20.-^ OUTLINES OF EQUINE ANATOMY. 



side of pectoralis anticus, forming a broad muscular layer 

 attached to the tendinous aponeurosis of subscapularis ; 

 in proceeding up the neck about the middle third this 

 muscle becomes intimately connected with the internal 

 surface of levator humeri, so that these muscles are not 

 easily separable; it subsequently passes between the jugular 

 vein and the carotid artery to its insertion into the hyoid 

 bone. 



The muscles connecting the fore limb to the various 

 neighbouring parts must now be divided (reference 

 should be made to the several regions under the heads of 

 which their attachments are described), and the external 

 scapular miiscles exposed, these are — 



Antea spinatus, running from the anterior dorsal fossa 

 of the scapula, by a rounded prominent border clothing 

 the major portion of the anterior costa of that bone and 

 becoming attached to a ligament, which runs from here to 

 the coracoid process, between which and the bone pass the 

 dorsal scapular vessels and nerves. Inf eriorly it bifurcates 

 and with pectoralis magnus becomes inserted into the ex- 

 ternal and internal tubercles on the anterior part of the 

 humerus ; the surface between the two heads is lined by a 

 tendinous theca or sheath, which is reflected on the middle 

 tubercle of the bone to facilitate the gliding of the carti- 

 laginous superior extremity of 



Flexor brachii or coraco-radialis, which having arisen 

 by a strong tendon from the coracoid process of the scapula, 

 after passing through this sheath, where its tendon is in- 

 dented to fit upon the middle tubercle, runs down the front 

 of the humerus inclined to the inner side, forming a pro- 

 minent muscular cord which sends a strong band of white 

 fibrous tissue downwards to extensor metacarpi magnus, 

 and becomes inserted into the roughened spot previously 

 noticed as situated at the supero-internal part of the an- 

 terior surface of the radius and into the capsular ligament 

 of the elbow-joint; at the antero-superior part of its tendon 

 we see some muscular fibres. 



Postea spinatus is to be found in the posterior fossa 

 of the dorsum of the scapula, which it occupies for 

 its superior two thirds ; separating below it forms two ten- 

 dons, one of which is attached to the fourth or external 

 tubercle of the head of the humerus, while the other plays 

 over this, from which it is separated by a synovial bursa, 



