100 THE STOAT, OR ERMINE. 



their summer dress.* But I am inclined to conjecture that the 

 ermines said to have been seen in summer, are such as have 

 resided, during that season, in the higher and colder parts of the 

 rocks and mountains. 



Professor Bell thinks this change of colour is effected, " not by 

 the loss of the summer coat, and the substitution of a new one 

 for the winter, but by the actual change of colour in the existing 

 fur. It is not perhaps easy to offer a satisfactory theory of 

 this phenomenon, but we may perhaps conclude that it arises 

 from a similar cause to that which produces the grey hair of 

 senility in man, and some other animals : of this instances have 

 occurred in which the whole hair has become white in the 

 course of a few hours, from excessive grief, anxiety, or fear ; 

 and the access of very sudden and severe cold has been known 

 to produce, almost as speedily, the winter change, in animals of 

 those species which are prone to it. This transition from one 

 state of the coat to the other, does not take place through any 

 gradation of shade in the general hue, but by patches here and 

 there, the winter colour being intermixed with that of the 

 summer, and giving a pied coat to the animal. 



"In northern latitudes, even in the alpine districts of Scotland, 

 this change is universal ; but further south it becomes an occa- 

 sional, and even rare occurrence. In Northumberland, Durham, 

 and other counties in the north of England, it is very frequent, 

 although far from general : in Lincolnshire, and the midland 

 counties generally, it is sometimes seen ; and two specimens of 

 the ermine taken in Cambridgeshire are contained in the museum 

 of the Cambridge Philosophical Society. Mr. Couch states, that 

 he has seen it more than once in Cornwall. 



" It appears to be established that, whatever may be the 

 change which takes place in the structure of the hair, upon 

 which the alteration of colour immediately depends, this tran- 

 sition from the summer to the winter colours is primarily 

 occasioned by actual change of temperature, and not by the 

 mere advance of the season. 



* Mag. Nat. Hist., vol. viii. p. 50. 



