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Les diagrammes suivants iilustrent la m*thode. 1 2 3 1 2 3 4 5 6 S'Yf' '^.. ^ UNIVERSITY OF TORONTO STUDIES BIOLOGICAL SERIES ?oU' * "'"' ^'^^"^ «°" ^^'-^ ^■^^''-^ L, BV A. R. tSi i:sr„^r*"'' '''^"=«^'' "^ COMMITTEE OF MANAGEMENT >BEKT ALBXANDHit F'ALCC »SOR W. J, A:,RX,S.NDSR,^ ^■^OK VV. i-I. El.us, iSl.A.J'v^ SOR J. J. AfsCJi EOK J. F. McM'JSi- v., LitiP., LL.O-, D. if the Uiiivcrsjtj I9I4I A New Cestode from Auia Calva L. 8i A NEW CESTODE FROM AMTA CALVA L. By a. R. Cooper, M.A., (Read 26th October, IQ14) to ^B^J"^ l^vA^'u^n ^- ^- ^"^'^^ ^^^^ the writer's attention ZlT t t u^'^'^' ^"""« *h^ ^°"^^ °^ his earlier helmintho- enSVneT'?% ' ''^-'"""^ '" ^'"^ ^'^^^'^ ^- ^^ Relieved to be ent rely new. Later specimens of the same genus, and perhaps, too. o the same species, were procured from the same host taken in the viamty of the Lake Biological Station on Georgian Bay; andM "c^ a prehmmary ej^mmation showed that the worm had apparently not yet been described, .t was thought advisable to make it the sul^ect ofa more or less thorough mvestigation. and to publish the results B llJT'7'"^^^. to herewith express his indebtedness to Professor oretratTon V^.'^ ^^^'' ^!'''^"'' ^"^ ^^^'^^ '" connection with the sTv of I ^n • ; ^'^'' '"'^ '° ^'■°^^^^'- "• «• W^^d. of the Univer- fion, Li V ?r"'.''"' °" ^ preliminary description and for material trom his private collection. worI!'^^°"°'^!r^ '^■^" T. ^'^^^^^ only ^ith the morphology of the worm, a consideration of its systematic position having Ln dealt with inasecond paper published in the Transactions of the Royal Society of Canada (Series III. Vol. VIII. 1914. pp. 1-5). ^ Material. Apart from a few examples kindly sent to the writer by Dr. Ward to'abo. rt '°"''''' °^ ^°™' """"^"^ '" '^"^h from a few millimeters o about ten centimeters, taken from the duodenum of three or four specimens of An^^a calva, L. These were all fixed in Alcoholic-acetic CeTs Add"ca ''" ^'"'' '°^ transparency-preparations with Meyers Ac^ Carmine and in sections with Heidenhain's Iron-Haenia- toxylm and Orange G or Mallory 's stain, the latter to bring out basemm membranes in particular. ^.'^sciucnc General Appearance. nnri^'"r""T''-^™'"u"'' ^"*'"°'" '"^ °^ ^^e intestine of the host to no mal saline solution the cestodes are quite active, undergoing changes m length and breadth particularly in the middle and posterior^ portiot ofthestrobila; those in the scolex and most anterior proglottides are le^ XT '^J*/ Taenioid Cestodes of North American Birds, by B. H Ransom- Proc ir«; Nat. Mus., Bulletin 69, ig09. ^ Kansom, Proc. U.S. 1— 8. T«HSACT,0N5 OF ™e RovAL Canadun Institute, (vol, x. fore™<«, join.,, white tahSkti^^^X;:" '.'"'l'"'^ »' '"^ distended with eggs. ^ **^^ "^^" be'ng greatJy The largest specimens examined were two UnanAoa containingrespectivdy59and65 proglottid^' Frn" .""",!" '""^*'' the number of the latter is obtainS hf % ""cleared material wanl and depending on [he dt '!„ o'f ^hrut'eri-tt"^ T ZT ^°^- genital openings are very minutP— Jn ?!. u- ? ^ ""^^ ^"** '^n^ale indicate the sefs of repSuXe oVns 1 " J^ '"' °^ ^'^^ ^^-^ila to of proglottidation in this i^gio^ ^ ' '^''^ "^'"^ "° ^t^^^"" '" evidence summit is somewhat orolonlL . '^^"^ ''^ attachment. The comparable tT^^ti'^S^.Zt'uoZ'^^^^^^^^ ^'^^^ ^'-' ^^^ family Triaenophor^^nS^Luehe^L^ ^°""1'" ^'^^ "^^'"bers of the sub- outward appearances this stru^'-.r • ^'''^^^'"''>'^' ^'though to all the cuticle^^Xs i weHal '%"""™f • ^^^ain modifications of to be described ^orilriv Te^H ' ^/°'''"^^^^ proglottides. which ^„.i,,.,,,^j:;:^:^^^,^^^^ *'^^?^""*- ^ooks with end of the scolex is modified to form wn nl ^T"^^' '^^^ °PP°«'t« closely resembling internX^!:in^''::^eZlW joints (Fig. 1). The following meas^'m.^^ T °^ '^^ '""^""^^ for future diagnoses of sped^"L""'"*' °' ^'^* ^'" ^ of use Width, at base of terminal disc 0 20 -ft 4n Width, at posterior end of bothria 0 ^ Z n « """' Width at tipsof appendages oL Zo'^S "*'"• Length, mcludingappendages J;^ _ J'^^ -- scol^T4^'.t:LT'Set^^^^ ^'^-d the together e^en in refaxS' st^T ^rrbilf "t^ "^^^ ^^^^^^ umted to form a sort of rine into v.h;l ^i™'"'^" ^he appendages are next joint fits, leav^n^re^ bT^^^^.r'^^^ '"'^'^^ ^"** ^' *^^ forward a little farther lIS atH "^ ^° ^'' ^^^ P^ the diagonal diameter^ FrSS) In mTnT''"''^ "".^ "' ^^ -^-°^ *rig. do;. In many preserved specimens these I9I4] A New Cestode from Auia Calva L. 83 appendages with those of the terminal disc stand out as thin leaf-like structures, concaved anteriorly, thus suggesting their probable use as accessory organs of attachment ("StOtzorgane") to the wall of the host's mtestme. The bothria, although provided with a well-developed musculature (vide infra), would seem to be incompetent to securely fasten the worm; poss.^jly the appendages of the scolex and foremost proglottides may combine to act as temporary suckers, as suggested by several authors. Unfortunately no observations on the methods of attachment were made on the living animals. On passing backwards, the joints are seen to elongate considerably. especial y ,n all parts ahead of the ring of appendages which remain relatively more constant in size. A transverse section through the former is oblong in shape, while one through the Jatter is more broadly elliptical to circular in outline. This part of the strobila is the most mobile, elongation often reaching the degree mentioned above in which the appearances are quite like a knotted thread. Fig. 2 shows different degrees of contraction in a portion of the chain, but it can be seen that the middle joint is naturally somewhat shorter than the other two In many chains this region is subject to considerable variation. It was observed that now and then one of the longest proglottides was provided with one or two additional pairs of appendages, generally abortive and situated antenorly some distance apart. In a few cases staining and clearing brought out a distinct division of the parenchyma, especially posteriorly, into what seems to be the beginnings of a division of the longer proglottis into several smaller ones. Furthermore in one strobila an undivided region was intercalated between two jointed regions the the second of which was followed by the normal posterior end. Youne scohces are shown in Figs. 5 and 6. (In this connection note evidence given below under the excretory system that the latter are incomplete). Although the foregoing facts point to possibly occasional augmentation in the number of proglottides in this region in adult worms, the usual appearances are as described below. Beginning at the 15th to 17th. the proglottides enlarge somewhat abruptly until the size shown in Fig. 3 is reached. The dotted ovals here represent the gravid uteri which give rise to the distended appearances of the posterior two-fifths, or neariy, of the joints. There is also some increase in width anterioriy. On the other hand the auricular appen- dages gradually dimmish in size, until after the 23rd or 24th joint they are not to be seen, the strobila then resembling a ribbon swollen at regular intervals, as mentioned above. For some distance farther the remains of the constnctions of the anterior ends of the joints are seen in slight approaches of the lateral borders, while still farther back a tendency 84 Transactions of the Royal Canadun Institute [vol. x. [alerSSd 'tr^ '" ™ • °^ ^''' ""^'^ •« ^^^ ^""'«' t° break immed- ^y behind the ovary is the only other indication, apart from there- furtive organs of proglottidation. This tendencyXwever ^ f^ 33 could be determined is not based on any differentkt ion If Ihe ^et chymatous tissues mtemally at this level but more probably on^S^ .tSrS mTi^J V'^ '^"^^' '"^ --y rendering'the partsTmmS mtely ahead more resistant to strain. The following are some relative measurements of a typical strobila (Fig. 3) — relative IWIottis. Length. Greatest Width. ■» 1.85 mm. 0.48 mm. ~ a. 37 mm. 0.48 mm. .r!^^' \"PP^«»tly the end-proglotUs is rounded p^steriX(F.> la) and provided with a functioning set of genital organs. The endings o o? th?T K? 7"*? '" '^'' ^'°'"*' »»°*«^^^' ^^^o point to ime 1^ tl^^i^^ell^r'r^'-' ^-' ^^ ^^ ^'^ ^^) ^^S lost ar^eSj CUTICULA. hese. about two-thirds as thick as the inner, does not stain as weSl the ktter owing to the fact that it is made up of alternating dark rd %hter S ^^'tZZ:'' r ' ^^"^^^^ ^PP^— • The dai-i^ te seem to be composed of minute granules while the lighter are morP ^mogeueous (Fig. 7). Bounding this layer peripherally there^ to S «^n in many sections an extremely narrow clear line, foHowed by a son TZ nit 1- ""'^ ^'"^ ™""'^ '^'^ ^^^^^ ^-^ to ^ conrinuations hv.r 1™ . 1 ?^' • " °''™ separated from the homogeneous toSS ^ T,^ °"°" " '''<^"^ eranolar in some quite thm sections. The cuude .s traversed at short intervals by the mtoute 19141 A New Cestode from Auu Calva L. 85 excretory canals forming the foramina secundaria which appear in tangential sections as circular openings in a homogeneous matrix. Since these course through the cuticle quite obliquely, they give the latter the appearance of being pierced with holes at different levels. Two of them are shown in Fig. 7, one having reached the outside while the other has not yet passed the basement-membrane. In many cases a splitting of the outer layer of the cuticle into pro- cesses takes place evidently along the lighter striations. It is quite con- ceivable that the cuticular processes, if not "cilia", described for many Bothriocephalids may arise in this manner in young scolices. The cuticle covering the scolex is, on the whole, somewhat thinner than that on the posterior proglottides. This statement is also applicable to that on the inside of the auricular appendages of the scolex and fore- most joints. The other modification of the cuticle, referred to above, is best seen in young scolices where the minute spines have not been worn away. It will be seen, by reference to Fig. 8, that the latter are developed as a thickening in the outer layer followed by a breaking up of the mater- ial into stout spine-like processes. These minute spines are restricted to a very narrow line running along the edge of the auricle, and are all directed towards the inner concave surface of the latter, that is, towards the central longitudinal axis of the worm. They gradually disappear with the appendages posteriorly. Since these spines appear in great numbers, and, since the appendages are provided with well-developed sets of muscles (v.i.), obviously arranged to activate them, they must be of actual service to the worm in obtaining a hold on the smooth mucous lining of the host's intestine. SUBCUTICULA. The subcuticular cells (Fig. 7) are not clearly defined as to boundaries but are fused together to form a syncitium the extent of which is in- dicated chiefly by the nuclei. There are, however, condensations of protoplasm around the latter in ripe proglottides, giving the appearance of columnar cells which have been described for many Bothriocephalids. These may even be more or less distinct towards the centre of the pro- glottis, yet they are directly continuous with processes from the cells of the parenchymatous tissu>^ beneath, the whole forming in many places a meshworkof protoplasmic strand surrounding vacuoles, as shown in the left of the figure. The nuclei are comparatively large structures with well-defined walls, non-uniform in thickness, and clear contents, except- ing for the deeply-staining ' ' nucleoli ' ' . The thickness of the subcuticula varies in different regions, especially since its inner boundaries are rather indefinite, averaging about 05;^. Numerous processes proceed towards r 86 Transactions of the Roval Canadian Institute. (vol. X. t?iS*'' Th.'