266 



THE HORSE. 



CUT OF THE HOCK. 



concavity near the 

 base of another bone, 

 and with which it 

 is united by very 

 strong ligaments. 

 This bone c, is called 

 the OS calcis, or bone 

 of the heel, and it 

 projects upwards, 

 flattened at its 

 sides, and receives, 

 strongly implanted 

 into it, the tendons 

 of powerful muscles. 

 These bones rest on 

 two others, the os 

 cuboides, d, (cube- 

 formed) behind, and 

 the larger cuneiform 

 or wedge-shaped 

 bone e, in front. The 

 larger wedge-shaped 

 bone is supported by 

 two smaller ones 

 /, and these two 

 smaller ones and 

 the cube- bone by the 

 upper heads of the 

 shank-bone g, and 

 the splint-bones h. 

 The cube-bone is 

 placed on the exter- 

 nal splint-bone, and 

 the cannon bone ; the 

 small wedge-bone 

 principally on the 

 inner splint-bone, 

 not seen in the cut ; 

 and the middle 

 wedge bone rests on 

 the shank-bone only, g. These bones are all connected together by very 

 strong ligaments, which prevent dislocation, but allow a slight degree of 

 motion among them, and the surfaces which are opposed to each other are 

 thickly covered by elastic cartilage. 



Considering the situation and action of this joint, the weight and 

 stress thrown upon it must be exceedingly great, and it must be liable 

 to much injury in rapid and powerful motion. What are the provisions to 

 prevent injury? The grooved or pulley-like heads of the tibia, and the as- 

 tragalus, received deeply into one another, and confined by powerful liga- 

 ments, admit freely of hinge-like motion, but of no side motion, to which 

 the joint might be exposed in rapid action, or on an uneven surface. The 

 shghtest inspection of the cut will shew that the stress or weight thrown 

 by the tibia a on the astragalus 6, does not descend perpendicularly, but 

 in a slanting direction, by which a great deal of concussion is avoided, or 



