MICROCOCCUS GONORRHG. §25 
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 gonorrhceal 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° ©. 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 86° 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. 
