Abstract
The existence of a dietary complex essential for reproduction (vitamin E) first described by Evans and Bishop, 1 now corroborated by Sure, 2 Mason 3 and Matill and his associates, 4 has not been generally accepted. Evans and Bishop found that on a synthetic diet composed of casein 18, corn starch 54, lard 15, milk-fat 9, salt mixture 4, plus a daily ration of 0.4 to 0.6 gm. of yeast, rats were for the most part sterile in the first generation, and wholly so in the second. This deficiency is corrected by the addition of lettuce, wheat germ, egg-yolk, meat, and to a less extent milk-fat, or a small quantity of a fat-free concentrate prepared by extraction from wheat germ oil (Evans, 5 and Sure 6 ). On the other hand, Nelson, Heller and Fulmer, 7 using a synthetic diet consisting of casein 18, salt mixture 3.7, filtered butter fat 5, yeast 1-8 and dextrine up to 100, encountered no difficulty in securing litters, although only a small percentage of the young could be reared. Likewise, Hogan, Harshaw 8 employing synthetic rations containing casein 20, milk-fat 10, cod liver oil 5, yeast 6, salts 4, corn-starch 50-55 and agar 2-5, reported no sterility in their rats, but rather failure in lactation.
From data accumulated for the past two years in this and in Professor Mendel's laboratory in New Haven, (which are summarized in Tables I and 11) and from a review of the more recent literature, it seems clear that what appears to be contradictory evidence regarding the existence of vitamin E is only apparently so. On Ration 1, young rats grew more or less normally but were practically sterile; on Ration 2 they reproduced repeatedly.
Get full access to this article
View all access options for this article.