ACKERT ‘The Innervation of © ue he i si ihe Integument of Chiroptera . i. Zoology ts PLD ee ee ost 29180 oe an UNIVIOR | TLELIN OLS AOR ARSE THE UNIVERSITY OF ILLINOIS LIBRARY 913 eee) Digitized by the Internet Archive in 2013 http://archive.org/details/innervationofintOOacke THE INNERVATION OF THE INTEGUMENT OF CHIROPTERA BY JAMES EDWARD ACKERT A. B. University of Illinois, 1909. A. M. University of Illinois, 1911. THESIS Submitted in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY IN ZOOLOGY THE GRADUATE SCHOOL OF THE UNIVERSITY OF ILLINOIS 1913 Sk > J \ TVEMUSSTHL SPIO Mbit AASZTSO MAD SS - i, oo) Nt Bot : ; RUC YS TISIADA CAA Was eR AL a siondil ts winesviel) FA . i eet oni] lo wistevint! iA ALGT elendutT sd. 10) eenmauyedl ais to tnomillated leitreS | 2} io ta2getl YHIOZOAING IO BOTIOI ~ st YOOQUOOS a] JOOHI2 STAUGASD SP 0" be I9\3 Acd UNIVERSITY OF, ILLINOIS THE GRADUATE SCHOOL Mey fs. 10g 3 | | HEREBY RECOMMEND THAT THE THESIS PREPARED UNDER MY SUPERVISION BY SAuard (heheh | ENTITLED eer i of the Le Lepismnt eeeeeErreD AS FULFILLING THIS PART OF THE REQUIREMENTS FOR THE are 4) q DEGREE OF . Racker - Phrlert hay +. Ww. bei i In Charge of Major Work re J ra . Mae ea Department Committee on Final Examination 1 <=. (2 Zo bie 4 u — Sa; t a 7 “TiIZEa vine Ue Ae Th wy = 2 es) Je a —— ar 4 fy > *. _ r .~ * -. * - a { a 7” - ee. 2) —a ee a fe we « UIUC 7 a %, : = = - TABLE OF CONTENTS. Introduction cecsccceccccvercscccccvevrsesesesseceesceseeess Physiological and Anatomical Evidence of the Extreme Sensi- tiveness of the Skin of Bats wccveccsevvcccsescesseees Material and Methods ...cccsccesesvccccccesccscccesessesecs Observations and DISCUSSION coeeeevesesccccsavecvsessvecees I.-General Structure of the Integument ..csccsvscscccee 1. Integument of ris hale bidlole s/0 Hew Vie #6 16'S Fee Kae aiaem 2. Flying and Interfemoral Membranes .ccccccccccccee II.-Nerve Layers of the Integument .cccccccsccccceceves 1. Nerve Layers of the Body Integument .wcccccccceee 2. Nerve Layers of the Flying and Interfemoral Mem- branes @eseovee2eoedse ees oeaeeaseeeeeeee2028028080280880873808082093 III.-Nerve Endings in the Integument @e2eee¢0280808808880809282808886 1. Free Nerve Terminations in the EpidermisS ...eccoee Be Nerve Endings on Hairs .cccccsveseoscccecscvvvsecsecees 5. Special Sensory End-OrgansS ..cccocccvcccsccccccoce Be ENG—BulLDS sccccceccseccccccccccvccscscccccccceese © Bb. Parmingal Corpuscles .ceccececeveeveecesvcesccne 4. Motor Nerve Endings on Striated Muscles ..cccccee 5. Nerve Endings on Modified Sweat Glands ...ceccoee IV.-What Sensory Organs are Concerned when Blinded Bats Avoid Obstacles While on the Wing ? .ccccccccececee 49 Summary @eereeeeeeeeeeseesee eset esoaesseeseeseeeooseseeoevses Sseoeeene028 48 - - - « Cae S 4 = 2 * 8 4 . + 7* 7 aA coe ase at Co. a - . - Oe =e eaete we ea fe ¢ Ce ne 7 - TT ss «A « - 46 = - a ¢ a yy £4 3 + [Ww oe? oe eae ’ t«a~< Seukdiy tiyich e's Ee ee ¢ bm qo +. 4 , ys j n@ee + + & 414° 8 @€:4 2 e * 2 4 Cr at. 3 & @ «& i ety oh ’ , A > ¥ "Z ° ? - ‘ iw t : Th cae ee oes a] : aoe’ FY 6 et ‘ fed ay oe we a tM Chie a el rn we ing PP % < = Ae Fj " 7 oo © , «© ; = . 7) : ea AMOS be i. lk e “ay! ' vie Co : tm 4 © ¥26 46 2 ae ee is evi fa =i re ; ie soo ree BOR GRRETIOY sari ' mn a utbod ‘ Ke au, * adil 2) Beak a iil oe ; i ‘ 4 “Ee , ! TAL. 4 ae j aay) Ate Y a, i iw ir Bibliography e@eeseeeeeveeoeveeeeeeeeaeeeneeeeeeeeeeeneeeneaeeee ee eee Explanation of Figures .wccccccccescccccsvesscsessssesesees 5G INTRODUCTION. The ease and precision with which blinded bats avoid obsta- cles while on the wing attracted the attention of eighteenth century investigators, who, at that early date, thought the wing membranes were sensitive to external stimuli. Cuvier, in 1796, set forth the theory that the patagium and ears were capable of perceiving air currents set up between the object and the ap- proaching animal. Later, Sch8bl (1871) described special sensory Organs, "“Terminalkérperchen", at the base of each hair. As both end-organ and hair were thought to be richly innervated, they were supposed to form the mechanism for the perception of obsta- cles. Recently, attempts have been made to explain this phenom- enon by other means. Rollinat and Trouessart (1900) attributed this power to a sixth sense, that of direction; while Hahn (1908) was convinced that objects were perceived chiefly through sense organs located in the internal ear. Responses of captive bats to tactile stimuli applied to various parts of their bodies and membranes are very vigorous. The lack of agreement among observers on the nature and location of the perceptive organs of bats, the extreme sensitiveness of the integument, and the possibilities of modern technique seem- ed to justify a further search for sensory structures in the skin of these animals. Furthermore, at the time this work was begun, no investigator had made an extensive study of the inner- @e@e eee © + $F to OOOH 9 6 2 ERS Re 4s Re Tere ree y ant oy 4. «4-30 a, 2 eee . . a ee a y y* => £ > _ ‘ vation of the skin of bats since Sch8b1l published in 1871 his account of the terminal corpuscles in the flying membrane. The work has been carried on during the last three years in the Zoological Laboratory of the University of Illinois un- der the direction of Professor Frederic W. Carpenter, to whom I am indebted not only for his personal interest in the progress of the work, but also for his constant advice and helpful criti- cisms. PHYSIOLOGICAL AND ANATOMICAL EVIDENCE OF THE EXTREME SEN- SITIVENESS OF THE SKIN OF BATS. The first investigation of the sensitiveness of the skin of bats, so far as the writer has been able to ascertain, was the well known experiment of Spallanzani in 1793, This investigator blinded bats, and observed that they avoided with accuracy not only large obstacles placed in their way, but even silken threads stretched in such a manner as to leave only sufficient space for the bats to pass between with their wings expanded. In 1796 Cuvier called attention to the exquisite sense of touch in the membranous skin covering the wings and ears. Upon examination he found the wings to be supplied with an enormous number of nerves. He inferred that during flight the blinded bat, on approaching the object, sets up air currents, which, reacting on the sensitive patagium and ears, enable the animal to perceive and to avoid the obstacle. Jurin, in 1798, performed experiments similar to those of Spallanzani. The blinded bats avoided the obstacles success-— a ~ WS ~ \ \ 4 oY ‘ e a : ' 4 / c < XY} Rah Ah” A a ” * ‘ ey ae sed “ine if ater iia ty dived cdc’ pete f acdtenbh vie ae ade senate Beat” i eis resi tents hay trent a hs he ai iden? Abell ‘any 2 a BR 4 ie: ehh Se cowie eit \ wi elias c= cy Be i? bes i a* j > -— + 3 fully, but were unable to do this when their organs of hearing were destroyed. Leydig (1859), who was of the opinion that the nerves of the flying membrane were not more numerous than those of the ordinary skin, thought that Cuvier had mistaken the elastic bridges (Balken) for nerves. Sch8Bb1 (1871) experimenting on a bat kept for a year in his living room confirmed Spallanzani’s findings. This investi- gator made an extensive anatomical study of the flying membranes of Chiroptera. He found not only an abundance of nerves, but also an intricate network of nerve fibers and, at the bases of the hair follicles, numerous end-organs, "Terminalk8rperchen", which in his opinion were closely allied to the touch organs (TastkBrperchen) of other mammals. In the same year Boll, work- ing with Sech8b1, confirmed the latter's findings. Stieda (1872) seriously questioned Sch8b1's results. He emphatically denied that Sch8bl1's "TerminalkBrperchen" were found as a rule in all bats. Moreover, he treated these struc- tures as hair growths (Haarkeime) and not as nerve organs, During the same year, Veleeky repeated Sch8bl1's work, us- ing the latter's method. This investigator also failed to find the so-called "Terminalk§rperchen". Furthermore, he used an- other method (gold) and still failed to find the structures in question at the bases of the hairs. Jobert (1872) was of the opinion that the touch apparatus of bats was located in the flying membrane, and that these touch organs, viz., the richly innervated hairs, played an im- t tod pees ae nee Peed “ o Te SEEN test ois ia wat te ae on? AAG .2o oe tan ero ; by 70 Sad aves ac ARONA “reie) f A iw) e ee Ee steed ott weds: then sone Tee cr ras: vem Ande eA ee Th : tdasy ath ac ote ah Au oh Oey eves te aiawt ow 04 ola Jie. Kap f in: Sheena caee ds ‘oa (iesols ot oe axe hei oud O20) gt)! Leen seteg Te” | te Sa ap bbe) “ete ied ott. Baws? Tao Oy Ce er ‘ahem date ea 3 bine kre ; Be Se ! | ~ ees » fae ae ee a! Sa CO aate ee: #th ' sgh ode. pera, Soa ado nay A a riod 3 tek ited eet area) ate oty: eet J t [aug en aah Veep iey gee: Aetna BRE we 7 be iat ofl s Vote thee h eS olay sites aint tale , Pranks or TEES eco tt Labametee bag ‘oe he t Gers. ot he Lia TL Sa ata ae Gite | ip Lak wot 26) poem” + ec oi) aha BU re a ots dma jp ea qnialt wd Aff i 4 F 4 hed gem dane ee car fan" portant part in determining the habits of the animals. Accord- ing to this investigator each movement of the hair was trans- mitted to the nerve ring which surrounded it. In this way ner- vous impulses were originated, and objects were perceived and avoided. In 1873, Redtel repeated Spallanzani's experiments. Threads, etc., were stretched across a small room, in which a normal bat was liberated. The animal flew with great speed. While it sel- touched the thread with its wings, it never touched the threads with its head. The bat was then blinded and set free again. Its flight was now somewhat less accurate, but it avoided the threads just as it did before. He then clipped the vibrissae from the face, but the flight of the bat was not affected. From the abundance of nerves found by Sch8bl1 in the flying membrane, and from his own experiments, Redtel inferred that it was possi- ble for bats to perceive the slightest change of air pressure upon the wings. He explained the few failures to avoid the ob- stacles in the following way: Ordinarily, the flying bat begins to prepare itself for turning away from the obstacle when it is approximately at the distance of a meter from it, but when fly- ing rapidly there is not always sufficient time for the avoid- ing movement to take place. Arnstein (1876) investigated the innervation of the flying membrane. He found nerve trunks, closely interwoven nerve net- works, free thread-like fibers extending up from the networks into the epidermis, and perceptive corpuscles. Flower and Lydekker (1891) advanced the view that it is the ies Pte ‘pea | re. , are iP hs De al hike -~ j 3 , . Sataeenr Bosh ars . Tis 4 ® = a > , ~ E 1 Pe | ab ott: a palpce hil ts " ~/* at . iv + he eee «te debe: oir? étoeg Foch any ; , a ‘. “ 0h amet te oa yg . aCe ; a ees! ue no fer re , iy ‘te " ott ig bac Shae = ieesee ‘ ret ring rt delicate sense of touch which enables bats deprived of sight, hearing and smell to avoid obstacles. They were of the opinion that tactile organs exist in connection with the vibrissae of the face, in the ear conchs, and in the wing membranes. In 1907, Schumacher mentioned the presence of a large num- ber of layer-like corpuscles (LamellenkBrperchen) among the phalanges of bats. Hahn (1908) carried out extensive experiments in which he caused a large number of mutilated bats to make a given number of flights in an enclosure through which numerous wires had been stretched. His experiments showed that the destruction of the sense of sight does not seriously impair their ability to perceive objects, nor does the loss of external ears and tragi. As the hairs of the body and flying membrane were supposed to have a sensory function, Hahn coated them with thick vaseline, which caused them to adhere to one another,and, hence, to be less sensitive to slight stimulation. The results of this ex- periment are given thus in Hahn's paper: "Five examples of My- otis lucifugus with the hair so coated struck 34.6 per cent.of | the chances. Five M. sublatus struck 39.6 per cent. of trials with hair covered, and 24.4 per cent. when normal. For five Pi- pistrellus subflavus the proportions were 32.4 per cent. and 25.2 per cent." Thus it is seen that in this experiment the av- erage number of hits of all the bats whose hair was covered, was approximately 10 per cent. greater than that of normal bats. From this and other experiments Hahn concluded that the organs of touch located in the skin and probably associated with the hairs are of value in enabling the animals to avoid objects, - oS aden mnt Un a?) tet aE aie ©) 7 “a * 7 = =) F cia ayia —— t by see ye ys ‘ r a | a) ,o a, 4 \ 7 x ”“ 4 ’ r + Gane P] iv + ¥ U - ' : ’ ‘ ' 4 4 — Ph bik yy Phe. : ies wrk 4] a i, a ed f i ) ~ a, though of less value than