THE FORE-LIMB. 327 



The distal end of the ulna is small, and 

 articulates with the carpus. 



3. The wrist. In the rabbit the wrist or carpus consists 

 of nine small bones, of which one, the pisiform, is 

 commonly regarded as a sesamoid bone or ossifica- 

 tion in the tendon of a muscle, but by some ana- 

 tomists is considered to be a vestige of a sixth digit. 

 The arrangement of the remaining eight can best 

 be understood by comparison with more primitive 

 types. 



The typical carpus consists of nine bones, 

 arranged in a proximal row of three, articulating 

 with the radius and ulna ; a distal row of five, each 

 of which supports one of the digits ; and a central 

 bone wedged in between the proximal and distal 

 . rows. In the rabbit the arrangement is as follows : 



a. The proximal row of carpals consists of the three 



typical bones. 



i. The radiale, or scaphoid, is on the inner or pre- 

 axial side, and articulates with the radius. 



ii. The intermedium, lunar, or semilunar, is the 

 middle bone of the three, and articulates 

 with the radius. 



iii. The ulnare, or cuneiform, is the outer or post- 

 axial bone of the proximal row, and articu- 

 lates with the ulna. 



b. The central bone. 



i. The centrale is a small bone, articulating with 

 the distal surfaces of the intermedium and 

 radiale, and appearing to belong to the distal 

 row of carpals. 



c. The distal row of carpals consists of four bones, 



the two outermost of the typical carpus having 

 fused to form a single bone, 

 i. The first carpale, or trapezium, is on the inner or 



