Difficulties and Methods 5 



writes out an account of it. In others, the animal is a pet, 

 in whose high intellectual powers its master takes pride. 

 It is safe to say that this method of collecting information 

 always labors under at least one, and frequently under 

 several, of the following disadvantages : 



1 . The observer is not scientifically trained to distinguish 

 what he sees from what he infers. 



2. He is not intimately acquainted with the habits of the 

 species to which the animal belongs. 



3. He is not acquainted with the past experience of the 

 individual animal concerned. 



4. He has a personal affection for the animal concerned, 

 and a desire to show its superior intelligence. 



5. He has the desire, common to all humanity, to tell a 

 good story. 



Some of these tendencies to error it is unnecessary to illus- 

 trate. A good example of the dangers of (2), lack of ac- 

 quaintance with the habits of the species, is given by Mr. 

 and Mrs. Peckham. They quote the following anecdote 

 reported by no less eminent and trained an observer than 

 Wundt. "I had made myself," says that psychologist, 

 "as a boy, a fly- trap like a pigeon cote. The flies were 

 attracted by scattering sugar and caught as soon as they 

 had entered the cage. Behind the trap was a second box 

 separated from it by a sliding door, which could be opened 

 or shut at pleasure. In this I had put a large garden 

 spider. Cage and box were provided with glass windows 

 on the top, so that I could quite well observe anything 

 that was going on inside. . . . When some flies had 

 been caught, and the slide was drawn out, the spider of 

 course rushed upon her prey and devoured them. . . . 

 This went on for some time. The spider was sometimes 

 let into the cage, sometimes confined to her own box. But 



