120 



THE AVORLD OF LIFE 



CHAP. 



through corn and haystacks when these cross their path. 

 The following recent statement of the ascertained facts as to 

 these strange migrations — from the work on Mammals by 

 the late Sir H. Flower and R. Lydekker — will prove 

 interesting : — 



" The usual dwelling-place of the Lemmings is in the highlands or 

 fells of the great central mountain chain of Norway and Sweden. 



Fig. 12. — The Lemming (Myodes lemmus). 



South of the Arctic circle, they are, under ordinary circumstances, 

 exclusively confined to the plateaus covered with dwarf birch and 

 juniper above the conifer region, though in Tromso and Finmarken 

 they occur in all suitable places down to the level of the sea. The 

 nest is found under a tussock of dry grass or a stone, constructed of 

 dry straws and usually lined with hair. The number of young in 

 each nest is generally five, and at least two broods are produced 

 annually. Their food is entirely vegetable, especially grass roots 

 and stalks, shoots of the birch, reindeer-lichen and mosses, in search 

 of which they form in winter long galleries through the turf or under 

 the snow. They are restless, courageous, and pugnacious little 

 animals. When suddenly disturbed, instead of trying to escape, 



