XVI] VIBRIO AND SPIRILLUM 453 



resembles the proteus vulgaris. Gelatine liquefied by the 

 cholera vibrio has no smell, whereas in the case of vibrio 

 Finkler it has a more or less putrid smell, just like that of a 

 growth of proteus vulgaris. 



The cultures of vibrio Finkler act on the guinea-pig in 

 the same way as the cholera vibrio, subcutaneously, intra- 

 peritoneally, and by ingestion ; there is no difference gene- 

 rally in this respect between the two vibrios. There are, 

 as stated on a former page, particularly virulent cultures of 

 the cholera vibrio which in intensity of action on the guinea- 

 pig surpass the vibrio of Finkler, but they surpass also other 

 less virulent cultures of undoubted cholera vibrios. 



Vibrio Finkler grows best at 20-21° C. ; it does not at all 

 grow well at 37° C., that is at a temperature when the 

 cholera vibrio grows best. If the peptone salt solution is 

 inoculated in one set of tubes with the cholera vibrio, in a 

 second set with the vibrio of Finkler, and of each set one 

 tube is kept in the incubator at 20° C, and likewise of each 

 set one tube is kept at 37" C, a very marked difference will 

 be observed between the two species of vibrios after twenty- 

 four hours, viz. the peptone culture of cholera vibrio incu- 

 bated at 20° C. is only very slightly turbid, there is just an 

 indication of growth having taken place, while the peptone 

 culture of vibrio Finkler shows marked turbidity, good 

 growth having taken place ; whereas the peptone culture of 

 cholera vibrio incubated at 37" C. shows uniform good 

 turbidity, the peptone culture of Finkler vibrio shows no 

 turbidity. The same holds good for cultures in broth pep- 

 tone. By incubating the peptone cultures at 37° C. for even 

 from twelve to eighteen hours the difference between the 

 two species is marked. Also on growing on the slanting sur- 

 face of Agar at 37° C. vibrio Finkler shows faint growth after 

 twenty-four or even after forty-eight hours, while the vibrio of 



