250 INTERNAL SECRETIONS 



of Seitz) and the lutein cells of the real corpus luteum. On 

 the other hand, some authors, as Winiwarter and Sainmont, 

 hold that the atretic follicle, like the corpus luteum is com- 

 posed only of cells of the granulosa. But if the assumption 

 of Lane-Claypon quoted from Marshall, 1905), of Ochoterena 

 and Ramirez (1920) and of Goormaghtigh (1921) as to the origin 

 of the interstitial cells and of the cells of the folHcular wall 

 from the germinal epithelium is true, all these controversies 

 lose their importance. 



Speaking generally, the process of formation of a corpus 

 luteum seems to be as follows. The epithelial cells of the 

 membrana granulosa become hypertrophied ; there is also 

 probably a proliferation of these cells. The follicular membrane 

 between the membrana granulosa and the theca interna 

 ruptures; both cells intermingle, if the origin of the corpus 

 luteum is a mixed one, as possibly is the case in some species, 

 since the epithelioid cells of the theca interna often resemble 

 the cells of the granulosa to such a degree as to be indistinguish- 

 able from one another. Connective tissue with blood vessels 

 grows into the mass of epithelioid cells, and the whole structure 

 becomes vascularized in such a manner that every cell seems 

 now to be in direct communication with a blood vessel. Fatty 

 inclusions appear in the cells; these inclusions are sometimes 

 of a yellow colour — the so-called lutein. In the ovary of man 

 or of the horse the corpus luteum may occupy half of the ovary, 

 in the cow much more. The corpus luteum persists only for 

 a certain time, undergoing afterwards sclerotization or hyaline 

 degeneration; it may be that in some species, as in the rabbit, 

 the corpus luteum becomes converted into interstitial tissue. 

 No essential difference exists between the corpus luteum 

 graviditatis and the corpus luteum menstruationis ; the 

 difference is only that in pregnancy the corpus luteum persists 

 for a longer time. 



We mentioned that there are in the mammal transitions 

 between the atretic follicle and the corpus luteum. In the 

 preceding sections we pointed out that there are transitions 

 between the interstitial tissue, like that in the ovary of the 

 rabbit, and the masses of epithelioid cells of the theca interna 

 remaining in the wall of an atretic follicle. I think it is clear 

 enough that there is a close histological and genetic relation- 

 ship between all the epithelioid cells in the ovary, between the 



