BACILLI 433 



BACILLUS CLOACAE 



LIQUEFIES GELATINE 



Authority. Jordan, A Report on certain Species of Bacteria observed in 

 Sewage, State Board of Health, Massachusetts, 1890, p. 821. 



"Where Found. Found in the Lawrence sewage, and described as one of 

 the most common bacteria in this sewage. 



Microscopic Appearance. Short, plump oval bacilli, with rounded ends, 

 about -8 jj. to 1-9 M long, and *7 A* to 1 /j. broad. Variable in size, slightly longer 

 and thicker on potato cultures than on agar. Occurs frequently in pairs. No 

 spore formation observed. It is very motile. 



Cultures. 



GELATINE PLATES. Is visible in from twenty-four to forty-eight hours as a 

 round yellowish centre ; on reaching the surface it forms a slight bluish ex- 

 pansion, with irregularly notched edges, and the gelatine is almost immediately 

 liquefied. Under a low power the centre is dark, an outer translucent zone 

 enclosed by a darker edge ; the interior is finely granular. In from three to 

 four days the whole plate is liquefied. 



GELATINE TUBES. Grows rapidly, and liquefies the gelatine all along the 

 needle's path. Forms an iridescent scum on the surface, and a heavy, flocculent, 

 whitish deposit. Will grow equally well in slightly acid gelatine. 



AGAR-AGAE. Forms a moist, slimy porcelain-white surface growth. Grows 

 also abundantly in the depth. 



MILK. Coagulates milk in about four days, rendering it strongly acid. 



BROTH. Benders it turbid in two days. A white deposit is formed, and 

 a light skin forms on the surface, which sinks on shaking the tube. 



POTATOES. Produces in two days an abundant raised yellowish white growth. 



Remarks. Reduces nitrates in bouillon. The following is the analytical com- 

 position, of the solution employed : 



Albuminoid ammonia (from Merck's peptone) . . 8*88 parts per 100,000 

 Free ammonia ........ '92 



Potassium nitrate 8'5 



Unfortunately tlie synthetical composition of the medium is not stated. 



F F 



