iii. 2 — iii. 3. 63 



Let us now consider how the necessary results of the material 

 nature are made available by rational nature for a final cause.'^ 



In the first place, then, the larger the bulk of animals, the greater 

 is the amount of corporeal and earthy matter which they contain. 

 Thus no very small animal is known to have horns, the smallest 

 horned animal that we are acquainted with being the gazelle.^''^ 

 But in all our speculations concerning nature, what we have to 

 consider is the general rule ; for that is natural which applies 

 either universally or generally.'^ And thus when we say that 

 the largest animals have most earthy matter, we say so because 

 such is the general rule. Now this earthy matter is used in the 

 animal body to form bone. But in the larger animals there is an 

 excess of it, and this excess is turned by nature to useful account, 

 being converted into weapons of defence. Part of it necessarily 

 flows to the upper portion of the body, and this is allotted by her 

 in some cases to the formation of tusks and teeth, in others to the 

 formation of horns. Thus it is that no animal that has horns 

 has also front teeth in both jaws, those in the upper jaw being 

 deficient.'^ For nature by subtracting from the teeth adds to 

 the horns ; the nutriment which in most animals goes to the 

 former being here spent on the augmentation of the latter. Does, 

 it is true, have no horns and yet are equally deficient with the 

 males as regards the teeth. The reason, however, for this is that 

 they, as much as the males, are naturally horn-bearing animals ; 

 but they have been stripped of their horns, because these would 

 not only be useless to them but actually baneful ;^ whereas the 

 greater strength of the males causes these organs, though equally 

 useless, to be much less of an impediment. In other animals, 

 where this material is not secreted from the body in the shape 

 of horns, it is used to increase the size of the teeth ; in some cases 

 of all the teeth, in others merely of the tusks, which thus become 

 so long as to resemble horns projecting from the jaws.^^ 



(Ch. 3.J So much, then, of the parts which appertain to the 

 head. Below the head lies the neck, in such animals as have one. 

 This is the case only with those that have the parts to which a 

 neck is subservient. These parts are the larynx^ and what is 

 called the oesophagus. Of these the former, or larynx, exists 

 for the sake of respiration, being the instrument by which such 

 animals as breathe inhale and discharge the air. Therefore it is 

 that, when there is no lung, there is also no neck. Of this 

 664 a. 



