414 Pellagra-Producing Diets. V 
strated to have their origin in the lack of a sufficient amount of 
the fat-soluble A and water-soluble B respectively in the diet. 
_The experiments described in this paper make it clear that the 
diet of Chittenden and Underhill is not deficient in the sense that 
it fails to furnish a sufficient amount of another specific substance 
which when present protects against the development of the syn- 
drome of pellagra. The deficiencies of their diet are all depend- 
ent upon the shortage of the fat-soluble A, the character of the 
inorganic moiety, and the relatively poor quality of its protein 
mixture. The experimental demonstration of-this fact, provided 
the interpretation be accepted that their dogs were suffering 
from a disease analogous to pellagra in man, eliminates a second 
syndrome, pellagra, from the list of supposed ‘‘deficiency”’ 
diseases. 
On the appearance of Chittenden and Underhill’s paper, we 
were at once convinced that their interpretation of the nature of 
the deficiencies of their diet could be only partially correct. This 
conclusion is inevitable in the light of our many studies of all the 
more important seeds, which are in use as foods for men and 
animals. Each of these, we have shown, can be supplemented 
by the addition of inorganic salts, purified protein, and a growth- 
promoting fat, so as to be dietetically complete (14). It must 
follow, therefore, that the fat-soluble A is the only unidentified 
dietary factor of which there is any relative lack in any of the 
seeds which we have studied. The deficiency of the seeds in fat- 
soluble A is only relative, not absolute. Each of the seeds ap- 
pears to contain at least 50 per cent of the requirements of the 
erowing rat for this substance, provided the other factors in the 
diet are of good quality. A mixture of peas, wheat flour (or 
crackers), and cottonseed oil, should, in the light of our data with 
each of the common seeds, be susceptible of fairly accurate ap- 
praisal as to its dietetic value. The experiments described in this 
paper demonstrate the correctness of this view. 
Chart 1. Lot 1,915.—The standard food mixtures of peas, 
patent flour, and cottonseed oil induced no growth in Period 1. 
In Period 2 the addition of purified protein did not correct the 
ration so as to produce growth. 
Lot 1,916 A shows that a suitable salt addition was not suffi- 
cient to render this food mixture capable of supporting growth, 
