The child depends on the mother's nutrition for its food supply, after birth, for as long as it continues to nurse. Her own diet is as important to her child during the nursing period as before birth. These two periods--gestation and lactation--may be considered, from the trophologic viewpoint, as one. They are one both as regards the mother and as regards the child.

Observers have recorded cases where infants at the breast became affected with scurvy although their mothers were in apparent health. Sucklings have been known to be affected with beri-beri while their mothers were in apparent health. This is attributed to vitamin deficiency. It does not matter whether it is a lack of vitamins or calcium; the mother's diet is certainly inadequate. Children may become rachitic or may develop xerophthalmia (a dry and thickened condition of the conjunctiva) because the mother's diet is inadequate.

That undernourished mothers cannot nurse their babies is proven by the results of fasting, by the experience of mothers in certain parts of war-ravished Europe, by animal experiment and by examples existing all around us. A fast quickly reduces the quantity of milk and impairs its quality. Experiments have shown that after 14 days of fasting the amount of milk secreted is only about one-seventh of the normal amount. The milk becomes poorer in water, protein, sugar and mineral salts. The fat content remains practically unchanged. Lusk found that in fasting goats, the fat content increased. Others have found the fat content of milk to remain practically the same in cow's milk, although the other elements all decreased.

Within wide limits the composition of milk is independent of the food eaten by the mother. For, so long as the needed tissue-building elements are present in the mother's own body, she will be able to produce milk of a definite composition. The mammary glands manifest great energy in extracting the needed materials--whether fats, proteins, sugars, minerals or vitamins--from the tissues of the mother and the source of milk does not "dry up" so long as the mother's organism can yield up the requisite materials for its production.

The quantity of milk produced is greatly influenced by the mother's diet, but this will not greatly affect its quality, so long as her own tissues may be drawn upon to make up the deficiencies. When the supply of any tissue building element fails, the quantity of milk falls off, but the composition remains practically unchanged. If there is complete failure of only one tissue-building element from both the diet and the maternal organism, the secretion of milk is arrested.

Carl Rose carried on experiments on goats over considerable periods. He states that he could not find that extensive variations in the diet resulted in any changes in the composition of their milk. It is certain, however, that no female animal can provide, indefinitely, food elements in her milk, if these are not supplied by her diet. The persistent robbing of her own tissues, to supply the needs of her young, results in their exhaustion, and in serious disease in the mother. The milk suffers and this produces, as shown by Steenbock and Hart, grave debility in the young. Long continued malnutrition in mothers results in degeneration of the mammary glands, as was seen in Central Europe during World War I.

Kauppe, in Germany, examined the milk of a number of nursing mothers during the war, and found the fat content practically normal. He resorted to a fanciful interpretation of psychic influences as an explanation for the failure of infants to thrive on their milk. In Central Europe the half famished mothers during the war were unable to nurse their children. How ridiculous to call in "psychic influences" to account for what was so evidently due to partial starvation.