes relative to reproduction before and after the extirpation of the antenn4 ,relation of insects to smelling substances before and after the loss of their antenn4--,taking a glass rod dipped in carbolic acid and holding it within #aj cm4 of ,philonthus neus1 found under stones at the end of ,february1 it was seen to raise its head1 turn it in different directions1 and to make lively movements with its antenn4 ,but scarcely had ,hauser placed the rod close to it when it started back as if frightened1 made a sudden turn1 and rushed1 extremely disturbed1 in the opposite direction4 ,when he removed the glass rod1 the creature busied itself for some time with its antenn1 while it drew them1 with the aid of its fore limbs1 through its mouth1 although they had not come into direct contact with the carbolic acid4 ,there was the same reaction against oil of turpentine1 and it was still more violent against acetic acid4 ,after having many times carefully tested the relations of the normal animal to the substances mentioned1 the antenn were removed from the socket-cavity4 ,on the second day after ,hauser experimented with the insects1 they exhibited no reaction either against the carbolic acid1 the oil of turpentine1 or even against the acetic acid1 although he held the glass rod which had been dipped into it for one or two minutes before and over the head4 ,the creatures remained completely quiet and immovable1 at the most slightly moving the palpi4 ,they showed otherwise no change in their mode of life and their demeanor2 they ate with great eagerness flesh which had been placed before them1 or dead insects1 and some were as active as usual as late as ,may4 ,these beetles had1 as proved by the experiments1 lost the sense of smell alone2 how far the sense of touch was lost ,hauser could not experimentally decide4 ,the same results followed experiments with species of the genus ,ptinus1 ,tenebrio1 ,ichneumon1 ,formica1 ,vespa1 ,tenthredo1 ,saturnia1 ,vanessa1 and ,smerinthus2 also many species of ,diptera and ,orthoptera1 besides ,julus and ,lithobius1 while many larv reacted in the same manner4 ,less satisfactory were the experiments with ,carabus1 ,melolontha1 and ,silpha2 there is no doubt that the species of these genera1 through the extirpation of their antenn1 become more or less injured as to the acuteness of their powers of smelling2 but they never show themselves wholly unable to perceive strong-smelling substances4 ,the allurement of the substance acts for a longer time on those deprived of their antenn1 then they become restless1 then they wander away from the glass tube held before them2 still all their movements are but slightly energetic1 and the entire reaction is indeterminate and enfeebled4 ,experiments with the ,hemiptera gave still more unfavorable results2 after the loss of their antenn they reacted to smells as eagerly as those did which were uninjured4 ,experiments on the use of the antenn in seeking for food4--,under this head experiments were made with ,silpha1 ,sarcophaga1 ,calliphora1 and ,cynomyia4 ,silpha and its larva were treated in the following manner3 they were placed in large boxes whose bottoms were covered with moss1 etc42 in a corner of the box was placed a bottle with a small opening1 in which was placed strong-smelling meat4 ,so long as the beetles were in possession of their antenn they invariably after a while discovered the meat exposed in the bottle1 while after the loss of their antenn they did not come in contact with it4 ,in a similar way acted the species of ,sarcophaga1 ,calliphora1 and ,cynomyia4 ,hauser1 in experimenting with these1 placed a dish with a large piece of decayed flesh on his writing-table4 ,in a short time specimens of the flies referred to entered through the open window of the room4 ,the oftener he drove them away from the meat would they swarm thickly upon it4 ,then closing the window and catching all the flies1 he deprived them of their antenn and again set them free4 ,they flew about the room1 but none settled upon the flesh nor tried to approach it4 ,where a fly had alighted on a curtain or other object1 the decayed flesh was placed under it so that the full force of the effluvium should pass over it1 but even then no fly would settle upon it4 ,experiments testing the influence of the antenn of the males in seeking the females4--,for this purpose ,hauser chose those kinds in which the male antenn differ in secondary sexual characters from those of the female1 and in which it is known that they readily couple in confinement1 as ,saturnia pavonia1 ,ocneria dispar1 and ,melolontha vulgaris4 ,the two first-named insects did not couple after the extirpation of their antenn4 ,of ,melolontha vulgaris twenty pairs were placed in a moderately sized box4 ,on the next morning twelve pairs of them were found coupling4 ,hauser then1 after removing the first lot1 placed a new set of thirty pairs in the same box1 cut off all the antenn of the males and those of a number of females4 ,on the following morning only four pairs were found coupling1 and at the end of three days five others were observed sexually united4 ,from these experiments ,hauser inferred that those insects deprived of their antenn were placed in the most favorable situation1 such as they would not find in freedom2 for the space in which the insects moved about was so limited that the males and females must of necessity meet4 ,but at the same time the results of the experiments cannot absolutely be regarded as proving that the males1 after the loss of their antenn1 were then not in condition to find the females1 because in the case of the above-mentioned moths1 under similar conditions1 after the extirpation of the antenn no sexual union took place4 ,if1 however1 the experiments made do not all lead to the results desired1 ,hauser thinks that the results agree with those of his histological researches1 that in the greater number of insects the sense of smell has its seat in the antenn4 ,his results also agree with those of ,perris4 ,structure of the organs of smell in insects4--,the olfactory organs consist1 in insects1--i4e41 all ,orthoptera1 ,termitid1 ,psocid1 ,diptera1 and ,hymenoptera1 also in most ,lepidoptera1 ,neuroptera1 and ,coleoptera1-- #a4 ,of a thick nerve arising from the brain1 which passes into the antenn4 #b4 ,of a sensitive apparatus at the end1 which consists of staff-like cells1 which are modified hypodermis cells1 with which the fibres of the nerves connect4 #c4 ,of a supporting and accessory apparatus1 consisting of pits1 or peg- or tooth-like projections filled with a serous fluid1 and which may be regarded as invaginations and outgrowths of the epidermis4 ,hauser adds a remark on the distribution of the pits and teeth in the larv of insects1 saying that his observations are incomplete1 but that it appears that in the larv the teeth are most generally distributed1 and that they occur not on the antenn alone1 but on the palpi2 but in very many larv neither pits nor teeth#dg occurred4 ,in the ,myriopoda teeth-like projections occur on the ends of the antenn4 ,in ,lithobius they form very small1 almost cylindrical1 pale organs4 ,illustration3 ,,fig4 #bfh4--,olfactory organ of ,caloptenus4 ,illustration3 ,,fig4 #bfi4--,olfactory pits of the antenna of ,stenobothrus4 ,this and ,fig4 #bfh after ,hauser4 ,,lettering ,,for ,,figs4 #bfh1 #bfi1 #bgc1 #bge1 #bgf1 #bgh-bha4--;a1 a1 circular thickening of the skin surrounding the opening of the olfactory pit2 ax1 thread-like continuation of the nerve-cell2 b1 vesicle-like bottom of the olfactory pit1 through which the olfactory style passes2 br bristle in ,fig4 #bhc1 stout1 and protecting the olfactory pit2 bs1 bent bristle or seta2 ch1 chitinous integument of the antenn2 d1 seen in section2 f1 invaginated pit2 ,fv1 ,forel's flask-shaped organ2 ,fvo1 its opening seen from the surface2 gl1 gland-like mass of cells2 hyc1 hypodermic cells2 i1 entrance into the canal belonging to the pit2 m1 olfactory membrane2 m1 m1 mc1 membrane-forming cell2 n1 nerve of special sense2 nc1 nucleus of the sense- or ganglion-cell2 o1 opening into the olfactory pit2 p1 olfactory pit2 cp1 compound pits2 pw1 wall of the pit2 s1 a large seta2 sc1 sense- or ganglion-cell2 st1 olfactory or sense-style1 sometimes peg-shaped2 tb1 tactile bristle4 ,illustration3 ,,fig4 #bgj4--;,a1 b1 sense-organ on the abdominal appendages of a fly 7,chrysopila72 c1 sense-organ on the terminal joint of palpus of ,perla4 ,illustration3 ,,fig4 #bga4--,longitudinal section of part of cercus of ,acheta domestica3 ch1 cuticula2 hyp1 hypodermis2 n4 nerve2 h#a1 integumental hairs1 not sensory2 h#b1 ordinary hair2 h#c1 sensory hair2 h#d1 bladder-like hair2 sz1 sense-cell4--,after ,vom ,rath1 from ,sharp4 ,in the course of a special description of these sense-organs in the ,orthoptera1 ,hauser describes at length those of dipoda crulescens and ,caloptenus italicus4 ,on one antennal joint of ,caloptenus 7,fig4 #bfh7 was often counted #ej pits2 on the anterior joints the number diminishes to about #cj4 ,hauser thinks that in all ,orthoptera whose antenn are like those of ,caloptenus occur similar pits1 as he found them in ,stenobothrus 7,fig4 #bfi7 as well as in dipoda4 ,gryllotalpa possesses similar pits1--four to six on each antennal joint1 making between #cjj and #djj pits on each antenna4#dh ,in ,mantis religiosa the pits were not detected1 but on each joint1 except the eighth basal1 there are about #bjj small1 hollow1 curved teeth with a fine opening in front4 ,in the ,neuroptera 7,chrysopa7 there occur on the antenn1 besides numerous very long tactile bristles1 small pale1 transparent teeth4 ,no pits could be detected4 ,in the ,hemiptera 7two species of ,pyrrhocoris only were examined7 only two kinds of tactile bristles occurred1 but ,hauser detected no pits1 though ,lesps states that they are present4 ,illustration3 ,,fig4 #bgb4--,longitudinal section of apex of palpus of ,pieris brassic3 sch1 scales2 ch1 cuticula2 hyp1 hypodermis2 n1 nerve2 sz1 sense-cells2 sh1 sense-hairs4--,after ,vom ,rath1 from ,sharp4 ,of the ,diptera1 ,hauser examined more than #fj species4 ,the pits in the ,diptera brachycera 7,muscid1 etc47 are unexceptionally confined to the third antennal joint4 ,their number varies extraordinarily in the different species4 ,helophilus florens has on each antennal disk only a single pit1 while ,echinomyia grossa possesses #bjj of them4 ,in flies of certain families the pits are compound1 and contain #aj1 #bj1 and often #ajj olfactory hairs1 partly arising from the coalescence of several pits4 ,such pits are usually divided by lateral walls into several chambers1 whose connection is only indicated by their common outlet4 ,simple olfactory pits with a single olfactory style were observed only in the ,tabanid1 ,asilid1 ,bombylid1 ,leptid1 ,dolichopid1 ,stratiomyid1 and ,tipulid4 ,in the last the compound forms do not occur at all1 but in the other families mentioned also occur compound pits1 receiving from two to ten nerve-terminations4 ,the antennal pits of flies are always sac-like invaginations of the external chitinous integument1 of manifold shapes1 opening externally and never closed by a membrane4 ,the pits differ but slightly in the different species1 and that of ,cyrtoneura stabulans 7,fig4 #bgc7 is described at length as typical of those of brachycerous flies in general4 ,the olfactory pits of the ,tipulid seem to have a somewhat different structure1 since the external passage is closed4 ,it is circular1 surrounded with a slight chitinous wall1 and not covered with bristles4 ,such pits in their external appearance are like those of the locust 7,caloptenus7 and many ,hymenoptera4 ,they are situated usually on the third antennal joint4 ,pachyrhina pratensis ,l4 has about #fj of them1 as have ,tipula oleracea ,l4 and ,ctenophora4 ,in the ,lepidoptera1 olfactory pits are much like those of flies4 ,hauser describes in detail those of ,vanessa io4 ,those of the moths were not examined1 but they can be readily and satisfactorily proved to be the site of the olfactory sense4 ,illustration3 ,,fig4 #bgc4--,longitudinal section through the third antennal joint of a fly 7,cyrtoneura stabulans71 showing the compound pits from above and in section4--,after ,hauser4 ,illustration3 ,,fig4 #bgd4--;,antenna of ,adelops1 showing the olfactory organs 7p7 in the five last joints4 ,historical researches in respect to the ,coleoptera generally gave a very unfavorable result1 contrary to ,lesps's views4 ,that author states that in the ,carabid the pits are found on the four first joints1 but ,hauser could discover them in none which he examined4 ,usually only tactile bristles occur1 so also in the ,cerambycid1 ,curculionid1 ,chrysomelid1 and ,cantharid4 ,in a blind silphid beetle 7,adelops hirtus7 of ,mammoth ,cave we have found well-marked olfactory organs 7,fig4 #bgd74 ,similar organs occur in the antenn of the ,panorpid4 ,olfactory pits1 however1 without doubt occur in ,silpha1 ,necrophorus1 ,staphylinus1 ,philonthus1 and ,tenebrio4 ,the openings of the pits are small and surrounded with a small chitinous ring2 in ,silpha1 ,necrophorus1 and ,tenebrio they cannot easily be distinguished from the insertion-cavities of the bristles1 but in ,philonthus and ,staphylinus they are less like them1 being distinguished by their somewhat larger size and their often more oval form4 ,in ,philonthus neus about #ajj such small pits occur irregularly on the terminal joints2 besides1 in this species on each side of the terminal joint is an apparatus which is like the compound pit generally occurring in the ,diptera4 ,illustration3 ,,fig4 #bge4--,olfactory pits of the antenna of ,melolontha vulgaris4--,after ,kraepelin4 ,illustration3 ,,fig4 #bgf4--;,antennal pit of ,melolontha vulgaris1 seen in vertical section4--,after ,hauser4 ,very remarkable pits occur in the antennal lamell of ,melolontha vulgaris 7,fig4 #bge7 and other lamellicorns4 ,on the outer surface of the first and seventh 7in the female the sixth7 antennal leaf1 as also on the edges of the other leaves1 only arise scattered bristles2 on the inner surface of the first and seventh leaves1 as also on both surfaces of the second to sixth leaves1 are close rows of rather shallow depressions of irregular form1 some circular1 others regularly hexagonal4 ,their number is enormous3 in the males #ci1jjj1 in the females about #ce1jjj1 occur on each antenna4 ,illustration3 ,,fig4 #bgg4--,organ of smell of ,anophthalmus4--,after ,hauser4 ,a1 a1 b1 the same in ,a4 tenuis1 ,b in ,a4 tellkampfii4 ,illustration3 ,,fig4 #bgh4--,section through antennal joint of ,vespa crabro1 showing the great number of olfactory pits1 olfactory and tactile bristles4 ,a1 section through an olfactory pit of ,vespa crabro4--,after ,hauser4 ,the antennal pits and teeth of ,dyticus marginalis are morphologically and physiologically identical with those of bees and wasps4 ,in ,anophthalmus bilimekii1 ,hauser found on the last antennal joints about #fj teeth1 which essentially differ in form from those previously described2 they are very pale1 transparent1 cylindrical1 elongated1 and bent elbow-shaped on the first third1 so that the last two-thirds run parallel with the antenna4 ,the length of these remarkable teeth is #j4jce mm41 their breadth #j4jje mm4 ,he only found them in ,anophthalmus1 and in no other species of ,carabid2 they must resemble the teeth described in ,chrysopa4 ,our species possesses similar processes 7,fig4 #bgg74 ,similar teeth occur on the maxillary and labial palpi of beetles4 ,dyticus marginalis possesses at the end of each terminal palpal joint a group of very small teeth1 which were also detected in ,anophthalmus bilimekii1 ,melolontha vulgaris1 etc4 ,in ,carabus violascens were detected on the maxillary palpi large1 plainly microscopical1 white disks1 which are surrounded with a great number of extremely small teeth4 ,whether the above-described organs on the palpi of beetles should be considered as olfactory or gustatory in their nature can only be determined by means of physiological experiments2 they probably receive taste-nerve terminations4 ,illustration3 ,,fig4 #bgi4--,olfactory pits of the antenna of ,vespa vulgaris4--,after ,kraepelin4 ,the ,hymenoptera furnished very good material for histological purposes1 so that ,hauser could not only study the terminal apparatus of the olfactory nerves in the perfect insect1 but also in three different stages of the pupa4 ,these are described at length1 as regards the distribution of the pits and teeth1 in ,vespa crabro2 each joint of the antenna 7flagellum7 possesses between #acjj and #adjj pits1 nearly #fj teeth1 and about #gj tactile hairs2 on the terminal joint there are more than #bjj teeth1 so that each antenna has between #ac1jjj and #ad1jjj olfactory pits and about #gjj teeth 7,kegeln74 ,fig4 #bgh represents a cross-section through the penultimate antennal joint of ,vespa crabro2 we can see how thick are the series of openings on the surface of the antenn1 and how regular is the distribution of the teeth4 ,the distribution of the olfactory pits and olfactory teeth is thus seen to be very general2 the deviations are so insignificant that there is no reason for the establishment of more than one type4 ,antennal pits with a small crevice-like opening occur in genera nearly allied to ,vespa and also in most ,ichneumonid1 ,braconid1 and ,cynipid4 ,but the crevice-like openings in these families are considerably longer and often are of a somewhat twisted shape4 ,in all the species with translucent antenn we can recognize the inner mouth of the pit as a round or nearly round disk situated usually under the middle of the opening4 ,the antennal pits of ,apis mellifica1 as well as those of ,bombus 7,fig4 #bhj7 and allied genera1 differ from those of the ,ichneumonid in being not like crevices1 but circular openings4 ,illustration3 ,,fig4 #bhj4--,olfactory pits of the antenna of ,bombus4--,after ,kraepelin4 ,illustration3 ,,fig4 #bha4--,olfactory pits of the antenna of ,formica3 ,fv1 ,hicks' 8bottle10 ,forel's flask-shaped organ1 ,fvo1 its opening4--,after ,kraepelin4 ,illustration3 ,,fig4 #bhb4--,supposed olfactory organs at end of antenna of ,campodea3 ,a1 ,c4 staphylinus4 ,b1 ,c4 cookei1 from ,mammoth ,cave4 ,illustration3 ,,fig4 #bhc4--,vertical section through a single olfactory pit in the antenna of the horse-fly 7,tabanus bovinus74 ,for lettering see p4 #bgb4--;,after ,hauser4 ,the distribution of the olfactory peg or tooth-like projections seems to be much more limited than that of the pits in the ,ichneumonid4 ,hauser could not find any4 ,apis mellifica possesses on each antennal joint only about twenty slender pale teeth1 scarcely a third as many as in ,vespa crabro2 on the other hand1 ,formica1 of which genus several species were examined1 seems to have far more teeth than pits2 they are relatively long1 pale1 transparent1 and somewhat clavate2 they are not unlike those of ,chrysopa2 on the terminal joint only occur the round openings 7,fvo71 which lead into a bottle-shaped invagination of the integument 7,fv7 and contain an olfactory style 7,fig4 #bha74 ,in the ,tenthredinid only teeth and no pits were to be detected4 ,sirex has on the under side of the nine last joints of each antenna a group of from #bjj to #cjj small teeth1 which resemble those of ,vespa crabro2 ,lyda has on the terminal joints about #ajj teeth4 ,we may add that supposed organs of smell occur on the antenn of ,campodea 7,fig4 #bhb74 ,kraepelin also thus briefly summarizes ,hauser's statements as to the forms of the different organs of smell4 ,the manifold nature of the antennal organs has1 by ,hauser1 from thorough studies of the nerve-elements belonging to them1 been not simplified but rendered more complicated4 ,according to this naturalist we may distinguish the following forms which the olfactory organs may assume3 #a4 8,pale1 tooth-like chitinous hairs on the outer surface of the antenn1 which are perforated at the end2 nothing is known as to the relation of the nerve passing into it 7,chrysopa1 ,anophthalmus74 #b4 ,in pit-like depressions of the antenn arise nerve-rods 7without a chitinous case7 which stand in direct relation with a ganglion-cell lying under it4 ,these pits are either simple1 viz4 with only an #8olfactory rod' 7,tabanus1 ,fig4 #bhc1 and other ,diptera1 ,vanessa71 or compound 7,muscid1 and most other ,diptera1 and ,philonthus74 ,it is important that these pits are partly open 7in the above-named groups of insects71 and partly closed and covered with a thin membrane1 under whose concavity the olfactory rods end 7,orthoptera1 ,melolontha1 and other lamellicorns74 #c4 ,short1 thick pits sunken slightly into the surface of the antenn1 and over this a chitinous peg perforated at the end1 in whose base1 from the interior1 projects a very singular nerve-peg1 which is situated over an olfactory ganglion-cell1 and provided with a slender crown of little rods1 and flanked on each side by a flagellum-cell 7,hymenoptera74 #d4 ,round or crevice-like pits covered over by a perforated chitinous membrane with nerve-rods like those in #c1 but in place of the flagellum-cell with #8membrane-forming' cells spread before it4 ,hauser finally mentions further differences in the ganglion-cells sent out into the nerve-end apparatus4 ,these exhibit in ,diptera and ,melolontha only one nucleus1 in ,hymenoptera a single very large one 7with many nucleoli7 and three small ones1 in ,vanessa six1 in ,orthoptera a very large number of nuclei1 etc40 ,,literature ,,of ,,the ,,organs ,,of ,,smell ,raumur1 ,rn ,ant4 de4 ,mmoires pour servir l'histoire des insectes4 ,paris1 #agcd-db4 7i1 #bhc2 ii1 #bbd74 ,lesser1 ,f4 ,c4 ,insecto-theologia1 #agdj1 p4 #bfb4 ,roesel1 ,a4 ,j4 ,insektenbelustigungen1 #agdf1 ii1 p4 #ea4 ,reimarus1 ,h4 ,s4 ,allgemeine ,betrachtung ueber die ,triebe der ,thiere hauptschlich ihre ,kunsttriebe 7,instinct74 ,hamburg1 #agfj1 p4 #cee4 ,sulzer1 ,j4 ,h4 ,die ,kenntzeichen der ,insecten4 ,zrich1 #agfa4 ,lyonet1 ,p4 ,trait anatomique de la chenille1 #agfb1 pp4 #db1 #if1 #aie4 ,comparetti1 ,a4 ,de aure interna comparata4 ,patavii1 #agfi4 ,bonnet1 ,c4 uvres compltes1 #aggi-aghc1 ii1 p4 #cf4 ---- ,contemplation de la nature1 ,ch4 iii1 p4 #ah4 ,scarpa1 ,ant4 ,anatomic disquisitiones de auditu et olfactu4 ,ticini1 #aghi4 ,huber1 ,f4 ,nouvelles observations sur les abeilles1 #agib1 ii1 p4 #dge4 ,lehrmann1 ,m4 ,c4 ,g4 ,de antennis insectorum4 ,londini1 ,hamburgi1 #agii1 p4 #dh1 ,diss4 posterior2 ,hamburg and ,london1 #ahjj1 p4 #hj 7especial sense1 rocepsis74 ,latreille1 ,p4 ,a4 ,histoire naturelle des crustacs et des insectes1 #ahjf-ahji1 ii1 #ej4 ,blainville1 ,m4 ,h4 ,d4 ,principes d'anatomie compare1 #ahbb1 i1 p4 #cci4 ,dugs1 ,a4 ,l4 ,trait de physiologie compare1 #ahch1 i1 p4 #afa4 ,newport1 ,g4 ,on the use of the antenn of insects4 7,trans4 ,ent4 ,soc41 ,london1 ii1 #ahdj1 pp4 #bbi-bdh47 ,robineau-,desvoidy1 ,a4 ,j4 ,b4 ,sur l'usage rel des antennes chez les insectes4 7,ann4 ,soc4 ,ent4 ,france1 #ahdb1 xi ,bull41 pp4 #bc-bg47 ,erichson1 ,w4 ,f4 ,de fabrica et usu antennarum in insectis4 ,berlin1 #ahdg1 #a ,tab41 p4 #ac4 ,perris1 ,e4 ,mmoire sur le sige de l'odorat dans les articuls4 7,ann4 sc4 nat41 ,sr4 #c1 #ahej1 xiv1 pp4 #aei-agh47 ,dufour1 ,l4 ,quelques mots sur l'organe de l'odorat et sur celui de l'ouie dans les insectes4 7,actes d4 l4 ,soc4 ,linn41 ,bordeaux1 #ahej1 xvii1 ,ann4 sc4 nat41 ,sr4 #c1 ,zool41 xiv1 #ahej1 pp4 #agi-ahd47 ,leydig1 ,f4 ,zum feineren ,bau der ,arthropoden4 7,mller's ,archiv1 #ahee1 pp4 #cgf-dhj72 ,lehrbuch der ,histologie1 #aheg1 p4 #bbj2 ,zur ,anatomie der ,insekten 7,archiv fr ,anatomie1 #ahei1 pp4 #ce-hi and #adi-ahc74 ---- ,ueber ,geruchs- und ,gehrorgane der ,krebse und ,insekten4 7,archiv f4 ,anat4 u4 ,phys41 #ahfj47 ---- ,die ,hautsinnesorgane der ,arthropoden4 7,zool4 ,anzeiger1 #ahhf1 pp4 #bhd-bia1 #cjh-cad1 #bfe-cad47 ,landois1 ,h4 ,das ,gehrorgan des ,hirschkfers4 7,archiv f4 mikrosp4 ,anat41 #ahfh1 iv1 pp4 #hh-ie47 ,troschel1 ,h4 ,ueber das ,geruchsorgan der ,gliedertiere4 7,verhandl4 d4 naturhist4 ,vereins d4 preuss4 ,rheinlande u4 ,westfal41 xxvii ,jahrg41 #ahgj1 pp4 #afj-afa47 ,packard1 ,a4 ,s4 ,the caudal styles of insects sense-organs1 i4e41 abdominal antenn4 7,amer4 ,naturalist1 #ahgj1 pp4 #fbj1 #fba4 ,also ,proc4 ,bost4 ,soc4 ,nat4 ,hist41 #ahfh1 xi1 p4 #cih47 ,paasch1 ,a4 ,von den ,sinnesorganen der ,insekten im ,allgemeinen1 von ,gehrund ,geruchsorganen im ,besondern4 7,archiv fr ,naturgesch41 xxxix ,jahrg41 i1 #ahgc1 pp4 #bdh-bge47 ,chadima1 ,jos4 ,ueber die von ,leydig als ,geruchsorgane bezeichneten ,bildungen bei den ,arthropoden4 7,mitteil4 d4 naturwiss4 ,ver4 f4 ,steiermark1 #ahgc1 pp4 #cf-dd47 ,forel1 ,a4 ,les ,fourmis de la ,suisse4 7,neue ,denkschr4 ,allg4 ,schweiz4 ,gesellsch4 f4 d4 ges4 ,naturw41 xxvi1 #ahgd1 pp4 #aah1 #add47 ---- tudes myrmcologiques en #ahhd1 avec une description des organes sensoriels des antennes4 7,bull4 ,soc4 ,vaud4 sc4 nat41 #ahhe1 ,sr4 #b1 xx1 pp4 #caf-chj47 ,graber1 ,v4 ,die ,insekten4 ,mnchen1 #ahgg4 ---- ,neue ,versuche ber die ,functionen der ,insektenfhler4 7,biol4 ,centralb41 vii1 #ahhg1 pp4 #ac-ai47 ,trouvelot1 ,l4 ,the use of the antenn in insects4 7,amer4 ,naturalist1 xi1 #ahgg1 pp4 #aic-aif47 ,mayer1 ,p4 ,sopra certi organi di senso nelle antenne dei ,ditteri4 7,atti ,r4 ,accad4 d4 ,lincei1 ,roma1 ,ser4 #c1 ,mem4 ,cl4 sc4 fis41 mat4 e natur41 iii1 #ahgi1 p4 #aa47 ,hauser1 ,gustav4 ,physiologische und histiologische ,untersuchungen ber das ,geruchsorgan der ,insekten4 7,zeitschr4 f4 wissens4 ,zool41 xxxiv1 #ahhj1 pp4 #cfg-djc1 #c ,taf47 ,kraepelin1 ,karl4 ,ueber die ,geruchsorgane der ,gliedertiere 7,oster-,programm der ,realschule des ,johanneums4 ,hamburg1 #ahhc1 pp4 #dh1 #c ,taf47 ,schiemenz1 ,paulus4 ,ueber das ,herkommen des ,futtersaftes und die ,speicheldrsen der ,bienen nebst einem ,anhange ber das ,riechorgan4 7,zeitschr4 f4 wissens4 ,zool41 xxxviii1 pp4 #ga-ace1 #c ,taf47 ,plateau1 ,f4 ,expriences sur le rle des palpes chez les arthropodes maxills1 ,i41 ,palpes des insectes broyeurs4 7,bull4 ,soc4 ,zool4 ,france1 x1 #ahhe1 pp4 #fg-ij47 ,plateau1 ,f4 ,une exprience sur la fonction des antennes chez la ,blatte 7,periplaneta orientalis74 7,comptes rend4 ,soc4 ,ent4 de ,belgique1 #ahhf1 pp4 #aah-abb1 #a ,fig47 ,lubbock1 ,j4 ,on some points in the anatomy of ants4 7,monthly ,micr4 ,journ41 #ahhg1 pp4 #aba-adb47 ,ruland1 ,franz4 ,beitrge zur ,kenntniss der antennalen ,sinnesorgane der ,insekten4 ,diss4 ,marburg1 #ahhh1 p4 #ca1 #a ,taf4 ,wasmann1 ,e4 ,die ,fhler der ,insekten4 7,stimmen aus ,maria-,laach4 ,freiburg i4 ,b41 #ahia1 p4 #cg47 ,sergi1 ,g4 ,ricerche su alcuni organi di senso nelle antenne delle formiche4 7,riv4 ,filos4 ,sci4 ,milano1 #ahia1 p4 #aj1 #c ,figs47 ,nagel1 ,wilibald4 ,die niederen ,sinne der ,insekten1 #ai ,figs41 ,tbingen1 #ahib1 pp4 #fg4 ,with the writings of ,baster1 ,lamarck1 ,cuvier1 ,treviranus1 ,oken1 ,lefebure1 ,dumril1 ,schelver1 ,bousdorf1 ,rosenthal1 ,burmeister1 ,slater1 ,balbiani1 ,marcel de ,serres1 ,garnier1 ,bert1 ,porter1 ,sazepin1 ,reuter1 ,pierret1 ,duponchel1 ,driesch1 ,kster1 ,peckham1 ,lubbock1 ,a4 ,dohrn1 ,lesps4 c4 ,the organs of taste ,the gustatory organs of insects are microscopic pits or setae1 either hair-like or resembling short pegs1 which form the ends of ganglionated nerves4 ,they are difficult to distinguish morphologically from certain olfactory structures1 and it is owing to their position at or very near the mouth that they are supposed to be gustatory in nature4 ,meinert was the first 7#ahfj7 to suggest that organs of taste occurred in ants4 ,he observed in the maxill1 and tongue of these insects a series of canals in the cuticula of these organs connected with ganglion-cells1 and through them with the nerves1 and queried whether they were not organs of taste4 ,forel afterwards 7#ahgd7 confirmed these observations4 ,wolff in an elaborate work 7#ahge7 described a group of minute pits 7,fig4 #bhd7 at the base of the tongue of the honey bee1 which he supposed to possess the sense of smell1 but ,forel and also ,lubbock attributed to these sensory pits the function of taste4 ,ten years afterward ,will showed conclusively1 both by anatomical studies and by experiments1 that ,diptera and ,hymenoptera possess gustatory organs4 ,he1 however1 denied that the organs of ,wolff were gustatory1 and maintained that organs of smell were confined to the maxill1 paragloss1 and tongue4 ,as we shall see1 however1 what appear to be with little doubt taste-pits1 with hairs or pegs arising from them1 are most numerous on the epipharynx of nearly all insects1 and situated at a point where they necessarily must come in contact with the food as it enters the mouth and passes down the throat4 ,illustration3 ,,fig4 #bhd4--,taste-pits on the epipharynx 7,c7 of the honey-bee3 ,b1 horny ridge2 ,r1 ,r1 taste-pits2 ,l1 ,a1 ,a1 muscular fibres2 ,s1 ,s1 a b c d e f1 section of skin of sophagus4--,after ,wolff4 ,illustration3 ,,fig4 #bhe4--,tip of the proboscis of the honey bee1 #adj3 ,l1 terminal button or ladle3 ,gs taste-hairs2 ,sh1 guard-hairs2 ,hb1 hooked hairs4--,after ,will4 ,kraepelin 7#ahhc7 discovered taste-organs on the proboscis of the fly1 and taste-hairs at the end of the tongue of the humble-bee 7,fig4 #bhe71 and afterwards ,lubbock critically discussed the subject1 and concluded that the organs of taste in insects are situated 8either in the mouth itself1 or on the organs immediately surrounding it40 ,structure of the taste-organs4--,the organs have been best studied by ,will1 who1 besides describing and figuring the chitinous structures1 such as the pits or cups1 hairs and the pegs1 showed that they were the terminations of ganglionated nerves4 ,figure #bhf represents the taste-cups on the maxilla of a wasp1 and ,fig4 #bhg the taste-cone or peg projecting from the cup or pit4 ,the cell out of which the pit and projecting hair or peg are formed is a modified hypodermis cell2 and the seta is apparently a modification of a tactile hair1 situated at the end of a nerve1 which just beneath the chitinous structures passes into a ganglion-cell1 which sends off a nerve-fibre to the main nerve4 ,will detected on the tongue of the yellow ant 7,lasius flavus7 from #bj to #bd1 and in ,atta from #dj to #eb1 of these structures4 ,the number of pits on the maxill vary much1 not always being the same on the two sides of the same insect4 ,we have observed these taste-cups in the honey and humble bee1 not only at the base of the second maxill 7,fig4 #bhh1 g71 but also on the paragloss 7pg74 ,distribution in other orders of insects4--,the writer has detected these taste-cups in other orders than ,diptera and ,hymenoptera4 ,they very generally occur in mandibulate insects on the more exposed surface of the epipharynx 7compare pp4 #dc-df74 ,we have not observed them in the ,synaptera 7,lepisma and ,machilis74 ,in the ,dermaptera the taste-cups appear to be undeveloped in the nymph1 while in the adult they are fewer in number than in any other pterygote order yet investigated4 ,in a species of ,forficula from ,cordova1 ,mexico1 the taste-pits are few in number1 there being only about a dozen on each side in all2 most of them being situated on the anterior half1 and a few near the base4 ,the taste-pits are provided each with a short fine seta1 as usual arising from the centre4 ,illustration3 ,,fig4 #bhf4--,under side of left maxilla of ,vespa3 ,gm1 taste-cups2 ,shm1 protecting hairs2 ,tb1 tactile hairs2 ,mt1 base of maxillary palpus4--,after ,will4 ,in the order ,platyptera 7including ,perla1 ,pteronarcys1 ,psocus1 ,termes1 ,eutermes1 and ,termopsis7 we have been unable to detect any organs of taste4 ,illustration3 ,,fig4 #bhg4--,section through a taste-cup3 ,,sk1 supporting cone2 ,n1 nerve2 ,,sz1 sense-cell4--,after ,will4 ,this and ,figs4 #bhd-bhf from ,lubbock4 ,illustration3 ,,fig4 #bhh4--,tongue of worker honey-bee3 pg1 paragloss2 ,b1 the same enlarged1 showing the taste-papill2 ,c1 ,d1 base of a labial palpus 7mx4p7 with the taste-papill2 ,e1 taste-cups on paragloss of ,bombus2 ,f1 group of same on left1 ,g1 on right side1 at base of labial palpus4 ,in the ,odonata1 however1 they are fairly well developed2 in ,calopteryx1 about #ej taste-cups were discovered2 in a species of ,diplax about #bh1 there being a group of #ad at the base of the epipharynx on each side of the median line1 while in schna heros there are two groups of from #be to #cj taste-cups1 situated as in the two aforenamed genera4 ,in the ,orthoptera the gustatory cups are numerous1 well developed1 and present in all the families except the ,phasmid1 where1 however1 they may yet be found to occur4 ,in a large cockroach 7,blabera7 from ,cuba they are well developed4 ,on each side of the middle of the epipharynx is a curved row of stiff1 defensive spines1 and at the distal end of each row is a sensory field1 containing #bj taste-cups on one side and #bc on the other4 ,near the front edge of the clypeal region are two more sensory fields1 situated on each side of the median line1 there being #ce taste-cups in each field4 ,the taste-cups in this form are rather smaller than usual in the order4 ,in the ,acrydiid they are more numerous than in the ,blattid4 ,for example1 in ,camnula pellucida1 near what corresponds to the front edge of the clypeus are two gustatory fields1 each bearing about #ce taste-pits4 ,just in front1 under the clypeo-labral suture1 are two similar fields1 each containing from #dj to #db taste-pits4 ,there are none in front of these4 ,there are thus about #adj-aej sense-cups in all4 ,the members of the ,locustid 7,fig4 #bf7 appear to be better provided with the organs of taste than any other ,orthoptera1 those of the katydid numbering from #agj to #ahj4 ,there are from #ej to #fj taste-cups in the front region2 behind the middle a group of #be on each side1 and over an area corresponding to the base of the labrum and front edge of the clypeus is a sensory field with about #gj taste-cups on each side4 ,they are true cups or beaker-like papill1 some with a fine1 others with a short1 stout1 conical seta4 ,the gustatory organs in the cave cricket 7,hadencus subterraneus1 ,fig4 #bg71 from ,mammoth ,cave1 are highly developed1 being rounded papill with the nucleus at the top or end4 ,they are grouped on each side of the middle near the front edge1 there being #be on each side4 ,an irregular row of these beaker-like organs extends along each side2 some occur under the base of the labrum1 but they are most numerous in a field corresponding to the front edge of the clypeus1 there being #ej on each side1 or #ajj in all1 where in ,ceuthophilus there are only #i or #aj4 ,it would thus appear as if the sense of taste were much more acute in the cave-dweller than in the out-of-doors form4 ,in the ,coleoptera taste-cups and set are very generally distributed1 though we were unable to detect them in ,dendroctonus or in ,lucanus dama4 ,as seen in ,fig4 #eg1 we have observed numerous taste-pegs along the maxilla of ,nemognatha lurida1 but otherwise taste-organs have only been detected in the epipharynx4 ,they not only occur in the adult beetles1 but we have found them in the larv of cerambycid1 scarabid1 and other beetles4 ,in the adults taste-cups appear to be about as well developed in the carnivorous forms 7,carabid7 as in the phytophagous or lignivorous groups4 ,in ,chlnius tomentosus there are about half as many of these organs as in ,harpalus1 while in ,calosoma there are #ij taste-cups1 #de on each side1 under the base of the labrum4 ,the cups are papilliform1 being rather high1 with a seta arising from each4 ,in the ,cicindelid1 the epipharynx bears a sensory field quite different from that of the ,carabid4 ,there are no normal taste-cups1 except a few situated on two large1 round1 raised areas which are guarded in front by a few very long set4 ,on the surface of each area are numerous very long set which may1 if not tactile1 have some other sense1 as they arise from cup-like bases or cells4 ,those on the outside are like true taste-cups1 with a bristle but little larger than normal in taste-cups generally4 ,we are disposed to regard this sensory field as a highly specialized gustatory apparatus4 ,in the ,dyticid the taste-cups are nearly as described in the ,carabid4 ,the ,staphylinid are not well provided with taste-organs4 ,under the clypeus of ,staphylinus violaceus1 on each side near the middle1 is a bare rounded area1 in which are situated #d or #e papilliform taste-cups1 and at the base behind them is another linear group of about #g slenderer1 somewhat curved1 taste-cups4 ,in the ,elaterid these organs are scantily developed4 ,in the ,buprestid 7,buprestis maculiventris alone examined7 no true taste-cups were detected4 ,on the other hand1 the ,lampyrid are well supplied with them4 ,under the clypeus is situated a sensory field bearing #bf taste-cups1 which are rather smaller than usual4 ,over the epipharyngeal surface are scattered a few taste-cups1 but they are small and perhaps not gustatory4 ,under the clypeus of ,lucidota punctata ,lec4 is a group of #ab taste-cups1 and in the middle region of the epipharynx1 situated in a field extending from near the base to near the front edge1 are about #dj taste-cups1 which1 however1 are not1 as is usual1 arranged on each side of the median line1 but are scattered among the hairs of the pilose surface of the epipharynx4 ,in the ,clerid the taste-cups are few in number4 ,in the great family of ,scarabid1 the presence of gustatory organs is variable4 ,none occur in ,lucanus dama1 though in the ,june beetle 7,lachnosterna fusca ,frhl47 they are abundantly developed4 ,the epipharynx bears on each side outside of a spiny area a group of about #ej taste-cups1 each bearing a long seta1 those on the outside of the area passing into a few high1 rather slender1 papill1 without a seta4 ,on the under side of the clypeus is a median group of #aj taste-cups of singular form1 the cups being large1 with broad bases1 which posteriorly bear three spines1 of which the median one is the largest4 ,taste-cups occur without any known exception in the longicorn beetles4 ,in ,leptura canadensis they are numerous2 in ,euryptera lateralis they are abundant along and near the middle of the anterior half of the labral region1 and in ,cyllene robini ,forst4 7or pictus ,drury7 they are more numerous than usual1 extending in an unbroken sensory field from near the front margin of the clypeal region to near the front edge of the epipharynx4 ,the cups vary much in size1 some being one-half as large as others2 and those on the sides of the sensory field bear short1 and a few others rather long1 bristles1 showing that the taste-cups are modified tactile bristles4 ,the ,tenebrionid are fairly well endowed with taste-cups1 their number in ,eleodes obsoleta ,say amounting to #cj or #dj4 ,those of the ,meloid especially are unusual in size and number4 ,illustration3 ,,fig4 #bhi4--;,epipharynx 7ep7 of ,nemognatha3 cl1 clypeus2 gh1 gathering hairs2 tc1 triangular sensory field dotted with taste cups2 ,a1 the field enlarged4 ,in ,nemognatha lurida ,lec4 7,fig4 #bhi7 the front edge of the epipharynx contains about #hj remarkably small taste-cups1 arranged irregularly in a triangular sensory space1 and not more than to 1 as large as those on the maxill of the same beetle4 ,unless the former structures are gustatory it is difficult to account for their presence here1 and it will be observed that the taste-cups in ,epicauta are unusually abundant4 ,thus in the middle and near the front of the epipharynx of the blister-beetle over #ajj gustatory cups were counted4 ,they are conical1 papilliform1 and truncated at the end as if open1 the edge of the opening being ragged1 though bearing no bristle1 except in a few cases4 ,around the edge of the sinus1 on the under side of the labrum1 is a regular marginal row of large1 longer1 more distinctly chitinized taste-cups1 whose walls are streaked up and down by chitinous thickenings4 ,in ,e4 callosa ,lec4 there are about #ee taste-cups under the labrum1 besides about #aj cells1 which may be gustatory structures1 situated on either side of a median setose ridge which passes back under the clypeal region4 ,the taste-cups of the leaf-beetles are fairly numerous1 judging from an examination of ,diabrotica vittata4 ,the surface of the epipharynx is pilose1 but the median region is naked1 and on the anterior half bears from #aa to #ab taste-cups1 arranged each side of the median line in a rude ,y4 ,on each side1 at the base of the labial region1 are two sensitive fields1 each bearing about #be to #bf taste-cups4 ,more were seen under the clypeus4 ,in the ,neuroptera unmistakable taste-cups are not always present4 ,in ,sialis infumata along the median line of the epipharynx and near the front are about #bj scattered gustatory pegs1 which are minute1 but longer and more acute than usual4 ,in ,chauliodes maculatus there are one or two taste-cups under the front edge of the clypeus2 others are scattered along the middle from the base of the labrum to the front1 but are not arranged in definite order4 ,in ,corydalis cornutus no sense-cups1 pits1 or rods are present4 ,in ,chrysopa there are scattered cups armed with a short acute bristle1 which are possibly gustatory in function4 ,in ,myrmeleon diversum also the presence of sense-pits or of taste-cups is doubtful1 though a group of about #ab pits on each side of the clypeal region of the epipharynx1 and a few situated at the base of the labral region1 may be endowed with the sense of taste4 ,in ,mantispa brunnea1 however1 along the middle of the epipharynx are scattered about #cj unmistakable taste-cups1 each bearing a short1 fine hair4 ,in the ,mecoptera 7,panorpa debilis87 taste-cups1 giving rise to a minute hair1 occur on the labium in two regions1 and also on the maxill situated on the stipes near the base of the palpi1 and on the lacinia and galea4 ,they are also to be found on the maxill of ,boreus californicus1 but were not detected on the labium4 ,they were first detected by ,reuter in various microlepidoptera1 and occur on the 8basal spot0 of the palpi of many butterflies4 ,in a ,tineid moth 7,coleophora coruscipennella7 we have detected what we suppose to be a group of four taste-pits on the inner side of the basal joint of the labial palpi4 ,experimental proof4--,no one1 says ,lubbock1 who has ever watched a bee or wasp can entertain the slightest doubt as to their possession of the sense of taste4 8,forel mixed morphine and strychnine with some honey1 which he offered to his ants4 ,their antenn gave them no warning4 ,the smell of the honey attracted them1 and they began to feed2 but the moment the honey touched their lips they perceived the fraud40 ,will at first fed wasps with sugar1 so that they frequently visited it2 afterwards he substituted alum for the sugar4 ,eagerly flying to it1 they had scarcely touched it when they drew back from the distasteful substance with the most comical gestures1 and cleaned their tongues by frequently running them in and out1 repeatedly stroking them with their fore feet4 ,he noticed a great repugnance to quinine in nearly all the insects experimented on4 ,bees and wasps were observed to have a more delicate gustatory sense than flies1 etc41 which are more omnivorous in their tastes4 ,,literature ,,on ,,the ,,organs ,,of ,,taste ,meinert1 ,f4 ,bidrag til de danske myrers naturhistorie4 7,kgl4 ,dansk ,vidensk4 selsk4 skrifter4 ,kjoebenhavn4 ,raekke #e ,naturvid4 og math4 ,afd41 v1 #ahfa1 pp4 #bgc-cdj47 ,wolff1 ,o4 ,j4 ,b4 ,das ,riechorgan der ,biene4 7,nova acta d4 ,k4 ,leop4-,carol4 ,akad41 xxxviii1 #ahge1 pp4 #a-bea1 #h ,taf47 ,joseph1 ,g4 ,zur ,morphologie des ,geschmacksorganes bei ,insekten4 7,amtlicher ,bericht der #ej4 ,versammlung deutscher ,naturforscher und ,aerzte in ,mnchen1 #ahgg1 pp4 #bbg-bbh47 ,knckel et ,gazagnaire4 ,du sige de la gustation chez les insectes ,diptres4 ,constitution anatomique et physiologique de l'epipharynx et l'hypopharynx4 7,comptes-rend4 ,acad4 ,sc41 ,paris1 #ahha1 xcv1 pp4 #cdg-cej47 ---- ,recherches sur l'organisation et le dveloppement des ,diptres et en particulaire des ,volucelles1 i1 #ahge1 ii1 #ahha1 #bf ,pls4 ,kraepelin1 ,k4 ,zur ,kenntniss der ,anatomie und ,physiologie des ,rssels von ,musca4 7,zeitschr4 f4 wissens4 ,zool41 xxxix1 #ahhc1 pp4 #fhc-gai1 #b ,taf47 ,kirbach1 ,p4 ,ueber die ,mundwerkzeuge der ,schmetterlinge4 7,zool4 ,anzeiger1 #ahhc1 pp4 #eec-eeh1 #b ,figs47 ,will1 ,f4 ,das ,geschmacksorgan der ,insekten4 7,zeitschr4 f4 wissens4 ,zool41 #ahhe1 xlii1 pp4 #fgd-gjg1 #a ,taf47 ,gazagnaire1 ,j4 ,du sige de la gustation chez les insectes ,coloptres4 7,comptes-rend4 ,acad4 ,sc41 ,paris1 #ahhf1 cii1 pp4 #fbi-fcb2 ,ann4 ,soc4 ,ent4 ,france1 ,sr4 #f1 ,bull41 pp4 #gi-hj47 ,forel1 ,a4 ,expriences et remarques critiques sur les sensations des insectes4 #bme ,part4 7,recueil ,zool4 ,suisse1 iv1 #ahhg1 pp4 #afa-bdj47 ,reuter1 ,enzio4 ,ueber den 8,basalfleck0 auf den ,palpen der ,schmetterlinge4 7,zool4 ,anzeiger1 #ahhh1 pp4 #ejj-ejc47 ---- ,ueber die ,palpen der ,rhopaloceren1 etc41 #f ,taf4 ,helsingfors1 #ahif1 pp4 #a-egh4 7,acta ,soc4 ,sc4 ,fennic1 xxii1 #ahif47 ,packard1 ,a4 ,s4 ,on the occurrence of organs1 probably of taste1 in the epipharynx of the ,mecoptera 7,panorpa and ,boreus74 7,psyche1 #ahhi1 v1 pp4 #aei-afd47 ---- ,notes on the epipharynx1 and the epipharyngeal organs of taste in mandibulate insects4 7,psyche1 #ahhi1 v1 pp4 #aic-aii1 #bbb-bbh47 ,also ,lubbock's ,senses1 etc41 of animals1 and the writings of ,briant1 ,breithaupt 7titles on p4 #he74 d4 ,the organs of hearing ,although it has been denied by ,forel that insects have the sense of hearing1 yet the majority of writers and experimenters agree that insects are not deaf4 ,on general grounds if1 as we know1 many insects produce sounds1 it must follow that they have ears to hear1 for there is every reason to suppose that the sounds thus made are1 as in other animals1 either for attracting the sexes1 for a means of communication1 or to express the emotions4 ,we will begin by briefly describing the structures now generally supposed to be auditory in function1 and about which there can be no reasonable doubt1 and then consider the more problematical organs1 closing with an account of the extremely various means of producing sounds and cries4 ,the ears or tympanal and chordotonal sense-organs of ,orthoptera and other insects4--,the ears or tympana of locusts 7,acrydiid7 are situated one on each side1 on the basal joint of the abdomen1 just behind the first abdominal spiracle4 ,that this is a true ear was first suggested by ,j4 ,mller1 and his opinion was confirmed by ,siebold1 ,leydig1 ,hensen1 ,graber1 ,schmidt1 ,lubbock1 etc4#di ,illustration3 ,,fig4 #bij4--;,ear of a locust 7,caloptenus italicus71 seen from the inner side3 ,t1 tympanum2 ,,tr1 its border2 o1 u1 two horn-like processes2 bi1 pear-shaped vesicle2 n1 auditory nerve2 ga1 terminal ganglion2 st1 stigma2 m1 opening1 and m1 closing1 muscle of the same2 ,m1 tensor muscle of the tympanum membrane4--,after ,graber4 ,the apparatus consists of a tense membrane1 the tympanum1 surrounded by a horny ring 7,fig4 #bij74 8,on the internal surface of this membrane are two horn-like processes 7o1 u71 to which is attached an extremely delicate vesicle 7bi7 filled with a transparent fluid1 and representing a membranous labyrinth4 ,this vesicle is in connection with an auditory nerve 7n7 which arises from the third thoracic ganglion1 forms a ganglion 7ga7 upon the tympanum1 and terminates in the immediate neighborhood of the labyrinth by a collection of cuneiform1 staff-like bodies1 with very finely pointed extremities 7primitive nerve-fibres871 which are surrounded by loosely aggregated ganglionic globules0 7,siebold's ,anatomy of the ,invertebrates74 ,illustration3 ,,fig4 #bia4--;,fore tibia of ,locusta viridissima4 td1 cover of the drum2 tr1 fissure between the drum and its cover4--,after ,graber1 from ,lang4 ,in the green grasshoppers1 katydids1 and their allies1 the ears are situated on the fore tibi1 where these organs can be found after a careful search 7,figs4 #bia1 #bib74 ,the presence of the structure is indicated by the oval disc1 the drum1 which is a thin tense membrane covering the auditory apparatus of nerves1 ganglion cells1 and auditory rods beneath4 ,the tympana1 or drums1 are not present in all ,locustid and ,gryllid1 and1 as ,lubbock states1 it is an additional reason for regarding them as auditory organs1 that in those species which possess no stridulating organs the tympana are also wanting4 ,in many of the ,locustid the tympana are covered or protected by a fold of the skin projecting over them4 ,these covered ones are1 ,graber thinks1 derived from the open ones4 ,illustration3 ,,fig4 #bib4--;,a1 fore tibia of a ,european grasshopper 7,meconema71 containing the ear3 ,ty1 tympanum or outer membrane2 ,tr #a1 ,tr #b1 trache4 ,b1 diagrammatic cross-section through the tibia and ear of the same2 ,ty1 tympanum2 ,ct1 cuticula2 ,,cm1 hypodermis3 ,a1 the auditory organ connecting with the tympanum2 ,b1 supra-tympanal auditory organ2 ,,gz1 the ganglion-cell belonging to them2 ,hst1 the auditory rod connecting with the ganglion-cells4--,after ,graber1 from ,judeich and ,nitsche4 ,on examining the apparatus within the leg under the drum1 it is seen to consist of the trachea1 the auditory vesicles and rods1 ganglion cells1 and acoustic nerve4 ,the trachea is greatly modified 7,fig4 #bib1 ,tr #a74 ,on passing into the tibia the trachea enlarges and divides into two branches1 which reunite lower down4 ,the spiracles supplying the air to this enlarged trachea are considerably enlarged1 while in the dumb species it is of the normal size4 ,the enlarged trachea passes close to the tympanum1 which thus has air on both sides of it3 the open air on the outer1 the air of the trachea on its inner surface4 ,in fact1 as ,lubbock states1 8the trachea acts like the ,eustachian tube in our own ear2 it maintains an equilibrium of pressure on each side of the tympanum1 and enables it freely to transmit the atmospheric vibrations40 ,illustration3 ,,fig4 #bic4--,the auditory apparatus in the tibia of a grasshopper1 showing the tympanal nerve-endings in situ3 ,,ebi1 terminal vesicles of ,siebold's organ2 ,,sn1 nerve of the organ of ,siebold2 ,gr1 group of vesicles of same2 ,,so1 nerve-endings of the same2 v,t1 front tympanum2 v,tr1 front branch of the trachea2 h,t1 hinder tympanum2 h,tr1 hinder branch of the trachea2 ,sp1 space between the trache2 go1 supra tympanal ganglion2 r,n1 connecting nerve-fibrils between the ganglion cells and the terminal vesicles2 ,r1 upper1 n-,s1 lower1 root of the transparent covering membrane4 7,other lettering not explained by author47--,after ,graber4 ,illustration3 ,,fig4 #bid4--;,auditory rod of ,gryllus viridissimus3 fd1 auditory rod2 ko1 terminal piece4--,after ,graber1 from ,lubbock4 ,these trache1 says ,graber1 though formed on a similar plan1 present many variations1 corresponding to those of the tympana1 and showing that the tympana and the trache stand in intimate connection with one another4 ,for instance1 in those species where the tympana are equal1 the trache are so likewise2 in ,gryllotalpa1 where the front tympanum only is developed1 though both tracheal branches are present1 the front one is much larger than the other2 and where there is no tympanum1 the trachea remains comparatively small1 and even in some cases undivided 7,lubbock1 ex ,graber74 ,the acoustic nerve1 which next to the optic is the thickest in the body1 divides soon after entering the tibia into two branches1 one almost immediately forming a ganglion1 the supra-tympanal ganglion1 the other passing down to the tympanum1 where it expands into an elongated flat ganglion1 the organ of ,siebold 7,fig4 #bic71 and closely applied to the anterior trache4 ,at the upper part of the ganglion is a group terminating below in a single row of vesicles1 the first few of which are approximately equal1 but which subsequently diminish regularly in size4 ,each of these vesicles is connected with the nerve by a fibril 7,fig4 #bic1 v,n71 and contains an auditory rod 7,fig4 #bid74 ,they are said by ,graber to be brightly refractive1 hollow 7thus differing from the retinal rods1 which are solid71 and terminate in a separate end-piece 7ko74 ,the rods were first discovered by ,siebold1 and1 as ,lubbock remarks1 may be regarded as specially characteristic of the acoustic organs of insects4 ,illustration3 ,,fig4 #bie4--;,chordotonal organ in nymph of a white ant4--,after ,mller1 from ,sharp4 ,illustration3 ,,fig4 #bif4--,right half of #hth body-segment of ,corethra plumicornis3 g1 ganglion of ventral cord2 lm1 longitudinal muscle2 cn1 chordotonal nerve2 cl1 chordotonal ligament2 cg1 chordotonal ganglion2 cs1 rod of chordotonal organ2 cst1 terminal cord2 tb1 tactile set2 hn1 out-going fibres of the integumental nerves4--,after ,graber1 from ,lang4 ,as will be seen in ,fig4 #bic1 at the upper part of the tibial organ of ,ephippigera there is a group of cells1 and below them a single row of cells gradually diminishing in size from above downwards4 8,one cannot but ask oneself10 says ,lubbock1 8whether the gradually diminishing size of the cells in the organ of ,siebold may not have reference to the perception of different notes1 as is the case with the series of diminishing arches in the organ of ,corti of our own ears40 ,these organs were supposed to be restricted to the ,orthoptera1 but in #ahgg ,lubbock discovered what seems to resemble the supra-tympanal auditory organ of ,orthoptera in the tibia of the yellow ant 7,lasius flavus74 ,graber confirmed ,lubbock's account1 and also discovered these organs in the tibia of a ,perlid 7,isopteryx apicalis71 and ,fritz ,mller has detected them in the fore tibi of the nymph of ,calotermes rugosus 7,fig4 #bie74 ,to these structures ,graber gave the name of chordotonal organs4 ,he has also detected these organs in all the legs of other insects 7,trichoptera1 ,pediculid71 and auditory rods have been discovered in the antenn of ,dyticus and of ,telephorus by ,hicks1 ,leydig1 and ,graber4 ,graber classifies the chordotonal organs into truncal and membral4 ,in ,coleoptera and ,trichoptera they may occur on several joints of the leg2 others are more localized1--thus he distinguishes femoral 7,pediculid71 tibial 7,orthoptera1 ,perlid1 ,formicid71 and tarsal organs 7,coleoptera74 ,a type of chordotonal organ1 observed in the body-segments of the larv of several insects by ,leydig1 ,weismann1 ,graber1 ,grobben1 and ,bolles ,lee1 is to be seen in the transparent larva of ,corethra 7,fig4 #bif71 where the auditory organ extends to the skin4 ,it contains at the point cs two or three auditory rods4 ,in the opposite direction a fine ligament 7cl7 passes from cg to the skin2 in this way the auditory organ is suspended in a certain state of tension1 and is favorably situated to receive even very fine vibrations4 ,a similar apparatus has been detected in the larva of ,ptychoptera4 ,antennal auditory hairs4--,it is not at all improbable that the antenn of different insects contain auditory as well as olfactory structures4 ,lubbock has suggested that the singular organs which have only been found in the antenn of ants and certain bees1 and to which he gives the name of 8,hicks' bottles0 7,fig4 #bha71 may act as microscopic stethoscopes1 while ,leydig also regards them as chordotonal organs4 ,that1 however1 some of the antennal hairs of the mosquito1 as first suggested by ,johnson and afterwards proved experimentally by ,mayer1 are auditory1 seems well established4 ,fastening a male mosquito down on a glass slide1 ,mayer then sounded a series of tuning-forks4 ,with an ,ut#d fork of #eab vibrations per second1 some of the hairs were seen to vibrate vigorously1 while others remained comparatively at rest4 ,the lower 7,ut#c7 and higher 7,ut#e7 harmonics of ,ut#d also caused more vibration than any intermediate notes4 ,these hairs1 then1 are specially tuned so as to respond to vibrations numbering #eab per second4 ,other hairs vibrated to other notes1 extending through the middle and next higher octave of the piano4 ,mayer then made large wooden models of these hairs1 the one corresponding to the ,ut#c hair being about a metre in length1 and on counting the number of vibrations they made when they were clamped at one end and then drawn on one side1 he found that it 8coincided with the ratio existing between the numbers of vibrations of the forks to which covibrated the fibrils10 or hairs4 ,it should be observed that the song of the female mosquito corresponds nearly to this note1 and would consequently set the hairs in vibration4 ,mayer observed that the song of the female vibrates the hairs of one of the antenn more forcibly than those of the other4 ,those auditory hairs are most affected which are at right angles to the direction from which the sound comes4 ,hence from the position of the antenn and the hairs a sound will be loudest or most intense if it is directly in front of the head4 ,if1 then1 the song of the female affects one antenna more than another1 the male turns his head until the two antenn are equally affected1 and is thus able to fly straight towards the female4 ,from his experiments ,mayer found that the male can thus guide himself to within #e of the direction of the female4 ,hence he concludes that 8these insects must have the faculty of the perception of the direction of sound more highly developed than in any other class of animals40 7,also see ,child's work47 ,special sense-organs in the wings and halteres4--,organs of a special sense1 which ,hicks supposed to be those of smell1 were found by him near or at the base of the wings of ,diptera1 ,coleoptera1 and less perfect ones in ,lepidoptera1 ,neuroptera1 and ,orthoptera1 with a trace of them in ,hemiptera2 but these were considered by ,leydig to be auditory organs1 since he found the nerves to end in club-shaped rods1 like those of ,orthoptera4 ,hicks found1 as to the halteres and their sense-organs1 that the nerve in the halter is the largest in the insect1 except the optic nerve2 and that at the base of the halteres is a number of vesicles arranged in four groups1 to each of which the nerve sends a branch4 ,afterwards ,bolles ,lee discovered that the vesicles1 undoubtedly perforated1 contain a minute hair1 those of the upper groups being protected by hoods of chitin4 ,he regarded them as olfactory organs1 while ,lubbock seems inclined to consider them as auditory structures4 ,graber also regards the vesicles of ,hicks as chordotonal organs4 ,in his elaborate account of the balancers1 ,weinland concludes that the organs of sense of varying structure occurring at the base of these appendages allow the perception of movements which the halteres perform and which enable the fly to steer or direct its course4 ,the halteres can thus cause differences in the direction of the flight of a fly in the vertical plane4 ,if the balancers act unequally1 there is a change in direction4 e4 ,the sounds of insects ,insects have no true voice2 but sounds of different intensity1 shrill cries1 and other noises are produced mechanically by insects1 either being love-songs to attract the sexes1 to give signals1 to communicate intelligence1 or perhaps to express the emotions4 ,the loud1 shrill cry of the ,cicada1 or chirp of the cricket1 is evidently a love-call1 and results in the mating of individuals of separate broods more or less widely scattered1 thus preventing too close interbreeding4 ,the simplest means of making a noise is that of the death-watch 7,anobium71 which strikes or taps on the wall with its head or abdomen4 ,longicorn beetles make a sharp sound by the friction of the mesoscutellum against the edge of the prothoracic cavity1 the head being alternately raised and lowered1 ,burying-beetles 7,necrophorus7 rub the abdomen against the hinder edges of the elytra4 ,weevils make a loud noise by rapidly rubbing the tips of the abdomen on the ends of the elytra4 ,landois offers the following summary of the kinds of noises produced by beetles3 #a4 ,tapping sounds 7,bostrycin1 ,anobium74 #b4 ,grating sounds 7,elaterid74 #c4 ,friction without special rasping organs 7,euchirus longimanus74 #d4 ,rasping sounds produced by friction3 a4 ,rubbing of the pronotum on the mesonotum 7,cerambycid except ,spondyli and ,prionus74 b4 ,friction of the prosternum on the mesosternum 7,omaloplia brunnea74 c4 ,elytra with a rasp at the end 7,curculionid1 ,dyticid1 ,pelobius74 d4 ,with a coxal rasp 7,geotrupes1 ,ceratophyus74 ,the male of ,ateuchus stridulates to encourage the female in her work1 and from distress when she is removed4 7,darwin47 e4 ,friction of the edge of the elytra against the femur 7,chiasognathus grantii74 f4 ,pygidium with two rasps in the middle 7,crioceris1 ,lema1 ,copris1 ,oryctes1 ,necrophorus1 ,tenebrionid74 g4 ,abdomen with a grating ridge and four grating plates 7,trox74 h4 ,abdomen with two toothed ridges rubbing on a rasp on edge of wing-cover 7,elaphus1 ,blethisa1 ,cychrus74 i4 ,rubbing the elytra on a rasp on the hind wings 7,pelobius hermanni74 j4 ,friction of the wing against the abdominal segments 7,melolontha fullo74 ,mutilla makes a rather sharp noise by rubbing one abdominal segment against another4 ,ants 7,ponera7 have a stridulating apparatus1 and other genera numerous 7#bj7 ridges between the segments4 ,even certain moths and butterflies emit a rasping or crackling noise4 ,the death's-head moth and other sphinges cause it by rubbing the palpi against the base of the proboscis4 ,these and certain butterflies are provided with parallel ridges forming a rasp on the 8basal spot0 of the inner side of the basal joint of each palpus 7,reuter74 ,a ,south ,american butterfly 7,ageronia feronia7 can be heard for several yards as it flies with a crackling sound4 ,hampson finds that the cause of the clicking sound is due to a pair of strong chitinous hooks attached to the thorax1 against which play the spatulate ends of a pair of hooks attached to the fore wings4 ,an ,australian moth 7,hecatesia7 flies with a whizzing sound2 ,vanessa is said to be sonorous4 ,the males of ,orthoptera produce their shrill cries or chirping noises1 #a1 by rubbing the thighs against the sides of the body 7,acrydiid72 #b1 by the friction of the base of the fore wings on each other 7,locustid72 #c1 by rubbing the base of the upper on the base of the hinder or under pair 7,gryllid71 in the two last there being a shrilling apparatus consisting of a file on the hind wings1 which rubs on a resonant surface on the fore wings4 ,the females are not invariably dumb1 both sexes of the ,european ,ephippigera being able to faintly stridulate4 ,corixa also produces shrill chirping notes4 7,carpenter47 ,certain insects also hum1 and have what may perhaps be called a voice4 ,the cockchafer1 besides humming with the wings1 produces a sound almost like a voice4 ,in the large trachea1 just behind each spiracle1 is a chitinous process1 which is thrown into vibrations by the air during respiration1 and thus produces a humming noise4 7,lubbock47 ,such is also the case with flies1 the mosquito1 dragon-flies1 and bees4 ,in flies and dragon-flies the 8voice0 is caused by the air issuing from the thoracic spiracles2 while in the humble-bee the abdominal spiracles are also musical4 ,the sound made by the spiracles bears no relation to that caused by the wings4 ,landois tells us that the wing-tone of the honey-bee is ,a2 its voice1 however1 is an octave higher1 and often goes to ,b and ,c4 ,the sounds produced by the wings are constant in each species1 except where1 as in ,bombus1 there are individuals of different sizes2 in these the larger ones generally give a higher note4 ,thus the comparatively small male of ,bombus terrestris hums on ,a1 while the large female hums an entire octave higher4 ,from the note produced the rapidity of the vibrations can be calculated4 ,for example1 the house-fly1 which produces the sound of ,f1 vibrates its wings #ba1abj times in a minute1 or #cce times in a second2 and the bee1 which makes a sound of ,a1 as many as #bf1djj times1 or #ddj times in a second4 ,on the contrary1 a tired bee hums on ,e1 and therefore1 according to theory1 vibrates its wings only #ccj times in a second4 ,marey has confirmed these numbers graphically1 and found by experiment that the fly actually makes #ccj strokes in a second4 7,lubbock47 ,a different kind of musical apparatus is that of the cicada1 which has been elaborately described by ,graber4 ,the shrill1 piercing notes issue from a pair of organs on the under side of the base of the abdomen of the male1 these acting somewhat as two kettle-drums1 the membrane covering the depressions being rapidly vibrated4 ,,literature ,,on ,,the ,,organs ,,of ,,hearing a4 ,the auditory organs ,siebold1 ,c4 ,th4 ,e4 von4 ,ueber das ,stimm- und ,gehrorgan der ,orthopteren4 7,archiv f4 ,naturgesch41 #ahdd1 x1 pp4 #eb-ha47 ,johnston1 ,christopher4 ,auditory apparatus of the culex mosquito4 7,quart4 ,journ4 ,micr4 ,soc41 #ahee1 iii1 pp4 #ig-ajb1 #a ,fig47 ,hicks1 ,braxton4 ,on a new organ in insects4 7,journ4 ,linn4 ,soc4 ,zool41 ,london1 #aheg1 pp4 #acj-adj1 #a ,pl47 ---- ,further remarks on the organ found on the bases of the halteres and wings of insects4 7,trans4 ,linn4 ,soc41 ,london1 #aheg1 xxii1 pp4 #ada-ade1 #b ,pls47 ,hensen1 ,v4 ,ueber das ,gehrorgan von ,locusta4 7,zeitschr4 f4 wissens4 ,zool41 xvi1 #ahff1 pp4 #aij-bjg47 ,graber1 ,v4 ,bemerkungen ber die ,gehr- und ,stimmorgane der ,heuschrecken und ,cicaden 7,wiener ,sitzungsber4 ,math4-natur-wiss4 ,cl41 lxvi1 #a ,abt41 #ahgb1 pp4 #bje-bac1 #b ,figs47 ---- ,die tympanalen ,sinnesapparate1 der ,orthopteren4 7,denkschr4 d4 k4 ,akad4 d4 wissens4 ,wien1 xxxvi1 #ahgf1 #b ,abt41 pp4 #a-adj1 #aj ,taf47 ---- ,die abdominalen ,tympanalorgane der ,cicaden und ,gryllodeen4 7,ibid41 #ahgj1 xxxvi1 pp4 #bgc-bij1 #b ,taf47 ---- ,ueber neue1 otocystenartige ,sinnesorgane der ,insekten4 7,archiv f4 mikroskop4 ,anat41 #ahgh1 pp4 #ce-eg1 #b ,taf47 ---- ,die chordotonalen ,sinnesorgane und das ,gehr der ,insekten4 7,archiv f4 mikroskop4 ,anat41 #ahhb1 xx1 pp4 #ejf-fdj2 #ahhc1 xxi1 pp4 #fe-ade1 ,taf47 ,mayer1 ,alfred ,marshall4 ,researches in ,acoustics ,no4 #e4 #c4 ,experiments on the supposed auditory apparatus of the culex mosquito4 7,amer4 ,jour4 ,sc4 and ,arts1 ,ser4 #c1 viii1 #ahgd1 pp4 #ha-ajc2 also ,amer4 ,naturalist1 viii1 pp4 #egg-eib47 ,schmidt1 ,oscar4 ,die ,gehrorgane der ,heuschrecken4 7,archiv f4 mikroskop4 ,anat41 xi1 #ahge1 pp4 #aie-bae1 #c ,taf47 ,ranke1 ,j4 ,beitrge zu der ,lehre von den ,uebergangssinnesorganen1 das ,gehrorgan der ,acridier und das ,sehorgan der ,hirudineen4 7,zeitschr4 f4 wissens4 ,zool41 xxv1 #ahge1 pp4 #adc-afd1 #a ,taf47 ,lee1 ,a4 ,bolles4 ,les balanciers des ,diptres1 leurs organes sensifres et leur histologie4 7,recueil ,zool4 ,suisse1 ii1 #ahhe1 pp4 #cfc-cib1 #a ,pl47 ---- ,bemerkungen ber der feineren ,bau der ,chordotonalorgane4 7,archiv f4 mikroskop4 ,anat41 #ahhc1 xxiii1 pp4 #acc-adj1 #a ,taf47 ---- ,les organes chordotonaux des ,diptres et la mthode du chlorure d'or4 7,observations critiques47 7,recueil ,zool4 ,suisse1 #ahhd1 ii1 pp4 #fhe-fhi1 #a ,pl47 ,weinland1 ,e4 ,ueber die ,schwinger 7,halteren7 der ,dipteren 7,zeitschr4 f4 wissens4 ,zool41 #ahij1 li1 pp4 #ee-aff1 #e ,taf47 ,adelung1 ,n4 v4 ,beitrge zur ,kenntnis des tibialen ,gehrapparates der ,locustiden4 ,inaug4 ,diss41 ,leipzig1 #ahib1 #b ,taf4 ,child1 ,ch4 ,m4 ,ein bisher wenig beachtetes antennales ,sinnesorgan der ,insekten1 mit besonderer ,bercksichtigung der ,culiciden und ,chironomiden4 7,zeitschr4 f4 wissens4 ,zool41 lviii1 #ahid1 pp4 #dge-ebh1 #b ,taf42 also1 ,zool4 ,anzeiger1 xvii ,jahrg41 pp4 #ce-ch1 and in ,annals and ,mag4 ,nat4 ,hist41 #ahid 7#f71 xiii1 pp4 #cgb-cgd74 ,also the writings of ,j4 ,mller1 ,kirby and ,spence1 ,burmeister1 ,gilbert ,white1 ,westwood1 ,guilding1 ,meinert1 ,paasch1 ,leydig1 ,viallanes1 ,minot1 ,forel1 ,mayer1 ,darwin 7,descent of ,man1 i1 ch4 x471 ,f4 ,mller1 ,lubbock 7,senses of animals71 ,westring1 ,kppen1 ,bates1 ,vom ,rath1 ,peckham1 ,jourdan1 ,nagel1 etc4 b4 ,the sounds made by insects ,scudder1 ,s4 ,h4 ,notes on the stridulation of grasshoppers4 7,proc4 ,bost4 ,soc4 ,nat4 ,hist41 xi1 #ahfh1 pp4 #cjf-cac and #caf47 ---- ,the songs of the grasshoppers4 7,amer4 ,naturalist1 ii1 #ahfh1 pp4 #aac-abj1 #e ,figs47 ,riley1 ,c4 ,v4 ,the song notes of the periodical ,cicada4 7,proc4 ,amer4 ,assoc4 ,adv4 ,science1 xxxiv1 #ahhe1 pp4 #ccj-ccb2 also in ,kansas ,city ,rev41 ,october1 #ahhe1 pp4 #agc-age47 ,swinton1 ,a4 ,h4 7,ent4 ,month4 ,mag41 #ahgg47 ,sound produced in ,ageronia by a modification of the hook and bristle of the wings4 ,hampson1 ,g4 ,f4 ,on stridulation in certain ,lepidoptera1 etc4 7,proc4 ,zool4 ,soc4 ,london1 #ahib1 ii1 pp4 #ahh-aic1 ,fig2 also ,psyche1 vi1 p4 #dia1 #a ,fig47 ,with the writings of ,landois1 ,lubbock1 ,graber1 ,kolbe1 ,carpenter 7,nat4 ,science71 ,bruyant1 and others4 ,,the ,,digestive ,,canal ,,and ,,its ,,appendages ,illustration3 ,,fig4 #big4--,transverse section through an abdominal segment of larva of ,megalopyge crispata1 showing the relations of the digestive canal to the other organs3 int1 hind-intestine1 with its mucous or epithelial layer 7ep71 and ml its outer or muscular layer2 ng1 ventral ganglion2 ht1 heart2 mp1 urinary tubes2 f1 fat-body2 sc1 thickened portion of the hypodermis 7hy7 containing the setigenous cells2 m1 muscles2 m1 a pair of retractor muscles inserted near the base of the lateral glandular process 7lgp72 cut1 cuticula2 l1 legs4 ,also compare ,figs4 #adb-add and #bcd4 ,illustration3 ,,fig4 #bih4 ,the alimentary or digestive canal of insects is a more or less straight tube1 which connects the mouth and anus1 the latter invariably situated in the last segment of the body1 under the last tergite or suranal plate4 ,it lies directly over the ventral nervous cord and under the dorsal vessel1 passing through the middle of the body 7,fig4 #big74 ,it is loosely held in place by delicate retractor muscles 7retractores ventriculi1 found by ,lyonet in the larv of ,lepidoptera1 and occurring in those of ,diptera71 but is principally supported by exceedingly numerous branches of the main trache4 ,,fig4 #bih4--;,internal anatomy of ,melanoplus femur-rubrum3 at1 antenna and nerve leading to it from the 8brain0 or suprasophageal ganglion 7sp72 oc1 ocelli1 anterior and vertical ones1 with ocellar nerves leading to them from the brain2 1 sophagus2 m1 mouth2 lb1 labium or under lip2 if1 infrasophageal ganglion1 sending three pairs of nerves to the mandibles1 maxill1 and labium respectively 7not clearly shown in the engraving72 sm1 sympathetic or vagus nerve1 starting from a ganglion resting above the sophagus1 and connecting with another ganglion 7sg7 near the hinder end of the crop2 sal1 salivary glands 7the termination of the salivary duct not clearly shown by the engraver72 nv1 nervous cord and ganglia2 ov1 ovary2 ur1 origin of urinary tubes2 ovt1 oviduct2 sb1 sebaceous gland2 bc1 bursa copulatrix2 ovt1 site of opening of the oviduct 7the left oviduct cut away72 #a-aj1 abdominal segments4 ,the other organs labelled in full4--,drawn from his original dissections by ,mr4 ,edward ,burgess4 ,illustration3 ,,fig4 #bii4--;,digestive canal of ,anabrus3 m1 mouth3 1 sophagus2 sm1 the sympathetic nerve passing along the crop2 t1 tongue2 fg1 frontal ganglion2 br1 brain1 the nervous cord passing backward from it2 sr1 salivary reservoir2 sg1 salivary gland2 pv1 proventriculus2 ur1 origin of urinary tubes2 sb1 sebaceous gland2 #a-aj1 the ten abdominal segments4--,burgess del4 ,it is in the higher adult insects differentiated into the mouth and pharynx1 the sophagus or gullet1 supplementary to which is the crop 7ingluvies7 or 8sucking stomach0 of ,lepidoptera1 ,diptera1 and ,hymenoptera2 the proventriculus or gizzard2 the ventriculus1 8chyle-stomach10 or1 more properly1 mid-intestine1 and the hind-intestine1 which is divided into the ileum1 or short intestine1 the long intestine1 often slender and coiled1 with the colon and the rectum4 ,morphologically1 however1 the digestive or enteric canal is divided into three primary divisions1 which are indicated in the embryo insect2 i4e41 the fore-intestine 7stomodum of the embryo71 mid-intestine or 8chyle-stomach10 and hind-intestine or proctodum 7,fig4 #cjj74 ,the three primary regions1 with their differentiations1 may be tabulated thus3-- ,fore-intestine 7,stomodum74 ,mouth and pharynx4 ,pumping apparatus of ,hemiptera1 ,lepidoptera1 and ,diptera4 sophagus4 ,crop or ingluvies1 food reservoir1 or 8sucking stomach40 ,proventriculus4 ,mid-intestine 7,mesenteron74 ,mid-intestine1 8chylific stomach10 or ventriculus 7with ccal glands74 ,hind-intestine 7,proctodum74 ,ileum1 or short intestine 7with the urinary tubes74 ,long intestine4 ,colon4 ,rectum 7with rectal glands74 ,anus 7with anal glands74 ,illustration3 ,,fig4 #cjj4--,the three primary divisions of the alimentary canal of an embryonic orthopterous insect3 br1 brain2 sbg1 subsophageal ganglion2 ng1 nervous cord2 st1 stomodum2 pr1 proctodum2 mv1 malphigian tubes2 mesen1 mid-intestine2 ht1 heart2 md1 mandibles2 mx1 mx1 #ast and #b;d maxill4--,after ,ayers1 with some changes4 ,the appendages of the alimentary canal are3 7#a7 the salivary and poison glands1 which arise from the stomodum in embryonic life2 7#b7 while to the chylific stomach a single pair of ccal appendages 7,orthoptera and larval ,diptera1 e4g4 ,sciara71 or many cca may be appended2 7#c7 the urinary tubes1 also the rectal glands and the paired anal glands4 ,in a ,hemipter 7,pyrrhocoris apterus7 appendages arise from the intestine in front of the origin of the urinary tubes4 ,in certain insects a single ccal appendage 7,nepa1 ,dyticus1 ,silpha1 ,necrophorus1 and the ,lepidoptera7 arises from the proctodum4 ,illustration3 ,,fig4 #cja--,larva of honey-bee3 g1 brain2 bm1 ventral nervous cord2 1 sophagus2 sd1 spinning-gland2 cd1 mid-intestine or chyle-stomach2 ed1 hind-intestine1 not yet connected with the mid-intestine2 vm1 urinary tube2 an1 anus2 st1 stigmata4--,after ,leuckart1 from ,lang4 ,in certain larval insects1 as those of the ,proctotrypid 7first larval stage71 the higher ,hymenoptera 7ichneumons1 ants1 wasps1 and bees1 ,fig4 #cja71 in the ,campodea-like larv of the ,meloid and ,stylopid1 the larva of the ant-lion 7,myrmecoleo71 and those of ,diptera pupipara 7,melophagus71 the embryonic condition of the separation of the proctodum and mid-gut 7mesenteron7 persists1 the stomach ending in a blind sac2 in such cases the intestine1 together with the urinary tubes1 is entirely secretory4 ,the anus is wanting in the larva of the ant-lion1 as also in the wasps 7in which there is a rudimentary colon7 and in freshly hatched bees1 though it becomes perfectly formed in the fully grown larv 7,newport1 art4 ,insecta1 p4 #ifg1 and ,h4 ,mller74 ,in the larv of lamellicorn ,coleoptera 7,melolontha vulgaris7 the digestive tube is nearly as simple as in bees1 though there is a large colon1 which at its beginning forms an immense ccum1 and has also one anal aperture 7,newport74 ,the length and shape of the digestive canal is dependent on the nature of the food and also on the mode of life1 especially the ease or difficulty with which the food is digested4 ,newport1 while stating that the length of the alimentary canal in larv is not in general indicatory of the habits of the species1 makes this qualification after describing the digestive canal of ,calandra as compared with that of ,calosoma3 8,the length and complication of the intestines1 therefore1 appear to have some reference to the quality of the food to be digested1 since it is well known that the food of these latter insects 7weevils7 is of difficult assimilation1 being as it is chiefly the hard ligneous fibres of vegetable matter2 but they cannot be received as always indicatory of a carnivorous or vegetable feeder1 since1 as above remarked1 the length of the canal is considerable in one entirely carnivorous larva1 while it is much shorter in some herbivorous1 and particularly in pollenivorous larv1 as in the ,melolontha and the apodal ,hymenoptera40 ,illustration3 ,,fig4 #cjb4--;,digestive canal of a carabid beetle3 b1 sophagus2 c1 crop2 d1 proventriculus2 f1 mid-intestine1 or 8chyle-stomach10 with its ceca2 g1 posterior division of the stomach2 i1 the two pairs of urinary tubes2 h1 intestine2 k1 rectum2 l1 anal glands4--,after ,dufour1 from ,judeich and ,nitsche4 ,newport also contends that the length of the alimentary canal is not more indicative in the perfect insect of the carnivorous or phytophagous habits of the species than in the larva4 ,it is nearly as long 7being from two to three times the length of the whole body71 and is more complicated1 in the rapacious ,carabid 7,fig4 #cjb7 than in the honey-sipping ,lepidoptera1 whose food is entirely liquid4 ,referring to the digestive canal of ,cicindelid1 which is scarcely longer than the body1 he claims that 8we cannot admit that the length of the digestive organs1 and the existence of a gizzard and gastric vessels1 are indicatory of predacity of habits in the insect1 because a similar conformation of parts exists often in strictly vegetable feeders4 ,the existence and length of these parts seem rather to refer to the comparative digestibility of the food than to its animal or vegetable nature40 ,newport then refers to the digestive canal of ,forficulid 7in which the gizzard is present1 the canal1 however1 passing in an almost direct line through the body1 making but one slight convolution71 8a farther proof that the length of the canal must not be taken as a criterion whereby to judge of the habits of a species40 ,he adds this will apply equally well to the omnivorous ,gryllid1 in which there exists a short alimentary canal1 but a gizzard of more complicated structure than that of the ,dytiscid4 ,in larval insects and others 7,synaptera1 ,orthoptera1 etc471 in which the digestive canal is simplest1 it is scarcely longer than the body1 and passes through it as a straight tube4 ,in the caterpillar1 which is a voracious and constant feeder1 the digestive canal is a large straight tube1 not clearly differentiated into fore-stomach1 stomach1 and intestine2 but in the imago1 which only takes a little liquid food1 it is slender1 delicate1 and highly differentiated4 ,in the larva the mid-gut forms the largest part of the canal2 in the imago1 the intestine becomes very long and coiled into numerous turns2 at the same time the food-reservoir 7the 8sucking stomach07 develops1 and the excretory tubes are longer4 a4 ,the digestive canal ,illustration3 ,,fig4 #cjc4--;,interior view of the bottom of the head of ,danais archippus1 the top having been cut away1 showing1 in the middle1 the pharyngeal sac with its five muscles3 the frontal 7f4m71 dorsal pair 7d4m71 and the lateral pair 7l4m72 cl1 clypeus2 cor1 cornea2 1 sophagus2 p4m1 one of the large muscles which move the labial palp4--,after ,burgess4 ,it will greatly simplify our conception of the anatomy of the digestive canal if we take into account its mode of origin in the embryo1 bearing in mind the fact that during the gastrula condition the ectoderm is invaginated at each pole to form the primitive mouth and fore-gut 7stomodum7 and hind-gut 7proctodum74 ,the cells of the ectoderm secrete a chitinous lining 7intima71 which forms the continuation of the outer chitinous crust1 and thus the lining of each end of the digestive canal is cast whenever the insect molts2 while the mid-intestine 7mesenteron71 arising independently of the rest of the canal much later in embryonic life from the mesoderm1 is not the result of any invagination1 being directly derived from the mesoderm1 and is not lined with chitin4 ,the mouth1 or oral cavity1 and pharynx4--,this is the beginning of the alimentary bounded above by the clypeus1 and labrum1 with the epipharynx1 and below by the hypopharynx1 or tongue1 as well as the labium4 ,into it pour the secretion of the salivary glands1 which passes out through an opening at the base of the tongue or hypopharynx4 ,on each side of the mouth are the mandibles and first maxill4 ,the sucking or pharyngeal pump4--,this organ has been observed by ,graber in flies and ,hemiptera1 but the fullest account is that by ,burgess1 who was the first to discover it in ,lepidoptera4 ,in the milk-weed butterfly 7,danais archippus7 the canal traversing the proboscis opens into a pharynx enclosed in a muscular sac 7,figs4 #cjc1 #cjd1 and #caj74 ,the pharyngeal sac1 says ,burgess1 serves as a pumping organ to suck the liquid food through the proboscis and to force it backwards into the digestive canal4 ,illustration3 ,,fig4 #cjd4--,longitudinal section through the head of ,danais1 showing the interior of the left half3 mx1 left maxilla1 whose canal leads into the pharynx2 hph1 floor of the latter1 showing some of the taste-papill2 oe1 sophagus2 ep1 epipharyngeal valve2 sd1 salivary duct2 d4m1 f4m1 and cl1 as in ,fig4 #cjb4--;,after ,burgess4 ,meinert 78,trophi ,dipterorum07 has made elaborate dissections of the mouth and its armature1 including the pharynx of several types of ,diptera1 with its musculature4 ,he describes the pharynx as the principal1 and in most ,diptera1 as the only part of the pump 7antlia71 and says3 8,by the muscles of the pump 7musculis antli7 the superior lamina of the pharynx is varied that the space between the two lamin may be increased1 and the liquid is thus led through the siphon formed by the mouth-parts into the mouth0 7,fig4 #ha74 ,the sophagus4--,this is a simple tube1 largest in those insects feeding on solid1 usually vegetable1 food1 and smallest in those living on liquid food4 ,it usually curves upwards and backwards1 passing directly under the brain1 and merges into the crop or proventriculus either at the back part of the head or in the thorax1 its length being very variable4 ,its inner walls longitudinally are folded and lined with chitin4 ,according to ,newport1 in the sophagus of the ,gryllid1 of the two layers of the mucous lining the second is distinctly glandular and secretory1 and in it there are many thousands of very minute granular glandular bodies1 which probably secrete the 8molasses0 or repellent fluid often ejected by these and other insects when captured4 ,the crop or ingluvies4--,this1 when present1 is an enlargement of the end of the sophagus1 and lined internally with a muscular coat4 ,it is very large in locusts 7,fig4 #bih71 ,anabrus 7,fig4 #bii71 and other ,orthoptera 7the ,phasmid excepted71 in the ,dermaptera1 and most adult ,coleoptera4 ,a crop-like dilatation in front of a spherical gizzard is also present in the ,synaptera 7,podurid and ,lepismid71 as well as in the ,mallophaga 7,nirmid74 ,illustration3 ,,fig4 #cje4--;,digestive canal of ,calandra3 ,h1 pear-shaped sophagus2 ,i1 crop2 ,k1 gastric cca ,l1 ilium2 ,,mn1 colon2 ,p1 urinary tubes4--,after ,newport4 ,illustration3 ,,fig4 #cjf4--,section of the crop 7,h71 gizzard 7,i71 and stomach 7,k7 of ,athalia4-,after ,newport4 ,illustration3 ,fig4 #cjg4--,upper side of head and digestive canal of ,myrmeleon larva3 a1 crop2 b1 8stomach02 c1 free ends of two urinary tubes2 c1 common origin of other six tubes2 d1 ccum2 e1 spinneret2 ff1 muscles for protruding its sheath2 gg1 maxillary glands4--,after ,meinert1 from ,sharp4 ,in the larv of weevils 7,calandra sommeri7 there is a crop 7,fig4 #cje71 but not in the larva of ,calosoma2 also1 according to ,beauregard1 in the pollen-eating beetles ,zonitis1 ,sitaris1 and ,malabris it is wanting1 while in ,meloe it is highly developed 7,kolbe74 ,the crop forms a lateral dilatation of the end of the sophagus in the larv of weevils and of saw-flies 7,athalia centifoli1 ,fig4 #cjf74 ,the 8sucking stomach0 or food-reservoir4--,this is a thin muscular pouch connected by a slender neck with the end of the sophagus or the crop1 when the latter is present4 ,there is no such organ in ,orthoptera1 except in ,gryllotalpa4 ,it is wanting in the ,odonata and in the ,plectoptera 7,ephemerid72 in ,platyptera 7,perlid and ,termitid71 in ,trichoptera1 and in ,mecoptera 7,panorpid74 ,in most adult ,neuroptera 7,myrmeleonid1 ,hemerobiid1 and ,sialid71 but not in ,rhaphidiid1 the long sophagus is dilated posteriorly into a kind of pouch or crop1 and besides there is often a long 8food-reservoir0 arising on one of its sides1 that of ,myrmeleon 7,fig4 #cjg7 and ,hemerobius being on the right side4 ,illustration3 ,,fig4 #cjh4--;,digestive canal of ,sarcophaga carnaria3 a1 salivary gland2 b1 sophagus2 c1 food reservoir2 f-g1 stomach2 h1 intestine2 i1 urinary tubes2 k1 rectum4--,from ,judeich and ,nitsche4 ,a true food-reservoir is present in most ,diptera 7,fig4 #cjh7 as well as in the larv of the ,muscid1 but according to ,dufour it is wanting in some ,asilid and in ,diptera pupipara1 and according to ,brauer in the strid4 ,the food-reservoir in ,diptera is always situated on the left side of the digestive canal2 there is usually a long neck or canal1 while the reservoir is either oval or more usually bilobed1 and often each lobe is itself curiously lobed4 ,in ,lepidoptera 7,figs4 #cji1 #caj7 the so-called 8sucking stomach0 is1 as ,graber has proved1 simply a reservoir for the temporary reception of food2 though generally found to contain nothing but air1 ,newport has observed that in flies it is filled with food after feeding4 ,he has found this to be the case in the flesh fly1 and in ,eristalis he has found it 8partially filled with yellow pollen from the flowers of the ragwort upon which the insect was captured10 the pollen grains also occurring in the canal leading to the bag1 in the gullet1 and in the stomach itself4 ,graber has further proved by feeding flies with a colored sweet fluid that this sac is only a food-receptacle4 ,as he says3 8,it can be seen filling itself fuller and fuller with the colored fluid1 the sac gradually distending until it occupies half the hind-body40 ,the food-reservoir of the ,hymenoptera is a lateral pouch at the end of the long1 slender sophagus1 and has been seen in the bee to be filled with honey4 ,illustration3 ,,fig4 #cji4--;,digestive canal of ,sphinx ligustri3 h1 sophagus2 i1 rudiment of the gizzard2 k1 8stomach02 q1 its pyloric end2 t1 food reservoir2 p1 urinary tubes2 l1 ilium2 m1 ccum of colon2 n1 rectum2 v1 vent4--,after ,newport4 ,in the mole-cricket the hinder part of the crop is armed within with hook-like bristles directed backwards so as not to prevent the energetic pressure of the food backwards into the proventriculus1 and to obviate the possibility of a regurgitation4 7,eberli47 ,the fore-stomach or proventriculus4--,this is especially well developed in the ,dermaptera1 in the ,orthopterous families ,locustid1 ,gryllid1 and ,mantid1 while in the ,thysanura 7,lepisma7 there is a spherical gizzard provided with six teeth4 ,it also occurs in many wood-boring insects1 and in most carnivorous insects1 notably the ,carabid1 ,dyticid1 ,scolytid1 in the ,mecoptera 7scorpion-flies71 in the fleas1 and in many kinds of ants1 as well as ,cynips1 ,leucospis1 and ,xyphidria4 ,it is very muscular1 lined within with chitin1 which is usually provided with numerous teeth arising from the folds4 ,these folds begin in the sophagus or crop1 and suddenly end where the mesenteron 78chylific stomach07 begins4 ,it has been compared with the gizzard of birds1 and is usually called by ,german authors the chewing or masticating stomach4 7,kaumagen47 ,the proventriculus is best developed in the ,gryllid 7,acrida viridissima71 where the six folds at the end of the crop close together to form a valve between the crop and proventriculus4 8,they are each armed with five very minute hooked teeth2 and1 continued into the gizzard1 develop many more in their course through that organ4 ,these first teeth are arranged around the entrance to the gizzard1 and seem designed to retain the insufficiently comminuted food and to pass it on to that organ4 ,illustration3 ,,fig4 #caj4--;,anatomy of ,danais archippus after removal of right half of the body4 ,lettering of the head3 a1 antenna2 ph1 pharynx2 pl1 labial palpi2 r1 proboscis2 g1 brain2 usg1 subsophageal ganglion4 ,lettering of the thorax3 ,i4 ,,ii4 ,,iii4 thoracic segments2 b#a1 b#b1 b#c1 the coxal joints of the three pairs of legs2 bm1 muscles of the wings2 ac cephalic aorta with its swelling2 1 sophagus2 bg1 thoracic ganglia of the ventral cord2 sd1 salivary glands of one side1 those of the other side cut off near their entrance into the common salivary duct4 ,lettering of the abdomen3 #a-i4 abdominal segments2 h1 heart2 sm1 so-called sucking-stomach 7food-reservoir72 cm1 chyle-stomach2 ag1 abdominal ganglia3 ed1 hind intestine with colon 7c7 and rectum 7r72 rm1 urinary vessels2 ov1 ovarial tubes1 those of the right side cut off2 ove1 terminal filaments of the ovaries2 bc1 bursa copulatrix2 obc1 its outer aperture2 od1 oviduct2 vag1 vagina2 wo1 its outer aperture2 ad1 glandular appendages of the vagina partly cut away2 vk1 connective canal between the vagina and bursa copulatrix with swelling 7receptaculum seminis72 an1 anus4--,after ,burgess1 from ,lang4 ,illustration3 ,,fig4 #caa4--,transverse section of the proventriculus of ,gryllus cinereus3 muc1 muscular walls2 r1 horny ridge between the large teeth 7sp74--,after ,minot4 ,illustration3 ,,fig4 #cab4--,transverse section of the proventriculus of the cockroach4--,after ,miall and ,denny4 ,illustration3 ,,fig4 #cac4--;,digestive canal of the honey-bee3 ,a1 horizontal section of the body2 lp1 labial palpus2 mx1 maxilla2 e1 eye2 pro4 t1 prothorax2 mesa4 t1 mesothorax2 meta4 t1 metathorax2 dv1 dorsal vessel2 v1 v1 ventricles of the same2 ,no4 #a1 ,no4 #b1 ,no4 #c1 salivary gland systems2 sophagus2 g1 g1 ganglia of chief nerve-chain2 n1 nerves2 hs1 honey-sac2 p1 petaloid stopper or calyx of honey-sac or stomach-mouth2 c4 s1 chyle stomach2 bt1 urinary tubes2 si1 small intestine 7ilium72 l1 8lamell or gland-plates of colon10 rectal glands2 li1 rectum4 ,b1 cellular layer of stomach2 gc1 gastric cells1 #bjj4 ,c1 urinary tube2 bc1 cells2 t1 trachea4 ,d1 inner layer1 with gastric teeth 7gt74--,after ,cheshire4 8,next to these in succession on each of the longitudinal ridges are four flat1 broad1 somewhat quadrate teeth1 each of which is very finely denticulated along its free margin4 ,these extend about half-way through the gizzard4 ,they appear to be alternately elevated and depressed during the action of the gizzard1 and to serve to carry on the food to the twelve cutting teeth1 with which each ridge is also armed1 and which occupy the posterior part of the organ4 ,these teeth are triangular1 sharp-pointed1 and directed posteriorly1 and gradually decrease in size in succession from before backward4 ,each tooth is very strong1 sharp-pointed1 and of the color and consistence of tortoise shell1 and is armed on each side by a smaller pointed tooth4 ,these form the six longitudinal ridges of the gizzard1 between each two of which there are two other rows of very minute teeth of a triangular form1 somewhat resembling the larger one in structure1 occupying the channels between the ridges4 ,the muscular portion of the gizzard is equally interesting4 ,it is not merely formed of transverse and longitudinal fibres1 but sends from its inner surface into the cavity of each of the large teeth other minute but powerful muscles1 a pair of which are inserted into each tooth4 ,the number of teeth in the gizzard amounts to #bgj1 which is the same number in these ,gryllid as found formerly by ,dr4 ,kidd in the mole-cricket4 ,of the different kinds of teeth there are as follows3 #gb large treble teeth1 #bd flat quadrate teeth1 #cj small single-hooked teeth1 and #ab rows of small triangular teeth1 each row being formed of #ab teeth4 ,this is the complicated gizzard of the higher ,orthoptera40 7,newport47 ,in the more generalized cockroach1 there are six principal folds1 the so-called teeth1 which project so far inwards as to nearly meet 7,fig4 #cab74 ,the entire apparatus of muscles and teeth is1 as ,miall and ,denny state1 8an elaborate machine for squeezing and straining the food1 and recalls the gastric mill and pyloric strainer of the crayfish4 ,the powerful annular muscles approximate the teeth and folds1 closing the passage1 while small longitudinal muscles1 which can be traced from the chitinous teeth to the cushions1 appear to retract these last1 and open a passage for the food40 ,as in the fore-stomach or proventriculus of the lobster1 the solid1 rounded teeth do not appear to triturate the solid fragments found in the organ1 but act rather as a pyloric strainer to keep such bodies out of the chylific stomach4 ,we accept the view of ,plateau that this section of the digestive canal in insects1 which he compares to the psalterium of a ruminant1 is a strainer rather than a masticatory stomach1 and both ,forel and ,emery1 as well as ,cheshire1 take this view4 ,the proventriculus of the honey-bee 7,fig4 #cac1 hs7 is called by apiarians the 8honey-sac0 or 8honey-stomach40 ,cheshire states that if it be carefully removed from a freshly killed bee1 its calyx-like 8stomach-mouth0 may be seen to gape open and shut with a rapid snapping movement4 ,the entrance to the stomach is guarded by four valves1 each of which is strongly chitinous within1 and fringed along its edge with downward-pointing fine stiff bristles4 ,by the contraction of the longitudinal muscles 7lm71 the valves open to allow the passage of food from the honey-sac to the 8chyle-stomach40 ,it is closed at will by circular muscles 7tm74 ,then the bee can carry food for a week's necessities1 either using it rapidly in the production of wax1 or eking it out if the weather is unfavorable for the gathering of a new store4 ,illustration3 ,,fig4 #cad4--8;,honey-sac stopper10 8stomach-mouth10 or calyx-bell of honey-bee1 #ej4 ,a1 front view of one of the lobes of the calyx-bell2 l1 lip-like point1 covered by down-turned bristles 7b72 sm1 side membrane4 ,b1 longitudinal section of the stomach-mouth1 with continuations into entrance of chyle-stomach2 l1 l1 lip-like ends of leaflets2 s1 set2 lm1 longitudinal muscles2 tm1 transverse muscles in cross-section2 cl1 cell-layer of honey-sac2 ,,lm1 ,,tm1 longitudinal and transverse muscles of same2 nc1 nucleated cells of tubular extension of stomach-mouth into chyle-stomach2 lm1 tm1 longitudinal and transverse muscles of chyle stomach2 c1 c1 cells covered within by an intima4 ,c1 cross-section of stomach-mouth2 m1 cross-section of muscles seen at lm in ,b2 tm1 transverse muscles surrounding stomach-mouth4 ,d1 cross-section through small intestine2 a and m1 longitudinal and surrounding muscles4--,after ,cheshire4 ,cheshire also shows that when bees suck up from composite and other flowers nectar together with much pollen1 the outside wrinkled membrane 7sm1 ,a1 ,fig4 #cad7 8is seen to continually run up in folds1 and gather itself over the top of the stomach-mouth1 bringing with it1 by the aid of its set1 the large pollen-grains the nectar contains40 ,the lips 7l1 l1 ,b1 ,fig4 #cad71 now opening1 take in this pollen1 which is driven forwards into the cavity made between the separating lips by an inflow of the fluid surrounding the granules4 ,the lips in turn close1 but the down-pointing bristles are thrown outwards from the face of the leaflet1 in this way revealing their special function1 as the pollen is prevented from receding while the nectar passes back into the honey-sac1 strained through between the bristles aforesaid1 the last parts escaping by the loop-like openings seen in the corners of ,c1 ,fig4 #cad4 ,the whole process is immediately and very rapidly repeated1 so that the pollen collects and the honey is cleared4 8,three purposes1 in addition to those previously enumerated1 are thus subserved by this wondrous mechanism4 ,first1 the bee can either eat or drink from the mixed diet she carries1 gulping down the pollen in pellets1 or swallowing the nectar as her necessities demand4 ,second1 when the collected pollen is driven forwards into the chyle-stomach1 the tube extension1 whose necessity now becomes apparent1 prevents the pellets forming into plug-like masses just below p1 ,fig4 #cac1 for1 by the action of the tube1 these pellets are delivered into the midst of the fluids of the stomach1 to be at once broken up and subjected to the digestive process4 ,and third1 while the little gatherer is flying from flower to flower1 her stomach-mouth is busy in separating pollen from nectar1 so that the latter may be less liable to fermentation and better suited to winter consumption4 ,she1 in fact1 carries with her1 and at once puts into operation1 the most ancient1 and yet the most perfect and beautiful1 of all #8honey-strainers4'0 ,forel's experiments on the proventriculus of ants prove that through its valvular contrivance it closes the passage from the crop to the mid-intestine 78chylific stomach071 and allows the contents of the former to pass slowly and very gradually into the latter4 ,emery confirms this view1 and concludes that the organ in the ,camponotid and in the ,dolichoderid provided with a calyx-bell1 usually regarded as a triturating stomach 7,kaumagen71 but more correctly as a pumping stomach1 consists of parts which perform two different functions4 ,under the operation of the muscles of the crop the entrance to the pumping stomach becomes closed1 in order by such spasmodic contraction to prevent the flow of the contents of the crop into the proventriculus4 ,by the pressure of the transverse muscles of the proventriculus its contents are emptied into the mid-intestine1 while simultaneously a regurgitation into the crop is prevented4 ,in the ,dolichoderid and ,plagiolepidin the closure in both cases is effected by the valves4 ,in the true ,camponotid there are two separate contrivances for closing2 the calyx belonging to the crop-musculature1 while the valves essentially belong to the proventricular pumping apparatus4 ,opinions vary as to the use of this portion of the digestive canal4 ,graber compares it to the gizzard of birds1 and likens the action of the rosette of teeth to the finer radiating teeth of the sea-urchin1 and styles it a chopping machine1 which works automatically1 and allows no solid bits of food to pass in to injure the delicate walls of the stomach 7mid-gut74 ,he also states that the food when taken from the proventriculus is very finely divided1 while that found in the sophagus contains large bits4 ,kolbe says that this view has recently been completely abandoned1 and that the teeth are used to pass the food backwards into the chylific stomach4 8,but ,goldfuss had denied the triturating action of the proventriculus of the ,orthoptera 7,symbol ad ,orthopterorum quorundam conomiam1 #ahdc71 stating that the contents of the same are already fluid in the gullet1 so that the fore-stomach 7,kaumagen7 does not need to comminute the food0 7,kolbe74 ,in the ,gryllid and ,locustid1 just before the posterior opening of the proventriculus into the stomach the chitinous lining swells into a ring and projects straight back as the inner wall of the cylindrical chylific stomach4 ,the muscular layer forms two sac-like outgrowths or folds1 which separate on the circular fold from the chitinous membrane4 ,this apparatus only allows very finely comminuted food to pass into the stomach4 ,in the ,acrydiid 7,eremobia muricata7 at the end of the proventriculus1 where it passes into the stomach1 is a small circular fold which hangs down like a curtain in the stomach4 ,the sophageal valve4--,weismann#ej states that the origin of the proventriculus in the embryo of flies 7,muscid7 shows that it should be regarded as an intussusception of the sophagus4 ,while in the embryo the invaginated portion of the sophagus is short1 after the hatching of the larva it projects backwards into the mid-intestine4 ,kowalevsky also observed in a young muscid larva1 #b4b mm4 in length1 that the sophagus1 shaped like a tube1 extends back into the expanded portion 7proventriculus7 and opens into the stomach 7,fig4 #cae1 ,a74 ,in a larva #aj mm4 long the funnel is shorter1 the end being situated in the proventriculus 7,fig4 #cae1 ,b1 pr74 ,in the cavity between the outer 7o7 and inner wall 7i7 no food enters1 and the use of this whole apparatus seems to be to prevent the larger bits of food from passing into the chylific stomach 7,kowalevsky74 ,illustration3 ,,fig4 #cae4--sophageal valve of young muscid larva3 m1 its opening3 t1 thickening of the cells2 mes1 mesoderm4--,after ,kowalevsky4 ,beauregard has found a similar structure in the ,meloid1 and calls it the 8cardiac valvule0 7,fig4 #cah1 ,kl74 ,it was observed by ,mingazzini in the larv of phytophagic lamellicorn beetles1 and ,balbiani described it in a myriopod 7,cryptops7 under the name of the 8sophageal valvule40 ,gehuchten describes a homologous but more complicated structure in a tipulid larva 7,ptychoptera contaminata71 but differing in containing blood-cavities1 as a tubular prolongation of the posterior end of the sophagus which passes through the proventriculus and opens at various positions in the anterior part of the chylific stomach 7,fig4 #caf74 ,the three layers composing this funnel are distant from each other and separated by blood-cavities1 the whole forming 8an immense blood-cavity extended between the epithelial proventricular lining and the muscular coat40 ,according to ,schneider the longitudinal muscular fibres of the fore and hind gut in insects pass into the stomach 7mid-gut74 ,the anterior part of the fore-gut has generally only circular fibres4 ,when1 however1 the longitudinal fibres arise behind the middle1 then they separate from the digestive canal and are inserted a little behind the beginning of the chylific stomach4 ,hence there is formed an invagination of the proventriculus1 which projects into the cavity of the stomach4 ,schneider describes this process1 which he calls the 8beak10 as an invagination of the fore-stomach which projects into the cavity of the stomach4 ,the two layers of the invagination in growing together form a beak varying in shape1 being either simple or lobed and armed with bristles or teeth4 ,this beak is tolerably large in ,lepisma1 ,dermaptera 7,forficula71 ,orthoptera1 and in the larv and adults of ,diptera1 but smaller in the ,neuroptera and ,coleoptera1 while in other insects it is wanting4 ,proventricular valvule4--,gehuchten also describes in ,ptychoptera what he calls 8the proventricular valvule10 stating that it is 8a circular fold of the intestinal wall0 7,fig4 #caj1 vpr74 ,he claims that it has not before been found1 the 8proventricular beak0 of ,schneider being regarded by him as the sophageal valvule4 ,illustration3 ,,fig4 #caf4--;,digestive canal of ,ptychoptera contaminata3 gs1 salivary glands2 ra1 sophagus2 pr1 proventriculus2 gt1 crown of eight small tubular glands2 im1 mid-intestine2 ga1 two accessory white glands2 vm1 urinary vessels2 ig1 small intestine2 gi1 large intestine2 r1 rectum2 ,a1 the proventriculus in which the hinder end of the sophagus extends as far as the chyle-stomach4 ,b1 longitudinal section of the proventricular region2 sph1 muscular ring or sophageal sphincter2 ppr1 wall of the proventriculus2 e1 circular constriction dividing the cavity of the proventriculus in two2 vpr1 circular fold of the wall of the mid-intestine forming the proventricular valve2 v1 sophageal valve4--,after ,gehuchten4 ,the peritrophic membrane4--,this membrane appears first to have been noticed by ,ramdohr in #ahaa in ,hemerobius perla4 ,it has been found by ,schneider1 who calls it the 8funnel40 ,on the hinder end of the fore-stomach1 he says1 the cuticula forms a fold enclosing the outlet of the fore-stomach1 and extending back like a tube to the anus4 ,this 8funnel10 he adds1 occurs in a great number of insects4 ,it has been found in ,thysanura1 but is wanting in ,hemiptera4 ,in the ,coleoptera it is absent in ,carabid and ,dyticid4 ,it is generally present in ,diptera and in the larv of ,lepidoptera1 but not in the adults4 ,in ,hymenoptera it has been found in ants and wasps1 but is absent in ,cynipid1 ,ichneumonid1 and ,tenthredinid4 ,all those insects 7including their larv7 possessing this funnel eat solid1 indigestible food1 while those which do not possess it take fluid nourishment4 ,it is elastic1 and firmly encloses the contents of the digestive tract4 ,until ,schneider's discovery of its general occurrence1 it had only been known to exist in the viviparous ,cecidomyia larv 7,miastor74 ,wagner1 its discoverer1 noticed in the stomach of this insect a second tube which contained food4 ,pagenstecher was inclined to regard the tube as a secretion of the salivary glands4 ,metschnikoff1 however1 more correctly stated that the tube consisted of chitin1 but he regarded it as adapted for the removal of the secretions4 7,schneider47 ,plateau1 however1 as well as ,balbiani1 the latter calling it the 8peritropic membrane10 considers this membrane as a secretion of the chylific stomach1 and that it is formed at the surface of the epithelial cells4 ,it surrounds the food along the entire digestive tract1 forming an envelope around the fcal masses4 ,on the other hand1 ,gehuchten states that in the larva of ,ptychoptera its mode of origin differs from that described by ,plateau and by ,schneider1 and that it is a product of secretion of special cells in the proventriculus4 ,the mid-intestine4--,this section of the digestive canal1 often1 though erroneously1 called the 8chylific stomach0 or ventriculus1 differs not only in its embryonic history1 but also in its structure and physiology from the fore and hind intestine of arthropods1 and also presents no analogy to the stomach of the vertebrate animals4 ,in insects it is a simple tube1 not usually lined with chitin1 since it is not formed by the invagination of the ectoderm1 as are the fore and hind intestine1 the absence of the chitinous intima promoting the absorption of soluble food4 ,into the anterior end either open two or more large ccal tubes 7,fig4 #bii71 or its whole outer surface is beset with very numerous fine glandular filaments like villi 7,fig4 #cag and ,fig4 #cbi74 ,the mid-intestine varies much in size and shape2 it is very long in the lamellicorn beetles 7,melolontha and ,geotrupes71 and while in ,melo it is very large1 occupying the greatest part of the body-cavity1 in the longicorn beetles and in ,lepidoptera it is very small4 ,the pyloric end consists of an internal circular fold projecting into the cavity4 ,in the ,psocid 7,ccilius7 the pyloric end is prolonged into a slender tube nearly as long as the larger anterior portion4 ,the limits between the mid and hind intestine are in some insects difficult to define1 the urinary tubes sometimes appearing to open into the end of the mid-intestine 78stomach074 ,the latter also is sometimes lined with an intima4 ,the limits are also determined by a circular projection1 directly behind which is an enlargement of the intestine in the shape of a trench 7rigole71 or circular cul-de-sac 7the 8pyloric valvule0 of some authors1 including ,beauregard71 while the walls of the small intestine contract so as to produce a considerable constriction of the cavity of the canal4 ,this constriction exactly coincides with the beginning of the double layer of circular muscles in the wall of the small intestine4 ,an internal layer1 which is the continuation of the circular muscles of the chylific stomach1 and an external layer much more developed probably belong to this part of the alimentary canal4 ,since the homologue of the circular fold occurs in the locust as well as in ,diptera1 it is probably common to insects in general4 ,illustration3 ,,fig4 #cag4--;,digestive canal of ,carabus monilis3 h1 sophagus2 i1 gizzard or proventriculus2 k1 8stomach10 with its cca 7r72 p1 urinary tubes2 q1 their point of insertion2 m1 n1 colon1 with ccal glands2 s1 anal glands2 a1 b1 c1 a gastric ccum2 a1 b1 portion of lining of gizzard4--,after ,newport4 ,illustration3 ,,fig4 #cah4--;,digestive canal of ,meloe3 sch1 sophagus2 ,kl1 sophageal valve2 m,d1 mid-intestine2 e,d1 hind-intestine2 ,ei1 eggs2 g1 sexual opening4--,after ,graber4 ,gehuchten adds that the limit set by the circular projection does not exactly coincide with the opening into the intestine of the urinary tubes and the two annexed glands4 ,he shows by a section 7his ,fig4 #acc7 that the tubular glands open into the alimentary canal in front of the circular fold4 ,it is the same with the ,malpighian tubes4 ,they are not1 therefore1 he claims1 dependences of the terminal intestine1 but of the mid-intestine4 ,beauregard has observed the same thing in the vesicating insects 7,meloid74 ,the ,malpighian tubes1 he says1 open into the 8chylific stomach0 before the valvular crown4 ,this arrangement does not seem to be general1 because1 according to ,balbiani1 the ,malpighian vessels open into the beginning of the intestine in ,cryptops4 ,compare also ,minot's account of the valve in locusts separating the stomach from the intestine1 and in front of which the urinary or ,malpighian tubes open4 ,histology of the mid-intestine4--,the walls of the stomach are composed of an internal epithelium1 a layer of connective tissue1 with two muscular layers1 the inner of which is formed of unstriated circular muscular fibres1 and the outer of striated longitudinal muscular fibres4 ,in the cockroach short processes are given off from the free ends of the epithelial cells1 as in the intestine of many mammals and other animals4 8,between the cells a reticulum is often to be seen1 especially where the cells have burst2 it extends between and among all the elements of the mucous lining1 and probably serves1 like the very similar structure met with in mammalian intestines1 to absorb and conduct some of the products of digestion40 7,miall and ,denny47 ,gehuchten shows that the epithelial lining of the mesenteron 7chylific stomach7 of the dipterous larva ,ptychoptera is composed of two kinds of cells1 i4e4 secreting or glandular cells and absorbent cells1 the former situated at each end of the stomach1 and the absorbent cells occupying the middle region4 ,the part played by these cells in digestion will be treated of beyond in the section on digestion4 7,see p4 #cbg47 ,the hind-intestine4--,in many insects this is divided into the ileum1 or short intestine1 and the long intestine4 ,the limit between the intestine and stomach is externally determined by the origin of the urinary tubes1 which are outgrowths of the anterior end of the proctodum4 ,like the fore-intestine the hind-intestine is lined with a thick muscular layer1 and1 as ,gehuchten states1 the passage from the epithelial lining of the stomach 7mid-intestine7 to the muscular lining of the intestine is abrupt4 ,large intestine4--,in ,ptychoptera1 as described by ,gehuchten1 there are no precise limits between the small and large intestine2 the epithelium of the large intestine has a special character1 and its constituents present a close resemblance to the absorbed cells of the chylific stomach1 being like them large and polygonal4 ,the muscular layer is not continuous1 and is formed of longitudinal and circular fibres1 the latter being the larger4 ,the ileum--,though in most insects slender1 and therefore called the small intestine1 the ileum is in locusts 7,fig4 #bih7 and grasshoppers 7,anabrus1 ,fig4 #bii7 as thick as the stomach4 ,in many carnivorous beetles 7,dyticus1 ,fig4 #cbj1 il1 and ,necrophorus7 it is very long1 but rather slender and short in the ,carabid and ,cicindelid1 as well as those insects whose food is liquid1 such as ,diptera4 ,in the ,lepidoptera it varies in length1 being in ,sphinx quite long and bent into seven folds 7,fig4 #cji71 while it is very short in the ,psocid1 ,chrysomelid1 and ,tenthredinid4 ,in the locust the ileum is traversed by six longitudinal folds with intervening furrows2 outside of each furrow is a longitudinal muscular band4 ,seen from the inner surface the epithelium has an unusual character1 the cells in the middle of each of the flat folds being quite large1 polygonal in outline1 while towards the furrows the cells become very much smaller4 ,the walls are double when seen in transverse section1 the inner layer consisting of epithelial cells resting on connective tissue1 the outer layer formed of circular muscles4 ,the cuticula is thin1 but probably chitinous2 it resembles that on the gastro-ileal folds1 except that there are no spinules1 but unlike the cuticula of the stomach it extends equally over the folds and the furrows4 7,minot47 ,in the cockroach the junction of the small intestine with the colon is abrupt1 a well-developed annular fold assuming the nature of a circular valve4 7,miall and ,denny47 ,the gastro-ileal folds4--,in the locust the intestine is separated from the chylific stomach by what ,minot calls 8the gastro-ileal folds10 which form a peculiar valve4 ,the urinary vessels open just underneath and in front of this valve4 ,in ,melanoplus1 and probably in the entire family of ,acrydiid1 they are indicated as 8dark spots1 round in front and lying at the anterior end of the ileum so as to form a ring around the interior of the intestine40 ,they are #ab in number1 and all alike4 ,they are pigmented and round in front where they are broadest and stand up highest2 they narrow down backwards1 the pigment disappears1 and they gradually fade out into the ileal folds4 ,directly beneath them1 and just at the posterior end of the stomach1 there is a strong band of circular striated muscular fibres4 ,the epithelium of these folds is covered with minute conical spines1 which are generally1 but not always1 wanting between the folds4 7,minot47 ,the colon4--,this section of the intestine 7,fig4 #cai7 is sometimes regarded as a part of the rectum4 ,in the locust the six longitudinal folds of the ileum are continued into the colon1 but their surface1 instead of being smooth as in the ileum1 is thrown up into numerous irregular curved and zigzag secondary folds4 ,the cells of the epithelium are of uniform size1 and the layer is covered by a highly refringent cuticula without spines2 and1 like that in the ileum1 it rests on a layer of connective tissue1 beyond which follows 7#a7 an internal coat of longitudinal1 and 7#b7 an external coat of circular striated muscular fibres4 7,minot47 ,illustration3 ,,fig4 #cai4--;,digestive canal of ,lucanus cervus3 ,g1 anterior muscles of the pharynx2 ,h1 sophagus2 ,i1 gizzard2 ,k1 chyle-stomach2 ,l1 ilium2 ,m1 colon 7ccal part of72 ,n1 colon2 ,o1 rectum2 a1 frontal ganglion of the vagus2 b1 vagus nerve2 c1 anterior lateral ganglion connected with the vagus4--,after ,newport4 ,in butterflies 7,pontia brassic71 in ,sphinx ligustri1 and probably in most ,lepidoptera the colon is distinct from the rectum1 and is anteriorly developed into a very large more or less pyriform or bladder-like ccum 7,figs4 #cji1 #caj71 which in certain ,coleoptera 7,dyticus1 ,fig4 #cbj1 d2 ,silpha1 ,necrophorus1 etc47 is of remarkable length and shape2 it also occurs in ,nepid 7,fig4 #cbg74 ,in the cockroach a lateral ccum 8is occasionally1 but not constantly1 present towards its rectal end10 and a constriction divides the colon from the rectum4 7,miall and ,denny47 ,the rectum4--,the terminal section of the hind-gut varies in length and size1 but is usually larger than the colon1 and with thick1 muscular walls4 ,in ,lepidoptera it is narrow and short4 ,the rectum is remarkable for containing structures called rectal glands 7,fig4 #bih74 ,chun describes those of ,locusta viridissima as six flat folds1 formed by a high columnar epithelium and a distinct cuticula2 there is a coat of circular bands corresponding to the furrows between the glands4 ,minot states that this description is applicable to the locusts 7,acrydiid7 he has investigated1 the only difference being in the structural details of the single layers4 ,he claims that the rectal folds 8do not offer the least appearance of glandular structure10 neither is their function an absorbent one1 as ,chun supposed4 ,from their structure and position ,fernald regards the rectal glands of ,passalus as acting like a valve1 serving to retain the food in the absorptive portions of the digestive tract till all nutriment is extracted4 ,illustration3 ,,fig4 #cbj4--;,dyticus marginalis1 opened from the back3 a1 crop2 b1 proventriculus2 c1 mid-intestine beset with fine ccal glands2 d1 long ccal appendage of the colon2 apodemes2 ,b#a-;,b#c1 apodemes2 vhm1 coxal extensor muscle1 moving the hind leg2 ho1 testis2 dr1 accessory gland2 r1 penis2 e1 reservoir of the secretion of the anal gland4--,after ,graber4 ,the epithelial folds of the larv of dragon-flies serve as organs of respiration1 the water being admitted into this cavity1 and when forcibly expelled serving to propel the creature forward4 ,paired and single anal glands 7repugnatorial7 enter the rectum of certain ,coleoptera 7,figs4 #cjb1 l2 #cag1 s2 #cbj1 e74 ,the vent 7anus74--,the external opening of the rectum is situated in the end of the body1 in the vestigial #ajth or #aath abdominal segment1 and is more or less eversible4 ,it is protected above in caterpillars1 and other insects with #aj free abdominal segments1 by the suranal plate4 ,it is bounded on the sides by the paranal lobes1 while beneath is the infra-anal lobe4 ,the anus is wanting in certain insects1 and where this is the case the hind-gut1 owing to a retention of the embryonic condition1 is usually separated from the mid-intestine4 7,see p4 #cjj47 ,illustration3 ,,fig4 #cba4--;,enteric canal of ,psyllopsis fraxinicola3 1 sophagus2 md1 mid-intestine2 ed1 hind-intestine2 vm1 urinary vessels2 s1 the coil formed by the hind-intestine and the most anterior part of the mid-intestine4--,after ,witlaczil1 from ,lang4 ,some remarkable features of the digestive canal in hemipterous insects are noteworthy4 ,in the ,coccid1 according to ,mark1 the anterior end of the long mid-intestine forms1 with the hinder end of the sophagus1 a small loop1 whose posterior end is firmly grown to the wall of the rectum1 and forms a cup-like invagination of the latter4 ,then the rest of the tube-like stomach turns sidewise and forms a large loop1 which turns back on itself and occupies a large part of the body-cavity4 ,this loop receives on the anterior end1 near the sophagus1 the two urinary vessels1 and forms just below the opening into the rectum a short ccum4 ,in other homopterous genera 7,psyllid and some ,cicadid7 ,witlaczil describes nearly the same peculiarity1 the mid-gut and part of the intestine forming a loop growing together for a certain distance and winding round each other 7,fig4 #cba74 ,histology of the digestive canal4--,in all the divisions of the digestive canal of insects the succession of the cellular layers composing it is the same3 #ast1 a cuticula2 #b;d1 an epithelium2 #c;d1 connective tissue2 #dth1 muscular tissue4 ,in the locust1 the first division of the canal 7fore-gut71 there are two muscular coats1 an internal longitudinal and an external circular coat2 the fibres are all striated4 ,the lining epithelium is not much developed1 but forms a thick1 hard1 and refringent cuticula1 which is thrown up into spiny ridges4 ,in the second division 7mid-gut1 8stomach07 the epithelium is composed of very high columnar cells1 which make up the greater part of the thickness of the walls1 while the cuticula is very delicate1 slightly refringent1 with no ridges1 and is probably not chitinous2 the fibres of the muscular coats are not striated1 while this division is also distinguished by the presence of glandular follicles and folds4 ,the stomach and the ccal appendages have all these peculiarities in common1 while no other part of the canal is thus characterized4 ,the third division 7intestine and rectum7 is composed of an epithelium1 the cells of which are intermediate in size between those of the fore and mid gut4 ,the cells are often pigmented1 and they are covered by a much thicker cuticula than that of the stomach1 but which is not so thick and hard as that of the sophagus and proventriculus4 ,the very refringent cuticula is not thrown up into ridges1 though in some parts it is covered with delicate conical spines1 which are very short4 8,the epithelium and underlying connective tissue 7tunica propria7 are thrown up into six folds1 which run longitudinally1 being regular in the ileum and rectum 7as the rectal glands71 but very irregular in the colon4 ,outside the depression between each two neighboring folds there is a longitudinal muscular band1 these making six bands4 ,this peculiar disposition of the longitudinal muscles does not occur in any other part of the canal2 it is1 therefore1 especially characteristic of the third division40 7,minot47 ,,literature ,,on ,,the ,,organs ,,of ,,digestion ,treviranus1 ,g4 ,r4 ,resultate einiger ,untersuchungen ber den inneren ,bau der ,insekten4 7,verdauungsorgane von ,cimex rufipes47 7,annal4 d4 ,wetterau4 ,gesells41 #ahji1 i1 pp4 #afi-agg1 #a ,taf47 ,ramdohr1 ,c4 ,a4 ,abhandlungen ber die ,verdauungswerkzeuge der ,insekten4 #ahaa1 vii1 pp4 #bba1 #cj ,taf4 ,dutrochet1 ,r4 ,j4 ,h4 ,mmoire sur les mtamorphoses du canal alimentaire dans les insectes4 7,journal de ,physique1 #ahah1 lxxxvi1 pp4 #acj-ace1 #ahi-bjd2 ,meckel's ,archiv1 #ahah1 iv1 pp4 #bhe-bic47 ,suckow1 ,f4 ,w4 ,l4 ,verdauungsorgane der ,insekten4 7,heusinger's ,zeitschr4 f4 organ4 ,physik41 #ahbh1 iii1 pp4 #a-hi47 ,doyre1 ,l4 ,note sur le tube digestif des ,cigales4 7,ann4 ,sc4 nat4 ,zool41 #ahci1 #b ,sr41 xi1 pp4 #ha-he47 ,grube1 ,a4 ,e4 ,fehlt den ,wespen- oder ,hornissenlarven ein ,after oder nicht8 #a ,taf4 7,mller's ,archiv fr ,physiol41 #ahdi1 pp4 #dg-gd47 ,sirodot4 ,recherches sur les scrtions chez les insectes4 7,ann4 ,sc4 nat4 ,zool41 #aheh1 #d ,sr41 x1 pp4 #ada-ahi1 #bea-cbh1 #ab ,pls47 ,milne-,edwards1 ,h4 ,leons sur la physiologie et l'anatomie compare1 v1 #ahei1 pp4 #dih-ecf1 #eha-fch4 ,dufour1 ,l4 ,recherches anatomiques sur les ,carabiques et sur plusieurs autres insectes ,coloptres4 ,appareil digestif4 7,ann4 ,sc4 nat41 ii1 #ahbd1 pp4 #dfb-dhb1 #b ,pls42 iii1 #ahbd1 pp4 #bae-bdb1 #e ,pls41 pp4 #dgf-dia1 #c ,pls42 iv1 #ahbd1 pp4 #ajc-abe1 #d ,pls42 iv1 #ahbe1 pp4 #bfe-bhc47 ---- ,recherches anatomiques sur l',hippobosque des chevaux4 7,ann4 ,sc4 nat41 #ahbe1 vi1 pp4 #bii-cbb1 #a ,pl47 ---- ,description et figure de l'appareil digestif de l',anobium striatum4 7,ibid41 xiv1 #ahbh1 pp4 #bai-bbb1 #a ,pl47 ---- ,recherches anatomiques sur les ,labidoures4 ,appareil de la digestion4 7,ibid41 xiii1 #ahbh1 pp4 #cdh-ced1 #b ,pls47 ---- ,recherches anatomiques et considerations entomologiques sur quelques insectes ,coloptres1 compris dans les familles des ,dermestins1 des ,byrrhiens1 des ,acanthopodes et des ,leptodactyles4 ,appareil digestif4 7,ibid41 ,sr4 #b1 ,zool41 i1 #ahcd1 pp4 #fg-gf1 #b ,pls47 ---- ,rsum des recherches anatomiques et physiologiques sur les ,hmiptres4 7,ibid41 pp4 #bcb-bci47 ---- ,mmoire sur les mtamorphoses et l'anatomie de la ,pyrochroa coccinea4 ,appareil digestif4 7,ibid41 ,sr4 #b1 ,zool41 xiii1 #ahdj1 pp4 #cbh-ccj1 #ccd-ccg1 #b ,pls47 ---- ,histoire comparative des metamorphoses et de l'anatomie des ,cetonia aurata et ,dorcus parallelepipedus4 ,appareil digestif4 7,ibid41 ,sr4 #b1 ,zool41 #ahbd1 xviii1 pp4 #agd-agf1 #b ,pls47 ---- ,anatomie gnrale des ,diptres4 ,appareil digestif4 7,ibid41 ,sr4 #c1 ,zool41 i1 #ahad1 pp4 #bdh1 #bdi47 ---- ,histoire des mtamorphoses et de l'anatomie du ,piophila petasionis4 ,appareil digestif4 7,ibid41 ,sr4 #c1 ,zool41 i1 #ahdd1 pp4 #cgb-cgg1 #a ,pl47 ---- tudes anatomiques et physiologiques sur les insectes ,diptres de la famille des ,pupipares4 ,appareil digestif4 7,ibid41 ,sr4 #c1 ,zool41 iii1 #ahde1 pp4 #fg-gc1 #a ,pl47 ---- ,recherches sur l'anatomie et l'histoire naturelle de l',osmylus maculatus4 ,appareil digestif4 7,ibid41 ,sr4 #c1 ,zool41 ix1 #ahdh1 pp4 #cdf-cdi1 #a ,pl47 ---- tudes anatomiques et physiologiques1 et observations sur les larves des ,libellules4 ,appareil digestif4 7,ibid41 ,sr4 #c1 ,zool41 xvii1 #aheb1 pp4 #aja-ajh1 #a ,pl47 ---- ,recherches anatomiques sur les ,hymnoptres de la famille des ,urocerates4 ,appareil digestif4 7,ibid41 ,sr4 #d1 ,zool41 i1 #ahed1 pp4 #bab-baf1 #a ,pl47 ---- ,fragments d'anatomie entomologique4 ,sur l'appareil digestif du ,nemoptera lusitanica4 7,ibid41 ,sr4 #d1 viii1 #aheg1 pp4 #f-i1 #a ,pl47 ---- ,recherches anatomique et considerations entomologiques sur les ,hmiptres du genre ,leptopus4 ,appareil digestif4 7,ibid41 ,sr4 #d1 ,zool41 #aheh1 x1 pp4 #ceb-cef1 #a ,pl47 ---- ,recherches anatomiques sur l',ascalaphus meridionalis4 ,appareil digestif4 7,ibid41 ,sr4 #d1 xiii1 #ahfj1 pp4 #bjj-bjb1 #a ,pl47 ,leydig1 ,f4 ,zur ,anatomie von ,coccus hesperidum4 7,zeitschr4 f4 wissens4 ,zool41 v1 #ahec1 pp4 #a-ab1 #a ,taf47 ,lubbock1 ,j4 ,on the digestive and nervous ,system of ,coccus hesperidum4 7,proc4 ,roy4 ,soc41 ix1 #ahhf1 pp4 #dhj-dhf2 also ,ann4 ,mag4 ,nat4 ,hist41 #ahei1 ,ser4 #c1 iii1 pp4 #cjf-caa47 ,scheiber1 ,s4 ,h4 ,vergleichende ,anatomie und ,physiologie der striden-,larven4 ,v4 ,das chylo- und uroptische ,system4 7,sitzber4 d4 k4 ,akad4 d4 ,wissens4 ,wien4 ,math4-naturwiss4 ,cl41 #ahfb1 xlv1 pp4 #ci-fd1 #a ,taf47 ,gerstaecker1 ,a4 ,bronn's ,klassen und ,ordnungen des ,tierreichs4 ,v4 ,gliederfssler4 7,ernhrungsorgane1 pp4 #hg-aje47 ,graber1 ,v4 ,zur naheren ,kenntnis des ,proventriculus und der ,appendices ventriculares bei den ,grillen und ,laubheuschrecken4 7,sitzber4 d4 k4 ,akad4 d4 ,wissensch4 ,wien4 ,mathem4-naturwiss4 ,cl41 lix1 #ahfi1 pp4 #bi-df1 #c ,taf47 ---- ,ueber die ,ernhrungsorgane der ,insekten und nchstverwandten ,gliederfssler4 7,mitteil4 d4 naturwiss4 ,vereins fr ,steiermark4 ,graz1 #ahga1 ii1 pp4 #aha1 #ahb47 ---- ,verdauungssystem des ,prachtkfers4 7,ibid41 ,graz1 #ahge47 ---- ,die ,insekten41 i1 #ahgg4 7,verdauungsapparat1 pp4 #cjh-cbh47 ,wilde1 ,k4 ,f4 ,untersuchungen ber den ,kaumagen der ,orthopteren4 7,archiv f4 ,naturgesch41 xliii ,jahrg41 #ahgg1 pp4 #ace-agb1 #c ,taf47 ,simroth1 ,h4 ,ueber den ,darmkanal der ,larven von ,osmoderma eremita mit seinen ,anhngen4 7,giebel's ,zeitschr4 f4 d4 ges4 ,naturwiss41 #ahgh1 li1 pp4 #dic-eah1 #c ,taf47 ,mller1 ,h4 ,ueber die angebliche ,afterlsigkeit der ,bienenlarven4 7,zool4 ,anzeiger1 #ahha1 pp4 #ecj1 #eca47 ,schiemenz1 ,paulus4 ,ueber das ,herkommen des ,futtersaftes und die ,speicheldrsen der ,bienen1 nebst einem ,anhnge ber das ,riechorgan4 7,zeitschr4 f4 wissens4 ,zool41 xxxviii1 #ahhc1 pp4 #ga-ace1 #c ,taf47 ,rovelli1 ,g4 ,alcune ricerche sul tubo digerente degli ,atteri1 ,ortotteri e ,pseudo-,neurotteri4 7,como1 #ahhd1 p4 #ae47 ,beauregard1 ,h4 ,structure de l'appareil digestif des ,insectes de la tribu des ,vsicants4 7,compt4 rend4 ,acad4 ,paris1 #ahhd1 xcix1 pp4 #ajhc-ajhf47 ---- ,recherches sur les ,insectes vsicants41 #a ,part1 ,anatomie4 7,journ4 ,anat4 ,phys4 ,paris1 #ahhe1 xxi ,anne1 pp4 #dhc-ebd1 #d ,pls42 #ahhf1 xxii ,anne1 pp4 #he-ajh1 #bdb-bhd1 #e ,pls47 ---- ,les ,insectes vsicants1 ,paris1 #ahij1 ,chap4 ,,iii1 ,appareil digestif1 pp4 #fc-ii2 7,phnomnes digestifs1 pp4 #afa-agj2 ,pls4 #f-i47 ,wertheimer1 ,l4 ,sur la structure du tube digestif de l',oryctes nasicornis4 7,compt4 rend4 ,soc4 ,biol4 ,paris1 #ahhg1 ,sr4 #h1 iv1 pp4 #eca1 #ecb47 ,kowalevsky1 ,a4 ,beitrage zur ,kenntniss der nachembryonal ,entwicklung der ,musciden4 7,zeitschr4 f4 wissens4 ,zool41 xlv1 #ahhg1 pp4 #edb-eid1 #e ,taf47 ,schneider1 ,a4 ,ueber den ,darm der ,arthropoden1 besonders der ,insekten4 7,zool4 ,anzeiger1 #ahhg1 x ,jahrg41 pp4 #aci1 #adj47 ---- ,ueber den ,darmkanal der ,arthropoden4 7,zool4 ,beitrge von ,a4 ,schneider1 ii1 #ahhg1 pp4 #hb-if1 #c ,taf47 ,fritze1 ,a4 ,ueber den ,darmkanal der ,ephemeriden4 7,berichte der ,naturforsch4-,gesellsch4 zu ,freiburg i4 ,br41 #ahhh1 iv1 pp4 #ei-hb1 #b ,taf47 ,emery1 ,c4 ,ueber den sogenannten ,kaumagen einiger ,ameisen4 7,zeitschr4 f4 wissens4 ,zool41 #ahhh1 xlvi1 pp4 #cgh-dab1 #c ,taf47 ,meinert1 ,f4 ,contribution l'anatomie des ,fourmilions4 7,overs4 ,danske ,vidensk4 ,selsk4 ,forhandl4 ,kjbenhavn1 #ahhi1 pp4 #dc-ff1 #b ,pls47 ,mingazzini1 ,p4 ,richerche sul canale digerente dei ,lamellicorni fitofage 7,larve e ,insetti perfetti74 7,mitteil4 ,zool4 ,station zu ,neapel1 ix1 #ahhi-ahia1 pp4 #a-aab1 #bff-cjd1 #g ,pls47 ,fernald1 ,henry ,t4 ,rectal glands in ,coleoptera4 7,amer4 ,naturalist1 xxiv1 pp4 #ajj1 #aja1 ,jan41 #ahij47 ,visart1 ,o4 ,digestive canal of ,orthoptera4 7,atti ,soc4 ,toscana ,scient4 ,natur41 vii1 #ahia1 pp4 #bgg-bhe47 ,eberli1 ,j4 ,untersuchungen an ,verdauungstrakten von ,gryllotalpa vulgaris4 7,vierteljahresschr4 d4 ,naturforsch4 ,gesells4 ,zurich1 #ahib1 ,sep41 p4 #df1 ,fig47 ,holmgren1 ,emil4 ,histologiska studier fver ngra lepidopterlarvers digestionskanal och en del af deras ,krtelartade bildningar4 7,ent4 ,tidskr4 rg4 xiii1 pp4 #abi-agj1 #ahib1 #f ,pls47 ,ris1 ,f4 ,untersuchung ber die ,gestalt des ,kaumagens bei den ,libellen und ihren ,larven4 7,zool4 ,jahrb4 ,abth4 ,syst41 ix1 #ahif1 pp4 #eif-fbd1 #ac ,figs47 ,see also the works of ,straus-,drckheim1 ,newport1 ,mark1 ,witlaczil1 ,vayssire1 ,landois1 ,jordan1 ,oudemans1 ,berlese1 ,list1 ,grassi1 ,verson1 ,miall and ,denny1 ,leidy1 ,cheshire1 ,kowalevsky1 ,gehuchten1 ,locy1 etc4 b4 ,digestion in insects ,for the most complete and reliable investigation of the process of digestion1 we are indebted to ,plateau1 whose results we give1 besides the conclusions of later authors3 ,in mandibulate or biting insects1 the food is conducted through the sophagus by means of the muscular coating of this part of the digestive canal4 ,suctorial insects draw in their liquid food by the contractions followed by the dilatations of the mid-intestine 7chylific stomach74 ,dragon-flies1 ,orthoptera1 and ,lepidoptera swallow some air with their food4 ,where the salivary glands are present1 the neutral alkaline fluid secreted by them has the same property as the salivary fluid of vertebrates of rapidly transforming starchy foods into soluble and assimilable glucose4 ,in such forms as have no salivary glands1 their place is almost always supplied by an epithelial lining of the sophagus1 or1 as in the ,hydrophilid1 a fluid is secreted which has the same function as the true salivary fluid4 ,nagel states that the saliva of the larva of ,dyticus is powerfully digestive1 and has a marked poisonous action1 killing other insects1 and even tadpoles of twice the size of the attacking larva1 very rapidly4 ,the larv not only suck the blood of their victims1 but absorb the proteid substances4 ,drops of salivary juice seem to paralyze the victim1 and to ferment the proteids4 ,the secretion is neutral1 the digestion tryptic4 ,similar extra-oral digestion seems to occur in larv of ant-lions1 etc4 7,biol4 ,centralbl41 xvi1 #ahif1 pp4 #ea-eg1 #ajc-aab2 ,journ4 ,roy4 ,micr4 ,soc41 #ahif1 p4 #ahd47 ,in carnivorous insects and in ,orthoptera1 the sophagus dilates into a crop 7ingluvies7 ended by a narrow1 valvular apparatus 7or gizzard of authors74 ,the food1 more or less divided by the jaws1 accumulates in the crop1 which is very distensible2 and1 when the food is penetrated by the neutral or alkaline liquid1 there undergoes an evident digestive action resulting1 in carnivorous insects1 in the transformation of albuminoid substances into soluble and assimilable matter analogous to peptones1 and1 in herbivorous insects1 an abundant production of sugar from starch4 ,this digestion in the crop1 a food-reservoir1 is very slow1 and1 until it is ended1 the rest of the digestive canal remains empty4 8,any decided acidity found in the crop is due to the injection of acid food2 but a very faint acidity may occur1 which results from the presence in the crop of a fluid secreted by the ccal diverticula of the mesenteron40 7,miall and ,denny47 ,when digestion in the crop is accomplished1 the matters are subjected to an energetic pressure of the walls through peristaltic contractions1 and then1 guided by the furrows and chitinous teeth1 pass along or gradually filter through the valvular apparatus or proventriculus1 whose function is that of a strainer4 ,at the beginning of the 8chyle-stomach0 7mesenteron7 of ,orthoptera are glandular cca which secrete a feebly acid fluid4 ,this fluid emulsifies fats1 and converts albuminoids into peptones4 ,it passes forwards into the crop1 and there acts upon the food4 ,in the mesenteron 7mid-intestine7 the food is acted upon by an alkaline or neutral fluid1 never acid1 either secreted1 as in ,orthoptera1 by local special glands1 or by a multitude of minute glandular cca1 as in many ,coleoptera1 or by a simple epithelial layer4 ,it has no analogy with the gastric juices of vertebrates2 its function differs in insects of different groups2 in carnivorous ,coleoptera it actively emulsionizes greasy matters2 in the ,hydrophilid it continues the process of transformation of starch into glucose1 begun in the sophagus4 ,in the ,scarabid1 it also produces glucose1 but this action is local1 not occurring elsewhere2 in caterpillars1 it causes a production of glucose1 and transforms the albuminoids into soluble and assimilable bodies analogous to peptones1 and also emulsionizes greasy matters4 ,finally1 in the herbivorous ,orthoptera there does not seem to be any formation of sugar in the stomach itself1 the production of glucose being confined to the crop 7jabot74 ,when digestion in the crop is finished1 the proventriculus relaxes1 and the contents of the crop1 now in a semi-fluid condition1 guided by the furrows and teeth1 passes into the mesenteron1 which is without a chitinous lining1 and is thus fitted for absorption4 ,the contents of the mid-intestine 7chylific stomach7 then slowly and gradually pass into the intestine1 the first anterior portion of which1 usually long and slender1 is the seat of an active absorption4 ,the epithelial lining observed in certain insects seems1 however1 to indicate that secondary digestion takes place in this section4 ,the reaction of the contents is neutral or alkaline4 ,the second and larger division of the intestine only acts as a stercoral reservoir4 7,the voluminous ccum occurring in ,dyticid1 ,nepa1 and ,ranatra1 whether full or empty1 never contains gas1 and it is not1 as some have supposed1 a swimming-bladder47 ,the liquid product secreted by the ,malpighian tubes accumulates in this division1 and1 under certain circumstances1 very large calculi are often formed4 ,in his subsequent paper on the digestion of the cockroach1 ,plateau states that in the intestine are united the residue of the work of digestion and the secretion of the urinary or ,malpighian tubes1 this secretion being purely urinary4 ,these organs are exclusively depuratory and urinary1 freeing the body from waste products