THE ARCTIC ZONE. 27 



old acquaintance, the Silver-grey Fox, or Arctic Dog (which 

 also inhabits this zone), finds his favourite food, a species 

 of mouse called the Lemming. "He loves open coun- 

 tries, and never frequents the woods;" and here, at certain 

 times of the year, these foxes in vast troops together pursue 

 their helpless prey, a kind of hunt conducted on entirely 

 different principles to those received in England, particu- 

 larly where a fox is concerned. 



An extensive surface of dry and barren country, covered 

 with an incredible number of lichens, forms another and 

 very distinguishing feature of the Arctic Zone. In North 

 America there are numbers of Gyrophora ; and in the Old 

 World large tracts of land are clothed with the Eeindeer 

 Lichen, or Moss, as it is commonly called (Cenomyce rangi- 

 ferina) ; it forms " a matting over which it is very fatiguing 

 to travel in summer, when the plants are dried up by the 

 perpetual sunshine." 



It is however chiefly in winter that the Eeindeer Lichen 

 forms the food of the reindeer. In appearance it is very 

 much like the Iceland Moss we see in the chemists' shops ; 

 it must likewise possess the same nutritive qualities, for it 

 is a remarkable fact that " though the reindeer eats nothing 

 during the winter but great quantities of this moss, he always 



