136 CLINICAL BACTERIOLOGY. 



streptococcus pyogenes, the staphylococcus pyogenes, the 

 diplobacillus pneumonias Friedlander, the bacillus pyocya- 

 neus, alone or in mixed infection. All of these organ- 

 isms are more or less common inhabitants of the buccal 

 cavity, and migrate through the Eustachian tube into the 

 middle ear under special circumstances. Influenza-otitis is 

 associated with the presence of influenza-bacilli ; tubercu- 

 lous otitis, constantly with that of the tubercle-bacillus. 



Bacteriologic Diagnosis. The auditory canal is cleansed 

 carefully with mercuric-chlorid solution, paracentesis is 

 practised with a suitable needle or knife sterilized in the 

 flame, the escaping pus is taken up with a platinum wire 

 bent at an angle, and from it plates are cast (agar, on 

 account of the presence of pneumococci). 



After the occurrence spontaneously of perforation, the 

 examination is of little value, as the secretion will have 

 become contaminated by the numerous microorganisms of 

 the external auditory canal. If tuberculosis is suspected in 

 a case of chronic otitis media, the pus should be examined 

 microscopically for tubercle-bacilli, and possibly animals 

 should be inoculated with it. 



MENINGITIS. 



Inflammation of the cerebral meninges occurs, as a 

 primary disorder in the form of epidemic cerebrospinal 

 meningitis, and as a secondary (metastatic) condition in con- 

 nection with pyemia and numerous infectious diseases, espe- 

 cially in the sequence of otitis media, inflammation of the 

 accessory cavities of the nose, and croupous pneumonia. 

 A special position is occupied by tuberculous meningitis, 

 which preferably involves the base of the brain. From the 

 exudate in cases of secondary meningitis there have been 

 cultivated the diplococcus lanceolatus Frankel, the strep- 

 tococcus pyogenes, the staphylococcus pyogenes, the bac- 

 terium coli, and the diplobacillus pneumoniae Friedlander. 

 In cases of tuberculous meningitis the pus and sections of 

 tissue contain tubercle-bacilli, partly alone and partly in 

 association with phlogogenic cocci. These bacteria gain 

 access to the cerebral or spinal membranes from the naso- 

 pharyngeal space (lamina cribrosa), from the middle ear, 

 or from the original focus of suppuration : in the last in- 

 stance through the intermediation of the blood-stream. 



