SUBGROUPS AND GENERA OF THE BACTERIACEAE 49 



2. Bacterium. Short cylindric or elliptic cells, never in chains 

 or filaments, showing stages of motility and non-motility. Cohn 

 (1872b, 1875), Dallinger and Drysdale (1875), Magnin (1878), 

 Winter (1879), Luerssen (1879), Grove (1884), Van Tieghem 

 (1884), Fliigge (1886). 



3. Bacterium. Rod-shaped organisms which do not produce 

 endospores. Motility and cell groupings not emphasized. The 

 genus is contrasted with Bacillus in these characters. Zopf 

 (1885), Hueppe (1885), Schroeter (1886), De Toni and Trevisan 

 (1889), Ludwig (1892), Freudenrich (1894), Lehmann and Neu- 

 mann (1896), Lohnis (1913). 



Jf.. Bacterium. Not used as a generic name, all rod-shaped 

 organisms being placed in Bacillus or other genera. Baum- 

 garten (1890), Sternberg (1892), Fischer (1897), Matzuschita 

 (1902), Schneider (1912). 



5. Bacterium. Non-motile rod-shaped organisms. Migula 

 (1895, 1897, 1904), Chester (1901), Smith (1902), Kendall (1902), 

 EUis (1909), Heim (1911). 



6. Bacterium. Polar flagellate organisms of the type of the 

 fluorescent baciUi. E. F. Smith (1906), Vuillemin (1913). 



7. Bacterium. Organisms belonging to the colon-typhoid 

 group. Orla Jensen (1909a). 



This diversity in definition of this genus has led to consider- 

 able confusion in literature. It would seem logical to select one 

 of the species early named Bacterium, and designate it as the 

 generic type. However, of the species named before Cohn's 

 descriptions in 1872 there does not seem to be a single one which 

 can be identified with certainty. 



It might seem best to select some organism early named 

 Bacterium as the type and so word the generic diagnosis as to 

 include this form and the related species. 



E. F. Smith has attempted to identify the Bacterium termo 

 of Cohn, evidently intended by this author to constitute the 

 type of the genus. He states 



His (Cohn's) Bacterium termo was a small schizomycetous organism 

 capable of growing freely in Cohn's nutrient solution, containing acid 

 potassium phosphate and ammonium tartrate. It produced thereon 



