No reasonable doubt exists but that the Athapascas, Algonkins, Iroquois, Apalachians, and Aztecs all migrated from the north and west to the regions they occupied.

In South America, curiously enough, the direction is reversed.

If the Caribs belong to the Tupi-Guaranay stem, and if the Quichuas belong to the Aymaras, as there is strong likelihood,[34-1] then nine-tenths of the population of that vast continent wandered forth from the steppes and valleys at the head waters of the Rio de la Plata toward the Gulf of Mexico, where they came in collision with that other wave of migration surging down from high northern latitudes.

For the banks of the river Paraguay and the steppes of the Bolivian Cordilleras are unquestionably the earliest traditional homes of both Tupis and Aymaras.
These movements took place not in large bodies under the stimulus of a settled purpose, but step by step, family by family, as the older hunting grounds became too thickly peopled.

This fact hints unmistakably at the gray antiquity of the race.