324 BACTERIOLOGY 



slightly granular, slightly yellowish brown ; centre with a yellow browtt 

 nucleus, marmorated ; older colonies 6-8 mm., with a greenish tint, and. 

 the gelatin acquires a blue green fluorescence. 



Gelatin slant. Growth thin, translucent, slightly greenish, limited. 



Agar slant. Growth thin, moist, translucent ; acquires a greenish color. 



Bouillon. Turbid, with a pellicle ; becomes greenish. 



Potato. Growth moist, glistening, brown, spreading. 



Litmus milk. Slightly decolorized (after a month or so), reaction acid. 



Habitat. Water. 



33. Ps. foliacea (Wright) 



B , jtuorescens-foliaceus Wright : I.e., 439. 



Dr. Wright doubtless has good grounds for making this and the preceding- 

 distinct species ; a careful study of the descriptions, however, do not 

 reveal upon what specific differentiation can be well based. The features 

 of distinction appear to be in the character of the growth on gelatin slant, 

 which shows a central furrow, with also laterals, giving a leaf-like etching 

 of the medium. The surface gelatin colonies show heavy, brown, radial, 

 stripes. 



Litmus milk. A deeper blue, alkaline, becoming acid, pink. Indol slight. 



Habitat. Water. 



34. Ps. syncyanea (Ehrenberg) Migula 



Vibrio syncyaneus Ehrenberg: Gurit u, Hertwig's Magaz. f. ges. Thierheilk., VII, 1841- 



B. cyanogenes Fliigge : Die Milcroorganismen, 1886. 



Ps. syncyanea Migula: Die Natiirlichen Pflanzenfam., 1B92, 29. 



Morphology. Bacilli 0.3-0.5 : 1.0-4.0 /i. Flagella polar, in bundles of 1-5,, 



rarely bipolar. 

 Gelatin colonies. Deep: small, round, yellowish, granular. Surface: large,. 



thin, spreading, with erose edges like B. coli. Colonies rarely of the 



aerogenes type. 

 Gelatin stab. Slight growth in depth ; on the surface, growth white — bluish 



gray. 

 Potato. Growth slimy, bluish gray — brown. 

 Agar slant. Growth white ; agar variously colored. 

 Bouillon. Turbid, gray green — bluish green, with a pellicle. 

 Glucose bouillon. No gas, slightly acid, /w^o/ a trace. H2S negative. 

 Milk. Alkaline, blue. 

 Habitat. Isolated from blue milk. 



