EPIDEMIC CEREBRO-SPINAL MENINGITIS 215 



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 small 

 proportion 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 

 inflammatory condition may be produced in guinea-pigs by 

 intra-peritoneal injection, but large quantities of cultures must 

 be used, and none of the characteristic lesions found in the 

 human subject are reproduced. The intra-peritoneal injection 

 of the cerebro-spinal fluid or of cultures in mice is frequently 

 followed by death, the cocci being found in the exudate and even 

 in the blood. Flexner has shown that cerebro spinal meningitis 

 may be produced in monkeys by injections of the organism into 

 the spinal canal. 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 dis- 

 tribution and general characters, and also as regards the 

 histological changes, resemble the disease in the human subject. 

 Even these animals, however, are, .in comparison with man, 

 relatively insusceptible, as a considerable amount of culture has 

 to be injected. 



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 of those suffering from the disease in a consider- 

 able number of instances. It has also been obtained from the 

 same positions in healthy individuals, during an epidemic of 

 the disease. In some epidemics also a pharyngitis has been 

 found to occur, and the organism has been obtained from 

 the affected fauces. The general opinion is that the organism 

 spreads by means of the lymphatics from the pharynx or 

 nose to the base of the brain, but a spread by means of the 

 blood stream cannot be excluded, and infection by the alimentary 

 canal has also been suggested. Flexner in his experiments 

 found that when the organism was injected into the spinal 



