Miscellaneous. 541 



coloured granules, originally contained in the hepatic cells of the 

 stomach, to which are often added debris of alimentary matters, 

 such as Diatomaceae ; and in BowerbanJcia imhricata the plates and 

 teeth of the gizzard are found in it. Incapable of budding by itself, 

 it is, in the Vesicular ice, relegated into a corner of the chamber 

 when a new bud is developed ; on the other hand, in many species 

 (LepraJia, Eucratea chelata) it is pushed out of the zooecium by the 

 new polypide. For this purpose, as RepiachofF has very well ob- 

 served, the young bud englobes it in a cavity which will subse- 

 quently become the stomach, then, when developed, passes it into 

 the rectum, and, at the first expansion, rejects it by the anus. 



With regard to the fecundation of the ovum, I am in a position to 

 assert that in Valkeria cuscuta the ovum cannot be impregnated by 

 the spermatozoids, which are developed at the same time in the same 

 zocBcium and in the bosom of the same funicle ; in order to its seg- 

 mentation it needs the concourse of spermatozoids coming from 

 another chamber. In fact^ so long as there are spermatozoids in 

 the zooecium that it occupies, the ovum is only sketched out ; it 

 increases in size and shows distinctly its germinal vesicle and spot 

 long after all the spermatozoids have been evacuated. The latter 

 may be seen swimming actively in the surrounding water ; and the 

 mode in which their access to the ovum is facilitated is very curious. 

 When the ovum becomes distinct the spermatozoids are quickly 

 evacuated, the polypide which accompanied them then shrivels and 

 becomes reduced to the state of brown body, and the chamber com- 

 pletely closes. The ovum therefore becomes mature in a closed 

 zooecium. When the moment arrives for it to be fecundated, a new 

 bud is developed in its dwelling-place ; but the polypide produced 

 from it never attains the adult state ; it has no other purpose than 

 to reopen the chamber by developing in it a new opercular apparatus 

 and to lend its muscles to the nascent larva. With this object, after 

 having, notwithstanding its small size, produced all the parieto- 

 vaginal and great retractor muscles, it is atrophied and passes 

 behind the ovum, which, by a mechanism which it would take too 

 long to describe here, is finally placed in its tentacular sheath, in 

 free contact with the surrounding water and consequently with the 

 spermatozoids. By the action of the muscles which are now 

 attached to its envelope, the fecundated ovum, which has become 

 a larva, moves in the chamber, absolutely as a polypide would do ; 

 it may even be carried to the entrance, in consequence of the evagi- 

 nation of the sheath ; and it is in this way that the ciliated larva is 

 finally evacuated. 



I shall notice, in the last place, an embryo which shows that the 

 mode of organization described by Schneider in the Cyphonautes is 

 far from being an isolated fact. The embryo of Flustrella hispida, 

 Redfern, is bivalved and presents a complex organization. Like 

 the former it finally fuses completely into a mass of homogeneous 

 protoplasm, in the midst of which the first polypide is developed ! — 

 Comptes Rendus, August 13, 1877, p. 406. 



