485 
ANATOMY OF THE HORSE. 
Attachment . —Superiorly, to the coracoid process of the sca¬ 
pula ; inferiorly, to the inner parts of the head and neck of the 
radius, to the capsular ligament of the elbow joint, and to the 
brachial faschia. 
Relations. —Anteriorly, with the faschia and skin*; posteriorly, 
with the elbow joint and the humerus; externally, with the pec- 
toralis transversus; internally, with the coraco-humeralis. Its 
tendon, superiorly, issues from the space between the terminating 
portions of the antea-spinatus ; and the superficial brachial vein 
ascends to the outer side of it. 
Structure. —The muscle is fixed to the scapula by a broad, 
short, thick tendon, which runs within the groove between the 
tubercles of the humerus; its posterior surface (which much re¬ 
sembles cartilage in its texture) being hollowed and adapted to a 
cartilaginous eminence in the middle of that groove. At this 
part the tendon pierces the capsular ligament of the shoulder 
joint, from the internal cavity of which it is separated only by a 
reflection of synovial membrane. The anterior surface of the 
tendon exhibits a few pale fleshy fibres running upon it. The 
fleshy belly of the muscle is invested by an aponeurotic sheath, 
and appears as if it were made up of several very small cylindrical 
muscles, similarly invested, and afterwards joined together into 
one body. Its inferior attachments are wholly tendinous in one 
place, aponeurotic in another. 
Action. —To bend the arm, by carrying it forwards and upwards. 
humeralis EXTERNUS.—( Ilumero-radialis obliquus.) 
Situation .— Deep-seated upon the infero-external side of the 
shoulder. 
Form .— Oblong; twisted. 
Attachment .—Superiorly, to the entire postero-external parts 
of the neck and body of the humerus : inferiorly, to the supero- 
anterior part of the body of the radius, immediately below the 
attachment of the flexor brachii. 
Relations .— Externally, with the middle head of the triceps ; 
internally and posteriorly, with the humerus; anteriorly, with the 
flexor brachii. 
Direction .— Curvilinear and oblique. 
Structure .— Fleshy; excepting a single tendinous intersection 
through its inferior part, which proceeds to its termination. 
Action .—To assist in the flexion of the arm. 
[To be continued.] 
