460 BACTERIAL FLORA OF THE SYDNEY WATER SUPPLY, 



Potato. — There is formed a moist glistening, old-gold expansion. 



Milk. — The casein is not coagulated and the reaction is 

 unaltered. 



The organism appears to be a subspecies of Bac. arborescens, 

 Frankland, from which it differs in the appearance and colour on 

 agar stroke. Compared with the organism which I have described 

 under that name, the colonies on gelatine are white and the 

 processes forming the mycelioid structure are more delicate and 

 straight. 



Bacillus stellatus, n.sp. 



Shape, etc. — A stout rod of variable length and breadth, 

 measures generally 0-8-1 "0 : 2-3 ^; the ends are rounded. It is 

 non-motile and is stained by Gram's method. It forms oval 

 central spores quickly upon potato but slowly upon agar. 



Agar plate. — The colonies are dull white, circular, raised and 

 contoured. When magnified the structure appears folded and 

 filamentous, the margin lobed and the edge smooth. The deep 

 colonies are irregular, opaque and warty. 



Agar stroke. — The growth is dry, glistening, luxuriant, greyish- 

 white and longitudinally ribbed or terraced, the edge is straight 

 and rough. 



Gelatine plate. — The colonies at first are white and stellate, that ' 

 is, straight processes radiate from a central point. When mag- 

 nified, the surface and deep colonies are seen to have an irregular 

 centre from which thin and thick straight processes radiate. The 

 gelatine soon begins to liquefy and the processes become coarser 

 and flocose. When the liquefaction has become circular, the 

 contents are seen to be flocose and tufted, while from the margin 

 radiating flocose strands penetrate into the softening gelatine. 



Gelatine stab. — The filiform growth gives place to a funicular 

 liquefaction which is very turbid. There is a precipitate of 

 white floccules, but no film. 



Glucose-gelatine. — No gas is produced. 



Bouillon. — The medium becomes turbid; there is no film, the 

 precipitate is white, flocose and filamentous. A slight indol 

 reaction was obtained. 



