752 BACTERIAL FLORA OF THE SYDNEY WATER SUPPLY, 



bouillon and suspension. The organism was found in 800 c.c. and 

 upwards of water. Owing to there being so few organisms in 

 the water that can withstand the action of Parietti's solution, 

 transfers from the primary tubes, as advised by Hankin, were 

 found to be unnecessary. Bad. coli commune grew quite freely. 



In Eisner's potato gelatine, colonies were obtained on the 

 plates infected with the equivalents of 20 c.c. of water and 

 upwards, and on the potato medium the colonies appeared to 

 consist of two kinds. They were found to contain the same 

 organism, the difference in appearance having been induced by 

 surface and sub-surface growth. The separated organism, 

 Bacterium II., which appears to be an ally of Bac. pinnatus, 

 grows sparing at 37° C, and, probably, would not have been 

 separated by any method that necessitated the employment of 

 this temperature. 



Marpmann's citric acid gelatine entirely excluded the bacteria 

 and in their place there was obtained a luxuriant culture of 

 moulds, among which were Mucor racemosus and Penicillivm 

 glaucum. There were also many pink colonies of the common 

 pink yeast. The action of 2% sodium carbonate in an agar 

 medium at 37° C. was not tried because agar with - 75% sodium 

 carbonate proved to be too alkaline a medium for the organisms 

 of the water. The latter amount of carbonate was, I believe, 

 recommended by Burri some years ago, and was employed in 

 Stutzer's laboratory to indicate roughly the pollution of a water. 

 Alkalised gelatine remained sterile, a circumstance that was to 

 be expected from the behaviour of the alkaline agar. 



In the application of Theobald Smith's method gas developed 

 with a minimum quantity of 100 c.c. of water. The evolution was 

 slow ; but when the fermenting fluid was inoculated into fresh 

 glucose bouillon, gas was given off vigorous^. From the tube 

 with the minimum water infection, several organisms which 

 reddened litmus-lactose-agar were separated. Some of these lost 

 their red colour, the bacteria producing first acid and then alkali. 

 Bad. miniaceum was separated owing to the reddish colour of the 

 colonies. Bact. sinuosum reddened litmus and produced gas 



