80 WALTER S. HUNTER 



from the release box. At every trial, three possibilities of reac- 

 tion confronted the subject. A selection had to be made and 

 that box chosen in which the stimulus had appeared most 

 recently. 



2. The conditions under which the maximal delay was tested 

 and the results obtained are indicated as follows; 



(a) Different classes of subjects were used. Table XIV gives 

 the maximum and minimum delays that were obtained from 

 the different classes. 



TABLE XIV 

 Subjects Min. delay Max. delay- 

 Rats either no learning or 3rd stage of delay 10 sees. 

 Dogs 2 sees. 5 mins. 

 Raccoons 3 sees. 25 sees. 

 Children 50 sees. 25 mins. 



(b) Backgrounds of widely different grades of brightness did 

 not affect the intervals of delay. 



(c) The use of a large release which gave the animals the 

 freedom of the interior of the box lengthened the intervals of 

 delay in the case of some subjects. 



(d) The use of two boxes as opposed to three lengthened the 

 intervals of delay by increasing the accuracy of response. 



(e) Neither punishment nor the particular number of trials 

 per day appear to have affected the interval of delay. 



3. An analysis of the possible cues that may have been used 

 by the subjects in the solution of the present problem gave the 

 following results: (a) Overt orienting attitudes were the prob- 

 able cues for many reactions of the raccoons. These attitudes 

 must be assumed as cues for the rats and dogs in order to explain 

 their reactions, (b) Some intra-organic (non -orientation) factor 

 not visible to the experimenter niust be assumed in order to 

 explain a significant number of the correct reactions of the 

 raccoons and all of the successful reactions of the children. 

 These cues fulfilled an ideational function, (c) All of the re- 

 agents were influenced by external stimuli that were constantly 

 present from trial to trial, e.g., those gi\'en by the box itself. 

 However, these could not be used as a basis for selective re- 

 sponses inasmuch as they were constant from trial to trial and 

 hence could not furnish varying, or alternating, cues. 



