SPECIES CONCEPT IN RELATION TO ACTTNOMYCETES 



Figure 1. Morphology of the various genera of the Actinomycetales. Of these, only Actinomyces in 

 A. Nocardia in B, Streptomyces in C. Micromonospora, Thermoactinomyces, Waksmania, Actinoplanes, 

 and Streptosporangium in D are recognized in this i realise as true actinomycetes; Nocardia and Proac- 

 tinomyces are synonyms (Courtesy of T. G. Pridharo of the Northern Regional Laboratory, Agriculture 

 Research Service, U. S. Department of Agriculture). 



