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HUMAN EMBRYOLOGY AND MORPHOLOGY. 



posed of a layer of columnar epithelium, which is imbedded in, 

 and surrounded by, the stroma of the ovary. The entire capsule 

 — epithelium and stroma — forms a Graafian follicle (Fig. 62). 

 The ovary is covered by a layer of columnar epithelium, which is 

 named the germinal epithelium Amongst the columnar cells of the 

 germ epithelium during foetal life and for sometime after birth 

 larger cells occur. These are the primordial ova from which brood 

 ova arise. The ova are carried within the ovary by tubular 

 ingrowths of germinal epithelium (Fig. 62). These tubular 

 invasions of the ovary become broken up, the isolated masses of 

 the germinal epithelium remaining to form the linings of the 

 Graafian follicles. 



Discharge of the Ova. — At puberty, possibly also before it, 



]=z — germinal epithelium 

 tunica albuginea 

 stroma-capsufe 

 epithelial lining 



zona radiata 

 germinal vesicle 

 germinal spot 



ouum 

 discus proligerus 



Fio. 63.— Diagram of a ripe Graafian Follicle. 



and for 30 years after it, one egg after another ripens; the ovum 

 enlarges ; so does the Graafian follicle (Fig. 63). The cells of 

 the epithelial lining proliferate and a cavity appears amongst the 

 cells within the follicle, due to a collection of fluid— the liquor 

 folliculi. The ovum remains attached to the wall of the follicle 

 by a group of epithelial cells, the discus proligerus (Fig. 63). As 

 the fluid collects, the follicle works its way to the surface of the 



