Intelligence and the Acquisition of Habits. 153 



days-old chicks pecked repeatedly at something near the 

 corner of the turned-up newspaper which formed the wall 

 of the enclosure, the paper being propped against a more 

 solid support. The speck which had caught Blackie's keen 

 eye turned out to be the number of the page. He then 

 transferred his attention to the corner of the paper, which 

 he could just reach. Seizing this he pulled at it, bending 

 the paper down, and thus formed a breach through which 

 he escaped into the wider field of my study. I caught 

 and put him back near the same spot. He went at once 

 to the corner, pulled it down and escaped, but was 

 captured, and set down on the other side of the pen. 

 Presently, he sauntered round to the old spot, reached up 

 to the corner of the newspaper, pulled it down, and again 

 effected his escape. A single chance experience had 

 sufficed to teach him, and the association held good. I 

 parted with him in the evening of that day, so that I am 

 unable to say how long the association lasted ; but other 

 observations lead me to believe that an association once 

 formed is not soon obliterated. A moorhen that had 

 learnt to avoid cinnabar caterpillars refused to touch one 

 though three weeks had elapsed since he had seen any or 

 had opportunity of reviving the association, and though, in 

 the mean time, he had seen many strange worms. 



It does not appear to me that we are forcing upon a 

 technical term a meaning widely divergent from that 

 which current usage sanctions in a familiar word, in desig- 

 nating as "intelligent" Blackie's repeated escape from 

 confinement when chance had taught him how to break 

 bounds. In what essential respect does it differ from the 

 behaviour of Tony, my fox-terrier, who opens the gate by 

 lifting its iron latch with his head, having, after looking 

 out between the bars in a number of places in the railings, 

 at length chanced to gaze out under, and at the same 



