The development of architecture among the Pueblo Indians was comparatively rapid and is largely attributable to frequent changes, migrations, and movements of the people as described in Mr. Stephen’s account. These changes were due to a variety of causes, such as disease, death, the frequent warfare carried on between different tribes and branches of the builders, and the hostility of outside tribes; but a most potent factor was certainly the inhospitable character of their environment. The disappearance of some venerated spring during an unusually dry season would be taken as a sign of the disfavor of the gods, and, in spite of the massive character of the buildings, would lead to the migration of the people to a more favorable spot. The traditions of the Zuñis, as well as those of the Tusayan, frequently refer to such migrations. At times tribes split up and separate, and again phratries or distant groups meet and band together. It is remarkable that the substantial character of the architecture should persist through such long series of compulsory removals, but while the builders were held together by the necessity for defense against their wilder neighbors or against each other, this strong defensive motive would perpetuate the laborious type of construction. Such conditions would contribute to the rapid development of the building art. CHAPTER I. TRADITIONAL HISTORY OF TUSAYAN. EXPLANATORY. In this chapter[1] is presented a summary of the traditions of the Tusayan, a number of which were collected from old men, from Walpi on the east to Moen-kopi on the west. A tradition varies much with the tribe and the individual; an authoritative statement of the current tradition on any point could be made only with a complete knowledge of all traditions extant. Such knowledge is not possessed by any one man, and the material included in this chapter is presented simply as a summary of the traditions secured. [Footnote 1: This chapter is compiled by Cosmos Mindeleff from material collected by A. M. Stephen.] The material was collected by Mr. A. M. Stephen, of Keam’s Canyon, Arizona, who has enjoyed unusual facilities for the work, having lived for a number of years past in Tusayan and possessed the confidence of the principal priests--a very necessary condition in work of this character. Though far from complete, this summary is a more comprehensive presentation of the traditionary history of these people than has heretofore been published. SUMMARY OF TRADITIONS.