cit-title-group
Abstract
(From the -Department of Foods and Nutrition, Home Economics Section, Iowa Agricultural Experiment Station, Iowa State College, Ames) Received for Publicationââ¬âMarch 28, 1930 ~~INTRODUCTION like milk, has been subjected to many and varied tests in order to determine its rôlein nutrition. The earlier experiments, such as those of Watson (1), conducted before the formulation of the vitamin hypo thesis are not comparable with experiments of 'ÿo-daybecause the diets used were obviously inadequate or one-sided in the light of our present con ception of an animal's nutritive needs. More recent researches have taken the rôleof the vitamins into consideration and the rations have been plan ned to provide the accessory factors in so far as they are known. However, much of the recent work may be criticized because only por tions of the life cycles of the experimental animals were studied. It was McCollum and Davis (2) who pointed out that "even normal growth to the normal adult size and continued maintenance does not necessarily indicate perfect nutrition. Only when animals reproduce and nourish their young normally and repeat this at normal intervals, can it be said that the ration is physiologically sufficient." Simmonds (3), also, has observed that