PATHOGENIC BACTERIA. 313 



serum from the placental blood or pleuritic or peritoneal 

 transudates, or hydrocele fluid, has been employed. Human 

 urine, sterilized by filteration through porcelain, added to the 

 mixture of blood-serum and agar, improves its character, ac- 

 cording to some writers. 



Baer* recommends the following medium: Hydrocele, 

 pleuritic, or ascitic fluid should be caught under aseptic con- 

 ditions in sterile flasks, distributed into test-tubes, and tested 

 for sterility in the incubator for 24 hours at 37 C. This is 

 mixed with plain agar which has been previously condensed 

 to two-thirds its bulk in the proportion of two parts agar to one 

 of the transudate. The transudate is added to the agar in tubes, 

 the agar having been melted and cooled to 45 C. The tubes 

 so prepared are allowed to solidify in a slanting position, cap- 

 ped with rubber caps which have been sterilized in a i-iooo 

 corrosive sublimate solution, and then placed in the incubator 

 again for two days to test their sterility. The slant tubes may be 

 used for plating out the gonorrheal pus by taking a loopful of 

 the material to be examined and smearing it over the surface 

 of the agar, using the condensation water in the tube to assist 

 in the spreading. Other organisms identical in morphology 

 and in staining properties, including the negative Gram reac- 

 tion may be cultivated from suspected gonorrheal discharge, 

 but these grow on ordinary culture media. A poison has been 

 extracted from cultures of the gonococcus which produces toxic 

 symptoms in various animals. | 



The colonies of the gonococcus are very small, grayish- 

 white, circular, translucent; appearing after from twenty-four 

 to forty-eight hours. They may attain a diameter of i to 2 mm. 

 The gonococcus will occasionally develop on ordinary glycerin- 

 agar or Loffler's blood-serum medium, but the growth is likely 

 to be feeble and cannot be relied on. The cultures live for a 



*Journ. Infect. Dis. Vol. IV., 1904. pp. 313-326. 



fNeisser and Scholtz in Kolle and Wassermann. Bd. III., 1903. p. 174. 



