Must reading for anyone concerned about biodiversity and the fate of the hotly debated Endangered Species Act, which is up for congressional renewal in 1995. Mann and Plummer (co-authors of The Aspirin Wars, 1991) give an absorbing tour of the current species-extinction crisis. They transform arcane scientific argument into compelling explanation. Using the colorful examples of the endangered Karner blue butterfly, the American burying beetle, and the kanab ambersnail, the authors show how a series of small decisions--to build a highway here, a super-mall there--is squeezing these species out of existence. The authors call it ``The Problem of the Cooked Frog,'' citing the old chestnut that if you drop a frog into a pot of boiling water, it will jump out and save itself, but if you put it into the same pot with cold water and raise the heat in small increments, you soon have well-done frog meat. The metaphor cuts two ways, however, and therein lies the crux of this book. The authors claim that ``saving all species everywhere would cook our society to death.'' And that, they argue, is what the current Endangered Species Act seems likely to do. Time and again, they demonstrate, the few who live near a threatened species bear an undue burden in saving that species. In Austin, Tex., creators of a plan to save the area's threatened species failed to ask if the local inhabitants were willing to make the necessary sacrifices. Soon, people began destroying evidence of the species or habitat on private property in order not to have to deal with onerous restrictions. Mann and Plummer argue that a middle road must be found between the competing demands of economy and ecology, and that Congress needs to come up with something better than the present Endangered Species Act. While their conclusions will be highly controversial, this book is an admirable effort to deal fairly with both sides of a complex and critical issue.