596 



J. Frank Daniel 



The method and technique developed for the study of Stentor 

 were used as satisfactory also for a study of Spirostomum. The 

 animals were kept in a low percentage of alcohol (i per cent) for 

 a short time and were then tested for their resistance to a stronger 

 concentration. The conditions — such as the maintenance of con- 

 stant temperature and the like — ^were similar in all respects to 

 those of Stentor. 



Expernnent XII. In determining the effect of a low fatal per- 

 centage of alcohol upon Spirostomum a 6 per cent solution was 

 first used. In this, however, it was found that, although normal 

 animals succumbed, nine out of ten of those acclimatized were 

 alive at the end of thirty minutes. 



From this it was obvious that in order to get a quantitative 

 statement of the resistance a stronger test fluid was needed. There- 

 upon an 8 per cent medium was employed with the following typi- 

 cal results: 



Expernnent XII 



RESISTANCE OF SPIROSTOMA TO 8 PERCENT ALCOHOL AFTER LIVING 4 DAYS IN I PER CENT ALCOHOL 



A Four Days in I Per Cent Alcohol 



Seconds 

 ilxp. I cilia stop no 



2 cilia stop 145 



3 cilia stop 220 



4 cilia stop 45 



5 cilia stop 90 



6 cilia stop 1 50 



7 cilia stop 210 



8 cilia stop 165 



9 cilia stop 240 



10 cilia stop 190 



Exp. 



1 ci 



2 C! 



3 CI 



4 c 



SCI 



6 c 



7 ci 



8 c 



9 c 

 10 c 



C Control 



Seconds 



a stop 80 



a stop 



50 



a stop 65 



a stop 55 



a stop 50 



a stop 60 



a stop 180 



a stop 50 



a stop 135 



a stop 80 



1565 



80.5 



From Experiment XII it is seen that the increase is much like 

 that given in type F of Stentor. Although in Spirostomum there 

 is a greater range of variability yet the striking feature in the many 

 cases observed was that although the normal animals varied in 

 their resistance from time to time the ratio between acclimatized 

 and unacclimatized (control) animals remained practically the 

 same. 



