8. The line of demarcation between the Indians of the Yukon and the Eskimo, outside of language, is indefinite. Traces of old Eskimo admixture are perceptible among the Indians far up the river, and the cultures of the two peoples in many respects merge into each other; while among the Eskimo of the lower river and farther on there are physiognomies that it would be hard to separate from the Indian. Whether all this means simply extensive past mixture, or whether, as would seem, the Alaska Indians as a whole are nearer physically to the Eskimo than are the tribes in the States, remains to be determined. Among the Athapascan Mescalero Apache, who have reached as far south as New Mexico, a somewhat Eskimoid tinge to the face, especially in young women, was by no means very unusual 25 years ago when I studied this tribe. This problem will be touched upon again in this volume. 9. All along the Yukon, from near Tanana (Old Station) to the mouth of the river, in the Indian and in the Eskimo region, there prevailed the same type of winter house, namely, a largely subterranean room with a subterranean tunnel or corridor entrance; and also a similar type of summer dwelling, formerly a skin, now a canvas, tent. The winter dwellings were built within of stout posts and covered with birch bark and sod, looking from outside much like the present-day Navaho hogan; while the pits left by them remind one of the southwestern "pit dwellings," the kashims of the Pueblo kivas. As a hogan, so these largely subterranean dwellings along the Yukon had a smoke-air-and-light hole in the center of the top, a fireplace in the middle of the floor, and benches (of heavy hewn planks in the north) along the sides. Each village, furthermore, had at least one larger structure of similar nature, the "kashim," or communal house. All this may still be traced more or less plainly on the dead sites along the Yukon, and houses as well as a kashim of this type were seen at Kotlik and Pastolik, at the mouth of the river. 10. The native industry of the river presents also much similarity, though there are differences. Pottery, of much the same type and decoration, was made at least as far as the lower middle Yukon. Stone implements were made and used all along the river, and were much alike. But the double-grooved, cupid-bow ax of the Yukon Indian, hafted in the center and used for chipping rather than cutting, is lower down replaced by the same ax, in which one end has been broken off (or has not been finished), and which is hafted as an adze; or by oblong quadrilateral flat axes which have not been found up the river. The peculiar and apparently very primitive stone industry of Bonasila is, it seems, just a development of local conditions--nature of most available stone, and essentially hunting habit of the people that resulted in many skins which called for numerous scrapers. Nevertheless the site deserves a thorough further exploration.