146 



THE SKELETON 



occasionally another at the margin of the glenoid cavity. These epiphyses join by the twenty- 

 fifth vear. ^ 



The occurrence of a special primary centre for the coracoid process is of morphological im- 

 portance in that the process is the representative of what in the lower vertebrates is a distinct 

 coracoid hone. This primarily takes part in the formation of the glenoid cavity and extends 

 medially to articulate wnth the sternum. In man and all the higher mammals only the lateral 

 portion of the bone persists. 



THE HUMERUS 



The^humerus (figs. 174, 175, 176) is the longest and largest bone of the upper 

 limb, and extends from the shoulder above, where it articulates with the scapula. 



Fig. 174. — The Left Humerus. (Anterior view.) 



Subscapularis 



Latissimus dorsi 



Teres major" 



Supraspinatus 



Intertubercular groove 

 Pectoralis major 



Coraco-bracbialis ~ 



Brachialis- 



Pronator teres 



Fexor carpi radialis 



Palmaris longus 



Flexor digitorum sublimis 



Flexor carpi ulnaris 



-Deltoid 



Brachio-radialis 



Extensor carpi radialis longus 



Extensor carpi radialis brevis 

 Extensor digitorum communis 

 Extensor digiti quinti proprius 

 Extensor carpi ulnaris 

 Supinator 



to the elbow [cubitus] below, where it articulates with the two bones of the fore- 

 arm [anti-brachium]. It is divisible into a shaft and two extremities; the upper 

 extremity includes the head [caput], neck [coUum], and two tuberosities — great 

 and small; the lower extremity includes the articular surface with the surmounting 

 fossae in front and behind, and the two epicondyles. 



