Dyer (biology, Wheaton College, Massachusetts) presents a guide for naturalists, students, and teachers interested in "adding a bacterial dimension" to their nature studies. Written at a level accessible to amateur naturalists with or without access to a microscope, it is intended for use in field work. The text is organized by chapter according to the major taxonomic groups of bacteria, with guidelines on where to go and what to look for (and smell, taste, or touch) to identify a particular bacterial group. Includes b&w illustrations and 98 color plates. Annotation (c) Book News, Inc., Portland, OR (booknews.com)