THE STATUS OF THE GENERIC TERM BACTERIUM EHRENBERG 1828*

The status of the generic term Bacterium needs to be clarified by international action, as the status of Bacillus has been clarified by the action taken in regard to the proposals drawn up by Buchanan and Conn and reported upon by Breed and St. John-Brooks (1935). The history of Bacterium has been well outlined by Buchanan in his Systematic Bacteriology (1925). In this he quotes with approval the suggestion made by Breed, Conn and Baker (1918) that a temporary group be recognized to include species of non-spore-forming rods whose relationship to other spe-cies is obscure. As the type species concept has now been accepted as a method of defining generic terms (Art. 18, International Rules of Botanical Nomenclature adopted by the Fifth International Botanical Congress, 1930) suggestions that Bacterium be used for (1) non-spore-forming rods (Zopf1), (2) non-motile rods (Migula), (3) flu-orescent pseudomonads (Smith, Vuillemin), (4). the colon-typhoid group (Orla-Jensen, Winslow et al.), (5) gram-negative, non-spore-forming rods (Lehmann and Neumann, 1927) are invalid on the ground that the type species Bacterium triloculare Ehrenberg, 1828 (monotypy) is unrecognizable. Because this species is unrecog-nizable, subsequent authors have felt free to redefine the genus. As none of these new definitions has won universal approval, it is necessary to state how the term is being used each time it is used or confusion results. This situation pointedly illustrates the need for the rule tha