"A fascinating and useful handbook to both the science and science fiction of extraterrestrial life. Cohen and Stewart are amusing, opinionated, and expert guides. I found it a terrific and informative piece of work nothing else like it!" Greg Bear "I loved it." Larry Niven "Ever wonder about what aliens could be like? The world authority is Jack Cohen, a professional biologist who has thought long and hard about the vast realm of possibilities. This is an engaging, swiftly moving study of alien biology, a subject with bounds and constraints these authors plumb with verve and intelligence." Gregory Benford "A celebration of life off Earth. A hearteningly optimistic book, giving a much-needed antidote to the pessimism of astrobiologists who maintain that we are alone in the universe a stance based on a very narrow view of what could constitute life. A triumph of speculative nonfiction." Dougal Dixon, author of After Man: A Zoology of the Future