362 



THE ORGANS 



is known as the germ hill {discus proligerus — cumulus ovigerus). The 

 cells of the germ hill nearest the ovum become columnar and arranged 

 in a regular single layer around the ovum — the corona radiata (Fig. 

 258). The ovarian stroma immediately surrounding the Graafian 

 follicle becomes somewhat modified to form a sheath for the follicle — 



a 

 b 

 c 

 d 





Fig. 254. — Vertical Section through Cortex of Ovary of Young Girl. X190. (Bohm 

 and von Davidoff.) a, Germinal epithelium; h, tunica albuginea; c, follicular epithe- 

 lium; d, ovum; e, primitive Graafian follicles in ovarian cortex; /, granular layer of 

 large Graafian follicle. 



the theca folliculi (Fig. 256). This consists of two layers, an outer 

 more dense fibrous layer, the tunica fibrosa, and an inner more cellular 

 and vascular, the tunica vasculosa. Between the theca folKculi and 

 the stratum granulosum is an apparently structureless basement 

 membrane. 



While these changes are taking place in the follicle, the o\aim is 

 also undergoing development. The ovum of the primitive follicle 



