100 OF THE MUSCLES. 



by tendon common to the three heads. Action of the three 

 heads. These muscles are much used in draught, in pushing 

 the body against the collar ; or in forcing the fore leg under 

 the body. Between the point of the olecranon and the 

 tendon common to the three heads there is a bursa mucosa. 



HuMERALis {Fig \ . 8 ; Jig 2 . 2; Jig S . 2). Origin. 

 From the inner and upper side to the radius ; whence it takes 

 a spiral course, to be inserted into the posterior part of the 

 head of the humerus. Action. To pull down the humerus ; 

 to raise the radius ; and to co-operate with the flexor brachii. 



Anconeus {Fig 3.3), Origin. From the inner side of 

 the ulna. Insertion. To the sulcus behind the inferior head 

 of the humerus ; and to the capsular ligament. Action. To 

 co-operate with the triceps extensor brachii ; and to guard 

 the capsular ligament. 



CoRACO HUMERALIS {Fig \ . 10 ; ^'^ 2 . 1). Origin. By 

 tw^o heads from the body of the humerus ; and by the tendon 

 common to the teres internus and latissimi dorsi. Insertion. 

 Into a small bulb, upon the inner side of the coracoid pro- 

 cess of the scapula. Action. To pull the scapula erect ; 

 or to extend the humerus. 



ScAPULO HUMERALIS MAJOR {Fig 3 . 1). Origin. From 

 the upper part of the body of the humerus. Inserted. Into 

 the neck and posterior margin of the scapula. Action. To 

 flex the humerus or scapula. 



ScAPULO HUMERALIS MINOR. Origin. From the neck of the 

 scapula, by tendon. Inserted. Into the head of the humerus 

 upon the outer side ; and to the capsular ligament. Action. 

 To aid the major ; and to guard the capsular ligament. 



Minimus {Fig 2 . 5). The smallest muscle in the body of 

 the horse. Origin. From the posterior of the neck of the 

 scapula, hisertion. Through the substance of the humeralis, 

 into the posterior of the humerus, near the neck of the bone. 

 Action. To protect the posterior of the capsular ligament. 



Flexor brachii {Plate III. 5. Fig \ . 11; Jig 2 . 3). 

 Origin. From the coracoid process of the scapula, by strong 

 tendon. Insertion. By flattened tendon, to the inner side of 

 the upper head of the radius, underneath the lateral ligament. 



This muscle forms a cartilaginous joint with the trochlea 

 of the humerus ; and has a synovial membrane to facihtate 

 its movements. Near to the insertion of the flexor brachii 



