360 MUSCLES SITUATED ON THE SCAPULA. 



JV. J5. These two muscles are covered with a tendinous 

 membrane, from which a number of their fleshy fibres arise. 

 It serves besides to strengthen their actions, and keeps them 

 from swelling too much outwardly when in action. 



3. Teres Minor, 



Arises, fleshy, from all the* round edge of the inferior costa ol 

 the scapula, and runs forwards along the inferior edge of the 

 infra-spinatus muscle, and adheres to the ligament. 



Inserted, tendinous, into the back part of the large protube- 

 rance on the head of the os humeri, a little behind and below 

 the termination of the last named muscle. 



Use. To roll the humerus outwards, to draw the humerus 

 backwards ; and to prevent the ligament from being pinched 

 between the bones. 



Along the inferior costa of the scapula is, 



Teres Major, 



Arises, fleshy, from the inferior angle of the scapula, and from 

 all that portion of its inferior costa that is rough and thicker 

 than the rest ; its fleshy fibres are continued over part of the 

 infra-spinatus muscle, to which they firmly adhere. 



Inserted, by a broad, short, and thin tendon, into the ridge at 

 the inner side of the groove for lodging the tendon of the long 

 head of the biceps, along with the latissirnus dorsi. 



Use. To roll the humerus inwards, and to draw it backwards 

 and downwards. 



The two before the scapula are, 



1. Deltoides, 



Arises, fleshy, from all the posterior part of the clavicle 

 that the pectoralis major does not occupy ; tendinous and fleshy, 

 from the acromion, and lower margin of almost the whole 

 spine of the scapula opposite to the insertion of the cucullaris 

 muscle ; from the origins it runs in three different directions, 

 i. e. from the clavicle outwards and downwards ; from the 