the auditory organs. He also states that the tactile sense located in the vibrissae and in the lips is very delicate, and doubtless aids the animal in locating its food. MATERIAL AND METHODS. The material for this investigation consisted of forty-one bats of which thirty-one were cave bats (Myotis lucifugus) from Indiana. The remainder, the common red bats (Myotis sublatus), were taken the vicinity of Urbana, Illinois. As the greater part of the material was prepared by an in- tra vitam methylene blue method, the latter is here given in de- tail. Etherize or chloroform the animal until it is deeply nar- cotized, but not quite dead. To secure free circulation (free circulation) of the staining fluid through the wing and inter- femoral membranes it is best not to fasten the bat to the in- jection board. Open the thoracic and pericardial cavities and make an incision in the left ventricle (being careful not to ‘eut into the right ventricle). After allowing the blood to flow out through the cut, swab out the thorax with a bit of absor- bent cotton, and place a loose ligature around the base of the aorta. For injecting, a syringe with a detachable rubber tube and a small glass canula is very satisfactory. Insert the can- ula through the left ventricle into the base of the aorta, and tie it with the ligature. For an overflow make a small opening in the right auricle. Inject Ringer's solution warmed to body io, a ~. ‘ ; ¥ i oo f 4 ah ee 4 / : ’ ees N : ibe ‘ Ma ‘an ates ~+er: + ane ty “9 i. Cr. a Po oP =, tel a. ee 7 \, é rs ‘4 \ Pre fu beware at if terG Be temperature into the aorta until most of the blood is washed out, i.e., until the clear solution comes out at the right au- ricle. Inject a 1% solution of methylene blue in distilled wa- ter warmed to body temperature into the blood system until the integument looks blue. Clamp the right auricle. With the blood vessels still full of the staining fluid leave the animal free- ly exposed to the air three-fourths of an hour for oxidation. If, at the close of the injection, the integument is not a deep blue, inject more of the methylene blue solution after a period of ten minutes. After allowing ample time for oxidation, wash the methylene blue out of the vessels with Ringer's solu- tion (warmed to body temperature) and remove the apparatus. Small pieces of integument may now be taken off, exposed to the air for a few minutes, and then placed in a cold 8% solution of ammonium molybdate in distilled water. (Must be made fresh). Leave the pieces of skin in the ammonium molybdate (fixing) so- lution at least twelve hours. Wash in running water three hours, For this purpose small porcelain Sieves with minute perforations and cork stoppers are very serviceable. Pass the tissues through the alcohols, 70%, 95%, 100%, leaving them for a period of three hours in each. To prevent the methylene blue from dissolving out, the tissues should be kept cold (5 to 10° C) while they are in the alcohols. Clear in xylol (3to5 hours). A mixture of two parts hard paraffine to one part soft is best suited for imbedding the flying membrane, while for the skin of the body which is more cornified, hard paraffine is preferable. Sec- tions cut 20 micra are thick enough to enable one to follow — _ ee pa ry ak is x a, @ ea : Tote : ; : “aN 3); 7 ag ¢ e 4 . - wi 4 ttitewe” : oe, a rd ae vb) detey of Ate sie “Ge vat . r « Y Lo Pee at ey i: fay s2og PAG: @ ay: ba agent off Pum reine fC i) AL ee ni therey Bait : | rae? Fe : a7 Fh ae A oe “te idy es ie nerve fibers some distance, and sufficiently thin to admit am- ple light. Mount in balsam. The following short method of affixing the sections to the slide may be used to good advantage. Place on a clean glass slide a small drop of fixative prepared by mixing equal parts of oil-of-cloves and collodion,. Rub until a thin coating is formed. Lay upon the slide the paraffine ribbons of thick (20 micra) sections, and flatten them out by pressing down with the tip of the finger. Place slide in xylol until paraffine is dissolved off and mount in balsan. Other killing and fixing fluids used were corrosive subli- mate and acetic acid, Zenker's fluid, ammoniacal alcohol (8 to 10 drops of aqua ammonia to 1000 cc. 95% alcohol) and 10% for- mol. Besides methylene blue the following stains were used: sil- ver nitrate (Cajal method for nerve fibrils), carmalum as a counter stain for methylene blue, Mallory's connective tissue stain, Heidenhain's iron haematoxylin, Delafield's haematoxylin and eosin, and Hanson's haematoxylin and orange G. OBSERVATIONS AND DISCUSSION. : I.-General Structure of the integument. — aon: <—c—nsnEanERiaeiocs=s calles cimaabeags 1. Integument of the Body. The skin of the body of bats is covered with hair which, as Allen (1893) has found, varies in different regions in text- é ure and amount. In general, the crown of the head, the neck, a the sides of the under surface of the body, the rump and the pubis have a thick pelage, while the distal portions of the ears, the soles of the feet, the mammae and external genitalia are al- most naked. The snout is scantily clothed, but shows a limited number of vibrissae which arise from wart-like structures. In different regions of the body the skin varies greatly in thickness. The integument of the face is the deepest. That of other parts of the body diminishes in depth gradually in the following order: palmar region, plantar region, rump, ventral thoracic region, crown, and dorsal thoracic region. As a rule some difficulty is experienced in distinguishing all the layers commonly found in the human integument. In the epidermis the Malpighian or deeper stratum can be readily made out. Its deepest layer is made up of subcolumnar cells. The in- termediate layer of polygonal cells is for the most part absent, though in places (e.g., the face) it appears as a single sheet of isolated, more or less flattened cells, whose nuclei are somewhat reduced in size (Fig.1). Numerous pigment granules are present in this layer (Fig.2,pg). The stratum corneum is thickest in the palmar and plantar regions. It is made up of several layers of cornified epithel- ium, the outer ones of which are usually in the form of loose scales, The deeper layers are more compact, and appear to con- sist of flat, enucleate cells. In certain regions of the body (lining of the mouth, lumbar region) these layers resemble to some extent the stratum lucidum of the human skin, but the pres- ence of this stratum can be made out definitely only in the pal- mar and plantar regions. (Fig.2,s1). Fal a fi ®. 22% ahs’ ~) 1 Ss”) thed 18 Le o8et rremngolse ota the he Lim V cvmpaal ag : ! A Oto em RES ae ais . cahp is qi haan = a a s ray } . « t }? é 54 . ) ' me - r . ( ' roy . - el » - + « . i 5 my . rl . Epleitd 9 timye Mae, caiee wh as Lei ete, anure? _ rir ae 1 es |) AI a il inte ¥iy. eoae ea! : ji . eerie Hace eae sboxel 3 - tt { oe ; , LU ai Fi 2) JBhie we giesta Seite. ba eigen, mee haa The surface of the epidermis is frequently interrupted by hairs, and also by the openings of ordinary sudariparous and of modified sweat glands as Diem (1907), Porta (1910) and others have shown. The ordinary sweat glands and the modified sweat glands may open into the hair follicle, or independently on the surface, The distribution of skin glands over the body is very variable. Though not numerous in the region of the rump, sweat glands are, however, present. This is in accord with Diem's findings, but opposed to those of Hoffman (1898). The writer was unable to find sweat glands in the sole of the foot, and a- grees with Toldt (1907) that these glands do not occur in the ball of the thumb. Toldt found numerous glands in the "Sauge- scheibe", and also large groups of glands in the region of the neck and of the external genitalia. The upper lip is more abun- dantly supplied with skin glands than any other part of the body. As is frequently the case the superficial layer of the corium, the stratum papillare, is raised into ridges and papil- lae which project into the epidermis. These are most marked in the upper lip, where simple and compound papillae are present. The interlacing strands of connective tissue and the reticulum of elastic fibers which together form the ground work of the co- rium are comparatively fine and closely packed, thus causing this layer to be somewhat dense. Preparations stained with Mal- lory's connective tissue stain show that the general direction of these strands and fibers is parallel with that of the stra- tum Malpighii. While it is not possible to determine a boundary between the stratum papillare and the stratum reticulare, yet the deeper connective tissue bundles of the latter are obviously HW af as 4 ie oe ctehiqn edtets 2am 4 "! ‘1 tiro-% oR AEROS eho 2 > ie , oer) eae ame aa - i‘ : f én t i. &s ee ' i ) ; y : ’ 3 4 >t i" o> * ; : +2 -Ufeompe ee ee ,e2et lias Quien bad ' 8820. Bi sane “Sern bast ren he sented Lisidiltn od! cS woot * ais &, — ws 2 ie i iad caret ve penne pe titnaba ote Son Oe Lethe r rm wf? bit wee “oy wat hifvd. oie | . ee | 3 yw 11 more loosely interwoven than those of the superficial layer of the corium. As in other mammals, the corium contains blood ves- sels, hair follicles, sebaceous glands, sudariparous glands, striated and smooth muscle fibers, nerve trunks, medullated and non-medullated nerve fibers, tactile corpuscles, and nerve end- ings. The last three structures mentioned will be described in detail later. The upper lip of the bat is richly supplied with skin glands As one type of these, the modified sweat gland, differs somewhat from the typical sweat gland a description of its structure may not be out of place here. Compared with a hair follicle, this gland is enormous in size. It consists of a long, uncoiled, se- creting portion with an extended funnel-shaped duct. The secre- tory portion is lined by a single layer of columnar cells with finely granular protoplasm and round or oval nuclei (Fig.3,cc). Leydig, Sch8bl and Sabussow (1910) have called attention to the fact that these large modified sweat glands ( in the flying and interfemoral membranes) have a coating of smooth muscle.fibers, ‘which by their longitudinal course cause a slight spiral strip- ing of the gland. This coating of muscle fibers (Fig.3,mf) lies between the layer of columnar cells and an external covering or basement membrane (Fig.3,bm). The latter is homogeneous and without nuclei. The duct of the gland is lined throughout by short, somewhat irregularly cubic cells, arranged in a single layer, and surrounded by a delicate basement membrane. Not in- frequently secretion products are found in the lumina of the glands. The products are more or less similar in appearance to what Wimpfheimer (1907) terms degeneration products ("detritus") ‘ a ger as fo ey hy ww ie, eae en nat bres ry had Ned | i aude é 4 off ‘ L f iq 1 a pyre i ‘ ¥ ‘ft hake on 3 mee E "} ‘ ] By . eR . oe t en Mee tet | bail aionkong % ; t 4 Ae) Ly Bae - gant <8 piney ns found in uncoiled sweat glands in young moles. It is worthy of remark that pigment cells occur in the co- rium both of the body integument and of the flying and inter- femoral membranes (Fig.2,pc). These cells are more or less sim- ilar to those pointed out by Kohn (1910) in the hypophysis of man, and closely resemble the pigmented corium tissue cells of the pia mater of sheep described by Krause (1911). In the cori- um of the integument they are numerous, and appear to be scat- tered about promiscuously. Their form is very variable. They may be spherical, oval, elongate and slightly spiral, heart- shaped, pear-shaped, raggedly lobulated, and with or without processes (Plate III, Fig.5). In size they vary from 34 micra in length and 25.5 micra in width to 374 micra in length and 60 micra in width. The cell body is filled with fine brown granules. In haematoxylin-eosin preparations a few of the granules usually take the dull blue stain of the haematoxylin, while in the meth- ylene blue material some or all of the granules may stain a bright blue. Plate III, Fig.5,b represents a pigment cell con- taining stained and unstained granules. 