in.] CHOLERAIC COMMA-BACILLI. 47 



bacteria, and also crowds of comma-bacilli. Comparing 

 the comma-bacilli of such preparations with those made of 

 the same flakes while fresh, a marked difference was noticed : 

 in the former the comma-bacilli were obviously three or four 

 times longer and thicker than in the latter, and besides 

 there were present many long chains of comma-bacilli, wavy 

 but not spiral. On growing the comma-bacilli in 10 per 

 cent, gelatine and beef-broth, in plate-cultivations, after 

 three or four days the comma-bacilli are very finely curved 

 and all of about the same length, either single or 



7r J( ^ 



FIG. 8. ARTIFICIAL CULTIVATION OF CHOLERAIC COMMA-BACILLI IN ALKALINE 

 PEPTONE GELATINE. 



Magnifying power 700. 



in fact, the uniformly finest and most typical forms I have 

 ever obtained were seen in plate-cultivations in (10 per 

 cent.) gelatine and beef-broth. In 10 per cent, gelatine, 

 beef-extract and peptone (i per cent.), or gelatine (10 per 

 cent), beef-broth and peptone (i per cent), the comma- 

 bacilli are also fine, but not so uniformly curved and typical 

 as in the former medium. In alkaline or neutral beef broth 

 during the first two or three days of growth at 35-37C., 

 large numbers of very short comma-bacilli are met with 

 amongst longer ones and g-shaped ones ; but the curvature is 

 well-pronounced only in few, most of them are only slightly 



