OCCURRENCE OF PNEUMOBACTERIA 241 



Friedlander's pneumobacillus occurs in only about 5 per cent, of 

 the cases. It may be present alone or associated with Fraenkel's 

 organism. In a case of croupous pneumonia the pneumococci 

 are found all through the 



affected area in the lung, --^J^ 4 * " %v 



especially in the exuda- ^ *1f& ^.V % *** "y 



tion in the air-cells. They t % $J* V>* i 



also occur in the pleural ^ * \ ^ ***'< |*V** 

 exudation and effusion, A *x~"*ft* '< S*fttYr- v * **$ 

 and in the lymphatics of 

 the lung. The greatest 

 number are found in the 

 parts where the inflam- 

 matory process is most 

 recent, e.g., in an area '^ **"*>* */" 



of acute congestion in a ".^ .lf> * , \v ,f C / 



case of croupous pneu- * * vjj "i '* 



monia, and therefore such U^^* ^**i*' , ' 



parts are preferably to be 



for microscopic ^ IG- ^' Friedlander's pueumobacillus, 1 



from a culture 



examination, and as the gome rod-shaped forms. 



source of cultures. When Stained with thionin-blue. x 1000. 

 the inflammation is re- 

 solving, some of the organisms often stain badly (e.g., tend to 

 lose the Gram reaction) ; such individuals are probably either 

 dead or dying. Sometimes there occur in pneumonic consolida- 

 tion areas of suppurative softening, which may spread diffusely. 

 In such areas the pneumococci occur with or without ordinary 

 pyogenic organisms, streptococci being the commonest concomi- 

 tants. In other cases, especially when the condition is secondary 

 to influenza, gangrene may supervene and lead to destruction of 

 large portions of the lung. In these a great variety of bacteria, 

 both aerobes and anaerobes are to be found. 



In ordinary broncho-pneumonias also Fraenkel's pneumo- 

 coccus is usually present, sometimes along with pyogenic cocci ; 

 in the broncho-peumonias secondary to diphtheria it may be 

 accompanied by the diphtheria bacillus, and also by pyogenic 

 cocci ; in typhoid pneumonias the typhoid bacilli or the b. coli 

 may be alone present or be accompanied by the pneumo- 

 coccus, and in influenza pneumonias the influenza bacillus may 



1 The apparent size of this organism, on account of the nature of its sheath, 

 varies much according to the stain used. If stained with a strong stain, e.g., 

 carbol-fuchsin, its thickness appears nearly twice as great as is shown in the 

 h'gure. 



16 



