NUMBER OF OVA: ALBINO RAT 433 
According to Donaldson (’15), the corresponding ages for the 
body weight of 110 to 120 grams in the female albino rat is about 
seventy-five to eighty days, and as ovulation has occurred at this 
age fresh corpora lutea are already present. According to Jack- 
son, ovulation, that is the age of puberty, takes place at seventy 
TABLE 12 
The relation between the body weight and the weight of both ovaries; average number 
WEIGHT OF 
OBSERVED BOTH OVARIES PERCENTAGE 
en y i IN WEIGHTS 
wiinats|nopy werent | 4C® | worgnr | sore | MILLIGRAMS lor ovantzs ow 
ONTEISS BODY WEIGHT OBSERVED 
(DONALDSON) 
Rats without corpora lutea 
grams days grams mgm. 
1 1 yet) tz 
1 3 7.3 2-0 
1 5 10.6 3.4 
2 13.9-14.8 9 14.3 2.0 4.3 0.014 
2 20.5-23.7 18 2251 4.4 5.8 0.020 
3 30.2-34.9 31 33.3 Use haz 0.023 
2 50.0-58 .2 39 54.1 8.9 8.9 0.016 
3 61.0-69.5 50 64.7 11.9 9.4 0.018 
4 74.8-77.3 70 76.5 10.6 13.2 0.014 
3 93 .5-98.5 88 95.4 | 13.8 24.7 0.014 
Rats with corpora lutea 
2 97 .8-106.3 85 102.0 32.0 31.4 0.031 
4 MSro—tZ9F ol 110 122.8 33.8 43.9 0.027 
3 138.7-145.0} 305 142.1 46.9 46.2 0.033 
3 155.0-167.1) 271 161.1 53.6 47.4 0.033 
1 947 238 .0 65.2 50.0 0.027 
From this table the pregnant rats were omitted. 
days. In my rats, however, the age of seventy days is repre- 
sented by a rapid increase in the weight of the ovaries, but they 
have not yet attained their maximum. Consequently the sec- 
ond maximum of Jackson, or the period of rapid increase, would 
be caused principally by the formation of a number of corpora 
lutea in the ovaries. 
