A STUDY OF THE BEHAVIOR OF THE CROW 113 



trials distributed over a period of thirty-two days, but also 

 upon the observation that in the case of the setting 7-9, which 

 appeared twice in the series, as Nos. 1 and 9, and was therefore 

 presented to each crow one hundred times instead of fifty times, 

 the successes were surprisingly few. In the first presentation 

 of this setting, number 1 in the series, for both of the crows 

 there is marked increase in the number of correct first choices 

 between the beginning and the end of the training. But for 

 the second presentation, number 9 in the series, this is not the 

 case. Crow number 3, in the first ten presentations of this 

 setting, as number 9 in the series, chose correctly only twice, 

 and in the last ten, only four times, while crow number 4 chose 

 correctly in the first ten, four times, and in the last ten, four 

 times. Even without experience they should have chosen 

 correctly twice in ten trials. 



This is an easy setting and it is surprising indeed that the 

 crows should not have succeeded in reacting correctly in the 

 latter part of the training. Doubtless their failure is due to 

 the confusing effect of the diverse settings. 



We feel that our analysis and discussion of results is inadequate, 

 but the report is already overlong because of the necessarily 

 lengthy description of apparatus and experimental procedure, 

 and we may add only a brief summary. 



SUMMARY 



1 . Two crows, No. 3, a male, and No. 4, a female, about 

 three months old, were presented with two of the simplest types 

 of standard problem in the Yerkes multiple choice apparatus. 

 These problems were: (1) selection of the compartment first 

 at the right in a series; (2) selection of the compartment second 

 at the left; and (3) the other form of problem 1, the selection, 

 namely, of the compartment first at the left. 



2 . Of these three problems both birds succeeded in solving 

 perfectly, in from fifty to one hundred trials, the first and the 

 last. The second problem they failed to solve in five hundred 

 trials. 



3 . Various types of reaction and reactive tendencies appeared 

 during the work on problem 2. Examples of these are: (1) to 

 go to the first compartment at the right because of training 

 in problem 1 ; (2) to go to the first at the left, and then to the 



