I70 THB HORSE. 



For a thorough understanding of the parts described consult the 

 MANIKIN OF THE HORSE on pages 17 to 22, and the MANIKIN 

 OF THE FETEOCK, ANKJ^E, AND FOOT, just preceding this 

 chapter. 



Bones. The bones of the fetlock and foot constitute the skeleton on 

 which the other structures are built, and comprise the lower end of the 

 cannon bone (the metacarpus in the fore-leg and the metatarsus in the 

 hind-leg), the two sesamoid bones, the large pastern or suffraginis, the 

 small pastern or coronet, the coffin bone or os pedis, and the small sesa- 

 moid or navicular bone. 



Cannon Bone. This hone extends from the knee or hock to the 

 fetlock, and is cylindrical in shape, and stands nearly or quite perpen- 

 dicular. In the fore-leg it is called the metacarpus and in the hind-leg 

 the metatarsus. They correspond with the bones in the palm of the 

 hand and the ball of the foot in man. 



Sesamoid Bones. These occur in pairs, are small, shape resem- 

 bling a three-faced pyramid, and are set behind the fetlock joint, at the 

 upper end of the large pastern or suffraginis, having the base of . the 

 pyramid downward. 



Suffraginis, or I/arge Pastern. This is a very compact bone, 

 set in slanting direction downward and forward, and extends from the 

 cannon bone to the coronet or small pastern. 



Coronet, or Small Pastern. This is a short, cube-shaped bone, 

 set between the suffraginis and coffin bone, in the same slanting 

 direction. 



Coffin Bone. This forms the end of the foot and is shaped like the 

 horny box in which it is enclosed. 



Navicular Bone. This is short, flattened above and below, and is 

 attached to the coffin bone behind. 



All of these bones are covered on the surfaces with a cartilage which 

 goes to make up the joints, while the portions between are covered with 

 a fibrous membrane called the periosteum. 



Joints. The joints of the legs are of especial importance, since any 

 interference with their function very largely impairs the value of the 

 animal for most purposes. As the joints of the foot and ankle are at the 

 point of greatest concussion they are the ones most subject to injury and 

 disease. 



There are three of these joints — the fetlock, pastern, and coffin. 

 They are made by the union of two or more bones, held together 



