QUALITATIVE BACTERIOLOGICAL ANALYSIS. 147 



Gelatine-stab Culture. The growth at the surface is like a 

 superficial colony ; the growth down the stab is not character- 

 istic. ' Liquefaction sets in slowly. 



Gelatine-streak Culture. A coarsely-granular film appears, 

 which peripherally shoots out processes of very irregular shape. 



Gelatine-shake Culture. No bubbles of gas are formed. 



Agar-plate Cultures. The colonies are white in colour and 

 do not grow out in the same characteristic manner as on 

 gelatine. 



Agar-streak Culture. A greyish- white film, which at the 

 margin resembles the corresponding growth on gelatine. 



Potato Cultures. A transparent colourless film. 



Broth Cultures. Grows slowly ; a white deposit forms at the 

 bottom of the tube, leaving the liquid above fairly clear. 



Litmus-milk Cultures. In milk at 20 C. no change is visible 

 in three days ; later, the milk turns slightly acid ; no clotting is 

 visible even after one month. 



Indol Reaction. No indol is formed in broth after six days 

 incubation at 20 C. 



Reduction of Nitrates. No reduction takes place in four 

 days at 20 C. 



Microscopical Appearances. Large motile bacillus with rounded 

 ends ; solitary, in pairs, and in chains of varying length. It 

 forms spores. There is no growth at 37 C. 



Bacillus Fusiformis. 



Isolated from London crude sewage. 



Gelatine-plate Cultures. The growth is very slow. The 

 surface colonies are circular, of an opaque porcelain-white 

 glistening appearance. The periphery is slightly transparent. 

 By transmitted light the colonies are yellowish in colour. 

 Under a low power, no delicate details of growth can be made 

 out. No liquefaction of the gelatine takes place. 



Gelatine-stab Cultures. A white growth appears along the 

 line of the stab, and on the surface a scanty yellowish-white 

 layer slowlv develops. 



Gelatine-shake Cultures. No gas bubbles are formed. 



Agar-streak Cultures. A thin whitish layer is slowly formed, 

 which is not characteristic. 



