ARTICULATIONS OF THE UPPER EXTREMITIES. 295 



them, as on the back of the os magnum, where it answers as 

 a periosteum. 



In addition to the articulation just described, between the 

 two rows of carpal bones, the individual bones of each row have 

 particular fastenings of ligarnentous fibres, which run trans- 

 versely from the margin of one bone to the margin of the next. 

 These fibres, from their position, are called dorsal and palmar 

 ligaments. The upper row has one dorsal ligament between 

 the scaphoid and lunar, and another between the latter and the 

 cuneiform it has in the same way two palmar ligaments on 

 its front surface. The lower row has, after the same plan, 

 three dorsal and three palmar ligaments between its bones. 

 These several ligaments are best seen on the side of the syno- 

 vial membrane, as externally their fibres are very much mixed 

 with those of the capsular ligament. It is obvious that they 

 are highly useful in preventing the bones from sliding laterally 

 on each otherj, except to a small extent. 



The Pisiform Bone has an articulation with the cuneiform 

 completely distinct from any other. The articular faces of 

 this joint are covered with cartilage and invested by a synovial 

 membrane and a capsular ligament, which allow, from their 

 looseness, considerable motion. The capsule, though general- 

 ly thin, is strengthened by accessory fibres, which are well 

 marked below. These fibres arising from the inferior extremi- 

 ty of the pisiform, some of them are attached to the extremity 

 of the unciform process of the os unciforme, and others to the 

 base of the fifth metacarpal bone. The insertion of the tendon 

 of the flexor carpi ulnaris answers as a ligament to this bone 

 above, and there is a very strong fasciculus of ligament, passing 

 from the pisiforme to the end of the unciform process, and by 

 that means conveying the action of the flexor ulnaris to it. It 

 has but little motion from above downwards, and a good deal 

 laterally. 



Of the Carpo-Metacarpal Articulations. 



The. bony articular surfaces, here, as well as all the others, 

 of the hand, have been sufficiently described and are in the recent 

 state covered with cartilage. It will therefore be unnecessary 

 to renew the observations on these subjects., 



