344 BIOLOGY OF PNEUMOCOCCUS 



The ability of that animal when injected intradermally to elabo- 

 rate species-specific antibody, taken with the inability to manufac- 

 ture type-specific antibody when similarly injected, points to a 

 partial disruption of the molecular configuration of the pneumo- 

 coccal antigen during its sojourn in the skin. The type-specific 

 fraction of the antigen is probably destroyed and there remains 

 only the somatic protein and carbohydrate of the bacterial cell to 

 stimulate the immunological mechanism. That the mechanism is, 

 nevertheless, fully capable of functioning in producing type-spe- 

 cific immune substances is shown by the response of the rabbit 

 when the antigen is introduced directly into the blood stream. The 

 hypothesis is further supported by Julianelle's observation that 

 the intradermal injection of heat-killed R forms as well as S forms 

 of pneumococci calls forth the production of active immunity. 

 Julianelle therefore demonstrated that the route of administration 

 of pneumococcal antigen, at least in the rabbit, may be a deter- 

 mining factor in the qualitative nature of the immune response. 



An analogous process taking place in the human body was re- 

 ported in the same year by Francis and Tillett. 478 The repeated 

 injection of the specific capsular polysaccharide of pneumococci of 

 Types I, II, and III into the skin of patients suffering from lobar 

 pneumonia was followed in the second or third week of convales- 

 cence by the appearance of circulating antibodies for one or more 

 heterologous types. However, in none of the normal controls was 

 the phenomenon observed. In the next year (1931), Finland and 

 Sutliff 446 " 7 confirmed the observations of Francis and Tillett. Pneu- 

 monia patients receiving repeated intracutaneous injections of 

 soluble specific substance from Type I, II, and III pneumococci, in 

 a week or more developed in the blood agglutinins and protective 

 antibodies sometimes heterologous for the infecting type of organ- 

 ism but, unlike the effect in the rabbit, the immune bodies were ho- 

 mologous for the type of capsular carbohydrate injected. 



In a subsequent report (1932), Finland and Sutliff 448 announced 

 that the simultaneous intradermal injection into normal human be- 



