escent from the Prophet himself.

But along with this process of adaptation by amalgamation comes
unquestionably a lowering of the mental vitality of the higher race.
That is the price it has to pay for the privilege of survival under the
new conditions. But, in conformity to the principles already laid down
as accepted by all anthropologists, such a lowering must correspond to a
degeneration in the highest grades of structure, the brain cells.

We are forced, therefore, to reach the decision that the human species
attains its highest development only under moderate conditions of heat,
such as prevail in the temperate zones (an annual mean of 8 deg.-12 deg. C.);
and the more startling conclusion that the races now native to the polar
and tropical areas are distinctly _pathological_, are types of
degeneracy, having forfeited their highest physiological elements in
order to purchase immunity from the unfavorable climatic conditions to
which they are subject. We must agree with a French writer, that "man is
not cosmopolitan," and if he insists on becoming a "citizen of the
world" he is taxed heavily in his best estate for his presumption.

The inferences in racial psychology which follow this opinion are too
evident to require detailed mention. Natural selection has fitted the
Eskimo and the Sudanese for their respective abodes, but it has been by
the process of regressive evolution; progressive evolution in man has
confined itself to less extreme climatic areas.

The facts of acclimatization stand in close connection with another
doctrine in anthropology which is interesting for my theme, that of
"ethno-geographic provinces." Alexander von Humboldt seems to have been
the first to give expression to this system of human grouping, and it
has been diligently cultivated by his disciple, Professor Bastian. It
rests upon the application to the human species of two general
principles recognized as true in zoology and botany. The one is that
every organism is directly dependent on its environment (the _milieu_),
action and reaction going on constantly between them; the other is, that
no two faunal or floral regions are of equal rank in their capacity for
the development of a given type of organism.

The features which distinguish one ethno-geographic province from
another are chiefly, according to Bastian, meteorological, and they
permit, he claims, a much closer division of human groups than the
general continental areas whi