24 THE NECTURUS 



muscle that extends from the inner face of the supra- 

 scapula, anteriorly to the skull. Follow this muscle to its 

 origin. 



MUSCLES OF THE FORE LIMB 



Triceps 



This is a variable muscle that might better be named the 

 quadriceps, since it generally has four heads. It covers 

 the entire dorsal face of the humerus and has heads on 

 the humerus, scapula and coracoid. The first of these is 

 double thus making four heads for the entire muscle, 

 which is inserted on the olecranon process of the ulna. 

 Loosen the muscle at its insertion and separate the heads. 

 A superficial median, head takes origin from the base of 

 the scapula. Beneath this, a second slip takes origin from 

 the anterior face of the head of the humerus. Laterally, 

 one head originates on the outer side of the humerus, 

 while an inner slip originates on the posterior border of 

 the coracoid. 



Biceps 

 Ventral to the triceps and on the opposite side of the 

 humerus, the biceps occupies practically the same position 

 as the muscle of the same name does in the mammals. It 

 originates on the proximal end of the humerus and is 

 inserted on the outer face of the proximal end of the 

 radius. A few fibers may come from the coracoid. The 

 insertion is seen better after the removal of the muscles of 

 the lower arm. 



CORACO-BRACHIALIS 



This muscle is on the anterior or ventral face of the 

 humerus, paralleling the biceps but on the inner side of the 

 arm. It originates on the coracoid and is inserted on the 

 inner, distal part of the shaft of the humerus. 



