onsider whether the effects of the environment are
inherited, we attack a stronghold of sociologists and historians.
Herbert Spencer thought one of the strongest pieces of evidence in this
category was to be found in the assimilation of foreigners in the United
States. "The descendants of the immigrant Irish," he pointed out, "lose
their Celtic aspect and become Americanised.... To say that 'spontaneous
variation,' increased by natural selection, can have produced this
effect, is going too far." Unfortunately for Mr. Spencer, he was basing
his conclusions on guesswork. It is only within the last few months that
the first trustworthy evidence on the point has appeared, in the careful
measurements of Hrdlicka who has demonstrated that Spencer was quite
wrong in his statement. As a fact, the original traits persist with
almost incredible fidelity. (Appendix C.)

In 1911, Franz Boas of Columbia University published measurements of the
head form of children of immigrants[14] which purported to show that
American conditions caused in some mysterious manner a change in the
shape of the head. This conclusion in itself would have been striking
enough, but was made more startling when he announced that the change
worked both ways: "The East European Hebrew, who has a very round head,
becomes more long-headed; the south Italian, who in Italy has an
exceedingly long head, becomes more short-headed"; and moreover this
potent influence was alleged to be a subtle one "which does not affect
the young child born abroad and growing up in American environment, but
which makes itself felt among the children born in America, even a short
time after the arrival of the parents in this country." Boas' work was
naturally pleasing to sociologists who believe in the reality of the
"melting-pot," and has obtained widespread acceptance in popular
literature. It has obtained little acceptance among his
fellow-anthropologists, some of whom allege that it is unsound because
of the faulty methods by which the measurements were made and the
incorrect standards used for comparison.

The many instances quoted by historians, where races have changed after
immigration, are to be explained in most cases by natural selection
under new conditions, or by interbreeding with the natives, and not as
the direct result of climate. Ellsworth Huntington, the most recent and
careful student of the effect of climate on man,[15] finds that climate
has a great deal of in