of the organic elements4 ,the liquid they secrete contains urea 7871 uric acid and abundant urates1 hippuric acid 7871 chloride of sodium1 phosphates1 carbonate of lime1 oxalate of lime in quantity1 leucine1 and coloring-matters4 ,the products of the rectal or anal glands vary much in different groups1 but they take no part in digestion1 nor are they depuratory in their nature4 ,insects have nothing resembling chylific substances4#ea ,the products of digestion1 dissolved salts1 peptones1 sugar in solution1 emulsionized greasy matters1 pass through the relatively delicate walls of the digestive canal by osmose1 and mingle outside of the canal with the blood4 ,whatever substances remain undigested are expelled with the excrements2 such are the chitin of the integuments of insects1 vegetable cellulose1 and chlorophyll1 which is detected by the microspectroscope all along the digestive canal of phytophagous insects4 ,in his experiments in feeding the larv of ,musca with lacmus1 ,kowalevsky found that the sophagus1 food-reservoir1 and proventriculus1 with its ccal appendages1 always remained blue1 and had an alkaline reaction2 the mid-intestine1 also1 in its anterior portion1 remained blue1 but a portion of its posterior half became deep red1 and also exhibited a strong reaction4 ,the hind-intestine1 however1 always remained blue1 and also had an alkaline reaction4 7,biol4 ,centralbl41 ix1 #ahhi1 p4 #df47 ,the mechanism of secretion4--,gehuchten describes the process of secretion in insects1 the following extract being taken from his researches on the digestive apparatus of the larva of ,ptychoptera4 ,the products of secretion poured into the alimentary canal are more or less fluid2 for this reason1 it is impossible to say when an epithelial cell at rest contains these products4 ,for the secreting nature of these cells is only apparent at the moment when they are ready for excretion2 then the cellular membrane swells out1 and a part of the protoplasmic body projects into the intestinal cavity4 ,before going farther1 the terms secretion and excretion should1 he says1 be defined4 ,with ,ranvier1 he believes that the elaboration in the protoplasm of a definite fluid substance is1 par excellence1 the secretory act1 while the removal of this substance is the act of excretion4 ,illustration3 ,,fig4 #cbb4--;,different phases of the mechanism of secretion and of excretion4--,after ,gehuchten4 ,a glandular cell of the chylific stomach1 when at rest1 is always furnished with a striated 8platform10 or flat surface1 or face1 on the side facing the cavity of the stomach1 and the free edge of the platform1 or plateau1 is provided with filaments projecting into the digestive cavity 7,fig4 #cbb1 f74 ,these glandular cells1 when active1 differ much in appearance4 ,in a great number1 the platform 7plateau7 has disappeared1 and is replaced by a simple1 regular membrane4 ,during the process of secretion1 a finely granular mass1 in direct continuity with the protoplasm1 swells1 and raises the membrane over the entire breadth of the cell1 causing it to project into the intestinal cavity 7,fig4 #cbb1 ,a1 ,b74 ,these vesicles1 or drops of the secretion1 whether free or still attached by a web to the cells1 are clear and transparent in the living insect1 but granular in the portions of the digestive canal fixed for cutting into sections4 ,gehuchten then asks3 8,how does a cell gorged with the products of secretion empty itself80 ,both ,ranvier and also ,heidenhain believe that one and the same glandular cell may secrete and excrete several times without undergoing destruction1 but their researches made on salivary glands have not answered the question4 ,gehuchten explains the process thus3 when the epithelial cell begins to secrete1 the clear fluid elaborated in the protoplasm of the cell increases the intracellular tension1 until1 finally1 the fluid breaks through certain weak places in the swollen basal membrane of the platform1 and then easily passes through the closely crowded filaments1 and projects out into the intestinal cavity as a pear-shaped vesicle of a liquid rich in albumens at first attached to the free face of the cell1 but finally becoming free1 as at ,fig4 #cbb1 ,a1 ,b4 ,when the elaboration of the substance to be secreted is more active1 the mechanism of the secretion is modified4 ,the basal membrane of the platform may then be raised at several places at once2 instead of a single vesicle projecting into the intestinal cavity1 each cell may present a great number more or less voluminous4 ,if all remain small and rapidly detach themselves from the glandular cell1 the filaments of the platform are simply separated from each other at different points of the free face1 as in ,fig4 #cbb1 ,c4 ,on the other hand1 when the different vesicles of a single cell become larger1 the filaments of the platform are compressed and crowded against each other in the spaces between the vesicles remaining free1 and the undisturbed portions of the platform appear homogeneous 7,fig4 #cbb1 ,d74 ,after the excretion of the secretory products by this process of strangulation1 the cell then assumes the aspect of a glandular cell at rest1 and may begin again to form a new secretion4 ,to sum up3 ,the process of excretion may occur in two ways3 #a4 ,where the membrane ruptures and the substances secreted are sent directly out into the digestive cavity4 #b4 ,where the vesicles become free by strangulation1 floating in the glandular or intestinal cavity1 and ending by rupturing and coming into contact with the neighboring vesicles or with the food4 ,absorbent cells4--,besides the glandular or secreting cells in ,ptychoptera1 there is between the two regions of the chyle-stomach lined with these cells a region about a centimetre long composed of absorbent cells4 ,the absorbent cells are very large1 polygonal1 and contain a large nucleus1 in which is a striated convoluted chromatic cord4 ,the food on entering the chyle-stomach is brought into contact with the products secreted in the proventriculus1 in the first part of the chyle-stomach1 and in the tubular glands4 ,these products of secretion act on the food1 extracting from them useful substances which they render soluble4 ,these substances1 after having been absorbed by the absorbent cells in the middle region of the stomach1 undergo special modifications1 and are transformed into solid products1 which are situated at the bottom of these cells4 ,afterwards the alimentary substances freed from a portion of their useful substances are again placed in contact with the products of secretion in the distal part of the chylific ventricle1 and reach the terminal part of the intestine4 8,the products of secretion10 adds ,gehuchten1 8diverted into the intestinal canal do not come into immediate contact with the alimentary substances2 they are separated from it by a continuous1 structureless1 quite thick membrane 7the peritrophic membrane71 which directly envelops the cylinder of food matters1 extending from the orifice of the sophageal valvule to the end of the intestine4 ,between this membrane and the free face of the epithelial lining there exists a circular space1 into which are thrown and accumulate the excreted substances4 ,the latter then cannot directly mingle with the aliments2 but when they are liquid they undoubtedly pass through this membrane by osmose1 and thus come into contact with the nutritive substances4 ,it is the same with the products of absorption4 ,the absorption of soluble products of the intestinal cavity is not then so simple a phenomenon as it was at first thought to be1 since these products are nowhere brought into immediate contact with the absorbent cells0 7pp4 #ij1 #ia74 ,the most recent authority1 ,cunot1 states that absorption of the products of digestion takes place entirely in the mid-intestine1 and in its cca when these are present4 ,the mid-intestine exercises a selective action on the constituents of the food comparable to the action of the vertebrate liver4 ,,literature ,,on ,,the ,,physiology ,,of ,,digestion ,davy1 ,j4 ,note on the excrements of certain insects1 and on the urinary excrement of insects4 7,edinburgh ,new ,phil4 ,journ41 #ahdf1 xl1 pp4 #bca-bcd1 #cce-cdj2 #ahdh1 xlv1 pp4 #ag-bi47 ---- ,some observations on the excrements of insects1 in a letter addressed to ,w4 ,spence4 7,trans4 ,ent4 ,soc4 ,london1 ,ser4 #b1 iii1 #ahed1 pp4 #ah-cb47 ,bouchardat1 ,a4 ,de la digestion chez le ver soie4 7,revue et ,mag4 de ,zool41 ,sr4 #b1 #ahea1 iii1 pp4 #cd-dj47 ,lacaze-,duthiers1 ,h41 et ,a4 ,riche4 ,mmoire sur l'alimentation de quelques insects gallicoles et sur la production de la graisse4 7,ann4 ,scienc4 natur41 #ahed1 ,sr4 #d1 ii1 pp4 #ha-aje47 ,basch1 ,s4 ,untersuchungen ber das chylopoetische und uropoetische ,system von ,blatta orientalis4 7,sitzungsber4 d4 math4-naturwiss4 ,classe d4 ,akad4 d4 ,wissensch4 ,wien41 #aheh1 xxxiii1 pp4 #bcd-bfj1 #e ,taf47 ,lambrecht1 ,a4 ,der ,verdauungsprozess der stickstoffreichen ,nhrmittel1 welche unsere ,bienen geniessen1 in den dazu geschaffenen ,organen derselben4 7,bienenwirtschaftl4 ,centralbl41 viii ,jahrg41 #ahgb1 pp4 #gc-gh1 #hc-hi47 ,plateau1 ,f4 ,recherches sur les phnomnes de la digestion chez les insectes1 7,mm4 ,acad4 roy4 de ,belgique1 ,sr4 #b1 xli1 #a ,part1 #ahgc1 pp4 #abd1 #c ,pls47 ---- ,note additionelle au mmoire sur les phnomnes de la digestion chez les insectes4 7,bull4 ,acad4 roy4 de ,belgique1 ,sr4 #b1 xliv1 #ahgg1 pp4 #gaj-gcc47 ,tursini1 ,g4 ,fr4 ,un primo passo nella ricerca dell' assorbimento intestinale degli artropodi4 7,rend4 d4 ,r4 ,accadem4 di ,sc4 fis4 e matemat4 di ,napoli1 #ahgg1 xvi1 pp4 #ie-ii1 #a ,pl47 ,jousset de ,bellesme1 ,physiologie compare4 ,recherches exprimentales sur la digestion des insectes et en particulier de la blatte4 ,paris1 #ahgf1 vii1 and #if pp41 #c ,pls4 ---- ,recherches sur les fonctions des glandes de l'appareil digestif des ,insectes4 7,compt4 rend41 lxxxii1 ,paris1 #ahgf1 pp4 #ig-ii47 ---- ,travaux originaux de physiologie compare4 7i1 ,insectes1 ,digestion1 ,mtamorphoses47 ,paris1 #ahgh1 #e ,pls4 ,simroth1 ,h4 ,einige ,bemerkungen ber die ,verdauung der ,kerfe4 7,zeitschr4 f4 d4 gesammten ,naturwiss41 xli1 #ahgh1 pp4 #hbf-hca47 ,krukenberg1 ,c4 ,fr4 ,w4 ,versuche zur vergleichenden ,physiologie der ,verdauung und vergleichende physiologische ,beitrge zur ,kenntnis der ,verdauungsvorgange4 7,untersuch1 a4 d4 physiolog4 ,institut d4 ,universitt ,heidelberg1 #ahhj1 i1 #d1 pp #cbg1 ,figs42 ii1 #a1 p4 #a1 ,figs47 ,metschnikoff1 ,e4 ,untersuchungen ber die intrazellulre ,verdauung bei wirbellosen ,tieren4 7,arb4 d4 zool4 ,instit4 ,wien41 #ahhc1 v1 pp4 #ada-afh1 #b ,taf47 ,locy1 ,william ,a4 ,anatomy and physiology of the family ,nepid4 7,amer4 ,naturalist1 xviii1 #ahhd1 pp4 #bej-bee1 #cec-cfg1 #d ,pls47 ,vangel1 ,e4 ,beitrge zur ,anatomie1 ,histiologie1 und ,physiologie des ,verdauungsapparates des ,wasserkfers1 ,hydrophilus piceus4 7,termsz4 ,fzet41 x1 #ahhf1 pp4 #aaa-abf 7in ,hungarian72 pp4 #aij-bjh 7in ,german71 #a ,pl47 ,schnfeld4 ,die physiologische ,bedeutung des ,magenmundes der ,hnigbiene4 7,archiv f4 ,anat4 u4 ,physiol41 ,physiol4 ,abt41 #ahhf1 pp4 #dea-deh47 ,faussek1 ,v4 ,beitrge zur ,histiologie des ,darmkanals der ,insekten4 7,zeitschr4 f4 wiss4 ,zool41 #ahhg1 xl1 pp4 #fid-gab1 #a ,taf42 ,abstract in ,zool4 ,anz41 ,jahrg4 x1 pp4 #cbb1 #cbc1 #a ,taf47 ,frenzel1 ,j4 ,ueber ,bau und ,thtigkeit des ,verdauungskanals der ,larve des ,tenebrio molitor1 mit ,bercksichtigung anderer ,arthropoden 7,berlin4 ,ent4 ,zeitschr41 #ahhb1 pp4 #bfg-caf1 #a ,taf472 ,inaug4-,diss4 ,gttingen1 #ahhb4 ---- ,einiges ber den ,mitteldarm der ,insekten1 sowie ber ,epithel-regeneration4 7,archiv f4 ,mikrosk4 ,anat41 #ahhe1 xxvi1 pp4 #bbi-cjf1 #c ,taf47 ---- ,zum feineren ,bau des ,wimperapparates4 7,ibid41 #ahhf1 xxviii1 pp4 #ec-hj1 #a ,taf47 ---- ,die ,verdauung lebenden ,gewebes und die ,darmparasiten4 7,archiv f4 ,anat41 #ahia47 ,gehuchten1 ,a4 van4 ,recherches histologiques sur l'appareil digestif de la ,ptychoptera contaminata1 ,i ,part4 tude du revtment pithlial et recherches sur la scrtion4 7,la ,cellule1 #ahij1 vi1 pp4 #ahc-bia1 #f ,pls47 ,cunot1 ,l4 tudes physiologiques sur les ,orthoptres4 7,arch4 ,biol41 xiv1 #ahie1 pp4 #bic-cda1 #b ,pls47 ,needham1 ,james ,g4 ,the digestive epithelium of dragon-fly nymphs4 7,zool4 ,bull41 i1 #ahig1 ,chicago1 pp4 #ajd-aac1 #aj ,figs47 ,with the writings of ,mingazzini 7see p4 #cbc71 ,kowalevsky1 ,ranvier1 ,haidenhain1 ,beauregard 7p4 #cbc71 ,sadones4 ,,the ,,glandular ,,and ,,excretory ,,appendages ,,of ,,the ,,digestive ,,canal ,into each primary division of the digestive canal open important glands4 ,the salivary and silk-glands are offshoots of the sophagus 7stomodum72 the ccal appendages open into the stomach 7mesenteron71 while the urinary tubes grow out in embryonic life from the primitive intestine 7proctodum71 and there are other small glands which are connected with the end of the hind-intestine4 a4 ,the salivary glands ,we will begin our account of these glands with those of the ,orthoptera1 where they are well developed4 ,in the cockroach a large salivary gland and accompanying reservoir lie on each side of the sophagus and crop4 ,the gland is a thin1 leaf-like1 lobulated mass1 divided into two principal lobes4 ,these open into a common trunk1 which after receiving a branch from a small accessory lobe1 and from the salivary reservoir1 unites with its fellow to form the unpaired salivary duct which opens into the under side of the lingua4 ,each salivary reservoir is a large oval sac with transparent walls4 7,miall and ,denny1 also ,figs4 #bii1 sr1 and #cbg47 ,the ducts and reservoirs have a chitinous lining1 and the ducts are1 like the trache1 surrounded by a so-called spiral thread1 or by separate1 incomplete1 hooplike bands1 which serve to keep the duct permanently distended4 ,in the locust 7,fig4 #bih7 the lobules are more scattered1 forming small separate groups of acinose glands4 ,in the embryo of ,forficula ,heymons has observed a pair of salivary glands opening on the inner angle of the mandibles1 a second pair opening in the second maxill1 while a third pair of glands1 whose function is doubtful1 is situated in the hinder part of the head1 opening to the right and left on the chitinous plate 7postgula7 behind the submentum4 ,in ,perla1 there are two pairs segmentally arranged 7,fig4 #cdc74 ,illustration3 ,,fig4 #cbc4--,left side of the head of the silkworm3 a1 adductor muscle of the mandible1 from which the muscular fibres have been removed2 b1 upper fibres of the same2 c1 lower fibres cut away to show the adductor muscle 7e72 d1 fibres inserted on the accessory adductor lamella2 f1 sophagus1 much swollen2 g1 salivary gland2 h1 dorsal vessel2 i1 l1 trache of the mandibular muscles2 k1 trachea2 n1 optic nerve4--,after ,blanc4 ,illustration3 ,,fig4 #cbd4--,lower side of the head of the silkworm exposed1 the spinning apparatus1 the sophageal ganglion1 and the adductor of the left mandible removed3 ,m1 mandible2 ,p1 abductor of the mandible2 ,r1 adductor2 ,n1 salivary gland attached at ,o to the edge of the adductor muscle2 o1 o1 transverse portion of the 8hyoid02 #c1 masticator nerve and its recurrent branch 7#g72 ,l1 tongue cut horizontally4--,after ,blanc4 ,here we might refer to a pair of glands regarded by ,blanc as the true salivary glands4 ,they do not appear to be the homologues of the salivary glands of other insects1 though probably functioning as such4 ,the functional salivary glands of lepidopterous larv have been overlooked by most entomotomists1 and the spinning glands have been1 it seems to us1 correctly supposed to be modified salivary glands4 ,lucas also regards those of case-worms 7,trichoptera7 as morphologically salivary glands4 ,those of the silkworm were figured by ,raumur 7,tom4 i1 ,pl4 v1 ,fig4 #a71 but not described2 while those of ,cossus1 which are voluminous1 were regarded by ,lyonet as 8vaisseaux dissolvans40 ,dr4 ,auzoux 7#ahdi71 in his celebrated model of the silkworm1 represented them accurately1 while ,cornalia briefly described them as opening into the mouth4 ,the first satisfactory description is that of ,blanc 7#ahia71 who states that in the silkworm 8the two salivary glands0 are small1 flexuous1 yellow tubes1 which occupy a variable position on the sides of the sophagus 7,fig4 #cbc74 ,the glandular portion passes into the head1 ending at the level of the adductor plate of the mandibles 7,fig4 #cbd1 o71 and entering the buccal cavity at the base of the mandible1 as seen in ,fig4 #cbc4 ,it is plain1 when we recognize the direct homology of the silk-glands of the caterpillars with the salivary glands of other insects1 and of the spinneret with the hypopharynx1 that these so-called 8salivary glands0 in lepidopterous larv are different structures4 ,they are probably modified coxal glands1 belonging to the mandibular segment4 ,illustration3 ,,fig4 #cbe4--,one of the two salivary glands of ,ccilius burmeisteri3 d1 excretory duct2 cn1 the lumen or canal2 cg1 gland-cells2 ct1 salivary fluid4--,after ,kolbe4 ,the polygonal epithelial cells of these glands contain branched nuclei1 recalling those of the spinning-glands4 ,in those caterpillars which feed on leaves1 the salivary glands are slightly developed1 but in such as bore into and eat wood1 as the ,cossid1 the glands are1 as figured by ,lyonet1 very large1 forming two sausage-shaped bodies passing back to the beginning of the mid-intestine1 each ending in a long convoluted filament4 ,the salivary glands of the imago are very long and convoluted 7,fig4 #caj1 sd74 ,in the ,panorpid these glands differ in the sexes1 the males having three pairs of very long tortuous tubes1 while1 in the females1 they are reduced to two indistinct vesicles4 7,siebold47 ,in the ,diptera in general there are two pairs1 one situated in the beak1 the other in the thorax4 ,in the larv there is a single pair 7,fig4 #cda74 ,kraepelin describes a third pair in the ,muscid at the point of transition from the fulcrum to the sophagus1 but ,knppel has apparently found only what may be fat cells at this point1 so that the supposed presence of a third pair in ,diptera needs confirmation4 ,in the ,psocid there are two salivary glands1 of simple tubular shape 7,fig4 #cbe74 ,in the ,nepid the salivary glands are four in number1 and of conglomerate structure1 two being long and extending back into the beginning of the abdomen1 while the other two are about one-fourth as long4 7,figs4 #cbg1 #cbh47 ,in ,cicada1 besides a pair of simple tortuous tubes1 there is in the head another pair of glands1 each composed of two tufts of short lobes1 situated one behind the other4 7,dufour47 ,in many ,hemiptera 7,pyrrhocoris1 ,capsus1 etc47 there is but a single pair1 each gland consisting of four lobes2 in the ,coccid each gland is divided into two lobes 7,fig4 #cbf72 in the ,aphid1 according to ,witlaczil1 they consist of two lobes grown together4 ,in the ,psyllid they are said to be absent4 ,in ,phylloxera vastatrix the saliva is forced through a salivary passage out of the duct and into the mouth by a pumping apparatus furnished with special muscles4 7,krassilstschik47 ,in the ,odonata acinose glands are present in the imago1 but not in the nymph until in its last stage1 ,poletaiew accounting for their absence in the earlier stages by the fact that the larva swallows more or less water while taking its food4 ,in the ,coleoptera1 as we have observed in ,anopthalmus1 there are three pairs of salivary glands 7,fig4 #gd74 ,in the ,blapsid these glands consist of many ramifying tubes united on each side of the sophagus into a single duct2 in others they are but slightly developed1 while in still others they are wanting4 ,the salivary glands are most highly differentiated in the ,hymenoptera1 and especially in the bees 7,bombus and ,apis71 where ,schiemenz found not less than five systems of glands 7,fig4 #cbi2 also #hg71 of which four systems are paired4 ,one pair of these glands lies in the tongue1 three in the head1 and one in the thorax4 ,illustration3 ,,fig4 #cbf4--;,acinous salivary glands of ,orthezia cataphracta4 ,in some acini the nuclei and boundaries of the cells are shown4--,after ,list1 from ,field's ,hertwig4 ,system ,i is situated in the head1 and consists of unicellular glands2 the duct from each cell leads into a common1 strongly chitinized duct1 opening into the gullet4 ,system ,,ii1 composed of acinose glands1 lies also in the head2 its duct is united with that of ,system ,,iii1 situated in the thorax4 7,fig4 #cbi1 #b1 #c47 ,system ,,iv is situated at the base of the upper surface of the mandibles1 and forms a delicate sac lined within with glandular cells2 its duct opens at the insertion of the mandibles4 ,system ,v lies in the beak1 and is a single gland consisting of unicellular glands2 it opens into the common opening of ,systems ,,ii and ,,iii4 ,this system is wanting in the honey-bee1 but occurs in ,bombus and other genera4 ,illustration3 ,,fig4 #cbg4--;,appendages of digestive canal of ,belostoma4--,after ,locy4 ,illustration3 ,,fig4 #cbh4--,salivary and other glands of ,ranatra4--,after ,locy4 ,in all the five systems there constantly occur three cellular layers3 the intima1 epithelial1 and propria4 ,as regards their origin ,schiemenz states that ,systems ,i and ,,iv are new structures1 that ,system ,,iii arises in part1 and ,systems ,,ii and ,v wholly1 from the silk-glands of the larva4 ,as the glands differ much in the sexes1 and in different species and genera1 ,schiemenz believes that their function is very manifold4 ,in addition to those previously discovered by ,schiementz1 ,bordas has detected two additional pairs of salivary glands in the worker and male honey-bee1 i4e4 the internal mandibular and sublingual glands1 so that in ,apis there are in all six pairs1 and apparently one unpaired4 ,the delicate chitinous external layer of the gland is perforated by many very fine pores through which the salivary fluid secreted by the epithelial cells passes into the salivary duct4 ,the glands are externally bathed by the blood4 ,in many insects1 including lepidopterous larv1 the single median opening of the salivary duct is converted into a spraying apparatus4 ,in the adult ,lepidoptera1 according to ,kirbach3-- ,illustration3 ,,fig4 #cbi4--,salivary glands of the honey-bee3 systems ,no4 #a-c1 #ae3 sv1 salivary valve 7of systems #b and #c7 at base of tongue2 lp1 labial palpus2 mx1 maxilla2 so1 salivary opening of system #a in hypopharyngeal plate2 no1 openings in plate for termination of taste-nerve2 1 sophagus2 sd1 salivary duct2 b1 junction of ducts of system ,no4 #b2 c1 junction of ducts of system ,no4 #c2 sc1 sc1 salivary sacs2 fl1 front lobe2 bl1 back lobe2 a1 chitinous duct1 with spiral thread4 ,b1 single acinus of system ,no4 #a1 #gj3 n1 nucleus2 st1 salivary tract2 d1 large duct4 ,c1 single pouch1 or acinus1 from system ,no4 #b3 a1 propria or outer membrane2 sc1 secreting cells4 ,d1 termination of system ,no4 #c3a1b1c1d1 lines marking end of section2 d1 duct in section2 sc1 secreting cells in section2 n1 nucleus4--,after ,cheshire4 8,its lower half forms a thick chitinous gutter1 with a concave cover above1 in which the similarly shaped upper half lies encased1 so that between the two only a small semicircular opening remains4 ,powerful muscles extend from the cover to the lower side and to the two ridges of the bottom plate2 through their contraction the upper channel is elevated1 and presses out of the hinder part of the ducts into the space thus formed a great quantity of the saliva1 which by allowing the contraction of the cover-muscle through the crevice-like opening1 which is situated in the lower edge of the mouth-opening1 becomes squeezed out in order either to mix with the fluid where the #b;d maxill fuse1 passing up into the canal in the proboscis1 or to penetrate into and thus dilute the semi-fluid or solid substances taken1 into the proboscis40 ,the morphology and general relations of the salivary glands have been sketched out by ,hatschek1 ,patten1 and by ,lucas1 from observations on those of the case-worms or larval ,trichoptera4 ,illustration3 ,,fig4 #ccj4--;,eight pairs of glands of ,andrena3 ,i1 thoracic2 ,,ii1 postcerebral2 ,,iii1 supracerebral2 ,,iv1 lateropharyngeal2 ,v1 mandibular2 ,,vi1 internomandibular2 ,,vii1 sublingual2 ,,viii1 lingual2 ,md1 mandible2 ,l1 tongue2 o1 eye2 1 sophagus2 ,j1 honey-sac4--,after ,bordas4 ,patten states that the spinning-glands in ,neophylax are formed by a pair of ectodermal invaginations on the ventral side of the embryo1 between the base of the #b;d maxill and the nervous cord4 ,they increase rapidly in length1 and 8they also unite to form a common duct1 which opens at the end of the upper lip40 ,the salivary glands in the same insect are 8formed by invagination of the ectoderm on the inner sides of the mandibles1 in the same manner as are the spinning glands40 ,lucas has shown that in trichopterous larv 7,anabolia7 there are three pairs of salivary glands in the head1 which are serially arranged4 ,the first pair belong to the mandibular1 the second pair to the #ast maxillary1 and the third pair1 or spinning glands1 to the #b;d maxillary segment4 ,the first or mandibular glands open into the mouth at the base of the mandibles directly behind the dorsal condyle4 ,the second pair open between the #ast and #b;d maxill2 at the base of the latter1 near the ventral condyle of the mandibles4 ,the third pair open into the hypopharynx1 which is modified to form the spinneret4 ,lucas agrees with ,korschelt in regarding them as modified coxal glands1 ,schiemenz having previously regarded the headglands of the imago of the bee as belonging to the segments bearing the three pairs of buccal appendages1 so that each segment originally contained a pair of glands4 ,it is thus proven that the silk-glands are modified salivary glands adapted to the needs of spinning larv1 and indeed in the imago the sericteries revert to their primitive shape and use as salivary glands4 ,the serial arrangement of the salivary glands in the ,hymenoptera1 where the number varies from five to ten pairs1 is clearly proved by ,bordas4 ,he has detected five more pairs than were previously known1 and names the whole series as follows3--#a1 the thoracic salivary glands1 which are larger than the others1 and nine other pairs1 which are all contained in the head as follows3 #b1 postcerebral2 #c1 supracerebral2 #d1 lateropharyngeal2 #e1 mandibular2 #f1 internomandibular1 situated on the inner side of the base of mandible2 #g1 sublingual2 #h1 lingual 7these and #a to #g common to all ,hymenoptera72 #i1 paraglossal 7in ,vespid72 #aj1 maxillary 7very distinct in most wasps74 ,these glands do not all occur in the same species1 being more or less atrophied4 ,bordas further shows the segmental arrangement of the cephalic glands by stating that the supracerebral glands correspond to the antennal segment1 the sublingual glands to the labial1 the mandibular glands 7external and internal7 to the mandibular segment1 the maxillary glands to the #ast maxillary segment1 the lingual glands to the #b;d maxillary segment1 while the thoracic and postcerebral salivary glands1 he thinks1 correspond to the ocular segment1 a view with which we are indisposed to agree1 although conceding that each of the six segments of the head has in it at least one pair of salivary glands4 ,functions of the different salivary glands in ,hymenoptera4--,the secretion of the thoracic glands is feebly alkaline4 ,the postcerebral salivary glands1 considered by ,ramdohr to be organs of smell1 secrete1 like the preceding1 a distinctively alkaline fluid1 which mingles with the products of the thoracic glands4 ,the supracerebral glands1 also equally well developed in all ,hymenoptera1 though much atrophied in the females and especially the males of ,apis mellifica1 also in the ,vespin and ,polistin1 secrete an abundant1 feebly acid liquid1 which is actively concerned in digestion4 ,as to the mandibular glands1 which ,wolf supposed to be olfactory organs1 their acid secretion1 though smelling strongly1 acts energetically on the food as soon as introduced into the mouth4 ,the sublingual glands1 atrophied in most ,apid1 but relatively voluminous in ,sphegid1 ,vespin1 ,polistin1 ,crabronid1 etc41 empty their secretion into a small prebuccal excavation1 where accumulate vegetable and earthy matters collected by the tongue1 and the saliva secreted by these glands1 acts upon them before they pass into the pharynx4 ,the lingual glands secrete a thick1 sticky liquid1 which causes foreign bodies to adhere to the tongue1 and also agglutinates alimentary substances4 ,the uses of the other glands1 maxillary and paraglossal1 are from their minuteness undetermined4 7,bordas47 ,,literature ,,on ,,the ,,salivary ,,glands ,leydig1 ,f4 ,zur ,anatomie der ,insekten4 7,archiv ,anat4 und ,phys4 #ahei47 ---- ,untersuchungen zur ,anatomie und ,histiologie der ,tiere4 ,bonn1 #ahhc1 pp4 #agd1 #h ,taf4 ---- ,intra- und interzellulare ,gnge4 7,biolog4 ,centralblatt1 x1 #ahij1 pp4 #cib-cif47 ,dohrn1 ,a4 ,zur ,anatomie der ,hemipteren4 7,stettin4 ,entom4 ,zeit41 #ahff1 salivary glands1 pp4 #cbh-ccb47 ,kupffer1 ,c4 ,die ,speicheldrsen von ,periplaneta orientalis und ihr ,nervenapparat4 7,beitrge zur ,anatomie und ,physiol41 #ahge47 ,schiemenz1 ,p4 ,ueber das ,herkommen des ,futtersaftes und die ,speicheldrsen der ,biene4 7,zeitschr4 f4 wissens4 ,zool41 xxxviii1 #ahhc1 pp4 #ga-ace1 #c ,taf47 ,korschelt1 ,e4 ,ueber die eigentmlichen ,bildungen in den ,zellkernen der ,speicheldrsen von ,chironomus plumosus4 7,zool4 ,anzeiger1 #ahhd1 pp4 #ahi-aid1 #bba-bbe1 #bda-bdf47 ,hofer1 ,b4 ,untersuchungen ber den ,bau der ,speicheldrsen und des dazu gehrenden ,nervenapparates von ,blatta4 7,nova ,acta d4 ,kais4 ,leopold4-,carol4 ,deutsch4 ,akad4 d4 ,naturforscher1 li1 #ahhg1 pp4 #cde-cie1 #c ,taf47 ,knppel1 ,a4 ,ueber ,speicheldrsen von ,insekten4 7,archiv fr ,naturg41 #ahhg1 ,jahrg4 #eb1 pp4 #bfi-cjc1 #b ,taf47 ,blanc1 ,louis4 ,la tte du ,bombyx mori l'tat larvaire1 anatomie et physiologie4 7,extrait des ,travaux du ,laboratoire d'tudes de la ,soie1 #ahhi-ahij2 ,lyon1 #ahia1 p4 #ahj1 many figs47 ,bordas1 ,l4 ,anatomie des glandes salivaires des ,hymnoptres de la famille des ,ichneumonid4 7,zool4 ,anzeiger1 #ahid1 pp4 #aca-acc47 ---- ,glandes salivaires des ,apides1 ,apis mellifica4 and 4 7,comptes rendus ,acad4 ,sc41 ,paris1 cxix1 pp4 #cfc1 #dhc1 #fic-fie1 #ahid2 also two articles in ,bull4 ,soc4 ,philomath4 ,paris1 #ahid1 pp4 #e1 #ab1 #ff47 ---- ,appareil glandulaire des ,hymnoptres4 7,ann4 ,sc4 ,nat4 ,zool41 xix1 ,paris1 #ahid1 pp4 #a-cfb1 #aa ,pls47 7,see also p4 #cff47 ,berlese1 ,antonio4 ,le cocciniglie ,italiane viventi sugli agrumi4 ,firenze1 #ahif1 #ab ,pls4 and #bjj ,figs4 ,with the writings of ,mark1 ,minot1 ,locy1 ,list1 ,krassilstschik1 ,nagel 7#ahif74 b4 ,the silk or spinning glands1 and the spinning apparatus ,the larv of certain insects1 chiefly those of the ,lepidoptera1 possess a pair of silk or spinning glands 7sericteries7 which unite to form a single duct opening in the upper lip at the end of the lingua1 which is modified to form the spinneret4 7,see pp4 #ga1 #ge47 ,all caterpillars possess them1 and they are best developed in the silkworms1 which spin the most complete cocoon4 ,silk-glands also occur in the larv of the ,tenthredinid1 in the case-worms or larval ,trichoptera1 also in certain chrysomelid beetles 7,donacia1 ,hmonia71 and in a weevil 7,hypera74 ,in a common caddis-worm 7,limnophilus7 the glands are of a beautiful pale violet-blue tint1 and two and a half times as long as the larva itself2 viz4 the body is #bj mm4 and the glands #ee mm4 in length4 ,in caterpillars the glands are of tubular shape1 shining white1 and much like the ordinary simple tubular salivary glands of the imago4 ,when only slightly longer than the body they are twice folded1 the folds parallel and situated partly beneath and partly on the side of the digestive canal2 not usually1 when folded in their natural position1 extending much behind the end of the stomach2 but in the silkworms they are so long and folded as to envelop the hinder part of the canal4 ,in geometrid caterpillars the glands when stretched out only reach slightly beyond the end of the body2 in ,datana they are half again as long as the body4 ,helm thus gives their relative length in certain ,eurasian caterpillars1 and we add that of ,telea polyphemus3-- ,vanessa io length of body #cb mm42 of the silk glands #bf mm4 ,smerinthus tili length of body #fc mm42 of the silk glands #bje mm4 ,bombyx mori length of body #ef mm42 of the silk glands #bfb mm4 ,anthera yamamaya length of body #ajj mm42 of the silk glands #fbe mm4 ,telea polyphemus length of body #fj mm42 of the silk glands #dej mm4 ,thus in ,telea the silk-glands are about #ah4ej inches in length1 being about seven times as long as the body4 ,for the most complete accounts of the spinning glands of ,lepidoptera and their mechanism we are indebted to ,helm and to ,blanc1 and for that of the ,trichoptera to ,gilson4 ,the unpaired portion1 or spinning apparatus 7filire of ,lyonet71 is divided into two portions2 the hinder half being the 8thread-press10 the anterior division the 8directing tubes40 ,the silk material1 stored up in the thickest portion of the glands1 passes into the thread-press 7,fig4 #ccd1 ,a71 which is provided with muscles which force the two double ribbon-like threads through the directing tube1 as wire is made by molten iron being driven through an iron plate perforated with fine holes4 ,the entire spinning apparatus1 or filator1 as we may call it1 is situated in the tubular spinneret4 ,the opening of the spinneret is directed anteriorly1 and the anterior end of the directing tube passes directly into this opening so that the directing tube may be regarded as an invagination of the lingua4 ,the silk thread which issues from the mouth of the spinneret is1 as ,leeuwenhoek discovered1 a double ribbon-like band1 as may be seen in examining the silk of any cocoon4 ,the process of spinning4--,since the appearance of ,helm's account1 ,gilson1 and also ,blanc1 have added to our knowledge of the way in which the silk is spun and of the mechanism of the process4 ,gilson has arrived1 in regard to the function of the press or filator1 at the following conclusions3 #a1 the press regulates the thread1 it compresses it1 gives it its flattened shape2 #b1 it regulates the layer of gum#eb 7grs7 which surrounds the thread2 #c1 it may render the thread immovable by compressing it as if held by pincers4 ,the process of spinning in the silkworm1 says ,blanc1 comprises all the phenomena by which the mass of silk contained in the reservoir is transformed into the silk fluid of which the cocoon is spun4 ,the excretory canals each contain a cylindrical thread of silk having a mean diameter of #j4b mm4 and surrounded by a layer of gum 7grs7 which in the fresh living organ exactly fills the annular space situated between the fibroin cylinder and the wall4 ,arrived within the common duct1 the two threads receive the secretion of ,filippi's gland1 where the silken fluid is formed1 but has not yet assumed its definite external characters4 ,the two threads press through the common canal and arrive at the infundibulum 7,fig4 #ccd1 c7 of the press1 at the bottom of which is situated the orifice of the spinning canal1 almost completely divided into two by the sharp edge of the rachis 7,figs4 #ccd1 a1 #cce1 l74 ,the threads each pass into one of the two grooves1 and the layer of gum 7grs7 fills the rest of the canal of the press or filator4 ,illustration3 ,,fig4 #cca4--,longitudinal section of the spinneret3 a1 horizontal portion of the tongue2 b1 vertical portion2 c1 f1 circle of the tongue2 d1 tongue-pad2 e1 orifice of the spinneret2 g1 body of the lyre2 h1 prebasilar membrane forming a fold2 i1 internal canal of the spinneret2 k1 filator4--,after ,blanc4 ,illustration3 ,,fig4 #ccb4--,the lower lip 7labium7 of ,bombyx mori1 isolated1 seen from the left side3 ,a1 lyre2 ,b1 spinneret2 ,c1 labial palpus2 ,d1 vertical part of the labium2 ,e1 horizontal part of the same2 ,h1 ,l1 silk-canal2 ,k1 right gland of ,filippi2 ,l1 canal of the left gland2 ,n1 labial nerve2 a1 oblique fibre of the elevator of the labium2 b1 right fibre of the same2 c1 depressor of the labium2 d1 superior spinning muscles4 ,illustration3 ,,fig4 #ccc4--,the labium in a horizontal position1 seen from the side3 f1 the filator or press situated under the external part of the spinneret 7d71 between the branches 7b71 of the lyre 7a72 e1 labial palp2 c1 tongue4 ,illustration3 ,,fig4 #ccd4--,longitudinal section of the spinneret and press 7filator73 ,a1 filator or press2 ,b1 spinneret2 ,c-,d1 body of the lyre2 ,f1 lower part of the labium2 ,e1 common canal2 eh1 its epithelium2 ,g1 superior muscle of the press2 a1 rachis2 b1 its posterior enlargement2 c1 infundibulum2 d1 cuticle2 o1 orifice of the spinning canal2 op1 central canal of the lyre and of the spinneret2 fi1 hypodermis of the lyre2 f1 f1 hypodermic pad of the lyre4 ,the silken substance is then pressed by the more or less powerful contractions of the muscles of the filator1 so that the passage of the threads is facilitated4 ,if the muscles totally contract1 the spinning canal is opened wide1 the threads pass easily upwards and assume the form of a triangular prism 7,fig4 #ccf74 ,illustration3 ,,fig4 #cce4--,spinning apparatus1 seen from above3 ,a1 opening of the spinneret2 ,b1 central canal of the spinneret 7,c72 ,d1 common canal2 ,e1 canal of ,filippi2 ,f1 excretory canal of a silk-gland2 i1 orifice of the canal of ,filippi's gland2 l1 rachis2 k1 ring of the infundibulum2 b1 c1 d1 e1 f1 cavity of the different canals2 h1 spur which separates the two excretory canals4--,this and ,figs4 #cca-ccd after ,blanc4 ,if this contraction diminishes1 the chitinous wall of the spinneret comes together1 owing to its elasticity2 the ceiling of the canal approaches the floor2 the cavity tends to take the form of a semicircular slit1 and the threads are compressed1 flattened4 ,as each mass or thread of silk is much more voluminous than the canal1 except when the latter is extremely dilated1 it follows that the two threads are always compressed1 or squeezed together1 and that each of them is compelled to mould itself in the groove it occupies and to take its shape4 ,hence the variations in the appearance of the two masses or divided portions of silk1 which as stated present all grades between the form of an isosceles-triangular prism and that of a nearly flat ribbon2 but this last case is quite rare4 ,the use of the spinneret1 then1 is to compress the thread and to change its form more or less considerably1 at the same time as it diminishes its diameter4 ,illustration3 ,,fig4 #ccf4--;,diagram of the press and its muscles3 a1 lower2 b1 lateral2 c1 upper muscles of the press4--,after ,blanc4 ,moreover1 this constant compression of the thread as it passes through the press keeps it in a certain state of tension so as to allow the caterpillar while spinning to firmly hold its thread4 ,finally1 when the worm suspends the contraction of its spinning muscles1 the press flattens1 vigorously compresses the thread1 and arrests its motion1 in such a way that if there was a strain on the silken fluid 7bave71 it would break rather than oblige the caterpillar to let go any more of it4 ,the press does not act directly on the silken thread1 but through the gummy layer 7grs7 which transmits over the whole surface of the silken fluid 7brin7 the pressure exerted on it4 ,after having overcome this difficult passage1 the silk thread has acquired its definite form2 it rapidly passes out of the spinneret4 ,how the thread is drawn out4--,having seen1 says ,blanc1 how the two masses of silk 7brins71 in passing through the spinning apparatus 7or press71 join each other1 constituting the frothy silken fluid1 thus becoming modified in form1 it remains to examine the way in which the thread is drawn out of the spinneret4 ,if we examine a caterpillar while spinning1 it will be seen that in moving its head it draws on the frothy mass of silk fixed to the web of the cocoon4 ,this traction certainly aids very much the exit of the thread1 but it is not the only cause4 ,the silk1 ,blanc affirms1 is pushed out by a force a tergo1 developed by different agents1 such as the pressure of the distended cuticle or the silky mass contained in the reservoir1 as seen in the section of a worm which has spun its cocoon4 ,but if we consider a caterpillar before it has begun to spin1 it is difficult to explain the mechanism of spinning4 ,as ,blanc has often observed1 in making sections of the heads of silkworms1 two cases arise4 ,sometimes the worm has already spun a little1 and a certain length of the frothy silk 7bave7 issues from the orifice of the spinneret1 where it forms a small twisted bundle4 ,at other times the worm has not spun since its last moult or the frothy mass of silk has broken within the head1 and we find the end in the common tube4 ,in the first of these two cases1 the worm1 dilating its press1 is able by a general contraction to discharge a little of the gritty material 7grs7 which lines the ball of silk hanging at the end of the spinneret4 ,it can also reject a certain quantity of the secretion of ,filippi's glands and thus soften the gritty substance4 ,the little plug of silk can then adhere to the body with which it comes in contact4 ,in the same case it is necessary that the two bits or portions of silk traverse the press1 and this normally has a calibre less than their diameter4 ,the worm should then distend the spinning tube as much as is practicable1 so as to make the openings as large as possible4 ,it has been stated that the press is1 in this condition1 at least as large as the mass of frothy silk4 ,this ,blanc believes 7although ,gilson thinks otherwise7 is pushed by a force a tergo1 and reaches the funnel of the spinning canal2 its two bits of silk 7brins7 unite there1 penetrate into the canal itself1 and1 owing to successive impulses produced by the general contractions of the worm1 press through and pass out of the spinneret4 ,while the silkworm is engaged in spinning its cocoon1 the spinneret and press execute very varied movements1 determined by the elevator1 depressor1 retractor1 and protractor muscles of the labium1 as well as those of the press4 ,these movements1 originally very numerous1 may combine among themselves1 so that the spinneret is susceptible of assuming during the process of spinning still more diverse positions4 ,illustration3 ,,fig4 #ccg4--,portion of the silk-gland of ,bombyx mori3 p1 tunica propria2 i1 tunica intima2 s1 secretion-cell with branched nuclei2 a1 separate secretion-cell from the anterior part of the silk-gland of ,amphidasis betularia2 b1 the same of ,vanessa urtic2 c1 the same in ,smerinthus tili4--,after ,helm4 ,illustration3 ,,fig4 #cch4--;,a1 section of gland of lepidopter3 ,b1 section of silk-gland of a saw-fly larva2 n1 nucleus2 i4d1 canals2 d4s1 cavity4--,after ,gilson4 ,histologically the silk-glands are composed of three layers1--the outer1 or tunica propria 7,fig #ccg72 the inner1 the tunica intima2 the middle layer being composed of extraordinarily large epithelial cells which can be seen with the naked eye1 and are also remarkable for the branched shape of the nuclei 7a1 b1 c1 #ccg71 the branches being more or less lobed1 and the larger the cells the more numerous are the branches of the nucleus4 ,gilson#ec finds that those of ,trichoptera1 ,lepidoptera1 ,diptera1 and ,hymenoptera ordinarily consist of a small number of cells2 and it is quite common1 he says1 to find only two cells in a transverse section 7,fig4 #cch1 ,a74 ,in the ,tenthredinid1 however1 8the organ still consists of a tube1 the wall of which is composed of flat cells1 but in addition to that1 two series of spheroidal cells are attached to the sides4 ,each of these cells contains a system of tiny canals running through their cytoplasm 7,b1 i4 d74 ,these cells are the secreting elements2 they continually cast the silk substance into the tube40 ,a peculiarity of the tunica intima is its distinct transverse striation4 ,illustration3 ,,fig4 #cci4--;,branching nucleus of spinning gland of ,pieris larva4--,after ,korschelt1 from ,wilson4 ,illustration3 ,,fig4 #cdj4--;,filippi's glands 7,g7 isolated and seen from above3 e1 e1 its lobules2 d1 its excretory canal2 ,e1 silk-duct2 ,c1 common canal2 c1 upper spinning muscle2 b1 lower muscle2 a1 lateral muscle2 ,t1 spinneret4--,after ,blanc4 ,the lining of the glands and of their common duct is moulted when the caterpillar casts its skin1 and this1 as well as the mode of development1 shows that the glands are invaginations of the ectoderm4 ,gilson finds that the silk-glands and silk-apparatus of ,trichoptera are very similar to those of caterpillars1 and that the silk is formed in the same way4 ,appendages of the silk-gland 7,filippi's glands74--,in most larv there is either a single or a pair of secondary glands which open into the spinning glands near their anterior end4 ,they are outgrowths of the gland provided with peculiarly modified excretory cells or evaginations of the entire glandular epithelium4 ,those of ,bombyx mori 7,fig4 #cdj7 are very well developed1 and1 according to ,blanc1 form two whitish1 lobulated masses in the labium on each side of the common duct of the spinning gland4 ,externally they appear to be acinose2 but their structure1 as described by ,blanc and by ,gilson1 is very peculiar4 ,helm thinks1 with ,cornalia1 that the function of these glands is to secrete the adhesive fluid which unites the silk threads1 and also to make the silk more adhesive in the process of spinning1 but ,blanc states that this is done before the thread passes into the common excretory tubes1 and he is inclined to think that the secretion serves to lubricate the spinneret1 and thus to facilitate the passage of the thread4 ,on the other hand1 in certain caterpillars these glands are situated quite far from the spinning apparatus4 ,the silk-glands in the pupa state undergo a process of degeneration1 and finally completely disappear4 ,they are specific larval organs evolved in adaptation to the necessity of the insect's being protected during its pupal life by a cocoon4 7,helm47 ,morphologically the silk-glands are by ,lang regarded as modified coxal glands1 and homologues of the setiparous parapodial glands of chtopod worms1 the coxal glands of ,peripatus1 and the spinning glands of spiders4 ,in ,scolopendrella1 spinning glands are situated in the two last segments of the body1 opening out at the end of the cercopods 7,fig4 #ae1 s4gl71 and the larv of the true ,neuroptera 7,chrysopa1 ,myrmeleon1 etc47 which spin cocoons1 have spinning glands opening into the rectum4 ,the silk forming the cocoon of the ant-lion1 as ,siebold and the older observers have stated1 is secreted by the walls of the rectal or anal sac4 ,siebold 7,anatomy of the ,invertebrates1 p4 #dde7 states that in the larva of ,myrmeleon1 the silk-apparatus is very remarkable1 8for the rectum itself is changed into a large sac and secretes this substance which escapes through an articulated spinneret projecting from the opening of the anus0#ed 7,fig4 #cjg1 e74 ,the larv of the ,mycetophilid have spinning glands at the hinder end of the body1 as also the imago of the female of the tineid moth ,euplocamus4 7,kennel47 ,the larv of ichneumons1 wasps1 bees1 of ,cecidomyia1 and other ,diptera1 spin silken cocoons1 but their glands have not yet been examined4 ,it should also be observed that during the process of pupation the larv of butterflies1 of certain flies 7,syrphus71 and beetles 7,coccinellid and some ,chrysomelid7 attach themselves by silk spun from the anus1 so that the pupa is suspended by its tail2 such glands are probably homogenetic with the coxal glands4 ,the silk in its fluid or soft state is mucilaginous1 and according to ,mulder1 in the silkworm consists of the following substances1 varying somewhat in their relative proportions by weight3 ,silk-fibre material #ec4fg ,glue 7,leim7 #bj4ff ,protoplasm #bd4dc ,wax #a4ci ,coloring matter #j4je ,fat and resin #j4aj ,,literature ,,on ,,the ,,spinning ,,glands ,helm1 ,e4 ,anatomische und histiologische ,darstellung der ,spinndrsen der ,schmetterlingsraupen4 7,zeitschr4 f4 wissens4 ,zool41 xxvi1 #ahgf1 pp4 #dcd-dfi1 #b ,taf47 ,lidth de ,jeude1 ,th4 ,w4 van4 ,zur ,anatomie und ,physiologie der ,spinndrsen der ,seidenraupe4 7,zool4 ,anzeiger1 #ahgh1 pp4 #ajj-ajb47 ,engelmann1 ,w4 ,zur ,anatomie und ,physiologie der ,spinndrsen der ,seidenraupe4 7,onderz4 ,phys4 ,lab4 ,utrecht1 iii1 #ahhj1 pp4 #aae-aai47 ,joseph1 ,g4 ,vorlufige ,mitteilung ber ,innervation und ,entwickelung der ,spinnorgane bei ,insekten4 7,zool4 ,anzeiger1 #ahhj1 pp4 #cbf-cbh47 ,poletajew1 ,n4 ,ueber die ,spinndrsen der ,blattwespen4 7,zool4 ,anzeiger1 #ahhe1 pp4 #bb-bc47 ,meinert1 ,fr4 ,contribution l'anatomie des fourmilions4 7,overs4 ,danske ,vidensk4 ,selsk4 ,forh4 ,kjbenhavn1 #ahhi1 pp4 #dc-ff1 #b ,pls47 ,blanc1 ,louis4 tude sur la scrtion de la soie et la structure du brin et de la bave dans le ,bombyx mori4 ,lyon1 #ahhi1 pp4 #dh1 #d ,pls4 ---- ,la tte du ,bombyx mori l'tat larvaire4 ,anatomie et physiologie4 7,extrait du volume des ,travaux du ,laboratoire d'tudes de la ,soie4 ,annes #ahhi-ahij1 ,lyon1 #ahia1 pp4 #ahj1 #ie figs47 ,gilson1 ,g4 ,recherches sur les cellules scrtantes4 ,la soie et les appareils sricignes3 ,i4 ,lpidoptres4 7,la ,cellule1 #ahij1 vi1 pp4 #aae-ahb1 #c ,pls4 ,i1 ,lpidoptres 7suite72 ,,ii1 ,trichoptres4 ,ibid41 x1 pp4 #ga-ic1 #ahic1 #a ,pl47 ,garman1 ,h4 ,silk-spinning dipterous larv 7,science1 xx1 #ahic1 p4 #bae74 ,also the writings of ,meckel1 ,pictet1 ,dumril1 ,klaplek1 ,wistinghausen1 ,loew1 ,hagen1 ,fritz ,mller1 ,kolbe1 ,mc,lachlan1 de ,selys-,longchamps4 c4 ,the ccal appendages4 ,these diverticula of the mid-intestine 78stomach07 are appended to the anterior end1 and in the living1 transparent larva of ,sciara1 which has two large1 long1 slender cca 7,fig4 #cda71 the partly digested food may be seen oscillating back and forth from the anterior end of the stomach into and out of the base of each ccum4 ,in the ,locustid 7,anabrus1 ,fig4 #bii7 and ,gryllid 7,fig4 #cdd1 e7 there are two large1 short cca1 and in the locusts 7,caloptenus7 there are six cca1 while cockroaches have eight4 ,in the ,coleoptera 7,carabid and ,dyticid7 these large cca appear to be replaced by very numerous slender1 minute villi or tubules1 which arise from the anterior part of the stomach 7,figs4 #cag1 r1 also #cdb74 ,these cca differ in structure from the stomach1 as shown by ,graber1 as well as by ,plateau and by ,minot4 ,the latter states that a single transverse section of one of the diverticula of the locust demonstrates at once that its structure is entirely different from that of the stomach4 ,illustration3 ,,fig4 #cda4--,larva of ,sciara3 s4gl1 salivary gland2 ur4t1 urinary tubes2 i intestine2 st1 stomach2 cae ccal appendages2 t1 testis4 ,its inner surface is thrown up into longitudinal folds1 generally twelve in number4 ,these folds shine through the outer walls1 and are accordingly indicated in the drawings of ,dufour1 ,graber1 and others4 ,the entire ccum has an external muscular envelope1 outside of which are a few isolated longitudinal muscular bands4 ,the folds within are formed mainly by the high cylindrical epithelium which lines the whole interior of the cavity4 ,trache ramify throughout all the layers outside the epithelium4 ,there are appearances of glandular follicles in the bottom of the spaces between the folds4 7,minot47 ,burmeister supposed that these cca were analogous to the pancreas1 and this view has been confirmed by ,hoppe ,seyler1 ,krukenberg1 ,plateau1 and others1 who claim that the digestive properties of the fluid secreted in them agrees with the pancreatic fluid of vertebrates4 ,illustration3 ,,fig4 #cdb--;,cross-section of mid-intestine of ,acilius sulcatus1 showing the arrangement of the cca1 two trache passing into each ccum4--,after ,plateau4 d4 ,the excretory system 7urinary or ,malpighian tubes7 ,the excretory matters or waste products of the blood tissue of worms are carried out of the body by segmentally arranged tubes called nephridia4 ,as a rule they arise in the blood sinuses of the body and open externally through minute openings in the skin4 ,as there is a pair to each segment 7in certain oligochete worms two or three pairs to a segment71 they are often called segmental organs4 ,in the annulate worms each segment of the body1 even the cephalic or oral segment1 originally contains a pair of these excretory organs4 ,these vessels may have survived in myriopods and perhaps do exist in insects as urinary tubes1 and also occur in many of the ,arachnida1 and thus are characteristic of each important class of land arthropods1 but are either wanting or are very rudimentary or much modified in the marine classes1 notably the ,crustacea and ,merostomata 7,limulus71 where they are represented by the shell-glands of ,copepoda1 green glands of the lobster1 and the brick-red glands of ,limulus4 ,illustration3 ,,fig4 #cdc4--;,digestive canal of ,perla maxima3 l1 upper lip2 mh1 buccal cavity2 ap1 common end of salivary ducts 7ag72 o1 sophagus2 s1 s1 salivary glands1 arranged segmentally2 b1 cca of chyle-stomach2 lg1 their ligaments of attachment2 mp1 urinary tubes2 r1 rectum2 af1 anal orifice4--,after ,imhof1 from ,sharp4 ,in the earliest tracheate arthropod1 ,peripatus1 these tubes are well developed and are highly characteristic1 each segment behind the head bearing a pair 7,fig4 #d1 so#d-so#i74 ,it has been suggested by some1 but not yet proved1 that the urinary tubes of insects are morphologically the same as the segmental organs of worms and of ,peripatus2 but there are no facts directly supporting this view1 and1 as ,sograff states1 it is a pure hypothesis and can only be confirmed or disproved by very detailed researches on the development of the urinary tubes of myriopods and of insects4 ,others regard them as probably homologous with the trache1 since they have a similar origin4 ,as1 however1 they arise in the embryo as outgrowths of the proctodum they may have arisen in myriopods and insects independently1 and not be vermian heirlooms4 ,while in worms and in ,peripatus a pair of these segmental organs occur in each segment1 in insects this serial arrangement is not apparent2 those with a purely excretory function are not segmentally arranged1 with outlets opening externally1 but arise as outgrowths of the hind-intestine or proctodum of the embryo1 not being segmentally arranged4 ,the place of their origin is usually the dividing line between the mid and hind intestine 7,fig4 #cdc1 mp72 this applies to ,scolopendrella 7,fig4 #ae1 urt7 as well as to insects4 ,the urinary tubes are usually long1 slender1 blind1 tubular glands varying in number from two to over a hundred1 which generally arise at the constriction between the mid and hind intestine1 and which lie loosely in the cavity of the body1 often extending towards the head1 and then ending near the rectum 7,figs4 #cja1 #caj1 vm74 ,they were first discovered by the ,italian anatomist ,malpighi1 after whom they were called the ,malpighian tubes4 ,while at first generally regarded as 8biliary0 tubes1 they are now universally considered to be exclusively excretory organs1 corresponding to the kidneys of the higher animals4 ,illustration3 ,,fig4 #cdd4--;,digestive canal and appendages of the mole-cricket2 a1 head3 b1 salivary glands and receptacle2 c1 lateral pouch2 d1 stomatogastric nerves2 e1 anterior lobes of stomach2 f1 peculiar organ2 g1 neck of stomach2 h1 plicate part of same2 i1 rectum2 k1 anal gland2 m1 urinary tubes4--,after ,dufour1 from ,sharp4 ,usually arising from the anterior end of the hind-intestine where it passes into the mid-intestine1 in certain forms they shift their position1 in some ,hemiptera 7,lygus1 ,cimex7 opening into the rectum1 while in the ,psyllid they arise from the slender hinder part of the mid-intestine1 being widely separated at their origin4 7,fig4 #cba47 ,the length varies in different groups2 where they are few in number 7two to four1 six to eight71 they are very long1 but where very numerous they are often short1 forming dense tufts1 each tuft connecting with the intestine by a common duct 7ureter71 or1 as in the mole-cricket1 the numerous tubes empty into a single duct 7,fig4 #cdd72 in the locusts 7,acrydiid71 however1 they are arranged in #aj groups1 each group consisting of about #ae tubes1 making about #aej in all2 and are much convoluted and wound irregularly around the digestive canal1 and when stretched out being about as long as the entire body4 ,the urinary tubes occur in twos1 or in multiples of two1 though a remarkable exception is presented in the dipterous genera ,culex and ,psychodes1 in which there are five tubes2 the young and fully grown larv1 as well as the pupa and imago of ,culex1 having this number 7,fig4 #dcc1 mg47 ,in many insects 7,pentatoma1 ,cimex1 ,velia1 ,gerris1 ,haltica1 ,donacia1 and often in caterpillars71 the vessels open into a sort of urinary bladder connecting with the intestine on one side4 ,illustration3 ,,fig4 #cde4--;,a1 section of urinary tube of ,periplaneta2 ,b1 part of tube of ,perla2 p1 peritoneal membrane2 c1 cavity or lumen2 n1 nucleus of a secreting cell4--,after ,schindler4 ,in the larv of some insects the blind ends of the tubes are often externally bound to the rectum1 in the silkworms being attached by fine threads to the intestine1 while in some flies 7,tipula and ,ctenophora71 two vessels may unite to form a loop4 ,in all larval ,cecidomyi1 the two tubes are united to form a loop which curves backward1 opening near the vent1 the proctodum being very short4 7,giard47 ,illustration3 ,,fig4 #cdf4--,portion of a urinary tube of ,calliphora vomitoria3 tr1 trachea2 l1 lumen2 k1 nucleus4--,after ,gegenbaur4 ,while usually the urinary vessels form simple tubes1 in many species of ,lepidoptera and ,diptera they are branched1 thus resembling those of spiders and scorpions4 ,moreover1 in many ,lepidoptera and ,diptera 7,fig4 #cjh71 the tubes are not simple1 but are lobulated1 and in some ,hemiptera 7,pentatoma1 ,notonecta1 and ,tettigonia7 are twisted or lace-like4 ,in rare cases there are two kinds of urinary tubes2 in ,melolontha vulgaris1 two of them are partly lobulated and yellow1 while the other two are simple and white4 ,their color in beetles varies1 some being whitish or yellowish2 in ,geotrupes1 ,dyticid1 ,hydrophilid1 etc41 reddish brown2 in ,gryllotalpa as well as ,locusta viridissima1 there are two different kinds of vessels1 differing in contents and in color 7white or yellow71 as well as histologically4 7,schindler47 ,the exterior of the tubes is richly provided with trache1 which often form a web around them1 and the fine branches often seem to attach them to the intestine4 ,in ,acheta they are enveloped by a very delicate1 loose network of muscular fibres4 7,schindler47 ,the urinary tubes consist1 according to ,schindler1 of at least three cellular layers 7,fig4 #cde73-- #a4 ,an external1 connective1 nucleated membrane1 the peritoneal membrane4 #b4 ,a very delicate homogeneous basal membrane1 the tunica propria4 #c4 ,a single layer of large polygonal excretory cells4 #d4 ,lining the internal canal a chitinous layer penetrated by pore-canals1 the intima often wanting4 ,the secretory cells are usually of the same size1 but in many cases are relatively small2 sometimes four to six or more form the periphery of the canal1 sometimes three or only two4 ,in some insects the cells are so very large that a single cell forms the entire periphery4 ,the nuclei in the ,lepidoptera 7,papilio1 ,pontia1 ,cossus7 are large and irregularly branched4 ,the excretions of the ,malpighian vessels1 derived from the blood and from the fat-body1 are more or less fluid and granular1 sometimes pulpy4 ,from the cells they pass into the canal1 thence into the intestine1 and thence out of the body4 ,how1 says ,kolbe1 the secretion passes into the intestine1 whether by the contraction of the fine fibrill of the peritoneal membrane1 or by the external pressure of the other organs1 or by the pressure of the secretory matter behind1 is not yet known4 ,grandis observed in living ,hydrophilus that the urinary tubes moved1 without the muscles seeming to show what caused the motion4 ,moreover1 the cells incessantly changed their form4 ,at a lower temperature such motions ceased4 ,the trache1 ending freely in the cells1 did not anastomose4 7,kolbe47 ,the different colors of the tubes 7white1 yellow1 red1 brown1 or green7 is due to the hue of the excretions1 and is independent of the color of the blood and of the urinary substances held in the secreted matter4 ,schindler found that insects of different stages1 collected in winter1 differed very much in their urinary secretions1 the tubes in the adults being entirely empty1 while in the larv they were filled full1 so that he concluded that in the former the process of excretion during the winter hibernation is very slow1 but in the latter very rapid4 ,as to the activity of the urinary vessels the following experiments will throw some light4 ,tursini fed a ,pimelia with fuchsin2 its urinary tubes were consequently colored red4 ,schindler fed insects with indigo-carmine1 which was excreted by the urinary tubes2 ,kowalevsky arrived at the same results1 which seems to prove that these vessels are analogous to the kidneys of vertebrates4 ,moreover1 ,schindler injected through the side of the first abdominal segment into the cavity of the body of a ,gryllotalpa a concentrated solution of sodium salt of indigotin-disulphonic acid4 ,after one or two hours the external portion of the epithelium of the urinary vessels was stained deep blue1 while the inner portion remained of the normal transparency2 the nuclei being for the most part deeply stained4 ,between one and two days after1 the staining matter had not yet wholly passed through the central canal1 the surface recently stained still appearing light blue4 ,the solid contents of the urinary tubes consist partly of crystals1 which occur singly in the epithelial cells1 or form scattered masses when situated in the central canal4 ,besides tabular rhombic crystals1 there occur concretions which contain uric acid1 and probably consist of urate of soda1 also octahedral crystals of chloride of soda1 and quadro-pyramidal crystals of oxalate of lime4 ,also acicular prisms occur2 besides chloride of soda1 phosphates1 carbonate of lime1 oxalate of lime in quantity1 leucine1 coloring matters1 etc42 while the fluid secretion also contains urea 7871 uric acid1 and abundant urates2 uric acid crystals were precipitated by the addition of acetic acid1 and by adding hydrochloric acid crystals belonging to the dimetric system were formed4 ,the often numerous spheroidal small granules are biurate of soda and biurate of ammonia4 ,pale1 concentrically banded concretions are leucine pellets4 ,according to ,klliker the contents of the urinary vessels#ee in general are3 7#a7 round granules of urate of soda and urate of ammonia2 7#b7 oxalate of lime2 and 7#c7 pale transparent concretions of leucine4 ,crystals of taurin are also said to occur4 7,claus' ,zology1 p4 #eca47 ,although uric acid is characteristic of the urinary tubes1 yet sometimes it is wanting in them1 while uric acid substances in quantity occur in the fat-body or in the mid-intestine4 ,in the living insect the urinary tubes remove urates from the blood2 8the salts are condensed and crystallized in the epithelial cells1 by whose dehiscence they pass into the central canals of the tubules and thence into the intestine40 7,miall and ,denny47 ,the process of excretion is carried on not only by the urinary tubes1 but also1 as ,cunot has recently shown 7#ahif7 in ,orthoptera1 by the pericardial cells and certain cells of the fat-bodies4 ,in the last-named cells urates are stored throughout life2 the pericardial cells apparently secrete but do not store waste products1 which are finally eliminated by the urinary tubes1 the latter constantly eliminating waste4 ,primitive number of tubes4--,wheeler considers the primitive number of urinary tubules to be six1 other authors regarding two pairs as the primary or typical number2 and while ,wheeler agrees that the more ancestral tracheate arthropods had but a single pair1 ,cholodkowsky supposes the primitive number in insects themselves to be a single pair4 ,this view is strengthened by the fact that ,scolopendrella has but a single pair 7,fig4 #ae74 ,while ,peripatus has no urinary tubes1 in ,myriopods a single pair arises1 as in insects1 from the hind-intestine4 ,illustration3 ,,fig4 #cdg4--,section of proctodum of embryo locust1 showing origin of urinary tubes 7ur4t72 ep1 epithelial or glandular layer2 m1 cells of outer or muscular layer2 a1 section of a tube4 ,when in insects the number of these tubes is few1 they are1 with rare exceptions1 arranged in pairs1 so that ,gegenbaur and others have considered this paired arrangement as the primitive one4 ,when the tubules are very numerous in the adult1 as in ,orthoptera1 the embryos and larv have a much smaller number1 ,wheeler stating that 8in no insect embryo have more than three pairs of these vessels been found40 ,we have observed #aj primary tubes in the embryo of ,melanopus 7,fig4 #cdg71 from each of which afterwards arise #ae secondary tubules4 ,in the ,termites1 only1 do the young forms have more urinary tubes than the adults4 ,in ,campodea there are about #af urinary tubes and in ,machilis either #ab 7,grassi7 or #bj 7,oudemans72 but in other ,thysanura the number is much less1 ,lepisma having either four1 six1 or eight1 according to different authors1 and both ,nicoletia and ,lepismina having six1 opening separately into the hind-intestine4 ,on the other hand1 these organs have not yet been detected in ,japyx4 ,whether they exist at all in the ,collembola1 which are degenerate forms1 is doubtful4 ,the weight of opinion denies their existence1 though they may yet be found existing in a vestigial condition4 ,they are said by ,tullberg and by ,sommer to exist in ,podura1 but are of peculiar shape4 ,coming now to the winged insects1 in what on the whole is perhaps the lowest or most generalized order1 the ,dermaptera1 the number is over #cj1 and their insertions regularly encircle the intestine4 7,schindler47 ,in the most ancient and generalized family of ,orthoptera1 the ,blattid1 ,schindler detected from #fj to #gj tubes1 but in a nymph of ,periplaneta not quite #aj mm4 in length he found from #af to #ah1 and in nymphs #d to #e mm4 long there were only eight vessels2 while ,wheeler has found in the embryo of ,phyllodromia germanica but four tubes4 ,in the adult ,acrydiid there are as many as #aej1 in the ,locustid between #dj and #ej1 and in the ,gryllid about #ajj4 ,the ,ephemerid with about #dj1 the ,odonata with #ej to #fj tubules1 the ,perlid with from #ej to #fj1 are polynephrious2 while the ,termitid and ,psocid are oligonephrious1 the former having from six to eight and the ,psocid only four tubes4 ,so also all the other orders not mentioned1 except the ,hymenoptera1 have few of these tubes4 ,the ,hemiptera1 with none in ,aphid1 a single pair in the ,coccid1 and two in all the rest of the order1 have the fewest number4 ,in the ,neuroptera there are from six to eight1 while in a larva1 possibly that of ,chauliodes1 ,wheeler finds the exceptional number of seven4 ,the closely allied order ,mecoptera 7,panorpid71 and also the ,trichoptera1 agree with the ,neuroptera 7,sialis7 in having six4 ,according to ,cholodkowsky all ,lepidoptera have six of these vessels1 except ,galleria1 which has but four4 ,he finds that in ,tinea biselliella 7also ,t4 pellionella and ,blabophanes rusticella7 the larva has six vessels1 which1 however1 undergo histolysis during pupation1 a single pair arising in their stead4 ,on this account he regards the primitive number of urinary tubes as two1 or a single pair1 this return from six vessels in the larva to two in the imago being considered a case of atavism4 ,in the ,coleoptera1 the number of urinary tubes is from four to six2 in what few embryo beetles have been examined 7,doryphora1 ,melolontha71 there are six vessels1 but in the embryo of ,dyticus fasciventris1 ,wheeler has detected only four1 this number being retained in the adult4 ,he thinks that in beetles in general1 a pair of vessels must be 8suppressed during post-embryonic development1 presumably in early larval life40 ,in ,diptera and ,siphonaptera1 the number four is very constant1 there being1 however1 a fifth one in ,culex and ,psychoda 7,fig4 #djj47 ,the number of these vessels is very inconstant in the ,hymenoptera1 varying from six 7,tomognathus1 an ant1 worker7 to #ab 7,myrmica71 and in ,apis reaching the number of #aej4 ,in the embryo of the honey-bee and wall-bee 7,chalicodoma71 there are only four2 we still lack any knowledge of the number in embryo saw-flies4 ,the following is a tabular view of insects with few urinary tubes 7,oligonephria7 and many 7,polynephria74 ,it will be seen that the number has little relation to the classification or phylogeny1 insects so distantly related as the ,orthoptera and ,hymenoptera being polynephrious3-- ,oligonephria ,collembola1 #b 7,podura71 ,tullberg and also ,sommer4 ,thysanura1 #d 7,lepisma72 in ,campodea1 #af2 in ,machilis1 #ab or #bj2 wanting in ,japyx4 ,psocid1 #d4 ,termitid1 #f 7many in the young1 ,rathke74 ,mallophaga1 #d4 ,physapoda1 #d4 ,hemiptera1 #b 7,coccid1 none in ,aphid74 ,neuroptera1 #f-h4 7,in ,sialid and ,rhaphidid #f2 in ,myrmeleonid and ,hemerobiid1 #h74 ,trichoptera1 #f4 ,mecoptera1 #f4 ,lepidoptera1 #b-d-f 7#b in ,tinea1 ,tineola1 and ,blabophanes2 in ,pterophorus and ,yponomeuta1 #d74 ,coleoptera1 #d-f2 never more4 #d ,carabid1 ,dyticid1 ,staphylinid1 ,gyrinid1 ,palpicornes1 ,lamellicornes1 ,cantharid1 ,buprestid 7in larva1 #f2 in beetle1 #d74 #f ,byrrhid1 ,nitidulid1 ,dermestid1 ,clerid1 ,meloid1 ,pyrochroid1 ,bruchid1 ,bostricid1 ,cerambycid ,chrysomelid1 ,coccinellid4 ,diptera1 branching into #d 7,gegenbaur72 in ,culicid1 and ,psychoda1 #e4 ,siphonaptera1 #d4 ,polynephria ,orthoptera1 #ajj-aej4 7,in embryo ,blattids1 #d2 in embryo locust1 #aj2 in nymph of ,gryllotalpa1 #d47 ,dermaptera1 8over #cj0 7,schindler74 ,perlidae1 #ej-fj4 ,plectoptera 7,ephemerid71 #dj4 ,odonata1 #ej-fj4 ,hymenoptera1 #bj-aej4 7,in embryo bees only #d2 ,cynipid1 ,ichnenumonid1 and ,formicid have the smallest number1 #f-ab47 ,here should be mentioned the singular fact discovered by ,koulaguine that in the larva of ,microgaster1 the urinary tubes have no connection with the intestine1 but open dorsally on the outside of the body on each side of the anus4 ,ratzeburg had stated that the last segment of the body was in the form of a vesicle4 ,koulaguine now shows that this vesicle is in reality the end of the intestine opening upwards2 as the result of this dorsal opening of the intestine the ,malpighian vessels open on the sides of the oval vent1 and have no connection with the intestinal canal4 ,whether this is of morphological import1 or is only a secondary adaptation1 ,koulaguine does not state1 his paper being a preliminary abstract4 ,wheeler thus sums up our present knowledge regarding the number and homologies of the ,malpighian or urinary tubes3 #a4 ,it is very probable that the so-called ,malpighian vessels of ,crustacea and ,arachnida are not the homologues of the vasa ,malpighi of the ,eutracheata 7insects and myriopods74 #b4 ,the ,malpighian vessels of the ,eutracheata arise as paired diverticula of the hind-gut and are1 therefore1 ectodermal4 #c4 ,in no insect embryo are more than six vessels known to occur2 although frequently only four are developed4 #d4 ,the number six occurs either during embryonic or post-embryonic life in members of the following groups3 ,apterygota1 ,orthoptera1 ,corrodentia2 ,neuroptera1 ,panorpata1 ,trichoptera1 ,coleoptera1 ,lepidoptera1 and ,hymenoptera4 #e4 ,the number four seems to be typical for the ,corrodentia1 ,thysanoptera1 ,aphaniptera1 ,rhynchota1 ,diptera1 and ,hymenoptera4 #f4 ,the embryonic number in ,dermaptera1 ,ephemeridea1 ,plecoptera1 and ,odonata has not been ascertained1 but will probably be found to be either four or six4 #g4 ,there is evidence that in at least one case 7,melolontha71 the tetranephric is ontogenetically derived from the hexanephric condition by the suppression of one pair of tubules4 #h4 ,it is probable that the insects which never develop more than four ,malpighian vessels have lost a pair during their phylogeny4 #i4 ,the post-embryonic increase in the number of ,malpighian vessels in some orders 7,orthoptera1 ,odonata1 ,hymenoptera7 is secondary and has apparently arisen to supply a demand for greater excreting surface4#ef ,,literature ,,on ,,the ,,excretory 7,,urinary7 ,,organs ,malpighi1 ,m4 ,dissertatio epistolica de ,bombyce1 ,societati regi ,londini ad scientiam naturalem promovendam institut dicata4 7,londini1 #affi1 #ab ,pls47 ,herold1 ,m4 ,j4 ,d4 ,entwicklungeschichte der ,schmetterlinge4 #ahae4 ,rengger1 ,j4 ,r4 ,physiologische ,untersuchungen ber den tierischen ,haushalt der ,insekten4 ,tbingen1 #ahag1 pp4 #hb4 ,wurzer4 ,chemische ,untersuchungen des ,stoffes in den ,gallgefssen von ,bombyx mori4 7,meckel's ,archiv f4 ,physiol41 iv1 #ahah1 pp4 #bac-bae47 ,gaede1 ,h4 ,m4 ,physiologische ,bemerkungen ber die sogenannten ,gallgefsse der ,insekten4 7,nova ,acta ,acad4 ,caes4 ,leopold4-,carolin41 #ahba1 x1 ,pars ,,ii1 pp4 #ahf-aif47 ,meckel1 ,j4 ,f4 ,ueber die ,gallen- und ,harnorgane der ,insekten4 7,meckel's ,archiv1 i1 #ahbf1 pp4 #ba-cf47 ,audouin1 ,j4 ,v4 ,calculs trouvs dans les canaux biliaires d'un cerf volant4 7,ann4 sc4 nat41 #b ,sr41 #ahcf1 v1 pp4 #abi-acg47 ,frey und ,leuckart4 ,anatomie und ,physiologie der ,wirbellosen4 #ahdc4 ,dufour1 ,l4 ,mmoire sur les vaisseaux biliaires ou le foie des ,insectes4 7,ann4 sc4 nat41 #ahdh1 ,sr4 #b1 xix1 pp4 #ade-ahb1 #d ,pls47 ,karsten1 ,h4 ,harnorgane von ,brachinus complanatus4 7,mller's ,archiv f4 ,anat4 und ,physiol41 #ahdh1 pp4 #cfg-cgd47 ,fabre1 ,j4 ,l4 tude sur l'instinct et les metamorphoses des ,sphgiens4 7,ann4 d4 sc4 nat41 #d ,sr41 #ahef1 vi1 pp4 #acg-ahi47 ---- tude sur le rle du tissu adipeux dans la scrtion urinaire chez les ,insectes4 7,ibid41 #d ,sr41 xix1 pp4 #cea-chb47 ,schlossberger1 ,j4 ,e4 ,untersuchungen ber das chemische ,verhalten der ,krystalle in den ,malpighischen ,gefssen der ,raupen4 7,archiv f4 ,anat4 und ,physiol41 #aheg1 pp4 #fa-fb47 ,leydig1 ,f4 ,lehrbuch der ,histiologie4 #aheg4 ,sirodot1 ,s4 ,recherches sur les scrtions chez les ,insectes4 7,ann4 sc4 nat41 #d ,sr41 ,zool41 #aheh1 x1 pp4 #ada-ahi1 #bea-ccd1 #ab ,pls47 ,klliker1 ,a4 ,zur feineren ,anatomie der ,insekten 7,ueber die ,harnorgane1 u4s4w47 7,verhandl4 d4 ,physikal4-medizin4 ,gesellsch4 in ,wrzburg1 viii1 #aheh1 pp4 #bbe-bce47 ,schindler1 ,e4 ,beitrage zur ,kenntnis der ,malpighischen ,gefsse der ,insekten4 #c ,taf4 7,zeitschr4 f4 wiss4 ,zool41 xxx1 #ahgh1 pp4 #ehg-ffj47 ,chatin1 ,g4 ,note sur la structure du noyau dans les cellules marginales des tubes de ,malpighi chez les ,insectes et les ,myriapodes4 7,ann4 d4 sc4 nat41 #f ,sr41 xiv41 #ahhb1 pp4 #g1 #a ,pl47 ,witlaczil1 ,e4 ,zur ,anatomie der ,aphiden4 7,arbeiten a4 d4 ,zool4 ,instit4 d4 ,univers4 ,wien41 iv1 #ahhb1 pp4 #cig-dda1 #c ,taf47 ,cholodkowsky1 ,n4 ,sur les vaisseaux de ,malpighi chez les ,lpidoptres4 7,compt4 rend4 ,acad4 d4 ,sc41 ,paris1 xcix1 #ahhd1 pp4 #fca-fcc47 ---- ,sur la morphologie de l'appareil urinaire des ,lpidoptres4 7,archives de ,biologie1 #ahhg1 vi1 pp4 #dig-ead1 #a ,pl47 ,loman1 ,j4 ,c4 ,c4 ,ueber die morphologische ,bedeutung der sogenannten ,malpighischen ,gefsse der echten ,spinnen4 7,tijdschr4 ,nederl4 ,dierk4 ,ver4 7#b7 ,deel #a1 #ahhg1 pp4 #aji-aac1 #d ,fig47 ,marchal1 ,p4 ,contribution l'tude de la dsassimilation de l'azote4 ,l'acide urique et la fonction rnale chez les ,invertbrs4 7,mm4 ,soc4 ,zool4 de ,france1 #ahhi1 iii1 pp4 #db-eg47 ,kowalevsky1 ,a4 ,o4 ,ein ,beitrag zur ,kenntnis der ,exkretionsorgane4 7,biol4 ,centralbl41 ix1 #ahhi-ij1 pp4 #cc-dg1 #fe-gf1 #abg-abh47 ---- ,sur les organes excrteurs chez les arthropodes terrestres4 7,congrs international de ,zool41 #bme ,session ,moscou1 #ahib1 ,pt4 ,i1 pp4 #ahf-bce1 #d ,pls47 ,griffiths1 ,a4 ,b4 ,on the ,malpighian tubules of ,libellula depressa4 7,proc4 ,roy4 ,soc41 ,edinburgh1 #ahhi1 xv1 pp4 #dja-djc1 ,figs47 ,grandis1 ,v4 ,sulle modificazioni degli epitelii ghiandolari durante la secrezione4 7,atti ,accad4 ,torino1 #ahij1 xxv1 pp4 #gfe-ghi1 #a ,pl42 ,archiv ,ital4 ,biol41 #ahij1 xiv1 pp4 #afj-ahb1 #a ,pl47 ,koulaguine1 ,n4 ,notice pour servire l'histoire du dveloppement des hymnoptres parasites4 7,congrs internat4 de ,zool41 #bme ,session ,moscou1 #ahib1 ,pt4 ,i1 pp4 #bec-bgg47 ,sograff1 ,nicolas4 ,note sur l'origine et les parents des ,arthropodes1 principalement des ,arthropodes trachates4 7,congrs internat4 de ,zool41 #bme ,session ,moscou1 #ahib1 ,pt4 ,i1 pp4 #bgh-cjb47 ,giard1 ,alfred4 7,note on the urinary tubes of larval ,cecidomyia4 ,annals ,ent4 ,soc41 ,france1 lxii1 #ahic1 pp4 lxxx-lxxxiv1 #a ,fig47 ,wheeler1 ,william ,m4 ,the primitive number of ,malpighian vessels in insects4 7,psyche1 vi1 ,may-,december1 #ahic1 ,parts #a-f1 pp4 #deg-dfj1 #dhe-dhf1 #dig-dih1 #eji-eaj1 #eci-eda1 #ede-edg1 #efa-efd47 ,metalnikoff1 ,c4 ,k4 ,organes excrteurs des insectes4 7,bull4 ,acad4 imp4 ,sci4 ,st4 ,ptersbourg1 #ahif1 iv1 pp4 #eg-gb1 in ,russian1 #a ,pl47 ,see also the works of ,straus-,drckheim1 ,will 7,mller's ,archiv4 #ahdh1 p4 #ejb71 ,brugnatelli1 ,leidy1 ,dufour1 ,ramdohr1 ,basch1 ,davy1 ,grassi1 ,minot1 ,berlese1 ,adlerz1 ,marchal 7,bull4 ,ent4 ,soc4 ,france1 #ahif1 p4 #beg72 ,bordas 7,appareil glandulaire des ,hymnoptres1 #ahid71 also ,c4 ,r4 ,acad4 ,sc4 ,paris1 #ahig4 e4 ,poison-glands ,poison-glands are mainly confined to the stinging ,hymenoptera1 i4e4 certain ants1 and the wasps and bees1 but also occur in the mosquito1 while many1 if not most bugs1 seem to instil a drop of poison into the punctured wounds they make4 ,in the honey and other bees the poison apparatus consists of two poison-glands whose secretion passes by a single more or less convoluted efferential duct into the large poison-sac1 and thence by the excretory duct1 which is enlarged at the base of the sting 7,figs4 #aid1 #aie71 out through the sting by the same passage as the eggs4 ,according to ,carlet1 the poison apparatus of bees consists of two kinds of glandular organs1 of which one kind secretes a feebly alkaline fluid1 the other an acid product4 ,the poison is only effective when both fluids are mixed4 ,the resultant venom is always acid4 ,the action of this venom upon some animals1 as rabbits1 frogs1 and certain beetles1 is slight2 but the domestic fly and the flesh-fly are immediately killed by it4 ,the inoculation of a fly with the secretion of one of the glands does not produce death until after a considerable time1 but death follows very quickly if the same fly is subjected to a second inoculation1 this time with the secretion of the other gland4 ,the alkaline glands are in bees and all poisonous ,hymenoptera strongly developed1 but become vestigial in those forms which sting their prey to serve as food for their larv4 ,the poison which the solitary sand and wood wasps and ,pompilid inject into their victims only paralyzes them4 ,illustration3 ,,fig4 #cdh4--,the poison apparatus of ,ichneumon3 ,t1 sting2 ,,ga acid gland2 ,,tg1 ,r1 its tubes opening into the common poison-sac or reservoir2 ce1 its efferent canal2 ,ga1 the tubular alkaline gland2 ,r1 the glandular end2 a1 the reservoir2 ce1 its duct2 ,gac1 the accessory gland--,after ,bordas4 ,illustration3 ,,fig4 #cdi4--;,cephalic gland of ,belostoma4 ,bordas has found both the alkaline gland 7gland of ,dufour7 and the acid gland to occur in a hundred species of ,hymenoptera1 including not only ,aculeata1 but also ,ichneumonid 7,fig4 #cdh71 ,tenthredinid1 and they may be safely said to be of general occurrence4 ,the acid gland consists of three parts1 the glandular portion1 the reservoir for the poison1 and the secretory canal4 ,the alkaline gland is an irregular tube1 with a striated surface and without a reservoir4 ,in most ,hymenoptera there is still a third gland1 which is unpaired1 granular1 rectangular or lanceolate1 with a short filamentous duct which opens beside the orifice of the alkaline glands4 ,the poison in ants1 wasps1 and bees consists of two substances1 i4e4 formic acid and a whitish1 fatty1 bitter residue in the secretion of the glands2 the corroding active formic acid is the essential part of the poison4 7,will47 ,in ,melipona the sting and poison-glands are aborted2 in certain ants 7,formica1 ,lasius1 etc47 the sting is wanting1 but the poison-sac is extraordinarily large4 ,bordas finds in various species of ,ichneumon three kinds of glands opening into the base of the sting4 ,the first two correspond to the acid 7,fig4 #cdh1 ,g4,a7 and alkaline 7,g4,a7 glands of bees and wasps 7,vespid1 etc471 and the third 7,g4ac7 is situated between the two lateral muscular bundles which attach the base of the sting to the last abdominal segment4 ,the poison-reservoir 7,fig4 #cdh1 ,v7 is recognized by its yellow color and diaphanous and striated appearance4 ,it is situated on the left of the hind-intestine1 a little in front of the rectum4 ,the tubular gland 7,ga7 or alkaline gland of aculeate ,hymenoptera is remarkably large2 it is situated on the left side of the body4 ,the accessory gland 7,g4,a7 is elongated1 triangular1 flat1 its duct opening at the base of the alkaline gland2 it is formed of small spherical cells4 ,bordas has met with well-developed poison-glands in forty species belonging to the ,terebrantia1 including that of ,tenthredo1 ,emphytus1 as well as various genera of ,ichneumonid1 but in all these species the accessory gland was wanting4 ,illustration3 ,,fig4 #cej4--,view from above of the cephalic gland of ,belostoma1 #bj4--,this and ,fig4 #cdi after ,locy4 ,under the name of cephalic glands 7,fig4 #cdi71 ,locy describes a pair of glands in the head of ,nepid4 ,the epithelial or secreting cells are #h-sided 7,fig4 #cej74 8,when these insects are irritated10 he says1 8a secretion is freely thrown out around the base of the beak1 which produces death very quickly when introduced on a needle point into the body of an insect40 ,he infers that the cephalic glands may be the source of this poisonous secretion4 ,the poisonous salivary fluid of the larva of ,dyticus is referred to on p4 #cbd4 ,that the mosquito injects poison into the wound it makes has been proved by ,macloskie1 who discovering fine droplets of a yellow oily-looking fluid escaping from the end of the hypopharynx1 afterwards detected the poison-glands4 ,it appears that the two salivary glands are subdivided1 each into three lobes1 the middle of which 7,fig4 #cea1 pg7 differs from the others in having evenly granulated contents and staining more deeply than the others4 ,having examined the preparations1 we agree with the discoverer that these lobes secrete the poison4 ,the poison is diluted by the secretion of the salivary lobes1 and the two efferent ducts1 one from each set of glands1 8carry forward and commingle the venomo-salivary products in the main duct2 and the stream is then carried by the main duct to the reservoir at the base of the hypopharynx40 ,illustration3 ,,fig4 #cea4--;,a1 median section of head1 showing 7du7 the venomo-salivary duct1 with its insertion in 7hy7 the hypopharynx2 cb1 brain2 below is the pharyngeal pump1 leading from 77 the sophagus2 lre1 base of labrum-epipharynx2 m1 muscle2 n1 commissure 7other parts removed74 ,b1 the venomo-salivary duct1 showing its bifurcation1 and the three glands on one of its branches2 pg1 poison gland2 sg1 the upper of the two salivary glands4 ,c1 the bifurcation of the duct1 with its nucleated hypodermis4--,after ,macloskie4 f4 ,adhesive or cement-glands ,dewitz has discovered in ants and bees1 in close connection with the poison-glands1 and like them discharging their secretion through the sting1 cement-glands4 ,they arise by budding at the base of the poison-glands4 ,the two glands in these ,hymenoptera correspond to the tubular glands of the ,orthoptera1 which open at the base of the inner sheath of the ovipositor 7,fig4 #bii1 sb71 so that the secretion flows out through it as the poison of bees1 etc41 out of the sting4 ,the use of the secretion of these glands is either to glue the eggs together1 or to afford material for the egg-case of cockroaches and ,mantid and the gummy egg-case of the locusts1 etc4 ,the contents of the cement-glands serves for the fixture of the eggs after deposition4 ,in the stinging ,hymenoptera one of the cement-glands is an accessory gland2 the other becomes the poison-sac4 ,the cement-glands are in the ,hemiptera only short blind sacs1 in the ,lepidoptera and ,diptera long convoluted tubes1 tubular and branched in the ,coleoptera1 or richly branched in the ,ichneumonid and ,tenthredinid4 ,in the cockroach there are two cement-glands1 but the right one is probably of no functional importance4 ,the left one is filled with a milky substance1 containing many crystals and a coagulable fluid1 out of which the egg-capsule 7otheca7 is formed4 7,miall and ,denny47 ,in the locusts the sebific or cement-gland 7,fig4 #bih1 sb7 secretes a copious supply of a sticky fluid1 which is poured out as the eggs pass out of the oviduct and agglutinates the eggs into a mass1 forming a thin coating around each egg1 which from the mutual pressure of the eggs causes the tough coating to be pitted hexagonally4 ,in other insects also 7,trichoptera1 ,chrysopid1 ,lepidoptera1 etc47 there are similar secretions for the protection or fastening of the eggs when laid4#eg ,the ,trichoptera lay their eggs either in or on the surface of the water in bunches or in strings or in annular gelatinous masses on stones or on plants4 ,this jelly-like substance is secreted by two highly developed paired anal glands4 7,weltner1 in ,kolbe1 p4 #fba47 ,also in certain dragon-flies 7,libellula1 ,diplax1 and ,epitheca7 the eggs are laid in jelly-like masses4 ,with a similar secretion1 spun from the end of the abdomen1 the ,psocid cover their little bunches of eggs laid on the under side of leaves2 and the silk thread forming the egg-sac of the great water-beetle 7,hydrophilus7 is secreted from such anal glands4 g4 ,the wax-glands ,besides the honey-bee1 which secretes wax in little scales on the under side of the abdomen1 the bodies of many other insects1 such as the plant and bark lice1 as well as the ,psyllid1 ,cicadid 7especially ,flata and ,lystra71 are covered with a waxy powder1 or as in ,chermes1 ,schizoneura1 ,flata1 etc41 with wool-like filaments of wax4 ,illustration3 ,,fig4 #ceb4--,under side of worker honey-bee1 carrying wax scales1 #c4--;,after ,cheshire4 ,illustration3 ,,fig4 #cec4--,nymph of ,lachnus1 showing position of wax-glands4--,gissler del4 ,the wax is secreted by minute unicellular dermal glands1 which in the lower insects 7,hemiptera7 are distributed nearly all over the body1 but in the bees are restricted either to the under 7,apis1 ,fig4 #ceb7 or upper side 7,trigona7 of the end of the abdomen4 ,the wax-glands of ,pemphigus1 ,chermes1 etc41 lie under the little warts1 seen in ,lachnus strobi1 the white-pine aphis1 to be distributed in transverse lines across the back and sides of the abdominal segments 7,fig4 #cec74 ,these warts are surrounded by a chitinous ring1 and divided into delicately marked areas4 ,through the delicate numerous pits in the chitinous membrane of these areas the little waxen threads project1 since under each area ends a duct leading from a large glandular cell1 which is a specially modified hypodermis cell 7,claus74 ,the wax threads are hollow1 and all those arising from a single glued cell form a bundle1 whose threads separate from each other and form a white woolly down or bloom covering the body4 ,witlaczil also shows that gall-forming ,aphids secrete a wax-like substance1 which1 during the movements of the insects in the gall1 is rubbed off1 becoming a watery layer mixed with the fluid excrement1 which forms a spherical impervious layer lining the gall1 and thus rendering possible the mode of life of the gall-lice4 ,in the ,psyllid ,witlaczil has discovered wax-glands which also secrete slender waxen threads4 ,they are situated in groups of two or three at the end of the abdomen near the anus1 and arise from hypodermis cells4 ,the wax threads surround the liquid excrement as it passes out of the vent1 covering it with a continuous layer of wax4 ,the excrement accordingly is discharged very slowly and gradually1 in sausage-shaped masses slightly strung together and rolled into close spirals4 ,the body becomes unavoidably smeared with the sticky excrement1 since it is not entirely covered by the waxy layer4 ,moreover1 in the larv of many ,psyllid waxen threads are formed on the upper side of the abdomen2 they are for the most part tightly curled or frizzly1 like wool1 and form1 though partly torn1 a waxen coat1 chiefly on the side and back of the thorax and abdomen4 ,the insects appear therefore as if covered with dust4 ,the mature animals of many species are also covered with a waxen down4 ,the wax threads rapidly dissolve and disappear in alcohol4 ,from a wax-like substance more or less easily dissolved in alcohol arise peculiar hair-like structures which1 in the larv of ,psyllid1 are situated on the side and end of the body and also on the rudiments of the wings4 ,they are readily distinguished from ordinary hairs1 as they arise from glandular cells1 and are of very different lengths1 more or less like bristles1 but hollow1 and very brittle4 ,they are leaf-like in the first nymphal stages of ,trioza rhamni1 but in following stages become narrow and form a row around the entire periphery of the body4 ,the waxen dorsal shield which protects the body of bark-lice 7,coccid7 is a similar product4 ,illustration3 ,,fig4 #ced4--,young nymph and developing scale of ,aspidiotus perniciosus3 a1 ventral view of nymph1 showing sucking beak with set separated1 with enlarged tarsal claw at right2 b1 dorsal view of same1 somewhat contracted1 with the first waxy filaments appearing2 c1 dorsal and lateral views of same1 still more contracted1 illustrating further development of wax secretion2 d1 later stage of same1 dorsal and lateral views1 showing matting of wax secretions and first form of young scale2 all greatly enlarged4--,after ,howard and ,marlatt1 ,bull4 #c1 ,n4 ,s41 ,div4 ,ent41 ,u4 ,s4 ,dept4 of ,agr4 ,witlaczil has described the way it is formed in ,aspidiotus and ,leucaspis4 ,the freshly hatched nymph shows no signs of a waxy secretion4 ,but eventually waxen threads arise first on the hinder and anterior end of the body1 and then over the whole surface4 ,these threads interlace into a sort of felting and thus form the shield1 which is usually much larger than the body and lies closely upon it4 ,the shield is formed after the first moult4 ,it is noteworthy that these threads are matted together to form as thick a tissue as that of the shield itself4 ,the shield is whitish or gray and rather thin4 ,on the thinnest part of the edge the single threads may be drawn out4 ,the growth of the shield advances with the increase in size of the nymph around the entire edge1 but is greatest behind4 ,the first two larval skins are retained on the back under the shield4 ,also a very thin waxen pellicle remains on the resting place of the insect when it is raised4 ,the wax-glands open in the pitted fields1 and appear as clear brownish cells which are distinguished from the ordinary hypodermis cells by their greater size4 7,witlaczil4 ,compare also ,fig4 #ced47 ,illustration3 ,,fig4 #cee4--,wax disks of social bees3 a1 ,apis mellifica1 worker2 b1 do41 queen2 c1 ,melipona1 worker2 d1 ,bombus1 worker4--,from ,insect ,life1 ,u4 ,s4 ,dept4 ,agr4 ,the wax-glands in the honey-bee are scale-shaped organs situated on the under side of the four last abdominal segments 7,fig4 #cee74 ,these secrete the wax1 which appears as whitish scales1 and secretion is only possible when the bees have sufficient honey and pollen4 ,the wax is secreted by the hypodermal cells rather than by glands within the abdominal cavity2 the wax traverses the cuticular layer1 and accumulates on its outer surface 7,carlet74 ,according to ,fritz ,mller1 in the stingless bees 7,trigona7 which he observed1 the wax-glands are situated on the back of the abdomen1 but ,ihering states that in many species of ,trigona and ,melipona there are also slightly developed wax-organs on the ventral side4 ,it has been found that certain caterpillars secrete wax4 ,thus the cells of the ,tortrix of the fir 7,retinia resinella7 formed of resin are lined with wax1 as on dissolving away the resin with alcohol1 ,dr4 ,knaggs found a slight film of wax2 also a secretion of wax has been detected in the larva of a butterfly 7,parnassius apollo74 ,the bodies of certain saw-fly larv are covered with a white powdery secretion1 while the remarkable larva of a ,selandria is clothed with snow-white1 long1 flocculent1 waxy masses1 nearly concealing the body 7,fig4 #cef74 h4 8,honey-dew0 or wax-glands of ,aphids ,the so-called 8honey-dew0 of ,aphids which oozes from two wart-like tubercles or tubes situated near the end of the body1 is secreted by hypodermal unicellular glands which open into a modification of a pore-canal1 the tube itself being an outgrowth of the cuticula4 ,witlaczil states that both in the 8honey0 tubes and in the body beneath1 the sugary matter exists in cells of the connective tissue in the form of granules4 8,these large #8sugar-cells' in contact with the air undergo destruction1 while the sugar crystallizes into needles1 and thus each cell is transformed into a radiated crystalline mass40 8,a muscle extends from a horseshoe-shaped place 7a valve87 in the middle of the flat terminal plate of the honey tube1 through this and down through the abdomen to the ventral surface4 ,by this muscle the honey tube is at times erected1 and we then find1 as also when we lightly press the body of the insect1 lumps of crystallized sugar which have been expressed through the tips of the honey tubes40 7,zool4 ,anzeiger1 #ahhb1 p4 #bda47 ,illustration3 ,,fig4 #cef4--,wax-secreting larva of a saw-fly4 ,illustration3 ,,fig4 #ceg4--,lachnus strobi1 and its two 8honey0 warts4--,gissler del4 ,busgen1 after careful research1 denies that this is a sugar1 but claims as the result of chemical analysis1 that it is more like wax4 ,he observed that on reaching the air the drops issuing from the 8nectary0 or 8honey0 tube stiffened almost instantly into a wax-like mass1 which was easily crushed between the teeth1 and had no taste at all4 ,no sugar-like substance or urea could be detected4 ,he therefore concludes that the secretion in question should be regarded as a wax-like mass1 which agrees well with ,witlaczil's anatomical observations1 and confirms the statements of previous observers4 ,thus1 as early as #ahae1 ,kyber stated that the ,aphides expelled an excrementitious substance through the 8sap tubes40 ,burmeister states that the tubes give out a fluid which 8dries gumlike1 but1 so far as ,i have observed1 has no peculiar taste40 ,raumur1 and also ,kaltenbach1 state that the 8honey0 does not issue from the tubes1 but from the anus4 ,lastly1 ,forel emphatically states that 8the two dorsal tubes of ,aphides do not secrete a sweet fluid1 but a gluey wax1 which is not sought by the ants4 ,moreover the shield-lice and many leaf-lice have no such tubes1 but yet are often sought by ants4 ,the drops of sugar which the ants lick up are rather the excrement of the insects in question40 ,hence the opinion first stated by ,linn1 that a sweet fluid is secreted by ,aphides1 must be abandoned4 ,on the other hand1 ,busgen1 after careful observations1 finds that the use of the sticky1 waxen secretion is in reality a protective one1 as he observed that when a larval ,chrysopa rudely attacks the ,aphides1 they smear its face with the sticky wax1 causing at least a momentary interruption in its attacks4 ,he also observed that ,aphides when invaded by coccinellid larv set their tubes in motion and besmear their heads and front part of the body4 ,he thus seems to establish the fact that these tubes secrete a protective1 sticky fluid4 i4 ,dermal glands in general ,we have seen that certain of the hypodermal cells may be modified or specialized to form secretory unicellular glands4 ,such are those 7trichogens7 which secrete chitinous set1 hairs1 and spines1 certain set in some insects being hollow and containing a poison 7p4 #ahg72 others secrete wax1 certain ones in ,aphids 8honey-dew02 in some cases dermal glands may excrete protective1 sticky1 or otherwise offensive matters1 or may be depuratory1 or facilitate the process of moulting4 ,there are other minute1 unicellular1 or compound dermal glands whose function is unknown4 ,dermal glands may be segmentally or serially arranged4 ,thus ,verson has detected a series of one or two pairs of unicellular glands near the stigmata in each thoracic1 and the first eight abdominal segments of the silkworm 7,b4 mori74 ,in the earliest stages of growth of the caterpillar they give out oxalate of lime1 and in later stages uric acid4 ,they thus appear to act interchangeably with the urinary tubes1 as excretory organs4 ,they do not1 however1 carry their products directly outwards1 but leave them between the hypodermis and cuticula1 in order to facilitate the sloughing off of the latter in the process of moulting4 ,,literature ,,on ,,the ,,secretory ,,glands a4 ,general ,sirodot1 ,s4 ,recherches sur les scrtions chez les ,insectes4 7,ann4 sc4 nat41 #d ,sr41 ,zool41 #aheh1 x1 pp4 #ada-ahi1 #bea-cbh1 #ab ,pls47 ,gazagnaire1 ,g4 ,des glandes chez les ,insectes4 7,compt4 rend4 ,acad4 ,sc41 ,paris1 #ahhf1 cii1 pp4 #aeja-aejc2 ,annal4 ,soc4 ,ent4 ,france1 #ahhf1 ,bull41 pp4 #ajd-ajf47 ,leydig1 ,f4 ,beitrage zur ,anatomie und ,histiologie der ,insekten4 #ahhg4 ,hanow1 ,karl4 ,ueber ,kerfabsonderungen und ihre ,benutzung im eigenen ,haushalte4 7,programm des ,realprogymnasiums zu ,delitzsch fr das ,schuljahr #ahhi1 xc2 ,delitzsch1 #ahij1 pp4 #c-bb47 ,verson1 ,e4 ,di una serie di nuovi organi escretori scoperti nel filugello4 7,publ4 ,r4 ,stazione ,bacologica di ,padova1 v1 #ahij1 pp4 #cj4 #d ,pls47 ---- ,altre cellule glandulari di origine postlarvale4 7,ibid41 vii1 #ahib1 pp4 #af1 #a ,pl47 ---- ed ,e4 ,bisson4 ,cellule glandulari ipostigmatiche nel ,bombyx mori4 7,ibid41 vi1 #ahia47 ,borgert1 ,h4 ,die ,hautdrsen der ,tracheaten4 ,jena1 #ahia1 pp4 #hj4 ,batelli1 ,andrea4 ,di una particolarit nell' integumento dell' ,aphrophora spumaria4 7,monitore ,zool4 ,ital41 #ahia1 ,anno ii41 pp4 #cj-cb1 dermal gland in last segment47 ,koschewnikow1 ,g4 ,a4 ,on a new compound dermal gland found in the sting of the bee4 7,journal of the ,zoological ,section of the ,society of the ,friends of ,natural ,science4 ,moscow1 ii1 ,nos4 #a1 #b1 #ahib1 p4 #cf4 ,preliminary notice4 ,in ,russian47 ,willem1 ,v41 et ,h4 ,salbe4 ,le tube ventral et les glandes cphaliques des ,sminthurus4 7,ann4 ,soc4 ,ent4 ,belg41 #ahig1 xli1 pp4 #acj-acb47 ,henseval1 ,maurice4 ,les glandes essence der ,cossus ligniperda4 7,la ,cellule1 #ahig1 xii1 pp4 #ai-bf1 #bg1 #bi47 ---- ,recherches sur l'essence der ,cossus ligniperda4 7,la ,cellule1 #ahig1 xii1 pp4 #afi-aha1 #ahc47 b4 ,poison-glands ,macloskie1 ,george4 ,the poison-apparatus of the mosquito4 7,amer4 ,nat41 xxii1 #ahhh1 pp4 #hhd-hhh4 #a ,fig4 ,also in ,science1 #ahhg1 p4 #ajf47 ,beyer1 ,otto ,w4 ,der ,giftapparat von ,formica rufa1 ein reduziertes ,organ4 7,jena4 ,zeitschr4 f4 ,wissens1 xxv1 #ahia1 pp4 #bf-aab1 #b ,taf47 ,bordas1 ,l4 ,sur l'appareil venimeux des ,hymnoptres4 7,comtes rend41 cxviii1 #ahid1 pp4 #bif-bii and #hgc-hgd2 also ,zool4 ,anzeiger1 xvii ,jahrg41 #ahid1 pp4 #che-chg1 ,figs47 ---- ,appareil glandulaire des ,hymnoptres4 7,glandes salivaires2 ,tubes de ,malpighi et glandes venimeuses47 ,paris1 #ahid1 pp4 #cfb1 #aa ,pls4 ---- ,description anatomique et tude histologique des glandes venin des insectes ,hymnoptres4 ,paris1 #ahig1 pp4 #ec1 #b ,pls4 ,see ,forel 7p4 #ahf72 also the standard authors1 ,kolbe1 etc42 also ,locy 7,amer4 ,nat41 xviii1 #ahhd1 p4 #cee71 ,nagel 7p4 #cbd71 ,fenger4 c4 ,wax-glands ,brandt und ,ratzeburg4 ,medicinische ,zoologie1 ii1 #ahcj1 p4 #agi4 ,taf4 xxv1 ,fig4 #ah4 ,treviranus1 ,george ,r4 ,ueber die ,bereitung des ,wachses durch die ,bienen4 7,zeitschrift fr ,physiologie1 etc41 iii1 #ahcb1 pp4 #fb1 #bbe47 ,dufour1 ,l4 ,note anatomique sur la question de la production de la cire des abeilles4 7,comptes rend4 ,acad4 ,sc41 ,paris1 #ahdc1 xvii1 pp4 #hji-hac1 #abdh-abec2 ,revue ,zool4 #ahdc1 l',institut1 #ahdc1 xi47 ,dujardin1 ,f4 ,mmoire sur l'tude microscopique de la cire1 etc4 7,ann4 ,sc4 ,nat41 xii1 #ahdi1 pp4 #bej-bei47 ,tarzione-,tozzetti1 ,h4 ,studii sulle cocciniglie4 ,milano1 #ahfg1 #g ,pls4 ---- ,sur la cire qu'on peut obtenir de la cochenille du figuier 7,coccus caric74 7,comptes rend4 ,acad4 ,sc41 ,paris1 lxv1 #ahfg1 pp4 #bdf-bdg47 ,claus1 ,c4 ,ueber die wachsbereitenden ,hautdrsen der ,insekten4 7,sitzungsber4 ,gesells4 z4 ,befrd4 d4 ,gesammt4 ,naturw4 zu ,marburg1 ,june1 #ahfg1 ,no4 #h1 pp4 #fe-gb47 ,witlaczil1 ,e4 ,die ,anatomie der ,psylliden4 7,zeitschr4 wissens4 ,zool41 xlii1 #ahhe1 pp4 #ehb-ehf47 ---- ,zur ,morphologie und ,anatomie der ,cocciden4 7,zeitschr4 wissens4 ,zool41 xliii1 #ahhf1 pp4 #adi-agd1 #a ,taf47 ,ihering1 ,h4 von4 ,der ,stachel der ,meliponen4 7,ent4 ,nachrichten1 xii ,jahrg41 #ahhf1 p4 #ahe47 ,carlet1 ,g4 ,sur les organes scrteurs et la scrtion de la cire chez l',abeille4 7,comptes rendus1 cx1 pp4 #cfa-cfc1 #ahij47 ---- ,la cire et ses organes scrteurs4 7,le ,naturaliste1 #ahij1 pp4 #adi-aea1 #b ,figs47 ,also the works of ,siebold1 ,cheshire1 ,kolbe1 ,howard and ,marlatt 7,bull41 #c1 ,n4 ,s41 ,div4 ,ent4 ,u4 ,s4 ,dept4 ,agr41 #ahif1 p4 #dj71 ,knaggs1 ,berlese4 d4 ,wax-like glands of ,aphides ,huber et ,forel1 ,a4 tudes myrmcologiques1 #ahge4 ,witlaczil1 ,e4 ,zur ,anatomie der ,aphiden4 7,zool4 ,anzeiger1 v ,jahrg41 #ahhb1 pp4 #bci-bda2 ,arbeiten a4 d4 ,zool4 ,institut der ,univ4 ,wien41 iv1 #ahhb1 pp4 #cig-dda1 #c ,taf47 ,busgen1 ,m4 ,j4 ,der ,honigtau4 ,biol4 ,studien an ,pflanzen u4 ,pflanzenlause4 7,jena4 ,zeitschrift1 xxv1 #ahia1 pp4 #cci-dbh47 ,,defensive ,,or ,,repugnatorial ,,scent-,,glands ,while these eversible glands are not found in marine or aquatic arthropods such as ,crustacea or ,merostomata 7,limulus71 they are often present in the air-breathing forms1 especially insects4 ,in the winged insects they are of frequent occurrence1 existing under great variety of form1 varying greatly in position1 and appearing usually to be in immediate relation with their active volant habits4 ,their presence is in direct adaptation to the needs and habits of their possessors1 and being repellent1 warning1 or defensive structures1 the odors they secrete being often exceedingly nauseous1 they appear to have been called into existence in direct response to their biological environment4 ,the fact that these singular organs do not exist in marine or aquatic ,crustacea suggests that the air-breathing1 arial1 or volant insects by these eversible glands1 usually in the form of simple evaginable hypodermic pouches1 are enabled to protect themselves by emitting an infinitesimal amount of an offensively odorous fluid or ether-like spray which charges the air throughout an extent of territory which may be practically illimitable to the senses of their enemies4 ,the principle is the same as in the mephitic sulphuretted oil ejected by the skunks1 the slight quantity these creatures give out readily mixing with and charging the atmosphere within a radius of many miles of what we may call the centre of distribution4 ,as is now well known1 the very delicate1 attenuated highly volatile odors exhaled are perceived by insects with extreme ease and rapidity1 the degree of sensitiveness to such scents being enormously greater than in vertebrates1 their organs of sense being developed in a corresponding degree4 ,professors ,fischer and ,penzoldt1 of ,erlangen1 have recently established the fact that the sense of smell is by far the most delicate of the senses4 ,they find that the olfactory nerve is able to detect the presence of #ab1gfj1jjj1jjj of a grain of mercaptan4#eh ,the smallest particle of matter that can be detected by the eye is sodium1 when observed by the spectroscope1 and this particle is #bej times coarser than the particle of mercaptan which can be detected by the human nose4 ,in those ,arachnida which are provided with poison-glands1 these scent-glands are absent1 but in certain ,acarina and ,linguatulid1 which have no poison-glands1 there are various oil-glands1 stigmatic glands1 as well as scent-glands1 and in seizing a ,thelyphonus with the forceps we have observed it to send out from each side of the body a jet of offensive spray4 ,we not infrequently find in myriopods 7,polydesmid1 ,julid1 and ,glomeris7 repugnatorial or the so-called cyanogenic glands1 which are either paired1 opening on the sides of the body1 or form a single row along the median line of the under side of the body4 ,leidy describes and figures the spherical glands of ,julus marginatus1 of which there are #ej pairs4 ,these glands have been regarded as modified nephridia1 but are more probably coxal glands1 and the homologues of the parapodial glands of annelid worms4 ,illustration3 ,,fig4 #ceh4--,sternite of ,machilis maritima1 with the pair of coxal sacs 7cb7 on the right side everted2 hs1 coxal appendages2 m1 retractor muscles4--,after ,oudemans1 from ,lang4 ,eversible coxal glands4--,true coxal glands occur in ,scolopendrella immaculata on the #b;d to #aath segment1 on the inner side of the base of the legs 7,fig4 #ae1 c4g474 ,homologous glands also occur in the same position in ,campodea staphylinus 7also in ,c4 cookei and ,c4 mexicana7 on the #ast to #hth abdominal segments1 and ,oudemans has described a pair of eversible sacs on each side of segments one to seven of ,machilis4 ,these eversible sacs in the synapterous insects are evidently modified coxal glands1 and are probably repugnatorial as well as respiratory in function4 ,the apparatus consists of an eversible gland1 composed of hypodermic cells1 usually retracted by a slender muscle and with an efferent passage1 but the glands vary greatly in shape and structure in different insects4 ,in some cases these ftid glands appear not to be the homologues of the coxal glands1 but simply dermal glands4 ,these repugnatorial glands are of not infrequent occurrence in the lower or more generalized winged insects1 and in situation and appearance are evidently the homologues of the coxal glands of the ,symphyla and ,synaptera4 ,ftid glands of ,orthoptera4--,in the ear-wigs 7,forficula and ,chelidura7 ,meinert has detected a pair of what he calls ftid glands at the posterior margin of the dorsal plates of the #b;d and #c;d abdominal segments4 ,vosseler also describes the same glands as consisting of a retort-shaped sac1 in whose walls are numerous small hypodermal cells and large single glandular cells provided with an efferent passage1 the fluid being forced out by the pressure of the dermal muscles1 one acting specially to retract the gland4 ,the creature can squirt to a distance of #e and even #aj cm4 7#d inches7 a yellowish-brown liquid or emulsion with the odor of a mixture of carbolic acid and creosote4 ,the large eversible dorsal glands of the ,blattid1 since they contain numerous hairs1 which1 when everted1 are fan-like or like tufts1 serve1 as in the spraying or scent apparatus1 to disseminate the odor1 and might be classified with the alluring unicellular scent-glands or duftapparat of other insects1 as they are by some authors2 but as the glands are large and compound they may prove to be the homologues of the coxal glands rather than of the dermal glands4 ,evaginable organs in the ,blattids were first observed by ,gerstcker in both sexes of ,corydia2 they are yellowish white1 covered with hairs1 and are thrust out from between the dorsal and ventral plates of the #ast and #b;d abdominal segments4 ,illustration3 ,fig4 #cei4--,under side of end of ,aphlebia1 showing the two eversible sacs2 ,v-,x1 five last abdominal segments2 ,a1 portion showing the hairs2 ,b1 showing origin of a hair in its follicle4--,after ,krauss4 ,in the cockroach 7,p4 orientalis7 ,minchin detected two pouch-like invaginations of the cuticle1 lying close on each side of the middle line of the body between the #eth and #fth tergites of the abdomen4 ,they are lined by a continuation of the cuticle1 which forms1 within the pouches1 numerous stiff1 branched1 finely pointed bristles1 beneath which are a number of glandular epithelial cells4 ,in the male nymph of ,p4 decorata he also found beside these glandular pouches 8an additional gland1 opening by a tubular duct under the intersegmental membrane between the #eth and #fth terga above the glandular pouch of each side1 and extending forward into the body cavity4 ,the gland and its duct are proliferations of the hypodermis1 and there is no invagination of the cuticle40 ,these eversible glands are most complicated in ,phyllodromia germanica4 ,while it is absent in the female1 in the male it is relatively of enormous size1 extending over the #fth and #gth somites1 as well as projecting far into the body cavity 7,minchin74 ,haase states that these glands become everted by blood-pressure and give out the well-known disagreeable smell of these insects4 ,he states that in the male of ,p4 germanica the dorsal glands in the #fth and #gth abdominal segments are without hairs and produce an oily secretion2 they function as odoriferous organs in sexual union4 ,in the male of another ,blattid 7,aphlebia bivittata7 of the ,canary ,islands1 ,krauss has detected two yellowish dorsal sacs #a4e mm4 in length1 opening out on the #gth abdominal segment1 and filled full of long yellowish hairs1 the ends directed towards the opening1 where they form a thick tuft4 ,these eversible glands lined with hairs appear to be closely similar to the long slender eversible hairy appendages or scent organs of certain ,arctian and ,syntomid moths4 7,fig4 #cei47 ,illustration3 ,,fig4 #cfj4--;,external flaps 7gl7 of glands of ,platyzosteria4 ,we have found the external median wart with lateral lids or flaps in between the #eth and #fth tergites of ,platyzosteria ingens ,scudder1 a large wingless ,blattid living under the leaf scars of the cocoanut tree in ,southern ,florida 7,fig4 #cfj71 but were unable to detect them in ,polyzosteria or in the common ,blabera of ,cuba1 or in another genus from ,cordova1 ,mexico4 ,in another group of ,orthoptera1 the ,phasmid1 occur a pair of dorsal prothoracic glands1 each opening by a pore and present in both sexes4 ,in the walking-stick1 ,anisomorpha buprestoides1 and 1 these openings are situated on each side of the prothorax at its upper anterior extremity1 situated at the bottom of a large deep pit4 ,when seized it discharged a 8milky white fluid from the pores of the thorax1 diffusing a strong odor1 in a great measure like that of the common ,gnaphalium or life everlasting0 7,peale in ,say's ,american ,entomology1 i1 p4 #hd74 ,boll states that the females when captured 8spurt from the prothorax1 somewhat after the manner of bombardier beetles1 a strong vapor1 which slightly burnt the skin2 when the females were seized by the males a thick fluid oozed from the same spot40 ,scudder describes these glands in another ,phasmid 7,autolyca pallidicornis7 as two straight1 flattened1 ribbon-like bodies1 with thick walls1 broadly rounded at the end1 lying side by side and extending to the hinder end of the mesothorax4 ,in ,anisomorpha buprestoides the glands are of the same size and shape 7,scudder74 ,in ,diapheromera femorata the repugnatorial foramina are very minute1 and the apparatus within consists of a pair of small obovate or subfusiform sacs1 one on each side of the prothorax1 about #a mm4 in length1 with a short and very slender duct opening externally at the bottom of the pit 7,scudder74 ,in the ,mantid these seem to be genuine coxal glands1 as there is a pair situated between the cox of the first pair of legs4 ,an evaginable organ like a wart1 with a glandular appearance1 occurs on the hind femora of the ,acrydiid in a furrow on the under side1 into which the tibia fits1 about one-fourth from the base 7,psyche1 iii1 p4 #cb74 ,in the male cricket1 the anal odoriferous glands are small lobes opening into a reservoir on each side of the rectum 7,dufour74 ,homologous glands also occur in the ,coleoptera 7,fig4 #cjb1 l and #cag1 s74 ,illustration3 ,,fig4 #cfa4--;,glands 7g7 of ,lachnus2 h1 8honey0 wart4--,gissler del4 ,most ,hemiptera or bugs send out a ftid or nauseous odor due to a fluid secreted by a single or double yellow or red pear-shaped gland1 situated in the middle of the mesothoracic segment1 and opening between the hinder or third pair of cox4 ,in ,belostoma ,leidy describes these glands as consisting of two rather long ccal tubes situated in the metathorax1 beneath the other viscera1 extending backwards into the abdomen1 and opening between the cox of the third pair of legs4 ,locy states that the smell arising from these glands is pleasant1 resembling that of well ripened pears or bananas4 ,other bugs1 moreover1 emit an agreeable odor1 that of ,syromastes resembling that of a fine bergamot pear4 7,siebold47 ,the fluid given out by the ,european fire-bug 7,pyrrhocoris apterus7 has a sweetish smell1 like ether4 ,in the nymph there are three pairs of dorsal glands1 on abdominal segments #b-e1 which are atrophied in the mature insect4 ,in the bed-bug1 the nymph has three odoriferous glands each with paired openings in the three basal abdominal segments respectively1 and situated on the median dorsal line1 being arranged transversely at the edge of the tergites2 but after the last moult these are aborted1 and replaced by the sternal metathoracic glands 7,knckel74 ,gissler has detected a pair of glands in ,lachnus strobi 7,fig4 #cfa74 ,anal glands of beetles4--,certain beetles are endowed with eversible repugnatorial glands4 ,eleodes gigantea and ,e4 dentipes of both sexes are said by ,gissler to possess these glands4 ,when teased 8they stand on their anterior and middle legs1 holding the abdomen high up and spurting the contents of the glands right and left40 ,the glands 7,fig4 #cff1 #a7 are two reddish brown1 somewhat bilobed sacs1 and extend from the base of the last up to the middle of the #b;d abdominal segment1 with an average length of #f4e mm4 ,the liquid stains the human skin1 has an acid reaction1 with a peculiar1 8intensely penetrant odor1 causing the eye to lachrymate4 ,it is soluble in water1 alcohol1 and ether4 ,boiled with concentrated sulphuric acid and alcohol an ethereal aromatic vapor is produced1 indicating the presence of one or more organic acids1 though neither formic or acetic acid could be detected40 ,williston has observed the same habits in seven other species of ,eleodes1 all ejecting a pungent vile-smelling liquid1 one species 7,e4 longicollis7 ejecting a stream of fluid from the anal gland1 backwards sometimes to the distance of #aj cm4 or more1 and he regards these beetles as 8the veritable skunks of their order40 ,leidy briefly describes the odoriferous glands of ,upis pennsylvanica4 ,the anal glands consist1 according to ,meckel and also ,dufour1 of two long1 simple1 flexuous cca with reservoirs having two short excretory ducts situated near the anus 7,siebold74 ,glands like those of ,eleodes found in ,blaps mortisaga are described in detail by ,gilson 7,fig4 #cff1 #b74 ,they form two pouches or cuticular invaginations situated in the end of the abdomen on the sides of the end of the intestine and unite on the median line underneath the genital organs1 forming a very short tube with a chitinous wall1 continuous with the cuticle of the last abdominal segment4 ,into each pouch open a large number of fine slender lobules varying in shape1 giving a villous aspect to the surface4 ,these lobules are composed of as many as fifty unicellular glands1 each of which is composed of four parts3 7#a7 ,a radiated vesicle1 7#b7 a central sac1 giving rise 7#c7 to a fine excretory tube1 and 7#d7 a sheath near the origin of the excretory tube4 ,these are all modifications of the cytoplasm of the cell with its reticulum2 the nucleus with its chromosomes is also present1 but situated on one side of the central sac4 ,the fine excretory tubules form a bundle passing down into the mouth of each lobule4 ,similar glands1 though usually smaller1 which have not been carefully examined1 occur in ,carabus 7,fig4 #cjj1 #c7 and ,cychrus1 which eject from the vent a disagreeable fluid containing butyric acid 7,pelouse74 ,the bombardier beetle ,brachinus1 with its anal glands1 ejects a jet of bluish vapor accompanied with a considerable explosion1 which colors the human skin rust red2 it is caustic1 smells like nitrous acid1 and turns blue paper red4 ,westwood states that individuals of a large ,south ,american ,brachinus on being seized 8immediately began to play off their artillery1 burning and staining the flesh to such a degree that only a few specimens could be captured with the naked hand1 leaving a mark which remained for a considerable time40 ,the fluid ejected by another species1 in ,tripoli1 blackened the fingers of the collector4 8,it is neither alkaline nor acid1 and it is soluble in water and in alcohol40 7,kirby and ,spence1 iv1 p4 #adi47 ,species of other genera 7,agonum1 ,pheropsophus1 ,galerita1 ,helluo1 ,paussus1 ,ozna7 are also bombardiers1 though less decidedly so than ,brachinus4 ,a ,paussid beetle 7,cerapterus7 ejects explosively a fluid containing free iodine 7,loman71 while ,staphylinus1 ,stenus1 ,ocypus olens1 ,lacon1 etc41 have similar anal ftid glands1 the liquid being more or less corrosive4 ,the secretion of ,mormolyce phyllodes is so corrosive that it is said to paralyze the fingers for #bd hours after4 7,cunot47 ,illustration3 ,,fig4 #cfb4--,median section through the femoro-tibial joint of leg of ,coccinella1 showing at o the opening through which the blood oozes out2 f1 femur2 t1 tibia2 e1 extensor muscle of the tibia3 s1 sinew of the same2 at ch1 chitinized2 h1 articular membrane2 v1 tibial process4--,after ,lutz4 ,the two pairs of remarkably large1 soft1 eversible1 forked1 orange-yellow glands of the ,european genus ,malachius1 are thrust out from the side of the #ast and the #c;d thoracic segments4 ,they are everted by blood-pressure1 and retracted by muscles4 ,the larva of ,hydrophilus piceus ejects by the anus a black1 ftid fluid4 ,claus has shown that the larva of ,lina populi and other ,chrysomelid possess numerous minute1 eversible glands in each of the warts on the upper surface of the body1 each gland containing a whitish1 repellent fluid smelling like the oil of bitter almonds and containing salicylic acid derived from its food-plant1 which issues as pearl-like drops4 ,candze thinks the fluid may contain prussic acid4 ,the fluid is secreted by a variable number of glandular cells1 each provided with an efferent duct4 ,the larv of saw-flies1 notably ,cimbex americana1 also eject droplets of a clear fluid from non-evaginable glands situated near each stigma 7,chlolodkovsky74 ,the blood as a repellent fluid4--,in this connection it may be mentioned that though there are no special glands present1 many beetles emit drops of blood from the femoro-tibial joints of their legs as a means of defence4 ,such are the oil-beetles 7,melo71 ,cantharis1 ,lytta4 ,the cantharadine secreted by these beetles1 according to ,beauregard1 is an efficient means of defence1 as birds1 reptiles1 and carnivorous insects will not usually attack them4 ,this substance is formed in the blood and also in the genital organs1 and is so extremely caustic that scavenger insects which feed upon their dead bodies will leave untouched the parts containing cantharadine1 and if ,may-beetles or mole-crickets are washed with the blood of ,melo or with cantharidate of potassa1 it will for several days render them safe from the attacks of the carabids which usually prey upon them4 ,the eggs even after deposition are strongly vesicant1 and are thus free from the attacks of egg-eating insects 7,cunot74 ,the ,coccinellid are also protected by a yellow1 mucilaginous1 disagreeable fluid oozing out of the ends of the femora2 in our common1 two-spotted lady-bird 7,c4 bipunctata7 the yellow fluid is disagreeable1 smelling like opium4 ,lutz has found that the blood in ,coccinellid passes out through a minute opening situated at the end of each femur 7,fig4 #cfb74 ,the blood is very repellent to insectivorous animals4 ,the ,dyticid eject from the anus a colorless1 disagreeable fluid1 while these beetles1 and especially the ,gyrinid1 when captured send out a milky fluid which appears to issue from the joints of the body4 ,the ,silphid throw out both from the mouth and vent a ftid liquid with an ammoniacal odor4 ,they possess but a single anal gland1 the reservoir opening on one side of the rectum 7,dufour74 ,other malodorous insects have not yet been investigated2 such are the very persistent odors of lace-winged flies 7,chrysopa74 ,more agreeable secretions1 but probably formed by similar glands1 is the odor of rose or hyacinth given out by ,cicindel1 or the rose fragrance exhaled by the ,european ,aromia moschata4 ,eversible glands of caddis-worms and caterpillars4--,gilson1 while investigating the segmentally disposed thoracic glands of larval ,trichoptera1 has found in the larva of ,limnophilus flavicornis that the sternal prothoracic tubercle gives exit to an underlying tubular gland4 ,in ,phryganea grandis each thoracic sternum affords an exit to an eversible gland4 ,many caterpillars1 as our subjoined list will show1 are very well protected by eversible repugnatorial glands situated either in the under or upper side of the body4 ,since the time of ,de ,geer 7#agej7 the fork-tailed larva of ,cerura has been known to throw out a secretion1 which was described by ,bonnet in #agee as a true acid1 sharp1 sour1 and biting4 ,this spraying apparatus in ,cerura 7,harpyia7 vinula has been well described by ,klemensiewicz 7,fig4 #cff1 #d71 though ,rengger in #ahag noticed the general form of the secretory sac1 and that it opens out in two muscular eversible tubes1 out of which the secretion is ejected4 ,the fork-tailed larva of ,macrurocampa marthesia1 which is much like that of ,cerura1 when teased sends out a jet of spray to the distance of nearly an inch from each side of the neck4 ,while examining the very gayly-colored and heavily-spined caterpillars of ,schizura concinna we observed that when a fully-grown one was roughly seized with the forceps or fingers it sent out a shower of spray from each side of the prothoracic segment1 exactly like that of ,cerura and ,macrurocampa4 ,in the ,european ,cerura vinula the apparatus consists of a single sac1 which opens by a narrow transverse slit on the under side of the neck1 out of which is rapidly everted four lateral tubes1 two on each side 7,fig4 #cff1 #d1 t71 which are withdrawn within the opening by the contraction of several fine muscles4 ,the apparatus in the ,american ,c4 multiscripta is as in the ,european ,c4 vinula4 ,in a living specimen the large secretory sac was seen to be of the same size and shape as in ,macrurocampa1 and of the color of raw silk4 ,the sac when distended extends back to a little behind the middle pair of legs1 and is nearly two-thirds as wide as the body4 ,the caterpillar sent out the fluid when handled1 but we could not make it spray4 ,in the larva of ,macrurocampa marthesia the cervical or secretory gland 7,fig4 #cff1 #e7 is situated in the #ast and #b;d thoracic segments1 extending to the hinder edge of the latter and lying between the nervous cord and the sophagus and proventriculus1 and when empty the bulk of it lies a little to one side of the median line of the body4 ,it is partly held in place by small trache1 one quite large branch being sent to it from near the prothoracic spiracle4 ,the short1 large duct1 leading from it to the transverse opening in the membrane between the head and prothoracic segment1 is a little narrower than this opening1 and is kept distended by tnidia1 or a series of short1 spiral threads which are pale1 not honey-yellowish1 in color4 ,this duct lies on one side of the prothoracic ganglion1 resting just under the commissures passing up to the brain2 it is also situated between the two silk ducts4 ,the very distensible sac 7,fig4 #cff1 #e7 is rendered elastic by a curious arrangement of the cuticle1 the tnidia of the duct itself being represented by very thickly-scattered1 irregular1 separate1 sinuous1 chitinous ridges1 which stand up from the cuticular lining of the wall of the sac 7,fig4 #cff1 #f74 ,the secretory cells of the walls of this sac in ,cerura vinula are said by ,klemensiewicz to be large hexagonal cells1 resembling those of silk-glands1 having like them large branched nuclei4 ,the fluid thrown out is said by ,poulton to be formic acid2 it causes violent effervescence when allowed to fall upon sodium-bicarbonate1 and colors blue litmus paper red4 ,it also appears from the researches of ,latter that these creatures in the imago state secrete free potassium hydroxid1 a substance for the first time known to exist in the animal kingdom4 ,in the caterpillar of ,astyanax archippus 7,limenitis disippus7 a dark1 bladder-like sac is everted1 but the lateral tubes appear to be wanting1 and no spray is sent out2 it occurs in the larv of many ,nymphalid and other butterflies and moths4 ,these glands are functionally active in ,perophora1 but obsolete 7at least the external openings7 in ,lacosoma4 ,the osmeterium in ,papilio larv4--,the caterpillars of the swallowtailed butterflies 7,papilio1 ,doritis1 and ,thais71 as is well known1 when irritated thrust out from a transverse slit on the upper part of the prothoracic segment a large orange-yellow ,v-shaped fleshy tubular process 7the osmeterium71 from which is diffused a more or less melonlike but disagreeable1 in some cases insufferable1 odor2 the secretion is acid and reddens litmus paper4 ,the mechanism has been described and figured by ,klemensiewicz4 ,when at rest1 or retracted1 the osmeterium lies in the upper part of the body in the three thoracic segments1 and is crossed obliquely by several muscular bundles attached to the walls of the body1 and by the action of these muscles the evagination of the osmeterium is strongly promoted4 ,after eversion the tubes are slowly retracted by two slender muscles inserted at the end of each fork or tube1 and arising from the sides of the #c;d segment behind the head1 crossing each other in the median line 7,fig4 #cff1 #g r4m474 ,the secretion is formed by an oval mass of glandular cells at the base of the forks2 in the glandular mass is a furrow-like depression about which the secretory cells are grouped4 ,the secretion collects in very fine drops on the side of each furrow opposite the glandular cells4 ,according to ,c4 ,d4 ,ash the larva of an ,australian ,notodontid 7,danima banksii ,lewin7 protrudes from the under side of the prothoracic segment a ,y-shaped red organ like that of ,papilio2 no fluid or odor is given out4 ,dorsal and lateral eversible metameric sacs in other larv4--,the showy caterpillars of ,orgyia and its allies have a conspicuous coral-red tubercle on the back of the #fth and also the #gth abdominal segment1 which on irritation are elongated1 the end of the tubercles being eversible4 ,when at rest the summit is crateriform1 but on eversion the end becomes rounded and conical4 ,these osmeteria are everted by blood pressure1 and retracted by a muscle4 ,fig4 #cff1 #i1 represents a section of an osmeterium of ,orgyia leucostigma when retracted by the muscle 7m72 at the bottom of the crater are the secreting or glandular cells 7gc71 being modified hypodermal cells4 ,these doubtless serve as terrifying organs to ichneumons and other insect enemies1 and though we have been unable to detect any odor emanating from the tubercles1 yet possibly they give out a scent perceived by and disagreeable to their insect assailants4 ,illustration3 ,,fig4 #cfc4--;,freshly hatched larva of ,hyperchiria io1 with its two pairs of eversible glands 7g74 ,illustration3 ,,fig4 #cfd4--,young larva of ,megalopyge crispata1 enlarged1 showing the seven pairs of lateral processes 7lp73 sp1 spiracle2 abl1 abl#f1 six pairs of abdominal legs besides the anal pair4 ,in the ,hemileucid there is a pair of lateral osmeteria1 on the #ast and on the #gth abdominal segments1 which however1 are not highly colored 7,figs4 #cfc1 #cff1 #aj74 ,in ,megalopyge 7,lagoa1 ,fig4 #cfd7 there is a lateral row of singular pale permanently everted processes which appear to be the homologues of the osmeteria of larv of other lepidopterous families4 ,as these are repeated on seven segments1 their metameric arrangement is obvious4 ,the relation of these curious glands to the viscera is seen in ,fig4 #big1 lgp1 and their minute structure in ,fig4 #cfe4 ,at ,a1 the lumen 7l7 is a deep narrow cavity1 with the secretion 7secr471 collected at the mouth of the cavity1 composed of a thin1 mucus-like1 coagulated fluid1 containing granules of varying degrees of fineness1 which take the stain readily4 ,outside of these are collected fine nuclei 7bc71 stained dark1 and enveloped in a slight1 transparent1 pale1 protoplasmic envelope1 which may be blood corpuscles4 ,the glandular cells themselves are simply modified hypodermal cells1 as seen at ,c4 ,in some of the nuclei1 indistinct nucleoli are seen1 and deeply stained granules1 especially around the periphery of the nuclei4 ,at ,b is represented a section on one side of the middle1 but still showing the spacious lumen4 ,in the section represented by ,c1 the knife passed through the process still nearer the outer edge1 and near the base2 at ,c#a1 three of the glandular cells1 with their large1 deeply stained nuclei1 are drawn4 ,a transverse section at ,d shows the large lumen or cavity 7l74 ,as to the function and homologies of these structures1 it is difficult to decide4 ,we have never noticed that they give off any odor1 though they may prove to be repugnatorial2 they are not visible in the fully grown1 living insect1 being concealed by the long1 dense hairs clothing the body2 they are not spraying organs1 as they are imperforate at the end1 not ending as the lateral1 eversible glands of ,hyperchiria io1 etc41 in a crateriform orifice4 ,they may be permanently everted glands1 or osmeteria1 which have1 by disuse1 lost their power of retraction and their crateriform opening1 as well as the power of secreting a malodorous fluid4 ,illustration3 ,,fig4 #cfe4--,section of lateral processes of larva of ,megalopyge4 ,in certain of the butterflies1 the ,heliconid 7,colnis1 ,heliconius1 ,euides1 and ,dione71 there is thrust from the end of the abdomen a pair of large1 irregular1 rounded1 eversible glands1 which give out a disagreeable odor1 and are consequently repellent1 and which seem to be the homologues of the odoriferous glands of other butterflies4 ,the large1 soft1 rounded1 eversible glands1 looking like puff-balls or a rounded pudding 7,fig4 #cff1 #ab71 are everted1 when the butterflies are roughly seized1 from the dorsal side of the penultimate segment of the abdomen4 ,the males possess two smaller tubercles on the inside of the anal claspers or lobes4 ,mller also detected1 in the females of various species of the ,heliconid enumerated above1 a pair of club-shaped processes like the balancers of flies1 which are thrust out on each side of and under the odoriferous puff-balls of the hinder edge of the penultimate segment 7,fig4 #cff1 #ac74 ,the club or head is armed with hairs or bristles1 which1 in ,heliconius1 are like the scales of a butterfly4 ,illustration3 ,,fig4 #cff4--,scent-glands of insects3 #a4 ,anal eversible glands of ,eleodes4--,after ,gissler4 #b4 ,anal eversible glands of ,blaps4--,after ,gilson4 #c4 ,anal glands 7agl7 of ,carabus hortensis3 rs1 reservoir2 d1 excretory duct2 i1 intestine2 r1 rectum4--,after ,kolbe4 #d4 ,prothoracic spraying apparatus of ,cerura vinula3 gl1 the gland2 d1 its duct1 with tnidia2 t1 the spraying tubes2 m1 muscles2 rm1 retractor muscles4--,after ,klemensiewicz4 #e4 ,the thoracic glandular sac of ,macrurocampa marthesia3 gl1 the glandular sac2 d1 its duct2 e1 peritracheal epithelium2 t1 the spiral threads or tnidia4 #f4 ,irregular separate masses of chitinous ridges on the cuticular lining of the wall of the sacs of ,macrurocampa marthesia4 #g4 ,osmeterium 7os7 of the larva of ,papilio machaon at rest3 rm1 the retractor muscles at the ends2 m1 the numerous oblique muscles2 dm1 dorsal longitudinal muscles2 t1 trachea2 oe1 sophagus2 gang1 brain2 #a1 head2 #b1 #c1 #d4 thoracic segments4 #h4 ,osmeterium 7os7 of one side1 enlarged3 g1 glandular portion at the base2 d1 depressions in the cuticula of the glandular portion2 t1 trachea4--,this and ,fig4 #g after ,klemensiewicz4 #i4 ,eversible dorsal glands 7ev4 gl7 of larva of ,orgyia leucostigma in ,stage ,,ii3 gc1 glandular cells at bottom of the crater-like depression2 m1 retractor muscle2 p1 poison gland-cells of the root of the seta 7s72 c1 cuticula2 hyp1 hypodermis2 ,a1 portion of the cuticle and hypodermis enlarged4 #aj4 ,lateral eversible gland of ,hyperchiria io1 ,stage ,,ii3 rm1 retractor muscle2 oen1 nocytes4 #aa4 ,the same as ,fig4 #aj1 but representing a section through one side of the eversible gland4 #ab4 ,a1 end of body of ,colnis julia2 ev1 eversible anal gland2 oa1 odoriferous appendages2 ,b1 the same in ,heliconius apseudes1 side view2 ,c1 odoriferous appendages of ,colnis dido in fresh condition2 ,d1 tested with alcohol and benzine4 #ac4 ,odoriferous appendages of ,heliconius eucrate1 head cleansed4--,figs4 #ab1 #ac1 after ,f4 ,mller4 #ad4 ,odoriferous glands 7ogl7 in the pupa of ,vanessa io3 r1 rectum2 h1 the folds of hypodermis which forms the terminal papilla of the abdomen2 ov1 oviduct4--,after ,jackson4 ,in the caterpillars of certain blue butterflies 7,lycnid7 is an internal osmeterium1 being a very minute sac which is everted from a transverse slit on the top of the #gth abdominal segment4 ,its function is quite the opposite of those of the caterpillars of other families1 since the sac exudes a