154 DELLA DRIPS 
Series 5. Effects of the removal of one ovary on the one remaining 
in non-pregnant spermophiles 
Experiment 219-15 (spermophile 143). Captured in the spring of 
1915. Operated on June 3, 1915. The left ovary was removed. 
Gross observations. There are spots marking placental sites in the 
uterus. ‘ 
Right ovary removed September 20, 1915. 
Microscopic observations of the ovaries. Both ovaries: fixative, 
formalin zenker; stain, hematoxylin and eosin. The left ovary contains 
several large corpora lutea of the late lipoid stage. The right ovary 
contains no corpora lutea. It is a typical ovary of the fall of the year. 
There are many medium-sized growing follicles and many primordial 
ova. There is no demonstrable pathology. The corpora lutea must 
have disappeared normally. 
Experiment 221-15 (spermophile 159). Captured in the spring of 
1915. Operated on June 29, 1915. The left ovary was removed. 
Gross observations. The uterus is normal and inactive. 
The right ovary was removed August 5, 1915. 
Microscopic observations of the ovaries. Both ovaries; fixative, 
formalin zenker; stain, hematoxylin and eosin. The left ovary con- 
tains six very large corpora lutea of the lipoid stage. The right ovary 
contains two small corpora lutea in the final stage of their life cycle, 
evidenced by their size, the large amount of fatty degeneration, the 
numerous large blood-vessels, and the great invasion of connective 
tissue. This ovary contains many medium-sized, ripening follicles, 
also many small follicles and primordial ova. No pathology is evident. 
It is a typical ovary of August 5. The results of these two successful 
experiments were so evidently negative that it seemed unnecessary to 
repeat them the next year. 
Series 6. Effects of the removal of one ovary on the other ovary and 
the uterus in pregnant spermophiles 
These experiments were controls for the experiments under 
series 4. 
Experiment 352-16 (spermophile 372). Captured May 20, 1916. 
Weight, 148 grams. Operated on May 22, 1916. The left ovary was 
removed. 
Gross observations. The animal is pregnant, the fetuses measuring 
1.5 em. in length. There are not many fetuses. 
Sacrificed May 25, 1916. Weight, 135 grams. 
Gross observations. All the fetuses are alive and no abnormalities 
are apparent. There are five fetuses in the right horn and two in the 
left. They measure 2.7 cm. by 1.5 cm. 
