1922] Swartk: Birds and Mammals of the Stikine Region 167 



boundary, both on account of the gradual change in the entire Pero- 

 myscus population of the intermediate territory and because of indi- 

 vidual variation, which brings typical examples of each far within the 

 margin on either side of the debatable strip. Allowing for such varia- 

 tion, however, it seems proper, though an arbitrary division, to con- 

 sider as horealis the mice from the upper Stikine, as far down as 

 Glenora, macrorhinus extending up stream as far as Doch-da-on Creek. 





borealis 



Fig. E. Diagram showing individual and geographic variation in length of 

 hind foot of adult white-footed mice (both sexes). Figures at left of the ver- 

 tical lines indicate numbers of specimens measured; length of lines shows range 

 of individual variation; points connected by lines mark positions of averages. 



"White-footed mice were found in abundance about human habita- 

 tions. Usually they were uncommon elsewhere. At the Junction the 

 trapping was done along a stream and in poplar woods, miles from 

 houses, and white-footed mice, while perhaps more abundant than any 

 other small mammal, were not at all numerous. At Telegraph Creek 

 most of our specimens were caught in the house in which we were 

 staying; a few were taken in our several trap lines a mile or more 

 from town. The rows of empty houses at Glenora formed a haven for 

 white-footed mice, and they swarmed there in almost incredible num- 

 bers. At Doch-da-on Creek white-footed mice were abundant in the 



