18 HORSESHOEING. 



3. The radius (12) and the ulna (13), to form the elbow-joint. 

 These two bones are the basis of the forearm. The uhia, 

 smaller and weaker than the radius, lies behind and projects 

 above it to form the point of the elbow. The lower end of the 

 radius articulates with — 



4. The carpus, or knee (14), which comprises seven small, 

 cubical bones disposed in two horizontal rows, one above the 

 other. The upper row comprises four bones and the lower row 

 three. The lower row rests upon — 



5. The large metacarpal or cannon hone, and the two rudimen- 

 tary metacarpal or splint-bones. The lower end of the radius, the 

 upper ends of the metacarpal bones, and the small carpal bones 

 together form the carpal or knee-joint (wrist of man). Of the meta- 

 carpals, the middle one is the largest, longest, strongest, and most 

 important, and is called the large metacarpal, cannon, or shin- 

 bone (15). It articulates at its lower end with the os suffraginis, 

 or long pastern (17), and with the two small sesamoid bones (20). 

 On each side of the upper part of its posterior surface lie the 

 two long, slender splint-bones (16). The inner splint-bone is 

 sometimes affected with bony thickenings (exostoses) called 

 " sphnts." 



6. The bones of the phalanges (all bones below the cannon) 

 will be fully described in another place. 



The bones of the hind limbs articulate directly with the pelvis 

 at the hip-joint. They are stronger than the bones of the ante- 

 rior limbs. We distinguish the following bones in the hind legs : 



1. The highest bone in the hind limb is the femur (21). It is 

 the strongest bone in the entire body. It lies in an oblique 

 direction downward and forward, and at its lower end articulates 

 with — 



2. The patella (22), the tibia (23), and the fhula (24), to form 

 the stifle-joint (knee of man). The patella plays over the ante- 

 rior surface of the lower end of the femur. The fibula is small, 

 and lies against the upper and outer side of the tibia. The latter 

 at its lower end articulates with — 



