62 BACTERIOLOGY 



weeks, or even months, chronic cases sometimes occurring and 

 usually leading to mental impairment of the victim. The 

 organism is harboured especially in the nose and throat of 

 contacts, and may be communicated by such persons, who 

 may themselves not exhibit signs of illness, to others, and 

 cause the meningeal form of the disease, i.e. that in which the 

 covering membranes of the brain and spinal cord are attacked. 



Microscopically the organism occurs in the inflammatory ( exu- 

 date over the brain and the spinal cord, and its presence may be 

 demonstrated by withdrawing (by " lumbar puncture " as it is 

 called) and examining a little of the cerebro-spinal fluid which 

 bathes these organs and is usually increased in amount in this 

 disease. In shape it closely resembles the Gonococcus, and like 

 the latter, as its name implies, is usually found inside the cells 

 of the exudate. It can be differentiated from the Gonococcus 

 by cultural methods and by tests based on certain immunity 

 reactions (see p. 49). Serum treatment, especially by the 

 serum introduced by Flexner of New York, has done some- 

 thing to lower the case-mortality of this terrible disease, the 

 serum being introduced directly into the spinal canal. A 

 very closely allied organism, known as Still's Micrococcus of 

 Posterior Basic Meningitis, can be differentiated from the 

 Meningococcus only by careful and elaborate cultural and im- 

 munity tests. 



The Micrococcus catarrhalis and certain closely allied 

 organisms are common in the nose and throat, and are 

 increased in many cases of catarrhal inflammation such as 

 colds, sore throats, and bronchitis. Though not themselves 

 highly pathogenic, they add their adverse influence in infection 

 by other organisms such as Pneumococci, Streptococci, B. 

 influenzae, B. diphtheriae and others mixed vaccines in such 

 cases being sometimes very efficacious in bringing about a cure. 

 The M. catarrhalis, unlike the Gonococcus and Meningococcus, 

 grows easily upon ordinary media and at ordinary room- 

 temperature (20 0.). 



Group of Organisms producing Specific Infective 

 Fevers, etc. 



Micrococcus melitensis (Bacillus or Cocco-bacillus meli- 



tensis). This organism is a very minute, slightly elongated 

 Gram-negative cocco-bacillus (i.e. an organism coming between 

 the cocci and bacilli as regards its shape), and is the cause of 

 Malta, or as it is now preferably called, Mediterranean Fever, 

 a long-continued disease characterised by intermittent or 

 undulating waves of temperature, with joint-pains, emaciation, 