^''^"!**'' basement-membrane of which they could not be It^i ^ '^ ^*'^^^" ^''^ '^"^^ ^"d the circular cuticular muscle! ^:'s^^1^yi:'Z^m: Z ^ ^ -densation^^t tTptm jt^biias. these p^rippiLirr^^^^^^^ iSbcutT^ condensations in the syndtium. mentioS So^X subcuticula 18 poorly developed in the scolex. ^ ^°o^- ihe Parenchybia. lon^tudiiC^^f 'Vhtd" "'""''• *'' '"° *"•"« ^P^^^*«* by the arrangem^t of he nln. ^"°" T*° '*° ^^^ *^ ^^^ '^^^^ «" ^^e r.t.vV.f .the nuclei, smce the cytoplasm forms a verv ooen reticulum excepting immediately around the nuclei (fZ «/^7wV. Vh cell-boundaries cannot be seen In *h^ * • ^ F' ^^^' *" ^"'*^** the nuclei eachfrnrit r^ ,,• ^"**"°'" Proglottides most of beinl" JlTl!?"^"^?^' parenchymatous reticulum is very vacuolated In 2^1 „< S . , '»""^''"' muscles situated there (vj.). boe from Amia Calva L. Musculature. The musculature consists of two series of fibres, namely, the muscles of the parenchyma, coursing in three different directions, and those of the cuticle, which are closely related through what will be described below as the outer longitudinal gioup of the former. Since a careful study of the muscles was made, they will be dealt with somewhat in detail, beginning with the simplest histologically, the dorso-ventral and coronal fibres. Those of the scolex will be described separately. In his researches on Bothridiutn pUhonis Blain. Roboz ('83) was unable to find the myoblastic nuclei of the longitudinal muscles, which, he says, are pointed at both ends, but observed a longitudinal fibrillar striation. Zemecke ('95), working on several species, makes the follow- ing statements concerning the individual muscle-fibres: "Hier finden wir denn auch die von Salensky fUr die Muskeln von Atnphilina bescbrie- bene Differenzirung der Fasem in eine centrale (Mark-) und eine periphere (Rinden-) Schicht. Letztere umgiebt den centralen Theil als ein breiter Ring und ist von diesem durch die intensive Farbung zu unterscheiden. Sie ist von homogener Structur und starker licht- brechend als das Centrum. Letzteres erscheint im Querschnitt als eine dunklere, feinkSmige plasmatische Markmasse"; further, "Hier (at the level of the myoblastic nucleus; ist der Zusammenhang der Mark- substanz mit der Zelle zu sehen. Die Rindenschicht bildet hier nicht mehr ein geschlossenes Rohr um die Markmasse, sondem offnet sich an einer Seite, so dass eine Rinne entsteht, durch welche das Plasma der Bildungszelle mit dem Mark communidrt." Essentially the same conditions were found in the musculature of this form, excepting that the peripheral layers of the individual fibres of all of the different groups are characterized by being broken up into a varying number of fibrils (Figs, loa, b, c, and 9a) which diverge at the ends, excepting in the case of the longitudinal fibres of the parenchyma. An example from the coronal series (Fig. 9a) shows how the f.brils are related to the nucleus and cytoplasm. Although in most of the fibres of the longitudinal muscles the latter are situated close to the fibrils, as shown in Fig. 9d, others, Fig. 9b and c, are widely separated from them, the connection being scarcely visible in many cases. The two figures given are of the most distinct examples that were seen. The fibrils themselves are very easy to follow in every part of the strobila. In cross-sections of the external longitudinal fibres at certain levels, a large area of highly-staining mater- ial at one side of the fibre (Fig. loa and b) was considered to be the re- mains of the nucleus, since no other trace of it was found. This and the fact that the myoblastic nuclei of the dorso-ventral fibres between the bothria were somewhat degenerate and quite closely related to the 88 r^»s^cno„. OF ™b Rov«. c«,abun ,»st,t„„. [vol. X, as two thin sheets of Ybres' Mn^ Z'Ja- T!^' °' """^'^^ '« Ranged muscles of the Parenchy^'/^huVSn? K t'" ''^ '°"^*"d'"-' boundary between the medulla "and cortL,^^^^^^^ " '°^™"^ ^'^^ verse sections the fibres of these two lav^^? P^^^"<=hyma. In trans- mnermost cross or mterdigitlTe ^fortl^S^' ''*''^"^ ^ *^^' *he cuticle. In the posterior 4d of tl? ! • ^ '^'^'"^ attached to the many fibres to th^auSi ap^f/^^^^^^^^ layer send: (F'g. 35). which curve shghtlyCtSv w'^'"''"'^'^*'^*^^^^^^ fibres of the latter. While Z ?'^*^"°'^'y ^o form part of the radiatine fn,m joint to joint thr^houtthe^^^^ '"' "'"'^"' '^"^« ^^ ^^ntinuouf is a decided augmentaS^th tXToTfir"" °i "^^ ^^°^"^' ^«- o^ the proglottis opposite the a^rfe"^ „^^^^^^^^^ ^ck they diminish in number x^thti^J^^ ^^^ P^- ''^'^er appendages, relatively morT q^icUv in th'1"'^°'i '" *^^ «^« °f the until in the unsegmented hinder end onlv^f '^'' °^ *^" ^■°'"^' mjHe interproglotti^al ^e^^beVw^trStS 1S;rZ^^^^ -an"g:2'^r;iri:-r^^^^ developed in the first three or four lotts th. ''"^ ^f^'^'y ^''^^ groups, two for each surface anH I "! .^^ ^^ ^' "^'^ed into eight subcuticula. Each ^oup 'cotls^ ^^^^^jr^iately beneath fhe the whole of the edge ^f the prXi/^ ^.^'^^ ^«'"« ^ong passing obliquelyandposten^rKtrtheo^^^^^^ ''^ ?P^"^^8«« and surface. Thus there is a decusslt^^n in the ^ ' ''^'^ "^"^^^^"'^^ compHcatedappearancesincro^^cJil Z;^^^^ which can be best seen in sagittaTSons ^ ?PT°"^*«'-^««>»P« exactly the same way; they arfh1wrve72T^^*"^'° ^^** °'^^^ expected from the ligulate'^haStoTrworttT'"*'"^'"^'^^^^ even m these foremost joints bein^ conJI?! m 1 *^°'^-'^«"tral diameter Beginning at the base o} the app^nZ^ t^^^^^^^^ ^^ ^- .t^e transverse. nng (vide supra) to which they ^ra^t^rh^^' ^ coronal muscles are cut off f^^ Je innt ' "^' ^"P^ °^ ^hese diagonal uiameters of the join^by Z TeLTT"^- V^' ^"^' °^ ^^e I9I41 A New Cestode from Auia Cakva L. for the movements of the auricles alone. From their arrangement they doubtless serve, in conjunction with other fibres to be described below, to extend the appendages away from the body as the leafrlike structures mentioned above. The dorso-ventral or sagittal muscles are divided into six groups by the three excretory vessels and the two nerve strands which in the foremost joints occupy most of the medulla and are situated so close together in many sections that only individual fibres appear between them. The fibres themselves are more numerous, like the coronal muscles, anterior to the junction of two proglottides where the four most lateral groups, i.e., those between the nerve strands and the lateral vessels and those outside of the nerve strands pass from auricle to auricle on each side of the worm (Fig. 35). In the forward end of the joint more fibres are situated between the vessels and fewer laterally. The middle lot could not be traced beyond the subcuticula, while the lateral groups, on the other hand, can be easily followed to the cuticula of the auricular ring and appendages, in which latter they, along with the coronal fibres mentioned above, constitute the transversely radiating group. Farther back they dwindle down gradually until in gravid proglottides only a few coiled fibres appear between the testes and vitelline follicles or alongside the dmis-pouch and uterine>cavity. The individual fibre closely resembles that of the coronal series, shown in Fig. 9a, excepting that it is shorter. The longitudinal muscles of the parenchyma are divisible into two series, an inner and an outer, of which the latter appears only in the anterior end of the strobila. In transverse sections through the middle of the foremost joints they are arranged in small groups, with no constant number of fibres in each, in two concavo-convex bands between the medullary and cortical parenchyma, that is, about half way from the centre of the section to the periphery excepting laterally where they are situated relatively farther out. Here the thin edges come together immediately outside of the nerve strands. Throughout their course transversely they are penetrated by the s^ttal muscles. As one nears the very short region between successive proglottides, in following through a transverse series, some of the fibres (more correctly fibrils, from the above view of the constitution of the fibre) decrease in diameter and number, especially laterally, and become more loosely arranged, as they divi ge from one another. Immediately ahead or behind, as the case may be, they again appear as above. On the other hand a great many pass from joint to joint uninterrupted. From this fraying out of the fibres between successive joints it was concluded that the lengths of some of them, at least, did not exceed that of the proglottis : in the mature, 90 Transactions of thk Rova. Canadian Institute. [vol. X, here, since, as above sS n^lnH^?^^ f " '°"^"'" '"'"^ '« *« be found the separate sets o7 ^^ l«°>^^tlT P™^'^"'^-*-". apart from acertainamountofinterCtioTfnthfl' "^^^ fT"^^' '^^^'^ '« *!>"« corresponding to theXSon^Wn ?"'?! °^ *^' longitudinal muscles Leuckart fof Cia .Srr^*'";^'' ^ P*''"*^** °« ^^^'y by there is a slight contr^ctiZTfhe^reclSSr ^'li ^"^'>---' proglottidal space is neared {mT^)lSl^ ? ^u'"' ^' *^" '"*^'- auricles have disappeared 37). which ,s not to be seen after the ^^^^^T:^^^2^-:^^^^^^r only in the anterior prog.ot- which they are obvious ylvdo^^^ W^ ''''' '°'" '''' '"^^^'"^'^^ o^ glottis they lie very cloL to thrT' .^" i.''^^"t«rior half of the pro- which they can be^istineuish.H 'r?*"'^^"^' ""*'^"'^'- '""^^^les ^om they pass the slight iSSonwr^"^ "^ '"'''^ ^"^'^^'^ '^'^'^ «'»• ^ end of the appeLage ?Ca"e1^td r^"^ ^^^^^ anterior portion of th; out^ waC le U'^'^ ^^'^ ^«-<^h«J to the =>onverging towards the center to L« • . u^'' ^ ^^^"^ ^'^^^ ^^ey are a ring of fibi^s more pro^nent^^^^^^ '^" "? P°''«'°"'«' *bey form longitudinal group (fT^T r^rT"^''V^^ '^"^ ^^ *he inner more pn^minfnt oppo he the alric^tr' '""'K"^^^ ^hey are also ventral and transve^ diameter^ ? .I ^l '^^ ""^^ ^^ *»>« do^so- behind the auricle a few fibres ^e cJt oVf '"^ °u *'' """^ ^^^ P^^^'^-* about half way along the Se ^th. In T '^' "^^^ ^^ ^o pass supplied with very many Ees lilonrin^r.lf ^'' ^^' '"«^^ '« ^"^^er which pass between its outer and ?nn"^ ., ' "T^ ^°"P ^^uehe '97) and. by their contractionXouslvZir '° '^' ^^'^ ^'P ^f^'g' 37 cle and thus to allow the mh^Z^ ^ ° P~*'^*=^ *^^ ^«^ of the auri the host's intestine As trannlnr 'T*''^ '" '''' '""^^"^ ""-? "f muscles gradually become rLtS'f.^'^T"]'^ '" '''' ^^is series of and eventually dfsapp:rXh?ftlf ""'" ^"' °^ ^^^ P-^'^"" exte^^lo^irudtaTl^^t^^^^^^^ the a.angement of the uniserialis Rud. and stmnl u ' • * ^'^^''^^ ''esembles Zi£«/a that: "wenn die ^^Tn'^^^s ^^tr ''"^'!' ^-eralizaffo; wenigstensbei Jugendlhen p^^^^iSeTS^T- ''" '" ^'' ^'^'' einen grosseren Querschnitt Sen I am v" j'*' T "'nterende dass die einzelne Proglottis i^Tn« scolex Wd. however, the ^rJ^^ZTtlT' 1« ^^ ^-"ow them excretory vessels, which separate s^xSS . "' *^°^ ^^^^ the 34). enlarge considerably to form the cllf ^''^"^odate them (Fig. traction of these in confuncdo„ wkh that ^.K ' °' *''' '^^■"- ^°" transverse fibres will deepen "hT both • 5^ *^"gentially arranged sucking-apparatus. ByThdr ^1^^*^''/"^^ ''^"^ ^^'"^ ^n efficient onal fibres the bothria^Sron t^^XTh ^'^ ^ ^^^'^^ ^^ ^'^^ <=<>- substratum. Anteriorly th^ So^Ventr^ fi"b ' "^ 'T"^ '^"^ ^^^^ r sTi- 1^"^ '- "- - -PearT tfe /X^r^llS v^^^vtss:is^t^:r'S--o-p.