This is the first book on bacterial systematics at undergraduate level. The first part explains why bacteria are classified and how they are named, and covers the practice of classification including evolutionary studies and identification. The applications of these methods are illustrated in the second part of the book, which describes progress in the classification and identification of the spirochaetes, helical and curved bacteria, Gram-negative aerobic, facultative and strictly anaerobic bacteria, Gram-positive cocci, rods and endospore formers, mycoplasmas, and actinomycetes; and outlines the importance of these organisms.