A comprehensive, overall look at the role of zoos down through history, with emphasis on modem-day zoological institutions' concerted efforts to save endangered animals. Here, Luoma, author of Troubled Skies, Troubled Waters (1984), touches on the key conservation issues of the day. He discusses why habitats (and the plant and animal life they sustain) are being destroyed at an unprecedented pace, how species are selected to be part of the ""Species Survival Plan,"" and the various techniques used by zoos to save species--artificial insemination, the freezing of embryos and sperm, inter-zoo exchanges, and the setting up of ""natural habitats"" wherein animals can feel comfortable enough to breed. But in his determination to be thorough, Luoma quotes from so many different zoo and wildlife authorities that his book, at times, reads like little more than a ""who's who in endangered species."" And often his descriptions are far too detailed, as in a long-winded discourse on Gregor Mendel's discovery of genetics. Throughout, Luoma touches on the criticism of zoos by conservationists and others outside the zoological world. But his final message is a sound one: ""if only a few hundred of the hundreds of thousands of endangered species are to be saved,"" then a more unified effort will have to be made by all of those who care.