sweet fluid very attractive to ants1 which may be diffused more widely by the delicate spinulose bristles crowning the summit4 ,w4 ,h4 ,edwards states that in several species of ,lycna1 besides that on the #gth abdominal segment1 there is on the #hth segment a pair of minute dorsal evaginable tubercles4 ,a pair of small ramose odoriferous glands are said by ,siebold1 who regarded them as alluring glands1 to occur in ,argynnis1 ,melita1 and ,zygna1 to be situated near the orifice of the oviduct1 and ,scudder has detected them near the anus of the female pupa of ,danais archippus4 ,the appearance of the odoriferous glands in the pupa of ,vanessa io is well shown by ,jackson 7,fig4 #cff1 #ad74 ,they develop as two tubular ingrowths of the hypodermis1 perfectly distinct one from the other1 each having its own separate aperture to the exterior4 ,in ,fig4 #cff1 #ad the condition of parts is nearly as in the imago1 the glands being situated below the rectum and opening of the oviduct4 ,in both sexes of another ,brazilian butterfly 7,didonis biblis7 on the median line of the abdomen between the #dth and #eth segments are two roundish vesicles covered with short gray hairs1 which emit a disagreeable smell4 ,it is possible that the dark-green fluid in ,parnassius1 secreted by an evaginable gland1 and which is moulded into shape by the scimetar-shaped peraplast 7,scudder71 is formed by the homologues of the anal glands of other butterflies4 ,distribution of repugnatorial or alluring scent-glands in insects#ei ,a4 ,,larval ,,insects a4 ,each thoracic segment2 sternal4 ,phryganea grandis4 b4 ,prothoracic1 sternal1 discharging a lateral jet of spray2 with a single large internal sack4 ,,lepidoptera ,family ,,tineid ,hyponomeuta evonymella4 ,family ,,noctuid ,bryophila1 ,cucullia formosa1 ,c4 scrophulari1 ,habrostola1 ,cleophana linari1 ,catocala 7sp471 ,aporia cratg1 ,aplecta nebulosa1 ,leucania staminea1 ,l4 hispanica1 ,l4 nonagrioides1 ,plusia gamma4 ,family ,,notodontid ,pheosia rimosa1 ,schizura concinna1 ,danima ,banksii 7,australia71 ,macrurocampa marthesia1 ,heterocampa pulverea1 ,cerura vinula1 ,c4 furcula1 ,c4 borealis1 ,c4 multiscripta4 ,family ,,nymphalid ,probably all the species4 c4 ,prothoracic1 dorsal2 sending out a ,v-shaped odoriferous organ 7osmeterium74 ,family ,,papilionid ,all the species as a rule4 d4 ,thoracic sternal1 evaginable glands4 ,family ,,perophorid ,lacosoma chirodota1 ,perophora melsheimerii4 ,family ,,nolid ,in three1 and probably in all the species of ,nola4 e4 ,lateral1 abdominal1 non-eversible glands1 one near each spiracle1 emitting a clear fluid4 ,family ,,tenthredinid ,crsus septentrionalis1 ,c4 varus1 ,cimbex americana1 ,c4 betul1 ,trichiosoma4 f4 ,lateral1 abdominal1 partly eversible glands emitting neither moisture nor odor1 but flesh-colored4 ,family ,tineid ,phyllocnistis8 7eight pairs47 ,family ,,hemileucid ,hyperchiria io 7two pairs1 viz4 on #ast and #gth segments71 ,h4 sp4 7,mexico71 ,hemileuca yavapai1 pamina1 ,h4 maia1 ,h4 artemis1 ,pseudohazis eglanterina4 g4 ,lateral1 abdominal1 permanently everted1 metameric glands1 not known to secrete a fluid1 nor to be odoriferous4 ,family ,,megalopygid ,megalopyge crispata4 h4 ,medio-dorsal1 partly eversible glands1 emitting a spray of liquid but no odor7871 and colored coral-red or orange-yellow 7,p4 auriflua71 but usually in the ,european species yellowish4 ,family ,,liparid ,all the species except those of ,demas4 i4 ,a single1 median1 abdominal1 dorsal gland1 emitting a fluid attractive to ants1 on #gth segment2 with a pair of minute1 index glands on the #hth segment4 ,family ,,lyc,,nid ,all the species4 j4 ,protrusile organs near the anus4 ,myrmeleon larva 7,hagen8 ,dimmock74 ,b4 ,,nymph ,,of ,,heterometabolous ,,insects a4 ,paired1 dorsal glands1 on abdominal segments #a1 #b1 and #c4 ,cimex lectularius 7,knckel74 b4 ,the same on abdominal segment #e4 ,lachnus strobi4 ,c4 ,,pupa ,,of ,,certain ,,bombyces ,at anterior end of certain pup1 internal glands to moisten threads of the cocoon for exit of moth4 ,d4 ,,adult ,,insects a4 ,occurring on the prothorax only2 strongly repugnatorial1 best developed in 4 ,anisomorpha buprestoides1 ,autolyca pallidicornis1 ,phasma putidum1 ,phyllium 7sp471 ,heteropteryx 7sp471 ,diapheromera femoratum 7probably in all the species of the family71 ,mantis carolina4 b4 ,occurring on the pro- and mesothorax1 and on the middle of the abdomen1 orange-yellow1 fleshy tubercles or evaginations4 ,malachius bipustulatus1 ,anthocomus equestris1 ,evus thoracicus4 c4 ,segmental1 eversible glands1 homologues of the coxal glands of other ,arthropods1 occurring on all1 or nearly all1 the abdominal segments4 ,scolopendrella immaculata 7coxal glands on #c;d to #aath pair of legs71 ,campodea staphylinus 7a pair of coxal glands on #ast to #hth abdominal segments71 ,machilis maritima 7eversible1 coxal glands on segments #a-g74 d4 ,occurring in the abdomen4 d#a4 ,in the two first abdominal segments4 ,corydia carunculigera and 4 d#b4 ,alluring 787 organs situated on the dorsal side of the abdomen1 in the #fth1 or #fth and #gth1 abdominal segment4 ,periplaneta americana 1 ,p4 orientalis 7nymph71 ,p4 decorata 7nymph71 ,ectoblatta germanica 1 ,ectobia lapponica 1 ,phyllodromia 1 ,aphlebia bivittata 1 ,platyzosteria ingens 7on seventh segment74 e4 ,at the end of the body4 ,colnis julia 7,f4 ,mller71 ,heliconius apseudes 7,f4 ,mller74 ,,literature ,,on ,,defensive ,,or ,,repugnatorial ,,glands ,aldrovandus1 ,u4 ,de animalibus insectis libri septem cum singulorum iconibus ad vivum expressis4 7,denuo impress3 ,bonon4 apud ,clementem ,ferronium1 #afch1 p4 #bgc4 ,the first edition was in #afjb47 ,moufet1 ,t4 ,insectorum sive minimorum animalium theatrum1 etc4 ,london1 #afcd1 pp4 #ahe1 #ahf4 ,gdart1 ,j4 ,metamorphosis naturalis sive insectorum historia1 etc4 ,amstelodami1 #agjj1 ,pars ii1 p4 #acf4 7,french ed4 of #agjj1 ii1 p4 #afb2 ,lister's ,latin ed41 ,london1 #afhe1 p4 #fj47 ,raumur1 ,r4 ,a4 ,f4 ,mmoires pour servir l'histoire des insectes1 etc4 ,paris1 #agcf1 ii1 pp4 #bff-bfi1 ,pls4 #ba1 #bb4 ii1 partie ii1 pp4 #ba-bc1 of the ,amsterdam ed4 of #agcg-agdh4 ,de ,geer1 ,c4 ,observation sur la proprit singulire qu'ont les grandes chenilles quatorze jambes et double queue1 du saule1 de seringuer de la liqueur4 7,mm4 sav4 trang1 ,paris1 #agej1 i1 pp4 #ecj1 #eca1 ,pl42 ,goetze und ,bonnet1 etc41 ,auserlesene ,abhandlungen1 #aggd1 p4 #bbj47 ,schaeffer1 ,j4 ,c4 ,neuendeckte ,theile an ,raupen und ,zweyfaltern1 etc4 ,regensburg1 #aged4 ,sulzer1 ,j4 ,h4 ,die ,kennzeichen der ,insekten1 etc4 ,zrich1 #agfa1 pp4 #fe-fg1 ,taf4 #e1 ,fig4 #cd4 ,mller1 ,o4 ,f4 ,pile-larven med dobbelt ,hale1 og dens ,phalne1 etc4 ,kjbenhavn1 #aggb1 pp4 #ec-ef1 ,pl4 #b1 ,figs4 #c-e4 ,bonnet1 ,c4 ,mmoire sur une nouvelle partie commune plusieurs espces de chenilles4 7,mm4 math4 d4 savants trang41 ,paris1 #agee1 ii1 pp4 #dd-eb2 ,collection complte des uvres de ,c4 ,bonnet1 #aggi1 ii1 pp4 #c-af47 ---- ,mmoire sur la grande chenille queue fourchue du saule1 dans lequel on prouve1 que la liqueur que cette chenille fait jaillir1 est un vritable acide1 et un acide trs-actif4 7,mm4 math1 de savants trang41 ,paris1 #agee1 ii1 pp4 #bfg-bhb2 ,collection complte des uvres de ,c4 ,bonnet1 #aggi1 ii1 pp4 #ag-bd47 ,amoreux1 ,p4 ,j4 ,notice des insectes de la ,france1 rputs venimeux1 etc4 ,paris1 #aghi1 pp4 #bhb-bhe4 ,schwarz1 ,c4 ,neuer ,raupenkalender4 ,nrenberg1 #agia1 ,abth4 i1 p4 #ei4 ,petzhold1 ,c4 ,p4 ,lepidopterologische ,beytrge4 7,l4 ,g4 ,scriba's ,beitrge zu der ,insekten-geschichte1 ,frankfurt am ,main1 #agic1 ,heft #c1 pp4 #bcj-bea47 ,nouvelle ,dictionnaire d',hist4 ,nat41 xv1 p4 #dhg4 7,larva of ,hydrophilus ejects with a slight noise a ftid and blackish fluid47 ,rengger1 ,johann ,rudolph4 ,physiologische ,untersuchungen ber die thierische ,haushaltung der ,insecten4 ,tbingen1 #ahag4 7,in the chapter entitled ,abgesonderte ,sfte bei den ,raupen1 he speaks of the glandular apparatus of the larva of ,b4 vinula1 noticing the general form of the secretory sac1 that it opens out in two muscular evertible points1 out of which the secretion is ejected47 ,dufour1 ,l4 ,mmoire anatomique sur une nouvelle espce d'insecte du genre ,brachinus4 7,ann4 de mus4 d'histoire nat41 xviii1 #ahaa1 pp4 #gj-ha47 ---- ,recherches anatomiques sur les carabiques et sur plusieurs autres coloptres4 7,ann4 d4 ,sci4 ,nat41 #ahbf1 viii1 pp4 #e-ed47 ---- ,mmoire sur les mtamorphosis et l'anatomie de la ,pyrochroa coccinea4 ,glande odorifique4 7,ibid41 ii sr4 ,zoologie1 xiii1 #ahdj1 pp4 #cdj1 #cda47 ---- ,recherches anatomiques sur les ,diptres4 #ahea1 pp4 #aie1 #cac4 7,alimentary canal of ,sepsis contains the seat of a 8glande odorifique407 ,kirby and ,spence4 ,introduction to entomology1 etc4 7#b;d ed41 i1 #ahae2 ,london1 #ahah1 ii1 pp4 #bch1 #bci47 ,lyonet1 ,p4 ,recherches sur l'anatomie et les metamorphoses de diffrentes espces d'insectes4 ,ouvrage posthume4 ,paris1 #ahcb4 ,morren1 ,c4 ,mmoire sur l'migration du puceron du pcher 7,aphis persic71 et sur les caractres et l'anatomie de cette espce4 7,ann4 ,sci4 ,natur4 ,zool41 #ahcf1 vi1 pp4 #fe-ic1 ,pls4 #f1 #g47 ,ratzeburg1 ,j4 ,t4 ,c4 ,die ,forstinsekten1 etc4 7,theil i1 ,die ,kfer1 etc41 #ahcg1 p4 #bdf47 ,aub1 ,c4 ,note sur une scrtion ftide d',eumolpus pretiosus4 7,ann4 ,soc4 ,ent4 ,fr41 #ahcg1 i1 vi2 ,bull41 p4 #eh47 ,lacordaire1 ,j4 ,s4 ,introduction l'entomologie4 #ahch1 ii1 p4 #de4 ,meckel1 von ,hemsbach1 ,johann ,friedrich4 ,mikrographie einiger ,drsenapparate der niederen ,thiere4 7,anat4 ,phys4 u4 wiss4 ,med41 #ahdf1 pp4 #a-gc1 ,taf4 #a-c2 p4 #df1 ,mller's ,archiv47 ,stein1 ,friedrich4 ,vergleichende ,anatomie und ,physiologie der ,insekten4 ,berlin1 #ahdg4 ,leidy1 ,joseph4 ,history and anatomy of the hemipterous genus ,belostoma4 7,journ4 ,acad4 ,nat4 ,sci4 ,philadelphia1 ,ser4 #b1 #ahdg1 i1 ,part i1 pp4 #eg-fg1 ,pl4 #a47 ---- ,odoriferous glands of invertebrata4 7,proc4 ,acad4 ,philadelphia1 #ahdi1 iv1 #bcd-bcf1 #a ,pl42 ,ann4 and ,mag4 ,n4 ,h41 ,ser4 #b1 #ahej1 v1 pp4 #aed-aef47 ,chapuis et ,candze4 ,catalogue des larves des coloptres1 etc4 7,mm4 ,soc4 ,sci4 de ,lige1 #ahec1 viii1 pp4 #cea-fec1 ,pls4 #a-i1 pp4 #faa1 #fab47 ,siebold1 ,carl ,theodor4 ,lehrbuch der vergleichenden ,anatomie der wirbellosen ,thiere1 #ahdh4 7,burnett's transl41 ,boston1 #ahed47 ,burnett1 ,waldo ,irving4 ,translation of ,siebold's ,anatomy of the ,invertebrates1 #ahed4 7,note on the osmeteria of ,papilio asterias1 which he regards as an odoriferous and defensive1 rather than tactile1 organ1 p4 #dae47 ,karsten1 ,h4 ,bemerkungen ber einige shaarfe und brennende ,absonderungen verschiedener ,raupen4 7,mller's ,archiv fr ,anat4 ,phys4 u4 wiss4 ,med41 #ahdh1 pp4 #cge-chb1 ,taf4 #aa1 #ab47 ,describes the poison-glands at the base of the spines of ,saturnia larv4 ---- ,harnorgane des ,brachinus complanatus4 7,mller's ,archiv1 #ahdh1 pp4 #cfg-cgf1 ,taf47 ,laboulbne1 ,alexandre4 ,note sur les caroncules thoraciques du ,malachius4 7,annales de la ,soc4 ,ent4 de ,france1 #c;e ,sr41 vi1 #aheh1 pp4 #eba-ebh47 ,saussure1 ,henri de4 ,recherches zoologiques de l',amerique centrale et du ,mexique4 7#f;e ,partie1 tudes sur les ,myriopodes et les ,insectes1 ,paris1 #ahfj47 ,gerstaecker1 ,c4 ,e4 ,a4 ,ueber das vorkommen von ausstlpbaren ,hautanhngen am ,hinterleibe an ,schaben4 7,archiv f4 ,naturgesch41 #ahfa1 xxi1 pp4 #ajg-aae47 ,liegel1 ,hermann4 ,ueber den ,ausstlpungsapparat von ,malachius und verwandten ,formen4 ,inaug4 ,diss41 ,gttingen1 pp4 #ca1 #a ,taf4 7n4 d41 since #aheh and before #ahgh47 ,leydig1 ,f4 ,zur ,anatomie der ,insecten4 7,archiv f4 ,anat4 ,phys4 u4 wiss4 ,med41 #ahei1 pp4 #cc-hi1 #adi-ahc1 ,taf4 #b-d1 pp4 #ce and #ch47 ---- ,ueber bombardier ,kfer4 7,biolog4 ,centralbl41 x1 #ahij1 pp4 #cie1 #cif47 ,claus1 ,c4 ,ueber die ,seitendrsen der ,larve von ,chrysomela populi4 7,zeits4 f4 wissens4 ,zool41 xi1 #ahfa1 pp4 #cji-cad1 ,taf4 xxv47 ---- ,ueber ,schutzwassen der ,raupen des ,gabelschwanzes4 7,wrzburger ,naturw4 ,zeitschrift1 #ahfb1 iii1 xiv2 ,sitz4 am41 #bh ,juni1 #ahfb47 ,rogenhofer1 ,alois4 ,drei ,schmetterlingsmetamorphosen4 7,verhandlungen der k4 k4 zoolog4-bot4 ,gesellschaft1 ,wien1 xiii1 #ahfb1 pp4 #abbd-abcj47 ,fitch1 ,asa4 ,eighth report on the noxious and other insects of 444 ,new ,york4 7,trans4 ,n4 ,y4 ,state ,agric4 ,soc41 #ahfb1 xxii1 pp4 #feg-fhd71 p4 #fgg4 7,separate47 ,guene1 ,achille4 ,d'une organe particulier que prsente une chenille de ,lycna4 7,annales ,soc4 ,ent4 de ,france1 ,sr4 #d1 #ahfg1 pp4 #ffe-ffh1 ,pl4 #ac47 ,landois1 ,l4 ,anatomie der ,bettwanze1 ,cimex lectularius1 mit bercksichtigung verwandter ,hemipterengeschlechter4 7,zeitsch4 f4 wissens4 ,zool41 #ahfh1 xvii1 pp4 #bjf-bbd1 #bah-bbc1 ,taf4 #aa1 #ab47 ,studer1 ,theodor4 ,mittheilungen der naturforsch4 ,gesellschaft in ,bern1 #ahgb-ahgc1 ,no4 #gib-haa1 p4 #aja4 ,candze1 ,e4 ,les moyens d'attaque et de dfense chez les insectes4 7,bull4 ,acad4 royale de ,belgique1 #b ,sr41 xxxviii1 #ahgd1 pp4 #ghg-haf47 ,mayer1 ,paul4 ,anatomie von ,pyrrhocoris apterus4 7,reichert und du ,bois-,reymond's ,archiv f4 ,anat4 ,phys41 etc41 #ahgd1 pp4 #cac-cdg1 #c ,taf47 ,scudder1 ,samuel ,hubbard4 ,odoriferous glands in ,phasmid4 7,psyche1 i1 pp4 #acg-adj1 ,jan4 #ad1 #ahgf2 ,amer4 ,nat41 x1 p4 #bef1 ,april1 #ahgf47 ---- ,prothoracic tubercles in butterfly caterpillars4 7,psyche1 i1 pp4 #fd1 #afh1 #ahgf47 ---- ,organs found near the anus of the pupa of ,danais1 which recall the odoriferous organs mentioned by ,burnett1 transl4 ,siebold's ,comp4 ,anat4 as occurring in ,argynnis and other genera4 7,psyche1 iii1 p4 #bgh1 #ahhb1 p4 #dec1 note #bb47 ---- ,glands and extensile organs of larv of blue butterflies4 7,proc4 ,bos4 ,soc4 ,nat4 ,hist41 xxxiii1 pp4 #ceg1 #ceh1 #ahhh47 ---- ,butterflies of ,eastern ,united ,states4 i-iii1 #ahhi4 ---- ,new light on the formation of the abdominal pouch in ,parnassius4 7,trans4 ,ent4 ,soc4 ,london for #ahib1 ,january1 #ahic1 pp4 #bdi-bec47 ,mller1 ,fritz4 ,die ,stinkklbchen der weiblichen ,maracujfalter4 7,zeitschr4 f4 wissens4 ,zool41 #ahgg1 xxx1 pp4 #afg-agj1 ,taf4 #i47 ,plateau1 ,flix4 ,note sur une scrtion propre aux coloptres dytiscides4 7,ann4 ,soc4 ,ent4 ,belg41 #ahgf1 v1 xix1 pp4 #a-aj47 ,edwards1 ,william ,h4 ,notes on ,lycna pseudargiolus and its larval history4 7,can4 ,ent41 x1 ,jan41 #ahgh1 pp4 #a-ad4 ,fig47 ---- ,on the larv of ,lycna pseudargiolus and attendant ants4 7,can4 ,ent41 x1 ,july1 #ahgh1 pp4 #aca-acf47 ---- ,butterflies of ,north ,america1 i-iv4 ,many ,pls4 ,phil41 #ahfh--4 ,voges1 ,ernst4 ,beitrge zur ,kenntniss der ,juliden4 7,zeitsch4 f4 wissens4 ,zoologie1 xxxi1 p4 #abg1 #ahgh4 ,the scent-glands are retort-shaped bodies1 the necks of which open into foramina repugnatoria47 ,rye1 ,e4 ,c4 ,secretion of water-beetles4 7,ent4 ,month4 ,mag41 xiv1 #ahgg-ahgh1 pp4 #bcb1 #bcc47 ,forel1 ,a4 ,der ,giftapparat und die anal ,drsen der ,ameisen4 7,zeits4 f4 wissens4 ,zool41 #ahgh1 xxx1 ,suppl41 pp4 #bh-fh1 ,taf4 #c1 #d47 ,saunders1 ,william4 ,notes on the larva of ,lycna scudderi4 7,can4 ,ent41 x1 ,jan41 #ahgh1 p4 #ad47 ,weismann1 ,a4 ,ueber ,duftschuppen4 7,zool4 ,anzeiger1 #bfth ,aug41 #ahgh1 ,jahrg41 i1 pp4 #ih1 #ii47 ,gissler1 ,carl ,friedrich4 ,on the repugnatorial glands in ,eleodes4 7,psyche1 ii1 ,feb41 #ahgi1 pp4 #bji1 #baj47 ---- ,odoriferous glands on the #eth abdominal segment in nymph of ,lachnus strobi4 7,fig4 #bgc1 p4 #hjd1 of ,packard's ,report on ,forest and ,shade ,tree ,insects1 #ahij47 ,brunner von ,wattenwyl1 ,k4 ,ueber ein neues ,organ bei den ,acridiodeen4 7,verhandl4 k4 k4 ,zool4 ,bot4 ,gesells4 ,wien41 #ahgi1 xxix2 ,sitzungsber41 pp4 #bf1 #bg47 ---- ,verhandl4 k4 k4 ,zool4 ,bot4 ,gesells4 ,wien4 7,a peculiar organ on hind femora of ,acridiid47 ,rougement1 ,p4 ,observations sur l'organe dtonnant du ,brachinus crepitans ,oliv4 7,bull4 ,soc4 ,sci4 ,nat4 ,neuchtel1 #ahgi1 xi1 pp4 #dga-dgh1 ,pl47 ,goossens1 ,th4 ,sur une organe entre la tte et la premire paire de pattes de quelques chenilles4 7,ann4 ,soc4 ,ent4 ,france1 ix1 p4 #d1 #ahji2 ,bull41 pp4 #fj1 #fa47 ---- ,des chenilles vsicantes4 7,ann4 ,ent4 ,soc4 ,france1 vi1 pp4 #dfa-dfd1 #ahhg47 ,coquillett1 ,d4 ,w4 ,on the early stages of some moths4 7,can4 ,ent41 ,march1 #ahhj1 xii1 pp4 #dc-df47 ,chambers1 ,victor ,tousey4 ,notes upon some ,tineid larv4 7,psyche1 iii1 ,july1 #ahhj1 p4 #fg4 ,certain retractile processes 8from the sides of certain segments of the larva407 ---- ,further notes on some ,tineid larv4 7,psyche1 iii1 p4 #ace1 ,feb4 #ab1 #ahha4 ,larva of ,phyllocnistis has eight pairs of lateral pseudopodia on first eight abdominal segments47 ,french1 ,g4 ,h4 ,larv of ,cerura occidentalis ,lint1 and ,c4 borealis ,bd4 7,can4 ,ent41 ,july1 #ahha1 xiii1 pp4 #add1 #ade47 ,passerini1 ,n4 ,sopra i due tubercoli abdominali della larva della ,porthesia chrysorrha4 7,bull4 ,soc4 ,ent4 ,ital41 #ahha1 xiii1 pp4 #bic-bif47 ,klemensiewicz1 ,stanislaus4 ,zur nheren ,kenntniss der ,hautdrsen bei den ,raupen und bei ,malachius4 7,verhandlungen d4 ,zool4 ,bot4 ,gesellsch4 ,wien41 xxxii1 pp4 #dei-dgd1 #ahhb1 #b ,taf47 ,weber1 ,max4 ,ueber eine ,cyanwasserstoffsure bereitende ,drse4 7,archiv fr ,mikr4 ,anat41 xxi1 pp4 #dfh-dge1 xxiv1 #ahhb47 ,bertkau1 ,philip4 ,ueber den ,stinkapparat von ,lacon murinus ,l4 7,archiv f4 ,naturg41 #ahhb1 ,jahrg41 xlviii1 pp4 #cga-cgc47 ,dimmock1 ,george4 ,organs1 probably defensive in function1 in the larva of ,hyperchiria varia ,walk4 7,saturnia io ,harris74 7,psyche1 iii1 pp4 #ceb1 #cec1 ,aug4 #ai1 #ahhb4 ,account of lateral eversible glands on #ast and #gth abdominal segments2 they emit neither moisture nor odor47 ---- ,on some glands which open externally on insects4 7,psyche1 iii1 pp4 #chg-cii1 ,jan4 #ae1 #ahhc4 ,treats of poison-glands1 glandular hairs1 eversible glands of ,cerura1 etc47 ,coleman1 ,n4 ,notes on ,orgyia leucostigma4 7,papilio1 ,november-,december1 #ahhb1 ,jan41 #ahhc1 ii1 pp4 #afd-aff47 ,mller1 ,f4 ,der ,anhang am ,hinterleibe der ,acra-weibchen4 7,zool4 ,anzeiger1 #fth ,aug41 #ahhc1 ,jahrg41 vi1 pp4 #dae1 #daf47 ,dewitz1 ,h4 ,ueber das durch die ,foramina repugnatoria entleerte ,secret bei ,glomeris4 7,biol4 ,centralblatt1 iv1 pp4 #bjb1 #bjc1 #ahhd47 ,williston1 ,s4 ,a4 ,protective secretion of ,eleodes ejected from anal gland4 7,psyche1 iv1 p4 #afh1 ,may1 #ahhd47 ,poulton1 ,edward ,bagnall4 ,notes in #ahhe upon lepidopterous larv and pup1 including an account of the loss of weight in the freshly-formed lepidopterous pup4 7,trans4 ,ent4 ,soc41 ,london1 ,june1 #ahhf1 pp4 #aef1 #aeg1 #aei47 ---- ,notes in #ahhf upon lepidopterous larv1 etc4 7,trans4 ,ent4 ,soc41 ,london1 ,sept41 #ahhg1 pp4 #bie-cja47 ---- ,notes in #ahhg upon lepidopterous larv1 etc4 7,trans4 ,ent4 ,soc41 ,london1 #ahhh1 p4 #eig47 ,knckel-d',herculais1 ,j4 ,la punaise de lit et ses appareils odorifrants4 7,comptes rendus1 ciii1 #ahhf1 pp4 #ha-hc2 ,annals ,mag4 ,nat4 ,hist41 #eth ,ser41 xviii1 #ahhf1 pp4 #afg1 #afh47 ---- tude compare des appareils odorifiques dans les differents groupes d',hemiptres htroptres4 7,compt4 rend4 ,acad4 ,sc41 ,paris1 cxx1 pp4 #ajjb-ajjd47 ,packard1 ,a4 ,s4 ,the fluid ejected by notodontian caterpillars4 7,amer4 ,nat41 #ahhf1 xx1 pp4 #haa1 #hab47 ---- ,an eversible 8gland0 in the larva of ,orgyia4 7,amer4 ,nat41 #ahhf1 xx1 p4 #had47 ---- ,fifth ,rep4 ,u4 ,s4 ,ent4 ,comm4 ,insects injurious to forest and shade trees1 p4 #acf1 #ahij4 ---- ,hints on the evolution of the bristles1 spines1 and tubercles of certain caterpillars4 7,proc4 ,boston ,soc4 ,nat4 ,hist41 xxiv1 #ahij1 p4 #eea47 ---- ,notes on some points in the external structure and phylogeny of lepidopterous larv4 7,proc4 ,bost4 ,soc4 ,nat4 ,hist41 xxv1 #ahij1 pp4 #hc-aad47 ---- ,a study of the transformations and anatomy of ,lagoa crispata1 a bombycine moth4 7,proc4 ,amer4 ,phil4 ,soc41 ,philadelphia1 xxxii1 #ahic1 pp4 #bge-bib1 #g ,pls47 ---- ,the eversible repugnatorial scent glands of insects4 7,journ41 ,n4 ,y4 ,ent4 ,soc4 iii1 #ahie1 pp4 #aaj-abg2 iv1 p4 #hif2 pp4 #bf-cb1 #a ,pl47 ,loman1 ,j4 ,c4 ,c4 ,freies ,jod als ,drsensecret4 7,tijdschr4 ,neder4 ,dierk4 ,ver4 ,deel #a1 #ahhg1 pp4 #ajf-ajh47 ,riley1 ,charles ,valentine4 ,proc4 ,ent4 ,soc41 ,washington1 ,march #ac1 #ahhh1 i1 pp4 #hg-hi4 ---- ,notes on the eversible glands of larv of ,orgyia and ,parorgyia leucopa and ,p4 clintonii 7achatina74 7,see #eth ,rep4 ,u4 ,s4 ,ent4 ,comm41 p4 #acg47 ,denham1 ,ch4 ,s4 ,the acid secretion of ,notodonta concinna4 7,insect ,life1 i1 p4 #adg1 #ahhh2 hydrochloric acid47 ,michin1 ,edward ,a4 ,note on a new organ1 and on the structure of the hypodermis1 in ,periplaneta orientalis4 7,quart4 ,journ4 ,micros4 ,sc41 ,dec41 #ahhh1 xxiv1 #a ,pl47 ---- ,further observations on the dorsal gland in the abdomen of ,periplaneta and its allies4 7,zool4 ,anz41 #bg ,jan41 #ahij1 pp4 #da-dd47 ,maynard1 ,c4 ,l4 ,the defensive glands of a species of ,phasma1 ,anisomorpha buprestoides4 7,contributions to ,science1 i1 ,april1 #ahhi47 ,schaeffer1 ,csar4 ,beitrge zur ,histologie der ,insekten4 7,zool4 ,jahrb4 ,morph4 ,abth4 iii1 pp4 #faa-feb1 ,taf4 xxix1 xxx1 #ahhi2 treats of the ventral glands in prothorax of caterpillars2 scales and hairs are secretions from the very greatly enlarged hypodermic cells47 ,gilson1 ,g4 ,les glandes odorifres der ,blaps mortisaga et de quelques autres espces4 7,la ,cellule1 v4 pp4 #a-ba1 #a ,pl41 #ahhi47 ---- ,the odoriferous apparatus of ,blaps mortisaga4 7,rep4 #ehth ,meeting ,brit4 ,assoc4 ,adv4 ,sc41 #ahhi1 pp4 #gbg1 #gbh47 ,haase1 ,erich4 ,ueber die ,stinkdrsen der ,orthoptera4 7,sitzgsber4 ,ges4 ,naturf4 ,freunde1 ,berlin1 pp4 #eg1 #eh1 #ahhi47 ---- ,zur ,anatomie der ,blattiden4 7,zool4 ,anz41 xii ,jahrg41 pp4 #afi-agb1 #ahhi47 ,herbst1 ,curt4 ,anatomische ,untersuchungen an ,scutigera coleoptrata4 ,ein ,beitrag zur vergleichenden ,anatomie der ,articulaten4 ,dissert41 ,jena1 pp4 #cf 7,hautdrsen1 ,coxal-,organ472 p4 #a1 #ahhi4 ,wheeler1 ,william ,m4 ,hydrocyanic acid secreted by ,polydesmus virginiensis ,drury4 7,psyche1 v1 p4 #dbb47 ---- ,new glands in the hemipterous embryo4 7,amer4 ,nat41 ,feb4 #ahij1 p4 #ahg2 odorous787 glands47 ,jackson1 ,w4 ,hatchett4 ,studies in the morphology of the ,lepidoptera1 ,pt4 i4 7,trans4 ,linn4 ,soc41 ,london1 #b ,ser41 ,zol41 v1 ,may1 #ahij47 ,krauss1 ,hermann4 ,die ,duftdrse der ,aphlebia bivittata ,brull 7,blattid7 von ,teneriffa4 7,zool4 ,anz41 xiii ,jahrg41 #ahij1 pp4 #ehd-ehg1 #c ,figs47 ,fernald1 ,h4 ,t4 ,rectal glands in ,coleoptera4 7,amer4 ,nat41 xxiv1 pp4 #ajj1 #aja1 ,pls4 #d1 #e1 #ahij47 ,verson1 ,e4 ,hautdrsen system bei ,bombyciden 7,seidenspinner74 7,zool4 ,anzeiger1 #ahij1 pp4 #aah-abj47 ,vosseler1 ,julius4 ,die ,stinkdrsen der ,forficuliden4 7,arch4 ,mikr4 ,anat41 xxxvi1 #ahij1 pp4 #efe-egh1 ,taf4 #bi47 ,carrire1 ,j4 ,die ,drsen am ersten ,hinterleibsringe der ,insektenembryonen4 7,biol4 ,centralblatt1 xi1 pp4 #aaj-abg1 #ahia47 ,borgert1 ,henry4 ,die ,hautdrsen der ,tracheaten4 ,inaugural ,diss41 ,jena1 #ahia1 pp4 #a-hj4 ,lang1 ,arnold4 ,lehrbuch der vergleichende ,anatomie1 ,english ,trans4 by ,henry ,m4 and ,matilda ,bernard1 #ahia1 pp4 #deh1 #dei4 ,kennel1 ,j4 von4 ,die ,verwandtschaftverhltnisse der ,arthropoden4 7,schriften herausgegeben von der ,naturforscher ,gesellschaft bei der ,universitt ,dorpat1 vi1 ,dorpat1 #ahia47 ,patton1 ,w4 ,h4 ,scent-glands in the larva of ,limacodes4 7,can4 ,ent41 xxiii1 ,feb4 #ahia1 pp4 #db1 #dc2 eight pairs of glands with pores along the edges of the back47 ,batelli1 ,andrea4 ,di una particolarita nell integumento dell' ,aphrophora spumaria4 7,monitore ,zol4 ,ital4 ,anno #b1 pp4 #cj-cb1 #ahia4 ,dermal glands in the hindermost segment47 ,ash1 ,c4 ,d4 ,notes on the larva of ,danima banksii ,lewin4 7,ent4 ,month4 ,mag41 ,sept4 #ahib1 p4 #bcb1 ,fig47 notodontian larva protrudes from under side of prothoracic segment a ,y-shaped1 red organ like that of ,papilio2 no odor or fluid given out4 ,bernard1 ,henry ,m4 ,an endeavor to show that the trache of the ,arthropoda arose from setiparous sacs4 7,spengel's ,zool41 ,jahrbuch1 #ahib1 pp4 #eaa-ebd1 #c ,figs47 ,latter1 ,oswald4 ,the secretion of potassium hydroxide by ,dicranura vinula1 and the emergence of the imago from the cocoon4 7,trans4 ,ent4 ,soc4 ,london1 #ahib1 #bhg1 also xxxii2 ,prof4 ,meldola adds that the larva of ,d4 vinula secretes strong1 formic acid1 and is the only animal known to secrete a strong1 caustic alkali47 ---- ,further notes on the secretion of potassium hydroxide by ,dicranura vinula 7imago71 and similar phenomena in other ,lepidoptera4 7,trans4 ,ent4 ,soc4 ,london2 ,nature1 #ahie1 p4 #eea1 ,march #bj1 #ahie47 ,zograff1 ,nicolas4 ,note sur l'origine et les parentes des ,arthropodes1 principalement des ,arthropodes trachates4 7,congrs ,internationale de ,zoologie1 #b;e ,session ,moscow1 ,aug4 #ahib2 ,part i1 ,moscow1 #ahib1 pp4 #bgh-cjb1 #ahib2 cyanogenic glands in ,myriopods1 p4 #bhg47 ,swale1 ,h4 ,odor of ,olophrum piceum4 7,ent4 ,month4 ,mag41 v1 ,jan4 #ahif1 pp4 #a1 #b47 ,cunot1 ,l4 ,moyens de dfense dans la srie animale1 ,paris1 n4 d4 7#ahib72 the ejection of blood as a means of defence by some ,coleoptera4 7,comptes rendus1 ,acad4 ,sc4 ,france1 ,april #af2 ,nature1 ,april #bf1 #ahid47 ---- ,sur la saigne rflexe et les moyens de dfense de quelques insectes4 7,arch4 ,zool4 expr4 7#c71 #ahig1 iv1 pp4 #fee1 #fgi1 #fhj47 ,holmgren1 ,emil4 ,studier fverhudens och de krtelartade hudorganens morfologi hos skandinaviska macrolepidopterlarver4 7,k4 ,svenska ,vetenskaps-,akademiens ,handlingar1 xxvii1 ,no4 #d1 ,stockholm1 #d #ahie1 pp4 #hb1 #i ,pls47 ,lutz1 ,k4 ,g4 ,das ,blut der ,coccinelliden4 7,zool4 ,anzeiger1 #ahie1 pp4 #bdd-bee1 #a ,fig47 ,gilson1 ,gustav4 ,studies in insect morphology4 7,proc4 ,linn4 ,soc4 ,london1 ,march #e1 #ahif2 ,nature1 p4 #ejj47 ---- ,on segmentally disposed thoracic glands in the larv of the ,trichoptera4 7,journ4 ,linn4 ,soc41 ,london1 xxv4 #ahig47 ,cholodkowsky1 ,n4 ,entomotomische ,miscellen1 v1 ,ueber die ,spritzapparate der ,cimbiciden ,larven1 pp4 #ace-adc1 #b ,taf4 ,ibid41 vi4 ,ueber das ,bluten der ,cimbiciden ,larven1 pp4 #ceb-ceg1 #a ,fig4 7,hor ,soc4 ,ent4 ,rossic1 xxx1 #ahig47 ,also the writings of ,darwin1 ,wallace1 ,poulton1 ,weir1 ,beddard1 ,butler1 ,busgen1 7pp4 #cfe-cfg71 ,girard1 ,kolbe1 ,locy4 ,,the ,,alluring ,,or ,,scent-,,glands ,it is difficult to draw the line between repelling and alluring glands4 ,attention was first definitely called to the alluring odors of ,lepidoptera by ,fritz ,mller1 who showed that the males of certain butterflies are rendered attractive to the other sex by secreting odorous oils of the ether series4 ,he pointed out that the seat of the odor is the androconia 7see p4 #aii71 while either repellent or pleasant odors are exhaled from abdominal glands4 ,those of ,pieris napi yield a scent like that of citrons1 ,didonis biblis gives off three different odors from different parts of the body1 besides having a distinctly odorous spot on the hind wings4 ,both sexes have a sac between the fourth and fifth abdominal segments which exhales a very unpleasant 7protective7 odor1 while the males have on the succeeding segment a pair of glands from which proceeds an agreeable odor like that of the heliotrope4 ,callidryas argante throws off a musky odor4 ,in ,prepona laertes the odor is like that of a bat1 in ,dircenna xantho it is vanilla-like1 the androconia being situated on the front edge of the hind wings4 ,in ,papilio grayi the odor is said to be as agreeable and intense as in flowers4 ,certain sphingids are known to exhale a distinct odor1 which ,mller has traced to a tuft of hair-like scales at the base of the abdomen1 and which fits into a groove in the first segment1 so as to be ordinarily invisible4 ,illustration3 ,fig4 #cfg4--,scent-tufts3 #a1 of ,leucarctia acra2 #b1 of ,pyrrarctia isabella4--,after ,smith4 ,in the noctuid genus1 ,patula1 the costal half of the hind wing is modified to form a large scent-gland1 and in consequence the venation has been modified4 ,the still greater distortion of the veins in the allied genus1 ,argida1 was attributed by the author to its once having possessed a similar scent-gland1 now become rudimentary by disuse4 7,hampson47 ,peculiar white or orange-colored1 hairy1 thread-like processes have been found protruding from narrow openings near the tip of the abdomen of ,arctian moths 7,fig4 #cfg71 which throw off1 according to ,j4 ,b4 ,smith1 8an intense odor1 somewhat like the smell of laudanum40 ,we have perceived the same unpleasant odor emanating from the males of ,spilosoma virginica and ,arctia virgo1 as well as ,leucarctia acra4 ,we are informed by ,c4 ,dury that similar but longer hairy appendages are thrust out by the male of ,haploa clymene4 ,many glaucopid moths protrude similar glandular processes4 ,thus ,mller tells us that on seizing a glaucopid female by the wings1 nearly the whole body became enveloped in a large cloud of snow-white wool which came out of a sort of pouch on the ventral side of the abdomen4 ,the male of a glaucopid was seen to dart out a pair of long hollow hairy retractile filaments which in some species exceed the whole body in length4 ,the apparatus secretes a peculiar odor1 probably serving to allure the female 7,nature71 and certain ,zygnid have on the inner side of the paranal lobes 7,afterklappen7 glands filled with a sweetly scented fluid4 ,smith has detected a peculiar brush of hair-like scales in a groove between the dorsal and ventral parts of the basal two segments of the abdomen of ,schinia marginata 7family ,noctuid71 and when removed it exhaled a laudanum-like smell4 ,the pupa of ,citheronia regalis gives out from the end of the abdomen a scent reminding us of laudanum4 ,illustration3 ,,fig4 #cfh4--,scent-tufts on middle legs of ,catocala concumbens4--,after ,bailey4 ,another mode of disseminating pleasant1 alluring odors is that of the males of certain moths1 which bear pencils and tufts on their fore or hind legs1 and in the case of an ,indian butterfly on the greatly elongated palpi4 ,those on the legs are ordinarily concealed in cavities or furrows in the leg1 and may be thrust out and expanded so as to widely diffuse their odor4 ,such are those of the males of ,catocala 7,fig4 #cfh71 which resemble an artist's fitch brush4 ,in ,hepialus hecta1 where the arrangements for protecting the tufts are quite abnormal1 ,bertkau has detected the cells which secrete the odorous fluid4 ,in the male of another ,hepialus 7,h4 humuli7 a peculiar scent proceeds from the curiously aborted and altered hind tibi4 7,barrett47 ,in one case1 that of a geometrid moth 7,bapata dichroa of ,new ,guinea71 these pencils occur on all the legs4 7,haase74 ,in many species a distinct odor is perceptible when the leg bearing the pencil or tuft is crushed4 ,these eversible scent-glands have been supposed to be mostly restricted to the ,lepidoptera1 and to a single known case in the ,trichoptera1 but similar alluring male glands also occur in the ,orthoptera 7,locustid74 ,h4 ,garman has described and figured in the cave cricket 7,hadencus subterraneus7 8a pair of white fleshy appendages protruding from slits between the terga of the #ith and #ajth abdominal somites1 the nature of which is not clear10 adding1 8the slits through which the organs appear are situated one on each side anterior to and a little within the cerci4 ,when fully protruded1 the glands are white1 cylindrical1 a little tapering1 and are about one-eighth of an inch long40 ,he believes that they are protruded during the period of sexual excitement1 and suggests that 8the sense of smell is certainly the one best calculated to bring the sexes together in the darkness of caves40 ,we had previously noticed these organs in alcoholic specimens1 but supposed that they were fungous growths4 ,on dissecting and making microscopic sections of them1 the gland is1 when extended 7,fig4 #cfi71 seen to be a long1 ensiform1 sharp1 band-like process1 with numerous retractor muscular fibres4 ,when at rest each gland is folded about five times1 forming a bundle lying on each side of the end of the intestine4 ,the walls are formed of a single layer of epithelium1 as seen in ,fig4 #cfi1 ,b4 ,illustration3 ,,fig4 #cfi4--;,eversible scent-glands 7a7 of ,hadencus1 nat4 size3 ,kingsley1 del42 ,a1 a gland outstretched1 with the retractor muscular fibres2 t1 part of the tergite4 ,b1 section of the gland1 showing the single layer of epithelial cells1 and the muscular fibres 7m74--,author del4 ,in the male of the common wingless cricket1 ,ceuthophilus maculatus1 we have discovered what appears to be a pair of scent-glands lying directly over the last abdominal ganglion4 ,they form two large white sacs situated close together1 with a short common duct which passes back and opens externally upwards by a transverse slit on the under side of the last segment of the body4 ,,literature ,,on ,,alluring ,,glands ,watson1 ,j4 ,on the microscopical examination of plumules1 etc4 7,ent4 ,month4 ,mag41 ii1 #ahfe1 p4 #a47 ---- ,on certain scales of some diurnal ,lepidoptera4 7,mem4 ,lit4 and ,phil4 ,soc4 ,manchester1 ,ser4 #c1 ii1 #ahfh1 p4 #fc47 ---- ,on the plumules or battledore scales of ,lycnid4 7,mem4 ,lit4 and ,phil4 ,soc4 ,manchester1 ,ser4 #c1 iii1 #ahfi1 p4 #abh47 ,further remarks1 etc4 7,ibid41 p4 #bei47 ,anthony1 ,j4 ,structure of battledore scales4 7,month4 ,microsc4 ,journ41 vii1 #ahgb1 p4 #bej2 see also p4 #bjj47 ,morrison1 ,herbert ,knowles4 ,on an appendage of the male ,leucarctia acra4 7,psyche1 i1 pp4 #ba-bb1 ,october1 #ahgd47 ,mller1 ,fritz4 ,the habits of various insects4 7,nature1 ,june #aa1 #ahgd1 pp4 #ajb-ajc47 ---- ,ueber ,haarpinsel1 ,fitzflecke und hnliche ,gebilde auf den ,flgeln mnnlicher ,schmetterlinge4 7,jena4 ,zeitschr4 f4 ,naturw41 #ahgg1 xi1 pp4 #ii-aad47 ---- ,beobachtungen an brasilianischen ,schmetterlingen1 ii4 ,i4 ,die ,duftschuppen der mnnlichen ,maracujfalter4 7,kosmos1 #ahgg1 i1 pp4 #cia-cie1 ,figs4 #e1 #f47 ,,ii4 ,die ,duftschuppen des mnnchens von ,dione vanill4 7,kosmos1 ii1 #ahgg1 pp4 #ch-db1 #g ,taf47 ---- ,as maculas sexuaes dos individuos masculinos das especies ,danais erippus e ,d4 gilippus4 7,arch4 ,mus4 ,nac4 ,rio ,janeiro1 ii1 #ahgg 7#ahgh71 pp4 #be-bi1 #a ,pl47 ---- ,die ,duftschuppen der ,schmetterlinge 7nach dem 8,kosmos0 in ,ent4 ,nachr41 #ahgh1 pp4 #bi-cb1 #aji74 ---- ,wo hat der ,moschusduft der ,schwrmer seinen ,sitz8 7,kosmos1 ii ,jahrg41 #ahgh1 pp4 #hd1 #he47 ---- ,os orgaos odoriferos dos especias ,epicalia acontius1 ,lin4 e de ,myscelia orsis1 ,dru4 7,arch4 ,mus4 ,nac4 ,rio ,janeiro1 ii1 #ahgi1 pp4 #ca-ce47 ---- ,os orgaos odoriferos nas pernas de certos ,lepidopteres4 7,arch4 ,mus4 ,nac4 ,rio ,janeiro1 ii1 #ahgi1 pp4 #cg-df1 #c ,pls47 ---- ,os orgaos odoriferos da ,antirrha archa4 7,arch4 ,mus4 ,nac4 ,rio ,janeiro1 iii1 #ahgh1 pp4 #a-g1 #a ,pl47 ---- ,a prega costal das ,hesperideas4 7,arch4 ,mus4 ,nac4 ,rio ,janeiro1 iii1 #ahhj1 pp4 #da-ej1 #b ,pls47 ,weismann1 ,august4 ,ueber ,duftschuppen4 7,zool4 ,anzeiger1 i1 #ahgh1 pp4 #ih1 #ii47 ,arnhart1 ,l4 ,sexundre ,geschlechtscharaktere von ,acherontia atropos4 7,verh4 d4 k4 k4 zool4 bot4 ,ges4 ,wien1 xxix1 #ahgi1 p4 #ed47 ,bertkau1 ,philipp4 ,duftapparat an ,schmetterlingsbeinen4 7,ent4 ,nachrichten1 #ahgi1 ,jahrg41 pp4 #bbc1 #bbd47 ---- ,ueber den ,duftapparat von ,hepialus hecta4 7,archiv f4 naturg41 xlviii ,jahrg41 #ahhb1 pp4 #cfc-cgj1 ,figs42 also in ,biol4 ,centralblatt41 ii ,jahrg41 #ahhb1 pp4 #ejj-ejb47 ---- ,ergnzung 7,duftvorrichtungen bei ,lepidopteren74 7,ent4 ,nachr41 #ahhj1 p4 #bjf47 ---- ,entomologische ,mizellen4 #a4 ,ueber ,duftvorrichtungen einiger ,schmetterlinge4 7,verh4 d4 naturhist4 ,ver4 d4 preuss4 ,rheinlande und ,westf41 #ahhd1 pp4 #cdc-cej47 ,reichenau1 ,w4 von4 ,der ,duftapparat von ,sphinx ligustri4 7,ent4 ,nachr41 #ahhj1 p4 #ada2 also ,kosmos1 iv ,jahrg41 #ahhj1 pp4 #chg-cij47 ,fgner1 ,r4 ,duftapparat bei ,sphinx ligustri4 7,ent4 ,nachr41 #ahhj1 p4 #aff47 ,lelievre1 ,ernest4 7,note in ,le ,naturaliste1 ,june #a1 #ahhj4 ,both sexes of ,thais polyxena emit an odorous exhalation4 ,notes on exhalation from ,spilosoma fuliginosa47 ,hall1 ,c4 ,g4 ,peculiar odor emitted by ,acherontia atropos4 7,entomologist1 ,london1 xvi1 p4 #ad47 urivillius1 ,christopher4 ,ueber secundre ,geschlechtscharactere nordischer ,tagfalter4 7,stockholm1 #ahhj1 ,bihang till ,k4 ,svensk4 ,vet4 ,akad4 ,handl41 v1 pp4 #ef1 #c ,taf47 ---- ,des caractres sexuels secundaires chez les papillons diurnes4 7,ent4 ,tidskrift1 #ahhj1 pp4 #afc-aff47 ---- ,anteckningar om ngra skandinaviska fjrilarter4 7,ent4 ,tidskr41 iv1 rg41 #ahhd1 pp4 #cc-cg2 ,rsum 7,french71 ibid41 pp4 #ee-eg47 ,kirby1 ,w4 ,f4 ,fans on the fore legs of ,catocala fraxini4 7,papilio1 ii1 p4 #hd1 #ahhb47 ,bailey1 ,james ,s4 ,femoral tufts or pencils of hair in certain ,catocal4 7,papilio1 ii1 #ahhb1 pp4 #ea1 #eb1 #adf2 also in ,stettin ,ent4 ,zeitung1 xliii1 p4 #cib47 ,edwards1 ,henry4 ,fans on the feet of ,catocaline moths4 7,papilio1 ii1 p4 #adf1 #ahhb47 ,stretch1 ,r4 ,h4 ,anal appendages of ,leucarctia acra4 7,papilio1 iii1 pp4 #da1 #db1 #ahhc1 #a ,fig47 ,weed1 ,clarence ,m4 ,appendages of ,leucarctia4 7,papilio1 iii1 #ahhc1 p4 #hd47 ,grote1 ,aug4 ,r4 ,appendages of ,leucarctia acra4 7,papilio1 iii1 #ahhc1 p4 #hd47 ,haase1 ,erich4 ,ueber sexuelle ,charactere bei ,schmetterlingen4 7,zeitschr4 f4 ,ent41 ,breslau1 ,n4 ,f41 #ahhe1 pp4 #ae-ai1 #cf-dd2 also ,ent4 ,nachr41 xi ,jahrg41 pp4 #ccb1 #ccc47 ---- ,duftapparate indo-australischer ,schmetterlinge4 7,corresp4 ,blatt4 ,ent4 ,ver4 ,iris1 ,dresden1 #ahhf1 pp4 #ib-ajg1 #a ,taf42 ibid41 #ahhg1 pp4 #aei-agh2 ibid41 #ahhh1 pp4 #bha-ccf47 ---- ,ueber ,duftapparate bei ,schmetterlingen4 7,sitzgsber4 ,nat4 ,ges4 ,iris1 ,dresden1 #ahhf1 pp4 #i-aj2 ,abstr4 in ,journ4 ,r4 ,micr4 ,soc41 vi1 pp4 #ifi-igj1 #ahhf47 ---- ,der ,duftapparate von ,acherontia4 7,zeitschr4 f4 ,ent41 ,breslau1 ,n4 ,f41 #ahhg1 pp4 #e-f47 ---- ,dufteinrichtung indischer ,schmetterlinge4 7,zool4 ,anzeiger1 #ahhh1 pp4 #dge-dha47 ,dalla ,torre1 ,k4 ,w4 von4 ,die ,duftapparate der ,schmetterlinge4 7,kosmos1 #ahhe1 ii1 pp4 #ced-cfd1 #daj-dbc2 ,abstr4 by ,j4 ,b4 ,smith in ,proc4 ,ent4 ,soc41 ,washington1 i1 pp4 #ch1 #ahhh47 ,smith1 ,john ,b4 ,cosmosoma omphale4 7,entomologica ,americana1 i1 pp4 #aha-ahe1 #ahhf4 ,describes and figures cavities in under side of #b;d-#dth abdominal segments of male1 filled with a silky substance4 ,this may be for display to attract 1 as the whole mass must be very conspicuous when protruded4 ,no odor noticed47 ---- ,scent organs in some ,bombycid moths4 7,entomologica ,americana1 ii1 ,no4 #d1 pp4 #gi-hj1 #ahhf4 ,describes and figures long1 slender1 forked hairy1 orange or white1 eversible glands1 everted from between #gth and #hth segments of abdomen of of ,leucarctia acra1 ,pyrrharctia isabella1 ,scepsis fulvicollis1 and ,cosmosoma omphale47 ---- ,notes on odors and odoriferous structures of various moths and a note by ,l4 ,o4 ,howard on odor of ,dynastes4 7,proc4 ,ent4 ,soc41 ,washington1 i1 pp4 #dj1 #ee1 #ef47 ,mller1 ,w4 ,duftorgane der ,phryganiden4 7,archiv f4 ,naturgesch41 #ahhg1 ,jahrg4 liii1 pp4 #ie-ig47 ,pollack1 ,w4 ,duftapparate der ,hadena atriplicis und ,litargyria4 7xv ,jahrb4 ,westphl4 ,prov4 ,ver4 ,mnster1 #ahhg1 p4 #af47 ,patton1 ,w4 ,h4 ,scent-glands in the larva of ,limacodes4 7,can4 ,ent41 #ahia1 xxiii1 pp4 #db1 #dc47 ,garman1 ,h4 ,on a singular gland possessed by the male ,hadencus subterraneus4 7,psyche1 #ahia1 p4 #aje1 #a ,fig47 ,barrett1 ,c4 ,g4 ,scent of the male ,hepialus humuli4 7,ent4 ,month4 ,mag41 ,ser4 #b1 iii1 #ahib1 p4 #bag4 ,arises from the curiously aborted and altered hind tibi47 ,also the writings of ,baillif1 ,duponchel1 ,f4 ,mller1 ,scudder 7,psyche1 iii1 p4 #bgh1 #ahha71 ,burgess1 ,keferstein1 ,alpheraky1 ,plateau1 ,marshall and ,nicville1 ,wood-,mason1 ,white1 ,hampson4 ,,the ,,organs ,,of ,,circulation ,although ,malpighi was the first to discover the heart in the young silkworm1 it was not until #ahbf that ,carus proved that there was a circulation of blood in insects1 which he saw flowing along each side of the body1 and coursing through the wings1 antenn1 and legs of the transparent larva of ,ephemera1 though three years earlier ,herold demonstrated that the dorsal vessel of an insect is a true heart1 pulsating and impelling a current of blood towards the head4 ,this discovery was extended by ,straus-,drckheim1 who discovered the contractile and valvular structures of the heart4 ,it is noteworthy that both ,cuvier and ,dufour denied that any circulation1 except of air1 existed in insects2 and so great an anatomist as ,lyonet doubted whether the dorsal vessel was a genuine heart1 though he pointed out the fact that there are no arteries and veins connected with this vessel4 ,another ,french anatomist1 ,marcel de ,serres1 thought that the dorsal vessel was merely the secreting organ of the fat-body4 ,the so-called peritracheal circulation claimed by ,blanchard and by ,agassiz has been shown by ,mc,leod to be an anatomical impossibility1 the view having first been refuted by ,joly in #ahdi4 ,except the aorta-like continuation in the thorax and head which divides into two short branches1 there are1 with slight exceptions 7p4 #dje71 no distinct arteries1 such as are to be found in the lobster and other ,crustacea1 and no great collective veins1 such as exist in ,crustacea and in ,limulus4 ,this is probably the result of a reduction by disuse in the circulatory system1 since in myriopods 7,julid and ,scolopendrid7 lateral arteries are said to diverge near the ostia4 a4 ,the heart ,the heart or 8dorsal vessel0 is a delicate1 pulsating tube1 situated just under the integument of the back1 in the median line of the body1 and above the digestive canal4 ,it can be partially seen without dissection in caterpillars4 ,it is covered externally and lined within by membranes which are probably elastic2 and between these two membranes extends a system of delicate muscular fibres1 which generally have a circular course1 but sometimes cross each other4 ,the heart is divided by constrictions into chambers1 separated by valvular folds4 ,the internal lining membrane referred to forms the valvular folds separating the chambers4 ,each of these chambers has1 at the anterior end1 on each side1 a valvular orifice 7,fig4 #cgj1 ostium1 i7 which can be inwardly closed4 ,miall and ,denny thus describe the different layers of the wall of the heart of the cockroach3 8,there are3 7#a7 a transparent1 structureless intima1 only visible when thrown into folds2 7#b7 a partial endocardium1 of scattered1 nucleated cells1 which passes into the interventricular valves2 7#c7 a muscular layer1 consisting of close-set1 annular1 and distant1 longitudinal fibres4 ,the annular muscles are slightly interrupted at regular and frequent intervals1 and are imperfectly joined along the middle line above and below1 so as to indicate 7what has been independently proved7 that the heart arises as two half-tubes1 which afterwards join along the middle4 ,elongate nuclei are to be seen here and there among the muscles4 ,the adventitia 7#d71 or connective tissue layer1 is but slightly developed in the adult cockroach40 ,illustration3 ,,fig4 #cgj4--,part of the heart of ,lucanus cervus3 a1 the posterior chambers 7the anterior ones are covered by a part of the ligaments which hold the heart in place72 i1 auriculo-ventricular openings2 g1 g1 the lateral muscles fixed by the prolongations h1 h1 to the upper side of the abdomen4--,after ,straus-,drckheim4 ,graber says that the heart of insects may be regarded not as an organ de novo1 but only as the somewhat modified contractile dorsal vessel of the annelids1 in which1 however1 the transverse arteries arising on each side became1 with the gradual development of the trache1 superfluous and finally abortive4 ,he describes it as a muscular tube composed of very delicate annular fibres1 which within and without is covered by a relatively homogeneous1 strong1 elastic membrane4 ,the division into separate chambers is effected by means of a folding inwards and forwards of the entire muscular wall4 8,a portion of each side of the heart is first extended inwards so as very nearly to meet a corresponding portion from the opposite side1 and then1 being reflected backwards1 forms1 according to ,straus 7,consid41 etc41 p4 #cef71 the interventricular valve which separates each chamber from that which follows it4 ,posteriorly to this valve1 at the anterior part of each chamber1 is a transverse opening or slit 7,fig4 #cga1 b71 the auriculo-ventricular orifice1 through which the blood passes into each chamber1 and immediately behind it is a second1 but much smaller1 semilunar valve 7c71 which1 like the first1 is directed forwards into the chamber4 ,it is between these two valves on each side that the blood passes into the heart1 and is prevented from returning by the closing of the semilunar valve4 ,when the blood is passing into the chamber1 the interventricular valve is thrown back against the side of the cavity1 but is closed when1 by the contraction of the transverse fibres1 the diameter of each chamber is narrowed1 and the blood is forced along into the next chamber40 7,newport47 ,illustration3 ,,fig4 #cga4--;,a1 heart of ,lucanus cervus3 a1 valves or chambers2 bb1 alary muscles2 c1 supposed auricular space around the heart4 ,b1 division into arteries of the end of the aorta in larva of ,vanessa urtic4 ,c1 interior of the chamber1 showing the transverse fibres2 b1 auriculo-ventricular opening and valve into the chambers2 c1 semilunar valve2 d1 interventricular valve4--,after ,straus-,drckheim1 from ,newport4 ,illustration3 ,,fig4 #cgb4--;,heart of ,belostoma4--,after ,locy4 ,according to ,mller1 there is but a single pair of ostia in ,phasma1 and1 in the larva of ,corethra1 the heart is a simple1 unjointed tube1 not divided into chambers1 and ,viallanes states that1 in the very young larva of ,musca1 there are no ostia 7,kolbe74 ,in the larva of ,ptychoptera1 ,grobben found a short oval heart1 with one pair of ostia situated in the #fth abdominal segment2 a long aorta proceeds from it1 the thoracic portion of which pulsates2 from behind the heart arises a pulsating pouch1 which connects with the hinder aorta1 which does not pulsate1 and ends at the base of two tracheal gills4 ,burmeister was able to find only four pairs of openings in the larva of ,calosoma4 ,newport states that1 while ,straus figures nine chambers in ,melolontha1 and1 consequently1 eight pairs of openings1 he has not been able to observe more than seven pairs of openings in ,lucanus cervus4 ,he has invariably found eight pairs of openings both in the larva and imago of ,sphinx ligustri1 as well as in other ,lepidoptera4 ,according to ,bla-,dezso1 the number of pairs of ostia corresponds to that of the pairs of stigmata4 ,there also occur1 on each side of each chamber1 two so-called pear-shaped bodies which are separated from the tubular portion of the heart itself1 but1 by means of muscular fibres1 are united with the chamber and with their valves4 ,these pyriform bodies appear as vesicles or cells with granular contents1 besides some nuclei with nucleoli4 ,they are of very small size4 ,according to the measurements of ,dogiel1 in the larva of ,corethra plumicornis1 they are #j4jb to #j4a mm4 long1 and #j4jf to #j4jh mm4 broad4 ,he regards these peculiar bodies as apolar nerve-cells of the heart4 7,kolbe47 ,illustration3 ,,fig4 #cgc4--;,a1 part of the heart of ,dyticus marginalis1 showing the spiral arrangement of the muscular fibres2 c1 closed1 e1 open1 valve2 a1 dorsal diaphragm with interwoven muscular fibres2 b1 arrangement of fibres1 recalling the screw-like features of the fibres of the human heart2 d1 narrow end4 ,b1 diagrammatic figure of the valvular openings1 with the terminal flap 7e71 and the cellular valve1 of a ,may beetle2 a1 valvular opening of a dipterous larva1 with the interventricular valve 7b74 ,c1 abdomen of a mole-cricket1 ventral view2 c1 the segmented heart2 a1 aorta2 b1 segmented diaphragm under it4--,after ,graber4 ,besides the venous openings of the heart which open into the pericardial region1 ,kowalevsky has discovered1 in the heart of some ,orthoptera 7,caloptenus1 ,locusta1 etc471 five pairs of openings by which the cardiac chambers receive the blood of the peri-intestinal region4 ,graber had divided the clom of insects into three regions 7pericardial1 peri-intestinal1 and perineural regions71 and hitherto only a union of the heart with the pericardial region by slit-like openings was known4 ,these openings are symmetrically distributed on five abdominal segments2 each section of the heart in this region has1 therefore1 four openings1 which are all of a truly venous nature4 ,these openings1 called cardio-clomic apertures1 are visible to the naked eye1 being situated on conical papill of the walls of the heart4 ,these papill pass through the outer diaphragm1 and open into the peri-intestinal part of the clom1 in the ,acrydiid directly1 in the ,locustid through special canals4 ,the cells of the papill are spongy1 possessing large nuclei1 and similar1 as a whole1 to glandular cells4 7,comptes rendus1 cxix1 #ahid47 ,the mechanism by which the ostia are closed consists1 according to ,graber1 of an -shaped muscle passing around the two openings1 and which1 being interlaced1 is sufficient to close the openings4 ,but this is not all4 ,the fore and hinder edge of the ostia project1 leaf-like1 into the cavity of the heart1 and thus form1 with the outer walls1 two valves which1 during the systole1 filled with the blood rushing in1 not only hermetically close the lateral openings1 but also1 by the simultaneous closure of the entire chamber by the circular muscles in the middle of the same1 the two valves1 simultaneously approaching each other1 so nearly touch that they form a transverse partition wall in the chamber4 ,but1 for the last purpose1 i4e4 for the separation of the chambers from one another1 there is a very special contrivance4 ,in the ,may beetle1 we find1 besides a valve 7,fig4 #cgc1 ,b1 e71 opening into the middle of the chambers1 a large1 stalked cell 7d71 which1 in the diastole1 i4e4 in the expansion of the heart1 hangs down free on the walls of the heart2 but1 in the systole or contraction1 like a cork1 closes the middle of the valve1 but does not wholly close the cavity4 ,he has observed1 in the larva of ,corethra1 formal1 interventricular valves1 which also are not in the middle1 but are separated from one another in the interlaced ends4 ,they consist of two longitudinally membranous flaps which move against each other like two valves 7,fig4 #cgc1 ,b1 b74 8,but what is the necessity for such a complicated mechanism8 ,all the blood from behind passes into the heart1 and1 for its propulsion a simple muscular tube1 whose circular fibres would draw together and contract it1 would be thought to be sufficient4 ,but the heart1 except in some larv1 ends posteriorly in a blind sac1 and the blood can only pass into it by a series of pairs of lateral openings4 ,now1 as regards the reception and the propulsion of the blood forwards1 two modes are conceivable4 ,the simplest way would be that the tubular heart should1 along its whole length1 contract or expand2 that1 moreover1 the blood should be simultaneously sucked in through all the openings1 and that then1 also1 the contraction1 or systole1 should take place in every part of the heart at the same moment4 ,but this would1 plainly1 in so long and thin-walled a vessel1 be highly impracticable1 since1 through such a manipulation1 the mass of blood enclosed in the heart would be crowded together rather than really impelled forwards4 ,only the second case could be admissible1 and that is this1 that each chamber pulsates1 one after another1 from behind forwards4 ,but1 then1 each segmental heart must be separated from the others by a valve4 ,to make the matter wholly clear1 we may observe an insect heart pulsating1 and this is best seen in one of its middle chambers4 ,this chamber expands 7simply by the relaxation of its circular muscles71 the ostia1 also1 consequently open1 and a given quantity of blood is drawn in from the pericardial cavity4 ,what now would happen after the succeeding contraction if there were no valves between8 ,the blood would not flow forwards1 but seek a way out backwards4 8,but1 in fact1 the valve of the hinder chamber1 at this time1 closes itself1 while1 by the simultaneous expansion of the anterior ones1 their door opens1 and this section of the heart1 at the same time1 causes a sucking in of the contents of the posterior chamber4 ,this phenomenon is repeated1 in the same way1 from chamber to chamber1 which also acts alternately as ventricle and auricle1 or by a sucking and pumping action4 ,one is involuntarily reminded of the ingenious manipulation by which1 by the alternate opening and shutting of the flood-gates1 a vessel is carried along a canal4 8,this wave-like motion of an insect's heart also has the advantage that1 just before a pulse-wave has reached the chambers farthest in front1 the hinder ones are already prepared for the production of a second1 for1 as a matter of fact1 often #fj1 and even #ajj1 and1 in very agile insects1 #aej1 waves pass1 in a single minute1 through the series of chambers1 which make it very difficult to follow the flowing of their waves40 7,graber47 ,the propulsatory apparatus4--,but the heart itself is only a part of the entire propulsatorial apparatus to which belongs the following contrivance1 the nature of which has been worked out by ,graber4 ,under the dorsal vessel is stretched a sort of roof-like diaphragm1 i4e4 a membrane1 arched like the dorsal wall of the hind-body which is attached1 in a peculiar way1 to the sides of the body4 ,the best idea can be gained by a cross-section through the entire body 7,fig4 #cgd73 ,h is the true dorsal vessel2 ,s1 the diaphragm4 ,a surface view is seen at #cgc1 ,c1 b1 where it appears as a plate with the edge regularly curved outwards on each side4 ,its precise mode of working is thus3 from each dorsal band of the sides of the abdomen arises a pair of muscles spreading out fan-like1 and extending to the heart1 so that the fibres of one side pass directly over to those of the other1 often splitting apart1 or1 between the two1 extends outwards a perforated1 thin web1 like an elastic1 fibrous sheet 7,fig4 #cgc1 ,a1 a71 with numerous perforations1 forming a diaphragm4 ,illustration3 ,,fig4 #cgd4--;,diagram of transverse section of pericardial sinus of dipoda crulescens3 ,h1 heart2 s1 septum2 m1 muscles1--the upper suspensory1 the lower alary4--,after ,graber1 from ,sharp4 7,see also ,fig4 #cgg47 ,graber has thus explained the action of the pericardial diaphragm and chamber1 as freely translated by ,miall and ,denny3 8,when the alary muscles contract1 they depress the diaphragm1 which is arched upwards when at rest4 ,a rush of blood towards the heart is thereby set up1 and the blood streams through the perforated diaphragm into the pericardial chamber4 ,here it bathes a spongy or cavernous tissue 7the fat-cells71 which is largely supplied with air-tubes1 and having been thus aerated1 passes immediately forwards to the heart1 entering it at the moment of diastole1 which is simultaneous with the sinking of the diaphragm40 ,in the cockroach1 however1 ,miall and ,denny think that the facts of structure do not altogether justify this explanation3 8,the fenestr of the diaphragm are mere openings without valves4 ,the descent of a perforated non-valvular plate can bring no pressure to bear upon the blood1 for it is not contended that the alary muscles are powerful enough to change the figure of the abdominal rings4444 ,the diaphragm appears to give mechanical support to the heart1 resisting pressure from a distended alimentary canal1 while the sheets of fat-cells1 in addition to their proper physiological office1 may equalize small local pressures1 and prevent displacement4 ,the movement of the blood towards the heart must 7we think7 depend1 not upon the alary muscles1 but upon the far more powerful muscles of the abdominal wall1 and upon the pumping action of the heart itself40 8,the peculiar office10 says ,graber1 8performed by the heart has already been stated4 ,it is nothing more than a regulator2 than an organ for directing the blood in a determinate course in order that this may not wholly stagnate1 or only be the plaything of a force acting in another way1 as1 for example1 through that afforded by the body-cavity and the inner digestive canal4 ,at regular intervals a portion of the blood is sucked through the same1 and then by means of the anterior supply tube it is pushed onward into the head1 whence it passes into the cavities of the tissues4 ,the different conditions of tension under which the mass of blood stands in the different regions of the body then causes a farther circulation4 ,besides this1 the blood passes through separate smaller pumping apparatuses1 and through vessel-like modifications of cavities1 also through hollow spaces between the muscles1 as1 for example1 in the appendages where a regular backward and forward flow of the blood1 especially in the limbs1 wings1 antenn1 and certain abdominal appendages takes place4 ,here and there may occasionally occur a narrow place where the flow of blood is obstructed by the accumulation of the blood corpuscles1 causing a considerable stagnation40 7,graber47 ,illustration3 ,,fig4 #cge4--,libellula depressa1 opened from the back1 showing the nervous cord 7b#a-;b#c1 thoracic1 h#a-;h#g1 abdominal1 ganglia71 also the furrow-like ventral sinus closed by a muscular diaphragm4 ,illustration3 ,,fig4 #cgf4--;,a1 part of the ventral furrow of ,libellula depressa more highly magnified3 a1 a sternal plate 7urite72 c1 the septum stretched over it1 at s in a relaxed or collapsed state2 b and d1 the wing-like1 sternal processes from which the muscular bundles of the diaphragm arise4 ,b1 same in ,acridium4 ,illustration3 ,,fig4 #cgg4--;,diagrammatic section of the abdomen of ,acridium tartaricum1 showing the ventral septum 7i1 p1 l7 contracted1 and 7i1 k1 l7 stretched out2 oh1 rib-like lateral processes of the urite2 f1 ganglia2 b1 heart1 with its suspensorium 7a72 c1 fat tissue in the pericardial tissue sinus2 d1 dorsal septum or diaphragm contracted4 q1 extended2 g1 fat-body2 e1 muscular part of diaphragm2 no1 expiration1 hm1 inspiration1 muscle4--,this and ,figs4 #cge1 #cgf1 after ,graber4 ,the supraspinal vessel4--,in many insects there is a ventral heart acting on the heart's blood as an aspirator1 or more correctly a ventral sinus lying on the nervous cord1 and closed by a pulsating diaphragm4 ,this was discovered by ,raumur in the larva of a fly1 and by ,graber in the dragon-fly and locusts 7,acrydiid74 ,a glance at ,figs4 #cge and #cgf will save a long description4 ,the ventral wall forms a furrow1 and between its borders 7,fig4 #cgg1 e7 extends the diaphragm4 ,during the contraction of the muscles--and this1 here1 acts from before backwards--the membrane rises up and makes a cavity for the blood1 which passes backwards over the nervous cord4 ,the dorsal and ventral sinuses together thus bring about a closed circulation4 ,it thus appears that the insects are well provided with the means of distribution of their nutritive fluid1 and that the blood is kept continually fresh and rich in oxygen4 7,graber47 ,the aorta4--,while the heart is mostly situated within the abdomen1 it is continued into the thorax and the head as a simple1 non-pulsating tube1 called the aorta4 ,in ,sphinx the aorta1 as described by ,newport1 begins at the anterior part of the #ast abdominal segment1 where it bends downwards to pass under the metaphragma and enter the thorax2 it then ascends again between the great longitudinal dorsal muscles of the wings1 and passes onwards until it arrives at the posterior margin of the pronotum2 it then again descends and continues its course along the upper surface of the sophagus1 with which it passes beneath the brain1 in front of which and immediately above the pharynx1 it divides into two branches1 each of which subdivides4 ,newport1 however1 overlooked a thoracic enlargement of the aorta called by ,burgess the 8aortal chamber0 7,fig4 #caj1 a1 c74 ,illustration3 ,,fig4 #cgh4--;,a1 last three abdominal segments and bases of the three caudal processes of ,cloon dipterum3 r1 dorsal vessel2 kl1 ostia2 k1 special terminal chamber of the dorsal vessel with its entrance a2 b1 blood-vessel of the left caudal process4 ,b1 #bfth joint of the left caudal appendage from below3 b1 a portion of the blood-vessel2 o1 orifice in the latter4--,after ,zimmermann1 from ,sharp4 8,in ,sphinx and ,vanessa urtic1 immediately after the aorta has passed beneath the cerebrum1 it gives off laterally two large trunks1 which are each equal in capacity to about one-third of the main vessel4 ,these pass one on each side of the head1 and are divided into three branches which are directed backwards1 but have not been traced farther in consequence of their extreme delicacy4 ,anterior to these trunks are two smaller ones which appear to be given to the parts of the mouth and antenn1 and nearer the median line are two others which are the continuations of the aorta4 ,these pass upwards1 and are lost in the integument4 ,the whole of these parts are so exceedingly delicate that we have not1 as yet1 been able to follow them beyond their origin at the termination of the aorta1 but believe them to be continuous1 with very delicate1 circulatory passages along the course of the tracheal vessels4 ,it is in the head alone that the aorta is divided into branches1 since1 throughout its whole course from the abdomen1 it is one continuous vessel1 neither giving off branches1 nor possessing lateral muscles1 auricular orifices1 or separate chambers40 7,newport1 art4 ,insecta1 p4 #igh47 ,dogiel observed in the transparent larva of ,corethra plumicornis that the aorta extends only to the hinder border of the brain4 ,here it divides into two lamell1 each of which independently extends farther on4 ,one lamella is seen under the brain and under the eye1 the other reaches near the eye4 ,the lamell are tied to the integument by threads4 ,at the point of division of the aorta is an opening4 7,kolbe47 ,true blood-vessels appear to exist in the caudal appendages of the ,may-flies1 as the heart appears to divide and pass directly into them 7,fig4 #cgh74 ,the last chamber of the heart diminishes in size at the end of the body1 and then divides into three delicate tubular vessels which pass into the three caudal appendages1 and extend to the end of each one1 along the upper side4 ,while the valves of the heart1 in all insects1 are directed anteriorly because the blood flows from behind1 in the larva of the ,ephemerid the valves of the last chamber of the heart are directed backwards1 because from this chamber the blood flows in the opposite direction1 i4e4 into the caudal appendages4 ,during the contraction of the heart1 the elongated section of the same in the last abdominal segment receives a part of the mass of blood contained in the last chamber1 which is driven by independent contractions into the caudal appendages4 ,these vessels have openings before the end through which the blood enters into the cavity of the appendages1 and can also pass back1 in order to be taken up by the body cavity4 ,it is possible that these blood-vessels stand in direct relation to respiration4 7,zimmermann1 ,creutzburg1 in ,kolbe1 p4 #edd47 ,the pericardial cells4--,along the heart1 on both sides1 occur the so-called pericardial cells1 which differ from the fat-cells1 and also the peritracheal cells of ,frenzel1 and are mostly arranged in linear series1 which have a close relation to the circulation of the blood4 ,in the larva of ,chironomus1 they lie in groups2 in that of ,culex1 they are arranged segmentally4 ,in caterpillars1 these pericardial cells are not situated in the region of the heart1 but are arranged linearly on the side1 and form a network of granulated cells situated between the fat-bodies4 ,other rows of these cells are situated near the stigmata and the main lateral trache4 7,kolbe47 ,according to ,kowalevsky1 the pericardial cells1 and the garland-shaped1 cellular cord consist of cells1 whose function it is to purify the blood1 and to remove the foreign or injurious matters mingled with the blood4 ,illustration3 ,,fig4 #cgi4--;,diagram of the circulatory organs in the head of the cockroach1 seen from above3 ,a1 ampulla2 ,v1 antennal vessel2 ,m1 chief muscular cord2 m1 muscular band2 ,bs1 wall of the blood sinus2 am1 opening of the aorta 7a72 rg1 anterior sympathetic or visceral ganglion2 hg1 hinder visceral ganglion2 ,f1 ,f1 facetted eyes2 o1 vestigial ocellus2 ,g1 ,g1 brain2 ,s1 sophagus4--,after ,pawlowa4 ,ampulla-like blood circulation in the head4--,in the head of the cockroach occurs1 according to ,pawlowa1 a contractile vascular sac at the base of each antenna4 ,the cavity has a valvular communication with the blood space below and in front of the brain1 and muscle-fibres effect systole and diastole4 ,each sac is beyond doubt an independently active part of the circulatory system4 ,these organs also occur in ,locusta and other ,acrydiid1 and ,selvatico has described similar structures in ,bombyx mori and certain other ,lepidoptera4 ,pulsatile organs of the legs4--,accessory to the circulation is a special system of pulsatile organs in the three pairs of legs of ,nepid1 generally situated in the tibia just below its articulation with the femur1 but in the fore legs of ,ranatra1 in the clasp-joint or tarsus1 just below its articulation with the tibia4 ,first observed by ,behn 7#ahce71 ,locy has studied the organ 7,fig4 #chj7 in ,corixa1 ,notonecta1 ,gerris1 besides the ,nepid4 ,it is a whip-like structure attached at both ends1 with fibres extending upward and backward to the integument of the leg1 separate from the muscular fibres and does not involve them in its motions1 and is not affected by the muscles themselves4 8,as the blood-corpuscles flow near the pulsating body they move faster1 and around the organ itself there is a whirlpool of motion40 ,the beating of these organs aids the circulation in both directions1 and when the motion ceases1 the blood-currents in the legs stop2 the rate of the pulsating organ is always faster than that of the heart1 and the action is automatic4 ,illustration3 ,,fig4 #chj4--,pulsating organs in ,hemiptera3 ,a1 ,belostoma nymph1 ,b1 legs of ,corixa4 ,c1 ,ranatra1 adult1 to show the exceptional position of the pulsating organ in the fore legs4 ,d1 pulsatile organ in tibia of ,ranatra4--,after ,locy4 b4 ,the blood ,the blood of insects1 as in other invertebrates1 differs from that of the higher animals in having no red corpuscles4 ,it is a thin fluid1 a mixture of blood 7serum7 and chyle1 usually colorless1 but sometimes yellowish or reddish1 which contains pale amboid corpuscles corresponding to the white corpuscles 7leucocytes7 of the vertebrates1 though they are relatively less numerous in the blood of insects4 ,the yellow fluid expelled from the joints of certain beetles 7,coccinella1 ,timarcha1 and the ,meloid7 is1 according to ,leydig1 only the serum of the blood4 ,in phytophagous insects the blood is colored greenish by the chlorophyll set free during digestion4 ,the blood of ,deilephila euphorbia is colored an intense olive-green1 and that of ,cossus ligniperda is pale yellow4 7,urech47 ,the blood of case-worms 7,trichoptera7 is greenish4 ,in some insects it is brownish or violet4 ,the serum is the principal bearer of the coloring material1 yet ,graber has shown that in certain insects the corpuscles are more or less beset with bright yellow or red fat-globules1 so as to give the same hue to the blood4 ,the leucocytes4--,the corpuscles are usually elongated1 oval1 or flattened oat-shaped1 with a rounded nucleus1 or are often ambiform2 and they are occasionally seen undergoing self-division4 ,when about to die the corpuscles become ambiform or star-shaped4 7,cattaneo47 ,their number varies with the developmental stage of the insect1 and in larv increases as they grow1 becoming most abundant shortly before pupation4 ,the blood diminishes in quantity in the pupal stage1 and becomes still less abundant in the imago4 7,landois47 ,the quantity also varies with the nutrition of the insect1 and after a few days' starvation nearly all the blood is absorbed4 ,crystals may be obtained by evaporating a drop of the blood without pressure2 they form radiating clusters of pointed needles4 ,the freshly drawn blood is slightly alkaline4 7,miall and ,denny47 ,the size of the corpuscles has been ascertained by ,graber1 who found that the diameter of the circular blood-disks of the leaf-beetle1 ,lina populi1 is #j4jjf mm42 of ,cetonia aurata and ,zabrus gibbus1 #j4jjh to #j4ja mm42 and those of certain ,orthoptera 7,decticus verrucivorus1 ,ephippiger vitium and dipoda crulescens71 #j4jaa to #j4jad mm4 ,the longest diameter of the elongated corpuscles of ,carabus cancellatus is #j4jjh mm42 of ,gryllus campestris1 ,locusta viridissima1 ,cossus ligniperda1 ,sphinx ligustri 7pupa71 and others1 #j4jjh to #j4ja mm42 of ,caloptenus italicus1 ,saturnia pyri1 ,anax formosus1 and others1 #j4jaa to #j4jad mm42 of ,ephippiger vitium1 dipoda crulescens1 ,pezotettix mendax1 ,zabrus gibbus1 ,phryganea1 and others1 #j4jab to #j4jbb mm42 in ,stenobothrus donatus and variabilis1 #j4jab to #j4jce mm4 ,the largest known are those of ,melolontha vulgaris1 which measure from #j4jbg to #j4jc mm4 ,illustration3 ,,fig4 #cha4--;,blood corpuscles1 or leucocytes1 of insects3 ,a1 a-g1 of ,stenobothrus dorsatus 7the same forms occur in most ,orthoptera and in other insects74 ,b1 a1 leucocyte of the same insect with the nucleus brought out by ether2 b1 another of serpentine shape4 ,c1 leucocytes of the same insect after a longer stay in ether4 ,d1 leucocytes of the same after being in glycerine #ad days4--,after ,graber4 ,as regards the nature of the corpuscles1 ,graber concludes that they are more like the cells of the fat-bodies than genuine cells4 ,that they are not true cells is shown by the fact that after remaining in their normal condition a long time they finally coalesce and form cords4 ,after shrivelling1 or after the blood has been subjected to different kinds of treatment1 the nucleus is clearly brought out 7,fig4 #cha74 ,besides the blood corpuscles there have been detected in the blood round bodies which are regarded as fat-cells4 ,they are circular1 and for the most part larger than the blood corpuscles1 have a sharp1 even1 dark outline1 and an invariably circular nucleus4 7,kolbe47 ,the blood of ,meloe1 besides the amboid corpuscles1 according to ,cunot1 contains abundant fibrinogen1 which forms a clot2 a pigment 7uranidine71 which is oxidized and precipitated when exposed to the air2 a dissolved albuminoid 7hmoxanthine71 which has both a respiratory and nutritive function2 and1 finally1 dissolved cantharidine4 ,the corpuscles arise from tissues which are very similar to the fat-bodies1 and which1 at given times1 separate into cells4 ,the position of these tissues is not always the same in different insects4 ,in caterpillars1 they occur in the thorax1 near the germs of the wings2 in the saw-flies 7,lyda71 in all parts of the thorax and abdomen2 in larval flies 7,musca71 in the end of the abdomen1 just in front of the large terminal stigmata4 ,the place where the blood corpuscles are formed is usually near1 or in relation with1 the fat-bodies4 ,but while the fat-bodies mostly serve as the material for the formation of the blood-building tissues1 in caterpillars the tracheal matrix also1 and1 in dipterous larv1 the hypodermis serve this purpose4 7,csar ,schaeffer in ,kolbe4 ,see also ,wielowiejski1 ,ueber das ,blutgewebe47 ,other substances occur in the blood of insects4 ,landois 7#ahfd7 demonstrated the existence of egg albumen1 globulin1 fibrin1 and iron in the blood of caterpillars4 ,poulton found that the blood of caterpillars often contained chlorophyll and xanthophyll derived from their food plants4 ,a4 ,g4 ,mayer has recently found that the blood 7hmolymph7 of the pup of ,saturniid 7,callosamia promethea7 contains egg albumin1 globulin1 fibrin1 xanthophyll1 and orthophosphoric acid1 and ,oenslager has determined that iron1 potassium1 and sodium are also present4 7,mayer47 c4 ,the circulation of the blood ,every part of the body and its appendages is bathed by the blood1 which circulates in the wings of insects freshly emerged from the nymph or pupal state1 and even courses through the scales of ,lepidoptera1 as discovered by ,jaeger 7,isis1 #ahcg74 ,in describing the mechanism of the heart we have already considered in a general way the mode of circulation of the blood4 ,the heart pumping the blood into the aorta1 the nutritive fluid passes out and returns along each side of the body2 distinct1 smaller streams passing into the antenn1 the legs1 wings 7of certain insects71 and into the abdominal appendages when they are present4 ,all this may readily be observed in transparent aquatic insects1 such as larval ,ephemer1 dragon-flies1 etc41 kept alive for the purpose under the microscope in the animalcule box4 ,carus1 in #ahbg1 first discovered the fact of a complete circulation of the blood1 in the larva of ,ephemera4 ,he saw the blood issuing in several streams from the end of the aorta in the head and returning in currents which entered the base of the antenn and limbs in which it formed loops1 and then flowing into the abdomen1 entered the posterior end of the heart4 ,wagner 7,isis1 #ahcb7 confirmed these observations1 adding one of his own1 that the blood flows backward in two venous currents1 one at the sides of the body and intestine1 and the other alongside of the heart itself1 and that the blood not only entered at the end of the heart1 but also at the sides of each segment1 at the position of the valves discovered by ,straus-,drckheim4 ,newport maintains that the course of the blood is in any part of the body1 as well as in the wings1 almost invariably in immediate connection with the course of the trache1 for the reason that 8the currents of blood in the body of an insect are often in the vicinity of the great tracheal vessels1 both in their longitudinal and transverse direction across the segments40 ,the circulation of the blood in the wings directly after the exuviation of the nymph or pupa skin1 and before they become dry1 has been proved by several observers4 ,as stated by ,newport1 the so-called 8veins0 or 8nervures0 of the wings consist of trache lying in a hollow cavity1 the peritracheal space being situated chiefly under and on each side of the trachea4 ,illustration3 ,,fig4 #chb4--;,circulation of the blood in hind wing of ,periplaneta orientalis3 the arrows indicate the usual direction of the blood currents4--,after ,moseley4 ,newport gives the following summary of the observations of the early observers1 to which we add the observations of ,moseley4 8,a motion of the fluids has been seen by ,carus in wings of recently developed ,libellulid1 ,ephemera lutea and ,e4 marginata1 and ,chrysopa perla2 among the ,coleoptera1 in the elytra and wings of ,lampyris italica and ,l4 splendidula1 ,melolontha solstitialis and ,dytiscus40 ,ehrenberg saw it in ,mantis1 and ,wagner in the young of ,nepa cinerea and ,cimex lectularius4 ,carus detected a circulation in the pupal wings of some ,lepidoptera1 and ,bowerbank witnessed it in a ,noctuid 7,phlogophora meticulosa72 ,burmeister observed it in ,eristalis tenax and ,e4 nemorum1 and ,mr4 ,tyrrel in ,musca domestica1 but it has not been observed in the wings of ,hymenoptera4 ,bowerbank observed that in the lower wing of ,chrysopa perla the blood passes from the base of the wing along the costal1 post-costal1 and externo-medial veins1 outwards to the apex of the wing1 giving off smaller currents in its course1 and that it returns along the anal vein to the thorax4 ,he found that the larger veins1 #adjh in4 in diameter1 contained trache which only measured #abbbb of an inch in diameter2 but in others the trache measured #aacdj1 while the cavity measured only #aejj of an inch4 ,he states1 also1 that the trache very rarely give off branches while passing along the main veins1 and that they lie along the canals in a tortuous course4 7,newport1 art4 ,insecta1 p4 #ihj47 ,bowerbank1 also1 in his observations on the circulation in the wings of ,chrysopa1 8used every endeavor to discover1 if possible1 whether the blood has proper vessels1 or only occupied the internal cavities of the canals2 and that he is convinced that the latter is the case1 as he could frequently perceive the particles not only surrounding all parts of the trache1 and occupying the whole of the internal diameter of the canals1 but that it frequently happens that globules experienced a momentary stoppage in their progress1 occasioned by their friction against the curved surface of the trache1 which sometimes gave them a rotatory motion40 ,illustration3 ,,fig4 #chc4--,parts of a vein of the cockroach1 showing the nerve 7n7 by the side of the trachea 7tr72 c1 blood corpuscles4--,after ,moseley4 ,moseley found1 owing to the large size and number of the corpuscles1 that the circulation of the blood in the wings of insects is most easily observed in the cockroach1 especially the hind wings4 ,as seen in ,moseley's figure1 the blood flows outward from the body through the larger veins 7,i and ,,ii7 of the front edge of the wings1 which he calls the main arteries of the wings1 and more generally returns to the body through the veins in the middle of the wing2 the blood also flows out from the body through the inner longitudinal veins 7those behind vein ,,iv71 and the blood is also seen to flow through some of the small cross-veins4 ,fig4 #chc shows one of the main trunks during active circulation4 ,the corpuscles change their form readily1 8the spindle-shaped ones doubling up in order to pass crossways through a narrow aperture4444 ,in the irregularly formed corpuscles1 which seem to represent leucocytes amboid movements were observed4444 ,corpuscles pass freely above and under the trache1 showing that these latter lie free in the vessels40 ,the hypodermis lining the vessels is best seen in the small transverse veins4 ,the pulse or heart-beat of insects varies in rapidity in different insects1 rising at times of excitement1 as ,newport noticed in ,anthophora retusa1 to #adb beats in a minute4 ,when an insect1 as1 for example1 a tineid caterpillar1 has been enclosed in a tight box for a day or more1 the pulsations of the heart are very languid and slow1 but soon1 on giving it air1 the pulsations will1 as we have observed1 rise in frequency to about #fj a minute1 ,herold observed #cj to #dj in a minute in a fully-grown silkworm1 and from #df to #dh in a much younger one4 ,suckow observed but #cj a minute in a full-grown caterpillar of ,gastropacha pini1 and #ah only in its pupa4 ,in a series of observations made by ,newport on ,sphinx ligustri from the fourth day after hatching from the egg until the perfect insect was developed1 he found that before the larva cast its first skin the mean number of pulsations1 in a state of moderate activity and quietude1 was about #hb or #hc a minute2 before the second moult #hi1 while before the third casting it had sunk down to #fc2 and before its fourth to #de1 while1 before leaving its fourth stage1 and before it had ceased to feed1 preparatory to pupating1 the pulse was not more than #ci4 8,thus the number gradually decreases during the growing larva state1 but the force of the circulation is very much augmented4 ,now when the insect is in a state of perfect rest1 previously to changing its skin1 the number is pretty nearly equal at each period1 being about #cj4 ,when the insect has passed into the pupa state it sinks down to #bb1 and subsequently to #aj or #ab1 and after that1 during the period of hibernation1 it almost entirely ceases4 ,but when the same insect which we had watched from its earliest condition was developed into the perfect state in ,may of the following spring1 the number of pulsations1 after the insect had been for some time excited in flight around the room1 amounted to from #aaj to #aci2 and when the same insect was in a state of repose1 to from #da to #ej4 ,when1 however1 the great business of life1 the continuation of the species1 has been accomplished1 or when the insect is exhausted1 and perishing through want of food or other causes1 the number of pulsations gradually diminishes1 until the motions of the heart are almost imperceptible40 ,insects1 then1 he remarks1 do not deviate from other animals in regard to their vital phenomena1 though it has been wrongly imagined that the nutrient and circulatory functions are less active in the perfect than in the larval condition4 ,the heart of a larval ,gastrus equi taken the day previous from a horse's stomach beat from #dj to #dd times a minute 7,scheiber72 while ,schrder van der ,kolk observed only #cj beats in the same kind of maggot4 ,in the larva of ,corethra1 while at rest1 the heart contracts from #ab to #af or #ah times a minute1 but when active the number rises to #bb4 ,the systole and diastole last from #e to #f minutes4 7,dogiel47 ,temperature also affects the pulsations1 as they increase in frequency with a rise and decrease with a fall in temperature4 ,influence of electricity4--,the influence of electricity on the action of the insect's heart1 from ,dogiel's experiments1 is such as to cause an acceleration in the frequency of the beats1 while an increase in the strength of the electric currents either diminishes the frequency of the beats or entirely stops the heart's action4 ,a violent excitation with the induction current causes a systole when the heart's action has stopped for a long time2 and if the excitation lasts uninterruptedly1 then the contractions after a while become noticeable1 according to the strength of the current4 ,in such a case there are1 however1 interruptions in the regularity1 strength1 and order of the contractions4 7,kolbe47 ,effects of poisons on the pulsations4--,dogiel has also experimented on the influence of poisons in the form of vapor or as liquid solutions on the pulsations of insects1 which is much as in vertebrates4 ,the application of carbonic oxide to the larva of ,corethra1 whose heart one minute previous to the poisoning beat #ae times a minute1 accelerated the heart-beats in about #ee minutes to #be pulsations in a minute4 ,afterwards there was a retardation in the pulse to the normal beat4 ,carbonic acid had a similar effect4 ,the following results obtained by ,dogiel are somewhat as tabulated by ,kolbe3-- ,i4 ,substances which cause the pulsations of the heart to accelerate4 a4 ,an induction current of electricity1 acting feebly4 b4 ,ammonia1 acting feebly4 c4 ,ethyl ether1 acting feebly4 d4 ,oxalic acid1 acting feebly4 e4 ,carbolic acid1 acting feebly4 f4 ,potassium nitrate1 acting feebly4 g4 ,aconite1 acting feebly4 ,,ii4 ,substances retarding the heart's action4 a4 ,an induction current of electricity1 acting energetically4 b4 ,ammonia1 acting energetically4 c4 ,ethyl ether1 acting energetically4 d4 ,oxalic acid1 acting energetically4 e4 ,carbolic acid1 acting energetically4 f4 ,veratrine1 acting energetically4 g4 ,atropine1 acting energetically4 h4 ,aconitine1 acting energetically4 i4 ,potassium nitrate1 acting energetically4 g4 ,ethyl alcohol4 h4 ,chloroform4 i4 ,carbonic oxide4 j4 ,carbonic acid4 k4 ,sulphuretted hydrogen4 ,,iii4 ,substances whose action is indifferent4 #a4 ,muscarine4 #b4 ,curare4 #c4 ,atropine1 acting slowly4 #d4 ,strychnine4 ,the above-named substances comprise those which in the vertebrates effect a change in the activity of the motor nerve-ganglia of the heart and the muscular fibres4 ,hence it follows that the heart of the larval ,corethra consists of muscular fibres provided with ganglia1 and that the contractions of the muscular fibres are provoked through the agency of the ganglia4 ,but since muscarine1 atropine1 and curare1 whose influence in stopping the heart's action of vertebrates is known1 in insects either have no action or only make the pulsations slower2 it seems to follow that the heart of the larval ,corethra possesses no similar apparatus for lessening the heart's action1 and this is also confirmed by anatomical studies4 ,on the contrary1 aconite acts1 as we must from observations conclude1 exclusively on the motor centres and the muscles1 but not on the apparatus for lessening the heart's action1 which1 as has been remarked1 is not present in the larval ,corethra4 7,kolbe ex ,dogiel47 ,dewitz has discovered an onward movement of the blood corpuscles1 somewhat independent of the general circulation4 ,this independent motion of the blood corpuscles is not only a creeping one like the amboid motion of the white corpuscles of vertebrates1 but they have besides a peculiar swimming movement4 ,dewitz noticed this in the hind wings of a recently emerged meal-worm beetle 7,tenebrio molitor71 still white and soft1 after they had been cut off4 ,the tissues forming the matrix within the wings constitute a network filled with blood4 ,the current of blood within the wing thus cut off may be stopped flowing by a tap on the firmly clamped object-bearer on which the wing is placed1 or by drawing it by an apparatus described by the same author1 to incite in one way or another the blood corpuscles to swim forwards4 ,when a corpuscle is disposed to move1 we see it first stirring restlessly1 or wabbling about1 in this way changing its form2 then it moves forwards1 and does not come to a standstill4 ,if it remains still there1 after a while1 by tapping1 it begins again its movements4 8,should one yet doubt the fact of this spontaneous movement of the blood corpuscles1 he will surely be convinced of its correctness by observing the so-to-speak reluctantly springing motion of a blood corpuscle in the wing of ,tenebrio molitor with the simultaneous change of appearance and shape of the corpuscle40 ,this spontaneous or independent motion of the blood corpuscles is also produced by the heating apparatus4 ,as soon as the corpuscles lie still in the severed wing and they are warmed1 the corpuscles begin to pass through the meshes of the tissue4 ,when cooled1 the motion ceases1 but as soon as the temperature rises to a certain grade1 the corpuscles again move onwards4 ,to explain this independent motion ,dewitz thinks that they take up and then expel the blood-fluid1 and in this way cause their motion4 ,this independent motion is necessitated1 in order that the stream of blood may become so regulated1 that the blood corpuscles shall not be arrested in their course1 but even turn back again out of the farther end of the antenn and limbs4 ,the chief mechanical power for the blood circulation must go on independently of the propulsatorial apparatus and of the heart4 7,kolbe47 ,,literature ,,on ,,the ,,heart ,,and ,,on ,,the ,,circulation ,,of ,,the ,,blood a4 ,anatomy of the organs ,meckel1 ,j4 ,f4 ,ueber das ,rckengefss der ,insekten4 7,meckel's ,archiv1 i1 #ahae1 pp4 #dfi-dgf47 ,mller1 ,j4 ,g4 ,de vasi dorsali ,insectorum4 ,berolini1 #ahaf1 pp4 #bb4 ,serres1 ,p4 ,marcel de4 ,observations sur les usages du vaisseau dorsal ou sur l'influence que le cur exerce dans l'organisation des animaux articuls1 etc4 7,ann4 du ,mus4 d'hist4 nat41 #ahah1 iv1 pp4 #adi-aib1 #cac-chj1 #b ,pls42 v1 #ahai1 pp4 #ei-adg1 #a ,pl47 ,herold4 ,physiologische ,untersuchungen ber das ,rckengefss der ,insekten4 7,schriften d4 ,gesellsch4 z4 ,befrderung d4 ,naturk4 in ,marburg1 #ahbc1 i1 pp4 #da-ajg47 ,carus1 ,c4 ,g4 ,entdeckung eines einfachen vom ,herzen aus beschleunigten ,blutkreislaufes in den ,larven netzilgliger ,insekten4 ,leipzig1 #ahbg1 pp4 #dj1 #c ,taf4 ---- ,fernere ,untersuchungen ber ,blutlauf in ,kerfen4 7,acta ,acad4 ,leopold4 ,carol41 #ahca1 xv1 pp4 #a-ah1 #a ,taf47 ,stadelmayr1 ,l4 ,ansichten vom ,blutlauf nebst ,beobachtungen ber das ,rckengefss der ,insekten4 ,diss4 ,mnchen1 #ahbi1 pp4 #bd4 ,berthold4 ,beitrage zur ,anatomie1 ,zoologie und ,physiologie4 ,gttingen1 #ahca4 ,treviranus1 ,g4 ,r4 ,ueber das ,herz der ,insekten1 dessen ,verbindung mit den ,eierstocken und ein ,bauchgefss der ,lepidopteren4 7,zeitschr4 f4 d4 ,physiologie1 von ,f4 ,tiedemann4 ,g4 ,r4 u4 ,l4 ,c4 ,treviranus1 #ahcb1 iv1 pp4 #aha-ahd1 #a ,taf47 ---- ,beobachtungen aus der ,zootomie und ,physiologie4 ,bremen1 #ahci4 ,wagner1 ,r4 ,beobachtungen ber ,kreislauf des ,blutes und den ,bau des ,rckengefsses bei den ,insekten4 7,isis1 #ahcb1 iii1 p4 #cj2 vii1 pp4 #cbj-cca1 #ggh-ghc1 ,fig47 ,bowerbank1 ,j4 ,s4 ,observations on the circulation of the blood in insects4 7,ent4 ,mag41 #ahcc1 i1 pp4 #bci-bdd1 #a ,pl2 also in ,mller's ,archiv f4 ,physiolog41 #ahcd1 i1 pp4 #aai-abj47 ---- ,observations on the circulation of the blood and the distribution of the trache in the wing of ,chrysopa perla4 7,ent4 ,mag41 #ahcg1 iv1 pp4 #agi-ahe47 ,jaeger4 ,ueber die ,entdeckung von einer ,bewegung in den ,schuppen des ,schmetterlingsflgel4 7,isis1 #ahcg1 v1 p4 #eab47 ,behn1 ,w4 ,dcouverte d'une circulation de fluide nutritif dans les pattes de plusieurs insectes hmipteres4 7,ann4 ,sc4 nat41 #ahce1 ,sr4 #b1 iv1 pp4 #a-ab47 ,newport1 ,g4 ,insecta1 in ,todd's ,cyclopdia of ,anatomy and ,physiology1 #ahci4 ,london1 pp4 #hec-iid4 ,on the circulation of the blood1 p4 #igf1 ,figs4 ,duvernoy1 ,g4 ,l4 ,rsum sur le fluide nourricier1 ses rservoirs et son mouvement dans tout rgne animal4 7,ann4 ,sc4 nat41 #ahci1 ,sr4 #b1 xii1 pp4 #cjj-cdf47 ,dufour1 ,l4 tudes anatomiques et physiologiques sur une mouche dans le but d'eclairer l'histoire des metamorphoses et de la prtendue circulation dans les insectes4 7,ann4 ,sc4 nat4 ,zool41 ,sr4 #b1 #ahda1 xvi1 pp4 #e-ad47 ---- ,note sur la prtendus circulation dans les insectes4 7,compt4 rend4 ,acad41 ,paris1 #ahdd1 xix1 pp4 #ahh-ahi47 ---- tudes anatomiques et physiologiques sur une mouche1 dans le but d'claircir l'histoire des metamorphoses et de prtendue circulation des insectes4 7,mm4 mathmat4 des ,savants trangers1 ,paris1 #ahdf1 ix1 pp4 #ede-fbh1 #a ,pl47 ---- ,sur la circulation dans les insectes4 ,bordeaux1 #ahdi1 #h1 pp4 #dj4 7,compt4 rend4 ,acad4 ,sci41 ,paris1 #ahdi1 xxviii1 pp4 #bh-cc1 #aja-ajd1 #afc-agj47 ---- ,de la circulation du sang et de la nutrition chez les insectes4 ,bordeaux1 #ahea4 7,act4 ,soc4 ,linn41 ,bordeaux1 #ahea1 xvii1 p4 #i47 ---- tudes anatomiques et physiologiques et observations sur les larves des ,libellules1 ,appareil circulatoire4 7,annal4 ,sci4 nat41 ,sr4 #c1 ,zool41 xvii1 #aheb1 pp4 #ih-aja1 #a ,pl47 ,schrder van der ,kolk1 ,j4 ,s4 ,c4 ,mmoire sur l'anatomie et physiologie du ,gastrus equi4 7,n4 ,verhandl4 ,kl4 ,nederl4 ,instit41 #aa1 #ahde1 pp4 #a-aee1 #ac ,pl47 ,nicolet1 ,h4 ,note sur la circulation du sang chez les ,coloptres4 7,ann4 ,sc4 nat41 #ahdg1 ,sr4 #c1 vii1 pp4 #fj-fd47 ,verloren1 ,c4 ,mmoire en rponse la question suivante3 claircir par des observations nouvelles le phnomne de la circulation dans les insectes1 en recherchant si on peut la reconnatre dans les larves de diffrents ordres de ces animaux4 7,mm4 couronn4 et ,mm4 d4 savants trang4 de l',acad4 ,roy4 ,belgique1 xix1 #ahdg47 ,blanchard1 ,e4 ,de la circulation dans les insectes4 7,ann4 ,sc4 nat41 #ahdh1 ,sr4 #c1 ix1 pp4 #cei-cih1 #e ,pls47 ---- ,sur la circulation du sang chez les insectes et sur la nutrition4 7,compt4 rend4 ,acad4 ,sc41 ,paris1 #ahdi1 xxviii1 pp4 #gf-gh2 #ahea1 xxxiii1 pp4 #cfg-cgj47 ---- ,nouvelles observations sur la circulation du sang et la nutrition chez les insectes4 7,ibid41 pp4 #cga-cgf47 ,joly1 ,n4 ,mmoire sur l'existence suppose d'une circulation pritrachenne chez les insectes4 7,ann4 ,sc4 nat4 ,zool41 ,sr4 #c1 #ahdi1 xii1 pp4 #cjf-caf47 ,bassi1 ,c4 ,a4 ,rapporto alla sezione di zoologia1 anatomia comparata e fisiologia del congresso di ,venezia1 sul passagio delle materie ingerite nel sistema tracheale degli insetti4 7,gazette di ,milano1 #ahdg1 vi2 also ,ann4 ,sc4 nat4 ,zool41 ,sr4 #c1 #ahea1 xv41 #cfb-cga47 ,agassiz1 ,louis4 ,on the circulation of the fluids in insects4 7,proceed4 ,amer4 ,assoc4 ,adv4 ,sc41 #ahdi1 pp4 #adj-adc2 ,ann4 ,sc4 nat4 ,zool41 ,sr4 #c1 xv1 #ahea1 pp4 #ceh-cfb47 ,leydig1 ,f4 ,anatomisches und ,histiologisches ber die ,larve von ,corethra plumicornis4 7,zeitschr4 f4 wissen4 ,zool41 iii1 #ahea1 pp4 #dce-dea47 ,wedl1 ,c4 ,ueber das ,herz von ,menopon pallidum4 7,sitzungsber4 der k4 ,akad4 d4 ,wissensch4 ,wien41 #ahee1 xvii1 pp4 #agc-ahj47 ,scheiber1 ,s4 ,h4 ,vergleichende ,anatomie und ,physiologie der ,oestriden ,larven4 7,sitzungsber4 d4 k4 ,akad4 d4 ,wiss4 ,wien4 ,math4-naturwiss4 ,cl41 xli1 #ahfj1 pp4 #dji-dif1 #b ,taf42 ,the circulatory system1 pp4 #dfc-dij47 ,brauer1 ,fr4 ,beitrag zur ,kenntnis des ,baues und der ,funktion der ,stigmenplatten der ,gastrus-,larven4 7,verhdl4 d4 k4 k4 zool4-bot4 ,gesellsch4 ,wien41 xiii1 #ahfc1 pp4 #acc-acf47 ,moseley1 ,h4 ,n4 ,on the circulation in the wings of ,blatta orientalis and other insects1 and on a new method of injecting the vessels of insects4 7,quart4 ,jour4 of ,micr4 ,science1 xi1 n4 s41 pp4 #chi-cie1 #ahga1 #a ,p#a47 ,graber1 ,v4 ,ueber die ,blatkrperchen der ,insekten4 7,sitzber4 ,akad4 ,wien4 ,math4-naturw4 ,classe1 lxiv1 #ahga1 pp4 #i-dd1 #a ,taf47 ---- ,vorlufiger ,bericht ber den propulsatorischen ,apparat der ,insekten4 7,sitzber4 d4 k4 ,ak4 d4 ,wiss4 ,wien41 lxv1 #ahgb1 pp4 #af1 #a ,taf47 ---- ,ueber den propulsatorischen ,apparat der ,insekten4 7,archiv f4 mikroskop4 ,anatomie1 ix1 #ahgc1 pp4 #abi-aif1 #c ,taf47 ---- ,ueber den pulsierenden ,bauchsinus der ,insekten4 7,archiv f4 mikroskop4 ,anat41 xii1 #ahgf1 pp4 #ege-ehb1 #a ,taf47 ,grobben1 ,carl4 ber blschenfrmige ,sinnesorgane und eine eigenthmliche ,herzbildung der ,larve von ,ptychoptera contaminata ,l4 7,sitzb4 k4 ,akad4 ,wissensch4 ,wien41 #ahge1 lxxii1 p4 #bb1 #a ,taf47 ,liebe1 ,otto4 ,ueber die ,respiration der ,tracheaten1 besonders ber den ,mechanismus derselben und ber die ,menge der ausgeatmeten ,kohlensure4 ,inaug4-,diss4 ,chemnitz1 #ahgb1 pp4 #bh4 ,dogiel1 ,john4 ,anatomie und ,physiologie des ,herzens der ,larve von ,corethra plumicornis4 7,mm4 ,acad4 imp4 ,st4 ,petersbourg1 #g ,sr41 xxiv1 #ahgg1 ,nr4 #aj1 pp4 #cg1 #b ,pls47 ,separate1 ,leipzig1 ,voss4 ,btschli1 ,o4 ,ein ,beitrag zur ,kenntnis des ,stoffwechsels1 insbesondere der ,respiration bei den ,insekten4 7,reichert's und ,du ,bois-,reymond's ,archiv f4 ,anatomie u4 ,physiologie1 #ahgd1 pp4 #cdh-cfa47 ,bla-,dezso4 ,ueber den ,zusammenhang des ,kreislaufs und der respiratorischen ,organe bei den ,arthropoden4 7,zool4 ,anzeiger1 i ,jahrg41 #ahgh1 p4 #bgd47 ,plateau1 ,f4 ,communication prliminaire sur les mouvements et l'innervation de l'organe central de la circulation chez les animaux articuls4 7,bull4 ,acad4 roy4 de ,belgique1 ,sr4 #b1 xlvi1 #ahgh1 pp4 #bjc-bab47 ,jaworovski1 ,ant4 ,ueber die ,entwicklung des ,rckengefsses und speziell der ,muskulatur bei ,chironomus und einigen anderen ,insekten4 7,sitzgsber4 d4 k4 ,akad4 d4 ,wissensch4 ,wien4 ,math4-naturwiss4 ,cl41 lxxx1 #ahgi1 pp4 #bch-beh47 ,zimmermann1 ,o4 ,ueber eine eigentmliche ,bildung des ,rckengefsses bei einigen ,ephemeridenlarven4 7,zeitschr4 f4 wissens4 ,zool41 #ahhj1 xxxiv1 pp4 #djd-djf47 ,burgess1 ,e4 ,note on the aorta in lepidopterous insects4 7,proc4 ,bost4 ,soc4 ,nat4 ,hist41 xxi1 #ahha1 pp4 #aec-aef1 ,figs47 ---- ,contributions to the anatomy of the milk-weed butterfly1 ,danais ,archippus ,f4 7,anniversary ,memoirs ,boston ,soc4 ,nat4 ,hist41 #ahhj1 pp4 #af1 #b ,pls47 ,vayssire1 ,a4 ,recherches sur l'organisation des larves des phmrines4 7,ann4 ,sc4 nat4 ,zool41 ,sr4 #f1 xiii1 #ahhb1 pp4 #a-acg1 #aa ,pls47 ,viallanes1 ,h4 ,recherches sur l'histologie des insectes et sur les phnomnes histologiques qui accompagnent le dveloppement post-embryonnaire de ces animaux4 7,ann4 ,sc4 nat41 ,sr4 #f1 xiv1 #ahhb1 pp4 #a-cdh1 #ah ,pls47 ,schimkewitsch1 ,w4 ,ueber die ,identitt der ,herzbildung bei den wirbel und wirbellosen ,tieren4 7,zool4 ,anzeiger1 #ahhe1 viii ,jahrg41 pp4 #cg-dj1 ,fig47 ---- ,noch etwas ber die ,identitt der ,herzbildung bei den ,metazoen4 7,zool4 ,anzeiger1 #ahhe1 pp4 #chd-chf47 ,creutzburg1 ,n4 ,ueber den ,kreislauf der ,ephemerenlarven4 7,zool4 ,anzeiger1 #ahhe1 pp4 #bdf-bdh47 ,poletajewa1 ,olga4 ,du cur des insectes4 7,zool4 ,anzeiger1 #ahhf1 ix ,jahrg41 pp4 #ac-ae47 ,selvatico1 ,s4 ,l'aorta nel corsaletto e nel capo della farfalla del bombice del gelso4 7,padova1 #ahhg1 p4 #ai1 #b ,pls47 ---- ,die ,aorta im ,brustkasten und im ,kopfe des ,schmetterlings von ,bombyx mori4 7,zool4 ,anzeiger1 #ahhg1 x ,jahrg41 pp4 #efb-efc47 ,kowalevsky1 ,a4 ,ein ,beitrag zur ,kenntnis der ,excretionsorgane4 7,biol4 ,centralbl41 #ahhi1 ix1 pp4 #cc-dg1 #fe-gf1 #abg-abh47 ,tosi1 ,alessandro4 ,osservazioni sulla valvola del cardias in varii generi della famiglia delle ,apidi4 7,ricerche ,lab4 ,anat4 ,r4 ,univ4 ,roma1 v1 #ahie1 pp4 #e-bf1 #af ,figs41 #c ,pls47 ,pawlowa1 ,mary4 ,ueber ampullenartige ,blutcirculationsorgane im ,kopfe verschiedener ,orthopteren4 7,zool4 ,anzeiger1 xviii ,jahrg41 #ahie1 pp4 #g-ac1 #a ,fig47 ,also the writings of ,kolbe4 b4 ,the blood1 blood corpuscles1 leucocytes1 and blood tissue ,wagner1 ,r4 ,ueber ,blutkrperchen bei ,regenwrmern1 ,blutegeln und ,dipterenlarven4 7,mller's ,archiv f4 ,anatomie u4 ,physiologie1 #ahce1 pp4 #caa-cac47 ---- ,nachtrage zur vergleichenden ,physiologie des ,blutes4 7,archiv f4 ,anat4 u4 ,physiologie1 #ahch47 ,newport1 ,g4 ,on the structure and development of the blood4 ,first series4 ,the development of the blood corpuscle in insects and other invertebrata1 and its comparison with that of man and the vertebrata4 7,abstr4 of the paper in ,roy4 ,soc41 #ahde1 v1 pp4 #edd-edf3 also in ,ann4 ,mag4 ,nat4 ,hist41 ,ser4 #c1 #ahde1 iii1 pp4 #cfd-cfg47 ,landois1 ,h4 ,beobachtungen ber das ,blut der ,insekten4 7,zeitschr4 f4 wissens4 ,zool41 xiv1 #ahfd1 pp4 #ee-gj1 #c ,pl47 ----1 and ,l4 ,landois4 ,ueber die numerische ,entwicklung der histiologischen ,elemente d4 ,insektenkrpers4 7,ibid41 xv1 #ahfe1 pp4 #cjg-cbg47 ,rollett1 ,a4 ,zur ,kenntnis der ,verbreitung des ,hmatins4 7,sitzgsber4 d4 k4 ,akad4 d4 ,wiss4 ,wien41 lxiv1 #ahga47 ,wielowiejski1 ,h4 v4 ,ueber das ,blutgewebe der ,insekten4 ,eine vorlufige ,mitteilung4 7,zeitschr4 f4 wissens4 ,zool41 #ahhf1 xliii1 pp4 #eab-ecf47 ,mac,munn1 ,c4 ,a4 ,researches on myohmatin and the histohmatins4 7,proc4 ,roy4 ,soc4 ,london1 #ahhf1 xxxix1 pp4 #bdh-beb47 ,peyron1 ,j4 ,sur l'atmosphere interne des insectes compare celle des feuilles4 7,compt4 rend4 ,acad4 ,sc41 ,paris1 #ahhf1 cii1 pp4 #acci-acda47 ,cunot1 ,l4 tudes sur le sang1 son rle et sa formation dans la srie animale4 ,part #b1 invertbrs2 note prliminaire4 7,arch4 ,zool4 ,expriment41 #ahhh1 ,sr4 #b1 v1 pp4 xliii-xlvii4 ,see also ibid41 ,sr4 #c1 #ahig1 pp4 #fee1 #fgi-fhj47 ,dewitz1 ,h4 ,die selbstandige ,fortbewegung der ,blutkrperchen der ,gliedertiere4 7,naturwiss4 ,rundschau4 ,braunschweig1 #ahhi1 iv ,jahrg41 pp4 #bba-bbb47 ---- ,eigenthtige ,schwimmbewegung der ,blutkrperchen der ,gliedertiere4 7,zool4 ,anzeiger1 #ahhi1 xii ,jahrg41 pp4 #deg-dfd1 ,fig47 ,schffer1 ,c4 ,beitrage zur ,histiologie der ,insekten4 ,,ii1 ,ueber ,blutbildungsherde bei ,insektenlarven4 7,spengel's ,zool4 ,jahrbcher ,abt4 f4 ,anat4 u4 ,ontogenie1 iii1 #ahhi1 pp4 #fbf-fcf1 #a ,taf47 ,cattaneo1 ,g4 ,sulla morfologia delle cellule ameboidi dei ,molluschi e ,artropodi4 7,boll4 ,sc4 ,pavia4 ,anno #aa1 #ahhi1 p4 #ei1 #b ,pls47 ,wagner1 ,w4 ,a4 ,ueber die ,form der krperlichen ,elemente des ,blutes bei ,arthropoden1 ,wrmern und ,echinodermen4 7,biolog4 ,centralblatt1 #ahij1 x1 p4 #dbh47 ,preyer1 ,w4 ,zur ,physiologie des ,protoplasma4 ,,ii1 ,die ,funktionen des ,stoffwechsels4 ,die ,saftstrmung4 7,patanie's ,naturwiss4 ,wochenschr41 #ahia1 vi1 pp4 #a-e47 ,cholodkowsky1 ,n4 ,ueber das ,bluten der ,cimbiciden-,larven4 7,entomologische ,miscellen1 vi1 ,hor ,soc4 ,ent4 ,st4 ,petersburg1 #ahig1 pp4 #ceb-ceg1 #a ,fig4 ,the fluid thrown out through pores or fissures in the skin is the blood47 ,with the writings of ,korotaiev1 ,tichomeroff1 ,pkarsky1 ,balbiani1 ,korotneff1 ,cunot1 and others4 c4 ,the fat-bodies ,dufour1 ,l4 ,recherches anatomiques sur les ,carabiques et sur plusieurs autres insectes ,coloptres4 ,du tissu adipeux splanchnique4 7,ann4 ,sc4 nat41 viii1 #ahbf1 pp4 #bi-ce47 ---- ,histoire comparative des mtamorphoses et de l'anatomie des ,cetonia aurata et ,dorcus parallelepipedus4 ,tissu adipeux splanchnique4 7,ann4 ,sc4 nat41 ,zoologie1 ,sr4 #b1 #ahdb1 xviii1 pp4 #agh-agi47 ,meyer1 ,h4 ,ueber die ,entwicklung des ,fettkrpers1 der ,tracheen und der keimbereitenden ,geschlechtsteile bei den ,lepidopteren4 7,zeitschr4 f4 wissens4 ,zool41 #ahdi1 i1 pp4 #age-agi1 #d ,taf47 ,fabre1 ,j4 ,h4 tude sur le rle du tissu adipeux dans la scretion urinaire chez les insectes4 7,ann4 ,sc4 nat41 ,sr4 #d1 xix1 #ahfb1 pp4 #cea-chb47 ,leydig1 ,fr4 ,einige ,worte ber ,fettkrper der ,arthropoden4 7,reichert1 u4 du ,bois-,reymond's ,archiv f4 ,anat41 #ahfc1 pp4 #aib-bjc47 ,lindemann1 ,k4 ,zoologische ,skizzen4 #a4 ,struktur des ,fettkrpers4 7,bull4 ,soc4 ,imp4 d4 ,natural4 ,moscou1 #ahfd1 pp4 #eba-ebf1 #a ,pl47 ,landois1 ,leonh4 ,ueber die ,funktion des ,fettkrpers4 7,zeitschr4 f4 wissens4 ,zoologie1 xv1 #ahfe1 pp4 #cga-cgb47 ,wielowiejski1 ,h4 v4 ,ueber den ,fettkrper von ,corethra plumicornis und seine ,entwicklung4 7,zool4 ,anzeiger1 #ahhc1 vi ,jahrg41 pp4 #cah-cbb47 ---- ,ueber das ,blutgewebe der ,insekten4 7,zeitschr4 f4 wissens4 ,zool41 #ahhf1 xliii1 pp4 #eab-ecf47 ,kowalevsky1 ,a4 ,o4 ,sur les organes excrteurs chez les arthropodes terrestres4 7,congrs internat4 ,zool41 #bme ,sess41 pp4 #aif-bje1 ,moscou1 #ahib47 ,,the ,,blood ,,tissue ,under this name ,wielowiejski has included several important tissues or cellular bodies intimately concerned with the nutrition of the insect4 ,these are3-- #a4 ,the blood corpuscles4 7,see p4 #djg1 leucocytes and phagocytes47 #b4 ,the fat-body proper 7,corpus adiposum74 #c4 ,the pericardial fat-body 7pericardial cells74 #d4 ,the nocytes4 #e4 ,the garland-shaped cord of muscid larv4 #f4 ,the subsophageal body1 a peculiar organ found by ,wheeler in the embryos and young larv of ,blatta and ,xiphidium4 #g4 ,the phosphorescent organs4 a4 ,the fat-body ,in the body cavity of winged insects and of their larv occur yellowish masses of large cells filled with small drops of fat1 and forming the 8fat-body40 ,it is of various shapes1 more or less lobulated or net-like1 and covers or envelops parts of the viscera1 also forming a layer under the integument 7,fig4 #adc74 ,the tracheal endings are usually enveloped by the fat-body4 ,it is larger in the larv than in the adults1 especially in ,lepidoptera1 in them forming a reserve of nutrition1 used during metamorphosis and during the formation and ripening of the eggs and male cells4 ,wielowiejski has shown that there is a regular arrangement of the fat-body in the general cavity of the body4 ,for example1 in the larva of ,chironomus occur the following forms of this tissue4 ,around the periphery1 on each side of the body cavity1 is a loose network of lobes with large meshes constituting the peripheral layer or external lobular fat-body2 these lobular masses are segmentally arranged4 ,within these segmental lobes1 on each side of and along the digestive tract1 extending along through almost the entire body1 is an unbroken strand of this tissue1 forming the internal fat-body cords4 ,from the first larval stage1 and even before hatching1 its cells are so unusually large1 being filled with large1 clear1 mostly colorless fat-drops1 that their limits cannot be defined1 and their nuclei can only with great difficulty be detected4 ,only in some large larv of ,chironomus has ,wielowiejski found clearly defined cells2 the protoplasm of these cells contain almost no fat-drops4 ,the fat-body is of mesodermal origin1 and as ,wheeler insists1 is not derived from the nocytes1 as supposed by ,graber4 ,formed from the mesoderm1 it is a differentiation of portions of the clomic walls1 and therefore metameric in origin4 ,that the fat-body gives origin to the blood corpuscles ,wheeler is doubtful4 ,the fat-cells are distinct1 spherical1 and as a rule possess only one nucleus1 though in those of ,apis and ,melophagus there are two nuclei1 and in ,musca several4 ,sometimes the cells contain a substance like the white of an egg1 and concretions of uric acid1 or these take the place of the fat-drops4 ,the presence of uric acid shows that a very active metabolism goes on in the fat-body4 8,in some cases it has been proved that the fat-body in the larva is rich in fat and poor in concretions of uric acid1 while in the imago it is poor in fat and rich in concretions of uric acid0 7,lang74 ,leydig1 in #aheg 7,lehrbuch der ,histiologie71 spoke of the presence of dark concretions in the fat-body1 and afterwards 7#ahfd7 showed that there was a wide distribution of uric acid salts and concretions4 ,witlaczil1 also1 has detected concretions in the fat-body of the ,psyllid1 in larval ,cecidomyiid1 in the larv and pup of ants1 and in the pupa of ,musca4 ,the physiological processes which take place in the fat-bodies are obscure4 ,graber regarded the whole system of the fat-bodies as 8a single1 many-lobed lung10 while before him ,landois1 taking into account the intimate relation existing between the finer tracheal branches and the fat-body1 considered that the latter was concerned in respiration4 ,marchal thinks that the fat-body is a urinary organ1 as the urates are formed within the cells of this body4 ,moreover1 ,schffer maintains that a special kind of fat-body cell has the important function of taking up and giving out nutritious matters during the internal processes of metamorphosis1 while he also believes that there is a genetic connection between the fat-body and the blood corpuscles--a view combated by ,wheeler4 ,kowalevsky finds that the fat-body remains absolutely insensible to the action of the substances which stained the ,malpighian tubes 7p4 #ceb74 ,so long as the cells are healthy and living they are not stained and do not absorb the colors in question2 and this insensibility persists1 even when the cells are of a different nature1 as those of the fly 7adipose and 8intercalary0 cells74 b4 ,the pericardial fat-body or pericardial cells ,we have already1 on p4 #dje1 called attention to these organs1 but they also have an intimate relation to the fat-body4 ,kowalevsky 7#ahib7 remarks that the disposition of these cells varies much in different insects and even in the same animal4 ,thus1 in the ,diptera and the ordinary flies there are found around the lower part of the dorsal vessel #ac pairs of large pericardial cells which lie next to a crowded bed of small cells forming a compact mass around the anterior part of the dorsal vessel4 ,in caterpillars1 notably silkworms1 from the compact layer of pericardial cells which surround the heart1 pass off trunks which are directed towards the lateral walls of the body1 also forming close networks around the trache and then passing down into the abdominal cavity of the body of the larva4 ,in the larv of certain ,hymenoptera1 the trunks which pass off from the pericardial region form a loose cord1 a sort of fatty tissue covering the entire body cavity4 ,this tissue1 adds ,kowalevsky1 entirely differs from nocytes1 or from the so-called glandular body whose formation in ,gryllotalpa has been described by ,korotaiev1 and in ,bombyx mori by ,tichomiroff4 ,in a recent work wherein has been collected everything known regarding these last-named cells1 ,pkarsky proves that they are unique in nature and cannot be regarded either as fat-cells1 or as pericardial cells1 or even as formative leucocytes4 ,as to the structure of the pericardial cells1 ,kowalevsky adds that they are always attached to muscular fibres passing off from the heart1 and that they lie1 so to speak1 upon them4 ,in the locusts the muscular fibres supporting the pericardial cells appear distinctly like little staves or sticks4 ,the attachment of the pericardial cells to the muscular fibres has been observed by ,cunot and reproduced by him in his work1 but his description somewhat differs from that observed by ,kowalevsky in the locust 7,acrydium migratorium74 ,as to the nature of the acid excretions which are formed in the pericardial cells1 in spite of his attempts to solve the problem1 ,kowalevsky has been unsuccessful4 ,the only observations in this direction are those of ,letellier on the pericardial glands of lamellibranch molluscs1 which he found to contain hypouric acid1 and it is probable1 says ,kowalevsky1 that the acidity of the pericardial cells in insects is due to the presence of the same acid4 ,leucocytes or phagocytes in connection with the pericardial cells4--,it is thought by ,schffer that the leucocytes or phagocytes may be free or wandering fat-body cells4 ,they play an important part in metamorphosis1 while they absorb or feed upon the remains of the larval organs1 and thus prove of use in the building up of the organs of the adult insects4 ,while the faculty of phagocytosis is wanting in the urinary tubes1 ,balbiani and more recently ,cunot have expressed the opinion that the pericardial cells of insects may have the power of absorbing hard bodies1 8acting as a phagocytic gland40 ,this1 however1 is called in question by ,kowalevsky1 from studies made on different insects4 ,on introducing powdered carmine into the body of an insect it has not been absorbed by the pericardial cells1 as they have not been colored red4 ,it is the leucocytes which absorb the grains of carmine1 and which1 after having dissolved them1 transmit them to the pericardial cells4 ,hence1 then1 the pericardial cells have not the phagocytic power of which ,cunot speaks4 ,returning to his own observations on hard bodies introduced into insects1 or large globules introduced under the form of a milk emulsion1 ,kowalevsky has found that these bodies were absorbed in the first place by the free-swimming leucocytes1 and in the second place by whole groups or nests of leucocytes situated in different parts of the body1 principally on the threads of the adipose body4 ,in the ,orthoptera the absorption is immediately effected by means of the cells of the membrane which separates the pericardium from the cavity of the body underneath the heart4 ,the regions where the hard bodies are absorbed in great number coincide with the regions of formation of the blood corpuscles4 ,in his researches on the larv of ,hyponomeuta and other ,lepidoptera1 ,schffer describes these regions as forming a sort of island4 ,the nests where the blood globules are formed are the most active centres of phagocytosis4 ,illustration3 ,,fig4 #chd4-,section of the heart 7c7 and pericardial cells 7pc1 pc7 from the posterior part of the heart of a fly3 l1 l1 nests of leucocytes situated between the heart and pericardial cells4--,from a microphotograph1 after ,kowalevsky4 ,illustration3 ,,fig4 #che4--;,cross-section of the heart of ,truxalis nasata and of the structures around it3 c1 heart3 ep1 epithelium under the cuticula 7hvpodermis72 or1 ovarian tubes2 pc1 pericardial cells1 with one or two nuclei containing a deposit of carmine2 l and l1 group of leucocytes1 which have absorbed granules of ,india ink4--,after ,kowalevsky4 ,balbiani1 and also ,cunot1 have supposed that the formation of the blood corpuscles takes place in the pericardial cells1 but ,kowalevsky insists that these cells cannot form the leucocytes1 which 8are probably formed in different parts of the body1 notably in the special nests ,herde of ,jger situated near the heart1 but outside of the pericardial cells40 ,in ,fig4 #chd1 where the nests of leucocytes 7l7 are shown1 it is evident that they are formed where observed1 and 8could not have come from the pericardial cells1 which have their own structure and their special function10 these cells being very large and characteristic4 ,in ,kowalevsky's preparations of ,truxalis1 the pericardial cells with deposits of carmine and the groups of leucocytes 7,fig4 #che1 l and l7 stained with ,india ink1 we have to deal with elements absolutely different4 ,if the formation of leucocytes was caused by the pericardial cells1 these last would be obliged to free themselves from their contents and to modify their essential nature4 c4 ,the nocytes ,illustration3 ,,fig4 #chf4--;,cluster of nocytes from a nearly mature ,phryganeid larva3 o1 nocytes2 t1 large tracheal branch2 tt1 smaller tracheal ramifications2 h1 tracheal hypodermis4 ,illustration3 ,,fig4 #chg4--;,a nearly mature embryo of ,xiphidium ensiferum3 o1 o1 nocyte clusters seen from the surface through the integument2 a1 pleuropodium of the right side 7appendage of the first abdominal segment72 s1 styli2 c1 cercopods4--,this and ,fig4 #chf after ,wheeler4 ,these cells 7,fig4 #chf71 with the exception of the eggs1 are the largest in the body1 and occur in most if not all winged insects4 ,they were called nocytes 7oinos1 wine2 kustis1 cyst71 by ,wielowiejski in allusion to their wine-yellow color4 ,these cells are arranged segmentally 7,fig4 #chg7 in clusters1 held in place by trache1 and are situated mostly on each side of the abdomen1 rarely being found in the adjoining parts of the thorax4 ,they are more or less intimately associated with the blood and fat-body4 ,unlike the fat-body1 however1 they arise in embryonic life from the ectoderm1 either by delamination or by immigration1 just behind the tracheal involutions4 ,the separate cells of each cluster are usually separate1 but in rare cases may fuse in pairs or form smaller clusters4 ,in shape they are round or oval1 often sending out pseudopodia-like processes1 by which they are attached to the tracheal twigs or to each other4 8,the cytoplasm1 which is very abundant1 is full of yellowish granules and is sometimes radially situated towards its periphery4 ,the large spherical or oval nucleus contains a densely wound and delicate chromatic filament40 7,wheeler47 ,graber first pointed out the identity of these clusters of cells with certain metameric cell-masses in insect embryos1 observed by ,tichomiroff in those of the silkworm1 and by ,korotneff in the embryo mole-cricket4 ,although they resemble the blood corpuscles in some insects1 they are always much larger1 and do not seem to be amboid1 while they are never seen to undergo self-division1 or to exhibit any appearance of giving rise to the blood-cells 7,wheeler74 ,they have not yet been detected in ,thysanura 7,synaptera7 or in ,myriopoda4 d4 ,the phosphorescent organs ,phosphorescence is not infrequent in the ,protozoa1 clenterates1 worms1 and has been observed in the bivalve ,pholas1 in a few abyssal ,crustacea1 in myriopods 7,geophilus71 in an ascidian1 ,pyrosoma1 and in certain deep-sea fishes4 ,illustration3 ,,fig4 #chh4--;,a1 sagittal section through the hinder end of a male ,luciola1 the organs above the phosphorescent plate only drawn in outline3 s1 integument of the last segment1 somewhat removed by the section-knife from the phosphorescent tissues2 d1 dorsal layer of the phosphorescent plate penetrated by irregular tracheal branches1 and rendered opaque by numerous urate concretions imbedded in it2 v1 ventral phosphorescent layer of the plate1 with perpendicular tracheal stems whose branches1 where they pass into capillaries1 bear lumps which stain brown with osmic acid2 n1 structureless substance 7coagulum87 filling the end of the last ventral segment4 ,b1 isolated portion of the ventral layer of the phosphorescent plate2 tr1 tracheal stem surrounded by a cylindrical lobe3 p1 parenchym cell attached to the cylinder2 c1 capillary1 without the spiral threads2 m1 coagulum stained brown4 ,c1 a tracheal stem of the ventral layer3 at the fork of the brown-stained capillaries are lumps stained brown with osmic acid4 ,d1 a part of ,c1 more highly magnified1 showing the remains of the tracheal end-cells 7tc7 enveloping the brown lumps 7m74--,after ,emery4 ,in insects luminosity is mostly confined to a few ,coleoptera1 and besides the well-known fireflies1 an ,indian ,buprestid 7,buprestis ocelata7 is said to be phosphorescent2 also a telephorid larva4 ,other luminous insects are the ,poduran ,anurophorus1 ,fulgora1 certain ,diptera 7,culex1 ,chironomus#fj and ,tyreophora71 and an ant 7,orya74 ,the seat of the light is the intensely luminous areas situated either in the head 7,fulgora71 in the abdomen 7,lampyrid71 or in the thorax 7in a few ,elaterid of the genus ,pyrophorus74 ,the luminous or photogenic organ is regarded by ,wielowiejski and also by ,emery as morphologically a specialized portion of the fat-body1 being a plate consisting of polygonal cells1 situated directly under the integument1 and supplied with nerves and fine tracheal branches4 ,in ,luciola as well as in other fireflies1 including ,pyrophorus1 the phosphorescent organ or plate consists1 as first stated by ,klliker1 of two layers lying one over the other1 a dorsal one 7,fig4 #chh1 d7 which is opaque1 chalky white1 and non-photogenic1 and a lower one 7v71 the active photogenic layer1 which is transparent4 ,through the upper or opaque layer and on its dorsal surface extend large trache and their horizontal branches1 from which arise numerous very fine branches which pass down perpendicularly into the transparent or photogenic layer of the organ4 ,each tracheal stem1 together with its short branches1 is enveloped by a cylindrical mass of transparent tissue1 so that only the short terminal branches or very fine tracheal capillaries project on the upper part of the cylinder4 ,these finest tracheal capillaries are not in ,luciola filled with air1 but with a colorless fluid1 as was also found by ,wielowiejski and others in ,lampyris4 ,these transparent cylinders1 with the trache within1 forming longitudinal axes1 resemble lobules4 ,these lobules are so distributed that they appear on a surface section of this plate as numerous round areas in which circular periphery the tracheal capillaries are arranged with the axially disposed tracheal end-cells4 ,these 8tracheal end-cells0 are only membranous enlargements at the base of the tracheal capillaries 7,wielowiejski74 ,the cylindrical lobules are separated from each other by a substance consisting of abundant large granular cells 7parenchym cells7 among which project the tracheal capillaries4 ,the cylindrical lobules extend to the hypodermis and come in contact only by their lateral faces with the parenchym4 ,the structure of the upper opaque chalky white layer of the phosphorescent organ is1 compared with that of the photogenic lower portion1 very simple4 ,in its loose1 pappose1 mass are no cellular elements1 but when treated with different reagents it is seen to be filled with countless urate granules 7guanine7 swimming in the fluid it contains1 the cell plasma appearing to be dissolved1 the cells having lost their cohesion4 ,in comparing the phosphorescent plate or organ of ,luciola with that of ,lampyris1 the general structure1 including the clear cell elements of the cylindrical lobules1 which envelop the perpendicular tracheal twigs and their branches1 and also the granular parenchymatous cells are alike in both1 though the arrangement and distribution of the elements in ,luciola is more regular1 in ,lampyris the tracheal stems being irregularly scattered through the parenchym4 ,wielowiejski found in the larval and female ,lampyris a higher degree of differentiation than in the male1 and ,luciola has a more differentiated photogenic organ than ,lampyris1 as seen in the more regular structure of the lobules4 ,as regards the light-apparatus of ,pyrophorus1 or the cucujo1 ,heinemann shows that1 as in the ,lampyrid1 it consists of distinct cells1 and may be regarded as a glandular structure4 ,it is rich in trache and the other parts already described4 ,in still later researches on a ,brazilian ,pyrophorus ,wielowiejski shows that the phosphorescent plate consists of two layers1 the upper usually being filled with crystalline urate concretions1 and entirely like those of the ,lampyrid1 consisting of distinct polygonal cells1 among which are numerous tracheal stems1 with tnidia1 coursing in different directions1 when freshly filled with air1 and sending capillaries into the underlying photogenic layer4 ,the latter shows in its structure a striking difference in the cellular arrangement from that of ,lampyrids4 ,in the upper or non-photogenic layer are tracheal capillaries which pass down into the underlying cellular plate and which are in the closest possible relations with the single cells--a point overlooked by ,heinemann4 ,physiology of the phosphorescence4--,as is well known1 the phosphorescence of animals is a scintillating or glowing light emitted by various forms1 the greenish light or luminous appearance thus produced being photogenic1 i4e4 without sensible heat4 ,langley rates the light of the firefly at an efficiency of #ajj per cent1 all its radiations lying within the limits of the visible spectrum4 8,langley has shown that while only #b4d per cent of luminous waves are contained in the radiation of a gas-flame1 only #aj per cent in that of the electric arc1 and only #ce per cent in that of the sun1 the radiation of the firefly 7,pyrophorus noctilucus7 consists wholly of visible wave-frequencies40 7,barker's ,physics1 p4 #che47 ,the spectrum of the light of the cucujo was found by ,pasteur to be continuous4 7,c4 ,r4 ,french ,acad4 ,sc4 #ahfd1 ii1 p4 #eji47 ,a later examination by ,aubert and ,dubois showed that the spectrum of the light examined by the spectroscope is very beautiful1 but destitute of dark bands4 ,when1 however1 the intensity diminishes1 the red and orange disappear1 and the green and yellow only remain4 ,heinemann studied the cucujo at ,vera ,cruz1 ,mexico4 ,at night in a dark room it radiates a pale green light which shows a blue tone to the exclusion of any other light4 ,the more gas or lamp light there is present1 the more apparent becomes the yellowish green hue1 which in clear daylight changes to an almost pure very light yellow with a very slight mixture of green4 8,in the morning and evening twilight1 more constantly and clearly in the former1 the cucujo light1 at least to my eyes1 is an intensely brilliant yellow with a slight mixture of red4 ,in a dark room lighted with a sodium light the yellow tone entirely disappears2 on the other hand1 the blue strikingly increases40 ,as regards the spectrum he found that almost exactly half of the blue end is wanting and that the red part is also a little narrower than in the spectrum of the petroleum flame4 ,professor ,c4 ,a4 ,young states that the spectrum given by our common firefly 7,photinus87 is perfectly continuous1 without trace of lines either bright or dark4 8,it extends from a little above ,fraunhofer's line ,c1 in the scarlet1 to about ,f in the blue1 gradually fading out at the extremities4 ,it is noticeable that precisely this portion of the spectrum is composed of rays which1 while they more powerfully than any others affect the organs of vision1 produce hardly any thermal or actinic effect4 ,in other words1 very little of the energy expended in the flash of the fire is wasted4 ,it is quite different with our artificial methods of illumination4 ,in the case of an ordinary gaslight the best experiments show that not more than one or two per cent of the radiant energy consists of visible rays2 the rest is either invisible heat or actinism2 that is to say1 over #ih per cent of the gas is wasted in producing rays that do not help in making objects visible40 ,panceri also remarks that while in the spectroscope the light of some ,chtopteri1 ,bero1 and ,pyrosoma exhibit one broad band like that given by monochromatic light1 that of ,lampyris and ,luciola is polychromatic4 7,amer4 ,nat41 vii1 #ahgc1 p4 #cad47 ,the filtered rays of ,lampyris pass 7like ,rntgen and uranium rays7 through aluminium 7,muraoka74 ,the physiology of insect phosphorescence is thus briefly stated by ,lang3 8,the cells of this luminous organ secrete1 under the control of the nervous system1 a substance which is burnt during the appearance of the light2 this combustion takes place by means of the oxygen conveyed to the cells of the luminous body by the trache1 which branch profusely in it and break up into capillaries40 ,emery states that the males of ,luciola display their light in two ways4 ,when at night time they are active or flying1 the light is given out at short and regular intervals1 causing the well-known sparkling or scintillating light4 ,if we catch a flying ,luciola or pull apart one resting in the day time1 or cut off its hind body1 it gives out a tolerably strong light1 though not nearly reaching the intensity of the light waves of the sparkling light4 ,in this case the light is constant1 yet we notice1 especially in the wounded insect1 that the phosphorescent plate in its whole extent is not luminous1 but glows at different places as if phosphorescent clouds passed over it4 ,it is self-evident that a microscopic observation of the light of the glow-worm or firefly is not possible1 but an animal while giving out its light1 or a separated abdomen1 may readily be placed under the microscope and observed under tolerably high powers4 ,by making the experiment in a rather dark room ,emery saw clear shining rings on a dark background4 8,all the rings are not equally lighted4 ,comparing this with the results of anatomical investigation1 it is seen that the rings of light correspond with the previously described circular tracheal capillaries1 i4e4 the limits between the tracheal-cell cylinder and the parenchym-cells4 ,the parenchym-cells are never stained of a deep brown2 this proves that its plasma may be the seat of the light-producing oxidation4 ,hence this process of oxidation takes place in the upper surface of the parenchym-cells1 but outside of their own substance4 ,the parenchym-cells in reality secrete the luminous matter2 this is taken up by the tracheal end-cells and burnt or oxidized by means of the oxygen present in the tracheal capillaries4 ,such a combustion can only take place when the chitinous membrane of the trache is extraordinarily fine and easily penetrable1 as is the case in the capillaries of the photogenic plate2 therefore the plasma of the tracheal cells only oxidizes at the forking of the terminal tracheal twigs and in the capillaries40 7,emery47 ,the color of the light of ,luciola is identical in the two sexes1 and the intensity is much the same1 though that of the female is more restricted4 ,the rhythm of the flashes of light given out by the male is more rapid1 and the flashes briefer1 while those of the female are longer1 more tremulous1 and appear at longer intervals4 ,emery then asks3 ,what is the use of this luminosity8 ,is it only to allure the females of ,luciola1 which are so much rarer than the males8 ,contrary to the general view that it is an alluring act1 he thinks that phosphorescence is a means of defence1 or a warning or danger-signal against insectivorous nocturnal animals4 ,if we dissect or crush a ,luciola1 it gives out a disagreeable cabbage-like smell1 and perhaps this is sufficient to render it inedible to bats or other nocturnal animals4 ,an acrid taste they certainly do not possess4 ,it has long been known that the eggs of fireflies1 both ,lampyrid and ,pyrophorus1 are luminous4 ,both ,newport and more recently ,wielowiejski attributes the luminosity not to the contents of the egg1 but to the portions of the fat-body cells or fluid covering on the outside of the eggs1 due to ruptures of the parts within the body of the female during oviposition4 ,the larv at different ages are also luminous4 ,the position of the luminous organs changes with age4 ,in the larv of ,pyrophorus before moulting1 according to ,dubois1 the luminous organs are situated only on the ventral side of the head and prothoracic segment4 ,in larv of the second stage there are added three shining spots on each of the first eight abdominal segments1 and a single luminous spot on the last segment4 ,these spots are arranged in a linear series and thus form three luminous cords4 ,in the adult beetles there is a luminous spot in the middle of the first abdominal sternite1 but the greatest amount of light is produced by the two vesicles on the hinder part of the prothorax1 the position of which varies according to the species4 ,,literature ,,on ,,phosphorescence ,peters1 ,w4 ,ueber das ,leuchten der ,lampyris italica4 7,mller's ,archiv f4 ,anatomie1 #ahda1 pp4 #bbi-bcc47 ,klliker1 ,a4 ,die ,leuchtorgane von ,lampyris1 eine vorlufige ,mittheilung4 7,verhandl4 d4 phys4 medizin4 ,gesellsch4 ,wrzburg1 #aheg1 viii1 pp4 #bag-bbd47 ,schultze1 ,max4 ,ueber den ,bau der ,leuchtorgane der ,mnnchen von ,lampyris splendidula4 7,sitzber4 d4 niederrhein4 ,gesellsch4 f4 ,natur4 u4 ,heilkunde zu ,bonn1 #ahfd1 ,sep4 p4 #g47 ---- ,zur ,kenntniss der ,leuchtorgane von ,lampyris splendidula4 7,archiv f4 mikroskop4 ,anat41 #ahfe1 i1 pp4 #abd-acg1 #b ,taf47 ,wielowiejski1 ,h4 ,ritter von4 ,studien ber die ,lampyriden4 7,zeits4 f4 wissens4 ,zool41 #ahhb1 xxxvii1 pp4 #ced-dbh1 #b ,taf47 ,emery1 ,carlo4 ,untersuchungen ber ,luciola italica ,l4 7,zeits4 f4 wissens4 ,zool41 #ahhd1 xl1 pp4 #cch-cee1 #a ,taf47 ---- ,la luce della ,luciola italica osservata col microscopio4 7,bull4 ,soc4 ,ent4 ,ital4 ,anno xvii1 #ahhe1 pp4 #cea-cee1 #a ,taf47 ,wheeler1 ,william ,morton4 ,concerning the blood tissue of the ,insecta1 ,,iii2 ,psyche1 vi1 #ahib1 p4 #bee4 7,structure of the light organ of ,photuris pennsylvanica47 ,heinemann1 ,c4 ,zur ,anatomie und ,physiologie der ,leuchtorgane ,mexikanischer ,cucujos1 ,pyrophorus4 7,archiv f4 mikroskop4 ,anat41 #ahhf1 xxvii1 pp4 #bif-chc47 ,dubois1 ,r4 ,contribution l'tude de la production de la lumire par les tres vivants4 ,les ,elaterides lumineux4 7,bull4 ,soc4 ,zool4 ,france1 #ahhf1 ,anne ii1 pp4 #a-bge1 #i ,pls47 ,wielowiejski1 ,h4 ,ritter von4 ,beitrge zur ,kenntniss der ,leuchtorgane der ,insekten4 7,zool4 ,anzeiger1 #ahhi1 ,jahrg4 xii1 pp4 #eid-fjj47 ,hudson1 ,g4 ,v4 ,the habits and life-history of the ,new ,zealand glowworms4 7,trans4 ,n4 ,zealand ,inst41 xviii1 #ahij1 pp4 #dc-di1 #a ,p#a47 ,dubois1 ,r4 ,sur le mechanisme de la production de la lumire chez l',orya barbarica d',algrie4 7,comptes rend4 ,acad4 ,sc4 ,france1 #ahib1 cxvii1 pp4 #ahd-ahf4 ,also in ,ann4 and ,mag4 ,nat4 ,hist41 #ahic 7#f71 xii1 pp4 #dae-daf47 ,schmidt1 ,p4 ,ueber das ,leuchten der ,zuckmcken 7,chironomid74 7,zool4 ,jahrb4 ,morph41 ,abth4 viii1 #ahid1 pp4 #aia-baf1 #b ,taf4 ,also ,ann4 and ,mag4 ,nat4 ,hist41 xv1 pp4 #acc-ada1 #ahie4 ,the light is due to bacteria4 ,nature1 #ahig47 ,chun1 ,c4 ,leuchtorgane und ,facettenaugen4 7,biol4 ,centralbl41 #ahif1 pp4 #cae-cbj47 ,muraoka1 ,h4 7,on the filtered rays of ,lampyris1 ,wiedemann's ,annalen1 ,dec41 #ahif47 ,see also the writings of ,audouin1 ,carus1 ,d4 ,turner1 ,thompson4 ,,the ,,respiratory ,,system ,while land vertebrates breathe by inhaling the air through the mouth into the lungs1 insects respire by internal air-tubes 7trache71 which ramify throughout every part of the body and its appendages4 ,the air enters these tubes through a few openings1 called spiracles or stigmata1 arranged segmentally in the sides of the body4 ,these trache are everywhere bathed by the blood1 and thus the latter is constantly arated or kept fresh2 the blood not1 as in vertebrates or as in molluscs1 seeking the lungs or gills1 or any specialized respiratory portion of the body where the oxygen combines with the hmoglobin1 but the respiratory tubes1 so to speak1 themselves seek out the blood and the blood-tissue in every part of the insect body1 penetrating to the tips of the antenn and of the legs1 entering the most delicate tissues1 even perhaps passing through the walls of epithelial cells4 ,as ,lang remarks1 the want of an arterial vascular system is compensated for as well as conditioned by the extremely profuse branching of the trache4 ,illustration3 ,,fig4 #chi4--,rat-tailed larva of ,eristalis4 ,the aquatic larv of certain dragon-flies 7,agrionid71 may-flies1 case-worms1 etc41 respire by means of tracheal gills or branchi1 which are either filamental or leaf-like appendages containing trache4 ,somewhat similar structures appended to the thorax of pupal aquatic ,diptera1 as in the mosquito and its allies1 enable them to breathe while stationed a little beneath the surface of the water4 ,other larv1 as the rat-tail larva of ,eristalis1 etc41 lying at the bottom of shallow pools or in ditches1 etc41 can breathe by raising slightly above the surface a long appendage with two spiracles at the end1 through which the air enters the tracheal system4 7,see p4 #dfa47 ,although ,aristotle1 as well as the natural philosophers of the ,middle ,ages1 supposed that insects did not breathe1 one can easily see that they do by holding a grasshopper or dragon-fly in one's hand and observing the rhythmical rise and fall of the upper and lower walls of the abdomen1 during which the air enters and passes out of the air-openings or spiracles on each side of the body4 ,it is plain that insects consume very little air1 since caterpillars may be confined in very small1 almost air-tight tin boxes1 and continue to eat and undergo their transformations without suffering from the confinement4 ,according to ,h4 ,mller an insect placed in a small1 confined space absorbs all the oxygen4 ,insects can survive for many hours when placed in an exhausted receiver1 or in certain irrespirable gases4 8,cockroaches in carbonic acid speedily become insensible1 but after twelve hours' exposure to the pure gas they survive and appear none the worse40 7,miall and ,denny1 p4 #afe47 ,insects of the swiftest flight breathe most rapidly1 their great muscular activity requiring the absorption of an abundance of oxygen4 ,illustration3 ,,fig4 #cij4--,section of ,sphinx embryo1 showing at s the ectoderm invaginated1 and forming the germ of a stigma and trachea 7t74--,after ,kowalevsky4 ,warmth1 plenty of food1 besides muscular activity1 increases the demand for oxygen and the quantity of carbonic acid exhaled4 a4 ,the trache ,illustration3 ,,fig4 #cia4--,portion of a trachea of a caterpillar1 with its branches ,b1 ,c1 ,d3 a1 peritracheal membrane2 b1 nucleus4--,after ,leydig1 from ,gegenbaur4 ,illustration3 ,,fig4 #cib4--,structure of a trachea1 diagrammatic3 portions of the peritracheal membrane 7hy7 and chitinous intima 7cc7 removed to show the structure2 in the chitinous intima or endotrachea 7cc7 can be seen the spiral thickenings or tnidia4--,after ,lang4 ,it will much simplify our conception of the nature of the air-tubes when we learn that they originate in the embryo as tubular ingrowths of the integument 7ectoderm71 these branching and finally reaching every part of the interior of the body4 ,they are elastic tubes1 and being filled with air are silvery in