MORPHOLOGY AND BIOLOGY. 



251 



are joined end to end they resemble the letter S (Fig. 103). 

 Long chains are occasionally formed in culture (Fig. 106). 



The cholera bacillus can be stained with the anilin dyes, 

 but with some difficulty. It stains best in a hot carbol- 

 fuchsin solution. It does not stain by Gram's method. It 

 is exceedingly motile and has terminal flagella. It is one of 



FIG. 104. 



Spirillum of Asiatic cholera : colonies two days old upon a gelatin plate. 



(Heim.) 



X35. 



the monotrichia, which have only one or two flagella project- 

 ing from one end. It does not form spores, although Hueppe 

 believed that arthrospore-formation existed. 



It is strongly aerobic, growing quite readily on all culture- 

 media either at the room or the -body temperature, but the 

 medium must be slightly alkaline, as the cholera spirillum is 

 quite sensitive to even small amounts of acid. 



Schottelius gives the following method for making pure 

 cultures of the cholera germ : A small quantity of the intes- 

 tinal mucus or fecal matter is transferred to a flask or tube 



