PATHOGENIC BACTERIA. 



3" 



typhoid fever. Its growths in other media are mostly whitish. 

 Bouillon becomes clouded. Nitrates are reduced to nitrites. 

 In peptone solution it forms indol. On potato it forms an 

 abundant visible growth from cream color to pale brown. 

 Milk becomes acid and is usually, but not always, coagu- 

 lated slowly. It causes the development of gas and acid in 

 media containing dextrose or lactose. In media containing 

 neutral red it is stated that the colon bacillus produces a yellow 

 color with a green fluorescence. Differential points between 



\ 



^- ' V.'"*' "nXi 



•■^ -^^ ' ■'• 'X' 



Fig. 94. — Bacillus coli communis with Flagella, Stained by Van 

 Ermengem's Method. (X 1000.) 



the bacillus of typhoid fever and the Bacillus coh communis 

 are as follows: 



ist. The typhoid bacillus is actively motile; the colon bacil- 

 lus less actively motile. 



2d. The typhoid bacillus has numerous flagella which rise 

 from all parts of the surface ; the colon bacillus has a smaller 

 number of flagella. 



