nge of
commodities and ideas. The amalgamation of races in such regions depends
upon the similarity or diversity of the ethnic elements and the duration
of the common occupation. The broad, open valley of the Danube from the
Black Sea to Vienna contains a bizarre mixture of several stocks--Turks,
Bulgarians, various families of pure Slavs, Roumanians, Hungarians, and
Germans. These elements are too diverse and their occupation of the
valley too recent for amalgamation to have advanced very far as yet. The
maritime plain and open river valleys of northern France show a complete
fusion of the native Celts with the Saxons, Franks, and Normans who have
successively drifted into the region, just as the Teutonic and scanter
Slav elements have blended in the Baltic plains from the Elbe to the
Vistula.

[Sidenote: Change of habitat.]

Here are four different classes of geographic influences, all which may
become active in modifying a people when it changes its habitat. Many of
the characteristics acquired in the old home still live on, or at best
yield slowly to the new environment. This is especially true of the
direct physical and psychical effects. But a country may work a prompt
and radical change in the social organization of an immigrant people by
the totally new conditions of economic life which it presents. These may
be either greater wealth or poverty of natural resources than the race
has previously known, new stimulants or deterrents to commerce and
intercourse, and new conditions of climate which affect the efficiency
of the workman and the general character of production. From these a
whole complex mass of secondary effects may follow.

The Aryans and Mongols, leaving their homes in the cool barren highlands
of Central Asia where nature dispensed her gifts with a miserly hand,
and coming down to the hot, low, fertile plains of the Indian rivers,
underwent several fundamental changes in the process of adaptation to
their new environment. An enervating climate did its work in slaking
their energies; but more radical still was the change wrought by the
contrast of poverty and abundance, enforced asceticism and luxury,
presented by the old and new home. The restless, tireless shepherds
became a sedentary, agricultural people; the abstemious nomads,--spare,
sinewy, strangers to indulgence--became a race of rulers, revelling in
luxury, lording it over countless subjects; finally, their numbers
increased rapidly, no lo