REPRODUCTION IN MAN 1223 



We shall have later to discuss the relation of ovulation in the human female 

 to the periodic changes occurring in the other parts of the reproductive 

 apparatus. 



After the discharge of the ovum the remaining portions of the follicle 

 undergo a characteristic series of changes, which result in the production 





dp 



FIG. 561. Graafian follicle of mammalian ovary. (PRENANT and Bourn.) 



ov, ovum ; dp, discus proligerus ; Iq.f, liquor folliculi ; ch. theca ; 



gr, membrana granulosa. 



of the corpus luteum. Immediately after the rupture the follicle becomes 

 filled with blood, apparently resulting from the sudden release of the pressure 

 on the capillaries in the walls of the follicle. The cells of the membrana 

 granulosa rapidly increase in size, a few of them undergoing mitotic division, 

 so that a dense mass of cells is formed, nearly filling the original follicle. At 

 the same time the cells of the internal theca proliferate, with the formation 

 of connective tissue, which grows in among the cells filling the Graafian 

 follicle. These cells finally attain a size four or five times that of the cells 

 of the membrana granulosa in the mature follicle. Blood-vessels grow from 

 the external theca towards the centre of the follicle. The cells within the 

 follicle then undergo fatty degeneration and present a yellow colour due to 



