MICROCOCCUS GONORRHCEjE. 525 



the gonococcus, and it is a test that should never be 

 neglected in differentiating this organism from others 

 which are morphologically similar. 



Biological Characters. The elaborate experiments of 

 Bumm and others have shown that at the ordinary room- 

 temperature no growth of the specific micrococcus occurs 

 on the culture media. Apparently positive results which 

 have been reported are found to be due to other diplo- 

 cocci morphologically almost identical with the gono- 

 coccus. 



Since Bumm's experiments a number of culture 

 methods have been proposed for the gonococcus which 

 are an improvement on Bumm's, partly because the 

 growth produced is more constant and luxuriant and 

 partly because the media employed are more readily 

 prepared. Wertheim (1892) succeeded in developing 

 luxuriant and virulent cultures to many generations on 

 a mixture of placenta blood-serum and 2 per cent, pep- 

 tone-agar. His method is briefly as follows : Several 

 loops of gonorrhoeal pus are diffused through liquid 

 blood-serum warmed to 40 C. contained in a test- 

 tube. Two dilutions are made from this, and an 

 equal quantity of melted 2 per cent, agar cooled to 

 40 C. is added to the three tubes, and the contents, 

 after thorough mixing, poured into Petri dishes. The 

 Petri dishes are placed in an incubating oven at a 

 temperature of 36 to 37 C. At the end of twenty- 

 four hours there will have developed on at least one of 

 the plates distinct colonies; these are translucent, finely 

 granular, with scalloped margin. By transferring such 

 a colony to slant-cultures of serum-agar, pure cultures 

 of the gonococcus are obtained; these are somewhat 

 shining in appearance and of a grayish-white color. 



