MICROCOCCUS MENINGITIDIS 243 



it grows in milk without clotting or change in reaction. 

 Arkwright found that grown in gelatin at 37 C. the 

 meningococcus causes liquefaction, while the M. catarrhalis 

 does not. The organism needs constant transplantation 

 to maintain vitality in culture. The fermentation re- 

 actions, which are somewhat variable, are given in the 

 table on p. 248. 



Symmers and Wilson 1 examined the fermentation 

 reactions of a number of strains of the meningococcus. 

 Glucose, maltose, and dextrin were fermented with the 

 production of acid, laevulose, galactose, lactose, mannitol, 

 dulcitol, anda number of glucosides were never fermented. 



Pathogenesis. In man the organism causes epidemic 

 cerebro- spinal meningitis, and is occasionally met with 

 in sporadic cases of cerebro-spinal meningitis. It is also 

 capable of producing a hsemorrhagic septicaemia without 

 meningitis. It occurs in the cerebro-spinal fluid (obtained 

 by lumbar puncture) in the blood in 25 per cent, of the 

 cases provided quantities of 5 to 20 c.c. be cultured, 

 sometimes in the upper respiratory passages, particularly 

 the nose, in the middle ear, eye and joints. Park states 

 that the organism is usually present in the nose in the 

 early days of the illness. The meningococcus is patho- 

 genic to mice and guinea-pigs by intraperitoneal or intra- 

 pleural, but not by subcutaneous, injection. Intraspinal 

 injection into monkeys produces a typical meningitis. 



An agglutination reaction is given in some cases, but 

 is neither constant nor marked enough to form a sure 

 means of diagnosis. 



Symmers and Wilson 1 have found that the blood of 

 epidemic cerebro-spinal meningitis cases may occasionally 

 agglutinate the B. typliosus and B. coli in comparatively 

 high dilutions. 



1 Journ. of Hygiene, vol. ix, 1909, p. 9. 

 1 Ibid. vol. viii, 1908, p. 314. 



