THE OVARY OF THE SPERMOPHILE 125 
Frank and Rosenbloom (’15) published the results of some 
experimental work done on rabbits with extracts of the placenta 
and the corpus luteum. They claim to have gotten better results 
than former investigators because they used a more concentrated 
and an alcoholic (fat solvent) solution of the active substance 
of the luteal extract. This active substance, they say, “‘is not a 
lipoid but is carried along the lipoids.’”’ They state that the 
only corpus luteum substance extracted, which was found to be 
active, was derived from pregnant animals. 
Dannreuther (’14) reported his results obtained clinically from 
the use of corpus luteum extract. He calls attention to the 
necessity of using the extract of pregnant animals only. 
Up to date, the most noteworthy publication concerning the 
clinical value of the extract of the corpus luteum is that of 
Culbertson (’16), entitled, ‘‘A study of the menopause.” He 
regards the climacteric as a’ ‘‘functional disarrangement on the 
part of the endocrine glands, the ovarian secretion having 
ceased.” His theory concerning the value of luteal extract in 
the treatment of menopause disorders in as follows: 
“Thus the chief characteristic stamping the vasomotor dis- 
turbances of the climacteric seems to be a disarrangement of the 
systolic-diastolic relation producing elevation in the pulse 
pressure. In blood-pressure estimations, then, we find a fairly 
reliable measure of the vasomotor disturbances of the menopause, 
as will be shown, a satisfactory method of treatment. 
“Tf we accept the propositions thus far laid down, that the 
cessation of ovarian activity leads to a functional over-efficiency 
on the part of the pituitary and adrenal glands and that this, in 
turn, produces an arterial hypertension, the corollary is that by 
the administration of corpus luteum extract, the pressor sub- 
stances will be neutralized and the tension will decrease.”’ 
In summing up, it may be stated that up to 1906 practically 
all the literature on corpus luteum had to do with the histologic 
origin and consequent structure at various succeeding periods in 
its life cycle. The writings of Sobotta and Cohn practically 
established the epithelial’ nature of the luteal cells and the 
glandular character of the structure as a whole. From 1906 to 
