444 GENERAL SYSTEMATIC BACTERIOLOGY 



name. The Committee on Classification of Bacteria, of the Society of American 

 Bacteriologists, however, has recommended the use of the generic name Rhizo- 

 bium as better known and probably resulting in less confusion than the use of 

 Phyto7nyxa. 



The genus is included by Bergey et ah (1923, p. 40) as the second 

 in the tribe Azotohactereae with the following description. 



Minute rods, motile when young, branching forms abundant and characteris- 

 tic when grown under suitable conditions. Obligate aerobes, capable of fixing 

 atmospheric nitrogen when grown in the presence of carbohydrates and in the 

 absence of organic nitrogen compounds. Produce nodules upon the roots of 

 leguminous plants. 



Rhizobiinae. The name of a subtribe proposed by Buchanan 

 (1918; p. 43) for the third subtribe of the tribe Baderieae with the 

 description: "Rod-shaped organisms, securing their growth energy 

 by the oxidation of carbonaceous compounds, as carbohydrates, alcohol, 

 etc. Do not require serum, etc. Not parasitic in animals." 



Three genera are included, Mycoderma, Rhizohium and Azotohacier. 



Rhizomonas. A generic name proposed by Orla- Jensen (1909, p. 

 334) as a substitute for Rhizohium (q.v.) to designate the organisms 

 which are responsible for the development of nodules on the roots 

 of leguminous plants. It may be regarded as a synonym of Rhizo- 

 hium and Phytomyxa {q.v.). 



Rhodobacillus. A genus of bacteria named by MoHsch (1907, p. 

 14) to include bacteria containing bacterio-purpurin and bacterio- 

 chlorin but no free sulfur granules. The organisms are short rods, 

 rounded at the ends, usually solitary and motile. One species is 

 described, Rhodobacillus palustris Molisch. 



Meyer (1912, p. 2) used Rhodobacillus as a designation for the second 

 section of the genus Bacillus with the description: "Sie sol die durch 

 Bakteriopurpurin gefarbten Spezies der Gattung Bacillus enthalten, 

 sowohl die schwefelfreien wie die schwefelhaltigen Spezies." 



Buchanan (1918, p. 473) included this as the fifth genus of the tribe 

 Rhodohacterioideae, as "Rod shaped cells, sohtary, usually motile" 

 with the type species designated as Rhodobacillus palustris Molisch. 



Bergey et al. (1923, p. 406) followed Buchanan. 



Rhodobacteria. An order of bacteria named by Molisch (1907, p. 

 27) with the following description: "Bakterien, deren Zellinhalt durch 

 Bakteriopurpurin und (sowert untersucht) durch Bakteriochlorin rosa, 

 rot, violett oder karminrot gefarbt sind." Two families are included, 

 Thiorhodaceae and Athiorhodaceae. 



