The author, a prominent English geneticist who has contributed largely to the knowledge of heredity in poultry, rabbits, roses and man, has given an exceptionally clear account of the detailed mechanisms of heredity and variation. No other book gives so much of the actual evidences on which the chromosomal and gene theories of evolution rest. The book is well illustrated, many of the pictures occupying a full page; in fact, nearly half of the book consists of illustrations.
While the book presents orthodox modern genetics in language as plain and simple as may be, the author disclaims a materialistic view. "Evolution," he says, "is not a deterministic machine, and creative evolution, as we shall see, is far from being mechanistic—on the contrary, it is peculiarly indeterminate throughout all its phases." The book develops along familiar lines throughout most of its length, beginning with an exceptionally clear and intelligible account of