ARTICULATION, 137 



strikingly similar in kind. For example, one of the parrots 

 which I kept under observation in my own house learnt to 

 imitate the barking of a terrier, which also lived in the house. 

 After a time this barking was used by the parrot as a 

 denotative sound, or proper name, for the terrier — i.e. when- 

 ever the bird saw the dog it used to bark, whether or not the 

 dog did so. Next, the parrot ceased to apply this denotative 

 name to that particular dog, but invariably did so to any 

 other, or unfamiliar, dog which visited the house. Now, the 

 fact that the parrot ceased to bark when it saw my terrier 

 after it had begun to bark when it saw other dogs, clearly 

 showed that it distinguished between individual dogs, while 

 receptually perceiving their class resemblance. In other 

 words, the parrot's name for an individual dog became 

 extended into a generic name for all dogs. Observations of 

 this kind might no doubt have been largely multiplied, if 

 observers had thought it worth while to record such apparently 

 trivial facts. 



In this general survey of articulate language, then, we 

 have reached these conclusions, all of which I take to be 

 established by the evidence of direct and adequate observa- 

 tion. 



There are four divisions of the faculty of articulate sign- 

 making to be distinguished : — namely, meaningless imitation, 

 instinctive articulation, understanding words irrespective of 

 tones, and intentional use of words as signs. Cases falling 

 under the first division do not require consideration. Cases 

 belonging to the second, being due to hereditary influence, 

 occur only in infants, uneducated deaf-mutes and idiots. 

 Understanding of words is shown by animals and idiots as 

 well as by infants, and implies, /^r se^ a higher development 

 of the sign-making faculty than does the understanding of 

 tones, or gestures — unless, of course, the latter happen to be 

 of as purely conventional a character as words. And, lastly, 

 concerning the intentional use of words as signs, we have 

 noticed the following facts. 



