Even from a first halting conversation with men who found anything but sheer statement of fact a difficulty, Theodore was able to construct in outline the common life of this new humanity, its politics, internal and external. The constitution of the tribe—the origin and keystone of the social system—had been, in the beginning, as much a matter of reckless chance as the mating of himself and Ada; small wandering groups of men, who had come alive through the agony of war and famine, had been knit together by a common need or a terror of loneliness, and insensibly welded into a whole, an embryo community. It was a matter of chance, too, in the beginning whether the meeting with another little wandering group would result in bloodshed for the possession of food—sometimes for the possession of women—or a welcome and the joining up of forces; but to the joining-up process there was always a limit—the limit of resources available. A tribe which desired to augment its strength as against its rivals was faced with the difficulty of filling many hungry mouths.... Their own community had once been faced with such a difficulty and had solved it by driving out three or four of its weaker members. “What became of them?” asked Theodore, and was told no one knew. It was winter when food ran short and they were driven out—and some of them had come back after nightfall to the edge of the camp and cried to be allowed in again. Till the men ran out and drove them off with sticks and stone-throwing. After that they went and were no more seen.... Later, in the summer, there had broken out a sickness which again reduced their numbers. When the wind blew for long up the valley it brought a bad smell with it—and flies. That was what caused the sickness. There had been a great deal of it; it was said that in a village lower down the river more than half the inhabitants had died.