APPENDIX TO CHAPTER XI. 197 



These small, straight bacilli are non-motile, they are never, 

 missed in a free state in the mucus-flakes, and when grown 

 artificially they form spores. Neither the comma-bacilli nor 

 these small bacilli show in their mode of growth, in artificial 

 cultivations in various media, greater peculiarities than other 

 kinds of bacteria. The peculiar mode of growth of the 

 comma-bacilli in gelatine mixtures is shown in the accompany- 

 ing woodcuts. 



Both the comma-bacilli and small straight bacilli grow well 

 m alkaline and neutral media, and are not killed by weak acids 



FIG. G. 



Pure cultivation of choleraic comma-bacilli in gelatine-peptone-Lroth. The 

 inoculation had been made, not in a channel, as in the previous figures, but 

 on the surface. There is also here a. depression of the growth on the sur- 

 face, and in the extent of the growth the gelatine is liquefied, with a 

 whitish precipitate at the bottom. 



although they do not show growth in them, or only to a 

 very limited degree. Neither the comma-bacilli nor the 

 straight small bacilli can be considered as connected with the 

 cause of cholera. 



The result of the experiments performed by Nicat and 

 Rietsch, by Koch and others, viz., death following in some of the 

 animals after injection of choleraic mucus-flakes or of cultiva- 

 tions of comma-bacilli into the cavity of the small intestine, were 

 not due to cholera, but were probably due either to the opera- 



