Wtist and Hand. 91 



of the flexor tendons and the median nerve to 

 the hand. (3) The deep palmar fascia is composed of 

 three parts a central portion, occupying the hollow of the 

 palm an internal lateral, covering the muscles of the lit- 

 tle finger, and an external lateral, those of the thumb. 

 Partitions are sent backwards from the lines of junction 

 of this central portion with the lateral portions, and these 

 partitions join a transverse layer of deep fascia which lies 

 behind the long flexor tendons, and thus form a fibrous 

 canal for the passage of the flexor tendons through the 

 hand. The central portion of the deep palmar fascia 

 is triangular in shape, and is composed principally 

 of the expansion downwards of the palmaris lon- 

 gus tendon, and hence its fibres are arranged, 

 chiefly, in a longitudinal direction. Its apex is at- 

 tached to the lower border of the annular ligament, while 

 its base ends opposite the heads of the metacarpal bones 

 by dividing into processes for each of the fingers. This 

 fascia is very dense and strong, and affords ample protec- 

 tion to the delicate structures of the palm. The pro- 

 cesses, into which the fascia divides, are bound together by 

 means of oblique bands, and, near the webs of the fingers 

 by a transverse band, called the superficial transverse liga- 

 ment of the fingers. From the anterior surface of these 

 processes, fibres run forwards to the integument of the 

 palm, while, from the sides of the processes, some fibres 

 pass to the deep transverse ligament and others, backwards, 

 to the sides of the necks of the metacarpal bones. These 

 latter form the entrances to the channels for the passage 

 of the long flexor tendons in their course to the fingers, 

 while the processes referred to above, blend, below, with 

 the vaginal sheaths or channels for the flexor tendons 

 of the fingers. These vaginal sheaths are composed of 

 fibres directed chiefly in a transverse manner, i.e., from 



