} 
IN MAN AND OTHER MAMMALIA. 367, 
that its protoplasm presses against and distends the follicular wall. Little 
fusiform corpuscles in the walls, and belonging to the stroma of the ovary, indent 
the protoplasm of each young ovum as it lies in its follicle. (Fig. 24, m, m.) 
In an empty follicle from which the young ovum has been removed, these 
little connective tissue corpuscles appear as minute buds projecting into the 
cavity of the follicle from its wall. 
In the deeper parts of the ovary numerous young egg-containing follicles 
are seen. In the youngest follicles but two or three fusiform corpuscles are 
found in contact with the yelk of the contamed ovum. As the follicles increase 
in size and become older, the number of small corpuscles in contact with the 
contained ova also increases. In some we find seven or eight, and in still older 
follicles a perfect wreath of minute corpuscles is formed round the yelk of the 
young ovum. The oldest follicles are found in the deepest parts of the ovary, 
and in most of them there is a perfect wreath of minute corpuscles (fig. 30, 7) 
lining the follicle. Now, from these young connective tissue corpuscles in the 
wall of the young follicles which lie in contact with and indent the yelk of the 
primordial ova, the corpuscles of the membrana granulosa are derived. 
In describing the growth of fibre-like bodies in the stroma into connective 
tissue corpuscles, I stated that the middle parts of such fibres become swollen 
out, and in the swollen out part a distinct nucleus appears. This nucleus, 
though at first appearing semi-solid, may become distinctly vesicular, and 
within it a nucleolus is afterwards seen. By a careful examination of a whole 
series of young Graafian follicles, we trace the development of the corpuscles of 
the membrana granulosa in the following way:—Around the young ovum in 
each follicle the connective tissue corpuscles increase in number by division. 
As a single fusiform corpuscle divides, its nucleus appears to commence the 
division, and each half of the nucleus carries with it a small quantity of the pro- 
toplasm which originally invested the single nucleus. When a little wreath of 
such corpuscles is formed round the young ovum the nucleus of each cor- 
puscle swells out and becomes a distinctly vesicular little body, presenting a 
very fine double contoured wall, around which is a small quantity of proto- 
plasm. Within the nucleus generally a minute spot is seen. The protoplasm 
which surrounds the vesicular nuclei acts as a sort of cement substance, hold- 
ing them together in the form of a capsular membrane round the young ovum. 
This capsular membrane is the first appearance of the membrana granulosa. 
Only those connective tissue corpuscles which lie in actual contact with the yelk 
_ of the ovum in the follicle develope into corpuscles of the membrana granulosa; 
; 
; 
. 
while those in the wall outside the membrana granulosa remain as connective 
tissue corpuscles, and follow the usual developmental process into ordinary 
fibrous tissue, of which the main part of the follicular wall at last consists. We 
shall afterwards see that in some of the oldest Graafian follicles in the adult 
