442 BACTERIAL FLORA OF THE SYDNEY WATER SUPPLY, 



appear as translucent white, raised spots, which when magnified 

 are seen to have a wavy, erose margin and a transparent crumpled 

 centre. Gelatine is not liquefied. In stab culture there is 

 formed a terraced nail-head. The organism is small and oval, 

 actively motile, and measures 03 : 06 /*. It is decolorised when 

 treated by Gram's method. Gas is produced from glucose, and 

 milk is not coagulated. Bouillon becomes turbid, and forms a 

 flocculent precipitate. A slight indol reaction is obtained. On 

 potato the growth is moist glistening, flat, spreading, and of a 

 light stone colour, which deepens to a light drab. 



This organism is decidedly small, while Wright describes it as 

 medium-sized. The growth on potato shows a difference from 

 Bad. minutum. 



Bacterium No. 46, Conn. 



This is a short rod-shaped bacterium with rounded ends, and 

 measures 0*4 : 1-1*5 p. It is actively motile, and is not stained 

 by Gram's method. On agar it forms circular white colonies, 

 and on gelatine translucent white colonies that sink into the 

 medium. When the gelatine colonies are viewed under a mode- 

 rate power, they are seen in the deep to be rounded or irregular, 

 almost opaque and apparently flocose. The surface colonies are 

 circular witli fluid contents in which there are large brown tloccules. 

 On agar stroke there is formed a pale white, moist glistening, flat 

 expansion. In gelatine stab culture the liquefaction is crateri- 

 form, then saccate and tubular. There is a uniform turbidity, and 

 no film forms on the surface. After a month the liquefied gelatine 

 is yellow and turbid near the surface, clear below, and at the 

 bottom of the tube there is a yellowish-white granular precipitate. 

 On potato the dry glistening, brownish layer which is first formed 

 becomes yellowish-brown, shining, flat and irregular. The potato 

 is darkened. No gas is produced in glucose-gelatine. Nitrates 

 are reduced to nitrites. Milk is coagulated, the reaction being 

 acid. 



Conn describes the agar stroke culture as white, becoming 

 yellowish, and the reaction of the milk when coagulated as 



