18 GENERAL SYSTEMATIC BACTERIOLOGY 



Ehrenberg's Classification of the Infusoria (1838) 



a. Forms which ingest solid particles, as carmine 



Polygastrica 

 aa. Forms which never ingest particles. 



b. Family Monadina. Genus Monas, of which Monas crepusculutn was 

 probably a bacterium. 

 bb. Family Vibrionia. Forms which tend to form filaments as a result of 

 incomplete fission. 

 c. Cells not flattened. 



d. Cells not flexuous. 



e. Forming straight rods . . .Bacterium 



ee. Forming spiral rods Spirillum 



dd. Cells Hfcxuous. 



e. Straight rods Vibrio 



ee. Spiral rods Spirochaeta 



cc. Cells in form of a flattened spiral . . . Spirodiscus 



He also described as a member of the diatom genus Gaillonella, a 

 G. ferruginea now generally included among the bacteria. Later he 

 changed the spelling to Gallionella. In spite of the fact that it is that 

 of a recognized diatom genus, this name is still frequently incorrectly 

 used as a bacterial generic name in the designation of this iron organism. 

 In the form finally assumed by the Ehrenberg classification (1838) the 

 bacterial species recognized were as follows: Bacterium triloculare, 

 Vibrio lineola, V. tremulans, V. subtilis, V. rugula, V. pro- 

 lifer and V. bacillus, Spirillum undula, S. tenue, Spirochaeta plicatilis 

 and Spirodiscus fulvus. Later (1840, p. 202) he described Vibrio syn- 

 cyaneus and V. synianthns. 



Kiitzing (1833, p. 385) described as a fresh water alga a form which 

 he termed Sphaerotilus natans. This is now generally included among 

 the filamentous water or iron bacteria. 



Dujardin (1841, p. 209) used the family designation Vibrionia to 

 include "Animaux sans organes locomoteurs visibles, se mouvent par 

 I'effect de leur contractibilite generale." The genera recognized may 

 be differentiated as follows: 



Dujardin's Classification of Vibrionia (1841) 



A. Cells straight, non-flexuous, more or less definitely jointed, with slow 



wave-like motility Bacterium 



B. Cells straight or bent, more or less definitely jointed, flexuous 



Vibrio 



C. Filamentous forms spiral or screw shaped, never straight, and revolving 



rapidly on the axis Spirillum 



