The Speech of Monkeys

[Sidenote: MODES OF EXPRESSION] At the point where we begin to discuss this question there are two distinct modes of expression, either one of which can be used without the other. But I may mention here a cogent fact, that in the lower forms of life the normal mode of expression is by signs with supplemental sounds. In the higher forms, expression is by sounds, and signs are supplemental. And from the lower to the higher forms this transition is in harmony with the development of physical types. It occurs to me that signs were the first form of expression, and that sounds were first used to call attention to the sign made; and by an association of ideas the sounds became a factor of expression, and were used to emphasise 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 emphasise 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.