Did you know that human sperm is ejaculated at a speed of 17km/h? Or that ejaculate is pushed out in 0.8 second intervals? Or that the male orgasm, which usually lasts between 3 and 10 seconds, only in exceptional cases lasts longer than 15 seconds? Or that it is accompanied by an increase in heart frequency to 180 beats per minute, and that breathing can accelerate to 40 breaths per minute? Just about any question about semen, fertility, male sexual potency, and sexual physiology, is answered by Vivien Marx in this lively, informed and entertainingly written book. It is a book for both men and women. It is a reference book, a textbook and a good read. If you ever wondered what the purpose of orgasm is, what determines the smell and colour of semen, wondered about delayed ejaculations – retrograde ejaculations, how best to look after testicles, how smoking, alcohol, drugs, stress and lifestyle affect potency and fertility, how the environment influences fertility, (are British men an endangered species?) , about semen and diseases – the unloved companions of the sperm cells, semen and criminology, the history of semen science, how semen is tested – you will find the answers to these and hundreds of other questions here.