Dr. Waksman's lifework has been the study of soil microbiology, and his attention has been focused during the past decade on one group of soil inhabitants, the actinomycetes, because they occupy a prominent place in modern medicine as sources of antibiotics.
Bergey's "Manual of Determinative Bacteriology," 1948, is accepted by the author as his basis for classifying the order actinomycetales, subdivided to include genus I, Actinomyces; genus II, Nocardia; genus III, Streptomyces, and genus IV, Micromonospora. The actinomycetes were so classified because of their similarity to bacteria, and yet they are distinct from the eubacteriales, or true bacteria. Considerable space is devoted to the terminology, phylogeny and taxonomy of this group.
The actinomycetes are universally found in nature and comprise a large and heterogenous group of micro-organisms. Their roles in human, animal and plant diseases; their importance in the maintenance of the carbon and nitrogen cycles in nature; their metabolic