288 Profs. Percy Frankland and Marshall Ward. 



Characteristics of Bacillus fluorescens Uquefaciens (Miigge). 





Thames water at all seasons. 



Morphologi- 

 cal characters 



Very small short rodlets, average size 1 — 1'5 ju x 0'5/x, some- 

 times in pairs or short chains, and often slightly constricted. 





None found in any medium. 



Colonies on 

 gelatine 

 plates 



Small, circular, rapidly enlarging to the size of a shilling and 

 more, and then forming liquefied depressions with perfectly 

 circular clear edges, and flocculent greenish- white granular 

 masses of the organism floating in the centre, often with 

 networks radiating from denser centre. 



In gelatine 

 tubes 



Streak cultures rapidly liquefying at all ordinary tempera- 

 tures, and the liquefied slimy gelatine with a jellowish- 

 emeral hue, fluorescing greenish-blue. Slight putrefactive 

 odour. Stab cultures very characteristic. The liquefaction 

 begins above, forming a concave funnel-like depression, and 

 extends down the puncture ; in two or three days a " thistle- 

 head " funnel of liquefied gelatine, very green and fluorescent, 

 especially above. The greyish flocculent colonies gradually 

 settle down the stem of the "funnel," widening the area of 

 liquefaction above. 



On agar .... 



At all ordinary temperatures to 20 — 25° C, spreading as a 

 greenish-white wet layer, at first thin. The fluorescent 

 green tinge penetrates a couple of millimetres or more into 

 the agar, which remains solid. 



On potato . . . 



In five days at 20 — 25° C. forms a yellowish-brown, and 

 shining, often granular layer, deepening in colour subse- 

 quently. 



In bouillon . . 



Turbidity, green fluorescence, and deposit. 





Precipitates the casein, and then completely peptonises it. 

 Acid reaction. Liquid clear in 10 — 14 days at ordinary 

 temperatures. 



Temperature 



Grrows well at all temperatures from 10° C. to 25° C. Car- 

 dinal points not determined. 



Eapidity .... 



Very rapid development and liquefaction. It is the earliest 

 form to appear on gelatine plates. 



Air require- 

 ments 



Markedly aerobian. Will not grow under glass plates, or 

 submerged in solid media. 





Grrows well in the dark. 



Pigment .... 



Soluble in the medium. Becomes paler on boiling, but is not 



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chloric or acetic acid, but reappears on neutralising with 

 ammonia; an excess of alkali deepens the green fluor- 

 escent hue. 



Pathogenic 

 or not 



Not. It is a chromogenic saprophyte, and grows well in water 

 containing mere traces of soluble organic materials. 



