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SCIENCE PROGRESS 



duction than in the colder waters where the current metabolism 

 is relatively less ; and consequently the density of individuals 

 is less, although the total mass of food-matter in the process of 

 exchange may be approximately similar in the two cases. It is 

 true that the intensity of both current and structural metabolism 

 increases with the temperature, but the increase is more rapid in 

 the former than in the latter case. 



