94 THE BACTERIA IN ASIATIC CHOLERA. [CH. 



this occurrence of comma-bacil.U as a matter of course, which 

 "every one knew before." It must be plain to every im- 

 partial reader that not even Koch knew this until Lewis 

 pointed it out. 



The comma-bacilli of Lewis are not the same as those 

 afterwards described and isolated by Miller, since the latter 

 have been isolated and grown in 10 per cent, alkaline gela- 

 tine, and behave similar to those of Finkler and Prior, while 

 those of Lewis do not behave in this way. Neither Lewis 

 nor Koch, nor any of the many workers in Koch's labora- 

 tory who have tried to grow them in alkaline 10 per cent, 

 gelatine, have succeeded. It occurred to me that inasmuch 

 as the fluid of the mouth often has a neutral or even faintly 

 acid reaction, it might be possible to grow these comma- 

 bacilli in neutral or faintly acid nutritive gelatine. I examined 

 the fluid of my own mouth, and as had been already shown 

 by Lewis, I found that comma-bacilli vary greatly in numbers 

 at different times : sometimes 1 could find in every specimen 

 (made by drying on a cover-glass a thin film, and staining 

 it afterwards in gentian-violet or Spiller's purple) several 

 examples of comma-bacilli ; at other times only in one or 

 the other could a few be found, while at other times 

 again I found numbers of them in groups and as isolated 

 examples. On such occasions I made a number of 

 plate-cultivations in 5 per cent, neutral nutritive gelatine, 

 and in one instance after several fruitless attempts I did 

 get a colony of liquefying comma-bacilli, which in their 

 manner of growth in the plate-cultivation seemed indis- 

 tinguishable from the choleraic comma-bacilli; from such 

 a colony 10 per cent, alkaline nutritive gelatine in test-tubes 

 was then inoculated, and the growths produced therein were 

 not distinguishable from those of choleraic comma-bacilli. 

 I have afterwards, on many occasions, repeated the original 



