170 THE ARTISTIC ANATOMY OF ANIMALS 



tionately long) ; and even in them only to the slightest 

 extent. It is covered partly in these latter, and completely 

 in other animals, by the great pectoral and the inferior 

 portion of the mastoido-humeral — that is to say, that part 

 of the latter which represents the whole of the clavicular 

 fibres of the human deltoid. 



The biceps is a flexor of the forearm on the arm. It also 

 contributes to the movement of extension of the humerus. 



Brachialis Anticus (Fig. 68, 22 ; Fig. 69, 19 ; Fig. 70, 

 27 ; Fig. 72, 12). — In veterinary anatomy further desig- 

 nated as the short flexor of the forearm, this muscle, which is 

 thick, occupies the musculo-spiral groove, and arises from 

 it, reaching upwards to just below the head of the humerus. 

 But it does not, as in man, extend to the internal surface of 

 the bone. 



Situated on the outside of the biceps, it is directed towards 

 the forearm, and terminates by a flattened tendon, which, 

 dividing into two slips, passes below the bicipital tuber- 

 osity, on the internal surface of the radius, into which one of 

 these slips is inserted, while the other proceeds to terminate 

 on the ulna. 



The inferior half of this muscle is visible on the superficial 

 layer, in the space limited posteriorly by the triceps brachi- 

 alis, and below by the muscles of the forearm, which corre- 

 spond to the external muscles of the human forearm, and in 

 front by the great pectoral and the mastoido-humeral. It 

 is in the upper part of the interspace which separates these 

 latter from the brachialis anticus that the deltoid insinuates 

 itself to proceed to its insertion into the humerus. 



These relations precisely recall those which we meet with 

 when we examine the external surface of the human arm, 

 with this difference, however — that in the latter the anterior 

 brachialis anticus is extensively related, in front, to the biceps. 

 However, in animals it is not absolutely the same, since, 

 as we have shown above, the biceps is covered, more or 

 less completely, by the mastoido-humeral and the great 

 pectoral. 



The brachialis anticus flexes the forearm on the arm. 



Coraco-brachialis. — In man this muscle, which occu- 



