To another and a very different people, namely, the Polynesians, the same notion of a differential evolution may be profitably applied.  They were in the stone-age when first discovered, and had no bows and arrows.  On the other hand, with coco-nut, bananas and bread-fruit, they had abundant means of sustenance, and were thoroughly at home in their magnificent canoes.  Thus their island-life was rich in ease and variety; and, whilst rude in certain respects, they were almost civilized in others.  Their racial affinities are somewhat complex.  What is almost certain is that they only occupied the Eastern Pacific during the course of the last 1500 years or so.  They probably came from Indonesia, mixing to a slight extent with Melanesians on their way.  How the proto-Polynesians came into existence in Indonesia is more problematic.  Possibly they were the result of a mixture between long-headed immigrants from eastern India, and round-headed Mongols from Indo-China and the rest of south-eastern Asia, from whom the present Malays are derived.

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We have completed our very rapid regional survey of the world; and what do we find?  By no means is it case after case of one region corresponding to one type of man and to one type of culture.  It might be that, given persistent physical conditions of a uniform kind, and complete isolation, human life would in the end conform to these conditions, or in other words stagnate.  No one can tell, and no one wants to know, because as a matter of fact no such environmental conditions occur in this world of ours.  Human history reveals itself as a bewildering series of interpenetrations.  What excites these movements?  Geographical causes, say the theorists of one idea.  No doubt man moves forward partly because nature kicks him behind.  But in the first place some types of animal life go forward under pressure from nature, whilst others lie down and die.  In the second place man has an accumulative faculty, a social memory, whereby he is able to carry on to the conquest of a new environment whatever has served him in the old.  But this is as it were to compound environments—­a process that ends by making the environment coextensive with the world.  Intelligent assimilation of the new by means of the old breaks down the provincial barriers one by one, until man, the cosmopolitan animal by reason of his hereditary constitution, develops a cosmopolitan culture; at first almost unconsciously, but later on with self-conscious intent, because he is no longer content to live, but insists on living well.