^ scole.. here they disappear ^ ^'^^^ ^^'^ '^ay along the but^t;r srr ^rn:::r r - ^" ^^^ ^— -ta. groups each of which is situated nelrLj 7 T'"^ ^°"^^d ^ font at the edge of the bothrial waH outSdeTi^ 7"'°^^ *="^*="'^'- ™"«cles ahead of which they do no^Z^^Xl ^' ?"^""*'*' 8«>"P» (^g- 34) of the scolex. "^ °' ^^P^"' '''^t is. they do not pass to the tip The second group of muscles peculiar tntho . •n Its anterior third. These areTriTuli^f ^'^ ^^'^ « to be seen concentrically around the edg^o Zt^ '^-f"""**^ ^'"^ ^^S^ at each end of the diagonafrmeL^'orZ'^l^''^ !" '°" ^"P«' o^ The,r function is obviously to -^ °'tt ff°"r *^.'°"«'' "-^^ '^'^on. bands of minute spines (Fig. i. ^^ °^ *•»« ^o^er with its as wI!l^a:ti':?t'he7o^£^^^^ longitudinally arcuate short and spindle-shaped Annr« • . ^ ™"^'^* a** comparativelv strainmuch'^more reXiF'STZV'S "Hf"^ ^''^^^ takeTllr more muscular in composition and can S^ ^'^f "/'^«'- ends which seem This is due to the fact'That It is in this iSdT "^ '°"°"^ '*» '"""^ ^"^<^'«- cytoplasm and the nucleus are loSt^X ' tP" *''' "°^* °' ^''^ tha(i::eri-rro?rst^^^^^^^ cuucu^ar fib.^. excepting a few drculS „ "''t'^'u''^^"™' ^^^^ the towardsthe latter, quickly di4^SarionaT '"'^''t ^^ ^^^' <« cularcdls on the hinder ,irderT^err:SLtir(?ig^;^^^ '"^'^- I9I41 A New Cestode from Auia Calva L. 93 Nervous System. The nervous system consists of a nerve-ring situated immediately beneath the tip of the scolex and covering the median excretory vesicle (vide infra) like a cap, and the two chief strands passing back from it through the whole of the strobila. The former is a comparatively weakly developed structure (Fig. ii). elliptical in transverse section, with diameters of 60 and 40^. The chief nerve strands are 18^ in dia- meter m the scolex, in which they are situated between the middle and lateral thirds of the medullary parenchyma (Fig. 34), while in the anterior proglottides they are somewhat larger, excepting in the inter- proglottidal region. Here they narrow down suddenly to a diameter of 8m. In the posterior unsegmented portion of the strobila they are quite flattened laterally, opposite the gravid uterine s,acs (Fig. 19), on the whole somewhat smaller than in the jointed region and situated in the medulla but quite close to the longitudinal muscles (Fig. 18). The nerve-ring gives off besides the two chief nerve strands, eight others, four being grouped around each of the former (Figs. 34 and 35). It was at first difficult to decide whether these were distinct strands or only the inter- sections of an extensive meshwork of nerves situated in the cortical parenchyma and thus comparable to the " plasmatische canal system" of Sommer and Landois ('72) ; however, with further search eight strands ^u" ^.^ ? ''"^ throughout the segmented portion of the strobila. The difficulty in following them is due to the fact that the nervous branches given off mostly centrally are quite as large as the strands themselves and that they anastomose freely with one another and with the chief strands which are, however, much more distinct. These colla- teral nenous tracts gradually disappear with the appendages posteriorly. Thus they are apparently developed in connection with the extra mus- culature of the latter. Since the Golgi method of impregnation was not used on any of the material for this study, the nerve-strands were seen to be made up of only a very fine fibrillar meshwork containing extremely minute granules and vacuoles. Excretory System. There are three excretory vessels coursing throughout the strobila, a large median one evidently the morphological equivalent of the dorsal pair of many Bothriocephalids and two much smaller, ventro-laterally situated, all being located in the medullary parenchyma (** Markschicht") between the chief nerve strands (Figs. 34, 35 and 37). Immediately behind the nerve-nng the median vessel expands to form a somewhat spherical vesicle from 25 to 40 ^ in diameter, into which the lateral 94 Transactions of tbe Royal Canadun lNST,n;TE. [vol. X ^adualorfunnel-sha^ Tnt^^^^^^^^^ ''-^J. -J abrupt but lively straight courseTraduallv nf„ • ^ ""^^'^ ^^'^^ * compara- proglottis. Ihey arf medln L Tl^ ""*"' ^^ '^^^ «"*^^ the first intheanteriorp'^-oStidmSwittW '*"?•' '^ '" ''^'"^*-= ^^ile of the lateral veLfdfowfn^^^^^^^^ cepting as they pass thetteZeTottld^? '' '^T °^ ''^^ "'^^•^"' «"■ and straighten out slight ^7^0^ ?^'f "^^''^ '^'^ "^'•''^^ ^own course of the vessel fn the J<^LTST''', '"'" T ^"'^ ^^^^'^''*- ment of the dorso-ventral LThrJ.^ doubtless due to the great develop- Posteriorly ^en^^ 3 ^L"^^^^^^^ ''r^' "'^'^'^ '""^y p^- productive ducts in the mX'^e Thfs !^^!^^^^'°P'"-t of the re- the larger median vessel s^cJZ I ^^^'^ '"°''^ particularly to laterally, are not m^ di tu'be^'" tZ ^^^V'^'^^ ^'^"^^«* --"t™" ductsthe median vesseflies n1S"„,^ '^^. ""'" °^ reproductive testes into two lateS^fie Ids (F ^' "tnd" ^^^.'-P'T' -P-ating the are situated below the testes hS' J vif- J^^'^^'^ethe smaller vessels As the former approaches ^'e c.W • '^" ""^^ °' ^'^^'""^ f°"'-'es. depressed in Fig ,8) and n.! 7 T '* "'"^"^ "^« (»t is somewhat uterus-sac and ove'^ l^t ov^ an'tf T' ">'* °^ '^'^' ^'^^ ^^e space to the med^ n line a2 ^ o J^*"'"^^ P°r°" °^ ^'^^ «^"«^^tive oneside to the other do^l Tth. .n. '^"■' i' ^'■"^"^"tly crosses from sac or the space bet^^^ and the 0^' '" V u''" ^^"^'°P'"« "^erus- Fig. 17. But the peTt^t Chanel i^T'"^ '^ the vagina, as shown in when the uterus b^omrs gtX kh eLrThe ''T ^'^"^'^ ^^'"^^ appear greatly flattened lattrX w thin^: . ?^ T""'' ^^^'« then sections, and not so distinctly towardlthV TT '^* ^^^""^ '" these trace of the larger medirve^nl it ''"'-' ^^'^' '^^' ^° uterus-sac excepting in you2^ sta^l . ^^"""^.'^^ "'^^^'^ °f the almost obliterated tube SuatS doS. I . !. " V"" '^' ^^^"^ °^ ^" teriorly. however, in severa^firiStWsT^r^^^^ ^"'""^^'^ ^"^ pos- the uterine sac ang^tiX Snri .^''^^'""^'^^^^ like valve. While tST^le^:,ZTtoll^'''f ''T' "'^^ ^ ^^P" of only secondary importance k w^ tho„ u^l ^ °"' ^"^ ^^ considered tended conditi^^of man^ of lieX L S n^f ^'""T '''' '""^^ ^'^■ especially behind the regL of iCr^f SeT "°' '"^ °^ '''' ^*^°^"^' (vide infra), might be due to flu Wfrom U^ temporary uterine opening the uterine cavity by the ab^rnf '"^'^'^" ^^^' ^sc^Ping into two extremely tWn^^'i'^^^^ °^ ^"P^"-' ^-ng distension, of the peculiar. The median vessel (Fig. „) gradually 1914] A New Cestode from Auia Calva L. 95 expands to forni a vesicle, varying in diameter from 25 to 55 a and is situated immedmely within an invaginated portion of the cuticleTnto ." '.J °^""- ^^t^P""'"^ °' '^' '^^-^' -^'^ are very d7ffic2 to make out. smce they seem to be quite closed in many cLs A stag^ between the condition shown in Fig. i. and one (in sma^colice Fig 6) m which all three vessels opened separately on the concave TtZl "Z' *'' '';°''''' ^''' °^^'"^^- Thus it would apSIr that this species bears out Leuckart's view that the relations between the posterior openmgs of the excretory system are developed after ^rTe pin InlTm^T. " 'f " ""^'^"'^^ ""^ ^^" separatedTrom the sTrXa In fact Fig. 12 is quite suggestive in all of its parts of a simple contraction of the hinder end of the worm to form a cuticular invagiSn?" 1 of h" vessels formerly opening on the outside. The flame-cell (Fig. 13) is quite typical in structure and closelv re^mbles that of the genus Proteocephalus Weinland, which hal been studied by the writer, in that the vestibulum i^ whkh ^e ciliary flame • is located is provided with peculiar darkly-stoinbe ongitudinal thickenings which do not seem trbe mention^ Tn he literature on the excretory system of the cestodes. Their significance is of course merely conjectural. The cell-body is usually nonsTsWt as that shown in the figure, since the cytoplasm is quite diar but Se nucleus and basal body, as well as the "flame", are very e^V made o^t m sections. It was found impossible to trace with (S^a^ty the lana" :■ "J'^" ''""r '" *° ""y °' '^^ l^^g^r vessels or smaller caLls mentioned below. The flame-cells, themselves, are few in numbeTand arranged more or less radially close around the large vessels AlthoulhT"''n '^" '"""f '^ '"^^^^ *° ^ '^^^^ «««nt in Fig. ,4. Although the wall is extremely thin, the following parts could be dis ra^menTLmtar^^-'"'^^^^^ ^ f '" ^"^'^"'^^ '^ '"' whh a dtinct basement membrane, Iming the tube; outside of that a clear line in XToTe^tremer"/ '^^^^ '" '°"^'^"^'-' -^--. thus r:LmbHng JT ° .*''*'^,'"^^y fi"e cuticular muscles; and farthest peripherally a condensation of cytoplasm with nuclei slightly smaller than thot of the parenchyma, but hard to distinguish from the myoblastic nucirnl at hand. The circular stnations appear to be more protoplasmic thii =i«.'rirr '- -^-^ -'^ --- ^ mL,^zz:z Foramina secundaria are to be found in tlie anterior proglottides 111 ?■ , T ! "I*?'"*'' tlKmselves, are very minute (vide supra, under .he cuocula) but the coun* of the capillaries leading to therS rtZeh .he subcuucula and peripheral portions of the cortiLl pLrchymat 9« T^NSAcnoNs o, ™h R„,«. c„„„» ,«„,„„ [vol. X. can be follow^ throughr^sui^u^^^^^^^^^^ ^li'?'^ '^^ -P'"aries them far towards the cent.^ of t^fs^lob L ^f/^""^ ""^^'^''''^ *° *^^^ with any of the main exc^tory ve^k 17,*=^ less to connect them however, they seem to unite to form H? v ~'^'*^' Parenchyma, of the tubes of which va,^ f,^™ ^o .^""^ T^?^* P'-'^"^. the diameter^ more foramina secundaria on the ^terior " I? ?T '^""^^^ '^^'^ ^^e ontheauricu,arrin..whiieveryraT;r:erJi;tT^^^^^^^^^^ Thp« • Genekative Organs. ^5th PrZ::^s':'re:ilZ'^^^:;:Ji^ ^^^ --»>^'- at or about the and behind which i„ oldr«robnr .^ '^*"' '^^ "°' ^^ instance, in one strobila ^mrtnraid'"^ "'^ - ' "''^ '^"'^'^'^- ^"-^ begimxings of the vitelline frdJs^^Tob^"^'"-"^'^ ^■"•"*^' ^^'^ ^^e and a few testes in proglottis »nn. ^" '" '^" '^th joint; more generative ducts in the mliianiine'in^h^^r'Tr'"'* in sections, of the the median excretory vessel fmm\. ^'''' * ™*^^°^""^'«i "ound and an uterus full Jeg^ni6 V "^'r' P'-^P^'-^tions) in ,5; surrounding the posterior k^l^or^t^n%^"^7^u'''^^^'^"'^^^^^^Se vessel, as shown in Figs. tTLdiTZ^'u" ^^^'^^ "'^'^'^ «^"«to^ proglottides 16 and I7.1^s^t^elv ^f"!^"^ ^'^ ^'•°'" transparencies of earliest traces of it c^ be 2^^ I! f ' °/ ^ ^^^^^ «*^°b"a- Soon after the end enlarges to become iVteTtSe aS« oT^h"' P'^P^'-^*'-^' ^^e anterior the vagina, while the posterior InH • ^ «'-™s-sac and entrance to of the "generative sp^TincLdin?^ "^ '° ^'^ °"^"^« ^"^ -^-s noddle part arises the '"uterine ^c'W^ 'utenne tube". From the All of the ducts seem tTXf f ' 7^ "* ^** ^^^ deferens, the vagina and cir^sTnot SThi"™?' f'^^' simultaneously, but somewhat later. Even ?he uterinf "'""''^^ ''^" °^ '^« Proglottis until at its posterior end in ^'e'^rrs^g^''?)^'"^ ^^"^-' «-^ace study of the development ofthe eS*I H ?"? ^'^^ necessarily brief corroborate, in general, the finds o?YotT%*^' """''' ^^ ^^le to to the manner of formation of th» 1 ""^.