THE SUB-ARCTIC ZONE. 37 



and three different species of Birch (Betula Alnus, B. nana, 

 and B.fruticosa). There are so many pretty little creatures 

 leaping about the boughs, it is impossible not to stop and 

 watch them for a little while ; the white squirrel of Siberia 

 darting up the trees to its nest on the top, and the Siberian 

 grey squirrel, with its beautiful long hair, quite silvery at 

 the ends; that curious animal too, the flying squirrel, 

 dozing away the whole day on a bed of leaves ; he grows 

 more brisk when twilight comes, though he is but a lazy 

 fellow at best ; but an empty larder acts as a stimulant, and 

 so with one spring, his skin expanded like wings between 

 his fore and hind legs, and his bushy tail serving for a rud- 

 der, he sails a distance of twenty-five or thirty feet from one 

 tree to another, making a dainty supper on the buds and 

 young shoots of the Pines and Birch-trees. At the foot 

 of the trees gleams the delicate little white ermine, darting 

 after mice like a cat. 



But there is yet another beautiful animal, the sable ; 

 hiding away from the rays of the sun where the trees are 

 thickest, as if he knew it would fade the beauty of his fur, 

 he leaps perpetually with such agility from tree to tree, that 

 he seems to be only doing it for amusement. But he has 

 probably more utilitarian ends in view ; for some say, that 



