130 DELLA DRIPS 
Gross observations of the ovaries. The ovaries of rut show several 
changes from those of the fall. They are larger and seem to be slightly 
congested. On the surface of each ovary may be seen several slightly 
raised, tiny, colorless, cyst-like bodies which are the mature follicles. 
Microscopic observations of the ovaries. Fixative, formalin zenker. 
Stain, hematoxylin and eosin. Serial sections show ten larger follicles, 
all of which lie at the surface of the ovary and several of which are 
projecting slightly from the surface. One of these follicles measures 
0.5 mm. x 0.4 mm., and another 0.5 mm. x 0.6 mm. None of them 
shows atretic changes and all are apparently mature. There is con- 
siderable liquor folliculi, and few mitotic figures among the granulosa 
cells (fig. 12). 
The internal and external theca of these large follicles are distinct 
and comparatively thick layers. There is a well-marked membrane 
between the stratum granulosum and the internal theca. Acetic osmic 
bichromate sections stained with acid fuchsin and methyl green show 
a red secretion along this membrane and between the cells of the gran- 
ulosum near it. The cells of the granulosum seem to have an increased 
amount of protoplasm which makes them larger. 
Of the smaller follicles, a few are in good condition, but the greater 
number have become hyalinized. The hyalinization of so many of 
the smaller follicles gives a characteristic appearance to the ovaries of 
the spring (fig. 11). Indeed, it would seem that a few mature follicles 
have been produced at the expense of many. The primordial ova are 
few in number. ‘The interstitial cells are not at all conspicuous. 
Toward the end of the rutting season many uteri present a different 
picture. They are smaller and instead of appearing edematous appear 
congested. 
Experiment 256-16 (spermophile 298). Date of capture April 27, 
1916. Sacrificed April 28, 1916. Weight, 105 grams. (For measure- 
ments of uterus see table.) 
Gross observations of the uterus. The blood-vessels to the uterus 
are all much congested and the organ itself shows some congestion 
throughout. There is one especially congested area in each horn 
about 1 em. from their point of union. There is another specially con- 
gested area in the body near the point of union of the horns. 
As there are no corpora lutea in the ovaries of this spermophile, the 
uterus is still one of rut, not pregnancy. What brings about this 
change in the uterus is not evident. The congested condition is, how- 
ever, without doubt preparatory to the reception of the fertilized ova. 
This brings us in the life cycle to the ovaries of pregnancy. It 
has been shown that the ovaries of the fall, winter, and early 
spring contain no corpora lutea. Occasionally some remains of 
these bodies of the previous year may be found, but this is very 
unusual. Thus when coitus takes place during rut and the 
