514 RODENTIA. 



of America, under tlie polar circle, and climbs rocks almost as well 

 as a goat. The horns meet at their base in front of their forehead, 

 almost in a straight line. It stands low, and is covered, with tufted 

 hair that reaches to the ground. It diffuses a strong smell of musk, 

 with which its flesh is also impregnated. The Esquimaux make 

 caps of the tail, the hairs of which, falling over their face, defend 

 them from the mosquitoes. 



Order IV. — Gnawixg Quadrupeds. 



RODENTIA.* 



The Quadrupeds that have hitherto Decupled our 

 attention, all of them herbivorous, have derived their 

 food either from the grass of the fields or the foliage 

 of trees, for the mastication of which their teeth are 

 admirably adapted. The animals that next present 

 themselves are constructed for devouring less prac- 

 ticable materials. They live principally upon the 

 harder parts of vegetables, the bark, the roots, the 

 woody stems and even the nuts and stony seeds, 

 and are consequently provided with incisor teeth, 

 adapted to • gnaw and reduce to fragments the 

 tough and resisting substances upon which the}' feed. 

 These sfnawins: or Rodent teeth consist of four laro^e 

 incisors, two of which are situated in the front of 

 each jaw ; they are separated from the grinders by 

 a wide space devoid of teeth, and are neither adapted 

 for seizing living prey, nor cutting flesh, but are 

 shaped like chisels, and are thus fitted for chipping 

 off and destroying piecemeal the hardest and most 

 intractable materials. In order that they may be 

 better capable of such employment, these chisel- 

 teeth are provided in front with a thin layer of 

 enamel, hard as the hardest steel, whilst behind, they 

 are composed of a much softer material called ivory, 

 so that they always present a sliarp cutting edge. 

 These teeth are constantly gi'owing from the pulpy 

 core at their base ; but as those of the upper jaw 

 meet those of the lower at their tips, they are 



* Redo, 1 gnaiv. 