^ '3) and Schaefer (',3) as tial aniage. Further remarl^o^tie^" 'm' f^'*''^""'" ^-™ ^^1 s^X during the formation of Zcutldet T'^". ''' °! ''^ ^P'*''^"^' "^c'- I9I4I A New Cestode from Auu Calva L. 97 du'^^ oTtV'^"^- '^^^ ^^''' ^°*^^^'-' '^^' '^^ epithelium of the genital ducts of this spec.es seems to be almost entirely a syncitiu- 1 evenTn f^i mature proglottides, should have special emphasis I^ZXt fomard. There ,s m gen.tal sinus, although in some states of co^t^f ™n a more or less w.lMe8„ed depression into which thftrd^sl^" All of the reproductive system is accommodated in the meduIUrv penpherally. thelatter immediately within the longitudinal muscles of th^ ^nl^^^V'^ ''T ^'^ '""'^'^ ^'°"«^*«^ anterof^sterior^S Xta Male System the^V^t^^/^^'r"^^"'* '" ""^""^ '^^ "^«™«-«^^ i« ^hort and narrow sTtuateS Jlni Jh ^ K ""^^"""'^^ '"^^ *^° '^^^^*' fi^^s by the medially 40 m eacli lateral field, or about 80 in all (Fig. 17). 98 Transactions op tbu Roval Canadun Institute. [vol. X, ^h testis is surrounded by a verv thJ„ ^ u continuous with the wall of the val e^etnwp" ''"^' ^'*'** » ^"^'y ratherdifficulttomakeoutsincethrtlSr ^ !J° ' * P°'"' '^»''<* » the vasa efferentia anastom^ r^ r^^^^^'.'^''°^'y*°«^^''erand about ten. developing cytoXr^Tn v " """"• Numerous, even younger testes. ^^y'^Pho^es '" various stages may be seen in the The anastomoses of the v a s a » f f vicinity of the posterior end of the vL deferen" %^ "^ *^* "^ '° ^« notsowelI,amongthetesteslaterX^ I- u ^.^'^''7.21 ^n^ »2) and Thus it is conceivable t?a?sirmT;"^^ regions between the sets of gSS^^ T^T* ^'*"^*^ ^^^e deferensof the same progIottisrt?h"r.r^ ^"? ^^^^^ ^^V ^ the vas as the case may be. Th fwrid bl 1 • . " ^^^^^ «' behind, delicate walls of the te^Z whil ^ ^^^^''^^^^ed by the rupturing of th<^ form larger and mor:S^.^ibtch^^^^^^^^^^^^ of such ruptures were seen .n thi IrfS ^^l?" 'P"''"lf; ^any instances Ifndois (•;.) found that the testesTlr T- "''"^^- ^™™«^ ^"^ vas deferens of the joint ahead, but SSfrit '^'"" *° '^^ m this species in spite of the otherw^i [^°"* "^^"^ "°t found arrangement of the'genitaS duct' o"ti^ ^7'^?"''^ '^'"-" ^« selves, vary considerably i„ diam^hl! ^i "*^ ^^ efferentia, them- which scattered and flatten^ nucTdl^f """T^ ^"^^ ^'^'^ ''^'« « berg ('91) in ^./W^S^^S^T^.^w' ^ observed by Lonn- Just ahead of the uterine r^rJ!^- .u ^' ^^'^^- ^° and 21). rather indefinite s p elm r e TeTv'otr T '"i"^"*'^ ""'*^ *<^^-- « posterior end of the vas deferens m^V \l ^^ ^ continuous with the bling the similar structure of minV^L" *°^ "^ *"d 'hus resem- intermediate, as to thrst^ctu eTtJe^^^.^^^ ''' -^'» ^ vasa efferentia and those of the v^l?";?.' ^^'^^ ^^^^ of the boundary of the sperm-cistlt J^k^tv^Jh ^^''' "^^ ''''' ^*«"or of one to three separate vasa eff^rpn.- ^J^. *^.Po«'tion of the foremost that side towards which thetttfiX^eSt^^^^^^ "" ^«^^-"« o" ra^ydovasaefferentia empty in;;1jn:fde?rr^^^ ^^s^tran^-;:-^^^^^^^ tenor ends and graduatS ll ^K "^T' '^^"^^^ Pointed at tlieir^^ •tain very dense^Uh Hel*K^ ^^'JT''' '''' *^'- '^'^«« "e^d^ aequently quite eiy to pfcfou" " hi e [he'^r***'''^"" ^"^ '^ «>"- cernableinthemassesto^besee^in-J:^^^^^ I9I41 A New Cbstodb prom Auia Calva L. 99 The vas deferens passes forward from the sperm-reservoir almost m the median line and dorsal to the uterus-sac. taking many irregular roils m its course (Fig. 17). I„ older proglottides, however, owmg to the relatively enormous distension of the latter, it is pushed to one side untU all parts, excepting those close to the vtsicula seminalis, may eventually become obliterated. It seems to be crowded more often to the right, doubtless because of its position in younger stages; at any rate, the anastomotic reservoir formed at its posterior end by the vasa efferentia lies more often to the left. Fig. 17 is an exception to this, as It IS a dorsal view. In ripe joints before it is pushed aside by the developing uterine cavity, the vas deferens is tubular in shape, from n to 14 m in diameter at Its anterior end where it joins the vosicula seminalis, 17 to 25 a at its middle and 22 to 35 m at its posterior expansion, the latter being the diameter of the sperm-cistern. Later when it becomes gorged with sperms and the walls ar«, in consequence, thinner, the diameter varies from 40 to 55^. '^ The wall of the vas deferens consists of a low epithelium in which, as in the sperm-reservoir, no cell boundaries can be made out. supported by a pooriy-developed basement-membrane (Figs. 21 . 23a and b). It is thus a syndtium. In older proglottides, where the vas deferens con- tains sperms, the epithelium is flattened out so that the nuclei appear here and there along the duct as thickenings in an otherwise thin mVm- brane. In young, and, as yet, non-functioning vasa deferentia nuclei from the outer layer of the anlagen remain close to the basement-mem- brane, especially towards the vesicula seminalis, to form the myoblasts ot scattered and fine circular muscles (Fig. 23). The vesicula seminalis, which is morphologically an ex- pansion of the vas deferens, is situated close to the dorsal body-wall, immediately behind the cirrus-pouch (Fig. 17). It is ovate to spherical m shape m mature proglottides, before it is flattened against the latter by the gravid uterus-sac, with the more pointed end directed anterioriy, while in younger (but ripe) joints it graduates less abruptly posteriorly, that IS. It is more broadly spindle-shaped. The wall has the same structure as that of the vas deferens, excepting that the syncitial epithe- hum IS so much thmned out. especially when the organ is filled with spmns. tiiat the nuclei, which appear singly or in groups of two or three and surrounded by small amounts of clear cytoplasm, seem to be applied to the inside of the basement-membrane itself. Outside of the latter there are to be seen numerous fine muscle-fibies, with their myoblastic nuclei, roursing in general longitudinal and circular directions. These are similar m structure to those surrounding the vas deferens. On 100 Tiuw«c„oK. or ™. R„,, can«uk Ik„„„„. fvot. X. 0092 mm. 0.090 mm. Income the ductus e j a c u U tTr " u « T.^'"'^:' ^'''^- '7) to takes three of four turns ii the do^Il tlirS of thi ' ^"'°" °^ ^''^ ^"« pass^ on as an enlargement, the s7^ o n H • ""^'■'^"^^h and then occupying approximately he middle thir7 V "u" ' " ""»inalis. VlTiile the walls of the DrLjm!i . ?"^^ °^ *'»^ pouch (Fig rg) closeiy resemble in st:u'creTh^"or^^^^^^^^ eJaculatJrius qS or posterior seminal vesicle, th^ o theT .."■'"' ^''"^ *''« •^'• very thin, showing few nucld dotlylpUed ' n ^H T''"'" ««"i"alisTe The diameter of the duct at thTS -f .S '^ ^^"»ent-membrane. between the ductus ejaculatoriusTnS th/^ ^''" • ^' '^' ^""^on approached the epithel urn be^^mL brlk '""'' '^"''""'^ ^"'"^^^ « which, however, did not ap^ar t^ t^^ "?, .'"^° ""'"e™"' Processes ciha do not seem to presenHn ^"^^ "''*• ^^ » -"atter of fact The third divisioitf the !L^5T°'*h^"-'« reproductive duc^^^^^^ ;= rrus proper, ul^ cTmmtrarth" ''' "'^'■^-'^' '^^ latter, courses forward and tLrbT^^S '^^ P^*""°^ P^^* of the pouch and open on the ventral sul^^^J^r '° ^7** ^« ^^^ of the shown m Fig. ,7. The diameter of ^c- ' '''^'°"'« *' ^^e point (F'g. 38. c) is about 20^; it enW^ tj'T ^' '^" ^"^ '" »*« <=our8e the outside. '^' ^"'^'^^ gradually to 30;, before opening to This region of the male ditm^ u mostcestodes, to form a copuirtor^ ^vaginated, presumably, as in not a single case of eyen7d^ZZu' '!l'" '" *^^ ""^^^"^ ^^ hand can be offered, in regard7o"t?fu^? "^^^ <^°"««iuently. nothing from the frequent aplro^WtW^^^^^ the sugg^on tha? noted above, self-fertili^ation may ^.S' ^"'^ ^''"^" ^^^^ structure of the cirrus would atTZ.^!f^ °*'*'" '" ^^is species. lS become quite an efficient o' J ^tl*^^^^^^^ ^^er eve^ion it might mner lining of cuticle throi^Tto fnZ f ^^'?- **) '« composed of an a basement membrane whlS can h! ? . "^""^'"^ '^^'^^*«' ^"PPorted by I9I41 A Nbw Cbstodb FKoif AuiA Calva L. toi procewes from parenchymatous cells lying farther out. The circular muscles increase in number at the opening of the cirrus and form a dis- tinct sphincter. In that portion of the cuticle next the lumen, that is towards the functional outer surface of the organ, there are to be seen numerous highly-staimng granules which seem to be the bases of fine bnstle-hke processes extending into the lumen. While the granules show very plainly m sections, the processes themselves are difficult t^ make out clearly m many cases. They are. however, probably homo- logous with the spines, hooks, etc.. described for the cirri of other specTeT Hg. 25 shows a somewhat younger stage in the development of the cjmis than that shown in Fig. 24, and is of interest in connection w th ^H^t" J?^- u°T''°"°''***^"^' -'• Considerable attention was paid to detail in this figure in order to bring out the following points. It will be seen that four or five nuclei lie close to the cuticle in^ .act against the basement-membrane, while otherB farther out appear to be connected with the cuticle, or at least with the syncitium of protoolasm IZ^ ^°T, °^ "' ^ '^"^ '''^"^'- M^"y of these peripherally situated nuclei belong to the myoblasts of the circular muscle-fibres i th.!^'. v r •r^'*'^ the former, are fairly easy to distinguish from the majority of h. numter wh ch have the central protoplasmic connec- If ^. J°""^ ^ '^^ *"^ ^^^^^^' ^^3). working with different species -T ,• .^' *^T *° "1"'** opposite conclusions regarding the fate of the epithelial nuclei during the formation of the cuticle in the distal portions of the vas deferens and of the vagina. Young asserts that thVnuclei disintegrate in situ as the cuticle is being formed, while Schaefer ob- T^^J 'idoubtless the migration of the nuclei into the surrounding cytoplasm. The wnter does not pretend to have gone into the matter at all exhaustively, but from the few observations he has made on the matenal studied it would appear that this species falls into line with bchaefer s discoveries. At any rate, no conclusive evidence of nuclei having disintegrated in situ in either the cuticle of the cirrus or that of the vagina was met with, but appearances like that shown in Fig. 25, where the original syncitial nuclei seem to have migrated some distance from «ie developing cuticle, retaining their protoplasmic connections and possibly functioning m the formation of that layer by secretion, are very common. In later stages, evidently when the cuticle is completely formed these connecUng strands fuse with the general mass of paren- chymatous cytoplasm surrounding the cirrus and its retractor muscles gmng the appearances shown in Fig. 24. More will be given below in this connection under the vagina which, on account of its comparatively peater length, is better adapted to show the stages in the development I03 T»A»«CT.OHS OP THE R„v». a»AO„K I.ST,r„,, ^ [vol. X. and ven47s;r":<.:oVth: »stld™?r ^*"-" ^'^^ <^o--' Kmmalis (Figs. 17 and ,8^ T l •^'''^^^'y ^''^^^ of the vesicula laterally and'somLhat pro Jcti''^'' " ^P''^!^'^^'' «-"« ^aS the cirrus to the latter'soSnSgS^thXo"^*'"^^^^ ^"""^ '' ^-"^^^^ longitudinal diameter. o.^T^ 21 '1 °^"«'""^"'^'"«"t«'•ndicate: and co.Xd°'ot;^o"::tr?b;it^^^^^ ^« -HoH^ .uscuiar such ,n younger proglottides thin h^ S ^ ^"" distinguished as cou,^ irregularly and obhquely O? ^^IZ ^^^'^^^s where they larly disposed while the outer are aLfrZ^T "^'''^^ '""^^ ^'^ '^rcZ Ponding to the description LI^T^ ]°"^*"^'"^"y' thus corres- of the wall intermingle wfth thJ ;^\ P°«tero-do.