THE CLASSIFICATION OF BACTERIA 317 



Potato. Growth moist, glistening, pasty, light yellow, becoming cadmium- 

 yellow to golden brown. 



Bouillon. A slight turbidity, and a yellow deposit adhering to walls at sur- 

 face, becoming clear, with a yellow granular precipitate. 



Litmus milk. In 10 days pink; no true curd, but a layer of whey on top. 

 The casein is gradually digested. No gas in glucose and lactose bouillon ; 

 growth only in the open end of fermentation tubes. 



Pigment. Soluble in ethyl and methyl alcohol ; color destroyed by mineral 

 acids. Bouillon rendered slightly alkaline. Non-pathogenic to rabbits. 



Habitat. Associated with a bacterial rot of cabbages and allied plants. 



21. Ps. turcosa (Zimmerman) 



B. turcosus Zimmerman : Bak. Nutz u. Trinkwasser, Chemnitz, II Theil, 1894, 32. 



Morphology. Bacilli 0.2-0.3 : 0.3-1.5 /A. A single polar flagellum. 



Gelatin colonies. Small, punctiform, translucent, intense yellow. Microscopi- 

 cally, amorphous. 



Gelatin stab. Surface growth small, slowly growing, round, convex, intense 

 yellow, with a slight greenish tint, becoming gradually sunken, without 

 liquefaction. 



Agar slant. A scanty growth, intense yellow. 



Potato. A scanty growth, greenish yellow, dry, with a soft, glistening appear- 

 ance. 



Bouillon. Weakly turbid. H 2 S negative. Indol negative. 



Ghicose bouillon. No gas. 



Milk. Not coagulated. 



Habitat. Water. 



22. Ps. janthina (Zopf) 



B.janthinus Zopf: Spaltpilze, 1885, 68. 



B. violaceus Mace: Ann. d'Hyg. publ. et de Med. leg. XVII, 1887. 



B. violaceus Frankland : Zeitsch. f. Hygiene, 1889, 394. 



B. violaceus-laurentius Jordan : State Board of Health, Mass., 1890, 838. 



Morphology. Bacilli 0.5-0.8: 1.5-5.0 /x, ends rounded. One or two polar 

 flagella; according to Lehmann-Neumann it may show 3-4 peritrichic 

 flagella. Stain by Gram's method. 



Gelatin colonies. Small yellow points, becoming violet ; becoming liquefied 

 and depressed, with grayish centres and violet borders. The unliquefied 

 colonies may be yellowish violet, with ragged, erose, lobular borders. 

 Microscopically, fragmental grumose, dark yellow-brownish. 



