66 



Scientific Proceedings (36). 





z 



2 



3 



4 



5 



6 



Total. 



Control 

 Rats. 



Number of rats inoculated with tumor. 



10 



10 



10 



10 



IO 



IO 



60 



60 



Number of rats survived at the final 

 examination 25 days after inocula- 

 tion. 



5 



10 



IO 



10 





10 



Si 



57 



Number of days before inoculation 

 autolyzed liver injected. 



10 



c 



3 



5 













Number of days after inoculation 

 autolyzed liver injected. 









9 



9 



12 







Number of rats without growth or 

 with small abortive nodules. 



2 



7 



5 



7 



4 



9 



34 



6 



Number of rats with tumors. 



3 



3 



5 



3 



2 



1 



17 



5i 



Per cent, of takes. 



60% 



30% 



50% 



30% 



33% 



10% 



34% 



85% 



favorably with the results obtained by L. Michaelis with the injec- 

 tion of liver emulsion, as is apparent from the second diagram, or 



Treated 



Animals. Controls. 



Number of mice inoculated with tumor 20 18 



Number of mice without growth or with small stationary 



tumors 14 5 



Number of mice with tumors 6 13 



Per cent, of takes 30 per cent. 72 per cent. 



even with Ehrlich's statement, that thirty mice immunized with a 

 non-malignant hemorrhagic tumor took the subsequent inoculation 

 of cancer in from 30 to 50 per cent., while the 30 control animals 

 took in 100 per cent. Only Bridre claims to have obtained an 

 absolute immunity with injection of normal spleen, but his con- 

 clusions are based on experiments on eight animals only. 



It seems then possible to produce in rats a certain amount of 

 resistance to growth of tumor by treatment with tissue, of which 

 the cells are killed, but some endocellular enzyme-like substances 

 may not have been injured in the process. 



If we turn now to analyze the investigations of those who have 

 worked with normal tissue, it seems feasible to interpret the results 

 obtained by them in a similar way. It is hard to suppose that 

 when a piece of tissue or an emulsion is injected under the skin, 

 all the cells remain alive and are capable of normal function ten or 

 twelve days later. It seems more probable that the majority of 

 the cells die and undergo some changes similar to the autolytic 