^ portion postero-ventrally they conv^^^ tot^H, 1 "^^ ^'^'^^"'^ ^'"'"alis; around which, with the dorso^ISr.i/''^ °P^"'"« of the cirrus neighbourhood, they ^ITZ'ltZt^:!^,^'^'^^'''^^'^--^^^ very few fibers, on the other hand d^ffi i. ^- '^*™' ^"•^ace. A dorsoventral parenchymal ^sdes'ai?^.K^^^^^^ from these to the dorsal body-wail. ThuTreSon "f ^f ^°^' ^"" °^ '^^ «^« ever everted, would appear to 4 bmulr t ^l ''"■"'' '^' '"d^. it is 'ts tissues and of thoJ^Tuioun'Sng? ^ ''°"' '^ ^''^ ""^^ ^'-ticity of acc^mtSat^trcrtia^^^^^^^^^^^^^ yesicula seminalis. is filled Sn^em" "" ''r"°"' '""^ --"^ "regularly around the duct outsid" of th. TT^^""^' ^^"« ^^"Ped fibers following the course of the atter Th '°r*"dinal muscular are visible as spindle-shaoed ZIm I • ■ ">yoblastic nuclei of these the fibers themLves. T^;.e^^irhln^ bodies, closely applied t the other hand, appears mnc\. S^i comiS ' ^^^^"^ °^ '^^ '^^^ «" preparations, since it is in this r^^onXt the ". '^"°"' ""^ transparent cirrus are located. The latter .1 the large retractor fibers of the attached evidently to the ^ti^: ^at '"hT''.^ ^^'^- ^^^ ^^ peripherally with the fibers comS,sinrthf " ^ '^^^ intermingle blastic nuclei are related to theSs »« • ^f °^ ^'^^ ^^- ^he myo- muscles of the parenchyma, th^ is ^ne^ ",''' ''" °' ^^« 'ongitudinal or four fibrils. In addition to he drcurfit' '' '"^"'"^ ^'^^^ ^^^^ outside of the cuticle of the aWs pro- " L " "T'"^ immediately feen for some distance beyon^the ^n;i ^"^ °"'"'" '^"^^ °"«« to be -ter^inghng with the larrre't;i:r,oT^l^^-[^^^^^^^ above-mentioned. 1914) A New Cestode from Auia Calva L. 103 Female System. A- l^^lt^\ u* °'^"' °" ^''^ ^^"*'*' ^"'•fa^ of the proglottis imme- oZ 1 '' T d>ameter, ,t is occasionally found in preserved material to be transversely elongated, more especially when it approximates the male opening (vjde supra). The first portion of the vagina is in the form l'er:i: ' ""r^*' "'^"'^' 5' " •" *^^"-«^^ diameter and ^tuated t^the 'Uh.r' ' ""V^f c' '' " ^"'*^ comparable, in shape at le^t. J.flt.pH H r"^^^ °^ ^'"'""'' ^"^ Landois. After being slightl^ deflected dorsally, a« m Z?. /«/«,. the duct then passes back alonf the ventral s;de of the uterus-sac. on either side of the ^ian line, or cros^ from one side to the other at different levels ahead of the uterus^open nj^ n young proglottides ahead, necessarily, of the limb of the uterus^ir^L towards the latter. In either case it turns to the median line again dote to the posterior wall of the uterus-sac. and then passes over the ovarian isthmus and into the "generative space" where it expands, as it cour^ ventrallyagain.toformar-eptaculumseminis. ^ »t courses of ^J'^l'Tr^ °^ '**« ''^"^ '' ''"'^^ comparable, on the whole, to that s ptrt^ bf r- /r"°;'y '* '« "-d with a syncitial epithelium, supported by an indistinct basement membrane which is relatively somewhat thinner than that of the vas deferens of the same pro^loSs excepting m the region of the receptaculum seminis (vide infra) S ::.tt"u^"frtm T' '^^ '''!i'"""^ '^' ^"^ °^ diffe^ntiati jn of the two tubes from the middle and narrower portion of the common anlage of the genital ducts the vagina is somewhat in advance of the vas defer! Tthfl' ."• " ^ru'^P" ^ •"■""" ^"«^*'y P'^^'""^ t« the formation of one ^Itl A^^^ "''"' "^^'"''y •^^P^ '" ^^^^'^ °f >t during subsequent Serus r t r""°"- f°™ * P°'"* °PP°^'*« '"^^ ^"t^ri- end of the cIl ;r I^^a'"^ '^^ ''^^'"^ '' ""^ ^''^ a ^"ti<=J« ^hich in many cases islacerated and torn, especially at the surface next to the lumen. I^ this region, at the proper stage, that is. about the time when only a few eggs appear m the uterus-sac. what was considered by the writer to te the transformation of the epithelium into the cuticle can be obs^^ed much more clearly than in the case of the cirrus where only a corZj. .vdy short length of duct develops a cuticle. This seems to be bought a^ut almost wholly by the sinking of the nuclei into the surrounding sTde o? th h T""^ K°" *'' ""*^^ '^y«" °^ '"^^ ^"•a^e -"d lying out^ atra iln At """""uT? ""^ ''^^"'"' '""«^'^^' ^"d by the subs^uent alteration of the epithelial substance to form the homogeneous ^licle Very few nuclei in their passage through the membrane were ^n ,i„<^ no lengthy study of this subject was undertaken and since. as^g^JS 104 Transactions of the Rovat n THE KoYAL Canadian Institute. [vol. X. bv Sch f • thus renllXT^;:!^?he'^^^^^^^^^^^ «'' Probability, quite rapidly some difficulty in a comparat Idy sS nit °' /'^ ^'^^^^ ^ '"^"er of' are given, however, to illustrate whTt ^' °^ ^"^- Three figures connection. Fig. 39 is a phot:;api Tatrl '^ ^'^ ^"^^ ^ "^S fim pomon of the vagina^he Ttrance to th? ""'"u" ''''■°"«'» ^^e V . The latter is seen to be sunrminn!^ k ""^^'"^ ^'"^ ^hown at cylindrical cells with roundedlrTn^r^ . ^^ ^ ""'"^e'- ^^ radiating -rnewhatresemblingthecetoft^^^^^^^^^^^ more numerous around the enwl? ''"''^'^ticular layer. They are much the duct farther back At ' V'TneXr '' ^ ^^«'"^ ^^^ -ound nucleus situated at its extremity rattLh.T/'?^"*^ *=^"«' ^'th the and m such an intimate manned L to ,ead *'' '"^^'^'^ tangentially functions, possibly. i„ the formatio^ o? thelT '\*'''"^ *^^* '^ «till y . F'g. 40, two nuclei with tl,« 1 .. ^"^'■- Again at "x" and JSf r "^'^ '""^ bar:LltTbret?tT^'"'" ^^P^- 'o hfve d stance beyond it. A similar c^ i shotn ifp '"' ^°"^ ^^'^ ^ ^^ort at the point marked "x" a nucfeus ha7" L^' *' ** >"' ^hile at membrane is to be seen. As the nul. f / *^~"^^ ^''^ baseraent surrounded in many cases hycCtj^ '^-.^^^ '^' '^««^ they are m consistency, as noted by tchaerin"!?:* "J-"^^^^^ Thus It appears-to the writer I? i ^"^^^^^^m pithonis Blain t.on of the epithelium of theX^'^'ir?!''*' '" ^^^ transforma 'nto the cuticle, the nuclei of th^?^^'*'" ^"^'"^^^dvas deferens parenchymatous tissue, and may thjrr' -^"^ '"*° '^^ surrouS 'atter. While the aboU eviSe'^! I ""?°" '" '^' '°™-tion of hf elusive it is given in the ho^s "hat it^'u k^ *° ^ "°"«'dered as con! f^ader in connection with trqueTtion f .^ ^' ^'^' ^"8«««tive to the •" -^todes. which is again o^cu^^ the it tenV "^^^^^^ °' ^'^'^ -*Se . Pe musculature of the vaeina ;«V attention of helminthologists m C3-a/A.ce/>Aa/«. /r«„JrSL^^^ '"Tf^ °^ "^^"'ar fibers on^as outside of the basemenrmimS; " vl'? "'"^^"^ immediate" the greater part of the canS fnH ^- ^. ^^"^ °^ them surround but a comparatively large numi)erj'?^ '' ""*^"°^ enlargement between the latterand thf o^ to Lm' ""^ '" the short' r^ 40 Mm length. ^"'"» ^° ^^rm a powerful sphincter, 30 to V'-Jg- a,;. The diameter of the tuh*. o^Tu- . **'^ ^"'ost tie tube at this point varies from I9I41 A New Cestode fkom Auu Calya L. 105 30 to 45 n, depending on the amount of its distension with sperms The receptaculumsemini. is lined with a direct continuation of E^cSl epjAehum of the vagina, in which, however, some tenden^ to fo^S bom^dane. appears, especially in the earliest stages, lio vd^Hke modifications of the wall sm rlA«- ThiB musculaTureTe^! dratiy developed for the purpose of passing along, by swallowing moC^ Z^'^^ ^ '7 '"^ "' ^ *''"«• ^ indicated in'^.he dS wS shows a string of sperms connecting the mass in the center of Z ^^ ^^^^hthespermaduct. The latter in all lH^^ li fited^S Immediately behind and ventral to the i«ceptaculum seminis th.. yagtna narrows down abruptly to form the s p e r mad" c t ml^' ts fim portion, as indicated in Fig. ,6. is ver? small, ^ing only^m dir«I^«i,^K t;°''"'J' ~°° ^^"^^ *° *'°»°»t twi;e that d^leT the size which obtains throughout the rest of iti. rn..«« iZ ™*™®^*^' die intense staining power/of thr:u:^u:d „g ^u^lat^^T^' difficuhto a«»rtain the nature of the wall at thSl^e ' h^w^ 7i. composed of a very thin epithelium in which no nuclei waT^' r^" the other hand, certain nuclei situated outside of tiie ba^iZT r^*K„ ot' oTS^nS- T ^?^ ^^^'""^^ strand^. on\'rXtremtdtg one of the radiating cells surrounding the cirrus and the entrance tolh! :^;:CeTnd^'ottr t" '7r ^^^^^ ^'^-"Sm att nucl7o?^edrStr'r^,es'°Tolt™-^ nuclei it »«.;w ir ""*^'^- To determme the exact origin of these of le iu^ nf .^ "''*'^ '° "*^ * -P^'^ «t"dy of the dVvelopnL^ durt i^ generative space, since the musculature of the s^^! duct anses very early, even before some of the other ducts in the^ diat. n«ghbourhood are completely differentiated T^Tj^^ Z^ dimimri* in number throughout the remainder ofthe durt b^^ ^ r 106 TmnsACHONS or THE ROVM, CANADIAN IKSHTUTE. [vOL. X. "'''5';fP^'«l behind (Somm^ a„d U„S The o^knhT ihe largest ova (Fig. 28a), which appear in the ventral narf «f ♦!, With Mallnr«'. * • u . °' """^ °"* extremely dark blue •rercgation of nucleoplaanfc jarticL v«T5l, '^ ° ' """ I«o« of which .b«,ptior -re p«,b.bly f p««„S in Fig .T I9I4J A New Cestode from Auia Caw a L. 107 The o V i d u c t begins on the ventral surface of the ovarian isthmus with the o ocapt which is a broad funnel-shaped or hemispherical structure directed ventrally in the median line (Fig. 27). - ^ter of the latter, using the outer limits of the circular musculature as the boundary, since the organ is very gradually continuous with the wall of the isthmus, varies from 15 to 25^. It is lined with a cuticle-like sub- stance, which shows no nuclei for a short distance, and is surrounded by a system of circular muscles, arranged and extended quite like those of the spermaduct and posterior end of the receptaculum seminis. Further- more, the resemblance in structure is the more exact from the fact that Jie constncted portion of the duct, which immediately follows the muscular funnel, is surrounded by radially arranged nuclei, many of which belong, of course, to the myoblasts of the circular fibers The constncted part has a diameter of from 8 to 9^; after which the oviduct gradually enlarges to 15^, as it courses to the right or left and posterioriy until It meets the spermaduct almost in the median line of the proglottis The wall IS made up of a ciliated epithelium, in which are to be seen one layer of nuclei but no distinct cell-boundaries in the somewhat vacuolated cytoplasm, supported by a well-developed basement-membrane. A short distance from its union with the spermaduct the oviduct is joined by the short duct from the yolk-reservoir. Just behind this point there is a slight constriction, around which the circular muscles are augmented m number to form a small sphincter while they are accom- panied by a few longitudinal fibers. Two v i t e 1 1 i n e d u c t s , each about 6^ in diameter, collect yolk from the lateral fields of vitelline follicles and pass towards the median line to unite either within or outside of the generative space ventral to the ovary. Union within the latter is the usual arrangement, in which case each duct is accommodated in the groove situated on the ventral surface of the ovary between the oocapt and the anterior end of the limb on each side Each of these ducts may receive material from a few folhclM on the opposite side of the proglottis, but, in general, it collects from the same side to which it is directed. Their walls are composed of a thm epithelium, showing small flattened nuclei distributed at wide intervals, on the whole resembling those of the vasa efferentia. Their ^""TJ^n^"^ ^°"°*"* ^y observing the, in many places, greatly attended yolk-cells on their way to the yolk-reservoir (Fig. 29b.). On the otter hand, the arrangement and structure of the smallest ducts in immedAate connection with the yolk-foUicles were not determined to the writer 8 satisfaction, since the latter are packed so closely together; but from various appearances they seem to anastomose. 