2. Flying and Interfemoral Membranes. The flying membrane of bats appears as a skin duplicature formed by the lateral extension of the dorsal and ventral integ- ument of the body, The proximal parts of the membranes are cov- ered with fine hairs similar to those of the pelage, while over the distal areas extremely fine, more or less modified hairs oc- cur sparsely. In the natural condition there is a manifold wrink- pe ee - ie Sed ee ei% rea Ts < - igo teat, 24H. a > AS teeter ool Qnurts Sen hee ee heal! beige : Yivrewal Bik. ita’ rt p » } ¢ / 4 » a 5 rT a 7 yas wr een, ay i : at ae Lenggan) (eee : Lh. ag oe Teaneeciger a4! i ; dl? 9 i yf eee iw . fh ehat 3 aes et ; 13 ling and pleating due to numerous elastic bands within the mem- brane (Sch&8b1). Externally the flying membrane is seen to be made up of small hexagonal, plate-like cells which form a continuous mem- brane. Each cell contains pigment granules which are collected into an intramarginal zone much as Sch8bl has described (p.4). This investigator repots that the center and border of the cell (in Vesperuga serotinus) are free from pigment granules, In My- otis lucifugus and M. sublatus the writer found pigment in both of these regions, but in smaller quantities than in the intra- marginal zone. The cells of the outer (dorsal) surface of the flying membrane contain more and darker pigment granules than do those of the inner (ventral) surface (SchSb1). In fact this Surface in places contains almost no pigment at all. As in the integument of the body the epidermis of the fly- ing membrane stands out in the sections in contrast to the cu- tis. The Malpighian layer also can be readily distinguished from the stratum corneum. According to Sch8bl's findings the Malpighian stratum is composed of two layers of scattered cells, The writer, however, finds that one layer of cells occurs quite as frequently as two. The nuclei of the deep Malpighian layers of both dorsal and ventral sides are slightly more oval than those of the more superficial layers, the latter being somewhat flattened. From the shape of the nuclei one would infer that when a Single layer occurs it is the outer one. In the Malpigh- ian stratum of the dorsal side of the patagium numerous pigment granules are present, while in this stratum on the ventral side very little pigment occurs. Aside from being somewhat thinner, — =m i i ui es» r wee o ™ > (eg gt on | ew ca ¥: ; eB. i 7 - 7 ; } ; : * wiz pS r ei “ae pate: $0 henogteen. mibiiea tents Be , owed, sahil trite Gitte ris ae ond @ A , Woe vin are ing’ Xo ahs eaten eal i wy f i 1 abe iM 14 the stratum corneum does not differ from the corresponding struc- ture in the skin of the body. The tissue enclosed between the dorsal and ventral Malpigh- ian strata of the patagium constitutes the corium, which var- ies in thickness in different regions. In both the flying and interfemoral membranes it is thickest near the body, while in the more distal areas it gradually becomes thinner. The corium is made up of three poorly defined strata of connective tissue--a central,somewhat loose one, corresponding to the stratum reticulare of the body integument, and two others- one on either side--of denser tissue, more or less similar to the stratum papillare. The chief arteries, which are accompan- ied by the larger veins and nerve trunks, cause this stratum to be much thicker in those regions where they occur than else- where. Although the outer surfaces of this stratum is throw in- to folds to some extent, the writer has been unable to find pa- pillae. In the stratum reticulare are contained the larger blood vessels and nerves, and the striated muscle bundles and elas- tic bands (Balken) first described by Leydig, whose findings were later confirmed by Sch8bl. Here also are found the secret- ing portions of sweat glands, and the proximal third of hair follicles. The outer stratum of the corium contains the central portions of the hair follicles, their sebaceous glands, and the sweat glands. Each follicle, with the sebaceous, sudariparous and modified sweat glands associated with it, is surrounded by a capillary network. A shan, iy eae ‘ ee es te = Fe ite ‘ ss 7 7 i i y } vu c , a ag ee "4 ] Pa a oe ie fhe a, = pi SL : oa DEL Ls a os uf whon ? i/ 7W eS j VN WY RG Se a ay, 4 peu.) we nek: & > ie Pity Pa ‘ ty ei 1 nl : ‘ i ‘ , rit) ae | Rs. ee hae * % hen nara ne 6 4 S i a ee | ro vee - " A Vf aay atainorida Mbapsp, TAR aa) € au 4 4 a 7 - tp pee ee L vey II.-Nerve Layers of the Integument. 1. Nerve Layers of the Body Integument. In the sub-cutaneous tissue and in the reticular stratum of the body integument, are found large medullated nerve trunks and branches which, for convenience, are called the first nerve layer. By dichotomous branching these nerves break up into a loosely intertwined meshwork consisting of an enormous number of medullated nerves. These interweren nerves, which are not actu- ally united in a plexus, constitute the second nerve layer (Fig. 4,snl). Arising from the latter are medullated nerves which pass toward the periphery. Near the outer surface of the corium they begin to divide, The resulting branches pass directly to the Malpighian stratum forming the third nerve layer (Fig.4,tnl). Ordinarily so much pigment is present here that it is impossible to follow the fibrils to their endings. However, in places where the epidermis has accidently been torn, one can readily trace the fibrils well into the Malpighian stratum, noting branching fibrils which pass outward and terminate in or between the cells of the stratum granulosum. As these can be traced more readily in the membranes where little or no pigment is present they will be considered more fully later. Varicosities are numerous both in the second nerve layer and along the fibers which pass to the third layer (Figs.14,15,16,17). The greater number of these en- largements, however, occurs on the smaller fibers. Varicosities in the third nerve layer, i.e., on the surface of the corium or in the Malpighian stratum, have not as yet been observed by the ads Qc oy ear telnet 3 i “hy a J 2 . - ' - oe - —- 3 y . +! 7 a 7 ‘ Ces : ¢ arn, rhe > dj iu ¥ . * ¥ | 4 # + (ai a i. ’ : Poe. fg ote Hees t - f ot se - ' ‘ . e2 a ‘ tl be tay 6 0 VP hs is * a... ew ee fh. e 74g ep: ate selay a2 ¢ ie , 2 > 4 . ( Th a Pe om pina

hip Bite el: Bite Ve) art Gorgas “Caan a wt iid ; i 2 a is " is! Se ae Latomdet sede nia ti ad Find Nasty Bo ; >. S¢ what “ she n agen ne ae aie) yy tentin cml? fea ie Sonate ne SS ue D4 ice 2 Pet Pe Refer * (As Arial ot An seein ada a ie eo" of on Rad “T=. — LY meshwork in this layer, however, arises not by an interlacing of fibers, as is the case in the other two layers, but by di- rect anastomosis of single non=medullated fibers. On certain fibers of this layer Sch8bl noted a number of enlargements or swellings ("Krootenpunkten"), which were triangular, square, or polymorphic in form, having a fine granular appearance, but ex- hibiting no nuclei. He also occasionally saw more or less sim- ilar spindle-shaped enlargements in the course of a single fi- ber, especially the larger ones. The fifth and last nerve layer, also double, lies immediately over the previous one on the sur- face of the cutis, ordinarily remaining attached to the deepest cells of the Malpighian stratum. The fibers of this layer are likewise non-medullated, and have a diameter ranging from 0.9 micra to immeasurable fineness. This layer arises from the pre- vious one by the division of the finest fibers of the latter. At the places of division of the fibers, the swellings which were found so frequently in the last nerve layer seldom occur in this one, and the spindle-shaped variety is lacking entirely. This layer of extremely fine non-medullated nerve fibrils lying immediately at the surface of the corium partly between the low- est cells of the Malpighian stratum, Sch&bl holds as a terminal. He further states that in preparations in which the lowest cells of the Malpighian stratum remain undisturbed on the corium, no free endings of the finest non-medullated nerve fibrils are found, and that fibrils passing further toward the surface be- tween the cells of the stratum granulosum, are never to be found either on the surface of the preparation or in cross section. fe oa ee s to. v . "Z ry A mh exw tel $ : ce eae et? a $ ce ee ai@ nie " t ig? tee \ ; . (“ d o a. , t 7 a2 ie - z , = bal ; — — * 7 _— jee ; J ; 4 € i { > q F ¢ - ij cs. a7 bles e P 7 ii, { L * % “ae ' ive TA =4im a ' ) eu 4 ‘ er. i ‘ewe j Br £ ! nt mt . ts is foxy whe ite ea ry RD * ; EL ahirigtetie a sent a an 4 . sd % ‘+ = -s a — +, 4 open hp tay i a ae 18 However, he pointed out that, occasionally, round or elliptic- al swollen structures resembling fine nerve endings are to be seen, but these almost always prove to be nodal points of divis- ion of nerve fibrils. These minute swellings occurred so seldom that Sch8b1l attributed their presence to faulty technique. Sabussow (1910), working on the innervation of the flying membrane, did not wholly accept Sch8bl's idea of the distribu- tion of the nerves of this part of the body. This investigator found large nerve trunks in the innermost stratum of the pata- gium, but held that Sch8bl1's second nerve layer lay in the same plane as the first, and consequently could not be said to exist as a separate nerve layer. Concerning Sch8bl1l's third layer Sa- bussow simply stated that it is not double. But the existence of the fourth nerve layer of Sch8bl1 this investigator confirms, adding that no matter how the membrane is torn, this layer can be seen to be double. He also confirms Sch8b1's fifth layer, which is non-medullated and double; but instead of the few"swell- ings" which Sch8bl observed, Sabussow found numerous varicosities. The latter sums up the layers he found as follows: (1) a simple layer including the first two layers of Sch8bl; (2) a broadly meshed double network with triangular enlargements in it; (3) a network of varicose fibers also double. Consequently, according to Sabussow, there are five nerve layers in the pategiun. In a acpexae sections of my own preparations of the fly- ing and interfemoral membranes there can readily be seen here and there regions which are approximately twice as thick as that of the remaining area of these membranes. It is in these thick- ened regions that the chief arteries, veins, nerve trunks and i? pt de ea sepa A Pa ab . t = - 1 = * A * . \ 4 b 4 4 1 = i a . / y > Bs i : Pee ¥ Y Lon, ; é wn iy a 42 4 . x ‘ Mi hab ee ae s ‘ 7 ‘ i my 4 eed A Pi > § m3) . . | mia" 4 4 oat ¥ “ar 7) ie ; i ‘ i ay e *y lh COREE iM “ea 12") bia ies 19 frequently the principal muscle bundles are found. These partic- ular regions contain, as will be shown, one more layer of nerves than do the others. The main blood vessels, accompanied by the chief nerve trunks, pass out from the body through the flying and interfem- oral membranes in the stratum reticulare, giving off, here and there, important branches, which, as stated, are frequently found with the muscle bundles. These blood vessels, partly be- cause of their own size, and partly on account of the increased amount of connective tissue around them, cause the elongated thickenings or ridges in these membranes already etaees to. The medullated nerve trunks and their chief branches, both found in the innermost stratum (reticulare) and existing only in the aforesaid ridges, constitute the first nerve layer. The second, a double layer of nerves, arises from the first by repeated di- chotomous branching, traverses the deeper part of the coriun, and spreads throughout the entire area of the flying and inter- femoral membranes. In methylene blue preparations this layer is seen to consist of a loose harman ot medullated nerve fibers, many of which contain comparatively large varicosities (Plate III,Fig.13,va). The third and last nerve layer is likewise dou- ble. Numerous medullated fibers arising from the second nerve layer pass toward the two external (dorsal and ventral) sur- faces of the membranes. Many of these fibers on approaching the Malpighian stratum divide dichotomously; others do so at the surface of the corium. Both lose their medullation. The forked branching continues to some extent in the Malpighian stratum, a Tenney é F peer Ti % peyitene eh ee ee | iq iat "on aM w Ta ar aaah ad > Ts c J ¢ ’ — 4 ' \ l ‘ > é w : at fyi f mil Aci no y . >» b+ j ea 1 ‘fr A * * - 5 “ ae | tae) i = o ’ 7 . 14 ' : - me i Ly y wr i r/ ; ‘ evi Bie. % * nptoe ata : in hi 4 é ohn it, San Oy 20 the larger fibrils giving smaller ones until finally delicate nerve threads are seen to end in minute enlargements, which will be described in detail later. These branchings of non-medullated nerve fibrils at the surface of the corium and in the stratum Malpighii constitute the third nerve layer. While varicosities of different sizes (Figs.13,14,15) appear in the nerve fibers leading up to this layer, the writer has not observed them in the latter. | According to the present observations, then, certain re- gions of the flying and interfemoral membranes are supplied with three layers of nerves, others with but two. Briefly stated their number and distribution are as follows: 1. A layer of medullated nerve trunks and numerous medul- lated branches, occurring in the stratum reticulare, but only in the elongated ridges containing the largest blood vessels and much connective tissue. 2. A double medullated nerve layer in the deeper part of the corium extending throughout the membranes. 