THE MUSCLES. 329 



Pronator teres. This is a nearly constant muscle, being 

 present even in Menopoma and Menobranchus (Fig. 297). Its 

 size and importance are often relatively greater than in man. 

 It may, on the contrary, be quite absent, as in the Hedgehog 

 and the Horse. 



FIG. 296. MUSCLES OF INSIDE OF RIGHT ARM OF IGUANA. 

 B, biceps ; C, sternal margin of coracoid bone ; CB x and CB 2 , two parts of 

 coraco-brachialis ; CC, cpsto-coracoid ; FR, flexor carpi radialis ; FL7, flexor 

 carpi ulnaris ; Z.Z?, latissimus dorsi ; 6 2 , subscapularis ; T 1 , T 2 , and T 4 , parts 

 of triceps ; /, tendon from latissimus dorsi to triceps. 



Flexor carpi radialis. This is normal in man, but its 

 insertion may vary in other animals. It may arise from the 

 ulna only (and not from the humerus), as in Birds. 





FIG. 297. DEEPER FLEXOR MUSCLES OF RIGHT FORE-ARM OF Mfnopoma, the 



flexor longus being cut and reflected. 



B, biceps; FB, flexor brevis; FL, flexor longus; SL, supinator longus; PT, 

 pronator teres. 



The palmaris longus is often absent (as e.g. in the Hedge- 

 hog, in Ruminants, the Horse, &c.), or blends with the flexor 

 digitorum, as in the Echidna, or with the flexor radialis. Its 



