To revert to the Dakota principle, as Morgan points out,[18] the same principle has in part molded the Iroquois system, and when we find that in addition to the logically related elements the apparently irrational classification of cousins’ offspring is likewise common to the two terminologies, the case for historical connection becomes very strong. This becomes a certainty when we find that in its essentials the principle finds expression in the system of the intermediate Ojibwa, while among other Algonkian tribes and among Siouan tribes other than the Dakota a marked variant from the Dakota type makes its appearance. In short, we have the Dakota principle spread over a continuous region, which is sharply separated from adjoining regions. It has, then, developed in a single center in this part of North America and has thence spread by borrowing. If we ignore the mode of designating cross-cousins’, _i.e._, cousins who are children of a brother and a sister, and disregard certain other deviations constituting sub-types, we get a very much wider range of distribution for the Dakota principle in North America. The neglect of degree of kinship and the clear separation of the maternal and paternal line in the middle generations are features characteristic, probably, of the entire region east of the Mississippi and occur also in the Mackenzie River district, among the Tlingit and Haida of the Northwest Coast and most of the Plains tribes, in a part of the Pueblo territory (notably among the Hopi), and among the Miwok and adjacent populations in California. Since we are not by any means familiar with the kinship systems of the entire continent, it is necessary to supplement this statement with another indicating the regions where the Dakota principle is actually known to be lacking. The Dakota features are not found among the Eskimo, Nootka, Quileute, Chinook, various Salish tribes, the Kootenai, the Plateau Shoshoneans, nor in a large section of California to the north and east of the Miwok, and they are also absent from various Southwestern terminologies. The glib assumption of many writers that all of North America is characterized by a ‘classificatory system’ on the Dakota plan, is demonstrably false. The only reason for this belief is the historical accident that Morgan was conversant with the systems east of the Rocky Mountains and practically altogether ignorant of those of the Far West, and that since his time no one has systematically presented the data for what to him was a _terra incognita_. Let us extend our search for evidences of the Dakota principle to other regions.