tinent of Asia was Africa vitalized by
the pulse of another life. European influences penetrated little beyond
the northern coast.

Asia, on the other hand, radiating great peninsulas, festooned with
islands, supporting the vast corrugations of its highlands and lowlands,
its snow-capped mountains and steaming valleys, stretching from the
Equator through all the zones to the ice-blocked shores of the Arctic,
knowing drought and deluge, tundra waste and teeming jungle, has offered
the manifold environment and segregated areas for individualized
civilizations, which have produced such far-reaching historical results.
The same fact is true of Europe, and that in an intensified degree. Here
a complex development of mountains and highlands built on diverse axes,
peninsulas which comprise 27 per cent. and Islands which comprise nearly
8 per cent. of the total area,[772] vast thalassic inlets cleaving the
continent to the core, have provided an abundance of those naturally
defined regions which serve as cradles of civilization and, reacting
upon the continent as a whole, endow it with lasting historical
significance.[773] Even Strabo saw this. He begins his description of the
inhabited world with Europe, because, as he says, it has such a
"polymorphous formation" and is the region most favorable to the mental
and social ennoblement of man.[774]

[Sidenote: Structure of North and South America.]

In North and South America, great simplicity of continental build gave
rise to a corresponding simplicity of native ethnic and cultural
condition. There is only one marked contrast throughout the length of
this double continent, that between its Atlantic and Pacific slopes. On
the Atlantic side of the Cordilleras, a vast trough extends through both
land-masses from the Arctic Ocean to Patagonia; this has given to
migration in each a longitudinal direction and therefore constantly
tended to nullify the diversities arising from contrasted zonal
conditions. On the Pacific side of North America, there has been an
unmistakeable migration southward along the accessible coast from Alaska
to the Columbia River, and down the great intermontane valleys of the
western highlands from, the Great Basin to Honduras;[775] while South
America shows the same meridional movement for 2,000 miles along the
Pacific coast and longitudinal valleys of the Andes system. There was
little encouragement to cut across the grain of the continents. The
eastern ran