58 



BACTERIA 



tents and excreta, particularly so when the Peyer*s glands 

 have commenced ulceration. In the blood of the general 

 circulation the bacillus is not demonstrable, except in very 

 rare instances. Typhoid fever is not, like anthrax, a blood 

 disease. 



COMPARATIVE FEATURES OF BACILLUS TYPHOSUS AND 



B. COLI 



B. TYPHOSUS 



Morphology : Cylindrical bacillus 2.4 

 //, unequal lengths ; some fila- 

 ments. 



Flagella . Long, wavy, spiral, and 

 very numerous ; movement very 

 active. 



On Gelatine and Agar : Angular, ir- 

 regular, raised colonies ; slow 

 growth ; translucent ; medium re- 

 mains clear. 



In Gelatine : In ordinary gelatine and 

 in sugar gelatine no gas is pro- 

 duced. 



Milk : Not curdled by the bacillus. 



Indol : The production of indol in or- 

 dinary broth is nil. 



Potato: The "invisible growth,'' if 

 potato is acid. 



Lactose . Fermentation very slight. 



1^ per cent. Gelatine at y]"^ C: Strong- 

 ly and uniformly turbid (Klein). 



Eisner's Iodised Potato Gelatine : Slow 

 growth ; small, very transparent 

 colonies. 

 WidaVs Test: Bacilli become motion- 

 less and clumped together when 

 suspended in a drop of blood 

 ^erum from a typhoid patient. 



B. COLI 



Shorter, thicker ; filaments rare. 



Shorter, stiffer, fewer ; 

 active. 



movement less 



Even edge, homogeneous ; much 

 larger, quicker growth, and less 

 translucent thanj B. typhosus ; 

 medium becomes turbid or col- 

 oured. 



Under the same circumstances abun- 

 dant gas is produced. 



Milk is coagulated (within three days). 

 Indol is present. 



Thick, yellow growth. 



Fermentation marked. 



Gelatine remains limpid and clear, but 

 possesses thick pellicle. 



Very fast growth ; larger, brown, less 

 transparent colonies. 



Bacilli remain actively motile. 



