104 INANITION AND MALNUTRITION 



(Tuczek '93; Nichols '15, '19; Sundwall '17; Goldberger and Wheeler '20; and 

 others). In some cases, there is a tendency to edema ("wet form" of pellagra), 

 ascribed by Fraenkel ('69-'7o) to renal and cardiac lesions in "pellagra typhosus." 



Marie ('08, '10) states that loss in body weight is not a constant symptom, 

 but occurred in 84 per cent of the females and 74 per cent of the males. Calder- 

 ini ('47) found 514 out of 1,005 cases notably under weight. The decrease in 

 weight is said to correspond to progressive repugnance for food, although some 

 cases (especially of the typhoid type) may appear well nourished. In late 

 stages there is usually extreme emaciation. 



Deficiency in Fats and Carbohydrates. — It has generally been held that 

 carbohydrates are desirable in the diet, in order to avoid the ill effects of the 

 large amounts of protein or fat otherwise necessary to supply sufficient calories. 

 It is well known, however, that dogs and other carnivorous animals may thrive 

 upon a meat diet nearly free from both carbohydrate and fat. Prochownick 

 ('89, '01, '17), advocated a diet rich in protein and poor in carbohydrates and 

 water, in order to reduce fetal size. Osborne and Mendel ('12, '20a) obtained 

 normal growth in rats on nearly fat-free rations. They ('21b, '21c, '2id) 

 have recently shown that it is quite possible to obtain growth of rats to adult 

 size on a diet practically free from digestible carbohydrates; and the body weight 

 may be at least trebled without either fat or carbohydrate. Evans and Bishop 

 ('22) have also obtained excellent growth in rats on diets nearly free from fats or 

 carbohydrates. 



Most of the earlier experiments on fat deficiency were complicated by the 

 fact that the (then unrecognized) " fat-soluble A" vitamin was also eliminated, 

 which is now known to be essential for growth. This probably explains the 

 results of McCollum and Davis (,'13), Hatai ('15) and Stepp ('17), who found 

 growth retarded in rats on lipoid-free diets. Drummond ('20) observed good 

 health but subnormal growth (possibly due to other factors) on fat-free rations; 

 but Drummond and Coward ('21) obtained normal growth from weaning to 

 maturity in rats on a diet nearly free from neutral fat. 



It is well known that both fats and carbohydrates may be synthesized in 

 the animal body, and McCollum, Halpin and Drescher ('12) have shown that 

 this is true also for lecithin (phosphatized fat). Normal nutrition is therefore 

 possible in the absence of these substances from the diet, although the length of 

 life during total inanition is materially affected by the amount of body fat 

 present (Voit '01 a). 



Deficiency of Inorganic Salts. — The necessity for an adequate supply of 

 salts in the food-intake has long been recognized, and was emphasized by v. 

 Liebig. Their relative abundance in foods and their storage in the body are 

 discussed by Forbes ('19). Forster ('73) reviewed the earlier literature on this 

 question and experimented with low salt diets (also probably somewhat deficient 

 in vitamins). On such diets, pigeons perish in 13-29 days, and dogs survive 

 26-36 days, with progressive weakness and paralysis. Gaube ('97) found that 

 mineral hunger in pregnant rabbits causes abortion, with stillborn or poorly 

 developed young. A diet poor in minerals (Na, Ca, Mg, K and Fe) likewise 

 resulted in less vigorous chicks. Hart and McCollum ('14) concluded that the 



