How could marauding parties have entered them if the inhabitants were hostile? The cliff-dwellings were constructed partly for defense, but mainly for the shelter afforded by the overhanging cliff, and the cause of their desertion was not due so much to predatory enemies as failure of crops or the disappearance of the water supply. The writer does not regard these ruins as of great antiquity; some of the evidence indicates that they are of later time. Features in their architecture show resemblances derived from other regions. The Navaho ascribe the buildings to ancient people and say that the ruined houses existed before their own advent in the country, but this was not necessarily long ago. Such evidence as has been gathered supports Hopi legends that the inhabitants were ancient Hopi belonging to the Flute, Horn, and Snake families. There is no evidence that cliff-house architecture developed in these canyons, and rude structures older than these have been found in this region. Whoever the builders of these structures were, they brought their craft with them. The adoption of the deflector in the rectangular ceremonial rooms called kihus implies the derivation of these rooms from circular kivas, and all indications are that the ancient inhabitants came from higher up San Juan river. Many of the ruins in Canyon de Chelly situated east of Laguna creek show marked evidence of being modern, and they in turn are not so old as those of the Mesa Verde. If the ruins become older as we go up the river the conclusion is logical that the migration of the San Juan culture was down the river from east to west, rather than in the opposite direction. The scanty traditions known to the author support the belief in a migration from east to west, although there were exceptional instances of clan movements in the opposite direction. The general trend of migration would indicate that the ancestral home of the Snake and Flute people was in Colorado and New Mexico. [Illustration: BUREAU OF AMERICAN ETHNOLOGY BULLETIN 50 PLATE 22 SKETCH MAP OF THE ·NAVAHO NATL·MONUMENTS· FROM OFFICIAL REPORTS BY W·B·DOUGLASS U·S·GENL· LAND OFFICE 1910 ] It is evident from the facts here recorded that the ruins in the Navaho National Monument contain most important, most characteristic, and well-preserved prehistoric buildings, and that the problems they present are of a nature to arouse great interest in them. Having suffered comparatively little from vandalism, these are among the best-preserved monuments of the cliff-dwellers’ culture in our Southwest, and if properly excavated and repaired they would preserve most valuable data for the future student of prehistoric man in North America. It is not necessary to preserve all the ruins within this area, but it would be well to explore the region and to locate the sites of the ruins that it contains. FOOTNOTES: