io AFRICAN NATURE NOTES CHAP. 



of habitat no doubt has had an influence on the 

 colour of the latter animals ; since Peary's caribou, 

 the most northerly form of the genus, whose 

 habitat lies far within the Arctic Circle, where trees 

 of any kind are non-existent, is almost absolutely 

 white in colour. In spite, however, of the fact that 

 the caribou inhabiting Ellesmere Land and the 

 adjacent land masses are white, and therefore 

 harmonise well in colour with the snowy wastes 

 amongst which they live, they form the principal 

 food of the white wolves inhabiting the same regions, 

 which hunt them by scent and run them down just 

 as easily as the grey and black wolves of Alaska 

 capture the dark - coloured and very conspicuous 

 caribou which frequent the mountain ranges of 

 that country. It appears to me that the colour of a 

 caribou's coat, whether it be white, black, or brown, 

 cannot afford it any protection against wolves, which 

 probably possess as keen a sense of scent as any 

 animals in the world, and must surely hunt entirely 

 by scent during the long dark months of the Arctic 

 winter. If this is so, then the great diversity in 

 the coloration of the various species of caribou in- 

 habiting the North American Continent must be due 

 to some other cause than the necessity for protection 

 against wolves, practically their only four - footed 

 enemies. 



Speaking of other Arctic animals, Mr. Wallace 

 believes that the Arctic fox of necessity turns white 

 in winter in order to enable it to capture the white 

 Arctic hares upon which it chiefly lives. Very little, 

 however, is known as to the life-history of these two 

 animals. But if the Arctic foxes hunt by scent, as 

 they almost certainly do, during the constant dark- 

 ness of the long Arctic winter, and the hares burrow 

 beneath the snow, and are caught as a rule when 

 completely hidden from si^ht below its surface, I 

 think it is arguable that the influence of environment 



