BACILLI 451 



BACILLUS PHOSPHOEESCENS GELIDUS 



Authority.— Forster, ' Ueber einige Eigenschaften leuchtender Bakterien,' 

 Centralblatt f. Bakteriologie^ vol. ii., 1887, p. 337. 



"Where Found. — On phosphorescent sea-fish. 



Microscopic Appearance. — In very young cultures the bacilli are small, 

 about three times as long as broad, with slightly rounded ends. In cultures 

 more than twenty-four hours old the rods are for the most part thickened and 

 become egg-shaped. (Involution forms.) 



Cultures. — It grows abundantly on a culture material containing 2 to 7 per 

 cent, of common salt. A favourable medium is fish broth made with sea-water 

 or containing from 3 to 4 per cent, of common salt. If more than 7 per cent, of 

 salt is added the development ceases, and with 7 per cent, is already retarded. 



Gelatine Plates. — At ordinary temperatures forms small round dots in from 

 one to two days. Under a low power they are almost circular, grey white in 

 colour, with a faint green opalescence ; later they become granular, light yellow, 

 and their periphery slightly irregular. 



G-ELATiNE Tubes. — Very slight growth in the depth; forms a white expansion 

 on the surface. No liquefaction takes place. 



Agar-agar Similar to gelatine-tube cultures. 



Potatoes. — Forms a broad white expansion. 



Bemarks. — Cultivations of this bacillus give out a magnificent phosphorescence 

 in the presence of air and when seen in the dark. This phenomenon takes place at 

 0° to 20° C.,but ceases at 32° C. A temperature of from 35° to 37° C. destroys the 

 bacnins, but, on the other hand, it can grow at 0° C. without much retardation. 



BACILLUS PHOSPHORESCENS INDICUS 



LIQUEFIES GELATINE 



Authority. — Fischer, ' Bakteriologische Untersuchungen auf einer Eeise nach 

 Westindien,' Zeitschrift f. Hygiene, vol. ii., 1887, p. oi. See also Katz, ' Zur 

 Xenntmssderlienchihoktexien,^ Centralblatt f. Bakteriologie,vo\.iii..,lHdl, 1^.158. 



"Where Found.— In sea- water. 



Microscopic Appearance. — Small thick bacillus about two to three times as 

 long as broad, with rounded ends. Gives rise to threads more or less bent. 

 It is very motile. No spore formation observed. 



Cultures. — 



Gelatine Plates. — After thirty-six hours small round whitish grey dots are 

 visible. The surface colonies give rise to liquid depressions. Under a low 

 power the smallest centres are circular, smooth -rimmed, and of a pale bluish 

 or sea-green colour, often exhibiting a rose-coloured hue. When liquefaction 

 has proceeded still farther the colonies assume a brownish or dirty yellow colour. 

 The periphery becomes wavy, and the same rosy blush is sometimes visible. 



Gelatine Tubes. — Forms in about four days a depression mostly filled with 

 air at the point of inoculation ; a faint grey white, thread-shaped turbidity 

 extends all along the needle's path in the depth. In from eight to ten days the 

 depression has increased in size, so that a pea can easily lie in it, and the 

 bottom and sides are covered with a dirty yellow substance. The turbidity and 

 liquefaction below the depression have oaly increased very slightly. Later on a 

 dirty yellow pellicle forms on the surface of the liquid gelatine. 



Agar-agar.— Forms a grey white expansion which exhibits phosphorescence 

 in the dark. 



Potatoes.— At from 15° to 20° C. it forms a broad thin white expansion. 



Blood Serum. — Grows luxuriantly, forming a grey Avhite expansion with a 

 lobular periphery. 



Remarks. — Groi^ best at from 20° to 30° C. ; it will not grow below 10° C, and is 

 destroyed at 55° C. It will not phosphoresce below 0° C, and exhibits this property 

 best when kept between 25° and 30° G. Beyerinck (see p. 453) recommends a culture 

 material consisting of fish broth made with sea- water to which 1 per cent, of glycerine, 

 ^ per cent, of asparagin, and 8 per cent, of gelatine are added. 



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