PNE UMOBA GILL US. 459 



of this bacillus from that of the bacillus aerogenes, 

 which is otherwise very similar to it morphologically 

 and culturally. On gelatin plates colonies appear at the 

 end of twenty-four hours as small white spheres, which 

 rapidly increase in size. These colonies, when ex- 

 amined by a low-power lens, present a somewhat 

 irregular outline and a slightly granular appearance. 

 The growth on agar is in quite large and moist grayish 

 colonies. On blood-serum abundant, grayish-white, 

 viscid masses are developed. The growth on potato 

 is luxuriant a thick, yellowish-white, glistening layer 

 rapidly covering the entire surface. Milk is not coagu- 

 lated. Indol is produced in bouillon or peptone solu- 

 tions. Fermentation of rnilk-sugar and glucose is 

 caused. Growth occurs at 16 to 20 C., but is more 

 rapid at 37 C. 



Pathogenesis. Friedlander's bacillus is pathogenic 

 for mice and guinea-pigs, less so for dogs, and rabbits 

 are apparently immune. In Friedlander's experiments 

 mice proved to be particularly susceptible. These 

 animals, when pure cultures of the bacillus are in- 

 jected through the thoracic wall into the tissue of the 

 lung, invariably succumb to the disease. On autopsy 

 the pleural cavities are found to contain a sero-puru- 

 lent fluid, the lungs are intensely congested, and in 

 places show limited areas of red hepatization; the 

 spleen is considerably enlarged, and bacilli are present 

 in the lungs, the pleuritic fluid, and the blood. In 

 guinea-pigs which are killed by the inoculation similar 

 appearances are observed. 



Friedlander's bacillus has been found in man, not 

 only in patients suffering from croupous pneumonia 

 and other respiratory diseases, but also in healthy indi- 