color1 though at their origin near the spiracles they are reddish or violet bluish2 or1 in the larva of schna1 reddish brown1 this tint being due to a finely granular pigment situated in the peritoneal membrane4 ,illustration3 ,,fig4 #cic4--,longitudinal section of the trachea of ,hydrophilus piceus3 ep1 epithelium2 cu1 cuticula2 f1 spiral threads4--,after ,minot4 ,in their essential structure the trache consist of the chitinous intima1 which is a continuation of the cuticle of the integument1 and of a cellular membrane or outer layer of cells 7a continuation of the hypodermis7 called the peritoneal membrane1 or ectotrachea 7,figs4 #cib1 #cic74 ,leydig discovered that the spiral filaments are not distinct and separate1 but intimately connected with the inner membrane 7intima71 and he detected the outer or peritoneal membrane1 which ,chun afterwards found to be epithelial in its nature1 ,minot stating that it is a true pavement epithelium4 ,figure #cic represents a longitudinal section of a large trachea of ,hydrophilus1 showing the peritoneal membrane 7ectotrachea1 ep7 and the intima or endotrachea1 divided into the cuticula 7cu71 with the darker colored inner layer1 in which are embedded the dark-colored tnidia 7f74 ,illustration3 ,,fig4 #cid4--,testis of ,anabrus1 showing the ramifications of the trache4--,after ,minot4 ,distribution of the trache4--,the distribution of the air-tubes1 as ,lubbock and also ,minot state1 depends first upon the shape of the organs1 and upon the size of those whose size is variable4 ,around the large1 hollow organs 7digestive canal1 sexual organs7 the trache ramify in all directions1 forking so that the branches diverge at a wide angle4 ,in the organs which have muscular walls1 like the oviduct1 the trache run straight when the walls are distended1 but have a sinuous course when the walls are contracted4 7,minot47 8,around the organs of more elongated form the branches of the trache run more longitudinally1 as is shown by the air-tubes of the muscles1 which also present some peculiarities worthy of especial notice4 8,a short1 thick trunk arrives at the muscular bundle1 and dividing very rapidly1 breaks up into a large number of delicate tubes1 which penetrate between the muscular fibres1 then terminating in tubes of exceeding fineness1 which at first sight seem to form a network that might well be called a rete mirabile4 ,a closer examination1 however1 reveals that it is not a real network1 but rather an interlacing confusing to the eye4 ,the longitudinal direction of the trache of the muscles presents a striking contrast to the system of divarication represented in ,figs4 #ac and #ad4 ,the course of the trache of the ,malpighian tubes is also very curious4 ,there is one large trachea which winds around the tube in a long spiral1 giving off numerous small branches which run to the surface of the tube1 upon which they form delicate ramifications4 ,each tube has but a single main trachea1 and ,i think the trachea continues the whole length of the tube1 but of this last point ,i am not quite sure40 7,minot47 ,while in the nymphs of ,orthoptera the trache very closely resemble those of the adult1 in larv of insects with a complete metamorphosis the trache differ very much in distribution from those of the adult4 ,the larval trache are also more generalized and more like those of the original type than the trache of perfect insects4 7,lubbock47 ,in general there are two main trache1 one passing along each side of the body1 near the digestive canal1 connected with its mate by a few transverse anastomosing branches1 and sending off a branch to each spiracle1 this arrangement being most simple and apparent in the maggots of ,diptera4 ,from these two main branches smaller twigs branch off into every part of the body with its appendages1 passing among the different organs1 often serving as cables to hold them loosely in place2 they also penetrate into the component parts of the organ themselves1 passing into the fat-bodies1 and among the fibres of muscles1 where they become finely attenuated and refined like the capillaries of the vascular system of vertebrates4 7,figs4 #cie1 #cif47 ,illustration3 ,,fig4 #cie4--,melanoplus femur-rubrum1 showing distribution of air-tubes 7trache7 and air-sacs2 ,v1 main ventral trachea 7only one of the two shown72 ,s1 left stigmatal trachea1 connecting by vertical branches with ,d1 the left main dorsal trachea2 c1 left cephalic trachea2 oc1 ocular dilated trachea4 ,from the first1 second1 third1 and fourth spiracles arise the first four abdominal air-sacs1 which are succeeded by the plexus of three pairs of dilated trache1 ,i1 ,,ii1 ,,iii1 in ,fig4 #cif4 ,numerous air-sacs and trache are represented in the head and thorax4 ,the two thoracic spiracles are represented1 but not lettered4 ,illustration3 ,,fig4 #cif4--;,d1 left dorsal trachea2 ,s1 left stigmatal trachea2 ,i1 ,,ii1 ,,iii1 first1 second1 and third pairs of abdominal dilated trache1 forming a plexus behind the ovaries2 #a1 pair of enormous thoracic air-sacs2 #b1 pair of smaller air-sacs2 #c-g1 abdominal air-sacs2 oc1 ocular dilated trachea and air-sacs2 c1 cephalic trachea4 ,the relations of the heart to the dorsal trache are indicated4--,drawn by ,emerton from dissections by the author4 ,in the youngest larva of ,corethra plumicornis ,weismann ascertained the thickness of the longitudinal stem to be #j4jjag mm4 ,that of the finest tracheal endings in the silk-glands of the silkworm was found by ,von ,wistinghausen to be #j4jjaf mm4 7,zeits4 f4 ,wiss4 ,zool4 xlix1 #ahij1 p4 #ege47 ,weismann states that in the larv of ,corethra and ,chironomus the tracheal system is only incompletely developed2 the trache are not united with each other1 and in the youngest larv they do not contain air4 ,illustration3 ,,fig4 #cig4--,tracheal system of the right side of ,machilis maritima3 k1 head2 ,i1 ,,ii1 ,,iii1 thoracic segments2 #a-aj1 abdominal segments2 s1 stigma4--,after ,oudemans1 from ,lang4 ,each of the two main trache1 as ,kolbe states1 sends off into each segment of the body three branches4 #a4 ,an upper or dorsal branch1 which supplies the muscles of the dorsal region4 #b4 ,a middle 7visceral7 branch1 whose twigs pass to the digestive canal and back to the organs of reproduction4 #c4 ,a lower 7ventral7 branch1 whose twigs are distributed to the ganglia and to the muscles of the ventral region4 ,in certain ,thysanura1 as a species of ,machilis 7,fig4 #cig71 we probably have the primitive condition of the tracheal system1 the longitudinal and transverse anastomoses being absent1 but in other ,thysanura 7,japyx1 ,nicoletia1 ,lepisma1 and a few species of ,machilis7 they are present4 ,as ,kolbe remarks1 whether the fine ends of the trache are closed or open1 whether after the analogy of the blood capillaries of vertebrates they anastomose with each other1 whether the ends of the air-tubes pass between the cells or penetrate into them1 these questions are not fully settled4 ,according to ,leydig's#fa latest views the trache penetrate into the cells and unite with the hyaloplasma4 ,hence the process of respiration in the last instance takes place in the hyaloplasma4 ,this assumption accords with the fact that in the tracheate ,arthropods the terminations of the trache carry the atmospheric air into the space bounded by the cellular network1 also to the hyaloplasma filling the spaces4 ,leydig#fb also thinks that the finest tracheal endings penetrate into the muscular tissue and unite with the primitive muscular fibres4 ,kupffer is likewise of the opinion that the fine trache penetrate into the cells1 and ,lidth de ,jeude asserts that they enter the epithelial cells1 8each cell containing several branches40 ,klliker1 ,emery1 etc41 maintain1 however1 that the tracheal endings lie between the cells4 ,wielowiejski1#fc in describing the line trache of the phosphorescent organs1 thinks that the tracheal endings 7tracheal capillaries7 rarely end blindly1 but anastomose with one another1 forming an irregular network4 ,the latest observer1 ,gilson 7#ahic71 asserts that tracheal twigs penetrate deeply into the epithelial cells of the silk glands of larval ,trichoptera as well as of caterpillars1 passing through their protoplasm4 ,illustration3 ,,fig4 #cih4--,tracheal network of the male glands of ,lampyris splendidula3 tec1 tracheal end-cells2 cap1 tracheal capillaries2 at a1 an expanded matrix4--,after ,wielowiejski4 ,illustration3 ,,fig4 #cii4--,tracheal capillary end-network 7tr4 c4 n47 of silk glands of ,ocneria dispar3 p1 peritoneal 7peritracheal7 membrane4--,after ,wistinghausen4 ,a late investigator1 ,c4 von ,wistinghausen1 finds in the trache of the spinning-glands of caterpillars a completely formed network between the terminal branches of two or several tracheal groups4 ,the tracheal tubes of this series of terminal branches pass into this network1 which he calls the tracheal capillary end-network 7,figs4 #cih1 #djj74 ,this last varies in thickness and spreads out under the membrana propria of the glandular mass over the entire surface of the large gland-cells and on a level with the tracheal capillaries4 ,the tracheal endings do not penetrate into the cells1 but are separated from the plasma of the cells by a thin membrane4 ,the tracheal capillary end-network appears as a system of fine tubes like the tracheal capillaries1 consisting of a peritoneal layer and a chitinous intima 7,fig4 #djj74 ,the walls of these tubes are homogeneous1 not porous1 though readily permeable by the parenchymatous fluid4 ,the interchange of gases consequently may go on easier and more vigorously in a system of richly anastomosing tubules of the net-like mass of tracheal capillaries1 than in tubes ending blindly4 ,while the diameter of the tracheal capillaries is #j4jjaf mm4 or #a 1 that of the tubules composing the tracheal capillary end-network is scarcely measurable1 but is less than #a 4 ,illustration3 ,,fig4 #djj4--,tracheal end-cells of ,lampyris splendidula3 tr1 trachea with tnidia2 tre1 tracheal capillaries4--,after ,wielowiejski4 ,these tracheal capillaries also occur on the seminal and other sexual tubes1 on the intestine1 on the urinary tubes1 on the fat-bodies1 but are most easily detected on the silk-glands4 ,the latest researches are those of ,e4 ,holmgren1 who has studied the branching of the trache in the spinning-glands of caterpillars4 ,he prefers to call the end-cells 8transition cells10 as they lead from the tracheal tubes proper to the capillary network4 ,this latter is formed by slender nucleated cells1 often with an intracellular lumen1 and1 according to the author1 probably constituting a respiratory epithelium4 ,he finds that both large and small trache may penetrate the gland-cells4 7,anat4 ,anzeiger1 xi1 #ahie1 pp4 #cdj-f1 #c figs42 ,jour4 ,roy4 ,micr4 ,soc41 #ahif1 p4 #ahb47 b4 ,the spiracles or stigmata ,the spiracles are segmentally arranged openings in the sides of the thorax and abdomen1 through which the air passes into the air-tubes4 ,in its essential structure a spiracle1 or stigma1 is a slit-like opening surrounded by a chitinous ring1 the lips or edges of the opening being membranous and closed by a movable valve of the spiracle attached by its lower edge1 which is closed by an occlusor muscle 7,fig4 #dja74 ,the aperture when open forms a narrow oval slit2 and in most insects the slit is within guarded by a row of projecting spines or set1 which form a lattice work or grate to keep out dust1 dirt1 fluids1 etc4 ,illustration3 ,,fig4 #dja4--;,horizontal section of left third stigma and trachea of ,melolontha vulgaris1 showing the chamber or drum leading into the trachea3 a1 a1 external frame or valve protecting the outer opening of the stigma2 b1 c1 c1 inner frame closing the entrance into the trachea 7l1 k72 m1 occlusor muscle closing the inner orifice4--,after ,straus-,drckheim4 ,krancher#fd has described five leading types of stigmata1 not1 however1 taking into account those of the ,synaptera4 ,i4 ,stigmata without lips 7,primitive or generalized stigmata74 a4 ,the simplest stigma is an aperture which is kept open by a chitinous ring 7,acanthia74 ,the opening may be round or elliptical4 ,there are no lips nor any movement of the edges to be observed4 ,such air-holes occur in the abdomen of bugs 7,hemiptera7 and beetles 7,coleoptera72 within the opening of the stigmata in the same insects is a funnel-like contraction4 ,also in the ,diptera the abdominal stigmata are of the same type4#fe ,the stigmata of the ,pulicidae 7,siphonaptera7 are more complicated1 as the edges of the openings are provided with set 7,fig4 #djb74 ,illustration3 ,,fig4 #djb4--;,first abdominal spiracle with a part of the trachea of the cat-flea3 sp1 spiracle2 t1 trachea4 ,illustration3 ,,fig4 #djc4--,stigma of ,melolontha larva1 seen from without3 b1 bulla2 s1 sieve-like plate2 o1 curved slit-like opening4--,after ,boas4 b4 ,the stigma consists of a series of minute single stigmata1 which are usually surmounted by a common chitinous ring1 and whose tubular continuations unite within in a common trachea1 so that the single tubes pass off from the stigma like the fingers on the hand4 ,this form is found in the larv and puparia of ,diptera4 ,,ii4 ,stigmata with lips 7,secondary more specialized stigmata74 c4 ,the lips are represented by a single chitinous ring1 with sparse spines4 ,one side of the stigma is a little higher1 and partly overlaps the other posteriorly2 this form is peculiar to the ,orthoptera and ,libellulidae4 d4 ,the lips are roof-like1 bent inwards and densely hairy1 forming a peculiar kind of felting4 ,the set of the lips are in most beetles and many ,lepidoptera separate1 and more or less branched4 ,in caterpillars1 the set are so finely branched as to form a loose felt1 or sieve-like arrangement4 e4 ,the stigmata are round1 with a very broad border and a concentric middle portion1 the structure being complicated4 ,the concentric middle portion is pouch-like and bears the occlusor muscle4 ,this form occurs in the larv of lamellicorn beetles1 and can be seen with the naked eye1 or with a lens1 in ,oryctes1 ,cetonia1 and ,melolontha 7,fig4 #djc74 f4 ,over the outer opening of the spiracle is an incurved chitinous projection1 on one side of which the trachea takes its origin4 ,it is thus in the ,hymenoptera4 ,the remarkable grate-like stigma of the lamellicorn larv has the appearance as if the outer closing plate or valve were impenetrable4 ,the earlier observers considered these stigmata to be open1 but ,meinert regards them as closed2 ,schidte1 however1 has observed by pressing a preserved specimen of a ,melolontha larva the alcohol within passing out in drops1 through the grate-like plate1 and hence he considers this a proof that the stigma is permeable 7,kolbe74 ,more recently 7#ahic7 ,boas has examined the same structure in the same species of larva as examined by ,schidte1 and he finds it to be open only during the process of moulting4 ,he finds that on each side of the larva there are nine short and wide stigmatic branches1 each of which is shut off from the exterior by a brown plate2 this consists of a reniform sieve-plate1 and of a curved bulla which fits into the cavity of the plate4 ,the stigmatic branch1 however1 is provided with a large external opening1 which is homologous with the stigma1 but which is usually closed by the plate and bulla1 and is only open during the moulting2 at first it is circular1 but later becomes a cleft4 ,a transverse section shows that the bulla is a simple tegumentary fold1 the outer chitinous layer of which has become especially firm4 ,the plate forms a horizontal half-roof1 which springs from one side of the tracheal orifice1 and is supported by obliquely set bases1 which spring from the adjoining part of the inner side of the trache4 ,the plate and bars are purely cuticular structures4 7,zool4 ,anz41 #ahic2 also ,journ4 ,roy4 ,micr4 ,soc41 p4 #ed47 ,the tracheal system of libellulid nymphs is not closed2 on the other hand1 in the fully-grown nymphs the anterior stigmata occurring on the dorsal side are large1 and the trache arising from them are thick4 ,these stigmata are permeable by the air4 ,in half-grown and still younger stages of schna the two anterior thoracic stigmata are undeveloped4 ,in order to breathe1 the fully-grown nymph either rises up on the upper side and elevates the end of the body to the surface in order to take the air into the rectum1 or it rests with the back of the thorax at the surface in order to breathe through the large stigmata4 ,the young nymphs take in air only through the rectum4 ,the young nymphs of ,libellula and its allies1 on the other hand1 possess large thoracic stigmata1 but they prefer to breathe through the rectum4 ,the fully-grown nymphs of ,agrion breathe through the thoracic stigmata4 7,dewitz1 in ,kolbe47 ,the position and number of pairs of stigmata4--,the spiracles are usually situated in the soft membrane between the tergites and pleurites1 but their exact position varies in different groups4 ,in the ,coleoptera they occupy on the thorax a more ventral position1 and on the abdomen are placed near the edge of the dorsal side1 under the elytra4 ,in the dragon-flies1 the first pair is situated much more dorsally than the second and third pairs2 the following seven pairs are almost wholly ventral and lie concealed in the membranous fold near the external plate4 ,in the ,hemiptera1 also1 the abdominal stigmata1 though entirely free and visible1 are situated ventrally4 ,primarily1 in the embryo a pair of stigmata appear on each segment of the thorax and abdomen1 except the #ajth and #aath1 and even possibly in the head1 for a pair of stigmata are said to occur in the head of ,podurids 7,smynthurus7 7,lubbock71 though this statement needs confirmation4 ,scolopendrella1 however1 is known to possess a pair of cephalic spiracles4 ,from the foregoing statement it will be seen that while in existing winged insects no more than #aj 7in ,japyx #aa7 pairs of stigmata are to be found in any one species1 yet that #ab segments of the body1 in different groups taken collectively1 bear them4 ,the primitive number of pairs of spiracles1 therefore1 in winged insects1 was #ab1 i4e4 a pair in each thoracic segment1 and a pair in each of the first nine abdominal segments4 ,insects were originally all holopneustic1 and gradually as the type became differentiated into the different orders they became peripneustic or amphipneustic1 and1 in certain aquatic forms1 apneustic4 7,see pp4 #dei1 #dfa47 ,in the still more primitive1 probably wingless1 ancestors of insects there was a larger number of stigmata4 ,hatschek1 in #ahgg1 discovered a pair of tracheal invaginations in each of the three posterior head-segments of the embryo of a moth1 with stigmatal openings in the #ast and #b;d maxillary segments4 ,thus early in embryonic life every segment of the body1 except those bearing the eyes and the last abdominal1 bore a pair of stigmata1 so that the primitive insect had at least #ae1 and perhaps more1 pairs of stigmata4 ,the position of the stigmata is subject to much variation1 the result of adaptation to this or that mode of life4 ,examples are those insects which live in dusty situations or usually more or less concealed in the earth1 as in most beetles1 and in the ,hymenoptera4 ,in such beetles1 the stigmata are situated in the thin membrane between the segments2 in the ,hymenoptera1 on the upper edge of the segments4 ,in the ,siphonaptera1 ,pediculina1 bed-bug1 and similar forms1 which breathe an air freer from dust1 the spiracles lie free on the outside of the body4 8,when the stigmata are free and without any protection on the abdomen1 there are other ways by which the entrance of foreign bodies into the trache is prevented4 ,in such cases the body is covered with dense hairs1 as in most ,diptera and ,neuroptera1 as well as many ,lepidoptera2 or there is situated in front of the stigma either a small fissure which is covered over by a number of hairs arising from the edge1 as in many ,orthoptera2 or1 as in most insects1 a luxurious growth of hairs on the inside of the stigma forms a thick filter for the air4 ,thus we see that also in this respect each species of insect is completely adapted to its surroundings40 7,krancher47 ,illustration3 ,,fig4 #djd4--;,a1 thoracic stigma of the house-fly3 ,sb1 valve which closes the opening4 ,illustration3 ,,fig4 #dje4--;,diagrammatic figures of the internal apparatus which closes the trachea1 in the stag-beetle3 ,a1 trachea open2 in ,b1 closed2 ,st1 the stigma1 with its grated lips2 ,ct1 cuticula of the body-walls2 ,vk1 closing pouch2 ,vb1 closing bow2 ,vba1 closing band2 ,m1 occlusor muscle4--,from ,judeich and ,nitsche4 ,the closing apparatus of the stigma4--,whether the external opening of the stigma is permanently open or closed1 communication with the trache may be cut off at pleasure during respiration by an internal apparatus of elastic chitinous bands and rods and the occlusor muscle4 ,the parts concerned in this operation are3 #a4 ,the closing bow2 #b4 ,the closing lever or peg2 #c4 ,the closing band2 #d4 ,the occlusor muscle 7,figs4 #dje1 #djf74 ,illustration3 ,,fig4 #djf4--,stigma1 with the closing apparatus1 of ,smerinthus populi 7imago71 seen from within3 b1 closing bow2 c1 closing band3 o1 stigmatic opening2 r1 external chitinous ring2 l1 closing lever2 m1 occlusor muscle2 s1 scales which lie like roofing tiles over the stigma4--,after ,krancher4 8,the first three parts are chitinized2 they form a ring around the stigmatic opening1 and are united to each other by joints4 ,the bow is usually crescentic and as a rule surrounds one-half of the trachea4 ,on the other side is the closing band which1 by different contrivances1 representing the closing lever or peg1 becomes closely pressed against the closing bow4 ,this lever is usually of the shape of a slender chitinous rod1 which causes the closure2 but it can also bend rectangularly1 become converted into a typical lever as in the ,lepidoptera1 or it may assume the form of two peg-like processes1 which press with their base against the closing bow40 7,krancher47 8,the closure of the spiracular opening is effected by the contraction of the muscles1 while the opening is due to the elasticity of the chitinous parts4 ,when at rest the spiracle is naturally open1 so that the air in the trachea can directly communicate with the external air4 ,usually one end of the muscle is attached to the closing peg1 and the other end to the closing bow4 ,where1 as in ,melolontha1 the closing apparatus is provided with two levers1 then naturally the muscle binds these two together and brings about by powerful contractions a firm closure of the trachea02 but1 remarks ,krancher1 8this is not the only kind2 there are numerous modifications4 ,besides the form just described1 the levers assume the form of valves 7,sirex71 or of a brush 7,pulex72 or of a ring 7larv of ,diptera7 with a circular muscle attached to it2 or of a ring which simply becomes compressed 7thoracic stigmata of ,diptera740 c4 ,morphology and homologies of the tracheal system ,as first shown by ,btschli1 the tracheal system is a series of segmentally arranged tubular invaginations of the ectoderm2 a pair of stigmata primitively occurring on every segment of the body except perhaps the most anterior1 and the last two or last one1 a reduction in their number having since taken place1 until in the ,podurans none have survived4 ,in the supposed ancestor of myriopods and insects1 ,peripatus1 there are trache2 but they are very fine1 simple1 not-branched chitinous tubes which are united into tufts at the base of a flask-shaped depression of the integument1 the outer aperture of which depression is regarded as a stigma4 ,in one species 7,p4 edwardsii7 these tufts and their openings are scattered irregularly over the body2 but in another kind 7,p4 capensis7 some of the stigmata at least show traces of a serial arrangement1 being disposed in longitudinal rows--two on each side1 one dorsally and one ventrally1 those of each row1 however1 being more numerous than the pairs of legs4 7,see p4 #i and ,fig4 #d1 ,d47 ,it should be observed that in ,peripatus1 which does not possess urinary tubes1 the segmental organs or nephridia are well developed1 hence the tracheal tubes coexisting with them cannot be their homologues4 ,we are therefore compelled to regard the tracheal system as of independent origin1 arising in the earliest terrestrial air-breathing arthropod1 and not indebted for its origin to any structure found in worms1 unless perhaps1 as both ,kennell and ,lang suggest1 to dermal glands1 since1 according to ,kennell1 certain ,hirudinea and many ,turbellarian worms possess long1 mostly unicellular1 glands which spread far through the parenchyma of the body4 7,kennell47 ,thus ,kennell supposes that the ancestors of the ,tracheates had spiracles on every segment of the body where the internal organization allowed them to exist4 8,the reduction of the breathing holes to a smaller number1 and their restriction of a pair only to a single segment1 was brought about partly by adaptation to a peculiar mode of life1--as insect larv especially teach us1--partly also--,i may say mechanically--as a result of the obstruction to their development made by the growth or excessive development of other organs40 ,among these he reckons the thick1 dense cuticula of the integument1 the internal fusion of several segments to form body-regions1 and the arrangement and great development of the muscles in the head and thorax1 etc4 7p4 #bi47 ,illustration3 ,,fig4 #djg4--,section through a tracheal pit and diverging bundles of tracheal tubes taken transversely to the long axis of the body3 tr1 trache1 showing rudimentary spiral fibre2 tr4 c1 cells resembling those lining the tracheal pits1 which occur at intervals along the course of the trache2 tr4 o1 tracheal stigma2 tr4 p1 tracheal pit4--,after ,balfour1 from ,sedgwick4 ,kennell has suggested the origin of the trache of ,peripatus from the unicellular dermal glands of annelidan ancestors1 since he has found glands in certain land-leaches of tropical ,america1 which are provided with enormously long tubular passages united into bundles and opening externally1 these tubes appearing to be slightly chitinized4 ,fig4 #djg will show the appearance of a bundle of fine tracheal tubes of ,peripatus ending at the bottom of a follicle formed by a deep invagination of the integument1 which may be regarded as a primitive spiracle4 7,see ,kennell1 ,ueber einige ,landblutegel des tropical ,america1 ,zool4 ,jahrb4 ii1 #ahhf2 also ,die ,verwandtschaftsverhltnisse der ,arthropoden1 #ahia1 p4 #be47 ,we may add that ,carrire supposes from his study of the embryology of the wall-bee 7,chalicodoma muraria71 published in #ahij1 that not only the salivary glands1 but also the tentorium1 are homologues of the trache1 while other structures than trache may have evolved from unicellular dermal glands1 which are widely distributed4 ,it may in this connection be observed that some authors derive the book-lungs or book-leaf trache of ,arachnida from the gills of ,limulus2 hence if those of ,arachnida arose from quite different and more specialized organs than dermal glands1 it is not impossible that the trache of ,peripatus1 ,myriopods1 and insects arose de novo1 and then we need not look for any primitive structures in worms from which they arose4 ,although ,btschli in #ahgj in his embryology of the honey-bee called attention to the 8great similarity which the eleven pairs of invaginations in the eleven first trunk-segments in their first indication 7anlage7 have with the spinning-glands1 and also with the segmental organs of ,annelids10 he did not go further than this1 and it is now known that in the #b;d maxillary segment open not only spinning-glands1 but in the embryo a pair of stigmata4 ,paul ,mayer1 however1 regarded the trache and urinary tubes as homodynamous structures1 and this view was advocated by ,grassi 7#ahhe7 for the reason that while in the embryo honey-bee there are ten pairs of stigmata1 the first thoracic and two last abdominal segments wanting them1 the germs of the urinary tubes arise in a corresponding situation on the two last abdominal segments4 ,to this view ,emery 7,biol4 ,centralb41 #ahhf1 p4 #fib7 objects that in ,peripatus the nephridia and trache 8have nothing to do with the segmental organs10 as ,peripatus besides nephridia possesses both coxal glands and trache4 ,both ,kennell and ,lang derive the coxal glands of ,arthropoda from the setiparous or parapodial glands of annelid worms1 and the recent endeavor of ,bernard to show that the trache arose from setiparous glands seems to be disproved by the fact that in insects as well as in other ,arthropoda coxal glands with their outlets exist in the same segments as those bearing stigmata4 ,reasoning by exclusion1 we are led to regard ,kennell's original view as the soundest4 ,patten1 however1 regards the trache as modified ends of nephridia1 remarking3 8,since in ,acilius some of the abdominal trache at first communicate with the cavities of the mesoblastic somites1 it is probable that all the trache represent the ectodermic portions of the nephridia40 7,origin of ,vertebrates from ,arachnids1 p4 #cee47 ,it is probable1 therefore1 that the trache first arose as modifications of dermal glands1 as in mites and ,peripatus1 and that at first they were not provided with tnidia 7as in ,chilopoda71 while in later forms tnidia were developed4 ,in the earliest tracheate forms the stigmata were not segmentally arranged1 probably appearing irregularly anywhere in the body1 but afterwards in the myriopods and insects became serially arranged4 d4 ,the spiral threads or tnidia ,it is generally supposed that the so-called 8spiral thread0 forms a continuous thread from one end of a tracheal branch to the other4 ,this was first shown not to be the case by ,platner in #ahdd4 ,minot has proved that 8there is not a single spiral thread1 but several1 which run parallel to one another and end after making a few turns around the trachea40 ,the tnidia we have found to be in some cases separate1 independent1 solid rings1 though when there is more than one turn the thread necessarily becomes spiral4 ,the tnidia of a main branch stop at the origin of the smaller branches1 and a new set begins at the origin of each branch4 ,the tnidia at the origin of the branch do not pass entirely around the inside of the peritoneal membrane2 in the axils they are short1 separate1 spindle-shaped bands 7,fig4 #dji74 ,at one point in the main trachea of the larva of ,datana the tnidia were seen to end singly on one side 7at a considerable distance from any branch or axil7 at intervals1 with a tnidium situated between them1 making four or five turns2 then there is only one band situated between two ends2 this band or thread is succeeded by a set with five turns between the two ends1 this set being succeeded by one complete ring situated between two ends2 in all cases the ends vary in length1 some threads being short and others long1 so that they apparently end anywhere along the circumference of the trachea1 and this arrangement is seen to apparently extend along the whole length of the trachea4 ,hence it is seen that as a rule the tnidia vary much in length1 and never1 as generally supposed1 pass continuously from one end to another of a tracheal branch1 for there are many spirals in a branch1 each making only from one to five turns1 most usually four turns4 ,fig4 #djh1 part of a trachea of ,dyticus marginatus1 shows that at a slight bend in a trachea the tnidia is interrupted1 and short1 incomplete1 wedge-shaped tnidia 7e7 are interpolated2 at ,a1 d is seen a split in one of the tnidia 7compare also ,mac,leod1 ,pl4 #a1 ,fig4 #i74 ,the threads are quite irregular in width4 ,in the axils of the branches there is1 as seen in ,fig4 #dji1 a basketwork of independent1 short1 often spindle-shaped tnidia2 these are succeeded by longer ones1 until we have threads passing entirely around near the base of each new branch2 these being succeeded by others which make from two to five spiral turns4 ,illustration3 ,,fig4 #djh4--,tnidia of ,dyticus3 d1 a split tnidium2 e1 e1 ends of tnidia4 ,the shape of the tnidia appears to vary to a great extent4 ,in lepidopterous insects we have observed them to be in their general shape rather flat and slightly concavo-convex1 the hollow looking towards the centre of the trachea4 ,minot's section 7,fig4 #cic7 shows that in ,hydrophilus they are cylindrical and solid1 and ,chun states that those of ,stratiomys are round1 while in ,eristalis they are round1 with a ridge projecting into the cavity of the trachea2 in schna the thread is quadrangular4 ,mac,leod states that sometimes it is cylindrical1 in other cases flat1 likewise prismatic2 ,macloskie believes that the spiral threads of the centipede are 8fine tubules1 externally opening by a fissure along their course40 ,illustration3 ,,fig4 #dji4--,tnidia of ,dyticus in an axil of two branches3 e1 e1 ends of tnidia4 ,stokes confirms ,macloskie's statements1 stating that in the hemipterous ,zaitha fluminea 8the tnidia are fissured tubules formed within and from chitinized folds of the intima1 the convexity of the folds looking towards the lumen of the trache40 ,in ,fig4 #dad1 #a1 are represented portions of several tnidia showing the fissure1 which is sometimes interrupted2 at #b are seen 8the formation of what may be called apertures in a chitinous bridge40 ,stokes regards the tnidia as 8inwardly directed folds of the membrane40 ,near the spiracles the tracheal membrane is externally studded with minute papill1 as shown at #c1 where are represented three broad and incomplete tnidia1 with the tapering end1 or the beginning1 of another4 ,stokes adds1 8,here they are only broad grooves1 with no appearance of the narrow fissure of the completed tnidium4 ,at #d is figured a portion of the internal surface of a large trachea near the external orifice1 the tnidia being in an incipient stage1 evidently forming more or less of a network1 as is usually the case next to the stigma0 7compare p4 #dea1 and ,fig4 #dad74 ,illustration3 ,,fig4 #daj4--;,end of salivary duct in base of proboscis of ,stomoxys calcitrans3 a1 incomplete and irregular tnidia2 b1 two tnidia making incomplete rings near the distal end of the duct4 ,the trache of chilopod myriopods appear to be like those of insects4 ,a number of authors have failed to detect the spiral threads in the ,julid4 ,as to the ,arachnida1 several observers1 including ,menge and ,bertkau1 have denied the existence of the spiral thread in the spiders with the exception of the ,attid2 and ,mac,leod finds them 8scarcely visible0 in ,argyroneta4 ,besides the trache1 the salivary duct is kept permanently distended by tnidia1 which1 however1 are not spiral4 ,they usually form incomplete rings1 as in ,stomoxys1 arranged as shown in ,fig4 #daj4 ,the labella 7proboscis7 of flies are supported by incomplete chitinous tubes or 8pseudo-trache10 the ends of which form the scraping teeth1 this being1 according to ,dimmock1 their primary function4 ,dimmock describes them as cylindrical channels opening on the surface in zigzag slits4 ,these channels are held open by incomplete rings1 one end of which is forked4 8,these rings are apparently arranged so that one has its fork on one side of the opening of the channel1 the next ring the fork on the opposite side of the channel1 and so on1 in alternation4 ,their true structure is revealed when flattened out40 ,illustration3 ,,fig4 #daa4--;,abdominal spiracle 7left side7 of cockroach 7,p4 americana71 side view1 showing the bow3 p1 lateral pouch of spiracle 7in centre7 seen from within4 ,the tessellated structure of spiracle and trachea shown at ,a1 and the margin of the external aperture at ,b4--,after ,miall and ,denny4 ,the use of the elastic tnidia is to render the trache elastic1 and to keep them permanently open1 as is the case with the parallel rings of the trachea of the higher vertebrates4 ,the trache are thus rendered firm and solid1 at the least expense of chitinous material4 ,the spiral thread1 as ,mac,leod remarks1 8is the realization in nature of what engineers call a form of the greatest resistance40 ,the tnidia are wanting in the fine endings of the trache 7tracheal capillaries72 also in the cockroach1 according to ,miall and ,denny1 they are not developed in the large trache close to the spiracles1 and the intima or wall of the tube has a tessellated instead of a spiral marking 7,fig4 #daa74 ,the same structure is seen in the ,perlid 7,nemoura1 ,gerstaecker1 ,zeit4 f4 wissen4 ,zool4 xxiv1 ,taf4 xxiii1 ,figs4 #e and #g72 also in schna 7,hagen1 ,zool4 ,anz4 #ahhj1 p4 #aei74 ,in certain fine trache of the eyes of the fly no spiral threads are developed4 7,hickson47 ,the air-sacs or dilated trache are also without tnidia4 ,while in the living insect the main and smaller trache are filled1 with air1 it is stated by ,von ,wistinghausen that the fine capillary ends contain a fluid4 e4 ,origin of the trache and of the 8spiral thread0 ,while we owe to ,btschli the discovery of the mode of origin and morphology of the trache1 which as he has shown#ff arise by invaginations of the ectoblast2 there being originally a single layer of epiblastic cells concerned in the formation of the trache2 we are indebted to ,weismann#fg for the discovery of the mode of origin of the 8intima10 from the epiblastic layer of cells forming the primitive foundation of the tracheal structure4 ,weismann did not observe the earliest steps in the process of formation of the stigma and main trunk of the trache1 which ,btschli afterwards clearly described and figured4 ,weismann1 however1 thus describes the mode of development of the intima2 after describing the cells destined to form the peritoneal membrane1 he says3 8,the lumen is filled with a clear fluid and already shows a definite border in a slight thickening of the cell-wall next to it4 8,very soon this thickening forms a thin1 structureless intima1 which passes as a delicate double line along the cells1 and shows its dependence on the cells by a sort of adherence to the rounded sides of the cells 7,taf4 vii1 #ig ,a1 a b c74 ,throughout the mass1 as the intima thickens1 the cells lose their independence1 their walls pressing together and coalescing1 and soon the considerably enlarged hollow cylinder of the intima is surrounded by a homogeneous layer of a tissue1 whose origin from cells is recognized only by the regular position of the rounded nuclei 7,taf4 vii1 ,fig4 #ig1 ,b74 8,then as soon as the wavy bands of the intima entirely disappear1 and it forms a straight1 cylindrical tube1 a fine pale cross-striation becomes noticeable 7vii1 #ig1 ,b1 int71 which forms the well-known #8spiral thread1' a structure which1 as ,leydig has shown1 possesses no independence1 but arises merely from a partial thickening of the originally homogeneous intima4 8,meyer's idea that the spiral threads are fissures in the intima produced by the entrance of air is disproved by the fact that the spiral threads are present long before the air enters4 ,hence the correctness of ,leydig's view1 based on the histological structure of the trache1 is confirmed by the embryological development1 and the old idea of three membranes1 which both ,meyer and ,milne-,edwards maintain1 must be given up40 ,weismann also contends that the elastic membrane bearing the 8spiral thread0 is in no sense a primary membrane1 not corresponding histologically to a cellular membrane4 ,on the contrary1 the 8peritoneal membrane comprises the primary element of the trachea2 it is nowhere absent1 but envelops the smallest branches1 as well as the largest trunks1 only varying in thickness1 which in the embryo and the young larva of ,musca stands in relation to the thickness of the lumen40 ,the trachea1 then1 consists primarily of an epithelial layer1 the 8peritoneal membrane10 or the invaginated epiblast2 from this layer an intima is secreted1 just as the skin or cuticle is secreted by the hypodermis4 ,we may call the peritoneal membrane the ectotrachea1 the intima or inner layer derived from the ectotrachea the endotrachea4 ,the so-called 8spiral threads0 are a thickening of the endotracheal membrane1 sometimes arranged in a spiral manner4 ,for these chitinous bands we have proposed the name tnidia 7,greek1 little bands74 ,as to the origin of the spiral thread our observations#fh have been made on the caterpillar of a species of ,datana1 which was placed in alcohol1 just before pupation1 when the larva was in a semipupal condition1 and the larval skin could be readily stripped off4 ,at this time the ectotrachea of the larva had undergone histolysis1 nothing remaining but the moulted endotrachea1 represented by the tnidia1 which lay loosely within the cavity of the trachea4 ,the ectotrachea or peritoneal membrane of the pupa is meanwhile in process of formation2 the nuclear origin of the tnidia is now very apparent4 ,illustration3 ,,fig4 #dab4--,longitudinal section of a trachea1 showing the origin of the tnidia4 ,illustration3 ,,fig4 #dac4--,origin of the tnidia from nuclei4 ,fig4 #dab represents a longitudinal section through a secondary tracheal branch1 showing the origin of the chitinous bands1 or tnidia4 ,at t are pieces of six tnidia which have been moulted2 ectr indicates the nuclei forming the outer cellular layer1 the ectotrachea or peritoneal membrane4 ,these nuclei send long slender prolongations around the inside of the peritoneal membrane2 these prolongations1 as may be seen by the figure1 become the tnidia4 ,the tnidia1 being closely approximate1 grow together more or less1 and a thin endotracheal membrane is thus produced1 of which the tnidia are the thickened band-like portions4 ,the endotracheal membrane is thus derived from the ectotrachea1 or primitive tracheal membrane1 and the so-called 8spiral thread0 is formed by thickenings of the nuclei composing the secondary layer of nuclei1 and which become filled with the chitin secreted by these elongated nuclei4 ,the middle portion of the tnidia1 immediately after the moult1 is clear and transparent1 with obscure minute granules1 while the nuclear base of the cell is filled as usual with abundant granules1 and contains a distinct nucleolus4 ,illustration3 ,,fig4 #dad4--,tnidia and internal hairs of ,zaitha4--,after ,stokes4 ,the origin of the tnidia is also well shown by ,fig4 #dac1 which is likewise a longitudinal section of a trachea at the point of origin of a branch4 ,the peritracheal membrane or ectotrachea 7ectr7 is composed of large granulated nuclei2 and within are the more transparent endotracheal cells2 at t are fragments of the moulted tnidia4 ,the new tnidia are in process of development at t2 at base they are seen to be granulated nuclei1 with often a distinct nucleolus1 each sending a long1 slender1 transparent1 pointed process along the inside of the trachea4 ,these unite to form the chitinous bands or spiral threads4 ,internal hair-like bodies4--,in the large trache of ,lampyris very fine chitinous bristles project free into the cavity of the tube 7,gerstaecher71 while according to ,leydig there are similar chitinous points in the trache of the ,carabid beetle ,procrustes4 ,dugardin had previously 7#ahdi7 called attention to such hairs1 giving a list of the insects in which he observed them4 ,emery figures a section of the trache of ,luciola1 8in wendig behaart40#fi ,stokes has described those of ,zaitha fluminea 7,fig4 #dad7 as 8internal chitinous1 hair-like bodies arising from the fold of the tnidia and projecting into the lumen of the tubes40 ,they are hollow1 their minute cavity distinctly communicating with that of the tnidium1 from which they arise by an enlarged base4 ,they end in an exceedingly fine point which is occasionally bifid or trifid4 ,in ,fig4 #dad1 #d1 several are shown attached to the wrinkles of the trache near a spiracle1 and at #e is represented a transverse section of a trachea with three hairs projecting into its cavity4#gj ,stokes has also described 8certain minute1 elliptical bodies in the tnidia1 each with an internal1 presumably glandular1 appendage1 to all appearance forming part of the tnidium from which it springs40 ,these are shown in ,fig4 #dad1 at #a1 #c1 and1 more in detail1 at #f2 those at #g1 whose thickness is about #ahjjj of an inch1 appear as collections of exceedingly minute1 rounded apertures in a cushion-like mass4 ,although not commonly occurring on the tracheal membrane between the tnidia1 they may be found there1 as at #d4 f4 ,the mechanism of respiration and the respiratory movements of insects ,by holding a locust in the hand one may observe the ordinary mode of breathing in insects4 ,during this act the portion of the side of the body between the stigmata and the pleurum contracts and expands2 the contraction of this region causes the spiracles to open4 ,the general movement is caused by the sternal moving much more decidedly than the tergal portion of the abdomen4 ,when the pleural portion of the abdomen is forced out1 the soft pleural membranous region under the fore and hind wings contracts1 as does the tympanum1 or ear1 and the membranous portions at the base of the hind legs4 ,when the tergum or dorsal portion of the abdomen falls1 and the pleurum contracts1 the spiracles open2 their opening is nearly but not always exactly cordinated with the contractions of the pleurum1 but as a rule they are4 ,there were #fe contractions in a minute in a locust which had been held between the fingers about ten minutes4 ,it was noticed that when the abdomen expanded1 the air-sacs in the first abdominal ring contracted4 ,for expanding the abdomen no special muscles are required1 since it expands by the elasticity of the parts4 ,for contracting its walls there are two sets of muscles1 viz41 special vertical expiratory muscles serving to compress or flatten the abdomen 7,figs4 #dae-dah71 and other muscles which draw together or telescope the segments4 ,it was formerly supposed that when the abdomen contracted the air was expelled from the body and the trache emptied2 that1 when the abdomen again expanded by its own elasticity1 the air-tubes were refilled1 and that no other mechanism was needed4 ,but ,landois insisted that this was not enough2 as ,miall and ,denny state3 8,air must be forced into the furthest recesses of the tracheal system1 where the exchange of oxygen and carbonic acid is effected more readily than in tubes lined by a dense intima4 ,but in these fine and intricate passages the resistance to the passage of air is considerable1 and the renewal of the air could1 to all appearance1 hardly be effected at all if the inlets remained open4 ,landois accordingly searched for some means of closing the outlets1 and found an elastic ring or spiral1 which surrounds the tracheal tube within the spiracle40 ,by means of the occlusor muscle this ring compresses the tube1 8like a spring clip upon a flexible gas-pipe40 8,when the muscle contracts1 the passage is closed1 and the abdominal muscles can then1 it is supposed1 bring any needful pressure to bear upon the tracheal tubes1 much in the same way as with ourselves1 when we close the mouth and nostrils1 and then1 by forcible contraction of the diaphragm and abdominal walls1 distend the cheeks or pharynx40 ,thus an important point in the respiration of tracheate animals1 whether insects1 myriopods1 or arachnids1 is1 as ,landois claimed1 the closure of the spiracles1 in order that pressure may be brought upon the air in the tubes1 so that it may pass onward into the finest terminations4 ,the injection of air by muscular pressure into a system of very fine tubes may1 as ,miall and ,denny remark1 appear extremely difficult or even impossible4 ,graham 7,researches1 p4 #dd7 applies the law of diffusion of gases to explain the respiration of insects1 but until physical experiments have been made1 we may1 with ,miall and ,denny1 8be satisfied that an appreciable quantity of air may be made by muscular pressure to flow along even the finer air-passages of an insect40 ,as to the respiratory movements of insects1 ,plateau is the principal authority1 and the following account of the process is taken from his elaborate memoir1 and from the statements afterwards contributed by him to ,miall and ,denny's 8,the ,cockroach40 ,although many observers have superficially described the respiratory movements of various insects1 ,rathke was the first one to state precise views as to the mechanism of respiration4 ,his posthumous work1 treating of the respiratory movements of the movable chitinous plates of the abdomen1 and of the respiratory muscles characteristic of all the principal groups1 filled an important blank in our knowledge4 ,but1 notwithstanding the skill displayed in this research1 many questions still remain unanswered which require more exact methods than mere observations with the naked eye or the simple lens4 ,plateau1 who was followed a year later by ,langendorff1 conceived the idea of studying1 by such graphic methods as are now familiar1 the respiratory movements of perfect insects4 8,he has made use of two modes of investigation4 ,the first1 or graphic method1 in the strict sense of the term1 consisted in recording1 upon a revolving cylinder of smoked paper1 the respiratory movements1 transmitted by means of very light levers of ,bristol board attached to any part of the insect's exoskeleton4 ,unfortunately1 this plan is only applicable to insects of more than average size4 ,a second method1 that of projection1 consisted in introducing the insect1 carried upon a small support1 into a large magic lantern fitted with a good petroleum lamp4 ,when the amplification does not exceed #ab diameters1 a sharp profile may be obtained1 upon which the actual displacements may be measured1 true to the fraction of a millimetre4 ,placing a sheet of white paper upon the lantern screen1 the outlines of the profile are carefully traced in pencil so as to give two superposed figures1 representing the phases of inspiration and expiration respectively4 ,by altering the position of the insect so as to obtain profiles of transverse sections1 or of the different parts of the body1 and1 further1 by gluing very small paper slips to parts whose movements are hard to observe1 the successive positions of the slips being then drawn1 complete information is at last obtained of every detail of the respiratory movements2 nothing is lost40 8,this method1 similar to that employed by the ,english physiologist1 ,hutchinson1#ga is valuable1 because it enables us1 with a little practice1 to investigate readily the respiratory movements of very small arthropods1 such as flies or lady-birds4 ,it has this advantage over all others1 that it leaves no room for errors of interpretation40 8,not satisfied with mere observation by such means as these1 of the respiratory movements of insects1 the writer has also studied the muscles concerned1 and1 in common with other physiologists 7,faivre1 ,barlow1 ,luchsinger1 ,dnhoff1 and ,langendorff71 has examined the action of the various nervous centres upon the respiratory organs4 ,the result at which he has arrived may be summarized as follows3-- ,illustration3 ,,fig4 #dae4--,muscles of right half of the abdomen of ,forficula auricularia3 ,a1 a1 longitudinal tergal and sternal muscles2 ,d1 ,e1 oblique muscles2 a 7in upper figure7 vertical expirator muscles4 8#a4 ,there is no close relation between the character of the respiratory movements of an insect and its systematic position4 ,respiratory movements are similar only when the arrangement of the abdominal segments1 and especially when the disposition of the attached muscles1 are almost identical4 ,thus1 for example1 the respiratory movements of the cockroach are different from those of other ,orthoptera1 resembling those of the heteropterous ,hemiptera4 ,those of the ,trichoptera are like those of the aculeate ,hymenoptera1 while the ,locustid ally themselves in respect to these movements with the ,neuroptera and ,lepidoptera4 8#b4 ,the respiratory movements of insects1 when at rest1 are localized in the abdomen4 ,as graphically stated by ,graber1 in insects the chest is placed at the hinder end of the body4 ,if thoracic respiratory movements exist1 they do not depend on the action of special muscles4 8#c4 ,in most cases the thoracic segments do not share in the respiratory movements of an insect at rest4 ,the respiratory displacements of the posterior segments of the thorax are1 however1 less rare than ,rathke believed4 ,plateau has observed them in certain ,coleoptera 7,staphylinus1 ,chlorophanus1 ,corymbites71 and they are more feebly manifested in ,hydrophilus1 ,carabus1 and ,tenebrio4 ,among the singular exceptions to this rule is the cockroach 7,periplaneta orientalis71 in which the terga of the meso- and metathoracic segments perform movements exactly opposite in direction to those of the abdomen 7,fig4 #dai74 ,illustration3 ,,fig4 #daf4--,muscles of the left half of abdomen of ,staphylinus olens2 ,a1 ,b1 longitudinal dorsal muscles2 ,d1 ,e1 oblique fascia2 a1 longitudinal sternal muscles2 d1 respiratory muscles 7vertical expirators74 8#d4 ,leaving out of account all details and all exceptions1 the respiratory movements of insects may be said to consist of the alternate contraction and recovery of the figure of the abdomen in two dimensions1 viz4 vertical and transverse4 ,during expiration both diameters are reduced1 while during inspiration they revert to their previous amounts4 ,the transverse expiratory contraction is often slight1 and may be imperceptible4 ,on the other hand1 the vertical expiratory contraction is never absent1 and usually marked4 ,in the cockroach 7,p4 orientalis7 it amounts to one-eighth of the depth of the abdomen 7between segments #b and #c72 in ,eristalis tenax to one-ninth 7at the #b;d segment74 8#e4 ,three principal types of respiratory mechanism occur in insects1 and these admit of further subdivision3 8a4 ,sterna usually short and very convex1 yielding but little4 ,terga mobile1 rising and sinking appreciably4 ,to this class belong all ,coleoptera1 heteropterous ,hemiptera1 and ,blattina 7,fig4 #dbj74 8,in the cockroach 7,periplaneta71 the sterna are slightly raised during expiration 7,fig4 #dba74 8b4 ,terga well developed1 overlapping the sterna on the sides of the body1 and usually concealing the pleural membrane1 which forms a sunken fold4 ,the terga and sterna approach and recede alternately1 the sterna being almost always the more mobile4 ,to this type belong ,odonata1 ,diptera1 aculeate ,hymenoptera1 and acrydian ,orthoptera 7,fig4 #dbb74 ,illustration3 ,,fig4 #dag4-,muscles of right half of abdomen of ,phryganea striata1 3 ,a1 ,b1 longitudinal dorsal muscles2 a1 b1 longitudinal sternal muscles2 ,d1 e1 oblique muscles2 #a1 #b1 inspirator muscles4 8c4 ,the pleural membrane1 connecting the terga with the sterna1 is well developed and exposed on the sides of the body4 ,the terga and sterna approach and recede alternately1 while the pleural zone simultaneously becomes depressed1 or returns to its original figure4 ,to this type1 ,plateau assigns the ,locustid1 ,lepidoptera1 and the true ,neuroptera 7excluding ,trichoptera7 7,fig4 #dbc74 ,illustration3 ,,fig4 #dah4--,muscles of left half of abdomen of ,melolontha1 3 ,a1 ,b1 longitudinal muscles 7prtracteurs of ,straus72 a1 a1 true respiratory muscles 7expirators74--,this and ,figs4 #dae-dag1 after ,plateau4 8#f4 ,contrary to the opinion once general1 changes in length of the abdomen1 involving protrusion of the segments and subsequent retraction1 are rare in the normal respiration of insects4 ,such longitudinal movements extend throughout one entire group only1 viz4 the aculeate ,hymenoptera4 ,isolated examples occur1 however1 in other zological groups4 8#g4 ,among insects1 such as large beetles1 ,locustid1 dragon-flies1 etc41 sufficiently powerful to give good graphic tracings1 it can be shown that the inspiratory movement is slower than the expiratory1 and that the latter is often sudden4 ,illustration3 ,,fig4 #dai4--,profile of trunk of cockroach 7,p4 orientalis74 ,the black surface represents the expiratory contour1 while the inspiratory is indicated by a thin line4 ,the arrows show the direction of the expiratory movement3 ,ms4 th1 mesothorax2 ,mt4 th1 metathorax4 ,reduced from a magic-lantern projection4--,after ,plateau4 8#h4 ,in most insects1 contrary to what obtains in mammals1 only the expiratory movement is active2 inspiration is passive1 and effected by the elasticity of the body-wall4 8#i4 ,most insects possess expiratory muscles only4 ,certain ,diptera 7,calliphora vomitoria and ,eristalis tenax7 afford the simplest arrangement of the expiratory muscles4 ,in these types1 they form a muscular sheet of vertical fibres1 connecting the terga with the sterna1 and underlying the soft1 elastic membrane which unites the hard parts of the somites4 ,one of the most frequent complications arises by the differentiations of this sheet of vertical fibres into distinct muscles1 repeated in every segment1 and becoming more and more separated as the sterna increase in length4 ,special inspiratory muscles occur in ,hymenoptera1 ,acridiid1 and ,trichoptera4 8#aj4 ,the abdominal1 respiratory movements of insects are wholly reflex4 ,like other physiologists who have examined this side of the question1 ,plateau finds that the respiratory movements persist in a decapitated insect1 as also after destruction of the cerebral ganglia or sophageal connectives2 further1 that in insects whose nervous system is not highly concentrated 7e4g4 ,acridiid and dragon-flies71 the respiratory movements persist in the completely detached abdomen2 while all external influences which promote an increased respiratory activity in the uninjured animal1 have precisely the same action upon insects in which the anterior1 nervous centres have been removed1 upon the detached abdomen1 and even upon isolated sections of the abdomen4 8,the view formerly advocated by ,faivre1 that the metathoracic ganglia play the part of special1 respiratory centres1 must be entirely abandoned4 ,all carefully performed experiments on the nervous system of ,arthropoda have shown that each ganglion of the ventral chain is a motor centre1 and1 in insects1 a respiratory centre1 for the somite to which it belongs4 ,this is what ,barlow calls the #8self-sufficiency' of the ganglia40 7,miall and ,denny47 ,illustration3 ,,fig4 #dbj4--,transverse section of abdomen of a lamellicorn beetle4 ,the position of the terga and sterna after an inspiration is indicated by the thick line2 the dotted line shows their position after an expiration2 and the arrow marks the direction of the expiratory movement4 ,illustration3 ,,fig4 #dba4--;,cross-section of abdomen of cockroach4 ,illustration3 ,,fig4 #dbb4--;,cross-section of abdomen of bee 7,bombus74 ,illustration3 ,,fig4 #dbc4--;,cross-section of abdomen of ,sphinx4--,this and ,figs4 #dbj-dbb after ,plateau4 ,plateau has made similar observations upon the respiration of spiders and scorpions2 but1 to his great surprise1 he was unable1 either by direct observation1 or by the graphic method1 or by projection1 to discover the slightest respiratory movement of the exterior of the body4 ,this can only be explained by supposing that inspiration and expiration in pulmonate ,arachnida are 8intrapulmonary10 and affect only the proper1 respiratory organs4 ,the fact is less surprising because of the wide zological separation between ,arachnida and insects4 g4 ,the air-sacs ,in flying insects the trache are in certain parts of the body enlarged into sacs of various sizes4 ,these air-sacs were first observed by ,swammerdam in a beetle 7,geotrupes7 and afterwards by ,sir ,john ,hunter in the bee1 ,sprengel subsequently discovering them in other insects4 ,those of the cockroach were described and illustrated in a very elaborate and detailed way by ,straus-,drckheim 7,figs4 #dbd and #dbe74 ,these vesicles are without tnidia4 ,in the locust 7,m4 femur-rubrum7 there is a pair of very large vesicles in the prothorax 7,fig4 #cif74 ,the five pairs of large abdominal air-sacs arise1 independently of the main trache1 directly from branches originating from the spiracles4 ,all these large sacs are superficial1 lying directly beneath the hypodermis1 while the smaller ones are buried among the muscles4 ,we have detected #ec of these vesicles in the head4 ,in the honey-bee 7,fig4 #dbf7 and humble bee 7,fig4 #dbg7 as well as the flies there are two enormous air-sacs at the base of the abdomen4 ,in larval and wingless insects these sacs are entirely absent4 ,illustration3 ,,fig4 #dbd4--,thorax and abdomen of the cockchafer 7,melolontha vulgaris71 showing the trache and air-sacs4--,this and ,fig4 #dbe after ,straus-,drckheim4 ,the use of the air-sacs4--,it was supposed by ,hunter as well as by ,newport1 and the view has been generally held1 that the use of these sacs is to lighten the weight1 i4e4 lessen the specific gravity of the body during flight4 ,it has1 however1 been suggested to us by ,a4 ,a4 ,packard that this view from the standpoint of physics is incorrect4 ,it is evident that the wings have to support just as much weight when the insect is flying1 whether the trache and vesicles are filled with air or not1 the body of the insect during flight not being lightened by the air in the sacs4 ,the use of these numerous sacs1 some of them very spacious1 is to afford a greater supply of air or oxygen than that contained in the air-tubes alone1 and thus to afford a greater breathing capacity4 ,the sacs are largest in dragon-flies1 moths1 flies1 and bees1 which are swift of flight4 ,when we compare the active movements of these insects on the wing with those of a caterpillar or maggot1 it will be seen that the far greater muscular exertions of the volant insect create a demand for a sudden and abundant supply of air to correspond to the increased rapidity of respiration2 and the enlargements of the air-tubes1 rapidly filled with air at each inspiration1 render it possible to supply the demand4 ,illustration3 ,,fig4 #dbe4--;,head of ,melolontha vulgaris1 showing the numerous air-sacs1 represented only on the left side1 front view4 ,illustration3 ,,fig4 #dbf4--,tracheal1 nervous1 and digestive systems of the honey-bee 7the tracheal system on the right side only partially drawn73 tb1 the large vesicles in the abdomen2 st1 stigmata2 hm1 honey stomach2 cm1 chyle stomach2 vm1 urinary tubes2 rd1 rectal glands2 ed1 rectum2 a1 antenna2 an1 eye2 b#a-;b#c1 legs4--,after ,leuckart1 from ,lang4 ,the case is thus seen to be very different from that of those fishes which1 having a swimming-bladder1 can in the water change the specific gravity of their bodies4 ,the case of insects is almost exactly paralleled by that of birds1 where1 as stated by ,wiedersheim1 the air-sacs appear to form integral parts of the respiratory apparatus3 8a greater amount of air can by their means pass in and out during inspiration and expiration1 especially through the larger bronchi1 and consequently there is less necessity for the expansion of the lung parenchyma40 ,in other words1 the supply of air in these sacs1 as in insects1 increases the breathing capacity of the bird during flight4 ,wiedersheim's retention of the old idea that the specific gravity of the body is lessened 7p4 #bfb7 seems1 however1 to be incorrect1 as the weight of the bird's body is not diminished by the air contained in the sacs4 h4 ,the closed or partly closed tracheal system ,illustration3 ,,fig4 #dbg4--,the lateral and lower series of sacs of ,bombus terrestris1 3 a1 c1 longitudinal trache21 connected by b1 and dilated at f1 and again in the succeeding segments2 i1 k1 funnel-shaped dilatations passing over the dorsal surface of the abdomen and anastomosing 7g7 with their fellows opposite2 at l1 communicating directly by a large branch4--,after ,newport4 ,there are two chief morphological tracheal systems3 #a4 ,the open or normal and primitive 7holopneustic7 type1 and #b4 ,the closed1 or secondary and adaptive1 i4e4 apneustic1 type4 ,the open system is characterized by the presence of the stigmata4 ,through them the air directly enters into the tracheal tubes1 whose delicate walls allow the exchange of gases in the blood4 ,this type occurs in all sexually mature individuals1 and also in the greater number of larv4 ,the closed or apneustic tracheal system is distinguished either by the want of stigmata1 or1 if present1 they are not open1 and do not function1 so that the trache cannot communicate with the air4 ,in such cases the direct oxygenation of the blood is effected through the delicate integument1 especially over the surface of the body in general1 or in certain specialized places where the gill-like expansions of the skin are rich in trache2 such outgrowths1 generally tubular or leaf-like1 are called by ,palmn tracheal gills4 ,this closed form of the tracheal system only occurs in the larval stage of aquatic or parasitic insects1 as in the ,plectoptera 7,ephemerid71 ,perlid1 ,odonata1 and ,trichoptera1 besides single genera of other orders1 i4e4 among ,coleoptera1 ,gyrinus1 ,pelobius1 ,cnemidotus1 and the young larva of ,elmis2 in the aquatic caterpillar of ,paraponyx2 in certain ,diptera 7,corethra1 ,chironomus1 etc471 and some of the parasitic ,hymenoptera 7,microgaster74 ,palmn has discovered that in the nymphs of ,ephemerid1 ,perlid1 ,odonata1 and the larv of most ,trichoptera the tracheal branch 7stigmatal branch7 sent from the longitudinal trachea to where the thoracic stigmata would be situated if present1 or where their vestiges only exist1 are aborted1 becoming simple solid cords not filled with air 7,fig4 #dcf1 vf1 and #ddg1 f1 funiculus or stigmatic cord74 ,in the imago1 however1 they resume their function1 connecting with the open functional stigmata4 ,in ,corethra1 in its earliest stages1 the entire tracheal system is1 like the stigmatic branch1 a system of solid cords and empty of air4 7,palmn47 ,embryology shows that these stigmatal branches are well developed1 and are formed at the same time as the stigmata4 ,it was also shown by ,dewitz1 in a posthumous paper 7#ahij71 that in the young larval stage of the ,odonata and ,ephemerid the tracheal system is at first an open one1 and in some of the families 7,libellulid1 ,agrionid1 and ,ephemerid7 thoracic stigmata are seen at a very early stage4 ,from numerous experiments ,dewitz concludes that in the young stages of ,odonata and ,ephemerid there is an open tracheal system2 certainly in very young nymphs the thoracic spiracles allow the air to pass out4 ,fully grown nymphs of schnid1 ,libellulid1 and ,agrionid are capable not only of forcing the air out1 but also1 like the perfect insect1 of inhaling it4 ,moreover1 he proved that the gills of ,ephemerid and ,agrionid are not indispensable for the maintenance of life1 as the insects can live without them1 breathing either through the skin or by the rectum1 or in both ways4 ,it would seem that while in freshly hatched or very young larv of aquatic insects of different orders the skin is so delicate as to allow of dermal respiration1 in after life1 when the skin becomes thicker and denser1 these expansions 7gills71 provided with a very thin and delicate skin1 of a necessity grow out from the walls of the body4 ,it thus appears that the closure and total or partial abolition of the stigmata are in adaptation to aquatic life1 and that such insects have descended from terrestrial air-breathing winged forms4 ,this is an important argument against the view that the wings are modified tracheal gills4 ,in this connection may be noticed the closure of the #b;d and #c;d thoracic stigmata in holopneustic insects4 ,we have found on laying open the body of a ,sphinx larva that a large number of tracheal branches are seen to arise from the prothoracic and from the first pair of abdominal stigmata4 ,now between these points there are no spiracles or any external signs of them1 there being in ,lepidoptera no mesothoracic or metathoracic spiracles4 ,yet the main lateral trachea between the prothoracic and first abdominal segments deviates from its course and bends down to send off a small shrivelled stigmatal branch or cord to a place where1 did a spiracle exist1 we should look for it4 ,in the larva of ,platysamia cecropia1 a similar vestigial stigmata branch is present4 ,in the larva of ,corydalus1 also1 a trachea as large as the main longitudinal one takes its origin and passes directly under the main trachea4 ,now both trache send a stigmatal branch opposite to where the mesothoracic stigma should be1 if present1 i4e4 on the hind edge of the segment4 ,verson1 moreover1 has found in the freshly hatched silkworm vestiges of meso- and metathoracic stigmata1 each consisting of a circle of high hypodermal cells radially arranged around a common centre4 ,the stigmatal branch is long1 but shrivelled2 its peritoneum is widened out into several berry-like saccules filled with cell-elements4 ,in profile these rudimentary stigmata appear as a series of high hypodermal cells1 which form the basis of a short blind tube4 ,illustration3 ,lydia ,m4 ,hart del4 ,,plate ,i4--,examples of metapneustic insects3 #a1 ,bittacomorpha clavipes1 larva2 #a a1 false foot2 #a b1 its pupa2 #b1 ,limnophila luteipennis2 #b a1 end of larva2 #b b1 its pupa2 #c1 end of larva of ,tipula eluta4--,after ,c4 ,a4 ,hart4 ,after the second moult there begins a peculiar transformation of the rudimentary stigmata4 ,the stigmatal branch connected with them sends off at various points thick tufts of capillary trache which press against the base of the blind tube4 ,gradually lengthening1 they form a fold which continues to increase in length4 ,the numerous tufts of tracheal capillaries extend beyond the inner surface of the two layers of which the developing wing consists1 the berry-like saccules are drawn into the wing and converted into more or less thick tubes1 which finally form the 8veins40 ,it is clear1 therefore1 says ,verson1 as ,landois claimed1 that the wings of ,lepidoptera must be regarded as in the fullest sense organs of respiration4 7,zool4 ,anz41 #ahij1 p4 #aaf47 ,the number of pairs of stigmata varies1 especially in maggots or larval ,diptera1 in adaptation to their varied modes of life4 ,the larv of most flies 7,muscid7 have a pair of peculiarly shaped processes on the prothoracic segment bearing spiracular openings1 and two anal spiracles1 while in ,ctenophora atrata ,l4 only the anal pair are present4 ,in the rat-tailed maggots 7,eristalis7 the long caudal process ends in two stigmata forming a respiratory tube1 which can be thrust out of the water for the reception of air4 ,in the larval mosquito 7,fig4 #dcc7 and its ally1 ,mochlonyx1 a short thick dorsal tube arises from the penultimate segment of the body1 in which the two main trache end1 opening outward by a single spiracular aperture4 ,other dipterous larv 7,simulium1 ,tanypus1 and ,ceratopogon7 possess no spiracles1 the tracheal system being a closed one4 ,the larv of most water beetles 7,dyticid1 ,hydrophilid7 possess but two spiracles1 which1 as in maggots1 are situated at the end of the body4 ,the aquatic larva of ,amphizoa1 according to ,hubbard1 breathes much as in the ,dyticid1 by means of two large valvular spiracles placed close together at the end of the body2 8closed or rudimentary stigmata also occur on the mesothorax and on abdominal segments one to seven inclusive40 ,hubbard adds3 8,the larva of ,pelobius is wholly aquatic and breathes by branchi1 but the obsolete stigmata are indicated precisely as in ,amphizoa1 with the exception of the last pair1 which in ,amphizoa are open spiracles1 but in ,pelobius are suppressed2 the terminal eight segments being prolonged in a swimming stylet40 ,from a review of the distribution of spiracles1 and their atrophy1 partial or total1 it will be seen that there are intermediate stages between the open 7holopneustic7 and closed 7apneustic7 systems4 ,these1 following ,schiner1 ,brauer1 and ,palmn1 may be defined thus3 #a4 ,metapneustic type4--,the larv possess only a single pair of open stigmata situated at the end of the body4 7,the dipterous ,eristalis1 ,tipula1 ,culex1 ,ptychoptera1 ,bittacomorpha 7,plate ,i47 with certain ,tachinid1 and in ,coleoptera1 the larv of ,dyticus1 and allies of ,hydrophilus and ,cyphon47 #b4 ,propneustic type4--,the pup of ,corethra1 ,culex1 etc41 in which only the most anterior pair of spiracles are open4 ,illustration3 ,,fig4 #dbh4--,visceral tracheal system of the nymph of schna maculatissima3 o1 sophagus2 ,e1 stomach2 ,m1 urinary tubes2 ,r1 rectum2 ,a1 anus2 tv1 visceral tracheal trunks2 td1 dorsal trunks4--,after ,oustalet4 #c4 ,amphipneustic type4--,larv with a pair of open spiracles situated at each end of the body1 the intermediate spiracles being closed4 7,most dipterous larv1 ,musca1 after the first moult1 strid1 ,asilid1 and ,syrphus47 ,illustration3 ,,fig4 #dbi4--;,branchial tuft of nymph of schna4 #d4 ,peripneustic type2 with prothoracic and abdominal spiracles1 the mesothoracic pair atrophied or closed4 7,the larv of ,neuroptera1 ,mecoptera1 ,trichoptera1 ,lepidoptera1 of most ,coleoptera1#gb of most ,diptera1 and of most of the ,hymenoptera4#gc7 ,illustration3 ,,fig4 #dcj4--,part of three rows of respiratory folds from cuticular living rectum of schna4 ,the shaded parts are abundantly supplied with tracheal tubes4 ,the leaflets appear to be connected with a central trachea1 but this is not really the case4--,after ,miall4 ,these differences in the number of functional spiracles are in direct relation with the surroundings of the insects1 the physical conditions of existence evidently determining the position of the active functional open spiracles and the closure of those useless to the organism4 i4 ,the rectal tracheal gills1 and rectal respiration of larval ,odonata and other insects ,the remarkable mode of respiration by tracheal gills situated within the intestine of the nymphs of dragon-flies was first described by ,swammerdam and afterwards by ,raumur4 ,the most complete and best illustrated modern account is that of ,oustalet4 ,in these insects the large rectum is lined with six double longitudinal ridges1 in schna bearing numerous delicate tubes or papill1 each of which contains very numerous 7by estimate #bd1jjj7 tracheal branches 7,fig4 #dca72 while in ,libellula the gills are lamellate 7,fig4 #dcb74 ,the trache arise both from the main dorsal and visceral longitudinal trunks1 which give rise to secondary branches passing into the walls of the rectum and sending into the branchial papill fine twigs1 which1 extending to the distal end of the papilla or lamella1 recurve and anastomose with the efferent twigs4 ,illustration3 ,,fig4 #dca4--;,a small part of one leaflet1 highly magnified1 showing many fine tracheal branches4 ,the portion shown is marked by a small circle in ,fig4 #dcj1 lower left-hand corner4--,after ,miall4 ,illustration3 ,,fig4 #dcb4--,leaves1 mh1 from a lamellate tracheal gill of ,libellula3 t1 trachea4--,this and ,fig4 #dbi1 after ,oustalet4 ,the anal opening is externally protected by the suranal and lateral triangular chitinous plates1 three to five in all4 ,when open1 the water passes into the rectum and bathes the rectal gills1 where it may be forcibly expelled as if shot out from a syringe1 thus propelling the insect forward4 ,in ,libellula the anus affords direct access to the intestinal cavity1 but in schna ,oustalet describes 8a sort of vestibule separated from the rectum by a circular valvule40 ,he also states that the inspiration and the repulsion of water is produced at irregular intervals1 and rather by the movements of the dorsal and sternal arches of the abdomen than by the contractions of the rectum1 since the walls of this organ are less muscular than is supposed4 ,illustration3 ,,fig4 #dcc4--,larva of a mosquito 7,culex nemorosus7 of middle age1 seen from above1 the tracheal system omitted3 at1 antenn2 ab1 their middle joint2 eg1 elastic articular membrane2 atm1 antennal muscle2 atn1 antennal nerve2 zau1 compound2 eau1 simple eye2 os1 brain2 oex1 extensor2 ofl1 flexor of labrum2 ha1 neck2 1 sophagus2 spd1 salivary gland2 mau1 cca2 ch1 chyle stomach2 di1 contents of intestine2 mg1 urinary tubes2 dd1 ileum2 ed1 rectum2 a1 anus2 s1 sipho2 z1 its bristles2 kb1 tracheal gills3 k#a1 k#b1 k#c1 closing lobes of the sipho2 kn1 basal tubercle of tactile hair2 g1 its ganglion cell2 th1 tactile hair of the siphon valve4 ,the nymph of ,calopteryx 7and probably of all the group ,calopterygin7 possesses rectal gills besides external caudal tracheal gills4 ,there are three double rectal longitudinal folds or ridges1 interpenetrated by tracheal twigs4 7,dufour1 denied by ,poletaiew1 but confirmed by ,hagen47 ,dewitz claims that the caudal gills of the ,agrionid are not their sole means of respiration1 since he cut off the caudal tracheal gills of an ,agrionid nymph1 which continued to live for a week4 ,hence he thinks that there may be a rectal respiration1 since under the microscope he saw a stream of water pass in and out of the end of the intestine4 ,dewitz' experiments prove that in young ,ephemerids there may be besides branchial1 both rectal and skin respiration4 ,he saw under the microscope the anus for a while opened and then closed1 causing the rectum to move2 powdered carmine mixed with water was drawn into and then expelled from the rectum4 ,there was1 however1 no enlargement and contraction of the abdomen as in the rectal respiration of schna4 7,zool4 ,anz4 #ahij1 p4 #ejj47 ,illustration3 ,,fig4 #dcd4--;,end of the body of the same larva as in ,fig4 #dca1 seen from the side1 the branches of the main trache 7htr7 omitted3 kbl1 excrementitial pellet in rectum2 kb1 tracheal gills2 b1 funnel of the closing apparatus2 hz1 hollow tooth of the closing apparatus2 k#a1 k#b1 k#c1 siphonal lobes2 th1 tactile hair2 as1 chitinous plate2 str1 rudder2 l1 its thickened edge2 sch1 its shank2 z1 z1 bristles4--,this and ,fig4 #dcc1 after ,raschke4 ,eaton states that there is a rectal respiration in the nymphs of may-flies1 and ,palmn observed in young larv of ,btis and ,cloon that the rectum took in 8by gulps0 water colored by carmine and expelled the whole of it at once1 in order to fill it again in the same way4 8,this rectal respiration therefore corresponds to that of ,libellulid larv40 ,illustration3 ,,fig4 #dce4--,thorax and anterior abdominal segments of the nymph of a may-fly 7,cloon dimidiatum7 with tracheal gills 7tk#a1 tk#b1 tk#c7 and the rudiments of the fore wings 7,,vf7 and hind wing 7,,hf73 tl1 tracheal longitudinal trunks4--,after ,graber1 from ,lang4 ,illustration3 ,,fig4 #dcf4--;,gills on the middle abdominal segments of larva of ,btis binoculatus3 trl1 longitudinal tracheal trunks2 vf1 stigmatic cord2 ktr1 gill-trache2 trk1 tracheal gills4--,after ,palmn1 from ,lang4 ,besides breathing by spiracles1 by tracheal gills1 as well as through the integument1 the larva of ,culex has been observed by ,raschke to have a rectal respiration4 ,at the anterior end of the rectum arises a countless number of fine trache1 which pass through the walls and1 subdividing1 end in numberless very fine twigs in the papilla-like folds situated within the rectum4 ,the supply of tracheal twigs is greatest where the papill are largest4 7,figs4 #dcc1 #dcd47 j4 ,tracheal gills of the larv of insects ,in many aquatic insects respiration is carried on by tracheal gills4 ,these are delicate1 hollow1 leaf-like or tubular outgrowths of the integument usually attached to the sides or end of the hind-body1 and containing a trachea which usually sends off numerous minute branches1 so that the exchange of gases readily takes place in them4 ,illustration3 ,,fig4 #dcg4--;,a1 nymph of ,ephemerella ignita1 with gills of left side removed2 g1 gills4 ,b1 nymph of ,tricorythrus 7sp71 with gill-cover of right side removed2 gc1 gill-cover2 g1 g1 gills4--,after ,vayssire4 ,illustration3 ,,fig4 #dch4--,left maxilla of ,jolia weselii1 with the cephalic tracheal gill 7h7 inserted at the base on the under side4--,after ,vayssire4 ,palmn has shown that these tracheal gills1 as he calls them1 are not developed on the same segments as the stigmata1 and that the two structures have no genetic connection with each other4 ,it is evident that these gills are secondary1 adaptive organs4 ,in some cases 7see p4 #dge7 the trache are wanting1 but as such gills are filled with blood1 the air contained in the water must pass in through their delicate walls4 ,in the ,plectoptera 7,ephemerid7 the tracheal gills are either foliaceous or filamentous2 when foliaceous they form simple or double leaves1 with or without branches1 or with a fringe of tubules1 or under the leaf-like cover-bearing tufts of filaments4 ,they are situated on the 7usually7 basal seven abdominal segments1 at their hinder edge 7,figs4 #dce1 #dcf74 ,in ,oligoneuria and ,jolia a pair occurs on the under side of the head1 attached to the maxill1 while in ,jolia there is a pair on the under side of the first thoracic segment at the insertion of each of the legs4 ,in certain genera 7,heptagenia1 ,oligoneuria1 and ,jolia71 they are in the form of a flat cover1 under which lies a tuft of respiratory tubes1 or 7,ephemerella7 a small bifid cluster of very delicate leaves 7,fig4 #dcg1 ,a74 ,in ,cnis and ,tricorythus the tracheal gills of the second pair are modified to form plates covering all the succeeding pairs1 those of the first pair being nearly atrophied and well-nigh functionless4 7,fig4 #dcg1 ,b47 ,illustration3 ,,fig4 #dci4--;,inner side of a gill-cover of the first pair1 of ,ephemerella1 with the tracheal gills4--,after ,vayssire4 ,illustration3 ,,fig4 #ddj4--,nymph of ,btisca3 ,,iii1 section of abdomen2 a1 gills2 b1 flap2 #a-i1 abdominal segments4--,after ,walsh4 ,illustration3 ,,fig4 #dda4--,nymph of ,prosopistoma punctifrons3 o1 upper orifice of the respiratory chamber4--,after ,vayssire4 ,illustration3 ,,fig4 #ddb4--;,filamentous tracheal gill and part of a trachea of ,pteronarcys4--,after ,newport from ,sharp4 ,finally1 in the highly modified forms ,btisca and ,prosopistoma the tracheal gills are entirely concealed and protected by mesothoracic projections so as to form a true respiratory chamber1 to which the water has access either by an opening behind1 as in ,btisca1 or by three openings1 two ventral and one dorsal 7,fig4 #dda71 as in ,prosopistoma4 ,the slender cylindrical tracheal gills of ,heptagenia in the third or fourth nymphal stage are #b-;jointed1 and the first abdominal pair in ,cnis are said by ,palmn to be finger-shaped and #b-;jointed4 ,in ,polymitarcys virgo the gills do not appear until the eighth or tenth day after hatching4 ,dewitz found that young nymphs of ,ephemerids will well endure the amputation of their gills1 while fully grown ones die4 ,amputation of the lateral gills hastens ecdysis4 ,after the change of skin1 the gills are smaller than before1 and at first contain no trache1 but in a few weeks they develop as completely as in normal individuals4 ,the caudal gills were also renewed4 ,illustration3 ,,fig4 #ddc4--;,a1 larva of ,sisyra1 enlarged4 ,b1 one of the hinder gills1 with its trache4--,after ,westwood1 from ,sharp4 ,c1 a gill1 showing the branched trache4--,after ,grube4 ,in the nymphs of ,perlid the tracheal gills are usually present1 and are either foliaceous 7,nemoura7 or more commonly filamentous in shape 7,fig4 #ddb74 ,they are situated either on the prosternum 7,nemoura and ,pteronarcys71 or on each side of the thorax1 or on the sides of the abdomen1 or are restricted to a tuft on each side of the anus at the base of the caudal stylets 7,pteronarcys and ,perla74 ,unlike the ,ephemerid the gills persist in certain genera throughout life4 ,the larv of the aquatic ,neuroptera1 ,sisyra1 ,sialis1 and ,corydalus possess lateral pointed bristle-like tracheal gills1 which in ,sisyra are #b-;jointed2 those of ,sialis are1 in the living larva1 curved upwards and backwards 7,fig4 #ddd74 ,corydalus is also provided with a ventral tuft of delicate filamentous gills1 which1 however1 according to ,riley1 do not appear until after the first moult4 ,while the nymphs of ,agrionid 7which have rectal gills7 respire chiefly by the large caudal foliaceous gills 7,fig4 #dde71 there are1 according to ,hagen1 two genera of the ,calopterygin 7,eupha1 ,fig4 #dde1 and ,anisopleura7 whose nymphs possess seven pairs of external lateral tracheal gills1 in shape like those of ,sialis1 besides three caudal and three rectal tracheal gills4#gd ,illustration3 ,,fig4 #ddd4--,larva of ,sialis lutarius4--,after ,miall4 ,illustration3 ,,fig4 #dde4--;,caudal tracheal gill of nymph of ,agrion4 ,hagen has also detected in the under side of the #eth abdominal segment of ,epitheca and ,libellula a pair of sacs of the shape of a ,phrygian bonnet1 each of which contains a smaller sac lined with epithelium1--as in schna they occur in the #eth and #fth1 and in ,gomphus in the #dth1 #eth1 and #fth segments4 ,this serial arrangement appears to confirm ,hagen's suggestion that they are survivals of abdominal gills1 which in ,eupha are completely evaginated4 ,illustration3 ,,fig4 #ddf4--,nymph of ,eupha1 showing the lateral gills3 a1 one enlarged4--,folsom del4 ,in the ,trichoptera1 all of which1 except ,enoicyla1 are apneustic1 and most of which have tracheal gills1 the latter are filamentous1 and arise either from the dorsal and ventral sides of the abdominal segment1 or they grow out from the sides2 while in certain genera 7,neuronia1 ,phryganea1 etc47 the gills are represented by conical hooks on the sides of the #ast abdominal segment1 which are evidently respiratory1 as they contain numerous trache4 ,the tracheal gills are either single or more rarely form tufts 7,figs4 #ddg1 #ddh74 ,in ,hydropsyche 7,fig4 #ddh7 the tracheal gills persist throughout life1 while in other genera they only last through the pupal stage4 ,when first hatched1 the larva of ,phryganea lacks gills4 ,the larv of most of the ,hydropsychid1 ,rhyacophilid1 and ,hydroptilid have no gills1 though they appear well developed in the pupal stage4 7,klaplek47 ,illustration3 ,,fig4 #ddg4--;,a1 an abdominal segment of ,hydropsyche1 with the tracheal gills 7lbr73 trl1 longitudinal tracheal trunk2 f1 stigmatal branch4 ,b1 #eth abdominal segment of pupa of the same2 l1 the three lateral flaps of the tergite2 br#a1 br#b1 branchi4 ,illustration3 ,,fig4 #ddh4--;,imago1 abdominal segments ,,iv to ,,vi1 with the gills at a concealed in their natural condition2 at b1 drawn out with the needle2 at c1 projecting abnormally and dried4--,this and ,fig4 #ddg after ,palmn4 ,illustration3 ,,fig4 #ddi4--,larva and pupa of ,paraponyx stratiolata1 enlarged2 s1 spiracle4--,after ,de ,geer 7compare ,hart's figure of ,p4 obscularis1 living in the ,illinois ,river74 ,the only lepidopterous larva known to be provided with tracheal gills is that of the pyralid genus ,paraponyx4 ,its thread-like gills1 arranged in tufts of three or four1 arise from a common tubercle situated on the sides of nearly all the segments4 ,wood-,mason describes the ,east ,indian ,p4 oryzalis as 8covered with a perfect forest of soft and delicate white filaments10 arranged in tufts disposed in four longitudinal rows4 8,the stigmata of the #b;d1 #c;d1 and #dth abdominal somites only are clearly discernible40 ,the caterpillar crawls 8free and uncovered0 over the submerged leaves of the rice plant 8in the very midst of the water40 ,in a ,brazilian species of ,paraponyx described as ,cataclysta pyropalis1 by ,w4 ,mller1 the tufts are reduced to simple unbranched filaments1 and the case is more complex than in the ,european species 7,fig4 #ddi74 ,illustration3 ,,fig4 #dej4--;,anterior end of larva of ,p4 stratiolata1 showing the head and first two thoracic segments1 with their gills3 ,a1 a tuft of gills1 much enlarged4--,after ,de ,geer4 ,illustration3 ,,fig4 #dea4--,larva 7#a7 and pupa 7#b;a7 of ,paraponyx pyropalis enlarged3 st1 stigmata4--,after ,w4 ,mller4 ,of coleopterous larv breathing by tracheal gills there are but few4 ,the larva of ,gyrinus 7,fig4 #ded7 respires by #aj pairs of slender1 hairy abdominal gills similar to those of ,corydalus1 and the stigmata are entirely wanting4 ,somewhat similar are the tracheal gills of ,hydrocharis caraboides4 ,hydrobius has shorter setose gills1 our ,american species having seven pairs of short setose gills4 ,it has two spiracles at the end of the body1 through which the air is taken by thrusting the body out of the water4 ,the larv of two other aquatic coleopterous genera1 ,pelobius and ,cnemidotus1 also have gills2 those of the former situated at the base of the cox1 and brush-like1 but containing no trache1 though filled with blood1 while those of ,cnemidotus are very long1 bristle-like1 jointed1 and arising from the dorsal side of the thoracic and abdominal segments4 ,the stigmata are wanting4 7,schidte47 ,the larva of the dipterous genus ,tanypus respires by two caudal papilliform processes1 in each of which a trachea ramifies4 ,illustration3 ,,fig4 #deb4--;,freshly hatched larva of ,hydrobius3 t1 enlarged trache1 the heart between them2 g#a-;g#g1 the seven pairs of gills4 ,a1 end of body1 enlarged1 showing the two terminal stigmata4--,emerton del4 ,certain larv with both stigmata and tracheal gills are enabled either to live in or out of water or on the surface1 as in the case of certain beetles 7,cyphonid1 ,elmid1 ,hydrophilid1 ,fig4 #deb71 or the larval mosquito and ,psychodes 7,fig4 #dee72 also the nymphs of dragon-flies4 ,the larv of the ,cyphonid 7,helodes1 ,cyphon1 ,hydrocyphon7 possess but a single pair of stigmata1 situated in the penultimate abdominal segment1 while at the end of the abdomen are delicate tracheal gills4 ,the two main tracheal trunks are much swollen4 ,when on the surface of the water the larva breathes through the stigmata situated near the end of the abdomen2 when floating in the water1 the larva1 like that of ,gyrinus1 carries along at the end of its body a bubble of air4 ,the gills are only of use1 as ,rolph thinks1 when the insect is compelled to remain a long time under water4 ,the larva of our native ,prionocyphon discoideus 7,say7 is described by ,walsh as 8vibrating vigorously up and down a pencil of hairs proceeding from a horizontal slit in the tail02 this pencil is composed 8of three pairs of filaments1 each beautifully bipectinate4 ,i presume it is used to extract air from the water40 ,when the larva is at the surface the pencil of hairs touches the surface of the water1 and occasionally a bubble of air is discharged from the tail4 8,the general habit is to crawl on decayed wood beneath the surface1 occasionally swimming to the surface1 probably for a fresh supply of air40 7,proc4 ,ent4 ,soc4 ,phil41 i1 p4 #aag47 ,illustration3 ,,fig4 #dec4--,larva of ,psephenus1 enlarged4 ,illustration3 ,,fig4 #ded4--,larva of ,gyrinus4--,after ,westwood4 ,the larv of the small water beetles of the family ,elmid 7,elmis1 ,potamophilus1 ,macronychus1 and ,psephenus7 have similar habits4 ,that of ,elmis has ten dorsally situated pairs of spiracles1 and on the end of the body bushy gills which are protruded at pleasure4 ,the young larva is without spiracles1 its tracheal system being closed4 ,macronychus and ,potamophilus have similar habits4 ,in the larva of the latter genus1 which has nine pairs of spiracles1 there are at the end of the body on each side three tufts of thread-like gills which are connected with the two main horizontal trache1 while the branches of the abdominal trache are dilated into numerous 7#fd7 bladder-like sacs4 ,the larva usually breathes through the caudal gills4 ,when the water is low or dried up1 the air is inhaled directly through the spiracles4 7,kolbe47 ,the larva of ,psephenus lecontei1 by its broad hemispherical body1 is adapted to adhere to the smooth surface of rounded stones1 in which situation we have found it4 ,although it is said by ,rolph to have two pairs of spiracles1 one pair on the mesothoracic and the other on the #ast abdominal segment1 it probably rarely rises to the surface to breathe the air direct4 ,illustration3 ,,fig4 #dee4--;,end of body of a ,psychodes larva3 ,a1 end of body of a young1 freshly moulted larva1 side view3 a1 the three anal gills2 b1 the left air-cavity4 ,b1 older larva of the same species1 with the open air-cavity seen from above4 ,c1 end of larva of another species as it goes down into the water with a bubble of air1 b1 between the crown of hairs of the air-cavity or tube3 a1 the two pairs of anal gills2 b1 the two main trache4--,after ,f4 ,mller4 ,it possesses five pairs of gills on the under side of the #b;d to the #fth abdominal segments4 ,each gill has finger-shaped processes on its hinder edge1 which are 8from their constant motion evidently connected with respiration40 ,trache may be seen1 according to ,h4 ,j4 ,clark1 entering the gills1 and 8the circulation of water among the branchi is kept up by the flapping of the tail-pieces40 ,the larva of ,helichus fastigiatus is said by ,leconte to be 8very nearly allied1 while the remotely allied ,stenelmis crenatus has no external branchi40#ge ,the larva of the mosquito also has two modes of respiration1 breathing either at the surface of the water through the two spiracles situated on the projection 7siphon7 at the hinder end of the body which is thrust out into the air2 or when at the bottom respiring by tracheal gills4 ,the pupa also has a double mode of respiration1 either taking in air at the surface by the two thoracic horns with stigmatic openings1 or when submerged using its tracheal gills4 ,besides its long caudal tracheal air-tubes1 the larval ,eristalis is said by ,chun to thrust out from the anus a number 7#bj7 of short tracheal filaments which float about in the water and serve to absorb the air4 ,an aquatic ,brazilian larva of the family ,psychodid has been found by ,fritz ,mller to take down under the water a large bubble of air 7,fig4 #dee1 ,c71 the main tracheal trunk ending each in an opening at the end of the body 7,a1 ,b72 besides this1 while at the bottom it breathes by three digitiform tracheal gills2 another species having two pairs 7,c1 a74 ,illustration3 ,,fig4 #def4--,under side of body of larva of ,blepharocera4 showing the position of the tracheal gills3 ,a1 section of the body through a sucker1 showing position of the gills4 ,b1 section of a sucker3 br1 gill with numerous trache2 gl1 outlet of excretory gland2 ,m1 m1 muscles4--,after ,f4 ,mller4 ,the remarkable larv of the ,blepharocerid 7represented in the ,united ,states by ,blepharocera capitata71 which live permanently in swift streams1 attached by median suckers to stones1 are apneustic1 and breathe solely by leaf-like tracheal gills 7,fig4 #def1 br7 attached to the under side of the second to sixth abdominal segments4 ,those of the ,european ,liponeura are said by ,wierzejski to be branched1 tree-like4 ,also immediately in front of the anus and behind the last sucker are four membranous sacs provided with trache1 but which are not capable of being withdrawn4 ,these are said by ,mller to be the same as what ,dewitz states to serve as gills1 and by ,wierzejski they are homologized with the four anal gills of ,chironomus4 ,the double mode of respiration in the larva of the horse bot-fly has been described by ,scheiber4 ,on the hinder end of the body are the stigmatic plates1 which contain two lateral gill-plates and the middle stigmatal leaf4 ,besides this there is a pair of slightly developed prothoracic spiracles4 ,the embryo and also freshly hatched larva of ,gastrophilus equi do not possess these gill-plates1 but on the end of the body are1 according to ,joli1 two long thread-like gills4 ,the freshly hatched larva of the allied ,cephenomyia rufibarbis bears two caudal projections4 7,kolbe47 ,as in shrimps and other ,crustacea the gills are kept in constant motion1 the water being driven over them by the rapid movements of the telson1 so in the larval may-flies1 and in the case-worm 7,macronema71 the gills move more or less rapidly4 ,in case-worms as well as larval ,perlid1 ,sialid1 ,paraponyx1 and ,hydrophilid the abdominal region is constantly moved to promote respiration4 7,kolbe47 ,blood-gills4--,fritz ,mller describes in trichopterous larv certain delicate anal tubular processes into which the blood flows1 and which do not as a rule contain trache1 though occasionally very fine tracheal branches4 ,mller compares them with the gills of crabs and of shrimps4 ,they are eversible finger-like tubules4 ,they are used when the tracheal gills are temporarily not available4 ,their number varies even in the same genus4 ,there are six in certain ,rhyacophilid2 five in different ,hydropsychid2 in ,macronema there are four1 and they are green when filled with the green blood of that insect1 the tracheal gills being whitish4 ,in the freshly hatched larva1 while the tracheal gills are present1 no anal blood-gills are visible4 ,similar blood-gills also occur in the pup of certain caddis-flies4 7,pictet47 ,similar anal gills filled with blood occur in the larv of the fireflies 7,lampyris1 etc471 and perhaps1 ,kolbe thinks1 serve for respiration1 though other authors believe them to be adhesive organs4 ,the larva of ,pelobius has true blood-gills4 7,schidte4 ,see p4 #dfa47 ,the eversible ventral segmental sacs of ,scolopendrella1 ,campodea1 and ,machilis1 as well as the ventral tube 7collophore7 of ,podura1 ,smynthurus1 etc41 may1 as ,oudemans and ,haase have suggested1 serve a respiratory purpose1 though they lack trache1 and differ from blood-gills in containing no gases2 yet the blood is forced into them1 causing their eversion4 ,oudemans observed that ,machilis everted its sacs when the vessel in which it was put was filled with warm1 damp air4 ,the sacs are only thrust out when the creature is completely at rest4 ,structures referable to blood-gills also occur temporarily in the embryo of ,orthoptera2 ,rathke observed them in the mole-cricket2 ,ayres observed them in canthus niveus1 where they form two stalked broad oval appendages on the first abdominal appendages1 which he regarded as gills4 ,patten observed them in ,phyllodromia germanica1 as pear-shaped structures occurring in the same situation1 but regarded them as sense-organs1 as did ,cholodkowsky4 ,graber found these structures in the embryo of the ,may-beetle1 which looked like the other embryonic limbs1 but survived after the disappearance of the latter1 being longer and broader and unjointed4 ,these disappeared shortly before birth4 ,in ,hydrophilus they remain1 ,graber states1 after birth4 ,nussbaum has seen them in ,melo4 ,finally1 ,wheeler has discussed at length these embryonic organs1 which he regards as glandular structures1 and calls pleuropodia1 their primitive function having been that of limbs4 ,he has detected them in the embryo of ,periplaneta orientalis1 ,mantis carolina1 ,xiphidium ensiferum 7,fig4 #chg72 also in the ,hemiptera 7,cicada septemdecim1 ,zaitha fluminea71 and in ,sialis infumata4 ,he discards the view that they were once gills or sense-organs1 and concludes that they were glands4 ,but1 as we have suggested1 their function once that of gills1 and still respiratory in ,synaptera1 has perhaps become in the winged insects glandular and repugnatorial4 ,instead1 then1 of being modified abdominal limbs afterwards serving as glands1 as ,wheeler claims1 we are inclined to believe that they functioned as blood-gills4 k4 ,tracheal gills of adult insects ,tracheal gills are known to be retained by a few insects in the imago stage1 the nymphs in all stages breathing by them4 ,the most notable example is the perlid genus ,pteronarcys1 in which1 as ,newport states1 there are eight sets1 comprising #ac pairs of branchial tufts distributed over the under surface of the thoracic and first two abdominal segments4 ,the first set1 consisting of three pairs of tufts1 partly encircling the neck like a ruff1 arises from the soft membrane connecting the head and prosternum4 ,the thoracic tufts originate between and behind the cox1 as well as on the front margin of the meso- and metathoracic segments4 ,the number of filaments in each tuft varies from about #bj to #ej or more1 the densest tufts being those of the two hinder thoracic segments4 ,each filament is usually simple1 though in a few cases they are branched 7,fig4 #deg1 ,a74 ,the adult ,pteronarcys is nocturnal1 flying only at dewfall or in the night1 and ,mr4 ,barnston observed it when on the wing1 8constantly dipping on the surface of the water02 by day it hides 8in crevices of rocks which are constantly wetted by the spray of falling water1 under stones and in other damp places40 ,it may thus be compared with the ,amphibians1 ,necturus and ,proteus1 whose gills are retained in adult life4 ,a similar large ,chilian ,perlid 7,diamphipnoa lichenalis ,gerst47 differs in completely lacking the thoracic gills1 though there are four pairs on the abdomen1 i4e4 a pair on each of the first four segments4 ,in this form the number of individual filaments in the largest tufts may amount to about #bjj4 ,another ,perlid 7,dictyopteryx signata7 is said by ,hagen to have two pairs of gill-tufts on the under side of the head2 the first pair situated on the base of the submentum1 the second on the membrane connecting the head and prosternum4 ,kolbe states that in the imagines of ,perla marginata and ,p4 cephalotes on the hinder edge of the thoracic stigmata arise three very small chitinous plates1 which1 on their under side and on the edges are beset with numerous short white filaments4 ,these completely correspond to the filaments of the tuft-like larval gills4 ,persistent anal gills also occur in the imagines of ,perla4 ,illustration3 ,,fig4 #deg4--,under side of ,pteronarcys regalis1 showing the situation of the gills 7g1 b1 f7 and the sternal orifices3 ,a1 a branchial filament showing the direction of the current of blood2 c1 d1 trache4 ,b1 end of the abdomen enlarged4--,after ,newport4 ,in ,nemoura lateralis and cinerea the tracheal gills are differently disposed4 ,on each side of the anterior edge of the prosternum arise delicate tightly twisted filaments1 like those of the larva4 7,einfhrung1 p4 #ecf47 ,hagen also states that in the dragon-fly1 ,eupha1 the gills of the nymphs are retained in the imago1 and ,palmn remarks that in schna the rectal gills of the nymph persist in the imago1 though not used for respiration4 ,palmn gives an instance of a caddis-fly 7,hydropsyche1 ,fig4 #ddh7 retaining its gills through the imago stage1 but they are unfit for respiration1 as they are minute and shrunken4 ,a walking-stick 7,prisopus flabelliformis7 found in the mountains of ,brazil has the remarkable habit1 according to ,murray1 of spending 8the whole of the day under water1 in a stream or rivulet1 fixed firmly to a stone in the rapid part of the stream10 with its head turned up stream2 but leaving the water at dark4 ,the under side of the body1 including the head1 is hollowed so that the creature may adhere1 sucker-like1 to smooth stones2 the claws1 claspers1 and flaps on the legs aid in retaining its hold1 while the outer margin of the legs is dentate and thickly fringed with hair to repel the water4 ,another form1 closely related to ,prisopus1 from ,borneo 7,cotylosoma dipneusticum7 is said by ,wood-,mason to be even more profoundly modified for an aquatic life1 since it has not only spiracles1 but also1 as he claims1 tracheal gills4 ,from each side of the body1 in fact along the lower margins of the sides of the metathorax1 there stand straight out five equal1 small1 but conspicuous ciliated oval plates1 8which1 when the insect is submerged and its stigmata are closed1 doubtless serve for respiration40 ,the author did not note the actual presence of trache in these plates4 ,,literature ,,on ,,the ,,organs ,,and ,,physiology ,,of ,,respiration a4 ,on the tracheal system in general ,lyonet1 ,p4 ,trait anatomique de la chenille qui ronge le bois du saule4 7,la ,haye1 #agfj2 #b;d edit41 ,la ,haye1 #agfb1 pp4 #faf1 #ah ,pls47 ,treviranus1 ,g4 ,r4 ,beitrge zur ,anatomie und ,physiologie der ,tiere und ,pflanzen1 #ahaf4 ---- ,das organische ,leben4 ,bremen1 #ahca4 ,rengger1 ,j4 ,r4 ,physiologische ,untersuchungen ber die tierische ,haushaltung der ,insekten4 ,tbingen1 #ahag4 7,germar's ,mag4 f4 ,ent41 #ahah1 iii1 pp4 #daj-dac47 ,dufour1 ,l4 ,recherches anatomiques sur les ,carabiques et sur plusieurs autres insectes ,coloptres4 ,organes de la respiration4 7,ann4 ,sc4 nat41 viii1 #ahbf1 pp4 #ai-bg1 #b ,pls47 ---- tudes anatomiques et physiologiques sur les insectes ,diptres de la famille des ,pupipares4 ,appareil respiratoire4 7,ann4 ,sc4 nat4 ,zool41 ,sr4 #c1 iii1 #ahde1 pp4 #ef-fd1 #a ,pl47 ---- ,description et anatomie d'une larve branchies externes d',hydropsche4 7,ann4 ,sc4 nat1 ,zool41 ,sr #c1 #ahdg1 viii1 pp4 #cda-ced47 ---- tudes anatomiques et physiologiques1 et observations sur les larves des ,libellules4 ,appareil respiratoire4 7,ann4 ,sc4 nat4 ,zool41 ,sr4 #c1 xvii1 #aheb1 pp4 #gf-ig1 #c ,pls47 ---- ,recherches anatomiques sur les ,hymnoptres de la famille des ,urocerates4 ,appareil respiratoire4 7,ann4 ,sc4 nat4 ,zool41 ,sr4 #d1 i1 #ahed1 pp4 #bjc-bji1 #a ,pl42 see also p4 #cdd47 ,burmeister1 ,h4 ,handbuch der ,entomologie1 i1 #ahcb1 pp4 #afi-aid1 #daf-dcf4 ,kirby1 ,w41 and ,w4 ,spence4 ,introduction to entomology1 #ahcc1 iv1 pp4 #ce-ha4 ,bowerbank1 ,j4 ,s4 ,observations on the circulation of blood and the distribution of the trache in the wing of ,chrysopa perla4 7,ent4 ,mag41 iv1 #ahcg1 pp4 #agi-ahe47 ,platner1 ,e4 ,a4 ,mitteilungen ber die ,respirationsorgane in der ,haut bei der ,seidenraupe4 7,mller's ,archiv f4 ,physiol41 #ahdd1 pp4 #ch-di47 ,filippi1 ,f4 de4 ,alcuni osservazioni anatomico-fisiologische sugl' ,insetti in generale1 ed in particulare sul ,bombice del ,gelso4 7,ann4 ,r4 ,acad4 d' ,agricoltura di ,torino1 #ahej1 ii1 p4 #be1 #a ,pl42 ,transl4 by ,c4 ,a4 ,dohrn1 ,stettin1 ,ent4 ,zeit41 #aheb1 xiii1 pp4 #beh-bfg2 xiv1 pp4 #abd-acb1 #a ,pl47 ,newport1 ,g4 ,on the formation and the use of the air-sacs and dilated trache in insects4 7,trans4 ,linn4 ,soc4 ,london1 #ahea1 xx1 pp4 #dai-dbc47 ,lubbock1 ,j4 ,distribution of trache in insects4 7,trans4 ,linn4 ,soc4 ,london1 #ahfj1 xxiii1 pp4 #bc-ej47 ,landois1 ,l4 ,anatomie des ,phthirius inguinalis ,leach4 7,zeitschr4 f4 wissens4 ,zool41 xiv1 #ahfd1 pp4 #a-bf1 #e ,taf47 ---- ,anatomie des ,pediculus vestimenti ,nitzsch4 7,ibid41 xv1 #ahfe1 pp4 #cb-ee1 #c ,taf47 ---- ,anatomie des ,hundeflohs 7,pulex canis74 7,nova ,acta ,leop4-,carol4 ,akad4 der ,naturf41 ,dresden1 #ahff1 xxxiii1 #ahfg1 pp4 #fg1 #g ,taf47 ---- ,anatomie der ,bettwanze 7,cimex lectularius ,l474 7,ibid41 xviii1 #ahfh1 pp4 #bjf-bbd1 xix1 #ahfi1 pp4 #bjf-bcc1 #d ,taf47 ,meinert1 ,fr4 ,campode3 en familie af ,thysanurernes orden4 7,naturhistorisk ,tidsskr41 #c ,raek41 iii1 #ahfd-fe1 pp4 #djj-ddj1 #a ,pl47 ,reinhardt1 ,h4 ,zur ,entwicklungsgeschichte des ,tracheensystems der ,hymenopteren mit besonderer ,bezeichung auf dessen morphologische ,bedeutung4 7,berlin4 ,ent4 ,zeitschr41 #ahfe1 ix1 pp4 #ahg-bah1 #b ,taf47 ,gerstaecker1 ,a4 ,bronn's ,klassen und ,ordnungen des ,tierreichs1 v1 #ahff-ahgi4 ,organs of respiration1 pp4 #aai-aca4 ,pouchet1 ,g4 ,dveloppement du systme trachen de l',anophle 7,corethra plumicornis74 7,archiv zool4 exprimentale1 i1 #ahgb1 pp4 #bag-bcb1 #a ,fig47 ,graber1 ,v4 ,ueber eine ,art fibrilloiden ,bindegewebes der ,insektenhaut und seine lokale ,bedeutung als ,trachealsuspensorium4 7,archiv f4 ,mikroskop4 ,anat4 x1 #ahgd1 pp4 #abd-add1 #a ,taf47 ---- ,die ,insekten2 ,mnchen1 #ahgg4 ,organs of respiration1 pp4 #cdf-cfi4 ,packard1 ,a4 ,s4 ,on the distribution and primitive number of spiracles in insects4 7,amer4 ,naturalist1 viii1 #ahgd1 pp4 #eca-ecd47 ---- ,on the nature and origin of the so-called 8spiral thread0 of trache4 7,amer4 ,naturalist1 xx1 #ahhf1 pp4 #dch-ddb1 #b ,figs41 p4 #eeh47 ,wolff1 ,o4 ,j4 ,b4 ,das ,riechorgan der ,biene nebst einer ,beschreibung des ,respirationswerkes der ,hymenopteren1 des ,saugrssels und ,geschmacksorganes der ,blumenwespen4 7,nova ,acta d4 kais4 ,leop-,carol4 ,akad4 der ,naturf41 xxxviii1 #ahgf1 pp4 #a-bea1 #h ,taf47 ,palmn1 ,j4 ,a4 ,zur ,morphologie des ,tracheensystems4 ,leipzig1 #ahgg1 pp4 #adj1 #b ,taf4 ,moseley1 ,h4 ,n4 ,origin of trache in ,arthropoda4 7,nature1 xvii1 #ahgh1 p4 #cdj47 ,poletajew1 ,olga4 ,quelques mots sur les organes respiratoires des larves des ,odonates4 7,hor ,soc4 ,ent4 ,ross41 xv1 #ahhj1 pp4 #dcf-deb1 #b ,pls47 ,viallanes1 ,h4 ,sur l'appareil respiratoire de quelques larves de ,diptres4 7,compt4 rend4 ,acad4 ,sc41 ,paris1 #ahhj1 pp4 #aahj-aahb47 ,mac,leod1 ,j4 ,la structure des traches et la circulation peritrachenne4 ,bruxelles1 #ahhj1 pp4 #gj1 #d ,pls4 ,hagen1 ,h4 ,a4 ,beitrag zur ,kenntnis des ,tracheensystems der ,libellenlarven4 7,zool4 ,anzeiger1 #ahhj1 pp4 #aeg-afb47 ---- ,einwrfe gegen ,palmens ,ansicht von der ,entstehung des geschlossenen ,tracheensystems4 7,ibid41 #ahha1 pp4 #djd-djf47 ,macloskie1 ,g4 ,the structure of the trache of insects4 7,amer4 ,naturalist1 #ahhd1 xviii1 pp4 #efg-egc1 ,fig47 ,haase1 ,e4 ,das ,respirationssystem der ,chilopoden und ,symphylen 7,scolopendrellen7 vergleichen mit dem der ,hexapoden4 7,zeitschr4 f4 ,ent4 ,n4 ,f41 ix1 ,breslau1 #ahhd47 ---- ,das ,respirationssystem der ,symphylen und ,chilopoden4 7,zool4 ,beitrge1 von ,a4 ,schneider1 i1 #ahhd1 pp4 #fe-ie1 #c ,taf42 ,zool4 ,anzeiger1 #ahhc1 pp4 #ae-ag47 ,grassi1 ,b4 ,i progenitori degli ,insetti e dei ,miriapodi4 ,l',japyx e la ,campodea4 7,atti d4 ,accad4 ,gioenia d4 ,sc4 ,nat4 ,catania1 #ahhe1 ,sr4 #c1 xix1 pp4 #hc1 #e ,pls47 ---- ,i progenitori dei ,miriapodi e degli ,insetti4 ,anatomia comparata dei ,tisanuri4 7,reale ,accad4 d4 ,lincei di ,roma1 ,anno #bhd1 #ahhg47 ,meinert1 ,fr4 ,de eucephale ,myggelarver4 ,sur les larves eucephales des ,diptres4 7,vidensk4 ,selsk4 ,skrifter41 #f ,raekke1 naturvid4 og mathem4 ,afd4 ,kjbenhavn1 #ahhf1 iv1 pp4 #cfi-dic1 #d ,pls47 ,cajal1 ,s4 ,r4 ,coloration par la mthode de ,golgi des terminaisons des traches et des nerfs dans les muscles des ailes des insectes4 7,zeitschr4 f4 wiss4 ,microscopie1 #ahij1 vii1 pp4 #ccb-cdb1 #a ,pl47 ,wistinghausen1 ,c4 v4 ,ueber ,tracheenendigungen in den ,sericterien der ,raupen4 7,zeitschr4 wissensch4 ,zool41 xlix1 #ahij1 pp4 #efe-ehb1 #a ,taf47 ,stokes1 ,alfred ,c4 ,the structure of insect trache1 etc4 7,science1 #ahic1 pp4 #dd-df1 #g ,figs47 ,sadones1 ,j4 ,l'appareil digestif et respiratoire larvaire des ,odonates4 7,la ,cellule1 xi1 #ahie1 pp4 #bga-cbe1 #c ,pls47 ,holmgren1 ,emil4 ber das respiratorische ,epithel der ,tracheen bei ,raupen4 7,festschrift ,lilljeborg4 ,upsala1 #ahif1 pp4 #gf-gi1 #b ,taf47 ,see also p4 #dcg4 ,also ,gegenbaur's ,comparative ,anatomy1 ,engl4 ,trans4 b4 ,on the ,stigmata ,loewe1 ,c4 ,l4 ,w4 ,de partibus quibus insecta spiritus ducunt4 ,diss4 inaug4 ,hal1 #ahad1 pp4 #bh4 ,sprengel1 ,c4 ,commentarius de partibus quibus ,insecta spiritus ducunt4 ,lipsi1 #ahae1 pp4 #ch1 #c ,taf4 ,dufour1 ,l4 ,recherches anatomiques sur l',hippobosque des chevaux4 7,ann4 ,sc4 nat41 #ahbe1 vi1 pp4 #bii-cbb1 #a ,pl47 ---- ,nouvelles observations sur la situation des stigmates thoraciques dans les larves des ,bupresticides4 7,ann4 ,soc4 ,ent4 ,france1 ,sr4 #b1 #ahdd1 ii1 p4 #bjc47 ,landois1 ,h4 ,der ,tracheenverschluss bei ,tenebrio molitor4 7,reichert u4 ,dubois-,reymond's ,archiv f4 ,anat41 #ahff1 pp4 #cia-cig1 #a ,taf47 ---- und ,w4 ,thelen4 ,der ,tracheenverschluss bei den ,insekten4 7,zeitschr4 wissensch4 ,zool41 xvii1 #ahfg1 pp4 #ahg-bad1 #a ,taf47 ---- ,der ,stigmenverschluss bei den ,lepidopteren4 7,reichert u4 ,dubois-,reymond's ,archiv f4 ,anat41 #ahhf1 pp4 #da-di1 #a ,taf47 ,hagen1 ,h4 ,a4 ,beitrag zur ,kenntnis des ,tracheensystems der ,libellen-,larven4 7,zool4 ,anzeiger1 #ahhj1 pp4 #aeg-afb47 ---- ,einwrfe gegen ,palmn's ,ansicht von der ,entstehung des geschlossenen ,tracheensystems4 7,ibid41 #ahha1 pp4 #djd-djf47 ,krancher1 ,o4 ,der ,bau der ,stigmen bei den ,insekten4 7,zeitschr4 wissensch4 ,zool41 xxxv1 #ahha1 pp4 #eje-egd1 #b ,taf42 ,zool4 ,anz41 #ahhj1 pp4 #ehd-ehh47 ,meinert1 ,fr4 ,spirakelpladen hos ,scarab-,larverne4 7,vid4 ,meddel4 ,nat4 ,for4 ,kjbenhavn 7#d71 ,aarg4 iii1 #ahhb1 pp4 #bhi-bib47 ---- ,noget mere om ,spiracula cribraria og ,os clausum4 ,en ,replik4 7,ibid4 7#d71 ,aarg4 v1 #ahhd1 pp4 #fh-ia1 ,fig47 ,schidte1 ,j4 ,g4 ,spiracula cribraria--os clausum3 lidt om naturvidenskabelig ,methode og ,kritik4 7,nat4 ,tidsskrift 7#c71 xiii1 #ahhc1 pp4 #dbg-dgc2 also ,jahresber4 ,neapel1 #ahhc1 p4 #aje47 ,verson1 ,e4 ,il meccanismo di chiusura negli stimmati di ,bombix mori4 7,atti ,istit4 ,veneto4 ,sc41 #ahhg1 p4 #i1 ,pl47 ---- ,der ,bau der ,stigmen von ,bombyx mori4 7,zool4 ,anzeiger1 #ahhg1 x ,jahrg41 pp4 #efa1 #efb47 ,see also ,zool4 ,anzeiger1 #ahij1 p4 #aaf4 ,haase1 ,e4 ,die ,stigmen der ,scolopendriden4 7,zool4 ,anzeiger1 #ahhg1 x ,jahrg41 pp4 #adj-adb47 ---- ,holopneustie bei ,kfern4 7,biolog4 ,centralbl41 #ahhg1 vii1 pp4 #ej-ec47 ,carlet1 ,g4 ,note sur un nouveau mode de fermeture des traches1 8fermeture operculaire0 chez les insectes4 7,comp4 rend4 ,acad4 ,sci4 ,paris1 #ahhh1 cvii1 pp4 #gee-geg47 ,de ,meijere1 ,j4 ,c4 ,h4 ber zusammengesetzte ,stigmen bei ,dipterenlarven etc44 7,tijd4 ,ent41 xxxviii1 #ahie1 pp4 #fe-ajj1 #cc ,figs47 ,also the other writings of ,palmn1 ,dufour1 ,dewitz1 ,boas1 ,verson4 c4 ,on tracheal gills and tracheal respiration ,pictet1 ,f4 ,j4 ,mmoires sur les larves des ,nmoures4 7,annal4 ,sc4 nat41 #ahcb1 xxvi1 pp4 #cfi-cia1 #b ,pls47 ---- ,recherches pour servir l'histoire et l'anatomie des ,phryganides4 ,genve1 pp4 #bce1 #bj ,pls4 ---- ,histoire naturelle gnrale et particulire1 des insectes ,neuroptres4 ,i1 ,monographie3 ,famille des ,perlides1 ,genve1 #ahda1 #ahdb1 pp4 #dbc1 #ec ,pls4 ---- ,histoire naturelle gnrale et particulire des insectes ,neuroptres4 ,,ii1 ,monographie3 ,famille des ,ephmrines4 ,genve1 #ahdc-ahde1 pp4 #cjj1 #dg ,pls4 ,dufour1 ,l4 ,recherches anatomiques et considerations entomologiques sur les insectes ,coloptres des genres ,macronychus et ,elmis4 7,ann4 ,sc4 nat4 ,zool41 ,sr4 #b1 #ahce1 iii1 pp4 #aea-agd1 #a ,pl47 ---- ,description et anatomie d'une larve branchies externes d',hydropsyche4 7,ibid41 ,sr4 #c1 #ahdg1 viii1 pp4 #cda-ced1 ,fig47 ---- ,recherches anatomiques sur la larve branchies extrieures du ,sialis lutarius4 7,ibid41 ,sr4 #c1 #ahdh1 ix1 pp4 #ia-ii1 ,fig47 ---- ,de diverses modes de respiration aquatique chez les insectes4 7,compt4 rend4 ,acad4 d4 ,sc4 ,paris1 #ahdi1 xxix1 pp4 #gfc-ggj2 ,ann4 and ,mag4 ,nat4 ,hist41 ,sr4 #b1 #ahej1 vi1 pp4 #aab-aah47 ---- tudes sur la larve du ,potamophilus4 7,ann4 ,sc4 nat41 ,sr4 #d1 xvii1 #ahfb1 pp4 #afb-agc1 #a ,pl41 ,bericht v4 ,gerstaecker f4 #ahfb1 pp4 #af1 #ag47 ,grube1 ,a4 ,e4 ,beschreibung einer auffallenden an ,ssswasser-schwammen lebenden ,larve 7,sisyra74 7,wiegmanns ,archiv f4 ,naturgesch41 #ahdc1 ix1 pp4 #cca-ccg1 ,fig47 ,schrder van der ,kolk1 ,j4 ,l4 ,g4 ,mmoire sur l'anatomie et physiologie de ,gastrus equi4 7,nieuwe ,verhandl4 d4 ,k4 ,nederl4 ,instit4 ,amsterdam1 #ahde1 ix1 pp4 #a-aee1 #ac ,pls42 ,erichson's ,bericht4 f4 #ahde1 p4 #aji47 ,scheiber1 ,s4 ,h4 ,vergleichende ,anatomie und ,physiologie der striden-,larven4 ,respirationssystem4 7,sitzungsber4 ,akad4 ,wissensch4 ,wien4 ,math4-naturw4 ,cl41 #ahfb1 xlv1 pp4 #g-ci47 ,lubbock1 ,j4 ,on the development of ,chloon dimidiatum4 7,trans4 ,linn4 ,soc4 ,london1 ,i1 #ahfh1 xxiv1 pp4 #fa-gh1 #b ,pls42 ,,ii1 #ahff1 xxv1 pp4 #dgg-dib47 ,oustalet1 ,e4 ,note sur la respiration chez les nymphes des ,libellules4 7,ann4 ,sc4 nat4 ,zool41 ,sr4 #e1 xi1 #ahfi1 pp4 #cgj-chf1 #c ,pls47 ,rolph1 ,w4 ,h4 ,beitrag zur ,kenntnis eininger ,insektenlarven4 #a ,taf4 ,inaug4 ,dissertat4 ,bonn1 #ahgc4 ,chun1 ,c4 ,ueber den ,bau1 die ,entwicklung und physiologische ,bedeutung der ,rektaldrsen bei den ,insekten4 ,frankfurt a4 ,m41 #ahge4 ,haller1 ,g4 ,die ,stechmckenlarve4 ,kleinere ,bruchstcke zur vergleichenden ,anatomie der ,arthropoden4 ,i4 ,ueber das ,atmungsorgan der ,stechmckenlarven4 7,archiv f4 ,naturgesch41 xliv1 #ahgh1 pp4 #ia-if1 #a ,taf47 ,vayssire1 ,a4 ,recherches sur l'organisation des larves des ,ephmrines4 7,ann4 d4 ,sc4 nat4 ,zool41 ,sr4 #f1 xiii1 #ahhb1 pp4 #a-acg1 #aa ,pls47 ---- ,monographie zoologique et anatomique du genre ,prosopistoma ,latr4 7,ibid41 ,sr4 #g1 ix1 #ahij1 pp4 #ai-hg1 #d ,pls47 ,eaton1 ,a4 ,e4 ,notes on some species of ,cloon4 7,ann4 ,mag4 ,nat4 ,hist1 ,ser4 #c1 xviii1 #ahff1 pp4 #ade-adh47 ---- ,a revisional monograph of recent ,ephemerid or may-flies4 7,trans4 ,linn4 ,soc4 ,london1 #ahhc-ahhg1 ,ser4 #b1 iii1 #fc ,pls47 ,mller1 ,wilh4 ,ueber einige im ,wasser lebende ,schmetterlingsraupen ,brasiliens4 7,archiv f4 ,naturgesch41 #ahhd1 i ,jahrg41 pp4 #aid-bab1 #a ,taf47 ,vogler4 ,die ,tracheenkiemen der ,simulien-,puppen4 7,mitteil4 ,schweiz ,ent4 ,gesellsch41 #ahhg1 vii1 pp4 #bgg-bhb47 ,raschke1 ,e4 ,w4 ,die ,larve von ,culex nemorosus4 ,ein ,beitrag zur ,kenntnis der ,insekten-,anatomie und ,histiologie4 7,archiv fr ,naturgesch41 #ahhg1 liii ,jahrg41 pp4 #acc-afc1 #b ,taf42 ,zool4 ,anz41 #ahhg1 x ,jahrg41 pp4 #ah1 #ai47 ,klaplek1 ,fr4 ,untersuchungen ber die ,fauna der ,gewsser ,bhmens4 ,i4 ,metamorphose der ,trichopteren4 7,archiv f4 naturwissensch4 ,landesdurchforschung von ,bhmen1 ,prag1 #ahhh1 vi1 ,no4 #e1 pp4 #fc2 ,no4 #f1 #ahic1 pp4 #ade1 ,figs47 ,mller1 ,fritz4 ,larven von ,mcken und ,haarflglern mit zweierlei abwechselnd thtigen ,atemwerkzeugen4 7,ent4 ,nachr41 #ahhh1 xiv ,jahrg41 pp4 #bgc-bgg2 also ,zool4 ,anzeiger1 iv1 #ahha1 pp4 #dii-ejb47 ,kolbe1 ,h4 ,j4 ,ueber den ,kranzfrmigen ,laich einer ,phryganea4 7,sitzungsber4 d4 ,gesellsch4 naturforsch4 ,freunde in ,berlin1 #ahhh1 pp4 #bb-bf47 ,haase1 ,erich4 ,die ,abdominalanhnge der ,insekten mit ,bercksichtigung der ,myriopoden4 7,morpholog4 ,jahrbuch1 #ahhi1 xv1 pp4 #cca-dce1 #b ,taf47 ,dewitz1 ,h4 ,einiger ,beobachtungen1 betreffend das geschlossene ,tracheensystem bei ,insectenlarven4 7,zool4 ,anzeiger1 xiii1 #ahij1 pp4 #ejj-ejd1 #ebe-eca47 ,miall1 ,l4 ,c4 ,some difficulties in the life of aquatic insects4 7,nature1 xliv1 ,london1 #ahia1 pp4 #def-dfb47 ---- ,natural ,history of aquatic insects1 #ahie1 #aaf ,figs41 pp4 #a-cie4 ,weltner1 ,w4 7,note on ,sisyra47 7,ent4 ,nachr41 p4 #ade1 #ahid47 ,also papers by ,hagen1 ,dewitz1 ,williams1 ,tmsvry 7#ahhd74 d4 ,literature on rectal respiration ,suckow1 ,f4 ,w4 ,l4 ,respiration der ,insekten1 insbesondere ber die ,darmrespiration der schna grandis4 7,zeitschrift f4 d4 organ4 ,physik1 von ,heusinger1 #ahbh1 ii1 pp4 #bd-bi1 #d ,taf47 ,dufour1 ,l4 ,sur la respiration branchiale des larves des grandes ,libellules compare celle des poissons4 7,compt4 rend4 de l',acad4 ,sc4 ,paris1 #ahdh1 xxvi1 pp4 #cja-cjc47 ---- tudes anatomiques et physiologiques et observations sur les larves des ,libellules4 7,ann4 ,sc4 nat4 ,zool41 ,sr4 #c1 #aheb1 xvii1 pp4 #gf-ig1 #c ,pls47 ,gilson1 ,g4 and ,j4 ,sadones4 ,larval gills of ,odonates4 7,journ4 ,linn4 ,soc4 ,london1 #ahig47 e4 ,physiology of ,respiration ,bonnet1 ,ch4 ,recherches sur la respiration des chenilles4 7,mm4 ,math4 des ,savants trangers1 ,paris1 #agfh1 v1 pp4 #bgf-cjc47 ,treviranus1 ,g4 ,r4 ,biologie1 oder ,philosophie der lebenden ,natur1 fr ,naturforscher und ,aerzte4 #f ,bnde1 ,gttingen1 #ahjb-ahbb4 7,atmung1 in ,bd4 iv47 ---- ,die ,erscheinungen und ,gesetze des organischen ,lebens4 #b ,bnde1 ,bremen1 #ahca-ahcc4 7,atmung der ,insekten in ,bd4 i47 ---- ,versuche ber das ,atemholen der niederen ,tiere4 7,zeitschrift f4 d4 ,physiologie1 von ,f4 ,tiedemann1 ,g4 ,r4 u4 ,l4 ,c4 ,treviranus1 #ahcb1 iv1 pp4 #a-ci47 ,hausmann1 ,j4 ,f4 ,l4 ,de animalium exsanguinum respiratione commentatio4 ,hannover1 #ahjc1 vi1 p4 #gj4 ,spallanzani1 ,l4 ,memoirs on respiration4 ,london1 #ahjd4 ,sorg1 ,f4 ,l4 ,a4 ,w4 ,disquisitiones physiologic circa respirationem insectorum et vermium4 ,rudolstadt1 #ahje1 ,part ,,ii1 p4 #adf4 ,nitzsch1 ,c4 ,l4 ,commentatio de respiratione animalium4 ,viteberg1 #ahjh1 #d1 pp4 #ef4 ---- ,ueber das ,atmen der ,hydrophilen4 7,reil's ,archiv f4 ,physiologie1 #ahaa1 x1 pp4 #ddj-deh47 ,reimarus1 ,j4 ,a4 ,h4 ,ueber das ,atmen1 besonders ber das ,atmen der ,vgel und ,insekten4 7,reil u4 ,autenrieth1 ,archiv f4 ,physiologie1 #ahab1 xi1 pp4 #bbi-bcf47 ,dufour1 ,l4 ,anatomie de la ,ranatre linaire et de la ,npe cendre4 7,annal4 gnr4 ,scienc4 phys41 ,bruxelles1 #ahba1 vii1 pp4 #aid-bac1 #a ,pl47 ---- ,mmoire pour servir l'histoire du genre ,ocyptera4 7,annal4 ,scienc4 natur41 #ahbg1 x1 pp4 #bdh-bfa1 #a ,pl47 ---- ,recherches sur quelques entozoaires et larves parasites des insectes ,orthoptres et ,hymnoptres4 7,ann4 ,sc4 nat4 ,zool41 ,sr4 #b1 #ahcf1 vi1 p4 #ee2 ,sr4 #b1 #ahcg1 vii1 pp4 #e-bj47 ---- ,note sur le parasitisme4 7,compt4 rend4 ,acad4 ,sc4 ,paris1 #ahea1 xxxiii1 pp4 #ace-aci2 ,rev4 et ,mag4 de ,zool41 #ahea1 pp4 #djh-dab47 ,dutrochet1 ,r4 ,j4 ,h4 ,du mecanisme de la respiration des ,insectes4 7,ann4 ,sc4 nat41 #ahcc1 xxviii1 pp4 #ca-dd2 ,mm4 ,acad4 ,sc4 ,paris1 #ahch1 xiv1 pp4 #ha-ic47 ,newport1 ,g4 ,on the respiration of insects4 7,phil4 ,trans4 ,roy4 ,soc41 ,london1 #ahcf1 cxxvi1 pp4 #ebi-eff47 ,coquerel1 ,ch4 ,note pour servir l'histoire de l'pus robini4 7,ann4 ,soc4 ,ent4 ,france1 ,sr4 #b1 #ahej1 viii1 pp4 #ebi-ecb47 ,davy1 ,j4 ,on the effects of certain agents on insects4 7,trans4 ,ent4 ,soc4 ,london1 #ahea1 pp4 #aie-bab47 ,barlow1 ,w4 ,f4 ,observations of the respiratory movements of insects4 7,phil4 ,trans4 ,roy4 ,soc4 ,london1 cxlv1 #ahee1 pp4 #aci-adh47 ,rathke1 ,h4 ,anatomisch-physiologische ,untersuchungen ber den ,atmungsprozess der ,insekten4 7,schriften d4 k4 phys4-kon4 ,ges4 ,knigsberg1 i ,jahrg41 #ahfj1 pp4 #ii-ach1 #a ,taf47 ,lubbock1 ,j4 ,on two aquatic ,hymenoptera1 one of which uses its wings in swimming4 7,trans4 ,linn4 ,soc4 ,london1 xxiv1 #ahfc1 pp4 #ace-adb1 #a ,pl47 ,boyle1 ,r4 ,new pneumatical experiments about respiration4 7,phil4 ,trans41 #ahgj1 v1 ,no4 #fc1 pp4 #bjea-bjef47 ,lambrecht4 ,a4 ,das ,atmungsgeschft der ,bienen4 7,bienenwirtschaftl4 ,centralblatt1 vii ,jahrg41 #ahga1 pp4 #bj-be47 ---- ,luftverbrauch eines ,biens und die damit zusammenhngenden ,lebensprozesse der ,glieder desselben4 7,ibid41 #ahga1 pp4 #aae-abj47 ,monnier4 ,sur la rle des organes respiratoires chez les larves aquatiques4 7,compt4 rend4 ,acad4 ,sc4 ,paris1 lxxiv1 #ahgb1 p4 #bce47 ,liebe1 ,otto4 ,ueber die ,respiration der ,tracheaten1 besonders ber den ,mechanismus derselben und ber die ,menge der ausgeatmenten ,kohlensure4 7,inaug4 ,diss4 ,chemnitz1 #ahgb1 pp4 #bh47 ,plateau1 ,f4 ,recherches physico-chimiques sur les articuls aquatiques4 7,bull4 ,acad4 ,roy4 ,belg41 ,sr4 #b1 xxxiv1 #ahgb1 pp4 #bga-cba47 ---- ,recherches exprimentales sur les mouvements respiratoires des ,insectes4 7,mem4 ,acad4 ,belg41 #ahhd1 xlv1 pp4 #bai1 #g ,pls41 #ef ,figs47 ---- ,recherches physico-chimiques sur les articuls aquatiques4 ,part ,i4 ,action de sels en dissolution dans l'eau4 ,influence de l'eau de mer sur les articuls aquatiques d'eau douce4 ,influence de l'eau douce sur les ,crustacs marines4 7,mm4 cour4 et ,mm4 des savants trang4 de ,belgique1 xxxvi1 #ahga1 pp4 #fh47 ,part ,,ii4 ,rsistance l'asphyxie par submersion1 action du froid1 action de la chaleur1 temperature maximum4 7,bull4 ,acad4 ,roy4 de ,belgique1 ,sr4 #b1 xxxiv1 #ahgb1 pp4 #bga-cba47 ---- ,les ,myriopodes marins et la rsistance des ,arthropodes respiration arienne la submersion4 7,journ4 de l'anatomie et de la physiologie1 #ahij1 xxvi1 pp4 #bcf-bfi47 ,btschli1 ,o4 ,ein ,beitrag zur ,kenntnis des ,stoffwechsels1 insbesondere die ,respiration bei den ,insekten4 7,reichert und ,dubois-,reymond's ,archiv f4 ,anatomie1 #ahgd1 pp4 #cdh-cfa47 ,ritsema ,cz41 ,c4 ,acentropus niveus ,oliv41 in ,zijne levenswijze en verschillende toestanden4 7,tijdschr4 voor ,entom1 #ahgf1 xxi1 separate1 pp4 #cd1 #b ,taf47 ,pott1 ,rob4 ,chemical experiments on the respiration of insects4 7,psyche1 ii1 #ahgh47 ,sharp1 ,d4 ,observations on the respiratory action of the carnivorous water-beetles4 7,journ4 ,linn4 ,soc4 ,london1 xiii1 ,zoology1 #ahgh1 pp4 #afa-ahc47 ,krancher1 ,o4 ,das ,atmen der ,biene4 7,deutscher ,bienenfreund41 xvi ,jahrg41 #ahhj1 pp4 #di-ea47 ,gissler1 ,c4 ,f4 ,sub-elytral air-passages in ,coleoptera4 7,proc4 ,amer4 ,assoc4 ,advanc4 ,sc4 #bi ,meet4 7#ahha71 #ahha1 pp4 #ffg-ffi47 ,langendorff1 ,o4 ,studien ber die ,innervation der ,atembewegungen4 #f4 ,das ,atmungszentrum der ,insekten4 7,archiv f4 ,anatomie u4 ,physiol41 ,physiol4 ,abteil41 #ahhc1 pp4 #hj-hg47 ,macloskie1 ,g4 ,pneumatic functions of insects4 7,psyche1 iii1 #ahhc1 pp4 #cge47 ,chalande1 ,j4 ,recherches sur le mecanisme de la respiration chez les ,myriopodes4 7,compt4 rend4 ,acad4 ,sc4 ,paris1 civ1 #ahhg1 pp4 #abf1 #abg47 ,comstock1 ,j4 ,h4 ,note on respiration of aquatic bugs4 7,amer4 ,naturalist1 #ahhg1 xxi1 pp4 #egg1 #egh47 ,fricken1 ,w4 v4 ,ueber ,entwicklung1 ,atmung und ,lebensweise der ,gattung ,hydrophilus4 7,tagebl41 #fj1 ,versamml4 deutscher ,naturf4 u4 ,aerzte1 #ahhg1 pp4 #aad1 #aae47 ,schmidt1 ,e4 ,ueber ,atmung der ,larven und ,puppen von ,donacia crassipes4 7,berlin4 ,ent4 ,zeitschr41 #ahhg1 xxxi ,jahrg41 pp4 #cbe-ccd1 #a ,taf47 ,dewitz1 ,h4 ,entnehmen die ,larven der ,donacien vermittelst ,stigmen oder ,atemrohren den ,luftraumen der ,pflanzen die sauerstoffhaltige ,luft8 7,ibid41 #ahhh1 xxxii ,jahrg41 pp4 #e1 #f1 ,fig47 ,mller1 ,g4 ,w4 ,ueber ,agriotypus armatus4 7,spengel's ,zoolog4 ,jahrbcher4 ,abt4 f4 ,systematik1 etc41 iv1 #ahhi1 pp4 #aacb-aacd47 ---- ,noch einmal ,agriotypus armatus4 7,ibid41 v1 #ahij1 pp4 #fhi-fia47 ,devaux1 ,h4 ,vom ,ersticken durch ,ertrinken bei den ,tieren und ,pflanzen4 7,naturwiss4 ,rundschau1 vi ,jahrg41 #ahia1 p4 #bca2 ,compt4 rend4 ,soc4 de ,biol41 #ahia1 ,ser4 #i1 iii1 p4 #dc47 ,see also ,dewitz1 p4 #dhb2 ,kolbe1 p4 #dhb4 ,,the ,,organs ,,of ,,reproduction ,insects are without exception unisexual1 the male and female organs existing in different individuals1 no insects being normally hermaphroditic4 ,the reproductive organs are situated in the hind-body or abdomen1 especially near the end1 the genital glands opening externally either in the space between the #gth and #hth1 or #hth and #ith1 or #ith and #ajth abdominal segments1 but as a rule between the #hth and #ith segments 7,fig4 #bii74 ,the primary or essential male organs are the testes1 those of the female being the ovaries4 ,as we shall see1 the primitive number of seminal ducts and oviducts was two1 this number being still retained in ,lepisma and the ,ephemerid4 ,the reproductive organs of both sexes are at first1 in their embryonic condition1 of the same shape and structure1 becoming differentiated in form and function before sexual maturity4 ,these glands and ducts have a paired mesodermal genital rudiment1 the ends of the ducts being often connected with corresponding ectodermal invaginations of the cuticle4 ,the secondary sexual organs mainly comprise the external genital armature of the male1 and the egg-laying organs1 or ovipositor of the female4 ,besides these structures there are other more superficial secondary sexual characters1 such as differences in the size and ornamentation as well as coloring of the body1 or of parts of it4 ,the primary sexual organs of insects have been conveniently tabulated by ,kolbe1 thus3-- ,i4 ,male reproductive organs4 #a4 ,two testes1 with testicular follicles4 #b4 ,seminal ducts 7vasa deferentia74 #c4 ,seminal vesicle4 #d4 ,accessory glands4 #e4 ,the common seminal outlet1 with the penis4 #f4 ,the copulatory apparatus4 ,,ii4 ,female reproductive organs4 #a4 ,two ovaries1 with the egg-tubes4 #b4 ,two oviducts4 #c4 ,receptaculum seminis2 bursa copulatrix4 #d4 ,accessory sac4 #e4 ,the common oviduct1 vagina1 uterus4 #f4 ,the ovipositor4 ,the ducts of the sexual glands in ,peripatus being transformed nephridia or segmental organs1 it has been inferred that this is also the case with those of insects1 though1 as ,lang states1 there is a considerable difference in the two cases1 as the greater part of the ducts in ,peripatus arises out of the ectoderm1 while in the ,myriopoda and insects they come from the mesoderm2 but he adds that in the ,annelids the greater part of the nephridial duct is of mesodermal origin4 ,while in insects there is but a single pair of genital outlets1 the serial arrangement of the testicular 7,fig4 #deh7 and egg-tubes 7,fig4 #dei7 in some ,thysanura 7,campodea1 ,japyx1 and ,lepisma71 where the tubes 7#e to #g on each side7 open singly one behind the other in segmental succession1 indicates that in their ancestors these egg-tubes opened out on different segments situated one behind the other4 ,each egg-tube independently opens into one of the two oviducts1 which extend through the abdomen as straight canals4 ,the two oviducts open externally by a short unpaired terminal portion1 which in ,machilis is said to be wanting1 only the outer aperture of the two oviducts being in this case common to both4 ,in ,campodea and in the ,collembola the ovaries and testes on each side are simply tubes4 ,it is to be observed that in the young ,lepisma ,nassonow found that the external openings of the two ejaculatory ducts are paired 7,fig4 #deh ,b1 ed474 ,illustration3 ,,fig4 #deh4--,male genital organs of ,thysanura3 ,a1 ,lepisma in which the testes are segmentally arranged4--,after ,grassi4 ,b1 ,lepisma saccharina1 young 3 vd1 vas deferens2 ed1 ejaculatory duct2 ga1 external appendages1--,after ,nassonow4 ,c1 ,machilis1 the testis lateral and separate1 but not corresponding to the segments4 ,d1 ,japyx1 with an undivided testicular tube on each side2 tt1 testes2 cd1 vas deferens2 vs1 seminal vesicle2 ce1 ejaculatory duct4--,after ,grassi1 from ,perrier4 ,in the ,stylopid1 also1 though this may be the result of adaptation to the singular parasitic habits of the females whose bodies are mostly situated in the abdomen of their host1 the ends of the oviducts are formed by the invagination of the integument of the #b;d1 #c;d1 and #dth abdominal segments4 ,in the #b;d to #eth segments are situated tubes which open in the cavity of the body with funnel-like ends1 so that the ducts have a close resemblance to the segmental organs of worms4 7,nassonow47 ,illustration3 ,,fig4 #dei4--,ovaries of ,thysanura3 ,a1 of ,campodea4 ,b1 of ,japyx4--,after ,grassi4 ,c1 of ,machilis4--,after ,oudemans1 from ,sharp4 ,illustration3 ,,fig4 #dfj4--;,female genital organs of ,lepisma saccharina1 adult3 ov1 ovaries2 a1 part of the oviduct1 corresponding to the calyx of winged insects2 od1 oviduct2 vg1 vagina2 rs1 copulatory pouch2 gg1 accessory glands2 m1 muscles2 n1 nervous cord4--,after ,nassonow1 from ,perrier4 ,among the winged insects the reproductive organs of the cricket 7,fig4 #dff7 are perhaps as simple as any4 ,the testes are separate1 and the vasa deferentia very long4 ,the seminal vesicles bear numerous large and short utricles 7utriculi majores and breviores71 the penis being simple and dilated at the end2 while in ,phyllodromia germanica the testes are functional throughout life1 and consist of four lobes each4 ,in the common cockroach 7,p4 orientalis7 7,fig4 #dfa7 the testes are functional only in the young male2 they afterwards shrivel and are functionally replaced by the vesicul seminales and their appendages1 when the later transformations of the sperm-cells are effected4 ,the accessory glands are numerous and differ both in function and insertion4 ,two sets of these glands 7utriculi majores and breviores7 are attached to the vesicul seminales and the fore end of the ejaculatory duct1 while another appendage1 called by ,miall and ,denny the conglobate gland1 opens separately on the exterior upon a double hook1 which forms a part of the external genital armature4 ,the so-called penis is long1 slender1 and dilated at the end1 but is not perforated4 ,illustration3 ,,fig4 #dfa4--;,a1 male organs of the cockroach1 ventral view3 ,ts1 testis2 ,,vd1 vas deferens2 ,,de1 ductus ejaculatorius2 ,u1 utriculi majores2 u1 utriculi breviores2 #b1 dorsal view2 #c1 ,,cg1 conglobate gland and its duct4 ,b1 male organs1 side view3 ,a1 titillator2 ,b1 penis2 other letters as in ,a4--,after ,miall and ,denny4 ,in the locusts 7,acrydiid7 the testes are1 unlike those of most other ,orthoptera1 closely united to each other so as to form a single mass of tubular glands into which penetrate both simple and dilated trache2 the entire mass is situated in the #c;d1 #dth1 and #eth abdominal segments1 and above the intestine4 ,the anterior end of the testicular mass is rounded and held in place by a broad1 thin band1 one on each side2 two similar bands are situated a little behind the middle of the mass4 ,from the under side1 and a little in advance of the middle of the mass1 two straight small ducts1 as long as the testicular mass1 pass obliquely to the sides of the body1 at the posterior end of the #gth segment of the abdomen2 these are the vasa deferentia4 ,each vas deferens1 with its mate1 forms a convoluted mass of tubes1 comprising twenty folded bundles 7epididymis of ,dufour71 and two single1 long1 convoluted tubes1 the vesicul seminales1 which are lobed in the #fth and #gth segments of the abdomen4 ,the two vesicul unite over the #eth abdominal ganglion1 forming a thick1 very short canal 7ductus ejaculatorius71 which passes into a large spherical muscular mass 7prputium71 behind which is the large intromittent organ 7penis71 which forms a short chitinous cylinder1 quite complicated in structure1 being armed with hooks and projections and affording excellent specific characters4 ,it can be seen in place without dissection by drawing back the orbicular convex piece called the velum penis4 ,in the ,hymenoptera the reproductive system is quite simple1 as seen in ,fig4 #dfb4 ,illustration3 ,,fig4 #dfb4--,male organs of saw-fly 7,athalia centifoli73 a1 a1 testes2 b1 b1 epididymis2 c1 d1 vas deferentia2 e1 vesicul seminales2 f1 ductus ejaculatorius2 h1 penis 7see also p4 #ahj74--;,after ,newport4 ,the general shape and relations of the female reproductive organs are seen in ,fig4 #bih1 of the locust 7,acrydiid74 ,the ovaries consist of two large bundles of tubes1 each bundle tied to the other by slight bands1 with air-sacs and trache ramifying among them4 ,these tubes extend along the intestine1 passing into the prothorax4 ,the ovarian tubes opening into the oviducts unite to form the vagina1 which lies on the floor of the abdomen4 7,in the cockroach the vagina has a muscular wall and chitinous lining47 ,above the opening of the duct1 and directly communicating with it1 is the copulatory pouch 7bursa copulatrix71 a capacious pocket lined within with several narrow1 longitudinal1 