Transactions of the Zoological Society of London
Zoological Society of London
A C@ € SCM fe (WA 4 ce © Neg ©. C4 fF 4" ‘ENC Sas | Le a Care CR Cae eae c ten: Cee Sot aoe, CSI EE Cal GEIST Os CGM ESS aa & OE ELEC FE EE OE OE OE CG © (COw = a( ~ € UGG Ng ne a cl « Ge PA «6, C@ ae ig UU GF,,. = (Cc SS by XK COO eee CE FOO EE UE | ak Ce © CHC «. CCC QLCEO ( CCX @iic Cate CFat Ka (Ge f, = SIC GEGEN pon c ns ~% foal’ =~” « AE GGG Ge cae Kew < " «f a! Cee a SCG \ 2CCC Ee A A (AS HO oA Ceo Of SL HE ig, Cee OE CE ae Caml eM OT es (OU COR S GENS GAC Ez rare a CCCs GSO RR CAC OO at OEE Qe C's ee ON As RR Flee CC es arte 9s CO CN BOL IE SO LACIE, OO L OO E a oe 5 COCO OO COG GF (GAME & “oe Cr Gees = te a a OE or ce &_ SS ee OSM COOH CF (COB GL EO Le, wie COMMU (NCR Ce EM PEACE CCE Ogi, << - ENE COE OE SS COG G6 € qr a Se. aft, bel ae ae caer. CCK ‘a \ CO CC le le GAS QC! CX G CO LOE EER ICO OO MEE OR OC CUES OH FUE OS LECCE CEE CH MOLEC GK CULE oe +S | GOS SEES 6 GONE AE CO GUE CCG a ewan Ciara ean aia et WO EO EE BD COO Ei LOR OOS pee CNGS = Se te ee Ree Oh Oe eae ee GG Gg Ge. Sm OO eee K Gey Ce ON Gig Oi i = ere a Cater Geass WE ODEO OME OOO EN EC LEE OE Me Ce AG Se CE CEO MOLEC TE ~ oe CG, SAL ECS. Y (C4 CMC (a “aa “i Ce Car (rae ¢. y ec Ge : g Se € ih 4 COREG COG = — q CORRS a as (ef SS 4 CG « a G C¢ RO OF RIOR PERG Gren Wee Caer Re COE E SS ELEC EELET CO ELL EE COe o SS Petey SOM CE COO CE hE OER OSE Coe SSS COCO EOE COQ EF (COE © EC ‘CoO SS eT © ree qu & (tt fi wid oF aT é ay araac ae yar, - iG (¢ GC! as = = \ S [G CEN ww { GEC NN XA. <a a dim CGE gs a Me, Ce Gl al oe a ai Giada a. Cet Se ¥ : Se and See \ x A, q { Fao. Ce colo! OSS EIU CO EO ee EE GE GC. SE Oe CUE! OER EOE ORO CRORE MCG ( Ce EC —e- ee \ ~* ae eG 6 NaS _— Lay ¢€ ( TCG ALA © a = — x a ee WEG OO EOL BO CEI OO CO 1 EK Cae RCC aa Ge ge ge a EN RE SS et 1 Si eee OE OO a Gogh Cae @ (OE eC Oe liter. ana 1 = eS Se aera x ¢ CEM LE MEE OE OOO COO GEC ETE, i dae a, CT ACK, EEA AS GE GAG Pie « gaia aa KOC (GES, Keane GAR CR GSS eee auCSAR a0 Ue &e. ee RCE KEES CAM EE CEEOL EOE CE COO OME SE i < a CG's oe Part GC eee aia Gu Cate Gr Sie of CRs <— o ee OEE oa a DT ake a a gS cr a ae a a « ant Gee Gl Mar ae. GaGa Gi CG (4 Ge ee OE CL GS CC COZENS 2 2E CE. @ Car O¢ Ceraee Ce CMC Cs CMC CGO Qa ¢ KG a OE C@E ACO KG os & Sara C = é i CME @ ( SCE Rec ee as cae, ( ae C « a C Ce « UG « : ere COC CCE EMC CUE LMI EEE CCE <C (COC e cae, ( ae COC CCE EMC CUE LMI EEE CCE <C (COC e cae, ( ae COC CCE EMC CUE LMI EEE CCE <C (COC e cae, ( ae COC CCE EMC CUE LMI EEE CCE <C (COC e cae, ( ae COC CCE EMC CUE LMI EEE CCE <C (COC e cae, ( ae COC CCE EMC CUE LMI EEE CCE <C (COC e cae, ( ae COC CCE EMC CUE LMI EEE CCE <C (COC e cae, ( ae COC CCE EMC CUE LMI EEE CCE <C (C ee ce =< oo CC LLC @ CE & ‘i GC EGG & 6 CO COOKE EKG CELE CWC OOOEE COMME EOC ¢ CL. ee « Co G.. @ CORK Qe GGG A CEC COO MCE OEE KOO EEE EMME LEK CC CCE CC ECC Gj (cs ‘¢ CG c CCC cece C € LEME Cane eee a fe Co « Cte EC i oe COC & cal ws << ¢ < a ( ater « CX Gag CG A COO GCE ere a feo (CGE Cc | i iC CE mK <e eG a ( <- & C eccec @e ce. Gig GG = ay « c¢ : 4 i CE mice race Sse ‘€ Sees CEES EG COMME CCE (Ce = COCK COCO C¢ CCG eC EEE COE CC Cu ace. TAN Pen Lae TRANSACTIONS OF THE ZOOLOGICAL SOCIETY OF LONDON. VOLUME XX. LONDON: PRINTED FOR THE SOCIETY, SOLD AT THEIR HOUSE IN REGENTS PARK; AND BY MESSRS. LONGMANS, GREEN, AND CO., PATERNOSTER ROW. 1912-1915. 234821 CONTENTS. I. The Development of the Starfish Solaster endeca Forbes. By James F. Genin, M.A., M.D., D.Sc., F.Z.S., Lecturer in Embryology, Glasgow University, and in Zoology, Glasgow Provincial Training College. (Plates I-V.).... page 1 II. On the Sphingide of Peru. By the Rev. A. Mitus Moss, IA., F.Z.S., FES. WCQ CACC CART: JORDAN, 2s (ylates) Nile XGVe)) eae |e eeeynen (3, III. Second Contribution to our Knowledge of the Varieties of the Wall-Lizard (Lacerta muralis). by G. A. Bounencer, 7.2.S., F.Z.S, (Plates XVI.-XXIII. erayGl A Lexie a AUUREISHM Leas) Roel ig ate Sete es Wat al Ma eva Wn Peal) IV. On the Crustacea Isopoda of the * Porcupine’ Expedition. By the Rev. T. R. RB. SIEBBING, MEAS ile. S.) Fo0S.. F-Z.S.. ( Plates, XXXIV. OVI. 3 231 V. An Annotated List of the Batrachians and Reptiles collected by the British Ornithologists' Union Expedition and the Wollaston Expedition in Dutch New Guinea. By G. A. Bouuencrr, M.S.S., P.Z.S. (Plates XXVII-XXX.). 247 VI. Report on the Freshwater Fishes collected by the British Ornithologists' Union Expedition and the Wollaston Expedition in Dutch New Guinea. By C. Varn — ICM, JE Ale WEIS (OeMeNee DOO) RMR Sis Go Baugh og Wee OTS VII. Report on the Mollusca collected by the British Ornithologists' Union Expedition and the Wollaston Expedition in Dutch New Guinea. By Guy C. Rowson, B.A. (lelaies >XOXGXGIIEy So XOXONG Hand exten ures! O— lls)! neste) een VIL. Report on the kiver-Crabs (Potamonide) collected by the British Ornithologists’ Union Expedition and the Wollaston Expedition in Dutch New Guinea. By Wm. Canin, DSe5 LG,» (Messtenennes 14} Cs 8). 