154 Habit and Instinct. 



time inadvertently lift, the latch ? He, too, after a while 

 profited by the fortunate results of an originally fortuitous 

 experience, and now opens the gate whenever he wants to 

 do so. At any rate, using the word as a technical term 

 for behaviour based on direct association, this profiting by 

 individual experience is of the very essence of intelligence. 

 No doubt important conditions to the intelligent over- 

 coming of difficulties are persistency and varied effort. 

 I have noted this again and again in the case of young 

 birds. It was especially noticeable in jays. Every 

 projecting bit of wire or piece of wood in their cage was 

 pulled at from all points, and in varied ways. Every 

 new object introduced into the cage was turned over, 

 carried about, pulled at, hammered at, stuffed into this 

 corner and into that, and experimented with in all possible 

 ways. Such persistency and varied effort affords to in- 

 telligence abundant material from which some fortunate 

 and helpful association may arise. 



Dr. Mills, in his diary of the kitten,* describes how 

 persistent were its efforts, from the twenty-sixth to the 

 twenty-eighth day of life, to get into some partially filled 

 book-shelves, even when the entrance was barred up. 

 " The history of the kitten's whole bearing towards the 

 book-shelves has been to me," he says, " a most in- 

 structive one. I have never witnessed such perseverance 

 in the accomplishment of an object in any young animal 

 not excepting the child. It seemed that the greater 

 obstacles the greater the efforts the kitten put forth to 

 overcome them behaviour that we usually consider 

 especially human, and ever an evidence of unusual 

 strength of character." 



No doubt there are well-marked variations in this 

 innate persistency and experimentalism, if we may i 



* Trans. Boy. Soc. Canada, 2nd series, vol. i. sect. iv. pp. 197, 210. 



