464 THE FORE LEGS. 



yet not adhering; freely playing over each other, and a mucous fluid obviating at 1 

 friction. Both of them are inclosed in a sheath of dense cellular substance, attached 

 to them by numerous fib ils ; and they are likewise supported by various ligamentous 

 expansions. 



Near the fetlock the tendon still further expands, and forms a complete ring round 

 the tendon of the perforating muscle. This is seen at J, p. 113. The use of this 

 will be best explained when the fetlock is treated of. 



The perforated tendon soon afterwards divides, and is inserted into the smaller 

 and larger pastern bones, and serves to flex or bend the fetlock and joints, as it had 

 previously assisted in the flexion of the knee. 



The flexor perforans muscle has nearly the same origin as the perforatus ; but it 

 continues muscular farther down the arm than it, and lies before it. At the knee its 

 tendon passes, like the perforatus, under strong ligamentary arches, which confine it 

 in its situation. It then becomes round, and is partly enveloped in the perforatus, 

 and at the fetlock is entirely surrounded by it. It emerges from the perforatus when 

 that tendon divides, and continues its progress alone after the other has inserted itself 

 into the pasterns, and, passing over the navicular bone, is broadly implanted into the 

 posterior cavity of the foot. 



It is sufficiently plain that the arm should be large and muscular, otherwise it could 

 not discharge all these duties. Horsemen differ on a variety of other points, but here 

 they are agreed. A full and swelling fore-arm is the characteristic of every thorough- 

 bred horse. Whatever other good points the animal may possess, if the arm is nar- 

 row in front and near the shoulder, flat on the side, and altogether deficient in mus- 

 cular appearance, that horse is radically defective. He can neither raise his knee for 

 rapid action, nor throw his legs sufficiently forward. 



The arm should likewise be long. In proportion to the length of the muscle is 

 the degree of contraction of which it is capable; and in proportion also to the degree 

 of contraction will be the extent of motion in the limb beneath. A racer, with a 

 short arm, would be sadly deficient in stride ; a hunter, with the same defect, would 

 not be able to double his legs well under him in the leap. There is, however, a 

 medium in this, and the advantage of length in the arm will depend on the use to 

 which the horse is applied. The lady's horse, the cavalry horse, every horse in 

 which prancing action is esteemed a beauty, and in which utility is, to a certain 

 degree, sacrificed to appearance, must not be too long in the arm. If he is long 

 there, he will be proportionably short in the leg; and although this is an undoubted 

 excellence, whether speed or continuance is regarded, the short leg will not give the 

 grand and imposing action which fashion may require. In addition to this, a horse 

 with short legs may not have quite so easy action as another whose length is in the 

 shank rather than in the arm. 



THE KNEE. 



The Knee (M, p. 68, and cut, p. 256), answering to the human wrist, constitutes 

 the joint or joints between the arm and the shank or leg; and is far more complicated 

 t'.ian any joint that has been yet considered. Beside the lower heads of the bone of 

 the arm, and the upper heads of the three bones of the leg, there are no less than 

 six other bones interposed, arranged in two rows, three in each row, and the seventh 

 placed behind. 



What was the intention of this complicated structure 1 ? A joint between the elbow 

 and the fetlock was absolutely necessary to the action of the horse. An inflexible 

 pillar of that length could scarcely have been lifted from the ground, much less fai 

 enough for rapid or safe motion. It was likewise necessary, that the interposing 

 joint should be so constituted as to preserve this part of the limb in a straight direc- 

 tion, and possess sufficient strength to resist all common work and accidents. Being 

 in a straight direction, the shock or jar between the ends of the bones of the arm and 

 the leg would be dreadful, and would speedily inflict irreparable injury. The heads 

 of all bones are covered with elastic cartilage, in order to protect them from injury by 

 concussion ; but this would be altogether insufficient here. Six distinct bones are 

 therefore placed here, each covered above and below by a thick coating of cartilage, 

 connected together by strong ligaments, but separated by interposed fluids and mem- 

 oranes. The concussion is thus spread over the whole of them shared by th* 

 *hole of thrai ; and, by the peculiarity of their connexion, rendered harmless. 



