DIPLOCOCCUS PNEUMONIAE 

 (FRANKEL) 



In a large proportion of cases normal saliva contains 

 a capsulated micro-organism, usually appearing as a 

 diplococcus, which, when injected into the rabbit 

 produces a rapidly fatal septicaemia. First noticed 

 by Pasteur (1881) in the saliva, and studied by 

 Sternberg in relation to the rabbit septicaemia pro- 

 duced by its injection, this micro-organism, by the 

 work of Talamon, Frankel, Netter, Weichselbaum, 

 and others, was gradually connected with, and finally 

 regarded as, the cause of croupous pneumonia in 

 man. A normal inhabitant of the mouth, this 

 microbe requires for the development of its patho- 

 genic properties conditions which are at present 

 but ill understood. The production of a typical 

 pneumonia by its action seems to imply a con- 

 siderable power of resistance in the infected animal ; 

 otherwise a septicaemia is produced. The organism 

 possesses pyogenic properties and is found in otitis 



