230 MARSHALL— A STUDY OF THE 



[June 19, 



ulna and about the middle third of the radius. At its proximal 

 extremity it is crossed by a ligamentous band passing from ulna to 

 radius. It is also held close to the radius by fascia. The tendon 

 accompanies the m. extensor metacarpi ulnaris (radialis?) to the 

 apex of the os magnum and is there attached below that muscle. 



18. M. extensor indicis longus (E. ind. /. , PI. V, Figs. 22, 24). 

 This muscle arises by a very short tendon from the internal condyle 

 of the humerus. It passes directly to the ventral surface of the 

 radius, and is attached fleshily to the ulna facing surface of that 

 bone for fully five sixths of its length. The tendon bends under 

 the radius and becomes dorsal. It crosses the tendon of the m. 

 extensor digiterum communis, and finds attachment on the base 

 of the second phalanx of the third digit. It fails to agree with 

 Gadow's diagnosis. 



19. M. interosseus dorsalis {Int. d., PI. V, Fig. 21). Both 

 interossei spring from the facing surfaces of the third and fourth 

 metacarpals. In this description the name dorsalis is given to that 

 muscle which clings to the third metacarpal. At the distal end of 

 the interosseous space the muscle becomes tendinous and bends 

 posteriorly, passing along the dorsal surface of the phalanx of the 

 fourth metacarpal, then to the ventral distal end of the second 

 phalanx of third digit to become inserted about four fifths the 

 length of that bone from the proximal end. 



20. M. interosseus palmaris {Int. p., PI. V, Fig. 21). This 

 muscle comes from the anterior surface of the fourth metacarpal, 

 and terminates tendinously about one half the length of that bone. 

 The tendon turns dorsally, and is attached to the distal end of the 

 first phalanx of the third digit on its dorsal surface. 



21. M. abductor indicts {Ab. in., PI. V, Fig. 20). This muscle 

 springs fleshily from the ventral surface of the proximal two thirds 

 of the third metacarpal, its proximal end being at the base of the 

 ventral projection of that metacarpal. The round, strong tendon 

 is inserted on the proximal anterior rim of the second phalanx of 

 digit three. 



22. M. flexor pollicis (Ft. pi, PI. V, Fig. 20). This short 

 muscle comes from the proximal ventral surface of the third meta- 

 carpal, lying between the abductor pollicis and the ventral pro- 

 jection of this metacarpal. It terminates on the posterior proximal 

 projection of the pollex digit. 