5 5 5 aa 5 OU IX. Report on the Mammals collected by the British Ornithologists’ Union Expedition and the Wollaston Expedition in Dutch New Guinea. By Ouvriet D ‘Thomas, gS CSO a ee RRM A Gb al oo a a OOO BIS) X. Report on the Arachnida and Myriopoda collected by the British Ornithologists’ Union Expedition and the Wollaston Expedition in Dutch New Guinea. By STANIEY HORST, #78.) (Dext-feuress4 05) isle nines) cea) XI. Report on the Rhynchota collected by the Wollaston Expedition in Dutch New Guinea. By NVi lus Distant. \(Elate: XOOxeI() ie ay a enter er an 32.) XI. The Foraminifera of the Kerimba Archipelago (Portuguese East Africa).— Part I. By Epwarp Heron-Auiey, F.L.S., FZ. #.G.S., FR US. and ARTHUR HARLAND, F.A.MS. (Plates XXXV.=XXXVIT)...... 363 XII. Report on the Diptera collected by The British Ornithologists' Union Expedition and the Wollaston Expedition in Dutch New Guinea. By J. W. Evarts, B.A., F.Z.S. (Plate Book 6, 9, 4200 in 5 vg) 8 gi ohuawug 4 BON XIV. Report on the Spiders collected by the British Ornithologists' Union Expedition and the Wollaston Expedition in Dutch New Guinea. By H. R. Hoe, W.A., H.A. (Vext-figures 20-312) bo Moc ie rine ome ean: Ae ene nee 0) XV. Report on the Odonata collected by the British Ornithologists' Union Expedition and the Wollaston Expedition in Dutch New Guinea. By Wersert Campion. (Mext-fiounest3S—40s)ie ie) sk 48 1 ee ae ane ne mache XVI. Report on the Vermes (Oligocheta) collected by the British Ornithologists Union Kapedition and the Wollaston Expedition in Dutch New Guinea. by Dri Coennrrr pr) Marts, | (lext-iourey1e) sian wees oS XVIL. Report on the Coleoptera collected by the British Ornithologists’ Union Expedi- tion and the Wollaston Expedition in Dutch New Guinea. By Gi.Bert J. Arrow, Guy A. K. Marsnatt, #.Z.S., C. J. Gaman, and K. G. Buatr. (Bllate “XO KE) oe a SALI A eae a a 8 HO) XVIII. The Moraminifera of the Kerimba Archipelago (Portuguese East Africa).— Part Il. By Epwarp Heron-Auuen, #.2.S., £.Z7.S., #.G.S., FRAILS., and ARTHUR Haruand, 7.A.S. (Plates XL.—LIIT., and Text-figures 42—-44.). 543 MiphabeticalsMist on the Contributors) 2) einen een) MnO 9 Mir EY Se Sivhate esse Ae yee ag Veneta 2 ech a TRANSACTIONS OF THE ZOOLOGICAL SOCIETY OF LONDON. Vor. XX.—Parr 1. (Puares I.-V.) “nsonian Inst. > \\ ‘UR Ne % APR 19 1912 / : V4, A “0ngl Miysoth LONDON: —e PRINTED FOR THE SOCIRTY, SOLD AT’ THEIR HOUSE IN REGENT’S PARK; AND BY MESSRS, LONGMANS, GREEN, AND CO., PATERNOSTER ROW, February 1912. Price £1 4s. 0d. Taylor and Francis, Printers. | [Red Lion Oourt, Fleet Street, TRANSACTIONS OF THE ZOOLOGICAL SOCIETY OF LONDON. To Fellows. To the Public. Oles. Ud. Bis Suds VOLUME I. (1833-1835, containing 59 Plates) Spee Mul te SHI eee comarca dll (0-3 recat II. (1835-1841, cats TIPPlates) in ee ad MO penis 2c 0s 6. Om VOLUME III. (1842-1849, containing 63 Plates).., 3 8 8... 411 O* VOLUME IV. (1851-1862, containing 77 Plates).., 6 20... 8 2 6% cau V. (1862-1866, containing 67 Plates) Baiete arises DAC Soni ae sO Osa VOLUME VI. (1866-1869, containing 92 Plates).., 115 0...15 0 0 VOLUME VIII. (1869-1872, containing 92 Plates).., WED Sew Geese sd eB le (9) VOLUME IX, (1875-1877, containing 99 Plates).., 12 16...16 2 0 VOLUME X. (1877-1879, containing 95 Plates).., 5 10 0 38...187 *O GENERAL INDEX, Vols. I. to X. (1883-1879).,, One Oe e010 VOLUME XI. (1880-1885, containing 97 Plates).., 5 8 0... 7 40 VOLUME XIII. (1891-1895, containing 62 Plates).., 5 8 0... 7 40 VOLUME XIII. (1891-1895, containing 62 Plates).., 5 8 0... 7 40 VOLUME XIII. (1891-1895, containing 62 Plates).., 5 8 0... 7 40 VOLUME XIII. (1891-1895, containing 62 Plates).., 5 8 0... 7 40 VOLUME XIII. (1891-1895, containing 62 Plates).., 5 8 0... 7 40 VOLUME XIII. (1891-1895, containing 62 Plates).., 5 8 0... 7 40 VOLUME XIII. (1891-1895, containing 62 Plates).., 5 8 0... 7 40 VOLUME XIII. (1891-1895, containing 62 Plates).., 5 8 0... 7 40 VOLUME XIII. (1891-1895, containing 62 Plates).., 5 8 0... 7 40 VOLUME XIII. (1891-1895, containing 62 Plates).., 5 8 0... 7 40 VOLUME XIII. (1891-1895, containing 62 Plates).., 5 8 0... 7 40 VOLUME XIII. (1891- Eclipses. OE OM MIR es BLA VOLUME XIV. (1896-1898, containing 47 Plates).., bes. i Onda veers epee Ok 0) VOLUME XV. (1898-1901, containing 52 Plates).., 515 6... 714 0 No copies of these volumes remain in stock. Continued on page 3 of Wrapper. TRANSACTIONS OF A ZOOLOGICAL SOCIETY Or, LOND ON: I. The Development of the Starfish Solaster endeca Forbes. By James F. GumMILL, M.A., M.D., D.Sc., F.Z.S., Lecturer in Embryology, Glasgow University, and in Zoology, Glasgow Provincial Training College. (Received and read November 29, 1910.) [Puares I.-V.] CONTENTS. Page SURVEY DE OSEDEON | Maer eas Tala aco pete ika Mele else eens Cech ated Pala orens deter ay suai ceens oper 3 JOS (Qhyreubols: COSBD ONY chores onat cuts ono, cart cua ton atean veneeedeakcy bic i macieter ols Glaivtoee choice ected eon ieee ena 4 Arrangement and structure of the egg-tubes, 4; muscular tissue and sinus-spaces in their walls, 4; relation of the latter to genital sinuses and hemal tissue, 5; growth of the ova, 6; accumulation of yolk-granules, 6; yolk-nuclei, 7; follicle-cells, 7; ege-ducts, 8. MPS MAT GRATION SPAWININGS PH ERELLIZATION GCa lle ysis oe te tetciis ie keel 9 Time of maturation, 9; season, &c. of spawning, 9; the ova in water, 10; membrane of fertilisation, 11; cross-fertilisation, 11; early and later segmentation, 11; formation of blastula by egression and of gastrula by invagination, 12; appearance of cilia, 12; moyements of blastula and gastrula, 13; hypenchyme, 13; chronology, 13. IV. Exeract Cwaracrers, Movements, &c. PURIN THE FREN-swinine Perrop.............. 