GENERAL SYSTEMATIC BACTERIOLOGY 465 



Buchanan (1918, p. 51) has used this as a designation for the red 

 rod-shaped bacteria in the following description. 



Cells rod-shaped, without spores. Motile by means of peritrichous flagella or 

 non-motile. Gram stain variable. Aerobic, producing a red or pink pigment, a 

 lipochrome. Possibly closely related yellow and orange lipochrome-forming bac- 

 teria should be included here as well. 



The type species is Serralia marcescens Bizio, the organism usually termed 

 Bacillus prodigiosus. 



Erythrohacillus Fortineau (q.v.) was proposed by Winslow et al. 

 (1917, 1920, p. 209) as a substitute. 



Bergey et al. (1923, p. 85) include Serratia as the first genus of the 

 tribe Chromohactereae with the description: 



Small, aerobic rods, producing a red or pink pigment, usually a lipochrome. 

 Gram-negative. Motile or non-motile. 



The type species is Serratia marcescens Bizio. 



Shigella. A generic name proposed by Castellani and Chalmers 

 (1918, p. 934) for the third genus of the tribe Ebertheae, with the 

 following description: 



Ebertheae non-motile, partially fermenting glucose with the production of 

 acid, but no gas; lactose not fermented. Milk not clotted. 

 Types. Shigella dysenteriae (Kruse, 1899). 



It is also used by the same authors (1919, p. 937) as the name of 

 a subgenus of the genus Shigella to include those types which do not 

 ferment mannitol. 



Siderocapsa. A generic name proposed by MoUsch (1909, p. 29) 

 for an organism from the surfaces of immersed leaves of aquatic plants 

 showing iron stains. The organisms are epiphytic on parts of plants 

 in fresh water, such as the older stems and leaves of Elodea, the under 

 side of leaves of Nymphaea, etc., which show a brownish crust. Under 

 a magnification of 300 to 500 diameters the surface is seen to be made 

 up of irregularly circular areas, with a lighter center. The bacteria are 

 invisible in direct fight, and can be differentiated by staining only with 

 difficulty. He found colorless "Schiff" solution best. When the areas 

 are immersed for a time in this reagent the iron oxid area colors up 

 red-violet and the bacteria of the central area are recognizable. In 

 the species Siderocapsa treubii there occur one, two or occasionally 

 as many as six cells. The diameter of the "rusted" area was 5 to 

 18/x, of the clear central area 1.8 to 3.6/i, and of the coccus 0.4 to 0.6/x. 



