view. Dr. Abbott is inclined to attribute an Eskimo origin to
some of the palaeoliths of the Trenton gravel. On the other
hand, Mr. Clements Markham derives the American Eskimos from
those of Siberia. It seems to me that these views may be
comprehended and reconciled in a wider one. I would suggest
that during the Glacial period the ancestral Eskimos may have
gradually become adapted to arctic conditions of life; that in
the mild interglacial intervals they migrated northward along
with the musk-sheep; and that upon the return of the cold they
migrated southward again, keeping always near the edge of the
ice-sheet. Such a southward migration would naturally enough
bring them in one continent down to the Pyrenees, in the other
down to the Alleghanies; and naturally enough the modern
inquirer has his attention first directed to the indications of
their final retreat, _both_ northward in America and
northeastward from Europe through Siberia. This is like what
happened with so many plants and animals. Compare Darwin's
remarks on "Dispersal in the Glacial Period," _Origin of
Species_, chap. xii.

The best books on the Eskimos are those of Dr. Rink, _Tales and
Traditions of the Eskimo_, Edinburgh, 1875; _Danish Greenland_,
London, 1877; _The Eskimo Tribes, their Distribution and
Characteristics, especially in regard to Language_, Copenhagen,
1887. See also Franz Boas, "The Central Eskimo," _Sixth Report
of the Bureau of Ethnology_, Washington, 1888, pp. 399-669; W.
H. Dall. _Alaska and its Resources_, 1870; Markham, "Origin and
Migrations of the Greenland Esquimaux," _Journal of the Royal
Geographical Society_, 1865; Cranz, _Historie von Groenland_,
Leipsic, 1765; Petitot, _Traditions indiennes du Canada
nord-ouest_, Paris, 1886; Pilling's _Bibliography of the Eskimo
Language_, Washington, 1887; Wells and Kelly, _English-Eskimo
and Eskimo-English Vocabularies, with Ethnographical Memoranda
concerning the Arctic Eskimos in Alaska and Siberia_,
Washington, 1890; Carstensen's _Two Summers in Greenland_,
London, 1890.]

If we have always been accustomed to think of races of men only as they
are placed on modern maps, it at firs