3. A layer, likewise double, present in the entire Malpigh- ian stratum, and consisting of numerous branches of non-medul- lated nerve fibrils. A comparison of the foregoing findings shows that the first nerve layers of Sch8b1 and of the writer coincide; that Sabus- sow's first layer included Sch8bl1's first and second layers and the writer's first, together with the innermost branches of his second nerve layer. A study of sections from the differ- ent parts of the membranes has convinced the writer that SchU8bl's ;% J is “4 o > 4 wey reed etn Lag eae = oe ie Le ate re ey a i a ee at he } ES eS aa Oy Pee earygey ne uae gn'e sa Aye) eae MU eee me Paes sd a PU eT A a eres. “Oy r ar SMA nO DPeReiN i a ee e - Linh i ito Ceo: eee & ome leP eat rare a {te gud rey vis heer ev he taeda pe: ary. ee fs iu " ph Et Ca Oe) See Ore wh Lee Tae) ig. aia i. e . 1 “i tied af tae owe age a a Tien kt. ee tonbyoauinge a a ae meen x a 3 — \ . * . = ( ’ « s ‘ = ’ ri var) . 6 ea T * wake wt ; .2. TOS ethene eimbalrg ote af a yo ) = 4 le OY Ae Ney ot J b a ea) o4 i ¢ i. TAR rey ‘oak et! \ ta base aly sailed ee a Neon» . - 23 misinterpreted by Sch8bl, who, on observing in the stratum Mal- pighii a very limited number of minute round swellings resem- bling fine nerve endings, concluded that they were foreign par- ticles due to faulty technique. The end=-knobs take a deep blue stain similar to that of or- dinary axis cylinders, and appear to be homogeneous in structure. As to shape they are oval or spherical. Their size varies from 0.5 micra in length and 0.4 micra in width to 0.9 micra in length and 0.8 micra in width. In the sections studied, these end-knobs appear to be numerous. Ordinarily, one to a cell is observed, though occasionally even two are seen close to a single cell boundary. It also happens sometimes that a tiny fibril appears to end without any enlargement (Fig.7,x). This, however, may be due to the failure of the methylene blue to differentiate the end-knob, as those who have worked with this stain will readily understand. That these diminutive enlargements or end=kmobs are real nerve terminations and not the nodal swellings sometimes seen where fibers divide has been satisfactorily proven. For example, in focusing on the surface of the transparent stratum corneum no knobs nor fibrils can be seen. A deeper focus brings into view end-knobs with a fine nerve fibril running into each. A still deeper focus shows tissue below the end-knobs and enables one to follow the nerve fibrils from the now indistinct terminal swellings back to the branch from which the nerve fibrils are given off. Where little or no pigment is present, these nerve terminations can be seen without difficulty. » “el 7 Es i : ad ry cy anes io 7 : * ’, = a wae foal . vaM ied ai? a io. , ase Seeds = Pai i Peder tym rat ey & | Oa) oR 0 Clie VVN A SA? hemp iat: Yas 7 : i % oe pt ohne at \ - : : T2.d aeBers 3 . 5 Ee vie Gye t od ? ’ ° F j ve - ’ enh? (aoe ee a , i 44 . . L Lot) a ta of) Te ceee ame, aae ci en bea F is T Sov) NT ptay att ans 40 } Ty Ts QE Eady i a“ pe Tv aN or Cah) Gag, ba : << | = fs! at ayeodts ert a a, ; ” rede) kigtybe. ; See Gite) & ror arid j hy 7 ws. iy ‘ 3 ray tg ‘bn ke area Dae) ve () wrrets ee soo hbbae re a us yi i ; at oe ‘D4 Cd ¢4 ‘ ee ont iy eae re ‘7 i on ae : pe ees Fs eet 24 For a time the writer was unable to determine whether the nerve end-knobs are situated in the stratum Malpighii or in the deepest layers of the stratum corneum. At length, however, a section was found in which a part of the ventral surface of the interfemoral membrane curled up permitting an oblique view. The methylene blue stain was deep enough to show the margins of a number of consecutive superficial cells of the stratum granulo- sum (Fig.6), and little pigment was present. By focusing upon this obliquely turned portion of the surface of the membrane, it is comparatively easy to distinguish the flat, elongate, scale- like cells constituting the stratum corneum from the more oval, clearly defined, superficial cells of the Malpighian stratum. By focusing upon the curved surface it is possible to see a number of nerve end-knobs on or near the surface of the stratum granu- losum, but as yet no end-knobs have been seen by the writer in the stratum corneun. The question of the exact position of the end-knobs in re- spect to the epithelial cells naturally arises. It is certain that a large number of the structures in question are situated on the surfaces of the cells (Fig.7,es). Others appear to be within the cytoplasm. However, it is frequently possible by fo- cusing to see that these end-knobs are after all on the borders of the cells. If all were completely stained, it is not ioceke ble that the remaining end-knobs could be shown to be intercel- lular. So far as the writer has been able to ascertain the only reference to free nerve terminations in the epidermis of bats « ¢€ )s © ¢ x : < ; 7 oh, “Aty ae at a. ;e ia ia rae hee ys 4 is he she aaa — ts , lena hehe i a Rig 7 A ~ j * ‘4 f hy be — pry eg : , OF yy ease 2) 3 ‘ - P- 59) a is that of Botezat (1908). The study of this investigator was made principally on the nerves in the epidermis of the dog's nose, but he mentioned the finding of intracellular end-knobs ("EndkmBpfen") in the skin of the nose of the bat. He held that the free nerve terminations in the epidermis not only of bats, but of all classes of vertebrates, are intracellular, though none of his figures indicate it, Retzius (1892) in his monument- al work on the nervous system showed free nerve terminations in the epidermis of the lip of the human foetus and made the follow- ing statement: "The fine, varicose nerve fibrils branch and end intercellularly without any direct connection with the cell." He found the same to be true of the free nerve endimgs in the skin of the mouse and of the rabbit. Van Gehuchten, in 1893, describ- ed free nerve terminations in the epidermis of the face, lip, ear, paw and tail of the white mouse and white rat. He likewise. the free nerve endings to be intercellular. He stated, "Partout nous avons trouvé 1' existence de fibres nerveuses intra-epider- migues se ramifiant et se terminant librement entre les cellules epitheliales." While Dogiel (1903) did not hold intracellular endings as out of the question, yet he was strongly of the opin- ion that the free nerve terminations are intercellular. 2. Nerve Endings on Hairs. While the innervation of hairs has for some time been a field of fruitful investigation, there still remain some unsol- ved problems in connection with the hair of Chiroptera. In re- cent years especially, more attention has been directed toward a a ss Te ie i "4 lee 08d in re a ptt de ay ais a oe fa } : eit ee tae aioe oT a ‘oe araed Te natal — ‘ a ’ aa “we oun © “Orr eee ad coon he igiae i eadke foe hae 50% EG Leh Ce ce ite ie ee Rediounpae: J er eee ie ats Cran eMA ditt. ot heath, of even ea itiopdel acl oe wi ag dat > bee +e Oo Soarpeigene a0 Ss) TCR Doni) ae d } i: i - Low. Sue Sauber, we Pde 8 ah Fee ee ; et = te bal Bee ede ed iv ei he bh ages ob gegatiiee es entire Parag?) tC Paes tees 26 oF Ft sau t alhs vag ee a sae gs Peat ae esa 7 ceaeieet Gog) de onan (eres ba aailg NE ae Large ey ne sro ry i ‘ bad, Seta Fama | eat let Be ie, Ste ee 26 the innervation of tactile or sinus hairs than toward that of the hairs of the pelage. The writer's descriptions will be confined wholly to the latter. Observations made by different investigators on the inner- vation of the hairs of bats have been so conflicting that it seems advisable to give a brief review of the literature. Schtbl (1871) studied the innervation of the hair of the flying mem- brane, and set forth the following principal points: In the hairs of the bat, the nerves terminate in special corpuscles ("Termin- alkBrperchen") situated at the bases of the hair follicles. The hair receives a bundle of nerves which consists of from 2 to 5 medullated fibers. These twist many times in a spiral about the hair shaft forming a nerve wreath or ring. From this spiral ring two to four nerve fibers are given off, and these extend down- ward ending in the terminal corpuscle beneath the hair follicle. A superficial nerve ring which consists of from one to two coils is formed by fibers from the fourth nerve layer. Boll (1871) working on similar material confirmed Sch8b1'’s observations. The following year Stieda took exception to Sch&8bl's find- ings, especially in regard to his "Terminalk&8rperchen", This ob- server concluded that the structure in question was not a ner- vous apparatus but rather a differentiated part of the hair fol- licle ("Haarkeime"). The nerve ring was not mentioned by Stieda. Beil (1871) also denied the existence of Sch8b1l's end-cor- puscles, although he was able to see the nerve ring. Concerning the structure of the latter, its course, or the endings of its fibers, he could determine nothing definitely. Above the seba- “3 + , ’ . : he od ote t ty ore Pee | a a 6 . , ‘ + die Bu. . | ad i c OB _ Li 4 i mam Fi HLT 3G TRON Malis hheee wh ead Sat ieaers ars yliniee ae At. eae t rere ta Bese eae See Opges ay ) a2 a v. < i 7 4 g. Sotal pete ha tae are ie C a : , Ms i \y . bat a4 , wees Sat . ee eo ie ’ , 7 : y 5m sf ; Sc Oi Baty ae ae, } : ' 7 pa rel 28 gS eae ies “ees ‘ = Le ceous glands, however, Beil noted the entrance of two or three bundles of non-medullated nerves into the hair follicle. Using the method described by Sch8b1 himself, Veleeky (1872), investigating the flying membrane, likewise did not find the so-called end-apparatus; nor did the use of gold dis- close these "TerminalkBrperchen". By the latter method, however, he demonstrated non=medullated nerves which approach, from be- low, the cells of the epithelium of the outer root sheath of the hair, and spread into the intercellular spaces, forming a net. In the same year appeared a more important piece of work by Jobert in which he described in considerable detail the in- nervation of the hair in the bat's wing. The principal points brought out were as follows: (1) All the hairs of the skin are supplied with nerves and are perceptive. (2) The affirmation of Sch8b1 that into each hair follicle there enters one nerve is not true. Each hair is supplied with many nerve fibers, five to six or more, which approach the follicle, together or separate~ ly, and from different sides. They may unite into two or three small trunks. On reaching the neck of the hair the nerves di- vide, lose their medullation, and are distributed on the hyaline membrane more or less like radiations, ending freely at about the same level. (3) The nerve ring of Sch8bl does not exist, neither does the "TerminalkBrperchen". (4) At the level of the superficial subepithelial network of nerves, minute threads are Seen which surround the follicle and disappear in the epithel- ial sheath. e 4 7 , Tipe = let Sek rae eae ~ eae el ga - 2i~ephas mitt bo Seg ee tow af ot ots Cire “a So a {a bod Ldvage Segitut . Caggieadt het et re ' 3 ri a. My tes pare hee bi | bean ‘tet aod wt Fee Ae Geen Te rip eS ee y ad credit tee ot) ra an : it y tal! ‘ i bya ae rege hel 5. ; ir . oes , 4 x ‘ " # * 1 PF Ods Myr “yao ster vius ¥ ii @ : ‘ Ve ‘ i » ae i9" Fabs Cs et : ; & sale CW Mee yt eat Wit to 2 el * i zk pe or a ; ‘eel ot ike ete yer sh bes al on oon art. a Orv it ‘ . fs. fet Pogoo SE eee eee rit if Ont Geog Gye; AO Oe ct tas hen fee, vr. ae 4 Cc aee a r er, 4 3 resis shad. OF wees, ae wean Si yk) (ee hee acktpe thes jieda A i wt Lith ape Pa Beet whee aye: we Sos Se aris wat hei . = x . 