214 DR. JAMES FOULIS. 



the corpuscles of the membrana granulosa are produced, we 

 at once see how altogether different they are in appearance, 

 and how impossible it is that there can be any connection 

 between them. The epithelium on the surface of the adult 

 cat's ovary is separated from the deeply imbedded eggs by a 

 thick layer of connective tissue, and while the corpuscles of 

 the epithelium are flat, polygonal bodies, with oval nuclei, 

 the corpuscles in contact with the imbedded young eggs are 

 elongated fusiform bodies, similar to those which make up 

 the stroma in all parts of the ovary. By carefully examining 

 these fusiform bodies as they lie on the surface of the egg, 

 and as they lie round the egg, as in a profile view, it is seen 

 that they are entirely different from the epithelial corpuscles 

 on the surface of the ovary, and they are parts of the ovarian 

 stroma. These observations appear to me to prove very con- 

 clusively that Waldeyer's view as to the development of the 

 cells of the membrana granulosa is untenable. 



After a single layer of membrana granulosa corpuscles is 

 produced round the ovum, the wall of the follicle outside this 

 capsular layer becomes fibrous and vascular. The wall of a 

 nearly ripe Graafian follicle is very vascular. In the rabbit's 

 ovary, in a very young follicle, the corpuscles around the 

 egg, which give rise to the membrana granulosa corpuscles, 

 are at first minute fusiform bodies, and lie flattened against 

 the ovum, when seen in profile. As they develop into the 

 corpuscles of the membrana granulosa they swell up, and by 

 pressure against each other become columnar. Now, im- 

 mediately outside this layer of columnar corpuscles the tissue 

 consists of minute fusiform corpuscles (figs. 17, 18, V^,j,j,j) 

 and blood-vessels. In a nearly ripe Graafian follicle, just 

 before bursting to liberate the ovum, these minute corpuscles 

 in the wall of the follicle outside the membrana granulosa 

 swell up and enlarge, producing large fusiform corpuscles 

 (fig. 20,y,y) very similar to the corpuscles of the membrana 

 granulosa at a certain stage of development. This condition 

 of the wall of the ripe follicle is also well seen in the human 

 ovary. In the wall of the nearly ripe Graafian follicle of the 

 rabbit's ovary, we can trace these large fusiform corpuscles 

 becoming more and more like the ordinary small corpuscles 

 of the stroma, as we examine them in the more external parts 

 of the follicular wall. I have ascertained by careful obser- 

 vation that, from the very first appearance of the Graafian 

 follicles to their bursting, no blood-vessels pass into the cavity 

 of the follicle to reach the ovum, and yet this body increases 

 enormously in size in a short space of time. This great in- 

 crease in size is brought about by the production of proto- 



