434 SMITHSOXIAX MISCELLANEOUS COLLECTIONS VOL. 52 



regular enough for successful agriculture without irrigation. They 

 present a good field for the evolution of a sedentary, agricultural 

 stage of human culture dependent on artificial irrigation. The ex- 

 tent of the aboriginal ditches that can be traced for miles show that 

 the prehistoric inhabitants had discovered and applied a more exten- 

 sive system of irrigation than any of their contemporaries who dwelt 

 in other sections of what is now the United States. Here was 

 developed a highly organized autochthonous stage of social life 

 which we have good evidence to believe was of great antiquity.^ 

 The indications are that it was from this center that there radiated 

 a form of culture which influenced the whole area now embraced in 

 the territories of New ]\Iexico and Arizona and the southern parts 

 of Utah and Colorado. 



In order successfully to bring an area of the size of the Gila and 

 Salt River valleys under cultivation, the construction of large irriga- 

 tion ditches was necessary, but these great canals could not be dug 

 by individuals, and were possible only through cooperation of many 

 workers. There must have been an intelligent leader to carry this 

 work to completion. This cooperation of many under one head 

 meant a high social organization. The natural result would be a 

 sociological condition higher than any that existed among bands of 

 hunters, fishermen, or even agriculturists depending on natural rain- 

 falls. 



A people accustomed to building irrigation canals naturally be- 

 came accustomed to cooperation and combined to construct other 

 public works, as houses for defense, for ceremony, or for storage 

 purposes. Hence there occur wath these extensive irrigation ditches 

 great houses, and wherever the population was the densest, there are 

 great buildings and canals, the most numerous and largest.- Such 

 Casas Grandes as the Gila compounds are to be expected among 

 people in this high social condition resulting from cooperation. 



There seems no valid objection to the theory that these settlements 

 were built by ancestors of the present house-building Indians of the 

 Southwest. It can hardly be supposed that the builders of these 

 Casas Grandes disappeared from their native land without descend- 

 ants, even if they lost the habit of constructing massive houses and 



^ A somewhat similar culture arose independently in the valley of the Casas 

 Grandes in Chihuahua, which in certain arts, as cerainics, reached a higher 

 stage of development, perhaps being unmolested for a longer period. 



°The existence of artificial reservoirs, or vashki. in the deserts, miles from 

 any compound, implies an aboriginal population in their neighborhood living in 

 huts, or jacales, the walls of which can no longer be traced. 



