MICROCOCCUS GONORRHCEM 351 



"To the agar in each test-tube, which is fluid and of a 

 temperature of about 40 C., there is added about one-third 

 to one-half its volume of the filtered mixture of urine and 

 blood-serum. This is conveniently accomplished by pouring 

 the mixture from the receiving-flask through the lateral 

 tube, inserted near its neck directly into the tubes. The 

 preliminary melting of the agar is best effected in the steam 

 sterilizer, in order that any organisms which have found 

 lodgment in the cotton plugs of the tubes may be destroyed. 

 When the agar is melted it is cooled and kept fluid by plac- 

 ing the tubes in a water-bath at 40 C. Each tube, after the 

 addition of the urine and serum to the fluid agar, is quickly 

 shaken to insure a uniform mixture, and is then placed in 

 an inclined position to allow the agar to solidify with a 

 slanting surface. When the medium in the tubes has solidi- 

 fied the tubes are placed in the incubator for about twenty- 

 four hours to test for contaminations, after which. they are 

 ready for use." 



The successive dilutions are now to be made upon the 

 slanting surface of this mixture, as the mass in the tubes 

 cannot be redissolved without exposure to a degree of heat 

 that apparently interferes with the nutritive value of the 

 serum contained in the medium. 



When inoculated with gonorrheal pus, by smearing a 

 loopful over the surface, the tubes are to be kept at from 

 37 to 38 C. The organism does not develop properly at 

 a temperature below this point. 



After twenty-four hours the colonies of the gonococcus 

 appear on the surface of the medium, according to Wright, 

 as very tiny, grayish, semitranslucent points. After forty- 

 eight hours they may be about 1 millimeter or so in diameter, 

 slightly elevated, with a rounded outline, grayish in color, 



