242 LOCAL TLSSLE RKACriVLlY 



pernalant lliiid was hydroly/.cd wilii Hdl and three xoluiiu-s ol 

 ethyl aUohol were added. As imuh ol the lesiilliii^ ahoholic 

 ins()liil)le precipitate as would dissoixe in o.() per cent NaCll solii 

 tion was then used lor tlie injections. 



Foffo- tested itio tinnoi-bearino animals with the heat-killed 

 suspension ol /*. jjiolcus. The highest percentage ol recessions 

 xvas produced in sarcoma ^^7. It is interesting that foiu' complete 

 regressions ^vere produced in mic e hearing carcinoma 63. The toxic 

 effect Avas most pronounced in the case of carcinoma (]■-]. There 

 were no spontaneous tumors in this series w^hich were caused to 

 recede. An effect was jjroduced as evidenced by inhibition of 

 giowth, decrease in size, and in one case, hemorrhage followed by 

 shriveling, drying and temporary arrest of groxvth. In a total of 

 559 tiniior-bearing mice tested with the alcohol-insoluble frac- 

 tion, there were observed 2^^() complete regressions, or 42 per 

 cent. The number of tumors affected but not brought to com- 

 plete regression was 12^^ or 22 per cent, whilst about one-third 

 of the mice died from the treatment. Autopsies of the mice vvhich 

 died revealed that the tumors had been affected. The alcohol-in- 

 soluble fraction from B. coli produced the best results showing 

 about Go per cent complete regressions in 73 tumor-bearing mice. 

 There ^vere no ttnnors ^vhich ^vere not affected but the mortality 

 was high (23 per cent) . It is of interest that the alcoliol-insolulole 

 fraction from B. proteus also inhibited the groxvth of sarcoma 180 

 in tissue cidtures but had little effect upon the normal cells used 

 as controls. 



Thus, all the data presented thus far indicate a definite correla- 

 tion betxveen the effect of bacterial filtrates upon timiors and the 

 ability of the preparations employed to elicit the phenomenon of 

 local skin reactivity in the rabbit. The idea suggested itself, there- 

 fore, that the known antagonistic effect of spontaneous and induced 

 infections upon timiors may be contingent u}:)on the ability of the 

 infecting agents to produce the active princij)les of this phenom- 

 enon. The work described below deals with this subject. 



EFFECT OF SPONTANEOUS INFECTIONS ON THE DEVELOPMENT OF 

 MOUSE SARCOMA 1 8o 



An opportunity to study the effect of spontaneous infections on 

 the development of mouse sarcoma 180 was afforded by a sudden 

 outbreak of a spontaneous epidemic of B. euteritidis among the 



