10 



e. SASAKÎ. 



cate in its texture. 



The germogen ( PL II, fig. 6 e) in in the form of a thin walled 

 tube, and is filled up with a number of nucleated cells. These cells 

 have each a large nucleus and have a comparatively small amount of 

 protoplasm; in some cases, a few of these cells near the broad end of the 

 germogen, are seen to be sorrounded by a part of the epithelial layer 

 which envelopes the germogen, and are thus in the process of being dif- 

 ferentiated into an egg ( PL II, fig 10 a ). 



The first few eggs ( PL II, fig. 6 g) in the slender end of the 

 egg tube proper, contain also a number of nucleated cells which lie 

 close to one another. Each of these cells-groups is sui-rounded by 

 columnar epithelial cells arranged regularly side by side. As these 

 eggs grow, the nucleated cells contained in them increase also in size. 



In the next stage ( PL II, fig. 6 h,h) some nucleated cells which 

 occupy the lower portion of the egg seem to lose their membranes, and 

 their contents except the nuclei are converted into a mass of granulated 

 yolk ( P/. II, fig. 6i). Around this mass, there is found a vitelline 

 membrane which is probably formed of a peripheral finely-granulated 

 layer of it. The dissolution of the nucleated cells in an egg, and a 

 conversion of their contents into granulated yolk are very similar to 

 those studied by Dr. A. Weismann (*5) on Musca vomitaria. The later 

 stages of the development of the egg, I have not had an opportunity to 

 examine; but the same author says in regard to this point: — "Diess ist 

 dann das stadium, in welchem die Zellmembranen schwinden, der in 

 den Zellen gebildete Dotter zusammentritt zu einer Masse und die kerne 

 bis auf einen, welcher zum keimbläschen wird; zu grün dt; gehen. Es 

 scheint, duss immer der Kern derjenigen eibildenden Zelle das Keim- 

 l)lUschen liefert, welcher am ausfiihrungsgange der Kammer liegt,***" 



Around the mature egg (PL II, fig. 6j) which lies at the broad 



(ß) /oit. f. Wiss. Zool. Bd. 11.. p. 204. 



