336 BIOLOGY OF PNEUMOCOCCUS 



favorably modifying the course of pneumococcal infections in man. 

 However, in Warden's communication no experimental data were 

 presented to support these unusual claims. Aitoff and Lagrange 

 (1925) 6 stated that an injection of sterile medium T made at 

 least twenty-four hours previous to inoculation with Pneumococ- 

 cus conferred protection upon mice which was demonstrable for at 

 least two weeks after injection of the medium. 



In 1926, Horder and Ferry, 655 in a search for an ideal antigen 

 for therapeutic immunization, measured the agglutinin content 

 and complement-fixing titer of the serum of rabbits treated respec- 

 tively with washings from agar cultures, autolysates of the residue 

 from broth cultures, washed agar growth, and whole unwashed 

 agar cultures. Horder and Ferry concluded that the material con- 

 tained in the washings of agar cultures, because it could be pre- 

 pared in watery solution and was low in protein content, as well as 

 being practically non-toxic and high in antigenic properties, more 

 nearly approached the ideal antigen than any preparation which 

 had come under their observation. Barach (1928) 74 " 5 reported that 

 Berkefeld filtrates of pneumococci shaken in salt solution and also 

 filtrates of broth cultures caused in mice the development of pro- 

 tection which appeared on the fourth day after injection. The im- 

 munity produced was dependent upon type-specific protective sub- 

 stances and not upon the elaboration of the common protein anti- 

 body. 



Another method of preparing antigens from broth cultures of 

 pneumococci was that described by Maeji (1930), 850 ' 853 ~ 4 who em- 

 ployed the technique of Besredka for preparing antivirus. The su- 

 pernatant fluid from centrifuged beef-serum bouillon cultures of 

 Type I Pneumococcus, when injected subcutaneously into rabbits, 

 gave partial protection against infection with a Type I strain. In 

 the case of Type II Pneumococcus the protective substance ap- 

 peared only when goat serum was added to the medium, while with 

 Type III organisms no antivirus could be obtained. Maeji claimed 

 that after the administration of Type I antivirus by inhalation, 



