iv. 10, 125 



the foot, but renders the act of progression more secure. Thus 

 it is that even in such animals as have a huckle-bone, it "is only 

 in the posterior limbs and never in the anterior ones that this 

 bone is foundn For the anterior limbs, moving as they do in 

 advance of the others, require' to be light and capable of ready 

 flexion, whereas firmness and extension are what is wanted in the 

 hind limbs. Moreover a huckle-bone adds weight to the blow 

 of a limb, and so renders it a .suitable weapon of defence; 'and 

 these animals all use their hind legs to protect themselves, kicking 

 out with their heels against anything, which annoys them. In the 

 cloven-hoofed quadrupeds the lighter character of the hind legs 

 admits of there being a huckle-bone ; and the presence of the 

 huckle-bone prevents them from having a solid hoof, the bony 

 substance remaining in the joint, and therefore being deficient 

 in the foot. As to the polydactylous quadrupeds, none of them 

 have huckle-bones. For if they had they would not be poly- 

 dactylous, but the divisions of the foot would only extend to that 

 amount of its breadth which was covered by the huckle-bone.*^ 

 Thus it is that most of the animals that have huckle-bones are 

 cloven-hoofed. 



Of all animals man has the largest foot in proportion to the 

 size of the body.*^ This is only what might be expected. For 

 seeing that he is the only animal that stands erect, the two feet 

 which have to bear all the weight of the body must be both long 

 and broad. Equally intelligible is it that the proportion between 

 the size of the fingers and that' of the whole hand should be 

 inverted in the case of the toes and feet. ' For the function of 

 the hands is to take hold of objects and retain them by pressure ; 

 so that the fingers require to be long. For it is by its flexed 

 portion that the hand grasps an object. But the function of the 

 feet is to enable us to walk with security ; so that here the 

 undivided part is to be looked on as of most importance. How- 

 ever it is better for an extremity to be divided than to be un- 

 divided. For in an undivided foot disease of any one part would 

 affect by sympathy the whole ; whereas, if the foot be divided 

 into separate digits, there is not an equal liability to such an 

 occurrence.*'' The digits, again, by being short would be less 

 liable to injury. For these reasons the feet in man are many- 

 toed, while the separate digits are of no great length. The toes, 

 finally, are furnished with nails for the same reason as are the 

 690b. 



