Nevertheless it must be granted that in a theoretical consideration of the history of the types of mankind, of languages, and of cultures, we are led back to the assumption of early conditions, during which each type was much more isolated from the rest of mankind than it is at the present time. For this reason the culture and the language belonging to a single type must have been much more sharply separated from those of other types than we find them to be at the present period. It is true that such a condition has nowhere been observed; but the knowledge of historical developments almost compels us to assume its existence at a very early period in the development of mankind. If this is true, the question would arise, whether an isolated group at an early period was necessarily characterized by a single type, a single language, and a single culture, or whether in such a group different types, different languages, and different cultures may have been represented. The historical development of mankind would afford a simpler and clearer picture if we were justified in assuming that in primitive communities the three phenomena had been intimately associated. No proof, however, of such an assumption, can be given. On the contrary, the present distribution of languages, as compared with the distribution of types, makes it plausible that even at the earliest times the biological units may have been wider than the linguistic units, and presumably also wider than the cultural units. I believe it may be safely said that all over the world the biological unit—disregarding minute local differences—is much larger than the linguistic unit; in other words, that groups of men who are so closely related in bodily appearance that we must consider them as representatives of the same variety of mankind, embrace a much larger number of individuals than the number of men speaking languages which we know to be genetically related. Examples of this kind may be given from many parts of the world. Thus, the European race—including under this term roughly all those individuals who are without hesitation classed by us as members of the white race—would include peoples speaking Indo-European, Basque, and Ural-Altaic languages. West African negroes would represent individuals of a certain negro type, but speaking the most diverse languages; and the same would be true, among Asiatic types, of Siberians; among American types, of part of the Californian Indians.