CARNIVORA. 415 



associated with the above-defined structure of the skull, we 

 find that the fore paw consists of five digits (1-5) ; the 

 innermost and shortest (1) answering to our thumb, and 

 having two bones; the other four digits having each three 

 bones or "phalanges." All those digits enjoy a certain free- 

 dom of motion and power of reciprocal approximation for 

 grasping; but their chief feature is the modification of the 

 terminal phalanx, which is enlarged, compressed, subtriangular, 

 and more or less bent ; with a plate of bone, as it were, re- 

 flected forwards from the base, beyond which the pointed termi- 

 nation of the phalanx projects like a peg from a sheath. A 

 powerful, compressed, incurved, sharp-pointed, hard, horny 

 claw is fixed upon that peg, its base being firmly wedged into 

 the interspace between the peg and the sheath. The toe-joint 

 so armed is retractile. This complex, prehensile, and destruc- 

 tive paw is articulated to the two bones of the fore leg 

 (radius, n 9 and ulna, u) ; they are both strong, are both distinct, 

 are firmly articulated to the arm-bone (h) by a joint, which, 

 although well knit, allows great extent and freedom of motion 

 in bending and extension ; and, besides this, the two bones 

 are reciprocally joined so as to rotate on each other, or rather 

 the radius upon the ulna, carrying with it, by the greater 

 expansion of its lower end, the whole paw, which can thus be 

 turned "prone" or "supine;" whereby its application as an 

 instrument for seizing and tearing is greatly advantaged. The 

 humerus or arm-bone (h) is remarkable for the extension of 

 strong ridges from the outer and inner sides, just above the 

 elbow-joint. These ridges indicate the size and force of 

 the supinator, pronator, flexor, and extensor muscles of the 

 paw. To defend the main artery and nerve of the fore leg 

 from compression during the action of these muscles, a bridge 

 of bone (a) spans across them. The upper end of the arm- 

 bone is equally well marked by powerful ridges for muscular 

 implantation, especially for the deltoid ; but these ridges 



