Pathogenesis 511 



pneumonia there can be no room for doubt after the demon- 

 strations of Lamon and Meltzer,* who found that its experi- 

 mental introduction into the bronchi of dogs was followed by 

 true lobar pneumonia. The lesions in these dogs, like those 

 in human beings, were paler in color, the lung tissue less 

 friable, and the exudate more viscid than those caused by 

 the pneumococcus. 



Pneumonia in man, caused by Bacillus mucosus capsulatus, 

 is atypical clinically, very severe, and often fatal. 



Curryt found Friedlander's bacillus in association with the 

 pneumococcus in acute lobar pneumonia; in association with 

 the diphtheria bacillus in otitis media associated with croup- 

 ous pneumonia; and in the throat in diphtheria. In pure 

 culture it was obtained from vegetations upon the valves of 

 the heart in a case of acute endocarditis with gangrene of the 

 lung; from the middle ear, in a case of fracture of the skull 

 with otitis media ; and from the throat in a case of tonsillitis. 

 Zinsser has twice cultivated Friedlander's bacillus from in- 

 flamed tonsils in children. 



AbelJ cultivated it from the discharges of fetid ozena, 

 and supposed it to be the specific cause. 



Occasionally Friedlander's bacillus bears an important 

 relationship to lobular or catarrhal pneumonia, an interesting 

 case having been studied by Smith. The histologic changes 

 in the lung were remarkable in that the " alveolar spaces 

 of the consolidated areas were dilated and for the most 

 part filled with the capsule bacilli." In some alveoli there 

 seemed to be pure cultures of the bacilli; others contained 

 red and white blood-corpuscles; in some there was a little 

 fibrin. The bacillus obtained from this case, when injected 

 into the peritoneal cavity of guinea-pigs, produced death 

 in eleven hours. The peritoneal cavity after death con- 

 tained a large amount of thick, slimy fluid; the intestines 

 were injected and showed a thin fibrinous exudate upon the 

 surface; the spleen was enlarged and softened, and the 

 adrenals much reddened. Cover-glass preparations from 

 the heart, blood, spleen, and peritoneal cavity showed large 

 numbers of the capsule bacilli. 



* "Jour. Exp. Med.," 1912, xv, 133. 



f "Jour. Boston Soc. of Med. Sci.," March, 1898, vol. n. No. 8, p. 137. 



t "Zeitschrift fur Hygiene," xxi. 



"Jour. Boston Soc. of Med. Sci.," May, 1898, vol. n, No. 10, p. 174. 



