CTENOPHORA. j- 



ment was found b\ Chnii; Ctenoph. d. Golfes v. Neapel. Taf. XVI, Fig. 481. The ripe spermatozoa 

 are found in the upper part of the testis. They break through the entodernial Hning into the o-enital 

 cavity, where they may be found in large quantities in the sections (PI. VII, Fig. g). Tlie pecuHar fact 

 observed by Chun (Dissogonie p. 98, Taf. XIII, Fig. 2, 6) that in Boliiia "die Schwanze der Sperma- 

 tozoen zu keilformig gestalteten Biindehi vereint sind, welche aUmahHch sich zwisclien das Gefass- 

 epithel einzwangen und schHesslich nach der L,eibesh6hle durchbrechen" has not been observed here. 

 I have not found the material suited to working out the minor histological details of the development 

 of the spermatozoa. 



The figures 5 — 6, PI. VI, are of value for determining the question about the origin of the 

 genital cells in Tjalfiella. It is seen there, especially very distincth- in fig. 5, that the germinal 

 zone is a direct continuation of the low entodernial epithelium lining the lower wall of the genital 

 cavity. It appears that on the limit between this low epithelium and the higher epithelium which 

 covers the genital organ a constant proliferation of the cells takes place, most of the voung cells being 

 added to the germinal layer. It can scarcely be denied that all evidence is in fa\'our of the entodernial 

 origin of the genital cells in Tjaljiclla. This case is thus quite in accordance with the view main- 

 tained b\- Chun that the genital cells of the Ctenophores are of entodernial origin, which view is 

 also supported by the researches of Gar be'). The opinion of Hertwig (Op. cit.) later on maintained 

 anew by Samassa^) that they are of ectodermal origin seems to nie definitely refuted bv Chun; the 

 ectodermal invaginations of Callinira bialata which have caused this opinion appear to be a kind of 

 sense organs peculiar to this species and have not been found in any other Ctenophore as \et. — 

 It may be worth recalling here the series of glands which occur along the subventral ribs in 

 EurhaiiipJuca vcxilligera Gegenb. and which secrete a red fluid, when the animal is touched. (Comp. 

 Const. N. Jouescu: Uber die Ctenophore Eurhamphsea vexilligera. Jen. Zeitschr. f. Naturwiss. 

 Bd. 43. 1908. p. 685—691. Taf. XXIV). The structure of these glands being as yet unknown, it is, of 

 course, impossible to sa\' anything definitely about their homologies. But it might perhaps not be 

 unreasonable to suggest that they coidd have some relation to the ectodermal sacs of CaUianira. 

 That Chun (Ctenoph. Golfes v. Neapel, p. 296) is inclined to suppose a genetic relation between 

 Eurhamplura and Callia>iira is also worth mentioning in this connection. Though J one sen denies 

 the existence of any nearer relation between these two forms, the suggestion of Chun certainly 

 deserves a more careful investigation. 



More recently a third view of the origin of the genital cells of the Ctenophores has been 

 maintained by Karl Cam. Schneider'), viz. that they are of mesodermal origin. It does not appear 

 to me that the reasons produced by Schneider for this opinion are very convincing, as also 

 B. Hatschek (Das neue Zoologische System, 1911. p. 13) finds them "nocli nicht beweiskraftig" ; being, 

 however, not profoundly acquainted with histology, I do not venture on a detailed criticism of his state- 

 ment. I would only point to some facts, which appear to me very unfavourable to his theory of the nieso- 



M Aug. Garbe. Untersuchungeu iiber die Entstebung der Geschlechtsorgane bei den Cteuophoren. Zeitschr. f. wiss. 

 Zool. Bd. 69. 1901. p. 472—491. Taf. XXXVI- XXXVII. 



-) P. Saniassa. Uber die Entstebung der Genitalzellen bei den Cteuophoren. Verhaudl. d. naturh. -medic. Vereins zu 

 Heidelberg. N. F. Bd. V. 1893. (This paper has not been available to the author). 



3) Karl Camillo Schneider. Histologische Mitteilungen. 1. Die Urgenitalzellen der Ctenophoren. Zeitschr. f. wiss. 

 Zool. LXXVI. 1904. p. 388-399. Taf. XXIV. 



