PARTS OF ANIMALS, II. π. 



blood in other creatures : and thus we can explain 

 Avhy bees and other sinailar creatures are of a more 

 intelligent nature than many animals that have 

 blood in them ; and among the latter class, why 

 some (viz. those whose blood is cold and thin) are 

 more intelligent than others. Best of all are those 

 animals Λvhose blood is hot and also thin and clear ; 

 they stand well both for courage and for intelligence. 

 Consequently, too, the upper parts of the body have 

 this pre-eminence over the lower parts ; the male over 

 the female ; and the right side of the body over the 

 left. 



What applies to the blood applies as well to the 

 other uniform parts and also to the non-uniform 

 parts ; similar variations occur. And it must be 

 supposed that these variations either have some re- 

 ference to the activities of the creatures and to their 

 essential nature, or else bring them some advantage 

 or disadvantage." For example, the eyes of some 

 creatures are hard in substance, of others, fluid ; 

 some have eyelids, others have not. In both cases 

 the difference is for the sake of greater accuracy of 

 vision. 



Before we can go on to consider the reasons why all 

 animals must of necessity have blood in them or some- 

 thing which possesses the same nature, and also what 

 the nature of blood itself is, we must first come to 

 some decision about hot and cold. The nature of many 

 things is to be referred back to these two principles, 

 and there is much dispute about Avhich animals and 

 which parts of animals are hot and which are cold. 

 Some assert that water-animals are hotter than land- 

 animals, and they allege that the creatures' natural 

 heat makes up for the coldness of their habitat. 



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