PART III. 



SPECIFIC DISEASES OF BACTERIAL ORIGIN. 



TYPHOID FEVER, 



Morphology of the Typhoid-bacillus. The bacillus 

 of typhoid fever was first observed by Koch and Eberth, 

 and grown in pure culture by Gaffky in 1884. 



Fig. 48. Bacillus typhi, from an agar-agar culture twenty-four hours old ; X 650 



(Heim). 



The typhoid-bacilli are small, plump rods, with rounded ex- 

 tremities (0.5-0.9 X 1-3/0- I n tne tissues the organisms 

 lie, as a rule, isolated, while in cultures they are arranged in 

 pairs and not rarely in long filaments. They possess from eight 

 to eighteen terminal and lateral flagella, and, in consequence, 

 they are most actively motile, their movement being serpentine 

 in character. They do not stain so well as other bacteria and they 

 take the stain with some difficulty. It is, therefore, advisable to 

 warm the aqueous staining solutions and also the diluted carbol- 

 fuchsin solution. The bacilli do not stain by Gram's method. 



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