200 INFLAMMATORY AND SUPPURATIVE CONDITIONS. 



in the human subject in its characteristic form is almost invari- 

 ably due to a streptococcus, as was shown by Fehleisen in 1884. 

 He obtained pure cultures of the organism, and gave it the 

 name of streptococcus erysipelatis ; and, further, by inoculations 

 on the human subject as a therapeutic measure in malignant 

 disease, he was able to reproduce erysipelas. As stated above, 

 however, one after another of the supposed points of difference 

 between the streptococcus of erysipelas and that of suppuration 

 has broken down, and it is now generally held that erysipelas is 

 produced by the streptococcus pyogenes of a certain degree of 

 virulence. It must be noted, however, that erysipelas passes 

 from patient to patient as erysipelas, and purulent conditions 

 due to streptococci do not appear liable to be followed by ery- 

 sipelas. On the other hand, the connection between erysipelas 

 and puerperal septicaemia is well established clinically. 



In a case of erysipelas the streptococci are found in large 

 numbers in the lymphatics of the cutis and underlying tissues, 

 just beyond the swollen margin of the inflammatory area. As 

 the inflammation advances they gradually die out, and after a 

 time their extension at the periphery comes to an end. The 

 streptococci may extend to serous and synovial cavities and set 

 up inflammatory or suppurative change, peritonitis, meningitis, 

 and synovitis may thus be produced. 



Meningitis. Although almost any of the above-mentioned 

 pyogenic organisms may be concerned in the causation of 

 meningitis, some general statements may be made regarding it. 

 A considerable number of cases of meningitis, especially in chil- 

 dren, are due to the pneumococcus. In many instances where 

 no other lesions are present the extension is by the Eustachian 

 tube to the middle ear and thence to the brain ; in other cases 

 the path of infection is by means of the blood stream, usually 

 from some inflammatory lesion in the lungs. Meningitis is not 

 infrequently produced by a streptococcus, especially when middle 

 ear disease is present, less frequently by one of the staphylococci. 

 Occasionally more than one organism may be concerned. In 

 meningitis following influenza, the influenza bacillus has been 

 found in a few cases, and in tubercular meningitis the tubercle 

 bacillus of course is present, especially in the nodules along the 

 sheaths of the vessels. The pneumobacillus and B. typhosus 

 also have been found in a few cases of meningitis. 



