8o DOG STORIES 



are all handled by us, and must emit very 

 nearly the same odour. I do not, however, 

 rely on this, but have in use a number of 

 cards bearing the same word. When, for 

 instance, he has brought a card with "food" 

 on it, we do not put down the same identical 

 card, but another with the same word ; when 

 he has brought that, a third is put down, and 

 so on. For a single meal, therefore, eight or 

 ten cards will have been used, and it seems 

 clear, therefore, that in selecting them Van 

 must be guided by the letters. 



When I last wrote I had satisfied myself 

 that he had learnt to regard the bringing 

 of a card as a request, and that he could 

 distinguish a card with the word " food " on 

 it from a plain one, while I believed that he 

 could distinguish between a card with " food " 

 on it and one with "out" on it. 



I have now no doubt that he can distin- 

 guish between different words. For instance, 

 when he is hungry he will bring a " food " 

 card time after time, until he has had enough, 

 and then he lies down quietly for a nap. 

 Again, when I am going for a walk, and 