108 Transactions OF THE Royal Canadian Institute, [vol. x. The common duct, which is quite short (Fig. 27) is sliehtlv !a««.r *u ^e collecting ducts, and its epithelium cL^nrZt^y'rl^^^^,^ It "furthermore provided with cilia, directed towards the yoT^^^r After passing for a short distance dorsally and towards ei^r^X' o^ the proglottis, depending on the arrangement of all oTSfductsTn £ gene^tive space, this common yolWuct expands into the v1 tell in e IkLW- J' *" '"'^•^"' ""' ^'"^^h^t spherical sac varying from thSydkisaS^rh""'"'"? -^'^ -^ conta^ e4" ^iTf^ ciia^^^^^^^ ^r"""' '' 'i"""^" ''*" '''' ^°'"'"- d"<=t and shows tional dilatation tL !Iv?T • °' ^ """^ temporarily func- and flatSS by tJ^'con^^lXir'Thf" ~"''"^''^ ^'^^^"^"^ o^ductth^ughLho^tr^^ » Identical with that of the above-mentioned portion. ^ mJ^r/***"'u"^ follicles, like the testes. are situated in the medullary parenchyma, that is. within the longitudinal muSes a„d tT.Sut^'th"o^tf tf "^-^-T"'^ (-d« -P-). thus rermthng!"^ TeS^Tn^rdlll '^"' :ir^'r^^^- Montic. and AnJcko- handNbothfieldsaccommodaten'ovltet^^^^^^^^^ butlJril • ■'' ^'^T'''^^' ^^ "^"*"y spherical to ellipsoidal in shape- the smallest being only about 8^ in diameter, while the krSstwh oh L- inaSritv '^.'"J^^fi^'.obviously owing to their relative states of •cmnm^.*- ; ^* '^ *««"' however, seems to be the result of the «x»mmodat.onofanumberof semi-fluid bodies within a fairly te^se 19141 A New Cestode prom Auia Calya L. 109 membrane— the yolk-cells within the follicular wall. That the yolk- cells are semi-fluid in consistency cannot be doubted when one observes them in their passage through the vitelline ducts, as noted above in connection with the description of the latter, and as shown in Fig. 29b, where the nucleus with its surrounding clear area is distending the wall of the duct. The nucleus and, for that matter, the whole cell in many cases, resembles that of the ova; in fact, it is often quite difficult to decide which is the ovum in the egg-complexes to be found in the uterine tube. In most follicles the smaller cells are arranged around the wall more or less like an epithelium, as described by Sommer and Landois for D. latus, while the larger ones are to be found in the middle. The wall itself is a very thin membrane in which no definite nuclei were seen, although small flattened nuclei situated between the yolk-cells and close to the wall may belong to it. Perhaps the most noteworthy peculiarity of the yolk- cell is the large almost clear area to be seen in the cytoplasm, often surrounding the nucleus (Fig. 29), which is doubtless the fluid yolk which will later be absorbed by the developing egg. A short distance from the point where the oviduct receives the com- mon vitelline duct are located the shell-glands. Here the oviduct expands slightly— to a diameter of 20/x. In most of the series examinee' the shell-glands formed a sort of vacuolated meshwork, in which, although there were to be seen well-developed nuclei, 4 to 5^ in diameter, it was extremely difficult to distinguish individual glands. However, in one series, where quite a length of oviduct was cut longitudinally, two or three club-shaped unicellular glands could be made out (Fig. 30). Their connections with the former were in the form of darkly-staining bars traversing the epithelium between lighter areas of about the same widths. Furthermore, numerous thread-like processes situated in the lumen, of the oviduct and directed towards the uterine tube corresponded with these dark bands, at least in position, since they were divided into groups, each group being opposite a dark band, as shown in the tigure. While the outlines of the glands are quite difficult to discern, their connections with the oviduct are readily seen in sections through the region in almost any plane, tangential sections, for instance, showing dark circular spots on a much lighter background. Again, in younger proglottides treated with Mallory's stain, the glands and the otherwise dark bands appeared much lighter than the epithelium, which fact further supports the view that they are related anatomically. Thus, from the foregoing descrip- tion, it appears that the processes in the lumen probably constitute the material secreted by the glands, and that this material is passed along from the bodies of the cells through the narrow necks which act as duct- lets, suggestions which are strengthened by the facts that the so-called "O TRANSACTIONS OF THB ROTAL CaNADUN IKSTITCTB. (vot. X. ^'^:^'Ztr^s:::^^r''' ''^ ^'^-^^ -^ ^•^^ ^^« <»-... fim portion sTSirX^Sl ,h^^^^^^ **"* '" ^'^'^ '^'^^ 'ts the writer is inS toS^ 1 r "" T^''^^'' ^^^^e latter that farther ahead. 'necijlrmu^l.I"^^''.^^ demarcation somewhat developed, but what aD^aiLr^-!,'^.^^^^^ ^"^ '"°''« ""'formly of cUiltp^oh^ylZZ^^n of tT .^ ^J^-tation in the number the shell-glands. Wh^ tL S *^' *^'?^^' °^ '"^*^"«' ««"eted by dorsally. anterforlyTn^gterdlf to the TIT fu""' *"^ '^ ^''*'=*^ ginning of the uterLtuimakL a ^^^^^^^ P^°^'°"''' '"^^ be- again or expands immediaTe^ nto wh^ miZ J^'" ?rr\^"^^^^^ division of the uterus. (Fie 27) 80^^;, ^^ I ^ '^""^ ^^^ ^~"^ the uterus according to Braun '00) "Lt IIT '^" '"'"''^ ^'^^'^^ ^^ in the "Uterinean/" nr ?f • i' ^* '^'^ "°* ^"^ ^ recognize gically; his 3d%lXio„ Tt\e ^^^^ ""^ '"'^•°"«' ^'^^^^^ ^isfolo- thisspeciesitisin^hefZ^frttf^lT"::^/^*-^^^^ '" £ti;sit7s7:;;h:rrof:tri:frmT.r^^ of which are very thin aTd rom^^ ^ *° ^^^ '" diameter, the walls in which quite flTttln^nucleiT^ . ^ ^"f"" "'''""^"^ ^P'*''^"""* cing in the dorsal rrS>""f.\,'^^^'' ^'- '''^^^^' •"^«^^'«- ^ommen- and in ripe pro^o^rid^ Xrna^^^^^ "" ^ ^"^"''"^ «*««"«i «P-al. the uteru^s^c frKentiaSv r^^ down appreciably before entering composed of mry"S„3trndt t^.e^^'. 'S'JT' ^"^ or a small number of cells resulting from the filt ? ^- • ^^^"^ ^ o^™) by a thin shell. In develooment fhlT^ • ^ divisions, all enveloped into it dorsally and sSfvI?^ the uterine tube, the latter opening opening thTu er^slct„dLl?v / f ^''"°'' ^"^- ^^^^^^^ thif the apertu.^ wTw a^I^t whiC "* "?"'""^ '° '^' P°'"^ '''^««' forward in the mSr«>t dis^^^^^^^^ first as a narrow tube latPr « T« °»stance from the ventral surface, at It is composed of a svncitial *.nJ*K i- • 1. ^^ generauve ducts. 1914] A New Cestode fbom Amu Calva. Ill with growth, so that eventually, in gravid joints, the waU appears as a very thin membrane, showing practically no structure (Fig. 19) In slightly younger stages than that shown in Fig. 17 the lumen is not so umform m outhne, since its anterior half is divided into shallow evagina- tions, somewhat comparable to those seen in the uteri of the species of the order TetraphyUidea. These soon become obUterated, however, the inside of the wall in gravid conditions begin quite smooth. The opening of the uterus-sac, situated, as shown in Fig. 10. towards Its posterior end. seems to function for a short time only, since in the longest strobilas no trace of it was found near the end of the chain. In the middle region, on the other hand, it appears as a very narrow slit, about o. I mm. in length, in only a few proglottides. Furthermore the uten in which these openings are to be seen are generally almost free of eggs, as if the openings had been used for the dispersal of the eggs in the usual manner among the Bothriocephalids, while those behind the region in question are tensely filled. These facts would lead one to think that in most proglottides the eggs are freed by the rupture of the uterus and the body-wall, as in the higher cestodes, beginning with the TetraphyU hdea, while the uterine aperture either functions for a short time only or m proglottides, probably more or less constant in number and location Fig. 31a IS a view of the opening drawn from a transparent preparation in the uterus of which were comparatively few eggs. It is seen that the sht 18 surrounded by a clear area beyond which there is a more deeply- staining region. The latter is in reality made up of radially arranged nuclei which are related to the clear area in a manner better shown in coronal sections of stages prior to the breaking through of -he slit (Fig 31b). Here they are seen to be connected with the dark line, where the sht will appear later, by fine striations which continue farther out into the surrounding cytoplasm. Whether these radiating nuclei form a glandular organ around the aperture or give evidence of a migration from the clear area which remains as a cuticular rim, is difficult to say; but from the close resemblance to the structure of the cirrus and of the en^ trance to the vagina, the writer is inclined to the latter view. Development of the fertilized ovum, which begins, as mentioned above, in the uterine duct proceeds in the uterus-sac, eggs, bearing on- cospheres, being obtainable from proglottides situated towards tiie pos- terior end of the strobila. ^^ The e g g of this species is an ellipsoidal structure, from 60 to 70U in tength and from 40 to 43 ^ in breadth. The shell is uncolored and perfectiy transparent, so that the contents can be observed quite easily J^ig- 32)- It is lined by a very delicate membrane which, however, can be seen only when it is, in some cases, separated from the former (Fig. 33). iia T«^J«*cxioHt o, mu RoTAL Cakaouk Imrvn. Ivot. X. movements of the latttT^Z^T' '"*" •"PP''«J '^th cilia. The the .hell, especially uTli^^^ ITnT^? '^'t^^^^^ " within this case they vibrate 80^eo,^rtj!t^?"** J°.^^ cover-glass. In to the larger end of the ^^TdnuliJ ' embryo is driven - kept continually in*^'o't,t -Hr "sTSL^a^'^^^fr "'-' .henispro'vid^tt^;'':;tiHo?e:rJS^^^^ ^« account of theS^Tf'the^a^r T- 1^' '^"T'^"' '''*""' "•""*' «» the dlia anj freed they pr^ ?«^k^.*^ ''T ''^ 33- As fast as -ahne solution. andTsC^thl ,^^^*\**"»"8'y " "^"^ surrounding •wims away quickly Seehh.r^^°u''" ^^ '^^ ^« «*«" it erratically in ir«^,i ^Tj h w^'S'* ' '?:;r °' "°^« ^»>°" directed posterio^f^om Xi m^Tt^Zi^^u'*^ "***' *^^ *=^«* ^ a" within and without Sn-lZ^t,?'^ "^"^^^ °' ^^^ »^y. both only from its direction durinJCt^^tu; T""" ^V?^ " ^^*^°'' «<>* end of the oncosphere opS To ^W li! u"" '** *^°« "'"**«* '^^ ^he While the mantte is c^^Jilell iT^? .^commodates the hooks. about 45.. the oncospSTa^Sm a^t V." Ti t?^^^' **'"« no structure was observed inThl^H^^ ^^/ "* ''^"«*^- Practically oncosphere, on^e ^ h^/l """^^^ ^^ ^« mantle itself. The pair of A^e^eU^^'l'Z's^^J'r^-^ ^^ Pair» of hooks, a (Fig. 3.). Themovem^iTfSh^ks^roflf^''"^T^^ Phere are quite typical. They taL ?J!!l ?^ ^^^ °' *^^ °°cos. Within the shell, but. as h^b^^J^J'^^ ^^^ ^"^ ^"'tjryo is yet when the whole ^gg has beln s^n JS. ? '" "^^ Preparations, only are quite irregul!? aid ^^^w*? -J P"^"^' '° ^^^ ^ they perhaps a iiSe freeTwherS^l °"''-'?*i?' '^'"^*«*- Tb^V ^ in situ, is liberated ItZ^LtZ' -"''"fu"^ ^' *^"^*«» "^^^e shown in Fig. 3.. in thl fo^f^f t tetr^^L'S^ "^ "I"^!^' " situated at the center of the oncosphere wSe^^t ""^.