Some of the results of my studies of the evolutionary phase of the subject are embodied in an accompanying paper upon the "Origin and Development of Form and Ornament," and a second paper will soon follow. Before the final work is issued I hope to make close studies of all the principal collections, public and private. In such a work the importance of great numbers of examples cannot be overestimated. Facts can be learned from a few specimens, but relationships and principles can only be derived from the study of multitudes. I shall probably have occasion to modify many of the views advanced in these preliminary papers, but it is only by pushing out such advance guards that the final goal can be reached. Since the original issue of this paper in the Proceedings of the Davenport Academy of Sciences, a careful revision of the text has been made and much additional matter and a number of illustrations have been added. I wish in this place to express my obligations to the officers and members of the Davenport Academy of Sciences, and especially to Mrs. M. L. D. Putnam and Prof. W. H. Pratt, whose generous aid has been of the greatest service to me. CERAMIC GROUPS. In studying the collections from the Mississippi Valley, I find it convenient to classify the ceramic products in three great groups, which belong to as many pretty well-defined districts; these I have named, for convenience of treatment, the Upper Mississippi, the Middle Mississippi, and the Lower Mississippi or Gulf provinces. Other pottery occurs within the limits of these areas, but the examples found in the museums are so few that very little of importance can be learned from them. The three groups enumerated are not equally represented. The great body of our collections is from the middle province. The ware of the Lower Mississippi or Gulf district, of which we have but a small number of pieces, has many features in common with the pottery of the middle district, and at the same time is identical in most respects with that of the Gulf coast to the east. No well-defined line can be drawn between them; but the ware of the north is wholly distinct and need never be confounded with the other groups. MIDDLE MISSISSIPPI PROVINCE. DISTRIBUTION.--It must not be inferred that there is perfect uniformity in the pottery of this, or any other, extended region; local peculiarities are always to be found. The products of contiguous districts, such, for example, as those of Mississippi County, Arkansas, and New Madrid County, Missouri, have much in common, and will at once be recognized as belonging to the same family, yet the differences are so marked that the unskilled observer could point them out with ease.