_The Pueblo Indians of the Southwest_.--In northern Mexico and Arizona there are remains of ancient buildings which seem to indicate that at one time a civilization existed here that has long since become extinct. Long before the arrival of the Spaniards, irrigation was practised in this dry territory. Indeed, in the Salt River valley of Arizona, old irrigation ditches were discovered on the lines of which now flow the waters that irrigate the modern orchards and vineyards. The discoveries in recent years in the southwest territory indicate that this ancient civilization had been destroyed by the warlike tribes that were ever ready to take possession of centres of culture and possess or destroy the accumulation of wealth of the people who toiled. If one could fill in the missing links of history with his imagination, it would be easy to conjecture that the descendants of these people fled to the mountains, and became the Cliff-Dwellers of the Southwest. These people built their homes high on the cliffs, in caves or on projecting prominences. Here they constructed great communal dwellings, where they could defend themselves against all enemies. They were obliged to procure their food and water from the valley, and to range over the surrounding _mesas_ in the hunt. Gradually they stole down out of the cliffs to live in the valleys and built large communal houses, many of which now are in existence in this territory. {195} These people have several centres of civilization which are similar in general, but differ in many particulars. They are classed as Pueblo Indians. Among these centres are the Hopi Indians, the Zunian, Taoan, Shoshonean, and many others.[1] The pre-history of these widely extended groups of Indians is not known, but in all probability they have been crowded into this southwest arid region by warlike tribes, and for the shelter and protection of the whole tribe have built large houses of stone or adobe. The idea of protection seems to have been the dominant one in building the cliff houses and the adobe houses of the plain. The latter were entered by means of ladders placed upon the wall, so that they could ascend from one story to another. The first story had no doors or windows, but could be entered by means of a trap-door.