discussions have made it apparent that migration is exceptional rather than universal, still, the logical necessities of the case require some movements of population. One can scarcely conceive of the peopling of the New World except by the expansion and spread of its population gradually from one area to another. It may be, however, that this is not the important point here. Thus, when we consider the best known or most probable cases of migration, they all seem to have one common character, since they are circumscribed movements in a single area. For example, the Eskimo, whose first appearance in the New World must have been in Alaska, spread only along the Arctic coast belt to its ultimate limits. Yet, since they are the sole possessors of this territory, they offer a far less suggestive example than can be found elsewhere. We now have satisfactory data for the northern movement of the Iroquois, but if we superimpose a linguistic map and one showing topography, we see clearly that whichever way the tribes of Iroquoian stock moved, they kept close to the Atlantic Highlands. On the other hand, the Algonkin expanded in lands of less elevation, 500 to 2,000 feet, but chiefly in a wooded lake and portage region. In like manner, we may follow out the Siouan, Athapascan, Salishan, and Muskhogean, Shoshonean, Mayan, Arawakan, Cariban, and other stocks. It cannot be an accident that all the Muskhogean peoples lived at an elevation less than 500, that the Algonkin were, with few exceptions, between 500 and 2,000, that the Athapascan are chiefly inland between 2,000 and 5,000, while the Shoshoni-Nahuatl stock occupies land above 5,000. If, then, we turn from linguistic to culture characters, we find similar agreements. The Southeastern culture (Area 8, Fig. 67), is below 500 feet, the Eastern Woodland area (7) is, in the main, from 500 to 2,000, the Nahua area (10) above 5,000, as was also the home of Inca culture (12).
It is also suggestive to take a topographical map as our point of departure, and note the correlations between elevation and the variations in cultures. Thus, the Algonkin of the Atlantic Coast plain from Maine southward are below 500 feet, or on a level with the Muskhogean group, and it is
