170 GENERAL SYSTEMATIC BACTERIOLOGY 



Facultative anaerobic organisms which give the "white lead test" with pro- 

 duction of sulfides, and certain related ferment organisms. No spores. Very 

 resistant to drying. Ferment dextrose and levulose with production of gas 

 and usually lactic acid. Sulfates not reduced. Nitrates reduced to nitrites, 

 but not to NH3. 



Species. Bacillus coli communis Escherich, Includes here also B. liquefaciens 

 Tataroff, and Bad lactis aerogenes Escherich, the latter becoming Aerobacter 

 aerogenes. 



"Bergey (1923, p. 205) recognizes the genus with the following 

 description : 



Motile or non-motile rods, commonly occurring in the intestinal canal of 

 normal animals. Produce acetyl-methyl-carbinol. 



The type species is Aerobacter aerogenes (Escherich) Castellani and Chalmers. 



If the colon typhoid group is to be subdivided, it would seem that 

 Aerobacter should be regarded as a valid generic name with Aerobacter 

 aerogenes (Escherich) Beijerinck as the type. 



Aerogenesbacterium. A generic name suggested by Orla-Jensen 

 (1921, p. 272). His statement follows: 



The genus Bacterium will undoubtedly dissolve into several genera, of which 

 I may especially mention the Colibacterium, and Aerogenesbacterium. The reason 

 why I am now inclined, in contrast to my earlier opinion, to consider the coli- 

 and aerogenesbacteria as two different genera, is because they differ not only 

 in morphological, but, as later researches have shown, also in biological respects. 

 I have myself proved (1914), that the Aerogenesbacteria completely oxidize the 

 carbohydrates when the nutrient matter offers a sufficient buffer effect, and they 

 thus correspond with their name in forming more gas than do other bacteria, 

 :and Rogers, Clark and Davis (1914) have shown that in the gas developed by 

 the Colibacteria there is proportionately more hydrogen than in that developed 

 by the Aerogenesbacteria. 



This generic designation is apparently a synonym of Aerobacter 

 Beijerinck. It is also questionable whether the indirect reference is 

 sufficient to establish a species. It is probable that Aerogenesbac- 

 terium aerogenes would be considered the type species, although this 

 combination was not used by Orla-Jensen, 



Aethyl-BaciUus. A name used by Fitz (1878, p. 48) as a pseudo- 

 generic or casual designation for a rod shaped organism capable of pro- 

 ducing ethyl alcohol from glycerin. It is rejected by Smith (1905, 

 p. 174) and is invalid as a generic name. 



Agonium. A generic name used by Oersted (1844, p, 44) to desig- 

 nate a marine organism, probably an alga (See De Toni. Sylloge 



