You go to one section of ruins, and you come to certain definite conclusions. Then you go on to another group of ruins; and every one of your conclusions is reversed. For instance, what drove these races out? What utterly extinguished their civilization so that not a vestige, not an echo of a tradition exists of their history? Scientists go up to the Rio Grande in New Mexico, see evidence of ancient irrigation ditches, of receding springs and decreasing waters; and they at once pronounce--desiccation. The earth is burning up at the rate of an inch or two of water in a century; moisture is receding toward the Poles as it has in Mars, till Mars is mostly arid, sun-parched desert round its middle and ice round the Poles. Good! When you look down from the cliff dwellings of Walnut Canyon, near Flagstaff, that explanation seems to hold good. There certainly must have been water once at the bottom of this rocky box-canyon. When the water sank below the level of the springs, the people had to move out. Very well! You come on down to the cave dwellings of the Gila. The bottom falls out of your explanation, for there is a perpetual gush of water down these rock walls from unfailing mountain springs. Why, then, did the race of little people move out? What wiped them out? Why they moved in one can easily understand. The box canyons are so narrow that half a dozen pigmy boys deft with a sling and stones could keep out an army of enemies. The houses were so built that a child could defend the doorway with a club; and where the houses have long hallways and stairs as in Casa Grande, the passages are so narrow as to compel an enemy to wiggle sideways; and one can guess the inmates would not be idle while the venturesome intruder was wedging himself along. Also, the bottoms of these box-canyons afforded ideal corn fields. The central stream permitted easy irrigation on each side by tapping the waterfall higher up; and the wash of the silt of centuries ensured fertility to men, whose plowing must have been accomplished by the shoulder blade of a deer used as a hoe. Modern pueblo Indians claim to be descendants of these prehistoric dwarf races. So are we descendants of Adam; but we don't call him our uncle; and if he had a say, he might disown us. Anyway, how have modern descendants of the dwarf types developed into six-foot modern Pimas and Papagoes? It is said the Navajo and Apache came originally from Athabasca stock. Maybe; but the Pimas and Papagoes claim their Garden of Eden right in the Southwest. They call their Garden of Eden by the picturesque name of "Morning Glow." How reach the caves of the dwarf race?