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INANITION AND MALNUTRITION 



diets, confirming and extending the results of Lunin. His curves of body weight 

 (see Fig. 44) indicate clearly the presence in milk of elusive "accessory factors," 

 of which minute quantities are essential for growth. Osborne and Mendel 

 ('n, '12) and McCollum and Davis ('13) similarly found that although mainten- 

 ance of adult rats and growth in the young may be obtained for a time upon 

 isolated and purified food substances, nutritive decline and failure inevitably 

 follow, unless certain essential factors (designated as "vitamines" by Funk) 

 are added to the diet. Billard ('22) noted a dropsical condition and subnormal 

 growth in frog tadpoles on vitamin-free diet. 



It is impossible here to review the results of the numerous investigations 

 upon this phase of nutrition, which especially during the past decade have clari- 



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£5 



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Fig. 44. — Chart showing the effects of vitamin deficiency upon growth in body weight of 

 rats. The lower curve (up to the 18th day) shows the average retardation of growth (in 8 

 male rats) upon a vitamin-free dietary; the upper curve, for 8 similar rats, with addition of 3 

 c.c. of milk daily to the diet. On the 1 8th day, the milk was transferred from one set to the 

 other, with marked effect upon the growth in each case. (Hopkins '12; Med. Res. Comm. 

 •i9-) 



fied the relations of partial inanition to growth and have placed the etiology of 

 several "deficiency diseases " upon a fairly substantial basis. The present status 

 of the vitamin question was discussed in the symposium by McCollum, Mendel, 

 Sherman, Shipley, Holt and Hess ('22), and the literature is reviewed in detail 

 by the report of the Medical Research Council (by Hopkins et al., iQio)and in 

 the works by Langstein and Edelstein ('17), Stepp ('17), Aron ('20), McCarrison 

 ('21), Funk ('22), Ellis and Macleod ('22), Sherman and Smith ('22), McCollum 

 ('22), Mellanby ('22) and others. The following vitamins are now generally 

 recognized: "fat-soluble A" or vitamin A, with which is usually closely asso- 

 ciated the antirachitic factor or "fourth vitamin;" "water-soluble B" or 



