PARTS OF ANIMALS, II. i. 



the Elements ; just so the non-uniform parts come 

 later than the uniform. The non-uniform parts, 

 indeed, whose manner of composition is that of the 

 third sort, have reached the goal and End of the 

 whole process ; and we often find that processes of 

 formation reach their completion at this point. 



Now animals are composed out of both of these two 

 sorts of parts, uniform and non-uniform ; the former, 

 however, are for the sake of the latter, as it is to the 

 latter that actions and operations belong (e.g. eye, 

 nose, the face as a whole, finger, hand, the arm as a 

 whole). And inasmuch as the actions and movements 

 both of an animal as a whole and of its parts are mani- 

 fold, the substances out of which these are composed 

 must of necessity possess divers dynameis. Softness is 

 is useful for some purposes, hardness for others ; 

 some parts must be able to stretch, some to bend. 



In the uniform parts, then, such dynameis are 

 found apportioned out separately : one of the parts, 

 for instance, will be soft, another hard, while one is 

 fluid, another solid ; one viscous, another brittle. 

 In the non-uniform parts, on the other hand, these 

 dynameis are found in combination, not singly. For 

 example, the hand needs one dynamis for the action 

 of compressing and another for that of grasping. 

 Hence it is that the instrumental parts of the body 

 are composed of bones, sinews, flesh, and the rest of 

 them, and not the other way round. 



The Cause which I have just stated as controlling 

 the relation between them is, of course, a Final 

 Cause ; but when we go on to inquire in what sense 

 it is necessary that they should be related as they are, 

 it becomes clear that they must of necessity have 

 been thus related to each other from the beginning. 



Ill 



