ARTIODACTYLES AND PERISSODACTYLES 



like flattened nails. It can climb both rocks and trees 

 (that is, various species can), and lives in burrows, which 

 Ungulates generally do not. It has very strong and 

 chisel- like incisor teeth in the front of each jaw, which 

 are by no means unlike those so characteristic of rodents. 

 The molar teeth, however, are more like those of the 

 rhinoceros. The elephants form another and an equally 

 distinct group. Their characters can be readily verified 

 with a little trouble. The massive form and straight 

 limbs, not bent at the knee or elsewhere, and the scanty 

 hair distinguish them from others ; but it must be 

 borne in mind that the extinct mammoth was copiously 

 clad with hair, and so may have been other extinct 

 forms, with whose bones and teeth we are alone 

 acquainted. The trunk is a third feature, of which, 

 however, there are the beginnings in the tapir. The 

 gait is partly plantigrade, and the bones show that the 

 fingers and toes are the unreduced number of five to 

 each limb. The enormous tusks, which are in reality 

 an exaggeration of the large rodent incisors, mark out 

 the elephants, and the fact that only one or two of the 

 particularly large molar teeth come into use at one 

 time in each jaw is another feature of the living but not 

 of all the extinct elephants. 



The remaining Ungulates fall readily into two groups, 

 the Artiodactyles and the Perissodactyles, names which 

 we owe to the late Sir Richard Owen, which may be 

 fairly grouped together in contrast to either and to both 

 of the two groups which we have already characterized. 

 In these Ungulata vera, as they have been termed, we 

 have the furthest development of Ungulate characters. 

 The gait is purely digitigrade, and in connexion with 

 this is a lengthening of some of the bones of the feet 

 and hands. It is in this section only that horns are 

 developed, while the hoofs are more perfect as hoofs. 

 The fingers and toes are always reduced from the 



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