7. WARM-BLOODED VERSUS 

 COLD-BLOODED 



Two great energy divisions of the animal kingdom are 

 the warm-blooded animals and the cold-blooded 

 animals. 



The energy advantage of the warm-blooded state over 

 the cold-blooded state is expressed by van't HofFs law 

 that with each degree centigrade of rise in temperature 

 the speed of chemical activity is increased 10 per cent. 

 This law applies equally to living and to nonliving systems. 



In accordance with such a law it would follow that a 

 cold-blooded animal having a temperature of 22C. would 

 be at a disadvantage in a fight with a warm-blooded ani- 

 mal having a temperature of 37C., for the warm-blooded 

 animal, being 15 warmer than the cold-blooded animal, 

 would be endowed with a speed of chemical activity 150 

 per cent greater than that of the cold-blooded animal. 



Cold-blooded animals, with their low order of intelligence, 

 power, and personality, occupy a less favored place on the 

 earth. Many devices to protect them from the keener, more 

 alert, and powerful warm-blooded animals have evolved. 

 Snakes had to accept a life on their bellies. Other animals 

 were obliged to resort to color protection, as in the case of 

 certain lizards, or to a carapace, as in the case of the turtle. 

 The alligator and crocodile took to the swamps. Since they 

 are armored, it is unnecessary for them to build up mecha- 

 nisms for fighting. Like biologic traps, they lie in wait for 

 their prey and require but slight effort to find their food, 

 while energy is supplied to them directly through their 

 carapaces as they bask on the sunny bank. 



It may be urged that reptiles such as the alligator, the 

 crocodile, and the turtle breathe the same air, with its 20 

 per cent of available oxygen, that the lion and the porpoise 



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