Important as dendrochronology is, it is far from being the only outside science upon which archaeologists must depend. The records left by Spanish historians, who found the Pueblo Indians in the 16th century still untouched by European civilization and living essentially the same sort of life as their ancestors, have provided invaluable information. Also of great importance has been the work of ethnologists, scientists who analyze the culture of living primitive people. In the Southwest archaeologists are particularly fortunate, for in many cases descendents of the prehistoric people whom they study are still living in the same general area and under very similar circumstances. In spite of the outside influences to which they have been subjected there is still much to be learned from them. The knowledge of these people garnered by the historian and the ethnologist, added to that obtained by the archaeologist, gives us a far better picture of the life of prehistoric times. Although a study of material culture tells a great deal about a people, there is much of their social, political and religious life which it cannot reveal unless supplementary information is available. There are grave dangers inherent in too great a concentration on material culture. It has been said of the archaeologist that “sometimes he cannot see the people for the walls”[125] and it is the people themselves, after all, who are important. Two examples will show how ethnology and archaeology may complement each other. In certain prehistoric sites are found circular underground rooms with highly specialized characteristics. The objects found in these are usually non-utilitarian so that, even if no further information were available, archaeologists would consider them chambers having some religious significance. However, thanks to the fact that similar rooms or kivas, as they are called, are still in use in the modern Pueblo villages, the archaeologist may not only be sure of their ceremonial nature, but he is in a position to understand more of their significance through studying their function in modern Pueblo society. One point demonstrates very clearly how, through correlating ethnological and archaeological evidence, it is possible to understand something of the religious beliefs of people who died hundreds of years ago leaving no written records.