to divide into families or small clans, each occupying a single house.  The traces of these solitary farm-houses show that they were at first single-storied.  The name of an upper room indicates how the idea of the second or third story was developed, as it is osh ten u thlan, from osh ten, a shallow cave, or rock-shelter, and u thla nai e, placed around, embracing, inclusive of.  This goes to show that it was not until after the building of the first small farm-houses (which gave the name to houses) that the caves or rock-shelters of the cliffs were occupied.  If predatory border-tribes, tempted by the food-stores of the horticultural farm-house builders, made incursions on the latter, they would find them, scattered as they were, an easy prey.

ADDED STORIES FOR CLIFF DWELLINGS DEVELOPED FROM LIMITATIONS OF CLIFF-HOUSE SITES.

[Illustration:  FIG. 498.—­A typical cliff-dwelling.]

This condition of things would drive the people to seek security in the neighboring cliffs of fertile canons, where not only might they build their dwelling places in the numerous rock-shelters, but they could also cultivate their crops in comparative safety along the limited tracts which these eyries overlooked.  The narrow foothold afforded by many of these elevated cliff-shelves or shelters would force the fugitives to construct house over house; that is, build a second or upper story around the roof of the cavern.  What more natural than that this upper room should take a name most descriptive of its situation—­as that portion built around the cavern-shelter or osh ten—­or that, when the intervention of peace made return to the abandoned farms of the plains or a change of condition possible, the idea of the second story should be carried along and the name first applied to it survive, even to the present day?  That the upper story took its name from the rock-shelter may be further illustrated.  The word osh ten comes from o sho nan te, the condition of being dusky, dank, or mildewy; clearly descriptive of a cavern, but not of the most open, best lighted, and driest room in a Pueblo house.

To continue, we may see how the necessity for protection would drive the petty clans more and more to the cliffs, how the latter at every available point would ultimately come to be occupied, and thus how the “Cliff-dwelling” (see Fig. 498), was confined to no one section but was as universal as the farm-house type of architecture itself, so widespread, in fact, that it has been heretofore regarded as the monument of a great, now extinct race of people!

COMMUNAL PUEBLOS DEVELOPED FROM CONGREGATION OF CLIFF-HOUSE TRIBES.

[Illustration:  FIG. 499.—­Typical terraced communal pueblo.]