through physical environment by showing that it has not produced
tangible results in the last fifty or five hundred years. This attitude
recalls the early geologists, whose imaginations could not conceive the
vast ages necessary in a scientific explanation of geologic phenomena.

The theory of evolution has taught us in science to think in larger
terms of time, so that we no longer raise the question whether European
colonists in Africa can turn into negroes, though we do find the recent
amazing statement that the Yankee, in his tall, gaunt figure, "the
colour of his skin, and the formation of his hair, has begun to
differentiate himself from his European kinsman and approach the type of
the aboriginal Indians."[28] Evolution tells the story of modification
by a succession of infinitesimal changes, and emphasizes the permanence
of a modification once produced long after the causes for it cease to
act. The mesas of Arizona, the earth sculpture of the Grand Canyon
remain as monuments to the erosive forces which produced them. So a
habitat leaves upon man no ephemeral impress; it affects him in one way
at a low stage of his development, and differently at a later or higher
stage, because the man himself and his relation to his environment have
been modified in the earlier period; but traces of that earlier
adaptation survive in his maturer life. Hence man's relation to his
environment must be looked at through the perspective of historical
development. It would be impossible to explain the history and national
character of the contemporary English solely by their twentieth century
response to their environment, because with insular conservatism they
carry and cherish vestiges of times when their islands represented
different geographic relations from those of to-day. Witness the
wool-sack of the lord chancellor. We cannot understand the location of
modern Athens, Rome or Berlin from the present day relations of urban
populations to their environment, because the original choice of these