GENERAL METABOLISM. 



629 



This, however, of itself does not by any means explain the considerably 

 more active metabolism on the part of the younger individual. This is 

 evident when we compare not the metabolism of the whole external sur- 

 face, but rather that per unit of surface. On comparing, for example, 

 the metabolism per square meter in fully developed dogs of different sizes, 

 we will find that the value is the same for all dogs within certain narrow 

 limits. This is, however, not the case if we compare the metabolism of 

 young dogs with that of older ones. In the case of the former the metabo- 

 lism is greater per unit of surface than it is in the older dogs. 



I. 



CONSUMPTION OF OXYGEN, ARRANGED IN THE ORDER OF THE 



ANIMAL'S WEIGHT. 



II. 



COMPARISON OF THE EXCHANGE OF ENERGY IN ANIMALS (DOGS) 

 OF DIFFERENT SIZES WITH THEIR RELATIVE SURFACE DEVEL- 

 OPMENT. 



In the case of sucklings the metabolism per kilogram of body-weight 

 is likewise much greater than it is with fully developed dogs; but, on the 



