In the state of barbarism tribal organization may exist; some form of religion is usually recognised; definite marriage relations are entered into, although polygamy is commonly practised; permanent houses, perhaps for winter use only, are built; clothes are made from woven cloth as well as from skins; the plaiting of baskets and the art of making coarse pottery, frequently highly decorated, are understood; essentially all utensils, arms, etc., are of stone, wood, bone, or ivory, the metals other than those occurring in a native state being unknown; and writing is unknown, although pictographs may be employed. Civilization implies a well-marked development in ethics, laws, social organization, institutions, arts, writing, etc. Under this scheme of classification various divisions of the aborigines of North America at the time of the coming of Columbus occupied each of the planes of development designated; but those frequently classed as civilized had not arrived at an advanced stage of culture, and can perhaps with greater propriety be designated as semicivilized, or, better still, be referred to the highest stage of barbarism. Some of the native tribes, as those of southern California and certain of the peoples of Mexico and Central America, were in a state of savagery, and, in fact, have not advanced beyond that state at the present day. A large majority of the aborigines, as, for example, the Algonquins, Shoshoneans, etc., or, in general, all of the Indians to the northward of Arizona and New Mexico, together with certain of the tribes to the south of that boundary, had definite tribal organization, permanent homes at least for winter use, in part practised horticulture, and for these and other reasons are to be classed as in the barbarous stage of development. The Aztecs, Mayas, etc., of Mexico and Central America had well-established governments, built permanent and frequently large and elaborately decorated houses, some of which were of hewn stone, practised horticulture with the aid of irrigation, had developed a system of picture-writing, and were skilled in working native metals. These and other advances towards civilization were great and promising, but the use of iron was unknown, and their practice of human sacrifice and the absence of phonetic writing denies them a place among truly civilized peoples.