12 VETERINARY STUDIES 



regular bones, placed side by side just back of the upper part 

 of the pastern bone. These articulate with the large metacarpal. 

 They are side by side and together form a groove for the flexor 

 tendons. 



The second phalanx, or coronet bone, is short and somewhat 

 square in form. It articulates with the first phalanx above, and 

 the third phalanx and navicular below. The upper and lower 

 extremities of this bone resemble the upper and lower extremi- 

 ties of the first phalanx. About half of this bone is below the 

 crown of the hoof. 



The third phalanx, or pedal bone, is pyramidal in shape and 

 irregular. Its superior face shows two shallow cavities separated 

 by a median ridge fitted for articulation with the second pha- 

 lanx. The anterior face is convex and quite rough. The in- 

 ferior surface is the one on which the foot rests. It is called 

 the sole. The superior border of the anterior face has quite a 

 projection which is especially fitted for the insertion of a ten- 

 don. This is technically known as the pyramidal process. The 

 lower portion of this bone is continued outward and backward 

 on each side into what is known as the wing. 



The navicular hone is located just back of the upper part of 

 the third phalanx. It is long and narrow, and placed trans- 

 versely. Its anterior surface articulates with the third phalanx. 

 Its posterior surface is covered with cartilage and forms a glid- 

 ing surface for the tendon of the deep flexor muscle which passes 

 over this bone to its attachment on the sole or inferior surface 

 of the third phalanx. 



Practical application. — Note how the length and slope of the 

 scapula affects the type of shoulder, gait and speed; how the 

 length and slope of the humerus affects the type of arm and the 

 gait. The cow and hog, for instance, have a comparatively 

 horizontal humerus. Note the effect of length of radius and 

 principal metacarpal on conformation of the limb and the rela- 

 tive length of these two segments. Note effect of the first and 

 second phalanges on the relative length and slope of the pastern, 

 giving a springy pastern or a short, upright, stilty one. Which 

 horse interferes, the one with the long pastern toeing out or the 

 pigeon toed horse? 



Disorders of the bones on the front limb are numerous. The 

 scapula, radius and ulna are all liable to fracture, usually as 

 the result of a kick. The carpal bones are subject to a disease 



