FEWKES] CONCLUSIONS 219 
work of posts and wattling, the remains of houses not unlike in con- 
struction certain former habitations at Casa Grande.! 
In other words the ancient people of these regions seem to have 
constructed two kinds of buildings—forts on the hilltops and fragile 
habitations on the river terraces, which differed structurally and were 
occupied for special and distinct purposes. The former were defen- 
sive retreats for use in case of attack, the latter permanent domiciles 
or habitations, conveniently situated on terraces adjacent to farms. 
The same or an allied people erected also houses in natural caves or 
excavated them in soft rock. . Dwellings of the latter kind are found 
particularly in the area on the border of the Pueblo region, especially 
where the character of the rock lent itself to their construction. The 
inhabitants apparently had no kivas (rooms especially devoted to 
religious ceremonies), but they probably had a complicated ritual. 
Terraced ruins are rare or unknown. 
It appears that the dwellings of these people belong to a special 
type distinct from the terraced compact community houses, or pueblos, 
still represented among the Hopi, the Zuii, and the numerous Pueblos 
of the Rio Grande, although identical with some ancient houses in 
New Mexico. It is not strange if some of the descendants of clans 
formerly peopling this area have become amalgamated with the Hopi. 
In ancient times, however, the two cultures were as distinct, for 
instance, as are the present Havasupai and the Hopi, and in certain 
‘areas one of these cultures antedated the other. The Hopi and the 
Havasupai are friends and visit each other, and at times the Hopi 
allow some of the Havasupai to enter their kivas. 
The two types of artificial caves used as domiciles have been dis- 
tinguished elsewhere as those with vertical and those with lateral 
entrances. Both types may possess walled buildings above or in front 
of them, the cave becoming in the former case a storeroom, in the 
latter a rear chamber, possibly devoted to ceremonies. 
The association of walled buildings with artificial caves is quite 
general, the former being found either on the talus below or on the 
cliff above the latter, as well shown in the cavate dwellings on Oak 
Creek. A similar duality in cave-dwellings occurs in the case of 
some of the larger cliff-houses, as, for example, those in Canyon de 
Chelly. This duality is parallel with that existing in the forts and 
rancherias or terrace (bowlder) sites on Walnut Creek.? 
AGE or WaLNuT CREEK AND VERDE VALLEY Ruins 
It does not appear from evidences presented thus far that any con- 
siderable antiquity can be ascribed to the aboriginal structures in 
the Walnut Creek region, which were probably in use in the middle 
1 See Prehistoric Ruins of the Gila Valley, in Smithsonian Miscellaneous Collections, vol. 52, pt. 4. 
Massive-walled buildings for protection and fragile-walled habitations exist together within the inclo- 
sures of Gila Valley compounds, presenting the same dual combination, architecturally speaking. 