14 Elongation of gastrula, 14; formation of arms and of sucker, 14; preoral lobe and body of larva 14; formation of hydropore, 14; closure of blastopore, 15; movements of the larve, 15; ciliation at anterior and posterior ends and over general surface, 15; commencement of flexion and torsion of the preoral lobe, 16; first appearance externally of hydroccele lobes and of aboral arm rudiments, 17; chronology, 17. VOL. XX.—PART 1. No. 1.—February, 1912. Mode and site of attachment by the larval sucker, 17; fate of preoral lobe, and formation of oral and aboral surfaces, 19; the hydroccele pouches and order of their development, 20; numbering of pouches, 21; the aboral arm rudiments and their adjustment to the pouches, 22; attachment by first-formed sucker-feet, 22; appearance of the eyes, the mouth, the anus, and the spines, 23; constant position of anus in specimens with normal and abnormal numbers of rays, and in S. papposa, 23; movements &c. of the Starfish before and after formation of mouth, 24; surface-crawling, 24; chronology, 25. Vie ny nHOPMENTIORNC Avittes HAND) ORGANS eran een en eerie eer en iii erie ey ere Formation of (1) anterior and (2) posterior celom, and of (3) middle chamber or enteron, 25. GORA ntenion Colomandmutss Denuativesm ere eee enact ei ici cee elt Formation of right and left lateral diverticula, 26; hydroporic canal, 26; preoral celom, 26; epiderm of preoral lobe partly incorporated with oral surface of Starfish, 27; separation of the right lateral diverticulum from axial celom, 27; the hydroceele groove, 28; formation of first five radial pouches, 28; formation of succeeding radial pouches, 28; relation of pouch I to posterior celom, 29; the dorsal sac, 29; axial part of anterior celom, 29 Internal oral circular sinus, 30; axial organ, 30; stone-canal, 31; relation of madreporic pores to stone-canal and axial sinus, 31; pouch IX/I of external oral circular sinus, 31. (OQ) Posiariop Centon GH WHS IDA OUOAS cocccncx ecco oo noec os cons ago0cc DOHDEbODOOKE Dorsal and ventral horns, 32; extension of the horns, and the part played by them in separating preoral ceelom from axial and epigastric cceloms, 32; septum in madreporie interradius enclosing axial complex, 32; interbrachial septa, 33 ; extension of hypogastric ccelom on oral and aboral surfaces of enteron, 33; cir- cular epigastric mesentery, 33; aboral ligaments of stomach and paired cxca, 34; formation and extension of pharyngeal ccelom, 34; the circular hypogastric mesentery, 35; hypogastric ligaments of stomach, 35; formation and subsequent growth of pouches of external oral circular sinus, 35; genital rachis, &c., 36. (@) Wa PROD. Sso00060 0060 00s basco ODO oua ODD EK GE ODUaDOUIOODD ODO DONadHORGS Radial lobes of stomach, 88; mouth, 39; anus, 39; paired radial ceca, 40; rectal ceca, 40. WADE, IDsyaaLOpNtoocae Oip Gari) SVAN S a/c poco accddanovdtanuannopogoo oan DT UG abaGQE OOOH RGR Sequence in appearance of ambulacral and adambulacral plates, 41; plates of central and marginal parts of disc, 41; terminals double, 42; transition to adult reticulum, 42 ; development and grouping of spines, 43; the denticles, 43. VATTMS SEIISTOROG Mie pace Ne ee ES re eure cen Cae sae aR ME ye Re OV er us nenstias tia ats (lone < Mesenchyme and Yolk, 43; intracellular digestion of yolk, 44; reserve store retained in the mesenchyme, &c., 44; a more highly-yolked Starfish egg, 44; the hypenchyme, 45 ; yolk-granules in the enteron wall, 45. A Statolith-like Body in the posterior ccelom, 46; statocysts in Synapta, 46. Nervous System of larva, 46; relation to that of adult, 47; larval nervous system in other Echinoderms, 47. Origin of Muscle-fibrille in larva, 47; muscle causing flexion &c. of preoral lobe, 47. Ciliation, 48. X. Monn or Obrarnine AND REARING THE LARVEST... 2.2... 6 ee ee ee te eens 48 Spawning in the tanks at the Millport Marine Station, 48; arrangement to retain the ova and to keep the larve healthy in aquaria with sea-water circulation, and in smaller aquaria under aeration, 48; larvae obtained in tow-netting, &c., 49. DENS UMITAR Ven OCCHEp PETE anne ays ecient ancrerste cymiavcraieiet snes Geis he nieanrdladslia clcdsin fellas sista ons) crore, ebouenores 50 External characters, 50; development of cavities, 51; development of skeleton, 52; general comparison with Cribrella, 52; relations with development of other Starfish, 53. IREREREN CHSt a.cupnneiein a nme cu tives Wee ARES ESET Aba ae chin RUS tacit Paoce dian Sid clad ates sul BRN tno o od 53 EXPANATTONY OF ME TATHS a tart Wl Vartasea aie soot cep an Mal Wal SreRdn hc Sach Seid ey GEM CEI gone capers ey aaah ese 55 I. Structure anp Position. IN the classification of Perrier (21) the Solasteride form a Family of the Spinulose, one of The five Orders into which this author divides Starfish. Asterina and Cribreila, the development of which has been carefully investigated (12, 15, 18), come within the same Order, but are in different Families, viz., the Echinasteride and the Asterinidee respectively. The system of Sladen (23) makes the Solasteride one of the ten Families belonging to the Cryptozonia, the second of his two great Orders of Starfish. Cribrella falls within the same Order as a member of the Kchinasteride, but the Asterinide