Immunity of Lower Organisms to Ethyl Alcohol 583 



jection. This method consisted in the addition on succeeding 

 days of 4, 6 and 10 cc. of a 6 per cent concentration to 100 cc. of 

 a normal culture medium. 



Animals thus carefully reared on a gradually increasing scale 

 for the same number of days as Experiment III gave the following 

 results : 



Exp 



tVI 



erimen 



RESISTANCE OF STENTORS OF TYPE E TO 6 PER CENT ALCOHOL AFTER 3 DAYS IN AN ACCLIMATIZING 

 MEDIUM GRADUALLY BROUGHT UP TO I PER CENT 



A Three Days in Weak Alcohol 



Seconds 



Exp. I cilia stop 265 



2 cilia stop 170 



3 cilia stop 305 



4 cilia stop 340 



5 cilia stop 255 



6 cilia stop 240 



7 cilia stop 90 



8 cilia stop 160 



9 cilia stop 330 



10 cilia stop 420 



Average resistance = 257.5 



C Control 



Seconds 



Exp. I cilia stop 230 



2 cilia stop 240 



3 cilia stop 230 



4 cilia stop 250 



5 cilia stop 355 



6 cilia stop 340 



7 cilia stop 360 



8 cilia stop 75 



9 cilia stop 245 



10 cilia stop 255 



Average resistance = 258 



From the above it is reasonably certain that the low increase 

 in resistance shown in Experiment III was not due to an injury 

 attributable to the i per cent acclimatizing fluid, for in the same 

 strength, to which the animals were subjected so gradually as to 

 be without injury, no acclimatization whatsoever resulted. 



Since no injury and very doubtful acclimatization is evident 

 in a medium of i per cent strength, the question naturally follows: 

 May not the low degree of immunity be due to the fact that the 

 medium is too weak to produce an immunizing effect .'' 



To test this, Stentors were brought through a graduated series 

 of transfers to the highest percentage in which they could live 

 without apparent injury — -a 1.5 per cent solution. A test to 8 

 per cent alcohol of animals from this medium resulted as follows: 



