MICROCOCCUS INTRACELLULARIS MENINGITIDIS 379 



large numbers, both in this and foreign countries and the value of the 

 serum as a therapeutic agent seems firmly established. 



Hiss and Zinsser 1 have treated a number of meningitis patients with 

 subcutaneous injections of leucocyte extracts and believe that they have 

 favorably influenced the course of the disease. 



Pseudomeningococcus. Elser and Huntoon 2 have described a diplo- 

 coccus very similar to the meningococcus which they differentiated 

 from it only by serum reactions. This diplococcus could be identified 

 only by agglutinin absorption tests. They named it pseudomeningo- 

 coccus. 



Parameningococcus. Dopter 3 described a Gram-negative diplococ- 

 cus which was identical with meningococcus in its cultural and fer- 

 mentative characteristics. It failed to give agglutination and pre- 

 cipitation reactions in anti-meningitis serum, though it did give a 

 complement-fixation reaction. These organisms, at first isolated from 

 normal throats, have since been found in the spinal fluid of cases of 

 meningitis. In a recent study of strains from meningitis Amoss and 

 Wollstein found that besides the two distinct types normal menin- 

 gococci and parameningococci there were a number of intermediate 

 varieties. Olmstead and Dubois 4 and Neal and Schweitzer 5 also found 

 marked antigenic differences among the strains of meningococci which 

 they studied. The use of representatives of each of the types of 

 meningococci and parameningococci has been found essential for the 

 production of a potent anti-meningitis serum. 



1 Hiss and Zinsser, Jour. Med. Res., Nov., 1908. 



2 Elser and Huntoon, Jour. Med. Res., xxi, 1909. 



3 Dopter, "Conte Rendu de la Societe" de Biologie," 1909, Ixvii, p. 74, 



4 Olmstead and Dubois, Jour. Exper. Med., xxiii, p. 403. 



5 Neal and Schweitzer, Jour, of Immunol., 1916, i, p. 307, 



