476 BIOLOGY OF PNEUMOCOCCUS 



of B. typhosus agar-washings, to regain potency after being mixed 

 with (type?) specific horse antiserum and to a lesser degree with 

 type-specific rabbit antiserum. 



In a subsequent paper, Shwartzman 1265 reported additional ob- 

 servations on the ability of homologous antigen-antibody combina- 

 tions introduced into rabbits intravenously to render tissues vul- 

 nerable to the action of soluble products of heterologous bacterial 

 species previously injected into the skin of the rabbit ear. 



The work of Cope and Howell points to the species-specificity 

 and, to a certain extent, to the type-specificity of the phenomenon. 

 In following through the several communications of Shwartzman, 

 the conviction is formed that there is no specific immunological re- 

 lation between the action of the preparatory principle and that of 

 the reactivating substance. The conditions of the experiments as 

 conducted by Shwartzman give the impression that Pneumococcus 

 contains no substance preparatory or activating to itself, al- 

 though from the organism a substance may be obtained that 

 causes dermal tissues to become susceptible to the local action of 

 material present in typhoid agar-washings. It would be out of 

 place here to enter into any detailed discussion of the factors in- 

 volved in the operation of the Shwartzman phenomenon. However, 

 from the facts available, it is difficult at present to appraise its 

 significance in the pathology and immunology of pneumococcal in- 

 fections. 



Summary 

 Nature endows some animals with means for defending them- 

 selves against infection by pneumococci. The integument of the 

 body and of its passages and cavities presents obstacles to the 

 entrance of the bacteria into the deeper tissues. When, however, 

 entrance is effected, the cocci encounter in the blood stream an- 

 tagonistic forces. Among the forces may be a body temperature 

 inimical to the proliferation of the cocci — the naturally high tem- 

 perature in the case of birds, or the febrile reaction in rabbits 



