100 LOCALIZED INFECTIONS OF PUS NATURE 



MICROCOCCUS INTRACELLULARIS MENINGITIDIS. 



Meningitis, or inflammation of the membranes 

 covering the brain and spinal cord, may be caused by 

 several bacteria, such as streptococci, pneumococci, 

 and influenza bacilli, but we shall deal chiefly with 

 epidemic cerebrospinal meningitis or spotted fever. 

 (The latter is a common term which should be dis- 

 carded for meningitis, and confined to typhus or 

 jail fever.) Epidemic cerebrospinal meningitis is an 

 acute primary inflammation due to a coccus called 

 the Micrococcus or Diplococcus intracellularis menin- 

 gitidis of Weichselbaum . or the meningitis coccus or 

 meningococcus. The organism probably gains access 

 to the meninges by way of the nose, whence it passes 

 through the sieve-like bones through which the olfac- 

 tory nerves emerge from the skull. By this route it 

 penetrates to the under surface of the brain and 

 extends along the meninges. 



The other agents of meningitis, the pneumococcus 

 for instance, usually gain entrance by way of the 

 blood or lymph, directly through the skull-base or by 

 an extension from the middle ear, where suppuration 

 may burrow through the bone. 



The meningitis coccus is found in the nose and throat 

 of patients, and also in the nose and throat of about 

 10 per cent, of their attendants. 



The affection produces a thick, stringy, purulent 

 exudate in the spaces between the nervous system 

 and their coverings, the meninges, called the arachnoid 

 space. This exudate covers the brain and cord, and 

 fluid accompanying it distends the various cavities of 



