in.] CHOLERAIC COMMA-BACILLI. 49 



agar mixture for from several days to several weeks at 

 35-37C., a good many spiral forms are met with; some 

 have very close turns, others are more wavy, some contain 

 as many as ten to twenty and more turns, others one or two ; 

 a good many S-shaped ones are also present. 



In an alkaline mixture of egg-albumen and Agar-agar 

 the comma-bacilli assume a very striking morphological 

 character ; they are all of a uniform appearance as regards 

 length and thickness, but there is hardly any curvature to be 

 noticed ; that they are not quite straight is seen when they 



\ '.' 



rt J 



; J 



FIG. io. ARTIFICIAL CULTIVATION OF THE SAME COMMA-BACILLI IN ALKALINE 

 BEEF BROTH. 



Magnifying power 700. 



are in groups : looked at singly or situated at intervals many 

 look only slightly or not at all curved, and it would not 

 be easy to identify them as comma-bacilli. They are dis- 

 tinctly pointed at the ends, and longer than the normal 

 ones. A preparation from a gelatine-culture compared with 

 one from this medium shows apparently two totally different 

 organisms; no one would recognise them as the same 

 organism (see Fig. 13). Yet there can be no question 

 about it, since on changing the medium by transferring 

 them from nutritive gelatine into egg-albumen and Agar-agar, 







