32 STELLA BURNHAM VINCENT 



Summary of results of Experiment VII. 



Average number of errors in the first twenty-five trials. 74. 



Average number of errors in the first trial 11, i 



Average number of trials in learning 28.5 



Average time of the last ten trials in learning 25. sec. 



Average time of the last trials 12. " 



Slips and falls 74, avg. 6.7 



It will be noticed here that the average number of errors in 

 the first twenty-five trials exceed those of any other group thus 

 far reported and the time of learning is longer. The average 

 time of the last ten trials is high and the slips and falls are many. 

 In the previous cases the slips and falls were confined to the 

 early part of the learning period, but in this they persisted all 

 the way through, far beyond the twenty-five trials quoted, making 

 the total average about the same as for the rats with the vibrissae 

 cut from birth, but with the errors difterently distributed. There 

 was a disproportion between the time and the error curve and 

 the height of the time curve in the beginning was unlike anything 

 seen. Evidently these rats were more unfavorably situated for 

 learning the maze than any animals tried up to this time. 



Experiment VIII. Blind rats with vibrissae; the maze without 

 sides. This group consisted of six blind rats, females, whose eyes 

 were removed August 3d. They seemed to be little the worse 

 for the operation, were climbing all over the cage in an hour or so 

 and there were no ill after eftects. They were fed in the maze 

 five days and were put in to run Aug. 2 1 . 



They really seemed to run more freely at first than rats with 

 vision. They did not have the peculiar gait nor flattened, 

 lengthened bodies which characterized the others. 



In the beginning they ran to the extreme end of each path. 

 They never turned until they were obliged to. Thus they always 

 found it difficult to take the right way at B and even when they 

 had fully learned the maze they were still forced to slow up 

 here and feel for the turn. This was one of the last errors to be 

 cut out and the next was K. Here they apparently found it 

 easier to go to the end and then return than to accommodate 

 themselves to the turn at J. There was a great deal of " nosing " 

 and rising on hind feet and snifiing as if smelling. They tried to 

 jump in the usual places A, K, and M. 



Their early runs were most cautious ones, so very cautious 



