Immunity of Lower Organisms to Ethyl Alcohol 599 



A later series at the end of the second week gave the following 

 similar results: 



Experiment XV 



RESISTANCE OF SPIROSTOMA TO 8 PER CENT ALCOHOL AFTER I4 DAYS IN I PER CENT ALCOHOL 



Exp, 



A 14 Days in I Per Cent Alcohol 



Seconds 



1 cilia stop 215 



2 cilia Stop 60 



3 cilia stop 180 



4 cilia stop 75 



5 cilia stop 250 



6 cilia stop 230 



7 cilia stop 65 



8 cilia stop 55 



9 cilia stop 95 



10 cilia stop 50 



Exp. 



1 c 



2 c 



3 c: 

 4C1 



5ci 

 6d 



7 ci 



8 ci 



9 ci 

 10 ci 



127.5 



C Control 



Seconds 



lia stop 25 



lia stop 125 



lia stop 30 



lia stop 50 



lia stop 55 



lia stop 50 



lia stop 95 



lia stop 30 



lia stop 120 



lia stop 30 



61 



From these two experiments it appears probable that immunity 

 remains as long as the killing fluid is not markedly weakened. 



A study of Spirostomum shows a marked degree of similarity 

 between its reaction and that of type F of Stentor. In both there 

 was a well marked immunity which by the end of the fourth day 

 had reached a degree of constancy. 



The experiments just described show further that the immunity 

 which was constant on the fourth to the seventh day was still 

 present when tested at a much later date. 



With this we may conclude the present study and pass to a con- 

 sideration of another phase of the nature of immunity. 



IV SPECIFICITY OF IMMUNITY 



Ehrlich^'^ found that white mice which were immunized to 

 ri'cin were still susceptible to another poison — that of abrin. The 

 immunity conferred by the one substance in this case did not carry 

 with it protection against a difFeient substance. In other words 

 its action was specific. 



'^ Ehrlich, P., 1891, Deutsche med. Wochenschrift no. 12 (ricin), no. 14 (abrin). 