are included in the other Order, namely the Phanerozonia. As regards Solaster endeca, the following characters should be noted at this stage, other points of minor importance being referred to later as occasion arises: The normal number of rays is nine, but occasionally there are one or two more or less. The madreporite is single, no matter what may be the number of rays. The aboriginal skeleton forms a fine reticulum made up of small plates, many of which carry bunches of spines. Gills are present everywhere in the interspaces of this reticulum in groups of two or three. There are no pedicellar. The tube-feet in each ray form a double row. The mouth-armature is, on the whole, of the adambulacral type, but the first ambulacral are relatively prominent. The globular part of the stomach shows folded radial lobes; above it the usual radial ceca are given off from the pyloric sac, each pair arising by a long common duct. There are two small bunches of rectal ceca. The anus, though very close to the middle of the aboral surface, is slightly excentric in the direction of the interradius which on developmental grounds must be entitled V-VI (pp. 20, 23). Strong perforated interbrachial septa are present in all the interradial. DR. J. F. GEMMILL ON THE DEVELOPMENT OF II. Ovaries AND Ovules. The gonads are in pairs, interradially placed, and confined to the disc. Each consists of a bunch of short tubes, whitish in the male and orange-coloured in the female. These are attached to the inner aspect of the body-wall close to the mid-interradial line, a short distance Upwards from the margin on the aboral side. Here the body-wall is pierced by the egg-ducts. In full-grown specimens, the number of egg-tubes in each gonad may amount to several hundreds. These are somewhat indistinctly divided into a few main groups, which in turn are capable of subdivision into small ultimate clusters of three to seven tubes. The tubes in each of these clusters join together at their attached ends to open into the same terminal branch of the egg-duct. While the majority are cylindrical or sausage-like in shape, simple branching may occur, characterized usually by a single dichotomous division near the free end, and occasionally also by the presence of one or two short lateral branches on the stem. The wall of the egg-tubes consists of outer and inner layers separated by irregular spaces. The outer layer, which is considerably the stronger, is made up of connective and muscular tissue, the fibers of the latter being arranged chiefly in a circular direction. It is covered superficially by cubical ciliated cells, and during life the ciliary movement is such that currents of ccelomic fluid pass along the surface of the tubes from their attached to their free extremities. The inner layer is thinner and consists almost entirely of connective tissue, but I find that in addition it contains a number of muscular fibers which are longitudinal in direction and occur chiefly towards the attached ends of the tubes. The spaces between the outer and inner layers of the gonad-wall are best developed near the attached ends of the tubes. Here they open into an irregular cavity which almost surrounds the commencement of the egg-ducts, and which in its turn is continuous with one of the genital branches of the aboral circular perihemal sinus. An open communication is thus established between the aboral sinus and the spaces in the gonad-walls. Along this line of communication occur strands of the tissue interpreted by Ludwig and others as blood vascular or hemal. These strands arise from the hemal tissue within the aboral circular sinus and end by spreading out within the spaces between the inner and outer layers of the gonad-walls as fine branches attached to the inner of these two layers. No open communication exists between the interior of the egg-tubes and the genital sinuses or between either and the cavities of the hemal strands. In the adult Solaster endeca I cannot find definite cellular remains of the genital rachis either in the circular or in the genital sinuses; but in a young Solaster papposa of an inch and a half in diameter the rachis was still represented, in both these cavities, by a thin solid cord of characteristic cells. The occurrence of muscle fibers in the inner layer of the gonad-wall seems not to be usual, or at least not to be generally recognized. Ludwig (13, p. 599) and Delage (5, pp. 62-63) speak as if the layer in question consisted entirely of fibrous connective tissue. In the case of Asterias vulgaris, Field (7, p. 106) states that the muscular fibers of the egg-tube walls run in various directions, the outer and inner fibers being at right angles to one another. He makes no mention of spaces between the layers, nor are such spaces indicated in his illustration. In Starfish anatomy, it seems to be the rule that in hollow structures with muscular walls the longitudinal fibres lie internal to the circular ones, as, for example, in the walls of the tube-feet and of the disc itself, as well as in the peristome and the cesophagus and stomach. Vote.