racial contact. The principles and method employed by him differ essentially from those of Graebner. To Graebner the introduction of a new form of social organisation, a new language, or a new religion seems to be a process of the same order as the introduction of an element of material culture. To Rivers, social organisation, language, and religion seem to be bound up with the life of a people so far more intimately than material objects that it is not enough to say they have been introduced, but it is necessary to explain how an introduced element of culture has become part of the complex in which it is now found. Graebner began with material culture, where the signs of evolution are so far more doubtful and fragmentary that he has been led to ignore so largely the evolutionary character of the blending of cultures. He employs the geographical distribution of culture as the only trustworthy criterion for the arrangement of different elements of a cultural complex in order of time. The chief aim of Rivers in his History of Melanesian Society is to show how certain institutions and customs have arisen as the result of the interaction between peoples; Graebner regards the component elements as existing side by side and readily distinguishable from one another. It is not always quite clear why Graebner associates certain objects and customs together, and his relative chronological sequences are open to criticism. It should be remembered that he has never made investigations in the field. By his work in the field, and from other sources, Rivers, however, has established certain cultural complexes in Melanesia which can be definitely assigned to various immigrant peoples. The ideas, customs, and material objects which he has linked together were not merely assumed to be associated, but were proved to be associated as forming elements which belonged to a definite culture and to a definite cult. Certain beliefs, rites, customs, and objects were found to be linked together in an organic whole. The method formulated by Dr. Rivers
