86 HAROLD C. BIXGHAM 



4. The remaining factor in this primary learning process is 

 the number of approaches to the inside corner. The minimal 

 limit denoting perfection in this task, like the preceding, is zero. 

 This process of eliminating inside corner trials is also a negative 

 task and perfection, again, is approached relatively early. 

 Several of the first ten series contain only a single inside trial. 

 Absolute perfection, however, is not reached by any chick 

 before series 18. 



The effect of the preliminary series is suggested when one 

 compares the records of inside approaches with those of outside 

 and stimuli approaches. The inside trials in series 1 are slightly 

 less than one fourth the outside trials and one third the stimulus 

 approaches. The chicks, it would seem, had acquired in the 

 preliminary series a tendency to go to the outside rather than 

 the inside corners. Turning to the averages, it appears that 

 the outside corners are approached, on the whole, a greater 

 number of times than the stimuli and the inside corners com- 

 bined. This correctly indicates that the chick, in turning 

 from an outside corner, often went to some other part of the 

 box than my list here indicates. Often the turn was towards 

 the rear of the experiment box followed by a return. Some- 

 times it was a fairly direct course from one outside corner to 

 the other. Changes from outside corners to other parts followed 

 failure to make an adequate adjustment to the tripping device 

 at the first exit approach and the chicks frequently made 

 several exit attempts before effecting the release of the exit 

 door. 



The decline in the number of stimulus approaches is the 

 most abrupt change that appears in any of the four criteria. 

 This is partially due to the fact that the number starts nearly 

 as high as that for outside approaches, but the latter cannot 

 go below ten whereas the stimulus trials have zero for a 

 limit. The high beginning in number of stimulus trials is 

 probably due to the fact that the stimuli are the attracting 

 factors calling the animal to the exit end of the experiment 

 box. Efforts directed toward the stimulus are therefore more 

 to be expected at first than efforts at the inside corners. The 

 most significant feature in these stimulus records, however, is 

 the abrupt and rather permanent decreases that occur. 



