GENERAL SYSTEMATIC BACTERIOLOGY 87 



B. Cells spherical or short rods. 



1. In chains, each chain surrounded by a capsule. 



Genus II. Rhodonostoc 



2. Cells free Genus III. Rhodosphaera 



C. Cells free and elongate. 



1. Cells not bent. 



a. Non-motile Genus IV. Rhodohacterium 



b. Motile Genus V. Rhodobacillus 



2. Cells bent or curved. 



a. Cells short, comma shaped, with single polar flagellum. 



Genus VI. Rhodovibrio 



b. Cells spiral, with polar flagella 



Genus VII. Rhodospirillum 



Key to the Genera of Myxobacteriaceae 



I. Cells not transformed into coccus-like spores when encysted. 



A. Rods forming free cysts in v/hich they remain unmodified. Cysts 



various, sessile or borne on a more or less highly developed cystophore. 



Genus I. Chondromyces 



B. Rods forming large rounded cysts, one or more, free within a gelatinous 



matri.x raised above the substratum. 



Genus II. Polyangium 

 II. Rods transformed to form definite, more or less encysted, sessile or stalked 

 masses of coccus-like spores Genus III. Myxococcus 



Key to the Genera of Spirochaetaceae 



I. Usually saprophytic, free living in water. 



A. Protoplasm spirally wound around an elastic axis filament. 



Genus I. Spirochaeta 



B. Not as in (A), cross section circular. 



Genus II. Saprospira 

 II. Usually parasitic. 



A. Possessing a "crest" or ridge. Parasitic in mussels. 



Genus III. Cristispira 



B. Without a crest. Parasitic in warm blooded animals. 



Genus IV. Treponema 



In September, 1917, appeared the Preliminary Report of the Commit- 

 tee of the Society of American Bacteriologists on Characterization and 

 Classification of Bacterial Types (Winslow, Broadhurst, Buchanan, 

 Krumwiede and Smith) . An historical review of systems of classifica- 

 tion is given, likewise a review of the points found in the International 

 Botanical Code of principal interests to bacteriologists. Four orders 

 of bacteria were recognized. The subdivisions of the Eubacieriales 

 alone were recommended. The classification in outline follows: 



