x SOME EXPERIMENTAL RESULTS 197 



Many days later I gave him thirteen trials with the bolt 

 again, in all of which he succeeded in both movements (bolt and 

 lever). The average time of the second to the seventh trials 

 being, roughly, 29", of the last six, 23". 



This success was a case of acquired discrimination. 

 Jack had to learn that one sort of projection had to be 

 pulled out, while another had to be pulled at right angles. 

 This was perhaps rendered more rather than less difficult 

 by his spurious success at first. There was the further 

 difficulty, that, by using his strength, Jack could get out 

 the bolt, or possibly break it when pulling at a consider- 

 able angle. This was much against rapidity and neatness 

 of learning. 



This was the first experiment in which a double action 

 was made necessary. The bolt and lever being learnt 

 separately, the box was so arranged as to combine them. 

 Jack was baffled by this until twice shown. 



The cat learnt the bolt rapidly, and soon came to pull 

 it out scientifically, curling his claw round, and working 

 by a series of pulls. 



His record is as follows : 



i and 2. Shown. 



3. I now place box on floor. He claws bolt out. I put it 

 back, holding door firm, thinking he has done it accidentally. He 

 does it again, and gets meat. 



4 to 9. Pulls bolt out. N.B. Once in 5 after bolt is out, 

 does not see door is open, until I swing it for him. Afterwards 

 opens door himself. In 8, tries to open the door before bolt 

 is properly out. 



Next day. (Box tilted, so that door must definitely be opened 

 by cat after bolt is drawn.) 



1 . Claws about, has to be shown. 



2. After hesitation, pulls out awkwardly. Door not opening, 

 cat is puzzled, and I have to do it. 



3. Pulls out better, and opens. 



4. Same. 



After two days new smooth bolt. 



1. Several times tries bolt, but it is too slippery. I put in a 

 rough one. He refuses to try. I pull it out, and he opens door 

 by the bolt-catch. 



2. Pulls it out after two or three efforts. Opens. 



3. Same. 



