298 THE MANUS. [CHAP. 



form what appears externally to be a single bone, though 

 traces of their separate origin always remain ; the two distal 

 articular surfaces are quite distinct, each supporting a digit. 

 The lateral (second and fifth) metacarpus and digits are 

 generally rudimentary, sometimes completely absent. Some- 

 times not even the hoofs remain, as in the Giraffe, Prongbuck 

 (Antilocapra), and some other Antelopes ; sometimes the 

 hoofs alone, as in the Sheep, and Ox, supported, it may be, 

 by irregular nodules of bone, rudiments of the ungual 

 phalanges. In the Deer the three phalanges are complete, 

 sometimes with the lower end of the metacarpal, tapering 

 above, and not directly attached to other parts of the 

 skeleton of the foot. In other species (as in Fig. 103), 

 rudiments of the proximal ends only of the metacarpals are 

 present. 1 



In the Tragulina these metacarpals are completely deve- 

 loped, and articulate with the carpus. In Hyomoschus, 

 belonging to this section, the third and fourth metacarpals 

 commonly remain distinct through life, so that the manus of 

 this animal scarcely differs from that of one of the Suina. 



The Tylopoda, or Camels, differ considerably from the 

 true Ruminants in the structure of the fore-foot (see Fig. 

 104). In the carpus the trapezoid and magnum are distinct, 

 as in the Suina and Perissodactyla, whereas these bones are 

 confluent in \\\z Pecora and Tragniina. There are no traces 

 of any metacarpals or digits, except the third and fourth. 

 The metacarpals of these are very long and, as in the Pecora, 



1 The last-named condition occurs in most of the deer of the Old 

 World, the former in all the American deer, with Alecs, Rangifer, 

 llydropo'cs, and Capreolus. See Sir Victor Brooke, " Froc. Zoological 

 Society, 1874," p. 36. 



Regarding the occasional indication of a trapezium in the Ctii'idie, 

 see Baur : " Der Carpus der Paarhufer," Morphol. Jahrb. ix. pp. 599- 

 602. 



