152 



media, this organism should become irreversibly converted into the 

 common denitrifying species, Bacterium Stutzeri. 



It seems probable that younger microbiologists will be inclined to 

 cover these later publications of BEIJERINCK with the cloak of 

 charity; older workers in the field who are more familiar with the 

 tricky ways in which variation may manifest itself will be led to 

 wonder : senescence or accumulated wisdom ? 



