SQUIRRELS. 223 



pecially on account of their instinct for storing food. 

 The most interesting species are the squirrels, marmots, 

 beavers, dormice, rats, mice, voles, lemmings, chinchillas, 

 muskrats, capybaras, porcupines, agoutis, guinea-pigs, 

 hares, and rabbits. All, except the hare and rabbit, have 

 only one pair of upper incisors, the enamel being only in 

 front. Hares and rabbits have four upper incisors, the 

 enamel extending around the teeth. 



Squirrels are found in the forests of both continents. 



FIG. 152. 



They live on grains, fruits, and nuts, and make their 

 homes in hollow trees. The common squirrel is bright 

 red, with a white belly. The gray squirrel has a soft 

 light fur, which is the object of considerable commerce. 

 In this variety the back is a beautiful bluish gray, the 

 hair being dark gray at the roots and silver-gray at the 

 tips ; the belly is pure white. 



The chipmunk is a small species of squirrel, often 



