BRAIN FORCE. iii 



has to aid him. But it is perhaps premature to consider the resem- 

 blance between the style of the man and the action of the horse 

 now, as they will come in more appi'opriately hereafter. Neither is 

 it necessary to give elaborate attention to the anatomy of the horse, 

 and a brief review of the general structure and physiology of the 

 animal will be sufficient. 



The bones are the mechanical part ; the muscular system a portion 

 of the motive power. It is generally conceded that the brain and 

 the nerves which spring from the brain furnish the balance of the 

 force, and it will be all that the present purpose requires to accept 

 this as the correct theoiy. It may provoke a smile when I claim 

 that the action of the brain is affected by mechanical contrivances, 

 and yet I shall fail in my own estimation if I do not make it appar- 

 ent. The skeleton of the horse is tolei'ably familiar to those who 

 have given any attention to the formation of the animal, and if it 

 has not been studied when divested of all the tissues, a very good 

 idea is obtained from cuts and engravings. 



This frame has some similarity to that of man ; in other respects 

 the difference is strongly marked. Though all parts have more or 

 less to do with progression, the limbs and lumbar vertebrae are the 

 most actively employed. A glance at the skeleton will show that the 

 scapula, shoulder-blade, and the humerus, or upper arm, form quite 

 an angle. At the junction of the humerus and radius, the elbow 

 projects upward to a greater heighth than would be thought from 

 looking at the living animal. Pz-ojecting from the back part of the 

 knee is a bone, termed by some of the writers the trapezium, and 

 this is more prominent in the skeleton than would be supposed from 

 its appearance in life. At the ankle the external sessamoid has a 

 backward prominence, and from the elbow to the foot each joint 

 shows that the greatest force is required from behind, the attachments 

 for the tendons and ligaments being so much larger tlian in front. 

 "When these joints, as in the upper "parts, are so thickly covered with 

 muscles, and rigidly bound with ligaments, it is evident that there 

 cannot be much side motion, the bending being more like the straight 

 working of an ordinary hinge. 



When the foot is raised it is thrown outward a little, unless there 



