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THE OVARY OF THE SPERMOPHILE 159 
Gross observations. The uterus shows no signs of pregnancy. 
The ovaries show very small hemorrhagic areas, the smallest noted so 
far. In all probability, the animal has ovulated during the time if 
was with the male. 
Microscopic observations of the ovaries. Fixative, formalin zenker. 
Stain, hematoxylin and eosin. There are three corpora lutea in the 
right ovary and five in the left. They are in a very early stage of 
development, appearing just like other very early ones. There were a 
few mitotic figures, one very sure proof of their very recent develop- 
ment. 
Experiment 323-16 (spermophile 357). Captured April 27, 1916. 
Weight, 125 grams. This animal was kept separate from the time 
of her capture until May 8, 1916. At 3 p.m. on May 8 a male was 
placed with her and kept there until 10:45 a.m. on May 10, 1916. 
Sacrificed May 10, 1916, 10:45 a.m. 
Gross observations. Gross evidences did not show that the animal 
had ovulated. 
Microscopie observations of the ovaries. Fixative, formalin zenker. 
Stain, hematoxylin and eosin. Both ovaries showed beautiful early 
corpora lutea, three in the right ovary and four in the left. These 
could not have been more than twenty hours old. 
Discussion and summary of results. The results obtained in 
these two experiments prove that ovulation follows on coitus 
during rut. 
Series 9. To determine if ovulation is followed by the formation of 
corpora lutea when fertilization is prevented by the resection of 
1 cm. of the uterus. One ovary was removed, also, to determine 
absolutely whether the animal was pregnant or not.” 
Experiment 280-16 (spermophile 315). Captured May 3, 1916. 
Weight, 100 grams. Operated on May 5, 1916. The right ovary 
was removed and 1 cm. of the uterus just above the body was ligated 
and resected. 
Gross observations. The animal is not pregnant. She was placed 
with a male on May 20, 1916, and remained with him until sacrificed. 
Sacrificed June 5, 1916. Weight, 120 grams. 
Gross observations. The remaining ovary appears to contain 
corpora lutea. There is a good deal of pus about the ligature on the 
uterus, with adhesions to the intestines. 
Microscopic observations of the ovaries. Fixative, formalin zenker. 
Stains, hematoxylin and eosin and Weigert’s copper-chrome-hema- 
toxylin. There are no corpora lutea in the right ovary. Several 
* This series of experiments is at present being continued. No conclusions 
can be drawn from the results obtained so far. 
THE AMERICAN JOURNAL OF ANATOMY, VOL. 25, NO. 2 
