226 MARSHAL!.— A STUDY OF THE 



[June 19, 



joint, the more delicate portion of the split tendon being attached 

 to the radius on its inner surface, the other portion to the ulna at 

 the base of the m. flexor digitorum profundus and dorsal to the m. 

 brachialis inferior. 



4. M. brachialis inferior (Br. inf., PI. V, Fig. 24). This trap- 

 ezoid-shaped muscle arises fleshily from the distal end of the 

 humerus, and from its inner surface interior to the origin of the m. 

 extensor metacarpi ulnaris (radialis?). It crosses to the ulna and 

 is inserted on that bone beyond the elbow joint and between the 

 separated portions of the m. flexor digitorum profundus. 



5. M. triceps cubiti. This muscle consists of two parts, one long 

 head and two short ones. 



a. Pars scapuli-cubitalis (Pars. sc. cub., PI. V, Figs. 16, 17, 

 22 ; PI. Ill, Fig. 29). This one arises from the neck of the scap- 

 ula, posterior to the scapular projection which forms part of the 

 glenoid fossa. It passes obliquely across the humerus above the 

 insertion of the latissimus dorsi, continues down the dorsal pos- 

 terior side of the humerus and near its distal end comes off in a 

 strong flat tendon which is inserted on the rim of the dorsal prox- 

 imal process of the ulna. 



b. Pars humero-cubitalis (Pars. hu. cub., PI. V, Fig. 24; PI. 

 IV, Fig. 28) arises by two heads, the inner comes from within the 

 rim of the humeral head, while the stronger has its origin on the 

 outer aspect of the head of the humerus, and from about its proximal 

 quarter. This part ends in a tendon and a broad aponeurosis 

 inserted on the proximal edge of the olecranon process of the ulna, 

 and the intervening space between this process and the insertion of 

 the scapuli cubitalis. 



6. Mm. entepicondylo-antibrachiales. 

 a. Mm. entepicondylo-radiales. 



(1) Pronator sublimis (Pron. s., PI. V, Fig. 24). This is the 

 most superficial muscle of the inner arm. It springs tendinously 

 from above the internal condyle of the humerus, and interior to the 

 origin of the brachialis inferior. It passes obliquely across the 

 interosseus space to become inserted on the ventral side of the radius 

 for about one third its proximal length. 



(2) Pronator profundus. This muscle is smaller than the sub- 

 limis, and is covered for nearly its entire length by the superficial 

 muscles. It arises from the lower edge of the internal condyle of the 



