The last-mentioned term is suggestive in another way. Restricted among the Koranko and Susu to the father’s sister, it is applied by the Timne to the maternal aunt as well. Turning once more to the map, we discover that this latter mode of grouping, though not the same word phonetically, occurs among the Bulem, the immediate coastal neighbors of the Timne, who belong to the same linguistic subdivision, and also to the Mendi and Vai, to the east and southeast, who are members of the complementary subdivision. So far, this only indicates the spread of a terminological trait over a continuous area. But the data further suggest that the word _ntene_ may have been borrowed by the Timne rather than in the reverse direction, and that, as Mr. Thomas himself remarks, the Timne secondarily extended the term to include a maternal as well as a paternal aunt. This possibility is theoretically significant, first, because it indicates that Hawaiian analogies may develop independently of any such generation principle as dominates the Oceanian system; secondly, because it suggests that such simplicity of nomenclature, instead of being primitive as Morgan supposed, may represent a later development. To this point we shall have to revert later. _The Dakota Principle._ Let us now turn to that principle which first aroused Morgan’s interest and which since his time has occupied perhaps more attention than any other, the classificatory principle _par excellence_ in Dr. Rivers’ opinion, which finds expression among such tribes as the Iroquois and Dakota. Like the Hawaiian principle, the Dakota alignment groups together, regardless of proximity of relationship, members of the same generation, but differs because in the speaker’s generation, the first ascending and the first descending generations, it separates the paternal and the maternal line. Another way of expressing the facts is to say that collateral and lineal kin are merged irrespective of nearness of relationship but with strict bifurcation of the parental lines. Thus, in Dakota[15] the father, father’s brother, father’s father’s brother’s son, father’s father’s father’s brother’s son’s son are all addressed _até_; the mother, mother’s sister, mother’s mother’s sister’s daughter are all called _iná_. So far we have a classing together of kin who in English are distinguished from one another. But there is separation of kin whom we class together, inasmuch as the mother’s brother is designated by a term distinct from that for father’s brother, _viz._, by _dēkcí_, and the father’s sister by a term differentiating her from the mother’s sister, _viz._, by _t ‘uwí_. Now, relationship is a reciprocal phenomenon, and accordingly we may expect that all those whom I class together under the term _até_ or _iná_ will address me by a correlative term. Actually, we find that the Dakota have a single word, _mi tcíñkci_, for son, brother’s son (man speaking), father’s brother’s