7 6 



INANITION AND MALNUTRITION 



maintenance requirement, but still subnormal in amount, will cause a retardation 

 in growth proportional to the degree of deficiency. Thus Evans and Bishop 

 ('22) found that on optimum standard diet the albino rat at one year reached 

 a body weight of about 330 g. ; slightly underfed, 220 g.; on two-thirds normal 

 ration, 140 g.; and on half ration, 60-85 g. (see Fig. 34). As will be shown 

 later, however, the dystrophic growth under such circumstances is not only 

 decreased in rate but also often abnormal in character. 



360 



400 



Fig. 34. — Chart showing curves of average growth in female albino rats on various planes 

 of nutrition. The upper curve (light line) represents the average normal growth of littermate 

 controls on an abundance of "Standard Diet I." The 3 lower curves in heavier line represent 

 averages for the groups in which this ration was reduced slightly (in the upper curve), about 

 one-third (in the middle curve), and about one-half (in the lower curve), respectively. Circles 

 mark the average times of occurrence of the first estrus, which did not occur at all in the most 

 underfed group. (Evans and Bishop '22.) 



Prenatal and Larval Inanition. — Since the resistance to inanition in general 

 varies directly with age, it may be inferred that during prenatal or embryonic 

 stages, the organism is particularly susceptible to nutritional deficiencies. This 

 is probably true, but it is somewhat difficult to prove. Especially in mammals 

 the embryo and fetus are carefully protected against inanition by the food supply 

 through the placenta from the mother, even when the latter is severely underfed. 

 In oviparous forms the eggs are usually provided with an abundance of nutrient 

 yolk material, which in part may be carried over into the embryonic body as a 

 reserve supply and may for some time aid in the resistance to inanition. 



Among fishes, Fabre-Domergue and Bietrix observed that the young may 

 perish from inanition before complete absorption of the yolk material. In 

 amphibia, Brehm ('12) cites a remarkable case in which Nussbaum observed 

 that an adult Proteus anguinus after 13 months of starvation gave birth to a 



