OCCURRENCE OF PNEUMOBACTERTA 233 



seems only exceptionally sufficient to cause coagulation of milk. 

 With regard to indol formation the results of different observers 

 vary. Here, as with other reactions, it is to be noted that only 

 strains isolated from 

 cases <>t pneumonia are 

 to be taken into account. 

 It is said by some that 

 the bacillus is identical 

 with an organism com- 

 mon in sour milk, and 

 also a normal inhabitant 

 of the human intestiiu', 

 namely, the bacterium 



The Occurrence of 

 the Pneumobacteria in 

 Pneumonia and other 

 Conditions. Capsulated 

 organisms have been FlG - 68. Friedliinder's pueumobacillus,i 

 c i > from a young culture on agar, showing 



found m every variety some n.d -shaped forms. 



of the disease in acute Stained \vith thionin-blue. x 1000. 



croupous pneumonia, in 



broncho-pneumonia, in septic pneumonia. In the great majority 

 of these it is Fraenkel's pneumococcus which both microscopic- 

 ally and culturally has been found to be present. Fried lander'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, especially in the exudation 

 in the air-cells. They also occur in the pleural exudation and 

 effusion, and in the lymphatics of the lung. The greatest number 

 are found in the parts where the inflammatory process is most 

 recent, e.g. in an area of acute congestion in a case of croupous 

 pneumonia, and therefore such parts are preferably to be selected 

 for microscopic examination, and as the source of cultures. 

 Sometimes there occur in pneumonic consolidation areas of 

 suppurative softening, which may spread diffusely. In such 

 areas the pneuniococci occur with or without ordinary pyogenic 

 organisms, streptococci being the commonest concomitants. In 



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

 varies much according to the stain used. 1 1' stained with a strong stain, e.g. 

 carhol-fuchsin, its thi<-kne^ appears nearly twice as great as is shown in the 

 tigure. 



