36 Journal of Comparative Neurology and Psychology. 



starting off. Nine trials were clear-cut, legitimate cases of imme- 

 diate orientation. However, eight of the total number of imme- 

 diate orientations were made by two rats, and the influence of 

 the learning factor is evident in spite of the small number of trials 

 allowed to each animal. No immediate orientations were made 

 during the first day. Only three cases occurred during the first 

 half of the trials, while the remaining fourteen, cases were made 

 during the last half of the tests. 



There was a tendency for the rats to pick up the cue at dis- 

 tinctive points in the maze. In the 67 trials in which there was 

 a period of exploration, the cue was picked up 13 times at 0, 11 

 times at or near the corner M, 15 times at the turn N, 1 1 times at 

 the corner P, 7 times at the corner R, 3 times at S and once at 

 T. In only six trials was the orientation clearly eff"ected near the 

 middle of one of the alleys, to which number must be added the 

 number of trials in which immediate orientation occurred. This 

 fact, that the cue is picked up at distinctive positions, cannot be 

 explained on the hypothesis that each rat would finally learn to 

 orient itself at some one of these positions and hence that all of the 

 15 orientations at A^, for example, belong to that one rat, as might 

 very well be the case, if such a point offered a distinctive visual or 

 olfactory cue. As a matter of fact, the greatest number of orienta- 

 tions per rat at any position was four out of a total of twelve trials. 

 The 67 trials give an average of 8.37 per rat, and on the average, 

 these 8.37 orientations occurred at 4.75 positions — less than two 

 orientations per position. For any one rat, the greatest average 

 number of orientations per position was 2.2. This general fact 

 that orientation is secured at such distinctive positions as the 

 turns supports our general contention. 



The statistical results show no differences between the blind 

 and the normal rats in any respect. The females have better 

 records than the males. Their period of exploration is shorter, 

 fewer turns are made inside the alleys, fewer corners are turned, 

 and the percentage of immediate orientations is much higher. 

 Whether this difference is a matter of chance, or whether the 

 results represent individual or sex differences, it is impossible to 

 say. 



These various results of the experiment speak for themselves. 

 They can be easil}' interpreted in terms of our theory. We do not 

 mean to assert that they furnish conclusive and indubitable proof 



