191' ISAO IIJIMA. 



portions meet and coalesce in Trocheta ; but I have satisfied 

 myself by disseciions, as well as by microscopical observa- 

 tions, that no such union exists in our Nephelis. In this 

 respect what I have seen agrees entirely with Professor 

 Leuckart's (No. 4, p. 677-678) statement, that these tubes 

 have no communication with each other, except at the point 

 of their common outlet. Moquin-Tandon has represented 

 the ovaries of Nephelis as a single tube in the form of a 

 collapsed ring. 



Coiitetits of the Ovaries. — Within the ovaries there is a 

 number of so-called egg-strings, some of which are free, 

 while others (younger) are not yet detached from their 

 place of origin. Of these I will have to speak in detail 

 further on. The free egg-strings float in a clear fluid, pro- 

 bably of a protoplasmic nature. The origin of the fluid is 

 unknown, but it is certain that it is fed, partially at least, 

 by the dissolution of some of the bodies which are found 

 floating in it, and which are presently to be described. 



Whatever other purposes this fluid may subserve, there 

 can be no doubt that it holds nutritive substances in solu- 

 tion, which are appropriated by the growing egg-strings. 



Throughout the winter months I found ripe eggs floating 

 in the ovaries, but am unable to say what becomes of such 

 eggs. Possibly they may remain in a comparatively quies- 

 cent state until the time for laying approaches. Of one 

 thing there is no doubt, viz. that ripe eggs, after the forma- 

 tion of the archiamphiaster (Whitman), are retained for a 

 considerable length of time in the ovaries, during which 

 time no discernible changes take place. A similar fact has 

 been noted in Clepsine by Professor Whitman (No, 7, p. 231), 

 who found that ripe eggs were often retained four or five 

 days within the ovaries. 



Leydig (No. 3, p. 125) found in the ovary of Piscicola many 

 eggs that were undergoing regressive changes, and also some 

 empty egg-membranes. O. Hertwig (No. 8, pp. 14 and 19) 

 also mentions the occurrence of such eggs in Hsemopis. In 

 the case of Nephelis he states that some of the ripe eggs 

 break up and serve evidently as nourishment for the rest. 

 My observations accord fully with these statements. I have 

 often seen many eggs with their lecithin granules either in 

 irregular clumps or in otherwise disordered conditions. I 

 have also found empty membranes of broken eggs. 



In the ovarian fluid there is also a large number of free 

 cells, varying in size, but averaging ca. '015 mm. in diameter. 

 These are fuund floating about, or else packed among sper- 

 matophores (?)• They contain comparatively large, highly 



