THE MUSCULAR SYSTEM. 37 



the shoulder) by the bones of the pelvis. The socket Is still 

 further deepened by ligamentous substance attached to its rim. 

 The capsular ligament is thin, protection being afforded by the 

 muscles ; but within the capsular there are (unlike other joints) 

 two ligaments, one of which is called the ligamentum teres, and 

 is of great strength. It passes fi'om a notch in the ball to a 

 similar notch in the socket, whilst another portion of it is at- 

 tached to the pubes. This ligament greatly assists in main- 

 taining the weight of the limb during progression. 



The Stijie joint, which corresponds anatomically to the human 

 knee, is formed, like it, by the apposition of the femur, the 

 tibia, and the patella. Within the joint we find two moveable 

 cartilages, which ai'e confined to the tibia by several ligaments, 

 but which enable them to slide about, and thus increase the 

 motion of the joint without rendering it insecui'e. The patella 

 is a small bone situated in front of the joint, which it protects, 

 being bound by strong ligaments to the tibia, and receiving the 

 attachments of tlie tendons of the strong extensor muscles of the 

 leg, thus acting as a pulley. 



Besides those mentioned, there is a strong lateral ligament on 

 each side of the joint, attached to the femur and the tibia; and 

 Avithin the cavity of the joint, ligamentous slips, crossing each 

 other, are attached to the middle of these two bones. 



The Hock joint, like the stifle, is well furnished with liga- 

 ments ; and it has no less than six separate articulations, the 

 princi2)al of which, however, is that between the tibia and astra- 

 galus, to which bones the whole motion of the joint is confined. 

 There are two strong ligaments on each side, both of which pro- 

 ceed fi'om the tibia, and pass, one to the astragalus, and the 

 other to the os calcis, and expand on the other bones. There 

 are other ligaments attaching the astragalus to the metatai'sal 

 bones. The os calcis is bound by ligaments to the astragalus, 

 the tibia, and metacarpal bones ; and each articulation possesses 

 separately its capsular ligament. 



The joints below the hock in the hind leg correspond with 

 those in the fore extremity. Having much less weight to sus- 

 tain, they are less exposed to concussion, and more rarely 

 become diseased. — Ed. 



CHAP. VIII. 



ON THE MUSCULAR SYSTEM. 



It Is computed that there are no less than 312 separate muscles 

 in the body of the horse, of which only ten are single, the 



D 3 



