796 
Journal of Agricultural Research 
Vol. XXXI, No. 8 
GROWTH EXPERIMENTS ON RATS 
The usual laboratory routine for vitamin B tests was followed in 
these experiments. Young white rats were caged individually on 
screens which prevented access to excreta. The rats were fed once 
each day and weighed once a week. A record of feed consumption 
was kept. 
The following basal diet was fed until the rats were stationary 
or declining in weight: 
Per cent 
Casein 9 - 
Salts (McCollum’s No. 185) 
Agar_ 
Rice powder l0 _i- 
Butter fat 11 - 
18. 0 
3. 7 
2 . 0 
71.3 
5. 0 
The velvet beans or extracts 
were then added to the basal 
diet, replacing an equal amount 
of rice powder. When yeast was 
added, an amount of dried 
yeast 12 equal to 5 per cent of 
the daily allowance of feed was 
placed on top of the other feed 
m the feeder. 
The addition of 10 per cent 
of raw velvet beans to the basal diet/ checked the decline of rats and 
enabled them to make very slight gains (fig. 2). 
10 per 
,rts 2 to 
Pig. 2 .-—Weight curves of rats, 
cent raw velvet beans. Broken lines in 
10 represent periods in which the basal vitamin B 
free diet alone was used 
When 20 per cent of raw beans was added to the basal diet the 
ra ts g rew at approximately one-third of the normal rate (fig. 3). 
When 5 per cent of dried yeast was added to the above diet normal 
growth occurred (fig. 4). The females were bred, and then littered 
•Washed one week in 0.2 per cent acetic acid, 
w Heated in eleetric oven five hours at 120° C. 
ii Thoroughly washed and centrifuged, 
i* Dried yeast (Harris). 
