436 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 52 



A few years later the Sobypuri were forced westward and the 

 Pimas, who were probably the offspring of an earlier union of hos- 

 tiles and the house-builders they conquered, retreated to Casa Blanca 

 and Sacaton, leaving the Apaches to raid the whole of the eastern 

 part of the Gila Valley, including the San Pedro. 



The author would state in conclusion that he believes the abandon- 

 ment of the Casas Grandes was brought about by an invasion of 

 nomads from farther down the river, in prehistoric times. The 

 aborigines who inhabited the valley of the Gila when the Spaniards 

 first entered it were a mixed race, with blood of conquered and con- 

 queror. These people — Pimas, Papagos, and others — practically 

 inhabited fragile walled houses built in two forms — some rectangu- 

 lar, others circular — the former of which were practically the same 

 as those of their ancestors who built the Casas Grandes. The cir- 

 cular dwellings may have been introduced by the alien prehistoric 

 hostiles from the west. As the Great Houses on the Salt and Santa 

 Cruz seem to have been destroyed before those on the Gila, the con- 

 clusion would be that the prehistoric enemies came from the west and 

 south. The advent of the Apaches and their struggles with the 

 mixed race that replaced the builders of the Casas Grandes is a sub- 

 sequent practically historical event. 



