way from his original home to America, we must inquire as to the
geographical situation of that home. Judging by the climate which
mankind now finds most favorable, the human race must have
originated in the temperate regions of Europe, Asia, or North
America. We are not entirely without evidence to guide to a
choice of one of the three continents. There is a scarcity of
indications of preglacial man in the New World and an abundance
of such indications in the Old. To be sure, several skulls found
in America have been supposed to belong to a time before the
last glacial epoch. In every case, however, there has been
something to throw doubt on the conclusion. For instance, some
human bones found at Vero in Florida in 1915 seem to be very old.
Certain circumstances, however, suggest that possibly they may
not really belong to the layers of gravel in which they were
discovered but may have been inserted at some later time. In the
Old World, on the contrary, no one doubts that many human skulls
and other parts of skeletons belong to the interglacial epoch
preceding the last glacial epoch, while some appear to date from
still more remote periods. Therefore no matter at what date man
may have come to America, it seems clear that he existed in the
Old World much earlier. This leaves us to choose between Europe
and Asia. The evidence points to central Asia as man's original
home, for the general movement of human migrations has been
outward from that region and not inward. So, too, with the great
families of mammals, as we know from fossil remains. From the
earliest geological times the vast interior of Asia has been the
great mother of the world, the source from which the most
important families of living things have come.

Suppose, then, that we place in central Asia the primitive home