GONOOOCOUS. 263 



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 de- 

 gree of heat that apparently interferes with the nutri- 

 tive value of the serum contained in the medium. 



When inoculated with gonorrhoeal 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 gono- 

 coccus appear on the surface of the medium, accord- 

 ing to Wright, as very tiny, grayish, semi-translucent 

 points. After forty-eight hours they may be about 

 1 millimetre or so in diameter, slightly elevated, with 

 a rounded outline, grayish in color, and by transmitted 

 light semi-translucent. By reflected light their sur- 

 face has the appearance of frosted glass. Later, if few 

 in number, so that their growth is unimpeded, the colo- 

 nies may attain a diameter of 2 millimetres or more, 

 become thicker and denser, with a faintly brownish 

 tinge about their centres, and a slightly irregular out- 

 line. 



Under a low power of the microscope a fully de- 

 veloped colony is seen to consist of a general circular 

 expansion, with thin, translucent, smooth, sharply de- 

 nned margin, but becoming brownish, granular, and 

 thicker toward the central portion, which is made up 

 of coarse, granular, brown-colored clumps closely 

 packed together. 



The appearances coincide with the figure of such a 

 colony given by Wertheim. 



If transplanted from the original culture to either 

 glycerin agar-agar or to Loeffler's serum mixture, a 



