The time when the others expired has never been even approximately established. It may have been one, two, three, any number of centuries before our occupation. In that climate a house ruin might endure ages with hardly a noticeable change. But there are certain points leading to the belief that some of the depopulating was of sudden occurrence, and as diseases brought by the Europeans early spread from Mexico, and as sedentary people closely grouped would suffer even more than tribes living in open camps, it appears reasonable to assume that smallpox and kindred diseases ravaged the whole Wilderness soon after the landing of Cortez, and were particularly disastrous in the South-west. Nothing in the shape of skeletons would remain to tell the tales of destruction, because wolves and dogs would devour the bodies and scatter the bones. As they will dig a body out of a grave and strew the bones far and wide, dragging one from a house would be simple. When the smallpox finally swept through the plains tribes, in historical time, they were wofully reduced in numbers. Many killed themselves to avoid the lingering horrors. Whole tribes were exterminated, and the wolves and dogs consumed the putrid carcasses.[30] [Illustration: Necklace of Human Fingers.] Probably there was never a dense population, yet there might have been, say, three or four hundred thousand all told, in the Wilderness. This, with perhaps, six or seven hundred thousand east of the Mississippi, would give a total aboriginal population for the area of the United States of about a million.[31] The estimate of Major Powell was under three-quarters of a million. A quarter of a million are left, and they are not decreasing, for though they are very poor as a rule, owing to the destruction of their game and other food supplies and to their having no means of earning money, yet contagion no longer destroys them as of old, and wars are a thing of the past. They are now, however, a different people from those occupying the country at the beginning of the sixteenth century. To their enemies they were often horribly cruel, to those of their own hue as well as those who were white. And they learned speedily that the white man was much the same as themselves in this regard. They no longer burn victims at the stake, but the white man who, in the earliest time gave them fearful lessons in this art, still continues it; even within sight of our temples of justice. Their wars were multiplied by the compression of their free territory, which was the result of the white man's arrival, and by the impositions of the newcomers. There was one locality, a strip lying along the eastern base of the Rocky Mountains, which appears to have been a sort of No Man's Land, and this was called the "Hostile Ground," and the "War Road." Any one wandering in this tract was always in danger of attack from many directions.