1 8 2 BACTERIOLOGY. 



and produce the ripening" of cheese. They occur 

 also in solutions of starch, dextrine, and sugar, 

 and are the active agents in the fermentation of 

 sauerkraut and sour gherkins. 



METHOD OF STAINING THE BACILLUS OF BUTYRIC 

 ACID FERMENTATION. 



Treat the bacilli with iodine-solution. At certain stages of 

 the fermentation-process the plasma takes a blue or violet- 

 black coloration. The young rods give the former appearance, 

 and the older ones the latter. It is most easily observed 

 when the bacillus is cultivated in a substance containing 

 starch, or, if starch is wanting, in the presence of cellulose, 

 calcium-lactate, or glycerine ; in bacilli cultivated in sugar 

 solutions the reaction seldom appears. 



Clostridium polymyxa, Prazmowski. Threads 

 consisting of rods which vary in length ; cocci, 

 involution-forms, and spores are also present ; cul- 

 tivated on nourishing solutions they develop a thick 

 skin on the surface. On boiled beet and other 

 roots it forms a gelatinous scum, which often con- 

 sists of crinkled, tough masses, several cm. in diam., 

 somewhat similar to the Ascoccus Billrothii. They 

 cause fermentation in solutions of dextrine, and 

 more actively in potato or bean paste. Some cells 

 give the iodine reaction weakly, as in clostridium 

 butyricum. 



Clostridium of symptomatic anthrax (Rausch- 

 branct, Charbon symplomatique*}. Rods rounded at 



Arloing, Cornevin et Thomas, Bull, de r Acad. de Med. 1881. 



