122 ANIMAL LIFE OF THE BRITISH ISLES. 



showed that the senile whitening of human hair was due to the 

 activity of certain motile cells, which he termed chromophages 

 or colour-eaters, which remove the pigment granules and con- 

 sume them. At a later date he showed that the same process 

 caused the whitening of the hairs in the Scottish Hare, and of 

 the feathers of the Ptarmigan which undergoes a similar 

 change of colour. It is noteworthy that the black tips of the 

 ears, like the black tip of the tail in the Stoat, never change 

 colour. 



As already stated, the Alpine Hare is smaller than the Brown 

 Hare, the combined length of head and body being about 

 twenty inches, but the head is proportionately larger, the ears 

 and tail shorter, and the legs longer. The fur is more woolly 

 and of a duskier tint in summer, the whiskers shorter and finer, 

 the eyes rounder, and the hair on the underside of the foot 

 softer. Behind the breast the under parts are white, and the 

 tail wholly so. Another name Blue Hare is suggested by its 

 appearance in autumn and spring, when the summer and winter 

 tints are mingled in its fur. The coat becomes closer and longer 

 in winter than it is in summer. Sometimes the winter coat is 

 retained longer than usual, through some unexplained retarding 

 of the spring moult. Black and buff variations have been 

 recorded. The average weight is between five and six pounds. 



The habits of the Alpine Hare are very similar to those of 

 the Brown Hare ; but it is less timid, and when alarmed clears 

 off in a more leisurely and less excited manner. As contrasted 

 with the nervous terror of the Brown Hare and Rabbit, the 

 Alpine Hare may be said to be comparatively tame. Instead 

 of making a form it hides in rock crevices and among stones 

 where it may be sheltered from the sight of birds of prey over- 

 head. Occasionally, and especially where there are no rocks, 

 they excavate burrows a few feet in length in the hillside or 

 into the peat-bank. In general its food is similar to that of 

 the Brown Hare ; but it is said to add lichens to its bill of 



