288 A MANUAL OF BACTERIOLOGY 



Micrococcus [Neisseria] meningitidis 



Weichselbaum in 1887 isolated from cases of cerebro- 

 spinal fever (epidemic cerebro -spinal meningitis, spotted 

 fever) a coccus which he named the Diplococcus intracel- 

 lularis meningitidis, and further research has confirmed 

 the accuracy of Weichselbaum's discovery and the etio- 

 logical relationship of the organism to the disease. While 

 tending to be epidemic, the disease also occurs spora- 

 dically. 



Cerebro-spinal fever varies much in severity and pre- 

 sents every degree of duration from acute fulminating 

 cases, which may die within twenty-four hours of the first 

 onset, to cases running a lingering course of weeks or 

 months. In the acuter cases a hsemorrhagic septicaemia 

 may be present with haemorrhages in the skin, hence the 

 name " spotted fever " sometimes applied to it (typhus 

 fever has also been termed " spotted fever "). 



The meningococcus is met with in the exudate on the 

 meninges, in the cerebro-spinal fluid, occasionally in the 

 blood, rarely in the urine, and in other situations, e.g. 

 eye, ear, joints. It is also present in the naso-pharynx of 

 carriers and sometimes (perhaps always at an early stage) 

 in the same situation in cerebro-spinal fever. 



Morphology, etc. The meningococcus occurs as single 

 cocci and diplococci in groups within the leucocytes 

 (Plate III, a) ; in grouping and general appearance, in 

 fact, it closely resembles the gonococcus, and, like the 

 last-named, is Gram-negative, though staining well with 

 the ordinary anilin dyes and with the Leishman stain. 

 The cerebro-spinal fluid is generally turbid from the 

 presence of numbers of polymorphonuclear leucocytes, 

 many of which contain the cocci. Some of the cocci may 

 also be free in the fluid. At an early stage and in some of 

 the very acute and fulminating cases the fluid may be 



