MAN'S PLACE IN NATURE 373 



appearance of their brains. There are many accounts 

 of incidents which seem to indicate that reasoning power 

 is possessed by animals ; however, we are quite safe in 

 saying that man is the only animal that has reasoning 

 power, the power of forming abstract conclusions, and 

 the power of articulate speech. The delicate coordination 

 in man's brain is also reflected in the various refinements 

 in muscular action of which he is capable. 



Language. We can learn a great deal about the dif- 

 ferent races of mankind by a careful study of their lan- 

 guages. Primitive peoples used various means for com- 

 municating with one another, such as making gestures, 



FIG. 330. Picture Writing. 



uttering cries, speaking words, drawing pictures, and 

 writing with characters or letters (Figure 330). The 

 language was little enriched from outside influences ex- 

 cept in times of tribal wars, when the captives would 

 contribute in some degree to the civilization of their 

 captors. 



Crude methods of communication among friendly 

 tribes served to distribute bits of knowledge of general 

 usefulness but imperfectly. Centuries sometimes added 

 but little to the total sum of human attainments. The 

 slowly moving story of discovery and invention is neces- 

 sarily intricately interwoven with the story of the de- 

 velopment of language. Modern methods of rapid com- 

 munication and travel will serve to bring the peoples 



