342 THE VITAMINS 



in the testis leads to earlier exhaustion of the store of vitamin E in the 

 male than in the female. 



Mason (1930) has recently shown that both the A and E vitamins 

 are essential for the maintenance of a normal germinal epithelium of 

 the testis, since neither one of these factors was able to maintain testis 

 normality in the absence of the other. "In other words, they appear to 

 supplement each other in some peculiar way. On the basis of the simi- 

 larity in distribution, solubilities, and other characteristics of these two 

 factors, it is suggested that they may be concerned in certain phases of 

 fat absorption, assimilation, or synthesis essential for the complete 

 metabolic activities of the developing and maturing germ cells." 



As has been shown to be the case with the other fat-soluble vita- 

 mins, the animal body is capable of storing a certain amount of vitamin 

 E in its tissues, although curiously enough the chief storage centers are 

 the muscles and fat rather than the active organs as in the case of 

 vitamin A. Evans and Burr found that the tissues of normal rats when 

 fed to female rats which had been made sterile by vitamin E deficiency 

 rendered them fertile, while the tissues of such sterile rats were inefifec- 

 tive. Another proof of the storage of vitamin E in the animal body is 

 that fertile rats retain their fertility for three or four months after 

 being shifted to a vitamin E deficient ration and that when sterile rats 

 (female) are cured by the administration of vitamin E, the fertility may 

 last through two or three subsequent gestations, depending upon the 

 amount of vitamin E administered. 



The ability of the body to store and hold in reserve a surplus of 

 vitamin E has been shown still further by the restoration of fertility 

 in female rats by a single massive dose of vitamin E on, or within five 

 days after, the beginning of gestation. In the case of wheat germ oil, 

 one of the richest sources of vitamin E, the daily administration of one 

 drop (weighing between 23 and 30 milligrams) during the entire gesta- 

 tion period of 22 days, or a single feeding of the total amount, always 

 resulted in the birth of living young. Administration of the oil by 

 parenteral injection, either in a single massive dose or in small daily 

 doses, was likewise effective. 



The administration of foods or extracts of foods known to be from 

 twice to twenty times as rich in vitamin E as is required for normal 

 reproduction did not result, however, in any increase in the number or 

 size of the young nor did it in any other way improve the performance 

 of the reproductive mechanism beyond usual limits. 



With this highly specialized function of vitamin E in maintaining 

 fertility, the question naturally arises as to whether this is its sole 



