CHAPTER V. 

 TYPHOID FEVER. 



THE bacillus of typhoid fever (Fig. 72) was discovered 

 by Eberth in 1880, and was first secured in pure culture 



FIG. 72. Bacillus typhi, from a twenty-four-hours-old agar-agar culture ; x 



650 (Heim). 



from the spleen and affected lymphatic glands by Gaff ky 

 four years later. 



The organism is a small, short bacillus about 1-3 n 

 (2-4 1>. Chantemesse, Widal) in length and o. 5-0. 8 P. broad 

 (Sternberg). The ends are rounded, and it is rather ex- 

 ceptional for the bacilli to be united in chains, though 

 this arrangement is common in potato cultures. The 

 size and morphology vary distinctly with the nature of 

 the culture-medium and the age of the culture. Thoinot 

 and Masselin in describing these morphological peculi- 

 arities mention that when grown in bouillon it is a very 

 slender bacillus ; in milk it is a large bacillus ; upon 

 agar-agar and potato it is very thick and short ; and in 

 old gelatin cultures it forms very long filaments. 



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