A digest of landmark observations on the subject of sexual differences and behavior among animals and (in the last chapter, on Margaret Mead) humans, mixing some personable glimpses on the observers themselves--beginning with amateur naturalist Jean Henri Fabre who, reporting on the praying mantis ""gobbling him up during the act. . . beyond the wildest dreams of the most horrible imagination,"" added ""I have seen it done with my own eyes and have not yet recovered from my astonishment."" Such items, combined with a strong anti-sexist thesis, makes He and She more readable than Prince's fact-filled The Universal Urge (1972), but Hirsch's approach has drawbacks of another sort. Certainly we share his bias and his conviction that whatever differences might be inborn, ""learning, reason and will (allows) humankind to take a hand in its own destiny."" But from the insect-watching of Frisch and Fabre to Mead's studies of three New Guinea peoples, Hirsch gets more and more didactic in the sense of pushing value judgments without sufficient evidence and investigation. Nevertheless he does make the several significant studies easily accessible, he is conscientious and sensible on such issues as the controversies surrounding Lorenz' methods and conclusions, and there is substance for those just beginning to think about the nonsexual implications of sexual differences.