The long list of recorded migrations has been supplemented by the researches of ethnologists, which have revealed a multitude of prehistoric movements. These are disclosed in greater number and range with successive investigation. The prehistoric wanderings of the Polynesians assume far more significance to-day than a hundred years ago, when their scope was supposed to have its western limit at Fiji and the Ellice group. They have now been traced to almost every island of Melanesia; vestiges of their influence have been detected in the languages of Australia, and the culture of the distant coasts of Alaska and British Columbia. The western pioneers of America knew the Shoshone Indians as small bands of savages, constantly moving about in search of food in the barren region west of the Rocky Mountains, and occasionally venturing eastward to hunt buffalo on the plains. Recent investigation has identified as offshoots of this retarded Shoshonean stock the sedentary agriculturalists of the Moqui Pueblo, and the advanced populations of ancient Mexico and Central America.[135] Here was a great human current which through the centuries slowly drifted from the present frontier of Canada to the shores of Lake Nicaragua. Powell's map of the distribution of the linguistic stocks of American Indians is intelligible only in the light of constant mobility. Haebler's map of the South American stocks reveals the same restless past. This cartographical presentation of the facts, giving only the final results, suggests tribal excursions of the nature of migrations; but ethnologists see them as the sum total of countless small movements which are more or less part of the normal activity of an unrooted savage people. [Map page 101.] Otis Mason finds that the life of a social group involves a variety of movements characterized by different ranges or scopes. I. The daily round from bed to bed. II. The annual round from year to year, like that of the Tunguse Orochon of Siberia who in pursuit of various fish and game change their residence within their territory from month to month, or the pastoral nomads who move with the seasons from pasture to pasture. III. Less systematic outside movements covering the tribal sphere of influence, such as journeys or voyages to remote hunting or fishing grounds, forays or piratical descents upon neighboring lands eventuating usually in conquest, expansion into border regions for occasional occupation or colonization. IV. Participation in streams of barter or commerce. V. And at a higher stage in the great currents of human intercourse, experience, and ideas, which finally compass the world.[136] In all this series the narrower movement prepares for the broader, of which it constitutes at once an impulse and a part. [Sidenote: Importance of such movements in history.]