THE FORE-LIMB 289 



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 placed on the inner or 



preaxial side, and articulates with the radius. 



ii. The intermedium, 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 

 preaxial side of the wrist ; it articulates with 

 the radiale, and supports the first metacarpal. 



ii. The second carpale, or trapezoid, articulates 

 with the radiale and centrale, and supports 

 the second metacarpal. 



iii. The third carpale, or os magnum, is very small : 

 it articulates with the intermedium and cen- 

 trale, and supports the third metacarpal. 



iv. The fourth and fifth carpalia are fused to form 

 the unciform bone, which is much larger : it 

 articulates with the ulnare, and supports the 

 fourth and fifth metacarpals. 



d. The pisiform is a sesamoid bone on the posterior 



or flexor surface of the carpus, and articulating 

 with the distal end of the ulna and with the 

 ulnare. 



