70 



NATtJEAL HISTORY. 



Fig. 64— Skull of Rodent 

 Animal. 



being needed only for crushing ; in 

 the Rat they are raised into points, 

 he being carnivorous ; while in the 

 herbivorous Rodents they are real 

 grinders, as represented in Fig. 54. 

 116. The bushiness of the tail is 

 the peculiar characteristic of the 

 Squirrel family. This, when spread 

 out, is of some assistance in the leap- 

 ing of these arboreal animals, both guiding and buoying 

 them up. In the Flying Squirrel, Fig. 55, there is an ar- 

 rangement similar to 



that of the Flying 

 Lemur, § 57. 



117. The Ameri- 

 can Marmot, or 

 Woodchuck, as it is 

 commonly called, is 

 about the size of a 

 rabbit. It has an 

 underground habi- 

 tation, divided into 

 apartments, and 

 lives on clover and 



Fig, 55. — Flying Squirrel. 



esculent vegetables. Like some of the Monkeys (§ 52), 

 it has cheek pouches, in which it carries stores of food to 

 its burrow. 



118. The Mouse and Rat family is the most numerous 

 of all the families of the Mammalia, and contains the 

 smallest animals. Of the common Mouse, Cuvier says, 

 " it is known in all times and in all places." Of the Rats 

 there are two principal species, the Black Rat, and the 

 Brown or Brownish-gray. The Black Rat is called the 

 old English Rat, which was introduced into England from 

 France as late as the sixteenth century. This is now 

 nearly exterminated by the Brown Rat, which is a stron- 

 ger animal. This latter Rat was introduced into this 



