Interesting evidence on the effect of an inadequate diet in lowering the nutritive value of the milk secreted, is afforded by the studies of Andrews (10). It is well known that infants, who subsist upon the milk of mothers suffering from beri-beri resulting from a simple and monotonous diet of rice, fish and very small amounts of other foods, frequently develop the disease during the first few months of life. This is due, in such cases, to a lack in the milk of a sufficient quantity of the anti-neuritic substance, water-soluble B. Andrews fed the milk of women suffering from beri-beri to young pups and found that they soon lost the use of the hind legs and showed other evidences of beri-beri.

It will be seen, therefore, that although faulty diet in a lactating female will not ordinarily modify in respect to the ordinary components for which the chemist has methods for analysis the composition of the milk which she secretes, it may very easily lower the nutritive value of the milk to such an extent as to render it unfit food for an infant. McCollum and Simmonds (1) have established experimental conditions which serve to illustrate how far faults of various kinds and of different degrees in the diet of mother rats influence the rate of growth in their young.