chitinous bands4 ,behind the bursa copulatrix lies1 partly resting under the fifth abdominal ganglion1 the sebific1 cement1 or colleterial gland 7colleterium2 compare ,fig4 #bii1 sb71 which is flattened1 pear-shaped1 a little over half as long as a ripe egg of the same insect4 ,from the under side1 a little in advance of the middle1 arises the sebific duct1 which1 after making three tight coils next to the ganglion1 passes back and empties into the upper side of the bursa copulatrix1 dilating slightly before its junction with the latter4 ,the most primitive type of reproductive organs observed in insects is that of the young ,lepisma and the ,ephemerid1 in which the outlets of the oviducts and of the vasa deferentia respectively are double or paired1 showing that insects have probably inherited these structures from the segmental organs of their vermian ancestors4 ,raumur had already observed the process of oviposition and seen that the female ,ephemera had two openings near the end of the 8#fth0 abdominal segment1 from which he saw two masses of eggs pass out at a time 7,fig4 #dfc74 ,eaton afterwards 7#ahga7 referred to the oviducts as terminating between the #gth and #hth segments of the abdomen1 and after him ,joly2 but for a detailed monograph on the subject we are indebted to ,palmn4 ,he found that the outlets of the sexual glands are paired1 not only in the larv of all stages1 but also in the imagines1 and in both sexes4 ,in the males the vasa deferentia pass on the ventral side of the #ith segment through two external appendages1 both reproductive organs1 at whose tips or sides the openings are situated4 ,in the larv the female openings are not formed until after the last moult4 ,in the females the two oviducts open on the ventral side of the hind-body between the #gth and #hth segments4 ,illustration3 ,,fig4 #dfc4--,upturned end of body of ,ephemera1 with two egg-masses 7o7 issuing at the same time from the double oviducts2 q1 anus4--,after ,raumur4 ,palmn suggests that the ,ephemerids represent1 in respect to the reproductive system among insects1 a very primitive type of organization1 and he concludes that the inner sexual organs of insects are built up of two different morphological elements2 i4e4 7a7 internal primitive paired structures 7testes with vasa deferentia1 ovaria with oviducts71 and 7b7 integumental structures1 such as the ductus ejaculatorius and vagina4 ,in the younger larv the vasa deferentia form slender cords along which are situated the seminal glands2 these cords are inserted in the integument on the hinder edge of the #ith sternite1 where afterwards1 during the last moult1 the copulatory organs grow out4 ,in the older larv the sperm collects in the cavities of these cords4 ,their walls become expanded1 and this section then functions as vesicul seminales4 ,the ends of the cords remain contracted and act as ductus ejaculatorii4 ,common unpaired glandular structures are not present4 ,at the last moult the copulatory organs reach their complete development1 and the ducts become open externally4 ,the oviducts in the larva are at first slender1 string-like1 and bear the egg-follicles4 ,as soon as the eggs pass out of the follicles and collect in the oviducts1 the walls of the latter become stretched1 and this portion forms two uterus-like structures4 ,the terminal division of the two passages forms their vaginal portions4 ,but since there is no common vagina1 there are no unpaired glands and no receptaculum seminis4 ,the two ducts become open after the last shedding of the skin4 ,palmn adds that this paired or double nature of the sexual glands and their external ducts in this group of insects occurs in some ,myriopoda 7,fig4 #c1 ,e1 ,f7 and a few ,arachnida 7,fig4 #c1 ,c1 ,d1 the outlets being in this class unpaired71 numerous ,crustacea1 and most worms2 and as already stated it is very marked in ,limulus1 where the paired outlets are in both sexes very simple and wide apart 7,fig4 #c1 ,a74 ,in the worms the paired genital ducts are modified segmental organs4 ,as we have seen1 in the young male ,lepisma there are two male genital openings4 ,hence this double nature of the genital passages in the may-flies seems to be very primitive4 ,in the ,dermaptera1 also1 the genus ,labidura was found by ,meinert to have two independent ductus ejaculatorii1 opening externally in double external slit-like processes 7penes74 ,the two ducts arise from a single seminal vesicle1 which is either paired 7,l4 advena71 or forms a common passage 7,l4 gigantea74 ,in ,forficula 7,fig4 #dfd1 ,b7 only one ejaculatory duct persists1 the other is obliterated1 and one of the penes is atrophied1 the other assuming a position in the middle line of the body4 ,thus the single ejaculatory duct and seminal vesicle arise from the primitive vasa deferentia1 and not from the integument of the body1 as is the case in the following examples4 ,according to the researches of ,dufour1 ,loew1 etc41 most species of ,orthoptera 7dipoda71 ,libellula1 ,perla1 ,panorpa1 ,rhaphidia1 ,myrmeleon1 ,sialis1 and ,trichoptera 7,hydropsyche7 have double vasa deferentia and seminal vesicles1 and two ejaculatory ducts4 ,the male genital passages of ,rhaphidia have a double opening1 ,loew describing 8the two seminal vesicles as lying near each other and at last uniting in a common passage1 with an external opening1 which1 however1 must be very short1 since ,i could only once clearly observe it40 ,this opening is a deep invagination of the external integument1 at the bottom of which the two ducts open independently of each other4 ,in such insects1 ,palmn states that the single ejaculatory duct morphologically arises by an invagination of the integument4 ,in another group1 forming1 as regards the genital apparatus1 a step next above the ,ephemerid1 viz4 the ,perlid1 the oviducts open near each other at the bottom of a median single 8vagina10 situated between the #gth and #hth abdominal segment2 it is covered beneath by a valve-like1 enlarged sternite of the preceding segment1 and ,palmn homologizes it with the ovi-valvula of some ,ephemerid4 ,he regards this bell-shaped vagina as a cup-like1 deep1 intersegmental fold1 which projects into the body-cavity and there receives the two ducts4 ,this differentiation in the ,perlid may be regarded as the type for several groups of insects4 ,but in others occur a complication which in some degree modifies the type4 ,thus the invagination arises out from one segment alone1 but several segments during metamorphosis may become so reduced that the ventral portions of all may be invaginated to form the vagina4 ,thus in the larva of ,corethra1 according to ,leydig1 and also ,weismann1 the two testes are attached by two cords to the integument2 the hinder ones are inserted independently1 and share in the development of the outlets4 ,graber has observed the same relations in the pupa of ,chironomus1 the efferent genital tubes in both sexes being separate1 so that there are two vaginal passages and two penes present4 ,palmn comments on these relations in the dipterous insects1 remarking that during metamorphosis certain parts of the terminal abdominal segments are reduced1 while others are hypertrophied2 hence the points of insertion of the cords referred to becoming the openings of the vasa are carried within the abdomen2 and this part of the integument becomes an unpaired section4 ,in these insects1 also1 there is an unpaired vesicula seminalis1 but its morphological nature 7whether formed from the integumental duct or the fused vasa deferentia7 can only be settled after special investigation4 ,in the ,lepidoptera1 also1 it has been shown by ,herold1 ,suckow1 ,bessels1 and recently with full details by ,jackson1 that the paired larval oviducts are at first solid1 but become tubular early in pupal life4 ,a little later1 their cavities open into that of the azygos or unpaired oviduct4 ,the paired oviducts open in the female caterpillars on the hind edge of the #gth abdominal segment1 afterwards uniting with the unpaired vagina of the #hth segment1 which is developed from the hypodermis4 ,jackson adds that there are three stages traceable in the evolution of the genital ducts of ,lepidoptera3 8an ephemeridal stage1 which ends towards the close of larval life2 an orthopteran stage1 indicated during the quiescent period preceding pupation2 and a lepidopteran stage1 which begins with the commencement of pupal life40 ,as a summary of these results it appears that the genital organs of insects consist of two morphologically different elements3 #a4 the primitive internal paired structures 7testes with the vasa deferentia2 ovaries with the ovarian tubes71 and #b4 integumental structures 7,fig4 #dfd74 ,in the most primitive winged insects 7,ephemerid7 the latter structures are only represented by the two external sexual openings1 the entire reproductive system being paired4 ,the paired parts become in the more highly differentiated forms united into single parts1 while1 a1 a common integumental division1 grows in1 forming the ductus ejaculatorius1 or the vagina2 or1 b1 the inner passages anastomose together1 i4e4 the openings fuse together2 or1 c1 both of these cases occur at once2 or1 finally1 we have d1 where the superfluous paired parts by reduction become single4 ,illustration3 ,,fig4 #dfd4--;,evolution of the unpaired from the paired sexual organs of insects3 ,a-,e1 male organs4 ,the parts arising by invagination of the integument indicated by thick black lines4 ,a1 an ,ephemerid4 ,b1 ,forficula auricularia4 ,c1 nymph of ,orthoptera in general4 ,d1 dipoda4 ,e1 ,cetonia aurata4 ,f1 female organs of schna4--,after ,palmn1 from ,lang4 ,the male ducts open behind the #ith1 the female passages of ,ephemerids behind the #gth abdominal segment1 those of other insects behind the #hth1 except in the ,stylopid 7,strepsiptera71 in which they open much in front4 ,figure #dfd graphically shows their relation4 ,in the ,odonata 7,f7 the chitinous lining or integumental invagination extends inwards where the two oviducts begin1 in the ,coleoptera 7,e7 the vagina1 bursa copulatrix1 and receptaculum seminis being lined by a thick chitinous layer4 ,while in ,perla the two seminal ducts pass directly into the copulatory organ1 in the ,coleoptera they open into the unpaired ductus ejaculatorius at a distance from the copulatory organ4 ,the morphological results obtained by ,palmn1 and for the ,lepidoptera by ,jackson1 were apparently confirmed from an embryological point of view by ,nusbaum1 from observations on the development of the sexual passages in two genera of ,pediculid1 and are as follows3-- #a4 ,the prevalent impression that the larval ducts unite with each other and give origin to the whole system of sexual ducts is incorrect2 they form only the vasa deferentia or the oviducts4 #b4 ,all other parts of the efferent apparatus 7uterus1 vagina1 receptaculum seminis1 ductus ejaculatorius1 penis1 and appended glands7 develop from the hypodermis4 #c4 ,the connective tissue and the musculature of the efferent apparatus are derived from mesoblast cells present in the body-cavity4 #d4 ,the efferent ducts originate as paired rudiments4 ,all unpaired 7azygos7 parts 7uterus1 penis1 receptaculum seminis1 unpaired glands1 etc47 are at first paired4 ,the unpaired efferent apparatus of insects must therefore be regarded as morphologically a secondary and more complicated form4#gf #e4 ,the male and female efferent ducts are strictly homologous4 #f4 ,the cavities of the oviducts1 uterus1 vagina in the female1 of the vasa deferentia1 appended organs1 and ductus ejaculatorius of the male arise independently1 and come into connection secondarily4 ,the presence of two genital openings1 viz4 a bursa copulatrix or copulatory pouch1 and of the primitive oviducal orifice behind the #ith segment1 is peculiar to ,lepidoptera1 and the inquiry naturally arises whether they represent the outlets of two pairs of segmental organs4 ,the question has been fully set at rest1 however1 by ,jackson1 who shows that the copulatory pouch is a secondary invagination of the ectoderm1 being derived from the hypodermis1 while the second aperture is a special adaptation4 ,it is1 however1 the partial homologue of the vaginal orifice in other orders of insects4 ,it opens behind the sternite of the #hth abdominal segment1 the typical position of the vaginal aperture as shown by ,lacaze-,duthiers4 ,the lateral position of the bursa and its separation from the azygos oviduct are probably late features in the phylogenetic history of the ,lepidoptera1 subsequent even to the closure of the furrow4 8,the existence of a second or posterior aperture is probably to be attributed to the advantage gained by a terminal position for the aperture through which the ova are laid4 ,the remarkable way in which this aperture shifts backwards seems to point very distinctly to this explanation1 especially as the ,lepidoptera are entirely devoid of the outgrowths which form the ovipositor in some orders2 e4g4 most ,orthoptera40 ,the original condition of things appears to have been retained in a moth1 ,nematois metallicus1 which1 according to ,cholodkowsky1 possesses but a single external aperture1 the bursa opening into the dorsal wall of the unpaired oviduct4 a4 ,the male organs of reproduction ,bearing in mind that the testes with their efferent ducts are1 like the ovaries and egg-tubes1 primitive structures1 there are various secondary or adaptive structures which are either due 7#a7 to modifications of the male efferent ducts1 or of the ovarian tubes1 or 7#b7 to various accessory organs1 mostly glandular1 resulting from the invagination of the ectoderm4 ,illustration3 ,,fig4 #dfe4--;,a1 diagram of male sexual organs of ,carabus4 ,b1 of ,blaps4 ,c1 of ,hydrophilus4 ,the heavy black lines represent the ectodermal organs2 t1 testis2 a4 g41 accessory glands4--,after ,escherich4 ,the male organs are1 then1 the following3-- #a4 ,two testes 7,figs4 #dfe-dfi1 t1 ,h1 ho74 #b4 ,the two seminal ducts 7vasa deferentia1 v1 sl1 ,,sl71 whose lower or outer 7distal7 division becomes enlarged and acts as a seminal vesicle 7vesicula seminalis2 ,figs4 #dfg-dfi1 bl1 ,,sb74 #c4 ,the common ejaculatory duct 7ductus ejaculatorius71 with the penis 7,figs4 #dfg-dfi1 ag1 u,s,g74 #d4 ,accessory glands at the base of the vasa deferentia 7glandul mucos1 ,figs4 #dfe-dfi1 a4 g41 dr1 ,d71 whose secretion mixes with the semen or serves for the formation of the seminal packets 7sematophores74 ,in his paper on the internal male organs of beetles1 ,escherich states that those of the ,carabid illustrate the simplest1 most primitive condition 7,fig4 #dfe74 ,a simple blind tube on each side produces spermatozoa1 stores the elements1 and secretes mucus4 ,each of these tubes opens into a somewhat larger duct1 and the two unite in a common ejaculatory canal4 ,the terminal portion in these beetles is lined with chitin1 and is therefore ectodermal1 and not the result of the union of the mesodermic vasa deferentia4 ,the region corresponding to the testes1 vasa deferentia1 and seminal vesicles are mesodermic4 ,blaps 7,fig4 #dfe1 ,b7 is intermediate between the ,carabid and ,hydrophilus 7,fig4 #dfe1 ,c74 ,the accessory glands 7a4 g47 are developed1 and the seminal vesicles are situated in the middle1 and not at the lower end of the vasa deferentia1 as in ,hydrophilus4 ,the testes4--,each testis is composed of follicles or corresponding parts1 which according to the group of insects in which they occur are united in different ways2 or each testis consists of a single hank or skein-like blind tube which is enveloped by a membrane1 as in the ,carabid1 ,dyticid1 or ,lucanid4 ,illustration3 ,,fig4 #dff4--t1 testis2 v1 vas deferens2 g1 seminal vesicle of ,acheta campestris4--,after ,carus1 from ,gegenbaur4 ,illustration3 ,,fig4 #dfg4--,male sexual apparatus of a bark-beetle3 sl1 vas deferens2 ho1 testis2 bl1 seminal vesicle2 dr1 accessory gland2 ag1 ductus ejaculatorius4--,after ,graber4 ,the number of testicular tubes is small in most ,hemiptera1 but very great in the ,cicadid1 ,orthoptera1 ,coleoptera1 and many ,hymenoptera4 ,although the testes are usually separated from each other1 they are closely united in certain ,orthoptera 7,gryllotalpa1 ,ephippigera71 ,coleoptera 7,galerucella71 in many ,lepidoptera1 and in a number of ,hymenoptera 7,scolia1 ,pompilus1 ,crabro1 and others74 ,the two testes of most ,lepidoptera are so closely grown together or coalesced into a single body that one might regard them as a single testis4 ,but in the different families there occur all grades1 from the unpaired testes of most ,lepidoptera to ,hepialus with separate testes4 ,cholodkowsky therefore distinguishes four types3-- #a4 ,the embryonal or primitive type1 with two testes1 whose seminal follicles are entirely separate4 7,brandt47 ,these testes are contained1 as in all other ,lepidoptera1 in a well-developed thick chitinous membrane or scrotum1 analogous to that of the higher vertebrates1 which envelops each separate seminal follicle 7,hepialus humuli74 #b4 ,the larval type1 with two testes1 whose four follicles are enclosed by a common scrotal membrane 7,bombyx mori1 ,gastropacha quercifolia1 ,ichthyura anachoreta and anastomosis1 ,saturnia pyri1 ,aglia tau74 #c4 ,the pupal type 7since it first occurs in the pupa state71 with a single testis1 which possesses an external median lace-like covering4 7,adela1 ,lycna47 #d4 ,the imaginal type1 with a single testis enveloped by a lace-like scrotum1 within which the follicles are wound around the longitudinal axis of the testis4 7,most ,lepidoptera47 ,in ,nematois there are twenty seminal follicles1 the number of ovarian tubes being the same4 7,cholodkowsky47 ,in many insects the testes are not composed of tubes 7follicles71 but of button-like bodies1 each of which has its own duct4 ,the color of the testes is usually white1 but they may be orange 7,decticus71 yellowish green 7,locusta viridissima71 or deep yellow 7,chrysopa74 ,the testes of ,asilid flies are enveloped by a common dark-red membrane rich in trache1 like that in ,lepidoptera which clothes the separate testicular follicles4 ,the two testes of ,calliphora are enveloped by an orange-yellow capsule1 outside of which is a special membrane formed by the fat-body4 7,cholodkowsky47 ,in the honey-bee the testis has two envelopes1 the outer of which is formed by the fat-body1 the inner coat of connective tissue4 ,the entire testis corresponds to a portion only of that of ,bombyx mori4 ,illustration3 ,,fig4 #dfh4--,male organs of a weevil1 ,hylobius abietis3 ,h1 testis2 ,,sl1 vas deferens2 ,d1 slime gland2 ,,sb1 seminal vesicle2 u,s,g1 ejaculatory duct4 ,illustration3 ,,fig4 #dfi4--,male organs of ,tomicus4 ,lettering same as in ,fig4 #dfh4--,this and ,fig4 #dfh from ,judeich and ,nitsche4 ,the seminal ducts4--,the vasa deferentia are fine tubes1 which vary much in length2 being short in many beetles and locusts1 very short in many ,diptera 7,syrphid1 etc471 very long in ,cicada and many beetles2 according to ,burmeister1 being in ,dyticus about five times1 in ,necrophorus and ,blaps eight to ten times1 in ,cicada #ad times1 in ,cetonia aurata #cj times1 as long as the body4 ,they either resemble a skein of silk1 or form a tangled mass4 ,the distal or lower end of the vasa is in many insects dilated into a sac or seminal vesicle1 which serves for the reception and storage of the seminal fluid after it passes through the vasa deferentia4 ,in the honey-bee the vas deferens is given off from the reservoir1 forms loops in and outside of the testis1 and passes to the seminal vesicle4 ,the canal into which the vesicle narrows does not open into the ductus ejaculatorius1 but into the glandul mucos2 its epithelial cells are much vacuolated1 and have1 therefore1 a spongy appearance4 7,koschewnikoff47 ,illustration3 ,,fig4 #dgj4--;,a1 spermatozon of a beetle 7,copris71 partly macerated to show structure of flagellum1 which consists of a supporting fibre 7s4f7 and a fin-like envelope 7f72 n1 nucleus2 a1 a1 apical body divided into two parts4 ,b1 anterior part of that of ,calathus1 with barbed head and finmembrane4--,after ,ballowitz1 from ,wilson4 ,the ejaculatory duct during coition conducts the sperm into the copulatory pouch of the female4 ,in consequence of the stretching of the integumental membrane the end of the duct can be erected and again withdrawn4 ,for this purpose the end of the duct is thickened and is said to be provided with powerful muscles4 ,the evaginable terminal portion is covered by a strong chitinous membrane forming the penis or intromittent organ 7,fig3 #dfb1 h71 which is externally enveloped by a pair of chitinous lobes1 which in many beetles are converted into a capsule4 ,the ductus ejaculatorius of the honey-bee is inserted by two chitinous branches into the point of union of the two glandul mucos2 it and the entire copulatory apparatus are devoid of muscles1 though it is1 however1 well developed beneath the mucous glands4 7,koschewnikoff47 ,the accessory glands of the vasa deferentia are tubes whose secretions either directly mix with the semen1 or in many cases form seminal packets 7spermatophores74 ,in ,coleoptera1 ,lepidoptera1 and ,diptera there is usually one pair4 ,in many insects there are several pairs1 as in ,hydrophilid and ,elaterid2 they are branched in ,hemiptera1 and in ,orthoptera bushy4 ,the single glandular tubules are very long1 and form a skein-like mass4 ,in ,orthoptera1 in the larger number of accessory glands1 two forms may be distinguished1 which differ from each other in their contents 7,siebold74 ,in the cockroach 7,fig4 #dfa7 these glands form the 8mushroom0 shaped gland of ,huxley1 which was at first regarded as the testis4 ,the spermatozoa4--,these very minute bodies1 the sexual homologues of the eggs1 abound in the seminal fluid1 and are formed in the follicles of the testes from a germinal layer or epithelium1 as are the eggs4 ,they are hair- or thread-like1 usually consisting of a head1 a body or middle-piece1 and a long1 thread-like tail 7flagellum71 which vibrates rapidly1 causing the spermatozon to move actively forwards 7,fig4 #dgj74 ,in beetles1 according to ,ballowitz1 there are two main types of spermatozoa1 connected1 however1 by intermediate forms4 ,there is a double-tailed type1 already described by ,btschli and v4 la ,valette ,st4 ,george1 and there are others which are single-tailed4 ,btschli showed that in the double spermatozon one tail-filament is straight and stiff1 the other being undulating and contractile4 ,ballowitz describes this type in ,calathus 7,fig4 #dgj1 ,b71 ,chrysomela1 and ,hylobius1 etc41 and shows that the straight or supporting portion of the tail is elastic1 but somewhat stiff1 resistant to reagents1 and without any fibrillar structure1 while the contractile fringe consists of an extremely complicated system of fibrils 7,fig4 #dgj74 ,the single-tailed type of spermatozon1 as seen1 e4g41 in ,melolontha and ,hydrophilus1 has no supporting fibres4 ,the tail is twisted in a spiral1 corresponds to the contractile fringe of the double type1 and exhibits a complicated fibrillar structure4 ,the fringed type works its way ahead like the screw of a steamer4 ,illustration3 ,,fig4 #dga4--;,c1 anterior end of spermatid of a moth 7,pygra74 ,d1 young spermatozon of the same2 af1 axial filament2 c1 centrosome2 m1 middle-piece or mitosoma2 n1 nucleus2 p1 paranucleus2 e1 envelope of the tail4--,after ,platner1 from ,wilson4 ,each spermatozon is a modified but complete cell1 and the nucleus contains the chromatin1 a deeply staining substance of the nuclear network and of the chromosomes and the supposed bearer of heredity4 ,formation of the spermatozon4--,it arises from a primordial germcell called spermatogonium4 ,this cell contains a large1 pale nucleus and a dark body1 the accessory nucleus of ,btschli4 ,the spermatogonia subdivide1 but at a certain period pause in their subdivisions1 and undergo considerable growth4 8,each spermatogonium is thus converted into a spermatocyte1 which1 by two rapidly succeeding divisions gives rise to four spermatozoa1 as follows3 ,the primary spermatocyte first divides to form two daughter-cells1 known as spermatocytes of the second order1 or sperm mother-cells4 ,each of these divides again--as a rule without pausing1 and without the reconstruction of the daughter-nuclei--to form two spermatids or sperm-cells4 ,each of the four spermatids is then directly transformed into a single spermatozon2 its nucleus becoming very small and compact1 its cytoplasm giving rise to the tail and to certain other structures4444 ,as the spermatid develops into the spermatozon1 it assumes an elongated form1 the nucleus lying at one end1 while the cytoplasm is drawn out to form the flagellum at the opposite end40 7,wilson's ,the ,cell1 from ,la ,valette ,st4 ,george47 ,henking finds that the primordial sperm-cells correspond to the primordial ova1 both forms of cells in the insect he studied containing the characteristic number of twenty-four chromosomes4 ,the spermatogenesis of ,laphria1 according to ,cholodkowsky1 is very peculiar1 and strongly resembles that described by ,verson in ,bombyx mori4 ,in the blind end of the testicular tubes lies a colossal cell visible to the naked eye1 the spermatogone1 from which the entire contents of the testes originate4 ,in ,bombyx this spermatogone appears in the larva state4 ,such colossal spermatogones also occur in ,lepidoptera of different families 7,hyponomeuta1 ,vanessa1 and in the pupa of ,chareas graminis71 in ,trichoptera1 and in ,hemiptera 7,syromastes72 and ,cholodkowsky inquires whether they may not be typical of insects4 ,toyama has observed these colossal cells not only in the testes but also in the ovaries of the silkworm4 ,he regards them as supporting cells4 ,the spermatozoa are inclined to remain in bundles1 and in this state are expelled during copulation4 ,these bundles are either root-like1 bushy1 string-like1 sinuous1 or worm-like4 ,auerbach has observed the spermatozoa of ,dyticus marginalis in their passage through the convoluted seminal vesicles4 ,all those arising from one testicular tube are united in a bundle4 ,each has a very complex structure1 bilateral but unsymmetrical4 ,the right side of the head is concave1 the left convex2 the whole head is longitudinally curved to right or left2 and on the posterior half of the right side there is a projecting ridge bearing a hook-shaped cyanophilous 8anchor10 at the free end of which an erythrophilous spherule appears4 ,the most remarkable fact is that the spermatozoa unite in pairs in a perfectly definite way1 opposed and crossed in a manner somewhat suggestive of a pair of scissors1 with the right sides of the heads in contact4 ,during this conjugation1 or 8dejugation0 as ,auerbach calls it1 the anchors change their shape1 and the little spherules are lost4 ,hundreds of these double spermatozoa are found together in little balls4 ,the conjugation is a temporary one1 but it may permit a molecular exchange of substance1 perhaps with the result of mixing the hereditary qualities and limiting variability4 7,journ4 ,roy4 ,micr4 ,soc41 #ahic1 p4 #fbb47 ,in many insects which lack a true penis1 the bundle of spermatozoa are united in the ejaculatory duct1 forming packets which are enveloped by the secretion of the accessory glands which stiffens into a hard case4 ,these packets are called spermatophores4 ,they are either introduced into the vagina of the female or simply remain outside4 ,graber has repeatedly observed that the male crickets1 in the absence of the female1 let their spermatophores fall to the earth2 whether it is afterwards made available is not known1 because hitherto no case is reported that females seeking impregnation search1 as in the case of the ,isopod crustacean1 ,porcellio1 for the spermatophores4 ,in the ,gryllid and ,locustid the spermatophore lies in a cup-like cavity under the penis4 ,this is called the 8spermatophore cup0 7,chadima1 #ahga71 into which the ejaculatory duct of the testis opens4 ,according to the views of ,schneider1 the spermatophores1 with their capsule1 usually consist solely of seminal filaments1 which stick closely to each other1 and only exceptionally have a capsule formed by a glandular secretion4 ,in ,locusta1 however1 and perhaps also in ,gryllus1 the sperm is enveloped by the secretion of the accessory glands of the seminal ducts2 the spermatophores pass1 still fluid1 out of the sexual opening of the male into that of the female1 but become chilled on the outer surface1 so that the sperm1 without coming in contact with the air1 passes into the receptaculum seminis4 ,the mode of grouping of the spermatozoa of the ,locustid as they occur in the spermatheca of the female is remarkable4 ,their heads lie so close to each other that they form a long shaft1 while the numerous threads are arranged so as to look like the two vanes of a feather1 the entire mass being like a very long heron's feather4 7,siebold47 ,in the honey-bee the spermatophore is likewise enveloped by the secretion of the accessory glands1 and thereby becomes a sort of seminal cartridge4 ,this is a peculiar oval body which is carried during the marriage-flight into the air within the upper part of the penis1 the so-called penis-bulb4 7,leuckart47 b4 ,the female organs of reproduction ,the different parts of the female reproductive organs are the following3 #a4 ,the two ovaries4 #b4 ,the two oviducts4 ,illustration3 ,,fig4 #dgb4--;,female organs of generation of a saw-fly 7,athalia centifoli73 a1 b1 c1 the #ah ovarial tubes originating from each of the two oviducts 7d71 and containing the immature eggs2 e1 common oviduct2 f1 spermatheca2 g1 poison-sac2 h1 poison-glands2 #aj1 last ganglion4--,after ,newport4 #c4 ,the common egg-passage in nearly all insects 7its distal or hindermost part forming the uterus or vagina74 #d4 ,the receptaculum seminis1 or spermatheca4 #e4 ,the bursa copulatrix1 or copulatory pouch4 #f4 ,the accessory glands 7cement1 sebific1 or colleterial glands1 or 8oil reservoirs10 glandul sebace1 coleterium74 ,the ovaries and the ovarian tubes4--,as in the testes1 so each ovary consists of a variable number of ovarian tubes1 by some called ovarioles1 united by a thread at the distal end1 and at the lower or hinder end opening into the oviduct4 ,each ovarian or egg tube is divided into three sections3 7#a7 the terminal thread2 7#b7 the terminal chamber1 and 7#c7 the actual ovarian tube1 or chambered main division1 this forming the longest part of the egg-tube4 ,the slender terminal thread serves to attach or suspend each egg-tube near the dorsal vessel 7not directly to the heart1 as formerly supposed71 becoming lost in the fat-body4 ,illustration3 ,,fig4 #dgc4--,ovarian tube of ,p4 orientalis3 ,a1 section near the end2 tf1 base of terminal filament4 ,b1 section lower down2 ec1 egg-cells in egg-chamber4--,after ,brandt4 ,the terminal chamber contains undifferentiated cell elements1 supposed to be the remains of the ovarian rudiments4 ,from these arise 7either in the embryo or larva7 first1 the follicle epithelium of the ovarian tubes2 and1 second1 the material for the formation of the new eggs1 and nutritive cells4 8,in the terminal chamber these cell-elements remain undifferentiated1 excepting when required for the removal of the follicle epithelium1 eggs1 and nutritive cells in the adult insect40 7,lang47 ,this portion of the ovariole is called the germarium4 ,in ,blatta it is filled with protoplasm in which numerous small nuclei are imbedded4 7,wheeler47 ,the chambered main division of the egg-tube contains the ripening eggs1 one in each compartment1 the tube appearing like a string of beads4 ,the egg-tubes are of two types3 7#a7 those without1 and 7#b7 those with nutritive cells1 the first kind being the simplest1 and occurring in the ,synaptera 7except ,campodea7 and in ,orthoptera4 ,as an example may be cited that of the cockroach 7,fig4 #dgc71 where in each tube there is a simple continuous row of eggs from the terminal chamber to the oviduct4 ,the tube being constricted between these consecutive eggs1 gives it a beaded appearance4 ,in the cockroach 7,periplaneta orientalis7 each egg-tube has a beaded appearance4 ,its wall consists of a transparent elastic membrane1 lined by epithelium1 with an external peritoneal layer of connective tissue4 ,the terminal filament 7tf7 is filled with a clear protoplasm1 with a few nuclei4 ,in the terminal chamber 7tc7 are large nucleated cells1 with separate nuclei1 both entangled in a network of protoplasm4 ,in the third1 or egg-chamber 7ec71 are about twenty ripening eggs1 arranged in a single row4 8,between and around the eggs the nuclei gradually arrange themselves into one-layered follicles1 which are attached1 not to the wall of the tubes1 but to the eggs1 and travel downwards with them4 ,as the eggs descend1 the yolk which they contain increases rapidly1 and the germinal vesicle and spot 7nucleus and nucleolus71 which were at first plain1 disappear4 ,a vitelline membrane is secreted by the inner surface and a chitinous chorion by the outer surface of the egg-follicle4 8,the lowest egg in an ovarian tube is nearly or altogether of the full size2 it is of elongate-oval figure1 and slightly curved1 the convexity being turned towards the uterus4 ,it is filled with a clear albuminous fluid1 which mainly consists of yolk4 ,the chorion now forms a transparent yellowish capsule1 which1 under the microscope1 appears to be divided up into very many polygonal areas1 defined by rows of fine dots4 ,these areas probably correspond to as many follicular cells40 7,brandt1 from ,miall and ,denny47 ,in the second type1 i4e4 those egg-tubes with nutritive cells1 there are two kinds4 ,in the first the egg-chambers and yolk- or nutritive chambers alternate1 each of the latter containing one or more nutritive cells1 which serve for the nourishment of the ripening egg contained in the neighboring chamber4 8,the egg- and yolk-chambers may be distinctly separated externally by constrictions 7,hymenoptera and many ,coleoptera71 or one nutritive and one egg-chamber may lie in each section of the ovarian tube1 which is externally visible as a swelling 7,lepidoptera1 ,diptera740 ,in the second kind with nutritive cells1 the actual tube consists 7,fig4 #dgd1 ,c7 of ovarian chambers only2 the nutritive cells here remain massed together in the large terminal chamber4 ,the single egg in the tube is united with the terminal chamber by connective strands 7d4 s471 which convey the nutritive material to the eggs4 7,lang47 ,egg-cells1 nutritive cells1 and the cells of the follicle-epithelium 7epithelium of the chambers of the ovarian tubes7 are1 says ,lang1 according to their origin1 similar elements1 like the egg and yolk-cells of the flat worms 7,platodes72 division of labor leads to their later differentiation4 ,only a few of the numerous egg-germs develop into eggs1 the rest serving as envelopes and as food for these few4 ,korschelt considers that all the chief elements of the egg-tubes1 viz4 egg1 nutritive1 and epithelial cells1 arise by a direct transformation of the elements of the terminal chamber1 and that the last may be traced to the indifferent elements of the terminal thread1 the elements in question originating from the nuclear elements by a breaking down of the syncytium 7or masses of protoplasm with nuclei scattered through it7 composing it 7,fig4 #dge74 ,the latest work is that of ,wielowiejski 7,zoologische ,anzeiger1 ix1 #ahhf1 p4 #acb71 whose observations are based on a study of the ovarian tubes and the growing eggs of the ,hemiptera 7,pyrrhocoris71 the ,coleoptera 7,telephorus1 ,saperda1 ,cetonia and ,melolontha1 ,carabid1 and ,hydradephaga71 etc4 ,wielowiejski divides the ovaries of insects into three groups3-- #a4 ,comprising such ovaries in the ends of whose egg-tubes 7terminal filament7 the embryonal cells in the early stages are accumulated1 and are transformed into egg-1 yolk-1 and epithelial cells respectively4 7,ovaries of ,orthoptera1 geodephagous and hydradephagous ,coleoptera1 ,lepidoptera1 ,diptera1 and ,hymenoptera74 #b4 ,comprising ovaries whose ends above the egg-cells and egg-germs 7,eianlagen7 possess throughout life a more or less voluminous solid accumulation of cells 7terminal chamber71 but which stand in no close relation with the first4 7,ovaries of ,coleoptera1 with the exception of the ,geodephaga and ,hydradephaga1 and ,aphid in part47 ,illustration3 ,,fig4 #dgd4--,various types of ovarian tubes1 diagrammatic3 ,a1 ovarian tube without nutritive cells4 ,b1 egg-tube with alternating nutritive and egg-compartments4 ,c1 ovarian tubes in which the terminal chamber 7ek7 is developed into a nutritive chamber1 with which the developing eggs remain connected by means of threads 7ds72 ef1 terminal filaments2 efa1 egg compartments or chambers2 fe1 follicle epithelium2 df1 yolk-chambers4--,after ,lang 7,c from ,claus74 ,illustration3 ,,fig4 #dge4--,upper portion of the ovary in ,forficula1 showing eggs and nurse-cells2 below1 a portion of the nearly ripe egg 7e7 showing deutoplasm-spheres and germinal vesicle 7gv74 ,above it lies the nurse-cell 7n71 with its enormous branching nucleus4 ,two successively younger stages of egg and nurse-cell are shown above4--,after ,korschelt1 from ,wilson4 ,illustration3 ,,fig4 #dgf4--;,a1 ovarian egg of a butterfly 7,vanessa71 surrounded by its follicle2 above are the nurse-cells 7n4 c471 with branching nuclei2 g4v1 germinal vesicle4 ,b1 egg of ,dyticus1 living2 the egg 7o4v47 lies between two groups of nutritive cells2 the germinal vesicle sends amboid processes into the dark mass of food-granules4--,after ,korschelt1 from ,wilson4 ,illustration3 ,,fig4 #dgg4--;,a1 lower portion of one of the two ovaries of ,sphinx ligustri1 the four egg-tubes uniting to form the slightly developed calyx 7ov74 ,the egg-tubes above contain ripe eggs still surrounded by the follicle2 e4 c1 the empty egg-chamber4 ,beyond the empty egg-chambers 7e4 c7 are three egg-chambers with ripe eggs and the connecting cord4 ,the whole tube is surrounded by the peritoneal membrane and musculature4--,after ,korschelt4 #c4 ,comprising ovaries whose ends above the egg-germs contain a well-developed mass of cells functioning as a yolk-forming organ1 between whose special elements grow root-like offshoots of nearly ripe egg-cells4 7,hemiptera47 ,illustration3 ,,fig4 #dgh4--,ovary of a beetle1 drawn somewhat diagrammatically3 o1 egg-tube2 s1 stalk of the same2 c1 egg-calyx2 ov1 oviduct4--,after ,korschelt4 ,when the egg is ripe the food-chamber disappears because its contents have served for the formation of the egg below it4 ,in ,lepidoptera especially1 the egg-tubes resemble strings of pearls because most of the numerous eggs ripen simultaneously and are likewise deposited at the same period1 which is naturally not the case in those insects whose eggs gradually ripen 7,fig4 #dgg74 ,in other cases the egg- or food-compartments are transformed into each other1 but only one egg- and one food-compartment can be situated in the same dilatation of the ovarian tube4 ,finally1 there are insects in whose egg-tubes the egg-compartments are arranged in a single row1 while the capacious terminal chamber contains a large mass of food-cells4 ,egg-cells1 nutritive cells1 as well as the cells of the follicle epithelium 7epithelium of the chambers of the ovarian tubes71 originate as similar or homologous elements1 division of labor leading to their later differentiation4 ,only a few of the numerous egg-germs develop into eggs1 the rest serving as envelopes and also as food for these few4 7,lang47 ,in many insects the egg-tubes open into an egg-calyx 7,fig4 #dgh1 c71 in which the ripe eggs collect before passing into the oviduct 7ov74 ,as the result of his investigations on the origin of the cellular elements of the ovaries of insects ,korschelt concludes3-- #a4 ,the different cell-elements of the egg-tubes1 eggs1 nutritive cells1 and epithelium arise from identical undifferentiated elements situated in the contents of the earliest germ of the egg-tubes4 #b4 ,the first formation of the cellular elements present1 and the differentiation of the individual compartments of the egg-tube1 occur during embryonic and larval life4 #c4 ,the undifferentiated elements of the terminal chamber correspond to the embryonic condition1 while in post-embryonic time1 and even during imaginal life1 a new formation of the different kinds of cells takes place4 #d4 ,the mode of origin of the different kinds of cells from the undifferentiated elements varies greatly in different insects4 #e4 ,from their histological nature1 and from the mode of origin of their elements1 the most complex egg-tubes and those provided with nutritive compartments are phylogenetically derived from those without such nutritive compartments4 #f4 ,the nutritive cells in certain cases originate in the same way and at the same time as the germ-cells1 and are therefore to be regarded as germ-cells which have abandoned the function of egg-making1 and exchanged it for the production of nutritive material4 #g4 ,in the egg-tubes with numerous nutritive compartments the nutritive cells can originate at the same place as the egg-cells1 and they afterwards still lie intermingled with these in the beginning or upper part of the egg-tubes4 #h4 ,while the capability of egg-making of the germ-cells originally situated in the extremity of the terminal chamber gradually becomes transferred to those at the base of the terminal chamber1 and the first transform into nutritive cells1 egg-tubes with nutritive compartments at the base may be found4 #i4 ,the nutritive cells of certain forms arise independently of the germ-cells and therefore could not have previously originated from them4 #aj4 ,the epithelium has in all forms nearly the same mode of formation2 it everywhere shows a close similarity to the undifferentiated elements of the terminal chamber1 out of which it directly develops4 ,as to the fact of formation of epithelium through the germ-vesicles 7,keimblaschen71 nutritive-cell nuclei1 or the so-called 8oblasts10 ,i could not feel certain4 #aa4 ,neither the eggs of ,hemiptera or of other insects arise through the agency of 8oblasts10 but like the epithelial and nutritive cells arise by a gradual differentiation from the indifferent elements of the ovarian tubes4 #ab4 ,the different elements of the egg-tubes1 also the eggs1 have the morphological value of cells4 ,origin of incipient eggs in the germ of the testes4--,heymons has detected in the germ of the testes of the male larv of ,phyllodromia germanica #g mm4 in length1 young or incipient eggs1 similar to those seen in the ovarian tubes of the female larva of the same size4 ,in another male larva of the same size also occurred short cylindrical tubes each with a terminal thread1 which had the appearance of rudimentary egg-tubes4 ,hence he thinks that every part of the genital germs 7,anlagen7 in the male1 which are not concerned in the formation of testicular follicles1 represents the germ of a female genital gland4 ,as is well known1 no insects are hermaphroditic1 but this case of the practical origin of eggs and egg-tubes in the lowest division of the male efferent passage1 which is homologous with the egg-producing division of the female ovarian tubes1 points back to hermaphroditic ancestors4 ,and ,heymons suggests that the frequent occurrence of hermaphroditism in insects probably confirms this view4 ,illustration3 ,,fig4 #dgi4--;,abdomen of queen bee1 under side1 #h3 ,p1 petiole2 o1 o1 ovaries2 hs1 position filled by honey-sac2 ds1 place through which the digestive canal passes2 od1 oviduct2 co4d1 common oviduct2 ,e1 egg passing oviduct2 s1 spermatheca2 i1 intestine3 pb1 poison-bag2 p4g1 poison-gland2 st1 sting2 p1 palpi4 ,b1 vestigial ovaries of ordinary worker2 sp1 vestigial spermatheca4 ,c1 partially developed ovaries of fertile worker2 sp1 vestigial spermatheca4--,after ,cheshire4 ,the bursa copulatrix4--,the copulatory pouch in most insects is a special cup-shaped appendage of the vagina adapted for the reception of the male organ during sexual union4 ,its mode of formation in the cockroach is thus described by ,haase3-- 8,by the retreat of the female sexual aperture1 situated in the #hth ventral plate1 a considerable space1 the genital pouch1 is produced2 this is formed chiefly by the extended connective membrane between the elongated #gth and #hth ventral plates4 ,this serves for the development of the egg-cocoon1 which is retained by the internal appendages of the posterior gonapophyses40 ,the fertilization of the female takes place once for all a long time previous to oviposition2 the semen in the receptaculum seminis passes out as the eggs slip down the egg-passage1 and a spermatozon gains entrance into the interior of the egg through the micropyle4 ,in canthus1 according to ,ayers1 fecundation probably takes place while the egg is passing into the vagina1 8since it is hardly possible that the male element could gain access to the follicles before the chorion is secreted40 ,in the ,lepidoptera1 as has been stated1 the copulatory pouch opens separately from the opening of the oviduct 7vagina71 but a slender canal connects the pouch with the vagina 7,fig4 #caj1 bc74 ,the outlet 78vagina0 of ,burgess7 of the copulatory pouch opens between the #gth and #hth segments1 that of the oviduct 7vagina7 on the #ith segment being 8situated immediately below the anus and hardly separated from it1 between the lappets of the #ith segment40 7,burgess47 ,the opening of the copulatory pouch is1 as we have seen1 the genuine or primitive sexual opening4 ,illustration3 ,,fig4 #dhj4--,spermatheca of the honey-bee1 queen1 #dj3 a1 space filled by a clear fluid2 b1 mass of spermatozoa2 c1 duct2 d1 d1 active spermatozoa4-- ,after ,cheshire4 ,illustration3 ,,fig4 #dha4--;,female sexual organs of ,scolytus3 ,,er1 egg-tubes2 p,e,l1 paired oviducts2 ,,st1 spermatheca2 ,,bt1 copulatory pouch2 ,,kd1 cement-glands2 ,sch1 vagina4--,after ,lindeman1 from ,judeich and ,nitsche4 ,the spermatheca4--,this is a sac or pouch for the reception and storage or preservation of the semen4 ,while in most of the higher insects it opens into the dorsal wall of the vagina 7,fig4 #dgb1 f71 in the cockroach1 locusts1 and grasshoppers it opens into the bursa2 but in other ,european ,orthoptera1 as in most insects1 it lies upon the dorsal wall of the vagina4 7,berlese47 ,in the cockroach1 it is a short tube dilated at the end and wound into a spiral of about one turn4 8,from the tube a ccal process is given off1 which may correspond with the accessory gland attached to the duct of the spermatheca in many insects 7e4g4 ,coleoptera1 ,hymenoptera1 and some ,lepidoptera74 ,the spermatheca is filled during copulation1 and is always found to contain spermatozoa in the fertile female4 ,the spermatozoa are no doubt passed into the genital pouch from time to time1 and there fertilize the eggs descending from the ovarian tubes40 ,in ,melo the spermatheca is exceedingly large4 7,miall and ,denny1 pp4 #agj1 #aga47 ,the colleterial glands4--,we have already briefly referred to these glands4 ,those of the cockroaches form a number of long blind tubes opening into the vagina4 ,they furnish the material for the egg-capsule or otheca1 viz4 chitin and large crystals of oxalate of lime4 ,in ,phyllodromia germanica 8these glands are glistening white till the time of oviposition approaches1 when they assume a yellow tint1 and the octahedral crystals are seen imbedded in a viscid substance which fills their lumina4 ,this viscid substance is soluble in potassium hydrate1 and is consequently not chitin4 ,when excreted to form the otheca1 it slowly hardens1 deepens in color1 and becomes insoluble in potassium hydrate4 ,light has nothing to do with this change1 which is possibly produced by the oxygen in the air4 ,it is the same change which is undergone by the cuticula of the insect itself immediately after ecdysis40 7,wheeler47 ,the vagina or uterus4--,this is simply the end of the common oviduct1 which1 when dilated1 is called the vagina1 and1 in the pupiparous forms1 the uterus4 ,in the cockroach the vagina opens by a median vertical slit situated in the #hth sternite1 into the genital pouch or bursa1 upon the dorsal wall of which the orifice of the spermatheca is situated4 ,in the sheep-tick the oviduct is enlarged to form the so-called uterus1 which furnishes a milk-like secretion for the nourishment of the larva during its intra-uterine life4 ,in insects in general1 the external opening of the vagina is simple1 the chitinous structures 7valves7 at the opening being adapted to receive the male intromittent organ4 ,when the eggs are to be deposited deep below the surface of the earth1 or in wood1 or in wood-boring larv1 or in the body of caterpillars1 etc41 they are inserted by the ovipositor 7see p4 #afg74 ,signs of copulation in insects4--,leydig has collected1 partly from his own observations and partly from those of others1 a number of cases in which female insects bear traces of having had sexual union1 in the form of tags or plates attached to the body1 and apparently formed from material secreted by the male4 ,such probably is the 8pouch0 on the abdomen of ,parnassius apollo1 and a somewhat similar structure in ,fulgora laternaria1 and such is the plate which is found on the hinder part of the abdomen of ,dyticus latissimus and ,d4 marginalis4 ,leydig compares these structures with the white plate in ,astacus fluviatilis1 and with the little white lid on the spider ,argenna1 and finds analogues among vertebrates4 7,arbeit4 ,zool4 ,zoot4 ,inst4 ,wurzburg1 x1 #ahia1 pp4 #cg-ee1 #b ,figs47 ,,literature ,,on ,,the ,,organs ,,of ,,reproduction a4 ,general ,hunter1 ,j4 ,observations of bees4 7,phil4 ,trans4 ,roy4 ,soc4 ,london1 #agib1 lxxxii1 pp4 #abh-aie47 ,hegetschweiler1 ,j4 ,j4 ,dissertatio inauguralis zootomica de insectorum genitalibus4 ,turici1 #ahbj1 pp4 #bh1 #a ,pl4 ,audouin1 ,v4 ,recherches anatomiques sur la femelle du ,drile jaunatre et sur le male de cette espce4 7,ann4 ,sc4 nat41 ii1 #ahbd1 pp4 #ddc-dfb1 #a ,pl47 ,mller1 ,johannes4 ,ueber die ,entwickelung der ,eier im ,eierstock bei den ,gespenstheuschrecken4 7,nova ,acta ,acad4 ,leop4-,carol41 xii1 #ahbe1 pp4 #eee-fgb1 #f ,taf47 ,dufour1 ,l4 ,recherches anatomiques sur les ,carabiques et sur plusieurs autres insectes coloptres4 ,organes de la gnration 7,ann4 ,sc4 nat41 vi1 #ahbe1 pp4 #aej-bjf1 #f ,pls42 pp4 #dbg-dfh1 #d ,pls474 ---- ,recherches anatomiques sur l',hippobosque des cheveaux4 7,ibid41 #ahbe1 vi1 pp4 #bii-cbb1 #a ,pl47 ---- ,recherches anatomiques sur les ,labidoures4 ,appareil de la gnration4 7,ibid41 #ahbh1 xiii1 pp4 #ced-cei1 #b ,pls47 ---- ,recherches anatomiques et considrations entomologiques sur quelques insectes coloptres1 compris dans les familles des ,dermestins1 des ,byrrhiens1 des ,acanthopodes et des ,leptodactyles4 ,appareil gnital4 7,ibid41 ,sr4 #b1 ,zool4 i1 #ahcd1 pp4 #gf-hb1 #b ,pls47 ---- ,rsum des recherches anatomiques et physiologiques sur les ,hmiptres4 7,ibid41 ,sr4 #b1 i1 pp4 #bcb-bci47 ---- ,mmoire sur les mtamorphoses et l'anatomie de la ,pyrochroa coccinea4 ,appareil gnital4 7,ibid41 ,sr4 #b1 ,zool41 xiii1 pp4 #ccg-cci1 #a ,pl47 ---- ,histoire des mtamorphoses et de l'anatomie des ,mordelles4 7,ibid41 ,sr4 #b1 xiv1 pp4 #bce-bch1 #a ,pl47 ---- ,anatomie gnrale des ,diptres4 ,appareil gnital4 7,ibid41 ,sr4 #c1 ,zool41 i1 #ahdd1 pp4 #bej-bfd47 ---- ,histoire des mtamorphoses et de l'anatomie du ,piophila petasionis4 ,appareil gnital4 7,ibid41 ,sr4 #c1 ,zool41 i1 #ahdd1 pp4 #cgh-chf47 ---- tudes anatomiques et physiologiques sur les insectes diptres de la famille des ,pupipares4 ,appareil gnital4 7,ann4 ,sc4 nat41 ,sr4 #c1 ,zool41 iii1 #ahde1 pp4 #gc-ic1 #b ,pls47 ---- ,recherches sur l'anatomie et l'histoire naturelle de l',osmylus maculatus4 ,appareil gnital4 7,ibid41 ,sr4 #c1 ,zool41 ix1 #ahdh1 pp4 #cdi-cef1 #a ,pl47 ---- ,recherches anatomiques sur les ,hymnoptres de la famille des ,urocerates4 ,appareil gnital4 7,ibid41 ,sr4 #d1 ,zool41 i1 #ahed1 pp4 #baf-bcd1 #a ,pl47 ---- ,fragments d'anatomie entomologique4 ,sur les ovaires du ,nemoptera lusitanica4 7,ibid41 ,sr4 #d1 viii1 #aheg1 pp4 #i-aj1 #a ,pl47 ---- ,fragments anatomiques sur quelques latrides4 7,ibid41 ,sr4 #d1 viii1 #aheg1 pp4 #cfe-cgb1 #a ,pl47 ---- ,recherches anatomiques et considrations entomologiques sur les ,hmiptres du genre ,leptopus4 ,appareil gnital4 7,ibid41 ,sr4 #aj1 #aheh1 pp4 #cef-cfb1 #a ,pl47 ---- ,recherches anatomiques sur l',ascalaphus meridionalis4 ,appareil gnital4 7,ibid41 ,sr4 #d1 xiii1 #ahfj1 pp4 #bjc-bjf1 #a ,pl47 ---- ,sur l'appareil gnital male du ,corbus bifasciatus4 7,thomson's ,archiv ,ent41 #aheg1 i1 pp4 #cgh-cha47 ,suckow1 ,f4 ,w4 ,l4 ,geschlechtsorgane der ,insekten4 7,heusinger's ,zeitschr4 f4 organ4 ,physik41 #ahbh1 ii1 pp4 #bca-bfd1 #a ,taf47 ,rathke1 ,m4 ,h4 ,miscellanea anatomico-physiologica4 ,fasc4 #a4 ,de ,libellarum partibus genitalibus4 ,regiomonti1 #ahcb1 p4 #ch1 #c ,pls4 ,dutrochet1 ,r4 ,j4 ,h4 ,observations sur les organes de la gnration chez les pucerons4 7,ann4 ,sc4 nat41 #ahcc1 xxx1 pp4 #bjd-bji47 ,doyre1 ,l4 ,observations anatomiques sur les organes de la gnration chez la ,cigale femelle4 7,ann4 ,sc4 nat41 #ahcg1 vii1 pp4 #bjj-bjf1 ,fig47 ,siebold1 ,c4 ,th4 ,e4 von4 ,ueber die weiblichen ,geschlechtsorgane der ,tachinen4 7,wiegmann's ,archiv f4 ,naturgesch41 #ahch1 iv1 pp4 #aia-bja47 ---- ,ueber die inneren ,geschlechtswerkzeuge der viviparen und oviparen ,blattluse4 7,froriep's ,notizen1 #ahci1 xii1 pp4 #cje-cjh47 ---- ,ueber das ,receptaculum seminis der ,hymenopteren-,weibchen4 7,germar's ,zeitschr4 f4 ,ent41 #ahdc1 iv1 pp4 #cfb-chh1 #a ,taf47 ,loew1 ,h4 ,beitrag zur anatomischen ,kenntniss der inneren ,geschlechtsteile der zweiflgligen ,insekten4 7,germar's ,zeitschr4 f4 ,ent41 #ahda1 iii1 pp4 #chf-djf1 #a ,taf47 ---- ,hor anatomic1 ,abth4 ,i4 ,entomotomien4 ,heft i-iii1 ,posen1 #ahda4 ---- ,beitrge zur ,kenntniss d4 inneren ,geschlechtstheile der zweifl4 ,insecten4 7,germar's ,zeitschr4 f4 ,entomologie1 iii1 #ahda1 pp4 #chf-djf1 #a ,taf47 ,stein1 ,f4 ,vergleichende ,anatomie und ,physiologie der ,insekten4 ,i1 ,monographie4 ,ueber die ,geschlechtsorgane und den ,bau des ,hinterleibes bei den weiblichen ,kfern1 ,berlin1 #ahdg1 i1 pp4 #aci1 #i ,taf4 ,brauer1 ,f4 ,beitrag zur ,kenntniss des inneren ,baues und der ,verwandlung der ,neuropteren4 7,verhandl4 d4 zool4 botan41 ,vereins in ,wien1 #ahee1 pp4 #a-bf1 #e ,taf47 ,haliday1 ,a4 ,h4 ,note on a peculiar form of the ovaries observed in a hymenopterous insect1 constituting a new genus and species of the family ,diapriad4 7,nat4 ,hist4 ,review1 #aheg1 iv1 pp4 #aff-agd1 #a ,pl47 ,laboulbne1 ,a4 ,recherches sur les appareil de la digestion et de la reproduction du ,buprestis manca4 7,thomson's ,archiv ,ent41 #aheg1 i1 pp4 #bjd-bcf1 #b ,pls47 ,lubbock1 ,john4 ,on the ova and pseudova of insects4 7,phil4 ,trans4 ,roy4 ,soc41 ,london1 cxlix1 #ahfj1 pp4 #cda-cfi47 ,landois1 ,h4 ,ueber die ,verbindung der ,hoden mit dem ,rckengefss bei den ,insekten4 7,zeitschr4 f4 wissens4 ,zool41 xiii1 #ahfc1 pp4 #caf-cah1 #a ,taf47 ,leydig1 ,f4 ,der ,eierstock und die ,samentasche der ,insekten4 7,nova ,acta ,acad4 ,leop4-,carol41 xxxiii1 #ahfg1 pp4 #hh1 #e ,taf47 ---- ,beitrge zur ,kenntniss des thierischen ,eies im unbefruchteten ,zustande4 7,spengel's ,zool4 ,jahrbcher1 #ahhi4 ,abth4 f4 ,anat41 iii1 pp4 #bhg-dcb1 #g ,taf47 ,bessels1 ,e4 ,studien ber die ,entwicklung der sexual ,drsen bei den ,lepidopteren4 7,zeitschr4 wissens4 ,zool41 xvii1 #ahfg1 pp4 #ede-efc47 ,rajewsky4 ,ueber die ,geschlechtsorgane von ,blatta orientalis1 etc4 7,nachr4 d4 k4 ,gesellschaft d4 ,moskauer ,universitt1 xvi1 #ahge4 ,testes of cockroach4 ,in ,russian2 for abstract1 see ,hoffmann u4 ,schwalbe1 ,jahresbericht1 #ahge1 p4 #dbe47 ,brehm1 ,siegfr4 ,comparative structure of the reproductive organs in ,blatta germanica and ,periplaneta orientalis4 7,hor ,ent4 ,soc4 ,rossic1 ,st4 ,petersburg1 viii1 #ahhj47 7,in ,russian1 male organs only47 ,cholodkowsky1 ,n4 ,a4 ,ueber die ,hoden der ,schmetterlinge4 7,zool4 ,anzeiger1 iii ,jahrg41 #ahhj1 pp4 #aae-aag47 ---- ,ueber den ,bau der ,testikel bei ,schmetterlingen4 7,zool4 ,anzeiger1 #ahhj1 iii1 pp4 #bad-bae47 ---- ,ueber die ,hoden der ,lepidopteren4 7,zool4 ,anzeiger1 #ahhd1 pp4 #efd-efh47 ---- ,ueber den ,geschlechtsapparat von ,nematois metallicus4 7,zeitschr4 f4 wissens4 ,zool41 xliii1 pp4 #eei-efh1 #ahhe47 ,tichomirow1 ,a4 ,ueber den ,bau der ,sexualdrsen und die ,entwickelung der ,sexualprodukte bei ,bombyx mori4 7,zool4 ,anzeiger1 iii1 #ahhj1 pp4 #bce-bcg47 ,nusbaum1 ,f4 ,zur ,entwicklungsgeschichte der ,ausfhrungsgange der ,sexualdrsen bei den ,insekten4 7,zool4 ,anzeiger1 v1 #ahhb1 pp4 #fcg-fdc47 ----,on the developmental history of the efferent passages of the sexual glands in insects4 ,lemberg1 #ahhd 7in ,czech74 ,berlese1 ,ant4 ,ricerde sugli organi genitali degli ortotteri4 7,atti della ,r4 ,acad4 dei ,lincei4 ,ser #c1 xi1 #ahhb47 7,genital organs of ,european ,orthoptera47 ,balbiani1 ,g4 ,le ,phylloxera du chne et le ,phylloxera de la vigne4 ,paris1 #ahhd1 pp4 #de1 #aa ,pls4 ---- ,contribution l'tude de la formation des organes sexuel chez les insectes4 7,recueil ,zool4 ,suisse1 #ahhe47 ,schneider1 ,anton4 ,die ,entwicklung der ,geschlechtsorgane bei den ,insekten4 ,zool4 ,beitrge1 ,breslau1 i1 #ahhe4 ,beauregard1 ,h4 ,recherches sur les insectes vsicants4 ,suite4 7,journal ,anat4 ,phys41 ,paris1 #ahhg1 xxii ,anne1 pp4 #ebh-edh1 #a ,pl42 xxiii ,anne1 pp4 #abd-afc1 #f ,pls47 ---- ,les insectes vsicants4 ,paris1 #ahij4 ,chap4 v1 ,appareil de la gnration1 pp4 #ajc-aei1 ,pls4 #aj-ab4 ,nassonow1 ,n4 tudes morphologiques sur les ,lepisma1 ,campodea et ,podura4 7,mm4 ,soc4 ,imp4 ,anthropologie et d',ethn4 ,moscou1 iii1 #ahhg1 pp4 #he1 #b ,pls41 #fh ,figs47 ---- ,xenos rossii2 seine ,anatomie und ,entwicklungsgeschichte4 7,bull4 de l',universit de ,varsovie1 #ahib1 pp4 #gd1 #b ,taf47 7,in ,russian47 ---- ,position des ,strepsiptres dans le systeme selon les donnes du dveloppement post-embryonal et de l'anatomie1 p4 #aa1 ,warsaw1 #ahib4 ,grassi1 ,b4 ,j4 ,progenitori dei ,miriapodi e degli ,insetti4 ,memoria vii1 ,anatomia comparata dei ,tisanuri4 7,atti d4 ,r4 ,acad4 de' ,lincei1 ,cl4 scienc4 e fis41 ,serie #d1 iv1 #ahhh1 pp4 #dce-fjf1 #e ,pls47 ,heymons1 ,r4 ,ueber die hermaphroditsche ,anlage der ,sexualdrsen beim ,mannchen von ,phyllodromia germanica4 7,zool4 ,anzeiger1 #ahij1 pp4 #dea-deg47 ,koschewnikoff1 ,g4 ,zur ,anatomie der mnnlichen ,geschlechtsorgane der ,honigbiene4 7,zool4 ,anzeiger1 xiv1 #ahia1 pp4 #cic-cif47 ,verhoeff1 ,c4 7,see p4 #ahf47 ,ingenitzky1 ,j4 ,zur ,kenntniss der ,begattungsorgane der ,libelluliden4 7,zool4 ,anzeiger1 #ahic1 xvi ,jahrg41 pp4 #dje-djg1 #b ,figs47 ---- ,on the fauna and organization of dragon-flies of ,russian ,poland1 #ahic1 #a ,pl4 7,in ,russian47 ,escherich1 ,k4 ,anatomische ,studien ber das mnnliche ,genitalsystem der ,coleopteren4 7,zeitschr4 f4 wissens4 ,zool41 lvii1 pp4 #fbj-fda1 #ahid47 ,kluge1 ,max ,h4 ,e4 ,das mnnliche ,geschlechtsorgan von ,vespa germanica4 ,inaug4 ,diss4 ,leipzig1 #ahie1 pp4 #a-de1 #a ,taf4 ,verson1 ,e4 ,la borsa copulatrice nei ,lepidotteri 7,atti e ,mem4 ,accad4 ,sc4 ,lett4 ed ,arti1 ,padova1 #ahif1 xii1 pp4 #cfi-cgb1 #d ,pls474 ,klaplek1 ,fr4 ber die ,geschlechtstheile der ,plecopteren1 mit besonderer ,rcksicht auf die ,morphologie der ,genitalanhnge4 7,sitzungsb4 k4 ,akad4 ,wissens4 ,wien4 ,math4-,naturw4 ,cl41 cv1 #ahif1 pp4 #ef1 #e ,taf47 ,fenard1 ,a4 ,recherches sur les organes complmentaires internes de l'appareil gnital des ,orthoptres4 7,bull4 ,sc4 ,france ,belg41 xxix1 #ahig1 pp4 #cij-ebg1 #ebh-ecc1 #e ,pls47 ,consult also the ,works of ,ayres1 ,balfour1 ,burgess1 ,burmeister1 ,btschli1 ,claus1 ,dzierzon1 ,gensch1 ,henking1 ,honert1 ,huxley1 ,kluge1 ,kramer1 ,landois1 ,leuckart 7art4 ,zeugung71 ,leydig1 ,ludwig1 ,metschnikoff1 ,h4 ,meyer1 ,minot1 ,mller1 ,pfitzner1 ,schneider1 ,seeliger1 ,scholz1 ,siebold1 ,suckow1 ,swammerdam1 ,tichomiroff1 ,wagner1 ,waldeyer1 ,weismann1 ,wheeler1 v4 ,wielowiejski1 ,will1 ,witlaczil1 and ,ziegler4 b4 ,formation of the egg 7ogenesis7 ,claus1 ,c4 ,beobachtungen ber die ,bildung des ,insekteneies4 7,zeitschr4 wissens4 ,zool41 xiv1 #ahfd1 pp4 #db-ed47 ,brandt1 ,a4 ,ueber die ,eirhren der ,blatta orientalis4 7,mm4 ,acad4 ,imp4 ,scienc4 de ,st4 ,petersbourg1 ,sr4 #g1 xxi1 #ahgd1 p4 #cj47 ---- ,vergleichende ,untersuchungen ber die ,eirhren und die ,eier der ,insekten4 7,nachr4 d4 ,gesellsch4 ,freunde d4 naturwiss4 ,moskau1 xxiii1 #ahgf2 also xxiv1 #ahgg1 pp4 #gg-gi47 ---- ,das ,ei und seine ,bildungsstatte4 ,ein vergleichenden-morphologischer ,versuch mit ,zugrundelegung der ,insecteneies4 ,leipzig1 #ahgh4 ,kadyi1 ,h4 ,beitrge zur ,vorgnge beim ,eierlegen der ,blatta orientalis4 ,vorlufige ,mittheilung4 7,zool4 ,anzeiger1 #ahgi1 pp4 #fcb-fcf47 7,formation of the egg-capsules of cockroach47 ,brass1 ,arn4 ,das ,ovarium und der ,eibildung und der ersten ,entwicklungsstadien bei viviparen ,aphiden4 ,halle1 #ahhc4 7,zeits4 f4 ,naturwiss4 in ,halle1 ,jahrg4 #ahhb47 ---- ,zur ,kenntniss der mnnlichen ,geschlechtsorgane der ,dipteren4 7,zool4 ,anzeiger1 #ahib1 pp4 #agh-ahj47 ,will1 ,ludvig4 ,zur ,bildung der ,eies und des ,blastoderms bei den viviparen ,aphiden4 7,arbeiten ,zool4 ,inst4 ,univ4 ,wrzburg1 vi1 #ahhb1 pp4 #bag-beh47 ,korschelt1 ,e4 ,zur ,frage nach dem ,ursprung der verschiedenen ,zellenelemente der ,insectenovarien4 7,zool4 ,anzeiger1 #ahhe1 pp4 #eha-ehf1 #eii-fje47 ,wielowiejski1 ,h4 ,v4 ,zur ,morphologie des ,insektenovariums4 7,zool4 ,anzeiger1 #ahhf1 ix ,jahrgang1 pp4 #acb-aci47 ---- ,zur ,kenntniss der ,eibildung bei der ,feuerwanze 7,pyrrhocoris apterus74 7,zool4 ,anzeiger1 #ahhe1 pp4 #cfi-cge47 ,blochmann1 ,f4 ,ueber die ,richtungskrper bei ,insekteneiern4 7,morph4 ,jahrb41 #ahhg1 xii1 ix #edd47 ,also the writings of ,leydig 7p4 #eji74 c4 ,on the spermatozoa ,treviranus1 ,g4 ,r4 ,ueber die organischen ,krper des tierischen ,samens und deren ,analogie mit dem ,pollen der ,pflanzen4 7,zeitschr4 f4 d4 ,physiologie1 von ,f4 ,tiedemann1 ,g4 ,r4 und ,l4 ,c4 ,treviranus1 #ahce1 v1 pp4 #acf-aec1 #b ,taf47 ,siebold1 ,c4 ,th4 ,e4 von4 ,ueber die ,spermatozoen der ,crustaceen1 ,insekten1 ,gasteropoden und einiger anderer wirbellosen ,tiere4 7,mller's ,archiv f4 ,anatomie1 #ahcf1 pp4 #ac-eb1 #b ,taf47 ---- ,fernere ,beobachtungen ber die ,spermatozoen der wirbellosen ,tiere4 7,ibid41 #ahcf1 p4 #bcb2 #ahcg1 pp4 #cha-dcb1 #a ,taf47 ---- ,ueber die ,spermatozoen der wirbellosen ,tiere1 iv4 7,ibid4 #ahcg1 pp4 #cib-dcc47 ---- ,lange ,lebensdauer der ,spermatozoen bei ,vespa rufa4 7,wiegmann's ,archiv f4 ,naturgesch41 #ahci1 v1 pp4 #ajg1 #ajh47 ---- ,ueber die ,spermatozoiden der ,locustinen4 7,nova ,acta ,acad4 ,leop4-,carol41 #ahde1 xxi1 pp4 #bdi-bgd1 #a ,pl47 ,klliker1 ,a4 ,beitrge zur ,kenntnis der ,geschlechtsverhltnisse und der ,samenflssigkeit wirbelloser ,tiere1 nebst einem ,versuch ber das ,wesen und die ,bedeutung der sogenannten ,samentiere1 ,berlin1 #ahda1 pp4 #hh1 #c ,taf4 ---- ,die ,bildung der ,samenfaden in ,blschen als allgemeines ,bildungsgesetz4 7,neue ,denkschr4 d4 allg4 ,schweiz4 ,ges41 viii1 #ahdg1 pp4 #bh1 #c ,taf47 ---- ,physiologische ,studien ber die ,samenflssigkeit4 7,zeitschr4 f4 wissens4 ,zool41 vii1 #ahef1 pp4 #bja-bgb1 #a ,taf47 ,yersin1 ,a4 ,observations sur le ,gryllus campestris4 7,bull4 ,soc4 ,vaudoise sc4 nat41 #ahec1 iii1 pp4 #abh47 ,lesps1 ,ch4 ,mmoire sur les spermatophores des grillons4 7,ann4 ,sc4 nat41 ,sr4 #d1 iii1 #ahee1 pp4 #cff-cgg1 #a ,pl42 iv1 pp4 #bdd-bdi1 #a ,pl47 ,landois1 ,h4 ,entwicklung der bschelfrmigen ,spermatozoiden bei den ,lepidopteren4 7,schultze's ,archiv f4 ,anat4 u4 ,physiol41 #ahff1 pp4 #ej-eh1 #a ,taf47 ,btschli1 ,o4 ,vorlaufige ,mitteilungen ber ,bau und ,entwicklung der ,samenfaden bei ,insekten und ,crustaceen4 7,zeitschr4 f4 wissens4 ,zool41 xxi1 #ahga1 pp4 #djb-dae47 ,btschli1 ,o4 ,nhere ,mitteilungen ber die ,entwicklung und den ,bau der ,samenfaden der ,insekten4 7,ibid41 xxi1 #ahga1 pp4 #ebf-ecd1 #b ,taf47 ,la ,vallette ,st4 ,george1 ,a4 ,v4 ,ueber die ,genese der ,samenkrper1 ,,iii4 ,mitteilung4 7,archiv f4 ,mikroscop4 ,anat41 #ahgd1 x1 pp4 #die-ejd1 #a ,taf47 ---- ,spermatologische ,beitrage3 ,,ii4 ,mitteilung 7,ibid41 #ahhf1 xxvii1 pp4 #a-abb ,taf474 ,,iv4 ,mitteilung 7,ibid41 #ahhf1 xxviii1 pp4 #a-ac1 #d ,taf47 ,v4 ,mitteilung 7,ibid41 #ahhg1 xxx1 pp4 #dbf-dcd1 #a ,taf47 ,schneider1 ,a4 ,das ,ei und seine ,befruchtung1 pp4 #hh1 #aj ,taf42 ,arthropoden1 pp4 #eg-fh und #gi4 ,taf4 #h-aj1 #ahhc4 ,wielowiejski1 ,h4 de4 ,observations sur la spermatognse des ,arthropodes4 7,archiv ,slav4 de ,biologie1 #ahhf1 ii1 pp4 #bh-cf47 ,ballowitz1 ,e4 ,zur ,lehre von der ,struktur der ,spermatozoen4 7,anat4 ,anzeiger1 i ,jahrg41 #ahhf1 pp4 #cfc-cgf47 ---- ,untersuchungen ber die ,struktur der ,spermatozoen1 zugleiche in ,beitrag zur ,lehre von feineren ,bau der kontraktilen ,elemente4 ,die ,spermatozoen der ,insekten4 ,i4 ,coleopteren4 7,zeitschr4 f4 wissensch4 ,zool41 #a1 #ahij1 pp4 #cag-djg1 #d ,taf47 ---- ,zu der ,mittheilung des ,herrn ,professor ,l4 ,auerbach in ,breslau ber merkwrdiger ,vorgnger am ,sperma von ,dytiscus marginalis4 7,anat4 ,anzeiger1 #ahic1 viii ,jahrg41 pp4 #eje-ejf47 ---- ,die ,doppelspermatozoen der ,dyticiden4 7,zeitschr4 f4 wissensch4 ,zool41 lxvi1 #ahie1 pp4 #deh-dii1 #e ,taf47 ,beauregard1 ,h4 ,note sur la spermatognse chez la cantharide4 7,compt4-rend4 ,soc4 ,biol41 ,paris1 #ahhh1 iv1 pp4 #cca-ccc47 ,gilson1 ,g4 tude compare de la spermatognse chez les ,arthropodes1 in ,la ,cellule1 ,recueil de ,cytologie et d',histologie gn41 i1 #ahhh1 #h ,pl4 ,verson1 ,e4 ,zur ,spermatogenesis4 7,zool4 ,anzeiger1 xii ,jahrg41 #ahhi1 pp4 #ajj-ajc1 ,fig47 ---- ,la spermatogenesi nel ,bombyx mori4 7,padova1 #ahhi1 #be pp4 und #c ,taf47 ---- ,zur spermatogenesis4 7,zool4 ,anzeiger1 xii1 #ahhi1 pp4 #ajj-ajc47 ---- ,zur spermatogenesis bei der ,seidenraupe4 7,zeitschr4 f4 wissens4 ,zool41 lviii1 #ahid1 pp4 #cjc-cac1 #a ,taf47 ,henking1 ,h4 ,ueber ,reductionsteilung der ,chromosomen in den ,samenzellen von ,insekten4 7,internat4 ,monatsschr4 f4 ,anat4 und ,phys41 #ahij1 vii1 pp4 #bdc-bdh47 ---- ,i4 ,untersuchungen ber die erste ,entwicklungsorgnge in der ,eiern der ,insekten4 ,,ii4 ,ueber ,spermatogenese und deren ,beziehung zur ,eientwickelung bei ,pyrrhocoris apterus4 7,zeits4 wissens4 ,zool41 xlix1 #ahij1 pp4 #ejc-efd2 li1 #ahia1 pp4 #fhe-gcf47 ,,iii4 ,specielles und ,allgemeines4 7,ibid41 #ahib1 liv1 pp4 #a-bgd1 #ab ,taf47 ,sabatier1 ,a4 ,de la spermatognse chez les ,locustides4 7,comptes rend4 ,acad4 ,paris1 #ahij1 cxi1 p4 #gig47 ,cholodkowsky1 ,n4 ,zur ,frage ber die ,anfangsstadien der ,spermatogenese bei den ,insecten4 7,zool4 ,anzeiger1 #ahid1 pp4 #cjb-cjd47 ,see also ,zool4 ,anzeiger1 #ahib1 p4 #agi4 ,auerbach1 ,leopold4 ,ueber merkwrdige ,vorgnge am ,sperma von ,dytiscus marginalis4 7,sitz4 ,ber4 ,akad41 ,berlin1 #ahic1 pp4 #ahe-bjc1 #b ,figs47 ---- ,zu dem ,bemerkungen des ,herrn ,dr4 ,ballowitz betreffend das ,sperma von ,dytiscus marginalis4 7,anat4 ,anzeiger1 viii ,jahrg41 #ahic1 pp4 #fbg-fcj47 ,toyama1 ,k4 ,on the spermatogenesis of the silkworm4 7,bull1 ii1 ,no4 #c1 ,coll4 ,agric4 ,imp4 ,univ4 ,tokyo1 pp4 #abe-aeg1 #ahid1 #b ,pls47 ,wilcox1 ,e4 ,v4 ,spermatogenesis of ,caloptenus femur-rubrum and ,cicada tibicen4 7,bull4 ,mus4 ,comp4 ,zool41 xxvii1 #ahie1 pp4 #cb1 #e ,pls47 ---- ,further studies on the spermatogenesis of ,caloptenus femur-rubrum4 7,ibid41 xxix1 #ahif1 pp4 #aic-bjb1 #c ,pls47 ,wilson1 ,edmund ,b4 ,the cell in development and inheritance4 7,new ,york1 #ahif47 ,also the writings of ,platner1 ,waldeyer4 d4 ,on the paired genital efferent passages ,loew1 ,h4 ,abbildungen und ,bemerkungen zur ,anatomie einiger ,neuropterengattungen4 7,linna ,ent41 #ahdh1 pp4 #cde-che1 #f ,taf47 ,meinert1 ,f4 ,anatomia ,forficularum1 i1 ,kjbenhavn1 #ahfc1 #a ,pl4 ---- ,om dobbelte ,saedgange hos ,insecter4 7,naturhist4 ,tidsskrift1 #c ,raekke1 v1 #ahfh1 pp4 #bgh-bid47 ,palmn1 ,j4 ,a4 ,zur vergleichenden ,anatomie der ,ausfhrungsgnge der ,sexualorgane bei den ,insekten4 7,morph4 ,jahrb41 ix1 #ahhc1 pp4 #afi-agf47 ---- ,ueber paarige ,ausfhrungsgnge der ,geschlechtsorgane bei ,insekten4 ,eine morphologische ,untersuchung4 ,helsingfors1 #ahhd1 pp4 #ajh und #e ,taf4 ,nusbaum1 ,j4 ,zur ,entwicklungsgeschichte der ,ausfhrungsgnge der ,sexualdrsen bei ,insekten4 7,kosmos1 ,lemberg1 #ahhd1 ix ,jahrg41 pp4 #bef-bff1 #cic-djh1 #dfb-dgd1 #b ,taf4 ,in ,polish with rsum in ,german47 ,spichardt1 ,c4 ,beitrag zur ,entwickelung der mnnlichen ,genitalien und ihrer ,ausfhrgnge bei ,lepidopteren4 7,verhandl4 d4 naturwiss4 ,vereins zu ,bonn1 #ahhf1 xliii ,jahrg41 pp4 #a-cd1 #a ,taf47 ,jackson1 ,w4 ,h4 ,studies in the morphology of the ,lepidoptera4 ,i4 7,zool4 ,anzeiger1 xii ,jahrg41 #ahhi1 pp4 #fbb-fbf47 7,see p4 #chi47 ,lowne1 ,b4 ,th4 ,on the structure and development of the ovaries and their appendages in the blow-fly 7,calliphora erythrocephala74 7,journ4 ,linn4 ,soc4 ,london1 #ahhi1 xx1 pp4 #dah-ddb1 #a ,pl47 ,see also ,meinert 7#ahig71 ,heymons 7#ahig74 ,,end ,,of ,,part ,i ,,part ,,ii4 ,,embryology ,,of ,,insects a4 ,the egg ,illustration3 ,,fig4 #dhb4--;,female ,dyticus1 laying eggs3 ,a1 ovipositor extended4 ,b1 egg of ,notonecta1 attached to stem of rush4 ,c1 egg of ,dyticus1 laid in excavation in rush4--,after ,rgimbart1 from ,miall4 ,insects as a rule arise from eggs which are laid in a great variety of situations1 those species which are viviparous being exceedingly few in number compared with the class as a whole4 ,it is noteworthy that ,leydig has found in the same ,aphis1 and even in the same ovary1 an egg-tube producing eggs1 while a neighboring tube was producing viviparous individuals4#gg ,the viviparous species are confined to certain ,may-flies1 the ,aphid1 ,diptera 7,sarcophaga1 ,tachinid1 strid1 and ,pupipara71 and to certain ,coleoptera 7,stylopid and some ,staphylinid74 ,the number of eggs laid varies from a very few1 as in the ,collembola and in the ,psocid1 or #ae or even less in certain fossorial wasps1 and from #bj to #ce in some locusts to many thousands in the social insects1 the honey-bee laying by estimate over #a1jjj1jjj eggs in the course of her life4 ,dr4 ,sharp thinks that from #ej to #ajj may perhaps be taken as an average number for one female to produce4 ,the eggs of insects with a complete metamorphosis are said by ,brauer to be smaller in proportion to the parent than those laid by ametabolous or heterometabolous insects4 ,in this respect the insects are paralleled by the birds1 the highest forms laying smaller eggs than the water birds1 ostrich1 ,apteryx1 etc4 ,illustration3 ,,fig4 #dhc4--;,eggs 7e7 of ,hydrobius 787 and their capsules1 from which the larva1 ,fig4 #deb1 hatched4--,emerton del4 ,the egg1 or ovum1 when laid is not always ripe or perfect1 but1 as in those of ants1 continues to grow after oviposition4 ,others are laid some time after the embryo has begun to form2 and in the flesh-flies the larva hatches before the egg is deposited4 ,illustration3 ,,fig4 #dhd4--;,egg-masses of ,chironomus3 ,a1 string of eggs of ,c4 dorsalis1 divided into sections to show both sides4 ,b1 twisted fibres which traverse the string of eggs4 ,c1 egg-mass of ,chironomus 7sp74 ,d1 egg-mass of a third species4 ,e1 part of ,d1 more highly magnified4 ,f1 developing eggs1 two stages4--,after ,miall4 ,insects as a rule instinctively lay their eggs near or upon objects destined to be the food of the larva2 those of caterpillars on leaves1 those of many flies on meat or carrion1 those of ,copris and other dung-beetles in dung1 those of aquatic insects in water1 while many oviposit in the earth or in plants 7,fig4 #dhb71 or in the bodies of animals destined to be the hosts of the parasitic larv4 ,as the eggs are preyed upon by mites and other animals1 the contrivances and modifications of the mode of egg-laying1 and the situations in which they are placed1 are almost endless4 ,many insects lay their eggs in a mass1 covered with a gummy substance2 or those laid in the water1 as the eggs of dragon-flies1 caddis-flies1 ,chironomus 7,fig4 #dhd71 etc41 are enveloped by a jelly-like mass4 ,illustration3 ,,fig4 #dhe4--;,egg-capsule of ,periplaneta americana3 a1 side2 b1 end view2 c1 natural size4--,after ,howard and ,marlatt1 ,bull4 #d1 ,div4 ,ent4 ,u4 ,s4 ,dept4 ,agr4 ,the otheca of the cockroach 7,fig4 #dhe7 is a solid1 dense case1 which1 after being carried about by the mother1 can be left without harm in the crevices of the floors of houses4 ,the otheca of ,mantis 7,fig4 #dhf7 is formed by a large mass of frothy matter1 which hardens and is attached to stems of plants4 ,illustration3 ,,fig4 #dhf4--;,egg-capsules of ,mantis carolina4--,after ,riley4 ,on the other hand1 the female 8walking-stick0 7,diapheromera femoratum7 drops her eggs1 says ,riley1 loosely upon the ground1 from whatever height she may happen to be1 and 8one hears a constant pattering1 not unlike drops of rain1 that results from the abundant dropping of these eggs1 which1 in places1 lay so thick among and under the dead leaves that they may be scraped up in great quantities40 7,report for #ahgi47 ,the eggs of the lace-winged flies are supported on pedicels1 above the reach of ovivorous mites4 ,the female ,chrysopa usually lays between #dj and #ej eggs4 ,in one case1 we observed that #ah egg-stalks were deposited1 but there were only nine well-formed eggs in the batch1 and nine eggless stalks1 some only half the usual height1 others with the knob of cement at the end to which the egg is ordinarily fastened4 ,the eggs are evidently stuck on to the end of the pedicel after the latter has been formed1 as1 in one instance1 an egg was glued to the stalk very much out of centre1 the insect's abdomen not having been aimed straight1 so to speak1 at the mass of cement4 ,illustration3 ,,fig4 #dhg4--;,eggs of ,chrysopa1 with larva and fly4 ,the eggs of ,rhodites are fixed to a long stalk thickened at the end2 those of ,inquilines and certain ,chalcids 7,leucospis gigas1 ,fig4 #dhi1 ,a7 are also stalked2 and the use of this stalk in the eggs of ,cynips 7,e7 is thought by ,adler to be respiratory1 while1 also1 he states that the egg-cavity communicates with the egg-stalk1 so that a part of the egg-contents can pass into the latter1 and this happens at the laying of each egg4 ,the egg of certain ichneumons 7,paniscus1 ,fig4 #dhh7 ends in a short stalk1 which is inserted in the skin of the caterpillar destined to serve as the host of the parasite1 the eggs1 as stated by ,de ,geer1 being retained more firmly in the integument by the stalk so swelling as to form two knobs 7,fig4 #dih1 c74 ,illustration3 ,,fig4 #dhh4--,young larva of ,paniscus in position of feeding on the skin of a caterpillar3 a1 the egg-shell4--,after ,newport1 from ,sharp4 ,certain ,homoptera also have stalked eggs1 as those of ,psylla pyricola 7,fig4 #dhi1 ,b71 those of ,aleyrodes citri 7,c1 a1 b71 and of an allied form1 ,aleurodicus cocois 7,d71 and those of ,corixa 7,fig4 #dic74 ,illustration3 ,,fig4 #dhi4--,stalked eggs3 ,a1 of a ,chalcid 7after ,fabre72 ,b1 of ,psylla 7after ,slingerland72 ,c1 of ,aleyrodes2 ,d1 of ,aleurodicus 7after ,riley and ,howard72 ,e1 of ,dryophanta scutellaris 7after ,adler74 ,illustration3 ,,fig4 #dij4--;,eggs of ox bot-fly1 enlarged4--,after ,riley4 ,reference should also be made to the eggs of lice1 which are oval and attached to the hairs of their host4 ,those of the ox bot-fly 7,hypoderma lineata7 are usually placed four to six together1 and fastened to a hair4 ,the lower portion of the egg is admirably adapted for clasping a hair4 8,it consists of two lobes1 forming a bulbous enlargement1 which is attached to the egg by a broad1 but rather thin1 neck1 so that1 when the latter is viewed sidewise1 it appears as a slender pedicel0 7,fig4 #dij1 a-d74 7,riley in ,insect ,life1 iv1 p4 #cjg47 ,the egg of another fly 7,drosophila ampelophila1 ,fig4 #dia7 bears a pair of long1 slender appendages near the anterior end4 8,the egg is inserted into the soft pulp of the decaying fruit2 these appendages leave the ovipositor last1 and are spread out upon the surface of the mass4 ,they1 in this way1 serve to keep the egg in place1 and thus insure the emergence of the larva into the open air instead of into the more or less fluid mass in which the egg is situated4 ,the larva issues from the egg just above the base of these appendages40 7,comstock47 ,illustration3 ,,fig4 #dia4--;,egg of ,drosophila4--,after ,comstock4 ,mode of deposition4--,the exact process of oviposition has been rarely observed1 or at least not observed in detail1 and further observations are much needed4 ,in the cockroach 7,phyllodromia71 ,wheeler has seen the eggs pass out of the oviduct and become arranged in the otheca1 in a way similar to that in the account published by ,kadyi on ,periplaneta4 ,illustration3 ,,fig4 #dib4--,rocky ,mountain locust 7aa7 depositing its eggs 7c72 d1 the earth partially removed1 showing 7e7 an egg-mass already in place1 and 7d7 one being placed2 f shows where such a mass has been covered over4 ,a1 oviposition2 j1 position of oviduct2 g1 egg-guide2 e1 egg4 ,b1 egg-mass of the same2 a1 from side1 b1 from beneath1 c1 from above4--,after ,riley4 8,when about to form the capsule1 the female ,blatta closes the genital armature1 and the two folds of the white membrane which lines the othecal cavity close vertically in the middle line4 ,then some of the contents of the colleterial glands are poured into the chamber1 and bathe the inner surface of the posterior wall4 ,the first egg glides down the vagina from the left ovary1 describes an arc1 still keeping its germarium-pole uppermost1 after having pressed the micropylar area against the mouth of the spermatheca1 passes to the right side of the back of the chamber1 and is placed perpendicularly two-thirds to the right of the longitudinal axis of the insect's body4 ,the next egg comes from the right ovary1 describes an arc to the opposite side of the body1 decussating with the path of the first egg1 and is placed completely on the left side of the median line4 ,the third egg comes from the left ovary1 and is made to lie completely on the right side of the median line2 and so the process continues1 the ovaries discharging the eggs alternately1 and each egg describing an arc to the opposite side of the capsule4 ,the othecal chamber soon becomes too small to contain all the constantly accumulating eggs1 so the anal armature opens and allows the end of the capsule to project4 ,a raised line1 the impression of the edges of the white membrane1 runs down the end of the capsule4 ,the last egg deposited comes from the right ovary1 and lies two-thirds on the left1 and one-third to the right1 of the median line4 ,as soon as the egg is laid1 a further discharge from the colleterial glands spreads over the vaginal or anterior wall of the cavity1 and becomes evenly continuous with the secretion which has before been spread over the back and the sides of the capsule by the white membrane4 8,the crista1 a cord-like ridge running the full length of the dorsal surface of the capsule1 is a thick-walled tube1 either half of which is formed by the edge of the side walls of the capsule split into two lamin4 ,the rhythmical clasping of the three pairs of palpi which guard the vaginal opening is registered in an exquisite pattern on the inner face of either half of the crista40#gh ,the mode of oviposition in the locust has been fully described by ,riley1 who states that the eggs pass down and out of the oviduct1 and 8guided by a little finger-like style0 7,fig4 #bih71 they pass in between the horny valves of the ovipositor1 and issue at their tips amid the mucous fluid which forms the egg-capsule 7,fig4 #dib74 ,vitality of eggs4--,it is well known that the eggs of phyllopod and other fresh-water ,crustacea have wonderful vitality1 withstanding extreme dryness for several years1 at least from two to ten4 ,such cases are unknown among insects4 ,it has been observed1 however1 by ,t4 ,w4 ,brigham1 and also by ,l4 ,trouvelot1 that the eggs of the walking-stick 7,diapheromera femorata7 for the most part hatch only after the interval of two years4#gi ,the eggs of ,bittacus are said by ,brauer to lie over unhatched for two years2 indeed1 the first condition of their hatching is a complete drying of the earth in which the eggs lie1 the second is a succeeding thorough wetting of the ground in spring4 ,appearance and structure of the ripe egg4--,the eggs of insects are on the whole rather large in proportion to the size of the parent1 especially so in many minute forms1 as the fleas1 lice1 etc4 ,their general shape is spherical or oval1 often cylindrical2 where the eggs are long and cylindrical a dorsal and ventral side can be distinguished 7,fig4 #ejb74 ,they are in the ,tortricid and ,limacodid moths flattened1 thin1 and scale-like4 ,in the eggs of locusts and grasshoppers1 as well as certain ,diptera1 the ventral side of the embryo corresponds to the convex side1 and the concave side of the egg to the dorsal region of the embryo 7,figs4 #ejb and #dic74 ,there is an anterior and posterior end or pole1 the anterior end being that which in the body of the parent lies towards her head1 or towards the upper or distal end of the ovarian tube4 ,towards this end lies in the later stages of embryonic life the head-end of the embryo1 while the posterior end of the embryo is turned towards the hinder pole of the egg 7,figs4 #dic and #ebj74 ,the egg-shell and yolk-membrane4--,the ripe egg is protected by two membranes3 #a1 an inner or vitelline membrane or olemma 7dh7 7,fig4 #ejj1 d71 produced in the egg by a hardening of the outer layer1 and #b1 the outer or chorion 7c71 which is secreted by the cells of the ovarian follicle4 ,the latter is divided into two layers3 an inner1 the endochorion1 and an outer1 the exochorion4 ,illustration3 ,,fig4 #ejc4--;,fertilization of the egg of a round-worm 7,ascaris megalocephala73 ,a1 the ends 7centrosomes7 of the spindle formed4 ,b1 the spindle completed2 sp1 sperm-nucleus1 with its chromosomes2 ei1 egg-nucleus2 p1 polar bodies4--,after ,boveri1 from ,field's ,hertwig4 ,illustration3 ,,fig4 #dic4--;,eggs of ,corixa3 ,a1 early stage before formation of the embryo1 from one side4 ,b1 the same viewed in the plane of symmetry4 ,c1 the embryo in its final position2 a1 anterior1 p1 posterior1 end2 l1 left1 r1 right1 v1 ventral1 d1 dorsal1 aspect4 7,the letters refer to the final position of the embryo1 which is nearly diametrically opposite to that in which it first develops72 m1 micropyle2 p1 pedicle4--,after ,metschnikoff1 from ,wilson4 ,illustration3 ,,fig4 #did4--;,eggs of ,phasmid3 ,a1 ,lonchodes duivenbodi4 ,b1 ,platycrania edulis4 ,c1 ,haplopus grayi4 ,d1 ,phyllium siccifolium4--,after ,kaup1 from ,sharp4 ,while the yolk-membrane is usually a completely homogeneous1 thin1 structureless membrane1 the chorion or shell of the egg is usually covered with a network of ridges enclosing polygonal areas1 varying in shape according to the species or genus4 ,these external markings are due to the impress of the cellular structure of the epithelium of the ovarian follicle4 ,in the chorion of the cockroach the surface appears to be finely granular1 the finest granules being arranged in large1 more or less regularly hexagonal areas1 which are bounded by narrow1 dark spaces1 containing somewhat larger though less dense granules4 ,the surface of the eggs of certain ,phasmids are variously sculptured 7,fig4 #did74 ,the true structure of the chorion can only be1 as ,wheeler observes1 seen in cross-sections1 as shown by ,blochmann1 and also by ,wheeler4 ,the chorion consists of two chitinous lamin kept in close apposition by means of numerous minute trabecul or pillars4 ,it is the ends of these pillars that look like granules4 ,in the spaces between the hexagonal areas1 the trabecul are more scattered and individually thicker than those of the hexagons4 ,illustration3 ,,fig4 #die4--;,egg of cotton-worm moth1 ,aletia3 a1 top view1 showing the micropyle4--,after ,comstock4 ,illustration3 ,,fig4 #dif4--;,egg of ,danais archippus4--,after ,riley4 ,these markings are of singular beauty and complexity in the eggs of many ,lepidoptera1 whose ova are variously ribbed1 forming a beautiful fretwork of raised lines 7,figs4 #die and #dif71 while in the ,diptera and ,hymenoptera the chorion is less solid1 and usually smooth under low powers4 ,the exochorion of the egg of the house and meat fly 7,c4 vomitoria7 is pitted with elongated hexagonal depressions1 which cross the egg transversely4 ,that of the honey-bee is also divided into long hexagonal areas 7,fig4 #dig74 ,illustration3 ,,fig4 #dig4--;,egg with embryo of honey-bee1 #dj3 ch1 chorion2 ga1 ganglia2 s4 ga1 brain2 jm1 jaw-muscles forming2 c1 sophageal collar2 fb1 fore intestine2 mb1 mid-intestine2 ab1 hind-intestine4--,after ,cheshire4 ,illustration3 ,,fig4 #dih4--,micropyle 7,mk7 of eggs2 a1 of a fly1 ,antomyia2 b1 ,drosophila cellaris2 c1 stalked egg of ,paniscus testaceus4--,after ,leuckart1 from ,perrier4 ,when the eggs are deposited in exposed places1 and remain in such situations for several days1 or weeks1 or even through the winter1 the shell is either solid and strengthened by the ribs and ridges2 or the shell1 if of winter eggs1 is unornamented1 and is dense and solid1 to resist extremes in temperature or the attacks of egg-eating birds1 mites1 etc4 ,the micropyle4--,this is an opening or canal1 or1 as in most insects1 a group of canals situated at the anterior end of the egg for the entrance of the spermatozoa during the process of fertilization of the ovum 7,fig4 #dih74 ,in ,acrydians1 however1 the micropyle is situated at the posterior end of the egg4 ,the micropyle 7,fig4 #dii7 is a complicated apparatus within whose circumference the vitelline membrane appears to be firmly attached to the chorion1 so that the perforation passes through the chorion as well as the yolk-membrane4 ,the micropyles of the cockroach are probably as simple and generalized as in any insect4 ,wheeler states that they are in ,phyllodromia scattered over the end of the egg1 8over a quadrant of the upper hemisphere1 where the beautiful hexagonal pattern of the chorion gives away to an even trabeculation40 ,the micropyles are wide-mouthed1 very oblique1 funnel-shaped canals1 perforating the chorion1 the apertures of the funnels appearing under a low power as clear1 oval spots1 the long axis of which is parallel to the long axis of the egg4 ,illustration3 ,,fig4 #dii4--;a1 fragment of a micropylar papilla1 showing its lumen2 b1 optical section of another papilla1 in this one the lumen extends to the vitelline membrane1 but does not pass beyond it2 c1 d1 e1 and f1 papill of different forms4 ,a1 anterior end of an ovarian egg1 showing mode of growth of the micropylar papill3 a1 b1 two successive stages2 c1 surface view of modified papill from the lower edges of the cap2 d1 tunica propria of the ovariole2 e1 remnant of the cell-mass that secreted 787 the micropylar cap4--,after ,ayers4 ,illustration3 ,,fig4 #ejj4--;,egg of ,perla maxima3 c1 chorion2 d1 olemma2 gs1 glass-like covering of micropyle2 l1 cavity under same2 g1 canals penetrating chorion4--,after ,imhof1 from ,sharp4 8,with a higher power the tube of each funnel is clearly visible as a thin canal which dilates rapidly into the large oval aperture on the outer face of the chorion4 ,the narrow tube is sometimes fully as long as the large orifice4 ,the micropylar perforations are all directed from the germarium to the vaginal pole of the egg4 ,hence a line1 the hypothetical path of the spermatozon1 drawn through one of these oblique micropyles1 and continued into the egg1 would strike the equatorial plane4 ,the female pronucleus1 as we shall see further on1 moves in this plane40 7,wheeler1 p4 #bhi47 ,illustration3 ,,fig4 #eja4--,micropyles3 a1 of ,nepa cinerea2 b1 of ,locusta viridissima2 c1 of a bug 7,pyrrhocoris apterus74--,from ,gerstcker4 ,the micropylar region is generally1 at least in ,orthoptera and ,odonata1 covered by a gelatinous cap 7,figs4 #dii and #ejj1 gs71 which may form a covering membrane which extends over a large part of the egg1 or may envelop the entire outer surface4 ,in some cases micropyles are scattered over the entire surface of the egg1 but usually the perforation is situated at the end1 and is often guarded by raised processes1 either one or several1 like bristles1 or toadstools1 etc41 these being especially characteristic of the eggs of certain ,hemiptera 7,nepa1 ,fig4 #eja1 a1 and ,ranatra71 or the region is variously sculptured1 as in the eggs of butterflies4 ,in the micropylar apparatus of canthus the papill have a distinct lumen 7,fig4 #dii71 or a channel for the ingress of the male filament4 ,illustration3 ,,fig4 #ejb4--;,diagrammatic median section through egg of ,musca in stage of fertilization 7incorporating the figures of ,henking and ,blochmann73 ch1 chorion2 d1 dorsal2 v1 ventral side of the egg2 dh1 yolk-membrane2 do1 nutritive yolk2 g1 gelatinous cap over the micropyle 7m72 ,k1 outer layer of plasma 7,keimhautblastem72 p1 male and female pronucleus before copulation2 r1 directive body 7,richtungskrper74--,after ,korschelt and ,heider4 ,another use of the micropylar apparatus noticed by ,ayers in the egg of the tree-cricket is that it 8serves as a thick1 roughened plate1 against which the insect may push when ovipositing1 without injury to the egg1 and without danger that the ovipositor slips from its place40 ,in ,chrysopa eggs the micropyle forms a conspicuous button-like knob1 resembling the finely milled head of a certain kind of screw4 ,internal structure of the egg4--,the egg-contents are surrounded by an outer layer of protoplasm or formative yolk1 which is separate from the inner parts of the egg 7,fig4 #ejb1 do71 the latter being mostly composed of the nutritive yolk-element4 ,the superficial protoplasmic layer1 called by ,weismann ,keimhautblastem 7,k7 is1 in a few cases1 afterwards entirely lost1 but in most instances forms a very thin layer of clear protoplasm1 slight in extent compared with the yolk-mass within4 ,the eggs of insects are rich in yolk1 only certain eggs1 such as those of the ,aphides and the egg parasites 7,proctotrypid7 being poor in yolk4 ,the eggs of heterometabolous insects have been said by ,brauer to contain relatively more yolk than those of the ,metabola1 particularly the ,diptera2 though1 as ,wheeler observes1 this rule has some exceptions1 the eggs of the #ag-year ,cicada being very numerous and small4 ,this he thinks is a greater advantage to the insect than the production of a few large eggs1 8when we consider the extremely long period of larval life and the vicissitudes to which the larv may be subjected during all this time40 8,similarly1 ,melo angusticollis produces a large number of very small eggs1 while the eggs of the smaller beetles 7,doryphora1 e4g47 are much larger4 ,but ,melo is a parasitic form1 and probably only a few of its many offspring ever succeed in gaining access to the egg of the bee40 ,in the eggs of ,chrysopa the yolk-granules are remarkably small1 so that the primitive band is in strong contrast to the yolk in color and density4 ,when crushed1 the yolk does not flow out as a liquid1 but in a pasty mass1 and we have questioned whether1 as in the eggs of ,limulus1 whose yolk is solid with fine granules1 the denseness of the yolk is not connected in the way of cause and effect with their exposed situation4 ,the central or yolk-mass 7,fig4 #ejb1 do7 consists chiefly of rounded masses of yolk1 with fat-globules1 between which extends a fine network of protoplasm4 ,the elements of the yolk are spherical and strongly refractive1 by pressure becoming polygonal structureless homogeneous bodies4 ,the germinal vesicle of the ripe insect-egg lies in the centre of the yolk1 where it appears as a large vesicle-like cell-nucleus containing a few chromatin elements4 b4 ,maturation or ripening of the egg ,before the eggs of animals can be fertilized1 they require in some observed cases1 and probably in animals in general1 to undergo a series of changes1 which1 as observed in the starfish1 etc41 consists in the replacement of the germinal vesicle by a very much smaller egg-nucleus1 and also at the same time the construction at one pole of the egg of the directive or polar bodies 7,fig4 #ejb1 r74 ,towards the end of the ripening process of the insect egg this vesicle1 according to ,blochmann1 passes to the dorsal surface of the egg1 and is transformed into the directive spindles 7,richtungspindel74 c4 ,fertilization of the egg ,the egg next requires the penetration and admission into the yolk-interior of a spermatozon4 ,this process is essentially in insects1 as in other animals1 the fusion of the sperm-nucleus with the nucleus of the egg4 ,under normal conditions but a single spermatozon is required for fertilization4 ,as shown by ,hertwig1 in the sea-urchin1 after the spermatozon has penetrated into the egg1 the head1 and the small rounded body1 called a centrosome1 can still be recognized1 but the tail becomes fused with the yolk of the egg4 ,in the protoplasm of the egg 7called cytoplasm7 the achromatic end of the sperm-nucleus gives rise to conspicuous rays1 like those observed in ordinary cell-division4 ,preceded by these rays1 the sperm-nucleus or male pronucleus 7,fig4 #ejb1 p7 moves towards the nucleus of the egg1 and finally fuses with it1 thus forming a new single nucleus4 ,this latter1 which is called 8the cleavage nucleus10 rapidly forms a nuclear or 8cleavage spindle0 7,fig4 #ejc74 ,this act gives an impulse to the cleavage of the egg1 which is the first step in the formation of the embryo4 ,all these changes have yet to be worked out in detail in insects by microscopic sections of the egg1 whose generally hard and opaque egg-shells present great obstacles to such work4 d4 ,division and formation of the blastoderm#hj ,in insects as in most other ,arthropoda the segmentation of the yolk is superficial and not total4 ,the ovum is centrolicithal1 i4e4 the yolk is concentrated at the centre of the egg1 and surrounded by a peripheral layer of transparent protoplasm 7the ,keimhautblastem74 ,illustration3 ,,fig4 #ejd4--;,formation of the blastoderm of ,pieris cratgi3 ,a1 longitudinal section through the egg1 with two masses of protoplasm in the yolk4 ,b1 a blastoderm-cell at the upper end4 ,c1 a later stage1 with more blastoderm-cells4--,after ,bobretsky4 ,the first step in segmentation is the movement of the first division-nucleus 7i4e4 that in the fertilized egg arising from the union of the sperm-nucleus with the female pronucleus7 towards the interior of the egg in order to multiply itself by the mode of indirect nuclear division 7,figs4 #ejd1 ,a1 and #ejg74 ,illustration3 ,,fig4 #eje4--;,embryology of the mole-cricket3 #a1 egg in which the amboid nuclei 7abc7 are moving toward the surface2 #b1 egg in which the nuclei 7abc7 have reached the surface1 and show an active nucleus-formation2 #c1 the blastoderm-cells have no nucleus1 and are placed at equal distances apart2 #d1 the blastoderm-cells now forming a continuous layer2 #e1 cross-section of the egg with blastodermic disk1 also showing the disposition of the endodermal cells2 #f1 cross-section of the blastodermic disk1 with the myoblast cells 7mb7 already formed2 #g1 cross-section through the thorax of the embryo1 the body-cavity extended into the limbs4 ,,lettering4 abc1 amboid blastodermic cells4 bc1 blastoderm-cells4 bl1 blastoderm4 en1 endodermal cells4 ,m1 cavity of the myoblast4 mb1 myoblast cells4 ,n1 nerve-furrow4 ,p1 primitive groove4 pd1 primitive disk4 ,illustration3 ,,fig4 #eje concluded4--,later stages in the embryology of the mole-cricket3 #h1 longitudinal section of the embryo2 the yolk-pyramids 7yp7 form a common inner yolk-mass 7y74 #i1 section through the heart2 ,h1 cavity of the heart2 the two halves of the heart-sinuses having united dorsally1 ventrally they are still open and are bounded by the walls of the mesenteron4 #aj1 cross-section of an embryo1 showing the blood-lacun separated on the back by the dorsal organ 7do72 the intestinal fasciated layer 7,darmfaserblatt7 has not completely enclosed the yolk4 #aa1 embryo completely segmented1 with the rudiments of the appendages1 labrum 7lab71 and nervous ganglia 7pc-ng74 #ab1 a more advanced embryo1 showing the stomodum 7st7 indicated as a frontal protuberance4 #ac1 section through the recently hatched larva1 showing the cells of the mesenteron or chyle-stomach1 and the cellular layer on the front surface1 also the proventriculus or crop4 ,,lettering4 ant1 antenna4 ar1 arterial sinus4 bl1 blastoderm4 bla1 abdominal vesicles4 cr1 proventriculus1 or crop4 dm1 ventral diaphragm4 do1 dorsal organ4 d pm1 dorsal diaphragm4 ent1 enteric layer4 f1 fat-body4 g1 ventral ganglion4 ,h1 ht1 heart4 l1 lacuna4 m1 mouth4 md1 mandible4 m4en1 mesenteron4 mx1 #ast maxilla4 mx1 labium1 or #b;d maxilla4 ml1 leaf-like portion of mesenteron4 oe1 sophagus4 pc1 procerebrum4 pm1 proctodum4 sg1 subsophageal ganglion4 sm1 stomodum4 tg1 thoracic ganglion4 vm1 ventral muscle4 y1 yolk4 yp1 yolk-pyramids4 ,i1 #ast pair of feet4 ,,ii1 #b;d pair of feet4 ,,iii1 #c;d pair of feet4 --,after ,korotneff4 ,the origin of numerous division-nuclei as the offspring of the first has been observed to take place in the eggs of those insects 7,aphides1 ,cecidomyia1 and ,cynips7 which have a slight amount of yolk4 ,yet in the large1 ordinary eggs of insects with an abundance of yolk there is no doubt1 say ,korschelt and ,heider1 that these numerous division-nuclei1 which soon after the process of oviposition are scattered within the egg between the yolk-spheres1 and are enveloped by a star-shaped protoplasmic layer1 and which constitute the formative elements of the blastoderm1--there is no doubt but that they have practically arisen through indirect nuclear division from the first division-nucleus4 ,the process of formation of the blastoderm in ordinary eggs with abundant yolk was first observed by ,bobretsky in the eggs of a moth 7,porthesia7 and ,pieris1 also by ,graber1 and more recently by ,blochmann in ,musca1 and by ,heider in ,hydrophilus4 ,in the earliest stage observed by ,bobretsky there first appear after fertilization a few 7the smallest number four7 cell-like1 minute amboid masses of protoplasm1 each with a distinct nucleus4 ,a few 7one at least7 of these bodies gradually pass out of the centre of the yolk to the surface of the egg 7,fig4 #ejd1 ,a1 n71 these becoming larger and rounder1 and from one or two of these nuclei 7,b1 bc7 the blastoderm originates 7,c1 bl74 ,those nuclei remaining in the yolk increase in number and afterwards become the nuclei of rounded masses of yolk-granules1 forming the so-called yolk-spheres which ,bobretsky regards as true cells4 ,to the few blastoderm cells situated on the upper end of the egg are added others which continue to pass from the yolk to the periphery1 and then the blastoderm spreads out farther and farther from the upper end of the egg until finally it covers or envelops the whole yolk4 ,this layer of cells is called the blastoderm4 ,as to the origin of the primitive amboid cells1 ,bobretsky is in doubt1 but is disposed to think that they are the result of the subdivision of the germinative vesicle or nucleus of the ovarian egg-cell4 ,in this connection may be quoted the observations of ,graber1 who states that an examination of the ovarian cell at an early period has revealed the presence1 in the centre of the yolk1 of a number of amboid cells1 which appear to have been formed by the division of the germinal vesicle4 ,these 8primary embryonic cells0 have a relatively large nucleus and a number of nucleoli4 ,several may be seen to unite with one another by means of their pseudopodia1 and they may also be observed to undergo division4 ,with this account may be compared the results obtained by ,korotneff in his work on the embryology of the mole-cricket 7,fig4 #eje74 ,illustration3 ,,fig4 #ejf4--;,four successive stages in the formation of the blastoderm of ,calliphora vomitoria 7the figures represent segments of cross-sections through the fly's egg73 ,a1 the nuclei of the division-cells have arranged themselves parallel with the outer surface of the egg4 ,b1 the division-cells fused with the 8keimhautblastem40 ,c1 the outer surface becomes furrowed by indentations2 all the nuclei of the blastoderm-cells in process of division4 ,d1 the blastoderm-cells form a high cylinder-epithelium3 b1 8keimhautblastem02 bz1 blastoderm-cells2 d1 nutritive yolk2 dz1 yolk-cell2 fz1 so-called division-cell2 i1 inner 8keimhautblastem40--,after ,blochmann1 from ,korschelt and ,heider4 ,the result of these and of later observations1 especially those of ,blochmann on ,musca1 and those of ,heider on ,hydrophilus1 show that the division-nuclei lie near the centre of the egg1 along the longitudinal axis 7,fig4 #ejg1 ,a74 ,each of these nuclei is enveloped by a star-shaped mass of protoplasm1 and on the whole resembles a wandering amboid cell4 ,these isolated masses of protoplasm are all connected by a fine network of rays1 which unite to form within the yolk a syncytium4 ,afterwards1 in the later stages1 these division-cells1 as they may be1 though somewhat incorrectly1 regarded1 move nearer the periphery and arrange themselves into a plane parallel with the surface 7,figs4 #ejf1 ,a1 #ejg1 ,b74 ,continuing to divide1 they reach the surface and fuse with the peripheral protoplasmic layer 7,figs4 #ejf1 ,b1 #ejg1 ,c74 ,then follows the division into single cell-territories 7,figs4 #ejf1 ,b1 #ejg1 ,c71 corresponding to the division-nuclei1 through the appearance of furrows which pass in from the outer surfaces of the egg into the interior and gradually penetrate the entire 8keimhautblastem40 ,in this way the surface of the egg is covered with an epithelium 7blastoderm74 ,in many insects the so-called inner 8keimhautblastem0 7,fig4 #ejf1 ,d1 i7 is formed by the separation of a layer of protoplasm which contains larger granules and are accumulated between the blastoderm and the upper surface of the central nutritive yolk-mass4 ,by the addition of this plasmic layer the cells of the blastoderm increase in height1 and now form a cubical or cylinder epithelium1 which continuously envelops the surface of the egg4 7,korschelt and ,heider47 e4 ,formation of the first rudiments of the embryo1 and of the embryonic membranes ,illustration3 ,,fig4 #ejg4--;,formation of the blastoderm in ,hydrophilus3 b1 completed blastoderm2 d1 yolk2 f1 so-called division-cells2 k1 8keimhautblastem02 z1 yolk-cells4--,after ,heider1 from ,korschelt and ,heider4 ,the embryo first arises as a whitish streak or band-like thickening on the ventral side of the egg1 and is variously called the 8primitive streak10 8primitive band10 8germinal band10 or 8embryonal streak40 ,in most cases the primitive band is divided at regular intervals by transverse furrows1 indicating the limits of what are to be the body segments4 ,cross-sections 7,fig4 #eji7 show that the band is composed of several layers1 i4e4 an outer layer 7ectoderm7 and an inner layer which comprises the endoderm and mesoderm1 and so long as these two layers are not sharply differentiated from one another1 this second layer may be called1 with ,kowalevsky1 8the inner lower layer1 or ento-mesoderm0 7,figs4 #ejh1 #eji1 ,b1 ,c1 u74 ,it is characteristic of insects1 only rarely occurring in other arthropods 7e4g4 the scorpion71 that the primitive streak is not situated on the surface of the egg1 but becomes overgrown by a folded structure 7,fig4 #ejh1 af7 rising from its edges1 the amnion-fold1 so that it appears somewhat depressed or sunken in under the upper surface of the yolk4 ,while the amnion-folds are extending from all sides over the primitive band1 there becomes formed under it1 by the invagination of the outer surface of the egg1 a cavity1 the amnion-cavity 7ah71 which1 when the amnion-fold has completely overgrown the primitive band and united together 7,fig4 #eji1 ,c71 appears completely closed from without4 ,illustration3 ,,fig4 #ejh4--,two schematic median sections through an insect-embryo to represent the development of the embryonal membranes4 ,in ,a the primitive streak is not wholly overgrown by the amnion-fold4 ,in ,b the amnion-folds have united with each other and completely overgrown the primitive streak3 a1 fore1 b1 hind1 egg-pole2 v1 ventral side2 d1 dorsal side2 af1 amnion-folds2 ah1 amnion-cavity2 am1 amnion2 do1 yolk2 ec1 ectoderm2 k1 head-end1 k1 hinder-end1 of the primitive streak2 s1 the part of the serosa arising from the amnion-fold2 s1 the part of the serosa arising from the unaltered blastoderm2 u1 lower layer4--,after ,korschelt and ,heider4 ,formation of the embryonic membranes4--,the amnion-folds finally completely overgrow the primitive band 7,fig4 #eji1 ,b and ,c71 and form the embryonal membranes4 ,the primitive band is seen after its completion to be overgrown by a double cellular epithelial membrane4 ,the outer of these two membranes1 that which arises from the outer leaf or layer of the amnion-fold1 is the serosa 7,figs4 #ejh1 ,b2 #eji1 ,c1 s2 #eaj74 ,this passes continuously into the unchanged part of the blastoderm1 which has no part in the formation of the primitive band and germ-layers1 and which covers the outer surface of the yolk4 ,thus the serosa1 which is usually held to include this portion also of the blastoderm1 forms a closed sac which covers the whole surface of the egg1 with one part extending over the surface of the yolk1 and the other over the primitive band 7,fig4 #eaj74 ,illustration3 ,,fig4 #eji4--;,diagrammatic cross-section through three successive stages of the primitive streak1 and growing embryonal membranes of insect-embryos4 ,a1 formation of the ventral plate and of the gastrula invagination 7g74 ,b1 upward growth of the amnion-folds 7af74 ,c1 complete overgrowth of the primitive band through the amnion-folds3 v1 ventral side2 d1 dorsal side2 af1 amnion-folds2 ah1 amnion-cavity2 am1 amnion2 bl1 blastoderm2 bp1 ventral plate2 do1 yolk2 ec1 ectoderm2 s1 serosa2 u1 under or inner layer4--,after ,korschelt and ,heider4 ,the inner of the two layers1 called the amnion 7,fig4 #eji1 am71 is more closely connected with the embryo4 ,the amnion and ectoderm of the primitive band together form a completely closed sac1 whose lumen forms the amniotic cavity4 ,originally connected with the serous membrane1 it splits off from the primitive band about the time the appendages begin to bud out1 and continues to closely envelop the body and appendages1 as seen in ,fig4 #eji4 ,both of these membranes are1 before the time of hatching1 either absorbed1 or1 as in ,lepidoptera1 retained4 ,the amnion is retained until after hatching in the locust1 etc4 ,in certain ,coleoptera the serosa is retained1 and the amnion is absorbed 7,fig4 #ecb71 while in ,chironomus and the ,trichoptera the serosa is absorbed1 and the amnion retained1 with the egg-shell or chorion4 ,hence we have eight layers in the winged insects#ha during embryonic life3 ,illustration3 ,,fig4 #eaj4--,surface view of fresh serosa from an canthus1 treated with acetic carmine2 the blastoderm completely formed1 #ejj3 p1 polar body2 rf1 radiating fibres2 nls1 nuclear substance2 nlm1 nuclear membrane4--,after ,ayers4 #a4 ,exochorion4 7,remains of the epithelium of the ovarian follicle47 #b4 ,chorion4 7,egg-shell or cuticle secreted in the ovarian follicle47 #c4 ,vitelline membrane4 7,primary egg-membrane4 ,yolk-skin or membrane47 #d4 ,serous or outer germ-membrane4 7,serosa47 #e4 ,amnion or inner germ-membrane4 ,derived from the blastoderm4 #f4 ,ectoderm4 #g4 ,mesoderm4 ,embryo4 #h4 ,endoderm4 ,in the embryo of ,xiphidium and ,orchelimum ,wheeler has found and described with much detail a membranous structure which he calls the indusium4 8,the organ10 he says1 8appears to have been retained by the ,locustid1 and completely lost by the embryos of other winged insects40 ,it arises in ,xiphidium1 as a simple circular thickening of the blastoderm1 between and a little in front of the procephalic lobes 7,figs4 #eaa1 #eab1 ,a-,e71 and afterwards spreads over nearly the whole surface of the egg1 leaving the poles uncovered1 as in ,fig4 #eac1 where it is divided into two further membranes1 the inner and outer indusium1 the former lying in contact with the amnion4 ,after this the serosa 8is excluded from taking any part in the development of the embryo2 both its position and function are now usurped by the inner indusium40 ,hence in an egg of the ,locustid ,wheeler distinguishes1 passing from within outward in a median transverse section of the egg1 the following envelopes3 #a4 ,the chorion4 #b4 ,the blastoderm-skin-like cuticle secreted by the serosa4 #c4 ,the serosa4 #d4 ,the outer indusium4 #e4 ,a layer of dark granular secretion 7probably some urate74 #f4 ,the cuticle secreted by the inner indusium4 #g4 ,the inner indusium4 #h4 ,the amnion4 ,while envelopes #a-g invest the whole egg2 layer #h1 the amnion1 covers only the embryo4 ,illustration3 ,,fig4 #eaa4--;,diagrams illustrating the movements and envelopes of the embryo of ,xiphidium3 ,a1 after the closure of the amnioserosal folds4 ,b1 during the embryo's passage to the dorsal surface4 ,c1 just after the straightening of the embryo on the dorsal surface2 ind1 indusium afterwards forming ind#a1 the inner1 and ind#b1 the outer indusium2 ch1 chorion2 sr1 serosa2 am1 amnion2 gb1 germ-band2 v1 yolk2 bl4 c1 blastoderm membrane4 ,wheeler further suggests that the so-called micropyle of the ,collembola 7,anurida71 which has been homologized with the 8dorsal organ0 of ,crustacea1 is a possible homologue of the indusium1 as also the 8primitive cumulus0 of spiders1 and the 8facette0 or 8cervical cross0 of ,pentastomids described by ,leuckart and also by ,stiles4 ,the gastrula stage4--,the primitive band invaginates so as to give the opportunity for the formation of the inner layer4 ,this invagination1 which at a certain stage is established along the whole length of the primitive band1 forms a median furrow and may be regarded as the gastrula-invagination of insects4 ,the lower 7inner7 layer thus arising afterwards spreads out under the entire primitive band 7,fig4 #eji1 ,b and ,c71 the edges of which become bordered by the growing amnion-fold4 7,korschelt and ,heider47 ,in certain forms the primitive band arises from several separate rudiments which afterwards unite4 ,thus in ,musca and ,hydrophilus the anterior and posterior ends develop first1 and in ,hydrophilus the procephalic lobes originate independently of the rest of the band4 ,in the ,aphides1 also1 according to ,will1 these lobes arise independently1 afterwards uniting with the primitive band4 ,illustration3 ,,fig4 #eab4--;,diagrams illustrating the movements and envelopes of the embryo of ,xiphidium3 ,d1 the stage of the shortened embryo on the the dorsal yolk4 ,e1 embryo returning to the ventral surface4 ,f1 embryo nearly ready to hatch2 ch1 chorion2 b4 lc1 blastoderm membrane2 sr1 serosa2 ind#a1 outer indusium2 ind#b1 inner indusium2 ind#b am1 inner indusium and amnion fused2 am1 amnion2 ind#a c1 cuticle of the inner indusium2 ind#b s1 granular secretion of the inner indusium2 am4 s1 amniotic secretion2 v1 yolk2 cl1 columella2 gb1 primitive band4 ,division of the embryo or primitive band into body-segments4--,meanwhile the primitive band grows at the expense of the yolk1 spreading out more and more over its surface1 until in certain cases 7,coleoptera1 ,diptera1 ,siphonaptera1 and ,trichoptera7 it lies like a broad ribbon over the yolk1 so that the two ends nearly meet on the dorsal side4 ,by this time it becomes divided by transversely impressed lines into segments1 which correspond to those of the larva and adult4 ,the first of these segments is divided into two broad and flaring flaps1 which are called the procephalic lobes4 ,it becomes the antennal segment4 ,illustration3 ,,fig4 #eac4--,two stages in the spreading of the indusium4 ,a1 lateral view of egg just after the arrival of the embryo on the dorsal yolk4 ,b1 lateral view of the egg with the indusium nearly reaching the poles4 ,c1 same egg seen from the dorsal surface4 ,the mouth 7stomodum7 now develops1 and is situated at the anterior1#hb and the rectum 7proctodum17 at the posterior pole1 or end of the primitive band4 ,illustration3 ,,fig4 #ead4--,median section of the egg of ,anurida maritima3 do1 8micropyle02 bld1 blastoderm4--,this and ,figs4 #eaa-eac1 after ,wheeler4 ,in ,blatta1 ,hydrophilus1 the ,trichoptera1 and the ,lepidoptera the hindermost part of the primitive band is turned in ventrally 7,figs4 #ecd1 ,c74 ,the preceding account of the relations of the primitive band to the yolk does not apply to all insects1 since there are variations which appear to depend on the form of the egg1 and on the amount and distribution of the yolk-masses4 ,in certain ,coleoptera1 the primitive band sinks down and thus becomes immersed into the yolk4 ,in ,donacia 7,klliker and ,melnikow7 and ,hydrophilus 7,heider71 and in the ,chrysomelid and ,attelabus1 a weevil1 as we have observed1 the primitive band rests on the outside of the yolk1 but in ,telephorus fraxini it is immersed4 ,in the ,hemiptera it is immersed 7,fig4 #eaf71 but there is much variation in this respect1 the degree of immersion being most marked in the ,coccid 7,aspidiotus71 and least so in ,corixa4 ,besides the position of the primitive band1 there are in ,odonata and ,hemiptera differences in the origin of the primitive band itself and of the embryonic membranes4 ,illustration3 ,,fig4 #eae4--,ventral view of five developmental stages of ,hydrophilus3 a and b1 places at which the blastopore contracts2 af1 edge of the amnion-fold2 af1 caudal fold2 af1 paired head-fold of the amnion2 an1 antenna2 es1 last segment2 g1 pit-like invagination 7first indication of the amniotic cavity72 k1 head-lobes2 r1 furrow-like invagination2 s1 portion of the primitive streak covered by the amnion4--,after ,heider1 from ,lang4 ,illustration3 ,,fig4 #eaf4--;,embryo of the louse3 am1 serosa2 db1 amnion2 as1 antenna2 vk1 clypeus4--,after ,melnikow4 ,korschelt and ,heider divide the early embryo of insects into two types3 #a4 ,into those with a superficial primitive band2 viz41 where there is no passage of yolk-elements into the space between the amnion and serosa4 ,the primitive band has in such cases a relatively superficial position 7,figs4 #ejh1 #eji1 #eba1 #ece74 ,examples are certain ,orthoptera 7,blatta1 canthus1 ,mantis1 ,gryllotalpa71 also certain ,hemiptera 7,corixa71 certain ,coleoptera1 and the ,trichoptera1 ,diptera1 and ,hymenoptera4 #b4 ,into those with an immersed primitive band1 with the space between the serosa and amnion filled with yolk 7,figs4 #eag1 #eah1 #ecd74 ,examples are the orthopterous ,stenobothrus1 ,odonata1 many ,hemiptera 7the ,pediculina and ,pyrrhocoris71 the ,coleoptera already mentioned1 and ,lepidoptera4 ,it should be observed1 however1 that these differences are of little phylogenetic or taxonomic value1 since genera of the same order1 notably the ,coleoptera1 differ as to the position of the primitive band1 so also two orders so nearly allied as the ,trichoptera and ,lepidoptera4 ,differences between the invaginated and overgrown primitive band4--,in respect to the mode of origin of the primitive band and its relative position1 there are two opposite types1 though connected by transitional forms4 ,in the one case the primitive band1 i4e4 its ventral portion1 the 8ventral plate0 7,fig4 #eah1 b1 p7 is pushed in or invaginated in the interior of the egg2 in the other case it becomes overgrown by the folds of the amnion arising from its edges4 ,illustration3 ,,fig4 #eag4--,primitive streak of a lepidopter in cross-section3 ah1 amniotic cavity2 am1 amnion2 c1 clomic cavity2 do1 nutritive yolk1 divided into single nucleated masses2 ec1 ectoderm2 m1 mesoderm2 pr1 primitive thickenings of the ventral nervous cord2 s1 serosa4--,combined figure after those of ,brobretsky and ,hatschek1 from ,korschelt and ,heider4 ,illustration3 ,,fig4 #eah4--;,five diagrammatic median sections representing the growth of a dragon-fly 7,calopteryx74 ,a-,c1 development of the primitive streak 7k1 k7 by invagination4 ,d1 the amnion-fold 7af71 growing over the head-end of the primitive streak4 ,e1 closing of the opening of the amnion-cavity 7ah73 v1 ventral1 d1 dorsal side2 a1 fore1 b1 hind end of egg2 bl1 blastoderm2 bp1 ventral plate2 do1 yolk2 k1 head-end1 k1 caudal end1 of the primitive streak2 kh1 germinal thickening or initial point of invagination2 s1 serosa4--,after ,brandt1 from ,korschelt and ,heider4 ,in insects with an overgrown primitive band1 the band at the beginning is generally short and always situated on the ventral side of the egg1 with the head-end looking forward1 and remains in this position throughout embryonic life4 ,there is no revolution of the embryo4 ,the embryonal membranes arise through the formation of folds4 ,illustration3 ,,fig4 #eai4--,three embryonic stages of ,calopteryx3 am1 amnion2 g1 edge of the ventral plate2 ps1 germ of primitive band2 se1 serosa4--,after ,brandt1 from ,balfour4 ,illustration3 ,,fig4 #ebj4--,three farther stages of growth of ,calopteryx4 ,b and ,c show the inversion of the embryo3 a1 opening of the amniotic-cavity1 out of which the embryo emerges2 ab1 abdomen2 am1 amnion2 at1 antenna2 md1 mandible2 mx#a1 mx#b1 #ast and #b;d maxill2 1 sophagus2 p#a1 p#b1 p#c1 legs2 se1 serosa2 v1 anterior end of the primitive streak4--,after ,brandt1 from ,balfour4 ,in insects with an invaginated primitive band1 of which the ,odonata afford examples1 the first rudiment of the primitive band is in the form of a ventral plate of slight extent passing ventrally in the hinder half of the egg1 in whose posterior section a process of invagination 7,fig4 #eah1 ,a1 kh71 soon occurs4 ,the cavity of this invagination is the first indication of the amnion-cavity 7,fig4 #eah1 ,b1 ah71 while its wall in its thickened ventral part 7,k7 is concerned in the formation of the primitive band1 and1 in its dorsal thin part1 in the formation of the amnion 7,b1 ,c1 am74 ,revolution of the embryo where the primitive band is invaginated4--,at first the head-end of the embryo is directed towards the posterior end of the egg1 as in dragon-flies 7,fig4 #eah74 ,also that surface of the primitive band which afterwards faces the ventral1 is at first turned towards the dorsal side of the egg4 ,in order to bring the primitive band into the later relations1 there must occur the process of revolution1 or turning1 of the embryo4 ,the somewhat advanced embryo of the ,odonata1 after the appearance of the head and thoracic appendages1 undergoes a rotating motion around its transverse axis1 and at the same time turns out of the amniotic cavity 7,fig4 #ebj1 ,b74 ,this process is so managed that near the head-region1 the amnion and serosa1 there closely situated to each other1 are fused together1 and at this place tear or burst open4 ,through this rent 7a71 in the same place in which the original invagination-opening was situated1 the amniotic cavity again opens1 and through the opening thus formed first the head and then the succeeding segments of the primitive band 7,fig4 #ebj1 ,b7 pass out1 and remain there while the head passes on to the anterior pole of the egg on the ventral side1 the embryo thus assuming a position like that of other insects4 7,kowalevsky47 ,in the parasitic ,hemiptera 7,pediculina71 according to ,melnikow1 the opening in the membranes near the head remains permanent1 and the embryo becomes everted through it1 while the yolk1 enclosed in the continuous membrane formed by the amnion and serous membrane1 forms a yolk-sac on the dorsal surface4 ,the same process occurs in ,mallophaga1 and also in canthus1 as described by ,ayers 7,fig4 #eba74 ,generally as soon as the embryo passes out of the amniotic cavity the latter soon becomes smaller and finally completely disappears4 ,illustration3 ,,fig4 #eba4--,revolution of the embryo of canthus 7diagrammatic73 a1 fore1 b1 hind end of egg2 am1 amnion2 d1 dorsal1 v1 ventral side of egg2 k1 primitive streak2 r1 dorsal plate 7originating by the contraction of the serosa 7s774--,after ,ayers1 from ,korschelt and ,heider4 ,as the embryo grows1 and the sides grow up and the back closes over1 the contents of the yolk-sac are soon taken up and absorbed in the intestinal cavity1 which communicates with it4 ,in ,phyllodromia1 according to ,wheeler1 the process of revolution is 8hurried through by the embryo from the beginning of the #afth to the end of the #agth day40 ,several successive stages are represented in ,fig4 #ebb4 ,in the #aeth day the embryo still occupies the middle of the ventral surface of the egg4 ,soon the envelopes 7amnion and serosa1 as7 rupture1 an irregular slit being formed1 and soon the egg and embryo are as seen in ,fig4 #ebb1 ,b1 the embryo standing out free from its envelopes on the yolk1 and the edges of its dorsal growing walls 7b7 are distinctly marked4 ,the tail now lies at the caudal end of the egg 7,fig4 #ebb1 ,c74 ,by the #agth day the walls have closed in the median dorsal line1 and the embryo has grown in length to such an extent as to bring its head to the cephalic pole 7,fig4 #ebb1 ,e74 ,korschelt and ,heider consider1 since the primitive band of the chilopod myriopods 7,geophilus7 is curved in at the middle and sinks into the interior of the yolk1 that in insects the invaginated primitive band is the ancestral or primitive one1 the overgrown primitive band being derived from it4 ,the overgrown primitive band by its position may also be better insured against certain mechanical attacks1 perhaps also against the danger of drying up4 ,illustration3 ,,fig4 #ebb4--;,embryo of ,phyllodromia1 #ae days old2 revolution about to begin4 ,the stages in revolution are represented1 after the rupture of the amnion and serosa1 in ,a to ,e1 which are from embryos #af1 #af1 #af1 and #ag days old respectively3 as1 amnion and serosa2 s1 edge of serosa2 b1 dorsal growing body-wall2 d4o1 dorsal organ2 x1 clear zone covered with scattered amniotic nuclei4--,after ,wheeler4 f4 ,formation of the external form of the body ,origin of the body-segments4--,as we have seen1 the first traces of segments appear very early1 the primitive band being divided by superficial transverse furrows into segments4 ,this segmentation into arthromeres 7somites or metameres7 can be observed in ,hydrophilus and ,chalicodoma at a time when gastrulation begins 7,figs4 #eae1 #ecf74 ,the segmentation extends not only across the median portion of the primitive band1 through whose invagination the inner layer 7endomesoderm7 results1 but also to the lateral portions which become a part of the ectoderm of the primitive band4 ,these transverse furrows correspond to thinner places in the epithelium1 which in this stage forms the embryonal rudiment4 ,it thus happens that1 in the forms named1 after the end of gastrulation not only the ectoderm1 but also the endomesoderm1 is already segmented4 ,so early an appearance of segmentation as that observed in ,hydrophilus and ,chalicodoma we must regard as a falsification of the process of development due to heterochrony4 ,we must consider the conditions observed in other forms as the primitive ones1 in which 7as1 for example1 in ,lina and in ,stenobothrus1 according to ,graber7 the gastrulation and separation of the ectoderm occurs in the still unsegmented primitive band1 the division into segments occurring in later stages 7,fig4 #ebd74 ,in these forms1 then1 the segmentation affects the invaginated endomesoderm1 as well as the ectoderm4 7,korschelt and ,heider1 p4 #ghi47 ,illustration3 ,,fig4 #ebc4--;,diagrammatic cross-section through three successive stages of ,gryllotalpa1 showing the formation of the heart4 7,compare ,fig4 #eje47 ,the germs of the glandular intestinal layer 7darmdrsenblatt7 are omitted4 ,a1 earliest stage2 the primitive streak extends from 99x to y994 ,the embryonal membranes are torn and pressed against the back3 am1 edge of the rent2 rp1 dorsal plate 7serosa72 l1 lamella 7amnion turned up7 standing in connection with the ectoderm of the primitive streak4 ,b1 second stage2 the primitive streak has completely grown around the yolk2 the dorsal organ is absorbed4 ,c1 third stage1 dorsal portion2 the formation of the heart is finished3 am1 vestige of the amnion-fold2 bs1 blood-sinus2 dd1 rudiment of the dorsal diaphragm2 dv1 ventral diaphragm 7compare ,fig4 #eje72 do1 yolk2 dz1 yolk-cells2 ec1 ectoderm2 gr1 vascular groove 7rudiment of the heart72 l1 lamella of the upturned amnion2 lh1 definite body-cavity2 m1 transverse muscle2 n1 nervous cord2 r1 heart2 rp1 dorsal plate2 sp1 splanchnic2 so1 somatic layer of the mesoderm2 us1 primitive segmental cavity2 99x1 y991 lateral terminations of the primitive streak4--,after ,korotneff1 from ,korschelt and ,heider4 ,in the completely segmented primitive band may be distinguished two regions of a peculiar appearance 7,figs4 #eae1 #ebg71 one at the anterior1 and the other at the hinder end4 ,the anterior1 the primary head-section1 contains the mouth-opening1 and is characterized by its lateral expansions1 or procephalic lobes4 ,the other section1 or posterior section1 the so-called anal segment or telson1 contains the anus4 ,between the two sections lies the segmented primary trunk-segment1 which in insects consists of #ag segments4 ,of these the three most anterior are those destined to bear the mandibles and two pairs of maxill2 the three following are the thoracic1 which are succeeded by #aj abdominal segments1 besides the #aath or telson 7pygidium1 or suranal plate74 ,it is now generally believed that there are primarily eleven abdominal segments1 while ,heymons has detected twelve in the embryos of ,blattids and ,forficula 7see p4 #afb74 ,in the later stages of embryonic development the number of abdominal segments is diminished1 the #ajth and #aath abdominal segments becoming fused4 ,in ,hydrophilus and ,lina this is the case1 but according to ,graber1 in the ,lepidoptera there is a fusion of the #ith and #ajth abdominal segments1 the llth remaining free4 ,according to ,wheeler1 in ,doryphora1 and also in ,chalicodoma 7,carrire71 between the primary head-region and the mandibular segment is interpolated a rudimentary and transitory body-segment1 the premandibular segment4 ,according to ,carrire this segment corresponds to a rudimentary pair of limbs1 and also to a ganglion1 which participates in the formation of the sophageal commissure 7see p4 #ea74 ,illustration3 ,,fig4 #ebd4--,three embryonic stages of a leaf-beetle 7,lina73 ,a1 unsegmented primitive streak2 in ,b and ,c the segmentation becomes distinct on the lower layer 7u74 ,b1 with the germs of the gnathal segments 7k-k71 and in ,c the three thoracic segments 7t'-t71 with the first two abdominal segments 7a1 a73 bl1 blastopore2 kl1 head-lobes2 th1 extension of the primitive streak into the thoracic region4--,after ,graber1 from ,korschelt and ,heider4 ,the procephalic lobes4--,the head-lobes1 or procephalic lobes1 appear at a very early period 7,fig4 #ebd1 kl71 before any traces of the segments of the trunk region4 ,ayers has shown that in canthus the primitive band1 in its earliest condition and before the appearance of the head-lobes1 is a simple oval plate or almond-shaped thickening near the posterior end of the egg 7,fig4 #ebe1 #a1 #b74 ,this plate is 8soon divided into two tolerably well-marked regions by the enlargement of the head-end10 the first indication of the head-lobes 7#c74 ,a depression next forms in what is to be the middle of the forehead4 8,it indicates the position of the future labrum1 and forms the inner boundaries of the two cephalic ganglia1 which are developed on either side of this depression at a much later stage40 ,almost simultaneously with the appearance of this depression1 two lateral folds are formed in the trunk portion of the band1 which are the first indications of the maxillary and thoracic regions1 the abdominal portion not yet showing traces of a division into segments 7,fig4 #ebe1 #e74 ,the thickened outer edges of the head-fold next gradually grow in towards the median line 7,fig4 #ebe1 #e71 and bend forward towards the region of the future mouth4 ,the rounded angle made by the posterior end of the head-fold is the first indication of the antenn4 ,the embryo is now composed of four well-marked regions3 cephalic1 maxillary1 thoracic1 and abdominal4 ,the primitive band then grows much longer1 the primitive mouth and anus appear1 and the appendages bud out1 and eventually the embryo revolves and appears on the ventral side of the egg 7,fig4 #ebe1 #f74 ,illustration3 ,,fig4 #ebe4--;,early stages in the embryology of canthus niveus4 ,fig4 #a1 the youngest observed primitive band1 the serosa not yet formed2 #b1 longitudinal optic section 7diagrammatic7 of ,fig4 #a2 #c1 the primitive band after the appearance of the head-fold1 which is indicated at this time by the more rapid growth and consequent greater breadth of the lower end of embryo1 x #be2 #d1 a young embryo after the appearance of the primitive segment-folds1 x #ej2 #e1 a more advanced embryo1 with the antennal folds distinctly marked off2 the free ends of the primitive folds have united across the embryo posterior to the antennal folds1 x #ej2 #f1 ventral view of the embryo with the appendages budding out1 x #be 7the embryo in this stage lies dormant through the six colder months of the year73 am1 amnion2 m1 micropylar end2 ch1 chorion2 gb1 primitive band2 bf1 brain-fold2 yl1 yolk2 tf1 caudal fold2 kf1 head-fold 7procephalic lobe72 p4fd4t1 primitive thoracic fold2 p4fd4m1 primitive maxillary fold2 p4fd4a1 primitive abdominal fold2 ab4c1 abdominal constriction2 t4c1 thoracic constriction2 at4l1 antennal lobe2 ,m1 mesoderm2 h4g1 head groove2 mo1 mouth2 sk invagination of ectoderm to form head-apodeme2 md1 rudiment of mandible2 m#a1 #ast1 m#b1 #b;d maxilla2 ,t#a-,t#e1 legs3 ab4p1 #ast abdominal appendage2 ap1 other appendages2 tb1 caudal expansion2 mf median furrow2 ,b1 primitive unpaired organ 7metastomum74--,after ,ayers4 ,these primitive regions of the primitive band1 before the segments are formed1 are called by ,graber macrosomites1 and the secondary segments into which they divide 7which afterwards become the body-segments71 microsomites4 ,the macrosomites are peculiar to insects1 and may be an inheritance from a hypothetical ancestral form4 ,with ,korschelt and ,heider1 we should hardly share this view4 ,illustration3 ,,fig4 #ebf4--,older embryo of canthus with the appendages budded out1 those of the abdomen distinct3 abp1 first pair2 a4s1 anal stylet2 pr1 proctodum2 am1 amnion4--,after ,ayers4 ,our observations on locusts show clearly 7#a7 that the procephalic lobes are the pleural portion of the first cephalic or antennal segment2 7#b7 that the antenna is an appendage or outgrowth of the procephalic lobes2 7#c7 that the eyes are a specialized group of epidermal cells of the upper part of the procephalic lobes1 and are not homologues of the antenn or of the appendages in general2 and 7#d7 it seems to follow from a study of the relations and mode of development of the clypeus and labrum1 that they arise between the procephalic lobes1 and probably represent the tergal part of the antennal segment1 forming the roof of the mouth1 i4e4 closing in from above the pharynx4 ,in general the formation of the body-segments into the primitive band is in succession from before to the hinder end4 ,this successive appearance has been observed by ,graber in genera of different orders 7,stenobothrus1 ,lina1 and ,hylotoma74 ,for example1 in the beetle ,lina1 after the appearance of the mandibular and two maxillary segments1 appear the three thoracic segments1 together with the two anterior abdominal segments1 the other abdominal segments arising afterwards4 ,in other cases1 the formation of segments seems to be simultaneous along the entire length of the primitive band4 ,an exception to the rule has been noticed by ,heider in ,hydrophilus1 as in this beetle the development of the segments of the middle region appears somewhat delayed1 while the fore and hind parts of the primitive band are more rapid in development4 ,in ,pieris1 according to ,graber1 the thoracic segments are more rapidly developed than the others2 soon after1 the gnathic segments 7mandibles and two pairs of maxill7 appear1 and finally the abdominal segments are formed4 ,fore-intestine 7stomodum7 and hind-intestine 7proctodum71 ,labrum4--,the digestive canal of insects consists1 as in other animals1 of three portions1 the fore1 mid1 and hind gut or intestine4 ,the next change after the completion of the segments of the primitive band is the development of the fore and hind intestine and the appendages4 ,the fore-intestine 7stomodum7 arises as an invagination in the area of the primary head-section1 and the hind-intestine 7proctodum7 in the terminal section 7,figs4 #cjj and #edf74 ,in insects generally the formation of the fore-intestine occurs earlier than that of the hind-intestine4 ,an exception was discovered by ,graber and also by ,voeltzkow in ,muscid1 where the proctodum appears earlier4 ,illustration3 ,,fig4 #ebg4--,rudiments of the appendages of the embryo of ,hydrophilus3 an1 antenna2 md1 mandibles2 mx#a1 #ast1 mx#b1 #b;d maxilla2 vk1 clypeal region2 m1 mouth2 p#a-p#c1 legs2 p#d-p#i1 rudiments of abdominal appendages1 #a-i2 st1 stigma2 a1 anus4--,after ,heider1 from ,lang4 ,usually at the time of origin of the stomodum a projection arises at the anterior edge of the primary head-region1 the so-called forehead 7,fig4 #ebg1 vk71 which is the common rudiment of the clypeus and labrum4 ,in many cases 7certain ,coleoptera and ,lepidoptera7 these rudiments first assume the form of paired hooks 7see ,figs4 #hc1 #ajb1 #ajd1 #aje1 of ,graber's ,keimstreif der ,insekten1 also ,figs4 #ebi and #edf71 which afterwards1 by fusion in the median line1 become single1 though notched in the middle2 but in the more generalized ,blatta and ,mantis1 as well as in bees1 the rudiment is single at the outset4 ,the view advanced by ,patten1 and also by ,carrire1 that the labrum is a first pair of antenn1 is scarcely tenable1 and we quite agree with ,korschelt and ,heider in regarding the clypeo-labral region as homologous with the upper lip of ,crustacea1 and1 we may add1 of ,merostomes and of ,trilobites4 ,it should be observed that in many insects1 in their earlier embryonic state1 directly behind the mouth arises1 from paired rudiments1 what seem provisional lower lip structures 7not to be confounded with the #b;d maxill of insects74 ,this under lip