THE MUSCLES OF THE UPPER EXTREMITY. 129 



flexor metacarpi radialis tapers to a point, then merges 

 into a strong, cord-like tendon, which passing through 

 the fibrous sheath to the outer side of the distal end of 

 the ulna, in common with the tendons of other muscles 

 previously alluded to, it goes directly to the prominent 

 process which juts from the proximal third of the 

 posterior aspect of the shaft of mid-metacarpal, where it 

 is firmly attached. This muscle, when brought fully 

 into action, is a powerful flexor of the hand upon the 

 antibrachium. 



In the Ostrich this muscle arises from the lower third 

 of the ulna, while in the Penguin it is entirely absent 

 (Owen). 



In Fig. 36 I have drawn the line occupied by the 

 tendons of this muscle, as well as the line of its axis, 

 which is supposed to be in the same straight line with 

 its tendon of insertion. 



77. The pronator brevis 1 is the uppermost of the 



1 Of the pronator group of muscles in birds, Gadow records the 

 following synonymy (loc. cit., pp. 266, 267) : 



" 82. M>I. ENTEPICONDYLO-ANTIBRACHIALES. 



" A. ENTEPICONDYLOKADIALES. 

 " /. Pronator sublirnis s. brevis. 



Le muscle qui tient lieu du pronateur rond. Vicq d'Azyr. 



Kurzer Speichenbeuger. Wiedemanu, p. 89. 



Pronator primus s. brevis. Tiedemaun, 260. 



Beuger des Vorderarrns. Meckel, p. 326. 



Pronator brevis. Schopss, p. 137, No. 25 ; d'Alton, p. 26 ; Riidinger, 



p. 113 ; Selenka, p. 127, No. 54 ; Carlsson, p. 22. 

 Kurzer Niederzieher des Vorderarms. Prechtl, 49. 

 Pronator sublimis. De Man, p. 112. 

 Pronator teres. Gervais et Alix ; Watson, p. 102. 



" //. Pronator profundus s. longus. 

 Le radial externe. Vicq d'Azyr. 

 Langer Speichenbeuger. Wiedernann, p. 89. 



K 



