34 R. E. BUCHANAN 



Fenobacter Beijerinck, 19(X), p. 200 

 Aplanobacter E. F. Smith, 1905, p. 171 

 Semiclostridium Maassen, 1905, p. 5 

 Myxohacillus Gonnermann, 1907, p. 877 

 Plennobacterium Gonnermann, 1907^ p. 887 

 Serratia Vuillemin, 1913, p. 521 

 not Serratia Bizio 1823 



Cells rod-shaped, straight or at least never spiral, motile by 

 diffuse flagella or non-motile. Endospores produced under favor- 

 able conditions, not usually distorting the cell, usually Gram-posi- 

 tive. Growth usually good on laboratory media; commonly liquefy- 

 ing gelatin. Aerobic or JacuUative. 



There has been much diversity in the literature as to the use 

 of the generic name Bacillus. It was first used by Cohn (1872, 

 p. 174) to include three species of rod-shaped organisms. Bacillus 

 subtilis, B. ulna, and B. anthracis. He characterized the genus 

 as including those rod-shaped organisms that grow in filaments. 

 Later he discussed at length spore production in B. subtilis, and 

 gave the first accurate description of endospores. Various 

 authors accepting either B. subtilis or B. anthracis as the type of 

 the genus have emphasized different characters so that there are 

 current in literature at least six conceptions of the genus. These 

 are as follows : 



1. Bacillus. Rod-shaped organisms growing in filaments or 

 in chains. Spore production, flagella distribution and motility 

 not emphasized or regarded as secondary. Among the authors 

 who have made use of this definition are Cohn (1872 and 1875), 

 Magnin (1878), Winter (1879), Luerssen (1879), Van Tieghem 

 (1884), Grove (1884), Fliigge (1886), and Schroeter (1886). 



2. Bacillus. Rod-shaped organisms producing endospores. 

 (Some authors recognize other spore-bearing genera in addition 

 to Bacillus.) The following have used this definition; De Bary 

 (1884 and 1887), Zopf-(1885), Hueppe (1885), Cornil and Babes 

 (1885 and 1890), De Toni and Trevisan (1889), Ludwig (1892), 

 Freudenreich (1894), Lehmann and Neumann (1896), Chester 

 (1897), Fliigge (1908), Jensen (1909), Heim (1911), Lohnis 

 (1913). 



