370 DR FOULIS ON THE DEVELOPMENT OF THE OVA, ETC. 
zone, fusiform connective tissue corpuscles (”, 7) may be seen lying in contact 
with the yelk substance of the eggs, and these fusiform corpuscles are exactly 
similar in appearance to the corpuscles which make up the stroma (7,7) in 
other parts of the ovary. Around many of the young eggs the corpuscles of 
the membrana granulosa may be traced as they develope from these fusiform 
connective tissue corpuscles. The nuclei of these connective tissue corpuscles 
divide, swell up, and gradually form a wreath of little nuciei round the ovum. 
Each little vesicular nucleus has around it a small quantity of protoplasm, and 
in the nucleus a spot is generally found. By a constant division of these 
corpuscles the membrana granulosa at last consists of a thick layer, just as in 
the case of the Graafian follicle in the rabbit’s ovary. 
In the adult human ovary an exactly similar development of membrana 
granulosa corpuscles can be followed out. As the eggs lie imbedded in the 
stroma, the nuclei of those elongated fibres of the stroma which are in contact 
with the yelk substance swell up, and by constant division produce a wreath of — 
little corpuscles round the ovum. 
On comparing the epithelium on the surface of these adult ovaries with 
the fusiform corpuscles which lie round the young eggs imbedded in the 
stroma of the ovary, from which 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 examin- 
ing 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 mem- 
brana granulosa is untenable. 
After a single layer of membrana granulosa corpuscles is produced round the 3 
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 develope into — 
the corpuscles of the membrana granulosa they swell up, and by pressure against 
each other become columnar. Now, immediately outside this layer of columnar 
corpuscles the tissue consists of minute fusiform corpuscles (figs. 35, 36, 37, J, 

