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PREFACE.

graphy and kindred sciences, as well as to historians, travellers, and missionaries. I will only mention apart two treatises of which I have made especial use: the 'Mensch in der Geschichte,' by Professor Bastian, of Berlin, and the 'Anthropologie der Naturvölker,' by the late Professor Waitz, of Marburg.

In discussing problems so complex as those of the development of civilization, it is not enough to put forward theories accompanied by a few illustrative examples. The statement of the facts must form the staple of the argument, and the limit of needful detail is only reached when each group so displays its general law, that fresh cases come to range themselves in their proper niches as new instances of an already established rule. Should it seem to any readers that my attempt to reach this limit sometimes leads to the heaping up of too cumbrous detail, I would point out that the theoretical novelty as well as the practical importance of many of the issues raised, make it most unadvisable to stint them of their full evidence. In the course of ten years chiefly spent in these researches, it has been my constant task to select the most instructive ethnological facts from the vast mass on record, and by lopping away unnecessary matter to reduce the data on each problem to what is indispensable for reasonable proof.

E. B. T.
March, 1871.