THE ODD-HOOFED ANIMALS. 189 



characteristic formation of the forehead. Wilckens 

 alone 1 has drawn attention to the resemblance 

 between the skull of the short-headed cattle of 

 Eastern Tyrol (Dux) and that of the bison, and 

 thinks that further investigations would furnish a 

 complete proof for this derivation. 



Perissodactyla, or Odd-hoofed Animals. 



The Odd-hoofed animals are at present repre- 

 sented by three groups : Tapir, Khinoceros, and 

 Horse, all of which are poor in species. The re- 

 duction in the fore and hind- foot has advanced 

 farthest in the horse ; the middle toe, owing to the 

 complete disappearance of the others, has become 

 the sole support for the weight of the body. There 

 exist only the mere rudiments of the metatarsals 

 of the second and fourth toe. The tapir comes 

 first with four toes on the fore-foot, and three on 

 the hind-foot; the rhinoceros has three toes on 

 both the fore and the hind limbs, and both these 

 groups have preserved very ancient characteristic 

 features. But in spite of its transformation having 

 advanced so far, no other mammal of the present 



1 Wilckens, ' Ueber die Schadelknochen des Eindes aus den 

 Pfahlbauten des Laibacher Moqres, 1877 ' (Communications to 

 the Anthropological Society of Vienna). 

 18 



