82 J. M. ESSENBERG. 



PLATE III. 



FIG. 12. Portion of transverse section of epithelium of the ovarian cavity 

 showing transformation of epithelial cells into definitive germ cells. X 1000. 



FIG. 13. Section of medium-sized ovum to show migration of nucleolus 

 from nucleus into cytoplasm. X 410. 



FIG. 14. Portion of a transverse section of a young female between an- 

 terior and posterior primordia of oviduct showing no central duct formation. 

 X 1000. 



FIG. 15. Portion of a section of a disintegrating ovum showing disorgan- 

 ized follicular epithelium. X 1000. 



FIG. 16. Section of medium-sized ovum to show migration of nucleolus 

 towards periphery of ovum. X 416. 



Symbols : 



af Various stages of transformation of epithelial cells into definitive 



germ cells. 



bv Blood vessel. 



ec Epithelial cell. 



fe Follicular epithelium. 



m Mesentery. 



mno Migrating nucleolus. 



no Nucleolus. 



oc Ovarian cavity. 



p Peritoneum. 



rt Rectum. 



thf Theca folliculi. 



ub Urinary bladder. 



y Yolk. 



