328 BACTERIOLOGY 



42. Ps. viridescens (Ravenel) 



B. viridescens-liquefaciens Ravenel : I.e., 24. 

 Morphology. Bacilli small, straight, ends rounded, 3-5 times their breadth, 



occur singly. Flagella polar. 

 Gelatin colonies. Deep : gray, granular, irregular margins, becoming lobed 



and fissured at edges. Surface : in 24 hours, gray, granular, with 



irregular margins ; centres of grayish cloudy masses ; liquefaction crateri- 



form; liquefaction proceeds rapidly and colonies lose their characters 



quickly. 

 Gelatin stab. Good growth in depth ; liquefaction infundibuliform, becoming 



in 3-4 days nearly stratiform to the depth of the stab ; no green color to 



the gelatin. 

 Agar slant. Growth smooth, elevated, greenish white, becoming spreading, 



with a green tint ; edges thin, yellowish green. 



Potato. Growth yellow, moist, glistening, not very thick, becoming brownish. 

 Bouillon. Turbid, medium greenish. 



Pepton rosolic acid solution. A thin film on the surface, unchanged. 

 Litmus milk. Acid, not coagulated. 



Glucose bouillon. No gas. Indol negative. Grow at 36. 

 Habitat. Soil. 



43. Ps. undulata (Ravenel) 



B.fluorescens-undulatus Ravenel : I.e., 20. 



Morphology. Bacilli slender, straight, ends rounded, 7-10 times their breadth, 

 in chains. Flagella polar. 



Gelatin colonies. Deep : dense, gray brown, with margins of fine wavy lines ; 

 do not exceed 0.25 mm. Surface: like drops of moisture, greenish 

 gray ; microscopically, gray, granular, with a nucleus and an outer zone 

 of fine hairs. In 3 days, i mm., elevated, dense, iridescent ; micro- 

 scopically, dense, with a finely striate border ; the gelatin becomes faint 

 green. 



Gelatin stab. Slight growth in depth ; on the surface, a button, white yellow ; 

 the gelatin tinged green near the surface. 



Agar slant. Growth thin, translucent ; agar tinged green. 



Potato. Growth yellow, moist, becoming dirty yellow brown, thin. 



Bouillon. Turbid, becoming clear; the medium becomes a clear green. 



Pepton rosolic acid solution. Slight growth, becoming in 3 weeks darker. 



Litmus milk. Rendered alkaline, not coagulated, consistency unchanged. 



Glucose bouillon. No gas. Indol negative. Grow at 36. 



Habitat. Soil. 



