Note 205 — Chapter IV · —The Movements Of Peoples In Their Geographical Significance

Much farther down in the cultural scale we find the fisher tribes of Central Africa extending their villages from point to point along the equatorial streams, and the river Indians of South America gradually spreading from headwaters to estuary, and thence to the related environment of the coast. The Tupis, essentially a water race, have left traces of their occupation only where river or coast enabled them to live by their inherited aptitudes.205 The distribution of the ancient mounds in North America shows their builders to have sought with few exceptions protected sites near alluvial lowlands, commanding rich soil for cultivation and the fish supply from the nearby river. Mountaineer folk often move from one upland district to another, as did the Lombards of Alpine Pannonia in their conquest of Lombardy and Apennine Italy, where all their four duchies were restricted to the highlands of the peninsula.206 The conquests of the ancient Incas and the spread of their race covered one Andean valley after another for a stretch of one thousand five hundred miles, wherever climatic and physical conditions were favorable to their irrigated tillage and highland herds of llamas. They found it easier to climb pass after pass and mount to ever higher altitudes, rather than descend to the suffocating coasts where neither man nor beast could long survive, though they pushed the political boundary finally to the seaboard. [Map page 101.]