582 



y. Frank Daniel 



Instead of giving clearer evidence, this shows the maximum 

 resistance found for control animals in the entire study, and an 

 increase for the acclimatized animals w^hich is lower than in the 

 first experiment. 



Whether a high normal resistance in any way obscures the degree 

 of immunity actually present is a further question which may be 

 tested by the use of a stronger killing fluid — thus reducing the 

 period of resistance. 



Animals kept in a i per cent acclimatizing medium for four days, 

 then tested to an 8 per cent killing solution should be satisfactory 

 for a determination of this point. Such a condition follows: 



Exp 



en men 



t F 



RESISTANCE OF STENTORS OF TYPE E TO 8 PER CENT ALCOHOL AFTER LIVING 4 DAYS IN 1 PER CENT ALCOHOL 



C Control 



A Four Days in I Per Cent Alcohol 



Seconds 



Exp. I C! 



2 c 



3 c 

 4C 

 Sci 

 6 



7 ci 



8 ci 



9 ci 

 10 c 



lia stop 120 



lia stop 30 



lia stop 30 



lia stop 25 



lia stop 30 



lia stop 30 



lia stop 40 



lia stop 20 



lia stop 105 



lia stop 35 



Average resistance = 46 . 5 



Seconds 



Exp. I cilia stop 125 



2 cilia stop 30 



3 cilia stop 20 



4 cilia stop 35 



5 cilia stop 20 



6 cilia stop 30 



7 cilia stop 60 



8 cilia stop 35 



9 cilia stop 60 



10 cilia stop 30 



Average resistance = 44 . 5 



The results as given in the foregoing experiment, however, show 

 that no advantage in this case followed shortening the period of 

 resistance. On the other hand, the experiment gives much less 

 evidence for immunity than either the first or the second. 



After trying many cases all terminating as did Experiments 

 III to V in marked variability from slight to doubtful acclimatiza- 

 tion, it was thought that the low degree of increase might be due 

 to injury resulting from rapid subjection to a i per cent acclimat- 

 izing medium. To obviate this, a method was adopted by which 

 small and increasing amounts of alcohol were added so gradually 

 to the normal media as to insure no injury from a too rapid sub- 



