One of the most remarkable results of nutrition researches in the last decade has been the demonstration that laboratory animals (rats, mice) can be successfully reared on simplified dietary mixtures consisting of protein, fat, carbohydrate, salts and the vitamins hitherto known and that, although healthy adulthood is reached, sooner or later such animals lack entirely the power of reproduction; i. e., sterility supervenes.
DISCOVERY OF VITAMIN E AND ITS CONFIRMATION
In 1921, having been previously concerned with the precise mechanism of the estrous cycle in the rat, Evans and Bishop1 began to study dietary influence on the ovulatory rhythm and on the various steps in the physiology of reproduction. To their surprise they found that on supposedly complete dietaries, and with both growth and external appearance normal, animals would also exhibit normal estrous cycles and would breed, ovulate and conceive, yet be unable to experience a normal gestation through