Malayan speech of an ancient form prevails everywhere, and though diversified into dialects, is everywhere so much alike that all Malagasies can manage to understand one another.[857] The first inhabitants were probably African; but the wide Mozambique Current (230 miles), with its strong southward flow, was a serious barrier to fresh accessions from the mainland, especially as the nautical development of the African tribes was always low.  Meanwhile, however, successive relays of sea-bred Malay-Polynesians crossed the broad stretch of the Indian Ocean, occupied the island, and finally predominated over the original Negro stock.[858] Then in historic times came Arabs, Swahilis, and East Indians to infuse an Asiatic element into the population of the coasts, while Portuguese, English, Dutch, and French set up short-lived colonies on its shores.  But despite this intermittent foreign immigration, the fundamental isolation of Madagascar, combined with its large area, enabled it to go its own slow historical gait, with a minimum of interference from outside, till France in 1895 began to assume control of the island.

[Sidenote:  Mixed population of small thalassic isles.]

Small thalassic islands, at an early date in their history, lose their ethnic unity and present a highly mixed population.  The reasons for this are two.  The early maritime development characterizing enclosed seas covers them with a network of marine routes, on which such islands serve as way stations and mid-sea markets for the surrounding shores.  Sailors and traders, colonists and conquerors flock to them from every side.  Such a nodal location on commercial routes insures to islands a cosmopolitanism of race, as opposed to the ethnic differentiation and unity which follows an outlying or oceanic situation.  Here the factor of many-sided accessibility predominates over isolation.

The prevailing small area of such thalassic islands, moreover, involves a population so small that it is highly susceptible to the effects of intercrossing.  Too restricted to absorb the constant influx of foreign elements, the inhabitants tend to become a highly mixed, polyglot breed.  This they continue to be by the constant addition of foreign strains, so long as the islands remain foci of trade or strategic points for the control of the marine highways.  Diomede Island in Bering Strait is the great market place of the polar tribes.  Here Siberian Chukches and Alaskan Eskimos make their exchanges.  The Eskimo of St. Lawrence Island in Bering Sea, from long intercourse, have adopted certain articles of dress, the boats and part of the vocabulary of the Chukches.[859] Kilwauru, located on a sand-bank at the eastern end of Ceram, on the border between Malayan and Papuan island districts, is the metropolis of native traders in the Far East.  Here gather the praus of the sea-faring Bugis bringing manufactured goods from Singapore, and boats laden with the natural products of New Guinea.[860]