LIMBS 



437 



has come to be inner, and in man ventral and anterior, is best 

 known as preaxial ; it is that which bears the radius and the thumb. 

 The parts of the chief bones are shown in Figs. 346 to 348. 



In the forearm the radius and ulna are distinct but not movable 

 upon one another, the radius lying in front of the ulna. In man the 



t.4,5 



A 



•c. 4, 5 



/// 



Fig. 348. — The skeleton of the left fore- and hind-feet of a rabbit. 



A, Fore-foot ; B, hind-foot. 



a., Tibiale ; c.i, first distal carpal or trapezium ; c.2, second distal carpal or trapezoid ; c.3, third distal 

 carpal or magnum ; c.4, 5, fused fourth and fifth distal carpals or unciform ; ce., centrale ; ce'., centrale 

 of hind-foot ; cm., fibulare ; im., intermedium ; mc, metacarpals ; met., metatarsals ; ph., phalanges; 

 ra., lower end of radius with its epiphysis ; r.c, radiale ; t.z, second distal tarsal or mesocuneiform ; 

 ^3, third distal tarsal or ectocuneiform; t.^, 3, fused fourth and fifth chstal tarsals or cuboid; !<.c.,u]nare; 

 ul., lower end of ulnar with its epiphysis ; I.-V., digits. 



lower end of the radius rotates round the ulna, so that the former 

 lies in front of and obliquely across the latter when the palm 

 faces downwards, but parallel with and outside it when the palm 

 is turned upwards. The position in which the palm is downwards 

 is known as pronation, that in which it is upwards as supination. 

 In the frog the limb is fixed half-way towards pronation ; in the 

 rabbit it is fixed in the prone position. On the hinder side of the 



y 



