300 



BACTERIA 



cal cavities and in certain suppurations in the region of the 

 face. It is a micrococcus usually in the form of small 

 tetrads. A capsule is always present and sometimes dis- 

 cernible. 



5. Bacillus coli communis and many putrefactive germs 

 commonly occur in suppurative conditions, but they are not 

 restricted to such disorders (see p. 64). 



6. Micrococcus gonorrhoea (Neisser, 1879). This organism 

 is more frequently spoken of as a diplococcus. It occurs at 

 the acute stage of the disease, but is not readily differ- 

 entiated from other similar diplococci except by technical 



DIPLOCOCCUS OF NEISSER 



laboratory methods. Each element presents a straight or 

 concave surface to its fellow. A very marked concavity 

 indicates commencing fission. The position which these 

 diplococci take up in pus is intracellular, and arranged 

 more or less definitely around the nucleus. Difficulty has 

 often been found in cultivating this organism in artificial 

 media outside the body. Wertheim and others have sug- 

 gested special formulae for the preparation of suitable media, 

 but it is a very simple matter to secure cultures on agar 

 plates smeared with human blood from a pricked finger. 

 The plate is incubated at 37 C. At the end of twenty-four 

 hours small raised grey colonies appear, which at the end of 



