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THE VITAMINS 



Fig. 14. — Showing comparison of diets containing different amounts of vitamin 

 A similar to the comparison shown in Fig. 13 except that in this case the diets 

 consisted of whole wheat, dried skimmed milk and lard or butter respectively, so 

 as to contain the same proportion of fat and dififer only in fat-soluble vitamin 

 contained. Again there was little difference in growth but the diet containmg 

 the higher proportion of vitamin A resulted in a much higher degree of vigor 

 as shown by capacity for reproduction and successful suckling of young. In this 

 case only one pair each of the second and third generations is charted. (Sherman 

 and MacLeod, 1925.) 



liberal allowance of vitamin A grew to fully average adult size, were 

 successful in reproduction and the rearing of young, and lived on 

 the average a little over twice as long as those on the diet equally good 

 in all other respects but lower in vitamin A. These experiments show 



