THE LIMBS 



147 



1 liumb (fore limb), hallux (hind limb) ; (II) index ; (III) 

 medins ; (IV) annularis ; 1 and (V) minimus. Though 

 five is the complete number, one or more may be in a 

 very rudimentary condition, or altogether suppressed. 

 If one is absent, it is most commonly the first ; next 

 follows the fifth. The third is never lost, although either 

 the second or fourth, or both, may be absent. 



In both limbs the normal arrangement is that the 

 carpus or the tarsus, as the case may be, supports five 

 long bones placed side by side, called the metapodials 

 (or metacarpals in the fore limb, metatarsals in the hind 

 limb), and to the end of each of these are three distinct 

 bones called phalanges, except in the case of the pollex 

 and hallux, which have only two. The terminal or 

 distal phalanges of the digits are often specially modified 

 to support the external horny covering usually present, 

 called nail, claw, and hoof, according to its form and 

 size, and hence are spoken of as the £ ungual phalanges.' 



This portion of the limb, being usually more or less 

 broadened and flattened, presents two surfaces and two 

 edges and borders. The surfaces are dorsal, which 

 in the ordinary position of the feet of most mammals 

 is turned forwards or upwards (the ' back ' of the 

 human hand), and ventral, or palmar in the fore limb 

 or plantar in the hind limb, turned backwards or 

 downwards. The edges are external (ulnar in the fore 

 1 Being in man the finger on which the ring is commonly worn. 



l 2 



