ULTIMATE EFFECTS OF INANITION ON SIZE 117 



HEAD, LIMBS AND TRUNK 



In rats underfed from birth to three weeks of age, Stewart 

 ('18) found the head about 16 per cent above normal weight, but 

 in those underfed to six or ten weeks the head was nearly normal. 

 In such underfed rats, on ample refeeding to a body weight of 

 25 to 75 grams, Jackson and Stewart ('19) found the head weight 

 nearly normal. Similarly in the present series (table 2), refed 

 to maximum body weight, the head weight is nearly normal, 

 the relatively small differences being probably of no significance. 



The limbs and trunk show no marked or constant change in 

 relative weight during the underfeeding period in young rats 

 (Stewart, '18), and likewise during ample refeeding up to body 

 weights of 25 to 75 grams (Jackson and Stewart,' 19). Similarly 

 in the present series, the limbs and trunk in general show no 

 marked deviation from the normal weight, except in the last 

 group (table 2, fourth column). Even in this case, the excess 

 weight of the fore limbs ( + 19.4 per cent) and the subnormal 

 weight of the trunk ( — 11.1 per cent) are of questionable signifi- 

 cance. The limbs are difficult to separate from the trunk in a 

 uniform way, and, as previously explained, no direct controls were 

 available for this group. On the whole, therefore, it is doubtful 

 whether the refed test rats show any significant abnormality in 

 the proportions of their head, limbs, or trunk. 



THE BODY SYSTEMS 



These body systems include the integument, skeleton, muscu- 

 lature, visceral group, and 'remainder.' 



Integument. In rats underfed from birth, Stewart ('16) found 

 the integument nearly normal in weight at three weeks, but 43 

 to 48 per cent subnormal at six and ten weeks of age. On re- 

 feeding such rats, Jackson and Stewart found the integument 

 still subnormal at a body weight of 25 grams, but normal (or 

 above) at 50 and 75 grams. The present series (table 2) shows 

 the integument averaging slightly subnormal ( — 5.6 to —7.8 per 

 cent) in all, but the third group ( +9.8 per cent) . The differences 

 are of questionable significance, as the skin is quite variable in 



