PROFESSOR OWEN ON THE AYE-AYE. 63 
to the middle of the forearm: its long tendon passes under the vola-carpal ligament to 
be inserted into the base of the index metacarpal. 
The palmaris longus (ib. fig. 1, 9), with a similar but superficial origin, is a more 
slender muscle, becomes tendinous halfway down the forearm, and is inserted partly 
into the vola-carpal ligament, and partly expands into the volar fascia. 
The flexor carpi ulnaris (ib. fig. 1, 29) is the largest of the superficial flexors of the 
forearm: it arises, fleshy, from the entocondyloid ridge, and by fascia from the ulnar 
ridge of the proximal part of the ulna ; its fibres converge to a tendon at the lower third 
of the forearm, which is inserted into the outer part of the pisiform (p), and, by a strong 
fascia, thence continued to the base of the fifth metacarpal. 
The flewor digitorum sublimis (Pl. XXIII. figs. 1 & 3,23) arises from the ento- 
condyloid prominence of the humerus and from the coronoid process of the ulna, being 
covered there by the palmaris longus and flexor carpi ulnaris ; it divides below the middle 
of the forearm into two fasciculi, each of which again divides. The tendons of the radial 
divisions (fig. 3, a, b) pass near each other, through the vola-carpal ligament, and 
diverge at the palm to the index and medius digits—the latter being a very slender 
tendon in relation to the slenderness of that finger. The ulnar pair of tendons have a 
similar course, rather removed from the preceding, to the annulus (c) and minimus (d) 
digits. Each tendon splits, as usual, at the base of its digit, giving passage to the 
tendon of the deep flexor, and itself being inserted into the sides of the proximal 
phalanx. Besides these four tendons, a short and strong one (fig. 4, e) is sent off 
from the inner or back part of the ulnar division of the flecor sublimis to join chiefly 
the division of the flevor profundus which supplies the middle finger. 
The deep flexors of the digits (Pl. XXIII fig. 4, ss) are two in number. The one on 
the radial side arises by three heads, the longest (a), answering to the flecor longus 
pollicis, from the upper part of the radius; the second (b) is a distinct strip, from the 
radius and interosseous space; the third (c) arises from the middle of the ulna, and 
from the interosseous space: the two first heads unite, and afterwards join with the 
third head, forming a strong tendon which, at the carpus, divides into two, one going 
to the distal phalanx of the thumb, the other to that of the forefinger; but this is 
united at the wrist with the tendons of the ulnar division of the flexor profundus. This 
division (@) arises from the entocondyloid tubercle and the whole of the fore part of the 
upper two-thirds of the ulna: it receives an accessory fasciculus from the middle of the 
ulna: their common tendon unites as it passes under the carpal ligament with that of 
the radial division by the short strip of tendon (f), then proceeds independently, and 
divides into two strong tendons—one for the fourth, the other for the fifth finger. The 
slender tendon of the middle finger comes off very near the point of union of the radial 
with the ulnar division of the flecor profundus, and also near the connecting tendon (e) 
between the superficial and deep flexors ; so that the action of all the flexor masses may 
be concentrated on that slender middle finger. 
