12 WALTER S. HUNTER 



the complex was absent, whereupon the rat ran to the other side. 

 The securing of food between trials was not necessary in order 

 .to produce the alternation. It was not the kinaesthetic complex 

 involved at the point of choice (at the top of the T) which deter- 

 mined the direction of the subsequent choice, but the sensory 

 complex at the end of the alley underlying a free or an obstructed 

 passage. 



Normally rat 104 behaved in the manner described in table 4, 

 running all to the left with the possible exception of the first one 

 or two choices. When tested with lllllrrrrr, the rat responded 

 rrlrrrllll, showing the tendency to alternate after success conflict- 

 ing at random with the position habit to the left. With the 

 series composed entirely of choices to the right, the animal made 

 the first choice to the right and all others to the left. 



We shall attempt later in the paper to explain why the rats 

 could not learn the temporal maze where the demand was for 

 double alternation through a continuous pathway. 



Problem 4- The simple alternation ft temporal maze. 11 We come 

 now to the experiments upon the temporal maze with simple 

 alternation. Here the apparatus and method described above 

 on pages 5-7 were used, except that the entrance- and end-stops 

 were shifted to require a simple alternation. The rat was thus 

 forced to run a continuous figure 8, once around the left of the 

 box and then once around the right, continued for ten choices. 



Seven untrained rats were used, nos. 108-114. Rats 108 and 

 109 were three months old when the tests began, and the others 

 were five weeks old. The detailed presentation of the records is 

 unnecessary, because they merely repeat what has already been 

 given for the double alternation temporal maze. Only one animal, 

 no. 110, mastered the problem. Table 5 shows the number of 

 trials given each rat. Each trial is equivalent to ten trials in the 

 T-box. Attention should be directed to the tremendous varia- 

 tion in difficulty existing between the simple alternation problem 

 in the T-box and in the temporal maze. 



In the course of the training, all rats acquired a position habit 

 to the right. This was uncomplicated by other reaction tenden- 

 cies as had been the case in the training on the previous tern- 



