the things they make and use, and which is so clearly manifest in their names of such things. It is a tendency so great, indeed, that neither change of environment and other conditions, nor yet substitution of unused materials for those in customary use for the making of things, will effect change in their forms at once, even though in preserving older forms in this newer sort of material the greatest amount of inconvenience be encountered. There is, indeed, but one influence potent enough to effect change from one established form to another, and that is acculturation; and even this works but slowly and only after long and familiar intercourse or after actual commingling of one people with a diversely developed people has taught them the safety and efficiency of unfamiliar forms in uses familiarly associated with their own accustomed but different forms. Sooner or later such acculturation invariably effects radical change in the forms of things used by one or the other of the peoples thus commingling, or by both; though in the latter case the change is usually unequal. In the case here under consideration there is to be found throughout the nearer Zuñi country ruins of the actual transitional type of pueblo thus formed by the union of the two ancestral branches of the Zuñis, the round town with its cliff-like outer wall merging into the square, terraced town with its broken and angular or straight outer walls; and in these composite towns earliest appears, too, the house wall built into (not merely against) the outer walls of the curved portions no less than into the outer walls of the squared or straight portions.