—In this connection, attention may be called to the statement in Bronn’s ‘Klassen’ (13, p. 580), that in the cesophagus, the circular layer is internal to the longitudinal one. This appears to be an error, as it is also said that these layers are the continuations of corresponding layers in the peristome, and the relative position of the circular and longitudinal muscles is correctly given on the page before. The statement made above, to the effect that in Solaster endeca the spaces between the inner and outer layers of the egg-tube wall are continuous with the genital sinuses, was based on a careful examination of serial sections through four gonads in an adult Solaster of large size, and I have not the slightest doubt as to its correctness for this particular species. In Ludwig’s view, the spaces in question are lacunar in character (13, pp. 599 & 615), being terminal expansions of the hemal vessels within the genital sinuses. Hamann, quoted in Ludwig (13, p. 599), described the spaces as having an endothelium-like lining and as communicating both with the genital sinuses and with the cavities of the heemal tissue. According to Cuénot (3, p. 88) the spaces in question belong to the perihemal sinus system, while the cavities of the hemal vessels lead directly into the interior of the ege-tubes. Macbride (15, p. 377, fig. 122) showed that in Asterina the spaces between the inner and outer layers of the gonad-walls arise as expansions at the ends of the genital branches of the aboral perihemal sinus, but apparently in later development these spaces become completely shut off, owing to the formation of the septum through which the growing egg-ducts burrow their way to the outside. However, the same author (16, p. 449) describes the genital branches of the aboral sinus as swelling out at their blind ends so as to enclose the gonad cell-masses. In my series of sections referred to above a distinct cellular lining was present in the larger spaces occurring around the roots and proximal parts of the egg-tubes, but further along the tubes it became less definite and finally ceased to be recognizable. This is not the only instance in which a perihemal sinus-cavity divides into branches which lose themselves within the mesoderm. I find in the adult Solaster that there is a branch extending aborally into each interbrachial septum from the corresponding segment of the external oral circular sinus. This branch soon divides into slit-like spaces, which cease to be recognizable when traced further upwards in the septum (8 @). In development the branch in question is not difficult to follow (p. 36), and indeed I was first led to Look for it in the adult from having noted it in a specimen of the age of four months. Contents of the Egg-Tubes—The egg-tubes contain: (1) ova in various stages of growth; (2) follicle-cells, both covering the ova and lining such parts of the gonad-wall as are free from ova; (3) irregular cells, free in the lumen of the tube, mostly rounded and loaded with fat-granules, but sometimes smaller and resembling leucocytes in form. Ova.—These rest directly against the inner wall of the egg-tubes without the intervention of follicle-cells. Quite young ova may occur anywhere along the length of the egg-tubes, but as a rule the youngest are most abundant towards the free ends of the tubes. The nucleus or germinal vesicle contains a single large nucleolus, and exhibits in general the characters which are usually found in the nuclei of highly yolked ova. That is to say, it is large from an early stage, and it increases with the growth of the egg; its membrane is definite and resistant; there is a delicate achromatic reticulum; the chromatin is diffuse and difficult to stain; and the fluid nucleusoplasm is abundant and coagulates in shreds. The cell-contents stain readily with hematoxylin, are finely punctate in character, and have a rich orange colour which dissolves out readily in alcohol and other reagents. These facts indicate the early presence of deutoplasmic granules; but this first deutoplasm is free from ordinary fatty yolk, being quite unaffected by treatment with osmic acid. Indeed, the growth of the ovum may be divided into two periods: the first up till the earliest appearance of the yolk-granules which are fatty in character, and the second till full size is reached and the egg is ready to undergo the changes of maturation. At the end of the first stage the egg has reached a diameter of -15 mm., a third of this measurement being occupied by the nucleus. Fatty yolk-granules now begin to gather closely round the nucleus, forming a zone which is at first thin and loose, but afterwards becomes thicker and more crowded, the additions taking place on the outside of the zone (PI. III. fig. 35). Throughout this zone only a small amount of protoplasm remains, forming a reticulum between the granules. Outside of the zone in question there is a layer of protoplasm gradually increasing in size during the active growth of the egg, but gradually also being invaded by the yolk, until in the end there remains under the egg-membrane only the thinnest possible yolk-free layer. It should be noted that while the gross aggregation of yolk takes place from the nucleus outwards, as above described, stray granules may be observed in all stages at lesser depths, or even close under the egg-membrane. Similar granules along with many coarser ones occur within the follicle-cells, and it seems not improbable that during growth the former are transferred through the