THE EGG AND SPERM RACE: The Seventeenth-Century Scientists Who Unravelled the Secrets of Sex and Growth
by Matthew Cobb
Free Press £17.99, 352 pages

Not for Antoni van Leeuwenhoek the post-coital cigarette that day in 1677. No sooner had he finished making love to his wife Cornelia than he was up at his home-made microscope, discovering in his semen a “vast number of living animalcules”, little wriggling creatures with rounded bodies and long, vigorous tails. The Dutch draper and microscopist had confirmed, for the first time, the existence of spermatozoa.

Van Leeuwenhoek’s discovery is the climax of Cobb’s lively if sometimes uneven account of the endeavours of 17th-century scholars to understand the reproductive process in man and other animals. It was a period of remarkable process. In 1650, knowledge had hardly advanced beyond the misguided imaginings of the Ancient Greeks - Aristotle believed the embryo originated from the union of semen and menstrual blood. Yet by the early years of the new century, the roles of the human egg and sperm had been established and a reasonably accurate account of embryonic development published.

In addition to van Leeuwenhoek, Cobb awards much of the credit to three individuals: Reinier De Graaf, a Catholic physician who proved the existence of the human egg; Niels Steno, the Dane who first suggested that all female animals have ovaries; and Jan Swammerdam, a skilful artist and dissectionist.

The newly invented microscope and the scalpel play a significant role in this story. Indeed, you can almost smell formaldehyde on the page as deer, pigs, rabbits, legions of insects and the occasional “delirious virgin who had drowned herself” yield their secrets to the knife.

The book also considers the sometimes bitter rivalry between scientists. Swammerdam and De Graaf, at first close friends, quarrelled over whose research had priority, a fierce war of words that almost certainly contributed to De Graaf’s death at the age of 32. De Graaf, incidentally, recognised the clitoris as the source of female sexual excitement, arguing that without its “exquisite sensitivity to pleasure and passion” no woman would be prepared to suffer the pains of pregnancy and child-bearing.

Wary of the inevitable innuendo around his subject, van Leeuwenhoek had his seminal discovery translated into Latin before transmitting his findings to the Royal Society, to avoid giving offence. He also assured the world’s premier scientific organisation that the sample “was not obtained by any sinful contrivance on my part” but was the “excess which Nature provided me in my conjugal relations”. Cornelia’s opinion was not recorded, Cobb notes drily.