TYPHOID FEVER 109 



In size the bacillus of typhoid is about three times 

 as long as it is broad, the rods having rounded ends^ 

 but with very little in its appearance to aid in its 

 identification. It is very actively motile, but the 



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Fig. 18. — Bacillus Fia. 19. — Bacillus typhosus, 



typhosus. showing flagella. 



flagella cannot be seen without special staining 

 (Loffler's method). During Hfe the bacilli may be 

 found in the blood, in the urine, in the rose-spots, and 

 in the feces of patients suffering with typhoid fever; 

 and after death may be found in the tissues of the 

 spleen, of the liver, of the kidneys, and of the intes- 

 tines. Colonies of typhoid bacilli show nothing es- 

 pecially characteristic, being irregular, with somewhat 

 wrinkled surfaces and a blue white color. Typhoid 

 bacilU grow best at about 35° C. (95° F.); they 

 are killed by a temperature of 60° C. (140° F.), but 

 sometimes survive freezing for weeks or even months. 

 They grow slowly, with or without oxygen, and form 

 no spores; their growth does not liquefy gelatin, 

 nor produce gaseous fermentation, nor coagulate 

 sterilized milk; these points and others are utiUzed 



