THE CLASSIFICATION OF BACTERIA 32 1 



Gelatin colonies. In 2 days, 1.5 mm., grayish white, translucent; micro- 

 scopically, with brownish centres, borders thin, with radiate structure ;. 

 later show a greenish white — blue green fluorescence. 



Gelatin stab. Liquefaction slow, crateriform, with a blue green fluorescence. 



Agar slant. Growth grayish, translucent ; agar fluorescent. 



Bouillon. Turbid, with a slight pellicle and a blue green fluorescence. 



Potato. Growth brownish, elevated, spreading. 



Litmus milk. Coagulated slowly, decolorized slowly. 



Glucose bouillon. No gas. Indol doubtful. 



Habitat. Water. 



28. Ps. pyocyanea (Gessard) Migula 



B. pyocyaneus Gessard : De la pyocyanine et son microbe, Th6se de Paris, 1882. 

 Ps. pyocyanea Migula: Die Natiirlichen Pflanzenfam., 1896. 



Morphology. Bacilli 0.4: i.4'-6 /«,, variable. A polar flagellum. Stain by 

 Gram's method. 



Gelatin colonies. Deep : round, oval, yellowish white — greenish yellow, often 

 moruloid. Surface : round, entire, yellowish ; later, the borders become 

 irregular and coli-like ; often beset with hairs, or fringed ; becoming 

 sunken, with an irregular, variable structure, gray or greenish gray, irregu- 

 lar, ragged, or coarsely granular. 



Gelatin stab. Liquefaction crateriform, becoming saccate, with a greenish, 

 yellow-blue green fluorescence ; contents granular, flocculent. 



Agar colonies. Deep: round, oval, entire, undulate, granular, yellow — green- 

 ish yellow. Surface: round, entire, glistening, greenish white — yellowish ; 

 . microscopically, round, entire, granular, moruloid, yellow — greenish, 

 yellow. 



Agar slant. Growth soft, glistening, spreading, yellowish green — greenish ;. 

 the agar shows a strong yellow green fluorescence. 



Bouillon. Turbid, with a pellicle, and a strong yellow green fluorescence. 



Milk. Coagulated, becoming fluid and alkaline, with a yellow green fluores- 

 cence. 



Potato. Growth yellowish, moist, glistening, slightly raised, becoming brown- 

 ish yellow — brown. Indol negative. HgS negative. 



Glucose bouillon. Acid, no gas. Nitrates reduced to nitrites. 



Pathogenesis. Subcutaneous inoculation of i cc. of a virulent bouillon culture 

 into guinea pigs and rabbits causes a purulent infiltration and inflamma- 

 tory oedema at the point of inoculation, and death in some cases in 24. 

 hours. Intraperitoneal inoculations cause peritonitis and death. With, 

 small doses only local inflammation, and recovery. 



Y 