vitelline membrane to the ovum, where they congregate round the germinal vesicle, the stray granules above mentioned being on their passage inwards from the periphery. A remarkable instance of transference of the granules is given on p. 49. The yolk-granules on their first appearance are small, rounded, and uniform in size. As growth proceeds they become slightly larger everywhere, the increase in the full-sized egg being least at the very surface close under the vitelline membrane. In the middle and later stages of growth, bodies resembling the so-called yolk-nuclei are very evident. Their substance is finely punctate. They stain well in hemalum, but with a characteristic reddish tinge. They are by no means regular in number, size, and position, though the largest are always found quite close to the germinal vesicle. They have no definite boundary, but merge at their periphery into the protoplasmic reticulum in which the yolk-granules lie. They disappear when the egg has reached full size and maturity. It seems probable that they are formed by the activity of the nucleus (germinal vesicle), and that migrating outwards from it they become broken up through contributing to the general protoplasmic meshwork of the cell. Chubb (2, p. 384) describes the yolk-nucleus In Antedon as formed by the throwing out of small globules from the nucleolus. A vitelline membrane is recognizable from a very early stage. In larger ova it remains thin, but is moderately tough, though not comparable in this respect with the membranes of many other ova of similarsize. It seemed to be perforated by numerous fine pores, and may accordingly be termed a “zona radiata.” Apart from distortion and facetting due to pressure, the shape of the ova within the egg-tube is already that of a spheroid with marked flattening at two opposite poles, one of which is on the side of the ovum next the gonad-wall. This, the future upper pole of the egg is bright orange in colour. The lower or yolk pole looks towards the lumen of the egg-tube and is distinctly paler than the first. The transition between the two colours is gradual, and occurs at the equator or widest part of the egg. The diameter in the equatorial plane averages 1 mm., while the vertical diameter is approximately -8 mm. Follicle-Cells—The follicle-cells give a covering to the eggs, except where the latter are attached to the gonad-wall, and also line such parts of the wall as have no ovate resting against them. Here, in places, they are folded inwards in the form of villus-like tufts, on the surface of which they assume an elongated form, many of them being crowded with granules or globules of fatty nature, while others have a large proportion of clear mucid contents. The larger villi rest on a fold of the inner layer of the egg tube-wall, and this fold may contain an extension. From the spaces previously described as existing between the inner and outer layers of the gonad-wall. The follicle-cells surrounding young and half-grown ova are cubical or polygonal in shape, and provide a covering several layers thick. As growth nears completion, these become reduced to a single layer made up of cubical or flattened cells. Still later they seem to undergo complete degeneration, the eggs when shed being destitute of a cellular covering. Practically all the follicle-cells contain fatty granules, mostly small and resembling those within the eggs, but often larger and comparable with ordinary fat-globules. As was indicated above, it is possible that the smaller granules are transferred directly through the vitelline membrane into the ovum during growth. There is no definite lumen within the egg-tube, the spaces between the eggs being occupied by follicle-cells, and by a small amount of fluid containing some irregular cells which are probably of leucocytic origin. In some cases masses may be noted which look like the debris of degenerating ova. These masses are without definite outline and consist of densely crowded fine yolk-granules, with small nuclei here and there among them. Round the nuclei a certain grouping of the yolk-granules is observable, as if each nucleus was establishing a cell-territory. The nuclei are probably of leucocytic nature. Egg-Ducts.—The walls of the egg-ducts contain inner and outer layers corresponding in structure with those of the gonad-tubes, but the gonad sinus-spaces are not continued into the depth of the body-wall. The ducts are lined with ciliated cylindrical epithelium rising into folds and having many cells with clear mucous contents. The transition between the germinal cells of the egg- tubes and the epithelium of the ducts is quite sudden, and even in immature specimens there is no septum intervening between the contents of the tubes and the lumen of the ducts. It is difficult to determine macroscopically the exact number of external genital openings. During active spawning, however, as many as four eggs emerged at the same time, but discretely, from a single interradius. Serial sections of an interradius in the adult showed that each of the gonads had two slit-like terminal ducts formed by the union of several tributary ducts, some of which joined the terminal one within the thickness of the body-wall. In Solaster papposa, according to Müller and Troschel (quoted from Ludwig, 13, p. 592) and Cuénot (4, p. 623), each gonad has a number of ducts which pierce the body-wall independently, but close together, the small area on which they open being thus sieve-like in character. THE STARFISH SOLASTER ENDECA. My own observations on S. papposa, made from serial sections of an interradius in a half-grown specimen, showed only two external apertures (one for each gonad). Each of these led to a crypt-like cavity, into the bottom of which several egg-ducts opened. Eversion of this cavity may occur during later growth or at the periods of ripeness, thus producing the condition described by the authors above named. For a further discussion of these points, see under reference 8 a. III. Maturation, SPAWNING, FERTILIZATION, &c. Maturation.