1896.] XATURAL SCIENCES OF PHILADELPHIA. 3o7 



west Alaskan Hares are considerably larger than any others from 

 either liigher or lower latitudes. The length of ear, which the laws 

 of variation lead us to suppose would increase southwardly, is actu- 

 ally less in Newfoundland than in Labrador, Baffin Land and 

 Greenland, while the hind foot follows a reverse order, being longer 

 in the south than in the north. 



GENERAL OBSERVATIONS ON SEASONAL, 8E5UAL AND JUVENILE 



PHASES OF COLOR. 



The Polar Hares of all countries and latitudes undergo a double 

 annual moult of the entire pelage, taking place during late spring 

 and early autumn. Throughout their more southern distribution, 

 the contrast between the perfect summer and winter coats, in color, 

 texture and quantity is very marked. As their habitat nears the 

 Pole, these sea.sonal differences diminish, so that it is difficult to dis- 

 tinguish at a distance the midsummer hares of North Greenland 

 and the Arctic Archipelago from the same animals in their snowy 

 winter dress. There is but one color character which remains con- 

 stant to all members of the group at all ages and seas^jns the world 

 over, namely, the black extreme lips of the ears. In winter this is 

 the only exception to the prevailing whiteness which characterizes 

 every American form of Polar Hare. 



In Scotland, Ireland and parts of Europe and Asia, the au- 

 tumnal change of color is incomplete in the Polar Hares which in- 

 habit the more temperate parts of the range of Lepus timidia of the 

 Old World. This peculiarity scarcely assumes the dignity of a 

 racial or geographical character, owing to its inconstancy, some in- 

 dividuals in a given neighborhood changing to a pure white winter 

 pelage while others acquire the grayish-brown or hoary dress which 

 was named canescens. by Nilsson,'* for the Swedish variety, and hi- 

 bernicus, by Bell,'^** for the Irish animal. 



In America I have found no instances which may be said to be 

 analogous to this variation. The Newfoundland Polar Hare reaches 

 a more southerly distribution than any of the Old World forms, but 

 I have seen no specimens nor know of authentic instances of its fail- 

 ing to become pure white in winter, unless a few gray hairs on the 

 fore part of the ears may be called an exception. 



The number of skins showing intermediate stages of the molt, 

 which would enable me to outline the process of change from winter 



>" Ofver. Ved. Akad., 1844, p. 1.33. 

 20 Brit. Quad., 18.37, p. -341. 



