FORMATION OF THE CORPUS LUTEUM. 
345 
membrane takes place so rapidly that it is thrown into folds or convolu¬ 
tions precisely the same as takes place in the brain of the faetus, which 
is at first smooth at the surface, and becomes convoluted by virtue of its 
rapid growth and limited confinement within the skull. 
“ At the same time, this new tissue assumes a peculiar color; in 
woman it is always yellow, in the cow it is first pinkish and then yellow, 
while in the pig it is orange followed by yellow. The growth of the 
thickened membrane goes on until the cavity of the follicle is entirely 
filled except a little spot in the centre, so that when the process is com¬ 
pleted your corpus luteurn represents nothing but a ruptured and healed 
Graafian follicle. 
“We will now proceed to an examination of this ovary. You see 
it is kidney shaped and quite vascular upon its surface, the blood ves¬ 
sels being shown best on its convex border. 
“ If the periods of heat had followed each other in their natural course, 
I should expect to find little transparent spots on the ovary indicating 
the presence of follicles approaching the surface. I find some follicles 
here which are cyst-like, with adventitious adhesions to the neighbor¬ 
ing tissues; but this is a morbid condition, which is also some¬ 
times seen in women, especially in prostitutes. These cysts contain 
nothing but fluid, although it is probable they were originally Graafian 
follicles, and had they remained in the ovary, protected by its tissue, 
might have come to maturity as usual. Be this as it may, after the nor¬ 
mal function of the ovary comes to an end, the organ becomes more 
solid, the follicles cease to develop, and the corpora lutea also dis¬ 
appear. 
“The normal Graafian follicle, as you see, is transparent, and its 
fluid less abundant than that of the cysts. After being evacuated by 
puncture its walls collapse, being very thin. I note one thing in the 
ovary of this mare, and that is that the peritoneal covering is quite 
loose, unlike that of the human ovary and of some other animals. In 
the specimen before us we find no corpora lutea; the Graafian follicles 
which we see are all quiescent. Had the usual periods of heat recur¬ 
red, we should probably have found some of these follicles which are 
near the surface ruptured, and forming corpora lutea. 
“In this second specimen, taken from a mare dead with acute 
enteritis, you will notice the unusually large size of the ovary, which is 
a morbid condition. Cutting into its tissue you see we have divided 
several large follicles, which all contain a purulent fluid. This increased 
size of the ovary, and the presence of pus in the cavity of the follicles 
