18 



have en stor, rund Kjerne med KjefneJegeme, og som er 

 omgiven af et fint granuleret Protoplasma. Hos Hunnen 

 begynder nu Ovariet at dannes.. Af de nævnte Celler, der 

 maa betragtes som ovigene Dannelser (Urkeimcellen), sees 

 mange, baade de. der ligge periferisk til Væggen og de. 

 som nærme sig Midten af Æggestokken, at udvikle sig til 

 Æg. De Epitheleeller, der ligger nærmest det i Udvikling 

 værende Æg. omfatter nu mere eller mindre ganske Ægget, 

 Tab, V. Fig. 1 a, 2 a, som. idet dette voxer, skyder Epi- 

 thelet foran sig. hvorved en Follikel dannes, Tab. V, Fig. 

 1 b. 2 b. Hos Bathycrinus Carpenteri er denne Follikel- 

 dannelse temmelig regelmæssig, omendskjont der ogsaa hos 

 denne Art forekommer nogen Uregelmæssighed. Det viser 

 sig nemlig, at enkelte Æg kun delvis ere omgivne af den 

 epitheliale Membran, saaledes at deres Halvdel kan være 

 ubedækket, imedens Mængden er fuldkommen indesluttet i 

 en Follikel, Tab. V, Fig. 2 b. Denne udvides, efterhaanden 

 som Ægget voxer, men bliver alt tyndere og tyndere. ind- 

 til den ved dettes Fuldmodenhed brister. Ægget gjen- 

 nemgaar sin fulde Udvikliug i Follikelen, hvad enten denne 

 dækker helt eller halvt Ægget, og først naar Kimblæren 

 er forsvunden og Retuingslegemerne ere udtraadte, brister 

 den follikulære Membran, for at det fuldmodne Æg kan 

 træde udenfor Ovariet. Xogen Oviduct findes ikke, ligesaa- 

 lidt som det har været muligt at opdage nogen Aabning 

 paa Æggestokkens Ydre. Ovariet hos Bathycrinus Carpen- 

 teri synes saaledes at have et Slags Stroma, bestaaende af 

 de ovenfor beskrevne, epitheliale Follikeldannelser. 



Naar Æggestokken er fuldt udviklet, har den antaget 

 en ellipsoid Form og fylder næsten hele Pinnulen. Tab. 1, 

 Fig. 12, saa at baade Dorsal- og Ventralkanalen er bety- 

 deligt sammentrængt. Tab. V, Fig. 1. Det ydre Geifitalror 

 har tiltaget betydeligt i Tykkelse og danner en fast Binde- 

 vrevsmembran, som egentlig udgjor Ovariets ydre Begrænds- 

 ning, og hvori der synes at have udviklet sig fine Muskel- 

 fibre. Tab. V, Fig. 2 c. Men imedens der i Æggestokken 

 hos Bathycrinus Carpenteri foregaar en temmelig regelmæs- 

 sig Follikeldannelse, er Forholdet noget anderledes hos 

 Antedon petasus og Antedon prolixa. Her er det ikke 

 Regelen, at Ægget er fuldt omgivet eller indesluttet i en 

 Follikel, tvertom horer det næsten til Sjeldenhederne. at 

 man hos disse to Arter træffer paa Æg, der har en fuldt 

 udviklet Follikel. Det almindelige er, at det begyndende 

 Æg blir delvis omgivet af de ■ nærmest tilgrændsende Epi- 

 thelialceller. der efterhaanden som Ægget voxer. danner 

 om dette en halv eller hel Membran, en Slags Follikel, 

 Tab. IV, Fig. 5, 6, ja man ser endogsaa Æg, som lige fra 

 Begyndelsen og til sin fulde Modenhed aldeles intet saadant 

 Overtræk (Follikel) har. 



Testikelen dannes ligesom Æggestokken af det udvi- 

 dede indre Genitalror; men her er ingen Follikeldannelse. 

 Fra Genitalrorets indre Væg udgaa en Mængde yderst fine, 

 listeformige Bindevævsforiængelser, der forgrene sig i for- 

 skjellige Retninger, Tab. V, Fig. 3, 4 a. Paa disse Binde- 



consisting of several lavers of pretty large, round cells 

 having a large round nucleus with corpuscle which is sur- 

 rounded by a fine granulated protoplasm. In the female 

 the ovary begins now to be form ed. Many of the cells 

 spoken of, which must be regarded as ovigenous formations 

 (Urkeimcellen), both those lying peripherically to the wall 

 and those that approach the middle of the ovary, are seen 

 to develope themselves into ova. The epithelial cells that 

 lie nearest to the ovum in course of development, now 

 enclose the ovum more or less completely (Pl. V. fig. 1 a, 

 2 a), which, as it grows, pushes the epithelium in front of 

 it, thereby producing a follicle (Pl. V, fig. 1 b. 2 b). In 

 Bathycrinus Carpenteri this follicular formation is pretty 

 regular, although there also appears in this spedes some 

 irregularity. It appears, namely, that a few ova are only 

 partially surrounded by the epithelial membrane, in such 

 manner that the half of the ovum may be uncovered, while 

 the bulk are perfectly enclosed in a follicle (Pl. V, fig. 2 b). 

 This becomes gradually expanded according as the egg 

 grows. but becomes thipner and thinner until. on the 

 maturity of the ovum, it bursts. The egg undergoes its 

 complete development in the follicle. whether the latter 

 covers it entirely or only half of it, and first when the 

 germinative sac has disappeared and the directional bodies 

 have appeared, does the follicular membrane burst. so that 

 the fully grown ovum may leave the ovary An oviduct 

 is not found, and just as little has it been possible to 

 observe any aperture on the exterior of the ovary. The 

 ovary in Bathycrinus Carpenteri seems thus to have a kind 

 of stroma. consisting of the above described epithelial 

 follicular formations. 



When. the ovary is fully developed it assumes an 

 ellipsoid form and occupies nearly the entire pinnule (Pl. 

 I. fig. 12), so that both the dorsal and ventral canals 

 are considerably compressed (Pl. V. fig. 1). The outer 

 genital tube increases considerably in thickness and forms 

 a firm connective-tissue membrane, which really forms the 

 exterior boundary of the ovary. and in which delicate 

 muscular fibres appear to have developed the.:iselves (Pl. 

 V, fig. 2 c). But whilst there. in the ovary of Bathycrinus 

 Carpenteri, takes place a pretty regular follicular formation, 

 the relation is somewhat different in Antedon petasus 

 and Antedon prolixa. In these it is not the rule that the 

 ovum is entirely surrounded or enclosed in a follicle, on 

 the contrary. it is quite exceptional that we, in those two 

 species, meet with ova that have a fully developed follicle. 

 The usual case is, that the rudimentary ovum is partially 

 surrounded by the nearest adjacent epithelial cells, which, 

 as the egg grows, gradually form round it a half or entire 

 membrane, a kind of follicle (Pl. IV. figs. f), 6), indeed we 

 even see ova which, quite from the commencement and to 

 their full maturity, have no such covering (follicle) whatever. 



The testicle, like the ovary, is formed by the expanded 

 inner genital tube, but there is here no follicular formation. 

 From the inner wall of the genital tube there issue a 

 multitude of extremely fine fillet-formed connective-tissue 

 prolongations, which ramify in various directions (Pl. V, 



