16 VITALITY AND EFFICIENCY WITH RESTRICTED DIET. 



intermittently the greater part of the 24 hours, the rabbit received an 

 insufficient amount of food on these first days, the intake being roughly 

 proportional to the length of time in which the rabbit had access to 

 food. The values obtained during these realimentation periods supply 

 the only data which have an interest in our discussion of the influence of 

 undernutrition. 



In the first 3 days of the first realimentation period, the solid matter 

 eaten was but 13, 34, and 36 per cent, respectively, of the amount eaten 

 during the normal period; on the corresponding days in the third reali- 

 mentation period, it was 62, 49, and 33 per cent, respectively. Since 

 the intake of solid material did not reach the normal amount until the 

 seventh day in the first realimentation period and the sixth day in the 

 third realimentation period, the animal was distinctly undernourished 

 in the earlier days of these periods. On the first day of the first reali- 

 mentation period, the oxygen consumption per kilogram of body-weight 

 per 24 hours was a Uttle more than one-half the normal value (15.81 

 grams as compared with 27.58 grams). In the third realimentation 

 period, the oxygen consumption for the first day was 25.08 grams. 

 The carbon-dioxide excretion on the first days of these realimentation 

 periods was 17.79 and 32.16 grams, respectively, and thus much lower 

 than the normal value of 42.41 grams. The oxygen consumption and 

 carbon-dioxide excretion, particularly in the third period, did not 

 return to normal until the food intake was essentially that prior to 

 fasting. During these two periods of undernutrition, therefore, the 

 metabolism per kilogram of body-weight was considerably lower than 

 normal, the oxygen being from 43 to 9 per cent less and the carbon 

 dioxide from 58 to 15 per cent less in the first and third realimentation 

 periods, respectively. While the difference in the carbon-dioxide 

 excretion may naturally be accounted for, in part, by the difference in 

 character of the carbonaceous material in the food, the values would 

 indicate that during chronic- undernutrition there is at first a distinct 

 lowering of the metabolism per kilogram of body-weight when meas- 

 ured by either the oxygen consumption or the carbon-dioxide excre- 

 tion, as compared with the metabolism with a normal amount of food. 

 The fact, however, that the oxygen consumption increases from 43 to 

 only 9 per cent below normal in the third realimentation period would 

 indicate that with the larger diet in the third period the metabolism 

 immediately tended to follow the higher plane of nutrition. 



This finding is substantiated by a comparison of the metabolism 

 during the realimentation periods with the metabolism on the first days 

 of the first fasting period, for, aside from the expected increase in 

 metaboUsm due to the influence of the ingestion of food, Albitsky 

 reports that the intensity of metabolism, even with an insufficient 

 amount of food, was greater in the later realimentation period as com- 

 pared with the earlier. Albitsky's whole conception, however, is com- 



