further from the mind of an orang than the idea of a new vocal
utterance as a means to an end.

Our Polly was the most affectionate and demonstrative chimpanzee
that I have ever seen, and her reaction to my voice was the best
that I have found in our many apes. She knew me well, and when I
greeted her in her own language, usually she answered me promptly
and vociferously. Often when she had been busy with her physical-
culture exercises and Delsartean movements on the horizontal bars
or the trapeze in the centre of her big cage, I tested her by
quietly joining the crowd of visitors in the centre of the room
before her cage, and saying to her: "Polly! Wah! Wah! Wah!"

Nearly every time she would stop short, give instant attention and
joyously respond "Wah! Wah! Wah!", repeating the cry a dozen times
while she clambered down to the lower front bars to reach me with
her hands. When particularly excited she would cry "_Who_-oo!
_Who_-oo! _Who_-oo!" with great clearness and vehemence,
the two syllables pitched four notes apart. This cry was uttered
as a joyous greeting, and also at feeding-time, in expectation of
food; but, simple as the task seems to be, I really do not know
how to translate its meaning into English. In one case it appears
to mean "How do you do?" and in the other it seems to stand for
"Hurry up!"

Polly screamed when angry or grieved, just like a naughty child;
and her face assumed the extreme of screaming-child expression.
She whined plaintively when coaxing, or when only slightly
grieved. With these four manifestations her vocal powers seemed to
stop short. Many times I opened her mouth widely with my fingers,