282 Cerebro-spinal Meningitis 



an aqueous solution of Bismarck brown. The meningococci 

 will be brown. 



Cultivation. The organism was successfully cultivated 

 by Weichselbaum, but does not readily adapt itself to 

 artificial media. It develops upon agar-agar and glycerin 

 agar-agar, upon Loffler's blood-serum mixture, and, accord- 

 ing to Goldschmidt,* upon potato. Weichselbaum did not 

 find that it developed upon potato. It does not grow in 

 bouillon or gelatin. There is nothing characteristic about 

 the cultures. The cocci grow only at the temperature of 

 the body, attain only a sparse development, and form a 

 more or less confluent line of minute, rounded, grayish 

 colonies which are easily overlooked upon opaque media 

 like blood-serum. The general characteristics of the growth 

 are not unlike those of the pneumococcus, streptococcus, 

 and gonococcus. 



Colonies. When grown upon agar-agar plates, the deep 

 colonies scarcely develop at all, appearing under the low- 

 power lens as minute, irregularly rounded granular masses. 

 The surface colonies are larger, and consist of an opaque 

 yellowish-brown nucleus about which a flat, rounded disk 

 spreads out. The edges may be dentate; the color is 

 grayish or yellowish near the center, becoming less intense 

 as the thin edges are reached ; the structure is finely granular. 



Vital Resistance. The vitality of the culture is low, 

 and the cocci die out readily, ceasing to grow when trans- 

 planted after eight or ten days. It becomes necessary, 

 therefore, when studying the organism to transplant it 

 frequently Park f says every two days. 



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- 

 * "Centralbl. f. Bakt. u. Parasitenk.," n, 22, 23. 

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





