CEREBROSPINAL MENINGITIS. 275 



The micro-organism is a diplococcus of biscuit shape, 

 bearing the greatest resemblance in form and arrange- 

 ment to the gonococcus. This resemblance is further 

 increased by the fact that the cocci usually occur en- 

 closed in the protoplasm of the leukocytes. Weichsel- 

 baum, by whom this arrangement was observed, found 

 it constant in sections of the brain and its membranes, 

 though in the exudate of the disease a good many free 

 cocci also occur. It was this peculiarity that led him to 

 call the organism the Diplococcus intracellularis. Many 

 of the cocci thus enclosed within the cells are apparently 

 dead and degenerated, as evinced by the fact that they 

 stain badly and refuse to grow when the pus is trans- 

 ferred to culture-media. 



Tlie bacterium is easily stained by the usual methods 

 with aqueous solutions of the anilin dyes. Its relation 

 to Gram's method has not yet with certainty been deter- 

 mined. According to Weichselbaum, it does not stain by 

 Gram's method. 



The organism was successfully cultivated by Weichsel- 

 baum, 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, according to Gold- 

 schmidt, 1 upon potato. Weichselbaum was, however, 

 unable to find that it developed upon potato. It does 

 not grow in bouillon or gelatin. There is nothing char- 

 acteristic about the cultures. The cocci grow only at 

 the temperature of the body, attain only a sparse devel- 

 opment, 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, etc. 



When sown 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 



1 Centralbl.f. Bakt. u. Parasitenk., ii., 22, 23. 



