1892.] Mental Evolution in Man and Lower Animals. 593 
MENTAL EVOLUTION IN MAN AND THE 
LOWER ANIMALS. 
By Arce BopIxGrToN. 
(Continued from page 494.) 
Among the lower animals the eager jumping of a dog 
when he is anxious to go for a walk, his growling, howling 
and barking to express various emotions are on a similar 
psychological level with the first demonstration of wishes on 
the part of the infant. Some of the signs and sounds 
expressed by domestic animals are indeterminate and some 
determinate, and every owner of a dog or cat can supply 
examples for himself. 
The next step in advance taken by the infant is the utter- 
ance of articulate sounds; first various vowels and labials, 
vaguely uttered without definite meaning; then similar sounds 
with a definite meaning, as mamma, dada, tata, etc. These 
early sounds have a very extended meaning, as in Chinese the 
same word “ bye-bye” means bed and bed-clothes, sleep and to 
goto sleep. But as the application of these simple syllables 
is usually taught to the child we are not quite at the stand- 
point of primitive man, who had no one to teach him. There 
are three different sets of opinions as to the origin of spoken 
words which have been named the “ Pooh-pooh,” the “ Bow- 
- wow ” and the “ Yo-heave-o” theories respectively. The first 
assigns the origin of language to interjectional sounds, the 
second attributes it to imitation of cries of animals and sounds 
in nature, and the third considers speech arose from the 
various noises made by men during concerted action. A 
fourth assumes language to be a heaven-sent gift and that 
primitive language began with abstract ideas. Applying the 
inductive method of reasoning and watching the development 
of speech in infants and the condition of language in low sav- 
ages we can hope to form some idea as to how much or how 
