Xvi] VIBRIO AND SPIRILLUM 433 



by vibrio of Tinkler, by proteus vulgaris, by bacillus pro- 

 digiosus, by bacillus coli, and bacillus of typhoid, and I 

 found that bacillus prodigiosus, coli, and typhoid are in this 

 respect more virulent than vibrio of cholera or of Finkler. 



The result of the intraperitoneal injection of living or 

 dead vibrios taken from Agar cultures does not therefore in 

 any way throw any light on the specific action of the cholera 

 vibrio, it being an action due to the presence of poisonous 

 substances, intracellular poisons or protein poisons, within 

 the bodies of the vibrios or in those of many other microbes 

 mentioned. Under all these injections of the bodies of the 

 most varied microbes the same disease and the same patho- 

 logical changes are produced. 



That there are different degrees of virulence amongst 

 diBferent cultures of the same species, amongst the different 

 varieties of a species and amongst the different species 

 themselves, has been already mentioned. 



A dose of hving microbes need be smaller than of dead 

 microbes of the same culture in order to produce a fatal 

 result. This is easily explained by remembering that in the 

 case of dead microbes no further addition is made after 

 introduction into the peritoneal cavity, whereas if the 

 microbes are injected in a living state their multiplication 

 within the peritoneal cavity — as mentioned above, the 

 peritoneal exudation is found crowded with them — adds 

 considerably to the original intracellular poisons as also the 

 metabolic products, specific toxins, produced in conse- 

 quence of this multiplication act towards bringing about 

 a fatal result. That the cholera vibrios create poisonous 

 metabolic products, toxins, in a culture is well established ; 

 in some fluids not much of it — e.g. in broth or in ordinary 

 gelatine — but in aqueous humour or in serum the cholera 

 vibrio produces this toxin rapidly and in considerable quan- 



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