280 ARTHUR C. WALTON 



of the sight of operator walking in front of release box, (2) the 

 sound of the operator's voice calling the dog, and (3) a whistle 

 call with a piece of meat hung before the door. The object 

 was to find out if such stimuli could or would cause the dog to 

 forget his cues to the food compartments. The dog answered 

 each of these diversions by giving his whole attention to them, 

 often by snapping at the meat through the screen or by getting 

 up and turning around when called and not released. 



These series of trials of this condition "CD" were given on 

 December 8th, 1913 and December 15th, 1913 and concluded 

 the trials on the 'Two Bowl" problems. The first series on 

 December 8th, 1913 was of Ten Seconds Delay with 100% 

 results. Five trials of One Hundred and Twenty Seconds Delay 

 also showed perfect reaction with no evidence of the effect of 

 the diverting stimuli. A series of light trials on Sixty Seconds 

 Delay followed and showed 75% of the reactions correct, the 

 last five being perfect. As there seemed to be no sign of the 

 dog losing his cue to either of the compartments, a sudden 

 jump was made to a delay of five minutes, and a series of five 

 trials showed all as perfect reactions. There was no hesitation 

 displayed in the dog's choice of compartments, nor did there 

 seem to be any sign of an hindering influence, due to the divert- 

 ing stimuli introduced during the delay. In order to ascertain 

 whether these results were chance, or whether they showed 

 the power of retaining a cue powerful enough to bridge the 

 five minute gap, and then discriminate perfectly between the 

 two bowls, another series of trials on these long delays was 

 held on December 15th, 1913. As usual the dog was kept at 

 a compartment until he succeeded, and no set of trials was 

 given up until five in succession had been correct. Beginning 

 with a two minute delay seven trials resulted in the last six 

 being correct (or a percentage of eighty-six.) With a three 

 minute delay, five trials were all correct. Then a five minute 

 delay showed seven successive correct trials. Then the next 

 trial was unsuccessful for the dog seemed to show fatigue and 

 during the delay period dozed in his box and did not pay atten- 

 tion to the attempts of the operators to attract his attention. 

 On release he went out slowly and wandered around and finally 

 reached the food compartments and entered the wrong one. 

 Because of the loss of attention, no more trials were given. 