^^ "^^"^ « tenoriy. From this oosition ♦»,» • l . ^® "^^^e is directed pos- each oA„ u..i.X^ iteX'Sr"^ 1^ "«"" 'PP^ •iiverge toward, the bounS Z^K^^'^' T"* *' «"«^ «■* I9I4] A Nbw CE9Tcn>B ntOM Amia Calva L. iij oncosphere up to the small process, situated a short distance from its tip (Fig. 32). This process and the slightly swollen central end of the hook seem to act as bases of attachment for what appears to be a well- developed musculature actuating them. The hooks again approach and the whole cycle is completed. In the most vigorous specimens these movements take place at the rate of about three per minute. As might be expected, the slightly smaller anterior end is much affected by the movements of the other end; however, it exhibits movements of its own, consisting of small waves of contraction commencing at the inner ends of the hooks and passing forward, thus in a direction opposite to those seen in the plerocercoid and in the young strobila. Concerning the life-history of this species nothing can be offered at the present. It was only noticed, as mentioned at the outset, that plerocercoids a few millimeters in length were found in the intestine of the host along with the largest strobila taken. The food of Amia calva consists, however, evidently entirely of small fish, mostly minnows, and it is possible that one or more species of these are the intermediate hosts. SUMHAKY. The form of the body of this worm is peculiar in that proglottidation is expressed externally only in the anterior end of the strobila, beginning immediately behind the scolex. Here the proglottis is prjvided at its hinder end with four ear-like appendages directed posteriorly, which, in conjunction with their fellows of the neighbouring joints, may act as important accessory organs of attachment, perhaps by forming temporary suckers or using certain rows of spines, arranged around their edges, to obtain a hold on the mucous membrane of the host's intestine. Pos- teriorly these appendages disappear, leaving no indication of proglot- tides apart from the sets of reproductive organs which follow each other at regular intervals in the usual manner. The scolex differs little internally as well as externally from the fore- most joints, the two bothria or suckers being comparatively feebly developed. The musculature is particularly well expressed in the jointed region of the strobila which > consequently the most mobile. All of the usual groups of muscles to be seen in Bothriocephalids are present, the external longitudinal fibers being quite distinct from the inner or longitudinal muscles of the parenchyma but confined to the anterior end only of the strobila, while the outer transverse series is divided into two sets on each surface of the proglottis, the fibers of which are directed postero-laterally and thus made to decussate in the mid-line. The individual fibers of nearly all of the groups of muscles are characterized by having their "4 T«AK1UCT,0KS or TH« RoTAt CahADUK InshTUT.. (vot. X. of the myoblast.. '""' ^""^t'OM with the protopIa«nic ... tance The nervou. .ystem coiuist. of two chief .tr««H- •* m the medullary parenchyma r"M»rW?u! *^ ?' "*"***** l*terally e<,«iltleS^r urirr^an^r '^ ^^^ ve«e..-the and ventrally. Ail of theL^ni^.-TT . ""*""' "'*"««* ^^^^Y ac^mmodati;di„the1:J,::S "thte^^^^^^ and^«ame^„3 are fairly numerou.. butXr""cS.„^rLrS:2: on the ventral surfa^in^Sedl ? ^'"?"' "f^""* ^"^ «" '"■^•'»*«^ the cirrus-opening towards tTer.''""' '''? ^J '''" ^^"^ <='°« '^hind the uterus much farth^back and ^^7 ^^^ °^ '**" P'^'^*^'' that of There is no distincttnitarat riul ^cS ' ""^'^ ^^^ -•^• vitelline glands seMranL?^ ? ^"**^' **"*^ '^t'* *«»t^ and fields". TlTe vaX?*n. ^'J: ^"'' ^^"^'^''y *° ^^^ clear "mid^ uterus-sac Jsp^C^dt^tjTsl^r^ 'J "^^ ""*'*" "°^ '^^"^ **> t^ glottis, with a spe^^A^S ^d Tk'"? "'"'/'^' "'^^^'^ °^ ^''^ P«>- vesicle situated irmSrihlnH^K^ ^ *''"°** "P''*^"*^^ ««™"a« spheroidal in shar^^^^nlf • ^ ^^"^ cirrus-pouch. The latter i. of the vas-deffrS:: S^ "nrth^ ',1^' ""'^'"' ^* ~"^°-^°^ second seminal vesik Tnd the dr^r ^^-^ "".'^^r'^^^^ ^"^' * in which there are small stout sn^ 7^ T " ""*^ '^'*'» ^"ticle of well developed cfrTulLTuLr ' "°""' "'^''^' ^^^^'^ » ^ "^ri- supp'L;Tra's;hVc^:rr3ci: TouI" ^^ ir^ ^^^ -^••^^^ -<» the "generative spaS"' toTorm ^ T^, ''""^'^'^^ *"^ ^''P*"^* '^thin from the very sm^L In I'tiSot r'""''' J^"^'^ "^P^^"* with the oviduct in the usu^wav S ^ ^""!?T ''**'^ ""^^ median and respectivelv vTtf,i ?^\, . "^""^ ^^ shell-glands are posed of nu^Z^Tmc^^n^^'T'. •'^.^ ^°"^-«'^"^^ ^^ «>'«- both within the i^Ss^iTu^ 2';ii"^^"^ r ""' ^' *"*«'•- large Volk-reservior, situatSr^f.^i^.-^'"'*^"^;.'^^ '" » divided into two distinct ^nt^rr::^^^^^^^ 1914] A Nbw Cbstoob raoM Auu Calva L. 115 common genital anlage, a much-coiled, proximal, thin-walled tube, the uterine tube ("Uteringang"), and a capacious uterus-sac ("Uterus- hOhle") which, when gravid, occupies almost the whole of the central portion of the proglottis. The eggs are provided with opercula. All of the genital ducts are lined with an epithelium which, on account of cell-boundaries being almost entirely absent, is of the nature of a syncitium. In certain regions, namely, in the cirrus and in the entrance to the vagina, this syncitial epithelium becomes transformed into cuticle with an accompanying migration of its nuclei through the basement- membrane and into the surrounding parenchymal cytoplasm. From the foregoing description it is to be seen that, although this species is in most respects a typical Bothriocephalid, its characters are such as to render the placing of it in the existing classification of the families and genera of the order, Pseudophyllidea, a matter of considera- ble difficulty. However, since this subject is dealt with in another paper, as mentioned at the outset, it will be sufficient to state here that, so far as the writer has been able to ascertain, this is a ntw species of cestode which must also be accommodated in a new genus. Consequently, the following names are proposed: Genus, Haplobothrium (AtXoO., simple; fioOplov, a small hollow or trench); species, globuUforme, {globulus, a bead ;/orma, shape or form), the significance of which specific name has been referred to above. The type-specimen of this species is included in the writer's private collection, while a co-type has been donated to Dr. H. B. Ward of the University of Illinois. Biological Department, University of Toronto, August, igi4. Il6 TRANtACTIONS OF THB ROYAL CANADIAN InsTITUTB. [vOL. Explanation op Figures. ^i l^iu, -^^ ^^^ "^ camera-lucida drawings, excepting Figs. 34 to t^Z^ ' "'^"'' ^ photomicrographs of sections or'poSoS oi c, cirrus. cent, circular cuticular muscles. cm, coronal muscles. cmc, circular muscles of cirrus. en, collateral nerves. cu, cuticula. cub, cuticula of cirrus. D, dorsal. g, ganglionic ring. its, second vesicula seminalis. lev, lateral excretory vessel. ln,y, longitudinal muscles of paren- chyma. tnev, median excretory vessel. n, nucleus. ns, nerve olm, outer longitudinal muscles. pc, cells of parenchyma. rmp, retractor muscles of cirrus. rs, receptaculum scminis. rvd, right vitelline duct. sc, cells of subcuticula. sg, shell-gland. sr, sperm-reservoir. t, testes. us, uterus-sac. ut, uterine tube. V, ventral. V, vagina. ve, vas efferens. vf, vitelline follicles, strand. Fig. I Fig. 2 Fig- 3 Fig- 4- Fig. Fig. Fig. Fig. 8. Fig. 9. Fig. 10. Plate V. Scolex and first three proglottides, X 3a. lath, 13th and 14th proglottides, X 8 . Proglottides 20 to 25, inclusive, coronal view, X 8 ■ dail*™x 8 ^''''*'°'^°«''''*P'*"^^°f auricular appen- S^SLi'T'"'''" "^7'!!^ *^^""'"'* of proglottidation. X 16. bmallest plerocercoid observed, x 16 Longitudinal section through the cuticle and subcuticle: cu' outer and cu" mner layers of the cuticle; / foramen secundanum of the excretory system; bm, base'.ent - .„" brane; km, longitudinal cuticular muscles, X 1600 Longitudinal section through the tip of an appendage, showing the minute spines, X 1500. ^ Relations between myoblasts and muscle-fibrils: a, coronal hber; b, c and d, myoblasts of longitudinal muscles of the parenchyma, X 1500. Transverse sections of muscle-fibers: a and b, from the external longitudinal series of the parenchyma; c, from the dorso- ventral group, actuating the bothria;/, fibrils, X 1500 I9I41 A New Cest -m vrmou Aw i Calya L. "7 Fig. II. Reconstruction of the nervous bycitem in the scolex and an- terior proglottides, X 40. Fig. la. Coronal section of the "end-proglottis", showing the relations of excretory vessels; cv, dilatation of the median excretory vessel, X 150. Fig. 13. Flame-cell : hb, basal body ; cf, cilliary flame, X 300. Fig. 14. Transverse section of a lateral excretory vessel in the posterior end of the scolex: btn, basement membrane; dvm, dorso- ventral muscles, X iioo. Fig. 15. Proglottis 16 of a strobila, showing very early stage in the development of the reproductive organs: agd, anlage of the genital ducts, X 37. Fig. 16. 17th proglottis of same strobila, X 37. Figs. 15 and 16 are drawn from oil-of-cedar transparencies. Fig. 17. Transparent preparation of a mature proglottis, — testes and vitelline follicles not complete: vs, vesicula seminalis; vd, vas deferens; cp, cirrus-pouch; co, cirrus-opening; vo, aper- ture of vagina; im, opening of uterus; ov, ovary; X 60. Fig. 18. Transverse section through the interproglottidal region of the unjointed portion of the strobila, X 130. Fig. 19. Same through the middle of the proglottis, only two eggs shown in the gravid uterus-sac, X 130. Fig. so. A single testis with its vas efferens: cyt, cytophore, X 365. Fig. 31. Sperm-reservoir at the posterior end of the vas deferens, X 365. Fig. aa. Anastomos of vasa eiferentia near the sperm-reservoir: m, me- dian line of the proglottis, X aoo. Plate VI. Fig.«3. Cross-sections of vas deferens: eo, syndtial epithelium; mem, m^'oblasts of circular muscles, X 1000. Fig. 24. Cross ction of cirrus, X 500. Fig. 25. Cross-section of younger cirrus, X 500. Fig. a6. Longitudinal section of receptaculum seminis and first portion of spermaduct: s, sperms; sd, spermaduct, X 235. Fig. a7. Genital ducts in the generative space, posterior view of a re- construction: cod, common vitelline duct; od, oviduct; sd, spermaduct; oc, oocapt; yr, yolk-reservoir. X 60. Fig. fl8. Ova, showing accessory cells in connection with two: ac, accessory cells; cy, cytoplasm, X looo. Fig.a9- Individual yolk-cells: a, from follicles; b, from a collecting ydk- duct, X 1000. Transactions of the Royal Canadian Institute. I--. "8 .«^^«,„.««,,^...™ « « [vol. X. ""' "' "^.SIT'"?; ';""■" " •-"■"""-y^ b. '«>". a coronal K. „ Ti. ^ ^'°'* "" '""""ion of the aperture X loo F«?- 34- Fig. 36. Fig- 37 Fig. 38. Fig. 39- Fig. 40. F'g. 41 Plate VII. ^''Trj'\°^ ^ ^'^"'^"'^ ^'^*'°" ^'^^"gh the middle of the Transverse section through the posterior end of one of the fore- dT:ir£"rsc.r ^"^^^-'^ --^^-■- «- ^-a, Coronal section, slightly aside from the median line, through Z It' ""^ ^''' *^° proglottides: 0/.. obliqu; fibrS^of thescolex;M.cuticularspinules nores 01 Similar section, in the median coronal plane: aev anterior ''"'to n'ucW °af i"*:S" T '?" "■""*" "" ^"^"^ ■*<>-■■« A„„lr , "^ '^ '''""8 "» epithelium. A™uK\°' "■' "''■"'•■ *°"'"« «"° ""clei pacing th^igh ti>e b.«me„, ™„b,„.. Le,^^„j ^ .__ P^^ I9I41 A Nbw Cbstodb from Auia Calva L. "9 LiTEKATUSE. BiACN. Max i894-i90o.