That the continent was entirely peopled by way of Bering Strait within the last thousand years, by migrations through a zone of ice, is improbable. To assume that a population came over and passed down to Mexico and Yucatan and even South America, carrying with them their arts, but not exercising them on this interminable journey, is ridiculous. No pottery has yet been found between the Yukon and the Humboldt, or even farther south, probably because the Eskimo learned what little they knew about it while in the St. Lawrence valley or the Atlantic region, and the tribes of the North-west coast never came into sufficiently close contact with potters to learn the art.[387] Furthermore, no authentic trace of any Old-World language thus far has been found on this continent, and the only Asiatic language now known to be allied to an American is that of a branch of the Eskimo family which crossed from this side within the last three hundred years. The Amerind languages change slowly. An immense period must have elapsed since their separation from the rest of the world. It is said that two Japanese vessels a year are wrecked on our California coast, and some have peopled the continent from this source; a more absurd theory than the other. The number of Japanese vessels that were afloat a thousand years ago was as nothing compared with those afloat to-day, and if only two per annum are wrecked on these shores to-day, the wrecks a thousand years ago did not add materially to the population.[388] It is possible, however, that a few persons may have reached either seaboard that way, and like Cabeza de Vaca, they may have wandered for years among the various tribes as teachers and medicine-men, giving rise to legends of “white and bearded strangers.” But in the early days vessels were frail and did not venture far from the coast, so that the chances of being driven to American shores without foundering were very slight. The Northmen made the voyage, however, and others may have done it. Yet the supposed visits of the Irish and Danes are hardly worthy of serious consideration, although it would be rash to deny the possibility of their having come. As for the Lost-Tribes-of-Israel theory, on which Kingsborough was wrecked, no archæologist of to-day would be willing to give it a second thought. A multitude of stock languages, differing from each other, yet forming a world-group by themselves, are found here. The people who speak them, from Panama to the Arctic, are in their habits, customs, and physical characteristics wonderfully homogeneous,[389] yet they appear to exhibit several types that have been moulded into a family resemblance by some strange circumstance. Toward Panama, some of them attained a considerable degree of progress, but these were not of one special stock but of diverse stocks. Farther north there was another group attaining to a less but a similar kind of progress, and they also were, and are, of diverse stocks. In the