262 BIOLOGY OF PNEUMOCOCCUS 



nostoc mesenteroides. With serum produced in rabbits in response 

 to injections of typical and rough strains of Types I and II Pneu- 

 mococcus, dextran in a dilution of 1 to 5,000 gave precipitates 

 with both anti-S and anti-R serums in low dilutions (1 to 2 to 1 to 

 16), showing a somewhat stronger action with the latter. When the 

 serums were first absorbed with the type-specific polysaccharide or 

 the C Fraction of Tillett and Francis, and then mixed with dex- 

 tran, the serum precipitated to the same degree as before absorp- 

 tion. The outcome of the experiment would argue for the existence 

 of a distinct antibody produced by the active group of the specific 

 polysaccharide, which is similar to the active group of the dextran 

 polysaccharide. 



Since the discovery of the soluble specific substance in Pneumo- 

 coccus by Dochez and Avery in 1917, similar complex carbohy- 

 drates have been demonstrated as components of several bacterial 

 species. Toenniessen 1413 was the first to isolate the nitrogen-free 

 polysaccharide from Friedlander's bacillus, which was later studied 

 by Kramar, 753 but failed to connect it with the immunological be- 

 havior of the organism. A related substance was recovered from a 

 strain of the same organism by Mueller, Smith, and Litarczek, 937 

 from yeast by Mueller and Tomcsik, 938 and from an encapsulated 

 colon bacillus and Bacillus aerogenes strains by Tomcsik. 1414 A 

 specifically precipitating, non-nitrogenous carbohydrate has been 

 isolated from tubercle bacilli by Laidlaw and Dudley, 771 and a 

 similar polysaccharide as well as a specifically reacting substance 

 was derived by Mueller 936 from the same bacilli by fractionation 

 with alcohol. 



In a preliminary report of a recent study, Kulp and Borden 764 

 described the successful immunization of mice against Type I 

 Pneumococcus by vaccination with a living culture of Alkaligenes 

 viscosus. The authors suggested that there might be an antigenic 

 relationship between the capsular material of these two organisms, 

 but they had obtained no confirmation of this possibility. There is 

 no doubt that other bacterial species contain analogous polysac- 



