X. 



HABITS AND FACULTIES. 



The animals of this order, indigenous to the United 

 States, are essentially inhabitants of the forest. It is 

 there, under the deep shadows of a dense foliage, where 

 the sun's rajs hardly penetrate to the sui'face of the 

 earth, and where the ground is covered with the mould- 

 ering trunks of trees and thick layers of decaying 

 leaves, that they find a constant moisture, a twilight 

 interinipted only by darkness, abmidance of vegetable 

 and animal food, and the means of shelter and protec- 

 tion. These constitute a combination of circumstances 

 very favorable to their increase, and hence they may be 

 discovered, in situations where these conditions exist, in 

 every part of the country where they can be found at 

 all. But when, with these, are conjoined a mild climate, 

 and a calcareous soil, the maximum of favoring influences 

 is reached, and large numbers are produced. It is in 

 the great valley of the Mississippi, based throughout 

 nearly its whole extent upon horizontal limestone forma- 



