PLATE 2 



EXPLANATION OF FIGURES 



5, 6, 7, 8 Four stages of atresia folUculi, to show the origin of the interstitial 

 cells from the theca interna. In the first figure the cells of the internal theca are 

 hardly discernible. The shape and position of the ovum indicates beginning 

 atresia. In the last figure the ovum has disappeared save the zona pellucida, 

 and the antrum is nearly obliterated. Intermediate stages appear in figures 8 

 and 9. Photographs. 



9 Photograph of section of ovary, young virgin adult; Hermann's fluid; no 

 stain; interstitial cell-groups black. To show the typical picture of atresia, and 

 its prevalence at this period. All the follicles save one are in some stage of 

 atresia. 



92 



