GERM CELLS OF HERMAPHRODITES 199 



elements is explained by Ancel by supposing the 

 transformation of the cells into sex cells to cease 



Fig. 58. — Helix arbustorum. Stages in the dififerentiation of male and 

 female sex cells. A. Nucleus of germinal epithelium, B, Nucleus 

 of nurse cell. C. Nucleus of indifferent sex cell. D. Spermatogo- 

 nium of first order. E. Spermatogonium of second order. F. Grow- 

 ing oocyte. (From Buresch, 1911.) 



before nurse cells are formed; thus all the sex cells 

 would become spermatogonia. 



More recently Buresch (1911) has repeated the 



