42 STRUCTUIIE AND ECONOMY OF THE HORSE. 



the femur, and below to the os calcis, or point of the hock. 

 The second is attached above to the femur, becomes tendinous 

 above the hock, passes over the point of the hock down the leg, 

 and is there called the perforatus, and is inserted into the small 

 pastern bone. 



The third, a very slender muscle, is attached above to the 

 fibula, and inferiorly to the os calcis. 



The deep-seated region is also composed of three muscles. The 

 first is short and thick, and is attached above to the outer and 

 back part of the femur and the capsular ligament, and taking an 

 oblique direction to the upper and inner part of the tibia. Thus 

 situated, it rotates in some measure the stifle joint. 



The next muscle, the flexor pedis, is attached above to the 

 outer and back part of the tibia and the fibula ; becomes tendinous 

 just above the hock, where it passes through a sheath, in a 

 groove on the inner side of the os calcis, and below the hock is 

 denominated the flexor perforans, having a similar destination to 

 the same tendon in the fore extremity. 



The third muscle rises from the outer and back part of the 

 tibia, becomes tendinous somewhat above the hock, on the inside 

 of which it passes through a sheath, and joins the former tendon 

 below. 



For a more particular account of the muscles, the student is 

 referred to Mr. Percivall's excellent work " On the Anatomy of 

 the Horse ; " and also to Mr. Blaine's " Outlines of the Veteri- 

 nary Art." 



The muscles are abundantly supplied with blood by the blood- 

 vessels, which renders their colour dark. The depth of their hue 

 is more or less in proportion as they are exercised, and thus in 

 the horse they are darker than in the ox or sheep. They are 

 also placed to greater mechanical advantage, the joints admitting 

 more extent of motion than in these weaker animals. Besides 

 which they are more abundantly supplied with nervous energy 

 by means of the nerves, to which, more than to any thing else, 

 is owing the untiring energy which a well-bred horse so often 

 displays. 



The muscles are susceptible of great alteration by means of 

 training, the object of which is to obtain the greatest possible 

 strength in the smallest possible compass. To effect this pur- 

 pose, a large supply of nutritious food is given, and the super- 

 fluous fat is removed by severe sweating. The muscles are thus 

 rendered hard and firm, and well developed, and the wind greatly 

 improved by exercise, until the animal reaches a degree of ex- 

 cellence, to attain and ascertain which, demands the utmost skill 

 and judgment in the trainer. 



The opposite effect to this takes place when a limb is thrown 

 out of work by lameness ; the muscles shrink in a short time to 



