224 GENERAL SYSTEMATIC BACTERIOLOGY 



Clements (1894, p. 27) defined the genus Bacterium as follows: "Cells 

 very short, ellipsoid, rarely cylindrical, motile or non-motile, often 

 imbedded in a gelatinous matrix and forming zoogloea." 



Two species only are described. Bacterium termo and Bact. aceti. 



The genus name Bacterium is not used by Fischer (1895) at all. Leh- 

 mann and Neumann (1896, p. 181) emphasized lack of endospores as the 

 most important character. They say 



Zellen mindestens l\ mal. meist aber 2-6 mal als lang als breit, gerade oder in 

 einer Ebene gekrummt, zuweilen lange echte oder Scheinfaden bildend, mit oder 

 ohne Geisseln. Stets ohne Endospores, fiir einzelne Arten sind Arthrosporen 

 beschrieben. 



Mace (1897) retained the older conception of the genus. He states: 



La longeur relative etait le seul caract^re qui le distingerait du genre Bac- 

 terium. Nous Savons que ce caract^re ne peut etre consid^re comme absolu, 

 mais qui varie au contraire dans des limites tres larges, pour des conditions de 

 vie qui peuvent etre considere^s comme normales. 



Migula in 1897 again discusses the importance of organs of motility 

 in a system of classification, and once more defined the genus as consist- 

 ing of non-motile rods. Chester in his Manual (1901, p. 117) adopts 

 Migula's definition of Bacterium, as does also Allan J. Smith (1902, p. 

 270) and Kendall (1902, p. 484). 



Klocker (1903, p. 332) evades the issue by using the generic name given 

 by the author of the specific name of the species under discussion. He 

 states "For distinguishing purposes the spore formation and the flagella 

 have been suggested, but these characteristics have proved to be 

 insufficient." 



Matzuschita (1902, p. IV) does not use the genus name Bacterium. 



Schmidt and Weis (1902, p. 294) define the genus as follows: 



Die Zellen sind cylindrisch, stabformig, frei oder zu Faden verbunden. Geis- 

 seln fehlen stets, und diese Arten sind daher zu keiner Zeit ihres Lebens beweg- 

 lich. Endosporenbildung bei vielen bekannt. Zur Gattung Bacterium gehort 

 eine sehr grosse Anzahl (iiber 300) Arten, von denen viele pathogen sind. 



Erwin F. Smith (1905, p. 160) discusses at considerable length the 

 history of the generic name Bacterium. He comes to the conclusion 

 that Bact. termo of Cohn can be identified with sufficient accuracy as a 

 green fluorescent organism with polar flagella, developing in Cohn's 

 nutrient solution when inoculated with beans. He, therefore, formu- 

 lates the following diagnosis : 



