THE MUSCLES OR FLESH. 309 



flesh surrounding this bone which composes the bulk of a leg 

 of mutlon. Its lower part forms with the tibia below the sti- 

 Jle joint, which is singular from having two cartilaginous bod- 

 ies within it ; and is protected in front by a small bone call- 

 ed the patella or knee-pan, which bone becomes a sort of 

 pulley, receiving the insertions of the very strong muscles 

 above, and is attached below to the tibia by strong ligaments. 



The tibia or leg bone runs backwards from the stifle, and 

 is not so long in proportion as in the horse ; it corresponds 

 to the radius in the fore extremity, and it forms the upper 

 part of the hock joint. 



This joint is composed of six bones arranged in rows so 

 as to form three articulations, but motion is confined to that 

 formed by the astragulus or knuckle bone and the tibia ; the 

 other bones serve as cushions to diminish concussion, with 

 the exception of the os calcis, situated at the back, which acts 

 as a lever receiving the insertions of the powerful muscles 

 which straighten the hock. This bone is much shorter than 

 it is in the horse, speed not being required. The bones be- 

 low the hock correspond with those found below the knee in 

 the fore extremity. 



THE MUSCLES OR FLESH. 



Although the shape of the body depends materially on that 

 of the skeleton, so that if the latter is anywise faulty the for- 

 mer wall not be perfect, yet there is a very great contrast be- 

 tween the appearance of the skeleton and that of the body 

 itself, of which it forms a part. Whilst the former is angu- 

 lar and extremely irregular, the latter is round and smooth, 

 so that though the good shape of the animal depends on the 

 skeleton, yet it requires the eye of the anatomist to detect, in 

 the conformation of the latter, the good points which in the 

 body itself are readily observed. 



The bulk of the body is formed of flesh or muscles ; their 

 principal use, when living, is to effect the movement of the 

 limbs ; when dead, to afford nutriment to man. The motion 

 of the body is occasioned by the contraction of the muscles, 

 which, being fastened to different bones, draw these bones 

 towards each other, and thus the limbs are bent whenever 

 particular muscles shorten or contract. These muscles, 

 which bend the limbs, are called the flexors, whilst an oppo- 

 site set which straighten them again, are denominated the 

 extensors ; the latter, however, are mostly smaller and weak- 



