114 ESSENTIALS OF BACTERIOLOGY. 



and growth, that it cannot be distinguished by these character- 

 istics alone. 



Form. As cholera bacillus. 



Growth. Two kinds are found on the gelatine 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. 



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 it produces a hemorrhagic 

 cedema, and a septicaemia which has been called " Vibrion 

 septiccemia." The blood and organs contain the spirilla in 

 great numbers. 



Products. The nitrites are formed just as in cholera bacillus, 

 and the red reaction given when mineral acids added to gelatine 

 cultures. Certain products also 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 pro- 

 duct injected. (5 c.cm. of a five days' old sterilized culture.) 



In a couple of weeks 1 to 2 c.cm. of the infected blood can be 

 injected without causing any fatal result. 



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 

 many other pathological processes have shown them they can 

 hardly be set down as the sole cause of pneumonia. 



Klebs in 1875 called attention to the presence of bacteria in 

 pneumonia, and in 1882 Friedlander developed a bacillus from 

 the lung tissue of a pneumonic person, which he thought was a 

 coccus, and called it piieumococcus. 



