REACTIVITY OF MALIGNANT NEOPLASMS 2.55 



per cent NaCl solution. The low \ irulence of the strain in this dilution was 

 previously determined. Five days later these mice and 4 normal mice (Group 

 3) each received intravenously 200 reacting units of meningococcus "agar 

 washings" filtrate. Three mice of Group 1 and all the mice of Group 2 died 

 within twenty-four hours, and 3 mice in Group 3 died five days after the 

 intravenous injection of meningococcus filtrate. The remaining mice of 

 Groups 1 and 3 survived. 



As is seen from the above experiments, the injection of 200 

 reacting units of meningococcus "agar ^vashings" filtrate caused 

 death within t^venty-four hours in most of the mice infected Avith 

 a strain of B. etitcritidis of low virulence. Normal mice resisted 

 this injection for three days. It appears, therefore, that the sec- 

 ondary infections of tmnor-hearing mice may render them more 

 susceptible to the lethal effect of bacterial filtrates employed in 

 this work. It seems, therefore, that the higher lethal effect of the 

 bacterial filtrates upon tumor-bearing mice than upon normal 

 mice cannot be fidly ascribed to destruction of the tumor biU is 

 possibly conditioned at least to some extent by the inciden- 

 tal secondary bacterial infection of tmnor-bearing animals 

 (Shwartzman, 1936/;) . 



As is seen from all the studies presented in this chapter, there 

 remains little doubt that the active principles of the phenomenon 

 of local tissue reactivity in the rabbit are the factors responsible 

 for production of the reaction in tumors described here and that 

 the reaction produced bears a very close similarity to this 

 phenomenon. The essential difference lies, hoAvever, in the fact 

 that no preparatory intratiunoral injection is necessary. This 

 means that the neoplastic tissue possesses spontaneously the neces- 

 sary state of reactivity of the phenomenon. Several explanations 

 suggest themselves. Gratia and Linz assume that the hypothetical 

 virus inducing tiunor formation elicits also the state of reac- 

 tivity similarly, for instance, to vaccinia virus infection eliciting 

 the state of reactivity in the rabbit. There is not much that can 

 be said concerning this hypothesis because no virus is knoAvn as 

 yet in the tiunors in which one obtains the reaction. The assump- 

 tion is contradicted by the fact that the Shope papilloma ^vhich 

 is apparently produced by a virus remains totally resistant to the 

 effect of the bacterial active principles. Conversely, the reaction 

 may be elicited in tar produced tumors. 



The other possible assumption is that the rapidly proliferating 

 and delicate blood vessels of nef)plasms are more susceptible to 



