I. The use of an excessive meat diet in rats induces a deterioration in the health of the animals. This deterioration is shown in (a) an imperfect physical development, (b) a loss of reproductive power, (c) defective lactation, and (d) a high mortality in early life in the second generation of meat-fed subjects.

II. The recuperative powers of these deteriorated animals, on a normal diet, is very striking.

III. In animals deprived of their ovaries, the minimum amount of proteid required is less than in normal females.