IRISH HARE TURNING WHITE. 327 



greyness at every period of life, and to the hoariness 

 of old age." * 



Let us consider therefore for a moment this question 

 of change of colour in the human hair. Each hair is 

 embedded in a depression of the skin, called a " hair 

 follicle," and the root of the hair dilates, at its lower 

 end, into a bulb, f as any one can see, by pulling a 

 single hair out of his head. Now, as we conceive, 

 the effect of great cold upon the skin of arctic birds 

 and animals is to cause contraction in the roots of 

 the hair, or the tissues from whence the feathers draw 

 their nourishment, so as to create either a complete 

 arrest of pigmentation, or else a modification in the 

 pigment, so that they become more or less completely 

 blanched. Feathers in all probability follow the same 

 rules as hair. That cold has the effect of causing 

 changes of colour in this respect has been noticed 

 and admitted by Darwin; but unfortunately he did 

 not proceed to explain in what way he believed these 

 changes to arise but that exposure to cold is of itself 

 sufficient to turn animals white, is to our mind clearly 

 proved by the case of hares in Ireland during the 

 exceptionally severe winter of 1878 1879. Upon 

 that occasion we happened to be there, at a place 

 where there were then (before the era of Mr. Gladstone's 

 Land Acts) many hares; all of which turned more or 

 less white, and some of them became completely snow- 

 coloured all over, a thing that had never occurred 

 there before within the memory of any living man. Yet 



* Medical Dictionary, by Richard Quain, M.D., 1883, Vol. i, p. 576. 

 (Art. "The Hair"). 



f See Encycl. Brit. Vol. i. (Article "Anatomy"), p. 898. 



Personal observations and notes made by the Author, at Hilton. 

 Park and other places in Ireland. 