-"Ce«o Bau der Cestoden", Zool. janrb., Bd. IX, Anatomie, 1896, pp. 92-161. ^*"{h:^i^MZ!'V^' I. Myologie de. Cestodes". Cong. Intemat. de Zool.. He aeaa. 4 Mo«»u, 1893, He partie, Moacou, 1893, PP. 13-27. iiiill m TRANS. ROYAL CANADIAN iNST. m 10 ^ h II .mev M 12 VOL. X PUATB V TRANS. ROYAL CANADIAN iNST. VOL. X. FLATS VI 83 ev. ^ '^^m'" %^ r 27 **-^^^^^ A. •. eecKAvMc, ■•• rRANS. ROYAL CANADIAN iNST. Lm* VOL. X. PLATE vn 34 ^ iivk •CTR ^mv I9I4] The Egg-Laying Habits of Pletbodoh Cisbmsvs. tax THE EGG-LAYING HABITS OF PLETHODON CINEREUS By W H. Piersol, B.A., M.B. (Read 15th November, IQIJ.) Two accounts of the natural history of this, our commonest sala- mander have appeared, one by Miss M E. Cochran (1911) and one by the writer (1909). Both agree in their descriptions of the eggs but neither gives any information as to the mode of deposition Th^writer has sought to determine this by observations madVon Pfe/Aol„T>th m .^ natura habitat and in a terrarium. The folJbg h ^aL^' end r:V""P«'^-t «bse-ations together with comment and iZ ence. Pert. hzat.on .s internal; this had been predicted in the earHer paper (,909) and has since been confirmed by the fact that a femaJe .solat«l .n a terrarium for four days laid eggs that developeTnlturluy J i;. , °"^ occasion the actual extrusion of the eges was ob- served. The female had been placed when captured in a sS gTi t dong with fragments of the log in which she was found; and the ja^/.? Chtflv7"'r'T^? u"" '^'"^'^ ^""^ *° '^' '^bo^^tory in a small bag Chiefly for the sake of theeggs which are very delicate the bag was ^ard^ from shocks as far as possible, then for another hour it sto^^n^f^ej a, removing the jar from the bag it was seen that the egg laying hSw b^n. fortunately in such a position that all its details Sild'L o Wed The lip^ of the cloaca are pressed against the surface from whSiX eres will eventually hang and a small quantity of mucus sTJu^ atd &aTso noth *° ''• I'" T^' '^' """ «""P'^*«* ^f°- <>b--t1on began so nothing can be said as to the interval that then elapses before ^ first egg is laid. The extrusion of each eg. occupies aS twenty «conds and an interval of five to ten minutes occurs before the^exl mentioned; the fourth, and last, adhered to them in turn through the tickiness of the egg-envelopes. As the female did not move during the enure process, all the eggs were laid at the same point, each egg as it ^e. crowding the preceding ones aside, thus making sure of bein^ n contact with them. Por over an hour after the last egg w^ iSdZ femde did not change her position; during the next hourlheTeft Si e^« a few minutes, then returned and coiled herself about them "« Transactions OF THE RoTAL Canadian Institute, [vol. x The extrusion of the egg causes it to become eloneated- thi» ^af., form may be retained for a consideraWe timT tJ^ . elongated another elongated egg its «I^^in/f o „ ^^ '*"*' *='"»*'^ ^"^ «>».:..• * ^*'. "^*''*'"840m.m. and3.om.m. The thr** ^aimng eggs were spherical ; all five were in the process of gastrjlatir Am.Uier egg. quite similar to the one first mentionS^lSdTy^emde This mode of egg-laying places PkthadoH »t th. ««j t however, by a short rtalk tS "^J^ ^^^"'^^'^S connection with it. je^ately to ite support-usually a stone-bTaTho^ ^k^S^ disappearance of this stalk for each e» exoeot th^ fil* J!!? Tt PQtot h.v. p„,p««, bey^t:;,"*"^ of . «™. mu« i. ,,^ I9»4l Thb Egg>Laying Habits of Plbtbooon Cinbkeu ia3 of them were suspended. Evidently under the somewhat unnatural conditions the female had moved after tlie extrusion of each of the last five eggs. Case III. In picking apart a decaying log there were exposed on one occasion a female and four eggs. One of these lay by itself, markedly elongated; the other three were in contact, two of them some- what elongated, the third apparently spherical. All four were lying on the floor of the cavity, which fortunately had been opened from the side. Examination of the female revealed the existence of four eggs in the posterior parts of the oviducts. Evidently the egg-laying process had been interrupted by the opening up of the nesting-chamber. These last two cases have been selected from among a few of the same general character because they differ from the rest in that the eggs were not suspended. In opening up logs a few clusters have been found un- attached. At first, in such cases, it was taken for granted that the open- mg up of the nesting-chamber had ii.volved the loosening of the eggs. Since attention has been directed to the possibility of a duster not having been attached, two such have been found under circumstances that would seem to preclude the idea of their having been torn from their attachment. In neither of these two cases could a stalk attached to the cluster be found. It would seem that occasionally the tendency to reduce the amount of material devoted to forming stalks for the eggs goes so far as to eliminate even the stalk of the first egg. No exact count has been kept of the number of such cases as compared with the normal, attached ones, but the impression left is that it is very small. As might be concluded from Case I, an examination of the relation of the stalk to the eggs shows that it does not come fmm any one parti- cular egg, but from a quantity of mucus that adheres to the outer en- velope of certain of them; the impression given is that of a material poured onto the bunch, part of it being drawn out to form the stalk. As IS the usual case among Urodeles the outer envelope of each egg is of a much more sticky mucus than the inner ones. Plethodon is peculiar m having this outer layer unusually thin, and in depositing a still more •ticky mass of mucus before the egg-laying proper begins. In most amphibia the impulse toward the deposition of the eggs, once these are ready for the act, is an imperative one. In some cases (e.f., many frogs) the assistance of the male is needed, but generally •peaking, when the proper time comes the spawn wUl be deposited even with conditions and surroundings that are far from natural. Both Bona P^wu and Sana caksbiama that have been kept over winter, without ffrZL ' ^*°^ '" ^* ba«ment of the Biotogical Building of the Univenity, have been known to spawn in spring and eariy summer iwpectivdy. (Such spawn has never devek>ped. evidently has never 124 Transactions of the Royal Canadian Institute. [vol. X for egg-layine For .Wo Preference for some particular log as a site contS %^1J n'llir r" '''°' "^ ^°°^'-^ waf found t visited on Jun^stTnttiarchJ^^^^^ *aVP""« °^ '^13 and was yielded only males or s«uX t °L '"'"" °' '"°'" ~"'"8 >««« found which, though a^aSrrtT/^''r"'' "' '^' °"^ '°^ '^^ eleven females with eg^Tnuml^^' f^T^ ^'•°'" ^'^^ ^^hers. yielded The logs so greatly pSerrta^tT/'^'"^"'^^^^^^ must enter into th^q^otfol^Z ""-r'^'^'^ ^'^^ ^^^er factors similar may be clo^ atlh^r^ . J^ • f "'^^^^s log that seems quite is the difficulty tha^ has^n"^!'^ '"*"'?^ ^^^*'*"*^- Equally strLng in a terrarium The thi„ aLoT^^'f '" ^'"'"« ^^^^'^^ "" '^^ egg^ men allows the e Jy ret^^itLn o eT"""' "'"*^"' "^' °' ^^« ^^S for deposition. If pieSfo tL «^ntaining eggs almost ready found are brough frSe fie d alT.K " "^^'"^ '^' ^"''"^^ '^^^^ been rium so as to recon Zct to„t^lt th^ i^' P-ces piled together in a terra- the animals alive andTg^'^Ltllt '^' " "? ^j'^'^"^^ '" keeping readily on small insec^.^^ Tphid bu/ ^ '^"°^" '^'^^^ '^•" ^^^^ suffer little from long ipri^atiof 'mJ'^' '"°'' "'"P'^^'* ^"^ *<> small terrarium last spring SuntHth! TTc ' ''''^'^^^ in a attention; at the end of Zt ^T-Ji u *^ ^""^ °^ September with no hadsufTer;dsonttLlha tW^^^^^^ ''^^'^'^.^ -"^'^-n and vigor to mingle with others brought i^froml^^^^^^ '"'""^'^^^ ^^^^ easy acceptance of life in fte^rarium th. 1 " ''"'" °^ ^'' ^PP^^nt inhibit the egg-laying reactions TnT.; '^^"^^ "'"^"^ '^ «"«i<='«nt to during the n«t fi^oTsLwife ^ ExJT '^''t^^ ""^ ^^'^^'^ under natural conditions bu'^l wtn?hetl^''t^ TH.*^ '^^ ^ from the field not mor* than thr«> nrf !, Tf^ ^"^ ^" ""^"Kht laying. It is not ^0^^^^^ • ^ ''^y' '^^^^ '*»« t'"** for egg- far as%xamin^!'aJ, mSuTfeiar^^^^^ ^^pregnation or its lack. for'L tacles filled with sperTs^me lwt5 .^" '°""^ '° ''^^^ t^*' ^e«P- The character Ke^Zn hLtt' •"'« '''^'^^^'"'^ ^^" ^^ the surface at which iee^a^lTrn'df"'"'' '" *'" ^^^^ ^°«^^ the most part but an inch MotTtht^l' ^ **^Pf »«>ns they will be for four or five inches Wow ™r,lferto^h ' ' K^"^ ""^"^ ^^^^^ ^" ^e to the time of egg-Iayi^g. ^"a^^" "^ ^^ ^"^^^ ^^ ^he season up pap^' cst^perie^:: z it^Tir ;::!""'°"«* - ^» -- always much uVder-Sed and tS^ ?„' ob^rvation. The egg i. female, accompanying Ste« of !^" f*^"' °"* ^'"* <>' «h« it i. then rapirat^^^^lJ^rtir^Srv^^^^^^^^ I9I41 The Egg-Laying Habits of Plbtbodos Cinbrbus. 135 jupply of nourishment for the female during her wait by the eggs. will be laid along with them, producing a cluster with one markedly smaJl egg. For example, in one cluster of seven eggs, six of them had a diameter of 375 m.m., the remaining one of 3.75 m.m. From a difference so marked as this there is a gradual transition to the state where al the eggs of the cluster are the same size; such are about one half of all cases. The writer has twice found similarly undersized eggs of Amblyskma; the numbers were small, nine and eleven in the t^ cases, and the eggs of but two-thirds the normal size. Th. y developed normally, producing under-sized larvae which were perfect anatomicaSy but defective m their feeding instincts. The one lot would not feed at all; the other would snap fitfully at Cyclops, etc.. but would not eat enough to grow or ever to maintain life. This was quite striking for botii lots were the speaes jeffersonianum the larva of which are normally voracious feeders and easy to raise. In Plethodtm the early development of the small egg is quite normal, its fate has never been followed past the time when the larva is well formed o ?^u ^^"f''' ^T '" * ^^••'■^""™ "^^^ her eggs, swallowed two of them, and three hours later regurgitated them. The eggs were killed by the process whether by digestive action or by the mechanical violence it is unpossible to say, for they were in the process of gastrulation at the time. This IS a most critical period for the egg. its delicacy is at the maximum Md very slight disturbance will cause its death. The swallowing of their spawn has been noted for many amphibia, usually wheie. as above, somethmg has happened to pervert the natural instincts. Smith (1907) however, describes it as normal for Cryptobranckus; in this case more- over when regurgitated the eggs frequently continue to develop. Means taken to determine the mating habits have so far been fruitier. The single observation of Wilder (1913) on Desmognathus is probably a close approximauon to the habits of PUtkodon in thU respect '•6 '^"^'^^"^Ns OF THE RovAL Canadian Institute, (vol. x Literature: *"'^ol.^^Nay:7'i3^^'°'°»''''»''«R«'-'««^ Salamander", Biol. Bmi.. PiBXSOL, W. H looo_"Tl.' u L- ^ nodus': T;a„rta„.T„ t. id Vm ^7' "^^^ "' '^'*«^ «-«« -^*r.^ PiBHSOL, W. H loio _"C ' \ ,' P*- *• P- 469. „ Nat. VoI.'xriV. ,.tr "' "^^ °' ^'""^^ ie/.,o,^„.«.. ^mer. Reese, A. M lood "Th ^ in ^ ««.,*«,' J;-, Biol ru^Vo Tno' f ''""' Salamander, Crypu^anckus RITTER, W. E. AND MiLLER, L iSoo -"aV . ^K ^- ""• S-™ 'r^"' ^™'- N«' Vol ScXni.7C" *"*"' "-''' Hirtory of ^««to OMITH, B. (J.. 1006 — " Pn>l.'«' i> >^i. ^ .**»^*?T Biol Su.TI'Jo? xTno", 'o' ^!^*"^'"''«' •'^ ^'>^-*« -«.- SWTB, B. G.. I0O7 — "TI,« I f u- ' ^' P- '4*- Bio. BurVol. XIII^ No^TpT"'' "''''^ °' ^'^i"*^"-*- ««.«*«.«««.". /"mx^xkS^p-;^*'-^'-'*-^ W^^..". Amer. Nat. '""xx'iv'TNo.'JfpTls';''' "-"'" "•''*°'>' *>' ^*««.*»a/A«,/«,a". Biol. Bull.. Vol.