152 THE SPEECH OF MONKEYS. 



types. It occurs to me that signs were the first 

 form of expression, and that sounds were first 

 used to call attention to the signs made ; and by 

 an association of ideas the sounds became a fac- 

 tor of expression and were used to emphasize 

 signs. As we ascend the scale of life sounds 

 become more abundant and signs less significant ; 

 and in the middle types they appear to be of 

 nearly equal value, while in the higher tribes of 

 man sounds are the normal mode of expression, 

 and signs or gestures are used to emphasize 

 them ; and thus we see that signs and sounds in 

 the development of the faculty of expression 

 have quite changed places. This is consistent 

 with the observed facts within the limits of 

 human speech. There are tribes of mankind 

 whose language is scarcely intelligible among 

 themselves unless accompanied by signs, and it 

 is said of some of the African tribes that their 

 gestures are more eloquent than their speech. 

 It appears to me consistent to believe that speech 

 appears in the animal organism simultaneously 

 with the vocal organs, and that the desire of ex- 

 pression must have preceded this. The con- 

 dition of the vocal organs depends upon the type 

 of speech which they are used to utter, and the 



