THE OVARY OF THE SPERMOPHILE 123 
class of fats different from the ordinary body fat. He thought 
these so-called glandular fats had to do with the neutralization 
of the glandular excretions or the ordinary poisons formed in 
the cellular activity. The specific action of the fat of the corpus 
luteum was to neutralize the poisonous products formed by the 
developing embryo. 
Miller (’10, ’14) published some studies on human corpora 
lutea. He tried out many fat stains on fresh corpora lutea and 
claimed they contain no fat. He says the negative result of 
the fat reaction on fresh corpora lutea makes it possible to tell 
the difference easily between these and other ovarian structures. 
When the involution of the yellow body begins, the neutral fat 
reaction begins. The peripheral parts show the fat reaction 
first. In the corpus luteum of pregnancy the reaction to neutral 
fat remains negative to the end of pregnancy. He says that in 
a corpus luteum of five days the fat reaction was negative, in 
one of six to eight days there was a little, in one of eleven days 
more, and in one of twelve to sixteen days the cells were rich in 
fat (not neutral fat). 
Meyer (’11, 713) wrote on the human corpus luteum. In his 
first paper he described the development and regression of the 
human corpus luteum of pregnancy, which confirms Sobotta’s 
and Cohn’s work. 
Van der Stricht (’12) published the results of his studies on the 
corpora lutea and the interstitial cells of the ovary of the bat. 
This is one of the most valuable studies ever published on the 
corpus luteum, because the ovary of the bat, with its contained 
structures, is one of the simplest ever studied. No confusion 
arises from old corpora lutea; these are gone before the new ones 
are formed, as the periods of ovulation are so far apart, occurring 
each spring only. The author describes two secretions in the 
luteal cells. The first is a serous secretion which is very like the 
liquor of the follicle. This is secreted by the cells from the time 
of bursting until about the time the egg enters the uterine horns. 
The second is a lipoid secretion. Beginning some time after the 
bursting, there is a slow elaboration of fatty granules from the 
depth of the cytoplasm of the luteal cells, the amount of which 
increases as the cells increase in size. 
