BACILLUS DIPHTHERIA 



IN 1873 Klebs described amongst the organisms 

 found in diphtheritic membranes a small bacillus 

 which from its constancy he regarded as probably 

 specific. This opinion was confirmed and the bacillus 

 isolated by Loffler (1884). The observations of this 

 investigator were confirmed and extended by Houx 

 and Yersin by their discovery of the diphtheria 

 poison, and the production of post-diphtheritic 

 paralysis after inoculation of the bacillus or its toxic 

 products. Our further knowledge, especially in 

 regard to methods of immunisation and the anti- 

 toxic action of the blood serum of immunised animals, 

 we owe to Frarikel and Brieger, Kitasato and 

 Behring, and many other observers. 



The bacillus is found in the superficial layer of the 

 false membranes, and in its purest condition in the 

 early stages of the disease. Subsequently it becomes 

 much admixed with other organisms, especially the 



