318 EDGAR ALLEN 
There are over thirty corpora lutea in these two ovaries. The 
most recent set number eight, which corresponds with the num- 
ber of ova in the tubes. They are blue staining and have large 
central lakes of liquor. Theca interna cells are still evident at 
the periphery and connective-tissue sprouts have not yet grown 
completely through the granulosa cells. No erythrocytes are 
included, indicating that vascularization is not far advanced. 
Judging by the position of the ova in the tubes, these corpora 
lutea are in their second day of development. 
The other corpora lutea are divisible into at least three sets. 
They are all red-staining, solid masses of cells, differing chiefly 
in size, location, and clearness of demarcation from the sur- 
rounding stroma. ‘The second oldest set are much larger than 
the recent ones, clearly defined, and peripherally situated. The 
third oldest set are smaller than the second, but larger than the 
first. They are separated from the germinal epithelium by 
several layers of connective-tissue cells. The second and third 
sets correspond to the ovulations during the oestrous periods 
nine to ten and fourteen to sixteen days previous to death. This 
mouse has apparently ovulated spontaneously at every oestrous 
period. 
The late metoestrum 
Animal 26 had been examined for twenty-two successive 
days before killing, during which time five complete cycles had been 
recorded, giving an average duration of 42 days. External 
signs were marked at only two of these five periods, and in one 
of these instances they extended into the late metoestrum. Her 
previous oestrous periods were 2 to 3, 6 to 7, 11, 16 to 17, and 
20 to 21 days previous to her death. 
The last smear shows all degrees of epithelial degeneration and 
cytolysis. The cornified cells present a varied staining reaction 
to eosin, some being bright red, others a faded pink, and a few 
almost colorless. Where one cell is isolated in a group of leuco- 
cytes its exoplasm is a clear colorless zone, suggesting the 
extraction of the eosin staining cytoplasm. 
Immediately after killing, gross examination showed hee 
uterus to be anemic, small, and opaque. 
