454 BACTERIAL FLORA OF THE SYDNEY WATER SUPPLY, 



mesenteric. The liquefied gelatine in stab culture is at first 

 turbid but soon clears, and further it is a medium-sized rod, 

 - 6 : 1 -2-2-5 p, and very motile. Bad. No. Jf.6, Conn, measures 

 0-4 : 0*8 fi, and forms a yellowish or brownish (presumably flat) 

 layer on potato; its colour upon agar and gelatine is yellowish- 

 white and it coagulates milk, the reaction being alkaline. 



Bacterium aerofaciens, n.sp. 



Shape, etc. — This is an oval bacterium measuring 04 : 0-8-1 p. 

 It is motile and is not stained by Gram's method. It grows well 

 at 37° C. and at 22° C. No spores were observed. 



Agar plate. — There are formed translucent white, wax-like, 

 circular, raised colonies, which when magnified are seen to be 

 homogeneous, circular and smooth-edged. The deep colonies are 

 irregular and rough. 



Agar stroke. — The growth is raised, moist glistening, grey-white, 

 and spreads irregularly from the inoculating line. 



Gelatine plate. — The colonies are. at first translucent white and 

 slightly irregular, later they become amoeboid and iridescent. 

 When magnified the surface colonies are seen to be yellowish- 

 brown and finely granular with a lacerate-erose margin; the deep 

 colonies are brown or opaque and rounded with a smooth edge. 



Gelatine stab. — The line of inoculation becomes filiform, with 

 a translucent white nail-head, which spreads out and becomes 

 somewhat depressed. Gas bubbles appear in the depth of the 

 medium. 



Glucose-gelatine.- — Gas is produced in quantity. 



Bouillon. — The medium becomes turbid, a precipitate is formed, 

 but no film appears. No indol reaction was obtained. 



Nitrate-bouillon. — Nitrate is strongly reduced to nitrite. 



Milk. — The medium is not coagulated. 



Potato.— A white, moist glistening, flat growth, which covers 

 the surface of the medium, is formed, and eventually it becomes 

 the same colour as the potato. 



The characters of this organism show that it has its closest 

 allies in the hog-cholera (Bact. suipestifer) class of bacteria. The 



