Page:The American Indian.djvu/414

348 Its variegated history is outlined in the diagram, showing how it first took definite form among the Pawnee by the union of certain foreign concepts and how later from this sprang the Grass Dance, and in turn the latter gave the Dream Dance. A close study of the rituals for each type indicates that the Dream Dance, which originated among groups belonging to the Eastern Woodland culture area is widely divergent from the Grass Dance, notwithstanding that this dance was its parent. The tribes in the Plains area took up the Grass Dance one after the other, but on the borders of the Eastern Woodland area the Dream Dance is found. Analysis of the two ceremonies shows that each is adapted to the prevailing pattern of its area. Hence, we may generalize with the statement that in taking over a foreign ceremony, concessions will be made to the tribal pattern.

Thus, it is apparent that a great advance has been made in empirical studies of the origin of particular culture-complexes. The spread of these complexes over a geographical area is explained by diffusion from a center. Some progress has been attained in observing the manner, or mechanism, of this diffusion. On the other hand, we are constrained to assume that since in many cases these trait-complexes are confined to a single area, they must have originated as new inventions within its borders. As an illustration, we may again refer to the societies of the Plains Indians. The native conception upon which this organization is based is the creation of a series of societies which one must enter in a fixed sequence at equal intervals. Further, as these organizations require that the youths who enter the lowest society shall be of about the same age, we have a system of age-grading. Now, this idea of age-qualifications for membership in a society is found only among the Blackfoot, Gros Ventre, Arapaho, Mandan, and Hidatsa tribes. Yet the same societies in all their other essential features are found to cover the entire area (Fig. 102). From the map, we see that the tribes having the age-grading system have a central position; at least, they do not reach the edges of the distribution area. Now, since we do not find these societies anywhere else in the New World, it is fair to