122 RELATIONSHIPS OF THE COCCACE^ 



described on the basis of its morphological characters 

 alone, as a coccus occurring in pairs of hemispherical, 

 " coffee-bean " cells, found in greatest numbers inside 

 the pus cells of the diseased secretion which it excites. 

 It stains easily and decolorizes easily both by the Gram 

 and Neisser methods. The organism is strongly parasitic 

 and may be grown on artificial media only with difficulty. 

 Bumm (1885) first succeeded in cultivating it on serum. 

 It has since been claimed by various observers that 

 D. gonorrhoea will grow on ordinary media if the reac- 

 tion be made slightly alkalin (Vannod, 1905). Colonies 

 of the organism appear as small grayish-white points like 

 those of D. pneumonia, but of somewhat denser and more 

 viscid consistency. Little or nothing is known .of its 

 biochemical powers. 



D. gonorrhoea has never been found outside the human 

 body. It occurs typically, as pointed out above, in the 

 pus cells in cases of gonorrheal disease and is occasionally 

 associated with secondary arthritis in affected persons. 

 Its virulence for experimental animals is insignificant. 

 Inoculation produces a more or less severe temporary 

 inflammation, but the gonococci rapidly die out and 

 disappear. 



In this type again we find a number of related but 

 slightly differing strains. Bumm (1884) showed long 

 ago that forms closely resembling D. gonorrhoea in 

 morphology may be found on the conjunctiva without the 

 occurrence of gonococcal infection, and that occasionally 



