DISTRIBUTION OF PNEUMO BACTERIA. 213 



on glycerine. The substances produced by the fermenta- 

 tion vary with the sugar fermented, but include ethylic 

 alcohol, acetic acid, laevolactic acid, succinic acid, along 

 with hydrogen and carbonic acid gas. The amount of 

 acid produced from lactose seems only exceptionally 

 sufficient to cause coagulation of milk. 



The Occurrence of the Pneumobacteria in Pneumonia 

 and other Conditions. The pathological anatomy of 

 pneumonia is so fully dealt with in all text -books on 

 pathology, that it is unnecessary for us to do more than 

 emphasise its strictly bacteriological features. Capsulated 

 organisms have been found in every variety of the disease 

 in acute croupous pneumonia, in broncho-pneumonia, in 

 septic pneumonia. In the great majority of these it is 

 Fraenkel's pneumococcus which both microscopically and 

 culturally has been found to be present. 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, 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 

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

 croupous pneumonia, and therefore such parts are prefer- 

 ably to be selected for microscopic examination, and as 

 the source of cultures. Sometimes there occur in pneu- 

 monic consolidation areas of suppurative softening, which 

 may spread diffusely. In such areas the pneumococci 

 occur with or without ordinary pyogenic organisms, 

 streptococci being the commonest concomitants. In 

 other cases, especially when the condition is secondary 

 to influenza, gangrene may supervene and lead to destruc- 

 tion 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 