—Preparation for the maturation changes begins after the egg has reached full size, and while it is still attached to the gonad-wall. The germinal vesicle elongates radially and migrates towards the attached side of the egg until one of its poles lies close under the surface. The nucleolus becomes vacuolated, ceases to react actively to stains, and finally disappears. Meantime the membrane of the germinal vesicle has broken down. The contents remaining in position help to form a tract or plug, which is free from fatty yolk-granules and extends right to the centre of the egg. This tract comes to the surface in the middle of what will afterwards be recognizable as the upper pole of the egg. Here it expands into a small circular disc. After the eggs are shed this disc appears under reflected light as an area slightly darker than the rest of the surface, no doubt owing to its greater transparency and freedom from yolk. In the ova examined, the formation of the first polar body was in active progress at the time of shedding. An egg fixed immediately after extrusion showed the first of the spindles lying obliquely within the disc above mentioned and close under the surface. In eggs fixed three hours after extrusion both polar bodies were found extruded and adherent to the surface, while the small female pro-nucleus, now difficult to detect, lay some distance below. No doubt the pro-nucleus next migrates towards the centre of the egg. Spawning.—Apparently the brooding habit is absent. Spawning occurs in the end of March or the beginning of April, and extends at intervals over a week or more. For example, a specimen taken in the trawl off the Marine Station at Millport on March 22nd, 1910, gave out over on the 25th, on the 30th of the same month, and again on April 2nd. No further spawning took place, although the specimen was kept under observation for the next four weeks. The number of eggs on the first occasion is not known approximately, but on the second it amounted to over three thousand, and on the third to between two and three hundred. On the second occasion (March 30th) the period of most active spawning lasted about two hours. During this time the Starfish was attached to one side of the tank near the surface, the body and arms being strongly arched so that only the tips of the latter were adherent. The ova could be seen emerging as many as four at a time from the genital aperture in each of several interradial. The same Starfish, when spawning on April 2nd, took up a somewhat different position, viz., on one side of the tank right at the surface, with the uppermost arms unattached, bent over, and separated so as to expose the interradial angles. The ova were emitted chiefly from these interradial, but also from one or two others, sometimes singly, sometimes two or three together, at short intervals, for two and a half hours. Some years ago I observed a specimen of Solaster papposa in the act of spawning. The process was almost exactly identical with that which has been last described. At the time of shedding, the eggs may be compressed in any direction, but they very quickly assume their proper form, that of an “oblate spheroid” (p. 7). Being rather lighter than sea-water, they rise gently to the surface and remain there when undisturbed. As was indicated previously, they float with the equator of the spheroid horizontal. The upper pole is of a rich orange-colour, and has in its centre the small area free from fatty yolk. The lower pole is paler in colour and of distinctly greater specific gravity, so that the egg rights itself almost at once, should its balance be disturbed. The vitelline membrane is closely applied to the surface of the egg all round. In the eggs shed on the first two occasions it was quite thin, transparent, and smooth on the surface, but in those which were shed last there was an additional outer covering, somewhat frayed on the surface, and with minute granular debris adherent. The difference is probably caused by the addition to the true egg-membrane of a mucous coat formed within the ovary itself. Two other specimens of S. endeca were kept in the same tank as the one which spawned, and fortunately one of these proved to be a ripe male. On March 30th, while ova were being shed by the female, the male was observed resting in an ordinary position on the side of the tank about two feet distant, and sending out thin streams of sperm from five or six interradii. On this occasion practically all the ova were fertilized, although in the end only a few of them developed quite normally