64 GERM-CELL CYCLE IN ANIMALS 



22 



ooc 



as __ 



FIG. 22. Miastor americana. Frontal section through posterior end 

 of embryo showing oogonia (odg^) forming two rows of four each. 



FIG. 23. Miastor americana. Ovary containing sixteen oogonia (00(74), 

 one dividing by mitosis (a), m = mesoderm. 



FIG. 24. Miastor americana. Ovary containing thirty-two oogonia 



cos. m = mesoderm. 

 FIG. 25. Miastor americana. Young oocyte (ooc) with nurse cells 

 (n.c). 



