ese inflections at all, although the phonation of a species is
generally uniform in other respects. In some cases it seems to me that
the inflections differ slightly in the same species, but long and
constant association seems to unify these dialects in some degree, very
much the same as like causes blend and unify the dialects of human
speech. I have found one instance in which a Capuchin had acquired two
sounds which strictly belonged to the tongue of the white-faced Cebus. I
was surprised when I heard him utter the sounds, and thought at first
that they were common to the speech of both varieties; but on inquiry I
found that he had been confined in a cage with the white-face for nearly
four years, and hence my belief that he acquired them during that time.

The most remarkable case which has come under my observation is one in
which a young white-face has acquired the sound which means food in the
Capuchin tongue. This event occurred under my own eyes. I regard this
matter as so noteworthy and attended by such conditions as to show that
the monkey had a motive in learning the sound, that I shall relate the
case in detail.

[Sidenote: THE WHITE-FACED CEBUS]

In the room where the monkeys were kept by a dealer in Washington, there
was a cage which contained a young white-faced Cebus of rather more than
average intelligence. He was a quiet, sedate, and thoughtful little
monk, whose grey hair and beard gave him quite a venerable aspect, and
for this reason I called him Darwin. From some cause unknown to me he
was afraid of me, and I showed him but little attention. On the same
shelf and in an adjacent cage lived the little Capuchin, Puck. The cages
were only separated by an open wire partition, through which they could
easily see and hear each other. For some weeks I visited Puck almost
daily, and in response to his sound for food I always supplied him with
some nuts, banana, or other food. I never gave him any of these things
to eat unless he would ask me for them in his own speech. On one of my
visits my attention was attracted by little Darwin, who was uttering a
strange sound which I had never before heard one of his species utter. I
did not recognise the sound at first, but very soon discovered that it
was intended to imitate the sound of the Capuchin, in response to which
I always gave Puck some nice morsel of food. Darwin had undoubtedly
observed that this sound made by Puck was always rewarded with something
go