I So NATURE STUDIES. 



done things which they have seen done by the persons 

 with whom they live, and more or less obviously with 

 the object of obtaining the result which they had 

 observed to follow from such actions. For this would 

 seem, if the animal can be clearly shown to have had 

 such a purpose, to be distinctly the result of reasoning. 

 Monkeys may or may not reason when they imitate 

 actions which, when performed by themselves, are of 

 no advantage to them, or are even mischievous. 

 Indeed, it is not improbable that they suppose their 

 human fellow-creatures would not perform such actions 

 except for a useful purpose, though what that purpose 

 may be they may have no conception. But whatever 

 opinion we may form on this point, we can have, it 

 would seem, no room for rejecting the belief that an 

 animal has reasoned who performs an act demonstrably 

 for the purpose of producing a certain effect, such as 

 he has observed to follow when human beings have so 

 acted. Now in some of the cases which follow, this 

 does seem to be most clearly made out. 



A writer in Nature gives the following case : " My 

 sister, who lives just opposite to my own house, 

 possesses a cat (now about thirteen years old), whose 

 intelligence is very remarkable. He has a habit of 

 making use of the knocker of a side door, which is 

 just within his reach as he stands on his hind legs, 

 whenever he desires admission. A single knock is 

 tried in the first instance ; but if this is not answered 

 promptly, it is followed by what is known as the 

 ' postman's knock ' ; if this is not successful, trial is 



