428 HAYATO ARAI 
followed by a period of approximate constancy up to an ovary 
weight of 16.5 mgm., the end of the period preceding the ap- 
pearance of the corpora lutea. This stage, marked by a break 
in the graph, passes into the stage in which the corpora lutea 
appear, and after the appearance of the corpora lutea the graph 
Ova of larger sizes 
1000 rT tal 
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AVS 
EHESRBAeSo 
FY esane 
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50. 60 70 80 
Weight of ovaries in milligrams 
Chart 4 Graph showing the relation between the weight of both ovaries and 
the total number of ova, together with those of the three groups more than 20 u 
in diameter. The graphs are broken after puberty. 
for the total number of ova falls very slowly to the end of the 
record. The several graphs for the number of ova more than 
20 uw in diameter are very similar in form to the corresponding ° 
graphs in chart 3 and are subject to a like interpretation. 
It may be appropriate, however, to call attention here to the 
relations of the various groups of larger ova. In the first place, 
all the larger ova are derived from small ova. Moreover, the 
