132 LECTURE III. 



it firm, in opposition to the power of the 

 thumb, when we grasp bodies with force. 



The bones of the fingers are made a Uttle 

 convex behind, but flat in front, for the 

 convenience of grasping. The second and 

 third joints of the fingers are formed into 

 hinges, admitting only of flexion and ex- 

 tension. The last bones of the fingers are 

 very small, the nail causing the apparent 

 breadth of the end of the finger. 



"&^ 



The thumb consists of three bones, the 

 first of which is articulated to the carpus, 

 and the joint appears like a hinge, though 

 from the looseness of the ligaments, it 

 admits of a small degree of motion in very 

 various directions; which motions appear 

 more considerable than they really are, 

 when their effect is observed, as the extre- 

 mity of so long a radius as the thumb 

 makes. In consequence of this freedom of 

 motion, we are enabled to apply the end 

 of the thumb to each of the fingers and to 

 different parts of the hand, and also to place 

 the thumb in direct opposition to the power 