structure was first discovered by ,btschli in the bee 7his inner or #b;d antenn71 and afterwards by ,tichomiroff in ,lepidoptera4 ,heider1 in his work on ,hydrophilus1 describes it as the 8lateral mouth-lips10 while1 more recently1 ,nusbaum has observed it in ,melo4 ,this under lip structure may be regarded as analogous to the paragnaths of ,crustacea1 although to attempt to homologize it with these seems useless4 7,korschelt and ,heider47 ,completion of the head4--,sufficient attention has not been paid to this subject by embryologists4 ,the head is at first1 dorsally1 mostly composed of the head-lobes1 or antennal segment only1 and the dorsal or tergal portion of the oral appendages develop at a later period4 ,we have observed in the embryo of dragon-flies 7schna7 that the tergites of the mandibles and first maxill are simultaneously fused with the head-lobes1 while the much larger tergal region of the #b;d maxill remains for some time separate from the anterior part of the head1 and is continuous with the thoracic segments1 and it is only just before hatching that this segment becomes fused with the rest of the head 7,fig4 #cf74 ,in a sense1 the #b;d maxillary segment when it is free from the head reminds us of the foot-jaw1 or #eth segment of chilopod myriopods 7see also p4 #ec74 g4 ,the appendages ,as we have seen1 nearly or quite simultaneously all the limbs as a rule bud out from each side of the median line of the primitive band4 ,they arise as saccular evaginations or outgrowths of the ectoderm1 directed a little backwards4 ,they are at first filled with mesoderm cells1 and in the ,orthoptera diverticula of the clom-sac are taken up into the rudimental limbs1 as in ,peripatus and ,myriopoda4 7,graber1 ,cholodkowsky47 ,as the antenn1 mouth-parts1 legs1 and abdominal appendages are all alike at first1 their strict homology with one another is thus demonstrated4 ,in insects never more than a single pair of limbs is known to arise from one segment4 ,the cephalic appendages4--,the antenn evidently arise from the hinder edge of the procephalic lobes 7,fig4 #ebg1 an74 ,as in ,limulus1 the first pair of appendages are at first postoral 7,fig4 #ebh1 at71 afterwards moving forward owing to changes in the relative proportions of the parts of the head1 and they are in all respects1 in their development and position in relation to the segment from which they arise1 homologous with the appendages succeeding them4 ,the occurrence of rudiments of a pair of preantennal appendages in ,chalicodoma which is claimed by ,carrire1 needs confirmation1 as other embryologists have not observed them4 ,the postoral appendages of the head are the mandibles and the #ast and #b;d maxill1 besides the supposed premandibular segment already referred to on pp4 #ej-ed1 which only temporarily exists4 ,the trophi or oral appendages are all alike at first1 but soon differ in shape1 acquiring their characteristic form shortly before the embryo leaves the egg4 ,the mandibles of canthus are said by ,ayers at the time of revolution of the embryo to be slightly bilobed1 and in his ,fig4 #e1 ,pl4 #ai1 they are represented as deeply trilobed1 but in general they are undivided4 ,the #ast maxill are at this time distinctly trilobed4 ,the #b;d maxill are separate1 and distinctly though unequally bilobed1 becoming united shortly before birth4 ,in the embryos of dragon-flies they are at an early date very large and long1 and directed backwards1 and are not fused together until just before hatching1 when the extraordinary mask-shaped labium is fully developed4 ,illustration3 ,,fig4 #ebh4--,two embryonic stages of the primitive streak of ,melolontha4 ,a1 younger stage1 with rudiments of eight pairs of abdominal appendages 7a#a-;a#h74 ,b1 older stage1 the primitive band now very broad3 a1 #ast abdominal appendage1 in ,b sac-like2 x1 place of adhesive disc2 g1 brain2 l1 clypeo-labrum2 s1 lateral cord of the ventral nervous cord2 other lettering as in previous figures4--,after ,graber1 from ,korschelt and ,heider4 ,the distal parts of the labium1 such as the ligula1 palpifer1 and palpus are elaborated before the mentum and submentum4 ,many details as to the final changes in the mouth-parts before hatching remain to be worked out4 ,the thoracic appendages4--,the three pairs of legs arise at the same period and in the same manner in all insects2 it is not until the end of embryonic life that they become jointed1 and that the claws and onychia are developed4 ,especial attention has not yet been given to the details of the development of the parts of the last joint of the tarsus4 ,in many forms the antenn are the first to appear1 the mandibles1 maxill1 and legs appearing at a latter date1 though simultaneously4 ,it is thus in ,stenobothrus1 ,hydrophilus1 and ,melolontha4 ,in ,lina1 according to ,graber1 the mandibles precede the antenn in appearance4 ,in the ,libellulid1 according to ,brandt1 the legs first appear1 then the jaws1 and lastly the antenn4 ,this did not seem to be the case in the embryos of schna observed by us1 although our observations were more superficial4 ,on the other hand1 in those insects whose larv are footless1 the rudiments of the legs are retarded and aborted just before hatching 7fossorial ,hymenoptera and ,apid71 or the rudiments of the legs are not developed at all4 ,the abdominal appendages4--,these appear soon after the thoracic limbs1 corresponding in most cases to the latter in shape and position1 and their position in the embryo is a matter of the greatest interest4 ,von ,rathke was the first embryologist to detect those of the first abdominal segment1 in his examination of the development of ,gryllotalpa4 ,long afterwards ,btschli detected them in the embryo of the honey-bee1 observing a pair on each segment4 ,patten observed them in ,trichoptera2 ,kowalevsky first perceived them in ,lepidoptera1 ,tichomiroff confirming his observations4 ,graber1 ,ayers1 and ,wheeler have observed them in ,orthoptera and ,coleoptera1 and the latter has detected them also in ,hemiptera and ,neuroptera2 and while they do not arise in the embryos of ,diptera and of ,siphonaptera1 they are to be looked for in any or all the lower or more generalized orders4 ,as the result of these discoveries of polypodous embryos occurring in all but the most specialized order 7,diptera71 it appears to be a rational deduction that the winged insects have descended from insects in which there were functional legs on each abdominal segment4 ,such an ancestor was the forerunner of the ,thysanura1 in which abdominal locomotive appendages still survive1 though in a modified1 more or less aborted condition4 ,this polypodous ancestral form was apparently allied to ,scolopendrella1 which has a pair of functional legs on each abdominal segment4 ,the subject1 then1 of polypodous embryo insects is one of special interest1 and has attracted much attention from ,graber1 ,wheeler1 ,haase1 and others4 ,that these are genuine1 though transitory appendages1 is shown by the fact that certain pairs persist throughout adult life4 ,the embryology of the ,thysanura when worked out will throw much light on this subject1 but we know that the spring 7elater7 of ,collembola 7and possibly the collophore7 and the cerci of the winged insects are survivals of these limbs4 ,that the three pairs of appendages forming the ovipositor1 or sting1 are most probably derived from these appendages is claimed by ,wheeler 7p4 #afg71 and seems proved by the fact that ,ganin and also ,bugnion has detected three pairs of imaginal disks in the embryo of parasitic ,hymenoptera4 ,hence the abdominal appendages may ultimately be found to arise in nearly all cases from imaginal disks like those giving origin to the cephalic and thoracic appendages4 ,as regards the ,diptera1 ,pratt has observed that each of the three thoracic and eight abdominal segments of the embryo brachycerous ,diptera 7seen especially well in ,melophagus7 has two pairs of imaginal disks1 a dorsal and a ventral pair4 ,he thinks there is no doubt but that the ventral abdominal disks are homologous with the rudimentary appendages which appear in the embryos of all other insects1 though not in the brachycerous dipters4 ,appendages of the first abdominal segment 7pleuropodia74--,as early as #ahdd ,rathke observed in the embryo of the mole-cricket a pair of appendages on the #ast abdominal segment1 which he described as mushroom-shaped bodies1 and supposed to be embryonic gills4 ,they are called pleuropodia by ,wheeler1 who1 with ,patten1 ,graber1 and ,nusbaum1 ascribes a glandular function to them1 while ,wheeler suggests that they were odoriferous repugnatorial organs4 ,in ,blatta 7,phyllodromia7 they are of large size1 in ,melolontha enormous 7,fig4 #ebh1 ,b7 and filled with blood4 ,wheeler distinguishes as varieties1 beside the mushroom-shaped appendages of ,gryllotalpa and ,hydrophilus1 the reniform 7canthus71 the broadly pyriform 7,blatta71 and the elongate pyriform 7,mantis carolina74 ,in the ,european ,mantis they are most limb-like1 with a digitiform continuation divided by a constriction into two sections4 7,graber47 ,in ,melo they assume the shape of a stalked cup4 7,nusbaum47 ,in the bee and in ,lepidoptera the pleuropodia are not present1 though the temporary appendages on the succeeding segments appear2 ,carrire1 however1 found them on the two first abdominal segments of very young larv of the wall-bee 7,chalicodoma74 ,their cellular structure is peculiar1 and they are either formed by evagination or invagination1 those of the latter type being subspherical and solid4 ,those of the former type have a cavity communicating by means of a narrow duct through the peduncle with the body-cavity 7,blatta74 ,no trache1 nerves1 or muscles enter them1 though blood-corpuscles have been seen in the cavities4 8,in some species the pleuropodia produce a secretion from the ends of their enlarged cells4 ,this secretion may be a glairy albuminoid substance 7,cicada1 ,melo71 a granular mass 7,stenobothrus71 a bundle of threads 7,zaitha71 or a thick1 striated1 cuticula-like mass 7,acilius740 ,they attain their greatest size during the revolution of the embryo1 and they are 8mere rudiments of what were probably in remote ages much larger and more complex organs40 7,wheeler47 ,lameere has observed that in ,phyllodromia the first pair of abdominal appendages1 after becoming of considerable size1 undergo an enlargement at their free end1 become detached1 and fall into the amnion4 ,wheeler also calls attention to the homology of these pleuropodia with the #ast abdominal appendages of ,campodea1 shown by ,haase to be originally glandular1 but with at present a respiratory function4 ,in the embryos of later1 higher orders of insects1 these appendages are in size and shape similar to those of the succeeding segments4 7,see also p4 #afd47 ,illustration3 ,,fig4 #ebi4--,primitive band of ,bombyx mori1 showing the temporary legs on abdominal segments #b-aa3 ,a1 early stage1 in which the abdominal legs al#b-;al#aj appear4 ,b1 later stage1 when they are very faint and all except al#c-;al#f and al#aj are about to disappear4 ,c1 the persistent abdominal legs al#c-;al#f and al#aj2 st#b1 st#i1 the #b;d and #c;d pair of stigmata2 sgl1 silk duct4--,after ,tichomiroff4 ,are the abdominal legs of larval ,lepidoptera and phytophagous ,hymenoptera true limbs8--,the presence of these abdominal legs in the embryos of ,sphinx 7,kowalevsky71 of ,bombyx mori 7,tichomiroff71 and both ,bombyx mori and ,gastropacha quercifolia 7except those of the first segment71 as well as in ,hylotoma1 which has #aa pairs of such appendages1 has suggested that the prop or prolegs of caterpillars and saw-fly larv are survivals of these outgrowths1 and not secondary1 adaptive structures4 ,opinions on this point vary4 ,balfour1 and also1 more recently1 ,cholodkowsky1 hold that the prolegs are survivals of the embryonic appendages4 ,graber cautiously1 after a lengthy and interesting discussion1 says that the question cannot be1 in the present state of our knowledge1 solved4 ,he1 however1 seems inclined to believe that the prolegs are not merely secondary structures1 and that the rudiments of limbs may remain for a long time in a latent state before their final development4 ,korschelt and ,heider are disposed to regard the abdominal appendages of ,lepidoptera and ,hymenoptera as true limbs1 referring to ,balfour's statement that in the ,crustacea there are different examples of the loss and later appearance of limbs1 such as the loss of the mandibular palpi of the zoa of decapods1 and the loss in the zoa of appendages in the ,erichthus form of the ,squilla larva corresponding to the third pair of maxillipedes and first two pairs of legs of ,decapoda1 and which are afterwards reproduced2 similar cases occurring in the ,acarina4 ,in the wasps and bees also1 as is well known1 the imaginal disks of the thoracic appendages appear1 the legs themselves being suppressed in the larva 7the imaginal disk probably existing in an indifferent state71 to reappear in the pupa and imago4 ,it does not1 however1 necessarily follow that the numerous pairs of hooked ventral tubercles of certain dipterous larv 7,ephydra7 are true appendages4 ,it seems to us that it is a strong argument for the view that these prolegs are survivals of primitive limbs1 that from similar embryonic paired outgrowths on different segments arise the spring of ,podurans1 the anal cerci1 and three pairs of appendages forming the ovipositor1 and the anal legs of the ,corydalus larva1 as well as those of caddis-worms2 at least five abdominal segments throughout the class of insects as a whole bearing appendages in the adult4 ,on the other hand the view of ,haase1 that the prolegs of caterpillars are secondary1 adaptive characters1 is supported by the fact of the rapidity with which two pairs on the #c;d and #dth segments nearly disappear in the larv of certain ,noctuid 7,catocala1 etc471 a reduction evidently due to disuse4 ,the trache4--,the tracheal system arises as ectodermal invaginations on one side of the appendages1 appearing soon after the latter4 ,the earliest condition of the tracheal invagination is seen in section at ,fig4 #eci1 ,e1 tr2 as it deepens1 it sends off diverticula or tracheal branches1 while the narrow mouth of the invagination forms the stigma4 ,the cup-like cavities situated serially one behind the other1 and arising from the single tracheal invaginations1 become at the end or bottom of the cup elongated along the length of the body and fused together at their ends2 then the two longitudinal stems of the system arise1 by a breaking through at the place where the original invagination had become fused1 thus forming a continuous tube1 the lumina opening into each other4 7,btschli47 ,the cuticular tracheal intima is differentiated late in embryonic life4 ,the entrance of the air is accomplished in part before the embryo hatches1 the air being derived from the tissues and fluids of the body4 ,the farther development of the tracheal branches is due to the progressive formation of diverticula4 ,the branches thus arising are intercellular formations4 ,on the other hand1 the finest twigs are intercellular structures4 ,however1 as ,schaeffer states1 the differences between the two modes of formation are not important4 ,wheeler mentions the existence of 8two pairs of very indistinct tracheal openings in the #ajth and #aath somites0 of the abdomen of ,doryphora 7,fig4 #edf1 t#ai1 t#bj71 and ,heider believes that they exist in ,hydrophilus4 ,the tracheal invaginations as a rule begin to appear after the appendages commence to bud out4 ,an exception is met with in the bee 7,apis71 where the tracheal ingrowths are seen before the rudiments of the legs4 ,most of the tracheal invaginations appear simultaneously4 ,only rarely do we see an indication of their successive development from before backwards4 ,thus in ,hydrophilus1 ,graber observed that the mesothoracic stigmata appeared somewhat earlier than those of the other segments4 h4 ,nervous system ,the rudiments of the nervous and tracheal systems essentially contribute to the building up of the relief of the primitive band of insects4 ,the nervous system is the earliest to appear1 being indicated very early1 in fact before the appendages begin to grow out4 ,the first traces of the nervous system are two ridges extending along the primitive band1 the depression between them being called the primitive furrow4 ,at an early period the segmentation is observed in the primitive ridges1 while widened spaces 7the rudiments of the ventral ganglia7 alternate segmentally with the narrow places which are the incipient longitudinal commissures 7,fig4 #ebg1 ,a1 g74 ,the primitive ridges extend anteriorly into the head-lobes2 this part must be regarded as the rudiment of the sophageal commissure4 ,the rudiments of the brain are from their first appearance directly connected with the ventral chain of ganglia4#hc ,completion of the definite form of the body4--,this is accomplished by the growth of the primitive band around the yolk1 the band widening1 so that its edges behind the head extend up1 and finally meet on the back1 forming the back or tergum of the embryo1 thus enclosing the yolk 7,fig4 #ecj1 ,f74 ,the tergal wall of the head is due to the dorsal growth of the head-lobes1 and of the clypeo-labral region4 ,in the course of this process the anterior end of the primitive band becomes turned up dorsally1 forming a dorsal curve or bend4 ,by this bending up of the primitive band the forehead nearest the mouth forms a transverse ridge1 the labrum1 while the basal or earlier part of the forehead now is differentiated into the clypeus4 ,this clypeo-labral region likewise forms the roof or palatal region of the mouth4 ,the head-lobes cause by this dorsal growth a rotating motion which carries the rudimental antenn back over the mouth4 ,illustration3 ,,fig4 #ecj4--;,diagram of the formation of the dorsal organ in ,hydrophilus4 ,a1 cross-section through an egg1 whose primitive streak is still covered over by amnion 7a7 and serosa 7s74 ,b1 amnion and serosa are grown together in the middle line1 then separated and drawn back to form a fold on each side4 ,c1 by the contraction of the serosa 7s71which becomes converted into the dorsal plate1 the folds become drawn up dorsally4 ,d1 the contracted serosa becomes partly overgrown by the folds4 ,e1 the folds grow together to form the dorsal tube4 ,f1 the mid-gut has closed over dorsally and enclosed the dorsal tube 7s73 a1 amnion2 d1 yolk2 ec1 ectoderm2 h1 heart2 l1 body-cavity2 m1 rudiment of the mid-gut2 n1 nervous system2 s1 serosa 7in ,c and ,d dorsal plate1 in ,e and ,f1 dorsal tube72 tr1 the chief tracheal stem4--,after ,graber and ,kowalevsky1 from ,lang1 and ,korschelt and ,heider4 ,the gnathal or post-antennal segments at first bear but a small part in completing the tergal region of the head1 but shortly before hatching the mandibles and their muscles enlarge1 giving fulness to the upper and back part of the head4 i4 ,dorsal closure and involution of the embryonic membranes ,illustration3 ,,fig4 #eca4--,schematic figure of the formation of the dorsal tube by invagination of the dorsal plate 7transformed serosa72 following after stage ,fig4 #ebj1 ,c1 and ,fig4 #eba1 ,d2 am1 amnion 7now forming the provisional dorsal closure72 r1 dorsal tube1 whose cells are already breaking away4--,after ,korschelt and ,heider4 ,in most other ,arthropoda 7,crustacea1 ,arachnida1 ,myriopoda1 etc47 development goes on by the formation of a so-called primitive band1 but without the appearance of peculiar embryonic membranes4 ,the outer surface of the entire egg becomes1 then1 in part covered by the band-like embryonic germ1 and partly by a portion of the blastoderm which remains unchanged4 ,the dorsal region is formed by the widening and spreading of the primitive band over the greater part of the surface of the egg1 while the area of the unchanged section of the blastoderm continually becomes more restricted4 ,it is generally accepted that the latter is concerned in the dorsal closure1 because1 together with a histological transformation1 it becomes involved in the formation of the ectoderm of the primitive band4 ,a similar form of retrograde structure possibly occurs in the embryos of ,podurid1 in which a dorsal organ has been observed to develop in an early embryonic stage1 which bears some relation to the cuticula enveloping the embryo1 but whose significance is in general rather obscure4 ,in most insects the relations are more complicated1 since in such cases1 the amnion-folds rise on the edges of the primitive band and of the unchanged section of the blastoderm1 whose retrograde development is intimately connected with the closure of the back4 ,a very simple case of dorsal closure1 but which certainly is not a primitive one1 occurs in ,muscid and certain other ,diptera whose amnion-folds are developed in a rudimentary way4 ,in this case 7according to ,kowalevsky and ,graber71 the amnion-folds become smoothed out again4 ,amnion and serosa become then a simple epithelium1 which throughout corresponds to the unmodified type of blastoderm of ,crustacea1 ,arachnida1 and ,myriopoda1 and here seems to share in the formation of the back4 ,more complicated and very manifold relations of dorsal closure and involution of the embryonal membranes occur in other insects1 of which ,korschelt and ,heider distinguish four different types3 #a4 ,involution under the formation of a continuous dorsal amnion-serosa-sac 7,odonata74 #b4 ,involution with exclusively dorsal absorption of the amnion 7,doryphora74 #c4 ,involution with exclusively dorsal absorption of serosa and separation of the amnion 7,chironomus and ,trichoptera74 ,illustration3 ,,fig4 #ecb4--;,diagram of the formation of the dorsal walls in ,doryphora in cross-sections3 am1 amnion2 in ,b1 serving as a provisional dorsal closure1 in ,c1 about to break up2 k1 primitive band2 s1 serosa4--,after ,wheeler1 from ,korschelt and ,heider4 #d4 ,involution with separation of both embryonic membranes 7,lepidoptera and ,hymenoptera1 ,hylotoma74 ,illustration3 ,,fig4 #ecc4--;,involution of the embryonic membranes of ,chironomus3 am1 amnion2 r1 dorsal umbilicus2 s1 serosa1 which has withdrawn into the region of the dorsal umbilicus1 and in ,c has passed into the interior of the embryo4--,after ,graber1 from ,korschelt and ,heider4 ,the first type occurs in the most primitive order of winged insects4 ,the second type 7,coleoptera7 appears to be an independently inherited form of dorsal closure4 ,in the first type1 the formation of the amnion-serosa-sac is initiated by a rupture of the two fused embryonic membranes4 ,this rupture in the ventral middle line occurs in ,odonata only in the region of the head-section4 ,in the second type only the amnion1 in the third only the serosa are concerned in this rupture1 while in the fourth type both membranes remain intact until the slipping out of the larva4 7,korschelt and ,heider47 j4 ,formation of the germ-layers ,illustration3 ,,fig4 #ecd4--;,diagram showing the formation of the embryonic membranes in ,lepidoptera 7,a1 after ,kowalevsky1 ,b and ,c1 after ,tichomiroff73 k1 primitive band2 am1 amnion3 se1 serosa2 do1 yolk2 vd1 invagination of the fore-gut1 ed1 of the hind-gut2 m1 mouth2 an1 anus2 x1 dorsal umbilical passage4--,from ,korschelt and ,heider4 ,the older views on the structure of the layers of the primitive band of insects were thoroughly unsatisfactory4 ,btschli first found that in the bee1 by a kind of folding process1 an inner layer of the primitive band arose4 ,soon afterwards ,kowalevsky1 by the employment of section-cutting and thorough researches1 laid the foundation of a more exact knowledge of these layers4 ,he found that in ,hydrophilus a furrow extended along the whole length of the primitive band 7,fig4 #eae1 ,a1 ,b1 r71 which1 while invaginating or sinking in1 gave rise to the inner layer of the primitive band1 i4e4 the common rudiment of endoderm and mesoderm 7,fig4 #eci1 ,a-,c74 ,kowalevsky also found similar conditions in the honey-bee 7,apis71 ,lepidoptera1 and other forms4 ,the furrow above mentioned must be regarded as a very long gastrula invagination1 extending along the entire ventral side of the embryo1 and the edges of the furrow as a long-drawnout blastopore4 ,the tube arising in ,hydrophilus through the closing of the furrow we may regard as a primitive intestinal canal4 ,the first rudiment of the gastrula furrow appears in insects as two folds extending along both sides of the median line in the thickened ventral plate 7,fig4 #ecf1 f71 through whose formation a more median section of the ventral plate1 the so-called middle plate 7m71 becomes separated from the side plates 7s74 ,as the middle plate curves in and becomes overgrown by the folds forming the edges of the blastopore1 the gastrula-tube 7,fig4 #eci1 ,a1 r7 is formed1 and furnishes the rudiments of the lower 7inner7 layer4 ,the ectoderm1 then1 according to ,heider1 arises from the lateral plates of the primitive band4 ,the growth of the edges of the blastopore1 by which the closure of the gastrula-tube is effected1 takes place latest in the region of the most anterior part of the furrow 7,fig4 #eae1 ,b and ,c71 corresponding to that place in the primitive band in which the stomodum afterwards develops4 ,illustration3 ,,fig4 #ece4--,two embryonic stages of a saw-fly 7,hylotoma berberidis7 in schematic median section3 a#a-;a#aj1 #ast to #ajth abdominal segments2 bg1 ventral nervous cord2 og1 brain2 ol1 germ of labrum2 sp1 salivary gland2 ed1 hind-gut2 x1 x1 inner folds of amnion3 other letters as before4--,after ,graber1 from ,korschelt and ,heider4 ,illustration3 ,,fig4 #ecf4--;,gastrula stage of the wall-bee 7,chalicodoma71 so-called flask-shaped stage3 f1 folds which on each side border the middle plate 7edge of the blastopore72 m1 the partly segmented middle plate 7here rudiment of the mesoderm72 s1 the segmented lateral plate 7becoming afterwards the ectoderm of the primitive band72 ve1 fore1 he1 hinder entodermal rudiment4--,after ,carrire1 from ,korschelt and ,heider4 ,illustration3 ,fig4 #ecg4--,two successive stages in the gastrulation of ,apis4 ,cross-section through the primitive band3 b1 lower 7inner7 layer2 ec1 ectoderm4--,after ,grassi1 from ,korschelt and ,heider4 ,during the invagination of the middle plate and its transformation into the gastrula-tube a change takes place in its histological character 7,fig4 #eci1 ,a and ,b74 ,while it originally consists of a high cylinder epithelium1 which after farther changes becomes divided into several layers1 since the wedge-shaped single cells push themselves over each other1 the cells in later stages become more and more cubical or irregularly polygonal 7,fig4 #eci1 ,b71 and are irregularly arranged4 ,at the same time the gastrula-tube is compressed in a dorso-ventral direction4 ,while it in this way spreads out laterally under the side plates 7ectoderm71 its originally circular primitive lumen passes into the form of a horizontal fissure1 which in ,hydrophilus long remains as the boundary between the two layers of the inner 7or lower7 membrane4 7,korschelt and ,heider47 ,there are numerous variations of the process of gastrulation1 which are by ,korschelt and ,heider divided into three types1 as follows3-- #a4 ,through invagination and formation of a tube 7,fig4 #eci1 ,a1 ,hydrophilus1 ,musca1 ,pyrrhocoris1 etc474 #b4 ,by a lateral overgrowth 7,fig4 #ecg1 ,lepidoptera and ,hymenoptera74 #c4 ,by an inward growth of cells from a median furrow 7,aphides and ,trichoptera74 ,in ,doryphora and ,lina 7,fig4 #ebd7 the hinder end of the gastrula furrow is forked4 ,illustration3 ,,fig4 #ech4--;,diagrammatic sketch of the formation of the germinal layers in ,doryphora3 ,a1 view of upper surface4 ,b1 cross-section through the fore end of the primitive streak at the line a-a4 ,c1 section through the middle of the primitive streak corresponding to the line b-b4 ,d1 section through the hinder end of the primitive band corresponding to the line c-c3 bl1 blastopore2 ec1 ectoderm2 en1 anterior ,u-shaped2 en1 hinder ,u-shaped germ of the endoderm2 ms1 mesoderm4--,after ,wheeler1 from ,korschelt and ,heider4 ,the cellular layer arising from the gastrula invagination 7lower layer7 forms the common germ of the endoderm and mesoderm4 ,it has only recently become known how these two germ-layers of insects have become differentiated4 ,kowalevsky first discovered in ,musca that the greatest part of the lower 7inner7 layer yielded mesoderm exclusively1 and that a cell-mass only corresponding to the most anterior and posterior end of the primitive band was used in the formation of the endoderm4 ,we must therefore1 in insects1 speak of a fore and a hinder endodermal rudiment4 ,in proportion1 now1 as the ectodermal invaginations1 which are destined to form the stomodum and the proctodum sink beneath the surface of the embryo1 the cell-masses of which the two endodermal rudiments are composed are pushed farther in1 and a separation between them and the mesoderm is thus effected4 ,the two endodermal rudiments now form accumulations of cells which lie closely adjacent to the blind ends of the stomodeal and the proctodeal invaginations4 ,they soon widen out into two hour-glass-shaped rudiments1 which are directed with their concavities towards each other1 but with their convex side towards the nearest pole of the egg4 ,they soon change their form2 two lateral stripes grow out from them1 and each now assumes the form of a ,u 7,fig4 #ech1 en74 ,the limbs of the fore and hind ,u-shaped rudiment are directed toward each other1 and grow towards each other until they meet1 and are fused together4 ,thus the endodermal rudiments arising out of the fusion of the two ,u-shaped rudiments form two stripes extending along the primitive band and situated mostly under the primitive segments4 ,at the two ends the endodermal rudiment fuses with the stomodeal and proctodeal invaginations4 ,these lateral endodermal streaks now spread out1 and gradually begin to grow over the yolk1 on whose outer surface they lie4 ,this overgrowth makes the greater advance on the ventral side1 so that the two endodermal streaks first unite in the ventral median line and afterward in the dorsal4 ,the yolk in this way passes completely into the interior of the rudiment of the mid-intestine4 ,kowalevsky has already proved that it is the median parts only of the inner layer which at the two ends of the primitive band become separated as endodermal rudiments through the advance of the stomodeal and proctodeal invaginations3 the lateral portions become mesoderm4 ,kowalevsky has compared the germ-layers of insects with those of ,sagitta4 ,this comparison is supported by the later researches of ,heider and of ,wheeler on ,coleoptera4 7,see ,korschelt and ,heider1 p4 #hji47 ,relations somewhat different from the common type of formation of germ-layers occur in ,hymenoptera4 ,kowalevsky and also ,grassi agree that here also the endoderm originally forms a part of the lower 7inner7 layer4 ,but the separation of the endoderm from the mesoderm goes on in ,apis in such a way that the two ends of the inner layer pass up to the dorsal side of the egg1 where the fore and hind rudiments of the endoderm extending along the back of the embryo grow together4 ,when the two horseshoe-shaped rudiments have met each other and become fused1 the enclosing of the yolk begins1 which accordingly here proceeds from the dorsal towards the ventral side1 instead of vice versa4 ,as a result the endodermal cell-layer in ,apis 7and also ,chalicodoma7 at first does not lie under the primitive band1 but on the dorsal side of the egg under that flat epithelium1 which1 arising from the amnion-fold1 completes the provisional closure of the back4 ,the yolk-cells and secondary yolk-segmentation are discussed by ,korschelt and ,heider at this point4 ,the yolk-cells are elements scattered throughout the yolk and which partly remain in the yolk during the formation of the blastoderm 7,fig4 #ejg1 ,c and ,d71 but which in part through a later immigration pass out of the blastoderm into the yolk4 ,graber has proved the fact of the migration of cells from the lower layer into the yolk1 and his observations have been confirmed by other authors4 ,indeed1 in certain cases 7,melolontha71 these later immigrant cells are clearly distinguishable by their histological characters from those originally found in the yolk4 ,the yolk-cells are regularly scattered throughout the yolk4 ,their use to the embryo lies in the fact that they absorb the particles of yolk1 which they digest and thus reduce to a fluid condition4 ,it usually happens that after the complete formation of the primitive band there results a delimitation of the areas enclosing each yolk-cell1 and this occurrence is called secondary yolk-division4 ,in special cases 7,apis1 ,musca7 this occurrence seems not to take place4 ,the yolk-cells are still1 after the complete formation of the mid-intestine1 to be recognized in the yolk-remnants filling the interior of the same1 and gradually become absorbed4 k4 ,farther development of the mesoderm4 ,formation of the body-cavity ,we have seen that by means of an invagination extending throughout the entire length of the primitive band a layer of cells is produced which soon spreads out on the inner side of the band and thus forms a second lower 7inner7 layer 7,fig4 #eci1 ,c74 ,from this inner layer is separated at the anterior and posterior ends of the primitive band1 the endoderm1 which lies in direct contact with the invaginations of the proctodum and stomodum4 ,the remainder1 by far the most extensive part of the inner layer1 is the mesoderm4 ,the mesoderm now becomes divided into two lateral streaks 7mesodermal streaks71 by the withdrawal of its cells from the median line 7,fig4 #eci1 ,d74 ,this withdrawal is not1 however1 always a complete one4 ,in the free median space thus formed1 the yolk often forms the so-called median yolk-ridge4 ,segmentally arranged cavities soon appear in the lateral region of the mesoderm 7the primitive segmental cavities71 and the bordering mesoderm-cells arrange themselves in the form of an epithelium1 and constitute the wall of the primitive segments or clom-sac4 7,korschelt and ,heider74 ,the primitive segmental cavities in general arise through a split in the mesoderm4 ,in ,phyllodromia1 according to ,heymons1 the primitive segments are very extensive4 ,the mesoderm1 at the time of the formation of the rudiments of the appendages1 is raised with the ectoderm from the surface of the yolk1 and in this way there arise in each segment cavities1 which1 since they are surrounded by mesodermal elements1 become the closed clom-sacs 7,fig4 #edj1 c1 c1 c74 ,the clom-sacs differ in different groups4 ,they are largest in ,orthoptera 7,phyllodromia71 where they take up almost all the cell material of the mesoderm in their formation1 and exhibit certain conditions recalling those of ,peripatus4 ,the very large primitive segmental cavities1 which in ,orthoptera also extend into the rudiments of the appendages 7,fig4 #edj1 ,b1 ex71 in their later stages are1 through the formation of a constriction1 divided into a dorsal and a ventral half 7,fig4 #edj1 ,b1 c1 c74 ,the ventral portions of these cavities extending into the extremities soon disappear1 while the cells of their walls lose their epithelial nature1 and group themselves irregularly into a sort of mesenchym4 ,in this tissue1 then1 arises1 partly through a separation among its cells1 partly through the elevation of the same from the upper surface of the yolk1 the definite body-cavity4 ,the dorsal portions of the primitive segmental cavities remain unchanged a longer time in order to play a rle in the formation of the intestinal muscular layer1 of the heart1 pericardial septum1 and sexual organs4 ,illustration3 ,,fig4 #eci4--;,cross-section through the primitive streak of ,hydrophilus in six successive stages3 ,a1 gastrula-stage 7compare ,fig4 #eae1 ,a1 corresponding to the point a74 ,b1 cross-section through stage1 ,fig4 #eae1 ,d1 in the most anterior section of the primitive band1 where the same is not completely overgrown by the amnion-folds4 ,c1 cross-section through the trunk-segment of stage1 ,fig4 #eae1 ,e4 ,d1 ,e1 ,f1 cross-sections through later stages3 am1 amnion2 b1 lower 7inner7 layer2 d1 yolk2 dz1 yolk-cells2 ec1 ectoderm2 en1 entoderm2 l1 definite body-cavity2 pr1 primitive groove 7 neural groove72 pw1 primitive roll1 or strip1 of the ventral nerve-cord2 r1 blastopore2 sp1 fissure in the mesoderm 7remains of the cavity of the primitive intestine72 se1 serosa2 s1 lateral cord of the rudiment of the nervous cord2 spm1 splanchnic layer of the mesoderm2 tr1 rudiment of a trachea 7in ,e appearing as an invagination of the ectoderm7 in ,f in cross-section2 us1 primitive segment 7 clomic sac74--,after ,heider1 from ,lang4 ,illustration3 ,,fig4 #edj4--;,cross-sections through the abdominal part of three successive stages of evolution of ,phyllodromia germanica3 am1 amnion2 bg1 rudiment of the ventral nervous chord2 c1 clomic cavity2 c1 dorsal1 and c1 ventral1 section of the clomic sac2 cz1 cells of the walls of the primitive segment1 which are joined to the genital rudiments2 gz1 genital cells2 dw1 dorsal wall of the clomic sac2 d1 yolk2 ec1 ectoderm2 ep1 epithelium-cells2 ex1 rudiment of the abdominal appendages2 f1 germ of the fat-body2 lw1 lateral wall of the clomic sac2 m1 mesoderm cells1 which take no part in the formation of the clomic sac2 mw1 median wall of the clomic sac2 so1 somatic mesoderm layer2 vm1 ventral longitudinal muscle4--,after ,heymons1 from ,korschelt and ,heider4 ,in the highest groups of insects 7,coleoptera1 ,lepidoptera1 and ,hymenoptera7 the primitive segments are not so extensively developed 7,fig4 #eci1 ,d-,f1 us74 ,they here form only relatively small sacs situated in the lateral parts of the primitive band which correspond to the dorsal section of the clom-sacs of ,orthoptera4 ,the ventral part is here from the very outset replaced by a mesenchym4 ,as a result in these forms also no clomic diverticula occur in the rudiments of the extremities4 ,the definite body-cavity of insects arises entirely independent of the clom cavities1 and in fact1 as ,btschli showed1 through the separation of the primitive band from the yolk 7,fig4 #eci1 ,f1 l74 ,it appears bounded on the one hand by the surface of the yolk1 on the other side by the irregularly arranged mesenchym cells4 ,originally we can in cross-sections distinguish three separate cavities of the definite body-cavity 7in ,hydrophilus according to ,heider71 a median and two larger paired lateral ones which later fuse with each other and with wide lacun 7e4g4 in the appendages7 arising by the separation of the mesenchym cells4 ,we refer the compartments of the definite body-cavity1 as in ,peripatus1 to the primary body-cavity or segmentation-cavity4 ,they are only lacun in the area of the mesenchym1 and throughout bear the character of a pseudocl4 ,in later stages of embryonic development the clom-sacs and the definite body-cavity enter into communication with one another 7,fig4 #ebc1 ,a1 us1 lh74 7,korschelt and ,heider47 ,then the hinder clom-sacs unite through the degeneration of the transverse dissepiments which separate them4 ,after this a fissure opens in the median wall of the clomic sac1 through which its cavity unites with the definite body-cavity4 ,in the subsequent changes which the wall of the clom-sacs undergoes1 these can be recognised no longer as separate divisions of the whole body-cavity4 l4 ,formation of organs ,the nervous system4--,as we have already seen 7p4 #eed71 the rudiments of the ventral nervous cord arise1 after the gastrula invagination is completed1 as two ectodermal thickenings situated on each side of the median line1 the so-called primitive rolls or strips 7,fig4 #ebh1 s71 which extend from the centre of the procephalic lobes of the head to the last segment1 enclosing between them the single median 8primitive groove0 7,fig4 #eci1 ,c1 pr1 and pw74 ,soon after the appearance of the primitive strips1 the first traces of segmentation may be detected4 ,the ventral cord is from the first in direct connection and continuous with the brain4 ,from the segmental expansions of the primitive strip arise the ventral nervous ganglia1 and from the intersegmental constrictions are developed the paired longitudinal commissures4 ,transverse sections of the ectoderm in the region of the primitive strips 7,figs4 #eci1 ,c1 and #eag7 show several layers of cells4 ,of these cellular layers the deeper ones afterwards1 by a kind of delamination1 separate from the superficial ones and form the 8lateral cords10 i4e4 the germs of the longitudinal cords of the ventral ganglionic cord4 ,meanwhile the primitive groove 7pr7 deepens and forms an invagination extending between the lateral cords4 ,the cells at the bottom of this invagination form the so-called 8median cord10 and give rise to the transverse commissures connecting the ganglia4 ,illustration3 ,,fig4 #eda4--,transverse section through the rudiment of the ventral nervous cord of ,xiphidium3 f1 fibrous mass2 m1 neuroblast cells of the median cord2 n#a-n#d1 neuroblasts of the lateral cord2 z1 pillar of ganglion-cells arising from the neuroblasts4--,after ,wheeler4 ,wheeler has detected in the rudiment of the ventral cord of several ,orthoptera1 on the upper surface of the lateral cords1 four large cells which he calls neuroblasts 7,figure #eda1 n#a-n#d71 from which cells arise by budding and become arranged in vertically arranged layers or pillars 7z74 ,graber has observed them in ,stenobothrus and ,viallanes in ,mantis4 ,these neuroblasts are only present in the inter-ganglionic region1 and soon move back to the hinder side of the transverse commissures4 ,at first there is a pair of ganglia to each of the #af trunk-segments of the embryo1 but afterwards these become more or less fused together2 thus those of the three gnathal segments unite to form the subsophageal ganglion of the adult1 and the last abdominal ganglia are fused together and move a little anteriorly 7see also pp4 #bbg1 #bbh74 ,development of the brain4--,the suprasophageal ganglion is due to the spreading out of the procephalic lobes4 ,the rudiment of the brain is due to a thickening of the ectoderm on the sides of the mouth and of the forehead1 this expansion of germinal brain-cells being the direct continuation of the primitive rolls or strips1 and which finally becomes differentiated into the protocerebrum1 deutocerebrum1 and tritocerebrum1 as stated on p4 #bbh4 ,the ganglion opticum1 now regarded as a part of the compound eye1 arises as an ectodermal thickening on each side of the rudimentary brain4 ,the optic ganglion belongs exclusively to the foremost division of the brain 7see also p4 #bbg74 ,development of the eyes4--,compound eyes do not appear until the beginning of pupal life1 the single eye 7ocellus7 being the primitive organ of vision4 ,the ocellus of ,acilius1 according to ,patten1 arises as a pit or depression of the ectoderm 7,fig4 #edb74 ,the long hypodermal cells which form the walls of this pit or hollow are arranged in a single layer1 and bear at their free ends a striated cuticular edge 7c71 while from their inner or basal end arise the fibres destined to form the common optic nerve4 ,at a later stage 7,fig4 #edb1 ,b71 the eye-pit is closed over1 the edges growing over and covering the deeper part of the eye4 ,in this way there arises out of the pit-like rudiment a two-layered optic cup4 ,the outer or superficial layer 7l7 becomes in its central part the crystalline lens1 while the peripheral parts form the iris4 ,from the cuticular striated border of these cells arise the chitinous or corneal lens4 ,on its outer edge the superficial layer of the eye passes gradually into the unmodified hypodermis 7h74 ,illustration3 ,,fig4 #edb4--,two stages of development of the #eth of the six ocelli of larva of ,acilius3 c1 cuticular striated band2 cl1 germ destined to form the corneal lens2 h1 hypodermis2 l1 crystalline-lens layer2 n1 optic nerve2 r1 retinal germ2 sp1 vertical fissure of the retina2 x1 the retina-cells bordering this fissure4 ,illustration3 ,,fig4 #edc4--,two later stages of development of the same eye as in ,fig4 #edb3 i1 iris2 m1 middle inverted layer of the eye2 r1 retina2 sp1 vertical fissure of the retina2 st1 rods2 other letters as in ,fig4 #edb4--,this and ,fig4 #edb after ,patten1 from ,korschelt and ,heider4 ,the inner1 deeper layer of the eye1 which forms the contracted cup-shaped portion1 appears to be the rudimentary retina 7r74 ,from its cuticular rod-like or fibrous edge arise the visual rods4 ,there soon arise certain peculiarities characteristic of the eye of ,acilius1 i4e4 the fissure 7sp7 bordered by the horizontally situated rods of the large retina-cells 7x74 ,in the farther developed eye 7,fig4 #edc7 there is a flattening of the cup-shaped inner edge1 by which the bottom of the eye is levelled and the little rods belonging to it stand up vertically 7,fig4 #edc1 ,b1 st74 ,then the cells belonging to the edge of the retinal cup 7m7 are turned in1 forming an inverted layer constituting the germs of a third layer interpolated between the two chief layers of the eye4 7,korschelt and ,heider1 from ,patten47 ,patten concludes that the structure of the retina in the larval ocelli of insects is much like that of myriopods1 and that the whole eye is constructed on the same plan as that of ,peripatus and most molluscs4 ,intestinal canal and glands4--,the intestinal or digestive canal is primitively divided1 as already stated on p4 #bii1 into three sections1 of which the anterior and posterior are called respectively the stomodum and proctodum1 and are invaginations of the ectoderm1 forming sacs whose blind ends face the future site of the mid-intestine4 ,the fore-intestine 7stomodum7 in most cases arises earlier than the proctodum4 ,its muscles are derived from the mesoderm4 ,from the stomodum arises at an early date an unpaired dorsal invagination out of which develops the ganglion frontale and the pharyngeal nerve4 ,the absorption of the ends of the blind sacs of the fore and hind intestine1 and opening up of the passage into the mid-intestine1 occur rather early in embryonic life4 ,in the wasps and bees1 as well as the larva of the ant-lion1 the mid-intestine remains closed at the end1 not communicating with the proctodum1 which has an exclusively excretory function 7,fig4 #dig74 ,the mid-intestine arises from two originally separate rudiments1 i4e4 the fore and hind endodermal rudiments1 which at the outset stand in the most intimate relation with the invagination of the fore and hind intestine4 ,originating as a simple collection of cells1 so closely adjoining these invaginations that ,voeltzkow1 ,patten1 and ,graber derived them directly through outgrowths of them1 they become extended by advancing cell-multiplication until they assume a ,u-shaped form4 ,the legs of the ,u-shaped rudiment are in the anterior endodermal mass1 directed backwards2 those in the posterior mass1 on the other hand1 are directed anteriorly4 ,these legs grow towards each other until they become fused together1 forming two paired endodermal streaks1 which pass under the primitive band along its whole length1 and are fused with it at the fore and hind ends4 ,in these places they stand in intimate union with the proctodeal and stomodeal invaginations4 ,the paired endodermal streaks belong to the lateral portions of the primitive band4 ,as a rule1 they lie directly under the row of clom-sacs 7,fig4 #eci1 ,f74 ,the dorsal wall of the primitive segments stands consequently in intimate contact with the endodermal streaks4 ,on this wall of the primitive segments an active cell-growth takes place1 and the cell-material produced in this way1 which separates from the dorsal wall of the primitive segments1 forms the outer or splanchnic layer of the rudiment of the mid-intestine 7spm1 ,figs4 #eci1 ,f1 #edd1 sp74 ,what remains of the dorsal wall of the clom-sacs after this separation joins the genital rudiments and gives rise to the so-called terminal thread-plate 7,fig4 #edd1 ef74 ,the endodermal streaks1 with the splanchnic layer lying next to them1 may now be considered as the rudiments of the mid-intestine 7,fig4 #ecj1 m1 etc474 ,these are noticeable in the following stages by their considerable lateral growth2 they spread out over the upper surface of the yolk1 around which they finally entirely grow 7,figs4 #eci1 ,c-,f1 #edd1 #ede74 ,this growth around the yolk goes on in most cases in such a way as to unite the two mid-intestinal streaks in the region of the ventral median line with each other4 ,then afterwards their union on the dorsal side takes place 7,figs4 #eci1 ,f1 #ede74 ,the yolk thus passes completely into the interior of the mid-intestine1 and with it the remains of the dorsal tube or dorsal organ1 when such an one is present4 ,illustration3 ,,fig4 #edd4--;,cross-section through the abdominal region of a somewhat older primitive band of ,phyllodromia germanica3 bg1 rudiment of the nerve-cord2 c1 remains of the clomic cavity2 cz1 rudiment of the genital efferent passage2 ec1 ectoderm2 en1 endoderm2 ef1 terminal cord-plate2 fk1 fat-body tissue2 gz1 genital cells2 h1 rudiment of the heart2 p1 rudiment of the pericardial cavity2 ps1 rudiment of the pericardial septum2 so1 somatic mesoderm layer2 sp1 splanchnic mesoderm layer4 ,the salivary glands4--,these segmentally arranged glands1 which open by pairs into the three gnathal segments of the head1 arise as ectodermal invaginations originally opening not into the stomodum1 but outwards on the surface of the body2 hence ,korschelt and ,heider suggest that they were originally dermal glands1 whose mouths became drawn into the buccal cavity4 ,illustration3 ,,fig4 #ede4--;,cross-section through the abdominal region of an embryo of cockroach 7,p4 germanica7 after the yolk has been completely enclosed by the primitive band and the closure of the back2 s1 tracheal stigma2 other letters as in ,figs4 #edj1 #edd4--,this and ,fig4 #edd after ,heymons1 from ,korschelt and ,heider4 ,illustration3 ,,fig4 #edf4--;,embryo of ,doryphora shortly after the appearance of the appendages1 unrolled and isolated3 o1 stomodum2 lb1 labrum2 b#a-;b#c1 three brain segments2 og#a-og#c1 three segments of the optic ganglion2 op#a-op#c1 three segments of the optic plate2 f#a-;f#e1 five pairs of invaginations which form the tentorium1 etc42 t#g-t#bj1 tracheal invaginations2 the two last pairs 7t#ai-t#bj7 either disappear or form the openings of the sexual ducts2 at1 antenn2 md1 mandibles2 mx#a-mx#b1 maxill3 p#a-p#c1 legs2 c1 commissure connecting the two ganglionic thickenings 7g#d7 of the premandibular segment2 gl1 ganglia2 mst1 middlecord thickenings2 mpg#a-mpg#c1 rudiments of three pairs of urinary tubes2 a1 proctodum4--,after ,wheeler4 ,for their serial arrangement1 see p4 #ccg4 ,korschelt and ,heider state that they would be inclined to homologize the salivary glands of insects with those glands of myriopods opening into the mouth-cavity1 were it not that these glands in myriopods opening into the mouth are in reality transformed nephridia originating from the mesoderm1 while the salivary glands of insects are clearly ectodermal structures4 ,we must1 therefore1 they add1 leave to later researches the question of the homology of these organs1 also of their relations to the similar glands of ,peripatus4 ,illustration3 ,,fig4 #edg4--,section of proctodum of embryo locust1 showing origin of urinary tubes 7ur4t73 ep1 epithelial or glandular layer2 m1 cells of outer or muscular layer2 a1 section of a tube4 ,the urinary tubes4--,these excretory vessels arise as paired evaginations of the hind intestine or proctodum4 ,they are ectodermal structures arising as lateral diverticula of the intestinal cavity 7,fig4 #edf74 ,figure #edg represents their mode of origin at the anterior end of the proctodum of a locust4 ,it will be seen that there are #aj primary tubes4 ,there are #aej such tubes in locusts1 or #aj groups of #ae each4 ,the #ae secondary tubes probably arise from the primary ones in the manner described by ,hatschek for ,lepidoptera 7see his ,taf4 ,,iii1 ,fig4 #g74 ,while the ,malpighian tubes usually first arise as diverticula of the proctodum1 in the ,hymenoptera 7,apis and ,chalicodoma7 they appear1 even before the completion of the proctodum1 as invaginations of the ectoderm which at first open out on the outer surface of the primitive band4 ,they seem1 then1 in some degree1 to be similar to the tracheal rudiments1 which perhaps is the reason why they have been homologized with them1 a view which we do not share1 and in which ,carrire does not concur4 ,they afterwards pass1 with the growing proctodum1 into the interior of the embryo4 7,korschelt and ,heider47 ,the heart4--,the dorsal vessel is first indicated1 according to ,korotneff1 by a long string or row of cells 7cardioblasts71 which on each side border the mesodermal layer of the primitive band 7,figs4 #edd1 h1 #edh1 h74 ,in the advancing growth of the primitive band around the yolk1 this rudiment steadily passes up more towards the dorsal side4 ,it is in connection with the wall of the primitive segment 7,figs4 #edd and #edh71 and represents the point at which the dorsal wall of the clom-sac passes into the lateral wall4 ,according to ,korotneff1 the cardioblasts arise directly through a migration out from the wall of the primitive segment4 ,in ,gryllotalpa the formation of the dorsal organ1 which1 as ,korotneff states1 is in this insect nothing else than a stopper which fills up the dorsal gap of the body-wall of the embryo1 is effected by the rupture of the embryonal membranes4 ,the serosa is drawn together to form a thick plate 7,fig4 #ebc1 ,a1 rp71 and the much degenerated amnion-folds 7am7 which are laterally attached to it have moved from the edges of the primitive streak 799x-99y7 far towards the dorsal side 7see ,fig4 #eci1 ,c1 which represents a similar stage74 ,the distance between the rudiment of the amnion-fold and the lateral edge of the primitive band 799x1 99y7 is occupied by an epithelial lamella 7l71 in which we recognize the earlier amnion4 ,this lamella does not lie directly on the yolk1 but is separated from it by a spacious blood-lacuna 7,a1 bs71 in which can be seen numerous blood-corpuscles which have migrated in from the mesoderm of the primitive band4 ,the cardioblasts which have arisen from the wall of the primitive segment 7us7 are on each side arranged into the form of a furrow 7gr71 which bounds the blood sinus below4 ,illustration3 ,,fig4 #edh4--;,cross-section through the abdominal part of an older primitive band of ,p4 germanica when beginning to grow around the yolk3 vm1 ventral longitudinal muscle2 other lettering as in ,fig4 #ede4--;,after ,heymons1 from ,korschelt and ,heider4 ,by the continuous growth of the primitive band around the yolk1 after the resulting invagination and degeneration of the dorsal plate1 the two blood-lacun unite together on the dorsal side into a single one 7,b1 bs74 ,these constitute the first cavity of the heart4 ,the vascular furrows 7gr7 come in contact with each other and grow together1 and the wall of the heart is thus formed4 ,ayers states that in canthus the heart is formed in the head region only after the yolk-sac has passed entirely within the body4 ,the venous ostia arise by two paired invaginations of the lateral walls1 forming a split at their bottom4 ,the rudiment of the heart stands1 as we have seen1 in intimate union with the primitive segments4 ,out of the lateral walls of these segments1 after giving off the elements of the somatic mesoderm1 arises an epithelial plate which becomes the rudiment of the pericardial septum or dorsal diaphragm 7,figs4 #ebc1 ,a-,c1 dd1 #edd-ede1 ps74 ,as soon as the two halves of the rudiments of the heart have united with each other in the dorsal middle line1 the two halves of the pericardial septum unite with each other and form the wall to the pericardial cavity and shut it off from the rest of the body-cavity4 ,for a long time the pericardial septum remains in union with the wall of the heart4 ,afterwards1 however1 it separates from it 7,fig4 #ebc1 ,c1 dd74 7,korschelt and ,heider47 ,the statements of other authors 7,ayers1 ,grassi1 ,patten1 ,tichomeroff1 ,carrire1 ,heider1 ,heymons1 etc47 as to the mode of origin of the heart in insects of other orders are all similar to the type described in ,gryllotalpa4 ,the difference consists mostly in the fact that the two large blood-lacun are wanting or only exist to a slight extent4 ,it results that the rudiment of the cavity of the heart in the earlier stages is of slight extent and often scarcely recognizable4 ,in canthus 7,ayers7 and in ,gryllotalpa1 the hinder section of the heart is the first to develop1 the development advancing from behind forward4 ,the blood-corpuscles4--,blood-cells are said by ,korotneff to be1 in ,gryllotalpa1 at an early period present almost everywhere between the yolk and mesoderm2 they are derived1 as he states1 from the cells of the somatic mesoderm layer1 which has lost its connection with the other parts of the mesoderm1 and fall into the body-cavity4 ,ayers states that the blood-corpuscles arise from serosa nuclei which have passed into the body-cavity1 where they become more vesicular1 and ultimately all of the nuclear substance goes to form from one to three spherical bodies1 which are surrounded by the common membrane4 8,these bodies are blood-corpuscles and are free nucleoli immediately on the rupturing of the vesicle which surrounds them40 7,ayers1 ,pl4 #bb1 ,figs4 #a1 #c1 p4 #bej47 ,more recently1 ,schaeffer has observed in caterpillars certain cell-complexes associated with the fat-body which he has called blood-forming masses4 ,musculature1 connective tissue1 fat-body4--,the muscles of various parts of the body1 as well as the connective tissue1 arise by histological differentiation from the somatic layer of the mesoderm 7,fig4 #ebc1 so74 ,the fat-body originates from the same source1 as shown by the researches of ,kowalevsky1 ,grassi1 and of ,carrire4 ,in ,hydrophilus a dorsal band of the fat-body passes over the digestive canal arising by direct transformation of the wall of the clom-sacs4 ,but also the other portions of the fat-body1 as the fat-body lobes accompanying the tracheal system1 are of undoubted mesodermal origin4 ,heymons' observations on the cockroach 7,phyllodromia7 agree with the foregoing view4 ,in this insect at a very early period certain cells in the wall of the clom-sacs undergo a change1 and may be recognized as the rudiments of what are afterwards fat-body tissues 7,fig4 #edj1 ,b and ,c1 f74 ,the reproductive organs4--,our knowledge of the mode of development of the genital organs is in a less satisfactory state than that of the other organs4 ,it is now known that the rudiments of the sexual glands belong to the mesoderm1 and are developed from the wall of the clom-sacs4 ,in the cockroach 7,phyllodromia71 the most generalized of the winged insects1 as ,heymons has shown1 in the earlier stages of the embryo separate genital cells are already distinguished by their histologically different characters from the other mesodermal cells4 ,the genital cells are larger and show a feebly stained nucleus with a clear nucleolus4 ,these genital cells1 which are transformed normal mesodermal cells1 lie originally within the mesoderm layer or on the surface of this layer turned towards the yolk1 on the edge of the segments4 ,after the complete formation of the clom-sacs we find them 7,fig4 #edi1 gz7 in the dissepiments which separate the successive clom-sacs from one another4 ,here new genital cells are constantly formed through the transformation of mesoderm cells4 ,the development of the genital cells takes place in the #b;d to the #gth abdominal segments4 ,afterwards the genital cells pass into the interior of the clom-sacs1 and soon pass to the dorsal wall of the same 7,fig4 #edj1 ,a1 gz7 and enter between the cells of this wall4 ,the clom-sacs 7c7 show in cross-section in this stage a triangular outline1 so that we can distinguish a dorsal1 lateral1 and median wall4 ,the dorsal wall lies next to the surface of the yolk1 and afterwards gives rise by separation or splitting to the splanchnic mesoderm 7,fig4 #edd1 sp71 while from its remains the terminal thread-plate 7ef7 originates4 ,the lateral wall1 which is turned towards the ectoderm of the primitive band1 is intimately concerned in the formation of the somatic layer 7,fig4 #edj1 ,c1 so7 of the mesoderm4 ,out of what remains arises the pericardial septum 7,fig4 #edd1 ps74 ,when the genital cells have entered into the dorsal wall of the primitive segments1 they are already so numerous that they form a continuous series extending from before backward4 ,the genital rudiment consists1 then1 of a string of cells lying on each side in the dorsal wall of the primitive segments1 which extend from the #b;d to the #gth abdominal segments4 ,in the formation of these strings or rows of cells not only are the genital cells concerned1 but also still undifferentiated mesoderm cells 7,fig4 #edj1 ,b1 ,c71 which originate from the dorsal wall of the clom-sacs and lie next to the genital cells4 ,some of these last tend to envelop the genital cells4 ,we designate them the epithelial cells of the genital rudiments 7ep71 while others form a cellular cord which takes a position medial and ventral to the genital cells4 ,illustration3 ,,fig4 #edi4--,sagittal 7longitudinal7 section through the abdominal part of a primitive band of cockroach 7,phyllodromia germanica7 after the end of the formation of the primitive segments3 #a-g1 #ast to #gth abdominal segments2 from the #hth abdominal segment 7#h7 to the last segment 7es7 extends the inturned ventral part of the primitive band2 am1 amnion2 c1 clom-sac2 d1 yolk2 gz1 genital cells1 lying partly in the dissepiments1 partly in the wall or in the cavity of the primitive segments4 ,from the genital cells in the female arise only the egg-cells 7and the nutritive cells in those forms which have such74 ,the follicular epithelium of the egg-tube1 on the other hand1 also the corresponding cells of the terminal chamber1 originate from the epithelial cells4 ,phyllodromia and ,orthoptera in general1 to which this description applies1 show in this respect tolerably simple relations1 since the germinal or terminal compartment of the ovary in them is composed of relatively few cells4 ,in most other insects1 and especially those which have a great number of food-cells in the ovary1 the germinal chamber 7,keimfach7 is extraordinarily large4 ,the ventral cellular cord 7cz7 develops into the proximal part of the oviduct1 which widens out and receives the single egg-tubes4 ,the clom-sacs in the farther course of their development1 through the retrograde development of the parts extending into the appendages1 through the development of the fat-bodies and through the delamination of the somatic and the splanchnic mesoderm layer1 become greatly diminished in size4 ,finally1 there remains left of them only a rather small cavity 7c71 which is bordered on the side by the rudiment of the pericardial septum 7ps7 and within by the terminal thread-plate 7ef74 ,the dorsally situated point where these two lamell pass into each other seems to stand in intimate connection with the cells of the rudiment of the heart 7h74 ,the cord-like genital rudiment hangs from the terminal thread-plate as from a mesentery 7,fig4 #edi1 gz74 ,illustration3 ,,fig4 #eej4--,longitudinal section through the female genital rudiments of ,p4 germanica4 ,a1 with beginning1 ,b1 with farther advanced growth of the ovarian tubes3 cz1 rudiment of the genital efferent passage2 ef1 terminal threads2 ep1 nucleus of the epithelial cells2 gz1 genital cells4--,after ,heymons1 from ,korschelt and ,heider4 ,together with the growth of the primitive band around the yolk1 and the formation of the back1 the paired rudiments of the heart gradually extend to the neighborhood of the dorsal median line1 followed by the genital rudiments which are connected with them by the terminal thread-plates4 ,the genital rudiments advance thus to the dorsal side of the developing mid-intestine 7,fig4 #ede1 gz74 ,the terminal thread-plate 7ef7 is at first a simple epithelial plate4 ,soon1 however1 follows an arrangement of its cells whereby they appear to be arranged in vertical rows1 each one of which corresponds to a developing ovarian tube4 ,in this way the terminal thread-plate separates into the separate terminal threads of the ovarian tubes 7,fig4 #eej1 ef74 ,in this process of division the uppermost dorsal edge of the terminal thread-plate takes no part4 ,from it afterwards grows a thread which extends anteriorly1 which becomes the common terminal thread of all the ovarian tubes1 the so-called ,mller's thread4 ,this is originally united with the pericardial septum1 but seems in later stages to have no longer an intimate connection with it4 ,the formation of the single ovarian tubes1 which in ,phyllodromia number about #bj1 is accomplished by the extension of indentations from the dorsal side towards the ventral side of the ovarian rudiment 7,fig4 #eej74 ,at the same time the epithelial cells 7ep71 which were originally situated in part between the genital cells1 become arranged in the form of an epithelium on the surface of the ovarian tubes1 which soon forms on its outer surface a structureless cuticular tunica propria4 ,the outer peritoneal membrane of the ovary becomes formed of the cells of the surrounding tissue of the fat-body4 ,the genital rudiment originally extends1 as already stated1 from the #b;d to the #gth abdominal segment4 ,in the last1 however1 the genital cells at first occur only sparingly1 and afterwards completely disappear1 so that here the genital cord appears composed of epithelial cells only4 ,this part is the rudiment of the oviduct proper1 and forms a direct continuation of the above-mentioned cell-cord which is situated ventralward from the genital cells1 from which1 as we have seen1 the proximal cup-shaped section of the oviduct is formed4 ,the hinder section of the oviduct turns down ventrally in order to unite at the boundary between the #gth and #hth abdominal segments with the hypodermis4 ,the rudiment of the oviduct originally forms a solid strand of cells4 ,afterwards a cavity is formed by the separation of the cells4 ,in later stages there is a considerable shortening of the genital rudiment1 so that it occupies a smaller number of abdominal segments than at first4 ,at the same time the single ovarian tubes pass out of their originally vertical position into one more horizontal4 ,the paired connections of the rudiments of the oviducts with the hypodermis of the intersegmental furrow between the #gth and #hth abdominal segments reminds us of the conditions in the ,ephemerid4 ,this is the primitive condition in insects4 ,in the female of ,phyllodromia there is developed during larval life1 from an ectodermal invagination1 an unpaired terminal section of the genital passage1 which becomes the genital pouch in which the egg-case 7otheca7 is held4 ,this genital pouch is formed1 as ,haase has already proved1 by the withdrawal of the chitinous ventral plate of the #hth and #ith abdominal segment by invagination into the interior of the body4 ,the development of the efferent passages has been investigated by ,nusbaum in the cockroach 7,periplaneta7 and in the ,pediculina4 ,he found that only the vasa deferentia and the oviducts arise from the hinder cord of the germs of the sexual glands1 that is1 out of the mesodermal rudiments1 while the other parts of the sexual efferent apparatus 7uterus1 vagina1 receptaculum seminis1 ejaculatory duct1 penis1 and all the accessory glands7 develop from the integumental epithelium and are of ectodermal origin4 ,in fact1 the unpaired parts 7uterus1 penis1 receptaculum seminis1 unpaired glands7 have developed from paired rudiments1 being outgrowths of the hypodermis4 ,the hinder portions of the rudiments of the sexual glands approach these hypodermal growths and fuse with them4 ,through a median fusion of the paired hypodermal growths arise the germs of the unpaired organs4 ,these observations are in complete agreement with the results at which ,palmn arrived by anatomical investigation 7see p4 #dib74 ,from the agreement of the position of the sexual openings in ,phyllodromia with the conditions observed in the ,ephemerid1 with which the ,perlid also agree1 we conclude that in the entire group of insects an opening between the #gth and #hth abdominal segments is the primitive condition1 and that only by a secondary shifting has a more posterior position of the opening 7in many forms7 been brought about4 ,in this category we must certainly include the ,thysanura1 in which the sexual opening is single and situated between the #hth and #ith abdominal segments4 ,development of the male germinal glands4--,these rudiments arise in exactly the same manner as those of the female4 ,sexual differentiation takes place in the later embryonic stages4 ,we then notice that in the male four masses of genital cells become surrounded by epithelial cells4 ,these masses1 which form the germs of the four testicular follicles of ,phyllodromia1 stand in intimate union with the rudiment of the vas deferens1 and in the later stages move in connection with the latter1 away from and behind the original genital rudiment4 ,there remains1 then1 with the terminal thread-plate a remnant of the genital rudiment1 which1 according to ,heymons1 forms the female part of the original hermaphroditic genital rudiment1 and in special cases may develop even into rudimentary egg-tubes and eggs4 ,the rudimentary organ arising out of this genital rudiment may also be demonstrated in the adult male of ,phyllodromia4 ,in the female the oviduct arises directly out of the originally established efferent passage4 ,in the male1 on the contrary1 it is not1 along its whole length1 transformed into the vas deferens1 but its distal terminal portion degenerates and is replaced by a newly formed terminal portion of the vas deferens1 which then unites with the ectodermal ductus ejaculatorius4 7,korschelt and ,heider47 ,on reviewing the facts as to the origin of the sexual organs1 as in ,phyllodromia1#hd as just described1 it will be seen that they afford proof that in the derivation of the genital cells from the epithelial cells of the clom-sacs1 there is a direct agreement with the annelids4 ,in the later development of the paired genital glands1 and of an efferent passage standing in direct union with the glands themselves1 there is a certain agreement with the conditions in ,peripatus4 ,in the first place1 the dorsal position of the genital glands is the same in the two groups4 ,on the other hand1 the genital glands of ,peripatus1 according to ,sedgwick1 are formed by direct fusion of the successive clom-sacs 7and a similar point of view has been taken by ,heathcote for the myriopods71 hence it results that in ,peripatus the genital cavities arise out of the clom-cavities4 ,in the insects1 on the other hand1 the genital rudiment lies1 to be sure1 in the wall of the clom-sac1 but the genital cavity 7lumen of the oviducts7 in them arises separately from the clom-sacs1 while the clom-cavities finally become a small part of the definite body-cavity4 ,we must consider the conditions in ,peripatus and the myriopods as the more primitive1 directly pointing to the annelids2 on the other hand1 those of the insects as derived and secondary4 ,if we attempt to homologize the sexual efferent passages of insects with those of ,peripatus1 we are compelled to refer them to a modified pair of nephridia1 and the origin of the latter 7,peripatus7 from the mesoderm agrees with that of insects4 ,in general1 however1 in the development of the sexual outlets of insects1 there are no characters which can be regarded as favorable to such a view4 ,we must here accept the fact that the mode of development is secondary4 ,mention should be specially made of the fact we owe to ,heymons1 that in the genital rudiment of ,phyllodromia the genital cells and epithelial cells can be distinguished from each other from the very beginning4 ,this fact does not favor the generally accepted view that the follicle-cells and egg-cells arise through a later differentiation from one and the same kind of cell4 ,from their first origin1 indeed1 in ,phyllodromia1 both kinds of cells may be referred to the same source4 ,the mode of origin of the genital rudiments in ,diptera and ,aphides deserve special mention4 ,in these groups the sexual germs are present in very early stages of life4 ,this certainly in part is the result of the parthenogenetic and pdogenetic mode of reproduction in the two groups1 which leads to an early differentiation of the sexual germs4 ,in the ,diptera the first germs of the genital glands are represented by the polar cells 7,fig4 #eea1 pz74 ,in the asexual developing eggs of the oviparous ,cecidomyia larva1 before the formation of the blastoderm1 there separates from the hinder pole 7,d7 a rather large cell rich in granules1 which soon divides into two and afterwards four polar cells4 ,after the completion of the blastoderm these polar cells then pass in among the blastoderm cells 7,g7 and into the interior of the embryo1 where they are in later stages symmetrically arranged in two groups1 and1 enveloped by the cells of surrounding tissues1 transformed into the genital rudiments4 7,metschnikoff47 ,in ,chironomus 7,fig4 #eeb1 p71 according to ,balbiani1 two polar cells almost simultaneously separate from the hinder pole of the egg1 which1 by division1 form a group of four and eight cells4 ,exactly as in the case in ,cecidomyia1 these cells are taken within the embryo1 where they lie divided into two groups on each side of the proctodum4 ,in all the young1 freshly hatched larv2 these two spindle-shaped groups1 whose cells soon increase in number1 may be seen situated dorsally on the side of the heart1 enveloped by a clear cellular membrane which ends before and behind in a ligament-like terminal thread4 ,the anterior terminal thread is the rudiment of the so-called ,mller's thread4 ,the thread at the posterior end is the rudiment of the paired efferent passage of the genital glands4 ,through a division of the cells lying in the interior of the rudiments of the ovaries1 there results the formation of a rosette-shaped group of cells which corresponds to the contents of an ovarian tube4 ,with this view of ,balbiani the later observations of ,ritter agree4 ,as in the ,diptera1 so in the ,aphides1 the first germs of the genital organs are differentiated very early in life4 ,in the early stage in which through an invagination from the hinder pole of the egg the first rudiment of the amnion-cavity is formed1 a group of cells becomes separated from the wall of this invagination before the formation of the lower layer1 which at this time lies as an unpaired roundish mass within the embryo4 ,this group of cells1 according to ,balbiani and ,witlaczil1 has arisen by division of a single cell4 ,afterwards it becomes horseshoe-shaped and divides into a number of roundish masses of cells1 which are arranged in similar numbers on each side of the median plane of the body1 and form the rudiments of the terminal fan 7,endfcher74 ,they are covered by an epithelial envelope which passes anteriorly into the terminal threads1 posteriorly into the efferent passage4 ,the origin of this epithelial case is unknown4 ,the efferent passages of the separate ovarian tubes are united into a common oviduct1 and this fuses with an unpaired ectodermal invagination lying under the hind intestine from which the accessory sexual organs are formed4 7,korschelt and ,heider from ,metschnikoff1 ,witlaczil1 ,will47 ,illustration3 ,,fig4 #eea4--;,first developmental stages of the parthenogenetic eggs of the larva of ,cecidomyia3 b1 peripheral protoplasmic layer 7,keimhautblastem72 bl1 blastoderm2 d1 central yolk2 f1 division-nuclei2 n1 nutritive cell 78corpus luteum07 about to break up2 pz1 polar cells4--,after ,metschnikoff1 from ,korschelt and ,heider4 ,in the ,hymenoptera ,ganin has observed in the embryo of ,platygaster the rudiments of the sexual glands in the form of two rounded masses situated near the posterior intestine and apparently derived from the same blastems or buds as the latter4 ,uljanin studied these organs in the larva of the honey-bee4 ,they are two reniform bodies in the middle of which will soon appear the ovarian tubes4 ,they also give birth to the internal parts of the excretory ducts1 while the external part of the genital tube1 as also the accessory glands which are connected with it1 are derived by an invagination of the hypodermis at the surface of the penultimate segment4 ,dohrn observed in the larva of ants the rudiments of the ovaries in the form of two pyriform masses1 each with eight prolongations which he regarded as young ovarian tubes4 ,illustration3 ,,fig4 #eeb4--,three longitudinal sections through the embryo of ,chironomus4 ,in ,a1 the blastoderm 7bl7 is beginning to form1 the polar cells 7p7 outside of it2 in ,b1 the polar cells have pressed in between the blastoderm cells2 in ,c1 they lie in the interior of the embryo3 b1 protoplasmic layer 7,keimhautblast72 d1 yolk2 k1 nucleus of the forming blastoderm4--,after ,ritter1 from ,korschelt and ,heider4 ,in ,encyrtus ,bugnion observed the rudiments of the sexual glands in the middle of the larval period2 they were rounded and with no apparent connection with the neighboring organs4 ,afterwards these rudiments elongated1 approached nearer to the ventral surface1 and placed themselves in relation with some small cell-groups which appeared under the rectum1 and seemed destined to form the efferent canal 7vas deferens7 and accessory glands of the genital organs4 ,he thought the sex could be recognized in the second half of larval life1 the male gland being distinguished by its rounded shape and smaller size2 the ovary by its oval form and larger size4 ,in larv ready to be transformed the testis formed a cellular mass enveloped by a cuticle1 and at its hinder end prolonged into an epithelial cord1 which is undoubtedly the vas deferens4 ,the ovary had a similar envelope1 and from its cellular mass arose epithelial cords which were destined to become the ovarian tubes4 m4 ,length of embryonic life ,the duration of embryonic life varies greatly in different insects4 ,the embryo of the blow-fly is fully developed in less than #bd hours1 that of the house-fly in #bd hours4 ,in the locusts and tree-cricket the embryos begin to develop at the end of the summer1 continuing to grow until the cool weather of autumn1 when growth is arrested1 the later stages being finished in the latter part of the spring4 ,it is so1 likewise1 with the embryos of many moths and other insects4 n4 ,the process of hatching ,this has been observed only in a few cases1 and careful observations as to the exact manner in which the embryo breaks the egg-shell and frees itself from the amnion are much needed4 ,also the rapid changes of form from that of the embryo within the egg-shell1 and that which it immediately assumes after breaking forth from the shell and membranes1 have yet to be observed2 for these will undoubtedly be found to have special phylogenetic significance4 ,indeed1 the phylogenetic importance of the latest embryonic changes in insects just entering on the nymph or the larval stages is very great1 though little attention has as yet been bestowed upon the matter4 ,as regards the changes at the time of hatching1 ,wheeler tells us that the cockroach 7,phyllodromia71 shortly after leaving its narrow place in the egg-capsule1 undergoes a peculiar change in shape4 ,before hatching1 and when confined in the egg-shell1 the body is about one-third as wide as thick2 but soon after breaking out of the chorion its body is much flattened1 its dorso-ventral diameter being only about a third as great as its greatest breadth4 ,this shows that the flattened shape of the body of cockroaches1 which adapts them for their life under bark and stones1 is a very late inheritance1 and that these insects have descended from those with more cylindrical bodies4 ,the end of the body1 also1 which in the egg is bent underneath the abdomen1 is1 after hatching1 bent dorsally1 as indicated by the anal stylets1 which now point directly upwards and outwards4 ,the spines and claws are developed shortly before hatching4 ,in the ,locustid 7,xiphidium1 etc47 ,wheeler has observed that the pleuropodia1 or #ast pair of abdominal temporary embryonic appendages1 are shed during hatching4 ,all the other embryonic appendages have also disappeared1 except those which persist and have rapidly become modified to form the cercopods1 or the ovipositor4 ,in locusts1 as we have observed#he in the case of ,melanoplus spretus1 the egg-shell bursts open at the head end1 when the nymph1 immediately after extricating itself from the egg1 casts off a thin pellicle 7the amnion71 as we have also noticed in the case of the larv of the flea1 currant saw-fly1 and other insects4 ,before the amnion is cast off1 the young nymph is almost motionless1 but by slight movements of the body draws itself1 in about five minutes1 out of the amnion4 ,the exact process of extraction is as follows3 ,while it lies motionless1 it puffs out the thin1 loose skin connecting the back of the head with the front edge of the prothorax4 ,the distention of this part probably ruptures the skin1 which slips over the head1 the body meanwhile curved over until the skin is drawn back from the head2 when the latter is thrown back1 it withdraws its antenn and legs1 and the skin is in a second of time pushed back to near the end of the abdomen2 finally1 it draws its hind tarsi out of the skin1 and in a moment or two more the young locust frees itself1 kicks away the cast skin1 which resembles a little white crumpled pellet1 and which has also been compared to a diminutive mushroom1 and walks actively off1--sometimes1 however1 with the cast skin adhering to the end of the abdomen4 ,before the shedding of the amnion the body and legs are soft and flabby2 immediately after1 it walks firmly on its legs4 ,all the eggs hatched--at least one or more hundreds--at about the same time1 i4e4 before #aa ,a4,m4 ,illustration3 ,,fig4 #eec4--,locust just before the amnion is cast1 enlarged4--,emerton del4 ,the nymph of ,stagmomantis carolina also sheds an amnion-skin1 like that of the locust2 but the embryo before casting it off is much elongated1 and probably1 like the ,european ,mantis religiosa1 the curious elongated embryos have the same singular habit of suspending themselves by threads1 as shown in ,fig4 #eed4 ,the account by ,pagenstecher of the first ecdysis of the ,european ,mantis was so extraordinary that we asked ,professor ,cockerell to collect the eggs of our ,stagmomantis in ,new ,mexico and send them to us4 ,this he has kindly done1 writing that he can 8hardly recognize a true moult1 since all that is cast off is the egg-membrane4 ,in short1 ,pagenstecher's account must be not a little fanciful1 unless our insect differs very much in its development from ,mantis religiosa4 ,the main change is that after leaving the egg the thorax enormously elongates1 producing a bulging out1 and thrusting the head forward40 ,our observations on the alcoholic specimens fully corroborate ,cockerell's conclusions4 ,pagenstecher's figure of the embryo appears to be inaccurate4 ,sharp states that the hatching nymphs remain suspended for some days until the 8first change of skin is effected40 ,this so-called 8skin0 is evidently the amnion4 ,the #ag-year ,cicada1 after hatching1 is enveloped by the amnion1 from which it soon extricates itself1 and then drops deliberately to the ground1 8its specific gravity being so insignificant that it falls through the air as gently and as softly as does a feather40 7,riley47 ,other insects1 as caterpillars1 have room enough to turn around within their shell and to eat their way through the walls of the chorion4 ,the meat-fly1 as we have observed1 hatches in the following manner4 ,the embryo moves to and fro1 the body twisting until the exochorion is ruptured2 the egg-shell splits longitudinally1 and in one or two seconds the larva pushes its way out through the anterior end1 and in a second or two more extricates itself from the shell4 ,the latter scarcely changes its form1 and the larva slips out1 leaving the amnion within4 ,illustration3 ,,fig4 #eed4--;,egg-case of ,mantis with young escaping3 ,a1 the case with young in their position of suspension4 ,b1 cerci magnified1 showing the suspensory threads4--,after ,brongniart1 from ,sharp4 ,in the case of a fossorial wasp1 ,specius speciosus1 which carries ,cicad into its burrow1 laying an elongated egg on the body under the median thigh of its victim1 the larva on hatching1 ,riley states1 8does not emerge from the skin of the egg1 but merely protrudes its head and begins at once to draw nourishment from between the sternal sutures of the ,cicada40 ,the hatching spines4--,animals belonging to quite distinct classes are provided late in embryonic life with hard knobs or spines1 which are temporary structures for the purpose of breaking or cutting open the egg-shell1 when it is too thick and solid to be ruptured by the movements of the embryo4 ,the embryos of certain lizards1 turtles1 the blind worm and some snakes1 of the crocodile1 and even birds1 as well as the duckbill and ,echidna1 are provided with them1 always occurring1 so far as we are aware1 on the end of the upper jaw4 ,in the ,arthropoda similar structures have thus far only been met with in myriopods and insects1 though an analogous structure on the cephalothorax of the embryo of phalangids has been observed by ,balbiani4 ,metschnikoff describes and figures a low conical spine serving this purpose situated on the embryonal cuticle over the head of the advanced embryo of ,strongylosoma1 and one on the #c;d pair of mouth-parts of ,geophilus4 ,in the winged insects1 the embryo of ,forficula is said by ,heymons to bear a single spine between the eyes1 which serves as an egg-tooth4 ,the embryo of the ,hemerobiid1 according to ,hagen1 8opens the egg with an egg-burster like a saw40 7,proc4 ,bost4 ,soc4 ,nat4 ,hist41 xv1 p4 #bdg47 ,riley states that the egg-burster1 or ruptor ovi1 as he calls it1 of ,corydalus cornutus1 has 8the form of the common immature mushroom10 and he adds that it is a part of the amnion1 being 8easily perceived on the end of the vacated shell40 ,wheeler has observed three pairs of broad-based chitinous 8hatching spines0 used by ,doryphora in rupturing its embryonic envelopes1 and which are secreted by pyramidal thickenings of the hypodermis 7,figs4 #eee1 #eef74 ,illustration3 ,,fig4 #eee4--,the three pairs of hatching spines 7hsp7 on the late embryo of ,doryphora4--,after ,wheeler4 ,illustration3 ,,fig4 #eef4--,rudiment of the hatching spine3 eb1 being a thickening of the ectoderm 7ec7 in embryo ,doryphora after formation of the heart2 s1 serosa4--,after ,wheeler4 ,illustration3 ,,fig4 #eeg4--;,head of freshly hatched larva of ,pulex canis3 eb1 hatching spine2 ant1 antenn2 md1 mandible2 mx1 maxilla2 mx1 #b;d maxilla2 lbr1 labrum4 ,the hatching spine of ,pulex canis 7,fig4 #eeg7 is a thin vertical plate1 like the edge of a knife1 situated in the median line of the head very near the posterior end1 and is somewhat cultriform1 the upper edge slightly hollow1 and turned up a little at the anterior end4 ,though we did not see it working1 it is situated at just the point on the head where it would come in contact with the egg-shell1 and it was evident that the larva1 by moving its head back and forth1 would produce a slight split in the chorion and cause it to burst asunder4 ,later on in larval life it disappears1 probably at the first moult4 ,,literature ,,on ,,embryology ,koelliker1 ,albert4 ,observationes de prima insectorum genesi1 etc4 ,turici1 #ahdb1 pp4 #bi1 #c ,pls4 ,rathke1 ,h4 ,zur ,entwickelungsgeschichte der ,maulwurfsgrille 7,gryllotalpa vulgaris74 7,mller's ,archiv1 #ahdd1 ii1 p4 #bg1 ,figs4 #a-e47 ,zaddach1 ,g4 ,untersuchungen ber die ,entwicklung und den ,bau der ,gliederthiere4 ,i4 ,die ,entwicklung des ,phryganideneies4 ,berlin1 #ahed1 pp4 #ach1 #e ,taf4 ---- ,ueber die ,entwicklung der ,insekten4 7,schrift1 d4 k4 phys4-oekon4 ,gesell4 ,knigsberg1 viii ,jahrg41 #ahfg1 ,sitzb41 p4 #af47 ,leuckart1 ,rudolph4 ,die ,fortpflanzung und ,entwicklung der ,pupiparen4 ,nach ,beobachtungen an ,melophagus ovinus4 7,abhandl4 ,naturf4 ,gesell4 ,halle1 iv1 pp4 #a-hb1 #c ,taf47 ,halle1 #aheh4 ,huxley1 ,t4 ,h4 ,on the organic reproduction and morphology of ,aphis4 ,pt4 ,i1 #aheh2 ,pt4 ,,ii1 #aheh4 7,trans4 ,linn4 ,soc41 xxii1 pp4 #aic-bai1 #bba-bcf1 #e ,pls47 ,weismann1 ,a4 ,die ,entwicklung der ,dipteren im ,ei1 nach ,beobachtungen an ,chironomus sp41 ,musca vomitoria und ,pulex canis4 7,zeitschr4 f4 wiss4 ,zool41 xiii1 #ahfc1 pp4 i-xvi1 #a-bfc1 #ad ,taf47 ---- ,zur ,embryologie der ,insecten4 7,arch4 f4 ,anat4 u4 ,physiol41 #ahfd47 ---- ,beitrge zur ,kenntnis der ersten ,entwicklungsvorgnge im ,insectenei4 ,in3 ,beitrge zur ,anatomie und ,embryologie1 etc4 7,festschrift fr ,j4 ,henle4 ,bonn1 #ahhb47 ,kupffer1 ,c4 ,ueber das ,faltenblatt an den ,embryonen der ,gattung ,chironomus4 7,arch4 ,micr4 ,anat41 ii1 #ahff47 ,metschnikoff1 ,e4 ,embryologische ,studien an ,insecten4 7,zeitschr4 f4 wiss4 ,zool41 xvi1 #ahff1 pp4 #chi-ejj1 #aj ,taf47 ,kupffer1 ,carl4 ,de embryogenesi apud ,chironomos ,observationes1 etc4 ,kili1 #ahfg1 pp4 #af1 #a ,pl4 ,packard1 ,a4 ,s4 ,on the development of a dragon-fly 7,diplax7 schna84 7,proc4 ,bost4 ,soc4 ,nat4 ,hist41 xi1 #ahfh1 pp4 #cff-cgb1 #h ,figs47 ---- ,embryology of ,isotoma1 a genus of ,podurid4 7,proc4 ,bost4 ,soc4 ,nat4 ,hist41 xiv1 #ahgj1 pp4 #ac-ae1 #d ,figs47 ---- ,embryological ,studies on ,diplax schna81 ,perithemis1 and the thysanurous genus ,isotoma4 7,mem4 ,peabody ,academy of ,science1 ,salem1 i1 #ahga1 pp4 #a-ba1 #c ,pls47 ---- ,embryological studies on hexapodous insects4 7,ibid41 #ahgb1 pp4 #a-ag1 #c ,pls47 ---- ,the embryological development of the locust4 7,chap4 ,x1 ,third ,report ,u4 ,s4 ,ent4 ,commission1 ,washington1 #ahhc1 pp4 #bfc-bhb1 #g ,pls47 ,brandt1 ,a4 ,beitrge zur ,entwicklungsgeschichte der ,libelluliden und ,hemipteren4 7,mm4 ,acad4 ,st4 ,ptersbourg 7#g71 xiii1 #ahfi1 pp4 #a-cc1 #c ,taf47 ---- ,ueber das ,ei und seine ,bildungssttte4 7,leipzig1 #ahgh1 pp4 #aif1 #d ,taf47 ---- ,commentare zur ,keimblschentheorie des ,eies4 ,i4 ,die ,blastodermelemente und ,dotterballen der ,insecten4 7,arch4 f4 ,micr4 ,anat41 #ahhj1 xvii47 ,melnikow1 ,n4 ,beitrge zur ,embryonalentwicklung der ,insecten4 7,arch4 f4 ,naturg41 xxxv1 #ahfi1 pp4 #acg-ahi1 #d ,taf47 ,btschli1 ,o4 ,zur ,entwicklungsgeschichte der ,biene4 7,zeitschr4 f4 wiss4 ,zool41 xx1 #ahgj1 pp4 #eai-efd1 #d ,taf47 ---- ,bemerkungen ber die ,entwicklungsgeschichte von ,musca4 7,morph4 ,jahrb41 xiv1 #ahhh1 pp4 #agj-agd1 #c ,figs47 ,kowalevsky1 ,a4 ,embryologische ,studien an ,wrmern und ,arthropoden4 7,mm4 ,acad4 ,st4 ,ptersbourg 7#g71 xvi1 #ahga1 pp4 #a-gj1 #ab ,taf47 ---- ,zur embryonalen ,entwicklung der ,musciden4 7,biol4 ,centralbl41 vi1 #ahhf1 pp4 #di-ed47 ,mller1 ,fritz4 ,beitrge zur ,kenntniss der ,termiten4 7,jena4 ,zeitschr4 ,wissens41 ix1 #ahge1 pp4 #bda-bfc1 #d ,taf47 ,oulganine1 ,w4 ,n4 7also spelled ,uljanin74 ,sur le dveloppement des ,podurelles4 7,arch4 ,zool4 ,expr41 iv1 #ahge1 pp4 xxxix-xl1 und v1 #ahgf1 pp4 xvii-xix47 ---- ,beobachtungen ber die ,entwicklung der ,poduren4 7,russian47 7,nachr4 k4 ,gesellsch4 ,freunde ,naturw41 ,anthrop4 und ,ethnogr41 xvi1 #ahge47 ,dohrn1 ,a4 ,notizen zur ,kenntniss der ,insectenentwicklung4 7,zeitschr4 f4 wiss4 ,zool41 xxvi1 #ahgf1 pp4 #aab-ach47 ,hatschek1 ,b4 ,beitrge zur ,entwicklungsgeschichte der ,lepidopteren4 7,jena4 ,zeitschr4 f4 ,naturw41 xi1 #ahgg1 pp4 #ch1 #c ,taf41 #b ,figs47 ,bobretzky1 ,n4 ,ueber die ,bildung des ,blastoderms und der ,keimbltter bei ,insecten4 7,zeitschr4 f4 wiss4 ,zool41 xxxi1 #ahgh1 pp4 #aie-bae1 #a ,taf47 ,graber1 ,vitus4 ,vorlufige ,ergebnisse einer grsseren ,arbeit ber vergl4 ,embryologie der ,insecten4 7,arch4 f4 ,micr4 ,anat41 xv1 #ahgh1 pp4 #fcj-fdj1 #a ,fig47 ---- ,ueber die ,polypodie bei ,insectenembryonen4 7,morph4 ,jahrb41 xiii1 #ahhh1 pp4 #ehf-fae1 #b ,taf47 ---- ,ueber die primre ,segmentirung des ,keimstreifs der ,insecten4 7,morph4 ,jahrb41 xiv1 #ahhh1 pp4 #cde-cfh1 #b ,taf41 #d ,figs47 ---- ,vergleichende ,studien ber die ,keimhllen und die ,rckenbildung der ,insecten4 7,denkschr4 ,acad4 ,wiss4 ,wien41 lv1 #ahhh47 ---- ,vergleichende ,studien ber die ,embryologie der ,insecten und insbes4 der ,musciden4 7,denkschr4 ,acad4 ,wiss4 ,wien41 lvi1 #ahhi47 ---- ,ueber den ,bau und die phylogenetische ,bedeutung der embryonalen ,bauchanhnge der ,insekten4 7,biol4 ,centralbl41 ix1 #ahhi1 pp4 #cee-cfc47 ---- ,vergleichende ,studien am ,keimstreif der ,insecten4 7,denkschr4 ,acad4 ,wiss4 ,wien41 lvii1 #ahij47 ---- eber die embryonale ,anlage des ,blut- und ,fettgewebes der ,insecten4 7,biol4 ,centralbl41 xi1 #ahia1 pp4 #bab-bbd47 ---- ,zur ,embryologie der ,insekten4 7,zool4 ,anzeiger1 xiv1 #ahia1 pp4 #bhf-bia47 ---- ber die morphologische ,bedeutung der ventralen ,abdominalanhnge der ,insekten-,embryonen4 7,morph4 ,jahrb41 xvii1 #ahib1 pp4 #dfg-dhb47 ,barrois1 ,j4 ,dveloppement des ,podurelles4 7,assoc4 ,franc4 p4 l',avance4 des ,sc41 #g;e ,sess41 #ahgi47 ,kadyi1 ,h4 ,beitrag zur ,kenntnis der ,vorgnge beim ,eierlegen der ,blatta orientalis4 7,zool4 ,anzeiger1 #ahgi1 ii1 pp4 #fcb-fcf47 ,tichomiroff1 ,a4 ,ueber die ,entwicklungsgeschichte des ,seidenwurms4 7,zool4 ,anzeiger1 ii ,jahrg41 #ahgi1 pp4 #fd-fg47 ---- ,zur ,entwicklungsgeschichte des ,seidenspinners 7,bombyx mori7 im ,ei4 7,arb4 ,laborat4 ,zool4 ,mus4 ,moskau1 i1 #ahhb1 pp4 vii1 v1 #a-hj1 #c ,taf41 #dh ,figs47 7,russian47 ---- ,ueber die ,entwicklung der ,calandra granaria4 7,biol4 ,centralbl41 x1 #ahij1 p4 #dbd47 ,balfour1 ,francis ,m4 ,a treatise on comparative embryology4 i1 ii4 ,london1 #ahhj4 #b;d edit41 ,london1 #ahhe4 ,hertwig1 ,o4 und ,r4 ,die ,coelomtheorie4 ,versuch einer ,erklrung des mittleren ,keimblattes4 ,jena1 #ahha4 7,jena4 ,zeitschr41 xv1 pp4 #aej1 #c ,taf47 ,selvatico1 ,d4 ,s4 ,sullo sviluppo embrionale dei ,bombicini4 7,boll4 ,bachicoltura1 viii1 #ahha47 ,lemoine1 ,v4 ,recherches sur le dveloppement des ,podurelles4 7,assoc4 ,fran4 pour l',avanc4 d4 ,sc4 ,congrs de la ,rochelle1 #ahhb47 ,balbiani1 ,e4 ,g4 ,sur la signification des cellules polaires des ,insectes4 7,compt4 rend4 ,ac4 ,sc4 ,paris1 xcv1 #ahhb47 ---- ,contribution l'tude de la formation des organes sexuels chez les ,insectes4 7,recueil ,zool4 ,suisse1 ii1 #ahhe47 ,korotneff1 ,a4 ,entwicklung des ,herzens bei ,gryllotalpa4 7,zool4 ,anzeiger1 vi ,jahrg41 #ahhc1 pp4 #fhg-fij1 #b ,figs47 ---- ,die ,embryologie der ,gryllotalpa4 7,zeitschr4 f4 wiss4 ,zool41 xli1 #ahhe1 pp4 #egj-fjd1 #c ,taf47 ,nusbaum1 ,j4 ,vorl4 ,mittheilung ber die ,chorda der ,arthropoden4 7,zool4 ,anzeiger1 vi ,jahrg41 #ahhc1 pp4 #bia-bie1 #c ,figs47 ---- ,die ,entwicklung der ,keimbltter bei ,melo proscarabus4 7,biol4 ,centralbl41 viii1 #ahhh1 pp4 #ddi-deb1 #b ,figs47 ---- ,zur ,frage der ,segmentirung des ,keimstreifs und der ,bauchanhnge der ,insectenembryonen4 7,biol4 ,centralbl41 ix1 #ahhi1 pp4 #eaf-ebb1 #a ,fig47 ---- ,zur ,frage der ,rckenbildung bei den ,insectenembryonen4 7,biol4 ,centralbl41 x1 #ahij1 pp4 #aaj-aad47 ---- ,ueber die ,entwicklungsgeschichte der ,ausfhrungsgnge der ,sexualdrsen bei den ,insecten4 7,in ,polish1 with ,german rsum1 pp4 #ci-db47 78,kosmos0 ,lemberg1 #ahhd1 ix ,jahrg47 ---- ,zur ,embryologie des ,melo proscarabus1 ,marscham4 7,in ,polish1 with ,latin explanation of plates47 78,kosmos0 ,lemberg1 #ahia47 ,schneider1 ,a4 ,ueber die ,entwicklung der ,geschlechtsorgane der ,insecten4 7,zool4 ,beitrge1 herausg4 v4 ,a4 ,schneider1 i1 #ahhc47 ,will1 ,l4 ,zur ,bildung des ,eies und des ,blastoderms bei den viviparen ,aphiden4 7,arb4 ,zool4 ,zoot4 ,inst4 ,wrzburg1 vi1 #ahhc1 pp4 #bag-beh1 #a ,taf47 ---- ,entwicklungsgeschichte der viviparen ,aphiden4 7,spengel's ,zool4 ,jahrbcher4 ,abth4 f4 ,anat4 und ,ont41 iii1 #ahhh1 pp4 #bja-bhf1 #e ,taf47 ,patten1 ,w4 ,the development of ,phryganids1 with a preliminary note on the development of ,blatta germanica4 7,quart4 ,journ4 ,micr4 ,sc41 xxiv1 #ahhd1 pp4 #ed1 #c ,pls47 ---- ,studies on the eyes of ,arthropods4 ,i4 ,development of the eyes of ,vespa1 with observations on the ocelli of some insects4 7,journ4 of ,morphol41 ,boston1 i1 pp4 #aic-bbf1 #a ,pl47 ---- ,studies on the eyes of ,arthropods4 ,,ii4 ,eyes of ,acilius4 7,journ4 of ,morphol41 ,boston1 ii1 #ahhh1 pp4 #ig-aij1 #g ,pl41 #d ,figs47 ---- ,eyes of molluscs and ,arthropods4 7,mitth4 ,zool4 ,station ,neapel41 vi1 #ahhh1 pp4 #edb-gef1 #e ,pls47 ,grassi1 ,b4 ,interno allo sviluppo delle api nell' uovo4 7,atti ,acad4 ,gioenia4 ,scienc4 ,nat4 ,catania 7#c71 xviii1 #ahhd47 ---- ,breve nota intorno allo sviluppo degli ,japyx4 ,catania1 #ahhd1 also in ,i progenitori degli ,insetti e dei ,miriopodi4 #a4 ,l' ,japyx e la ,campodea4 7,atti ,acad4 ,gioenia ,sc4 ,nat4 ,catania 7#c71 xix1 #ahhe47 ,ayers1 ,h4 ,on the development of canthus niveus and its parasite ,teleas4 7,mem4 ,boston ,soc4 ,nat4 ,hist41 iii1 #ahhd1 pp4 #bbe-bha1 #h ,pls47 ,witlaczil1 ,em4 ,entwicklungsgeschichte der ,aphiden4 7,zeitschr4 f4 wiss4 ,zool41 xl1 #ahhd1 pp4 #eei-fif1 #i ,taf47 ,hallez1 ,p4 ,orientation de l'embryon et formation du cocon chez la ,periplaneta orientalis4 7,compt4 rend4 ,ac4 ,sc4 ,paris1 ci1 #ahhe1 pp4 #ddd-ddf47 ---- ,sur la loi de l'orientation de l'embryon chez les ,insectes4 7,compt4 rend4 ,ac4 ,sc4 ,paris1 ciii1 #ahhf1 pp4 #fjf-fjh47 ,heider1 ,k4 ,ueber die ,anlage der ,keimbltter von ,hydrophilus piceus4 7,abh4 k4 ,acad4 ,wiss4 ,berlin1 #ahhe47 ---- ,die ,embryonalentwicklung von ,hydrophilus piceus ,l4 7,i4 ,theil4 ,jena1 #ahhi1 pp4 #a-ih1 #ac ,taf41 #i ,figs47 ,carrire1 ,j4 ,kurze ,mittheilungen aus fortgesetzten ,untersuchungen ber die ,sehorgane4 #g1 ,die ,entwicklung und die verschiedenen ,arten der ,ocellen4 7,zool4 ,anzeiger1 ix ,jahrg1 #ahhf1 pp4 #ada-adg1 #dgi-dha1 #dif-ejj47 ---- ,die ,entwicklung der ,mauerbiene 7,chalicodoma muraria ,fabr47 im ,ei4 7,arch4 f4 ,micr4 ,anat41 xxxv1 #ahij1 pp4 #ada-afe1 #a ,taf47 ---- ,die ,drsen am ersten ,hinterleibsringe der ,insectenembryonen4 7,biol4 ,centralbl41 xi1 #ahia1 pp4 #aaj-abg1 #c ,figs47 ,miall1 ,l4 ,c41 and ,denny1 ,a4 ,the structure and life-history of the cockroach 7,periplaneta orientalis74 ,london1 #ahhf4 7,the section on embryology by ,j4 ,nusbaum47 ,ryder1 ,j4 ,the development of ,anurida maritima ,guerin4 7,amer4 ,naturalist1 xx1 #ahhf1 pp4 #bii-cjb1 #a ,pl7 ,stuhlmann1 ,f4 ,die ,reifung des ,arthropodeneies nach ,beobachtungen an ,insecten1 ,spinnen1 ,myriopoden und ,peripatus4 7,ber4 ,freib4 ,naturf4-,gesellsch41 i1 #ahhf47 ,blochmann1 ,f4 ,ueber die ,richtungskrper bei ,insecteneiern4 7,morph4 ,jahrbuch1 xii1 #ahhg1 pp4 #edd-egd1 #b ,taf47 ,bruce1 ,adam ,todd4 ,observations on the embryology of insects and arachnids4 ,a memorial volume4 ,baltimore1 #ahhg1 #d1 pp4 #ca1 #f ,pls4 ,weismann1 ,a41 und ,ischikawa1 ,ch4 ,ueber die ,bildung der ,richtungskrper bei thierischen ,eiern4 7,ber4 ,naturf4 ,ges4 ,freiburg1 iii1 #ahhg47 ,cholodkowsky1 ,n4 ,ueber die ,bildung des ,entoderms bei ,blatta germanica4 7,zool4 ,anzeiger1 xi ,jahrg41 #ahhh1 pp4 #afc-aff1 #b ,figs47 ---- ,studien zur ,entwicklungsgeschichte der ,insecten4 7,zeitschr4 f4 wiss4 ,zool41 xlviii1 #ahhi1 pp4 #hi-ajj1 #a ,taf47 ---- ,zur ,embryologie von ,blatta germanica4 7,zool4 ,anzeiger1 xiii ,jahrg41 #ahij1 pp4 #acg-ach47 ---- ,zur ,embryologie der ,hausschabe 7,blatta germanica74 7,biol4 ,centralbl41 x1 #ahij1 p4 #dbe47 ---- ,ueber die ,entwicklung des centralen ,nervensystems bei ,blatta germanica4 7,zool4 ,anzeiger1 xiv ,jahrg41 #ahia1 pp4 #aae-aaf47 ---- ,zur ,embryologie der ,insecten4 7,ibid41 #ahia1 pp4 #dfe-dff47 ---- ,die ,embryonalentwicklung von ,phyllodromia 7,blatta germanica74 7,mm4 ,acad4 ,st4 ,ptersbourg 7#g71 xxxviii1 #ahia47 ,henking1 ,h4 ,die ersten ,entwicklungsvorgnge im ,fliegenei und freie ,kernbildung4 7,zeitschr4 f4 wiss4 ,zool41 xlvi1 #ahhh1 pp4 #bhi-ccf1 #d ,taf41 #c ,figs47 ---- ,ueber die ,bildung von ,richtungskrpern in den ,eiern der ,insekten und deren ,schicksal4 7,nachr4 ,ges4 ,wiss4 ,gttingen1 #ahhh47 ,platner1 ,g4 ,die erste ,entwicklung befruchteter und parthenogenetischer ,eier von ,liparis dispar4 7,biol4 ,centralbl41 viii1 #ahhh1 pp4 #eba-ebd47 ,schmidt1 ,f4 ,die ,bildung des ,blastoderms und des ,keimstreifs der ,musciden4 7,sitz4 ,naturf4 ,ges41 ,dorpat1 viii1 #ahhi47 ,viallanes1 ,h4 ,sur quelques points de l'histoire du dveloppement embryonnaire de la ,mante religieuse4 7,rec4 ,biol4 du ,nord de la ,france1 ii1 #ahhi-ahij47 ,voeltzkow1 ,a4 ,entwicklung im ,ei von ,musca vomitoria4 7,arb4 ,zool4 ,zoot4 ,inst4 ,wrzburg1 ix1 #ahhi1 pp4 #a-dh1 #d ,taf47 ---- ,melolontha vulgaris1 ein ,beitrag zur ,entwicklung im ,ei bei ,insecten4 7,arb4 ,zool4 ,zoot4 ,inst4 ,wrzburg1 ix1 #ahhi1 pp4 #di-fd1 #a ,taf47 ,wheeler1 ,w4 ,m4 ,ueber drsenartige ,gebilde im ersten ,abdominalsegment der ,hemipterenembryonen4 7,zool4 ,anzieger1 xii1 #ahhi1 pp4 #ejj-ejd1 #b ,figs47 ---- ,the embryology of ,blatta germanica and ,doryphora decemlineata4 7,journ4 of ,morph41 ,boston1 iii1 #ahhi1 pp4 #bia-cgd1 #g ,pls41 #af ,figs47 ---- ,on the appendages of the first abdominal segment of the embryo cockroach 7,blatta germanica74 7,proceed4 ,wis4 ,acad4 ,science1 ,arts1 and ,letters1 viii1 #ahij1 pp4 #hg-adj1 #c ,pls47 ---- ,ueber ein eigenthmliches ,organ im ,locustidenembryo 7,xiphidium ensiferum74 7,zool4 ,anzieger1 xiii1 #ahij1 pp4 #dge-dhj47 ---- ,neuroblasts in the ,arthropod embryo4 7,journ4 of ,morphol41 iv1 #ahia1 pp4 #ccg-cdc1 #a ,fig47 ---- ,a contribution to insect embryology4 ,in4 ,diss4 7,journ4 ,morph41 ,boston1 viii1 #ahic1 pp4 #a-afj1 #f ,pls41 #g ,figs47 ,heymons1 ,r4 ,ueber die hermaphroditische ,anlage der ,sexualdrsen beim ,mnnchen von ,phyllodromia 7,blatta7 germanica4 7,zool4 ,anzeiger1 xiii ,jahrg41 #ahij1 pp4 #dea-deg1 #c ,figs47 ---- ,die ,entstehung der ,geschlechtsdrsen von ,phyllodromia 7,blatta7 germanica ,l4 ,in4 ,diss4 ,berlin1 #ahia4 ---- ,die ,embryonalentwickelung von ,dermapteren und ,orthopteren unter besonderer ,bercksichtigung der ,keimbltterbildung4 ,monographisch bearbeiteit1 #ab ,lith4 ,taf4 und #cc ,figs4 ,jena1 #ahie1 #d1 pp4 #acf4 ---- ,ueber die ,fortpflanzung und ,entwickelungsgeschichte der ,ephemera vulgata ,l4 7,sitzungsb4 ,gesell4 ,naturf4 ,freunde1 ,berlin1 #ahif1 pp4 #ha-if47 ---- ,entwicklungsgeschichtliche ,untersuchungen an ,lepisma saccharina ,l4 7,zeitschr4 wiss4 ,zool41 lxii1 #ahig1 pp4 #ehh-fca1 #b ,taf47 ,ritter1 ,r4 ,die ,entwicklung der ,geschlechtsorgane und des ,darmes bei ,chironomus4 7,zeitschr4 f4 wiss4 ,zool41 #a1 #ahij1 pp4 #djh-dbg1 #a ,taf47 ,tichomirowa1 ,o4 ,s4 ,zur ,embryologie von ,chrysopa4 7,biol4 ,centralbl41 x1 #ahij1 p4 #dbc47 ,pedaschenko1 ,d4 ,sur la formation de la bandelette germinative chez ,notonecta glauca4 7,in ,russian47 7,revue ,sc4 ,natural4 ,st4 ,ptersbourg1 i1 #ahia47 ,korschelt1 ,e41 and ,heider1 ,k4 ,lehrbuch der vergleichenden ,entwicklungsgeschichte der wirbellosen ,thiere4 7,spec4 ,th4 ,heft ii1 ,jena1 #ahia1 many ,figs47 ,with the writings of ,lang 7,comp4 ,anatomy74 ,,end ,,of ,,part ,,ii ,,part ,,iii4--,,the ,,metamorphoses ,,of ,,insects ,we have seen that the embryo rapidly passes through extraordinary changes of form1 and now1 after hatching1 especially in the insects with a complete metamorphosis1 the animal continues to undergo striking changes in form1 in adaptation to different modes of life4 ,the life of a winged insect1 such as a butterfly1 fly1 or bee1 may be divided into four stages3 the embryo1 or egg state1 the larva1 pupa1 and imago1--the term metamorphosis being applied to the changes after birth1 or post-embryonic stages of life4 ,the transformations of the more specialized orders of insects involve wonderful changes of form1 which are only paralleled in other types of animals by the metamorphoses of the echinoderms1 of certain worms1 and of the ,crustacea1 as well as by those of the frog4 ,an insect1 such as a butterfly or bee1 during its post-embryonic life lives1 so to speak1 three different lives1 having distinct bodily structures and existing under quite dissimilar surroundings and habits2 so that a caterpillar is practically a different animal from the pupa1 and the latter from the imago1 with different organs1 the appendages and other structures being so modified as to be1 so far as regards their functions1 radically different4 ,these changes of functions or of habits have also been plainly enough the exciting cause of the divergency in structure of what fundamentally is one and the same organ1 the change having been brought about by adaptation of the same organs to quite different uses4 ,the changes are not only observable in the body and its appendages1 but also in the internal organs1 and consequently are both structural and physiological4 ,the term larva1 as applied to the first stage of animals1 is a very variable and indefinite one1 that of insects in general being a much more highly organized animal than the larva of a worm1 starfish1 or crustacean4 a4 ,the nymph as distinguished from the larval stage ,as there is no marked difference between the different stages of the young in the insects with an incomplete metamorphosis 7,heterometabola71 the chief difference being the possession of the rudiments of wings and the absence of a resting stage1 the terms larva and pupa are in reality scarcely applicable to them1 and we much prefer the term nymph1 first proposed by ,lamarck for the active 8pupa0 of ,orthoptera1 ,hemiptera1 the ,odonata and ,ephemerid1 and adopted in part by many4 ,indeed1 in the more generalized and older orders1 the larval and pupal stages are not differentiated1 though the term larval1 in its general sense1 will probably always be used2 just as we speak of the larval stages of worms1 echinoderms1 or ,crustacea4 ,eaton in his elaborate work on the ,ephemerid employs the term nymph to designate all the aquatic or early stages in the development of the young after hatching1 and he urges that the old-fashioned usage of larva and pupa seem scarcely worth retention4 8,nymphs are young which live an active life1 quitting the egg at a tolerably advanced stage of morphological development and having the mouth-parts formed after the same main type of construction as those of the adult insect40 ,the word nymph is used in the same sense by ,mc,lachlan1 and by ,cabot4 ,calvert also applies the term nymph 8to the stage of odonate existence between the egg and the transformation into the imago40 ,on the other hand1 ,brauer applies the term nymph to the pupa of holometabolous insects4 ,for larval ,hyatt proposes the term nepionic4 b4 ,stages or stadia of metamorphosis ,the intervals or periods between the moults or ecdyses of caterpillars and other eruciform larv are called stages or stadia2 thus1 as most caterpillars moult four times1 we have five stages or stadia1 or stage 7stadium7 ,i to ,v4 ,as observed by ,sharp1 there is1 unfortunately1 no term in general use to express the form of the insect at the various stadia2 8entomologists say1 #8the form assumed at the first moult1' and so on40 ,hence he adopts a term suggested by ,fischer1#hf and calls the insect as it appears after leaving the egg the first instar1 and what it is after the first moult the second instar1 and so on2 hence the pupa1 or chrysalis1 which assumed that condition after moulting five times would be the sixth instar1 and the butterfly itself would be the seventh instar4 c4 ,ametabolous and metabolous stages ,in the ,synaptera development is direct1 the young differing neither in form1 structure1 or habits from the adult4 ,hence they are said to be ametabolous4 ,since there is an absence of even a tendency to a partial metamorphosis1 it is evident that the insects have not inherited a tendency to undergo a transformation1 but that it is an adaptation induced in the hexapod type after the first winged insects appeared1 and which became more marked in the more specialized insects and at a period comparatively late in geological history1 i4e4 perhaps at or soon after the beginning of the ,carboniferous period4#hg ,the transformations of the pterygote insects vary greatly in degree1 and it is difficult to draw the line between the grades4 ,those in which the adults differ from the freshly hatched young only or mainly in having wings are generally said to have an incomplete or gradual metamorphosis4 ,there is no inactive1 resting1 or pupal stage1 and the wings are acquired only after successive moults4 ,insects with an incomplete metamorphosis are the ,orthoptera1 ,dermaptera1 ,platyptera 7,mallophaga1 ,plecoptera1 ,corrodentia1 ,embid71 ,ephemerid1 ,odonata1 ,thysanoptera1 and ,hemiptera1 with the exception of the male ,coccid1 in which there is a resting or sub-nymph stage4 ,as regards the number of moults in the ,synaptera1 ,grassi states that in ,campodea there is a single fragmentary ecdysis1 while ,sommers tells us that ,macrotoma plumbea sheds its skin throughout life1 even after attaining its full size4 ,as an example of the partial metamorphosis of the hemimetabolous insects we may select that of the locust1 in which there are five moults and six stages 7instars71 as seen in ,fig4 #eeh1 five of which are nymphal4 ,in the first two stages there are no rudiments of wings1 these appearing after the second moult4 ,besides the acquisition of wings there are slight differences after each moult1 both in structure and color1 besides size1 so that we may always recognize the comparative age and the particular stage of growth of any individual4#hh ,we have watched the development of ,melanoplus spretus from the egg to the imago1 and examined thousands of specimens which show the six stages4 ,on the other hand1 ,european authors differ as to whether there are three1 four1 or five moults in the migratory locust4#hi ,it is not improbable that1 as is the case with many other insects1 the number of moults may vary according to the temperature and food1 variation in these agencies causing either retardation or rapidity in development4 ,those with a complete metamorphosis are said to be metabolous or holometabolous4 7,lang47 ,leach#ij in #ahae gave the name of ,ametabola to insects without1 and ,metabola to insects with a metamorphosis4 ,illustration3 ,,fig4 #eeh4--,partial metamorphosis of ,melanoplus femur-rubrum1 showing the five nymph stages1 and the gradual growth of the wings1 which are first visible externally in #c1 #c;b1 #c;c4--,emerton del4 ,latreille 7#ahca7 called insects with an incomplete metamorphosis homotenous 7which means similar to the end of life71 and those with a complete metamorphosis1 polymorphous4 ,for the different degrees of metamorphosis of insects he employed two terms3 for the incomplete degree1 metamorphosis dimidia1 and for the total or pupal1 metamorphosis perfecta4 ,westwood in his ,introduction to the ,modern ,classification of ,insects 7#ahci71 taking into account the relation of the larva with the imago1 divided insects into two divisions3 the ,heteromorpha1 or those in which there is no resemblance between the parent and its offspring1 and ,homomorpha1 in which the larva resembles the imago1 except in the absence of wings4 ,illustration3 ,,fig4 #eei4--,manometabolous metamorphosis of the cockroach 7,phyllodromia germanica7 with its four nymphal stadia a-d2 e1 h1 adult2 f1 female with egg-case2 g1 egg-case4--,from ,riley4 ,from the point of view of the degree of metamorphosis1 insects have been divided into ,heterometabola and ,metabola4 ,i4 ,heterometabola4--,this group may be divided as follows3 #a4 ,manometabola1#ia embracing those forms with a slight or gradual metamorphosis1 but which are active in all the stages1 without any resting stage4 ,the orders passing through this degree of metamorphosis are the following3 ,orthoptera1 ,dermaptera1 ,platyptera1 ,thysanoptera1 and ,hemiptera 7,coccid excepted74 ,in all these groups1 the only external differences of importance between the freshly hatched nymph and the adult is the presence of wings4 ,the chief difference internally is the complete development of the sexual glands4 ,it should be observed1 however1 that in the last nymph stage of the ,thysanoptera the articulations of the limbs are enveloped by a membrane and the wings enclosed in short fixed sheaths2 the antenn are turned back on the head1 and the insect1 though it moves about1 is much more sluggish than in the other state4 7,haliday47 ,hence here we have a close approach to the following degree4 #b4 ,heremetabola1#ib including those forms with a gradual though slight or incomplete metamorphosis1 but with a quiescent or resting stage at the close of the nymph life4 ,lang has emphasized this stage1 calling attention to the fact that the fore legs of the nymph of the #ag-year ,cicada1 which lives underground on the roots of trees1 are thick and adapted for digging4 ,the transition from the nymph to the winged adult is signalized by the decided change in form of the fore legs1 as well as by the acquisition of the wings4 8,the last larval stage is1 then1 what is called quiescent1 i4e4 the organization of the imago develops within the chrysalis at the expense of the accumulated reserve material40 7,lang47 ,there seems to be a resting stage1 when the insect does not perhaps suck the sap from the roots1 and awaits in its chamber its approaching change to the imago2 but we should scarcely apply the term pupa to this stage1 though the antenn of the freshly hatched larva are larger and longer than in the fully grown nymph and are distinctly #h-;jointed4 #c4 ,hemimetabola4--,in this division1 so named by ,brauer1 the changes are more marked1 though there is no truly inactive pupa-like stage4 ,the orders are ,perlaria 7,plecoptera71 ,odonata1 and ,plectoptera 7,ephemerid74 ,the freshly hatched nymphs of these three groups are much alike in shape1 that of ,perlid1 and indeed most of the ,platyptera1 being more generalized1 unless we except that of ,chloon2 all closely recall ,campodea1 and are therefore in the ,campodea-stage4 ,these nymphs are indeed more generalized than the freshly hatched nymph of ,blattid1 or any other of the orders mentioned except the ,platyptera1 to which perlids belong4 ,they all have feet1 and the body is more or less flattened4 7,fig4 #efj47 ,,ii4 ,holometabola4--,in this division we have for the first time a true larva1 and a pupa stage as distinguished from the imago4 ,moreover1 the insect at each stage is distinguished by radical differences in form1 surroundings1 and in the nature of the food1 while the pupa is inactive1 usually immovable1 and incapable of taking any food1 and is often protected by a cocoon spun by the larva4 ,the holometabolous orders are the ,neuroptera1 ,coleoptera1 ,mecoptera1 ,trichoptera1 ,lepidoptera1 ,siphonaptera1 ,diptera1 and ,hymenoptera4 ,as we have among worms1 echinoderms1 and ,crustacea certain exceptional species in a metamorphic group whose metamorphosis is suppressed1 their development being direct1 so there is in pterygote insects1 though in a very much less degree1 cases of direct development4 ,in the wingless cockroaches such as ,pseudoglomeris1 etc41 of the tribe of ,periphriides1 in some of which1 however1 the males are winged1 and in the ,hemiptera1 occur wingless forms such as the lice and bed-bug4 ,the ,mallophaga are all wingless1 while certain ,dermaptera 7,chelidura1 ,anisolabis7 are also apterous4 ,the absence of wings in such cases is due to disuse from parasitism1 or to a life under stones or in cracks and fissures1 where the insects are driven to avoid their enemies1 and hence do not need wings4 ,the growth of wings and consequently the development of a metamorphosis is suppressed1 so that1 as ,lang says1 8in contrast to the original ametabola of the ,apterygota1 we have here an acquired ametabola40 ,it is rare that1 after the rudiments of wings have once appeared in the very young1 they should disappear in the late nymph stage2 this is1 however1 said by ,walsh to be the case with the ,ephemerid ,btisca 7,fig4 #ddj74 ,this is a case of retardation in an acquired ametabolesis4 ,,the ,,larva ,the term larva is peculiarly applicable to the young of the holometabolous orders4 ,the name 7,latin1 larva1 a mask7 was first given to the caterpillar because it was thought by the ancients to mask the form of the perfect insect4 ,swammerdam supposed that the larva contained within itself 8the germ of the future butterfly1 enclosed in what will be the case of the pupa1 which is itself included in three or more skins1 one over the other1 that will successively cover the larva40 ,what led to his conception of the nature of these changes was probably his observations on the semitransparent larva of the gnat1 in which the body and limbs of the pupa can be partially seen2 for ,weismann has shown that the great ,dutch observer's belief that the pupal and imaginal skins were in reality already concealed under that of the larva is partially founded in fact4 ,swammerdam states3 8,i can point out in the larva all the limbs of the future nymph1 or ,culex1 concealed beneath the skin10 and he also observed beneath the skin of the larv of bees1 just before pupating1 the antenn1 mouth-parts1 wings1 and limbs of the adult4 ,but1 as we shall see farther on1 the discovery by ,weismann in the larva of the germs of the imago has completely changed our notions as to the nature of metamorphosis1 and revolutionized our knowledge of the fundamental processes concerned in the change from larva to pupa1 and from pupa to imago4 ,not only are the larv of each order of insects characteristic in form1 so that the grub or larva of beetles is readily distinguished from those of other orders1 or the maggot of flies from the apodous larva of wasps and bees1 but within the limits of the larger orders there is great diversity of larval forms1 showing that they are the result of adaptation to their surroundings4 ,this is especially the case with the larv of the ,coleoptera1 ,lepidoptera1 ,diptera1 and ,hymenoptera4 ,in general1 the larv of insects may be divided into two types1--the ,campodea-form1 or campodeoid1 sometimes called thysanuriform1 and the eruciform4 a4 ,the ,campodea-form type of larva ,this is the most primitive and generalized type of larva 7,fig4 #efj74 ,a ,campodeoid larva is one nearest in general shape to ,campodea1 the form which we have seen to be the nearest allied to the probable ancestor of the insects1 and it also resembles the nymphs of the heterometabolous insects1 before the appearance of their rudimentary wings4 ,brauer1 in #ahfi1ic first suggested that the larv of a great number of insects may be traced back to ,campodea and ,iapyx4 ,the ,campodea-form larva is active1 with a more or less flattened body1 well developed mandibulate mouth-parts1 and usually long legs4 ,the nearest approach to the form of ,campodea is the freshly hatched nymph of cockroaches 7,blattid71 ,forficula1 ,perlid1 ,termitid1 ,psocid1 ,embid1 ,ephemerid1 ,odonata1 especially the more generalized ,agrionid1 the nymphs of ,hemiptera1 the larv of certain ,neuroptera1 the active pedate larv of the more generalized ,coleoptera1 such as those of ,carabid1 ,cicindelid1 ,dyticid1 etc41 and the first larva 7instar7 of ,stylopid and ,meloid 7,fig4 #efj1 d74 ,while the ,campodea-shape is retained throughout nymphal life1 of the orders above mentioned the ,neuroptera and ,coleoptera alone have a true resting pupal stage4 ,it should also be observed that great changes in the form of the nymph occur within the limits of the ,orthoptera2 the nymph of all the families except that of the ,blattid1 evidently the most generalized and primitive1 being more or less specialized1 while the nymphs of the other orders all vary in degree of specialization and modification4 ,the process of adaptation once begun went on very rapidly1 as it has in many other orders of insects1 as well as in animals of other phyla4 ,illustration3 ,,fig4 #efj4--;,examples of campodeoid nymphs and larv3 a1 ,campodea2 b1 ,podura 7,degeeria72 c1 ,lepisma2 d1 triungulin larva of ,melo2 e1 ,perla2 f1 ,forficula2 g1 ,chloon2 h1 ,may-fly 7,palingenia72 i1 schna2 j1 ,atropos2 k1 ,myrmeleon2 l1 ,sialis2 m1 ,corydalus2 n1 ,cicada4 b4 ,the eruciform type of larva ,brauer also sagaciously pointed out that 8a larger part of the most highly developed insects assume another larva form1 which appears not only as a later acquisition1 through adaptation to certain definite conditions1 but also arises as such before our eyes4 ,the larv of ,lepidoptera1 of saw-flies1 and ,panorpid show the form most distinctly1 and ,i call this the caterpillar form 7,raupenform74 ,that this is not the primitive form1 but one later acquired1 we see illustrated in certain beetles4 ,the larv of ,melo and of ,sitaris1 in their fully grown conditions1 possess the caterpillar form1 but the new-born larv of these genera show the ,campodea-form4 ,the last form is lost as soon as the larva begins its parasitic mode of life4444 ,the larger part of the beetles1 the ,neuroptera 7in part71 the bees and flies 7the last with the most degraded maggot form71 possess larv of this second form40 ,in #ahga we adopted these views1 giving the name eruciform to this type of larv1 and afterwards ,lubbock adopted ,brauer's views4 ,brauer considered that the eruciform larva was the result of living a stationary semi-parasitic life on plants1 in carrion1 or burrowing in the trunks and branches or leaves and buds of trees1 where they do not have to move about in search of their food4 ,the change from the ,campodea-form to the eruciform larva is a process of degeneration and often of atrophy of the limbs1 and1 in the footless forms of dipterous and hymenopterous insects1 of the gnathites1 accompanied by a tendency of the body to become more or less cylindrical4 ,the first steps in the origination of the eruciform larva were apparently taken in the order ,neuroptera1 as restricted by ,brauer and by myself1 where1 though the larv are campodeoid1 there is a true resting pupal stage4 ,the most generalized larval form is perhaps that of the ,sialid 7,fig4 #efj1 l71 in which the body tends to be slightly cylindrical1 though the legs are long1 and the gnathites well developed for seizing and biting their living prey4 ,the terrestrial larv of the ,hemerobiid1 though modifications of the sialid larval form1 are considerably specialized in adaptation to their active carnivorous habits4 ,but the life-history of ,mantispa1 where there are two larval stages1 gives us plainly enough the key to the mode in which the complete metamorphosis was brought about4 ,the larva1 born a true ,campodea-like form1 with large1 long1 #d-;jointed legs1 has a structure which would enable it to move about freely after its prey1 beginning at once to live a sedentary life in the egg-sac of a spider2 before the first moult it loses the use of its legs1 while the antenn are partly aborted4 ,the result is that1 owing to this change of habits and surroundings from those of its active ancestors1 it changes its form1 and the fully grown larva becomes cylindrical1 with small slender legs1 and1 owing to the partial disuse of its jaws1 acquires a small1 round head4 ,illustration3 ,,examples ,,of ,,coleopterous ,,larv1 ,,showing ,,the ,,passage ,,from ,,the ,,campodeoid ,,to ,,the ,,eruciform ,,type ,,of ,,larv4 ,,fig4 #efa4--;,coleopterous larv showing passage from campodeoid to eruciform larv3 a1 b1 ,harpalus2 c1 ,dyticus2 d1 ,staphylinus2 e1 ,silpha2 f1 ,melanactes2 g1 ,ludius2 h1 ,elater2 i1 ,donacia2 j1 ,chrysobothris2 k1 ,orthosoma2 l1 ,coccinella2 m1 ,byrrhus2 n1 ,trox2 o1 p1 ,lachnosterna2 q1 ,labidomera2 r1 ,ptinus2 s1 ,anobium2 t1 ,balaninus 7entirely apodous74 ,its antenn1 mouth-parts1 and legs not only retarded in growth1 but retrograding and becoming vestigial1 the body meanwhile becoming fat and cylindrical1 an apparent acceleration of growth goes on within1 with probably an enlargement of the intestine and fat-body1 and thus the pupal form is perfected while the larva is full-fed and quiescent4 ,it is not improbable that in the primitive neuropteron1 as the result of a mode of life like that of ,mantispa1 the quiescent life of the later stages graduated into a quiescent1 inactive pupal life1 allowing the changes going on in the internal organs to result in a complete metamorphosis1 which was transmitted to the later ,neuroptera1 thus making the complete metamorphosis a fixed1 normal condition4 ,it thus appears that a change of habits and of food1 and more especially the fact that the nymph became so surrounded with an abundance of food close at hand that it did not have to run actively about and seize it in a haphazard manner1 were the factors bringing about a change from the ,campodea-form nymph to the eruciform larva1 thus inducing a hypermetamorphosis4 ,the larv of the ,mecoptera 7,panorpid1 ,fig4 #efb1 b7 are still more caterpillar-like1 and besides their cylindrical body1 rounded head1 small short gnathites1 small thoracic legs1 they have what appear to be #b-;jointed legs to each of the nine abdominal segments1 and the close resemblance to caterpillars is farther carried out by the presence of a pair of prothoracic spiracles1 none existing on the other two thoracic segments4 ,illustration3 ,,fig4 #efb4--;,examples of eruciform larv3 a1 ,phryganea2 b1 ,panorpa2 c1 ,sesia2 d1 d1 caterpillars2 e1 ,selandria2 f1 ,tipula2 g1 ,simulium2 h1 ,chionea2 i1 ,musca2 j1 ,tachina2 k1 ,braula2 l1 flea2 m1 ,tremex2 n1 coarctate larva of ,melo2 o1 bee 7,andrena74 ,in the ,meloid 7,fig4 #efj1 d7 and ,stylopid the first larval stage is ,campodea-form2 the changes will be described in the subsequent section on ,hypermetamorphosis1 and while these cases of change from a campodeoid to an inactive eruciform larva are very salient1 if we compare the graduated series of larval forms throughout the order of ,coleoptera1 as represented by the illustrations in ,fig4 #efa1 we shall see that in nearly1 if not each1 case the form of the boring or mining1 or bark or bud or seed-inhabiting grub is the result of a change of habit and commissariat from active predaceous larv1 like those of the ,carabid and other adephagous families1 together with those of the ,staphylinid1 with their flat body1 big mandibles1 and well-developed maxill1 to the cylindrical bodies of such larv as those of ,dermestes and ,anthrenus1 which live a more sedentary life1 to the root-feeding wire-worm or elaterid larv1 and scarabid grubs1 onward to the phytophagous ,chrysomelid1 with the mining and boring buprestids and cerambycids1--in all these forms we see a gradual atrophy of the legs1 which is fully carried out in the vermiform or maggot-like larva of the weevils4 ,these changes throughout the members of the entire order are epitomized in the life-history of the ,meloid1 in which there are three typical forms of larva3 the ,campodea-form 7triungulin stage71 eruciform 7second or carabidoid stage71 and vermiform 7coarctate7 larva4 ,illustration3 ,,fig4 #efc4--,prodoxus cinereus3 a1 apodous larva2 b1 head and prothoracic segment2 c1 anal hooks2 d1 pupa2 e1 cast pupal shell protruding from stalk of ,yucca2 f1 female2 g1 side view of clasper4--,after ,riley1 from ,insect ,life4 ,illustration3 ,,fig4 #efd4--,larva of ,limacodes scapha1 nat4 size4 ,in the ,lepidoptera the eruciform1 pedate type is adhered to throughout the order1 with the rare exception of the nearly apodous mining larva of ,prodoxus 7,fig4 #efc1 a71 ,phyllocnistis1 and ,nepticula1 which have no thoracic legs1 and the limacodid larv1 whose abdominal legs are totally aborted1 while the thoracic ones are much reduced 7,fig4 #efd74 ,in the ,hymenoptera the phytophagous forms are eruciform1 while by the agency of the same factors as already mentioned1 i4e4 a sedentary or parasitic life and abundance of food within constant reach1 the larv lose their legs and become vermiform4 ,in the ,diptera1 which are the most highly specialized of insects1 the maggot or vermiform shape1 and absence of any legs1 prevails throughout the order1 though the eucephalous larv show their origin from a primitive eruciform type of larva4 ,the highly specialized larv of the ,culicid and ,simuliidae are undoubtedly related to the earliest and most generalized types1 while the maggots of the parasitic flies 7,tachinid7 and other muscids are later degradational forms1 and the result of adaptation induced1 as in the previous cases1 by a sedentary or parasitic mode of life1 living as they do immersed in an abundance of rich nitrogenous food1 with the result that the mouth-parts have become atrophied by disuse1 while the limbs have become entirely aborted1 though the thoracic imaginal discs develop normally in the embryonic or pre-larval stages4 ,it appears1 therefore1 highly probable that the metamorphoses of insects are the result of the action of change of conditions1 just as the polymorphism of ,termites is with little doubt the result of differences of food and other conditions4 ,these matters will be farther discussed under the head of ,causes of ,metamorphosis4 ,,literature ,,on ,,ancestry ,,of ,,insects1 ,,etc4 ,mller1 ,fritz4 ,fr ,darwin1 #ahfi1 pp4 #add1 #fg ,figs4 ,brauer1 ,friedrich4 ,betrachtung ueber die ,verwandlung der ,insekten im ,sinne der ,descendenz-,theorie4 7,verhandlung d4 k4k4 zool4 bot4 ,gesell4 ,wien41 #ahfi1 #a ,taf41 pp4 #a-bj47 ,packard1 ,a4 ,s4 ,amer4 ,naturalist1 iii1 p4 #de1 ,march1 #ahfi4 ---- ,proc4 ,boston ,soc4 ,nat4 ,hist41 xiv1 #ahgj1 p4 #fa4 ---- ,amer4 ,nat41 iv1 ,feb4 #ahga1 p4 #gef2 v1 #ahga1 pp4 #eb1 #efg4 ---- ,embryological ,studies4 7,memoirs ,peabody ,acad4 ,sc4 ,salem1 #ahga-gb47 ---- ,our common insects1 #ahgc1 ,chapter on ,ancestry of ,insects1 pp4 #age-agh4 ---- ,third ,report ,u4 ,s4 ,ent4 ,commission1 #ahhc1 pp4 #bie-cjd4 ,lubbock1 ,john4 ,on the origin of insects4 7,journ4 ,linn4 ,soc41 ,london1 xl1 #ahgc47 ---- ,origin and metamorphoses of insects4 7,nature1 #ahgc in book form1 #ahgd1 pp4 #ajh1 #ff ,figs47 ,mayer1 ,paul4 ,ueber ,ontogenie and ,phylogenie der ,insekten4 7,jena4 ,zeitschr4 ,wissens41 x1 #ahgf1 pp4 #abe-bba1 #d ,taf47 ,hyatt1 ,a41 and ,arms1 ,j4 ,m4 ,insecta4 7,bost4 ,soc4 ,nat4 ,hist4 ,guides for science-teaching1 viii47 ,boston1 #ahij1 pp4 #cjj1 #ac ,pls41 #bbc ,figs4 c4 ,growth and increase in size of the larva ,the rapidity of growth and enormous increase in size in early life is especially noticeable in caterpillars and other phytophagous larv4 ,the latest observations are those of ,trouvelot on ,telea polyphemus4 ,when this silkworm hatches1 it weighs #abj of a grain4 ,when #aj days old it weighs a grain1 or #aj times the original weight4 #bj days old it weighs #c grains #fj times the original weight4 #cj days old it weighs #ca grains #fbj times the original weight4 #dj days old it weighs #ij grains #ahjj times the original weight4 #ef days old it weighs #bjg grains #dadj times the original weight4 8,when10 he says 8a worm is #cj days old1 it will have consumed about #ij grains of food2 but when #ef days old1 it is fully grown and has consumed not less than #abj oak leaves1 weighing of a pound2 besides this it has drank not less than an ounce of water4 ,so the food taken by a single silkworm in #ef days equals in weight #hf1jjj times the primitive weight of the worm4 ,of this about of a pound becomes excrementitious matter1 #bjg grains are assimilated1 and over #e ounces have evaporated40#id ,dandolo stated that the ,asiatic silkworm 7,bombyx mori7 weighs on hatching not over #aajj of a grain1 but when fully grown about #ie grains4 ,during this period1 therefore1 it has increased #iejj times its original weight1 and has eaten #fj1jjj times its weight of food4 ,newport thought this estimate of the amount of food was a little too great4 ,but comparing it with ,trouvelot's estimate for the ,american silkworm1 which weighs when hatched five times as much1 it would not appear to be so4 ,newport found that the larva of ,sphinx ligustri at the moment of leaving the egg weighs about #ahj of a grain1 and when fully fed #abe grains1 so that in the course of #cb days it increases about #iigf times its original weight4 ,this proportion of increase is exceeded by the larva of ,cossus ligniperda1 which1 boring in the trunks of trees1 remains about three years in the larva state1 and increases1 according to ,lyonet1 to the amount of #gb1jjj times its first weight4 ,newport adds that those larv in which the proportion of increase is the greatest1 are usually those which remain longest in the pupa state1 as in the silkworm4 8,thus ,redi observed in the maggots of the common flesh-flies a rate of increase amounting to about #bjj times the original weight in #bd hours1 but the proportion of increase in these larv does not at all approach that of the ,sphinx and ,cossus40 ,from his observations on the larva of one of the wild bees 7,anthophora retusa7 ,newport believes that this is also the case with the ,hymenoptera4 ,the weight of the egg of this insect is about #aaej of a grain1 and the average of a full-grown larva #fhaj grains1 so that its increase is about #ajbj times its original weight2 8which compared with that of the ,sphinx of medium size1 is but as #a to #i1 and to a ,sphinx of maximum size only as #a to a little more than #aa40 ,the growth is most rapid after the last moult4 8,thus a larva of ,sphinx ligustri1 which at its last change weighed only about #ai to #bj grains1 at the expiration of eight days1 when it was fully grown1 weighed nearly #abj grains40 7,newport47 d4 ,the process of moulting 7ecdysis7 ,insects periodically shed the exoskeleton1 together with the chitinous lining of their internal organs of ectodermal origin1 which thus sloughed off are called the exuvia4 ,the process in the locust has been described by ,riley4#ie ,it occupies from half to three-quarters of an hour 7,fig4 #efe74 ,this process has naturally1 from the ease with which it can be observed1 been most frequently examined in the ,lepidoptera1 though careful and detailed observations of the inner and outer changes are still greatly needed1 especially in other orders4 ,in the caterpillar of most moths1 especially one of the more generalized bombycine moths1 