26 JOHN LINCK ULRICH 



RESULTS SHOWINCx EFFECT OF DISTRIBUTION OF PRACTISE 



As may have been predicted, a given problem, when learned 

 concurrently with two others, induces in the animal a different 

 type of behavior from what it would call out if that problem 

 were learned alone; e.g., the latch box when learned with two 

 other problems was far more difficult than when it was learned 

 alone. It was the first problem offered on any given day. Many 

 more random movements appeared under these more complex 

 conditions than when it was learned alone and many unique 

 ways of solving the problem were noticeable. The rats which 

 had partially learned the problem would often go to the door, 

 smell the latch and go away, and then return later and open 

 it with their snouts. Others would stand before the door and 

 move their heads to and fro before making the decisive move- 

 ments which would open the door. At times there appeared a 

 degree of helplessness not evident when the latch box was offered 

 alone. Further, with the maze, nothing very significant was 

 noticeable with two additional problems, with the exception that 

 hesitations were frequent at the entrance of the maze, and 

 errors were rather frequent throughout learning. Since the 

 inclined plane box was not taken alone, but only in connection 

 with other problems, no criticism can be made of the behavior 

 of the rats. 



A few points in regard to the learning of the inclined plane 

 box are of interest. The movements of the rats were more 

 complex than those made in learning either the maze or the 

 latch box. At first the plane was set off accidentally by the rats, 

 but on the third or fourth day the first indication of an associa- 

 tion of the plane and the getting of the food or the opening of 

 the door was estabhshed. At this time, the rats went to the 

 plane and then turned away, or in their wanderings when they 

 came near it they avoided it. Not until the sixth to the eighth 

 day did the first indication appear that some progress in learning 

 was being made; the rats then went to the plane and pushed it 

 down. It was the first precise movement made, and first appeared 

 in those animals given one trial daily. It was not until some 

 time later that the rats, after having learned this precise move- 

 ment, immediately responded to the noise of the opening of the 

 door and ran to get food. Apparently an additional integration 



