MENTAL EVOLUTION OF MAN 219 



more characteristic of man alone than the power of 

 reason itself. While organized language is clearly 

 something that as such we do not share with the lower 

 animals, nevertheless we cannot regard the communi- 

 cation of ideas or states of feeling by sound as an exclu- 

 sive property of mankind. All are familiar with the 

 difference between the whine and the bark of a dog 

 and with the widely different feelings that are ex- 

 pressed by these contrasted sounds. And we know too 

 that dogs can understand what many of their master's 

 words signify, as when a shepherd gives directions to 

 his collie. We could even go further down in the scale 

 and find in the shrill chirping of the katydid at the 

 mating season a still more elementary combination of 

 significant instinctive sound elements. To the com- 

 parative student the speech of man differs from these 

 lower modes of communication only in its greater com- 

 plexity, and in its employment of more numerous and 

 varied sounds, in a word, only in the higher degree 

 of its evolution. And it is even more evident that the 

 diverse forms of speech employed by various races 

 have gradually grown to be what they now are. 



At the outset it is well to distinguish between writ- 

 ing, as the conventional mode of symbolizing words, 

 and spoken language itself; the two have been more 

 independent in their evolution than we may be wont 

 to believe. Speech came first in historical develop- 

 ment, just as a child now learns to talk before it can 

 understand and use printed or written letters. Further- 

 more, many races still exist who have a well-developed 

 form of language without any concrete way of record- 

 ing it. It is true, of course, that back of the conven- 



