NO. 1873 PREHISTORIC RUINS IN GILA VALLEY FEWKES 405 



The architectural features of these prehistoric buildings of the 

 Gila plains is well shown in the historic Casa Grande, which may be 

 designated, for purposes of study, a "type ruin." Its walls have now 

 been excavated and are well preserved, showing the best example 

 of other Casas Grandes scattered over the valley of the Gila and its 

 largest tributary, the Salt River. The predominating feature of this 

 Gila type of ruin is a rectangular inclosure bounded by a massive 

 wall oriented about north and south and inclosing buildings, large 

 and small, courts, and plazas. From the universal existence of a 

 protective surrounding wall, the author has designated this type of 

 prehistoric ruin a "compound" to distinguish it from other prehis- 

 toric ruins of the Southwest above mentioned, with which it has 

 little in common. 



Although the more striking mounds of this valley are formed of 

 the debris of these great houses, or Casas Grandes, there is good 

 evidence that the prehistoric inhabitants built synchronously with 

 these other less conspicuous dwellings, which are not unlike the 

 ancestral dwellings of the Pima, Sobypuri, 1 and Papago. These 

 dwellings were rectangular in form. Their walls were supported 

 by upright logs, between which were woven matting or possibly 

 branches of the cactus called ocatilla, the whole frame being covered 

 with adobe. The floors of such houses were made of mud firmly 

 trodden down, while the fireplace was a simple depression near the 

 middle of the floor, generally in front of a doorway opening in the 

 longest side. We may suppose that the roof was also constructed 

 of mud laid on boughs or split logs, the interstices being filled 

 with mud. 



A typical prehistoric settlement of the Gila may be supposed to 

 have been composed of buildings constructed of massive walls one 

 or more stories high and smaller huts or jacales (Aztec, xa, earth; 

 calli, houses), the upright walls of which were supported by logs. 

 Both types of houses occur in the rectangular area that has been 



of the cliff, while the latter have taken advantage of natural caverns. The 

 two types grade into each other, and no strict line of demarkation separates 

 one from the other. The essential feature of the compound is the surround- 

 ing wall, which is sometimes morphologically represented in aboriginal build- 

 ings known as pueblos. 



*The walls of houses of rancherias of the Sobypuri in the San Pedro are 

 spoken of by Father Kino as made of "palos" (sticks) and "petates" (mat- 

 ting), the chinks being filled in with clay or mud. No reference is made in 

 his account of buildings in this valley with massive walls, although the 

 "capilla" at Victoria may have been a special house made of stone and set 

 aside for ceremonial purposes. 



