Chap. 14.] Scapular Mufdes. ijj 



by its connexion with the capfular ligament of the os 

 humeri, to draw it from berween the bones. 



The teres major arifes from the inferior angle and 

 inferior coda of the fcapula -, its flefhy fibres are con- 

 tinued over part of the infrafpinatus mufcle, to which 

 they firmly adhere. It is inferted, by a broad and thin 

 tendon, along with the latifiimus dorfi, into the ridge 

 at the inner fide of the groove for lodging the tendon 

 of the long head of the biceps. Its effecT: is to roll 

 die humerus inwards, and draw it backwards and 

 downwards. 



The deltoides arifes from the clavicle, proceflus 

 acromion, and the fpine of the fcapula ; from thefe 

 origins its fafciculi converge, forming a covering to the 

 anterior part of the joint of the os humeri. It is in- 

 ferted into a rough protuberance in the outer fide of the 

 os humeri. The chief effe6t of this mufcle is to raife 

 the arm ; but from the different direction of its fibres, 

 it may alfo move it backwards or forwards. 



The coraco-brachialis arifes from the fore part of 

 the coracoid procefs of the fcapula, is inferted into the 

 middle and inner fide of the os humeri, and moves the 

 arm upwards and forwards. 



The fubfcapularis arifes from the whole internal fur- 

 face of the fcapula ; after being attached to the cap- 

 fular ligament, it is inferted into the upper part of the 

 fmall internal protuberance at the head of the os humeri. 

 It rolls the os humeri inwards, draws it to the fide of 

 the body, and draws the capfular ligament from be- 

 tween the bones. 



The mufcles iituated on the os humeri, and which 

 move the fore-arm, are only four; two being placed 

 before for the flexion of the joint, and two behind for 

 its extenfion. Thofe placed before are, 



The biceps flexor cubid, which confifts of two heads, 

 which unite about the middle of the os humeri. Of 



thefe 



