How the Amerinds came here I explain by a theory that there was before, or perhaps during the early part of the glacial period, a wider distribution of land surfaces on latitudinal lines, which invited latitudinal migrations.[1] These land surfaces may have been no more than groups of larger or smaller islands which have been since wholly submerged or have left only their highest parts above the sea. Before the beginning of the glacial cold, a mild climate extended to the North Pole, facilitating migrations also in that region. Changes in the ocean’s bottom were probably greater in pre-glacial time than now, but they have not altogether ceased. It is little more than fifteen years since a new island appeared off the Aleutian chain, and I think it is doubtful if any of that group existed above water six or eight hundred years ago. I am also of the opinion that no human life was in Alaska or in Northeast Siberia five hundred years back. Races not being all of an even grade of culture before the beginning of the cold period any more than now, the tribes that found themselves isolated on this continent by changes in the land levels and by the southward extension of the glaciation, were unevenly developed, some being in advance of others in various ways, though none, of course, had passed beyond the use of stone tools, a condition in which they practically continued down to the Discovery. In this respect the term, “Stone Age,” as indicating a condition, is applicable, but it would not be possible to differentiate it into “Paleolithic” and “Neolithic” periods. The cold pushed them all southward, whether they came by northlands or by latitudinal lands, or both, towards the narrow funnel-like part of the continent, and also to the lower levels, as there was no chance for latitudinal expansion as in the Eastern Hemisphere, the most advanced tribes being the most southerly, if not from original position, because they were able to choose. Eventually communication with Asia and Europe by the north was by the glaciation severed completely, as it had previously been latitudinally by the disappearance of favourable land surfaces, and communication by the north remained closed till within three or four hundred years. The most crowded tribes developed most rapidly, because such development was imperative for self-preservation, and their culture filtered through in diminishing ratio, according to distance, to the less crowded regions—that is, to the climatically less favourable regions; but all who were closely crowded into the “funnel” progressed along similar lines and in much the same degree, _without regard to relationships_, so that we find in the narrow part of the continent, where the largest number found refuge from the cold, many different stocks in almost parallel stages of culture. There were no isolated “areas of characterisation” as in the latitudinally broader lands of the Eastern