1903 Animal Colouring in Winter 13 



still present by bubbles of gas within the hairs. Before 

 considering more at length the causes which may be the 

 efficient ones in producing this singular blanching in the fur 

 or feathers of many birds and mammals at the commence- 

 ment of winter, it is desirable to cast a glance over the actual 

 facts ascertainable. The most salient fact, perhaps, con- 

 cerning the matter is the apparent capriciousness of this 

 change. It is by no means every animal which passes its 

 entire life in the polar regions, or at least the more boreal 

 regions of Europe, Asia, and America, that undergoes this 

 marked seasonal metamorphosis. While the Arctic Fox and 

 the Polar Hare change to white as winter approaches, the 

 Musk Ox and the Glutton show no such changes. The 

 " Ptarmigans " of both Europe and America become white 

 in winter, but not so their close ally the Red Grouse of Scot- 

 land. The Stoat furnishes royal ermine in the winter, but 

 the Weasel, according to Mr de Winton, is only " paler in 

 colour in winter." One Lemming turns white seasonally, 

 another does not. Further than this, there is some caprici- 

 ousness seen among individuals. It is not every " Blue " 

 Fox which becomes a " White " Fox in winter. Again, the 

 habit of this extreme seasonal change is generally lost on 

 removal to a milder climate. Thus the Polar Hare does not 

 assume its white fur in Ireland ; and many years ago Daub- 

 enton kept a captive Ermine in order to study the changes 

 which accompanied the moult to the brown pelage of sum- 

 mer, which was duly accomplished. But that eminent 

 naturalist, though he kept the Stoat for upwards of two 

 years, " did not enjoy the satisfaction of seeing it resume its 

 former whiteness." This lack of sensitiveness he justly (in 

 our opinion) attributed to the milder climate of France. 



Of these facts the explanations have been various. Con- 

 cerning some of these attempted explanations we may perhaps 

 be allowed to quote the "ingenious" Mr John Ray, and 

 observe with him that " they need no other confutation than 

 ha, ha, ha ! " Thus the ancients gravely held that the Polar 

 Hare becomes white on a diet of snow. And Olaus Magnus, 

 the learned and, at times, acute historian of the Northern 

 peoples, addressed himself to a work of supererogation in 

 proving that the Hare in winter eats the bark of trees. 



