aces of animals have been produced by the combined
action of many different internal as well as external conditions, the
nature of which can not in all cases be defined, the most striking
varieties being found in those families which are capable of the
greatest distribution over the surface of the earth. The different
races of mankind are forms of one sole species, by the union of two of
whose members descendants are propagated. They are not different
species of a genus, since in that case their hybrid descendants would
remain unfruitful. But whether the human races have descended from
several primitive races of men, or from one alone, is a question that
can not be determined from experience."

Geographical investigations regarding the ancient seat, the so-called
cradle of the human race, are not devoid of a mythical character. "We
do not know," says Wilhelm von Humboldt, in an unpublished work, "On
the Varieties of Languages and Nations," "either from history or from
authentic tradition, any period of time in which the human race has
not been divided into social groups. Whether the gregarious condition
was original, or of subsequent occurrence, we have no historic
evidence to show. The separate mythical relations found to exist
independently of one another in different parts of the earth appear to
refute the first hypothesis, and concur in ascribing the generation of
the whole human race to the union of one pair. The general prevalence
of this myth has caused it to be regarded as a traditionary record
transmitted from primitive man to his descendants. But this very
circumstance seems rather to prove that it has no historical
foundation, but has simply arisen from an identity in the mode of
intellectual conception, which has everywhere led man to adopt the
same conclusion regarding identical phenomena; in the same manner as
many myths have doubtless arisen, not from any historical connection
existing between them, but rather from an identity in human thought
and imagination.

"Another evidence in favor of the purely mythical nature of this
belief is afforded by the fact that the first origin of mankind--a
phenomenon which is wholly beyond the sphere of experience--is
explained in perfect conformity with existing views, being considered
on the principle of the colonization of some desert island or remote
mountainous valley at a period when mankind had already existed for
thousands of years. It is in vain that we direct