FUNCTION OF VIBRISSAE IN BEHAVIOR OF WHITE RAT 33 



that five of the six rats did not make a single sHp or fall in the 

 first five days' trials. About the fourth day they began to 

 increase in speed yet the total time of a run was long because of 

 the increase in errors. They ran rather rapidly, cut corners, 

 fairly jumped some, and were more reckless every way than 

 some animals with eyes intact which were on the maze at the 

 same time. 



One saw more of the learning of the maze in sections, the 

 t3rpical retracing of paths than in any other group used on this 

 maze. 



They kept close to the edge and their chief error lay in going 

 past the turn and the next most common one in following an 

 edge with their vibrissae which led them into a blind alley. One 

 could always see in these rats their use of vibrissae on floor and 

 edge of path even in rather rapid mnning. (Fig. 13.) 



As the path was learned the kinaesthetic elements were very 

 prominent. One could invariably tell which way a rat was going 

 to turn before he came to the place of turning for after he had 

 passed one turn his body was bent for the next. The direction 

 of the turn seemed a much easier thing for them to compass than 

 the position : i.e. the distance of one turn from another. 



Summary of the results of Experiment VIII. 



Average number of errors in the first twenty-five trials. 68. 



Average number of errors in the first trial 20.6 



Average time of learning (trials) 33. 



Average time of the last ten trials in learning 17. sec. 



Average time of the last trial 14. 



Average slips and falls in the first twenty-five trials ... 3. 



A comparison of this summary with that for Experiment II, 

 shows that with these blind animals, all other conditions being 

 the same so far as known, the average number of errors for the 

 first twenty-five trials as well as for the first trial were doubled, 

 the average time of learning was doubled, and the average time 

 for the last ten trials. 



How shall we explain the slight difference in the number of 

 slips and falls? The loss of sight, it cannot be doubted, is a 

 real loss in this problem. The animals became unusually cau- 

 tious so that in the early learning period there were few s'ips 

 and falls. But the learning period was prolonged far beyond 

 the twenty-fifth trial and whereas the other animals had for the 



