PATHOGENIC BACTERIA. 289 



first the particles lie free in the various organs into which they 

 are carried, but soon they are taken up by phagocytes. The 

 makrophages are the elements mainly concerned in the process. 

 On the injection of typhoid bacilli into the peritoneum of 

 rabbits there occurs an explosive destruction of many of the 

 bacilli, but those which are not so destroyed are taken up as 

 described above. 



In inflammations of mucous membranes the common pyo- 



- * , . 



FIG. 64. Staphylococcus pyogenes aureus in pus stained by Gram's 

 method. (X 1000.) 



genie organisms are frequently the cause, though other organ- 

 isms are occasionally responsible. In acute bronchitis, pneu- 

 mococci and streptococci were found by Ritchie* to be the 

 commonest causes. 



In inflammations of the middle ear the principal causes are 

 the pneumococcus, the streptococcus and the Staphylococcus 

 aureus and albus.f 



* Ritchie. Journal Pathology and Bacteriology. Vol. VII.' December, 

 1900. 



fHasslauer. CentralUatt fur Bakteriologie. XXXII. Ref. 1902, p. 174. 

 Compare ibid., pp. 240 and 246. 



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