Scarcely less incredible are the theories which still have some distinguished advocates, that the continent was peopled from Polynesia, or directly from Japan or China. Several laborious works have been compiled with reference to “Fu Sang,” a land referred to as east of China, and identified by these writers with Mexico. A distinguished ethnologist has recently published a map showing the courses by which he supposes the Japanese arrived in America.[4] It is not impossible that in recent centuries some junks may have drifted on the Northwest coast. But their crews would undoubtedly have been promptly slaughtered; and it is only in later ages that the Chinese or Japanese constructed such junks. The theory, therefore, offers no solution to the problem. Still less does that in reference to the Polynesians. They had no such craft as junks, and though bold navigators, were wholly unprepared to survive so long a voyage as from the nearest of the islands of Oceanica to the coast of America. Moreover, we have satisfactory proof that the eastern islands of Polynesia were peopled from the western islands at a recent date, that is, within two thousand years. Probably the favorite theory at the present day is that the first inhabitants of the New World came from northeastern Asia, either by the Aleutian islands or across Behring Strait. Concerning the Aleutian islands we know by the evidence of language and archæology that they were first peopled from America, and not from Asia. Moreover, they are separated one from the other in places by hundreds of miles of a peculiarly stormy and dangerous sea.[5] It is otherwise with Behring Straits. From East Cape in Siberia one can see the American shore, and when first explored the tribes on each side were in frequent communication. No doubt this had been going on for a long time, and thus they had influenced each other in blood and culture. But so long as we have any knowledge of the movings at this point, they have been _from_ America into Asia, the Eskimos pushing their settlements along the Asian coast. It will be replied that we should look to a period anterior to the Eskimos. Any migration at that remote epoch is refuted by other considerations. We know that Siberia was not peopled till late in the Neolithic times, and what is more, that the vicinity of the strait and the whole coast of Alaska were, till a very modern geologic period, covered by enormous glaciers which would have prevented any communication between the two continents.[6] These considerations reduce any possible migrations at this point to such as may have taken place long after America, both North and South, possessed a widespread population. The question which should be posed as preliminary to all such speculations is, _When_ did man first appear on this isolated continent? To answer this we must study its later geological history, the events which have occurred since the close of the Tertiary, that is, during the Quaternary age.