36 THE SPEECH OF MONKEYS. 



his own mood, and he therefore had no cause to 

 shun it. I do think, however, that the present 

 form of speech used by monkeys is developed far 

 above a mere series of grunts and groans, and 

 that some species among them have much more 

 copious and expressive forms of speech than 

 others do. From many experiments with the 

 phonograph, I am prepared to say with certainty 

 that some have much higher phonetic types than 

 others do. I have traced some slight inflections 

 which I think beyond a doubt modify the val- 

 ues of their sounds. I find monkeys who do 

 not make certain inflections at all, although the 

 phonation of a species is generally uniform in 

 other respects. In some cases it seems to me 

 that the inflections differ slightly in the same 

 species, but long and constant association seems 

 to unify these dialects in some degree, very 

 much the same as like causes blend and unify 

 the dialects of human speech. I have found 

 one instance in which a Capuchin had ac- 

 quired two sounds which strictly belonged to 

 the tongue of the white-faced Cebus. I was 

 surprised when I heard him utter the sounds, 

 and thought at first that these sounds were com- 

 mon to the speech of both varieties, but on in- 



