This volume, and its companion volume on the oocyte, provide a wide-ranging analysis of the gametes and their reproductive role in humans. The authors give a detailed account of the spermatozoon that includes particularly helpful information on male infertility and its treatment. The book starts with an evolutionary perspective before focusing on the molecular and cellular biology of the sperm cell and its structure and function. It describes the development and maturation of sperm and their movement and transport in the male and female genital tract. It also covers practical issues such as sperm storage and assisted contraception. This volume will be an essential source of information for all clinicians and scientists with an interest in human reproduction.