lusions. The Negro, however, has been tested on an extensive
scale. The results seem to leave little doubt that there are real and
measurable differences in the mental powers of races, just as we know
to be the case among individuals. The matter is so important that we may
well dwell on it a moment before turning to the cause of the differences
in the three streams of American immigrants. If there is a measurable
difference between the inherent brain power of the white race and
the black, it is practically certain that there are also measurable
differences between the white and the red.

* D. G. Brinton. "The American Race."

Numerous tests indicate that in the lower mental powers there is no
great difference between the black and the white. In physical reactions
one is as quick as the other. In the capacity of the senses and in the
power to perceive and to discriminate between different kinds of objects
there is also practical equality. When it comes to the higher faculties,
however, such as judgment, inventiveness, and the power of organization,
a difference begins to be apparent. These, as Ferguson * says, are
the traits that "divide mankind into the able and the mediocre, the
brilliant and the dull, and they determine the progress of civilization
more directly than do the simple fundamental powers which man has in
common with the lower animals." On the basis of the most exhaustive
study yet made, Ferguson believes that, apart from all differences due
to home training and environment, the average intellectual power of the
colored people of this country is only about three-fourths as great as
that of white persons of the same amount of training. He believes it
probable, indeed, that this estimate is too high rather than too low. As
to the Indian, his past achievements and present condition indicate that
intellectually he stands between the white man and the Negro in about
the position that would be expected from the capacity of his brain. If
this is so, the mental differences in the three streams of migration
to America are fully as great as the outward and manifest physical
differences and far more important.

* G. O. Ferguson. "The Psychology of the Negro," New York, 1916.

Why does the American Indian differ from the Negro, and the European
from both? This is a question on which we can only speculate. But we
shall find it profitable to study the paths by which these diverse races
found their way