204 MICEOBES, FERMENTS, AND MOULDS. 



searches, and the first idea which will occur to any 

 unprejudiced micrographist, is that P. Ferrani is not 

 really Koch's comma bacillus, and consequently not 

 the cholera microbe.* 



We have, in fact, already shown that numerous 

 comma-shaped bacteria, or free cells, are found in 

 water and in the human body, and that these may 

 be easily confounded with the true comma bacillus 

 when staining reagents and a very precise mode of 

 culture are not employed. Ferran himself states that 

 this staining process must not be used in the culture 

 of P. Ferrani. Cornil has, however, shown that the 

 true comma bacillus is not destroyed by methyl 

 violet. Finkler had previously discovered in cholera 

 nostras, which is not epidemic, a comma-shaped 

 microbe resembling in many respects the one 

 described by Ferran. Koch has shown that this 

 microbe, as well as one of similar form found by 

 Lewis in the saliva, does not act in cultures like the 

 microbe of Asiatic cholera ; Lewis's microbe does not, 

 like the cholera bacillus, liquefy gelatine. 



The precautions necessary for the sowings of 

 culture liquids are so great that we may be permitted 

 to doubt whether Ferran has always guarded against 

 error. Brouardel's report shows, after a visit to 



* Our criticism on the description and illustrations of Laveran's 

 marsh-fever microbe might be applied, word for word, to Ferran 's 

 description and illustrations of the cholera microbe, which we have 

 reproduced above. 



