This, the long-awaited sequel to Campbell's Crystal Desert, finds our scientist-hero not in the Antarctic but rather far up the Amazon not only with a paddle but also with an eccentric coterie of fellow biologists and locals. Campbell writes with flair and insight of the people, history and ecological discoveries in the far western reaches of the Amazon Basin, a place where he has focused much of his work. A tropical ecologist who has a way with words, Campbell has eight permanent study sites in the Brazilian Amazon.  (AMZ90, $18.95)