Mixed Pneumonias 305 



infectious in nature and result from the aspiration, from 

 higher parts of the respiratory apparatus, of the staphylo- 

 cocci and streptococci of suppuration, Friedlander's bacillus, 

 the bacillus of influenza, and other well-known organisms. 



TUBERCULAR PNEUMONIA. 



The progress of pulmonary tuberculosis is at times so 

 rapid that the tubercle bacilli are distributed with the 

 softened infectious matter throughout the entire lung or to 

 large parts of it, and a distinct pneumonic inflammation 

 occurs. Such a pneumonia may be caused by the tubercle 

 bacillus, but more frequently depends upon accompanying 

 staphylococci, streptococci, tetragenococci, pneumococci, 

 pneumobacilli, and other organisms accidentally present in 

 a lung in which ulceration and cavity-formation are ad- 

 vanced. 



PNEUMONIC PLAGUE. 



The pneumonic form of plague is characterized by con- 

 solidation of the lung histologically and morbid changes 

 anatomically indistinguishable from pneumococcal and other 

 extensive pulmonary infections. 



MIXED PNEUMONIAS. 



It frequently happens that pneumonia occurs in the course 

 of influenza or shortly after convalescence from it. In these 

 cases a mixed infection by the influenza bacilli and pneu- 

 mococci is commonly found. Sometimes pneumococci and 

 staphylococci simultaneously affect the lung, purulent pneu- 

 monia with abscess-formation being the conspicuous feature. 

 Almost any combination of the described bacteria may occur 

 in the lungs, producing varying inflammatory conditions, 

 so that it must be left for the student to work out what the 

 particular characteristics of each may be. 



Among the mixed forms of pneumonia may be mentioned 

 those called by Klemperer and Levy "complicating pneu- 

 monias," occurring in the course of typhoid fever, etc. 



