buried in sleep, unstirred by any voice from the silent
shores of America. Semitic influences, in successive waves, spread over
the Dark Continent as far as Morocco, the Senegal, Niger, Lake Chad,
Nyanza, Tanganyika and Nyassa, and gave it such light as it had before
the 16th century. Only after the Atlantic gulf was finally crossed did
influences from the American side of the ocean begin to impinge upon the
West African coast, first in the form of the slave and rum trade, then
in the more humane aspect of the Liberian colony. But with the full
development of the Atlantic period in history, we see all kinds of
Atlantic influences, though chiefly from the Atlantic states of Europe,
penetrating eastward into the heart of Africa, and there meeting other
commercial and political activities pressing inland from the Indian
Ocean.

[Sidenote: The Atlantic abyss.]

The long Atlantic rift between the Eastern and Western Hemispheres,
which was such a potent factor in the primitive retardation of Africa
is, from the standpoint of anthropo-geography, the most important
feature in the distribution of the land-masses over the globe. Not till
the discovery of America bridged this abyss did the known world become a
girdle round the earth. Except the Norse ventures to the American
continent by way of Iceland and Greenland between 1000 and 1347, no
account of pre-Columbian intercourse between the two shores of the
Atlantic has ever been substantiated. Columbus found the opposite land
unfamiliar in race as in culture. He described the people as neither
whites nor blacks, the two ethnic types which he knew on the eastern
side of the Atlantic abyss. He and his successors found in the Americas
only a Stone Age culture, a stage already outgrown by Europe and Africa.
These continents from Lapland to the Hottentot country were using iron.
Prior to the voyage of the great Genoese, Europe gave nothing to America
and received nothing from it, except the Gulf Stream's scanty cargo of
driftwood stranded on bleak Icelandic shores. The Tertiary land-bridge
across the North Atlantic between Norway and Greenland may possibly have
guided a pre-Caucasic migration to America and given that continent part
of its aboriginal population.[756] However, no trace of any European
stock remains.

[Sidenote: Atlantic islands uninhabited.]

The collapse of the bridge at the close of the Glacial Epoch left the
Atlantic abyss effectually dividing the two hemispher