THE OVARY OF THE SPERMOPHILE 139 
Experiment 351-16 (spermophile 371). Captured May 20, 1916. 
The left ovary was removed on May 22, 1916. Weight, 135.5 grams. 
Gross observations. The fetuses in the uterus are 2 em. in length. 
This animal gave birth to young May 31, 1916, and was sacrificed 
June 17, 1916. 
Microscopic observations of the right ovary. Fixative, acetic osmic 
bichromate. Stain, acid fuchsin and methyl green. The individual 
luteal cells are of about the same size and shape. The red granules 
are still quite abundant, but there seems to be a marked difference in 
the cells as to their individual content of red granules. This appears 
to vary with the number of lipoid droplets in the cell. In a few cells 
where the latter are very abundant, the red granules are found only 
in a rim about the periphery. Where the lipoid droplets are still few 
the cell protoplasm still contains many red granules with these few 
droplets scattered among them or occupying a peripheral position. 
Many cells have not changed at all; they have no lipoid droplets. 
Some cells have a peculiar appearance. Their protoplasm appears 
honeycombed. Since none of the cells had this appearance in the 
unstained sections, it was concluded that the cells must have been filled 
with lipoid which was dissolved out in the staining process and the 
result was this honey-combed appearance to the protoplasm. This 
was later proved to be the case. The lipoid droplets, when they aré 
numerous, show much less variance in size than when they are few in 
number in the cell. The nuclei of these cells appear very similar to 
those of earlier cells. In some cells there is a slight change in their 
position. Instead of being directly in the center, in the cells filled 
with lipoid, the nucleus lies a little to one side of the center. The Ist 
of July, about thirty-five days after parturition, the corpora lutea in 
the ovaries were larger than at any other time. 
Experiment 412-16 (spermophile 415). Captured and sacrificed 
July 1, 1916. Weight, 125 grams. 
Gross observations. The ovaries are the largest yet seen, owing 
to the comparatively immense size of the corpora lutea. These are 
now of a yellowish-cream color and stand out prominently so that the 
ovary looks as if it were made up of several spherical bodies 1.5 mm. in 
diameter. Any other ovarian tissue except that holding the spherical 
bodies together can scarcely be distinguished. There are three corpora 
lutea in the right ovary and four in the left, which numbers correspond 
to the tiny white spots marking the former placental sites in the uterus. 
Experiment 413-16 (spermophile 416). Captured and sacrificed on 
July 3, 1916. Weight, 157.3 grams. 
Gross observations. The right ovary appeared grossly just like that 
of spermophile 415 (fig. 15). 
Microscopic observations of the left ovary. Fixative, acetic osmic 
bichromate. Stain, acid fuchsin and methyl green. The corpora 
lutea are much larger than those previously described (fig. 19). They 
measure 1.1 mm. x 1.5 mm. in diameter (1.7 mm. x 1.3 mm., grossly 
some shrinkage). The luteal cells are correspondingly larger, and their 
