120 THE PHYSIOLOGY OF REPRODUCTION 



germinal epithelial nuclei, (b) Protobroque cells, Variety 6. — 

 The cells belonging to Variety a divide, and give rise to more 

 cells of the same kind, as well as to protobroque cells of the b 

 variety. In the latter the nuclei are less granular, and contain 



Early ovogenetic stage. Leptotenic stage. 



Fl8. 24. — Developing ova from ovary two days before birth. (After 

 Lane-ClaypoD.) 



a certain number of fine chromatin filaments, (c) Deutobroque 

 cells. — The protobroque cells of the 6 variety hkewise divide, 

 and give rise to more protobroque ceUs, similar to themselves, 

 and also to deutobroque cells. These latter are larger in size, 



Early. Synaptenic stage. Zate. 



Fig. 25. — Developing ova from ovary about one day before birth. 

 (After Lane-Claypon.) 



and contain nuclei with the chromatin arranged in the form of 

 a reticulum. 



II. Later changes : (a) Leptotenic stage. — Certain of the 

 deutobroque nuclei become gradually differentiated, the 

 chromatin during the leptotenic stage passing through a process 

 in which it breaks up into fine filaments ; these are distributed 



