Chapter I 



11 — 



Taxonomy 



tin liquefaction, or upon their morphology, especially the manner of 

 sporulation. 



Buchanan (52) suggested placing the actinomycetes in the order 

 Act'moviycetales with a single family Actinoniycetaceae. The latter was 

 divided into four genera, Actinohacilhts, Leptotrichia, Actinomyces, and 

 Nocardia. Later (53), in the early editions of Bergey's Manual, the 

 Actinoinycetales were di\'idcd into two families, the Actinoniycetaceae 

 with the genera ActiiinhaciUus, Leptotricliia, Actinomyces, and Ery- 



FiG. 3.— Structure of actinomyces mycelium: (a) S. alhus Gasperini; (hj 

 S. aurantiacus Gasperini Qfrom Krassilnikov, 234). 



sipelothrix, and the Mycohacteriaceae with eight genera, including My- 

 cobacterium. In later editions of Bergey's Manual, Actinohacilhts was 

 dropped from the first family and Proactinoviyces added; the second 

 family was divided into the genera Corynehacterium and Mycobac- 

 terium. Further changes were made in the final, or sixth edition of 

 the Manual. 



Lehmann and Neumann (256) divided the order into two families, 

 the Proactinomycetaceae with the genera Corynebacteriiim and Myco- 

 bacterium, and the Actinoniycetaceae with a single genus Actinomyces. 

 K^uYVER and van Niel (224) suggested that the Mycobacteriaceae be 

 removed altogether from the order Actinomycetales. 



