358 NAVIX ON THE HOESE. 



The sJmttle, or navicular, lone has a body and two wings. It 

 is placed crosswise at the back of the coffin-joint, which it helps 

 to form. The perforating tendon passes over its body. The 

 lateral ligaments are attached to its extremities, or wings. 



The coffin-bone is the principal bone of the foot, being entirely 

 inside of it. It is a broad, semicircular, or rather half-moon- 

 shaped bone, being almost exactly the shape of the foot. It is 

 the lower bone forming the coffin-joint, the face of the bone 

 looking upward and backward being hollowed out to unite 

 with the lower end of the lower pastern-bone. It is not a solid 

 bone, but has many holes in it, through which blood-vessels 

 pass. The great, broad tendon, called the tendo-perforans, is 

 inserted into its back and under part. The sensible laminae 

 are attached to the convex or front part of the bone, and the 

 sensitive sole lines its under sides. 



BONES OF THE HIND EXTREMITIES. 



The number of bones belonging to each hind extremity, or 

 leg, is nineteen ; to both, consequently, thirty-eight. They are 

 named from above downward. The femur, or proper thigh- 

 bone ; the stifle-bone, or knee-cap, called the patella ; the leg- 

 bones, improperly called thigh-bones, named the tibia and 

 fibula; the hough-bones, six in number, called the os calcis, or 

 heel-bone ; the astragalus, or knuckle-bone ; the cuboid, or 

 square bone, and the three cuniform, or wedge-shaped bones ; 

 the cannon-bone, and two splint-bones ; the two sesamoid 

 bones; the pastern-bone; the coronet-bone, or lower pastern ; 

 the coffin, or foot-bone, and the shuttle-bone. 



H\iQ femur, or proper thigh-bone, is the heaviest bone of the 

 horse. It has a heavy body and two large heads, or extrem- 

 ities. Its upper head may be regarded as having two divi- 

 sions. One is a large round ball, resting in the cavity at the 

 lower part of the haunch-bone before described. A large, rough 

 process of the bone stands out behind this part. The great 

 muscles constituting the bulk of the rump are attached to this 



