LVI REPORT OF THE BUREAU OF ETHNOLOGY. 



rug'ged ranges rise from its surface. The land of the canyons 

 and the land of alluvial plains belong to the same pro\auce, 

 and their characteristics, as already' set forth, are due to a gen- 

 eral southwest ward tilting. In the canyons the aboriginal 

 habitations and temples were of stone, which was everywhere 

 abundant; in the plains the structures were of earthen grout 

 or cajon — a puddled mass of soil, perhaps mixed with pebbles, 

 molded into walls in successive layers, each allowed to dry 

 in the sun before the next layer was added; sometimes this 

 type of structure was modified by the incorporation of upright 

 or horizontal beams or poles, and sometimes the cajon was 

 combined with a sort of wattled structure composed of stems 

 and ribs of cacti, etc; but in general cajon was an important 

 element in the construction of the more permanent structiu'es 

 of the lowland. 



A considerable part of current knowledge concerning the 

 construction of the larger buildings of the plain springs from 

 studies of the Casa Grande (the "Great House" of Spanish 

 explorers), not far from the present town of Florence, Ai'izona. 

 This stnicture was discovered, already in ruins, in 1694, by 

 Padre Kino; and it has ever since been a subject of note by 

 explorers and historians. Thus its history is exceptionally 

 extended and complete. By reason of the early discovery and 

 its condition when first seen by white men, it is known that 

 Casa Grande is a strictly aboriginal structm-e ; and archeologic 

 researches in this country and Mexico aftbrd grounds for consid- 

 ering it a typical structure for its times and for the natives of the 

 southwesteni region. Many other structures were mentioned 

 or described by the Spanish explorers, but the impressions of 

 these explorers were tinctured by previous experiences in 

 an inhospitable region, and their descriptions were tinged by 

 the romantic ideas of the age. Moreover, nearly all of these 

 structures disappeared long ago — indeed, with the exception 

 of Casa Grande ruin, there is hardly a structure left by which 

 the early accounts of Spanish explorers in North America can 

 be checked and interpreted. Casa Grande is therefoi'e a relic 

 of exceptional importance and of essentially unique character. 



