WHITENESS IN POLAR REGIONS 
have even gone so far as to assert that the change is 
rare or never occurs, and that in consequence the two 
forms ave two forms, and not merely seasonal varieties. 
There is no doubt, however, that the change does take 
place ; for foxes at the Zoo have been known to put off 
one coat and take on the other. In Spitzbergen, and in 
all such very northerly latitudes, the change takes place ; 
but in Iceland, the southernmost land inhabited by this 
fox, there is no change in winter, a case which is paralleled 
by the polar hare of this country, which changes to 
white in winter in Scotland, but not in the damper, and 
thus warmer, Ireland. Though now limited to the 
frozen north, this fox in former days wandered farther 
south, as its fossil remains in this country show. The 
same is true of many animals now definitely confined to 
polar latitudes, such as the polar bear and the reindeer. 
This fox feeds upon ptarmigan or any birds that it can 
get, and upon cast up carcasses of seals and whales ; it 
is also fond of shell-fish and of eggs. In the winter 
of the north it is difficult for it to get any food at all, 
and it has been suggested that it stores up food when 
there is a surplus for a rainy or, better perhaps, a snowy 
day. But the exact observation wanting to confirm such 
a story appears to be lacking so far. It is described as 
uttering a “ yapping bark.” It is called a fox mainly 
because of its small size and long tail. The dogs, 
wolves, jackals and foxes, form in reality a highly uniform 
assemblage of carnivores. By certain small skull 
characters it is possible to separate a fox-like series from 
a wolf-like series. Viewed in this way, Azara’s fox of 
South America is a wolf and a jackal is a wolf ; but the 
Reynard of England, as well as its arctic ally, is a fox. 
To those who have not had the opportunity of examining 
the bones the jackals suggest a fox rather than a dog or 
wolf. But probably no one would doubt the fox-like 
nature of Canis lagopus, the arctic fox. 
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