The skills needed to describe and recognize perturbations in the Homo sapiens microecology are disappearing with the passing of the generations, leaving humanity, lulled into a complacency born of proud discoveries and medical triumphs, unprepared for the coming plague. 1 Machupo BOLIVIAN HEMORRHAGIC FEVER Any attempt to shape the world and modify human personality in order to create a self-chosen pattern of life involves many unknown consequences.