The objective, scientific approach is suitable to the author's purpose-- to instruct the uninformed about the human sex mechanisms--, and he treats the systems as mechanisms. The discussions of the various aspects of heredity are more successful than the presentation of facts about the male and female sex and reproduction systems. The author has carefully treated complex material in a comprehensible manner. Explanations of chromosomes and genes, of artificial insemination, of determination of sex, and other topics, are included. Diagrams throughout support the well organized text. A good book for the beginning biology student.