1024 
Journal of Agricultural Research 
Vol. XXXI, No. 11 
EXPERIMENT 3 
Experiment 3 was a counterpart of experiment 1, except that the 
lard employed was the same as that used in experiment 2, and that 
only 8 rats were used instead of 12. The composition of the ration 
has already been given in connection with experiment 1, and the 
samples of rancid and sweet lard have been described in connection 
with experiment 2. The pertinent data concerning the experimental 
.animals at the beginning of the experiment are recorded in Table V. 
Table V.— Description of rats used in experiment 8 
Rat 
No. 
Ration 
Sex 
Initial 
age 
Initial 
weight 
Litter 
Rat 
No. 
Ration 
Sex 
Initial 
age 
Initial 
weight 
Litter 
21 
Sweet... 
Male_ 
Days 
27 
Grams 
42 
115-A 
25 
Rancid 
Male 
Days 
27 
28 
Grams 
41 
42 
115-A 
115-B 
22 
--.do. 
Female_ 
27 
42 
115-A 
26 
--.do_ 
Female_ 
23 
_—do_ 
--_do_ 
28 
39 
115-B 
27 
...do-- 
_—do_ 
28 
43 
115-B 
24 
-—do_ 
Male_ 
27 
39 
115-A 
28 
...do_ 
Male_ 
27 
44 
115-A 
Throughout experiment 3 the rats receiving the rancid fat consumed 
less food and gained less weight than the corresponding controls. 
They were also less active and robust, and without exception devel- 
/so 
/so 
/40 
/30 
/*0 
//O 
\ M 
\90 
^80 
^70 
\so 
*50 
40 
JO 
20 
/O 
GAYS /O 20 30 40 SO 60 /O 20 JO 40 SO 60 /O 20 30 40 SO 60 /O 20 JO 40 SO 60 
Fig. 3.—Growth curves of rats in experiment 3 
oped pronounced cases of ophthalmia before the end of the experiment. 
In case of rat No. 25 of the rancid series, moreover, the hair remained 
scant and thin, the pink skin being clearly visible over the rump 
throughout the experiment. On the other hand, the rats of the 
rancid series manifested no definite symptoms of intestinal irritation 
as did the corresponding rats in experiment 1. 
The smaller growth made by the rats in the rancid series as com¬ 
pared with the control rats is clearly shown by the growth curves in 
Figure 3. In case of the rats receiving the rancid fat, the subnormal 
growth, the development of ophthalmia, and the ultimate decrease 
in weight of rats Nos. 25, 26, and 28 bear clear testimony of a defi¬ 
ciency of vitamin A. From the data on food consumption presented 
