THE FORE-LIMB. 319 



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, the cen- 

 trale, and 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 small bone on the posterior 

 or flexor surface of the carpus, and articulates 

 with the distal end of the ulna and with the 

 ulnare. 



4. The hand in the rabbit has five digits, as in man : 

 the bones of each consist of a proximal metacarpal, 

 followed by the phalanges, the last of which, the 

 ungual phalanx, is conical and slightly curved, and 

 supports the claw. 



The pollex, or preaxial digit, corresponding to 

 the thumb in man, is much shorter than the others, 

 and has only two phalanges, while each of the other 

 digits has three. 



Sesamoid bones are developed in the tendons of 

 the flexormuscles, opposite the metacarpo-phalangeal 

 and certain other joiats. 



Fig. 60.— Lepus cunieulus. Skeleton of the left hand, extensor sur- 

 face. The pisiform bone is not seen in this view. Natural size, 

 (o. H. H.) 



A, radius. B, epiphysis of radius. C, ulna. D, epiphysis of ulna. E, 

 radiale. P, intermedium. G-, ulnare. H, centrale. K.l, K.2, K.3, first tliree 

 carpalia. K.4, unciform bone. M.l, M.2, M.5, first, second, and fifth meta- 

 carpals. PA, proximal^phalanges of first and fifth digits. PB, PC, middle 

 and ungual phalanges of fifth digit. T, claw. 



Fig. 61. — Lepus cunieulus. Skeleton of the left foot, extensor surface. 

 Natural size. (o. h. h.) 



E, astragalus. G-, calcaneum. H, naviculare. K, process representing 

 first tarsale. K.2, K. 3, second and third tarsalia. K.4, cuboid. M.l, M,2, 

 first (rudimentary) and second metatarsals fused together. M.5, fifth meta- 

 tarsal. PA, PC, proximal and ungual phalajiges of second toe. T, claw 

 enclosing ungual phfdanx of fifth toe. 



