brings distress to a race. Again and again, to be sure, on
the way to America, and under many other circumstances, man has
passed through the most adverse climates and has survived, but he
has flourished and waxed strong only in certain zones.

Curiously enough man's body and his mind appear to differ in
their climatic adaptations. Moreover, in this respect the black
race, and perhaps the red, appears to be diverse from the white.
In America an investigation of the marks of students at West
Point and Annapolis indicates that the best mental work is done
when the temperature averages not much above 40 degrees F. for
night and day together. Tests of school children in Denmark point
to a similar conclusion. On the other hand, daily tests of
twenty-two Negroes at Hampton Institute for sixteen months
suggest that their mental ability may be greatest at a
temperature only a little lower than that which is best for the
most efficient physical activity. No tests of this sort have ever
been made upon Indians, but such facts as the inventiveness of
the Eskimo, the artistic development of the people of northern
British Columbia and southern Alaska, and the relatively high
civilization of the cold regions of the Peruvian plateau suggest
that the Indian in this respect is more like the white race than
the black. Perhaps man's mental powers underwent their chief
evolution after the various races had left the aboriginal home in
which the physical characteristics becamefixed. Thus the races,
though alike in their physical response to climate, may possibly
be different in their mental response because they have
approached America by different paths.

Before we can understand how man may have been modified on his