124 NORTH AMERICAN MUSTELID.E. 



therefore of an animal having white fur, would continue more 

 equable than that of one clothed in darker colours, although the 

 latter would enjoy a greater degree of warmth whilst exposed 

 to the sun's intlaence. Thus the mere presence of a degree of 

 cold, sufficient to prove hurtful if not fatal to the animal, is 

 itself the immediate cause of such a change in its condition as 

 shall at once negative its injurious influence." 



The latitudes in which the change occurs in this country in- 

 clude the northern tier of States, and the entire region north- 

 ward. In this area, the change is regular, complete, and uni- 

 versal. Complete change is also usually effected — but not 

 always — nearly to the southern limits of dispersion in mount- 

 ainous regions. White winter specimens are the rule in Mas- 

 sachusetts, ]S^ew York, and Pennsylvania ; and I have seen 

 others, pure white, from Illinois, Wyoming Territory, and Cal- 

 ifornia (Fort Crook). For the Southern States, from which I 

 have no white examples, I will quote Audubon and Bachman : — 

 " We received specimens from Virginia obtained in January, in 

 which the colours of the back had undergone no change, and 

 remained brown ; and from the upper and middle districts of 

 South Carolina, killed at the same period, when no change had 

 taken place j and it was stated that this, the only species of 

 Weasel found there, remained brown through the whole year. 

 . . . Those from the valleys of the Virginia mountains have 

 broad stripes of brown on the back, and specimens from Abbe- 

 ville and Lexington, South Carolina, have not undergone the 

 slightest change." It may be presumed that in the debatable 

 ground some individuals may change and others not, and that, 

 again, character of successive seasons may make a difference 

 in this respect. 



General Jiistory and habits of the species. 



For the meaning of the name of this animal, we may refer 

 again to Bell : — " The derivation of the word Stoat is very prob- 

 ably,- as Skinner has it, from the Belgic * Stout', bold; and the 

 name is so pronounced in Cambridgeshire and in some other 

 parts of England to the present time. Gwillim, in his 'Dis- 

 play of lleraldrie ', gives the following etymology of Ermine : — 

 'This is a little beast, lesse than a Squirrell, that hath his 

 being in the woods of the land of Armenia, whereof bee taketh 

 his name.''' The latter word is sometimes written in English 

 ' ermin ' or 'erraelin'; and the same term occurs in several 



