2']6 LOCAL TISSLE REACIIVITY 



nioitaliiN muk'r siuli (oiulitioiis was \cry low. It is iiotcwoilhy 

 tliat iiiliihilion was ohsciNcd Avillioiil an) aj)parciit veaclioii tak- 

 ing phuc in the tumors and, consccjiicntly, without any dant^er 

 to the life oi' the animal. Thus, ol 14 (ases of partial or total 

 inhibition y, ,t>ave a stvong liemonhagic reaction, 4 gave mild or 

 doubtful reactions, and 7 gave negative reactions. The average 

 length of life from the beginning of the treatment in mice show- 

 ing partial inhibition was eighty days, while the average for mice 

 whose tmnors were not inhibited was fifty days. The average 

 length of life in the 6 mice showing total inhibition Avas one 

 hinidred and seventy-one days. In ■■] of them no ttnnor could be 

 found at autopsy. In the other i] cases the ttnnor recmred after 

 the mice had remained free from growth for forty-six, sixty, and 

 one htnidred and eighty clays, respectively. 



The facts presented suggested to Duran-Reynals that the newly 

 formed vessels of malignant growth, either as a consequence of 

 an excessive permeability or through some other cause, are ex- 

 tremely sensitive to injections of blood-carried bacterial active 

 principles of the phenomenon and that it is this fact which creates 

 a very special state of ttimor vulnerability which is responsible 

 for the regression of malignant growths. This atithor also con- 

 cluded that only malignant and rapidly grooving tumors ^vere 

 likely to inidergo the reaction described. The question of the 

 mechanism of death in the treated ttmiors was left open. Numer- 

 ous control tests by Duran-Reynals have shown that normal mice 

 and rats stand the injection of the bacterial filtrate without 

 marked alterations in their health. The frequency of death 

 seemed to be in direct relationship ^vith the size and age of the 

 tumor. He asstmied, however, that there is also another intrinsic 

 factor depending on the strain of tumor itself. Mice bearing Bash- 

 ford adenocarcinoma showed the highest rate of mortality. The 

 question of the relation of mortality to the hemorrhagic necrosis 

 and regression of the tumors elicited by the bacterial filtrates will 

 receive further consideration at the end of this chapter. 



Apitz (i93^5c) carried out histological studies on the reaction 

 prodticed in Ehrlich's adenocarcinoma by means of bacterial 

 active prin(ij:)les of the phenomenon, reacting factors deri\'ed from 

 agar, and also by means of reacting factors of antigen-antibody 

 complexes, as compared to the effect of anti-motise serum and cer- 

 tain pharmacological vascidar jioisons. According to this author, 

 corresponding to the macroscopic appearance, there was also ob- 



