The above observations have an important bearing on the author’s differentiation of the village Indians of the Southwest, into two groups, which are culturally distinct and widely distributed geographically. The western group originated in the Gila Valley, and extending across Arizona spread northward making its influence felt as far as the Hopi villages; the eastern culture was born in Colorado and Utah and extended to the south along a parallel zone. The former sprang into being in low, level, cactus plains; while the latter was born in lofty mountains and deep canyons filled with caves. Each reflects in its architecture the characteristic environment of the locality of its origin. As they spread from their homes and at last came together each modified the other by acculturation. The expansion of these two nuclei of culture, and the products of their contact is the prehistoric, unwritten, evolution of primitive people in the Southwest upon which documentary accounts throw no light, and the function of archeology is to read this history through the remains left by this prehistoric people, as interpreted by surviving folklore, ceremonials, legends, and artifacts. Both types of culture reached their highest development before the arrival of the white man; and the advent of the European found both on the decline. The localities where both types originated and reached their highest development were either no longer inhabited or occupied by descendants with modified architectural ideas. Some of the survivors lived in houses of much ruder construction than the cliff dwellings or pueblos of their ancestors. The habitations of others were scattered rude, mud huts. In short the cliff dwellers of the Mesa Verde and the prehistoric inhabitants of the Gila compounds left survivors possessed of inferior skill. Both architecture and ceramic art had declined before the advent of white men. [Illustration: PL. 1 TEBUNGKI FIRE HOUSE, ARIZONA.] [Illustration: PL. 2 CLIFF DWELLINGS IN CHIN LEE CANYON, ARIZONA. a, b, Ruin A. c, Ruin B. (Photographs by G. H. Hoater.)] [Illustration: PL. 3 SITES OF RUINS NEAR GALLUP, NEW MEXICO. a, Zuñi Hill Ruin. b, Black Diamond Ranch Ruin. c, Kiva of Zuñi Hill Ruin.] [Illustration: PL. 4 KIN-A-A, CROWN POINT, NEW MEXICO. a, b, From west. c, Showing mounds near Kiva.] [Illustration: PL. 5 KIN-A-A. a, Inner wall of second story of Kiva. b, Outer wall of Kiva.] [Illustration: PL. 6 CROWN POINT, RUIN B. a, From east. b, From north.] [Illustration: PL. 7 HILL CANYON UTAH. a, Ruins A and B. b, View up the canyon. (Photographs by T. G. Lemmon.)] [Illustration: PL. 8 RUINS NEAR TAYLOR’S LOWER RANCH, HILL CANYON, UTAH. a, Ruin A. b, Ruin B. (Photographs by T. G. Lemmon.)] [Illustration: PL. 9 LONG MESA, HILL CANYON, UTAH. a, From north. b, From south. (Photographs by T. G. Lemmon.)] [Illustration: PL. 10