344 ROBERT M. YERKES 



was given up because of the risk of injury to the subject from 

 frequent electrical stimulation. 



Beginning with April 10, the original conditions of training 

 were reestablished, and, with few exceptions, the correct course 

 was taken in trials 781 to 860. Several series were perfect. 



The contrast between the features of behavior under the 

 differing conditions of training — with apparatus arranged for 

 escape by the left arm, and for escape by the right arm — is 

 indicated in table 5. With the new condition of training there 

 were few successful trials, with the old there were few failures. 

 With the new, the worm wandered, baffled; with the old it 

 escaped directly. 



In the three weeks of training, April 10-30, the tactual and 

 electrical stimuli were seldom received. The worm usually 

 followed the right wall of the stem of the T from the entrance 

 tube and turned to the right with a fair degree of directness 

 upon coming in contact with the "common" wall of the arms. 



The results of trials 781 to 860 were more clearly indicative 

 of a definite direction-habit than any previously obtained. 

 Table 6 presents a few typical series. Excellent evidences of 

 the association of tactual with electrical sensations also appeared. 



TABLE 6 



Results Indicative of Perfection of Habit Before Amputation of 



First Five Segments 



