252 



E. P. CHURCHILL, JR. 



10 20 30 40 



Figure 3. Curve for Group II, the position of the beginning of the curve being 

 indicated by the arrow. The abscissae represent trials, the ordinates, time 

 in minutes. 



greater than was true of Group I. It will be seen that the curve 

 descends more rapidly and farther and remains lower than does 

 that of Group I. The fish went back to a previously occupied 

 compartment more frequently than did the members of Group I. 

 Group III was made up of two fish which were used with the 

 wooden partitions. Their initial trials, although successful, re- 

 quired considerable time (Fig. 4). This seemed to be due to 



' 60 



50 

 40 

 30 

 20 

 10 

 



10 20 30 40 50 



Figure 4. Curve for Group III. The abscissae represent trials, the ordinates 

 time in minutes. 



the fact that the fish did not play about the dark wooden par- 

 titions to any extent. When they did reach a point an inch or 

 two directly before the opening they usually went through. 

 The reverse passage of the openings was made much more 



