ZOOLOGY: R. PEARL 
51 
(anterior lobe) substance. This was administered in No. 2 gelatine cap- 
sules with lactose as a diluent. Each bird in the second lot (B) received 
per OS the same amount (0.082 g.) per day of dessicated corpus luteum 
substance from pregnant cows, again administered in No. 2 gelatine 
capsules with lactose as a diluent. Finally lot C was a control, the 
birds receiving no capsules. All the birds were housed in the same 
house, and given the same food and care except for the capsule feeding 
as above noted. 
The experiment began August 13, 1915. The growth of the birds is 
shown in the table. 
TaUe shoiving the weights at various intervals of birds fed pituitary body {anterior lobe) substance 
and of those fed corpus luteum substance. 
DATE 
LOT A. (pituitary) 
LOT B. (corpus luteum) 
LOT C. (CONTROL) 
Total weight 
Mean weight 
per bird 
Total weight 
Mean weight 
per bird 
Total weight 
Mean weight 
per bird 
kilos 
grams 
kilos 
grams 
kilos 
grams 
Aug. 13. Initial weight.. . 
16.78 
1112.2 
16.78 
1112.2 
16.78 
1112.2 
Aug. 28 
22.09 
1472.6 
21.91 
1460.6 
22.14 
1475.7 
Sept. 4 
23.81 
1578.6 
23.59 
1571.1 
24.18 
1611.8 
Sept. 11 
24.68 
1645.0 
24.22 
1614.8 
25.40 
1693.4 
Sept. 18 
25.72 
1714.6 
25.45 
1696.4 
26.81 
1787.2 
Sept. 25 
27.12 
1808.3 
25.63 
1708.5 
28.26 
1883.9 
From this table it appears that: 
1. Both pituitary body (anterior lobe) substance and corpus luteum 
substance retarded the growth of the birds in this experiment. Through- 
out the experiment all of the birds were in a perfectly healthy and 
active condition. It was impossible to detect any differences in these 
respects between the three lots. There appears to be no means of ac- 
counting for the growth differences observed except as a result of the 
organ substances fed. 
2. The retardation of growth in the case of the birds fed corpus luteum 
substance (lot B) is greater than that in the lot fed pituitary substance 
(lot A). The differences are very small and not separately significant 
until the September 11 and later weighings, from which time they are 
relatively large. 
3. After 43 days of organ substance feeding of birds starting at the 
same body weight those birds fed pituitary substance average 4.01% 
less in body weight, and those fed corpus luteum substance average 9.31% 
less in body weight, than normal controls. 
