On the Sense of Feeling; 307 



and the carpus being merely ligamentous, and therefore not apparent in the 

 dry skeleton. 



The lateral bones of the carpus incline forwards, forming a hollow for 

 the jirotection of the blood-vessels. 



To the three inner bones of the second row of the carpus, and to one 

 side of the fourth, are articulated the metacarpal bones of the four fingers, 

 and opposed to these is the metacarpal bone of the thumb. These meta- 

 carpal bones are hollowed towards the palm, and, although united at either 

 end, recede from each other centrally, for the lodgement of muscles. The 

 further ends of these bones form the knuckles j they are round-headed, 

 and fit into corresponding concavities in the bones of the fingers or pha- 

 langes. 



The first row of the phalanges is common to all the fingers and the 

 thumb j the second is wanting to the thumb ; the third again is common 

 to all, forming the tips, and being flattened for the support of the nail. 



The bones which we have been describing are held together by a number 

 of fibrous bands, destitute of sensation, save when placed upon the stretch, 

 and called ligaments. 



Strips of these ligaments run in all directions from one bone to other, 

 and, by taking off from the jar, materially diminish the bad eflTects of a fall. 

 The most remarkable of these ligaments is stretched across the arch of the 

 palm, and thus ties down and alters the direction of the tendons, affording 

 also a safeguard to the nerves and vessels beneath. 



Each of the very numerous joints, formed by the bones which we have 

 been describing, is enveloped by a shut sac, called a synovial membrane, 

 from the interior of which an oleaginous fluid is secreted, for the lubrica- 

 tion of the joint. 



Having fastened our bones together with appropriate ligaments, and 

 supplied the joints with a fluid sufficient to prevent the injurious effects 

 of friction, we next proceed to clothe them with muscles, and, before we do 

 this, it will be proper to consider what motions will be required of them. 



The motions of the human hand may be considered as of two kinds, 

 those which it exercises to give effect to the motions of the arm and fore- 

 arm, of which it is the extremity, and those which are more especially 

 confined to itself. The throwing up a cricket ball is an instance of the 

 one. the management of the strings of a violin of the other. 



Now, to execute two such different sets of motions, two distinct arrange- 

 ments of muscles are required. Tlius there are a number of muscles, 

 which bend or extend the wrist on the. forearm, or which pronate or su- 

 pinate the hand : almost all of these arc placed upon the upper part of the 

 fore-arm, wiiere they form the graceful suell of that part; while their long 

 slender tendons run down to be aftixed to the wrist and fingers, where for 

 obvious reasons it is necessary that each part should occupy as little room 

 as possible. 



