UO BACTERIOLOGICAL EXAMINATION OF WATER. 



Council a report on the micro-organisms of sewage. They in- 

 vestigated specimens of sewage from various sources, and de- 

 scribed the following new species. The descriptions are taken 

 from the above-mentioned report : 



Proteus Cloacinus. 



Source. Found in every sample of sewage. 



Form and Arrangement. A short bacillus of variable length ; 

 0'4 to 0*5 u in breadth ; stained specimens from a two-days old 

 agar culture vary from 0'5 to 1 u in length ; the shorter forms 

 almost resembling cocci. On gelatine some longer forms are 

 seen up to 1'6 u in length, and these may be as much as 0'6 /i in 

 breadth. In a one-day-old broth culture the average length is 

 0*8 /LI. It is actively motile. It does not form spores, and 

 grows well at 37 C. and 20 C. 



Gelatine Plates. The colonies are visible to the naked eye in 

 nineteen hours, though still minute. Under the microscope the 

 surface colonies are thin, transparent, and irregular in outline ; 

 the deeper colonies globular and brownish by transmitted light. 

 In two days the surface colonies are more circular and regular 

 in outline. The largest are about 1 mm. in diameter ; a few 

 show a thin spreading edge, but no " swarming islands " are 

 given off. No further change occurs, except that the colonies 

 increase in size up to & mm. in diameter, and become raised at 

 the edge ; they are of a greyish-white colour. No liquefaction 

 occurs even at the end of a fortnight. The plates have a sour 

 smell. 



Gelatine-streak. Rapid growth with irregular edges, but 

 shows no " swarms " as a rule. The growth strongly resembles 

 that of B. coli communis. Liquefaction occurs in about three 

 weeks. Occasionally the gelatine is liquefied in three to five 

 days, and in these cases swarming islands are thrown out like 

 the common Proteus. 



Gelatine-stab. Growth is rapid and well-marked along the 

 needle track. Scanty gas bubbles are formed. Liquefaction 

 first commences in from two to three weeks. The growth is 

 white and nodular in the depth. 



Glucose-gelatine (shake). There is profuse formation of gas 

 bubbles in twenty-four hours. 



