552 



NEISSERIA 



N. pharyngis flava, i, ii and iii. — A number of Gram-negative cocci have been 

 described whose characteristic feature is the formation of greenish-yellow colonies on 

 agar or ascitic agar, von Lingelsheim (1906) and some other workers have called 

 them Micrococcus or Diplococcus pharyngis flavus, and have differentiated them on 

 the basis of colonial appearance and sugar reactions into three groups, i, ii and 

 iii (Martin 1911, Report 1916, Dopter 1921). Elser and Huntoon (1909) have called 

 them chromogenic cocci, and have divided them similarly into three groups i, ii and 

 iii; J. E. Gordon (1921) has likewise called them chromogenic cocci, and has divided 

 them into six groups, i to vi. Elser and Huntoon's chromogenic iii and Gordon's 

 chromogenic iii agree with von Lingelsheim's flava iii in fermenting glucose and maltose 

 only ; Elser and Huntoon's chromogenic ii and Gordon's iv agree with von Lingel- 

 sheim's i and ii in fermenting glucose, maltose and 

 laevulose ; Elser and Huntoon's chromogenic i agrees 

 with Gordon's chromogenic v in fermenting glucose, 

 maltose, laevulose, and sucrose ; but has no counter- 

 ' part in von Lingelsheim's classification. Over and 



above these are Gordon's chromogenic i, which fer- 

 ments glucose only, his chromogenic ii, which ferments 

 glucose and Isevulose, and his chromogenic vi, which 

 ferments glucose, maltose, Isevulose, sucrose, and lac- 

 tose. Undoubtedly one of the reasons for the dis- 

 crepancies in the sugar reactions is due to the fact 

 that von Lingelsheim, who described the flava group, 

 read all his reactions after 24 hours ; this probably 

 explains why he never observed the fermentation of 

 sucrose. In colonial appearance von Lingelsheim's 

 flava i and iii resemble the meningococcus, and flava 

 ii N. catarrhalis ; Elser and Huntoon's chromogenic ii 

 agrees with von Lingelsheim's flava i and iii. Gordon describes his organisms as giving 

 colonies either like the meningococcus or like N. catarrhalis ; his group vi gives pale 

 yeUow colonies, larger and more opaque than the others. In the face of these diver- 

 gencies in cultural and biochemical reactions, it is clear that no fixed types can be 

 described. Our own work has shown that the cultural appearances of the Gram-negative 

 cocci from the nasopharjTix are subject to great variation, and most workers agree now 

 that Isevulose is an unreUable sugar. Division therefore of these organisms either on 



Fig. 113. — Neisseria 'pharyngis. 



Surface colony on agar, 24 hours, 

 37° C. ( X 8). Smooth type. 



Fig. 114. — Neisseria pharyngis. 



Fig. 115. — Neisseria pharyngis. 



Surface colonies on agar, 5 days, Surface colonies on agar, 5 days, 

 37° C, showing differentiation. 37° C, showing formation of secon- 

 Secondary rough type ( X 8). dary papillae ( X 8). 



