SPECIAL FORMS OF CONJUNCTIVAL INFECTION 217 



Cultures kept for sixty days in the incubator still gave a profuse growth. A culture 

 dried for twenty-four hours on a sterile slide in the incubator gave the same. Accord- 

 ing to Ghon and Pfeiffer, they can resist drying much longer than this, even to 

 twenty-one days. 



At C. they remain for 40 days living. 



At 6 C. 6 



These authors also found greater resistance to heat. This may have been due 

 to their having used more vigorous cultures. Von Lingelsheim, working, like 

 Brons, with bouillon cultures, obtained practically the same results : 



50 C. was resisted for 1 hour. 

 60 C. ,, ,, 40 minutes. 

 70 C. ., 1 minute. 



Pathogenicity for Animals. Intraperitoneal, intravenous, and subcutaneous 

 injections in rabbits and guinea-pigs had no result. Intraperitoneal injection in 

 mice produced diarrhoea and death. A loopful introduced into a corneal pocket 

 produced a severe infiltration, which, however, healed without a hypopyon. In 

 the conjunctival secretion, and also the ulcers of these cases, large numbers of the 

 Diplococci can be found, many of them intracellular. 



Agglutination tests could not be carried out with Brons' cocci, as they formed 

 a deposit of themselves, and the most careful stirring only produced a fine 

 flocculent suspension. Von Lingelsheim, using older generations, obtained a more 

 homogeneous fluid, and then showed that a powerful meningococcal serum in a 

 dilution of 1 in 50 agglutinated Meningococci, but not the Micrococcus catarrhalis. 

 Powerful catarrhalis serum had the opposite effect. 1 



Meningocoecus Intraeellularis (Weichselbaum). 



The Meningococcus intraccllularis cannot be distinguished with 

 certainty from the Gonococcus by its morphology, though it is some- 

 what larger and not always so typical in its kidney shape. The cells 

 are not usually so full of the cocci as in the case of the Gonococcus. 

 The latest records regarding its Gram reaction agree especially those 

 of the latest meningitis epidemic as to its rapid and complete 

 decolorization. 



[Jitger's statement that they decolorize only partially or do not at 

 all is now generally regarded as a proof that this investigator had 

 other organisms in his cultures the more so as they grew and 

 formed chains at the room temperature, a thing which the true 

 Meningococcus never does. The latest results of Weichselbaum and 

 his school, obtained in the last great epidemic, absolutely oppose 

 those of Jiiger. The coccus of Jiiger, the Diplococcus crassus (von 

 Lingelsheim), is not uncommonly associated with the Meningococcus, 



1 Only highly efficient sera can give, in free dilution, different results with different 

 members of the same family. In strong concentration Meningococci, Gonococci, and 

 Mic. catarrhalis mutually agglutinate as members of the same family (group agglutination, 

 cf. also p. 197). The limits of this group agglutination are still being discussed. 



