The Corpora Lutea 



139 



histologists, it seems clear that the corpus luteum is developed entirely from the 

 theca cells of the burst follicle : these cells are themselves derived from stroma 

 cells, so that the follicular epithelium takes uo part in the formation of the 

 corpus luteum. 



Some authorities hold, however, that the follicular epithelium is not lost when 

 the follicle bursts, but that its cells undergo proliferation and become enlarged 

 and transformed into luteal cells, 

 so that a part if not the whole of 

 the corpus luteum is formed from 

 the epithelium which originally lined 

 the Graafian follicle. 



In the human subject, as in 

 the lower mammals, the luteal 

 cells at first form a layer lining 

 the wall of the follicle. Pre- 

 sently this layer becomes plaited 

 into thick folds tending to con- 

 verge towards the cicatrix of 

 the follicle. After a time the 

 cells forming the folds undergo 

 a peculiar change ; they lose 

 their distinct outlines, become 

 stained with great difficulty, and 

 are closely clumped together in 

 thick trabecule, the whole hav- 

 ing a characteristic appearance 

 and distinct yellow colour. 



The corpus luteum is well 

 marked throughout pregnancy, 

 although towards the end it be- 

 comes less sharply defined from 

 the ovarian stroma. Similar 

 changes occur — but with far less 



increase in size — in burst follicles where pregnancy has not supervened. 

 The corpora lutea thus produced have been termed corpora lutea spuria 

 to distinguish them from the corpora lutea vera of pregnancy. 



Fig. 95. — Part of the section shown in fig. 94. 

 Magnified 200 diameters. 



Effects of Removing and Reimplaxtixg Ovaries 



The effects resulting from removal of both ovaries {oophorectomy ; spay- 

 ing) are externally not so striking as with the similar operation in the 

 male sex. If the operation is performed in young animals, or if the ovaries 

 are congenitally atrophic, it is not infrequently found that characters 

 distinctive to the male are to some extent assumed. In the human subject, 

 as well as in animals, a constant result is that the uterus remains small : 



