38 THE SPEECH OF MONKEYS. 



For some weeks I visited Puck almost daily, and 

 in response to his sound for food I always sup- 

 plied him with some nuts, banana, or other food. 

 I never gave him any of these things to eat un- 

 less he would ask me for them in his own speech. 

 On one of my visits my attention was attracted 

 by little Darwin, who was uttering a strange 

 sound which I had never before heard one of his 

 species utter. I did not recognize the sound at 

 first, but very soon discovered that it was in- 

 tended to imitate the sound of the Capuchin, in 

 response to which I always gave Puck some nice 

 morsel of food. Darwin had undoubtedly ob- 

 served that this sound made by Puck was always 

 rewarded with something good to eat, and his 

 evident motive was to secure a like reward. Af- 

 ter this I always gave him some food in acknowh 

 edgment of his efforts, and I observed, from day 

 to day, that he improved in making this sound 

 until at last it could scarcely be detected from 

 the sound made by Puck. This was accom- 

 plished within a period of less than six weeks 

 from my first visit. In this case, at least, I have 

 seen one step taken by a monkey in learning the 

 tongue of another. This was most interesting 

 to me in view of the fact that I had. long believed, 



