QUALITATIVE BACTERIOLOGICAL ANALYSIS. 191 



Witters Peptone and Salt Solution. No indoi produced after 

 seven days incubation at 37 C. 



Potato. Growth at first transparent, later acquired a faint 

 yellowish tinge. 



Gelatine (25 per cent.) at 37 C. No film on the surface ; a 

 diffused growth through the tube. 



Proskauer and Capaldi, No. I. Growth, but no change in the 

 reaction of the medium. 



Proskauer and Capaldi^ No. II. Growth, medium rendered 

 slightly alkaline. 



Microscopical Characters. A small highly motile bacillus^ 

 about the same size as B. typhosus. 



Staining Reactions. Stained by basic aniline dyes ; decolor- 

 ised by Gram's method. 



Reaction to Anti-typhoid Serum. Anti-typhoid serum, even, 

 in a dilution of 1-10, produced no agglutination. 



This micro-organism only differed from the B. typhosus in that 

 it failed to grow typically in Proskauer and Capaldi's media, and 

 did not react to anti-typhoid serum. 



B. Typhosus Sinmlans (Cultures B 3 , B 4 , B 5 , and B 6 ). 



These cultures all gave the following characteristics, and 

 appeared to be the same micro-organism : 



Gelatine Plates. Identical with those of culture A. 



Gelatine-stab. Surface growth the same as the colonies, which 

 appeared to grow more slowly than B. coli ; a thin growth 

 along the stab. 



Gelatine-streak. A thin growth, whichdid not show thecrenated 

 margin of B. coli, but was distinctly more copious than that of 

 B. typhosus planted out at the same time. 



Witters Peptone and Salt Solution. No indol produced after 

 seven days incubation at 37 C. 



Glucose-gelatine Shake. No gas formation. 



Milk. Unchanged after one month. 



Potato. Growth at first transparent, later acquired a yellowish 

 tinge. 



Gelatine (25 per cent.) at 37 C. No film appeared on the 

 surface, but a diffused growth appeared throughout the tube. 



