The penetration of outside pioneers into the Amazon had been far from organized or peaceful, centering on rough, impoverished rubber-tappers, or seringueiros. Those tappers who had reached this far up the River of Doubt were likely alone, afraid, and in dangerous straits themselves. In approaching their huts from upriver, moreover, the members of the expedition were crossing the frontier from the wrong direction. The only humans the settlers expected to see coming from the river’s headwaters were hostile Indians, and they would do whatever they felt was necessary to defend themselves.
