ULTIMATE EFFECTS OF INANITION ON SIZE 115 



BODY LENGTH AND TAIL LENGTH 



The observations of Stewart ('18) indicate that at the end of 

 the underfeeding period in young rats there is a relative elonga- 

 tion of the body (nose-anus) length, as compared with that in 

 normal controls of the same body weight, amounting to an aver- 

 age of about 6 per cent in those underfed from birth to ten weeks, 

 and about the same in those underfed for long periods beginning 

 at three weeks of age. Jackson and Stewart ('19) have shown 

 that in the case of the rats underfed from birth, the body length is 

 still above normal on full refeeding to a body weight of 25 grams, 

 but about normal in those refed to 50 or 75 grams. The present 

 data (table 2) show the body length slightly subnormal (4.5 to 

 5.5 per cent) in such rats when refed for longer periods to maxi- 

 mum body weight. This means that in the test rats the body is 

 relatively slightly plumper than in the controls. In the group 

 refed after the longest period of underfeeding, however, as shown 

 in the fourth column of table 2, there is practically no difference 

 in body length between test rats and controls. It is therefore 

 apparent that in any case no trace of emaciation remains in the 

 underfed rats after refeeding to their maximum body weight. 



The tail length in the rats underfed from birth increases even 

 more than the body length (Stewart, '18), so the rats are rela- 

 tively long-tailed at the end of the underfeeding period. On 

 ample refeeding of such rats to a body weight of 25 to 75 grams, 

 Jackson and Stewart ('19) find the ratio of tail length to body 

 length nearly normal. The present data (table 2), however, in- 

 dicates that in such rats, as well as those starved for longer 

 periods, on amply refeeding to maximum body weight the tail 

 becomes relatively somewhat short, averaging 4 to 8 per cent 

 shorter than in the normal controls of the various groups. There 

 is a slight sexual difference in tail length (that of the female being 

 relatively slightly longer), but since the difference between test 

 and control rats appeared nearly equal in each sex, the sexes are 

 combined in the table. 