beyond the gastrula stage. On the next occasion of spawning (April 2nd) the emission of sperm by the male was not obvious. All the eggs were, however, fertilized, and a very large proportion of them underwent normal development. The eggs of Solaster are much too large and opaque to allow the process of fertilization to be watched under the microscope. It can readily be seen, however, that they attract the sperm strongly as soon as they are shed, and therefore a considerable time before the maturation changes are completed. No doubt the disc at the upper pole and the stalk leading from it down to the center of the egg serve as a track of entrance and guidance to the spermatozoon, which would find difficulty in boring a way through the densely crowded mass of fatty yolk-granules present everywhere else. THE STARFISH SOLASTER ENDECA. 11 Segmentation and Gastrulation (Pl. I. figs. 1-6; Pl. III. figs. 24, 25).—In from three to three and a half hours after they were shed the eggs began to separate off their vitelline membranes as ‘membranes of fertilisation’ *. The process was complete in from four to five hours. The width of the clear space left between membrane and egg varied considerably, but was on an average equal to about a seventh of the diameter of the egg itself. This membrane persists throughout segmentation and until the blastula is beginning to rotate within it—that is, till about the fifth day after fertilisation. Segmentation all through is total and equal, the first and second cleavage-planes (Pl. I. figs. 1-2) being vertical and at right angles to one another, while the third is horizontal. The succeeding divisions follow with regularity and give rise to a solid “morula” (figs. 3-4) made up of very numerous cells which are practically equal in size. As many as three hundred such cells may be counted in a median section. The flattening at the poles becomes less marked, but the mass floats as before, and the under half is still paler in colour than the upper. It should be stated that while equality of segmentation is certainly the normal condition, a slight degree of segmentation is usually ascribed to the function of keeping out other sperms after the entrance of the one which is to fertilize the egg. The sperms crowd actively round the ova immediately the latter are shed, and yet, as we have seen above, it was not till three hours afterwards that the membrane even began to separate. This might seem to give ample time, were no other factors at work, for the occurrence of polyspermy or even for the entrance of sperms of mixed origin. As is well known, cross-fertilization may occur between widely different echinoderms. In this connection, a series of experiments I made some time ago affords the following results with reference to Solaster:—The ovary of Solaster endeca are strongly attractive to the spermatozoa of Solaster papposa and are fertilized by them. Segmentation, though often very unequal, was sometimes quite regular and led to a very considerable degree of further development. Blastula, gastrula, and early larval stages were easy to obtain. Later, the larve tended to die off after showing various abnormalities of growth, such as malformation or loss of the larval arms and vesiculation of parts of the larval body. Serial sections of the larve showed very marked irregularity in the internal cavities, the typical arrangement being interfered with in many ways, though there was evidently an attempt at the formation of all the characteristic coeloms. The presence of several ciliated canals leading to the surface from one or other of the internal cavities was a common deviation. Some of the hybrid larve lived for over two months, but none of them entered on the stage of sucker fixation which leads to metamorphosis. The ova of Solaster papposa are also strongly attractive to the spermatozoa of S. endeca and are fertilised by them. The resulting segmentation showed greater irregularity than in the converse experiment, but unfortunately I had not the opportunity in this case of carrying the observations to later stages. In my experiments, the sperm of Solaster endeca was also tried with the ova of Hchinus esculentus L., Asterias rubens L., Uraster glacialis O. F. M., Cribrella oculata Penn., Brissopsis lyrifera Forb., Echino-cardium cordatum Penn., and Synapta digitata Mont. The results as regards fertilisation were negative in every instance, and the eggs of the sea-urchin alone exhibited the power of attracting the sperm. On the other hand, the ova of Solaster papposa attracted the sperm of Asterias rubens, and underwent Regular segmentation under their influence. The same ova neither attracted nor were fertilised by the sperm of the other species mentioned above. Dr. J. F. Gemmell on the Development of Substitution may also be present in healthy ova. One also comes across cases in which the early segmentation is very markedly unequal. Such ova may seem to develop normally during the gastrula and the early larval stages, but none of them which I isolated entered on the later larval stages or underwent metamorphosis. Blastula and Gastrula.—The process of blastula and gastrula formation presents those remarkable features which were first carefully described by Masterman (18, pp. 378-381) as occurring in the ova of Cribrelia. 