FUB-CLA.D FIGHTERS. 145 



ther south do not change at all. . . . The design or 

 final cause of this remarkable alteration is evident in 

 the screening of the animal from observation by as- 

 similation of its color to that of its surroundings. It 

 is shielded not only from its enemies, but from its 

 prey as v?ell." 



Now I quote in substance what Dr. Merriam says 

 to the contrary: "Temperature," he states, "time of 

 change, and fact of change have little to do with the 

 case. In the Adirondacks the ermine never turns 

 white until after the first snow. In late October or 

 early November, forty-eight hours after a snowstorm, 

 regardless of temperature, the coat has assumed a pied 

 appearance, often systematically marked and striking- 

 ly handsome; the change continues with great rapid- 

 ity. By early spring the process is reversed; the 

 change will even occur in a warm room indoors, al- 

 though the transition is tardy ; but it is really occa- 

 sioned by the inevitable influence of hereditary 

 habit." 



In northern New Hampshire, among the great 



hills, the temperature frequently falls to 20°, and even 



12°, between September 20th and November 10th. 



Yet, until the snow comes, the weasel remains brown. 



There is no lack of continued cold, either, between 



these dates, for almost every night in the latter part 



of October the mercury drops to the freezing point, 

 11 



