to America from man's primeval home. According to the
now almost universally accepted theory, all the races of mankind had
a common origin. But where did man make the change from a four-handed,
tree-dwelling little ape to a much larger, upright creature with two
hands and two feet? It is a mistake to suppose that because he is
hairless he must have originated in a warm climate. In fact quite the
opposite seems to be the case, for apparently he lost his hair because
he took to wearing the skins of slain beasts in order that he might have
not only his own hair but that of other animals as a protection from the
cold.

In our search for the starting-place of man's slow migration to America
our first step should be to ascertain what responses to physical
environment are common to all men. If we find that all men live and
thrive best under certain climatic conditions, it is fair to assume that
those conditions prevailed in man's original home, and this conclusion
will enable us to cast out of the reckoning the regions where they do
not prevail. A study of the relations of millions of deaths to weather
conditions indicates that the white race is physically at its best when
the average temperature for night and day ranges from about 50 to 73
degrees F. and when the air is neither extremely moist nor extremely
dry. In addition to these conditions there must be not only seasonal
changes but frequent changes from day to day. Such changes are possible
only where there is a distinct winter and where storms are of frequent
occurrence. The best climate is, therefore, one where the temperature
ranges from not much below the freezing-point at night in winter to
about 80 degrees F. by day in summer, and where the storms which bring
daily changes are frequent at all seasons.

Surprising as it may seem, this study indicates that similar conditions
are best for all sorts of races. Finns from the Arctic Circle and
Italians of sunny Sicily have the best health and greatest energy under
practically the same conditions; so too with Frenchmen, Japanese, and
Americans. Most surprising of all, the African black man in the United
States is likewise at his best in essentially the same kind of weather
that is most favorable for his white fellow-citizens, and for Finns,
Italians, and other races. For the red race, no exact figures are
available, but general observation of the Indian's health and activity
suggests that in this respect he is at one wit