THE CLASSIFICATION OF BACTERIA 315 



B. Gelatin not liquefied. 



21. Ps. turcosa (Zimmerman). 

 II. Pigment blue-violet on gelatin or agar. 



A. Gelatin liquefied. 



1. On potato, pigment violet. 



22. Ps.janthina (Zopf). 



2. On potato, growth grayish blue blue green. 



23. Ps. car u lea (Voges). 



3. On potato, growth dark blue blue black. 



24. Ps. Smithii. 



B. Gelatin not liquefied. 



25. Ps. indigofera (Voges). 



26. Ps. Berolinensis (Classen) Migula. 



17. Ps. pullulans (Wright) 



B.pullulans Wright : I.e., 445. 



Morphology . Bacilli small, short, in pairs. Flagella several, polar. 



Gelatin colonies. In 2-3 days 2 mm., yellowish gray, slightly elevated, trans- 

 lucent. Microscopically, with yellowish centres and colorless margins, 

 sausage-shaped granules on lower side of colony, surrounded by a zone 

 of liquefied gelatin. 



Gelatin stab. Surface growth raised ; liquefaction napiform. 



Agar slant. Growth yellowish, translucent. 



Glucose bouillon. No gas. Nitrates not reduced. Grow at 36 . Indol pro- 

 duced. 



Habitat. Water. 



18. Ps. annulate (Wright) 



B. artnulatus Wright : I.e., 443. 



Morphology . Bacilli small ; occur singly, in pairs, and as long forms. Fla- 

 gella several, at one or both ends. 



Gelatin colonies. In 3-4 days, 2-3 mm., round ; centres yellowish, edges 

 indistinct somewhat fringed; liquefaction saccate. 



Gelatin stab* Liquefaction crateriform, yellowish flocculi, a slight pellicle. 



Agar slant. Growth yellowish, translucent, glistening. 



Bouillon. Turbid, with a yellow pellicle. 



Litmus milk. Coagulated, decolorized. Indol slight. No growth at 36 . 



Habitat. Water. 



