EFFECTS ON THE INTEGUMENT 119 



the integument in the male, although somewhat less in the female (Table 6). 

 The percentage of dry substance remained nearly constant. 



In the young, the changes in the weight of the integument differ from those 

 in the adult. Manassein ('68, '69) in rabbits on total inanition at age of about 

 3 weeks obtained an average loss of about 35 per cent in body weight and of 40 

 per cent in skin weight; at the age of 3 months, body loss was 33 per cent, skin 

 19 per cent; in adults, body loss was 39 per cent, skin 27 per cent. Aron 

 ('10, '11) concluded that in underfed puppies the skin increases slightly in rela- 

 tive weight. Trowbridge et al. ('18) likewise observed a slight increase in the 

 weight of the integument of yearling steers held nearly at maintenance (con- 

 stant body weight) by underfeeding; while in those losing about 17 per cent in 

 body weight the hide lost only 3-6 per cent. 



In albino rats held at maintenance by underfeeding for various periods 

 beginning at 3 weeks of age or later, Jackson ('15a) found a marked loss (36 per 

 cent) in the weight of the integument in the rats beginning at 3 weeks of age 

 (Table 4), with smaller losses in those beginning later. Stewart ('18, '19) in 

 still younger rats observed the greatest loss (48 per cent) in those underfed 

 from birth to 10 weeks; in those underfed from birth to 3 weeks there was no 

 loss of weight in the integument; and in those held at birth weight by underfeed- 

 ing 16 days there was an actual increase of 25 per cent in the weight of the integu- 

 ment. This appeared to be normal developmental growth, and not merely an 

 increase in weight due to edema. A smaller relative increase (10 per cent) was 

 found by Barry ('20, '21) in the skin of newborn rats which had been stunted 

 prenatally by severe underfeeding of the pregnant mother. 



These results (shown in Table 4) demonstrate clearly that the dystrophic 

 growth of the integument varies greatly according to age. In the prenatal and 

 newborn rats, the tendency to increase in weight of the skin during subnutrition 

 appears greatest, but the growth impulse (m underfed animals) rapidly decreases 

 to a minimum, the greatest losses occurring at body weights of 15-25 g. 

 Later the growth impulse again increases, so that the losses become relatively 

 less, up to the adult stage, where the loss is nearly proportional to that of the body. 

 There are also differences according to the intensity of the underfeeding and 

 probably according to the type of inanition (to be considered later). 



For the human species, data as to changes in the weight of the integument 

 during inanition are scarce. Ohlmuller ('82) noted that in a normal infant of 

 56 days, the body weight was 4,195.5 g., the skin weight 1,291.67 g., or 31.16 per 

 cent; while in an atrophic infant of 56 days, the body weight was 2,381.2 g., the 

 skin weight 290.55 g., or 12.21 per cent. It is evident that the tela subcutanea 

 was here included with the skin proper, however, for Ohlmuller remarks that the 

 enormous loss was due to the adipose content. A few data upon the weight of 

 the integument, without tela subcutanea, as observed by me in autopsies of 

 atrophic infants are given in Table 3. Lack of norms for comparison makes it 

 difficult to draw any conclusions, however. 



Recovery in Weight of Skin upon Refeeding.— In albino rats held at 

 maintenance by underfeeding from 3-12 weeks of age, Stewart ('16) 

 found that upon full refeeding the integument rapidly recovers the marked 



