Concentrating more on the advances of microbiology than on the organisms themselves, Aylesworth reviews the discovery, control, effects and diseases caused by the different microbes (primarily bacteria and viruses, though flagellates, ciliates and other one celled organisms are more briefly treated) which he classes as protists, a ""third kingdom"" in between plants and animals. (Unfortunately he doesn't mention the conventional criteria used in classifying living things as plants or animals, though he does go into much extraneous territory such as the history of man's fascination with blood.) In fact Aylesworth never does get down to the biological basics and he often glides over essentials in favor of progress reports. However there is a little more science history here and far less puffery than in Bedeschi's Science of Medicine (p. 784, J--266) in the same series. And the many color photographs and drawings, never as informative or relevant as those in the Time-Life books, for example, do give it an appropriately unintimidating look. Additional.