imitating the life of the Eskimos, adopting their clothes, food, fuel,
dwellings, and mode of travel. Intense cold has checked both native and
Russian development over that major portion of Siberia lying north of
the mean annual isotherm of degree C. (32 degrees F.); and it has had a
like effect in the corresponding part of Canada. (Compare maps pages 8
and 9.) It allows these sub-arctic lands scant resources and a
population of less than two to the square mile. Even with the intrusion
of white colonial peoples, it perpetuates the savage economy of the
native hunting tribes, and makes the fur trader their modern exploiter,
whether he be the Cossack tribute-gatherer of the lower Lena River, or
the factor of the Hudson Bay Company. The assimilation tends to be
ethnic as well as economic, because the severity of the climate excludes
the white woman. The debilitating effects of heat and humidity, aided by
tropical diseases, soon reduce intruding peoples to the dead level of
economic inefficiency characteristic of the native races. These, as the
fittest, survive and tend to absorb the new-comers, pointing to
hybridization as the simplest solution of the problem of tropical
colonization.

[Sidenote: The relation of geography to history.]

The more the comparative method is applied to the study of
history--and this includes a comparison not only of different
countries, but also of successive epochs in the same country--the more
apparent becomes the influence of the soil in which humanity is
rooted, the more permanent and necessary is that influence seen to be.
Geography's claim to make scientific investigation of the physical
conditions of historical events is then vindicated. "Which was there
first, geography or history?" asks Kant. And then comes his answer:
"Geography lies at the basis of history." The two are inseparable.