The Muscles 107 



surface of the humerus, just distal to the lateral 

 process; while its superficial layer, especially the 

 upper fibers, come directly from the deltoides 

 scapularis inferior and therefore have their origin 

 on the scapula. In the middle of the upper arm 

 it becomes a slender round tendon that extends, 

 through a tendinous loop, to the radius, on whose 

 outer side, at the end of the proximal third, it is 

 inserted. 



MUSCLES OF THE FOREARM 



Humero-radialis Internus (Radialis internus, 

 Lange Vorwartswender, Pronateur, Pronator teres, 

 Pronator quadratus, Oberflachlich gelegener, lan- 

 ger runder Einwartsdreher) . This muscle arises 

 from the condylus internus (C. ulnaris s. medialis) 

 and attaches itself to the radius throughout almost 

 its entire length. It is a fairly strong muscle. 



Ulno-radialis (Carre pronateur, Pronator teres, 

 Pronator quadratus, Muskel welcher dem Prona- 

 tor quadratus entsprect). A strongly developed 

 muscle. It springs from the upper part of the 

 flexor surface of the ulna and is inserted on the 

 lower part of the flexor surface of the radius. 



Humero-radialis Longus (Plate II., Figs, i and 

 2, /) (Supinator longus, Long supinateur, Lange 

 Ruckwartswender, Supinator radii longus) . Among 

 the Crocodilia this and the following muscle are 

 well developed. This one springs from the con- 



