THE MUSCLES. 



of the anterior half of the humerus as far as the extremity ; the 

 outer head arises from the outer surface of the humerus. Additional 

 fibres, which may be regarded as a fourth origin (in. subanconaeus}, 

 arise from the upper surface of the hinder half of the humerus. 

 The fibres from these several origins unite to form a strong muscle, 

 which covers the upper, inner, and outer surfaces of the bone, and 

 then passes into a tendon. This tendon is attached to the capsule 

 of the elbow- joint and inserted into the proximal extremity of the 

 radio-ulnar. A cartilage, representing the olecranon, is found in the 

 capsule at the point of attachment of the tendon. 



B. MUSCLES OF THE FOREARM. 

 (I.) Muscles of the flexor surface. 



The muscles of this surface are arranged in two groups, so as to 

 form, at the elbow-joint, a triangular depression (plica cuuiti), into 

 which the tendon of the m. tternoradiali* sinks. 

 A. Muscles of the Inner Group. 



Fig. 74. 



57. M. flexor carpi I ?. rail'tali* (Fig. 



Fc 



74 



Duges, sous-humero-carpien, n. 83. 



This represents either the flexor carpi 

 radial is longior or radialis brevior of man ; it 

 has a broad origin from the inner border of 

 the humerus above the epicondylus medialis. 

 It becomes narrower as it passes downwards 

 to be inserted by a tendon into the os 

 xemilunare and nariciilare. The muscle is 

 much stronger in males than in females, 

 and the crest from which it takes origin is 

 correspondingly larger in the former sex 

 (p. 42). Tendinous fibres connect it with 

 the following muscles : 



58. M. flexor carpi Us. ulnaris (Fig. 



74 Fc'}. 



Duges, epitrochlo-carpien, n. 84. 

 This muscle represents the flexor carpi 

 vlnaris or ulnaris anterior, and is close to 

 the inner side of the foregoing. It arises 

 from the epicondylus medialis, being con- 

 nected by fibres with the flexor digitorum 

 commit-nix, and is inserted into the on navieuldre. 



Muscles of the right arm of 



liana esculenta. 

 cd M. extens. digitorum com- 



munis. 



ei M. abductor digiti 1 1 longus. 

 Fa' M. flexor antibrachii later- 



alis superficialis. 

 Fc M. flexor carpi radial. 

 Fc' M. flexor carpi ulnar. 

 Fd M. flexor digitorum com- 



munis. 

 tr Tendon of the M. sterno- 



radialis. 



