Examples from two parallel series on natural history that employ identical photographs and provide texts on two levels; books in the ""Animal Habitats"" series have detailed information on a reading level at least two years beyond those in the series called ""Where Animals Live"" (The World of. . .), which are actually abridgements and simplifications of books in the other series, following the same outlines, covering the most important points, but containing less than half as much information. The chicken books cover various breeds; habits and behavior of domestic fowl; mating, reproduction and growth; a brief history of domestication; and a contrast between the life of a chicken in a mass-production setting and on a farm where it is allowed free range, with no doubt as to the more humane environment. The two books on swans discuss range, various kinds of swans and their characteristics, mating, nesting, and raising young, and friends and enemies, including humans. The photographs are of uniformly high quality, well chosen to supplement the information in the text as well as being strikingly beautiful and well reproduced. The texts, including the abridged ones, include plenty of solid information conveyed with straightforward clarity. These would be a fine addition to any children's collection; those with limited budgets will need to select the more appropriate reading level for their needs if they don't wish to have two sets of the same pictures.