en visitor to reach our planet from
somewhere else; if he were endowed with only ordinary human common-sense,
he would very soon ascertain the common origin of the English-speaking
people in Canada, the United States, Australia and New Zealand, South
Africa, and many other places. Even if he could not understand a word of
the English language, he would be justified in regarding them all as the
descendants of common ancestors because they agree in so many physical
qualities. The anthropologist works according to the same common-sense
principle, obtaining results that find no explanation other than evolution
when the varying characters that are used to determine social relationship
are properly classified and related. It is to these characters that we
must now give some attention.

* * * * *

The average stature of adults varies in different races from four feet one
inch in certain blacks to nearly six feet and seven inches, as among the
Patagonians. These are the extreme values for normal averages, although
dwarfs only fifteen inches high have been known, while "giants" sometimes
occur with a height of nine feet and five inches. Such individuals are of
course rare and abnormal, and are not to be taken into account in
establishing the average stature of a race for use in comparison with that
of another group.

The color of the skin is another criterion of racial relationship, though
it is more variable in races of common descent than we are wont to assume.
We are familiar with the fair and florid skin of the northern European,
the fair and pale skin in middle and southern Europe, the coppery red of
the American Indian, the brown of the Malay, of the Polynesian and of the
Moor, the yellowish cast of the Chinese and Japanese, and the deeper
velvety black of the Zulu; but it has been found that many of the close
relatives of the black are lighter in skin color than some of our
Caucasian relatives, so that this character cannot be taken by itself as a
single criterion of racial affinity.

Perhaps the most conservative and most reliable character that serves for
the broad classification of the human races is the shape of the individual
hairs of the head. We are familiar with the straight lank hair of the
Mongolian peoples and of the various tribes of American Indians, in whom
the hair possesses these peculiarities because each element grows as a
nearly perfect cylinder from the cells of the sk