THE LIMBS. 163 



The consolidation of parts into a single support- 

 ing column, so conspicuous in the forearm, is carried 

 out to a still greater extent in the last segment of the 

 limb of the horse. The eight carpal bones of the hu- 

 man hand are, it is true (with one exception, the tra- 

 pezium, the inner bone of the distal or lower row, 

 which supports the thumb), all present, even to the 

 pisiform, which projects backwards from the others 

 on the outer side of the wrist. These bones are, 

 however, more solidly compacted together than in 

 the human hand, the flat surfaces by which they come 

 in contact scarcely allowing a trace of movement be- 

 tween them. The metacarpus consists mainly of one 

 great bone, the " cannon-bone " of veterinarians, rep- 

 resenting the third or middle metacarpal of the hu- 

 man hand (3w, Fig. 6, p. 39). Lying on each side 

 of this, and generally in full-grown animals united 

 with it, are two smaller bones, the " splint-bones " of 

 veterinary anatomy (2m and 4w). These represent 

 respectively the second and fourth metacarpals of the 

 human hand. Above they have thickened heads, 

 which articulate in the usual manner with the carpal 

 bones ; but below they taper off almost to nothing, 

 ending some way above the lower end of the great 

 middle bone. The part commonly called the " knee " 

 of the horse thus corresponds to the back of the wrist 

 of man, and everything beyond or below it corre- 



