NON-PATHOGENIC BACILLI. 661 



D. Non-chromogenic, Liquefying Bacilli. 



341. BACILLUS CYANEO-PHOSPHORESCENS (Katz). 



Obtained from sea water at Little Bay, near Sydney, New South Wales. 

 Very nearly related to Bacillus phosphoresceiis of Fischer (Katz). 



Morphology. Bacilli with round ends, about 2.6 ju long and 1 ft thick ; 

 solitary oriii pairs; occasionally grow out into long filaments. 



Stains by Gram's method. 



Biological Characters. An aerobic and facultative anaerobic, liquefy- 

 ing, motile bacillus. Spore formation not observed. The cultures give off 

 a bluish phosphorescence which has a faint greenish tint. Grows in the 

 usual culture media at the room temperature best at 26 C. ; very scanty 

 growth upon nutrient agar at 32 to 34 C. Upon gelatin plates, at the end 

 of eighteen hours, colonies are already visible ; those upon the surface and 

 those in the interior of the gelatin are of about the same dimensions 0.25 to 

 0.4 millimetre; under the microscope they are seen to be finely granular, 

 have a sharply defined, smooth contour and a dark-gray color; the superfi- 

 cial colonies are finely granular and pale yellowish-gray in color. At the 

 end of forty-eight hours the superficial colonies are surrounded by a broad 

 girdle of liquefied gelatin, at the bottom of which they lie in contact with 

 the glass plate ; they are of a dirty brownish-yellow color and irregular in 

 outline; the liquefied gelatin is pale-gray or yellowish-gray by transmitted 

 light, and contains here and there granular masses scattered through the 

 more finely granular structure. At this time the deep colonies are yet well 

 defined, have irregular outlines, and are of a dirty yellowish-brown color ; 

 they have a diameter of about 0.3 to 0.5 millimetre, and are surrounded by a 

 zone of liquefied gelatin about 0.05 to 0.1 millimetre in diameter ; this is finely 

 granular, light-brown or light-gray in color, and marked by delicate radial 

 striations. When the colonies are crowded upon a plate liquefaction may 

 be complete at the end of eighteen hours ; the liquefied gelatin gives off a 

 peculiar odor. In gelatin stick cultures (six-per-cent gelatin) liquefaction 

 commences beneath the surface growth, and at the end of forty-eight hours 

 a shallow cavity of Avatch-glass form is seen which has a diameter of about 

 five millimetres temperature of 20 to 22 C. ; at the bottom of this a gray- 

 ish-white layer is seen, and below this a line of development along the track 

 of the inoculating needle; this is surrounded by a narrow zone of liquefac- 

 tion. At the end of three or four days liquefaction at the surface reaches 

 the walls of the test tube ; when liquefaction is complete a yellowish, viscid 

 mass is seen at the bottom of the tube and a mycoderma upon the surface; 

 the gelatin is at first diffusely clouded and later becomes transparent; it has 

 a yellowish color, which gradually changes to reddish-brown. In six-per- 

 cent gelatin containing 2.7 per cent of sodium chloride development is espe- 

 cially abundant and rapid, and short, radiating processes are given off into 

 the gelatin in advance of liquefaction. In bouillon diffuse cloudiness occurs 

 and a mycoderma forms upon the surface. No development occurs in 

 simple flesh infusion, but the addition of 0.5 per cent of sodium chloride to 

 this constitutes a medium in which growth occurs still better 2.5 per cent. 

 Upon sterilized fish a glistening, sticky layer of a yellowish or yellowish- 

 brown color, in the thicker places, is developed. Phosphorescence depends 

 upon the free access of oxygen and the presence of certain salts, especially 

 sodium chloride. A very minute quantity of a culture added to sea water 

 causes it to exhibit phosphorescence. Cultures upon the surface of agar 

 give sufficient light to enable one to distinguish printed letters in a dark 

 room. No growth upon potato. 



342. BACILLUS ARGENTEO-PHOSPHORESCENS LIQUEFACIENS (Katz). 



Obtained from sea water at Bondi Bay, near Sydney, New South Wales. 

 Resembles Photobacterium luminosum of Beyerinck. 



56 



