NUMBER OF OVA: ALBINO RAT 451 
As is seen in the table, the first appearance of corpora lutea 
takes place in the ovaries of a rat having a body length of 148 
mm. From 148 mm. to 155.mm. we find but one exception in 
which the rat is notably short for its age. The body length of 
148 mm. to 150 mm. coincides with the age of sixty-two to sixty- 
TABLE 17 
The relation between the corpora lutea and the body length. Body length 145 to 
155 mm. 
AGE | BODY WEIGHT | BODY LENGTH ee hey Ae aad CORPORA LUTEA 
days | grams mm. mgm. 
60 93.5 145 10.3 
65 Hl 32 145 2E2) : — 
194 90.3 145 14.2 ~ 
50 74.6 146 11.2 _ 
95 72.0 146 - 
83 82.0 147 — 
110 94.3 147 18.9 - 
95 98.5 148 1282, a 
194 100.0 148 15.1 - 
112 86.5 148 — 
69 78.5 148 40.5 LL 
80.0 148 ai 
88 88.6 150 — 
102 95.0 150 =F 
62 84.0 152 30.8 + 
112 95.8 152 o 
61 80.5 153 23.0 + 
80 107.3 153 37.4 — 
69 88.8 154 34.1 a 
69 90.0 154 23-9 - 
74 87.3 154 2251 ~ 
75 91.7 155 2257 + 
five days in Donaldson’s table. In my rats, however, the corre- 
sponding ages are from sixty-nine to eighty-eight days, respec- 
tively. This disagreement between my own determination and 
that by Donaldson is undoubtedly due to the poor nutritional con- 
dition of the rats here employed. I therefore conclude that the 
body length is the best criterion among the three characters, 
age, body weight and body length, so far considered. I have 
