188 



The Dancing Mouse 



N 



FIGURE 24. Labyrinth Bon 

 an interrupted circuit board. I- 

 1-2-3-0, labyrinth path; B, nest- 

 box; AT, nest; EW ', board wound 

 with phosphor bronze wire; 1C, 

 induction apparatus; C, electric 

 cell; K, key. 



scribed on p. 94. At O, Figure 

 24, there was an opening closed by 

 a swinging door which led into 

 a box 40 by 24 cm. In one 

 corner of this box was a small 

 nest-box. The significance of this 

 rearrangement of the labyrinth is 

 apparent. As in the preliminary 

 tests, the dancer was started at I, 

 but instead of being allowed to 

 wander about without any other 

 result than delay in escape, it was 

 given a shock each time it made 

 an error. The satisfaction of 

 escaping from the narrow bounds 

 of the labyrinth's passages, which 

 alone was not strong enough to 

 impel a dancer constantly to do 

 its best to escape, was thus sup- 

 plemented by the powerful and all- 

 controlling tendency to avoid the 

 disagreeable stimulus which re- 

 sulted from entering certain of the 

 passages. The result of this modi- 

 fication of method is strikingly ex- 

 hibited by the data of Table 32. 

 This table was constructed for 

 the purpose of exhibiting the prin- 

 cipal features of the results ob- 

 tained with labyrinth B in certain 

 preliminary experiments in which 

 the conditions were changed in 

 various ways. Chief among the 



