136 APES AND MONKEYS 



go into any details about it, except that a certain sound 

 indicated "good " or " satisfaction," and another meant the 

 opposite. 



Among the sounds that I learned was one that is used 

 by a chimpanzee in calling another to come to it. Some 

 of the natives assured me that the mothers always use it 

 in calling their young to them. When Moses wandered 

 away from the cage into the jungle, he would sometimes 

 call me with this sound. I cannot express it in letters of 

 the alphabet, nor describe it so as to give a very clear idea 

 of its character. It is a single sound, or word of one syl- 

 lable, and can be easily imitated by the human voice. At 

 any time that I wanted Moses to come to me I used this 

 word, and the fact that he always obeyed it by coming 

 confirmed my opinion as to its meaning. I do not think 

 that when he addressed it to me he expected me to come 

 to him, but he perhaps wanted to locate me in order to be 

 guided back to the cage by means of the sound. As he 

 grew more familiar with the surrounding forest he used it 



o 



less frequently, but he always employed it in calling me or 



the bow When he was called bv it he answered with the 

 same sound ; but one fact that we noticed was, that if he 

 could see the one who called he never made any reply. 

 He would obey the call, but not answer. He probably 

 thought that if he could see the one who called he could 

 be seen bv him, and it was therefore useless to reply. 



The speech of these animals is very limited, but it is 

 sufficient for their purpose. It is none the less real 

 because of its being restricted, but it is more difficult for 

 man to learn, because his modes of thought are so much 



