144 FAMILIAR LIFE IN FIELD AND POKBST. 



like myself, have observed the animal only in the 

 ISTorth, it would seem as though Dr. Merriam's theory, 

 recently expressed, is the one which iB 



correct. 

 My experi- 

 ence inclines 

 me to believe that 

 the change from 

 brown to white occurs 



altogether too suddenly, i„ i^^ ^i^ter'coat. m many in- 

 stances, to admit of any other ex- 

 planation than that which Dr. Merriam gives, quoted 

 below. 



Elliott Cones says : " As Mr. Bell contends, tem- 

 perature* is the immediate controlling agent. This 

 is amply proved in the fact that the northern animals 

 always change ; that in those from intermediate lati- 

 tudes the change is incomplete, while those from far- 



* We may safely conclude that if the requisite temperature is 

 experienced at the periods of renewal of the coat, the new hairs 

 will come out of the opposite color ; if not, they will appear of 

 the same color and change afterward; that is, the change mayor 

 may not be coincident with shedding. That it is ordinarily not 

 so coincident seems shown by the greater number of specimens in 

 which we observe white hairs brown tipped. — Fur-Bearing Ani- 

 mals, page 1,23, E. Coues, 



