84 Life-histories of Northern Animals 



breeding. Albinism is a freak or disease by which the colour- 

 ing matter is left out of the hair on those parts of the body that 

 are affected, and the hair there comes white. Sometimes the 

 entire animal is involved, in which case usually the hoofs are 

 white and the eyes pink. It is not by any means certain that 

 the albino of this year will be an albino next year also. The 

 affection is sometimes associated with internal worms. 



The protective value of their blended tints, and the way in 

 which many animals turn them to account raises the question: 

 Are they conscious of their adaption to surroundings .? 



D. Wheeler writes me (January 7, 1901): "Deer seem to 

 realize their colour; they come to the water to drink and com- 

 monly pause to reconnoitre among dead brush that matches 

 their coat. I am sure that the Northern Hare does so; for in 

 the spring of the year, when they are still in white and when the 

 snow is in patches, they invariably squat or rest on the snow." 



R. Nichols, of Portland, Ore., assures me that Ptarmigan 

 in white always squat on the snow, if the ground be bare in 

 places. 



This does not agree with my own observations on Snow- 

 shoe Rabbits and White-jacks. Twice I saw a White-jack 

 crouch on a white rock, but I many times saw them when in 

 winter coat, crouch in brownish, grassy places where they were 

 ridiculously conspicuous. On the bare ground they are of 

 course more visible, and here they were very shy; though this 

 might be explained by the absence of cover. 



I am not yet satisfied that any animals actually realize the 

 protective value of their colour. 



EYE- The hearing and scent of Deer are marvellously acute, but 



their eyesight is not of the best. Audubon and Bachman 

 considered it actually imperfect; stating as proof that"^ **we 

 have often, when standing still, perceived the Deer passing 

 within a few yards without observing us, but we have often 

 noticed the affrighted start when we moved our position or 

 when they scented us by the wind. On one occasion we had 



"^^Loc. cit., p. 227. 



