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 

 >M, unequal lengths ; some fila- 

 ments. 



Plagella : 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. 



25 per cent. Gelatine at 37 C. : Strong- 

 ly and uniformly turbid (Klein). 



Eisner's Iodised Potato Gelatine : Slow 

 growth ; small, very transparent 

 colonies. 



Widal's Test: Bacilli become motion- 

 less and clumped together when 

 suspended in a drop of blood 

 serum from a typhoid patient. 



B. COLI 



Shorter, thicker ; filaments rare. 



Shorter, stiffer, fewer ; movement less 

 active. 



Even edge, homogeneous ; much 

 larger, quicker growth, and less 

 translucent than; 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. 



