For the science-minded reader, this should provide an excellent bird's-eye view of natural history -- that area of biology exploring the relationships of living things to each other and to their environment in time and space. Beginning with a brief summary of the principal divisions of plants and animals, their differing modes of reproduction and development, various factors are then discussed -- promoting or hindering the survival of the various forms of living things -- temperature, olimete, water, food, etc., being the inanimate factors while the great variety of constructive, neutral and hostile relationships are the animate factors. This, the main body of the book, terminates in an analysis of evolution, its probable mechanism, and the several schools of scientific and philosophical thought that have developed from it. A final section treats of naturalists themselves, both professional and amateur, and of the scientific method in theory and practice. The author, a research biologist on the staff of the International Health Division of the Rockefeller Foundation, and the son-in-law of David Fairchild, has done an extremely good job of achieving sprightliness without glibness and, by honestly labelling his own small orotohets and biases, manages to maintain a consistent objectivity throughout. A well-chosen bibliography, with brief descriptions, will be useful to the reader interested in going more deeply into the fields discussed herein.