CHEMICAL CONSTITUENTS 253 



and Caspar noted a difference in the microscopic appearance of 

 the precipitates produced by the carbohydrates when added to im- 

 mune horse and rabbit serum. The difference in the behavior of 

 these two kinds of serum is manifested in other reactions with 

 pneumococci and their constituents or products. The protein frac- 

 tions as a rule failed to establish protection in mice, although 

 one such preparation from Type II Pneumococcus did induce re- 

 sistance of a low order to pneumococci of both Types I and II. 



Jungeblut (1927) 698 had quite a different idea concerning the 

 chemical nature of the antigenic components of the pneumococcal 

 cell. Pneumococci of the first three types were extracted with 95 

 per cent alcohol and the filtrates of these extracts were tested for 

 specific flocculation by a modified Dujarric de la Riviere method. 

 Antipneumococcic serums of Types I, II, and III gave flocculation 

 of varying intensity with homologous alcoholic antigens. The re- 

 actions were species-specific and also type-specific to a high degree. 

 From an examination of the experimental facts, and after a con- 

 sideration of the data presented prior to this study, one is not in- 

 clined to go all the way with Jungeblut in concluding that this 

 serological reaction depended upon the presence of bacterial lip- 

 ids in the antigens. Remembering the activity of minute amounts 

 of specific carbohydrates in bringing down precipitins from im- 

 mune serum, one feels that emphasis should be laid on Jungeblut's 

 comment that the method of preparing these alcoholic antigens did 

 not preclude the possibility that "certain impurities of protein or 

 carbohydrate character may have been carried over into the ex- 

 tract." 



Wadsworth and Brown 1467 reported the antigenic action of the 

 ether-soluble fraction of Type I pneumococci. The preparation, 

 admittedly impure, was active in binding complement in the pres- 

 ence of antipneumococcic serum of all types but failed to stimu- 

 late the formation of agglutinins, precipitins, protective or com- 

 plement-fixing antibodies in rabbits. 



In 1928, Saito and Ulrich, 1214 following the lead of Heidelberger 



