418 E. L. SHAFFER. 



I have seen the cytoplasm gradually disintegrate, become vacuo- 

 lated, and disappear while the spindles remain as perfect as ever. 

 In testing the effects of reagents, too, I have been able to dissolve 

 practically the whole of the cytoplasm of all the cells of the cyst, 

 while the spindles remained, showing a system of connected 

 spindles throughout the whole cyst." 



There are other structures related to the spermatocytes which 

 are of a more or less problematical nature. In Figs. 8 and 28 

 there will be noticed a large vacuole in each of the spermatocytes ; 

 these are to be found in nearly every spermatocyte during the 

 late prophases and thus far I have been unable to find them in 

 the earlier stages. The vacuoles are filled with a homogeneous 

 fluid (perhaps a gel) which takes the plasma stain but lightly. 

 Sometimes there may be several vacuoles in a single cell. In 

 cysts of spermatocytes having such vacuoles, one often finds in 

 the cyst cavities round or oval bodies of a granular nature (Fig. 8) 

 resembling very much the cytoplasm of the spermatocytes. 

 Furthermore, in such cysts the sides of the spermatocytes 

 bordering on the cyst cavity are- of an irregular outline and 

 often distinct pseudopod-like projections of the cytoplasm are 

 given off. It is therefore highly probable that the small bodies 

 found free in the cyst cavity have arisen from the pseudopod- 

 like projections or buddings from the cytoplasm of the spermato- 

 cytes. What the significance of either the vacuoles mentioned 

 above, or of the casting off of portions of the cytoplasm may be, 

 I am unprepared to state. The presence of vacuoles and pseudo- 

 pods at the same time may indicate that the vacuoles are cast 

 out by means of setting free the pseudopods. But this view is 

 at present untenable, for I have never actually seen vacuoles 

 within the pseudopods; furthermore the contents of the vacuoles 

 are always of a homogeneous appearance, while the cast off 

 parts of the cytoplasm are granular as described above. Voiv- 

 nov has found in Cybister that vacuoles make their appearance 

 in the late prophases of the spermatocytes. These differ in 

 appearances, at least, from those found in Passalus in that 

 they contain definite bodies as inclusions. Voivnov also finds 

 that they are later cast out into the cyst cavity. He considers 

 these to be portions of the sphere (idiozome) which are under- 



