Io6 ANATOMY OF THE DOMESTIC FOWL 



portion from the tubercle found above the oblique trochlear facet 

 of the distal end of the radius. 



' Insertion. — Becoming a flat, broad, and strong tendon at about the 

 middle of the forearm, finally becomes inserted to the apex of the 

 anchylosed first metacarpal of the carpo-metacarpus. 



Shape. — ^A thick, fusiform belly, tendinous at both extremities. 

 . Relations. — By the side of the pronator brevis. 



Action. — Raises the hand, and draws it forward toward the radial 

 margin of the forearm and retains it on the same side. 



Extensor Digitorum Communis (Fig. 15, No. 2). Location. — The 

 upper metacarpal region. 



Origin. — Immediately below the tubercle of the external condyle 

 of the humerus. 



Insertion. — By a. small tendon to the outer side of the base of the 

 poHex, and at a mid-point upon the anterior rim of th€ proximal 

 phalanx of the middle finger. 



Shape. — Small spindle-shaped, becoming tendinous at about the 

 middle of the forearm. . 



Relations. — Occupies the middle of the group of muscles on the 

 outer side of the forearm. 



Action. — An extensor of the digit. 



Supinator Brevis (Fig. 14, No. 7). Location. — The superior part 

 of the radius. 



Origin. — From the external condyle of the humerus below the 

 origin of the tendon of the extensor digitorum communis. 



Insertion. — To the outer side of the shaft of the radius, for nearly 

 one-third of its length. 



Shape. — Thin, slender. 



Relations. — Interiorly, with the bone. 



Action. — ^A supinator of the radial region, and antagonistic to the 

 pronators. 



Flexor Metacarpi Radialis (Fig. 15, No. 10). Location. — The low- 

 est of the group of three muscles on the outer part of the forearm. 



Origin. — By two tendinous heads, the longer from the external 

 condyle of the humerus, and the other just beyond the base of the 

 olecranon. 



Insertion. — Becomes tendinous at about the middle of the shaft 

 of the ulna and inserts to a prominent process on the proximal 

 third of the posterior part of the shaft of the mid-metacarpal. 



Shape. — Fusiform. 



