336 NATURAL HISTORY. 



Chevrotain, the Roebuck, the Sheep, and the Camel, illustrate, better than can be done by words, the 

 difference in the degree of development of the outer toes found in the group. In the Pig all the four 

 toes are well developed, and there is no consolidation of their constituent elements. In the Water 

 Deerlet of West Africa the external toes are smaller, whilst, as in the Pig, each metacarpal which is 

 in the human hand the part of each finger included within the palm is independent of its neigh- 

 bour, the Javan Deerlet differing in having the third and fourth fused into a " cannon " bone. But 

 in the Red Deer the reduction of the second and fifth digits is so great that their metacarpals are not 

 perfect, being only present in their upper parts ; whilst the phalanges, or lower bones, are very small, 

 being reduced in the Sheep to mere bony spots with minute hoofs, which latter are quite absent in the 

 Camel, Llama, Giraffe, and Pronghorn Antelope. 



There are numerous other characters which associate these animals, and prove the natural 

 affinities of the different species, at the same time that in geologic times there existed other creatures 

 which fill up the intervals between existing forms, and conclusively demonstrate the manner in which 

 the order has been evolved from a common type in times long past. 



All the Artiodactyla are strictly terrestrial, none being arboreal in their habits. The Hippopotamus 

 is the only member of the group which is aquatic, spending much of its life in the water, without, 

 however, any special modification of its limbs or tail like that found in the more truly aquatic Seals, 

 Sirenia, or Whales. 



There is a great uniformity throughout the order in the general plan upon which the limbs are 

 constructed. In all the species the wrist in the fore limb commonly called the knee and the heel 

 in the hind limb the hock is raised a considerable distance above the ground, at the same time 

 that the whole weight of the body is carried upon the extreme tips of the toes, the terminal bones of 

 which are expanded within the hoof to increase the basis of support. The collar-bone is absent in all, 

 as it is in nearly every animal that does not use its fore limbs for any other purpose than that of 

 carrying the weight of the front parts of its body. 



In the Perissodactylate Rhinoceros the horn or horns is or are situated in the middle line of the 

 face above the nose, and are not supported upon any bony horn core. In all those Artiodactyla which 

 cany horns or antlers, there are appendages paired and lateral in position, at the same time that they 

 are either supported iipon bony cores, or are formed of bone itself, and are situated upon the forehead. 



The following table best represents our present knowledge as to the classification of the 

 Artiodactyla : 



f Pigs of the Old World. 



Non-ruminants . \ Peccaries of the New World. 

 v Hippopotami. 



ORDER TJNGULATA . \ SUB-ORDER ARTIODACTYLA 



Ruminants . J C hevrotains or Deerlets. 



Bovidae (Oxen). 

 V Cervidaa (Deer). 



A. H, GARROD. 



I. SHIM}, OR HOG FAMILY. 



THE Non-Ruminantia, or Artiodactyls which do not chew the cud, possess the following characters : 

 they usually have more than one pair of incisors in the upper jaw, they are devoid of horns, and the 

 stomach has rarely more than two divisions. In only one genus, that of the Peccary, are the metatarsal 

 and metacarpal bones united into one compact bony mass. They are divisible as the above table 

 indicates into three families : the Suidae, or Hogs, the Hippopotamidse, or Hippopotamuses, and 

 the Anoplotheridse,* or Anoplotheres, an extinct family, met with only in the Eocene strata of the 

 Old and New Worlds. 



* a, without ; oir\{], a hoof ; %n'oi/, wild beast ; wild beast without hoof. 





