VI] GENERAL CHARACTERS OF BACTERIA 



93 



symptomatic anthrax, bacillus of tetanus ; asparagin and 

 sodium sail in the case of phosphorescent bacteria (Bey- 

 rinck), milk sugar in the case of bacterium lactis, • 



The nature of the nutritive medium has in many cases an 

 important effect not only on the morphology but also on the 

 physiological action of bacteria in general, and of pathogenic 



Fig. 17. — Impression of a very young Growth of Bacillus 

 Radicicola. 



bacteria especially. Thus, for instance, the addition of 

 excess of salt to nutritive gelatine affects considerably the 

 morphology of a series of bacteria — e.g. bacillus coli and its 

 varieties. This in ordinary gelatine are mostly short oval 

 bacteria, some are cylindrical, and few even threadlike, but 

 if an excess of chloride of sodium is added most of these 

 bacteria grow out into threads, some of great length. Or 



