66 ANTHROPOLOGY. 
and fingers: these are the flexors. A second, nearly allied. to these, has 
the power of rolling the radius across the ulna, so as to turn the palm down- 
wards: these are the pronators. The extensors can extend the forearm, 
hand, and fingers; and a fourth set, the swpinators, can turn the palm of 
the hand upwards. The pronators and flexors arise chiefly from the internal 
condyle, and from the inner or ulnar side of the forearm. 
The pronators and flexors arising from the inner side of the forearm are 
eight in number, arranged in a superficial and a deep layer. The superficial 
are the pronator teres, flexor carpi radialis, palmaris longus, flexor digi- 
torum sublimis, and flexor carpi ulnaris. The deep are the flexor digitorum 
profundus, flexor pollicis longus, and the pronator quadratus. 
Pronator radii teres arises from the anterior part of the internal condyle 
and from the coronoid process of the ulna; it is inserted into the outer and 
back part of the radius about its centre. Use: to pronate the hand and 
bend the forearm. 
Flexor carpt radials arises from the inner condyle and from the inter- 
muscular septa, and is inserted into the base of the metacarpal bone of the 
index finger. 
Palmaris longus arises from the inner condyle, and is inserted into the 
annular ligament and the palmar aponeurosis. It bends the hand and 
stretches the palmar fascia. 
Flexor carpi ulnaris arises from the internal condyle, and is inserted into. 
the pisiform bone. | 
Flexor digitorum sublimis perforans arises from the internal condyle and 
internal lateral ligament, from the coronoid process, and from the portion 
of the radius below its tubercles and internal to the pronator teres. It ends 
in four tendons, two anterior for the middle and ring finger, and two 
posterior for the index and little finger; at the first phalanx of each finger, 
each tendon becomes inclosed in a strong sheath with one of the deep 
flexors. Near the end of the first phalanx, each superficial flexor tendon is 
split for the passage of the tendon of the deep flexor. Use: to flex the 
second joint of each finger on the hand, the hand on the forearm, and the 
forearm on the arm. 
Flexor digitorum profundus perforans arises from the superior three — 
fourths of the anterior surface of the ulna, and ends in four tendons, which 
pass beneath the annular ligament, and are inserted into the phalanges, as 
referred to when speaking of the last muscle. Use: to bend the last 
phalanx, and to co-operate with the superficial flexor in bending the other 
phalanges and the wrist. 
Flexor pollicis longus arises from the fore part of the radius below its 
tubercle and from the interosseous membrane, to within two inches of the 
carpus. It is inserted into the middle of the last phalanx of the thumb, 
which it serves to flex. 
Pronator quadratus is a small square muscle situated above the carpus, 
and arising from the inferior fifth of the internal and anterior surface of the 
ulna. It is inserted into the anterior part of the inferior fourth of the radius, 
and serves to roll the radius over the ulna. 
7172 
