The Horse as a Mechanism. 



In the mounted skeleton of a rearing horse and man I will call attention 

 to one or two points which may lead to a better understanding of the subject. 

 What is commonly called the knee of the horse, is comparable to the wrist of 

 man. The joint running down from the wrist is the cannon bone, and is com- 

 parable to the central finger of man. The hoof of the horse compares with the 

 nail of man, and the lateral fingers, disguised beneath the skin, as splints, cor- 

 respond to the index and ring fingers of man. Above the hind hoof we have the 

 hock, which corresponds with the heel of man. The elongated or middle toe cor- 

 responds to the middle toe in the human foot. These are a few points in the bony 

 anatomy of the horse about which we are more or less misled, owing to the entire 

 dissimilarity of terms. Fig. i. 



You will notice that the wrist of the horse and the heel are greatly elevated 

 above the ground. This, as you know, is for the purpose of giving speed to 

 this animal machine, because the elongation of the lower bones of the limb 

 means that where the upper joints of the limb go at a moderate rate of speed, 

 through the radius of a small circle, the lower joints go at a very high rate of 

 speed through the radius of a larger circle. In the ancestors of the horse this 

 was not the case, because in the very remote ancestors the wrist joint and the 

 hock joint were near the ground. 



In the musculature of the horse; I may say that all the muscles of the 

 fore limb and of the hind limb, which in the hand of man serve to turn or 

 rotate the joints of the palm or the back of the hand, have disappeared in the 

 horse, and all those muscles which tend to pull those joints forward and back- 

 ward in a perfectly direct line or plane of motion, are the ones which have been 

 developed; so that our first point in the movements of the animal is that the 

 horse is a mechanism in which the limbs are, as nearly as possible, confined 

 to a motion in which the plane of direction is fore and aft. To make this pos- 

 sible the joints of those limbs are perfected in a very high degree, and whereas 

 in our wrist or ankle-joint we can move the wrist or ankle in several directions, 

 right or left or up and down, the horse is confined to an up and down move- 

 ment. We shall look at three or four special types of horse without regard to 

 breed. 



We have here a specimen of the Rocky Mountain or Western horse, in the 

 ordinary act of scraping off the surface in order to get down to the bone bearing 

 layers beneath. You will see that this is the typical draft-horse action, a heavy 

 development of the hind limbs, and that the horse is pushing rather than pulling 

 against the collar. In order to perfect this mechanism, which is far more beau- 

 tiful than you would imagine without very careful study, this English type of 

 draft-horse has been selected as sprjnging from a certain type of wild horse. 

 The draft-horse has rather a low sloping hind quarter, a very heavy neck, 

 great weight of what we call 'bone' — and fetlocks which have no special sig- 

 nificance except as a fad in the eyes of horse fanciers. Fig. 2. 



I have skeletonized the percheron draft-horse in order to show the beauty 

 of its mechanism. From the side view you will get the impression of the ani- 

 mal straining with the collar against the scapula or shoulder- joint. The thrust 



