250 



PATHOGENIC BACTERIA. 



The artificial 

 Kitasato is not more 



cultivation which was achieved by 

 difficult than that of other an- 

 aerobic organisms. In gelatin 

 containing i to 2 per cent, of 

 glucose or 5 per cent, of gly- 

 cerin the organism develops 

 quite well, the exact appearance 

 depending somewhat upon the 

 method by which it was planted. 

 If the bacteria are dispersed 

 through the culture -medium, 

 the little colonies will appear 

 in the lower parts of the tube as 

 nearly spherical or slightly irreg- 

 ular, clouded, liquefied areas con- 

 taining bubbles of gas. If, on 

 the other hand, the inoculation 

 is made by a deep puncture, a 

 stocking - shaped liquefaction 

 forms along the whole lower 

 part of the puncture, leads to 

 considerable gas-production, and 

 finally causes the liquefaction of 

 all the gelatin except a thin 

 superficial stratum. A peculiar 

 acid odor is given off by the 

 cultures. 



When the bacteria grow anaerobically in Ksmarch 

 tubes, the colonies are irregularly club-shaped or spheri- 

 cal, with a tangled mass of delicate projecting filaments 

 visible upon microscopic examination. 



In agar-agar the development is similar to that in 

 gelatin. The gas-production is marked, the liquefaction 

 of course absent, and the same acid odor pronounced. 



The bacillus also develops quite well in bouillon, the 

 bacillary masses sinking to the bottom in the form of 

 whitish flakes, while the gas-bubbles collect at the top. 

 In this medium the virulence is unfortunately soon lost. 



FIG. 71. Bacillus of symp- 

 tomatic anthrax : four-clays-old 

 culture in glucose-gelatin (Fran- 

 kel and Pfeififer). 



