BACILLI 433 



BACILLUS CLOACAE 



I 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 baciUi, with rounded ends, 

 about '8 ju to 1-9 fx long, and •? ju to 1 /x 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. 



G-ELATiNE 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. 



Agah-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. 



Bboth. — Eenders 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. 



Bemarks. — 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 3'5 „ „ ,, 



Unfortunately the synthetical composition of the medium is not stated. 



F F 



