424 MUSCLES. 



radio-carpal articulation, and extends to the lower margin of the 

 annular ligament. It adheres by its circumference to this liga- 

 ment and to the capsule of the joint; internally, it sends in a 

 considerable number of processes, whereby each tendon is sur- 

 rounded, and connected to the adjoining tendons; while at the 

 same time no restraint is put upon the natural motions of the 

 part. In its texture this bursa resembles a dense and elastic 

 cellular membrane. 



In addition to this, the flexor tendons, as they pass from the 

 root to the extremity of each finger, are surrounded by a syno- 

 vial bursa; which by its secretion continually lubricates them, 

 and permits them to play freely backwards and forwards, ac- 

 cording to the flexions and extensions of the fingers. These 

 mucous or synovial sheaths, begin a little distance above the 

 first joint of the finger, adhere there to both flexor tendons, and 

 extend to about the middle of the last phalanx. They give to 

 the tendons a very polished lubricated surface; are reflected 

 over the anterior flat faces of the phalanges, being separated 

 from them by a small quantity of adipose matter; they are also 

 reflected over the anterior faces of the capsular ligaments, and 

 line of the vaginal ligaments. 



The Vaginal Ligaments of the fingers (Ligamenta Vaginalia) 

 bind down the flexor tendons and keep them applied to the 

 fronts of the phalanges. They are 'of the same extent from 

 above downwards, with the mucous sheaths just mentioned, and 

 are stretched between the ulnar and the radial margins of the 

 phalanges. The fibres of which they consist pass for the most 

 part transversely, and are of a fibre-cartilaginous character. 

 These fibres diminish in number towards the end of each finger, 

 and are stronger on the fore finger than on any of the others. 

 In front of the metacarpo-phalangial articulations, and the phu- 

 langial articulations, the vaginal ligaments are much thinner 

 than elsewhere, in order to permit the free flexions of the fingers. 

 The structure, indeed, at these points, is strongly marked off 

 by its diminished thickness ; and though the course of the fibres 

 is the same from side to side, yet some anatomists have thought 

 it worth while to designate it, particularly under the name of 

 Annuli Juncturarum Ligamentosi. 



Within the vaginal ligaments small tendinous fraena arise 

 from the first and second phalanges; they vary in number in 



