448 BACTERIAL FLORA OF THE SYDNEY WATER SUPPLY, 



gelatine begins to liquefy in two weeks, the liquefaction being 

 shallow-stratiform. The organism is a motile rod with rounded 

 or pointed ends, and measures 0'4-0-6 : 1-1-5 /*: involution forms 

 in the shape of clubbed threads are soon found in the cultures. 

 On potato there is formed a deep violet, irregularly spreading, 

 flat, glistening layer. Bouillon becomes turbid with a flocculent 

 precipitate and a strong violet film. The fluid becomes colourless 

 and then violet. The indol reaction was obtained in the fluid 

 after the elimination of the suspended bacteria by means of 

 calcium chloride and ammonia. A control test without nitrite 

 was made at the same time. A strong blue film formed on milk 

 which was not coagulated; the reaction was alkaline. 



Bacterium janthinum ii., n.subsp. 



The stroke on agar is violet, moist glistening, and slightly 

 raised, the margin is beset with processes which are at first white 

 but soon become like the centre of the stroke; the consistency 

 when the culture is touched with the needle is found to be thin. 

 The colonies in gelatine plate are circular, crateriform, pale 

 violet and zonate; when magnified the contents are seen to consist 

 of large granules; the edge is diffuse. In gelatine stab the 

 liquefaction of the medium is rapid. The liquefied area is funi- 

 cular, there is a violet deposit and a thin film of the same colour; 

 the liquefied medium is turbid. A slight film is formed on 

 bouillon, but there is no film formed on milk, which becomes 

 faintly acid in reaction. In other respects the organism is 

 identical with that described above. 



The main points of difference between this subspecies and 

 Zopfs organism are the rapid liquefaction of the gelatine 

 (24 hours), the diffuse growth on agar and the absence of an 

 alkaline reaction in milk. 



Bacterium putidum, Fliigge. 



On agar slope there is quickly produced a luxuriant, moist 

 glistening, raised, white layer which spreads over the lower 



