CALL FOR OXYGEN 5 



Later it has been found, however, that also in cold-blooded 

 animals a similar relationship between weight and metabolism 

 holds good, and it is therefore probably of a much more funda- 

 mental nature. An illustration is given in Table 3 from deter- 

 minations by Bornebusch (1930) on the animals living in 

 forest soil. 



The influence of organization. Many deviations from the 

 weight-metabolism relation sketched above become apparent 

 when different animals are compared — at a constant tem- 

 perature and during rest — but the majority can be explained 

 as due to differences in organization. Nobody would expect 

 two animals of the same live weight, but having respectively 

 1/2 and 20% dry substance, like a jelly-fish and a cuttle-fish, 

 to show the same rate of metabolism. Since a variable pro- 

 portion of the dry substance may also be inactive, a better 

 basis for comparison is the content of organic nitrogen, and 

 many large deviations from the 2/3 power weight relationship 

 disappear or become greatly reduced when comparisons are 

 made on this basis, but some remain, and we have to admit 

 as a fact that the metabolism during rest stands in a certain 

 relation to the habitual activity of an animal, sluggish forms 

 having a lower metabolism than active ones. Cases in point 

 are the mussels Cardium and Pecten according to Sparck (1936), 

 the fishes Cyprinus and Esox as shown in Table 1 and the 

 reptiles Anguis and Lacerta. 



The influence of temperature. The metabolism at rest is in all 

 animals a definite function of the body temperature. This is 

 true also for the warm-blooded animals, which habitually 

 maintain by regulation processes a more or less constant 

 body temperature, and it can be demonstrated when the body 

 temperature is altered artificially. 



The relation between temperature and metabolism can be 

 expressed in the form of a curve, and such a curve, valid at 

 least approximately for animals belonging to very different 



