Glory, glory testosterone! The male sex hormone is the hero of this testimonial celebrating its virtues in virility. Bahr does a good job in relating the history: Brown-Sequard's animal experiments and (mistaken) belief that he was rejuvenated by injections of testicular extracts, the formidable job of analysis, and, later, the synthesis of the hormone. Bahr is clearly anti-Unisex, decrying any attempt to downplay sexual differences as primarily cultural or psychogenic in origin. There is a trace of Fear of Feminism in his repeating dark reports that contemporary males report more guilt, angst, impotence, and anxiety that the partner be satisfied. Sexual politics aside, there's good material on the effectiveness of testosterone in treating adolescents or young men who do not mature normally, as replacement therapy in older men, as a hormone essential to muscle-building and other physiologic activities. Some interesting studies are at last attempting to track levels of the hormone in the bloodstream in search of hourly, daily, or monthly cycles. Bahr discusses normal development in utero (the critical period when circulating testosterone virilizes the male fetus), the quiescence of childhood, changes at adolescence and in aging. (Why should sexual decline be considered inevitable?) There are no magic formulas or royal roads to bedroom success in the book, but some solid biochemical information of interest--and reassurance--to both men and women.