Six rats per set. Weight on first day:

A 71 B 73

For four days both A and B were fed on the regular diet. At the end of the fourth day:

A 89 B 89

B were now fed on potatoes alone. On the 30 day:

A 167 B 92

Bread was now added to the potato diet of B. On the 72 day:

A 233 B 100

B were now given potatoes plus bread plus fat. On the 110 day:

A 258 B 125

At this point one rat of the B set died. On the 118 day:

A 268 B 138

The ill-effects of an exclusive potato diet are obvious. Note what brave attempts were made at recovery after bread and then potatoes were given.

The Effect of cm Exclusive Milk Diet (A) Using Young Rats. 5 rats in set. Weight on first day:

A 48 B 53

For three days both A and B were fed on the regular diet. At the end of the third day:

A 53 B58

B were now fed on milk alone. On the 50 day:

A 139 5 B 124

At this point the diets were exchanged, so that A received an exclusive milk diet, and B the regular diet. On the 78 day:

A 158 B 150

While there is a difference in favor of the control, the difference is not marked. It must also be remembered that rats weighing 100 grams and over are no longer "babies," so that it would be natural to suppose that something in addition to milk would be desirable.

5 During the course of this experiment a sick animal belonging to group A was removed. This sickness had obviously nothing to do with the diet fed.