116 LECTURES ON EVOLUTION in 



sary consequence of any sort of perfection, of 

 mechanical perfection as of others, you find that 

 the horse is a beautiful creature, one of the most 

 beautiful of all land-animals. Look at the perfect 

 balance of its form, and the rhythm and force of 

 its action. The locomotive machinery is, as you 

 are aware, resident in its slender fore and hind 

 limbs ; they are flexible and elastic levers, capable 

 of being moved by very powerful muscles ; and, 

 in order to supply the engines which work these 

 levers with the force which they expend, the 

 horse is provided with a very perfect apparatus 

 for grinding its food and extracting therefrom the 

 requisite fuel. 



Without attempting to take you very far into 

 the region of osteological detail, I must never- 

 theless trouble you with some statements respect- 

 ing the anatomical structure of the horse ; and, 

 more especially, will it be needful to obtain a 

 general conception of the structure of its fore and 

 hind limbs, and of its teeth. But I shall only 

 touch upon those points which are absolutely 

 essential to our inquiry. 



Let us turn in the first place to the fore-limb. 

 In most quadrupeds, as in ourselves, the fore-arm 

 contains distinct bones called the radius and the 

 ulna. The corresponding region in the horse 

 seems at first to possess but one bone. Careful 

 observation, however, enables us to distinguish in 

 this bone a part which clearly answers to the upper 



