li. 9—11. 10. 43 



substances flesh and bone form the basis. Semen and milk were 

 also passed over, when we were considering the homogeneous 

 fluids. For the treatise on generation will afford a more suitable 

 place for their examination, seeing that the former of the two 

 is the very foundation of the thing generated, while the latter is 

 its nourishment. 



(Ch. \o.) Let us now^ make, as it were, a fresh beginning, 

 and consider the heterogeneous parts, taking those first which 

 are the first in importance.^ For in all animals, at least in all 

 the perfect kinds,^ there are two parts more essential than the 

 rest, namely the part which serves for the ingestion of food, 

 and the part which serves for the discharge of its residue.^ For 

 without food growth and even existence is impossible. Interven- 

 ing again between these two parts there is invariably a third, 

 in which is lodged the vital principle. As for plants, though 

 they also are included by us among things that have life, yet 

 are they without any part for the discharge of residue.* For 

 the food which they absorb from the ground is already concocted, 

 and they give off as its equivalent their seeds and fruits. Plants, 

 again, inasmuch as they are without locomotion, present no 

 great variety in their heterogeneous parts. For, where the 

 functions are but few, few also are the organs required to effect 

 them.^ The configuration of plants is a matter then for separate 

 consideration. Animals, however, that not only live but feel, 

 present a much greater multiformity of parts, and this diversity 

 is greater in some animals than in others, being most varied 

 in those, to whose share has fallen not mere life but life of 

 high degree. Now such an animal is man. For of all living beings 

 with which we are acquainted man alone partakes of the divine, 

 or at any rate partakes of it in a fuller measure than the rest.** 

 For this reason, then, and also because his external parts and 

 their forms are more familiar to us than those of other animals, 

 we must speak of man first ; and this the more fitly, because 

 in him alone do the natural parts hold their natural position ; 

 his upper part' being turned towards that which is upper in the 

 universe. For, of all animals, man alone stands erect.''' 



In man, then, the head is destitute of flesh ; this being the 



necessary consequence of what has already been stated concerning 



the brain. There are, indeed, some ^ who hold that the life of 



man would be longer than it is, were his head more abundantly 



656 a. 