7 ¥ uP + Pe) wear i lnm ae . % \ as yf ans 712 boats ‘ie iran tee rt ard jena Var team - 28 Arnstein (1876) recognized two different kinds of nerve terminations on hairs: (1) The free endings on the hyaline mem- brane in the form of a "palisade". (2) The nerve network which occurs in the outer root sheath. Bonnet (1878), who investigated the innervation of the hair follicles of a number of mammals including the bat, con- firmed Arnstein's observations on the endings of nerves on the hyaline membrane. Bonnet's idea was that a nerve ring exists in connection with each hair. The small fibers which constitute this structure lie outside of the straight fibers, which ter- minate in a “palisade”, and surround them much as hoops sur- round a barrel, in the form of a ring consisting of six or more pale fibers. Of the root sheaths in the region of the sebaceous glands Bonnet says, "This is a rendezvous of the various small medullated nerve fibers which come to the hair partly above and partly below the sebaceous glands. These fibers going to the follicle spread out forming a woven net of minute medullat- ed fibers". | In describing the innervation of the hair of certain mam- mails including bats, Szymonowiez (1901) pointed out that the medullated fibers approach the follicle below the sebaceous : : glands, divide, losing their medullation, and penetrate to the hyaline membrane, where some of the fibrils encircle the hair, while others end on the hyaline membrane. The latter fibrils branch regularly, and run parallel to the long axis of the hair. This investigator observed perceptive menisci in a strongly de- veloped outer root sheath of a common hair in the face of Ves- » ‘ ae ve ak x if le vhs Laat has OF hes tll cee an perugo serotinus. According to the observations of Sabussow (1910) the hair of the flying membrane of bats is supplied with several medul- lated nerve fibers whose number is never less than two, These fibers approach the hair follicle, divide, spread around the hair spirally, more or less in the form of a ring, give off small fibrils from the latter, branch, and finally end in the form of a"palisade" on the hyaline membrane. The fibrils of the "“palisade” may contain varicosities along their courses, or their distal ends may be lance-shaped. The spiral ring around the “palisade" consists of small varicose threads. This Sabus- sow holds as a second kind of nerve ending on the hair. He as- serts that he never saw these two kinds of endings, viz., the "palisade" and the varicose threads of the spiral ring, at the same time in the same hair. From this he concludes that there exist two kinds of hairs, each of which is supplied with one of these nerve terminations. Parallel with the spiral ring just described and more su-~ perficial, Sabussow observed a broadly meshed network of fibers resembling a merve ring, and apparently surrounding the hair above the sebaceous glands, This network or ring, which belongs to the second nerve layer, could by deeper focusing be seen to give off more or less flattened fibers resembling the "palisade”, Being unable’ to find any definite connection between the "pali- sade” apparatus first described and this one which comes from the subepithelial network, Sabussow inferred that the two were independent. a Vi » 1 C € ‘ { -~ 2 2 f * a as cy Mi: ans a c +. 5 ’ Li 7 7 wary t i eI , ’ yy ety oe 8 trpe® Hiei pn op In the writer's deeply stained methylene blue preparations of the bat's skin, both of the body and of the membranes, the hair follicles with their numerous nerves stand out in bold con- trast to the surrounding, weakly stained connective tissue (Figs. 8,9). The nerves which supply the hairs arise from the second nerve layer, pass outward to approximately the level of the in- ner third of the hair follicle, where, at first, they appear to pass along from one hair to another. But upon close examination it is seen that nerves may be distributed in one of two ways: A. The whole fiber may end directly in a single follicle (Figs. 8,9,ff). B. Upon approaching hairs the nerve may divide, one or two branches going to a follicle, the others passing out to the epidermis (Figs.8,9,fe). By far the largest number of the nerves in question are distributed in the first way. The numerous fi- bers form a veritable network, which might justly be termed a nerve layer, but which for simplicity is not so considered by the present writer. As to nerve endings on the hair, it may be said that they occur at three different levels and in three separate layers of the follicle. 1. A superficial nerve ring situated above the orifice of the sebaceous glands and giving off nerve threads in the connective tissue sheath (Fig.9,sn). 2. Fine varicose or flattened nerve fibrils which lie immediately. the sebaceous glands, and end on the hyaline membrane parallel to the long axis of the hair (Fig.9,eh). 3. Nerve fibrils at the level of the lower third of the follicle, which take a horizontal posi- tion in the outer root sheath (Fig.9,eo). A further consider- tH 6 ae gh bb Be athe POR ye % ata oe * } 4 ca 4) er Pb. ¢ Ae OR Be ee ae a 421 b i. Bie as whys ngs at tA onan Frydtes: dent che ae a (2 bod Siow bu er ea + af anra yal ites Lhe, i alsa ae ET uties ode eins: cotta mY ir eet nr te Oey % ad, Pach eae es eae Paks the} Lia: ‘tee arte J wes Pacer obs eee - inv iw BAT OO Bae a2 Pe Aes T? Ue Caw PRE oie adr? hai ed crip tas ae , Mt we BTR (SORE ine edie ie 2g, te iG ee eS eB 78 colt Aveta cts Oe eater WB vier a) ag tea th a PR BweRe Dip agaah & a Atang yi ep) ee ad iat ed Kites Ny ced shen, ubauts + th one Ney as fredecnenna eer vip ae neon ert Me 7 ee nes orale anht ae, nie a sia aga OD eet TG Uc hda kiss ik: th ana a Cte meine peer ae weet 6 hag - ation of these types of nerve endings follow. 1. Superficial nerve ring.- Medullated nerve fibers ap- proach the hair above the opening of the sebaceous glands, At the outer border of the connective tissue sheath, they divide, spreading around the follicle and forming a loose ring of from two to six or more fibers. From the ring are given off non-med- ullated fibrils some of which are interwoven in a delicate net- work, while others appear to end freely in the connective tis- sue sheath of the follicle. This ring doubtless corresponds to the “broadly meshed network resembling a ring” described by Sa- bussow (1910) above the sebaceous glands. As is seen in Figure 9,f, the non-medullated fibrils show no tendency to pass down- ward to. a nerve ring below. 2s low the sebaceous glands medullated nerve fibers, chiefly of type A. enter the region of the hair follicle, penetrate the connective tissue layers, divide, losing their myelin, and en- circle the hair in a nerve ring. The number of. constituting the nerve ring varies from two to eight or even more. From the inside of the ring fibrils are given off which divide dichoto- mously. The branched fibrils assume a position parallel to the long axis of the hair, and usually end in slight enlargements © (Pig.9,eh), some of which are merely small varicosities, while Mitac) others resemble the minute end—knobs seen in the free nerve terminations in the epidermis. In certain cases there are no enlargements, but in these instances the terminal fibers are flattened. This type of nerve ending undoubtedly corres- c ¢ ae . 3 ) cs . , Te | ¢ S.. ic “co. mn 4 > | a NS. a - = ; he bye pec ets nef ‘yy ¥ Hts o rs ponds to the well known nerve ring and "palisade" described first by Arnstein (1876), and recognized since by Bonnet (1878), ‘Szymonowicz (1901), and Sabussow (1910). Merkel (1880) describ- ed a similar end-apparatus on a common hair in the lip of a cat. The "termaisons en fourchette" of the Hoggans (1883) and the nerve rings of Retzius (1894), van Gehuchten (1896) and Ostroumow (1900) are probably corresponding nervous structures. 3. Nerve fibrils in the outer root sheath.- At the level of approximately the lower third of the root of the hair, med~ ullated nerves penetrate the connective tissue layers of the follicle. When the hyaline membrane is reached they divide and run for a short distance onor near its surface. These nerve fi- bers give off a few strong non-medullated fibrils which pierce the glassy membrane, and end in the outer root sheath, usually taking a horizontal position in the latter (Fig.9,eo0). The nerve endings of this type are found in a slight swelling of the root sheath, which may. correspond’ to the superior swelling described in typical sinus hairs. So far as the writer has been able to ascertain nerve endings of this type have not pre- viously been described in the pelage hair of the bat. While Such examples are not numerous, yet they seem to him to be gen- uine. Nerve endings in the form of tactile corpuscles were de- scribed by Szymonowiez (1901) in the outer root sheath of a hair in the face of Vesperugo serotinus. The same observer in 1909, mentioned the finding of Merkel's corpuscles in this lay- er of the follicle in man. Retzius (1894) described a nerve fiber in the outer root sheath of a hair of a mouse, and Vin- ea Tae | ah a ‘on sonata bee koi io tLe) es ae sine: rb +e “os edo Ri ul os ee iy hy Re tes nee Y one FR Reec | oth (conta = pt ee “at 9 ‘A i, rea pt 5 Pa a = - — ee aS “Le ‘7 , CIDR ' 7 2 4 a Le Yay Ps i a — wire vata . oh Sipe) i Ne harley aaa * qe cH aa ey a4 i pry beeey yslia’ (ite OAT fp ; maT i ta eg7? tat Se eae wd 0, ie) GY earn bh / Wee SA cn cm ath, cP btel ahah ar ee ANAS OULOR DERE? OUR aa 80 aon yiaf Wie #11093 dui a Sy Sede nae, ‘ 1 em ue wi A ‘ ee sie cin hd a ‘a re waar xe aTp* on? ‘h eber3 she » food lian ain A speies afte de & re yor. capes ee * ot Cepeerpe 5! lig onl Sol er, ee eer? wi | af Kinty bei 2 1, wy cent (1913) found nerve fibrils in this layer of the sinus hair of the rat. 3. Special Sensory End-Organs. The literature dealing with special sensory end-organs in general has recently been reviewed by a number of investigators (Szymonowiez, 1895, Tretjakoff, 1902, Dogiel, 1903, Schafer, 1910). Therefore only a brief survey of the observations upon such end-organs in the skin of bats will be given here. Arnstein (1876) found in the flying membrane of a bat an end=bulb which he thought resembled the well known cylindrical end=-bulb of Krause. It was possible for him to trace an axis cylinder into the organ, but he was unable to make out the end- ing of the fiber. In one instance, however, he saw it break up into fine fibrils. Arnstein was of the opinion that these end- bulbs occurred in the flying membrane where no hairs were pres- ent. Schumacher, in 1907, mentioned the presence of a large num- ber of layer-like corpuscles("Lamellenk&8rperchen") among the phalanges. Sabussow (1910) investigated the flying membrane of two species of bats (Vesperugo noctula and Vespertilio Daubentonii). He stated that in weakly stained preparations he could see ter- minal bulbs which were divisible into two classes according to Size. Some were so small that upon slight magnification it was difficult to see them; others were comparatively large, had a zigzag course, and could be recognized with ease. The latter v ial Po +a he ae pre 1 a YA Peewee? Bs ee. i r - © e ms <7 ‘eee Pi | 2 “te < B/G ee Loe e4 yes tol ee oar ‘ , AF : y ri Fi i £ @'¥ Si : * VO Ba On Toe Nee) eae ey otaowend: PA dad Bar a “OG te ‘an i é é. y = i : & 3 Je ‘1s *| howe . ites 7? oon , ee - af ay Gr ATH atin We , ; .* ee, fey | es he = ue pe h i et: S60 ea ieee caeee wiper & feu ks tee * ass haiied: tly ae ( La ae ie iy : yt eA: ca 7 Tht Ci ee ae seainin pi LOnee te , ie Ab te ; tie aethen “lh tis stag ne 90 BO ‘gs f could also be seen in material prepared by Apathy's after-gild- ing gold chloride method, The general characteristics peculiar to all end-bulbs which Sabussow observed were: (1) a longitudin- al course of the fibers of the enveloping connective tissue mem- branes, apparent in gold preparations, and (2) a delicate wavy appearance of these membranes seen in methylene blue material. The connective tissue nuclei did not stain in methylene blue preparations, but on account of the difference of refraction, Sabussow thought that by focusing he could see them. He noted that the core of the bulb was narrow, but was unable to make out its finer structure. The consideration that led Sabussow to classify these structures under the cylindrical type of end-bulbs was chiefly the way in which the nerve fiber ended in the interior of the bulb. He observed that medullated nerve fibers divided at Ran- vier's nodes, giving off several medullated branches. Ocasion- ally, one of these branches entered an end-bulb, and passed through the whole interior of the organ to its opposite extrem- ity. This naked axis cylinder in the bulb became slightly ex- panded, and ended either with a sharp point or in a thickening resembling a button. In his Figure 10, Sabussow pictured an end=-bulb stained with methylene blue, which he called a variation of the cylin- drical end-bulb type. He described it as follows: "Within the bulb the axis cylinder expands, and, in the middle, broadens into a wide, paw-like plate with deep notches in its edges. From this plate there is given off a fiber which bends backward 7 P , 4 0% ay es 7 a caly py be LEA om ae vale ae i : ' | +”. J fp Mae “0h mM, wg ata 35 and upward, and in turn widens into a similar paw-like plate, The substance of the plate has a granular appearance, with here and there small masses of stain". In my own methylene blue preparations of the integument two kinds of special sensory end-organs have been observed, (1) A small elongate end-bulb into which a single medullated nerve fiber enters, passes approximately to the opposite end, and ter~ minates in a slight enlargement (Fig.18). (2) A large, round, cellular corpuscle innervated by a single fiber which disappears among the cells of the organ (Figs.19,20). A more detailed de- seription of each type follows. a. End-bulbs.