244 EPIDEMIC CEREBRO-SPINAL MENINGITIS 



bacteria. The life of the organism in cultures is a comparatively 

 short one ; after a few days cultures will often be found to be 

 dead, but, by making sub-cultures every three or four days, 

 strains can be maintained alive for considerable periods. The 

 organism is readily killed by heat at 60 C., and it is also very 

 sensitive to weak antiseptics ; drying for a period of a day has 

 been found to be fatal to it. The facts established accordingly 

 show it to be a somewhat delicate parasite. 



As stated above, the organism occurs in the exudate in the 

 meninges and in the cerebro-spinal fluid, and it can usually be 

 obtained by lumbar puncture. In acute cases, especially in the 

 earlier stages, it is usually abundant ; but in the later stages of 

 cases of more sub-acute character, its detection may be a matter 

 of difficulty, and only a few examples may be found after a 

 prolonged search ; in extremely acute cases also the organism 

 may be difficult to demonstrate. In most cases the disease is 

 practically restricted to the nervous system, but occasionally 

 complications occur, and in these the organism may sometimes 

 be found. It has been observed, for example, in arthritis, peri- 

 carditis, pneumonic patches in the lung, and in other inflam- 

 matory conditions associated with the disease. In a certain 

 number of cases it has been obtained from the blood during life, 

 but cultures in most instances give negative results. 



Experimental inoculation shows that the ordinary laboratory 

 animals are relatively insusceptible to this organism. An in- 

 flammatory condition may be produced in mice and guinea-pigs 

 by intra-peritoneal injection, and a fatal result may follow ; in 

 such cases the organism does not seem to undergo very active 

 multiplication, though it may sometimes be cultivated from the 

 blood, and none of the lesions in the nervous system are repro- 

 duced. Flexner and Stuart M 'Donald have shown that cerebro- 

 spinal meningitis may be produced in monkeys by injections of 

 the organism into the spinal canal, the latter observer finding 

 that exudate containing mehingococci was more effective than 

 cultures. In such experiments the organism extends upwards 

 to the brain, and produces meningitis within a very short time. 

 The resulting lesions, both as regards their distribution and 

 general characters, and also as regards the histological changes, 

 resemble the disease in the human subject. Even these animals, 

 however, are manifestly less susceptible than the human 

 subject. 



Many questions of great importance with regard to the spread 

 of the disease still require further investigation. The organism 

 has been obtained by culture from the throat and nasal cavities 





