[Sidenote:  Thalassic vicinal location.]

The unifying effect of vicinal location is greatly enhanced if the neighboring people are grouped about an enclosed sea which affords an easy highway for communication.  The integrating force of such a basin will often overcome the disintegrating force of race antagonisms.  The Roman Empire in the Mediterranean was able to evolve an effective centralized government and to spread one culture over the neighboring shores, despite great variety of nationality and language and every degree of cultural development.  A certain similarity of natural conditions, climatic and otherwise, from the Iberian Peninsula to the borders of the Syrian desert, also aided in the process of amalgamation.

Where similarity of race already forms a basis for congeniality, such circumthalassic groups display the highest degree of interactive influence.  These contribute to a further blending of population and unification of culture, by which the whole circle of the enclosing lands tends to approach one standard of civilization.  This was the history of the Baltic coast from the thirteenth to the sixteenth centuries, when the German Hansa distributed the material products of Europe’s highest civilization from Russian Novgorod to Norway.  The North Sea group, first under the leadership of Holland, later under England’s guidance, became a single community of advancing culture, which was a later reflection of the early community of race stretching from the Faroe and Shetland Islands to the Rhine and the Elbe.  This same process has been going on for ages about the marginal basins of eastern Asia, the Yellow and Japan Seas.  Community of race and culture stamps China, Korea and Japan.  A general advance in civilization under the leadership of Japan, the England of the East, now inaugurates the elevation of the whole group.

[Sidenote:  Complementary locations.]

An even closer connection exists between adjoining peoples who are united by ties of blood and are further made economically dependent upon one another, because of a contrast in the physical conditions and, therefore, in the products of their respective territories.  Numerous coast and inland tribes, pastoral and agricultural tribes are united because they are mutually necessary.  In British Columbia and Alaska the fishing Indians of the seaboard long held a definite commercial relation to the hunting tribes of the interior, selling them the products and wares of the coast, while monopolizing their market for the inland furs.  Such was the position of the Ugalentz tribe of Tlingits near the mouth of the Copper River in relation to the up-stream Athapascans; of the Kinik tribe at the head of Cook’s Inlet in relation to the inland Atnas,[245] of the Chilcats of Chilkoot Inlet to the mountain Tinnehs.  Similarly, the hunting folk of the Kalahari Desert in South Africa attach themselves to influential tribesmen of the adjacent Bechuana grasslands, in order to exchange