438 ANIMAL INTELLIGENCE. 



his labours the culmination of his experiment in the 

 transformed psychology of the dog. 



In my next work I shall treat of this subject with the 

 fulness that it deserves especially in its relation to the 

 origin of instincts and the development of the moral 

 sense ; but to enter upon this topic at present would 

 demand more space than can be allowed. 



To do full justice to the psychology of the dog a 

 separate treatise would be required. Here I can only 

 trace a sketch. 



Memory. 



As regards memory, one or two instances will suffice. 

 Mr. Darwin writes : ' I had a dog who was savage and 

 averse to all strangers, and I purposely tried his memory 

 after an absence of five years and two days. I went near 

 the stable where he lived, and shouted to him in my old 

 manner ; he showed no joy, but instantly followed me out 

 walking, and obeyed me, as if I had parted with him only 

 an hour before.' l 



It is not only persons or places that dogs remember 

 for long periods. I had a setter in the country, which one 

 year I took up with me to town for a few months. While 

 in town he was never allowed to go out without a collar 

 on which was engraved my address. A ring upon this 

 collar made a clinking sound, and the setter soon learnt to 

 associate the approach of this sound with the prospect of 

 a walk. Three years afterwards I again took this setter 

 up to town. He remembered every nook and corner of 

 my house in town, and also his way about the streets, and 

 the first time that I brought his collar, slightly clinking 

 as before, he showed by his demonstrations of joy that he 

 well remembered the sound with all its old associations, 

 although he had not heard this sound for three years. 



Emotions. 



The emotional life of the dog is highly developed 

 more highly, indeed, than that of any other animal. His 



1 Descent (f Man, p. 74. 



