BOXES OF THE KXEE. 355 



the groove of the upper arm-bone, and the two cavities receive 

 the two divisions of its head. The lower head of the radius 

 is broad, and marked by two slight ridges running from before 

 backward into three surfaces, which rest on the upper row of 

 knee-bones. 



Tlie smaller arm-hone^ or nlna, is situated at the back of the 

 radius, and has a long head, projecting far above the upper 

 head of the radius, forming the elbow. It extends only a lit- 

 tle over half-way down the radius, and terminates in a point. 

 The two bones are united by cartilage in younger horses, but 

 they become one solid bone in old age. 



The arm is the most important part of the horse. It is to 

 it, and particularly the elbow, that the great muscles are at- 

 tached, which act to gather up the fore extremity and extend 

 it when the horse is in motion. That the horse may have 

 length of stride and gather quick, it is necessary that the arm 

 should be long, and that the elbow particularly should be long. 

 It is almost impossible for the elbow to be too long, but very 

 common for a horse, othervrise well-formed, to have very poor 

 action solely on account of it being too short to enable him to 

 gather well. 



In addition to length in the arm and elbow, full, swelling 

 muscles are necessary to furnish the requisite power to raise 

 the knee, throw the limb forward, and gather up with proper 

 quickness. A narrow, flat, and short arm is a defect for which 

 no other quality can make up. 



The elbow is liable to be fractured, and it is a serious mis- 

 fortune, but not entirely without remedy. The elbow-joint is 

 sometimes punctured, causing rapid and high inflammation 

 in it. 



BONES OF THE KNEE. 



The knee is composed of eight bones, arranged in two rows 

 from side to side, and one bone behind the others. The upper 

 row consists of three bones, on wliich the lower head of the 



