1020 
Journal of Agricultural Research 
Vol. XXXI, No. 11 
Rat No. 7. —Well nourished, with plenty of fat. Viscera and muscles larger,, 
firmer, and apparently more healthy than*those of rats Nos. 5 and 6. 
Rat No. 10. —Similar in condition to rat No. 7. 
Table II.— Food-consumption data for experiment 1, covering first 73 days 
Ration 
Rancid. 
Do. 
Do. 
Average for males. 
Rancid. 
Do. 
Do. 
Average for females- 
Average for males and females. 
Sweet.. 
Do. 
Do. 
Average for males. 
Sweet.. 
Do. 
Do- 
Rat 
No. 
Sex 
Male. 
...do.. 
...do.. 
Total 
ration 
10 
Average for females- 
Average for males and females. 
Female. 
...do_ 
...do.... 
Male. 
...do.. 
...do.. 
Female.. 
..do_ 
..do_ 
Grams 
592 
538 
476 
535 
Coeffi¬ 
cient 
of food 
consump¬ 
tion 
Total 
gain 
508 
505 
539 
517 
526 
709 
679 
696 
657 
594 
677 
643 
Grams 
0.0886 
.0797 
.0846 
.0843 
.0827 
.0832 
.0857 
0839 
0841 
0854 
0802 
0835 
.0777 
.0768 
.0799 
.0781 
Grams 
108. 
89 
89 
85 
64 
82 
77 
83 
171 
172 
172 
172 
153 
109 
160 
141 
156 
By interpolation of the growth curves and the records of food consumption, the weight of food consumed, 
per day, per gram of weight of the given rat, was calculated for daily intervals. The average of the values 
thus obtained throughout the period covered by this table has been called the “coefficient of food consump¬ 
tion ’' for the rat in question. 
In the light of these observations it would appear that rancid lard 
is not toxic to white rats, and that the subnormal growth of rats Nos. 
1 to 6 must be attributed to undemutrition or to vitamin deficiency. 
Since the rancid ration may have been unpalatable, one immediately 
suspects that either or both of these conditions might have originated 
in a self-imposed curtailment of food consumption, and hence of 
vitamin-A intake, by the rats of the rancid series, under which circum¬ 
stances even the development of ophthalmia in rat No. 3 would signify 
nothing as to the adequacy of the ration. But this suspicion is not 
supported by the food-consumption data as presented in Table II, 
for the rats of the rancid series consumed an even larger average 
weight of ration per day and per gram of body weight than the con¬ 
trol rats receiving the sweet lard. Apparently, therefore, gross food 
consumption was limited by growth, not growth by the rate of food 
consumption; and the cause of this limitation of growth must be 
sought in the inferior quality of the ration containing the rancid fat 
as compared with the control ration. 
Although the experiment may not be conclusive as to the nature of 
this inferiority, the development of ophthalmia in rat No. 3 suggests 
that it consisted in a deficiency of vitamin A, while the similarity of 
the two rations in other respects would indicate that the inferiority 
was caused by the presence of the rancid lard. In view of the known 
susceptibility of vitamin A to oxidation, and of the presence of organic 
