538 THE EVOLUTION OF MIND 



namely ourselves, we know that a physical event, such as 

 the receiving of good news, will, we cannot explain how, 

 except on the unity-of-the-organism theory or symbolism, 

 set in motion a series of physico-chemical and vital processes, 

 complex beyond the ken of the wisest. 



There is another line of evidence of a particularly in- 

 teresting kind, that obtainable from the records of trained 

 animals. A dog may exhibit remarkable ability in doing 

 certain things in response to words. Speaking from where 

 he could not be seen in a room in the Johns Hopkins Labora- 

 tory, Mr. Dixie Taylor said to his dog Jasper, " Go to the 

 next room and bring me a paper lying on the floor." The 

 dog went and executed the command ; it appeared to have 

 an associative memory for about a hundred words. Prof. 

 J. B. Watson, a tough-minded behaviourist, ends his chapter 

 on " The Limits of Training in Animals ' by saying " the 

 behaviour laboratories must be prepared to admit that the 

 sympathetic upbringing of animals in the home, where they 

 are thrown into constant contact with human beings, does 

 produce in them a certain complex type of behaviour for 

 which the laboratory concepts, as they now exist, are in- 

 adequate to supply explanation ". 



A terrier was allowed in the dining-room, where it some- 

 times received a bone from the table. The convention was 

 that the door was at once opened for it when it sought exit 

 with the bone in its mouth. It disdained bread. One 

 evening it heard barking outside. It had, however, on that 

 occasion no bone. It snapped up a piece of bread and made 

 for the door. When it was opened, it dropped the bread 

 and ran out to join its fellows (McCabe, Evolution of 

 Mind, p. 222). 



Professor Whitman once said that he had studied pigeons 