on slipping out of its egg-shell the head is of enormous size as compared with the body1 but the latter soon fills out after the creature has eaten a few hours2 the head1 of course1 does not during this time increase in size1 and the larv of different instars may be exactly distinguished1 as ,dyar has shown1 by the measurements of the head4 ,illustration3 ,,fig4 #efe4--,process of moulting from nymph to imago in the locust 7,m4 spretus73 a1 nymph with skin just split on the back2 b1 the imago drawing itself out1 at c1 nearly free2 d1 the imago1 with wings expanded2 e1 the same with all parts perfect4--,after ,riley4 ,before the caterpillar moults1 it stops feeding1 and the head is now small compared with the body2 the head of the second instar is now large1 situated partly under the much-swollen prothoracic segment1 and pushes the head of the first instar forward4 ,newport has well described the mode of shedding the skin in ,sphinx ligustri1 and his detailed description will apply to most lepidopterous larv4 ,the whole body is wrinkled and contracted in length1 and there are occasionally powerful contractions and twitchings of its entire body2 the skin becomes dry and shrivelled1 and is gradually separated from the new and very delicate one of the next instar beneath4 ,after several powerful efforts of the larva the old skin cracks along the middle of the dorsal surface of the mesothoracic segment1 and by repeated efforts the fissure is extended into the #ast and #c;d segment1 while the covering of the head divides along the vertex and on each side of the clypeus4 8,the larva then gradually presses itself through the opening1 withdrawing first its head and thoracic legs1 and subsequently the remainder of its body1 slipping off the skin from behind like the finger of a glove4 ,this process1 after the skin has once been ruptured1 seldom lasts more than a few minutes4 ,when first changed the larva is exceedingly delicate1 and its head1 which does not increase in size until it again changes its skin1 is very large in proportion to the rest of the body40 7,art4 ,insecta1 etc47 ,trouvelot's account is more detailed and an advance on that of ,newport's view4 ,he explicitly states1 and we know that he was a very close observer1 that the old skin is detached by 8a fluid which circulates between it and the worm40 ,his account is as follows3 ,the polyphemus worm1 like all other silkworms1 changes its skin five times during its larval life4 ,the moulting takes place at regular periods1 which comes around about every #aj days for the first four moultings1 while about #bj days elapse between the fourth and fifth moulting4 ,the worm ceases to eat for a day before moulting1 and spins some silk on the vein of the under surface of a leaf2 it then secures the hooks of its hind legs in the texture it has thus spun1 and there remains motionless2 soon after1 through the transparency of the skin of the neck1 can be seen a second head larger than the first1 belonging to the larva within4 ,the moulting generally takes place after four o'clock in the afternoon2 a little before this time the worm holds its body erect1 grasping the leaf with the two pairs of hind legs only2 the skin is wrinkled and detached from the body by a fluid which circulates between it and the worm2 two longitudinal bands are seen on each side1 produced by a portion of the lining of the spiracles1 which at this moment have been partly detached2 meanwhile the contractions of the worm are very energetic1 and by them the skin is pulled off and pushed towards the posterior part2 the skin thus becomes so extended that it soon tears just under the neck1 and then from the head4 ,when this is accomplished the most difficult operation is over1 and now the process of moulting goes on very rapidly4 ,by repeated contractions the skin is folded towards the tail1 like a glove when taken off1 and the lining of the spiracles comes out in long white filaments4 ,when about one-half of the body appears1 the shell still remains like a cap1 enclosing the jaws2 then the worm1 as if reminded of this loose skull-cap1 removes it by rubbing it on a leaf2 this done1 the worm finally crawls out of its skin1 which is attached to the fastening made for the purpose4 ,once out of its old skin1 the worm makes a careful review of the operation1 with its head feeling the aperture of every spiracle1 as well as the tail1 probably for the purpose of removing any broken fragment of skin which might have remained in these delicate organs4 ,not only is the outer skin cast off1 but also the lining of the air-tubes and intestines1 together with all the chewing organs and other appendages of the head4 ,after the moulting1 the size of the larva is considerably increased1 the head is large compared with the body1 but #h or #aj days later it will look small1 as the body will have increased very much in size4 ,this is a certain indication that the worm is about to moult4 ,every #aj days the same operation is repeated4 ,from the fourth moulting to the time of beginning the cocoon the period is about #af days4 7,amer4 ,naturalist1 i1 pp4 #cg1 #ch47 ,little has been recorded as to the exact mode of casting the larval skin in ,coleoptera4 ,slingerland states that ,euphoria inda when pupating sheds the larval skin off the anal end in the same way as in caterpillars1 while in ,pelidnota punctata the larval skin splits down the whole length of the back1 retains the larval shape1 and forms a covering for the pupa which remains inside4 7,can4 ,entomologist1 xxix1 p4 #eb47 ,the old larval skin in the ,coccinellid and certain ,chrysomelid is retained crumpled up at the end of the body1 while in ,dermestes1 ,anthrenus1 etc41 it cloaks the pupa4 ,not only is the integument1 with its hairs1 set1 and other armatures1 as well as the cornea or facets of the eyes1 shed1 but also all the lining or intima of those internal organs which have been originally derived by an ingrowth or invagination of the ectoderm are likewise cast off1 with the probable exception1 of course1 of the mid-intestine1 which is endodermal in its origin4 ,even so early an observer as ,swammerdam noticed that the internal lining of the alimentary canal comes away with the skin4 ,he states that the larva of ,oryctes nasicornis sheds both the lining of the colon1 and of the smaller as well as the larger branches of the trache4 ,careful observations are still needed on the internal changes at ecdysis of most insects4 ,newport seems to have observed more closely than any one else1 notwithstanding the great number who have reared caterpillars but have not carefully observed these points1 the extent of the process internally4 ,he informs us3 8,the lining of the mouth and pharynx1 with that of the mandibles1 is detached with the covering of the head1 and that of the large intestines with the skin of the posterior part of the body1 and besides these also the lining of the tracheal tubes4 ,the lining of the stomach itself1 or the portion of the alimentary canal which extends from the termination of the sophagus to the insertion of the so-called biliary vessels1 is also detached1 and becomes completely disintegrated1 and appears to constitute part of the meconium voided by the insect on assuming its imago state40 7,art4 ,insecta1 p4 #hgf47 ,newport states on another occasion that he had 8noticed the remarkable circumstance now explained by the fact that the mid-intestine is of endodermal origin that the mucous lining of the true ventriculus was not cast off with the rest1 but was discharged with the fecula40#if ,burmeister also observed that the smaller trache as well as the internal tunic of the colon of ,libellul are shed4 ,in the apodous larv of ,hymenoptera which live in cells1 as we have observed in those of ,bombus1 during the process of moulting1 the delicate skin breaks away in shreds1 probably owing to the tension due to the unequal growth of the different parts of the body4 8,thus after the skin beneath has fully formed1 shreds of the former skin remain about the mouth-parts1 the spiracles1 and anus4 ,upon pulling upon these1 the lining of the alimentary tube and trache can be drawn out1 sometimes1 in the former case1 to the length of several lines40#ig ,we then added1 8,as all these internal systems of vessels are destined to change their form in the pupa1 it may be laid down as a rule in the moulting of insects and ,crustacea1 that the lining of the internal organs1 which is simply a continuation of the outer tegument1 or arthroderm1 is1 in the process of moulting1 sloughed off with that outer integument40 ,we have satisfied ourself that in the larv of the ,lepidoptera 7e4g4 ,datana7 the trache at the time of ecdysis undergo a complete histolysis1 and arise de novo from hypodermal cells1 the so-called spiral threads originating from elongated peritracheal nuclei4 7,see p4 #ddi1 ,fig4 #dab47 ,this is undoubtedly also the case with the salivary ducts1 which are strengthened and rendered elastic by tnidia like those of trache4 ,as the urinary tubes are diverticula of the proctodum1 itself an ectodermal invagination1 they may also1 though not lined with a chitinous intima1 be renewed4 ,with little doubt the intima of the ducts of poison1 spinning1 and most1 if not all the other glands1 though certainly the dermal glands1 is exuviated4 ,we have found that the lobster in moulting sheds1 besides the skin with the most delicate set1 the lining of the proventriculus1 and the apodemes of the head and thorax1 hence it is most probable that the tentorium of the head of insects as well as the apodemes and phragmas of the thorax are exuviated4 ,the formation of the inner skin1 or that of any succeeding stage 7instar71 is due to the secretion of the structureless chitinous layer by the cells of the hypodermis1 during the process of histogenesis4 ,these cells at this time are very active1 and the formation of the new layer of chitin arrests the supply of nourishment to the old skin1 so that it dries1 hardens1 and with the aid of the fluid thrown out at this time separates from the new chitinous layer secreted by the hypodermis4 ,mention of this fluid1 which ,newport was the first to observe1 and which he says causes the separation of the old from the underlying fresh integument of the caterpillar1 recalls a passage in ,hatchett-,jackson's ,studies in the morphology of the ,lepidoptera1 which we quote on a succeeding page1 where he calls attention to the formation of such a liquid1 which in the reptiles facilitates the process of moulting1 adding1 8,whether such is the case with the moult of the caterpillar1 ,i do not know40 ,is it not also possible that the growth of the set or tubercles on the cuticle of the caterpillar may likewise serve to loosen and detach the overlying skin about to be cast off8 ,after writing the foregoing1 we find that ,miall and ,denny have suggested that the set of the cockroach probably serve the same purpose as the casting-hairs of the crayfish and reptiles4 ,it is well known that in the crayfish and in lizards the skin is first loosened by the growth of temporary hairs or set1 which locally grow inward from the old cuticle and push the skin away when it is shuffled off by the movements of the body1 jaws1 and limbs1 as well as the body in general4#ih ,such spines arise in the pupa of many insects1 for ,verhoeff finds that the spines and teeth of pupal fossorial and other ,hymenoptera1 as well as ,coleoptera1 function as moulting-processes for loosening and pushing off the last larval skin1 rather than for locomotion4 ,he also claims that the spines of the pupa of the dipterous ,anthrax are both for locomotion and for boring1 especially the spines on the head and tail4 ,he therefore divides these pupal spines into helcodermatous 7boring or tearing7 and locomotor spines4 ,gonin has fully confirmed ,newport's discovery of the exuvial fluid4 ,he states that during pupation the outside of the pupa1 especially the parts of the head and thorax 8is coated with a viscous liquid secreted by special glands40 ,the parts only harden subsequent to pupation after exposure to the air 7p4 #da74 ,his observations were made under the direction of ,professor ,bugnion1 who kindly writes us3-- 8,m4 ,gonin has proved the formation of a liquid which passes under the cuticle at the time of the last moult and facilitates exuviation4 ,we think that this liquid is secreted by large cells 7unicellular glands7 which we see especially on the surface of segments #a-c4 ,these cells form part of the hypodermis1 and their pores open under the cuticle40 ,in a subsequent letter enclosing a sketch kindly made for me by ,m4 ,gonin 7,fig4 #eff71 ,professor ,bugnion writes me ,aug4 #bd1 #ahig1 regarding the functions of the large hypodermal cells 7l4 hy71 as follows3 8,it seems to me1 in fact1 after having again examined the sections1 that the function of these cells is not sufficiently elucidated4 ,indeed these cells occur only in the section passing through the #ast segment1 between the head and #ast thoracic segment4 ,it would seem1 if these cells supply the liquid which lubricates the surface at the time of ecdysis1 that they should be spread over the entire surface of the body4 ,moreover1 these cells have no distinct orifice1 and although there is seen at times to issue streams of a substance 7coagulated by the reagents71 they cannot be compared with true unicellular glands like those of the epidermis of fishes1 amphibians1 etc4 8,on the other hand1 if it is the blood which oozes out on the surface 7according to your hypothesis71 it would seem that the loss of blood would cause the death of the larva4 ,i believe then it is due to the secretion of the hypodermis which spreads over the whole surface when the cells are still soft 7not yet hardened from contact with the air74 ,at all events1 there is a liquid spread over the surface2 it is this liquid which glues the wings and the legs to the body at the moment the caterpillar issues from the rent in its skin4 ,if at this instant we plunge the pupa in the water the liquid is dissolved1 and the feet1 wings1 etc41 are not glued to the body40 ,dr4 ,t4 ,a4 ,chapman also writes us3 8,there is no question about the existence of a fluid between the two skins at moulting4 ,in hairy larvae the hairs are always wet at first1 or if the skin be renewed rather more quickly than the larva does it naturally1 the wetness of both surfaces is obvious4 ,i do not know the nature of the fluid1 but it is related to that which hardens into the dense pupal case1 and also hardens in a less degree the skin of the larva4 ,i suppose it must contain some chitin in a soluble form4 ,if a newly cast larva skin be taken1 there is no difficulty in extending the shrivelled mass to its full length and dimensions1 but if a short time elapses1 this chitin hardens1 and the skin cannot be extended after soaking in water1 alcohol1 ammonia1 or any other solvent ,i have tried40 ,it has been stated that there is a subimaginal pellicle in ,lepidoptera1 but as ,dr4 ,chapman writes me1 8what has been observed has been some of the inner pupal dissepiments1 such as the pupal cases of the under wings10 etc4 ,they may be observed in the head of the tineid pup1 and other small moths4 ,we have thought that the delicate1 purplish1 powdery layer left in the cast shells of the pup of saturnians1 ,catocal1 and other moths1 might possibly be such a pellicle1 but this view has been dispelled by the following statement of ,professor ,bugnion in a letter answering an inquiry whether he had noticed such a pellicle4 8,a liquid which is secreted in a few minutes at the time of the last moult1 forms in drying a yellowish layer spotted with black 7in ,pieris brassic74 ,this layer extends around the entire pupa1 and serves both to protect it and to glue together the wings1 legs1 etc41 in their new position4 ,the dried liquid on the surface of the pupa1 and by means of which the appendages are glued to the surface1 very likely corresponds to the pellicle of which you speak40 ,the newly exposed integument is at first pale and colorless1 but soon assumes the hues peculiar to the species1 and the insect1 at first exhausted1 after a short rest becomes active4 ,illustration3 ,,fig4 #eff4--,transverse section through the prothoracic segment 7ventral face7 of larva of ,pieris brassic1 about #ab hours before pupation3 c1 cuticula2 l4 hy1 large glandular 787 hypodermal cells2 gradually passing into normal hypodermal cells 7hy74--,gonin del4 ,e4 ,howgate has noticed under the microscope peculiar internal movements in a small immature transparent geometrid while moulting4 8,each separate segment10 he says1 8commencing at the head1 elongated within the outer skin1 whilst the next ones remained in their former state4 ,each segment in its turn behaved in this curious manner until the last was reached1 when the motion was reversed and proceeded toward the head1 when it was again reversed4444 ,the whole proceeding appeared as if the larva was gliding within itself1 segment after segment1 the outer skin remaining as if held by the other segments1 whilst the particular one in motion freed itself within4 ,after remaining motionless for a short interval1 the skin near the head swelled and burst1 open at the back4444 ,presently out comes the head of the new caterpillar1 pushing forward the old one4444 ,after a short struggle the new true legs appear1 pushing off and treading under foot the old ones4 ,then by violent wriggling movements the abdominal legs were extricated4 ,then all is clear1 and the larva1 which is quite exhausted1 coils itself up and literally pants for breath40 7,the ,naturalist1 ,november1 #ahhe1 ,no4 #abd1 p4 #cff1 quoted in ,psyche1 iv1 p4 #cbg1 #ahhg47 ,since the worms and most other ametabolous invertebrates are not known to moult their integument1 the body steadily increasing in size without frequent changes of skin1 it seems that growth may go on and still be accompanied by considerable changes in shape of the body without change of skin4 ,frequent ecdyses appear1 then1 to be the result of the great and sudden changes of the body1 necessitated by the adaptation of the animal to new or unusual conditions of life4 ,in young ,daphnia1 a cladocerous crustacean1 as many as eight moults were observed in a period of #ag days1 and spiders frequently moult even after reaching their full size4 ,the swollen bodies of the gravid female of ,gastrophysa1 ,melo1 or of ,termites1 and of the honey ant show that the skin can stretch to a great extent1 but in the metamorphoses of ,crustacea and of insects1 whose young are more or less worm-like or generalized in form1 with fewer segments and appendages1 or with appendages adapted for quite different uses from those of mature life1 the necessity for a change of skin is seen to be necessary for mechanical reasons4 ,hence ,crustacea and insects moult most frequently early in life1 when the changes of form are most thoroughgoing and radical1 while simple growth and increase in size are most rapid at the end of larval life1 as seen both in shrimps and crabs1 and in insects4 ,the hibernating caterpillars of certain butterflies are known to moult once oftener than those of the summer brood4 ,mr4 ,w4 ,h4 ,edwards has discussed the subject with much detail4 8,there seems10 he says1 8to be a necessity with the hibernators of getting rid of the rigid skin in which the larva has passed the winter2 that is1 if the hibernation has taken place during the middle stages1 as it does in ,apatura and ,limenitis4 ,in these cases very little food is taken between the moult which precedes hibernation and the one which follows it1 and the larva while in lethargy is actually smaller than before the next previous moult4 ,the skin shrinks1 and has to be cast off before the awakened larva can grow4 ,those species 7observed7 whose larva moults five times in the winter brood require but four moults during the summer40 ,he adds that while the larva is in lethargy1 it is actually smaller than before the next previous moult4 ,dr4 ,dyar writes3 8,i think there is no doubt about the number of stages of arctian larv4 ,they seem to have a great capacity of spinning out their life-history by interpolated stages 7as regards width of head74 ,i think it is because so many of them hibernate1 and only a single brood extends throughout the season40 7,psyche iii1 p4 #afa47 ,on the other hand1 it is difficult to understand why the caterpillars of arctians moult so frequently1 nearly twice as often as in most other caterpillars1 though the changes of form and armature are so slight4 ,dr4 ,chapman also writes me3 8,arctians resemble bears 7,arctos71 polar and others1 in having long hairs to protect them during winter1 and are1 in fact1 typically hibernators4 ,many of them have to half-hibernate1 having warmth enough to keep them awake1 but not enough food for growth1 but their tissues1 at least the chitinous ones of the cutis1 and also probably1 and perhaps especially1 of the alimentary canal1 become old and effete1 and require the rejuvenescence acquired by a moult4 ,other smooth-skinned hibernators have similar capabilities40 ,chapman has shown in his paper on ,acronycta that these caterpillars of this genus illustrate how larv may lose a moult1 and they do so to acquire a sudden change of plumage4 ,the number of moults in insects of different orders4--,it will be seen from the data here presented that the number of moults is as a rule greatest in holometabolic insects with the longest lives1 and that an excessive number of ecdyses may at times be due to some physical cause1 such as lack of food combined with low temperature4 ,in ,campodea there is a single fragmentary moult 7,grassi71 while the ,collembola 7,macrotoma plumbea7 shed their skin throughout life4 7,sommer47 ,in the winged insects1 especially ,lepidoptera1 the number of moults is dependent on climate4 ,insects of wide distribution growing faster in warmer climates consequently shed their skins oftener2 for example1 the same species may moult once oftener in the southern than in the northern ,states1 as in the case of ,callosamia promethea1 which in ,west ,virginia is double-brooded4 ,hibernating larv moult once oftener than those of the summer brood4 7,w4 ,h4 ,edwards47 ,weniger by rearing the larv of ,anthera mylitta and ,eacles imperialis1 and which1 when reared under normal conditions1 actually have six stages1 found that when reared in a warm moist atmosphere of about #be ,c4 they have but five stages1 i4e4 moult but four times4 ,in the hot and moist climate of ,ceylon1 ,a4 mylitta has but five stages4 7,psyche1 v1 p4 #bh47 ,among ,orthoptera ,acrydians moult five times2 ,diapheromera femorata but twice 7,riley72 a katydid 7,microcentrum retinervis7 moults four times 7,comstock74 ,mantis religiosa1 according to ,pagenstecher1 moults seven times1 having eight stages1 including that before the amnion is cast1 but the first 8moult0 being an exuviation of the amnion1 the number of stages is seven4 ,cockroaches 7,periplaneta americana7 are said by ,marlatt to 8pass through a variable number of moults1 there being sometimes as many as seven40 ,in the ,homoptera there are1 in general1 from two to four moults2 thus in ,typhlocyba there are five stages1 and in ,aphis at least three1 and in ,psylla four during the nymphal state4 ,psocus has four4 ,riley states that the nymph of the female coccid1 ,icerya purchasi1 sheds its skin three times1 and that of the male twice4 ,notwithstanding its slow growth1 ,riley says1 the #ag-year ,cicada moults oftener than once a year1 and the number of larval stages probably amounts to #be or #cj in all4 ,the bed-bug sheds its skin five times2 and with the last moult appear the minute wing-pads characteristic of the adult4 ,in ,conorhinus sanguisuga there are 8at least two larval stages and pupal stages40 7,marlatt47 ,in the dragon-flies moulting occurs1 ,calvert thinks1 many times1 since the rudiments of wings are said by ,poletaiew to only appear in odonate nymphs after the third or fourth moult4 ,in the ,may-fly1 ,chloon1 the number of ecdyses is #bj4 ,the neuropterous ,ascalaphus 7,helecomitus7 insimulans of ,ceylon moults three times before pupating4 ,among the ,mecoptera ,felt has shown that ,panorpa rufescens moults seven times4 ,in ,coleoptera the normal or usual number is not definitely known2 ,melo moults five times1 but this is a hypermetamorphic insect2 ,tribolium confusum has been carried by ,mr4 ,chittenden through seven moults4 ,phytonomus punctatus1 the clover-leaf weevil1 moults three times1 according to ,riley1 who has observed that ,dermestes vulpinus passes through seven larval stages4 ,in the breeding jars1 with plenty of food and a constant temperature of from #fh to #gh ,f41 the larv cast their #ast skin in from four to nine days1 the great majority moulting at seven days4 ,under the same conditions the #b;d skin was cast at from four to seven days1 the majority moulting at six days2 the #c;d skin at from three to six days1 the majority moulting at five days2 and the #dth skin at from three to six days1 the majority moulting at five days2 the #eth skin at from five to seven days1 and the #fth skin at six days4 ,there are thus seven larval stages4 7,report for #ahhe1 p4 #bfj47 ,riley has ascertained that by rearing isolated larv of ,tenebrio molitor1 one after being kept nearly a year had moulted #aa times1 when it died4 ,a second larva1 hatched ,june #e1 had moulted #ab times by ,june #aj of the following year1 7#ahgg71 when it also died4 ,of ,t4 obscurus three larv were reared to the imago state4 ,one moulted #aa times by ,aug4 #cj of the same year1 pupated ,jan4 #bj1 #ahgg1 and finally became a beetle ,feb4 #g1 #ahgg4 ,the other two both moulted #ab times1 and reached the imago stage ,feb4 #ah and ,march #i1 respectively4 8,all were1 as nearly as possible1 under like conditions of food and surroundings1 and in all cases the moult that gave the pupa is not considered among the larval moults40 ,two larv of the museum pest 7,trogoderma tarsale7 were kept by ,riley in a tight tin box with an old silkworm cocoon4 8,they were half-grown when placed in the box4 ,on ,nov4 #h1 #ahhj1 there were in the box #bh larva skins1 all very much of a size1 the larva having apparently grown but little4 ,the skins were removed and the box closed again as tightly as possible4 ,recently1 or after a lapse of two years1 the box was again opened and we found one of the larv dead and shrivelled up2 but the other was living and apparently not changed in appearance4 ,there were #ae larva skins in the box4 ,he could not tell when the one larva died1 but it is certain that within a little more than three and a half years1 two larv shed not less than #dc skins1 and that one larva did not1 during that time1 appreciably increase in size4 ,we know of no observations which indicate the normal or average length of life1 or number of moults in either ,tenebrio or ,trogoderma1 but it is safe to assume from what is known1 in these respects1 of allied species1 that in both the instances here referred to1 but particularly in the case of ,trogoderma1 development was retarded by insufficient nutrition1 and that the frequent moulting and slow growth resulted therefrom1 and were correlated40#ii ,further observations such as these are greatly needed4 ,of the ,siphonaptera the common cat and dog flea 7,pulex serraticeps7 moults three times before pupating4 7,howard47 ,in ,lepidoptera the usual or average number of moults is four1 but the number varies considerably1 the greatest number yet known occurring in ,phyrrarctia isabella1 which1 ,dr4 ,dyar informs me1 moults #aj times4 ,from ,dyar's observations it appears that there are usually five larval stages1 but six and seven stages are not infrequent1 while there are seven in ,seirarctia echo1 eight in ,ecpantheria scribonia1 ,scepis1 and ,apatelodes1 and nine and ten in arctians1 while the ,european ,nola centonalis moults nine times1 other species of this genus shedding their skins six times4 7,buckler47 7,psyche1 v1 pp4 #dbj-dbb47 ,callosamia promethea appears1 as a rule1 to moult but three times4 ,orgyia antiqua was found by ,hellins to moult from three to five times4 ,riley found that in ,o4 leucostigma the males moult four times1 the female four1 but sometimes five times1 while ,dyar states that in ,o4 gulosa the male larv moult three or four times1 the female always four times2 in ,o4 antiqua1 however1 there are six stages1 and in the female seven4 ,lithocolletis1 ,chambers thinks1 as a rule1 moults eight times1 and ,comstock thinks that ,l4 hamadryadella casts its skin seven or eight times4 ,in the blow-fly 7,calliphora7 ,leuckart and ,weismann have inferred at least two moults1 while ,weismann suspected that there are as many as four4 ,in ,musca domestica we have observed that the larva moults three times2 in strid there are three larval stadia4 7,brauer47 ,in ,corethra there are four larval moults1 and ,miall thinks there are probably as many in ,chironomus4 ,passing to the phytophagous ,hymenoptera1 there are three moults or four larval stages in ,nematus erichsonii1 but ,dyar informs us that less than four stages in saw-fly larv is very rare1 that he has only one record of less than five1 and that that is doubtful2 8five for nematid1 six and seven for others1 is certainly the rule4 ,the highest ,i have is the indication of #aa stages for ,harpiphorus varianus1 but this again is an inference only1 and attended with doubt40 7,can4 ,ent41 xxvii1 p4 #bjh47 ,in ,bombus we have observed five different sizes of larv1 and hence suppose the least number of ecdyses is five1 while we are disposed to believe that this insect1 as well as wasps and bees1 in general shed their skins as many as eight times during their entire existence4 ,the honey-bee1 ,cheshire thinks1 since he has found the old and ruptured pellicles1 probably moults six times before it spins its cocoon1 or passes into the semipupa condition4 7,bees and ,bee-keeping1 p4 #bj47 ,as to the cause of the great number of moults in the arctians and in the beetles experimented with by ,riley1 it would seem that cold and the lack of food during hibernation were the agents in arctians1 and starvation or the lack of food in the case of the beetles1 such cause preventing growth1 though the hypodermis-cells retained their activity4 ,reproduction of lost limbs4--,here might be discussed the subject of the renovation or renewal of maimed or lost limbs1 or the reparation of other injuries4 ,as is well known1 the clenterates1 echinoderms1 and worms under certain circumstances multiply by self-division1 or if artificially mutilated1 the parts are gradually restored by cell-proliferation or histogenesis4 ,it is so with the antenn and legs of crustaceans as well as the digits and tail of salamanders4 ,the experiments first made by ,le ,pelletier#ajj on spiders1 and later by ,heineken1#aja and others after him1 on different spiders1 as well as on ,orthoptera and ,hemiptera 7,blatta1 ,reduvius1 etc471 have proved that antenn and legs and other external parts which have been injured or shortened1 or entirely cut off in young individuals1 are replaced at the next1 or after successive moults1 though generally in diminished size4 ,this does not usually occur in adult life1 and the process of reparation of lost parts is apparently due to the active growth of the cells of the parts affected during the process of moulting1 when the histolysis of the maimed or diseased parts is succeeded by the rapid development of new cells1 not only of the hypodermis1 but also of the more specialized tissues within4 ,and this tends to prove that such histolysis and making over of the muscles and other structures within occur especially in all metamorphic insects1 and also in ametabolous forms1 though the process has been most thoroughly examined in the ,diptera1 where these changes are more marked4 ,gonin has found that the thoracic legs of the caterpillar correspond only to the tarsi of the imago 7,fig4 #fjh74 ,it results1 he says1 from this fact that in accordance with the observations of ,raumur 7which were wrongly interpreted by ,newport and ,knckel ,d',herculais7 that the amputation of the legs of the larva does not involve the entire leg1 but only the extremity of the leg of the imago4 ,formation of the cocoon4--,while the larv of many insects1 as those of the butterflies1 suspend themselves before transforming1 and spin no cocoon1 or dig into the earth for protection and to secure an immunity from too great changes of temperature1 a large proportion of the larv of metabolous insects which lead an inactive pupal life1 line their earthen cells with silk1 or spin a more or less elaborate case of silk1 called the cocoon4 ,we have seen that the inactive pupa of the male scale-insects is covered by the scale itself1 or even in one case the insect forms a true cocoon of fibres of wax4 ,the aquatic larv of the ,neuroptera and ,coleoptera creep out of the water1 and by the movements of their bodies make a rude earthen cell in the bank1 while that of ,donacia spins a dense1 leathery cocoon 7,fig4 #efg7 in the earth4 ,the larv of the ,embiid are protected by a cocoon1 which they renew at each moult4 ,coniopteryx spins an orbicular cocoon1 the ,hemerobiid a spherical1 dense1 whitish one4 ,the ,trichoptera transform within their larval cases1 which thus serve as cocoons1 as do certain case-bearing ,lepidoptera1 notably the ,psychid4 ,illustration3 ,,fig4 #efg4--;,cocoon 7natural size7 of ,donacia proxima4 ,illustration3 ,,fig4 #efh4--;,cocoon and larva of ,lucanus dama4 ,the pupa of certain leaf-eating beetles 7,chrysomelid71 as well as the ,coccinellid1 ,dermestid1 ,hister1 etc41 are usually protected by the cast larval skin1 which is retained1 forming a rude shelter4 ,while many beetles spin an oval cocoon 7,gyrinus1 ,silphid71 the wood-boring species make one of chips glued together1 and that of ,lucanus1 which feeds on decayed wood1 is lined with silk 7,fig4 #efh74 ,anobium constructs a silken cocoon1 interweaving the fine particles of its thin castings2 the larv of weevils also usually spin silken cocoons4 ,illustration3 ,,fig4 #efi4--,larva 7a71 puparium 7b71 and imago 7c7 of ,sarcophaga1 enlarged4 ,illustration3 ,,fig4 #egj4--;a1 ,erax bastardi2 b1 pupa4--,after ,riley4 ,the larval skin of the coarctate ,diptera is retained as a protection for the soft-bodied pupa within1 the old larval skin separating from the integument of the semipupa4 ,to this cocoon-like covering of the coarctate pupa we have restricted the term puparium1 originally used by ,kirby and ,spence to designate the pupa4 ,the puparium is usually cylindrical or barrel-shaped1 rounded at each end4 ,illustration3 ,,fig4 #ega4--,puparium of ,hypoderma bovis3 a1 side2 b1 ventral view1 showing exit hole of adult2 c1 cap which splits off for exit of fly4--,after ,clark1 from ,osborn1 ,bull4 #e1 ,div4 ,ent4 ,u4 ,s4 ,dept4 ,agr4 ,in the ,diptera cyclorhapha1 or common house and flesh flies1 etc41 the puparium remains in vital connection1 by means of four trache1 with the enclosed pupa1 which escapes from the case through a curved seam or lid at the anterior end and not by a slit in the back1 as do the orthoraphous families1 represented by the horse-fly 7,tabanid1 ,asilid1 ,fig4 #egj71 etc41 where in some cases the obtected pupa remains within the loose envelope formed by the old larval skin1 which ,brauer calls a false puparium4 ,the dry1 hard puparium is burst open at the cephalic end when the fly emerges1 by means of the frontal vesicle1 which is distended with fluid 7,fig4 #ega74 ,the exact mode of spinning the cocoon by caterpillars has been carefully observed by ,l4 ,trouvelot in the case of the polyphemus silkworm4 8,when fully grown1 the worm1 which has been devouring the leaves so voraciously1 becomes restless and crawls about the branches in search of a suitable place to build up its cocoon2 before this it is motionless for some time1 holding on to the twig with its front legs1 while the two hind pair are detached2 in this position it remains for some time1 evacuating the contents of the alimentary canal until finally a gelatinous1 transparent1 very caustic fluid1 looking like albumen1 or the white of an egg1 is ejected2 this is a preparation for the long catalepsy that the worm is about to fall into4 ,it now feels with its head in all directions1 to discover any leaves to which to attach the fibres that are to give form to the cocoon4 ,if it finds the place suitable1 it begins to wind a layer of silk around a twig1 then a fibre is attached to a leaf near by1 and by many times doubling this fibre and making it shorter every time1 the leaf is made to approach the twig at the distance necessary to build the cocoon2 two or three leaves are disposed like this one1 and then fibres are spread between them in all directions1 and soon the ovoid form of the cocoon distinctly appears4 ,this seems to be the most difficult feat for the worm to accomplish1 as after this the work is simply mechanical1 the cocoon being made of regular layers of silk united by a gummy substance4 ,the silk is distributed in zigzag lines of about one-eighth of an inch long4 ,when the cocoon is made1 the worm will have moved his head to and fro1 in order to distribute the silk1 about #bed1jjj times4 8,after about half a day's work1 the cocoon is so far completed that the worm can hardly be distinguished through the fine texture of the wall2 then a gummy resinous substance1 sometimes of a light-brown color1 is spread all over the inside of the cocoon4 ,the larva continues to work for four or five days1 hardly taking a few minutes of rest1 and finally another coating is spun in the interior1 when the cocoon is all finished and completely air tight4 ,the fibre diminishes in thickness as the completion of the cocoon advances1 so that the last internal coating is not half so thick and so strong as the outside ones40 7,amer4 ,naturalist1 i1 p4 #hf47 ,the mode of spinning the cocoon of an ichneumon 7,microgaster7 parasitic on ,philampelus has been well described by ,john ,p4 ,marshall1 as follows3-- ,illustration3 ,,fig4 #egb4--,microgaster larv2 spinning their cocoons3 a1 enlarged view of #e4--;,after ,marshall4 ,the first appearance of the parasite is represented in ,fig4 #egb1 #a4 ,a warty excrescence appears on the back of the caterpillar1 which slowly emerges until it is seen to be a larva enclosed in a delicate transparent membrane1 as represented in #b4 ,this it soon succeeds in bursting1 and1 rising to its full length1 balances itself a moment as in #c1 then1 bending double1 it ejects from its mouth a glairy liquid1 which instantly changes to silk1 and fastens the posterior end to the skin of the caterpillar1 as shown in #d1 side view4 ,it now begins to spin its cocoon by attaching a silken thread to the silky mass by which it had previously fastened itself to the caterpillar1 and forming a series of loops of uniform size1 first from right to left1 and then back again from left to right1 as represented in the front view1 #e1 and better in the enlarged view1 #e;a1 the arrow heads showing the direction in which the head of the larva moved while forming the loops4 ,the ends of the series1 numbered #a1 #b1 #c1 #d1 are fastened to the edges of the ventral side of the body1 which thus serves as a measure of the width of the cocoon1 and also acts as a support for the frail fabric in the first stages of spinning4 ,after the larva has fastened the fabric as far up on its ventral surface as it can1 conveniently1 it then begins to spin free1 as shown in the side view1 #f1 where it is represented as just completing the first half of its cocoon1 which resembles in form a slipper4 ,this accomplished1 the larva ceases to spin for the time being1 bends its head1 as in #g1 towards its ventral surface1 and pushes the half cocoon free from its body4 ,the form of the silken fabric enables it to stand unsupported1 while the larva1 sliding its head down to the base1 holds on firmly until it swings its posterior end into the toe of the slipper4 ,figure #egb1 #h1 shows it in the act of changing end for end1 and in #i the larva is seen erect1 beginning at the base to complete the other half of its cocoon2 #aj shows the larva contracting its body as it spins upward for about half the length of the cocoon1 when it again changes end for end1 as shown in #aa1 where it is beginning at the upper part to unite the two sides1 finally enclosing itself as represented in #ab4 ,it may now be seen1 under the microscope1 through the meshes of its cocoon actively engaged in lining the interior with layers of very fine silk ejected from its mouth in great abundance4 ,one half of the cocoon is first lined by a forward and back movement of its head1 and then reversing its position1 it lines the other half in a similar manner4 ,in one case the larva was disengaged from the skin of the caterpillar1 after beginning its cocoon4 ,it1 however1 began again1 and spun a portion while lying on the table4 ,this was removed1 when it began a third time1 and completed its cocoon4 ,in about #aj days the insect made its appearance through a hole in the upper end1 as represented in #ac4 ,the top was eaten off in a perfect circle and hung by a few threads1 so as to resemble a lid as it was thrown back4 ,one caterpillar observed had between #cjj and #djj cocoons on its back and sides1 and another was dissected after more than #cj larv had escaped1 and #acj were discovered in the soft integuments of the back4 ,the figures from #a to #ac are magnified five diameters1 but in order to observe the spinning of the cocoon a power of #ej is required4 7,amer4 ,naturalist1 xii1 pp4 #eei1 #efj47 ,certain differences observed by ,w4 ,a4 ,buckhout in a ,microgaster parasitic on the different species of ,macrosila1 are referred to in the same volume1 p4 #geb4 ,illustration3 ,,fig4 #egc4--;,body of larva of ,lithocolletis4 swollen and filled with cocoons of ,copidosoma1 enlarged4 ,while those chalcidid larv which feed internally on their host1 as a rule1 transform into naked1 more or less coarctate pup1 ,howard states that the larv of ,copidosoma1 ,bothriothorax1 ,homalotylus1 and perhaps others1 which are much crowded within their host1 cause a marked inflation of the body of the latter 7,figs4 #egc1 #egd74 ,the nature of this cocoon-like cell1 and how it is produced1 is unknown4 8,its structure shows it not to be silk1 nor yet the last larval skin of the parasite1 and whether it is an adventitious tissue of the host-larva or a secretion of the parasite1 or is explicable upon other grounds1 ,i cannot say40 ,the silken cocoon of an aphidiid ichneumon has been found by ,miss ,murtfeldt1 and also by ,dr4 ,riley1 under a rose aphid in which it had lived1 and referred by ,howard to the genus ,praon 7,fig4 #ege74 ,sanitary conditions observed by the honey-bee larva1 and admission of air within the cocoon4--,cheshire has observed that after the larva of the honey-bee has spun its cocoon or silken lining of its cell1 it observes the following means of preserving cleanliness4 ,the food given to the larva1 especially during the latter part of the growing period1 contains much pollen1 the cases of the grains of which consist of cellulose1 which is indigestible4 ,illustration3 ,,fig4 #egd4--;,coccinellid larva infested by ,homalotylus obscurus1 enlarged4 ,illustration3 ,,fig4 #ege4--;,cocoon of ,praon under the body of a dead ,aphis1 enlarged4--,this and ,figs4 #egc and #egd after ,howard1 from ,insect ,life4 ,illustration3 ,,fig4 #egf4--,pupation of ,proctotrupes in the body of a larva of a beetle1 representing a case mentioned by ,dr4 ,sharp1 where the parasites have pupated on the outside of the host1 a pair of each attached to nearly each segment of the body of their host4--,after ,sharp4 8,these cases1 with other refuse matters1 collect in quantity within the bowel1 which becomes distended1 since it has no opening4 ,the imprisoned larva1 having little more than enough room for turning1 must be freed of these objectionable residua4444 ,in a word1 the larva turns its head upon its stomach1 and pushes the former towards the base of the cell until its position is reversed1 the tail being outwards2 and1 thus placed1 it laps up all residue of food1 especially from its old clothes previously referred to1 until they are dried1 and practically occupy no space4 ,it now throws up its stomach and bowel1 with all their contents1 and without detaching them from its outer skin1 which is moulted as before1 but in this instance to be pressed against the cell1 so as to form for it an interior lining4 ,the dejectamenta of the bowel in this way lie between the cast skin and cell-wall 7as seen at e1 ,fig4 #egg71 and so the larva remains absolutely unsoiled4 ,it now turns its head and resumes its old position1 joining its cocoon to the edges of its last cast skin1 so that its habitation is relined1 it is cleansed1 and air can still pass to it through the imperceptible openings left by the bees in the sealing4 ,this point is of radical importance1 since breathing is carried on pretty rapidly during the latter part of its subsequent transformations1 the absorbed oxygen permitting then of a production of heat1 and causing also considerable diminution in weight40 ,illustration3 ,,fig4 #egg4--,larva and pupa of honey-bee in their cell3 ,,sl1 spinning-larva2 ,n1 pupa2 ,,fl1 young feeding larva2 co1 cocoon2 sp1 spiracles2 t1 tongue2 m1 mandible2 an1 antenna2 w1 wing2 ce1 compound eye2 e1 excrement2 ex1 exuvium4--,after ,cheshire4 ,as to the passage of air into the bee's cocoon1 ,cheshire states that before the cocoon can be built1 a cover1 technically called sealing1 is put over the larva by its nurses4 ,these covers are made of pollen and wax1 and are pervious to the air4 ,they are more convex and regular in form than those sealing in the honey4#ajb ,,the ,,pupa ,,state ,the word pupa is from the ,latin meaning baby4 ,linnus gave it this name from its resemblance to a baby which has been swathed or bound up1 as is still the custom in ,southern ,europe4 ,the term pupa should be restricted to the resting inactive stage of the holometabolous insects4 ,lamarck's term chrysalis was applied to the complete or obtected pupa of ,lepidoptera and of certain ,diptera1 and mumia1 a mummy1 to the pup of ,coleoptera1 ,trichoptera1 and most ,hymenoptera4 ,latreille 7#ahcj7 also restricted the term pupa to the 8oviform nymph10 or puparium1 of ,diptera4 ,brauer applies the term nymph to the pupa of metabolous insects4 ,illustration3 ,,fig4 #egh4--,pupa obtecta3 a1 of ,sesia1 with its cocoon-cutter on the head2 b1 of ,tortrix vacciniivorana4 ,the typical pupa is that of a moth or butterfly1 popularly called a chrysalis4 ,a lepidopterous pupa in which the appendages are more or less folded close to the body and soldered to the integument1 was called by ,linnus a pupa obtecta2 and when the limbs are free1 as in ,neuroptera1 ,mecoptera1 ,trichoptera1 and the lepidopterous genus ,micropteryx it is called a pupa libera 7,fig4 #egi74 ,when the pupa is enclosed in the old larval skin1 which forms a pupal covering 7puparium71 the pupa was said by ,linnus to be coarctate4 ,the pupa of certain ,diptera1 as that of the orthoraphous families1 is nearly as much obtected as that of the tineoid families of moths1 especially as regards the appendages of the head2 the legs being more as in pup liber 7,fig4 #ehj74 ,illustration3 ,,fig4 #egi4--,pupa libera of neuropterous insects a1 ,corydalus cornutus2 b1 ,sialis2 c1 ,hemerobius4 ,the male ,coccid anticipates the metabolous insects in passing through a quiescent state1 when1 as ,westwood states1 it is 8covered by the skin of the larva1 or by an additional pellicle40 ,the body appears to be broad and flat1 the antenn and fore legs resting under the head1 while the two hinder pairs of legs are appressed to the under side of the body4 ,there is but a slight approach to the pupa libera of a metabolous insect4 ,riley states that the male larva of ,icerya purchasi forms a cocoon waxy in character1 but lighter1 more flossy1 and less adhesive than that of the female egg-cocoon4 ,it melts and disappears when heated1 proving its entirely waxy nature4 ,when the mass has reached the proper length1 the larva casts its skin1 which remains in the hind end of the cocoon1 and pushes itself forward into the middle of the cocoon4 ,the pupa 7,fig4 #eha7 is of the same general form and size as the larva4 ,all the limbs are free and slightly movable1 so that they vary in position1 though ordinarily the antenn are pressed close to the side1 as are the wing-pads2 the front pair of legs are extended forward4 8,if disturbed1 they twist and bend their bodies quite vigorously40 ,the pupa state lasts two or three weeks4 ,a similar pupa is that of ,icerya ros4 7,riley and ,howard47 ,illustration3 ,,fig4 #ehj4--,pupa obtecta of ,diptera3 a1 ,ptychoptera2 b1 ,tabanus atratus2 c1 ,proctacanthus philadelphicus2 d1 ,midas clavatus4 ,illustration3 ,,fig4 #eha4--,pupa libera of ,icerya purchasi1 ventral view4--,after ,riley1 ,insect ,life4 ,the metamorphosis of ,aspidiotus perniciosus is of interest4 ,the male nymph differs much after the first moult from the female1 having large purple eyes1 while the female nymph loses its eyes entirely4 ,it passes into what ,riley terms the pro-pupa 7,fig4 #ehb1 b71 in which the wing-pads are present1 while the limbs are short and thick4 ,the next stage is the 8true pupa0 7,fig4 #ehb1 c1 d71 in which the antenn and legs are much longer than before4 ,there is no waxy cocoon1 but only a case or scale composed of the shed larval skin1 i4e4 8with the first moult the shed larval skin is retained beneath the scale1 as in the case of the female2 with the later moultings the shed skins are pushed out from beneath the scale10 and when they transform into the imago they 8back out from the rear end of their scale40 ,illustration3 ,,fig4 #ehb4--;,aspidiotus perniciosus1 development of male insect3 a1 ventral view of larva after first moult2 b1 the same1 after second moult 7pro-pupa stage72 c and d1 true pupa1 ventral and dorsal views4 ,all greatly enlarged4--,after ,riley4 ,the pup of ,coleoptera and of ,hymenoptera1 though there is1 apparently1 no near relationship between these two orders1 are much alike in shape1 and1 as ,chapman pertinently suggests1 those of both orders are helpless from their quiescence1 and hence have resorted for protection to some cocoon or cell4 ,but it is quite otherwise with the pup of ,lepidoptera and ,diptera1 which vary so much in adaptation to their surroundings1 and hence afford important taxonomical and phylogenetic characters4 ,this1 as regards the ,lepidoptera1 was almost wholly overlooked until ,chapman called attention to the subject1 and showed that the pup had characters of their own1 of the greatest service in working out the classification1 and hence the phylogeny1 of the different lepidopterous groups4 ,we have1 following the lead of ,chapman1 found the most striking confirmation of his views1 and applied our present knowledge of pupal structures to dividing the haustellate ,lepidoptera into two groups1--,paleolepidoptera and ,neolepidoptera4 ,the pup of the ,neuroptera1 ,coleoptera1 and ,hymenoptera differ structurally from the imago1 in the parts of the head and thorax being less differentiated4 ,thus in the head the limits or sutures between the epicranium and clypeus1 and the occiput and gula1 are obscurely marked1 while the tergal and pleural sclerites of the imago are not well differentiated until the changes occurring just before the final ecdysis4 ,it is easy1 however1 to homologize the appendages of the pup with those of the imago of all the holometabolous orders except in the case of the obtected pupa of the ,lepidoptera 7and probably of the obtected dipterous pup71 where the cephalic appendages are soldered together4 ,that the appendages of the lepidopterous pupa are1 as generally supposed1 merely cases for those of the imago has been shown by ,poulton to be quite erroneous4 ,he says3 8,if we examine a section of a pupal antenna or leg 7in ,lepidoptera71 we shall find that there is no trace of the corresponding imaginal organ until shortly before the emergence of the imago4 ,in the numerous species with a long pupal period1 the formation of imaginal appendages within those of the pupa is deferred until very late1 and then takes place rapidly in the lapse of a few weeks4 ,this also strengthens the conclusion that such pupal appendages are not mere cases for the parts of the imago1 inasmuch as these latter are only contained within them for a very small proportion of the whole pupal period40 ,on the other hand1 ,miall and ,hammond claim that there is a strong superficial contrast as to the formation of the imaginal organs1 between ,lepidoptera and tipularian ,diptera1 the appendages1 wings1 and compound eyes being substantially those of the imago4 8,with the exception of the prothoracic respiratory appendages and the tail-fin1 there is little in the pupa of ,chironomus which does not relate to the next stage40 ,the exact homology of the 8glazed eye0 of the lepidopterous pup and of the parts under the head1 situated over the maxill1 is difficult to decide upon1 and these points need farther examination4 ,in the dipterous pupa it is interesting to observe that the halteres are large and broad1 which plainly indicates that they are modified hind wings4 ,the number and arrangement of the spiracles is different in pup from those of the larva and imago4 ,illustration3 ,,fig4 #ehc4--,simulium piscicidium3 a1 larva2 b1 c1 d1 pupa2 e1 thoracic leg2 f1 row of bristles at end of body4 ,a1 ,s4 pecuarum1 pupa2 a1 b1 c1 adminicula4--,after ,riley4 ,there are also secondary adaptive structures peculiar to the pupa1 which are present and only of use in this stage4 ,these are the thoracic1 spiracular1 or breathing appendages of the aquatic ,diptera 7,fig4 #ehc71 the various spines situated on the head or thorax1 or on the sides1 or more often at the end of the abdomen1 besides also the little spines arranged in more or less circular rows around the abdominal segments1 the cocoon-breaker1 and the cremaster of many pup4 ,in the pupa of certain ,diptera1 there is a terminal cremaster-like spine1 as in that of ,tipula eluta 7,fig4 #ehd71 ,tabanus lineola 7,fig4 #ehe71 besides adminicula or locomotive spines like those of lepidopterous pup 7,fig4 #ehj1 a1 b1 c74 ,illustration3 ,,fig4 #ehd4--,pupa of ,tipula eluta4 ,illustration3 ,,fig4 #ehe4--,pupa of ,tabanus lineola4--,this and ,fig4 #ehd after ,hart4 ,illustration3 ,,fig4 #ehf4--,pupa of ,galerita lecontei1 and of ,adelops hirtus 7a1 b1 c74--,after ,hubbard4 ,the pup of ,coleoptera are variously spined or hairy 7,fig4 #ehf74 ,those of ,hydrophilus and of ,hydrobius are provided with stout spines on the prothorax and abdomen which support the body in its cells1 so that1 as ,lyonet first showed1 though surrounded on all sides by moist earth1 it is kept from contact with it by the pupal spines2 other pup of beetles1 such as that of the plum weevil1 which is also subterranean1 possess similar spines4 ,the abdomen of many coleopterous pup1 such as those of ,carabid1 end in two spines1 to aid them in escaping from their cells in wood or in the earth2 others have stiff bristles1 and others spines along each side of the abdomen 7,fig4 #ehf74 ,all these structures are the result of a certain amount of activity in what we call quiescent pup1 but most of these are for use at the end of pupal life1 at the critical moment when by their aid the insect escapes from its cocoon or subterranean cell1 or if parasitic1 bores out of its host4 ,if we are to account for the causes of their origin1 we are obliged to infer that they are temporary deciduous structures due to the need of support while the body is subjected to unusual strains and stresses in working its way out of its prison in the earth1 or its cell within the stems and trunks of plants and similar situations4 ,they are pupal inheritances or heirlooms1 and well illustrate the inheritance of characters acquired during a certain definite1 usually brief1 period of life1 and transmitted by the action of synchronous heredity4 ,the pup of certain insects are quite active1 thus that of ,raphidia1 unlike that of ,sialis1 before its final ecdysis regains its activity and is able to run about4 7,sharp1 p4 #ddh47 a4 ,the pupa considered in reference to its adaptation to its surroundings and its relation to phylogeny ,the form of the pupa is a very variable one1 as even in ,lepidoptera it is not entirely easy to draw the line between a pupa libera and a pupa obtecta 7,fig4 #egh72 and though the period is one of inactivity1 yet when they are not in cocoons or in the earth in subterranean cells1 their form is more or less variable and adapted to changes in their surroundings4 ,even in the obtected pupa of butterflies1 there is1 as every one knows1 considerable variability of shape and of armature1 which seems to be in direct adaptability to the nature of their environment4 ,scudder has well shown that in certain chrysalids1 such as those of the ,nymphalid1 which are variously tuberculated1 and hang suspended by the tail1 and often hibernate1 these projections serve to protect the body4 ,all chrysalids with projections or ridges on different parts of the body1 being otherwise unprotected1 move freely when struck by gusts of wind1 hence 8the greater the danger to the chrysalis from surrounding objects1 the greater its protection by horny tubercles and roughened callous ridges40 ,the greater the protection possessed in other ways1 as by firm swathing or a safe retreat1 the smoother the surface of the body and the more regular and rounded its contours4 ,the tendency to protection by tubercles is especially noticeable in certain ,south ,american chrysalids of nymphalid butterflies4 ,this response to the stimuli of blows or shocks is also accompanied by a sensitiveness to the stimulus of too strong light4 ,previously ,scudder#ajc had made the important suggestion that the smooth crescent-shaped belt of the 8glazed eye0 or 8eyepiece0 of chrysalids is1 as an external covering of the eye1 midway between that of the caterpillar and the perfect insect1 and he asks3 8,may it not be a relic of the past1 the external organ of what once was8 ,and are we to look upon this as our hint that the archaic butterfly in its transformations passed through an active pupal stage1 like the lowest insect of to-day1 when its limbs were unsheathed1 its appetite unabated80 etc4 ,scudder also shows that 8the expanded base of the sheath covering the tongue affords protection also to the palpi which lie beneath and beside the tongue40 ,all this tends to show the importance of studying the structure of the pupa1 in order to ascertain how the pupal structures have been brought about1 with the final object of discovering whether the pup of the holometabolic insects are not descended from active nymphs1 and if so1 the probable course of the line of descent4 b4 ,mode of escape of the pupa from its cocoon ,illustration3 ,,fig4 #ehg4--,pupa of ,micropteryx purpuriella1 front view3 md1 mandibles2 mx4 p1 maxillary palpus1 end drawn separately2 mx4 p1 labial palpi2 lb1 labrum4 8,in all protected pup10 as ,chapman says1 8the problem has to be faced1 how is the imago to free itself from the cocoon or other envelope protecting the pupa40 ,in the ,coleoptera and ,hymenoptera the imago becomes perfected within the cocoon or cell1 as the case may be1 and as ,chapman states1 8not only throws off the pupal skin within the cocoon1 but remains there till its appendages have become fully expanded and completely hardened1 and then the mandibles are used to force an outlet of escape10 and he calls attention to the fact that 8in many cases1 even in some entire families1 they are of no use whatever to the imago except in this one particular10 and he cites the ,cynipid as perhaps the most striking instance of this circumstance4 ,in those ,neuroptera which spin a silken cocoon1 e4g4 the ,hemerobiid1 the ,trichoptera1 and in ,micropteryx 7,fig4 #ehh71 the jaws used by the pupa for cutting its way out of the cocoon are even larger in proportion than in the pupa of caddis-flies 7,fig4 #ehh71 being of extraordinary size4 ,illustration3 ,,fig4 #ehh4--,mandibles 7md7 of ,micropteryx purpuriella1 enlarged4--,author del4 ,a1 pupal head of a hydropsychid caddis-fly1 showing the large mandibles4--,after ,reaumur1 from ,miall4 ,in ,myrmeleon the pupa pushes its way half out of the cocoon1 and then remains1 while the imago ruptures the skin and escapes 7,fig4 #ehi1 a74 ,thus in the ,neuroptera and ,trichoptera we have already established the more fundamental methods of escape from the cocoon1 which we see carried out in various ways in the more generalized or primitive ,lepidoptera4 ,the most primitive method in the ,lepidoptera of escaping from the cocoon seems to be that of ,micropteryx4 ,illustration3 ,,fig4 #ehi4--,larva of ,myrmeleon with 7a7 its cocoon and cast pupa-skin4 8,in this genus10 says ,chapman1 8though it is nominally the pupa that escapes from the cocoon1 it is in reality still the imago1 the imago clothed in the effete pupal skin4 ,to rupture the cocoon it uses not its own jaws1 but those of the pupal skin1 energizing them1 however1 in some totally different way from ordinary direct muscular action1 their movements being the result of the vermicular movements of the pupa1 acting probably by fluid pressure on the articular structure of the jaws1 by some arrangement not altogether different perhaps from the frontal sac of the higher ,diptera4 ,in the ,micropteryges the jaws of the pupa not only rupture the cocoon1 but appear to be the most active agents in dragging the pupa through the opening in the cocoon and through any superincumbent earth1 being merely assisted by the vermicular action of the abdominal segments1 and we find in accordance with this circumstance that the pupal envelope is still very thin and delicate1 and has little or no hardening or roughness by which to obtain a leverage against the walls of the channel of escape40 7,trans4 ,ent4 ,soc4 ,london1 #ahif1 pp4 #egj1 #ega47 ,illustration3 ,,fig4 #eij4--,pupa of ,talporia3 a1 cocoon-cutter2 with vestiges of four pairs of abdominal legs1 and the cremaster4 ,some sort of a beak or hard process1 more or less developed1 according to ,chapman1 adapted for breaking open the cocoon exists in nearly all the ,lepidoptera with incomplete pup 7pup incomplet71 except the limacodid and nepticulid section4 8,in all these instances the pupa emerges from the cocoon precisely as in the ,micropteryges1 that is1 the moth it really is that emerges1 but does so encased in the pupal skin4 ,to achieve this object1 it seems to have been found most efficient to have three1 four1 or five abdominal segments capable of movement1 but to have the terminal sections 7segments7 soldered together40 ,this cocoon-breaker1 as we may call it1 is especially developed in ,lithocolletis hamadryadella4 ,as described by ,comstock1 it forms a toothed crest on the forehead which enables it to pierce or saw through the cocoon4 8,each pupa first sawed through the cocoon near its juncture with the leaf and worked its way through the gap1 by means of the minute backward-directed spines upon its back1 until it reached the upper cuticle of the leaf4 ,through this cuticle it sawed in the same way that it did through the cocoon4 ,the hole was in each case just large enough to permit the chrysalis to work its way out1 holding it firmly when partly emerged4 ,when half-way out it stopped1 and presently the skin split across the back of the neck and down in front along the antennal sheaths1 and allowed the moth to emerge40#ajd ,we have observed and figured the cocoon-breaker in ,bucculatrix1 ,talporia 7,fig4 #eij1 a71 ,thyridopteryx1 and ceticus1 and rough knobs or slight projection answering the purpose in ,hepialid1 ,megalopyge1 ,zeuzera1 and in ,datana4#aje ,see also the spine on the head of ,sesia tipuliformis 7,fig4 #egh74 ,the imago of the attacine moths cuts or saws through its cocoon by means of a pair of large1 stout1 black spines 7sectores coconis71 one on each side of the thorax at the base of the fore wings 7,fig4 #eia71 and provided with five or six teeth on the cutting edge 7,c1 ,d74 ,illustration3 ,,fig4 #eia4--;,cocoon-cutter of the ,luna moth3 front view of the moth with the shoulders elevated and the rudimentary wings hanging down3 s1 cocoon-cutter2 p1 patagium4 ,b1 represents another specimen with fully developed wings3 ms1 scutum2 st1 scutellum of the mesothoracic segment2 s1 cocoon-cutter1 which is evidently a modification of one of the pieces at the base of the fore wings2 it is surrounded by membrane1 allowing free movement4 ,c and ,d1 different views of the spine1 magnified1 showing the five or six irregular teeth on the cutting edge4 ,illustration3 ,,fig4 #eib4--,larva and pupa of a wood-wasp 7,rhopalum71 enlarged3 h1 temporary locomotive tubercles on head of pupa4--,trouvelot del4 ,our attention#ajf was drawn to this subject by a rustling1 cutting1 and tearing noise issuing from a cocoon of ,actias luna4 ,on examination a sharp black point was seen moving to and fro1 and then another1 until both points had cut a rough irregular slit1 through which the shoulder of the moth could be seen vigorously moving from side to side4 ,the hole or slit was made in one or two minutes1 and the moth worked its way at once out of the slit4 ,the cocoon was perfectly dry4 ,the cocoon-cutter occurs in all the ,american genera1 in ,samia cynthia1 and is large and well marked in the ,european ,saturnia pavonia-minor and ,endromis versicolora4 ,in ,bombyx mori the spines are not well marked1 and they are quite different from those in the ,attaci4 ,there are three sharp points1 being acute angles of the pieces at the base of the wing1 and it must be these spines which at times perform the cutting through of the threads of the cocoon described by ,raumur1 and which he thought was done by the facets of the eyes4 ,it is well known that in order to guard against the moths cutting the threads1 silkraisers expose the cocoon to heat sufficient to destroy the enclosed pupa4 ,in ,platysamia the cocoon-cutters1 though well developed1 do not appear to be used at all1 and the pupa1 like that of the silkworm and other moths protected by a cocoon1 moistens the silk threads by a fluid issuing from the mouth1 which also moistens the hairs of the head and thorax1 together with the antenn4 ,it remains to be seen whether these structures are only occasionally used1 and whether the emission of the fluid is not the usual and normal means of egress of the moth from its cocoon4 ,dr4 ,chapman remarks that throughout the obtected moths 8there are many devices for breaking through the cocoon3 specially constructed weak places in the cocoon1 softening fluid1 applied by the moth1 assisted by special appliances of diverse sorts1 such as in ,hybocampa#ajg and ,attacus10 etc4 ,as to the fluid mentioned above1 ,trouvelot states that it is secreted during the last few days of the pupa state1 and is a dissolvent for the gum so firmly uniting the fibres of the cocoon4 8,this liquid is composed in great part of bombycic acid40 7,amer4 ,naturalist1 i1 p4 #cc47 ,the pupa of the dipterous genus ,sciara 7,s4 ocellaris ,o4 ,s47 resembles a tineid pupa1 and before transforming emerges for about two-thirds of its length from the cocoon2 the pupa-skin remaining firmly attached in this position4#ajh ,certain hymenopterous pup are provided with temporary deciduous conical processes4 ,thus we have observed in the pupa of ,rhopalum pedicellatum two very prominent acute tubercles between the eyes 7h1 ,fig4 #eib74 ,as the cocoon is very slight1 these may be of use either in extracting itself from the silken threads or in pushing its way along before emerging from the tunnel in the stem of plants4 7,see also p4 #faa47 c4 ,the cremaster ,although this structure is in general confined to lepidopterous pup1 and is not always present even in them1 since it is purely adaptive in its nature1 yet on account of its singular mode of development from the larval organs1 and the accompanying changes in the pupal abdomen1 it should be mentioned in this connection4 ,the cremaster is the stout1 triangular1 flattened1 terminal spine of the abdomen1 which aids the pupa in working its way out of the earth when the pupa is subterranean1 or in the pupa of silk-spinning caterpillars its armature of secondary hooks and curved set enables it to retain its hold on the threads of the interior of its cocoon after the pupa has partially emerged from the cocoon1 restraining it1 as ,chapman well says1 8at precisely that degree of emergence from the cocoon that is most desirable40 ,he also informs us that while in the 8pup incomplet the cremaster is attached to an extensible cable1 which always allows some emergence of the pupa1 in the pup obtect there is no doubt but that in such cases as the ,ichthyur1 ,acronyct1 and many others1 it retains the pupal case in the same position within the cocoon that the living pupa occupied2 this is also very usually the case in the ,geometr and in the higher tineids 7my pyraloids740 ,in many of the more generalized moths there is no cremaster 7,micropteryx1 ,gracilaria1 ,prodoxus1 ,tantura1 ,talporia1 ,psychid1 ,hepialid1 ,zeuzera1 ,nola1 ,harrisina71 though in ,tischeria and ,talporia 7,fig4 #eij1 but not in ,solenobia7 and ,psychid1 two stout terminal spines perform the office of a cremaster1 or there are simply curved set on the rounded1 unarmed end of the abdomen1 as in ,solenobia4 ,in the obtected ,lepidoptera1 for example in such a group as the ,notodontid1 where the cremaster is present1 though variable in shape1 it may from disuse1 owing to the dense cocoon1 be without the spines and hooks in ,cerura1 or the cremaster itself is entirely wanting in ,gluphisia1 and only partially developed in ,notodonta4 ,in the butterflies whose pup are suspended 7,suspensi71 the cremaster is especially well developed4 ,reference might here be made to the temporary pupal structures in certain generalized moths1 which take the place of a cremaster1 such as the transverse terminal row of spines in ,tinea1 the two stout spines in ,tischeria1 and the dense rough integument and thickened callosities of the pupal head and end of abdomen of ,phassus1 which bores in trees with very hard wood2 also the numerous stout spines at the end and sides of the abdomen in gerians4 ,these various projections and spines1 besides acting as anchors and grappling hooks1 in some cases serve to resist strains and blows1 and have undoubtedly1 like the armature in the larv and imagines of other insects1 arisen in response to intermittent or occasional pressure1 stresses1 and impacts4 ,mode of formation of the cremaster and suspension of the chrysalis in butterflies4--,we are indebted to ,riley#aji for an explanation of the way the cremaster has originated1 his observations having been made on species of over a dozen genera of butterflies 7,suspensi74 ,he shows that the cremaster is the homologue of the suranal plate of the larva4#aaj ,the preliminary acts of the larva have been observed by various authors since the days of ,vallisneri1 i4e4 the larva hanging by the end of the abdomen1 turning up the anterior part of the body in a more or less complete curve1 and the skin finally splitting from the head to the front edge of the metathoracic segment1 and being worked back in a shrivelled mass toward the point of attachment4 ,the critical feat1 adds ,riley1 which has most puzzled naturalists1 is the independent attachment of the chrysalis and the withdrawal from and riddance of the larval skin which such attachment implies4 ,raumur explained this in #agcd by the clutching of the larval skin between sutures of the terminal segments of the chrysalis1 and this is the case1 though the sutures act in a somewhat different way4 ,before pupation the larva spins a mass or heap of silk1 the shape of which is like an inverted settee or a ship's knee1 and 8one of the most interesting acts of the larva1 preliminary to suspension1 is the bending and working of the anal parts in order to fasten the back of the 7suranal7 plate to the inside of the back of the settee1 while the crotchets of the legs are entangled in the more flattened position or seat40 ,in shedding the larval skin1 the following parts are also shed1 and have some part to play in the act of suspension3 i4e4 #ast1 the tracheal ligaments 7,fig4 #eic1 tl71 or the shed trache from the last or #ith pair of spiracles2 #b;d1 the rectal ligament 7,fig4 #eic1 rl71 or shed intestinal canal2 #c;d1 the ,osborne or retaining membrane 7membrana retinens1 ,fig4 #eic1 mr71 which is the stretched part of the membrane around the rectum and in the anal legs1 and which is intimately associated with the rectal ligament4 ,illustration3 ,,fig4 #eic4--,shrunken larval skin of ,vanessa antiopa1 cut open from the back and showing 7mr7 the retaining membrane1 7rl7 the rectal ligament1 and 7tl7 the tracheal ligaments4 ,the structures in the chrysalis are1 first1 the cremaster1 with its dorsal 7,fig4 #eid1 dcr7 and ventral 7vcr7 ridges1 and the cremastral hook-pad 7chp71 said by ,riley to be 8thickly studded with minute but stout hooks1 which are sometimes compound or furnished with barbs1 very much as are some of our fishing-hooks1 and which are most admirably adapted to the purpose for which they are intended40 ,illustration3 ,,fig4 #eid4--;,ideal representation of the anal subjoint of ,vanessa antiopa1 from behind1 with the spines removed1 and all parts forced apart by pressure so as to show the homologies of the parts in the chrysalis which are concerned in pupation3 homologies indicated by corresponding letters in ,fig4 #eie1 except that r 7the rectum7 corresponds with pr in ,fig4 #eie4 ,illustration3 ,,fig4 #eie4--;,anal parts of chrysalis of ,vanessa antiopa1 just prior to final extraction from shrunken larval skin3 c1 cremaster2 chp1 cremastral hook-pad2 h1 one of the hooks1 more enlarged2 vcr1 ventral cremastral ridge2 dcr1 dorsal cremastral ridge2 lr1 larval rectum2 pr1 pupal rectum2 rp1 rectal plate2 sr1 sustentor ridges2 mr1 membrana retinens2 rl1 rectal ligament2 tl1 tracheal ligament2 the #aath or last spiracle-bearing joint and the #abth joint being numbered4 ,secondly1 there are the other structures1 viz41 the sustainers 7sustentors71 two projections which ,riley states 8homologize with the soles 7plant7 of the anal prolegs1 which take on various forms 7#c71 but are always directed forward so as easily to catch hold of the retaining membrane40 ,these sustentors are1 however1 as ,jackson#aaa has shown1 and as we are satisfied1 the vestiges of the anal legs4 ,illustration3 ,,fig4 #eif4--;,a1 chrysalis of ,terias4 ,b1 posterior end of chrysalis of ,paphia4 ,c1 posterior end of chrysalis of ,danais4 ,e1 one of the sustainers of ,terias1 greatly enlarged to show its hooked nature4 ,all the parts of subjoint lettered to correspond with ,fig4 #eie4 ,thirdly1 the sustentor ridges1 which1 as ,riley states1 may be more or less obsolete in some forms1 in ,paphia 7,fig4 #eif1 ,b7 and ,limenitis form 8quite a deep notch1 which doubtless assists in catching hold of the larval skin in the efforts to attach the cremaster40 ,illustration3 ,,fig4 #eig4--,pupation of butterflies3 a1 attachment of larva of ,danais archippus2 p1 attachment of larva of ,paphia glycerium2 b1 ideal larva soon after suspension2 d1 ideal larva a few hours later1 the needle 7n7 separating the forming membrane from the sustainers2 l1 ideal larva just before splitting of larval skin1 with retaining membrane loosened from the sustainers and showing its connection both with the larval and pupal rectum4 ,in all the figures the joints of the body are numbered2 the forming chrysalis is shaded in transverse lines2 the intervening space between it and larval skin is dotted3 h1 is the hillock of silk2 hl1 hooks of hind legs2 ap1 anal plate2 lr1 larval rectum2 pr1 pupal rectum2 mr1 retaining membrane2 c1 cremaster2 s1 sustainers4--,this and ,figs4 #eic-eif after ,riley4 8,it is principally10 adds ,riley1 8by the leverage obtained by the hooking of the sustainers in the retaining membrane1 which acts as a swimming fulcrum1 that the chrysalis is prevented from falling after the cremaster is withdrawn from the larval skin4 ,it is also principally by this same means that it is enabled to reach the silk with the cremastral hook-pads40 8,dissected immediately after suspension1 the last abdominal segment of the larva is found to be bathed1 especially between the legs and around the rectum1 in an abundance of translucent1 membranous material40 8,an hour or more after suspension the end of the forming chrysalis begins to separate from the larval skin1 except at the tip of the cremaster 7,fig4 #eig1 b74 ,gradually the skin of the legs and of the whole subjoint 7#ajth segment7 stretches1 and with the stretching1 the cremaster elongates1 the rectal piece recedes more and more from the larval rectum1 and the sustentor ridges diverge more and more from the cremaster1 carrying with them1 on the sustainers1 a part of the soft membrane40 ,the rectal ligament will sustain at least #aj or #ab times the weight of the chrysalis4 ,that of ,apatura seems to rely almost entirely on the rectal ligament1 assisted by the partial holding of the delicate larval skin4 ,,formation ,,of ,,the ,,pupa ,,and ,,imago ,,in ,,the ,,holometabolous ,,insects 7,,the ,,diptera ,,excepted7 ,we have seen that in the incomplete metamorphosis1 although there may be as many as five1 and possibly seven moults1 and in ,chloon as many as #bj1 and in ,cicada septemdecim perhaps #be or #cj1 there is but a slight change of form from one stage to another1 and no period of inactivity4 ,and this gradual outer transformation is so far as yet known paralleled by that of the internal organs1 the slight successive changes of which do not differ from those observed in the growth of ametabolous insects4 ,with the growth of the internal organs there probably goes on a series of gradual regenerative processes1 and ,korschelt and ,heider state that we may venture to assume that each changed cell or group of cells which have become exhausted by the exercise of the functions of life are reabsorbed and become restored through the vital powers of the tissues1 so that as the result there goes on a constant1 gradual regeneration of the organs4 ,while the ,hemiptera have only an incomplete metamorphosis1 the males of the ,coccid are1 as shown by ,o4 ,schmidt1 remarkable for passing through a complete or holometabolous development1 with four stages1 three of which are pupal and inactive4 ,hence1 as ,schmidt observes1 there is here a hypermetamorphosis1 like that of the ,meloid1 ,stylopid1 etc4 ,shortly before the end of the larval stage of the male appear the imaginal buds of the eyes1 legs1 and wings4 ,in the #b;d or #ast pupal stage there is an atrophy of the antenn and legs4 ,on the other hand1 at this stage the female completes its metamorphosis4 ,the rudiments of the wings arise on the edge of the dorsal and ventral side of the #b;d thoracic segment1 and this1 we would remark1 is significant as showing a mode of origin of the wings intermediate between that of the manometamorphic and holometamorphic insects4 7,see pp4 #acg-adb47 ,while ,schmidt could not ascertain the exact structure of the imaginal buds1 he says 8in general the process of formation of the extremities is exactly as ,weismann has described in ,corethra40 ,the two later pupal stages are 8as in other metabolic insects40 7,see p4 #fij1 ,fig4 #fcg47 ,thus far the internal changes in the metamorphosis of the ,coleoptera have not been thoroughly studied4 ,they are less complete than in the other holometabolous insects1 the differences between the larva and imago being much less marked than in the more specialized orders1 and so far as known all the larval organs pass1 though not without some great changes1 directly into the imaginal ones1 the only apparent exception being the mid-intestine1 which1 as stated by ,kowalevsky1 undergoes a complete transformation during metamorphosis4 ,the following account1 then1 refers almost wholly to the ,lepidoptera1 ,hymenoptera1 and ,diptera4 a4 ,the ,lepidoptera ,the first observations on the complete metamorphosis of insects which were in any way exact were those of ,malpighi1 in #affg1 and of ,swammerdam1 in #agcc4 ,while the observations of ,swammerdam1 as far as they extended1 were correct1 his conclusions were extraordinary4 ,they were1 however1 accepted by ,raumur and by ,bonnet1 and generally held until the time of ,herold in #ahae1 and lingered on for some years after4 ,the rather famous theory of incasement 78embotement07 propounded by ,swammerdam was that the form of the larva1 pupa1 and imago prexisted in the egg1 and even in the ovary2 and that the insects in these stages were distinct animals1 contained one inside the other1 like a nest of boxes1 or a series of envelopes one within the other1 or1 to use his own words3 8,animal in animali1 seu papilio intra erucam reconditus40 ,this theory ,swammerdam extended to the whole animal kingdom4 ,it was based on the fact that by throwing the caterpillar1 when about to pupate1 in boiling water1 and then stripping off the skin1 the immature form of the butterfly with its appendages was disclosed4 ,malpighi had previously observed the same fact in the silkworm1 perceiving that before pupation the antenn are concealed in the head of the larva1 where they occupy the place previously taken by the mandibular muscles2 also that the legs of the moth grew in those of the larva1 and that the wings developed from the sides of the worm4 ,even ,raumur 7#agcd7 remarked3 8,les parties du papillon caches sous le fourreau de chenille sont d'autant plus faciles trouver que la transformation est plus proche4 ,elles y sont neanmoins de tout temps40 ,he also believed in the simultaneous existence of two distinct beings in the insect4 8,il serait trs curieux de connatre toutes les communications intimes qui sont entre la chenille et le papillon4444 ,la chenille hache1 broye1 digere les aliments qu'elle distribu au papillon2 comme les mres prparent ceux qui sont ports aux ftus4 ,notre chenille en un mot est destine nourrir et defendre le papillon qu'elle renferme40 7,t4 i1 #h;e ,mmoire1 p4 #cfc47 ,lyonet 7#agfj71 even1 did not expose the error of this view that the larva enveloped the pupa and imago1 and1 as ,gonin says1 it was undoubtedly because he did not use for his dissections of the caterpillar of ,cossus any specimens about to pupate4 ,yet he detected the wing-germs and those of the legs1 stating that he presumed the bodies he saw to be the rudiments of the legs of the moth 7p4 #dej74 ,herold1 in his work on the development of the butterfly 7#ahae71 was the first to object to this erroneous theory1 showing that the wings did not become visible until the very end of larval life2 that as the larval organs disappear1 they are transformed or are replaced by entirely new organs1 which is not reconcilable with a simple putting off of the outer envelope4 ,the whole secret of metamorphosis1 in ,herold's opinion1 consisted in this fact1 that the butterfly in the larva state increases and accumulates a supply of fat until it has reached the volume of the perfect state2 then it begins the chrysalis period1 during which the organs are developed and take their definite form4#aab 7,abstract mostly from ,gonin47 ,still the old ideas prevailed1 and even ,lacordaire1 in his ,introduction l',entomologie published in #ahcd1 held on to ,swammerdam's theory1 declaring that 8a caterpillar is not a simple animal1 but compound10 and he actually goes so far as to say that 8a caterpillar1 at first scarcely as large as a bit of thread1 contains its own teguments threefold and even eightfold in number1 besides the case of a chrysalis1 and a complete butterfly1 all lying one inside the other40 ,this view1 however1 we find is not original with ,lacordaire1 but was borrowed from ,kirby and ,spence without acknowledgment4 ,these authors1 in their ,introduction to ,entomology 7#ahbh71 combated ,herold's views and stoutly maintained the old opinions of ,swammerdam4 ,they based their opinions on the fact1 then known1 that certain parts of the imago occur in the caterpillar4 ,on the other hand1 ,herold denied that the successive skins of the pupa and imago existed as germs1 holding that they are formed successively from the 8rete mucosum10 which we suppose to be the hypodermis of later authors4 ,in a slight degree the ,swammerdam-,kirby and ,spence doctrine was correct1 as the imago does arise from germs1 i4e4 the imaginal disks of ,weismann1 while this was not discovered by ,herold1 though they do at the outset arise from the hypodermis1 his rete mucosum4 ,thus there was a grain of truth in the ,swammerdam-,kirby and ,spence doctrine1 and also a mixture of truth and error in the opinions of ,herold4 ,the real nature of the internal changes wrought during the process of metamorphosis was first revealed by ,weismann in #ahfd4 ,his discovery of the germs of the imago 7imaginal buds7 of the ,diptera1 and his theory of histolysis1 or of the complete destruction of the larval organs by a gradual process1 was the result of the application of modern methods of embryology and histology1 although his observations were first made on the extremely modified type of the ,muscid or flies1 and1 at first1 he did not extend his view to include all the holometabolous insects4 ,now1 thanks to his successors in this field1 ,ganin1 ,dewitz1 ,kowalevsky1 ,van ,rees1 ,bugnion1 ,gonin1 and others1 we see that metamorphosis is1 after all1 only an extension of embryonic life1 the moults and great changes being similar to those undergone by the embryo1 and that metamorphosis and alternation of generations are but terms in a single series4 ,moreover1 the metamorphoses of insects are of the same general nature as those of certain worms1 of the echinoderms1 and the frog1 the different stages of larva1 pupa1 and imago being adaptational and secondary4 ,while the changes in form from the larva to the pupa are apparently sudden1 the internal histogenetic steps which lead to them are gradual4 ,in the ,lepidoptera a few days 7usually from one to three7 before assuming the pupa stage1 the caterpillar becomes restless and ceases to take food4 ,its excrements are now hard1 dry1 and1 according to ,gonin1 are 8stained carmine red by the secretions of the urinary tubes40 ,under the microscope we find that they are almost exclusively composed of fragments of the intestinal epithelium4 ,these red dejections were noticed by ,raumur1 and afterwards by ,herold1 and they are sure indications of the approach of the transformations4 ,it now wanders about1 and1 if it is a spinner1 spins its cocoon1 and then lies quietly at rest while the changes are going on within its body4 ,meanwhile1 it lives on the stores of fat in the fat-body1 and this supply enables it to survive the pupal period4 ,the amount of fat is sometimes very great4 ,newport removed from the larva of ,cossus ligniperda #db grains of fat1 being more than one-fourth of the whole weight of the insect1 he adds that the supply is soon nearly exhausted during the rapid development of the reproductive organs1 8since1 when these have become perfected1 the quantity that remains is very inconsiderable40 ,although the larval skin of a lepidopterous insect is suddenly cast off1 the pupa quickly emerging front it1 yet there are several intermediate stages1 all graduating into each other4 ,if a caterpillar of a ,clisiocampa1 which1 as we have observed1 is much shortened and thickened a day or two before changing to a pupa1 is hardened in alcohol and the larval skin is stripped off1 the semipupa 7pro-nymph1 pro-pupa of different authors7 is found to be in different stages of development1 and the changes of the mouth-parts are interesting1 though not yet sufficiently studied4 ,newport attributes the great enlargement and changes in the shape of the thoracic segments of the larva of ,vanessa urtic at this time1 to the contraction or shortening of the muscles of the interior of those segments1 8which are repeatedly slowly extended and shortened1 as if the insect were in the act of laborious respiration40 ,this1 he adds1 generally takes place at short intervals during the two hours immediately preceding the change to the pupa1 and increases in frequency as that period approaches4 ,he thus describes the mode of moulting the larval skin3 8,when the period has arrived1 the skin bursts along the dorsal part of the #c;d segment1 or mesothorax1 and is extended along the #b;d and #dth1 while the coverings of the head separate into three pieces4 ,the insect then exerts itself to the utmost to extend the fissure along the segment of the abdomen1 and1 in the meantime1 pressing its body through the opening1 gradually withdraws its antenn and legs1 while the skin1 by successive contortions of the abdomen1 is slipped backwards1 and forced towards the extremity of the body1 just as a person would slip off his glove or his stocking4 ,the efforts of the insect to get entirely rid of it are then very great2 it twirls itself in every direction in order to burst the skin1 and1 when it has exerted itself in this manner for some time1 twirls itself swiftly1 first in one direction1 then in the opposite1 until at last the skin is broken through and falls to the ground1 or is forced to some distance from it4 ,the new pupa then hangs for a few seconds at rest1 but its change is not yet complete4 ,the legs and antenn1 which when withdrawn from the old skin were disposed along the under surface of the body1 are yet separate1 and do not adhere together as they do a short time afterwards4 ,the wings are also separate and very small4 ,in a few seconds the pupa makes several slow1 but powerful1 respiratory efforts2 during which the abdominal segments become more contracted along their under surface1 and the wings are much enlarged and extended along the lateral inferior surface of the body1 while a very transparent fluid1 which facilitated the slipping off of the skin1 is now diffused among the limbs1 and when the pupa becomes quiet dries1 and unites the whole into one compact covering40 ,the changes in the head and mouth-parts4--,the changes of form from the active mandibulate caterpillar to the quiescent pupa1 and then to the adult butterfly1 are1 as we have seen1 in direct adaptation to their changed habits and surroundings1 and they differ greatly in details in insects of different orders4 ,in many ,lepidoptera and certain ,diptera the pupa and imago are without the mandibles of the larva1 and1 instead1 the #ast maxill in the former order1 and the #b;d maxill in the latter1 are highly developed and specialized4 ,the changes in the shape of the head1 with the antenn1 the latter rudimentary in the larv of the two orders named1 are noteworthy1 and will be referred to under those orders4 ,the same may be said of the thorax with the legs and wings1 and the abdomen with the ovipositor4 ,every part of the body undergoes a profound change1 though in the ,coleoptera1 ,trichoptera1 and the more generalized and primitive ,diptera1 each segment and appendage of the larva are directly transformed into the corresponding parts of the pupa1 and subsequently of the imago4 ,we shall see1 however1 beyond1 that this general statement does not apply to the ,hymenoptera1 in which there is a process of cephalization or transfer of parts headward1 peculiar to that order4 ,illustration3 ,,fig4 #eih4--;,internal organs of ,sphinx ligustri3 #a1 head2 #b-d1 thoracic1 #e-ac1 abdominal segments2 ,v1 fore-1 ,m1 mid-1 ,e1 hind-intestine2 gs1 brain2 gi1 infrasophageal ganglion2 n1 ventral ganglion2 vm1 urinary tubes2 c1 heart2 ,g1 testis2 o1 sophagus2 a1 anus2 m1 alary muscles of the heart4 ,illustration3 ,,fig4 #eii4--,pupa of the same4 ,illustration3 ,,fig4 #fjj4--;,imago of the same4--,this and ,figs4 #eih and #eii after ,newport1 from ,gegenbaur4 ,illustration3 ,,fig4 #fja4--,nervous system of the larva of ,sphinx ligustri4 ,illustration3 ,,fig4 #fjb4--,nervous system of the pupa of ,sphinx ligustri1 soon after pupation4--,this and ,fig4 #fja1 after ,newport4 ,the change in the internal organs4--,these were especially1 as regards the nervous system1 first carefully examined and illustrated by that great ,english entomotomist1 ,newport1 and those of the reproductive organs by ,herold as early as #ahae4 ,a glance at the figures 7#eih-fjd71 reproduced from ,newport's article ,insecta1 will show the changes wrought especially in the digestive and nervous systems of ,sphinx and ,vanessa1 his account of the alterations in the muscles having already been quoted4 ,as the pupal form is much nearer to that of the imago than of the larva1 so the digestive canal is seen to be nearly as much differentiated in the pupa as in the imago1 though the reservoir 78sucking-stomach07 of the imago is not indicated in the pupa4 ,these changes are such as occur in an insect which is enormously voracious as a larva1 and which often1 passing through a period of complete inactivity1 taking no food at all1 finally becomes an insect which needs to suck in only a minimum quantity of water or nectar1 and which practically abstains from all food4 ,the head and genital glands also1 as well as the urinary vessels1 are nearly the same4 ,on the other hand1 the salivary glands have undergone1 in the imago1 a thoroughgoing reduction4 ,the changes undergone by the nervous system of ,sphinx ligustri and ,vanessa urtic have been described by ,newport with fulness of detail4 ,an abstract of his observations on ,vanessa urtic1 which undergoes its changes in ,june in #ad days1 and in ,august in eight days1 we will now give1 in part verbatim1 the subject being rendered much clearer by his figures1 which are reproduced4 ,during the last larval stage1 certain changes have already taken place in different parts of the cord1 which shows that they had been a long time in progress4 ,besides the lateral approximation of the cords1 the first change consists in a union of the #aath and #abth ganglia1 the latter one being carried forwards2 these two ganglia being entirely separate before the #c;d moult4 ,two hours after the larva of ,vanessa urtic has suspended itself in order to pupate1 the brain is not yet enlarged1 but the subsophageal ganglion is nearly twice its original size and the ganglia behind are nearer together4 8,a little while before the old larval skin is thrown off there is great excitement throughout the body of the insect40 ,about half an hour 7,fig4 #fjc1 #b7 before this occurs the alary nerves and the cerebral1 #b;d1 #c;d1 #dth1 and #eth ganglia are slightly enlarged1 and the #ast subsophageal ganglion very considerably4 ,immediately after the insect has entered the pupa state 7,fig4 #fjc1 #c71 all the ganglia are brought closer together4 ,one hour after 7,fig4 #fjc1 #d7 pupation the cerebral ganglia are found to be more closely united1 the #dth and #eth ganglia are nearer1 and the distance between the remaining ganglia is also reduced4 ,seven hours after pupation there is a greater enlargement of the cerebral ganglia1 optic nerves1 and ganglia and cords of the future thoracic segments4 ,at #ab hours 7,fig4 #fjc1 #e7 the #eth pair of ganglia has almost completely coalesced with the cord and the #dth2 at #ah hours 7,fig4 #fjc1 #f7 the whole of the ganglia1 cords1 and nerves have become more enlarged1 especially those of the wings1 while the #dth and #eth ganglia of the cords have now so completely united as to appear like an irregular elongated mass4 ,at #bd hours 7,fig4 #fjd1 #g7 the #dth and #eth ganglia are completely united1 the #eth being larger than the #dth4 ,at #cf hours 7,fig4 #fjd1 #h7 the optic nerves have attained a size almost equal to that of the brain4 ,the #ast subsophageal ganglion now forms1 with the cerebral ones1 a complete ring around the sophagus1 the crura having almost disappeared4 ,the #fth ganglion has now disappeared1 but the nerves arising from it remain4 ,at #dh hours 7,fig4 #fjd1 #i7 the cord is straight instead of being sinuous1 and the #gth ganglion has disappeared1 while the thoracic ganglia are greatly enlarged4 ,at the end of #eh hours the #b;d and #c;d thoracic ganglia have united1 and the double ganglion thus formed is only separated from the large thoracic mass composed of the #dth1 #eth1 and part of the #fth ganglia1 by the short but greatly enlarged cords which pass on each side of the central attachment of the muscles4 8,the optic and antennal nerves have nearly attained their full development1 and those numerous and most intricate plexus of nerves in the three thoracic segments of the larva form only a few trunks1 which can hardly be recognized as the same structures4 ,the arrangement of the whole nervous system is now nearly as it exists in the perfect insect4 ,the whole of these important changes are thus seen to take place within the first three days after the insect has undergone its metamorphosis2 and they precede those of the alimentary canal1 generative system1 and other organs1 which are still very far from being completed1 and indeed1 as compared with the nervous system1 have made but little progress40 7,art4 ,insecta1 pp4 #ifb-ife47 ,illustration3 ,,fig4 #fjc4--;,changes in the nervous system of ,vanessa urtic1 during and after pupation4--,after ,newport4 ,illustration3 ,,fig4 #fjd4--;,changes in the nervous system of ,vanessa urtic1 from #bd to #eh hours after pupation4--,after ,newport4 ,the initial steps and many of the subsequent internal changes escaped the notice of ,newport and others of his time1 and it was not until the epoch-making work of ,weismann on the ultimate processes of transformation of ,corethra and of ,musca1 that we had an adequate knowledge of the subject4 ,weismann 7#ahfd7 was the first to show for the ,muscid and ,corethra that the appendages1 wings1 and other parts of the imago originate in separate1 minute1 cellular masses called imaginal disks1 buds1 or folds 7histoblasts of ,knckel74 ,these imaginal buds1 which arise from the hypodermis1 being masses of indifferent cells1 are usually present in the very young larva1 and even in the later embryonic stages4 ,it has been shown that such imaginal buds exist for each part of the body1 not only for the appendages and wings 7p4 #abf71 but for the different sections of the digestive canal4 ,during the semipupal stage these buds enlarge1 grow1 and at the same time there is a corresponding destruction of the larval organs4 ,the process of destruction is due to the activity of the blood corpuscles or leucocytes 7phagocytes71 the larval organs thus broken up forming a creamy mass1 the buds from which the new organs are to arise resisting the attacks of the virulent leucocytes1 which attach themselves to the weakened tissue and engulf the pigments 7see p4 #dbb74 ,the two processes of destruction of the larval organs 7histolysis7 and the building up of the imaginal organs 7histogenesis7 go hand in hand1 so that the connection of the organs in question in most cases remains entirely continuous2 while the last steps in the destruction of the larval organs only take place after the organs of the imago have assumed their definite shape and size4 ,other observers have corroborated and confirmed his statements and observations1 ,gonin extending them to the ,lepidoptera and ,bugnion to the ,hymenoptera4 ,it is a pity that the observations1 such as were set on foot by ,weismann1 were not first made on the ,trichoptera and ,lepidoptera1 which are much more primitive and unmodified forms than the ,diptera1 but mistakes of this nature have frequently happened in the history of science4 ,illustration3 ,,fig4 #fje4--;,full grown larva of ,pieris brassic opened along the dorsal line3 d1 digestive canal2 s1 silk-gland2 g1 brain2 st ,i1 prothoracic stigma2 st ,,iv1 #ast abdominal stigma2 a1 a1 germs 7buds7 of fore and hind wings2 p1 bud of thoracic segment2--those of the #c;d pair are concealed under the silk-glands2 ,i-,,iii1 thoracic rings4--,after ,gonin4 ,the latest and most detailed researches are those of ,j4 ,gonin on the metamorphoses of ,pieris brassic1 made under the direction of ,professor ,e4 ,bugnion4 ,they fill an important gap in our knowledge1 and show that the ,lepidoptera transform in nearly the same manner as described by ,weismann in ,corethra4 ,we give the following condensed account of ,gonin's observations4 ,on opening a caterpillar entering on the semipupa state 7,fig4 #fje71 the relative position of the germs 7imaginal buds or folds7 of the wings and of the legs are seen4 ,illustration3 ,,fig4 #fjf4--,section through thorax of a tineid larva on sycamore1 passing through the #ast pair of wings 7w73 ht1 heart2 i1 sophagus2 s1 salivary gland2 ut1 urinary tube2 nc1 nervous cord2 m1 recti muscles2 a part of the fat-body overlies the heart4 ,a1 right wing-germ enlarged4 ,illustration3 ,,fig4 #fjg4--,section of the same specimen as in ,fig4 #fjf1 but cut through the #b;d pair of wings 7w73 i1 mid-intestine2 h1 heart2 fb1 fat-body2 l1 leg2 n1 nervous cord4 ,these imaginal buds in a more advanced stage are seen in our sections of a tineid larva 7,figs4 #fjf1 #fjg74 ,the number of #ab imaginal buds found by ,weismann in the thorax of ,muscid does not occur in ,lepidoptera1 since1 as in the ,hymenoptera 7,bugnion71 the dorsal buds of the prothoracic segment are wanting4 ,gonin finds in ,pieris that the ventral buds of the three thoracic segments are each represented by several distinct folds attached to the femoro-tibial bud and to the tarsal joints4 ,the imaginal buds serve in some cases for the formation of new organs 7wings1 legs of insects with apodous larv72 in others for the growth and the transformation of organs already existing 7legs1 antenn1 #ast and #b;d maxill of ,lepidoptera74 ,as to the peripodal sac or hypodermic envelope which contains the imaginal bud1 a portion persists and is regenerated1 while the other part becomes useless and is detached under the form of dbris1 as shown by ,weismann1 ,viallanes1 and ,van ,rees in the ,muscid4 ,on this point ,gonin disagrees with ,dewitz1 who stated that the walls of the wing-sacs are not destroyed1 but are only gradually withdrawn at the time of pupation1 in order to allow the orifice to distend and let the wing pass out to the exterior4 ,the portion of the sac which persists 7basal portion1 peripheral pad of ,bugnion1 or annular zone of ,knckel7 serves at first to attach the appendage1 while forming1 to the hypodermis of the larva1 then afterwards to more or less completely regenerate the adjoining portion of the integument4 ,in this way the hypodermis of the thorax is partially1 that of the head is almost entirely1 replaced by the imaginal epithelium which proliferates at the base of the appendages1#aac while that of the abdominal segments persists1 at least in a modified way1 and only undergoes 7at the end of the pupal period7 transformations as regards the appearance of the scales and pigment4 ,the wings4--,the imaginal buds of the wings do not participate in the larval moults4 ,gonin has observed1 contrary to ,dewitz1 that their surface only forms a cuticle towards the end of the last larval stage4 ,the network of fine trache of the wing-bud is drawn out at the time of pupation with the internal cuticle of the large trache4 ,the permanent trache of the wing have already appeared at the time of the #c;d moult under the form of large rectilinear trunks1 the position of which corresponds afterwards to that of the veins1 but they are not filled with air until the time of pupation4 ,there are from eight to ten of these trache in each wing 7,fig4 #aei71 and they give rise in the pupa to a new system of fine trache 7tracheoles7 which replaces that of the larva4 7,for further details the reader is referred to pp4 #abf-acg47 ,development of the feet and the cephalic appendages4#aad--;,in the apodous larv of ,diptera and ,hymenoptera the rudiments of the legs are1 like those of the wings1 developed within hypodermal sacs2 at times they remain there up to the end of larval life1 but sometimes they appear early at the surface4 ,this origin of the legs1 thanks to ,weismann1 ,knckel1 and ,van ,rees1 is well known in the ,diptera2 in the ,hymenoptera it has been proved to be the case with ants by ,dewitz1 and in ,encyrtus by ,bugnion4 ,as for the ,lepidoptera our knowledge that the legs of the imago arise from the six thoracic legs of the caterpillar1 up to the date of ,gonin's paper has not been in advance of that of ,malpighi and ,swammerdam4 ,raumur1 moreover1 was supposed to have furnished the proof1 having from his experiments concluded that 8if the legs of the pupa appear longer and larger than those of the caterpillar wherein they were contained1 it is because they were folded and squeezed40 7#h;e ,mm41 p4 #cfe47 ,this explanation of ,raumur's has been generally accepted4 ,graber 7,die ,insekten1 p4 #ejf7 accepted it1 after examining microscopic sections of the legs1 and ,knckel averred that 8,raumur1 having1 in certain caterpillars1 completely cut off one of the thoracic legs1 had concluded that the butterfly which came from it lacked the corresponding member40 7,rech4 sur l'org4 et dv4 des volucelles1 p4 #afj47 ,newport1 it is true1 denied this disappearance of the legs1 but did not wish to put himself in opposition to received ideas1 and supposed that the member cut off was partly reformed in the imago4 ,knckel believes that he has found a better solution in his theory of histoblasts or imaginal buds2 in his opinion1 8,raumur and ,newport are both right10 but 8when ,raumur cut off a caterpillar's leg1 he at the same time removed the histoblast1 the rudiment of the leg of the butterfly4 ,when ,newport repeated this experiment1 he simply mutilated the histoblast without completely destroying it3 in the first case1 the adult insect was born with one leg less2 in the second case1 it appeared with an atrophied foot40 8,so ingenious an explanation10 says ,gonin1 8is not necessary40 ,to prove that the experiments of the two savants are not contradictory1 it would have been sufficient to cite1 as ,knckel did not do1 the exact words of ,raumur1 for he having cut from a caterpillar 8more than half of three of the thoracic legs on the same side10 says he found that the chrysalis had 8the three limbs on one side shorter than the corresponding ones on the other side40 ,the same operation repeated on a somewhat younger caterpillar again showed in the chrysalis three maimed limbs1 8so that they could not be said to be entirely absent4 ,these results are like those of ,newport2 the interpretation only was faulty1 as we shall attempt to prove40 ,the real relations of the adult legs to the larval legs are thus shown by ,gonin4 8,if we carefully strip off the skin of a caterpillar near the time of pupation 7,fig4 #fjh71 we see that the extremity only of the legs of the imago is drawn out of the larval legs2 the other parts are pressed against each side of the thorax3 near the ventral line a small pad represents the coxa and the trochanter2 the femur and the tibia are distinctly recognizable1 but soldered to each other and only separated by a slight furrow2 they form by their union a very acute knee or bend4 ,the femur is movable on the pad-like coxa1 the tibia continues without precise limits with the extremity concealed in the larval legs4 ,the three divisions of the latter do not appear to have any relation with the live joints of the perfect state4 ,under the microscope the rudiment appears very strongly plaited at the level of the tarsus1 much less so in the other regions4 ,a large trachea penetrates into the femur with some capillaries2 reaching the knee it bends into the tibia at a sharp curve1 but does not become truly sinuous in approaching the extremity4 ,it is then the tarsus especially which is susceptible of elongation2 it may1 on being withdrawn1 give rise to the illusion that the whole organ is disengaged from the larval leg4 8,this disposition is1 we believe1 not known4 ,it gives the key to the experiments of ,raumur and of ,newport4 8,even when we cut off the limb of the caterpillar at its base1 we only remove the tarsus of the imago2 the femur and the tibia remain intact4 ,from an evident homology ,raumur has erroneously concluded that there is an identity4 ,his opinion1 classical up to this day1 that the limb of the butterfly is entirely contained in the leg of the caterpillar1 has been found to be inexact and should be abandoned40 ,embryonic cells and the phagocytes4--,up to the last larval stage the legs do not offer1 says ,gonin1 any vestige of an imaginal germ1 but they contain a great number of embryonic cells 7,fig4 #ade1 ec74 ,they are almost always collected around a nerve or trachea2 sometimes they are independent1 and sometimes retained in the peritoneal sheath1 seeming to arise by proliferation from this sheath4 ,some thus contribute to the lengthening of the tracheal branches or nerves1 and the others1 becoming detached1 form leucocytes or phagocytes4 ,they are very numerous in the legs1 at the beginning of the #dth stage1 but are disseminated some days later throughout the whole cavity of the body4 ,at the time of histolysis they attack the larval tissues and increase in volume at their expense2 in return they serve for the nutrition of the imaginal parts and exercise no destructive action on them4 ,van ,rees agrees with ,kowalevsky in comparing these attacks of the embryonic cells1 sometimes victorious and sometimes impotent1 to the war which the leucocytes wage against both the attenuated and the virulent bacteria4 ,formation of the femur and of the tibia1 transformation of the tarsus4--,capillary trache appear in the leg at the same time as in the wing4 ,they arise from the end of a tracheal trunk near the base of the limb on the dorsal and convex side4 ,after the #c;d moult the hypodermis thickens near this place2 in a few days a pad is formed there and then a large imaginal bud with a circular invagination4 ,these buds were noticed by ,lyonet1 who supposed them to be 8les principes des jambes de la phalne40 ,nerves and a tracheal branch penetrate into the femoro-tibial bud and form a small bay or constriction which marks the point of junction of the femur with the tibia1 and the body-cavity remains in direct communication with the end of the limb4 ,illustration3 ,,fig4 #fjh4--;,feet of the ,pieris butterfly withdrawing from those of the larva4 ,illustration3 ,,fig4 #fji4--;,imaginal feet of ,pieris uncovered with great care to preserve the position which they had in the larva3 ta1 tarsus2 t1 tibia2 g1 knee2 f1 femur2 h1 coxa4 ,the tarsus undergoes a series of changes2 the surface is folded in a very complicated way2 at the level of each articulation1 but only in the internal and concave region of the leg1 is developed a deep fold2 on one side there is a hypodermic thickening1 on the other a simple leaf of the envelope1 which afterwards joins at its base with the parietal hypodermis1 and then two leaves are destroyed with the large cells of the set4 ,the internal part and end of the tarsus are then reconstituted with the elimination of the dbris1 while the external and convex region undergoes direct regeneration4 ,the coxa and trochanter are derived from the base of the larval leg1 and only the #ast pair are well separated from the base of the thorax4 ,one or two days before pupation the femoro-tibial bud1 after having1 until now1 preserved its antero-posterior direction1 is placed transversely as regards the larva1 then becoming directed obliquely forward4 ,this rotatory movement of the coxa may be attributed to the great extension of the fore wings1 which push before them the two first pairs of legs4 ,the last pair in their turn are simply covered by the hind wings and are but slightly displaced4 ,this new position of the legs is that of the imago3 the knee of the #ast pair is situated in front of the tarsus2 that of the #b;d a little outward2 that of the #c;d pair is directed backward4 7,gonin47 ,the antenn4--,these appendages also have the same relation with those of the caterpillar as in the case of the legs1 the larval appendages being only the point of departure of the imaginal growth4 ,weismann has observed in ,corethra how at the approach of each moult an invagination like the finger of a glove allows the antenna to elongate from its base4 ,the process1 says ,gonin1 is identical in the caterpillar of ,pieris4 ,at the last moult the invagination is so pronounced that it is not effaced with the renewal of the chitinous integument4 ,several days later it again begins to grow larger4 ,as the imaginal bud gradually sinks into the cavity of the head1 it presses back the hypodermic wall and thus forms an envelope around it4 ,its base1 widely opened1 gives admission to the nerves1 besides capillaries and sometimes a large trachea4 ,illustration3 ,,fig4 #faj4--,larva in same stage as ,fig4 #fac2 side view of head and thorax3 a1 a1 wings1 with the folds on the surface1 and the sinuous track of the tracheal bundles2 st ,i1 prothoracic stigma2 p1 p1 ends of the legs4 ,as soon as it reaches the posterior region of the head1 the antenna in lengthening becomes folded and describes the great curves which led ,raumur to compare it to a ram's horn 7,fig4 #fac74 ,the leaf of the envelope thickens in the interior and all around the base of the organ4 ,its ultimate rle is closely like that of the two other hypodermic formations4 ,it is at the outset this layer of cells which in the larva supports the ocelli4 ,this layer1 hidden on each side under the parietal region1 thickens and regenerates1 forming a circular pad which becomes more prominent and finally assumes the form of the compound eye of the imago4 ,illustration3 ,,fig4 #faa4--;,head of the larva just before pupation3 between the two mandibles 7m7 is seen the relief of the tongue or maxill 7m72 f1 spinneret2 l1 labrum2 a1 antenna4 ,illustration3 ,,fig4 #fab4--,same stage as in ,fig4 #faa1 but after the removal of the larval skin1 and including the lateral scale3 ,a1 side1 ,b1 front1 view2 c1 8cimier0 7the dotted line shows the position it takes in the pupa72 a1 antenna2 o1 eye2 t1 tongue4--,this and ,figs4 #fjh-faa1 after ,gonin4 ,finally1 this layer gives rise to a conical prolongation 7,fig4 #fab1 c71 which after exuviation appears as a tuft of long hairs1 and is called by ,gonin the crest 7cimier1 ,fig4 #fab71 which is characteristic of the pup of ,pierid4 ,it is only differentiated towards the end of the #dth larval stage in a median depression of the vertex4 ,it is an imaginal bud in the most general sense of the word4 ,illustration3 ,,fig4 #fac4--,larva of ,pieris brassic stripped of its skin some minutes before pupation3 the antenn 7a7 have been displaced1 and the tongue cut off1 to show the palpi 7p72 c1 cimier3 o1 eye2 m1 vestige of a mandible2 t1 insertion of the tongue 7see ,fig4 #fab72 aa1 fore1 ap1 hind1 wings2 g1 knee of a foot of the #c;d pair4 ,on each side the base of the antenna comes in contact with the germ of the crest4 ,the envelopes approach each other1 and their thickened part constitutes with the ocular disks a new cephalic wall4 ,the head of the butterfly thus marked off is triangular2 all the larval parts remaining out of this area then disappear4 ,the muscles and the nerves are resorbed by histolysis1 then the external part of the imaginal envelopes and the old parietal hypodermis1 reduced very thin and degenerated1 is detached in shreds4 ,the antenna becomes external throughout its whole extent4 ,the transformation is in this case1 then1 almost as complete as in the thorax of ,diptera or ,hymenoptera4 ,it is necessitated by the change of form and of volume of the head4 ,the region of the ocelli persists unchanged almost alone from the larva to the imago also4 ,the limit is not well marked between the portion which is the replacement or direct renovation of the epithelium4 ,maxilla and labial palpi4--,the development of the tongue 7#ast maxill7 is so like that of the antenn that it scarcely needs description4 ,beginning at the last moult1 the hypodermic contents of the maxill is withdrawn in the cephalic cavity under the form of a hollow bud whose base is turned inward4 ,the invagination remains less distinct than in the antenn2 it does not even reach to the anterior part of the sophagus4 ,the two symmetrical halves of the tongue approach each other and are thrice folded4 ,when the caterpillar stops feeding1 they each curve in in the form of an ,s1 remaining lodged under the floor of the mouth 7,fig4 #fac1 t74 ,underneath are to be seen two other buds1 which by an identical process become the labial palpi 7,figs4 #fad1 #fae1 p74 ,at the anterior part of the head1 where the organs are very close together1 the envelopes form several folds without any further use 7,fig4 #fae1 r74 ,the two leaves then fuse together and decay as at the surface of the tarsus4 ,finally1 in the mandibles and the labrum1 there is only a cellular thickening without any invagination4 ,illustration3 ,,fig4 #fad4--,section through the anterior region of the head of ,pieris larva1 four days after the #c;d moult3 o1 sophagus2 m1 m1 #ast maxill containing the two imaginal buds of the tongue2 p1 p1 labial palpi2 ,tr1 trachea4 ,illustration3 ,,fig4 #fae4--,section through the same place as in ,fig4 #fad1 #aj days after the #c;d moult1 the imaginal appendages having grown in size3 r1 r1 caducous folds of the old hypodermis and of the envelopes4 ,other letters as in ,fig4 #fad4--,this and ,figs4 #fac-fad1 after ,gonin4 ,process of pupation4--,notwithstanding the great number of persons who have reared ,lepidoptera1 close and patient observations as to the exact details are still needed4 ,gonin1 who has made the closest observations on ,pieris1 pertinently asks why the antenn1 which are appendages of the head1 are visible in the abdominal region1 and why the tongue 7maxill7 is extended between the legs as far as the #c;d abdominal segment4 ,to answer these questions he made a series of experiments4 ,selecting some caterpillars which were about to pupate1 he produced an artificial metamorphosis by removing the cuticula in small bits4 ,exposing the appendages in this way1 they preserved the position which they are seen to take during growth4 ,each wing appeared within the limits of the segment from which it grew out 7,fig4 #faj71 not extending beyond1 as it does in the normal pupa1 so that ,raumur was wrong in saying that 8the wings are here gathered on each side into a kind of band1 which is large enough to lie in the cavity which is between the #ast and #b;d segment40 7#h;e ,mm41 p4 #cei47 ,all these parts are coated with a viscous fluid secreted by special glands1 which hardens after pupation upon exposure to the air4 ,so long as the parts are soft1 they can easily be displaced4 ,gonin drew one of the antenn like a collar around the head1 and one half of the tongue upon the outer side of the wing4 8,when pupation is normal1 the integument splits open on the back of the thorax1 and the pupa draws itself from before backwards4 ,owing to the feeble adherence which the chitinous secretion gives it1 it draws along with it the underlying organs4 ,the legs1 antenn1 the two halves of the tongue 7maxill7 retained by their end1 each in a small chitinous case1 can only disengage themselves from it when in elongating they have acquired a sufficient tension4 ,the curves straighten out and the folds unbend4 ,the chitinous mask of the head in withdrawing from the larval skin follows the ventral line2 the tongue and labial palpi free themselves from its median part2 the antenn disengage themselves from the two lateral scales4 ,between these different appendages a space is left on the surface of the head for the eyes1 and on the thorax for the legs4 ,these are not completely extended on account of the lack of freedom of the femoro-tibial articulation2 the femur preserves its direction from behind forwards1 and the knee in the two first pairs remains at the same height4 ,the wings overlie them and cover the under side of the two basal abdominal segments2 their surfaces in becoming united increase much in size40 ,as the chitinous frame of each spiracle gradually detaches itself1 we see a tuft of trache passing out of the orifice4 ,it is at this moment that the provisional tracheal system is cast off1 and it is easy to see that the process is facilitated by the simultaneous elongation of all the appendages4 ,the permanent trache can follow this elongation because they are sinuous1 and need only to straighten their curves4 ,it is1 however1 not the same with the tracheoles1 as we have seen in the case of the wings 7p4 #acc71 and their extension or stretching is thus explained by a very simple mechanism4 8,the position which the organs assume in the chrysalis is not due to chance1 everything is determined in advance1 and the microscope shows us that the structure of the hypodermis is specially modified in all the parts which remain external4 ,it is a fact well known to those who rear ,lepidoptera that if this normal arrangement is disturbed there are few chances that the perfect insect will survive4 ,a leg lifted up1 or an antenna displaced1 leaves a surface illy protected against external influences4 ,almost always this accident causes a drying of the chrysalis4 8,several interesting experiments may be cited as bearing on this subject4 ,if during transformation the chitinous mask of the head is separated from the integument beneath1 it is arrested half-way in its development1 and the antenn and tongue are not fully extended4 ,when the case or skin of the caterpillar is drawn1 not from before backward1 but in the opposite direction1 all the appendages of the thorax are placed perpendicularly to the body4 ,dewitz and ,knckel d',herculais1 in stating that the skin of the caterpillar splits open along its whole length1 show that they were ignorant of the mechanism2 for it is precisely because the chitinous larval skin splits open only in front that it preserves sufficient adherence to the organs beneath to draw them after it in the direction of the abdomen4 8,to only read modern authors1 one would suppose that the mechanism of pupation had remained hitherto unknown4 ,in reality1 it did not escape the notice of ,swammerdam or of ,raumur1 both of whom have described it with care4 ,the first attached too much importance to the flow of blood1 the action of which would be rather to push the organs out than to extend them over the surface of the thorax2 the second insists on the movements of the insect4 ,this factor1 very admissible in caterpillars1 #8whose under side is situated on a horizontal plane' 7iii1 #i;e ,mmoire1 p4 #cie71 cannot be invoked for those which suspend themselves by the tail1 as in the genus ,vanessa40 7,gonin47 b4 ,the ,hymenoptera ,in the ,hymenoptera1 ,ratzeburg was the first to figure and describe the numerous intermediate stages between the larva and pupa1 his subjects being the ants1 ,cynips1 and ,cryptus1 which pass through five stadia before assuming the final pupal shape4 ,in the bees1 as we have observed in the larv of ,bombus 7,proc4 ,bost4 ,soc4 ,nat4 ,hist41 #ahff71 after hardening a series in alcohol of young in different stages of development1 it will be found difficult to draw the line between the different stages since they shade insensibly into each other1 those represented in ,fig4 #faf being selected stages4 ,the head of the incipient semipupa distends the prothoracic segment of the larva whose head is pushed forward and the thoracic segments are much elongated1 while the appendages and wings are well developed1 and have assumed the shape of those of the pupa4 ,development both in the head and thorax begins in the most important central parts1 and proceeds outwards to the periphery4 ,during this period the 8median segment10 or #ast abdominal1 has begun to pass forward and to form a part of the thorax4 ,illustration3 ,,fig4 #faf4--,transformation of the bumblebee1 ,bombus1 showing the transfer of the #ast abdominal larval segment 7c7 to the thorax1 forming the propodeum of the pupa 7,d7 and imago3 n1 spiracle of the propodeum4 ,a1 larva2 a1 head2 b1 #ast thoracic1 c1 #ast abdominal1 segment4 ,b1 semipupa2 g1 antenna2 h1 maxill2 i1 #ast1 j1 #b;d leg2 k1 mesoscutum4 l1 mesoscutellum2 m1 metathorax2 d1 urite 7sternite of abdomen72 e1 pleurite2 f1 tergite2 o1 ovipositor2 r1 lingua2 q1 maxilla4 ,in what may be termed the #c;d stage 7,fig4 #faf1 ,c71 though the distinction is a very arbitrary one1 the change is accompanied by a moulting of the skin1 and a great advance has been made towards assuming the pupal form4 ,the abdomen is very distinctly separated from the thorax1 the propodeum being closely united with the thorax1 and the head and thorax taken together are nearly as large as the abdomen1 the latter now being shorter and perceptibly changed in form1 more like that of the completed pupa1 while there are other most important changes in the elaboration of the parts of the thorax1 particularly the tergites1 and of the head and its appendages4 ,meanwhile the ovipositor has been completed and nearly withdrawn within the end of the abdomen4 ,the next to study the transformations of the ,hymenoptera was ,ganin1 who discovered the early remarkable pre-eruciform larv1 as we may call them1 of certain egg-parasites 7,proctotrypid74 ,he discovered the imaginal buds of the wings in the third larva of ,polynema 7,fig4 #ahe71 but his observations1 and those of ,ayers1 need not detain us here1 as they have little to do with the subject of the normal metamorphosis of the ,hymenoptera1 and will be discussed under the subject of ,hypermetamorphosis4 ,to ,bugnion we owe the first detailed account of the internal changes in the ,hymenoptera1 his observations being made on a chalcid parasite1 ,encyrtus fuscicollis1 a parasite of ,hyponomeuta4 ,the apodous larva 7,fig4 #fah7 moults but once1 the next ecdysis being at the time of pupation4 ,it passes through a semipupal stage4 ,illustration3 ,,fig4 #fag4--;,encyrtus larva3 #a1 #b1 #c1 ganglia in front of the brain2 m1 mouth2 s4 gl1 silk-gland2 br1 brain2 n1 nervous cord2 w1 bud of fore1 w1 bud of hind1 wing4 ,bugnion observed in the larva of ,encyrtus three pairs of lower thoracic or pedal imaginal buds1 two pairs of upper or alary buds1 a pair of ocular or oculo-cephalic buds destined to build up all the posterior part of the head1 a pair of antennal buds1 and three pairs of buds of the genital armature 7ovipositor74 ,he also detected the rudiments of the buccal appendages under the form of six small buds 7,fig4 #fai71 which do not invaginate1 and are not surrounded by a semicircular pad4 ,also in the abdomen1 behind each pair of stigmata1 there is a group of hypodermic cells 7,fig4 #fag71 which1 without doubt1 correspond to the wing-buds1 but are not differentiated into a central bud and its pad1 and does not merit the name of imaginal bud4 ,in fact1 except the eye-buds1 which are unlike the others1 he only observed the imaginal buds of the legs1 wings1 and ovipositor4 ,the antennal buds are1 like those of the buccal appendages1 without an annular zone4 ,the pedal buds were detected in the middle of larval life4 ,they each form a central bud surrounded by a circular thickening4 ,they gradually elongate and become tongue-like and somewhat bent2 soon a linear opening or slit appears1 forming the mouth of a cavity which communicates with that of the body1 allowing the passage into them of the trache1 muscles1 and nerves1 and afterwards of the blood4 ,finally1 the buds grow longer and slenderer1 are bent several times1 and show traces of the articulations2 and soon under the old larval skin1 now beginning to rise in anticipation of the moulting1 we see the coxa1 femur1 tibia1 and tarsus of the perfect insect1 the tarsal joints not yet being indicated4 ,illustration3 ,,fig4 #fah4--,older ,encyrtus larva1 lateral view1 showing the buds of the antenn 7ant71 legs1 and wings 7w1 w73 oe1 sophagus2 q#a1 q#b1 q#c1 buds of the genital armature2 o1 rudiment of the sexual gland 7ovary or testis72 ur4t1 urinary tube2 st1 stomach2 i1 intestine 7rectum72 n1 ventral nervous cord2 r1 rectum2 sp#a-sp#i1 spiracles4 ,illustration3 ,,fig4 #fai4--;,a still older larva1 ready to transform4 ,the imaginal buds of the antenn 7f71 eyes1 wings 7a#a1 a#b71 and legs have become elongated3 ch1 chitinous arch2 b1 mouth2 o1 eye-bud2 g1 brain2 e1 stomach2 x1 rudiment of the sexual glands 7either the ovary or testis74--,this and ,figs4 #fag and #fah1 after ,bugnion4 ,the wing-buds 7a#a1 a#b7 appear at the same time as those of the legs1 as racket-shaped masses of small cells situated directly behind the #ast and #b;d pair of stigmata1 in contact with the tissue ensheathed by the corresponding tracheal vesicle 7,fig4 #fah74 ,afterwards they have exactly the form of those of the ,lepidoptera 7,fig4 #fai74 ,the proliferation of the hypodermis is not limited to the thorax1 but takes place at corresponding points in the first seven abdominal segments4 ,these abdominal agglomerations of cells do not give rise to true buds1 but serve simply to reconstitute the hypodermis of the abdominal segments at the time of metamorphosis4 ,ocular or oculo-cephalic buds4--,the eye of insects1 as is well known1 is a modification of a portion of the integument1 the visual cells being directly derived from the hypodermis1 the cornea being a cuticular product of this last1 like chitinous formations in general4 ,the ocular buds appear towards the end of larval life as a simple mass of hypodermic cells1 and form a compact layer on the dorsolateral face of the prothoracic segment1 and clothe the cephalic ganglion or brain like a skull-cap4 ,the central portion only is destined to form the eye1 while the peripheral pad1 continuing to thicken1 gives rise to a voluminous and rounded mass1 which meets on the median line that of the opposite side1 and forms the integument of all the posterior part of the head4 ,bugnion also observed on the median line a group of small hypodermic cells which he regarded as the rudiment of the anterior ocellus1 but he did not detect those of the posterior ocelli4 ,the antennal buds4--,these appear at an early date under the cuticle of the head1 as two distinct rounded cellular masses1 with a central cavity1 but no annular zone 7,fig4 #fai1 f74 ,each one grows longer in a transverse sense1 and its summit1 extended from the outer side1 curves downward4 ,it now forms a hollow tube folded at the end1 and terminated by a disk whose centre is perforated 7,fig4 #fai1 f74 ,afterwards1 when the larva is ready to transform1 it grows longer1 becomes folded on itself in its cavity1 and1 passing beyond on each side the limits of the larval head1 encroaches on the prothoracic segment4 ,the buds of the buccal appendages4--,towards the end of the larval period1 the buds of the mouth-parts appear as small digitiform projections1 situated on each side and below the mouth4 ,formed of small epithelial cells pressed against each other1 they are all directed anteriorly1 and possess no furrow or pad4 ,the #b;d maxill 7labium7 is formed of two separate parts4 ,the imaginal buds of the lower lip appear on each side of the median line1 with a fissure indicating the differentiation of the palpus4 ,on each side are to be seen the #ast maxillary buds1 bearing each a rudimentary palpus1 and1 farther in front1 the buds of the mandibles4 ,the buds of the ovipositor4--,the six stylets of the ovipositor arise from six small imaginal buds which become visible in the second half of the larval period1 on each side of the median line1 on the lower face of the three last segments 7,fig4 #fbj1 q#a1 q#b1 q#c74 ,the bud is differentiated into a central discoidal bud1 a furrow1 and a marginal1 rather thick swelling or pad4 ,afterwards1 these buds elongate and form small papilliform projections directed backwards 7,fig4 #fba72 but only during the pupal period do they1 as already observed in ,bombus1 approach each other and assume their definite shape as an ovipositor4 ,illustration3 ,,fig4 #fbj4--;,end of larva of ,encyrtus of #b;d stage1 showing the three pairs of imaginal buds of the ovipositor q#a1 q#b1 q#c4 ,illustration3 ,,fig4 #fba4--,the same in an older larva ready to transform3 i1 intestine2 x1 genital gland2 a1 anus4--,after ,bugnion4 ,finally1 ,bugnion states that while metamorphosis in the ,hymenoptera is less highly modified than in the ,muscid1 it is more marked than in the ,coleoptera and ,lepidoptera4 ,in these orders the pupa moves the abdomen1 but in ,hymenoptera it is absolutely immovable throughout pupal life1 as long as the integument is soft4 ,,development ,,of ,,the ,,imago ,,in ,,the ,,diptera ,the flies1 particularly the ,muscid and their allies 7,brachycera71 are the most highly modified of insects1 their larv having undergone the greatest amount of reduction and loss of limbs1 this atrophy involving even most of the head4 ,the following account has been prepared in part from the works of ,weismann1 ,ganin1 ,miall1 and ,pratt1 but mostly from the excellent general summarized account given by ,korschelt and ,heider4 ,in the holometabolic orders of insects1 with their resting pupal stage1 during which no food is taken1 the entire activity of life seems to be turned to deep-seated and complicated internal developmental processes4 ,these inner changes involve an almost complete destruction of many organs of the larva1 and their renewal from certain germs 7the imaginal buds7 already present in the larva1 as will be seen in the highly modified ,muscid4 ,only a few larval organs become directly transferred into the body of the pupa and imago4 ,such are the rudiments of the genital system4 ,the heart also1 and the central portion of the nervous system1 suffer only slight and unimportant1 almost trivial1 internal changes4 ,on the other hand1 most of the other organs of the larva become completely destroyed3 the hypodermis1 most of the muscles1 the entire digestive canal with the salivary glands2 while their cells1 under the influence of the blood corpuscles 7leucocytes71 which here act as phagocytes1 fall into pieces1 which are taken up by them and become digested4 ,simultaneously with this destructive1 histolytic process1 the new formation of the organs by the imaginal buds1 already indicated in the embryo1 is accomplished in such a way that the continuity of the organs in most cases remains unimpaired4 ,this process of transformation can