- These structures occur in the corium near hair follicles, but clearly outside of the root sheaths. Ordinar- ily they are found below the level of the sebaceous glands par- allel with the long axis of the hair. Their size is approximate- ly 1.5 micra in length by 0.5 micra in width. In general appear- ance they are regularly club-shaped in outline, the interior being filled with a semi-fluid substance. The medullated nerve, on entering the bulb, loses its myelin, the sheath of which be- comes continuous with the sheath of the end=-bulb. After pass- ing through half the length of the organ, the axis cylinder ex- pands slightly into a flat plate (Fig.18,p) which gives off two or three short heavy branches, and terminates near the end of the bulb in a small enlargement (Fig.18,en). The deeply stained blue plate stands out in bold contrast to the weakly colored bulb about it. The distal branch arising from the thickened ax~ is cylinder usually bends to one side, breaks up into an irreg- — — ~4 TY 7 ete eT i ed ‘ ass ” < sa ww he —— i" ! Peo. ie 4 PA us ont i aed ay’ . i Aas) a fe tie , s s ” A Ww , FP x = 7* d é = . ’ ' ¥ s re = 1 ms ~ ba b a. . *. _ - * ¥ —- 7 = 1 7 ’ = a : 3 | od i ; ae : . yr ea & tf, 7 pe. hie wv. Bey e ee | ‘ { i Bd a bi Eke A « ey ; quae wae A ea “ Lae vikw r or ~ too a « = a Be . ist Gare adie Om See ; 7 , ; baPY ra NB Pit > % = et i er es erie sai tdi, tt - A wo 4 “ > 7 oe =~ Aimy ewe “ te | SNS Cheat het ular, elongate, granular mass, and as such extends back through the expanded part of the bulb (Fig.18,br). In the portions of the organ surrounding the plate and the recurrent granular mass no layers nor nuclei are visible. With the exception of the lack of nuclei the appearance of this end-bulb is practically iden- tical with that of the structure which Sabussow (1910) showed in his Figure 10, and which he termed a modified end=bulb of Krause. The absence in my preparations of the nucleated capsule characteristic of the cylindrical end-bulb of Krause can be ex- plained by the fact that such structures do not ordinarily stain in methylene blue. Although these organs are somewhat smaller than the cylnidrical end-bulbs in question, their location and structure are such that the writer is inclined to think that they are modified cylindrical end-bulbs of Krause. b. Terminal corpuscles.- These conparatively large spher- oidal corpuscles are found in the stratum reticulare of the co- rium, usually at some distance beneath the lower level of the hair follicles. In methylene blue preparations they stain deeply, exhibiting a cellular appearance, and frequently showing one or more nuclei (Figs.19,20). Their size, which is fairly constant, is approximately 20 micra in length by 10 micra in width. Each corpuscle is innervated by a medullated fiber which arises from the second nerve layer. The fiber passes into the deeper part of the corium, and after giving off a few branches enters the corpuscle, where it disappears among the cells. Occasionally, the fiber, on approaching the organ in question, forms a slight Spiral coil (Fig.19). Thus far it has been impossible to trace ie . See ae oa | ee ae et a a. meh << eat ete ene i= 1 oR eee ee ‘s aban o «itt Sy, i ae rs eae: ‘+ a aprrad we RPL Re On a a) A NU a b (nb: oe Ate ee gy eon cte ¥ i) F) = ni? ne’ vo ae 5 of FRI a v ; nthe: Fac we 4" ake _W* diy 5 Q : ~ erat ayy! Peel’) Pet CaM no ea we Pe ee Gs Sth el Hy ak bh et twit , vais Shel ae ie 1 eh states an rik ty =~ Ovret wie ¢ ah Th a. (iv iter aeeee deer. oa ar 29 fnp tert : \f f “or ae ae i ote pc Tb ten ae ee . : « 7 road} (eb a4 od he? ee ro oe 7 2 tae: fee ere ae oh finn gh a al Se ttcite + gy oe tae ad Aine”: (te? ee a i ee styles dh aba nk wee fetal ic - > ee” elit er epement ble 8 eh Ce iy BOE ee sowie re Se iene , shar ee ee kk i oa Anh ame wa aheyee erry. Pc by © er icin te aaa ik r te an re 4 "eta ————————— the course of the nerve fiber within the corpuscle. To establish the identity of these organs with any of the known types of cor- puscles is difficult. The layer-like capsules characteristic of Pacinian corpuscles are not apparent, but their absenee may be due to incomplete staining, They more nearly approach the size of the type in question than that of any other type of corpus- cles commonly found in the mammalian skin. Their location is identical with that of Pacinian corpuscles. From the facts set forth it seems possible that these spheroidal, cellular bodies may be Pacinian corpuscles. To these two types of sensory end-organs may be added ter- minal varicosities, which are abundant in the region of hair follicles, outside of the root sheaths. Comparatively strong nerve fibers can be seen to enter these structures, where they break up into fine fibrils, and are surrounded by neuroplasm. It is possible that these organs are varicosities in which the fi- bers beyond the enlargements fail to stain. But they are found constantly in deeply colored preparations, and moreover, are somewhat greater in size than those ordinarily occurring in the course of a fiber. Arnstein (1876) described varicosities in the outer root sheath of sinus hairs in bats, and Sabussow mention- ed the presence of these structures on the courses of nerves oute Side of the root sheaths, but it appears that terminal varicosi- ties external to the hair follicles have not previously been ob- served in Chiroptera. Remarks on Sabussow's second type of end-bulb.- As has been shown the writer confirms one type of Sabussow's end-bulbs, the . e e = r ¢ ¢ LJ ¢ 7 . € " ¢ j ’ x ( ? os ye ‘ oe" oe wm ae * 4 ow ‘ } i; » -* '- hkl, Ve wits ay. rH: hater] poo a ie PLS PU eR cv 24 io owe. | ; ieee a) .~6/ Tee. Te satura ae “en teeeger ne ere ah Op c aie BoT a> OG ee wuld te, oa6 Taira fs CONG AT YR DSe sjato' au then bb: bark) Cah) wid: oe ent tev. a! sf died efodwiat? gine 2 7 pet «2a ares at a sh Seo Gt ry ‘Jowett OR) Ne at) Bie eee ie Teng eee v fee b>: >. eo ttaod tht of arin pe Bere tae Sp |. GO she bat eg) a ier 00 (Ad) Sieben Y Goleta ehh iden 4 ’ tehute te ore okt, oe ni Ballbar oth eee «Sky ieee i ae ily i. ¢ ek 5, ; ot Uy olte 6 Ea ae died deg Utd i ADRNE bike ty ti» pote hegat, Chg ite beagle a ; nt 2 “el A 1 oa Sh. geile aan iste oily ay Saf 39 with carmalum, has failed so far to reveal the presence of this second type of "end-bulb” as described by Sabussow. 4, Motor Nerve Endings on Striated Muscles. Voluntary muscles in the integument of the face, especially in the upper lips of bats, are well developed. In sections stain- ed intra vitam with methylene blue these muscles are ordinarily deeply colored, the cross striations being of a slightly darker hue. Under such conditions it is usually possible to make out on- ly the muscle fibers and their nuclei; but in regions somewhat removed from the larger blood vessels, where the blue stain is weak, one can see medullated nerve trunks among the muscle bun- dles. Along the muscle fibers which are stained only sufficient- ly to see their outline, it is possible to trace medullated nerve fibers (Fig.11,nv) which give off a small number of branche The latter in terminating form motor end-plates (Figs. 11,12, mep) on the muscle fibers. It is not the purpose of the writer to enter into a discus- Sion of the literature on this important subject, but merely to describe his observations and to mention wherein they agree or disagree with the findings of a few recent workers. For a review of the literature on motor nerve endings see Boeke (1909), Dogiel (1906), Huber and DeWitt (1897). As a rule the medullated nerve fibers can be traced to the border of the muscle fiber. At, or near the edge of the latter the medullation stops, and the nerve fibers soon begin to sepa- rate into their component fibrillae, and finally end in a more Wahove” vote wis. or

tess enone sand, etna ¥ ice) honda a “Sts Rie oa a pyenvens een totem, ry | or se fenil iy sg DAN in ith -eeuby py os tenvoy 4) tee oka. rh Tillage a pare Sew one eter ee eae YY PEC ee OW ay! Oe a ae ah i ory re iota a ftet eid oe Soeur w be att eas? yt 3) aMeiyl te bas. My Vinh) @ eo eee eb a: > ein ReeD e nay , y i $ ; eat J ae | bare vo evo Ww wat en ee eee ee ‘ y ar Ce Tek dw eca ns OFM st eat Ste. ov ay et ide ire, $) auth a igo a edpanie, aC ves abt be ec anairg and i. pel Me mrrd yen 4} if af "ery? pmieh ee 40 or less regular end-net or arborization (Figs.11,12,ea). This is in accord with the observations of a number of investigators in- cluding Boeke, who described motor end=-plates on muscles in the tongue of the bat. At the point where the nerve fibers enter the enlarged motor end-plate there is a slight elevation of the surface of the muscle(Fig. 12,e1). The position of end-plates on muscle fibers has been in doubt for some time. In the preparations used in this study they appear to be beneath the sarcolemma (fig.11,sa). This shows especially well in cross sections of muscle fibers in the tongue (Fig.12,sa). Most investigators are now in accord in regarding this structure as under the sarcolemma. In weakly stained preparations the branched endings can be seen to lie in more or less irregularly shaped matrices. The lat- ter are of two kinds: (1) A weakly stained area containing nu- merous deeply colored granules of various sizes. (2) A somewhat smaller area without granules. In shape, the former are irregularly circular or even tri- angular. The granules, which vary greatly in size, stain almost if not quite as deeply as the nerve fibrils themselves (Fig.1l, mag). To structures corresponding to these Kitlhne (1887) gave the name soles ("Sohlen"). The smaller areas or soles, which ap- pear to be free from granules in this stain, are oval or pear- shaped, the axis cylinders always entering the narrowed end. Huber and DeWitt (1897), Dogiel (1890) and Retzius (1892) stated that the sole does not stain in methylene blue preparations, whether examined at once or fixed in ammonium molybdate and ~s : _ ha ee a ee vita voting einen i et ¢ he ahihe ei ales a Geo” | i =3Re tio teen r : ey. a + ah 4 Ae ett ees sil +e3008 ag eles ight 2M! meds & ag tt) ss 10h 3 bea 2 hl. VEG we er (lari? eae. wit aia | leut of e¢ OFS en Live eh! boone 4 tir 7 Pais i hed Py ae j 2 3 mee - - «vitae. nie s mig le OP ate: part ate : ; acme Malunomh teal ~ace rr ma ag a tate ehvane A fe | einie an a wt h2ay G6 algua Ts ieee ¥f stOie, cee habe aviem culisqettt. se “renweR sii? >, oa , ® 8 Prov hk Sus’ nes in. fetwhay eto’ , me. if int =?) eteen- Gav Se Vs st08 “e wt le i" Ta oe ihr Airc eg. BOLE eae ware Vike Bt it Metana) a6: fit vr Ch AES BE ed sett han | Si aa ae xc ee thee ey ahi? Coit | ela? * | Ci Ae - : lh. Sie). ee bison pean Me . uke sian ied ae Bo me ort i ee ie * watt 40 A are . : } 41 studied in sections. The material, from which the present obser- vations were made, was prepared according to the latter method. The irregularly shaped matrix in which the axis cylinder termin- ates is typically granular, but the nuclei, seen by Huber and others in such preparations countered with carmalum or picro- carmine, do not stain with methylene blue. In each of the two matrices or soles described above, the end=-arborizations are nearly similar. The fact that Huber and the other observers men- tioned failed to see soles whose granules stained in methylene blue preparations, may have been due to the inconsistency of the stain. This possibility, together with the fact that nerve terminations in the motor plates are very similar in each kind of sole described, and that the size of the so-called second kind comes within the possible range of that of the first, leads the writer to think that perhaps the apparently different kinds of soles found by him in the striated muscles in the epidermis of the bat are in reality one and the same type. In the one, the granules have stained, in the other they have not. 5. Nerve Endings on Modified Sweat Glands. Se far as the writer has been able to ascertain, the lit- erature contains no reference to the innervation of sweat glands in bats. As was noted elsewhere, the modified sweat glands (Fig. 10) have a coating of smooth muscle fibers which are arranged longitudinally (Fig.10,mu). In a weakly stained methylene blue preparation from the interfemoral membrane of a bat (Myotis lu- cifugus), such sweat glands have been observed with numerous o—p4 I z Y etau et? poaren® Clietest aes Aki iets vi0TR aici> Meh: not? te Siete istadrt ie i i Sent, haat vs cellew” eh ee voy rani | Le Ceutie oth aang iv Ei wae eve T t. oon a a es ‘ob: tears sae seth {uae « tu Pd ese litem eee cae © beeen Pes ead ay | poem Baad: “et sete rs Wis CePA he’. ane a2 | +! iw > Sarr Qe fe et ‘ey ie =e eA. te@ an to: need Serb) fae Bo ee Lo aie, op@rneaer ef ¢iggee a SS BO Bec AMT, rsus ai }GT oe! » eu civ iw heterayeas att pi ately ee Louie yotdw eee gay hee kee Avae. Ame ROME SOR 22 Pee eee Fy i‘. Sy Ses ewe ote mils Pie ak wr ee ls Aynibelnt | foe, die p 4 4 iy das , Ae | ae SN yr 1 dinner beh 4 ae + * int WIS YES pay 4 “7 way a8 enetesn soit: ery ons é tet APT, whi ae ' i rag.) Re ee ae pei sae a | 42 stripes running at right angles to the smooth muscle fibers (Fig. 10,fi). These stripes, which oceur at comparatively regular in- tervals, extend hoop-like around the secretory portion of the gland external to