These few and casual examples possibly suffice to show why kinship terms deserve the ethnologist’s attention. Terms of relationship are, in some measure, indices of social usage. Where relatives whom other people distinguish are grouped together, there is some likelihood that the natives regard them as representing the same relationship because they actually enjoy the same privileges or exercise the same functions in tribal life. Where relatives whom other peoples group together are distinguished, there is some probability that the distinction goes hand in hand with a difference in social function. Lewis H. Morgan, the pioneer in this domain of knowledge, was keenly alive to the social implications of kinship nomenclature. But while he endeavored to give an ultimate interpretation of it in terms of various social conditions, he was confronted with the fact that not every tribe had a terminology _sui generis_, but that nomenclatures of remote peoples were sometimes marvelously similar. Morgan boldly argued that such community of nomenclature established ultimate racial unity and on this ground coolly suggested a racial connection between the Hawaiians and the South African Zulu, between the natives of India and those of the Western Hemisphere.[1] These speculations as to racial affinity have been rightly disregarded by later students, because to accept Morgan’s premises means running counter to the most obvious facts of physical anthropology. As Lubbock pointed out, we cannot assume that the Two-Mountain Iroquois are more closely akin to remote Oceanians than to their fellow Iroquois because some of their kinship terms resemble in connotation those of the Hawaiians. Nevertheless, Morgan was right in feeling that _some_ historical conclusions could be drawn from similarities of relationship nomenclature. We must simply bring this particular group of ethnological data under the same principle as other cultural phenomena. When the same feature occurs within a definite continuous region, we shall assume that it has developed in a single center and spread by borrowing to other parts of the area. When the same feature occurs in disconnected regions, we shall incline to the theory of independent development and shall inquire whether the course of evolution may have been due to the same cultural determinants, _i.e._, in this case, to the same social institutions. After these preliminary remarks, we may turn to a closer scrutiny of the facts.