148 ESSENTIALS OF BACTERIOLOGY 



Growth. Two kinds are found on the gelatin plate one that 

 is identical in appearance with the cholera colony, the other 

 more liquefying, resembling the Finkler spirillum. If now a 

 second plate be inoculated from either one of these forms, both 

 kinds again are found grown, so that it is not a mixture of two 

 bacilli; on agar, brownish-yellow growth. 



Stab-culture. Similar to the cholera growth, a trifle faster in 

 growing. Staining, as cholera. 



Pathogenesis. To differentiate it from cholera, these bacilli, 

 when injected into animals, prove very fatal, and no especial 

 precautions need be taken to make the animal susceptible. In 

 the pigeon, guinea-pig, and chicken a hemorrhagic edema and 

 a septicemia is produced which has been called "Vibrion 

 septicemia." The blood and organs contain the spirilla in 

 great numbers. 



Products. The nitrites are formed in cultures just as with 

 cholera bacillus, and the red reaction produced when mineral 

 acids are added to gelatin cultures. Certain products are formed 

 which, when injected, give immunity. The cultures are first 

 heated for one-half hour at 100 C., which destroys the 

 germs, and then this sterilized product injected (5 c.c. of a 

 five-days'-old sterilized culture). In two weeks i to 2 c.c. of 

 the infected blood can be injected without causing any fatal 

 result. 



Many other spirilla resembling the spirillum of cholera have 

 been isolated from drinking-waters in the past few years, 

 and some bacteriologists are inclined to consider them as 

 varieties of the true cholera spirillum, which require only 

 certain conditions to make them pathogenic. Among these, 

 besides those already described, are Spirillum berolinense, S. 

 dunbarii, S. danubicum, S. of wernicke, S. bonhoffii, S. 

 weibeli, S. schuylkilliensis, S. milleri, S. aquatilis. The last 

 two are non-pathogenic for experiment animals. 



Bacteria of Pneumonia. Two forms of bacteria have 

 been found in this disease, and thought at different times to be 

 the cause of the same. 



Neither one of them is constant in pneumonia; and since 