the muscle fibers. The structures in question are much smaller than the muscle fibers, have a wavy course, and take the deep blue stain characteristic of nerve fibrils. A num- ber (2 to 5) of delicate non-medullated nerve fibers (Fig.10,no) ean be traced to the sides of these glands, but whether they con- nect with these circular stripes, the writer is at present un- able to ascertain. That sweat glands are under the control of the sympathetic nervous system is generally recognized. As is well known, pre- ganglionic neurites leave the spinal cord through the ventral roots of the spinal nerves, and, after a shorter or longer course, terminate in some sympathetic ganglion in a very characteristic manner. Here the pre-ganglionic neurites branch repeatedly, di- viding into numerous small varicose nerve fibers, which inter- lace to form intracapsular plexuses around the cell bodies of the sympathetic neurones. It is likewise well known that! the sympa- thetic ganglia of Mammalia such intracapsular pericellular plex- uses may be very simple, consisting of only a few varicose fi- brils, as well as very complex. The general structure of these pericellular plexuses, the absence of definite observations upon endings of sympathetic neurites (post-ganglionic) on sweat glands, and the striking hoop-like arrangement of these fibrillar stripes around the glands, lead the writer to question whether, perhaps, the post-ganglioniec neurites may not form simple plexuses about = - ct Pate | | 2 ati 27 nen yo ves ene iis: eae tote ay ant hela die ae it So dé) van baer odie: bP oi Bt de ote ‘dere ats JZ - cure vednvre Hid rata Bate aah te sei ts phen tek acl? at alee a parts att nae HORT OFM, SAG Sri Toa (8% a es} ines. = Bee | st One | 2: ee ae | | Tee i = ; ( i i i ; H wv i44! ms oe) ¢ ‘a ‘) » ed e 9 i y wy a tyr 4 ) iw: 8 a4 te i iio hi, vat, oe | uA 4 wy 2 6 «bay a” eS Tak yk rene ee. t if) ; nat f ime ae be GIS arc Ry oe - > oS yee ly Cee ORS Gaara Fe ' Lie = ¢4aa7 of ‘ = EE is cent ; & - ares a Se .5 ak See. 8 os Jet wri teterb> ylebin 3 k JHA & ft Bor LTeGgy i. \d 5 ae AIS : > i 7s Saeed {Zi + 5a _ | ecu Ct) iismise coped va: hi te noidaw +AOC TONS at a jae secl wie} tiedy” Saad), Seats eepe eee - end 7 satay 9 iit 106: Be batmood: J re. . . asc. exfy tei pedeutte 08 ste’ aden i aomenee fee tke sd Ei ‘oat. Haye. yl be test. phate our: wre cocoate ne eer Seek i Sedusmow et Ko thee oe ce yaacsg te ouisen bat ine ak i so Paataned alt twas 46 end-organ. This writer states that on account of the position of the ring, the fibrils are stimlated by any pressure exerted up- on the hair. The other nerve endings on hairs of bats are farther from the surface, so that movements of the hair sufficient to stimulate them would probably have to be more pronounced than those produced by condensations of the atmosphere. An examination of the anatomical evidence thus indicates that two types of sensory end-organs in the skin of Chiroptera meet the requirements mentioned for the perception of air pres- sures. These are the free nerve terminations, and the superfic- ial nerve rings of hairs. End=bulbs and terminal corpuscles no doubt are tactile in function, but their depth below the surface of the epidermis precludes any probability that they aid in the perception of condensation pressures of the air. As no sensory nerve endings on muscle fibers have been ob- served in this study they will not be discussed here. As to which of the two sensory endings mentioned above function to the greater extent in the perception of atmospheric pressures, it should be pointed out that the area of the integu- ment supplied by superficial nerve rings is insignificant in comparison with the area supplied with nerve end-knobs. Like- wise, the number of terminal fibers of the rings is not to be compared with the enormous number of end-knobs in the epider- mis. As is well known the human cornea is very sensitive to del- icate tactile stimuli. Conheim (1867) has shown that the only type of perceptor to be found in the cornea is that of free _— ? 7 or al GD — to seta ed? teat gle Peratog. ad aioe: ae es) inawe yrowae ner: tad? ats : Be > Becca - = 4 -: LOTeL ims oe to. etnasievorR att ds yoo e } eek tes) ~ | - _ ~ = 7 i & ¥ Z x ¥ _ & —¥ vie a = ’ + \ Les 6 2 ‘-. ~ = r > > eit} f = ’ wv Sus F oS m= . - » / Sree wi a. ey fom VES 5 sreaet pf Dow Lif wen2 Yoste 5 sai — ~~" io Suntbue’ yRoanen wwe ot te donite a zy noftdesteg edv at tietxe tetaoty eit ody 2 L sgale oytert tks Piper ee set le 7 a ~bog evvenr cic bw bee es a 4iy sob ao y= >: ‘q enihs- ante to exadkh: ae cutest To oy deci st | - ay pe aoe Lg ef Si tniciss - — i 4 . a L oBse - » = : s “Oo —— f Zt affect) ¢ “eH 20 AMS nel en? ae | rit » out anmtidee eal “att fxedo aed sce! seve a 0 weg, a, aa one atant ait te tien d } iy t : ‘ vw a oe >. ] ba e : a aran S — he ‘Coes doit ; @ evetenr ff a r nae. h, i 5 a. &. 2.98 he LO sO SRO -errblbenl more 5 "Sie eae ae? de ‘ ‘ + ry a to be (stetaet tatoels weidtslelam eft vhod eit rs trecirgad a. = HoRuIDe Ley af \er teon te atelaned sarardmom eat aed > y if ced) ef |.eam tod to wate “oem eco a cleats ated Entttataee rath ce et ersinehtel ectirte Bd taiabte ets eettin en A yerts mi encod a 4 9 ‘or eetietinn * fan 49 ed pigment cells are of frequent occurrence throughout the co- rium. ea ee t— 1. In the integument and subcutis of the body three layers of nerves are found. The first (most internal) layer consists of medullated trunks in the subcutaneous tissue. By dichotomous branching these nerves break up into a loosely intertwined mesh- work consisting of an enormous number of medullated nerves, and forming the second nerve layer. Arising from the latter are med- ullated fibers which pass to the stratum Malpighii. Here they divide, forming a simple network, which constitutes the third nerve layer. 2. Certain regions of the flying and interfemoral membranes have three layers of nerves, others but two. These are (1) a lay- er of medullated nerve trunks with numerous medullated branches, occurring in the stratum reticulare, but only in the elongated ridges containing the largest blood vessels and much connective tissue; (2) a double, medullated nerve layer in the deeper part of the corium extending throughout the membranes; (3) a layer, likewise double, present in the entire Malpighian stratum, and consisting of a large number of branching non-medullated nerve fibrils. 3. Numerous varicosities are’ found in the corium on branches from the second nerve layer. oa potiteased. ad tevome wat eke s ctr outs i 4 iqnattead wot tiade, ind gteieQo ,se7ten To. area mes Gita odaite evren S8tat (iued sn, Soe tieanmeret hye *) a> wl ; od ) — ort ry > eg Se ae 6S. ». DATS. Bae \ a * ye asiecatuntos ef7 wt etna - = *, ~ + he he . iG * {ee rt? 9 oe e@ 4G & ,elwe lier: tes arta ait ers ev tocld ¢negiel ent: sidan perer: betel Leben: , ekdogh.k take ef? teoraenndd grtinedes aut a 61 bdné ea. af daton ox . aids a h 3 x cies 50 1. Free nerve terminations occur in the Malpighian layer. Small medullated fibers from the third nerve layer can be traced Bea out among the deeper Malpighian cells to the stratum granulosun, where they terminate in minute end-knobs probably intercellular- ly. 2. Nerve fibers supplying the hair follicles may be dis- tributed in two ways. (a) The whole fiber may end directly in a single follicle. (b) On approaching hairs a fiber may divide, one or two branches going to a follicle and the others passing out to the epidermis. 3. Nerves end on pelage hairs at three levels and in three different sheaths of the follicles. These endings are: 1. A su- glands, and giving off nerve threads in the connective tissue Sheath. 2. Fine varicose or flattened nerve fibrils which lie immediately below the sebaceous glands, and terminate on the hy- aline membrane parallel to the long axis of the hair. 3. Nerve fibrils at the level of the lower third of the follicle, which take a horizontal position in the outer root sheath. 4, Two types of special sensory end-organs are found in the skin. 1. A small elongate end-bulb into which a single medullat- ed nerve fiber enters, passes approximately to the opposite end, and terminates in a slight enlargement. 2. A large, round, cellu- | lar terminal corpuscle innervated by a single fiber whose | I perficial nerve ring situated above the orifice of the sebaceous branches disappear among the cells of the organ. 5. Terminal varicosities are abundant in the region of the v= Ne te * b > a a ~e 4h. uy mors aia | Seu — 3 ‘ ' rx, : bo nd Bi fee aiqial séypeSamy ford=)he wien torah eg \ a . 5 Fie i * a9 a ‘ P agen? - e203 L5¢ ust. log, abg yng beantid. sai t: evaee bees rat snivty t ? ~ TS ca - nye t , .* * > i? r4 - ~ Pe Si et re ,sheals srosot es tie soled: ea sixe rel edt Of fefGetaq sieseae Fad Wsteh daeatan Fak ae ee an i ta te i ote" 1607 ! Nils level en? seaHo" ard” She ?tsag’ Set non tses ae > T0o-fie [eossed fat odie te sounds otsty oats — odag cole ae we & stel A 48 eigeayses: € 6 ce —< 6. In the skin of the face, especially, striated muscles are well developed. Motor end-plates occur on these mscles. In the integument the end-plates appear to be beneath the sarco- lemma, and in the muscles of the tongue these plates are clear- ly below the sarcolemma, | 7. Small fibers resembling sympathetic post-ganglionic neurites extend hoop-like around the large modified sweat glands external to the longitudinally arranged smooth muscle fibers. 8. Blinded bats when on the wing probably perceive obsta- cles through the sense of touch by the effect of condensations of the atmosphere (produced on approaching ‘the object) upon the free nerve terminations in the epidermis and the superficial 51 hairs outside of the sheaths of the follicles. nerve rings of the hair follicles. | I 4! toad eS ae bia 908) gat te arte » cite tach ead ers umnaD an en RROMEE EE CLE LA OLE GLOGS ALL LLL LL OL 52 BIBLIOGRAPHY. Allen, H. 1893. A Monograph of the Bats of North America. U. S. Nat. || Mus, Bull. 43. | | Arnstein, C. | 1876. Die Nerven der behaarten Haut. Sitz. Berich. d.k. Akadem. d. Wissensch. III. Abt. Het. Separat. 1876: 205-252, 3 Pi. Beil. 1871. Ueber die Nervenendigungen in den Haarb¥lgen einiger Tasthaare. Inaufur. Dissert. G8tt. Boeke, J. 1909. Die motorische Endplatte bie den h8heren Vertebraten, ihre Entwickelung, Form und Zusammenhang mit der Musk- elfaser. Anat. Anz. 35:193-226. 40 fig. Boll-Sch8b1. 1871. Die Flughaut der Fledermduse namentlich Endigung ihrer Nerven. Centralblatt f. d. Med. Wissensch. Bonnet, R,. 1878. Studien tiber der innervation der Haarbalge der Haus- thiere. Morph. Jahrb. 4:329-398. 3Pl. Botezat, E. 1908. Die Nerven der Epidermis. Anat. Anz. 33:45-75. 8 fig. Conheim, J. 1867. Archiv f, path. Anat. Berlin. 38. Diem, Fr. 19907. Beitrage zur Rsbaloiinee der Schweissdrtisen an der behaarten Haut der Sdugethiere. Anatom. Hefte. Abth.1. Dobson, G. 1873. On Secondary Sexual Characters in the Chiroptera. Proc. Zool. Soc. London. 1873:241-253. Dogiel, A. | 1890. Methylenblautinction der motorischen Nervenendigung- en in den Muskeln der Amphibien und Reptilen. Archiv f. Mikr. Anat. 35. 1903. Ueber die Nervend-apparate in der Haut des Menschen. Zeitschr. £. wissensch. Z001l. 75:46-111. 11.P1. . . * > . - ° *, “< 4 * > = - s * > . — - . a he ae Tos “y' or } - ry . .< . ttorise > {4 — in 2280 ae. _ 7 het . ray, io . , on ne oo Fae pbernce-Badtti nes a Aba SBAwD . | 53 muskeln und deren Sehnen beim Menschen und den SdAu- gethieren., Archiv f. Mikr. Anat. 68. Flower, W. and Lydekker, R. 1891. An Introduction to the Study of Mammals, Living and Extinct. London. Adam and Charles Black. 1891:1-763, van Gehuchten, A. 1896. Les nerfs des poils. Mem. Cour. Acad. Belg. 34:24-38. Goldscheider, A. 1886, Histologische Untersuchungen tiber die Endigungsweise der Hautsinnesnerven beim Menschen. Archiv f. Physiol. 1886:191-228. 2 Pl. Hahn, W. "1908. Some Habits and Sensory Adaptations of Cave Inhabit- ing Bats. Biol. Bull. 15:4:135-193. Hoffman. 1898, Ueber Talg- und Schweissdrisen, Diss. Tubingen. Huber, G. and DeWitt, L. 1897. A Contribution on the Motor Nerve Endings in the Mus- cle-spindles. Journ. of Compar. Neurol. 7: 169-230. 4 Pl. Jobert. 1872. Etudes d'anatomie comparee sur les organes du toucher. Ann. d. Secienc. Natur. 16. Kohn,A. "1910. Ueber das Pigment in der Neurohypophyse des Menschen. Archiv f. Mikr. Anat. 75:337-374. 1 Pl. Krause, R. 1911. Kursus der Normalen Histologie. Berlin. Urban & Schwarzenberg. 1911:1-441. 98P1. 30 fig. (text) Ktihne, W. 1887. Neue Untersuchungen tber motorische Nervenendigungen. Zeitschr. f. Biologie, N. F. 5. Leydig, Fr. | ' 1859. Ueber die H4usseren Bedeckungen der Sdugethiere. Archiv f. Anat. Physiol. u. wissensch. Med. (Reichert Archiv) 1859:677-747. 2 Pl. | Merkel, F. 1880. Ueber die Endigungen der sensiblen Nerven in der Haut der Wirbelthiere. Rostock. 