64 THE BACTERIA IN ASIATIC CHOLERA. [CH. 



On a former page it has been mentioned that very success- 

 ful cultivations of comma-bacilli can be made by placing 

 mucus-flakes of the rice-water stools or of the cholera in- 

 testine on linen, and keeping this damp in a covered glass 

 dish at 35-37 C. After twenty-four hours crowds of comma- 

 bacilli are available, from which plate-cultivations can be then 

 easily made. 



But this is only the case if the mucus-flakes initially 

 contain the comma-bacilli in considerable numbers. Another 

 method is this : with a particle of a mucus-flake or with a 

 minute droplet of the rice-water stool, a test-tube containing 

 sterile salt solution or sterile broth is inoculated, well shaken, 

 and from this a tube containing sterile solid nutrient gelatine 

 is inoculated, liquefied in warm water, and from it one or 

 more plate cultivations are established ; or if the comma- 

 bacilli are tolerably numerous in the stools a tube containing 

 sterile broth is inoculated with a trace of those materials and 

 then incubated at 35-37 C. Owing to the rapid power of 

 growth of the comma-bacilli, after twenty-four hours the 

 fluid contains them very abundantly, and now a tube con- 

 taining sterile salt solution or broth is inoculated, well shaken, 

 and from it nutrient gelatine is inoculated with a trace of a 

 droplet (with the end of a platinum wire or capillary pipette) ; 

 this is liquefied and used for plate-cultivations. As will be 

 stated further below, when other bacteria are numerous but 

 the comma-bacilli scarce in the original materials (stool or 

 mucus-flakes) a number of plate-cultivations (after the usual 

 method of dilution) will have to be made in order to obtain 

 a few colonies of the comma-bacilli. 



The appearances presented by these comma-bacilli when 

 grown in gelatine plates, in gelatine tubes, in Agar-agar 

 mixture, and on potato, in broth, milk, &c., are sufficiently 

 characteristic for all practical purposes of diagnosis. 



