DR. PAUL DE KRUIF is a writer better known, unfortunately, in his own country than in England. Beginning life as a bacteriologist, he soon abandoned academic science and research, and devoted his talents to the vulgarization (in the French sense) of scientific and medical discoveries becoming, in his own words, “a sort of human loud-speaker, a barker”, telling the world at large about some of the wonders of biology. In “Microbe Hunters” (1926), “Hunger Fighters” (1928), “Men against Death” (1932), he has already related, in colloquial American language, various outstanding ‘triumphs' of bacteriology, nutritional physiology, and medicine. All these books are distinguished by the accuracy of their scientific and historical data, though these are often presented in a picturesquely overdrawn manner and from a national point of view not always appealing to a more stolid English audience.