only be understood by considering that of the embryonal germs of the organs1 7#a7 only a part is destined for the use of the larva in growth1 and for the performance of certain functions which exhaust themselves during larval life1 so that it is no more capable of farther transformation1 and finally becomes destroyed2 while 7#b7 a second part of the embryonal germs or rudiments persists first in an undeveloped condition1 as imaginal buds1 in order to undertake during the pupa stage the regeneration of the organs4 ,though ,swammerdam knew that the rudiments of the wings were already present under the skin of the larv1 we are indebted1 for our present knowledge1 to the thorough and profound investigations of ,weismann on the metamorphosis of the ,diptera1 and also to the researches of ,ganin and others who have worked on the pup of ,muscid1 in which the development is most complicated and modified4 ,in the more generalized and primitive ,diptera1 such as ,corethra1 the processes of formation of the pupa and imago are much simpler than in the muscids and ,pupipara4 ,these processes are still simpler in the ,lepidoptera and ,hymenoptera1 and for this reason we have given a summary of what has been done on these organs by ,newport1 ,dewitz1 and especially by ,bugnion4 ,our knowledge of this subject is still very imperfect1 only the more salient points having been worked out1 and1 as ,korschelt and ,heider state1 there is still lacking certain proof as to how far the relations of the internal changes known to exist in the ,muscid also apply to other orders of insects1 though it must be considered that in the pupa of ,lepidoptera1 ,hymenoptera1 perhaps also the ,coleoptera1 and we would add in the ,neuroptera as well as the male ,coccid1 very similar metamorphic processes take place4 a4 ,development of the outer body-form ,the form of the imago is completely marked out in the pupa1 so that the transition from the pupa to the imago is comparatively slight and only depends on the modification and development of the parts already present4 ,illustration3 ,,fig4 #fbb4--;,anterior part of young larva of ,simulium sericea1 showing the thoracic imaginal buds3 p1 prothoracic bud 7only one not embryonic72 w1 w1 fore and hind wing-buds2 l1 l1 l1 leg-buds2 n1 nervous system2 br1 brain2 e1 eye2 sd1 salivary duct2 p1 prothoracic foot4--,after ,weismann4 ,in most cases the modification in question consists of the changes occurring during the passage from the larval form to the imago1 the reformation of parts already present being most marked1 while the new rudiments only participate in a limited way in the process4 ,thus1 for example1 the head of the caterpillar together with the antenn and mouth-parts1 also the thoracic limbs1 pass directly and unchanged from the larva into the pupa4 ,the compound eyes and the wings are1 however1 new formations1 the latter arising from imaginal buds4 ,the same is the case with many other ,heterometabola1 where the passage of the larva into the pupa in general is due to a transformation of parts already present4 ,the changes in the brain1 the fusion of certain ganglia of the ventral nervous cord1 the changes in the abdomen1 involving the reduction in the number of segments and the remodelling of the end of the body1 and the formation of the ovipositor or sting1 and in the higher ,hymenoptera the transfer of the #ast abdominal segment to the thorax1 and the origin of the genital armature1--all these should here be taken into account4 ,it should be observed that in every case where the larv are footless1 as in ,diptera1 all the ,hymenoptera except the phytophagous ones and certain coleopterous larv1 the limbs of the imago stage are1 in the earliest stages1 indicated as new structures in the form of imaginal buds4 ,formation of the imago in ,corethra4--,corethra may serve as an example of such a relatively simple metamorphosis4 ,its larva belongs to the group of eucephalous dipterous larv4 ,the head of the perfect insect is already indicated in the larva1 and its parts1 with certain modifications1 pass directly into the pupa4 ,the compound eyes1 and this is a rare exception among the ,holometabola1 are present in the larva4 ,on the other hand1 the thoracic legs1 the wings1 and halteres are developed out of new rudiments which are present in the last larval stage1 before pupation4 ,each thoracic segment has four of them1 two ventral and two dorsal 7,fig4 #fbb72 the ventral buds becoming the legs4 ,of the dorsal pairs1 that of the mesothorax develops into wings1 that of the metathorax into halteres1 while from the corresponding rudiments of the prothorax in ,corethra arise the stigma-bearing dorsal or respiratory processes of the pupa1 and in ,simulium a tuft of tracheal gills 7,fig4 #fbc1 ra2 see also ,fig4 #ehb74 ,illustration3 ,,fig4 #fbc4--,late larva of ,simulium1 showing the rudiments of the pupal structures within the larval skin3 l#a1 l#b1 l#c1 fore1 middle1 and hind legs of the fly2 ra1 respiratory appendages of pupa2 w1 wing of fly2 h1 halter of fly4--,after ,miall4 ,illustration3 ,,fig4 #fbd4--;,imaginal buds in larva of ,corethra 7diagrammatic cross-section of thorax73 invaginations 7fe and be7 of the larval hypodermis 7lhy7 in whose bases the rudiments of wings 7fa7 and legs 7ba7 arise2 lh1 chitinous integument of the larva4--,after ,lang4 ,these imaginal buds may be regarded as evaginations of the outer surface of the body4 ,the only difference is that the buds of the appendages as a whole seem sunken below the level of the surface of the body1 being situated at the bottom of an evagination1 as in the buds of the head and trunk in the ,pilidium larva of nemertean worms1 and in the rudiments of the lower surface of the body of ,echinus present in the pluteus larva4 ,the lumen of the invagination in which the appendages of ,corethra 7and other ,holometabola7 are situated is called by ,van ,rees the peripodal cavity1 and the external sheath bordering it1 which is naturally continuous with the hypodermis of the body1 the peripodal membrane 7,fig4 #fcf1 p74 ,we must adopt the view that the rudiments of the appendages 7imaginal buds7 are from the first divided into ectodermal and mesodermal portions1 which are derived from the corresponding germ-layers of the larva4 ,the ectoderm of the rudiments of the appendages is continuous with the peripodal membrane1 and through it with the hypodermis4 ,weismann was inclined to derive the organs 7trache1 muscles1 etc47 developing within the germs of the appendages from a hypertrophy of the neurilemma of a nerve passing down from within into the imaginal bud1 and held that nerves and tracheal branches soon after passed into the inner surface of the imaginal bud4 7,korschelt and ,heider47 ,when the imaginal buds of the appendages enlarge1 then the peripodal membranes become correspondingly distended1 and the limbs within assume a more or less crumpled position1 and in ,corethra are spirally twisted1 while the rudiments of the wings are folded4 ,the completion of the rudimentary limbs is accomplished simply by their passing out of the invagination in which they originated4 ,the limbs thus gradually become free1 the peripodal membrane is seen to reach the level of the rest of the hypodermis and become a part of it1 and the base of the extremity is no longer situated in a cavity4 ,the internal organs of ,corethra undergo but to a slight degree the destruction 7histolysis7 which is so thoroughgoing in the ,muscid4 ,kowalevsky states that in the mid-intestine of ,corethra a histolysis of the larval and reconstruction of the imaginal epithelium goes on in the same way as has been described in ,musca4 ,most of the larval organs pass without histolytic changes directly over into those of the pupal and imaginal stages2 the muscles in general are also unchanged1 but those of the appendages and wings are made over anew4 ,the last arise1 according to ,weismann1 in the last larval stage from strings of cells which are already present in the embryo4 ,when we consider how insignificant the internal transformations are during the metamorphosis of the ,tipulid1 of which ,corethra serves as an example1 we can scarcely doubt that we here have before us conditions which illustrate the passage between an incomplete and a complete metamorphosis4 ,thus1 among other things1 should be mentioned the short duration of the pupa stage and the activity of the pupa1 as also the early appearance of the germs of the compound eyes1 a character which ,corethra has in common with the ,hemimetabola4 7,korschelt and ,heider47 ,formation of the imago in ,culex4--,in respect to the formation of the imaginal head1 ,culex is still more primitive than ,corethra4 ,miall and ,hammond find from ,hurst's partly unpublished descriptions and preparations that there are no deep invaginations for the compound eyes or antenn of the imago4 8,the compound eye forms beneath the larval eye-spots1 and is at first relatively simple and composed of few facets4 ,the number increases by the gradual formation of partial and marginal invaginations1 each of which forms a new element4 ,the imaginal antenna grows to a much greater length than that of the larval antenna1 and its base is accordingly telescoped into the head1 while the shaft becomes irregularly folded4#aae ,culex1 though more modified than ,chironomus in many respects1 e4g4 in the mouth-parts1 is relatively primitive with respect to the formation of the imaginal head1 and shows a mode of development of the eye and antenna which we may suppose to have characterized a remote and comparatively unspecialized progenitor of ,chironomus40 ,formation of the imago in ,chironomus4--,the development of the head of the imago of ,chironomus dorsalis has been discussed by ,miall and ,hammond4 ,the invaginations which give rise to the head of the fly could not be discovered even in a rudimentary state until after the last larval moult4 8,weismann has given reasons for supposing that invaginated imaginal rudiments could not come into existence before the last larval moult in an insect whose life-history resembles that of ,corethra or ,chironomus4 ,if the epidermis were invaginated in any stage before the ante-pupal one1 the new cuticle1 moulded closely upon the epidermis1 would become invaginated also1 and would appear at the next moult with projecting appendages like those of a pupa or imago4 ,this is actually the way in which the wings are developed in some larval insects with incomplete metamorphosis4 ,in ,muscid the invaginations for the head of the imago have been traced back to the embryo within the egg1#aaf but the almost total subsequent separation of the disks from the epidermis renders their development independent of the growth of the larval cuticle and of the moults that probably take place therein40 ,the pupal and imaginal cuticles do not follow at all closely the larval skin1 but1 says ,miall1 become at particular places folded far into the interior4 8,the folds which give rise to the head of the fly are two in number and paired4 ,they begin at the larval antenna on each side of the head1 and gradually extend further and further backwards4 ,the object of the folds is to provide an extended surface which can be moulded1 without pressure from surrounding objects1 into the form of the future head4 ,on one part of each fold the facets of the large compound eyes are developed2 another part gives rise to the future antenna1 a large and elaborate organ1 which springs from the bottom of the fold1 and whose tip just enters the very short antenna of the larva4 ,the folds for the head ultimately become so large that the larval head cannot contain them1 and they extend far into the prothorax4 ,here a difficulty occurs4 ,if the generating cuticle of the prothorax were also to be folded inwards1 the future prothorax would take a corresponding shape4 ,but the prothorax of the fly has a form dictated to it by the limbs which it bears and by the muscles to which it gives attachment4 ,these call for a great reduction in its length1 and a peculiar shape1 which it is not here necessary to describe4 ,it will be enough to realize that the epidermis of the future prothorax cannot be sacrificed to the folds which are to give rise to the head of the fly4 ,all interference between the two developing structures is obviated by the provision of a transverse fold1 which pushes into the prothorax from the neck1 and forms a sort of internal pocket4 ,the floor of the pocket forms two longitudinal folds1 which prolong the folds originating in the larval head4 ,the roof of the pocket shrinks up and forms the connection between the head and thorax of the fly4 ,ultimately the head-part is drawn out1 leaving the prothoracic structures unaffected40#aag ,illustration3 ,,fig4 #fbe4--,process of formation of the parts of the head of the fly in the larva of ,chironomus 7male73 ,a1 the new epidermis thrown into complicated folds which have been cut away in places to show the parts within4 ,b1 the same parts in horizontal section2 lc1 larval cuticle2 tf1 transverse fold2 tf1 upper wall of the same2 m1 cut edge of new epidermis2 ant1 larval antenna2 an1 nerve to the same2 ant1 antenna of fly2 lf1 longitudinal fold2 o1 eye of fly2 on1 optic nerve2 an1 root of antennary nerve2 br1 brain2 s1 sophagus2 b1 bulb of antenna of fly2 s1 s1 s1 blood-spaces4--,after ,miall4 ,the development of the head of the fly of ,chironomus appears1 as ,miall and ,hammond state1 to be intermediate between the groups ,adiscota and ,discota of ,weismann2 i4e4 8between the types in which the parts of the head of the fly are developed in close relation to those of the larva1 and the types in which deep invaginations lead apparently to the formation of similar new parts far within the body1 the seeming independence of the new parts being intensified by thoroughgoing histolysis10 and they suggest that possibly types may be discovered intermediate between ,chironomus and ,muscid4 ,illustration3 ,,fig4 #fbf4--;,a1 ,b1 ,c1 ,d1 diagrams of transverse sections showing the development of the wings1 legs1 and the imaginal hypodermis of muscid flies from the imaginal buds of the larva during metamorphosis3 lh1 chitinous integument of larva from which the underlying hypodermis 7lhy7 has withdrawn2 iid1 imaginal buds of wings1 iiv1 of legs2 is1 the cords connecting them with the hypodermis2 fl1 wing-germs2 b1 leg-germs2 ihy1 imaginal hypodermis spreading out in ,d from the imaginal buds4 ,the imaginal rudiments of the hypodermis are indicated by thick1 black outlines1 the larval hypodermis by two thin1 parallel lines4--,after ,lang4 ,we are now prepared to consider the extremely complicated changes1 in the ,muscid1 leaving out of consideration the origin of the wings from imaginal buds1 which has already been discussed on pp4 #abf-acg4 ,formation of the imago in ,muscid4#aah--;,in the flesh1 and undoubtedly the house1 and allied flies the germs or imaginal buds of the legs and wings arise in the same way as in ,corethra4 ,but in the ,muscid1 the buds are situated far within the interior of the body1 the peripodal cavities appear closed1 and the peripodal membrane stands in connection with the hypodermis merely by means of a delicate thread-like stalk4 ,this connecting cord1 which was first detected by ,dewitz1 and whose interpretation was entirely right1 shows in its interior1 as ,van ,rees proved1 a narrow cavity4 ,though the earliest stages in the development of imaginal buds in the embryo of the ,muscid are still unknown1 yet we shall not go far astray if we refer them1 like the imaginal buds of ,corethra1 to hypodermal invaginations4 ,we must1 then1 regard the stalk-like connection just mentioned as the long drawn-out neck of this invagination4 ,in general1 the development of the appendages 7,figs4 #fbf1 #fbg7 goes on as described in ,corethra4 ,the rudiments of the legs enlarge and show at an early date the first traces of the later joints4 ,they are so packed in the peripodal cavities that the single joints of the extremities appear as if pushed in 8like the joints of a travelling cup40 7,van ,rees47 ,the evagination of the completely formed buds of the limbs1 which occurs on the first day after the beginning of pupation1 goes on in such a way that the stalk of the imaginal bud 7,figs4 #fbf1 ,b2 #fbg1 ,b7 shortens1 while its cavity widens so that the limbs finally1 as in ,corethra1 pass out through the widely opened mouth of the peripodal invagination1 which at the same time gradually completely disappears4 ,the peripodal membrane is converted into a thickened part of the hypodermis in the region adjoining the base of the leg1 and from this thickened hypodermal portion1 the formation of the hypodermis of the entire imaginal thorax goes on1 as the larval hypodermis is gradually destroyed4 ,illustration3 ,,fig4 #fbg4--;,imaginal buds of muscid flies in process of development3 ,a1 brain 7c7 and ventral ganglion 7v7 of a larva1 #g mm4 long1 of ,c4 vomitoria2 h1 head-rudiment2 rc1 portion of ventral cord2 pd1 prothoracic rudiment2 vc#c1 third nerve2 md1 mesothoracic rudiment4 ,b1 mesothoracic rudiment more advanced1 in a pupa1 just formed1 of ,sarcophaga carnaria1 showing the base of the sternum and folds of the forming leg1 the central part 7f7 representing the foot4 ,c1 the rudimentary leg of the same more advanced2 f1 femur2 t1 tibia2 f#a1 f#e1 tarsal joints4 ,d1 two buds from a larva1 #bj mm4 long1 of ,sarcophaga1 attached to trache2 msw1 mesonotal and wing-germ2 mt1 metathoracic rudiment4 ,e1 r1 mesothoracic germ of a #g mm4 long larva attached to a tracheal twig4--,after ,weismann and ,graber1 from ,sharp4 ,we must here settle the question as to the first origin of the mesodermal portions of the rudiments of the appendages4 ,we can already distinguish in the imaginal buds of the fully grown muscid larva a clear separation between an ectodermal and an inner mesodermal part4 ,ganin derived the mesodermal part through a sort of differentiation and separation of the innermost layer of the ectodermal part1 and ,van ,rees has1 in general1 confirmed this view4 ,kowalevsky1 on the other hand1 is inclined to the view that the mesodermal part of the imaginal bud is derived from the embryonal cells of the mesoderm4 ,he finds scattered throughout the mesoderm1 under the hypodermis of the larva1 so-called wandering cells 7,fig4 #fcb1 ,a1 w71 which are different in appearance from the leucocytes and from the elements from which the formation of the mesodermal parts of the imaginal rudiments proceed4 ,kowalevsky is inclined to believe that there are in each segment rudiments of the imaginal mesoderm1 but which are so delicate and indifferent that we cannot find them in the first stages of their origin4 ,from these mesodermal imaginal rudiments the above-mentioned wandering cells of the mesoderm are derived1 which afterwards come into connection with the ectodermal portion of the imaginal buds4 ,still more complicated and difficult to understand is the development of the head-section of muscids4 ,we must remember that in muscid larv the head-section exists in its most rudimentary form1 being the result of extreme modification and degeneration4 ,the small size of the head is also due to the fact that it is more or less retracted within the thoracic region4 ,then1 as shown by the researches of ,weismann1 in the last embryonal stages1 the forehead1 mandibles1 and the whole region of the head around the mouth invaginate and form a sunken cavity 7,fig4 #fbh1 p71 in which the chitinous supports of the hooks characteristic of muscid larv are soon developed4 ,this sunken part of the head1 at whose inner end is the sophagus1 is called by the not entirely appropriate name of 8pharynx10 and it must at present be remembered that the hollow space thus named is not a part of the digestive canal4 ,it is an invaginated section of the head1 and the formation of the head of the imago mainly depends on the evagination of this region4 ,the first rudiments of the most important parts of the head 7eyes1 antenn1 and forehead71 occur in the youngest larv as paired masses of cells which lie in the thorax next to the two halves of the brain 7for this reason called by ,weismann 8brain-appendages071 which are from their first origin connected with the pharynx1 and may be regarded as the imaginal buds of the head4 ,these appear very soon in later stages in the shape of elongated sacs widening at the hinder end 7,fig4 #fbh1 ,a and ,b1 h71 which from their origin are to be regarded as evaginations of the pharynx4 ,very soon epithelial thickenings appear in the wall of this sac-shaped brain-appendage1 in which the rudiments of the parts of the future head may be recognized4 ,disk-shaped thickenings in the hinder widened part of the brain-appendage form the rudiments of the compound eyes1 which therefore may be called the eye-buds4 ,on the basal surface of the eye-buds is situated a nervous expansion which is connected by a nerve with the suprasophageal ganglion4 ,this nerve becomes the optic nerve of the perfect animal1 while the optic ganglion is clearly separated from the brain4 ,in the anterior1 more cylindrical or tube-like part of the brain-appendage we find the 8frontal buds0 7ss71 on which the antennal rudiments 7at7 soon bud out1 in exactly the same way as the rudiments of the limbs arise from the imaginal buds4 ,illustration3 ,,fig4 #fbh4--;,diagrammatic representation of the position of the imaginal buds in the larva 7,a7 and pupa 7,b7 of ,musca 7the wing rudiments omitted73 as1 eye-buds2 at1 antennal germs2 b#a-;b#c1 germs of the legs2 bg1 central ganglionic cord3 g1 brain2 h1 so-called frontal appendage 7,hirnanhang73 m1 peripodal membrane2 o1 opening of the frontal appendage into the pharynx2 oe1 sophagus2 p1 so-called 8pharynx02 r1 rudiment of the proboscis2 ss1 frontal bud2 st1 stalk-like connection of the peripodal membrane with the hypodermis2 ,i-,,iii1 #ast1 #b;d1 and #c;d thoracic segments4--,adapted from ,van ,rees1 by ,korschelt and ,heider4 ,originally 7,fig4 #fbh1 ,a7 the brain-appendages lie tolerably far behind in the thorax of the larva1 so that they connect the hindermost part of the wall of the pharynx with the foremost section of the brain1 which they surround in the form of a mushroom4 ,afterwards1 however1 subsequent to pupation1 they move1 together with the central nervous system1 farther forward 7,b71 whereby they 7if we have correctly understood the descriptions of ,weismann and ,van ,rees7 laterally surround the pharynx with their anterior end1 which is somewhat ventrally bent4 ,at the same time1 there becomes established a gradually widening communication 7,b1 o7 between the brain-appendage and the pharynx1 which soon extends in the form of a lateral pharyngeal fissure along the entire length of the brain-appendage4 ,as a result1 the cavity of the brain-appendage and the pharynx so completely unite that the two soon form a single sac1 the head-sac or vesicle 7,fig4 #f-i1 k74 ,the walls of this head-vesicle are the later head-wall1 the most important parts of which can now be recognized 7the antenn1 eyes1 rudiments of the beak74 ,it is now necessary that the head-vesicle 7,fig4 #fbi1 1 7 be1 by the eversion of the pharynx1 turned outward in order that the head of the pupa may be completed4 ,by this eversion of invaginated parts1 the former mouth-opening of the pharynx becomes a neck-section 7,fig4 #fbi1 1 7 by which head and thorax are now united4 7,korschelt and ,heider47 ,illustration3 ,,fig4 #fbi4--;,diagram of the changes to pupa of ,musca before imago appears2 the wing-germs not drawn3 as1 eye-buds2 at1 antennal germs2 b#a-;b#c1 leg-germs2 bg1 ventral nerve-cord2 g1 brain2 k1 head-vesicle 7originating from the union of the pharynx with the hypophysis1 ,hirnanhngen72 oe1 sophagus2 r1 germ of the proboscis2 ss1 germ of the forehead2 ,i1 ,,ii1 ,,iii1 #ast1 #b;d1 and #c;d thoracic segments4--,based on ,kowalevsky and ,van ,rees1 with changes1 after ,korschelt and ,heider4 ,the cause of the eversion of the head-vesicle1 which ,weismann directly observed1 appears to be due to an increase of the inner pressure through a contraction of the hinder parts of the body4 ,the anterior end of the sophagus now becomes turned down ventrally corresponding to the conformation of the head of the imago4 ,it has been shown that the so-called pharynx is only an invaginated part of the outer surface of the larval head4 ,the brain-appendage ,korschelt and ,heider consider to be the diverticulum of this invagination1 in which the single parts of the body lie in an invaginated state4 ,they may throughout be compared to the rudiments of the thoracic limbs4 ,all these imaginal buds have been traced back to the invaginated parts of the outer surface of the body1 i4e4 the ectoderm4 ,it should be borne in mind that the process of development of the head of the highly-modified ,muscid is much more complex than in the more primitive ,diptera4 ,in their essay on the development of the head of the imago of ,chironomus1 ,miall and ,hammond arrange the dipterous types thus far examined1 in the order of complexity of the invaginations which give rise to the head of the imago1 in the following order3-- #a4 ,culex4 ,relatively simple4 ,invaginations of the imaginal buds1 shallow4 #b4 ,corethra1 ,simulium4 ,intermediate4 #c4 ,chironomus1 ,ceratopogon4 #d4 ,muscid4 ,relatively complex4 ,invaginations deep1 and apparently1 but not really1 unconnected with the epidermis4 b4 ,development of the internal organs of the imago ,illustration3 ,,fig4 #fcj4--,median longitudinal section through larva of blow-fly during the process of histolysis3 an1 antenna2 between an and w1 rudiments of eye2 w wings2 h1 halteres2 b#a-;b#c1 legs2 f1 fat-body2 d1 middle of intestine2 n1 ganglia2 st1 stigma2 #f1 #g1 #fth and #gth body-segments4--,after ,graber1 from ,sharp4 ,it has already been observed that most of the organs of muscid larv 7and this applies to most ,diptera1 ,lepidoptera1 ,coleoptera1 and ,hymenoptera7 are destroyed through the action of leucocytes1 and that their reformation is accomplished by definite groups of embryonal cells1 the imaginal buds or folds4 ,destruction and rebuilding occur during the pupa stage in such a way that in many cases while this process is going on the continuity of the organs does not seem to be disturbed4 ,these transformations especially concern the hypodermis1 the digestive canal1 the muscles1 the fat-body1 and the salivary glands4 ,the transformation of the tracheal system is only partial1 being in part a simple process of regeneration through cell-division4 ,slighter changes affect the heart1 the central nervous system1 and the reproductive system 7,fig4 #fcj74 ,illustration3 ,,fig4 #fca4--;,diagram of the formation of the imaginal hypodermis on the abdomen of ,muscid3 hi1 imaginal buds of the hypodermis2 lh1 larval hypodermis4--,after ,lang4 ,illustration3 ,,fig4 #fcb4--,section through the abdominal bud of the hypodermis of ,musca3 ,a1 of the larva2 ,b and ,c1 of the pupa2 h1 larval hypodermis2 h separated portion of the same attacked by phagocytes2 i1 imaginal bud2 k1 phagocytes with what are called cell-wrecks or fragments 7so-called granulated cells72 k1 phagocytes enclosing hypodermal nuclei2 m1 mesoderm-germ of the imaginal bud2 w1 wandering cells4--,after ,kowalevsky1 from ,korschelt and ,heider4 ,the hypodermis4--,the hypodermis of the imago arises through an extension of the ectodermal part of the imaginal buds4 ,we have already mentioned this for the thorax4 ,as the appendages of the thorax in the pupa gradually attain perfection1 the hypodermis layer spreads from the place of their insertion1 the layer consisting of numerous small cells whose origin we must refer to the peripodal membrane4 ,this layer continues to spread over the surface of the pupal thorax1 while at the same time the area of the larval hypodermis1 consisting of large cells1 is seen to diminish4 ,hence the thin edge of the newly-formed hypodermis 7,fig4 #fca1 hi7 slowly grows into the space between the superficial cuticula and the larval hypodermis 7,fig4 #fcb1 h71 so that at this place the old hypodermis undergoing destruction eventually lies on the inner side of the newly-formed epithelial layer 7,b74 ,we therefore see from this that1 during the replacement of the old hypodermis by the new1 the continuity of the superficial epithelium is never interrupted4 ,since the edges of the two kinds of hypodermis overlap1 the surface of the body is nowhere bare of epithelium4 ,the dissolution of the larval hypodermis is accomplished under the influence of the leucocytes 7,fig4 #fcb1 k71 which attack the larval hypodermis-cells and absorb their contents piece by piece1 and so fill themselves with bits of the hypodermis-cells and their nuclei2 since these fragments have the shape of roundish granules1 they were called by ,weismann granule-balls4 ,these granule-balls1 which fill the body-cavity of the later pupal stage1 are nothing else than the leucocytes 7blood corpuscles7 which have absorbed the fragments of tissue of the larval body4 ,it should here be said that the destruction of the larval tissues is not to be attributed to the previous death of the cells1 but is the result of the action of the leucocytes on tissues which1 though weakened in their vital power1 are still living4 ,while the completely healthy1 active tissues1 i4e4 those of the imaginal buds1 withstand the attacks of the leucocytes1 the less healthy larval tissues are by the attacks of the leucocytes divided into fragments and eaten and digested by them4 ,this process is most marked in the histolysis of the larval muscles4 ,the destruction of most of the larval organs depends1 therefore1 on the capacity of the amboid blood-corpuscles for taking food and on intracellular digestion1 as was first shown by ,metschnikoff1 who has given to these leucocytes the name of 8phagocytes40 ,this process of histolysis goes on in the same way in the head and abdomen as in the thorax4 ,in the abdomen1 as ,ganin first proved1 there are in each of the eight segments of which it consists in the larva four small cellular islets or imaginal buds 7,figs4 #fca1 hi1 #fcb1 i71 from which originate the new hypodermis4 ,van ,rees has lately found in the abdominal segments another pair of smaller imaginal buds4 ,the four imaginal buds occurring in the last segment are situated close to each other1 encircling the anal opening 7,fig4 #fcc1 ims71 and take part in the formation of the hind-intestine1 the rectal pouches and rectal papill4 ,to this segment also belong the two pairs of imaginal genital buds 7rudiments of the external sexual organs7 which were first found by ,knckel d',herculais in ,volucella4 ,the newly formed hypodermis spreads rapidly over the outer surface of the body1 so that hypodermal areas corresponding to the separate imaginal buds soon unite4 ,simultaneously with this completion of the definite epithelial layer the larval hypodermis becomes completely destroyed by the phagocytes4 ,the muscles4--,a similar process of destruction by phagocytes affects the greater number of the larval muscles1 except the three pairs of thoracic muscles employed in respiration1 and which pass intact from the larva to the imago4 ,indeed1 the dissolution of the muscles is the first process which occurs in the metamorphosis4 ,the destruction of the larval muscles is accomplished in such a way that1 a great number of leucocytes which have collected on the surface of the muscular fibres1 press through the sarcolemma and enter within the muscular tissue1 filling the spaces formed between them1 ,by this means the muscles break up into a number of rounded particles which are taken into the interior of the leucocytes4 ,thus a collection of granule-balls arise from the muscles1 which finally separate from each other and become scattered throughout the body-cavity of the pupa4 ,in the same way as the muscular substance1 the muscle-nuclei are taken up and digested by the phagocytes4 ,the imaginal muscles develop from the definitive mesoderm which has originated from the mesoderm of the imaginal buds 7,fig4 #fcb1 ,c1 m74 ,the digestive canal4--,as in the hypodermis and muscles1 the histolysis of the larval digestive tract and its new formation from separate imaginal buds go on simultaneously1 so that the continuity of the process is not interrupted4 ,illustration3 ,,fig4 #fcc4--;,digestive tract of a ,musca larva with the imaginal germs3 bd1 cca2 s1 food-reservoir2 is1 imaginal ring of the salivary gland 7sp72 f1 fat-cells at the end of the salivary gland2 pr1 proventriculus2 r1 its ring2 ie1 imaginal cells of the mid-intestinal epithelium2 ch1 chyle-stomach2 ma1 urinary tubes2 im1 imaginal cells of the mid-intestinal1 muscular layer2 ims1 binder1 abdominal1 imaginal buds2 h1 hind intestinal1 imaginal bud2 ht1 hind-intestine4--,after ,kowalevsky1 from ,korschelt and ,heider4 ,the imaginal buds of the much-shortened pupal digestive canal occur in the mid-intestine 7stomach7 in the form of numerous scattered groups of cells 7,fig4 #fcc1 ie71 and in the fore- and hind-intestine in the form of rings 7v and h7 of imaginal tissue4 ,the imaginal ring of the fore-intestine 7v7 lies in the region of the proventriculus 7pr1 compare ,fig4 #fce1 im71 while that of the hind-intestine is situated directly behind the base of the urinary tubes4 ,the regeneration of these two parts of the digestive canal is not entirely accomplished by these two rings1 but the imaginal rudiments of the neighboring parts of the outer surface of the body also have a share in it4 ,thus it appears that the foremost part of the sophagus is built up from the imaginal buds in the region of the mouth1 while the imaginal buds surrounding the anus in the #hth abdominal segment 7,fig4 #fcc4 ims7 produce by invagination the rectal pouches1 together with the rectal papill4 ,illustration3 ,,fig4 #fcd4--;,cross-section through the mid-intestine of pupa of ,musca3 e1 rejected and degenerate epithelium of the larval stomach2 f1 cellular layer newly formed around the same2 m1 muscular layer2 m1 imaginal cell of m2 o1 imaginal bud of the mid-intestinal epithelium2 t1 tracheal stem4--,after ,kowalevsky1 from ,korschelt and ,heider4 ,illustration3 ,,fig4 #fce4--,longitudinal section through the proventriculus of a muscid larva3 im1 fore-intestinal1 imaginal ring2 oe1 sophagus2 pr1 proventriculus4--,after ,kowalevsky1 from ,korschelt and ,heider4 ,the formation of the mid-intestine 7stomach7 takes place in such a way that the island-like imaginal buds spread out by cell-multiplication over the outer or basal surface of the larval mid-intestinal epithelium 7,fig4 #fcd1 o71 until they finally unite1 so as to form the wall of the imaginal mid-intestine 7stomach74 ,at the same time the entire larval epithelium 7e7 is cast in the interior and forms the so-called yellow body1 which becomes surrounded by a layer of small cells and a jelly-like mass1 and remains until its destruction in the pupal stomach4 ,the larval muscular layer 7m7 remains intact as long as the imaginal mid-intestine is not fully developed1 when it is attacked and destroyed by phagocytes4 ,the final muscular layer arises from single cells lying on the outer surface of the imaginal buds 7,figs4 #fcc1 im1 #fcd1 m71 which should be regarded as special imaginal cells of the mid-intestinal muscular layer4 ,the transformation of the fore-intestine is introduced by a degeneration of the proventriculus and sucking stomach4 ,the proventriculus 7,fig4 #fce1 pr71 which had been formed from a circular fold of the fore-intestine1 disappears by the smoothing out of this folded structure4 ,the sucking stomach also similarly degenerates by withdrawing gradually into the sophagus1 so that instead of the original diverticulum there remains only an enlargement of the sophageal cavity4 ,at the same time this part of the canal is attacked and destroyed by phagocytes1 while the destroyed portions become replaced by the gradually extending imaginal parts of the wall4 ,the imaginal ring of the fore-intestine 7,fig4 #fce1 im71 which1 according to ,kowalevsky1 is concerned in the formation of a great part of the definitive sophagus1 becomes closed at its hinder end so that the communication with the mid-intestine appears to be interrupted4 ,the hind-intestine of the imago is rebuilt in exactly the same manner4 ,here also the imaginal ring widens and forms a tube1 which while it grows around the openings into the urinary tubes1 closes itself against the mid-intestine1 while behind it remains in connection with the larval hind-intestine4 ,in a similar way the larval hind-intestine is attacked by the growth from behind of an imaginal ring1 which proceeds from imaginal buds near the anus1 until finally1 when the entire larval hind-intestine is reduced to granule-balls1 the two imaginal sections of the tube are brought into contact with each other4 7,kowalevsky in ,korschelt and ,heider47 ,the larval salivary glands 7,fig4 #fcc1 sp7 are completely destroyed by phagocytes4 ,then succeeds the new formation of these glands from imaginal buds1 which1 according to ,kowalevsky1 form rings situated at their anterior ends4 ,the nature of the transformation undergone by the urinary tubes is not yet well ascertained4 ,according to ,van ,rees1 there is in this case perhaps a regeneration of the larval cells by division1 but on the other side there may be a histolysis of these elements4 ,the above-described method of transformation of the digestive canal seems1 according to ,korschelt and ,heider1 to be very common among the holometabolic insects4 ,it has not only been observed in the ,diptera1 but also in the ,lepidoptera 7,kowalevsky1 ,frenzel71 ,coleoptera 7,ganin71 and ,hymenoptera 7,ganin74 ,the stripping off of the epithelium of the mid-intestine was found by ,kowalevsky to occur also in ,corethra1 ,culex1 and ,chironomus4 ,the tracheal system4--,as we have seen 7p4 #ddh71 the tracheal system of caterpillars just before pupation undergoes disintegration1 accompanied by a reformation of the peritoneal membrane and tnidia4 ,the larval ectotrachea undergoes histolysis1 that of the imago being meanwhile formed2 the larval tnidia also break up1 dissolve1 and are replaced by new tnidia which arise from the nuclei of the peritoneal membrane4 ,that the tracheal system in the ,muscid during metamorphosis undergoes a transformation is shown1 as ,korschelt and ,heider claim1 by the entirely different shape of the system in the maggot1 the pupa1 and the fly4 ,the air is admitted to the tracheal system of the maggot1 not by lateral openings1 but through the two stigmata at the end of the body4 ,on the other hand1 the pupa breathes by prothoracic spiracles1 while the fly has six pairs of lateral stigmata of the normal structure4 ,there may be in the larva and pupa vestigial closed stigmata1 as there are in the thorax of caterpillars1 with tracheal branches leading to where were once functional stigmata4 ,these stigmatal branches1 as well as some other portions of the tracheal system already observed by ,weismann1 seem1 according to ,van ,rees1 to function as imaginal buds for the regeneration of the tracheal matrix1 while frequently also a regeneration of this epithelium1 by a simple repeated division of cells1 may be recognized4 ,the disintegration of the tracheal system is accomplished by means of phagocytes in the manner already described4 ,the nervous system4--,the central nervous system passes directly from the larval into the imaginal stage1 since it must continue to exercise most of its functions throughout metamorphosis1 though it undergoes important changes of form and position4 ,at the same time1 certain histological transformations occur which may be regarded as a histolysis4 ,such is the destruction and rebuilding in the interior of the organs1 which1 however1 preserve their continuity4 ,every case of destruction of tissues in the pupa has come to be regarded as a histolysis4 ,the problem of the transformation of the peripheral nervous system is not yet well understood4 ,although during the destruction of the larval muscles the motor nerves also in part degenerate1 in the case of the nerves distributed to the appendages the conditions are different1 as these may be recognized in the larva in the form of the nerve-threads which place the imaginal buds in connection with the central nervous system4 ,these threads1 according to ,van ,rees1 pass from the larva into the pupa and imago1 so that with the farther development of the rudiments of the extremities1 only the distal part of the nerves belonging to them are to be regarded as new formations4 7,korschelt and ,heider47 ,the fat-body4--,the larval fat-body is also destroyed through the activity of the leucocytes in the same way as the other tissues4 ,the reformation of the fat-body seems to begin in the mesoderm of the imaginal buds4 ,possibly1 also1 the masses or collections of embryonic cells which are regarded by ,schaeffer as 8blood-forming cells10 may serve to regenerate the fat-body4 ,at all events1 they have been derived from the mesodermal tissues4 ,though ,wielowiejsky saw the fat-body of ,corethra arising from a cell-layer situated under the hypodermis1 yet it is not necessary to regard this observation as favorable to the view of ,schaeffer that in ,musca the larval fat-body is derived in part from the hypodermis1 and in part from the tracheal matrix1 thus from the ectodermal tissues4 7,korschelt and ,heider47 ,definitive fate of the leucocytes4--,we have seen that the formation of the organs of the imago originates in the imaginal buds1 in all cases where these do not pass directly from the larva into the pupa4 ,the leucocytes1 whose numbers in the pupa are greatly increased1 take no direct part in the formation of the tissues4 ,their importance seems to lie in this1 that they destroy those larval organs doomed to destruction1 the parts of which they take in and digest1 and possibly1 by their powers of locomotion1 convey particles of food to the developing organs4 ,what1 on the other hand1 is the fate of the leucocytes after the developmental processes in the pupa have ceased8 ,there can be no doubt that a part of the so-called granule-cells are again transformed into normal blood-corpuscles4 ,another1 and1 as it seems1 more considerable1 share suffer degeneration4 ,finally1 the leucocytes themselves serve as nourishment for the newly formed tissues4 ,of interest in this direction is the observation of ,van ,rees1 that numerous leucocytes finally pass into the newly-formed hypodermis and then degenerate in crevices between the hypodermis-cells4 7,korschelt and ,heider47 ,it has been suggested by ,van ,rees that the phagocytes attack all the larval organs indiscriminately1 but that the active metabolism of the imaginal buds preserves them from these attacks4 ,he also thinks that ,kowalevsky is probably right in supposing that the buds render themselves immune by some poisonous secretion4 ,pratt1 however1 thinks that the supposition of a protecting or poisonous secretion is scarcely necessary to account for the phenomenon1 and suggests that the larval tissues are a prey to the phagocytes1 because at the end of larval life they become functionless and inactive1 so as to become an easy prey to phagocytes or disintegrating influences of any sort4 ,on the other hand1 the imaginal buds 8in which there is an exceedingly active metabolism1 and all the larval organs which remain functional during the metamorphosis are immune from the attacks of the phagocytes4 ,the heart in the muscids continues to beat1 as ,knckel d',herculais has observed1 during the entire period of the metamorphosis1 with the exception of a day or two in the latter half of it4 ,the nervous system must continue functional during the entire time4 ,the three pairs of thoracic muscles which pass intact from the larva to the imago are probably employed in respiration during the metamorphosis4 ,the reproductive glands are1 like the imaginal disks1 rapidly growing organs40 ,he adds that among the other holometabolic insects many or most of the larval organs remain functional during metamorphosis1 hence there is but little histolysis4 8,but the larval intestine would always necessarily become unfunctional1 and1 as we have seen1 ,kowalevsky is of the opinion that the larval mid-gut in all holometabolic insects contains imaginal disks1 and undergoes degeneration during the metamorphosis40 ,the post-embryonic changes and imaginal buds in the ,pupipara 7,melophagus74--,the sheep-tick 7,melophagus7 is still more modified than the ,muscid2 the larva is apodous and acephalous1 but1 as ,pratt observes1 much less highly specialized than those of muscids1 and in respect to the position of the thoracic buds it closely resembles ,corethra4 ,they lie just beneath the hypodermis in two very regular rows1 and not in the centre of the body1 as in ,musca 7,figs4 #fbh1 #fcf1 ,c74 ,while1 however1 in ,corethra all the thoracic buds are of larval origin1 arising after the last larval moult1 in ,melophagus1 on the other hand1 each of these buds1 except the dorsal prothoracic1 arises in the embryo1 as is also the case in ,musca4 ,in the cephalic buds the conditions are similar to those in ,musca1 but still more complicated4 ,instead of a single pair of head-buds1 there are two pairs1 one dorsal and one ventral4 8,the dorsal pair corresponds to the muscidian head-disks in every respect2 they are destined to form the dorsal and lateral portions of the imaginal head1 together with the compound eyes4 ,the ventral head-disks have no counterpart in ,musca4 ,the fate of these disks or buds is to form the ventral portion of the head1 the paired projections forming the rudiments of the proboscis4 8,the formation of the head-vesicle proceeds in a way similar to that in ,musca4 ,the ventral disk fuses early at its lateral edges with the dorsal pair4 ,the communications between both ventral and dorsal disks and the pharynx rapidly widen 7in the old larva they have already become very large71 and soon the disks and pharynx form together a single vesicle1 which is the head-vesicle40 ,the imaginal buds of the abdomen ,pratt finds to be exactly as in the corresponding ones of ,musca4 ,in the embryo of ,melophagus the cephalic and thoracic imaginal buds first appear as local thickenings1 followed by the invagination of the ectoderm2 the cephalic buds first appear very early in the ontogeny of the insect 7,fig4 #fcf1 ,c71 just as the germs of the digestive canal1 nervous system1 and trache are appearing4 ,the single median thickening 7v7 is destined to form the ventral cephalic bud1 while the pair of thickenings behind 7d7 become the dorsal buds1 those homologous with the cephalic buds of ,musca4 ,illustration3 ,,fig4 #fcf4--;,imaginal buds in ,musca1--,a1 in ,corethra1--,b1 in ,melophagus1--,c1 in embryo of ,melophagus3 dorsal view of head2 b1 bud2 p1 peripodal membrane2 c1 cord2 hy1 hypodermis2 cl1 cuticula2 st1 stomodum2 v1 ventral cephalic bud1 behind are the two dorsal cephalic buds 7d74--,after ,pratt4 ,the thoracic buds1 which arise as hypodermic thickenings1 do not appear until late in embryonic life1 until the time of the involution of the head4 ,pratt did not observe in the embryo the buds of the internal organs and of the abdominal hypodermis1 and thinks it probable that they appear first in the larva4 c4 ,general summary ,we have seen that in ,coleoptera1 ,lepidoptera1 ,diptera1 and ,hymenoptera1 and with little doubt in all the holometabolous insects1 the parts of the imago originate in single formative cellular masses 7imaginal buds7 already present in the larva1 and often even in the later embryonic stages4 ,there are such imaginal buds for each part of the body1--for the appendages of the head1 for the legs and wings1 for the ovipositor1 and probably for the cercopods1 for the hypodermis of the abdomen1 and for the different sections of the digestive canal4 ,we have seen1 as ,korschelt and ,heider state1 that the formation of the mesodermal organs of the imago 7muscles1 connective tissue1 fat-body7 begins in the mesodermal part of the imaginal buds1 whose first origin is still obscure4 ,simultaneously with the formation of the imaginal organs1 there goes on under the influence of the leucocytes the destruction of the larval organs4 ,both processes 7destruction and regeneration7 therefore go on hand in hand1 so that the continuity of the organs in question in most cases remains perfect1 inasmuch as the complete destruction only ensues after the formation of the final organs4 ,the only exceptions are most of the muscles of the larva1 which are destroyed at a very early period4 ,moreover1 it is evident that the sharp division into larval1 pupal1 and imaginal stages only applies to the external surface of the body1 since they follow one another after successive moults4 ,the processes of the internal development1 on the other hand1 form an entirely continuous series of transformations between which is no sharp line of demarcation4 ,yet as a whole the form of the larva1 pupa1 and imago are kept distinct in adaptation to their separate environments and habits4 ,finally1 as ,pratt very truly remarks1 the epigenetic period in insects1 when new organs are forming1 does not end with the birth of the larva from the egg1 but extends through the larval1 and even through the pupal period4 8,the principal significance of the pupal period and the metamorphosis is that it is the time when the larval characters which were adapted for use during a period of free life in the midst of the development1 and which would be valueless to the imago1 are corrected or abandoned40 ,,hypermetamorphism ,when an insect passes through more than the three normal stages of metamorphosis1 i4e4 the larval1 pupal1 and imaginal1 it is said to undergo a hypermetamorphosis4 ,the best-known examples are the supernumerary stages of ,melo1 ,stylops1 etc4 ,illustration3 ,,fig4 #fcg4--;,hypermetamorphosis of male of ,aspidiotus nerii3 #a1 freshly hatched larva2 #b1 larva shortly before pupating2 b1 rudiments of the legs2 fl1 of the wings2 #c1 pupa before moulting2 #d1 the same after moulting2 #f1 larva farther advanced than in #b2 a1 antennal rudiments2 b1 rudiments of legs2 v1 stomach2 ,,og1 brain2 ,m4 ,fl1 rudiments of the elevator and depressor muscles of the wing2 ,m4 ,th1 rudiments of the dorsal muscles2 ,h1 rudiments of the testes2 #g1 pupa shortly before entering upon the imago state 7#e72 ,a1 eyes2 a1 antenna2 o1 mouth2 ,,wd1 wax-glands2 ,,bg1 ventral nervous cord2 ,sb1 caudal set2 tr1 trache2 p1 genital armature4--,after ,schmidt4 ,as has already been observed1 ,schmidt has shown that in the male of the ,coccid1 there is a true hypermetamorphosis1 as shown by ,fig4 #fcg4 ,in ,aspidiotus nerii there are five stages1 there being two larval 7#a1 #b7 and two pupal stages 7#c1 #d1 #g74 ,stage #c 7,fig4 #fcg1 #b7 may be compared with the pro-pupa stage of ,riley 7,fig4 #eha74 ,illustration3 ,,fig4 #fch4--,mantispa interrupta1 and side view of the same without wings3 natural size4--,emerton del4 a1 freshly-hatched campodeoid larva of ,mantispa styriaca1 enlarged2 b1 the same1 but older1 before the first moult2 enlarged4--,brauer4 ,we have already1 on page #fjb1 described the hypermetamorphosis of the neuropterous insect ,mantispa 7,fig4 #fch74 ,illustration3 ,,fig4 #fci4--,triungulin 7a7 of a ,californian ,melo3 b1 the three triungulin claws2 c1 antenna2 d1 maxillary palpus2 e1 labial palpus2 f1 mandible2 g1 an abdominal joint2 h1 imago1 2 i1 antenna of 4--,after ,riley4 ,in ,melo the freshly hatched larva1 or 8triungulin0 7,fig4 #fci1 a71 is an active ,campodea-like larva1 which runs about and climbs up flowers1 from which it creeps upon the bodies of bees1 such as ,anthophora and ,andrena1 who carry it to their cells1 wherein their eggs are situated4 ,the triungulin feeds upon and destroys the eggs of its hostess4 ,meanwhile its inactive life in the bee's cell reacts upon the organism2 after moulting1 the-second larval form 7,fig4 #fdj1 b7 is attained1 and now the body is thick1 cylindrical1 soft1 and fleshy1 and it resembles a lamellicorn larva1 with three pairs of rather long thoracic legs4 ,this is ,riley's carabidoid stage4 ,this second larva feeds upon the honey stored up for the young or larval bees4 ,after another moult1 there is another entire change in the body2 it is motionless1 the head is mask-like without movable appendages1 and the feet are represented by six tubercles4 ,this is called the semipupa or pseudo-pupal stage4 ,this form moults1 and changes to a third larval form 7c71 when apparently1 as the result of its rich1 concentrated food1 it is overgrown1 thick-bodied1 without legs1 and resembles a larval bee4 ,illustration3 ,,fig4 #fdj4--,oil-beetle3 a1 first larva2 b1 second larva2 c1 third larva2 d1 pupa4 ,illustration3 ,,fig4 #fda4--;,history of ,sitaris3 a1 triungulin or #ast larva2 g1 anal spinnerets and claspers of same2 b1 #b;d larva2 e1 pseudo-pupa2 f1 #c;d larva2 c1 true pupa2 d1 imago1 4--,after ,v4 ,mayet1 from ,riley4 ,after thus passing through three larval stages1 each remarkably different in structure and in the manner of taking food1 it transforms into a pupa of the ordinary coleopterous shape 7d74 ,the history of ,sitaris1 as worked out by ,fabre and more recently by ,valery-,mayet1 is a similar story of two strikingly different adaptational larval forms succeeding the triungulin or primitive larval stage4 ,the first larva 7,fig4 #fda1 a7 is in general like that of ,melo1 the second 7b7 is thick1 oval1 fleshy1 soft-bodied1 and with minute legs1 evidently of no use1 the larva feeding on the honey stored by its host4 ,the pseudo-pupal stage is still more maggot-like than in the corresponding stage of ,melo1 and the third larva 7f7 is thick-bodied1 with short thoracic legs4 ,in the complicated life-history of another cantharid1 ,epicauta vittata1 as worked out by ,riley 7,fig4 #fdb71 we have the same acquisition of new habits and forms after the first larval stage1 which evidently were at the outset the result of an adaptation to a change of food and surroundings4 ,the female ,epicauta lays its eggs in the same warm1 sunny situation as that chosen by locusts 7,caloptenus7 for depositing their eggs4 ,on hatching1 the active minute carnivorous triungulin1 ever on the search for eggs1 on happening upon a locust egg gnaws into it1 and then sucks the contents4 ,a second egg is attacked and its contents exhausted1 when1 owing to its comparatively inactive habits and rich nourishing food after a period of inactivity and rest1 the skin splits along its back1 and at about the eighth day from beginning to take food the second larva appears1 with much smaller and shorter legs1 a much smaller head1 and with reduced mouth-parts4 ,this is the carabidoid stage of ,riley4 ,after feeding for about a week in the egg a second moult occurs1 and the change of form is slight1 though the mouth-parts and legs are still more rudimentary1 and the body assumes 8the clumsy aspect of the typical lamellicorn larva40 ,this ,riley denominates the scarabidoid stage of the second larva4 ,illustration3 ,,fig4 #fdb4--;,epicauta cinerea3 a1 end of #b;d larval stage2 b1 portion of dorsal skin2 c1 d1 coarctate larva2 e1 f1 pupa4--,after ,riley4 ,after six or seven days there is another transformation1 the skin being cast1 and the insect passes into another stage1 8the ultimate stage of the second larva40 ,the larva1 immersed in its rich nutritious food1 grows rapidly1 and after about a week leaves the now addled and decaying locust eggs1 and burrows into the clear sand1 where it lies on its side in a smooth cell or cavity1 and where it undergoes an incomplete ecdysis1 the skin not being completely shed1 and assumes the semipupa stage1 or coarctate larval stage of ,riley4 ,in the spring the partly loose skin is rent on the top of the head and thorax1 and then crawls out of it the 8third larva10 which only differs from the ultimate stage of the second larva 8in the somewhat reduced size and greater whiteness40 ,the insect in this stage is said to be rather active1 and burrows about in the ground1 but food is not essential1 and in a few days it transforms into the true pupa state4 ,these habits and the corresponding hypermetamorphosis are probably common to all the ,meloid1 though the life-history of the other species has yet to be traced4 ,in the genus ,hornia described by ,riley1 the wings of the imago are more reduced than in any other of the family1 both sexes having the elytra as rudimentary as in the ,european female glow-worm 7,lampyris noctiluca74 ,these1 with the simple tarsal claws and the enlarged heavy abdomen1 as ,riley remarks1 8show it to be a degradational form40 ,its host is ,anthophora1 and the beetle itself lives permanently in the sealed cells of the bee1 and ,riley thinks it is subterranean1 seldom if ever leaving the bee gallery4 ,the triungulin is unknown1 but the ultimate stage of the second larva1 as well as the coarctate larva1 is like those of the family in general1 the final transformations taking place within the two unrent skins1 in this respect the insect 7,fig4 #fdc7 approaching ,sitaris4 ,it appears1 then1 that as the result of its semi-parasitic mode of life the ,campodea-form or triungulin larva of these insects1 which has free-biting mouth-parts like the larv of ,carabid and other carnivorous beetles1 instead of continuing to lead an active life and feeding on other insects2 living or dead1 and then like other beetles directly transforming into the normal pupa1 moults as many as five times1 there being six distinct stages before the true pupa stage is entered upon4 ,so that there are in all eight stages including the imaginal or last stage4 ,one cannot avoid drawing the very obvious conclusion that the five extra stages constituting this hypermetamorphosis1 as it is so well styled1 are structural episodes1 so to speak1 due to the peculiar parasitic mode of life1 and were evidently in adaptation to the remarkable changes of environment1 so unlike those to which the members of other families of ,coleoptera1 the ,stylopid excepted1 have been subjected4 ,the fat overgrown body and the atrophied limbs and mouth-parts are with little doubt due to the abundant supply of rich food1 the protoplasm of the egg of its host1 in which the insect during the feeding time of its life is immersed4 ,since it is well known that parthenogenesis is due to over1 or at least to abundant nutrition1 or to a generous diet and favoring temperature1 there is little reason to doubt that the greatly altered and abnormally fat or bloated body of the insect in these supernumerary stages is the result of a continuous supply of rich pabulum1 which the insect can imbibe with little or no effort4 ,illustration3 ,,fig4 #fdc4--a1 ,egg-pod of ,caloptenus differentialis with the mouth torn open1 exposing the newly hatched larva of ,epicauta vittata 7#a a7 eating into an egg and the passage which it made through the mucous covering2 natural size4 #b1 dorsal view of the #ast larva1 or triungulin1 of ,e4 vittata2 #b a1 one side of the head of same from beneath1 greatly enlarged so as to show the mouth-parts2 #b b1 terminal joint of maxillary palpus1 showing imbrications and flattened inner surface armed with stout points2 #b c1 leg1 showing more plainly the tarsal spines2 #b e1 labrum2 #b d1 one of the abdominal joints from above1 showing stout points1 stigmata1 and arrangement of spinous hairs4 #c1 eggs of ,e4 vittata1 the natural size indicated at side4 #d1 dorsal view of the carabidoid stage of the #b;d larva of ,e4 vittata3 #d a1 its antenna2 #d b1 its right maxilla2 #d c1 its leg2 #d d1 side view of same1 showing its natural position within the locust-egg mass4 #e1 lateral view of the ultimate or full-grown stage of the #b;d larva of ,e4 vittata2 #e a1 portion of the dorsal skin1 showing short setaceous hairs4 #f1 third head1 or that from the scarabidoid stage of the #b;d larva of ,e4 vittata from beneath1 showing the reduction of mouth-parts as compared with the first head 7#b a72 #f a1 antenna of same2 #f b1 maxilla of same2 #f c1 mandible of same4 #g1 fourth head1 or that of the full-grown larva of ,e4 vittata1 from above2 #g a1 leg of same2 #g b1 the breastplate or prosternal corneous piece4 #h1 lateral view of the pseudo-pupa or coarctate larva of ,e4 vittata1 with the partially shed skin adhering behind3 #h a1 dorsal view of same2 #h b1 its head1 from the front2 #h c1 same from side2 #h d1 tuberculous leg2 #h e1 raised spiracle2 #h f1 anal part of same1 #i4 lateral view of the true pupa of ,epicauta cinerea ,forst3 #i a1 ventral view of same4 #aj1 ,epicauta vittata 7lemniscata or trivittate var474 #aa1 ,epicauta cinerea ,forst4 7 marginata ,fabr474 #ab1 antenna of the triungulin of ,epicauta pennsylvanica3 #ab a1 maxilla of same2 #ab b1 labial palpus of same4 #ac4 ,hornia minutipennis1 dorsal view2 #ac a1 lateral view of same2 #ac b1 simple claw of same2 #ac c1 coarctate larva2 #ac d1 leg of ultimate stage of #b;d larva4--,after ,riley4 ,illustration3 ,,fig4 #fdd4--,triungulin stage of ,stylops childreni4 ,the life-history of the ,stylopid is after the same general fashion1 though we do not as yet know many of the most important details4 ,the females are viviparous1 the young hatching within the body of the parent1 as we once found as many as #cjj of the very minute triungulin larv issuing in every direction from the body of what we have regarded as the female of ,stylops childreni in a stylopized ,andrena caught in the last of ,april4 ,the larv differ notably from those of the ,meloid in the feet being bulbous and without claws1 yet it is in general ,campodea-like and in essential features a triungulin 7,fig4 #fdd74 ,the intestine ends in a blind sac1 as in the larv of bees1 and this would indicate that its food is honey4 ,the complete life-history of no ,stylopid is completely known4 ,it is probable that1 hatched in ,june from eggs fertilized in ,april1 the larv crawl upon the bodies of bees and wasps2 finally1 after a series of larval stages as yet unknown1#aai penetrating within the abdomen of its host before the latter hibernates1 and living there through the winter4 ,the females1 owing to their parasitic life1 retain the larval form1 while the free males are winged1 not leading in the adult stage a parasitic life1 though passing their larval and pupal stages in the body of their host1 and are so unlike ordinary beetles as to be referred by good authorities to a distinct order 7,strepsiptera74 ,illustration3 ,,fig4 #fde4--,stylops childreni1 3 a1 abdomen of ,andrena with ,stylops 7b74 ,the triungulin stage of these insects corresponds in general to the form of the larval ,staphylinid and allied families1 such as the ,tenebrionid1 which are active in their habits1 running about and obtaining their food in a haphazard way1 often necessarily suffering long fasts4 ,in the external-feeding1 less active coleopterous larv1 like the phytophagous species1 which have an uninterrupted supply of nutritious food1 we see that the body is thick and fleshy4 ,so also in the larv of the ,scarabid1 ,ptinid1 and the wood-boring groups4 ,in internal feeders1 like the larval weevils and ,scolytid1 which live nearly motionless in seeds1 fruits1 and the sap-wood of plants and trees1 with a constant supply of nourishing1 often rich food1 the eruciform body is soft1 thick1 and more or less oval-cylindrical4 ,so it is with the larv of ,hymenoptera1 especially in the parasitic forms1 and in the ants1 wasps1 and bees1 which are nearly if not quite motionless1 at least not walking about after their food4 ,now the change from the active triungulin stage to the series of secondary1 nearly legless1 sedentary1 inactive stages is plainly enough due to the change of station and to the change of food4 ,from being an independent1 active1 roving triungulin1 the young insect becomes a lodger or boarder1 fed at the expense of its host1 and the lack of bodily exertion1 coupled with the presence of more liquid food than is actually needed for its bare existence1 at once induces rotundity of body and a loss of power in the limbs1 followed by their partial or total atrophy4 ,that this process of degeneration may even occur in one and the same stage of larval existence is very well illustrated by what we know of the life-history of the wasp-parasite of ,europe1 ,rhipiphorus paradoxus4 ,thanks to the very careful and patient observations of ,dr4 ,t4 ,a4 ,chapman1 we have a nearly complete life-history of this beetle1 the representative of a family in many respects connecting the ,meloid and ,stylopid4#abj ,where ,rhipiphorus lays her eggs is unknown4 ,dr4 ,chapman1 however1 found a solitary specimen of the young larva in the triungulin stage4 ,he describes it as 8a little black hexapod1 about #aej inch 74#e mm47 in length1 and #aabj inch in breadth1 broadest about the fourth segment1 and tapering to a point at the tail2 a triangular head with a pair of three-jointed antenn nearly as long as the width of the head1 with legs very like those of ,melo larv2 the tibi ending in two or three claws1 which are supported and even obscured by a large transparent pulvillus or sucker of about twice their length2 this was marked by faint stri radiating from the extremity of the tibi1 giving it much the aspect of a lobe of a fly's proboscis4 ,each abdominal segment had a very short lateral spine pointing backwards2 the last segment terminated by a large double sucker similar to those of the legs2 and the little animal frequently stood up on this1 and pawed the air with its feet1 as if in search of some fresh object to lay hold of40 ,this almost microscopic larva finds a wasp grub and bores into its body1 probably entering at a point near the back of the first or second segment behind the head4 ,dr4 ,chapman succeeded in finding the larva of the beetle within that of the wasp1 before the latter had spun up4 8,assuming that the wasp larva lives six days in its last skin before spinning up1 ,i should guess that the youngest of these had still two or three days' feeding to do4 ,the ,rhipiphorus larv were but a little way beneath the skin of the back1 about the fourth and fifth segments counting the head as the first1 and indifferently on either side4 ,the smallest of these was #aaf inch in length1 and1 except its smaller size1 was precisely like the larger ones ,i am about to refer to1 having the same head1 legs1 plates1 etc4 ,these were of the same size as those of the larger larv1 the difference in size of the latter being due to the expansion of the intermediate colorless integument40 ,after the wasp grub has spun the silken covering of its cell the larva of ,rhipiphorus may still be detected in some of them1 being rendered visible by its black legs and dark dorsal and ventral plates4 8,on extracting this larva1 it bears a general resemblance in size and outline to the youngest larva of ,rhipiphorus that ,i had found feeding externally on the wasp grub1 but with the very notable exception of the already mentioned black marks4 ,these are1 in fact1 a corneous head1 six-jointed legs1 and a dorsal and ventral series of plates4 ,i immediately recognized the head and legs as identical with those of the little black mite already described1 but presenting a ludicrous appearance in being widely separated from each other by the white skin of the larva4 ,i have no doubt that the dorsal and ventral series of black marks are the corresponding plates of the mite-like larva floated away from each other by the expansion of the intervening membrane4 ,by measurement also they agree exactly in size1 although the larva extracted from the wasp grub is ten times the length and six times the width of the little ,melo-like larva4 ,in length it is inch 7#d4e mm471 and #abh inch in breadth40 ,the remarkable changes thus described in the larva of this beetle after it has begun its parasitic life within the body of its host are especially noteworthy because the great increase in size and difference in shape1 as well as in habits1 all take place before the insect has moulted4 ,the rapid development in size1 and consequent distension of the body and the separation of the sclerites of the segments behind the head1 are paralleled1 as ,chapman says1 by the greatly swollen abdominal region of the body in ,sarcopsylla penetrans and in the female of the ,termitid4 ,in those insects this distension is due to the enlargement of the ovaries and of the eggs contained within them1 but in the ,rhipiphorus it is due to the comparative inactivity of the larva1 and to its being gorged with an unending supply of rich food1 the blood and fat of its host4 ,it follows1 then1 that if a sedentary life and over1 or at least abundant1 nutrition will have this effect within the short period covered by the single first larval stage of the ,rhipiphorus1 it is reasonable to infer that the hypermetamorphosis is also due to the same factors4 ,chapman then goes on to say that finally1 within six hours of the time of spinning up of the wasp grub1 the ,rhipiphorus larva at the end of ,stage #a41 which is 8usually in motion1 and for its situation might be called tolerably active1 is seen to lay hold of the interior of the skin with its anterior legs1 and keeps biting and scratching with its strong and sharp jaws until it is able to thrust through its head1 when1 in less than a quarter of an hour1 it completely emerges by a vermiform movement2 and at the same time it casts a skin1 together with the black head1 legs1 plates1 etc40 ,the larva1 now in its second stage1 passes forward and seizes hold of the upper or lateral aspect of the prothoracic segment of the wasp grub4 ,on emerging it becomes shorter and thicker1 8and very soon loses length by that curving forward of its head which is so marked in the full-grown larva1 and which does not exist before its emergence40 ,the larva is now found 8lying like a collar immediately under the head of the wasp grub1 and is attached to it by the head1 though not very firmly40 ,at this stage the feeding of the young ,rhipiphorus is rather sucking than eating4 ,illustration3 ,,fig4 #fdf4--;,first larva 7a7 of ,bruchus fab1 greatly enlarged2 b1 thoracic processes2 c1 head1 from front2 d1 from side2 e1 antenna2 f1 thoracic leg2 g1 rear view of tarsus2 h1 same1 front view4--,after ,riley4 ,when about #f mm4 in length it moults a second time1 and the full-grown larva closely though superficially resembles a ,crabro or ,pemphredon larva1 the small head being bent over forwards4 ,by the time it is ready to pupate it has wholly eaten the wasp larva1 and the temperature of the cell being high1 a larva #e mm4 long grows large enough in two days to fill the top of the cell of its host1 and the larva is ready to pupate about a week after hatching1 so that its development is very rapid4 ,the beetles themselves do not live in the cells4 ,chapman thinks they hibernate1 and that the eggs are laid in the spring or summer4 ,we thus have in this insect three larval stages1 the triungulin1 and two later stages1 the great differences between the first and the last two being apparently due to their parasitic mode of life1 the larva spending its second stage within its host1 involving an existence in a cell with a high temperature1 an uninterrupted supply of rich1 stimulating food1 and a comparatively sedentary mode of life compared with that of the triungulin at the beginning of its existence4 ,it is quite obvious that the hypermetamorphosis is primarily due to a great change in its surroundings1 i4e4 the parasitic mode of life of the beetle1 habits of very rare occurrence in the ,coleoptera1 numerous in species as they are4 ,illustration3 ,,fig4 #fdg4--;,first larval stage of ,bruchus pisi3 a1 egg in pea-pod2 b1 cross-section of opening of mine2 c1 young larva and opening on inside of pod by which it has entered1 enlarged2 d1 d1 d1 eggs1 natural size2 e1 #ast larval stage2 f1 a leg of same2 g1 prothoracic spinous processes4--,after ,riley4 ,in this connection attention may be drawn to a supernumerary larval stage observed by ,riley in the pea- and bean-weevils 7,figs4 #fdf and #fdg74 ,the larva on hatching has long slender legs1 though differing from those of an ordinary coleopterous larva in having but three joints 7j1 g1 h74 ,this stage is very short1 and the legs temporary1 as1 after entering the bean or pea1 it casts its skin1 losing its legs1 and assuming the vermiform shape of the second larval stage4 ,in this case the change from a pedate to an apodous larva is plainly enough due to the change from an external feeder1 like a chrysomelid larva1 to a larva leading a boring1 internal1 almost quiescent life4 ,certain ichneumons also appear to have two distinct larval stages1 as ,ratzeburg inferred that in ,anomalon there are four larval stages 7,fig4 #fdh74 ,illustration3 ,,fig4 #fdh4--;,history of ,anomalon circumflexum3 ,a1 #ast instar or stage4 ,b1 #b;d instar4 ,c1 larva in the #c;d or encysted stage removed from its cyst4 ,d1 mature larva4 ,e1 pupa4--,after ,ratzeburg1 from ,sharp4 ,in another ichneumon1 ,klaplek detected what he calls the 8sub-nymph40 ,the insect pupates within the case of a caddis-fly1 ,silo 7,fig4 #fdi74 ,in the ,proctotrypid there is also a hypermetamorphosis1 though the remarkable precocious stages they pass through are rather embryonic than larval4 ,in a species of ,platygaster which is parasitic in the larva of ,cecidomia1 the first larva 7,cyclops stage7 is of a remarkable shape1 not like an insect1 but rudely resembling a parasitic ,copepod crustacean4 ,in this condition it clings to the inside of its host by means of its hook-like jaws1 moving about1 as ,ganin says1 like a ,cestodes embryo with its well-known six hooks4 ,in this stage it has no nervous1 vascular1 or respiratory system1 and the digestive canal is a blind one 7,fig4 #fea74 ,illustration3 ,,fig4 #fdi4--,metamorphosis of ,agriotypus3 ,a1 larva4 ,b1 8sub-nymph40 ,c1 case of the ,silo1 with the string of attachment formed by ,agriotypus4 ,d1 section of the case3 v#a1 operculum of case2 v#b1 cocoon2 ag1 pupa of ,agriotypus2 e1 exuvia of same2 w#b1 wall of cocoon2 s1 remains of ,silo2 w#a1 closure of case4--,after ,klaplek1 from ,sharp4 ,after moulting1 the insect entirely changes its form2 it is thick oval-cylindrical1 nearly motionless1 with no appendages1 but with a digestive canal and a nervous and vascular system 7,fig4 #feb74 ,after a second moult the third and last larval stage is attained1 and the insect is of the ordinary appearance of ichneumon larv4 ,not less striking is the life-history of ,polynema1 which lays its eggs in those of a small dragon-fly 7,agrion virgo74 ,the first larval stage is most remarkable4 ,it hatches as a microscopic immovable being1 entirely unlike any insect1 with scarcely a trace of organization1 being merely a flask-shaped sac of cells4 ,after remaining in this state five or six days it moults4 ,illustration3 ,,fig4 #fej4--;,development of ,platygaster3 ,a1 stalked egg3 a central cell giving origin to the embryo4 ,b1 g1 germ2 b1 blastoderm cells4 ,c1 the same1 farther advanced4 ,d1 cyclops-like embryo3 md1 rudiments of mandibles2 d1 rudimentary pad-like organs1 seen more developed in ,e2 st1 bilobed tail4 ,the second stage1 or ,histriobdella-like form1 as ,ganin names it1 is more like that leech-like worm than an insect4 ,the third larval form is very bizarre1 though more as in insects1 having rudimentary antenn1 mouth-parts1 legs1 and ovipositor4 ,in this condition it lives from six to seven days before pupating 7,fig4 #fec74 ,the strange history of another egg-parasite 7,ophioneurus7 agrees in some respects with that of the foregoing forms4 ,it is when hatched of an oval shape1 with scarcely any organs1 and differs from the genera already mentioned in remaining within its egg-membrane1 and not assuming their strange shapes4 ,from the cylindrical sac-like non-segmented larva resembling the second larva of ,platygaster it passes directly into the pupa state4 ,a fourth form1 ,teleas 7,fig4 #fed1 ,a-,d71 is an egg-parasite of ,gerris1 and in ,america one species oviposits in the eggs of canthus4 ,illustration3 ,,fig4 #fea4--;,first larva of ,platygaster3 m1 mouth2 at1 rudimentary antenna2 md1 mandibles2 d1 tongue-like appendages4 ,illustration3 ,,fig4 #feb4--,second larva of ,platygaster3 1 sophagus2 ng1 brain2 n1 nervous cord2 ga and g1 genital organs2 ms1 muscular band4 ,the spindle-shaped larva in its first stage roughly resembles a trochosphere of a worm rather than the larva of an insect so high in the scale as a ,hymenopter4 ,it is active1 but after moulting the second larva is oval1 still without segments4 ,dr4 ,ayers gives a profusion of details and figures of the first and second stages of our ,teleas1 the second strongly resembling the ,cyclops stage of ,ganin4 ,he describes three stages1 and though he did not complete the life-history of the insect1 he thinks it changes to an ovoid flattened form which succeeds the ,cyclops stage in other ,pteromalid1 and that there are at least four ecdyses4 ,it is difficult to account for these strange larval forms1 unless we suppose that the embryos1 by their rich1 abundant food1 have undergone a premature development1 the growth of the body-walls being greatly accelerated1 the insects so to speak having been1 under the stimulus of over-nutrition and their unusual environment1 and perhaps also the high temperature of the egg1 hurried into vermian existence on a plane scarcely higher than that of an active ciliated gastrula4 ,further observations1 difficult though they will be1 are needed to enable us to account for the singular prematurity of the embryo of these parasites4 ,that these stages are reversional and a direct inheritance from the vermian ancestors of these insects is not probable1 but the forms are evidently the result of adaptation in response to a series of stimuli whose nature is in part appreciable but mostly unknown4 ,illustration3 ,,fig4 #fec4--,third larva of ,polynema3 at1 antenna2 fl1 imaginal bud of wing2 l1 rudimentary legs2 tg1 buds of one of the three pairs of styles of the ovipositor2 fk1 fat-body2 eg1 ear-like process4 ,illustration3 ,,fig4 #fed4--;,a-,d1 development of ,teleas2 ,a1 stalked egg2 ,b1 ,c1 ,d1 the #ast larval stage3 at1 antenna2 md1 hook-like mandibles2 mo1 mouth2 b1 bristles2 m1 intestine2 sw1 the tail2 ul1 under lip or labium4 ,e1 larva of another parasite1 ,ophioneurus4--,this and ,figs4 #fej-fec after ,ganin4 ,it may be noted1 however1 that the appearance of a primitive band in the second larval stage suggests the origin of these forms1 as well as that of insects in general1 from a ,peripatus-like1 and again from an earlier leech-like ,annelid ancestor4 ,hence the first larval or ,cyclops stage is due to a precocious development caused by the unusual environment1 and is simply adaptational1 and not of phylogenetic significance4 ,,summary ,,of ,,the ,,facts ,,and ,,suggestions ,,as ,,to ,,the ,,causes ,,of ,,metamorphism ,an explanation of the causes of metamorphosis is one of the most difficult undertakings in biology1 and the phenomenon has been considered as one of the chief difficulties in the way of the acceptance of the theory of descent4 ,a review1 however1 of the facts of hypermetamorphism1 particularly the life-history of ,mantispa1 throws much light on the subject1 since it is very probable that the supernumerary stages and marked changes of form characterizing them are due to changes of environment1 of habits1 and of food1 causes which have exerted such a profound influence on organic beings throughout all time4 ,besides these1 as the result of changes in the environment and nature of the food1 we have the results brought about by the use or disuse of structures brought into existence by the action of stimuli from without1 the class of insects abounding in examples of temporary structures which perform a certain function1 and then disappear4 ,again1 if the origin of a hypermetamorphosis can thus be explained1 it follows that normal metamorphosis is most probably due to changes of habitat1 of seasons1 of food1 and to accelerated growth resulting from the approach of sexual maturity4 ,the following facts and conclusions appear to be well established3-- #a4 ,the apterous insects 7,synaptera7 are ametabolous1 only the winged insects undergoing a metamorphosis4 #b4 ,the complete metamorphosis was not inherited from the primitive ancestor of all insects1 but acquired at a later period 7,f4 ,mller74 ,the eruciform type is a secondary1 adaptive form1 derived from the earlier1 campodeoid type of larva4 #c4 ,the earliest1 most primitive pterygote insects passed through only a slight metamorphosis4 ,in other words1 as soon as the wings were evolved and insects became adapted to live or take refuge in a new medium1 the air1 at the approach of the period of adult life1 with the ripening or perfection of the reproductive organs1 a metamorphosis began to take place1 and the number of species greatly multiplied4 ,on the other hand1 the ,arachnida and ,myriopoda1 in which as a rule there is no metamorphosis1 being confined to a creeping life1 with no change of medium1 remained poor in number of species4 #d4 ,at first the nymphs mainly differed from the adults in lacking wings1 though having the same habits2 in holometabolous insects1 the larva became adapted to entirely different habits and environments1 so that in ,hymenoptera1 and especially ,diptera1 the larva became remarkably unlike the imago4 #e4 ,until the ,mesozoic age1 or late in the ,carboniferous period1 there were1 so far as we now know1 only ametabolous and heterometabolous insects1 and these orders 7,orthoptera1 ,dermaptera1 ,hemiptera1 ,plectoptera1 ,odonata1 and ,neuroptera7 were not numerically rich in genera and species1 while since early ,mesozoic times geological extinction has reduced their numbers4 #f4 ,during the ,mesozoic age1 and since then1 the number of species1 genera1 families1 and orders has greatly increased1 and insects have become more and more holometabolous4 ,the orders of ,coleoptera1 ,lepidoptera1 ,hymenoptera1 and ,diptera are many fold greater in number of species and variety of form than the heterometabolous orders4 ,the rapid increase in the number and variety of types of insects evidently is correlated with the profound geological changes which took place at the end of the ,paleozoic age1 involving the appearance of larger continental masses1 or a greater land area1 thus opening new regions for settlement4 ,also the origin of flowering plants at about this time undoubtedly had much to do with the genesis of new adaptive structures1 such as the changes in the mouth-parts and wings4 #g4 ,the process of metamorphosis1 at least in the subtropical1 temperate1 and polar regions1 is largely dependent on the change from summer to winter1 and1 in the tropics1 from the rainy to the dry season4 ,as regards the organization of larval 7nepionic7 as compared with imaginal forms1 the nymphs and larv of insects are1 with the exception of many ,diptera1 nearly as perfectly developed as the adult4 ,in this respect the immature insect differs fundamentally from the larv of certain worms 7for example1 the pilidium of ,nemerteans7 and from the pluteus and brachiolaria stages of echinoderms1 which possess only digestive and water-vascular organs4 ,insect nymphs and larv also differ from the nauplius and zoa of ,crustacea in having at birth all the most important systems of organs 7digestive1 circulatory1 respiratory1 nervous1 muscular1 with sometimes a nearly perfected reproductive system7 of the imago1 also the same number of cephalic1 thoracic1 and abdominal segments and appendages4 ,metamorphism in insects involves 7except in the ,diptera7 rather modifications in the form and functions of organs and appendages already present than the formation of new ones4 ,in larval ,crustacea1 the thoracic and abdominal appendages do not arise until some time after hatching from the egg4 #h4 ,while cases of the suppression or abbreviation of larval characters and direct development are not uncommon in echinoderms and crustaceans1 in insects this phenomenon occurs only so far as yet known in the ,diptera4 ,in these insects the polypody in the embryo is outgrown1 or lost1 the embryos and larv not having even the temporary rudiments of abdominal appendages4 ,the campodeoid characters also are entirely suppressed1 dropped1 or lost in the more specialized holometabolous orders1 ,lepidoptera1 ,hymenoptera1 and ,diptera1 though retained in the more primitive and generalized ,coleoptera4 7,this proves that the ,coleoptera are lower or more primitive and generalized than the other orders mentioned47 ,this abbreviation or loss of organs is1 as ,hyatt and ,arms claim1 due to the prepotency of acquired characters in phylogeny1 and are also the result of homochronous heredity4 8,the ,insecta of the more specialized orders1 x4-xvi41 afford1 next to some parasites1 the most notable examples of this mode of evolution4 ,their larval or nepionic1 and pupal or neanic1 stages are prolonged at the expense of the ephebic1 winged stage1 and the reasons for this prolongation are found in the great number of new features introduced into these stages of development in these orders as contrasted with those of the more primitive1 and1 in large part1 more ancient orders1 i4-ix4 ,the law of tachygenesis has been at work here1 as in the former cases alluded to above1 and it is shown in the encroachments of the adaptive characteristics of the caterpillar1 grub1 and maggot upon the inherited characteristics of the ,thysanuran stage1 which loses its ancestral characteristics1 until in most cases they are either obsolete or recognizable with difficulty40 7,hyatt and ,arms1 ,natural ,science1 #ahif1 p4 #djj47 #i4 ,in the holometabolous insects there is a resting1 quiescent stage during the pupal period1 when the insect takes no food4 ,in this respect the more specialized insects differ from other metamorphic animals4 ,the larva has an abundant supply of fat lasting through pupal life1 while in the quiescent pupa1 respiration and circulation is much lessened1 the animal being as a rule motionless4 ,this resting stage is also necessary for the histolysis and formation of the adult body from the imaginal buds present in the larva4 #aj4 ,the hypermetamorphosis of ,mantispa1 ,melo1 ,stylops1 etc41 indicate very plainly that the eruciform type of larva is derived from the campodeoid1 since one and the same insect passes through these stages before reaching sexual maturity4 #aa4 ,as observed by ,miall1 the larva of insects differs from that of other invertebrate animals in being larger than the adult4 #ab4 ,the metamorphoses of insects are in some important respects paralleled by those of the ,amphibia4 ,the case of pdogenesis of ,chironomus affords a parallel with that of the ,siredon1 or larva of ,amblystoma4 ,also the organs and appendages of the insects1 such as caterpillars1 are present1 just as the skeleton and other organs of the tadpole are the homologues of those of the adult1 although these parts undergo a profound modification1 and new structures are added4 7,see the discussion of this point by ,miall1 and by ,hyatt and ,arms47 ,theoretical conclusions2 ,causes of metamorphosis4--,it results from a review of the known facts1 together with reasonable inductions from such facts1 that so far from opposing the theory of descent1 the facts of metamorphosis1 and particularly of hypermetamorphosis1 seem to afford solid foundation for the theory4 ,while natural selection was not the initiative cause1 it plays a part as one of several factors2 but the fundamental causes are the same as those which have controlled the origin of species and of the larger groups of animals in general4 ,owing to the struggle for existence1 due to overcrowding1 the early insects were forced to take to the air1 acquiring wings to enable them to avoid the attacks of creeping and running insects4 ,in the end the insects became1 owing to this acquisition of wings1 and afterwards to the establishment of a complicated metamorphosis1 numerically the most successful type of life in existence1 the number of species1 extinct and living1 mounting into the millions4 ,all aquatic insects are evidently the descendants of terrestrial forms1 and the numberless contrivances and temporary larval organs1 particularly of dipterous larv1 are evidently adaptations to the needs of the insect during its aquatic life1 and which are cast aside when the creature passes to a different medium4 ,the sudden or tachygenic appearance of temporary structures1 such as hatching spines1 various set1 spines1 respiratory organs1 so characteristic of dipterous larv1 and of the protective colors and markings of caterpillars1 and which are discarded at pupation1 or imagination1 are evidently due to the action of stimuli from without1 to the primary neolamarckian factors1 the characters proper to each larval stadium1 and to the pupal and imaginal stadia1--characters probably acquired during the lifetime of the individual1--becoming finally fixed by homochronous heredity4 ,,literature ,,on ,,postembryonic ,,development ,,and ,,metamorphoses ,herold1 ,moritz ,johann ,david4 ,entwicklungsgeschichte der ,schmetterlinge anatomisch und physiologisch bearbeitet4 7,cassel1 u4 ,marburg1 #ahae4 #cc ,taf41 #d1 pp4 #a-aah1 i-xxxiv47 ,ratzeburg1 ,f4 ,t4 ,c4 ,ueber ,entwickelung des fusslosen ,hymenopteren-larven1 mit besonderer ,rcksigt auf die ,gattung ,formica4 7,nova ,acta ,natur4 ,curios41 xvi1 #ahcb1 pp4 #ade-agf47 ,agassiz1 ,louis4 ,the classification of insects from embryological data4 7,smithsonian ,contr41 ii1 ,washington1 #ahea1 pp4 #bh1 #a ,pl47 ,ganin1 ,m4 ,beitrge zur ,erkenntniss der ,entwicklungsgeschichte bei den ,insecten4 7,zeitschr4 f4 wiss4 ,zool41 xix1 #ahfi1 pp4 #cha-dea1 #d ,taf47 ---- ,ueber die ,embryonalhlle der ,hymenopteren- und ,lepidopteren-embryonen4 7,mm4 ,acad4 ,st4 ,petersbourg 7#g71 xiv1 #ahfi1 pp4 #ah1 #a ,pl47 ---- ,materialien zur ,kenntniss der post-embryonalen ,entwicklungsgeschichte der ,insecten4 7,russian47 ,warschau1 #ahgf4 7,abdruck aus den ,arbeiten der ,v4 ,versammlung russischer ,naturf4 und ,aerzte in ,warschau1 #ahgf4 ,abstract by ,hoyer in ,jahresber4 der ,anat4 und ,phys4 von ,hoffmann und ,schwalbe1 v1 #ahgf1 and in ,zeitschr4 f4 wiss4 ,zool41 xxviii1 #ahgg1 pp4 #chf-chi47 ,weismann1 ,a4 ,die nachembryonale ,entwicklung der ,musciden nach ,beobachtungen an ,musca vomitoria und ,sarcophaga carnaria4 7,zeitschr4 f4 wiss4 ,zool41 xiv1 #ahfd1 pp4 #aja-bfc1 ,taf4 #h-ad47 ---- ,die ,metamorphose von ,corethra plumicornis4 7,zeitschr4 f4 wiss4 ,zool41 xvi1 #ahff1 pp4 #a-hc1 #e ,taf47 ,packard1 ,a4 ,s4 ,observations on the development and position of the ,hymenoptera1 with notes on the morphology of insects4 7,proceedings ,boston ,society of ,natural ,history1 #ahff1 pp4 #bgi-bie47 ,knckel d',herculais1 ,j4 ,recherches sur l'organisation et le dveloppement des ,volucelles4 ,paris1 #ahge1 ,pt4 ,i1 pp4 #bjh1 #ab ,pis42 ,,ii1 #ahha4 ,atlas of #ae ,pls4 ,dewitz1 ,h4 ,beitrge zur ,kenntniss der post-embryonalen ,gliedmaassenbildung bei den ,insecten4 7,zeitschr4 f4 wiss4 ,zool41 xxx1 ,suppl41 #ahgh1 pp4 #gh-aje1 #a ,taf42 ,nachtrag1 ,ibid41 pp4 #be-bh47 ---- ,ueber die ,flgelbildung bei ,phryganiden und ,lepidopteren4 7,berl4 ,ent4 ,zeitschr41 xxv1 #ahha1 pp4 #ec-ff1 #b ,taf47 ,lowne1 ,b4 ,th4 ,anatomy1 physiology1 morphology1 and development of the blow-fly4 ,london1 ,part ,i1 #ahhj2 ,part ,,ii1 #ahia4 ,viallanes1 ,h4 ,recherches sur l'histologie des ,insectes et sur les phnomnes histologiques qui accompagnent le dveloppement post-embryonnaire de ces animaux4 7,ann4 ,sc4 ,nat4 7#f71 xiv1 #ahhb47 ,metschnikoff1 ,e4 ,untersuchungen ber intracellulre ,verdauung bei wirbellosen ,thieren4 7,arb4 a4 d4 zoolog4 ,inst4 zu ,wien41 v1 #ahhc47 ---- ,untersuchungen ber die mesodermalen ,phagocyten einiger ,wirbelthiere4 7,biol4 ,centralbl41 iii1 #ahhc47 ,wielowiejsky1 ,h4 v4 ,ueber den ,fettkrper von ,corethra plumicornis und seine ,entwicklung4 7,zool4 ,anzeiger1 vi ,jahrg41 #ahhc1 pp4 #cah-cbb47 ,pancritius1 ,p4 ,beitrge zur ,kenntnis der ,flgelentwicklung bei den ,insecten4 ,in4-,diss4 ,knigsberg1 #ahhd4 ,rees1 ,j4 van4 ,over intra-cellulaire spijsverteering en over de beteekenis der witte bloedlichampjes4 7,maandblad voor ,natuurwetenschappen1 xi ,jaarg41 #ahhd1 pp4 #bh47 ---- ,over de post-embryonale ontwikkeling von ,musca vomitoria4 7,maandblad voor ,natuurwetenschappen1 ,juli1 #ahhe47 ---- ,beitrge zur ,kenntniss der inneren ,metamorphose von ,musca vomitoria4 7,zool4 ,jahrb4 ,abth4 f4 ,anat4 u4 ,ontog41 iii1 #ahhh1 pp4 #a-acd1 #b ,taf41 #ad ,figs47 ,frenzel1 ,j4 ,einiges ber den ,mitteldarm der ,insecten1 sowie ber ,epithel-regeneration4 7,arch4 ,micr4 ,anat41 xxvi1 #ahhe47 ,kowalevsky1 ,a4 ,beitrge zur nachembryonalen ,entwicklung der ,musciden4 7,zool4 ,anzeiger1 viii1 #ahhe1 pp4 #ih1 #abc1 #aec47 ---- ,beitrge zur ,kenntniss der nachembryonalen ,entwicklung der ,musciden4 7,i4 ,theil41 ,zeitschr4 f4 wiss4 ,zool41 xlv1 #ahhg1 pp4 #edb-eid1 #e ,taf47 ,schneider1 ,ant4 ,ueber die ,anlage der ,geschlechtsorgane und die ,metamorphose des ,herzens bei den ,insecten4 7,zool4 ,beitrge1 #ahhe1 i1 pp4 #adj-adc1 #a ,taf47 ,rehberg1 ,a4 ,ueber die ,entwickelung des ,insectenflgels 7an ,blatta germanica74 7,marienwerder1 #ahhf1 pp4 #ab1 #a ,taf47 ,scheffer1 ,c4 ,beitrge zur ,histologie der ,insecten4 7,spengel's ,zool4 ,jahrb41 iii1 ,abth4 f4 ,anat41 #ahhi1 pp4 #faa-feb1 #b ,taf47 ,hurst1 ,h4 ,the post-embryonic development of a gnat 7,culex74 ,manchester1 #ahij1 pp4 #bf1 #a ,pl4 ,verson1 ,e4 ,der ,schmetterlingsflgel und die sog4 ,imaginalscheiben desselben4 7,zool4 ,anzeiger1 xiii1 #ahij1 pp4 #aaf1 #aag47 ,bugnion1 ,edouard4 ,recherches sur le dveloppement post-embryonnaire1 l'anatomie1 et les murs de l',encyrtus fuscicollis4 7,recueil zool4 ,suisse1 v1 #ahia1 pp4 #dce-ecd1 #f ,pls47 ,petersen1 ,wilhelm4 ,die ,entwicklung des ,schmetterlings nach dem ,verlassen der ,puppenhlle4 7,deutsch4 ,ent4 ,zeitschr41 #ahia1 #b lepid4 ,hft41 pp4 #aii-bad1 #e ,figs47 ,kulagin1 ,nicolas4 ,notice pour servir l'histoire de dveloppement des hymnoptres parasites4 7,congrs international de ,zoologie1 #b;e ,session1 ,moscou1 #ahib1 pp4 #bec-bgg4 ,also in ,zool4 ,anzeiger1 xv1 #ahib1 pp4 #he-hg47 ---- ,on the development of ,platygaster4 7,journ4 of ,friends of ,nat4 ,sc4 ,moscow4 ,zool41 #ahij47 7,in ,russian47 ---- ,beitrge zur ,kenntniss der ,entwicklungsgeschichte von ,platygaster4 7,zeitschr4 f4 wiss4 ,zool41 lxiii1 #ahig1 pp4 #aie-bce1 #b ,taf47 ,miall1 ,l4 ,c41 and ,hammond1 ,a4 ,r4 ,the development of the head of ,chironomus4 7,trans4 ,linn4 ,soc4 ,london1 #b;d ,ser41 v1 #ahib1 pp4 #bfe-bgi1 #d ,pls47 ,pratt1 ,henry ,s4 ,beitrge zur ,kenntniss der ,pupiparen4 ,in4-,diss4 ,berlin1 #ahic1 pp4 #ec 7,archiv f4 ,naturgesch41 #ahic71 #a ,taf4 ---- ,imaginal discs in insects4 7,psyche1 viii1 #ahig1 pp4 #ae-cj1 #aa ,figs47 ,gonin1 ,j4 ,recherches sur la mtamorphose des lpidoptres4 ,de la formation des appendices imaginaux dans la chenille du ,pieris brassic4 7,bull4 ,soc4 ,vaud4 sc4 nat41 xxx1 #ahid1 pp4 #a-eb1 #e ,pls47 ,heymons1 ,r4 ,ueber ,flgelbildung bei der ,larve von ,tenebrio molitor4 7,sitz4 ,ber4 ,gesell4 ,natf4 ,freunde4 ,berlin1 ,jahrg4 #ahif1 pp4 #adb-add1 #a ,fig47 ,also the writings of ,malpighi1 ,swammerdam1 ,de ,geer1 ,lyonet1 ,bonnet1 ,newport1 ,brauer1 ,chapman1 ,fabre1 ,valery-,mayet1 ,riley1 ,chobaut1 ,nassonow1 ,miall 7,nature1 #ahie1 pp4 #aeb-aeh71 ,hyatt and ,arms 7,natural ,science1 #ahif1 pp4 #cie-djc74 ,,end ,,of ,,part ,,iii4 ,,index ,illustration ,abantiades1 #eg4 ,abbreviation of larval characters1 #gjg4 ,abdomen1 #afb4 ,abdominal appendages1 in the embryo1 #afd2 embryonic appendages1 #dgf2 jointed appendages1 #dfh4 ,acetabulum1 #id4 ,acid1 formic1 #ceh2 uric1 #ceb4 ,acinose salivary glands1 #ccd4 ,acoustic nerve1 #bij4 ,acronycta1 #fae2 hastulifera1 #aid4 ,acrydium1 #dba4 ,actias luna1 its cocoon-cutters1 #fcd4 ,adelops1 #fcj4 ,adhesive hairs1 #aaa1 #aac2 fluid1 #aac2 glands1 #cfj4 ,adiscota1 #fgb4 ,adminicula1 #fbi4 ,adranes ccus1 #eg4 ,adult insects1 tracheal gills of1 #dgf4 roscepsis1 #bfe4 schna1 #ec2 rectal respiration in nymph of1 #dfc4 ,agriotypus1 hypermetamorphosis of1 #gja4 ,aileron1 #abd4 ,air-sacs1 #def2 use of1 #deg4 ,aletia xylina1 tongue of1 #ff4 ,aleurodicus1 #eah4 ,aleyrodes1 #eah4 ,alitrunk1 #ij4 ,alluring glands1 #cia4 ,alula1 #abc1 #abe4 ,ametabola1 acquired1 #eii4 ,ametabolia1 #eif4 ,amnion1 #ecc2 absence of1 #ecd2 cavity1 #ecb2 fold1 #eca2 skin1 shedding of1 #ehd4 ,amphizoa1 #dfa4 ,anabolia furcata1 buccal organs of1 #gd4 ,anabrus1 #di1 #gc2 cuticula of1 #ahg4 ,anal glands1 #cai1 #cbf1 #cgb2 operculum1 #aha2 silk glands1 #cdf4 ,androconia1 #aig1 #aii4 ,anisomorpha1 #cga4 ,anisopleura1 lateral gills of1 #dfh4 ,anobium1 #bic1 #fbj4 ,anomalon1 hypermetamorphosis of1 #gja4 ,anophthalmus1 brain of1 #bda2 head of1 #gd2 olfactory organs of1 #bgf2 salivary glands of1 #ccd2 tongue of1 #gd4 ,anoplus1 #aja4 ,ant1 cement glands of1 #cfj2 organ of hearing in1 #bia2 taste in1 #bhb2 phosphorescent1 #dbd2 poison sac of1 #cei2 sounds produced by1 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#ddd2 origin of1 #ddg1 #ddh4 ,thyridium1 #abd4 ,thyridopteryx1 #fcd4 ,thysanoptera1 nymph of1 #eig4 ,thysanura1 #gb2 cercopods of1 #afd2 genital organs of1 #dhf4 ,tibia1 #if2 formation of1 in imago of ,lepidoptera1 #fee4 ,tineid larva1 wing-buds of1 #feb2 wing-germs of1 #abi4 ,tipula1 #fbi2 flight of1 #aea1 #aeb2 thorax of1 #ia4 ,tissue1 connective1 #egd4 ,tongue1 #gj4 ,torulus1 #eg4 ,trache1 #dca1 #ddb2 capillary1 #fee2 distribution of1 #dcb2 end-cells1 #dcg2 hairs in1 #dea2 moulting of1 #fab2 origin of1 #eec2 origin of1 in worms1 #ddb2 size of1 #dcc2 of wings1 #add4 ,tracheal gills1 of adult insects1 #dgf2 rectal1 #dfc4 ,tracheal system1 amphipneustic type1 #dfb2 apneustic type1 #dei2 closed1 #dei2 holopneustic type1 #dei2 metapneustic type1 #dfa2 peripneustic type1 #dfb2 propneustic type1 #dfb2 reformation of1 in metamorphosis1 #fhc4 ,tracheoles1 #abf1 #fec4 ,tract1 optic1 #bec4 ,trajectory made by wings1 #aej4 ,tribolium1 #fag4 ,trichodes1 tracks of1 #aaj4 ,trichogen1 #ahh1 #aii1 #cff4 ,trichoptera1 #dfi2 appendages1 #eej2 development of wings of1 #adb2 embryology of1 #ecg2 eversible glands of1 #cge2 haustellum of1 #ge2 hypopharynx of1 #gd2 pupal jaws of1 #fcc2 spinneret1 #gd4 ,trilobita1 #e4 ,tritocerebrum1 #bca1 #bcg4 ,triunguline larva1 #ajj1 #fic1 #fie4 ,trochanter1 #dif2 divided1 #ig4 ,trochantine1 #ie4 ,trogoderma1 #fag4 ,trophi1 #ed1 #ei1 #edi4 ,trouvelot1 on the moulting fluid1 #faj2 process of moulting of ,telea1 #faj2 spinning of cocoon by ,telea1 #fba4 ,truxalis1 #dbb4 ,tubercles1 #ahg1 #aib4 ,tubes1 egg1 #eja2 ovarian1 #eja2 urinary1 #caf1 #cag1 #cdh1 #cec1 #egb4 ,tympanum1 #bhi4 ,typhlocyba1 #faf4 ,uljanin1 on the sexual cells of the honey bee1 #ehb4 ,ungues1 #if4 ,uranidin1 #bjf4 ,urates1 #ceb4 ,urea1 #ceb4 ,urech1 on pigments1 #bjf1 #bjh4 ,uric acid1 #ceb4 ,urinary bladder1 #cea2 tubes1 #caf1 #cag1 #cdh2 absent in ,collembola1 #cec2 excretions of1 #cea2 origin of1 #egb2 primitive number of1 #ceb2 solid contents of1 #ceb4 ,urine1 #bjf4 ,urite1 #afc4 ,uromeres1 #afc4 ,uro-patagia1 #ahc4 ,urosome1 #afc4 ,urosternites1 #afc4 ,uterus1 #ejg4 ,utriculi1 #dhg4 ,uzel1 on the embryology of ,campodea1 #ea1 #ec2 premandibular segment in ,campodea1 #ea1 #eb4 ,vagina1 #ejg4 ,valery-,mayet1 on life-history of ,sitaris1 #fia4 ,vallisneri1 on the cremaster1 #fcg4 ,valvule1 cardiac1 #cab2 proventricular1 #cac2 pyloric1 #cae4 ,van ,bemmelen1 on colors1 #bjh4 ,vanessa antiopa1 #fch4 ,vanessa io1 #cha4 ,vanessa urtic1 before pupation1 #fdd2 changes in nervous system during its metamorphosis1 #fdf4 ,van ,rees1 on post-embryonic changes of ,muscid1 #fgc1 #fgd1 #fgf1 #fhj1 #fhc1 #fhd4 ,vas deferens1 #dif2 origin of1 #egi4 ,vasa deferentia1 #dif2 origin of1 #egi4 ,vayssire1 on lingua of ,ephemera1 #gc4 ,veins of wings1 #aba1 #add4 ,velum penis1 #aha4 ,venomous glands1 #ceh4 ,vent1 #cai4 ,ventriculus1 #cad4 ,vermipsylla1 tongue of1 #gg4 ,verson1 on serially arranged dermal glands1 #cff2 vestigial stigmata1 #dfj4 ,vesicles1 air1 #def2 use of1 #deg2 frontal1 #fba2 of head of semipupal fly1 #fgg4 ,vespa crabro1 #bag2 olfactory organs of1 #bgf4 ,vessel1 dorsal1 #cig2 urinary1 #caf1 #cdh4 ,vestigial trache1 #dfj4 ,viallanes1 on brain1 #bca2 head segments1 #ea4 ,vision1 mode of1 by compound eyes1 #bef2 by simple eyes1 #bee4 ,vitelline membrane1 #ebj4 ,viviparous insects1 #eae4 ,volucella1 thorax of1 #ia4 ,vosseler1 on ftid glands1 #cfi4 ,wagner1 on the circulation1 #dai4 ,walking1 mechanics of1 #ajc1 #ajf4 ,walter1 on epipharynx of moths1 #dd2 on hypopharynx of moths1 #ge4 ,wasps1 taste-organs of1 #bgg1 #bhf4 ,wax1 of butterfly1 #cfd2 of caterpillar1 #cfd2 of saw-fly larva1 #cfd4 ,wax-glands1 #cfa1 #cfd4 ,weevil1 embryology of1 #ech2 bean and pea1 hypermetamorphosis of1 #gjj4 ,weismann's discovery of imaginal buds1 #eii1 #fdc1 #fej2 on formation of imago1 #fg2 vesicle of semipupal fly1 #fgg2 on trache1 #dcd2 on origin of trache1 #ddg2 on origin of wings1 #abg1 #abi2 theory of histolysis1 #fdc4 ,west1 ,tuffen1 on feet of fly1 etc41 #ajj2 on walking1 #ii4 ,westwood1 on head of ,hymenoptera1 #ee4 ,wheeler1 on embryonic abdominal appendages1 #eej2 on the homologies of the ovipositor1 #afg2 homology and primitive number of urinary tubes1 #ced1 #cee2 on nocytes1 #dbc2 on pleuropodia1 #dgf1 #eej1 #eea2 on the premandibular segment1 #ea2 on structure of chorion1 #eba4 ,wielowiejski1 on blood tissue1 #djh2 egg-tubes1 #ejb2 fat-body1 #dai2 phosphorescence1 #dbd2 trache and their endings1 #dcf4 ,williston1 on anal glands1 #cgb4 ,will1 on organs of taste1 #bhb4 ,wing-buds1 or discs1 #abg1 #abi2 rods1 #adf2 sheaths1 #abd4 ,wingless insects1 #eih4 ,wings1 #abj2 buds of1 #ffd2 cells1 #aba2 circulation of blood in1 #daj2 development of trache of1 #add2 development of veins of1 #add2 embryonic development of1 #abf2 folding of1 #aed1 #aef2 imaginal buds of1 #fec2 mechanism of1 #aec1 #aef2 origin of1 #ach2 primitive origin of1 #acg2 as respiratory organs1 #dfa2 rudimentary1 ground-membrane of1 #acf2 spreading of1 #aee2 theory of1 #add2 trache in1 #abb2 veins of1 #aba4 ,wistinghausen1 von1 on tracheal endings1 #dcf1 #ddg4 ,witlaczil1 on honey dew1 #cfd4 ,wood-,mason1 on gills of ,paraponyx1 #dgj2 on ,scolopendrella1 #ai1 #bb4 ,xiphidium1 embryo of1 #ecd2 indusium of1 #ecd1 #ece4 ,yersin1 on results of section of commissures1 #bde4 ,yolk1 amount of1 #ebd1 #ebi2 membrane1 #ebj2 segmentation of1 #ebf2 cells1 #efb2 ridge1 median1 #efc4 ,zaitha1 #dca2 pleuropodia of1 #eea4 ,zone1 annular1 #fec4 ----- ,footnote #a3 ,zool4 ,anzeiger1 xvi1 #ahic1 pp4 #bga-e4 ,footnote #b3 ,on the morphology of the ,myriopoda1 ,proc4 ,amer4 ,phil4 ,soc4 #ahhc1 pp4 #aig-bji4 ,footnote #c3 ,morphology and classification of the ,pauropoda2 also ,american ,naturalist1 #ahig1 p4 #daj4 ,footnote #d3 ,the term which we proposed for this hypothetical ancestor of insects1 8,leptus-like0 or 8,leptiform10 was an unfortunate one1 since the name ,leptus was originally given to the six-legged larva of a mite 7,trombidium71 the origin of the mites and other ,arachnida being entirely different from that of the myriopods and insects4 ,footnote #e3 ,proc4 ,bost4 ,soc4 ,nat4 ,hist41 xvi1 #ahgc1 p4 #c4 ,footnote #f3 ,american ,naturalist1 ,may1 #ahhj1 pp4 #cge1 #cgf4 ,footnote #g3 ,zoologische ,anzeiger1 ,bd4 xx1 #ahig1 pp4 #abe and #abi4 ,he also states that ,campodea resembles the myriopods1 especially ,geophilus1 in the primitive band at first lying on the surface of the yolk1 and in the absence of an amniotic cavity2 also before hatching the abdomen is pressed against the thorax1 as in myriopods4 ,footnote #h3 8,scolopendrella has very remarkable antenn2 they may be compared each to a series of glass cups strung upon a delicate hyaline and extensible rod of uniform thickness throughout2 so that1 like the body of the creature1 they shrink enormously when the animal is irritated or thrown into alcohol1 and they then possess scarcely two-thirds the length they have in the fully extended condition1 their cup-like joints being drawn close together1 one within the other4 ,peripatus1 ,japyx1 many 7if not all7 ,homoptera1 and the ,s4 ,asiatic relatives of our common ,glomeris have all more or less extensible antenn40 7,wood-,mason1 ,trans4 ,ent4 ,soc41 ,london1 #ahgi1 p4 #aee47 ,footnote #i3 ,lassaigne gave it the name of entomoline4 ,footnote #aj3 ,miall and ,denny ex ,krukenberg2 ,kolbe gives the formula as ,c#i;,h#ae,,no#f or ,c#ah;,h#ae,,no#ab4 ,as the result of his recent researches1 ,krawkow 7,zeits4 ,biol41 xxix1 #ahib1 p4 #agg7 states that the chemical composition of chitin may prove to be somewhat variable4 ,footnote #aa3 ,on allowing portions of a locust1 a piece of the integument of ,limulus1 a scorpion1 and a myriopod to soak for a month in white potash1 neither were dissolved or affected by the reagent4 ,footnote #ab3 ,we may add1 while correcting the proofs of this book1 that the important summary1 by ,uzel1 of his work on the embryology of ,campodea appears in the ,zoologischer ,anzeiger for ,july #e1 #ahig4 ,he observes that the premandibular segment in the embryo is very distinct1 and that the two projections arising from it persist in the adult4 8,campodea is now the first example where these appendages are present in the sexually mature insect and function as constituents of the completed mouth parts4 ,i propose for these hitherto overlooked structures the name of intercalary lobes40 ,they each form a slightly developed chitinous lobe covering a gap between the base of the labium and the fused external lobe and palpus of the first maxill 7which are inclined near the labium7 in place of the mandibles which have sunken inward4 ,uzel also homologizes these appendages with two similar projections 7,hcker7 observed in the embryo of ,geophilus by ,zograf to be situated in front of the mandibles4 ,heymons has also detected this segment in the embryo of ,lepisma4 ,footnote #ac3 ,while these pages are still in type1 we may add1 in confirmation of this view1 that ,uzel states1 from his researches on the embryology of ,campodea1 that the maxillary tergites of the embryo only slightly share in building up the tergal region 7occiput7 of the head1 but that they form the gen of the maxillary segments4 7,zool4 ,anzeiger1 ,july #e1 #ahig1 p4 #bce47 ,footnote #ad3 ,miall and ,denny in their work on the cockroach1 in describing the labium1 remark3 8,the upper edge is applied to the occipital frame1 but is neither continuous with that structure nor articulated thereto4 ,by stripping off the labium upwards it may be seen that it is really continuous with the chitinous integument of the neck0 7p4 #ie74 ,this is1 we think1 a mistaken view1 as proved by the embryology of the ,odonata and of ,nematus4 ,our statements on this subject were first published in part in #ahga1 and more fully in the third ,report1 ,u4 ,s4 ,ent4 ,commission1 #ahhc1 pp4 #bhd1 #bhe4 ,we also stated that all the gular region of the head probably represents the base of the primitive second maxill4 ,footnote #ae3 ,after we had arrived at this conclusion1 and written the above lines1 we received the ,zoologischer ,anzeiger for ,march #bi1 #ahig1 in which ,dr4 ,n4 ,lon publishes the same view1 stating that each side of the submentum is the homologue of the cardo1 and each side of the mentum corresponds to the stipes of a single maxilla 7p4 #gd74 ,footnote #af3 ,miall and ,denny were the first to homologize the paragloss with the galea and lacinia1 showing the complete resemblance of the second maxill to the first pair1 remarking that 8the homology of the labium with the first pair of maxill is in no other insects so distinct as in the ,orthoptera40 ,we have also independently arrived at a similar conclusion1 but believe that the mentum corresponds to the first maxillary cardo1 and the palpifer to the first maxillary stipes1 the sclerite of each maxilla being fused to form the base of the labium1 i4e4 the unpaired mentum and submentum4 ,footnote #ag3 ,uzel states that what is regarded as the ligula of ,campodea is formed from the sternite of the first maxillary segment2 while the two parts regarded as paragloss grow out from the sternite of the mandibular segment1 and these three structures together he regards as the hypopharynx4 7,zool4 ,anzeiger1 ,july #e1 #ahig1 p4 #bcd47 ,footnote #ah3 ,see1 also1 ,breithaupt1 ,ueber die ,anatomie und die ,functionen der ,bienenzunge1 #ahhf4 ,it confirms and extends ,cheshire's work4 ,footnote #ai3 ,cholodkowsky1 ,zool4 ,anz41 ix1 p4 #fae2 x1 p4 #ajb4 ,footnote #bj3 ,zool4 ,anz41 ix1 p4 #gaa4 ,footnote #ba3 ,ent4 ,amer41 v1 p4 #aaj1 ,pl4 ,,ii1 ,fig4 #g4 ,footnote #bb3 ,in his account of his studies on the locomotion of insects1 ,de ,moor states that he obtained the track of each of the feet in different colors by coating them with different pigments2 the insect1 as it moved1 left its track on a strip of paper4 7,archives de ,biologie1 ,lige1 #ahij47 ,footnote #bc3 ,carlet and also ,de ,moor 7#ahij7 confirm ,graber's statement that in beetles the first and last appendages on the same side are in contact with the ground1 while the middle one is raised4 ,on the other side of the body the middle appendage is on the ground and the first and last one raised4 ,footnote #bd3 ,trans4 ,amer4 ,ent4 ,soc4 xx1 p4 #afh4 ,footnote #be3 ,proc4 ,ent4 ,soc4 ,london4 ,feb4 #ai1 #ahif4 ,heymons also shows that the germs of the elytra of the larva of ,tenebrio molitor in the prepupal stage are like those of other insects4 7,sitzungs-,ber4 ,gesell4 natur f4 ,freunde zu ,berlin1 #ahif1 pp4 #adb-add47 ,footnote #bf3 ,zur ,entwickelungsgeschichte und ,reproductionsfhigkeit der ,orthopteren4 ,von ,vitus ,graber4 ,sitzungsberichte d4 math4-naturw4 ,classe der ,akad4 d4 ,wissensch41 ,wien4 ,bd4 lv1 ,abth4 i1 #ahfg2 also ,die ,insekten4 ,footnote #bg3 ,on the transformations of the common house fly1 by ,a4 ,s4 ,packard1 ,jr4 ,proceedings ,boston ,society of ,natural ,history1 vol4 xvi1 #ahgd4 ,see ,pl4 #c1 ,figs4 #ab;a1 #ab;b4 ,footnote #bh3 ,see our ,guide to the ,study of ,insects1 p4 #ff1 ,figs4 #fe1 #ff4 ,footnote #bi3 ,our ,common ,insects1 #ahgc1 p4 #aga4 ,footnote #cj3 ,compare the observations of ,palmn1 ,gerstcker1 ,vayssire1 and others4 ,footnote #ca3 ,beitrge zur ,kenntniss der ,termiten4 ,jenaische ,zeitschrift fr ,naturwissenchaft1 ,bd4 ix1 ,heft #b1 p4 #bec1 #ahge4 ,compare1 however1 ,palmn's ,zur ,morphologie des ,tracheensystems1 ,helsingfors1 #ahgg1 wherein he opposes ,mller's view and adopts ,gegenbaur's4 ,see p4 #h1 footnote4 ,footnote #cb3 ,pancritius1 who also adopted ,mller's views1 lays much stress on the fact that in larv of some orders the trache do not enter the rudimentary wings until the end of larval life1 and hence the wings have not originated from tracheal gills1 but were originally 8perhaps only protective covers for the body40 ,footnote #cc3 ,reproduced from the author's remarks in ,third ,report ,u4 ,s4 ,ent4 ,commission1 pp4 #bfh-bga1 #ahhc4 ,footnote #cd3 ,von ,lendenfeld1 however1 points out the fact that ,straus-,durckheim proved that the wings of beetles are moved by a complicated system of numerous muscles4 8,in the ,lepidoptera ,i have never found less than six muscles to each wing1 as also in the ,hymenoptera and ,diptera40 8,the motions of the wings of ,libellulid are the combined working of numerous muscles and cords1 and of a great number of chitinous pieces connected by joints40 ,footnote #ce3 ,heymons1 however1 denies that the so-called cerci in ,odonata are such1 and claims that they are the homologues of the 8caudal processes0 7superior terminal appendages of ,calvert71 because they arise from the tenth abdominal segment4 ,footnote #cf3 ,amer4 ,nat41 iv1 ,december1 #ahgj4 ,footnote #cg3 ,handbuch der ,zoologie1 p4 #ag1 #ahfc1 ,fig4 #afb4 ,footnote #ch3 ,in my account of the anatomy of ,melanoplus spretus1 #ast ,report ,u4 ,s4 ,entomological ,commission1 p4 #bei1 ,i have called these the infra-anal flaps or uro-patagia4 ,footnote #ci3 ,it has been suggested to us by ,a4 ,a4 ,packard that the power possessed by insects of transporting loads much heavier than themselves is easily accounted for1 when we consider that the muscles of the legs of an insect the size of a house-fly 7 inch long71 and supporting a load #cii times its own weight1 would be subjected to the same stress 7per square inch of cross-section7 as they would be in a fly #ajj inches long of precisely similar shape1 that carried only its own weight2 from the mechanical law that1 while the weight of similar bodies varies as the cube of the corresponding dimensions1 the area of cross-section of any part 7such as a section of the muscles of the leg7 varies only as the square of the corresponding dimensions4 ,in short1 the muscles of a fly carrying this great proportional weight undergo no greater tension than would be exerted by a colossal insect in walking4 ,footnote #dj3 ,this has been shown to be the case by ,michels1 who states that each commissure is formed of three parallel bundles of elementary nerve-fibres1 which pass continuously from one end of the ventral or nervous cord to the other4 8,the commissures take their origin neither out of a central punctsubstanz 7or marksubstanz71 nor from the peripheral ganglion-cells of the several ganglia1 but are mere continuations of the longitudinal fibres which decrease posteriorly in thickness1 and extend anteriorly through the commissures1 forming the sophageal ring1 to the brain40 ,footnote #da3 ,the following extract from ,newton's paper shows1 however1 that the infra or subsophageal ganglion1 according to ,faivre1 has the power of cordinating the movements of the body2 still1 it seems to us that the brain is primarily concerned in the exercise of this power1 as the nerves from the subsophageal ganglion supply only the mouth-parts4 8,the physiological experiments of ,faivre in #aheg 7,ann4 des ,sci4 ,nat4 tom4 viii1 p4 #bde71 upon the brain of ,dyticus in relation to locomotion1 are of very considerable interest1 showing1 as they appear to do1 that the power of cordinating the movements of the body is lodged in the infrasophageal ganglion4 ,and such being the case1 both the upper and lower pairs of ganglia ought to be regarded as forming parts of the insect's brain40--,quart4 ,jour4 ,micr4 ,sc41 #ahgi1 p4 #cdb4 ,footnote #db3 ,the arthropod protocerebrum probably represents the annelid brain 7suprasophageal ganglion74 ,the antennal segment 7deutocerebrum71 with the premandibular 7intercalary7 segment 7tritocerebrum7 originally postoral1 have1 as ,lankester suggests1 in the ,arthropoda moved forward to join the primitive brain4 ,see ,wheeler1 ,journ4 ,morphology1 ,boston1 viii1 p4 #aab4 ,footnote #dc3 ,viallanes' assertion that the instincts of the horse-flies and dragon-flies are 8lower0 than those of the locusts1 may1 it seems to us1 well be questioned4 ,footnote #dd3 ,a4 ,s4 ,packard1 ,experiments on the vitality of insects1 ,psyche1 ii1 #ag1 #ahgg4 ,footnote #de3 ,waterhouse1 ,trans4 ,ent4 ,soc41 ,london1 #ahhi1 p4 xxiv4 ,footnote #df3 ,j4 ,mller1 ,physiology of the ,senses4 ,trans4 by ,baly1 copied from ,lubbock1 p4 #agf4 ,footnote #dg3 ,hauser here uses the word taster1 but this means palpus or feeler4 ,it is probably a lapsus penn for teeth 7,kegeln74 ,footnote #dh3 ,in #ahgj ,i observed these sense-pits in the antenn and also in the cercopoda of the cockroach 7,periplaneta americana74 ,i counted about #ij pits on each cercus4 ,they are much larger and much more numerous than similar pits in the antenn of the same insect4 ,i compared them to similar pits in the antenn of the carrion-beetles1 and argued that they were organs rather of the smelling than hearing4 7,amer4 ,nat41 iv41 ,dec4 #ahgj47 ,organs of smell in the flies 7,chrysopila7 and in the palpi1 both labial and maxillary1 of ,perla were described in the same journal 7,fig4 #bgj74 ,compare ,vom ,rath's account of the organs in the cercopods of ,acheta 7,fig4 #bga72 also the singular organ discovered by him on the end of the palpus of butterflies1 in which a number of hair-like rods 7sh7 are seated on branches of a common nerve 7n1 ,fig4 #bgb74 ,footnote #di3 ,forel1 however 7,recueil ,zoologique ,suisse1 #ahhg71 denies that these tympanic organs are necessarily ears1 and thinks that all insects are deaf1 with no special organs of hearing1 but that sounds are heard by their tactile organs1 just as deaf-mutes perceive at a distance the rumbling of a carriage4 ,but he appears to overlook the fact that many ,crustacea1 and all shrimps and crabs1 as well as many molluscs1 have organs of hearing4 ,the ,german anatomist ,will believes that insects hear only the stridulation of their own species4 ,lubbock thinks that bees and ants are not deaf1 but hear sounds so shrill as to be beyond our hearing4 ,footnote #ej3 ,weismann1 ,die nachembryonale ,entwicklung der ,musciden4 ,zeitschr4 fr wissen4 ,zoologie1 xiv1 p4 #aif1 #ahfd4 ,footnote #ea3 ,plateau 7#ahgg7 states that the digestive fluid of insects1 as well as of ,arachnids1 ,crustaceans1 and ,myriopods1 has no analogy with the gastric juice of vertebrates2 it rather resembles the pancreatic sugar of the higher animals4 ,the acidity quite often observed is only very accessory in character1 and not the sign of a physiological property4 8,farther1 ,i have found it in insects2 ,hoppe-,seyler has demonstrated in the ,crustacea1 and ,i have proved in the spiders1 that the ferment causing the digestion of albuminoids is evidently quite different from the gastric pepsine of vertebrates2 the addition of very feeble quantities of chlorhydric acid1 far from promoting its action1 retards or completely arrests it40 7,bull4 ,acad4 roy4 ,belgique1 #ahgg1 p4 #bg47 ,footnote #eb3 ,the word grs we translate as the layer of gum4 ,not sure of the ,english equivalent for grs1 ,i applied to ,dr4 ,l4 ,o4 ,howard1 ,u4 ,s4 ,entomologist1 who kindly answers as follows3 8,i have consulted ,mr4 ,philip ,walker1 a silk expert1 who writes me the following paragraph3 #8,grs1 as ,i understand it1 is the gum of the silk fibre1 hence the ,french name for raw silk1 grye1 which is in distinction to the silk that has been boiled out in soap after twisting1 or throwing1 as it is called4 ,as ,i understand it1 the silk fibre is composed of the grs and fibroin4 ,the former is soluble in alkali1 like soap water1 and the latter is not4'0 ,while ,blanc considers the grs as the product of a special secretion of the wall of the reservoir1 ,gilson regards its production as simultaneous with that of the silk or of the fibroin 7l4c4 #ahic1 p4 #gd74 ,footnote #ec3 ,on cytological differences in homologous organs4 ,report #fc;d meeting of ,british ,assoc4 ,adv4 ,sc4 for #ahic4 #ahid4 p4 #iac4 ,footnote #ed3 ,see also ,giard1 ,bull4 ,soc4 ,ent4 ,france1 p4 viii1 #ahid4 ,footnote #ee3 8,the contents of the ,malpighian tubules may be examined by crushing the part in a drop of dilute acetic acid1 or in dilute sulphuric acid 7#aj per cent74 ,in the first case a cover-slip is placed on the fluid1 and the crystals1 which consist of oblique rhombohedrons or derived forms1 are usually at once apparent4 ,if sulphuric acid is used1 the fluid must be allowed to evaporate4 ,in this case they are much more elongated1 and usually clustered4 ,the murexide reaction does not give satisfactory indications with the tubules of the cockroach40 7,miall and ,denny1 ,the cockroach1 p4 #abi1 footnote47 ,footnote #ef3 8,there is a curious analogy between the excretory organs of these insects and the mesonephros of some vertebrates1 where a second1 third1 etc41 generation of tubules is added to the primitive metameric series4 ,when the embryonic number of ,malpighian vessels persists in insects1 the demand for greater excreting surface is supplied by a lengthening of the individual vessels40 ,footnote #eg3 ,for the mode of adhesion of ,cynips eggs1 see ,adler in ,deutsche ,ent4 ,zeits4 #ahgg1 p4 #cbj4 ,footnote #eh3 ,mercaptan is a mercury1 belonging to a class of compounds analogous to alcohol1 having an offensive garlic odor4 ,methyl mercaptan is a highly offensive and volatile liquid4 ,footnote #ei3 ,embryonic or temporary glands1 the 8pleuropodia0 of ,wheeler1 viz4 the modified first pair of abdominal legs1 occur in canthus1 ,gryllotalpa1 ,xiphidium1 ,stenobothrus1 ,mantis 7occasionally a pair on the second abdominal segment1 ,graber72 ,blatta1 ,periplaneta1 ,cicada1 ,zaitha1 ,hydrophilus1 ,acilius1 ,melolontha1 ,melo1 ,sialis1 ,neophylax4 7,see ,wheeler1 ,appendages of the ,first ,abdominal ,segment1 etc41 #ahij47 ,footnote #fj3 ,these midges owe their phosphorescence to bacteria in their bodies during disease4 ,footnote #fa3 ,untersuchungen zur ,anatomie und ,histologie der ,tiere1 #ahhd1 p4 #gb4 ,footnote #fb3 ,zelle und ,gewebe1 #ahhe1 p4 #dc4 7,see also our p4 #bag47 ,footnote #fc3 ,studien ber die ,lampyriden1 ,zeits4 fr wiss4 ,zool41 xxxvii1 #ahhb4 ,both ,wielowiejski and ,m4 ,wistinghausen have completely disproved the view of ,schultze1 that the trache end in star-like cells1 where respiration takes place1 as the 8star-like cells0 are simply net-like expansions of the peritoneal membrane of the trache4 ,footnote #fd3 ,the following summary compiled from ,krancher1 is translated1 with some minor changes1 from ,kolbe's work4 ,footnote #fe3 ,miall and ,denny state that in the cockroach the abdominal spiracles are permanently open1 owing to the absence of a valve1 but communication with the tracheal trunk may be cut off at pleasure by an internal occluding apparatus4 ,footnote #ff3 ,zur ,entwicklungsgeschichte der ,biene1 ,zeitschr4 wissens4 ,zoologie1 xx1 p4 #eai1 #ahgj4 ,footnote #fg3 ,die ,entwicklung der ,dipteren im ,ei1 ,zeitschr4 wissens4 ,zoologie1 xiii1 #ahfc4 ,footnote #fh3 ,amer4 ,naturalist1 ,may1 #ahhf1 p4 #dch4 ,footnote #fi3 ,zeitschr4 wissens4 ,zoologie1 xl1 #ahhd1 ,taf4 xix1 ,fig4 #h1 ,t4 ,footnote #gj3 ,science1 #ahic1 pp4 #dd-df4 ,footnote #ga3 ,art4 ,thorax1 ,todd's ,cycl4 of ,anat4 and ,phys4 ,footnote #gb3 ,the mesothoracic stigmata are open in ,carabus1 ,potamophilus1 ,elmis1 ,macronychus1 ,buprestis1 ,elater1 ,lampyris1 ,lycus1 ,triphyllus1 ,eucinetus1 ,dascillus1 ,psephenus1 ,ergates1 ,micralymna1 and probably many others4 ,the metathoracic stigmata are open in ,lycus and ,elmis4 ,footnote #gc3 ,in the ,hymenoptera the two pairs on the meso- and metathoracic segments are open in the ,aculeata1 also in the ,siricid1 among which sometimes that on the third segment is closed4 ,in ,pimpla and ,microgaster 7fully grown larv7 only the mesothoracic stigmata are open4 ,palmn adds that most dipterous larv are amphipneustic2 ,cecidomyia1 the ,mycetophilid1 ,bibionid1 and ,stratiomys are typically peripneustic4 7p4 #ib47 ,moreover1 a single insect1 as ,sialis1 may be apneustic as a larva1 peripneustic as a pupa1 and holopneustic in the imago stage4 ,footnote #gd3 ,mr4 ,j4 ,w4 ,folsom1 who has made the accompanying sketch of the nymph of ,eupha splendens in the ,cambridge ,museum1 finds only seven pairs of gills1 there being no traces of them on segments #a1 #i1 and #aj4 ,a stout trachea1 he writes us1 enters the base of each gill1 and subdivides into several long branches1 which course along the periphery4 ,hagen in his original account said there were eight pairs on segments #a-h respectively4 ,footnote #ge3 ,harris1 ,correspondence1 p4 #bbf1 ,pl4 ,,iii41 ,fig4 #g4 ,footnote #gf3 ,nusbaum's view has been questioned by ,heymons1 who1 from his studies on the embryology of the cockroach 7,periplaneta and ,phyllodromia71 ,forficula1 and ,gryllus1 concludes that the ectodermal ends of the sexual outlets owe their origin to an unpaired median hypodermal invagination1 and that it is quite doubtful whether the ectodermal portions of the sexual passages of insects were ever paired 7p4 #ajd74 ,on the other hand he appears1 even throwing out the case of ,ephemera1 to have overlooked ,nassonow's discovery of paired outlets in the young of ,lepisma4 ,footnote #gg3 ,acta ,acad4 ,german41 xxxiii1 #ahfg1 ,no4 #b1 p4 #ha4 ,quoted by ,dr4 ,sharp1 ,insecta1 p4 #adb4 ,footnote #gh3 ,journ4 ,morph41 iii1 ,boston1 pp4 #bii1 #cjj4 ,footnote #gi3 ,proc4 ,boston ,soc4 ,nat4 ,hist41 xi1 pp4 #hh1 #hi4 ,footnote #hj3 ,in the following general account of the embryology of insects1 ,i have closely followed the admirable arrangement and description of ,korschelt and ,heider1 in their ,lehrbuch der vergleichenden ,entwicklungsgeschichte der wirbellosen ,thiere1 pp4 #gfd-hdf1 often translating their text literally1 though not omitting to state the results of other writers4 ,footnote #ha3 ,korschelt and ,heider state that no cellular embryonal membranes are present in ,synaptera1 ,uljanin finding none in the ,podurids4 ,in the embryo of ,isotoma walkerii we1 however1 observed a membrane which we compared to the larval skin of many ,crustacea1 and both ,sommer and ,lemoine have detected in eggs of the same group a cuticular larval skin which is provided with spines for rupturing the chorion4 ,the amnion is also wanting in ,proctotrupids 7,ayers71 and is rudimental in ,muscid 7,kowalevsky1 ,graber71 in viviparous ,cecidomyid1 according to ,metschnikoff1 who also states that in certain ants of ,madeira the envelopes are represented only by a small mass of cells in the dorsal region4 ,footnote #hb3 ,in ,diptera the stomodum may be dorsal1 ,dr4 ,pratt tells us4 ,footnote #hc3 ,will 7,aphis7 and also ,cholodkowsky's statement 7,blatta71 as well as ,balfour and ,schimkewitch's statements that the brain is at first disconnected from the ventral cord1 are apparently erroneous4 ,footnote #hd3 ,the description perhaps applies not only to the cockroaches1 but1 as seen from the similar but fragmentary notices of ,heider and of ,wheeler on the ,coleoptera1 may be common to insects in general4 ,footnote #he3 ,report on the ,rocky ,mountain locust1 etc4 ,ninth ,annual ,report ,u4 ,s4 ,geol4 and ,geogr4 ,survey of the ,territories for #ahge1 pp4 #fcc1 #fcd4 ,footnote #hf3 ,orthoptera ,europa1 #ahec1 p4 #cg4 ,footnote #hg3 ,in his ,fr ,darwin 7#ahfc71 ,fritz ,mller gives his reasons for the opinion that the so-called 8complete metamorphosis0 of insects was not inherited from the primitive ancestor of all insects1 but acquired at a later period4 ,footnote #hh3 ,for further details see the #ast ,report of the ,u4 ,s4 ,entomological ,commission1 #ahgh1 pp4 #bgi-bha4 ,footnote #hi3 ,see ,kppen ueber die ,heuschrecken in ,sdrussland1 #ahfb1 pp4 #bb1 #bc4 ,footnote #ij3 ,in ,samouelle's ,the ,entomologist's ,useful ,compendium1 #ahai4 ,see ,westwood's ,class4 ,insects1 i1 p4 #b2 ,leach's ,ametabolia comprised the ,thysanura 7,synaptera7 and the lice4 ,footnote #ia3 ,from the ,greek 1 scanty2 1 change4 ,footnote #ib3 ,greek1 1 quiet2 1 change4 ,footnote #ic3 ,at the same date 7,march1 #ahfi7 we independently suggested that the insects had originated from some form like the hexapodous young of ,pauropus and ,podura4 ,in ,november1 #ahgj1 we suggested that the ,thysanura and the hexapodous ,leptus may have descended from some ,peripatus-like worm4 ,afterwards 7#ahga7 we proposed for the ancestral form the term leptiform1 which was later abandoned for ,brauer's term ,campodea-form4 ,footnote #id3 ,amer4 ,naturalist1 i1 p4 #he1 #ahfg4 ,footnote #ie3 ,first ,rep4 ,u4 ,s4 ,ent4 ,commission1 p4 #bha-bhc4 ,footnote #if3 ,trans4 ,ent4 ,soc4 ,london1 iii1 p4 xv4 ,see also ,ashton1 ,r4 ,j41 ,trans4 ,ent4 ,soc4 ,london1 iii1 #ahda-dc1 pp4 #aeg-aei4 ,footnote #ig3 ,proc4 ,bost4 ,soc4 ,nat4 ,hist41 x1 #ahff1 p4 #bhc4 ,footnote #ih3 ,see ,max ,braun's article entitled ,ueber die histologischen ,vorgange bei der ,hautung von ,astacus fluviatilis1 with a full bibliography1 in ,semper's ,arbeiten aus dem ,zool4 zoot4 ,institut in ,wrzburg1 ii1 pp4 #aba-aff4 ,also ,semper's ,animal ,life1 p4 #bj4 ,trouvelot also discovered the moulting fluid4 7,amer4 ,nat41 i1 p4 #cg47 ,footnote #ii3 ,american ,naturalist1 xvii1 ,may1 #ahhc1 pp4 #edg1 #edh4 ,footnote #ajj3 ,le ,pelletier4 ,a4 ,m4 ,l41 ,bulletin de la ,socit ,philomathique1 ,paris1 ,april1 #ahac4 ,footnote #aja3 ,heineken1 ,carl4 ,observations on the reproduction of the members in spiders and insects4 7,zool4 ,journ41 #ahbi1 vi1 pp4 #dbb-dcb47 ,footnote #ajb3 ,bees and ,bee-keeping1 pp4 #ba1 #bb4 ,footnote #ajc3 ,butterflies1 their structure1 changes1 and life-histories4 ,new ,york1 #ahha1 pp4 #cg-db4 ,butterflies of the ,eastern ,united ,states and ,canada1 #ahhh1 #ahhi4 ,also1 ,frail children of the air1 #ahie1 pp4 #bcb1 #bcc a4 ,dr4 ,chapman1 however1 finds that this piece in micropup has no connection whatever with the head or eye1 but belongs rather with the prothoracic segment4 7,trans4 ,ent4 ,soc4 ,london1 #ahic1 p4 #ajb47 ,we have been able to confirm his statements1 but still this piece is peculiar to the pupal state4 ,footnote #ajd3 ,rep4 ,ent4 ,u4 ,s4 ,dept4 ,agr41 #ahgi1 pp4 #bbh1 #bbi1 ,pl4 ,,iv1 ,fig4 #d4 ,footnote #aje3 ,monograph of bombycine moths1 ,pt4 ,i1 #ahig4 ,figs4 #bd1 #bh1 #bi1 #cc1 #cd1 #dj1 #gg4 ,footnote #ajf3 ,amer4 ,naturalist1 xii1 pp4 #cgi-chc4 ,footnote #ajg3 ,hybocampa milhauseni1 ,dr4 ,chapman tells me1 has a pupal spine 7imperfectly present in ,cerura7 with which it cuts out a lid of the cocoon4 ,footnote #ajh3 ,riley's ,report for #ahib1 p4 #bjc4 ,footnote #aji3 ,philosophy of the pupation of butterflies1 and particularly of ,nymphalid1 by ,charles ,v4 ,riley4 7,proc4 ,amer4 ,assoc4 ,adv4 ,science1 xxviii1 ,saratoga ,meeting1 ,august1 #ahhj1 pp4 #dee-dfc47 ,footnote #aaj3 ,the homology of the suranal plate of the larva with the cremaster of the pupa1 established by ,riley in #ahhj1 is also affirmed by ,jackson 7#ahhh7 and by ,poulton1 and for some years we have been satisfied that this is the correct view2 ,professor ,hatchett-,jackson discovered it1 he states1 in #ahgf4 ,footnote #aaa3 ,in his remarkable studies on the morphology of the ,lepidoptera1 ,professor ,w4 ,hatchett-,jackson states his belief that ,riley's homology of the sustentors with the soles or plant of the anal prolegs1 and the sustentor ridges with their limbs1 is wrong1 and that the eminences on either side the anal furrow1 or the 8anal prominences10 as they are termed by ,riley1 represent the prolegs1 and that the sustentor ridges and sustentors are probably peculiar developments of the body of the #ajth somite1 found only in some ,lepidoptera4 ,from our examination of pupa of different families of moths1 we are satisfied that ,jackson's view is the correct one4 ,we have not found the sustentors and their ridges in the pup of the more generalized moths1 but the vestiges of the anal legs are almost invariably present1 their absence in the pupa of ,nola and ,harrisina being noteworthy4 ,footnote #aab3 ,we copy from ,kirby and ,spence their abstract of ,herold's conclusions3 8,the successive skins of the caterpillar1 the pupa-case1 the future butterfly1 and its parts or organs1 except those of sex1 which he discovered in the newly excluded larva1 do not prexist as germs1 but are formed successively from the rete mucosum1 which itself is formed anew upon every change of skin1 from what he denominates the blood1 or the chyle after it has passed through the pores of the intestinal canal into the general cavity of the body1 where1 being oxygenated by the air-vessels1 it performs the nutritive functions of blood4 ,he attributes these formations to a vis formatrix 7bildende ,kraft74 8,the caul or epiploon 7fett-masse71 the corps graisseux of ,raumur1 etc41 which he supposes to be formed from the superfluous blood1 he allows1 with most physiologists1 to be stored up in the larva1 that in the pupa state it may serve for the development of the imago4 ,but he differs from them in asserting that in this state it is destined to two distinct purposes3 first1 for the production of the muscles of the butterfly1 which he affirms are generated from it in the shape of slender bundles of fibres2 and1 secondly1 for the development and nutrition of the organs formed in the larva1 to effect which1 he says1 it is dissolved again into the mass of blood1 and being oxygenated by the air-vessels1 becomes fit for nutrition1 whence the epiploon appears to be a kind of concrete chyle40 7,entwickelungsgeschichte der ,schmetterlinge1 pp4 #ab-bg47 ,it seems that ,herold was right in deriving the pupa and imago from the hypodermis 7his rete mucosum71 but wrong in denying that the germs did not prexist in the young caterpillar1 and wrong in supposing that the latter originated from the blood1 also in supposing that the muscles owe their origin to the fat-body4 ,swammerdam1 and also ,kirby and ,spence1 were correct in supposing that the imago arose from 8germs0 in the larva1 though wrong in adopting the 8embotement0 theory4 ,footnote #aac3 ,in the regions where the imaginal buds are not present 7dorsal aspect of the prothorax1 and abdomen71 the epithelium 7hypodermis7 may proliferate independently of these buds4 ,footnote #aad3 ,we shall translate portions and1 when the text allows1 make an abstract of parts of ,gonin's clear and excellent account1 often using his own words4 ,footnote #aae3 ,c4 ,herbert ,hurst1 ,the ,pupal ,stages of ,culex4 ,footnote #aaf3 ,lowne on the ,blow-fly1 new edit41 pp4 #b1 #da1 ,fig4 #g4 ,footnote #aag3 ,miall1 ,natural ,history of ,aquatic ,insects1 pp4 #acf-ach4 ,also ,trans4 ,linn4 ,soc4 ,london1 ,v1 ,sept41 #ahib4 ,footnote #aah3 ,this account is translated from ,korschelt and ,heider1 with some omissions and slight changes4 ,footnote #aai3 ,westwood in his excellent account of this group remarks3 8,hence1 as well as from the account given by ,jurine1 it is evident that the pupa of the ,stylops is enclosed in a distinct skin1 and is also in that state enveloped by the skin of the larva1 contrary to the suggestion of ,mr4 ,kelly40 7,class4 ,insects1 ,,ii4 #big47 ,this is all we know about the supernumerary larval stages4 ,footnote #abj3 ,some facts towards a life history of ,rhipiphorus paradoxus4 ,annals and ,magazine of ,natural ,history for ,october1 #ahgj4 ---------------------------------------- -------------------------------- ,,transcriber',s ,,notes ,p4 #caf1 changed 8abdominal cells0 to 8absorbent cells04 ,silently corrected typographical errors and variations in spelling4 ,archaic1 non-standard1 and uncertain spellings retained as printed4 ,enclosed italics font in underscores4 ,enclosed bold font in equals4 ,superscripts are denoted by a caret before a single superscript character or a series of superscripted characters enclosed in curly braces1 e4g4 ,mr4 or ,mister4 ,subscripts are denoted by an underscore before a series of subscripted characters enclosed in curly braces1 e4g4 ,h#b,o4