252 FAMILY SCIUBID^E ; FLYING SQUIRREL, MARMOT. 



(ANIM. PHYSIOL. 668,) this movement cannot be rightly 

 designated as flight, since the animal is not able to propel itself in 

 the air, nor even to sustain itself at the same height. In some 

 of the Squirrels, the tail is rounder and less bushy than in the 

 common one of this country; these, consequently, have less 

 power of taking sustained leaps through the air ; and they live 

 more upon the ground. 



220. The Marmot and the Dormouse seem to occupy an 

 intermediate position between this family and the next. The 

 Marmot has been commonly associated with the Rats ; but in its 

 dentition it more nearly resembles the Squirrels. The body is 



FIG. 127- ARCTOMYS, OB MARMOT. 



heavier, however, than it usually is in that family, and the limbs 

 are shorter ; the tail is of moderate length, and hairy. The 

 Marmots construct extensive burrows, with long galleries, pre- 

 ferring the sides of high and cold mountains. They pass the 

 winter in a state of profound torpidity ; not even occasionally 

 arousing themselves to take nourishment. They prepare a couch 

 of dry grass, in which they nestle ; and they securely close the 

 mouth of the burrow, and prevent the changes in the external 

 temperature from affecting their bodies, by carrying in a ball of 

 hay backwards, and drawing it firmly into the orifice. A sub- 

 division of this group, peculiar to North America, is remarkable 

 for its large cheek-pouches, which enable these little animals to 

 carry the stores of grain on which they feed. They are described 

 by Dr. Richardson as living in communities, and as occasionally 



