424 HAYATO ARAI 
three days, 89.7 grams. If, now, chart 3 is examined, we see 
that between these body-weight limits the number of ova shows 
little change—just as it did between the corresponding age limits 
in chart 2. The fall in number after the body weight of 89.7 
grams is, however, less marked in chart 3 than after sixty-three 
days in chart 2. This slight difference is due to the fact that 
1000 
ae STEHT 
900 if | y Coo a “AH z 
800 rales CO i SCHEELE i 
HiRisrssttejeetseceiett 
| FH 
rT 
Ova of larger sizes 
Peal 
Bate 
a sa 
gt ‘_ 
500 oo 
io YY 
400 eae 
a 
Z ae 
200 = eae 
BEB AREA 
i SeieeSs eeene A 
fo} 
al 
Bae 
[ih 
Bae 
~ ae 
PEER EE br Mei 
j00 150 200 250 
Body weight—gms. 
| I / 
ere 
Chart 3 Graph showing the relation between the body weight and the total 
number of ova in both ovaries, together with the number of the corpora lutea 
and of the three groups of ova more than 20y in diameter. 
some of the older rats were ill nourished and small for their 
age. This is shown by table 7, in which the observed body 
weights for given ages are compared with the expected ages as 
recorded by Donaldson (’15). 
As these figures show, the coincidence between the two series 
of ages is fair except for the last two body-weight groups. The 
animals in these groups were light for their age. 
