In the centuries since the Spaniards first arrived the presence of the many imposing ruins which dot the Southwest has naturally led to much speculation about their inhabitants, and the collecting of antiquities has been inevitable. The collecting instinct is such that some relationship between man and the pack rat might well be postulated if it were not that man takes without leaving anything in place of what he has removed. From the time when the ruins of the prehistoric dwellings of the Southwest were first observed, until about 1880, there was a period of exploration and the more obvious places of archaeological interest were described and superficially investigated. From then, until approximately 1910, much sound work was done but there was an unfortunate tendency toward digging up specimens for their own sake rather than for the information which they could reveal. In the last thirty-five years or so, however, the emphasis has come to be more on the acquiring of information and less on the collection of examples of material culture. This has led to the excavation of less physically spectacular ruins, increasing cooperation with workers in related fields of science, and more careful planning of attacks on specific problems. In a sense the development of archaeology in the Southwest may be compared with the putting together of a great jig-saw puzzle. First came the period of general examination of the pieces, then a concentration on the larger and more highly colored pieces, and finally a carefully planned approach to the puzzle as a whole with serious attempts to fill in specific blank areas. After all, archaeology as a science can justify its existence only as it serves to increase and deepen our knowledge of that strange, and to us most fascinating mammal—man. Archaeologists in the Southwest have been particularly fortunate for a number of reasons. Perhaps most important is that climatic conditions have made possible the preservation of much material which in most climates would have disappeared in a relatively short time. Under sufficiently arid conditions the bacteria of decay cannot survive and the lack of humidity in the Southwest has insured the survival of much material which would normally be lost. Another thing for which archaeologists may be grateful is that pottery-making came to be so well developed in this area, for pottery fragments are almost indestructible. Furthermore, pottery is a most sensitive medium for reflecting change. Since it is fragile there is constant breakage which leads to the frequent manufacture of new pieces and this accelerates the rate of technical change. Archaeologists have learned to recognize certain styles which are characteristic of specific areas and periods and it is remarkable how much information ancient vessels will reveal about the people who made them.