282 



THE HIND LEGS, 



CUT OF THE MUSCLES OF THE OUTSIDE 

 OF THE THIGH. 



There is another and smaller glutoeus 

 muscle under that which has been last 

 described, arising likewise from the 

 back of the ilium, inserted into the same 

 protuberance of the thigh-bone, and 

 assisting in the same office. It is not 

 visible in the cut. 



These muscles, as Mr. Percivall well 

 explains it, are extensors either of the 

 femoris upon the pelvis, or the pelvj« 

 and loins upon the hind quarter. \Vhen 

 the limb has been carried in advance 

 under the body by the muscles of the 

 anterior femoral region, and the toe 

 firmljf set down upon the ground, the 

 glutei, by extending the haur.ch, will 

 carr}^ the trunk forward ; thus becom- 

 ing potent agents in progression, and 

 the niaxinms being the most powerful 

 of them. 



In the acts both of rearing and kick- 

 ing, these muscles are thrown into vio- 

 lent and forcible contraction. In the 

 former action, the limbs become the 

 fixed points, and the trunk the weight 

 moved, and vice versa in the latter.* 



There are also several other muscles 

 proceeding from different parts of the 

 haunch-bones, and inserted about the 

 heads of the upper thigh-bone, and per- 

 forming the same work; but there are 

 two muscles to which we must par- 

 ticularly refer. The first occupies the 

 outer part of the quarter behind, and is 

 beautifully developed in the blood- 

 horse ; it is found at e, above. It lises 

 high up from the bones of the spine, 

 from others at the root of the tail, from the protuberances of the ischium (vide cut, p. 

 68), and from other bones of the pelvis. It in fact consists of two muscles, but is 

 usually described as one muscle with two heads, biceps femoris, the two-headed mus- 

 cle of the thigh. It is situated on the postero-external side of the haunch and thigh, 

 where, being superficial, it is well marked in the living animal. The two divisions 

 of it have an opposite action. The anterior or superior one assists the vasti in extend- 

 ing the thigh — the posterior one flexes it. They both, however, co-operate in 

 abducting the limb, and also in rotating it forward, the hock, at the same time, turn- 

 ing outwards. 



Those muscles alone have been selected which are particularly prominent in tht 

 thorough-bred horse, and are the source of his strength and speed. Tlie following 

 cut, containing one excellence above and many defects below, will not be unaccepta 

 ble here : — 



The Os Femoris, or Thigh Bone (see P, page G8), is long and cylindrical, taking 

 an oldique direction from above, downwards, and from behind, forwards. At its 

 upper extremities, and projecting from the Ijody, is a thick flattened neck, terminat- 

 ing in a large smooth hemispherical head, adapted to a hollow, or acetabulum, in the 

 superior ]ioint of the havmcli. 



This bone is commonly called the Round Bone. It has, in some rare instances, 

 been dislocated and fractured. It is much oftener sprained, but not so frecpiently as 

 the groom or farrier imagi)ies. There is nothing peculiar in the lamenc^,^ to detect 

 injury of this part, except, that the horse will drag his leg after him. Injury sf the 



* Percivall's Anatomy, p. 14S. 



