If the growth of the large pueblos has followed the lines above indicated, and if each unit type indicates a social unit as well, we necessarily have in this growth of the community house the story of the social evolution of the Pueblo people. Clans or social units at first isolated later joined each other, intermarriage always tending to make the population more homogeneous. The social result of the amalgamation of clans seeking common defense would in time be marked. The inevitable outcome would be a breaking down of clan priesthoods or clan religions and the formation of fraternities of priesthoods recruited from several clans. This in turn would lead to a corresponding reduction and enlargement of ceremonial rooms remaining. Two kivas suffice for the ceremonies of the majority of the Rio Grande pueblos; but Cliff Palace with a population of the same size had 23 and Spruce-tree House, a much smaller cliff pueblo, had 8. One can not fail to notice a similarity in sites of some of the great houses of the McElmo to neighboring cliff habitations and a like relation of Sun Temple to the cliff-dwellings in Fewkes Canyon in the Mesa Verde. Possibly the purpose of these great houses and Sun Temple was identical. Some of the great houses were probably granaries and Sun Temple may have been intended partly for a like use. No indications of remains of stored corn have been observed in any of these buildings, but Castañeda[61] speaks of a village of subterranean granaries (“silos”) in the Rio Grande country, which is instructive in this connection. [61] Fourteenth Ann. Rept. Bur. Amer. Ethn., pt. 1, p. 523. This village is spoken of as “lately destroyed;” in other words it was a ruin in 1540. INDEX ACMEN RUIN, described, 29 ANTIQUITIES, minor, 66 ARCHITECTURE, culture areas determined by, 69 ARCHITECTURE, PUEBLO— elements of, 73 of local origin, 70 AZTEC ARCHITECTURE, unlike that of Pueblos, 69 AZTEC SPRING, ruins at, 23 described by Holmes, 24 described by Jackson, 24 ground plan of, 26 BEAMS, WOODEN, method of shaping, 67 BLANCHARD RUIN, 23 BONE, objects made of, 67 BOWLDER CASTLE, description of, 57 BOWLS, MORTUARY, 66 BUG MESA RUIN, description of, 19 BUG POINT RUIN, excavation of, showing unit type, 29 BURIAL CUSTOMS, 66, 67 BURIAL PLACES— mentioned by Morgan, 21 near Holmes Tower, 59 on Grass Mesa, 64 on the Dolores, 11 BURKHARDT RUIN. _See_ MUD SPRING RUIN. BUTTE RUIN, description of, 32