MICROCOCCUS GONORRHCEJZ. 



175 



the surface of the medium. These colonies are very finely 

 granular and have a punctate centre (Fig. 75). The deeper 

 colonies are very nodular and are of a grayish-white color. 

 In a few days the colony looks like a blackberry. 



On blood-serum agar (1 part of liquid blood-serum and 3 

 parts of agar solidified in the slanting position) a luxuriant 

 growth is formed along the line of inoculation, consisting of 

 individual grayish colonies, which finally coalesce to form a 

 moist, sticky, glistening deposit. 1 part of human blood- 

 serum and 2 parts of peptone-bouillon are also a good culture- 



FIG. 75. 



Colonies of gonococci on pleuritic fluid agar. (Heiman.) 



medium. A pellicle forms on its surface, the medium remain- 

 ing transparent. 



Other media which have been used in the cultivation of 

 this germ are : a mixture of urine and blood-serum ; 2 parts 

 of peptone-agar and 1 part of acid human urine ; 1 part of 

 ascitic fluid; and 1 part of nutrient glycerin-agar. Wertheim 

 uses a mixture of placental blood-serum and 2 parts of pep- 

 tone-agar for making pure cultures of the gonococcus. 

 Hydrocele fluid and the serous effusion of pleurisy have been 

 used either alone or in combination with other media. Acid 

 urine or urine mixed with gelatin is also suitable. 



