In the 1940s, biologist Richard Evans Schultes uncovered many of the secrets of the rain forest, relying not only on his own prodigious investigations, but on the wisdom passed down by local tribes. Thirty years later his student, Wade Davis, followed in his footsteps. Two interwoven tales of scientific adventure bring to life the riches of the Amazon basin and bear witness to the destruction of its indigenous culture and natural wonders over two generations. photos.