Appropriately subtitled ""An Introduction to the Theory of Natural Selection,"" this consists of selections from the writings of collector-naturalists Alfred Wallace and Henry Bates, topically arranged, and framed by the editor's account of their lives and assessment of their work; the whole forms a fitting, sometimes fascinating, introduction to the two contemporaries of Darwin whose work is closest to his in implication and importance. Both spent many years in the Amazon Basin securing specimens and recording their observations--including the great diversity of species, their geographic distribution, their response to circumstance (normally terrestrial animals and plants driven by the density of the forest to climb trees) and the limitations of that response (the toucan's enormous bill, not invented for its function, but the likeliest form available); it was here too that Bates first identified mimicry in butterflies, thus providing ""one of the most dramatic demonstrations of how natural selection worked."" Bates subsequently settled in London with his specimens to study and write; Wallace, who lost his en route, went on to eight years' wandering in the Malay Archipelago, where he discovered the distributional boundary between the western (Asiatic-linked) and eastern (Australian-linked) islands, grasped at last how evolution worked (the famous paper that precipitated Darwin's own disclosure), and concluded wryly that neither animals nor plants ""appear to be organized with exclusive reference to the use and convenience of man."" The book is impeccably implemented: the source of each selection is given; the two maps are perfectly designed for their purposes; the index is thorough; there's a glossary of scientific terms and--wonder of wonders-- ""For Further Reading,"" articles from recent issues of Scientific American and National Geographic. The editor's contribution to an understanding of Wallace and Bates is considerable, which makes the book valuable for any age although it won't, of course, be everybody's Krutch.