4, 15 Pl. Ostroumow, P, 1900. Zur der Nervenendigungen in den Haarb¥lgen der Sduge- , ome be tT Be , thei od shh teed ocr al ‘ 7 , ei». np Egle cova : i ra n ty ~- \ * & ¢ ee . =a . : - a + -, Ww ea ~B ck BE : =.) 7 o ~ oak Fe ay r Sf 4 ' ts 4) oe fiz Os ; , / Bs sic, . = : te LAS S82 tae +. 4/44 a \ be A 7 * — Cr os Y - * * r a 5 hy c — ' a ’ ’ j e \ 1 2 ? —_—F . ~ ss a By + = tne «' 4 & v ras - ah s > = ‘ “i . —" ae. ich ; . o4 a te) ial C * > »' caper : a. , 4 : ? awWii »f ae be JT * ’ * or € 5 O£53 (a « ~del a : - ; 4 * . Ca i zt ‘iwwiimiecohet renorci® oki. 4 fc s Ae Fy f ‘ a es2 7 oe a ry eee te . - © as é a a ee eee eee thiere. Kasan. Porta, A. 1910. Sulle Glandule facciale del Vesperugo noctula (Schreb). Zool. Anz. 36:186~-189. 2 fig. Redtel, A. 1873. Der Nasenaufsatz des Rhinolophus hippocrepis. Zeitschr. f. wissensch. Zoologie. Leipzig. 23:254-288. Retzius, G. 1892. Ueber die sensiblen Nervenendigungen in den Epithelien bei den Wirbelthieren. Biolog. Untersuch. N. F. 4. 1892. Zur Kentniss der motorischen Nervenendigungen. Biolog. Untersuch. N. F. 3. 1894. Ein Beitrage zur Kentniss der intraepithelien Endig= ungsweise der Nervenfasen. Biolog. Untersuch. N.F. 6, Rollinat, R. and Trouessart, E. 1900. Sur le sens de la direction chez Chauves-Souris,. Compt. Rend. Soc. Biol. 52:604-607. Sabussow, ll. 1910. Zur Innervetion der Flughaut von Chiropteren. Trans. Soc. Nat. Univ. Kasan. 43:1-67. 2 Pl. Schufer, E. 1910. The Essential of Histology. New York. Lea & Febiger. 1910:1-571. Seh8bl1, J. 1871. Die Flughaut der Flederm’use, namentlich die Endig- ung ihrer Nerven. Archiv f. Mikr. Anat. 7:1-31. 6 Pl. Schumacher, S. | 1907. Ueber das Glomus coccygeus des Menschen und die Glo- meruli caudales der S¥ugethiere. Anat. Anz. Ergdnzungs- heft. 30:172-178. | Stieda, L. ' 1872. Die angeblichen Terminalk&Srperchen an den Haaren ein- iger Sdugethiere, Atehiv f. Mikr. Anat. 8:274-278. Szymonowicz, L. 1901. Lehrbuch der Histologie. Wurzburg. A. Stuber's Verlag. | Toladt, K. 1907. Ueber die Hautgebilde der Chiropteren.K.K. Verh. z. Bot. Ges, Wien. 57:83-91. 1 fig. ’ a a , me. — . rns - a * i a I : . — ge - al . a (hin ST 7 pki Store. Gaee AS RY ‘ sf : ge 7 i- : i . Le S: SAY ite cl LAR SOs r F . ~ p oo -* . oe = 3 io Tee ‘7. Z 2 F q a nd > a5 ‘ am 2 ro frvy fw ey om tr, - } i! oe. ra >» we J i“ ° 2 oaks A Lae e- - . bE) as —v" 4 om, Sue t - id ° . 5 « > - af Tbk r * * - t 2's yh ‘ i - a oy t : ‘. a ? =) = gy ’ be” hota * , = ° ‘ . 4 * 9 , 5 i J a7 ={t r Pd ‘it i - ~ F » 2 _ H, 4 i ‘. + as be cy é a : aw . r hws & 1 Pg. k : « rt = Tt Fi ve 4) ee (a S23 = _ ay — wre te Pee ae. mL OVO AT ; . ¢ rp pet ¥ ¥ . . * ‘ ab te r _ ey 3o0 aieeyoo0d srm6fe Ban's oteblteuvl? ceeS pe leas SRERAZELAEN 8 Veleeky. 1872. Die Endigungen der Nerven in den Haarbdlgen der Sdu- gethiere. St. Petersberg. Soc. Nat. 3. Vincent, S. 1913. The Tactile Hair of the White Rat. Journ. of Compar. Neurol. 23:1-38. 13 fig. Von Frey, M. 1896. Untersuchungen tiber die Sinnesfunction der menschlich- en Haut. Kbnigl. SAchsischen Gesellsch. der Wissen- schaften. Math-Phys. Klasse. 23:175-265. 16 fig. Wimpfheimer, C. 1907. Zur Entwicklung der Schweissdrisen der behaarten Haut. Anat. Heft. Abth. 1. 34:429-503. 4 Pl. ai ceeiit¥ Feeds t90'r. Serre ni 8S @S e«eeeeund-knob on surface of cell. f .-..--Fibrils from superficial nerve ring. fe .....Nerve fiber giving one branch to hair follicle and another to epidermis. ff ....-Whole fiber ending in single follicle. fi ..e..Hoop-like fibril on modified sweat gland. h ..ee¢eHyaline membrane. hf ....-Hair follicle. hs .-..e-eHair shaft. ma ....elMatrix of motor end-plate without granules. mag ....Matrix of motor end-plate with granules. mal ...ecotratum Malpighii. mep ...ellotor end-plate. mf ..eee0mooth muscle fiber. mi ....eNucleus of smooth muscle fiber. MU eeeeectriated muscle fiber. MN eeeeeeNerve of third layer. no ..-+--Non-medullated nerve. nu ...--lucleus. nv .....Mlotor nerve fiber. O eeeee-Outer root sheath. DP eeeeeePlate (expanded axis cylinder). PC esecertigment cell. Pg .eee-Pigment granules. we eoe--carcolemma. SC .+.--otratum corneum. sgl ....Sebaceous gland. ee Sgr ..e-Stratum granulosum. sl .....otratum lucidum. sn .....ouperficial nerve ring. snl ....Second nerve layer. tnl ....Third nerve layer. | Va «eee Varicosity. KX eeeeeeLerminal fiber without bulb. Fig. 1. Part of a transverse section of the skin of the face. pg Pigment granules. mal Stratum Malpifgii. se Stratum corneum. Fixed in corrosive-acetic, and stained in haematoxylin | and eosim. X 200. Fig. 2. Portion of transverse section of integument at base of thumb. co Corium. mal Stratum Malpighii. pe Pigment cell. sc Stratum corneum. sl Stratum lucidum. Fixed in corrosive-acetic, and stained in haematoxylin and eosin. X 300. Fig. 3. Transverse section of modified sweat gland from wing membrane. bm Basement membrane. cc Columnar cells. mf Smooth muscle fibers. mn Nucleus of smooth muscle fiber. Stained intra vitam with methylene blue, fixed in ammonium molybdate, and counter-stained with Mayer's carmalum. X 900. Pig. 4. Part of a transverse section of skin of face. ep Epidermis, hf Hair follicle. sgl Sebaceous gland. snl Second nerve layer. tnl Third nerve layer. Stained intra vitam with methylene blue, and fixed in ammonium molybdate. X 450. Fig. 5. Pigment cells in the corium of skin of face. a Cell with granules unstained. b cell containing both stained and un- Bs Lev sore ee PRY oh ae PAL ay Be a si: 2 ae ee ee a. i: od 2A Set GSR cata es 16 ipa bern he di i ee. ee a gna taney ume verb ne 7URM. ae ; I 1 Pes O. kew Lo Rh aa oe Vira ed rn | Lane Oh e n 7 2On09 Lae O09 Oa ae) Aa b igat} et a | bore yep tout drtesde fe ot seo OR ee area ghee skioxs aa a ia CretD thor he otro overeat oui) | con.) ot, eer teen wae: eet vail Kees cet OO CO mene came ant sora ~~ etal fe pepe, “let rom diGheda a iy mee ti na Hy we hE a aites: & ero HW TL AUT B i iret apie . "ge! Capers 58 1B ln LOTR re 4 Jy wthph pinaleee sy ONT a 0 2 Cy \ et i@ Cre ieee orem 6? tees s: colin hradgih ia tw is mat Sia ec7 fh ae vet , oe a4 a nt et. As Wiuery of ay ty: Aa ‘ph 0" d 59 Figs. 6,7. Portions of epidermis of interfemoral membrane. e End-kmob (free nerve termination). es End-knob on surface of cell. n Nerve of third layer. sgr Cell of stratum granulosum,. x Terminal fiber without end-knob. Stained intra vitam with methyl- ene blue, and fixed in ammonium molybdate. X 700. Fig. 8. Portion of transverse section of skin of back. ep Epidermis. fe Nerve fiber giving one branch to hair follicle and one to epidermis. ff Whole fiber ending in hair follicle. Stained intra vitam with methylene blue, and fixed in ammonium molybdate. X 200. Fig. 9. Longitudinal section of hair follicle. Drawn from a methylene blue preparation, but some features of the hair sheaths have been added from other preparations. cs Connective tissue sheath. eh Nerve endings on hyaline membrane. eo Nerve endings in outer root sheath. f Fibrils from the superficial nerve ring. fe Nerve fiber giving one branch to hair follicle and one to epi- dermis. ff Whole fiber ending in single follicle. h Hyaline menm- brane. hs Hair shaft. o Outer root sheath. sgl Sebaceous gland. sn Superficial nerve ring. Stained intra vitam with methylene blue, and fixed in ammonium molybdate. Other features from prepa- rations fixed in genker's fluid, and stained in haematoxylin and eosin. X 900. Fig. 10. Portion of modified sweat gland from interfemoral membrane. fi Hoop-like fibril resembling sympathetic nerve fibril. mu Smooth muscle fiber. no Non-medullated nerve. Stained intra vitam with methylene blue, and fixed in ammonium molybdate. X 700. Pig.1l1l. Striated muscle from upper lip. ea End arborization. 7% | i ¢ Ejed 2. alias ae gs sage Py t belch i jelttiaae 3 combing | S .a) Oha eee se brea an! oat UOT Rhee oS aN sy" b a, . j \ ae en Ae | ee ares eure 4 bd 4 7 ‘a , Hee) : ay r , Ve ty ee hg iy 2 f iy aie erty EA: AO AY TT ES a a fibialtatis - re ¢ CSTE ity eet 0) ey ie ee . he eae ae i Re +. tree eee Gee wey oe beni Ree ae hoot Ral eli cioh ale a eee BL ere Sk AB Hi. | be ea 6 Core Ds oh eae ener sae ae WA OMN a it FB ena Reg ae ot baht ok Seat for abo By es Cee BE 2 eye he eit 7 hes Thin err ae. cht: huge ‘a boxer: asta | Dew) ata ale ee oy eh ome D at iva mt ; titan’ bi i) Y (f° Srey) eee Day sae he ho ion Agree het, aid gid Thapar ot Were actuigi fis | Peete: het Tor ony Stat te iatooint a dnbmanek: ei Wath Die aie ae ever hs nd, ike eae aE et is eo ey, a j Py ete ie. nll ; Nita hs in) ee ay a J mag Matrix of motor end-plate. m Striated mscle fiber. nu Iu- cleus. nv Motor nerve fiber. Sa Sarcolemma. Stained intra vitam with methylene blue, and fixed in ammonium molybdate, X 1800. Fig. 12. Transverse sections of striated muscles of tongue, ea End arborization. el Elevation where axis cylinder pierces the sarcolemma. ma Matrix of motor end-plate without granules. mep Motor end-plate. sa Sarcolemma. Stained intra vitam with methylene blue, and fixed in ammonium molybdate. X 1800. Fig. 13. Portion of transverse section of wing membrane showing varicosity on fiber terminating in epidermis. mal Stra- tum Malpighii. sc Stratum corneum. va Varicosity. Stained intra vitam with methylene blue, and fixed in ammonium molybdate. X 1800, Figs. 14,15,16,17, Varicosities on nerve fibers in skin of face. Stained intra vitam with methylene blue, and fixed in an- monium molybdate. X 1800. | | Fig. 18. End-bulb from upper lip. br Distal branch of axis | cylinder. en Enlarged ending of axis cylinder. p Plate (expanded | axis cylinder. Stained intra vitam with methylene blue, and fix- | ed in ammonium molybdate. X 1800. | Figs. 19,20. Terminal corpuscles in skin of back. nu Nucleus. Stained intra vitam with methylene blue, and fixed in ammonium Daotybdete. X 900, Fig. 21. Section of nerve trunk from interfemoral membrane. ax Axis cylinder. Stained intra vitam with methylene blue, and fixed in ammonium molybdate. X 200. ; eee pytae coset f See wes wen of ; he Yap te apa htage nes AE 7 hee OS peor ae Faigle ae vie Ltn od | hee we: 0G kA. a aac f F wate i 1 206 Pepe n3.ce-shal tm AST) StS bes. . WE RT Re Age, ae 4 ; ne | on - ta : oF Has, oat ¢ Sates en's a bi alan: c N rT a wai: ven oo Hart ran Pa Fy an 5 en bap jek yal © p ‘ BA, état eter ina CPi ee ae eee bedi f i oer. Bal i e ; ahs _. ince tube be } ayer Pi nA. t | + ' is ® § x 4 ey Pa ‘ a a id aa <% en Vd on rretlae sty ie ext anwittertties +6 git re) a Pee eee ee tris ob ave aes ATO VBE as ae Susi Plate I. SS Tal \ SSSA = > NS Ts ee 4 q ge? os b5O ORG 9) iy 8 pIPTARY Of THE UNIVERSITY GF ILLINOIS. : LIBRARY oF THE UNIVERSITY OF guns “& a1 au 4 ee ug a eH — oO » roa re Ay y ‘ Plate IV. hy ? Te “yah eebe) base ene | ry Qh Ni : rrr hl eet, oy VITA. The writer was born August 31, 1879, at Woosung, Illinois. He received his elementary education in country schools in the vicinity of Dixon, Illinois. After teaching two years in a simi- lar school, he attended the Northern Illinois State Normal School, Dekalb, Illinois, completing the three-year course in this insti- | tution in June, 1903. The four succeeding years he was principal of the Algonquin (I11.) High School where he taught zoology, en- tomology and physiology. In 1907 the writer entered the Univer- sity of Illinois, Urbana, Illinois, registering in the General Science course and eae in zoology. Two years later he was graduated from this institution, with the degree of bachelor of arts. The two years following (1909-1911) he pursued graduate work in zoology at Illinois, serving at the same time as gradu- ate assistant in this subject, and received the degree of master of arts at the end of this period. During the years of 1911-1912 | and 1912-1913, while continuing his graduate work on a fellow- | ship, he investigated a problem in connection with the Vertebrate | nervous system. | In the last few years the writer has taken a six weeks' course at the University of Illinois Biological Station, Havana, Illinois; spent three weeks at the Biological Station of the Uni- versity of Colorado, Tolland, Colorado, taking notes on the fauna and flora of the region; and worked six weeks at the San Diego Marine Biological Station, La Jolla, California, collect- ing and identifying specimens. The writer is a member of the fol- : eee; 607 aap Aa vite ae ey \ ‘5 Sink: ee ee eae ‘ote | ‘ : P mae ea mia ye Ae oe ms | ongatea on = = - ~ ~ i ‘ - fain ow Se Tse Sole ee sulle dant rin ee hal ah ey 62 lowing scientific societies: Illinois State Academy of Science, American Microscopical Society, Sigma Xi, and the American As- sociation for the Advancement of Science. Titles of articles published: "Observatins on White-Footed Mice". Nature Study Review, Vol. 6, pp. 137-140. 2 fig. "Ona Tactile Organ in the Cheek of the Mole, Scalops Aquaticus." Anat. Anz., Vol. 41, pp 341-347. 5 fig. -_* (ie — © “NSB Sd : * PRY ye - YN # So". 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