E. V. McCollum and N. Simmonds 307 
applying the conventional factor to the nitrogen content, as the 
criteria by which the ration should be judged. Discussions of 
the economics of diet have therefore not infrequently, even in 
very recent times, presented as the main thesis the relative cost 
of 100 calories of energy and the cost of 100 gm. of protein. As 
a phase of the discussion of the diet in its relation to pellagra, we 
wish to illustrate clearly how far these data may fail to indicate 
the value of a food mixture, especially during growth. 
Aron (5),in his studies of the dietaries of the Filipinos, states 
that the diet of many of the poor laborers consists essentially of 
about 700 gm. of rice and 250 gm. of fish, the energy value of the 
fish being equivalent to about 60 gm. of rice. Dairy products 
are not eaten by these people, and Aron states that the energy 
value of the fruits and fresh vegetables eaten by his subjects was 
so small that it might be neglected in his records. Beri-beri is 
very prevalent where such a monotonous and inadequate diet of 
rice and fish is eaten. 
Chittenden and Underhill (6) have recently described a con- 
dition in dogs, which corresponds closely to the syndrome of 
pellagra in man. They produced this condition by feeding the 
animals a monotonous diet which consisted of crackers, peas, 
and cottonseed oil—a diet derived wholly from the seeds of plants. 
Goldberger (7) has described experiments in which he has pro- 
duced in man what he and other clinicians familiar with the dis- . 
ease believed to be incipient pellagra, by restricting the diet 
during 53 months to dishes prepared from corn meal, corn grits, 
wheat flour, rice, sugar, starch, syrup, pork fat, sweet potatoes, 
cabbage, collards, turnip greens, and coffee. We have pointed 
out (8) that the energy content of the diet was derived to the ex- 
tent of about 95 per cent from seeds and pork fat. It is with the 
purpose of emphasizing the impossibility of making an adequate 
diet from seeds or seed products that we present the data in the 
accompanying charts. The experimental diets described, illus- 
trate in addition, however, the exact nature of the deficiencies of 
such seed mixtures. They make clear the necessity both in 
human nutrition and animal production of supplementing the 
seeds with either milk or the leafy vegetables in liberal amounts 
if growth in the young is to be satisfactory, and if the vitality as 
reflected in longevity and the capacity to produce and rear large 
THE JOURNAL OF BIOLOGICAL CHEMISTRY, VOL. XXXIII, NO. 2 
