88 THE ANATOMY OF THE HORSE. 



The OS calcis is placed nearly behind the joint ; into 

 the point of which bone the tendon of the gastrocnemius 

 internus muscle is inserted : the longer therefore this pro- 

 cess is, the longer is the lever this muscle has to act upon ; 

 and a very slight increase or diminution in the length of 

 this bone must enlarge or lessen the power by which the 

 motion of the joint is effected. It is by tendons that the 

 lower part of the limb is moved ; having been bent by the 

 muscles misnamed extensors, by such means the angle be- 

 tween the cannon and the tibia is enabled again to open. 

 The calcis is placed so as to rise from the joint, rather 

 externally ; and this formation leaves a space on the inner 

 side for the flexor tendons of the foot to pass protected from 

 pressure ; the calcis anteriorly articulates with the depres- 

 sions of the astragalus. 



The remaining bones are more wedge-like ; and principally 

 serve to increase the surface of attachment. The large 

 cuneiform, or great wedge-like bone, is placed under the 

 astragalus, and articulates withtt: posteriorly its internal, 

 as well as part of its inferior surface, articulates with the 

 cuboid : it has likewise, posteriorly and inferiorly, a small 

 surface of attachment with the little cuneiform. Imme- 

 diately behind this, on the outer side, appears the cuboid, 

 resting inferiorly on the external small splent, or metatarsal 

 bone {Skel. L), and part of the cannon {Skel. K) : it has 

 likewise a surface of attachment with the great cuneiform. 

 The lesser, or inner cuneiform, is situated more posteriorly 

 on the inner side ; its principal portions articulate with the 

 great cuneiform superiorly ; and with the cannon as well as 

 the internal small splent, or metatarsal bone, inferiorly. 

 The cuneiform medium is seen in front of the hock, articu- 

 lating by its superior cartilaginous surface with the great 

 cuneiform, and inferiorly with the head of the cannon, or 

 great metatarsal. 



The bones of the hock are not so nicely placed for 

 description as those of the knee ; the entire joint appears 

 more irregularly bound together. A student would con- 

 clude it possessed but little motion. Such, however, is not 

 the fact ; in truth, it is endowed with more movement than 

 the more symmetrical knee. The motion between the astra- 

 galus and tibia is alone equal if not superior to that of the 



