32 



ANATOMY OF VERTEBRATES. 



The f sterno -mastoid eus,' or sterno-maxillaris, arises from the 

 anterior end of the sternum, and, running forward strong and 

 fleshy, is inserted by a flat tendon into the inferior maxilla 



underneath the parotid 

 gland, sending, however, 

 another tendon to be im- 

 planted into the root of 

 the paroccipital. 



Muscles inserted into 

 the humerus. 



The ' pectoralis major/ 

 from the aponeurosis of 

 the external oblique, from 

 the two hinder thirds of 

 the sternum; and from 

 the fore part of the ster- 

 num. The first of these 

 portions winds round to 

 be inserted into the head 

 of the humerus ; the 

 second ends in a fascia, 

 which descends over the 

 fore-arm, while the third, 

 running in a transverse 

 direction over the inferior 

 portion, is inserted into 

 the humerus along with 

 the ( levator humeri pro- 

 prius ' between the biceps 

 and the brachialis inter- 

 nus : a part of the sternal 

 portion joins the corre- 

 sponding portion of the opposite side to form the ' muscle 

 common to both arms,' by the action of which the two fore-legs 

 are made to cross each other. 



The i latissimus dorsi ' is powerfully assisted in its action by 

 the cutaneous muscle already described, a strong tendon from 

 which is inserted into the humerus along with that of the latis- 

 simus dorsi. Both are intimately connected with the tendon of 

 the teres major, and from this combination of tendons arises one 

 of the heads of the triceps extensor cubiti. 



The ( supraspinatus,' the ( infraspinatus,' the * subscapularis,' 

 the f teres major,' and the ' teres minor,' with similar attachments, 



Myology of the Horse. ir\ 



