418 MR. A. SANDERS ON THE [June 9, 
of the humerus and from the whole length of the ulna, and is inserted 
into the pisiform bone. 
Flexor sublimis digitorum arises from the strong tendinous arch, 
one end of which is attached to the pisiform bone and the other 
to the scaphoid, and from the palmar fascia ; it immediately divides 
into five muscular slips, each of which is attached to a tendon of the 
flexor profundus and to the head of the metacarpal bone of its re- 
spective digit ; although this is not perforated by the long tendon, it 
represents the perforatus, as it will be seen, when we come to the foot, 
that the corresponding muscle there allows the long tendon to pass 
between its two heads. 
Flexor profundus digitorum arises from the middle portion of the 
inner condyle of the humerus and from the lower two-thirds of the 
ulna; passing beneath the annular ligament, it becomes developed 
into a broad expansion, which, in the palm, divides into four long 
tendons, going to the terminal phalanx of the pollex, second, third, 
aud fourth digits. The fifth digit has a long tendon to itself, which 
is given off high up in the forearm. 
Pronator quadratus arises from the whole length of the ulna, and 
is inserted into the distal half of the radius, occupying the place of 
the interosseous membrane. 
Flexor accessorius digitorum.—There are four muscular slips 
which may be thus called; two of them arise from the tendinous 
expansion of the long flexor, and, forming very fine tendons, are 
inserted into the last phalanx but two of the third and fourth digits 
respectively. Two other slips arise from the bone of the carpus 
which appears to represent the cuneiform, and from others, in the 
first row ; one of these joining the long tendon, developes, in addition, 
a tendon of its own, which is inserted into the penultimate phalanx of 
the second digit ; it has also a muscular insertion into the base of the 
first phalanx of the same digit ; the other slip is simply attached to 
the long tendon going to the pollex, without having one of its own. 
Lumbricales.—There are five muscles which correspond to the 
lumbricales—viz. one on each side of the fourth, one on each side 
of the third, and one on the ulnar side of the second digit. 
Abductor quinti digiti arises from the pisiform bone, and is in- 
serted into the whole length of the ulnar edge of the metacarpal 
bone of the fifth digit. 
Abductor pollicis arises from scaphoid, and is inserted into the 
whole length of metacarpal bone of pollex. 
Beneath these there are five palmar interossei, which radiate from 
the first row of bones of carpus, and are inserted into the heads of 
the metacarpal bones of their respective digits, one for each. 
Supinator longus arises from the lower third of the outer edge of 
the humerus, above the condyle, and is inserted into the distal two- 
thirds of the radius. 
Supinator brevis arises from the outer condyle distad of the last, 
and is inserted into nearly the whole length of the radius. 
Extensor carpi radialis arises from the outer condyle of the hu- 
merus next to the last muscle, and, forming a long slender tendon, 
