MUSCLES OF THE ANTERIOR LIMBS. 261 



humerus : the biceps, coraco-brachialis, and the anterior brachialis ; behind are found 

 the triceps brachialis and the anconeus. 



The biceps, which corresponds to the coraco-radialis of animals, commences on the 

 capula by two heads, which unite towards the upper part of the humerus. The long 

 or lion is detached from the upper part of the rim of the glenoid cavity ; the shortest 

 commences from the summit of the coracoid process. The infer.or tendon of the biceps 

 gives oif, before fixing itself fcfa the bicipital tuberosity, a^bruus lamella which is con- 

 founded with the antibrachial aponeurosis. 



The coraco-brachialis has only one fleshy body. 



As in the Carnivora and Pig, the anterior brachialis terminates on the ulna, below 

 the coronoid process. 



The triceps brachialis exactly represents, by its three heads, the large, middle, and 

 short extensors of the fore-arm of animals (See Fig. 120.) 



There is nothing particular with regard to the anconeus. The long extensor of the 

 fore-arm of the Horse has no representative in Man. 



MUSCLES OF THE FORE-ARM. 



These muscles, nine in number, distributed in two regions anterior and 

 posterior envelop the bones of the fore-arm on every side except the 

 internal, where the radius is in mediate contact with the skin. They all 

 terminate on the different sections of the foot, which they flex or extend, 

 and are contained in a common fibrous sheath, which constitutes the anti- 

 brachial aponeurosis. 



Antibrachial Aponeurosis. 



This retaining fascia forms a very strong and resisting envelope, which 

 is firmly fixed around the antibrachial muscles by the insertions it has on 

 the bones of the fore-arm, being attached to the olecranon, the internal aspect 

 of the radius, and to the inferior extremity of that bone, both inwards and 

 outwards. 



Its external face is covered by superficial vessels and nerves, that are 

 separated from the skin by a very thin fibrous layer, which is more 

 particularly observable on the inner side, where it covers the antibrachial 

 aponeurosis in a very evident manner ; it is rendered tense by the sterno- 

 aponeuroticus. Up to the present time, this fibrous layer has not been 

 distinguished from the aponeurosis it covers. The inner face of the latter 

 gives rise to several septa, which penetrate the interstices of the muscles to 

 form around some of them special retentive sheaths ; it adheres to several 

 of them very intimately. At its upper border, this aponeurosis receives, 

 inwardly, the insertion of the long extensor of the fore-arm ; in front, the 

 accessory band of the coraco-radialis ; outwardly, it is continuous with the 

 fibrous fascia covering the external face of the olecranian muscles. Inferiorly, 

 it is prolonged around the knee to form the tendinous sheaths in that 

 region. 



The antibrachial aponeurosis is made tense by the contraction of the 

 long extensor of the fore-arm and the coraco-radialis. With reference to 

 the sterno-aponeuroticus, which has hitherto been regarded as intended to 

 play the same part, it can only act on the fibrous fas,cia which covers, 

 externally, the antibrachial aponeurosis. 



Preparation of the muscles of the fore-arm. The preparation of these muscles is 

 extremely simple, as it suffices to remove the antibrachial aponeurosis and the interstitial 

 cellulo-adipose tissue, to expose and to isolate them from each other. No special 

 recommendations need, therefore, be given, as a glance at figures 89, 119, 121, and 122 

 will guide the student in his dissection, and supplement the manual details which would 

 be superfluous here. 



Nevertheless, as the terminal insertioas of some of these muscles are inclosed within 

 the hoof, and as it is indispensable, in order to expose them, to remove this horny case, 

 some explanation will be given as to the manner in which this should be effected, 

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