446 bacterial flora of the sydney water supply, 



Bacterium miniaceum. 



Bacillus miniaceus, Zimmermann. 



On agar slope a brilliant vermilion, raised, spreading, moist 

 glistening stroke is formed, from the bottom of which amoeboid 

 processes spread out and gradually cover the entire lower surface. 

 The organism is a cocco-bacterium measuring 07 : 1 fi. In 

 gelatine plate culture the colony quickly liquefies the gelatine, 

 forming a crateriform, pink area. In gelatine stab the medium 

 is liquefied in a stratiform manner, the fluid being very turbid 

 from floating pink granules. The red pigment is not bleached 

 by zinc and hydrochloric acid. 



Bacterium rubefaciens. 



Bacillus rubefaciens, Zimmermann. 



On gelatine plate at 15° C, circular, raised, moist glistening- 

 colonies of a pale coral colour are formed. The medium is not 

 liquefied. Under a sixty-fold magnification the surface colonies 

 are seen to be rounded, reddish-brown and with a smooth edge; 

 the contents are finely granular. The deep colonies are irregular 

 and opaque. The bacteria are motile rods with rounded ends, 

 and measure 0*45 : 1-1*5 p; they occur singly and in twos. They 

 are decolorised by Gram's method of staining. The agar stroke 

 is raised, glistening and restricted, the edge slightly puckered. 

 At 22 C. the colour is light oak, while at 15° C. it is of a pale 

 terra-cotta colour, which eventually becomes pale coral. On 

 potato at 22° C. there is formed a light oak, scanty, glistening 

 growth; the medium in the vicinity of the growth is darkened. 

 At 15° C. the colour is like the agar culture, pale terra-cotta, and 

 when now incubated at 22° changes to a watery, raised, light 

 orange growth; the potato beneath becoming brownish. Bouillon 

 becomes slightly turbid; there is no film formed, and a compact, 

 pale coral precipitate is produced. The gelatine stab is filiform 

 with an irregular, flat, slightly terraced nail-head; the colour is 

 either pale coral or light oak, according to the incubation- 



