INTELLIGENCE OF EARTHWORMS 341 



All things considered, the results of the training by 20 trials 

 per day were less satisfactory than those of the earlier training 

 by 10 trials. The worm frequently exhibited fatigue before the 

 completion of a 20-trial series. Concluding that he had been 

 overworking his subject, the experimenter reduced the number 

 of trials to 10 per day from November 20 to November 30, — 

 trials 401-510. 



TABLE 4 



Results op First Trials in Daily Series Compared with Averages for 



the First Half of the Trials of the Daily Series 



Averages 2.76 1.32 151.2" Averages 1.34 .59 114.0" 



Table 4 presents, on the left, the results of the first trial 

 in each daily series up to the five-hundredth trial, and, on the 



