CHAPTER X. 



TYPHUS MURIUM. 



THE Bacillus typhi murium (Fig. 113), which created 

 havoc among the mice in his laboratory, causing most 

 of them to die, was discovered by Iv6ffler in 1889. It 

 is a short organism, somewhat resembling the bacillus 

 of chicken-cholera. It is rather variable in its dimen- 

 sions, and often grows into long, flexible filaments. No 



FIG. 113. Bacillus typhi murium, from agar-agar; x 1000 (Itzerott and 



Niemann). 



sporulation has been observed. It is a motile organism, 

 with numerous flagella, like those of the typhoid-fever 

 bacillus. It stains well with the ordinary dyes, but 

 rather better with Loffler's alkaline methylene blue. 



Upon gelatin plates the deep colonies are at first round, 

 slightly granular, transparent, and grayish. Later they 

 become yellowish-brown and granular. Superficial col- 

 onies are similar to those of the typhoid bacillus. In 



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