108 CLINICAL BACTERIOLOGY AND H/EMATOLOGY 



CEREBRO-SPINAL MENINGITIS 

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This disease, that has recently assumed such importance, is 

 one that cannot be recognized by other than bacteriological 

 methods. The clinical symptoms are uncertain, but the bac- 

 teriological findings are direct and simple, and the disease can 

 be diagnosed by means of a lumbar puncture, and in that way 

 only (see p. 175). 



The organism, the meningococcus (Plate III., Fig. i), is a 

 diplococcus which varies considerably in size, but is usually 

 somewhat smaller than the gonococcus. The opposed sur- 

 faces of two cocci making up the pair are usually somewhat 

 flattened, but this is not so marked as in the latter organism. 

 It is often contained within the polynuclear leucocytes in cere- 

 bro-spinal fluid, but is not grouped in large numbers in a 

 single cell most others being free as is usually the case with 

 the gonococcus (see Plate III., where the two organisms are 

 contrasted). But the two organisms present a very close 

 resemblance even to serological tests, and morphologically it 

 is impossible to distinguish between them and a number of 

 unimportant organisms frequently found in the nasal cavity, 

 etc. As a rule, no difficulty arises in dealing with a meningeal 

 exudate, but if the question of gonorrhoea should come in the 

 sugar reactions described below must be investigated. 



The organism grows only at or near the body temperature, 

 and badly on ordinary agar. Primary cultures i.e., those 

 inoculated with morbid fluid direct from the body can, how- 

 ever, usually be obtained on this medium, the albuminous 

 material in the exudate supplying the extra pabulum that the 

 organism requires. Glucose-glycerin agar or blood-serum 

 are better media, or some of the more complicated media 

 mentioned below may be used. Sometimes the organisms 

 are present in very small numbers, and nearly all dead. In this 

 case, a culture can usually be obtained by Warren Crowe's 

 method of adding a small amount of a sterile concentrated 

 solution of glucose to the fluid itself, so as to bring the 

 strength to i per cent., and incubating the mixture. Sub- 

 cultures cannot be obtained on ordinary agar. 



Growth usually occurs in twenty-four hours, but may be 

 delayed, especially, I think, if the fluid has been allowed to cool 



