444 BACTERIAL FLORA OF THE SYDNEY WATER SUPPLY, 



On potato the growth is orange-yellow, flat and glistening. No 

 gas is developed in the presence of glucose, no indol is produced 

 in bouillon, and milk is not coagulated. 



The colonies on gelatine appear to differ from those described 

 by Ravenal, but as the other characters agree this may be a 

 variety. 



Bacterium pullulans, Wright. 



This is a short rod with rounded ends, and measures 03 :06-l ft; 

 it is actively motile. On agar the colony is deep yellow and 

 circular, with a smooth edge; the stroke is deep yellow or old- 

 gold in colour, convex, moist glistening and restricted. The 

 gelatine stab is at first filiform with a spreading deep yellow nail- 

 head. The gelatine becomes slowly liquefied; the liquefied area 

 is funicular and turbid; a deep yellow precipitate is formed. In 

 gelatine plate culture the surface colonies have a deep yellow 

 centre and a pale yellow margin. When magnified sixty-fold 

 they are seen to have an irregular zonate centre and lobulated 

 margin, from the under-surface of which rounded buds are given 

 off. The small colonies, which have budded off, lie free around 

 the lobular margin, and are either circular or irregular, according 

 to their size, and brown in colour. Milk is not coagulated, and 

 a trace of indol is produced in bouillon culture. 



Bacterium cuticulare. 



Bacillus cuticularis, Tils. 



A rod with rounded or slightly pointed ends, measuring 

 0-4 : 0-8-1 p. It is motile and is stained by Gram's method. In 

 gelatine plate culture the deep colonies are, when magnified, seen 

 to be circular, brownish and zonate. The surface colonies are 

 transparent and crumpled or contoured with an irregular, erose 

 margin like Bad. cold commune. The stroke on agar is at first 

 pale white and iridescent, but becomes moist glistening and of a 

 primrose colour; when touched with the needle the culture has a 

 viscous consistency. The stab in gelatine is faintly filiform, but 



