322 Cerebro-spinal Meningitis 



planted after eight or ten days. It becomes necessary, 

 therefore, when studying the organism to transplant it 

 frequently Park* says every two days. Flexnerf found 

 that they do not survive beyond two or three days and that 

 transplantations do not succeed unless considerable quanti- 

 ties of the culture are placed upon the surface of the fresh 

 medium, showing that many of the organisms were already 

 dead. This is confirmed by the microscopic appearance of 

 the cultures. Those sixteen to twenty-four hours old stain 

 sharply and uniformly ; on the second day many of the cocci 

 show irregularities of size and staining, and after several 

 days no normal-looking cocci can be found. It was found, 

 however, that in carefully preserved cultures of certain 

 strains a few cocci might survive for many months. Vitality 

 is preserved longest when the cultures are kept in the 

 thermostat and not taken out when grown, and kept at 

 room temperature or in a refrigerator. The addition of a 

 small quantity of a calcium salt favors prolonged vitality 

 and will sometimes maintain vitality for four or five weeks 

 in cultures that would otherwise die in a few days. Sodium 

 chlorid is injurious to the cocci. The autolysis of the 

 cultures Flexner attributed to an enzyme. 



Pathogenesis. The results of animal inoculations made 

 with Diplococcus intracellularis meningitidis are disappoint- 

 ing. Subcutaneous inoculations into the lower animals are 

 continually without effect. Intrapleural and intraperito- 

 neal injections of cultures of the organism into mice and 

 guinea-pigs are sometimes fatal, the dead animals showing 

 a sero-fibrinous inflammation with the presence of the cocci. 

 The intravenous injection of the coccus into rabbits is 

 followed by death without important or conclusive symp- 

 toms, and usually without the presence of cocci in the blood. 



Weichselbaum endeavored to reproduce the original 

 cerebro-spinal meningitis in animals by trephining and in- 

 jecting the cocci beneath the dura. In this manner he 

 inoculated three rabbits and three dogs. Two of the rabbit 

 injections failed, probably because the injected material 

 escaped at once from the wound. The third rabbit died, 

 and showed marked congestion of the membranes of the 

 brain and a minute softened and hemorrhagic area. In 

 these the cocci were found by culture to be abundant. 



* "Bacteriology in Medicine and Surgery," 1899, p. 518. 

 f Loc. cit. 



