449 HAYATO ARAI 
On the weight of the ovaries and the presence of corpora lutea and 
of degenerate follicles 
The graph for the number of ova which illustrates the group 
in which the ovaries possess the corpora lutea, gradually falls, 
with some fluctuations, from 21.3 to 78 mgm. in the weight of 
the ovaries (chart 4). 
The two graphs which illustrate the numbers of corpora lutea 
show rather considerable fluctuations, but indicate that the 
number of small, increases more rapidly than the number of 
large corpora lutea—a result which is in accord with expectation. © 
In this (b) group, then, the relation between the weight of 
ovaries and the ova number is also inverse, though it is not so 
striking as in the (a) group, and the inverse relation is due in 
some measure to the appearance of the corpora lutea. 
It is desirable now to discuss the influence which the number 
of degenerate follicles may have on the weight of the ovaries. 
Previously it was mentioned that. an effort had been made to 
divide the degenerate follicles into four groups (p. 409). 
However, on account of the great difficulty in making even an 
approximate estimate of the number of the small degenerated 
follicles, I have not attempted to record these in the table. For 
convenience, the number of the C and D types of my classifica- 
tion, or those which correspond to large degenerated follicles, and 
the B type, or the middle-sized degenerated follicles, are grouped 
together and the results given in table 13. 
Table 13 suggests that in the rat before puberty the weight of 
ovaries, in which the large degenerated follicles are the more 
numerous, tend to be greater than that of the ovaries in which 
these are less numerous. After puberty, though the similar re- 
lation seems to hold, nevertheless the presence of the corpora 
lutea obscures the relation. Generally speaking, in the ovaries 
of young rats (twenty-six days old) before the corpora lutea are 
formed, we find a considerable number of large degenerated 
follicles. 
From table 13 it is clear that before the formation of the cor- 
pora lutea the number of these follicles decreases slowly with the 
