should be ranked as distinct species or varieties; for, as we shall see
in the following chapters, the different races of man express their
emotions and sensations with remarkable uniformity throughout the
world. Some of the expressive actions of monkeys are interesting in
another way, namely from being closely analogous to those of man. As I
have had no opportunity of observing any one species of the group under
all circumstances, my miscellaneous remarks will be best arranged under
different states of the mind.
_Pleasure, joy, affection_ It is not possible to distinguish in
monkeys, at least without more experience than I have had, the
expression of pleasure or joy from that of affection. Young chimpanzees
make a kind of barking noise, when pleased by the return of any one to
whom they are attached. When this noise, which the keepers call a
laugh, is uttered, the lips are protruded; but so they are under
various other emotions. Nevertheless I could perceive that when they
were pleased the form of the lips differed a little from that assumed
when they were angered. If a young chimpanzee be tickled and the
armpits are particularly sensitive to tickling, as in the case of our
children, a more decided chuckling or laughing sound is uttered; though
the laughter is sometimes noiseless. The corners of the mouth are then
drawn backwards; and this sometimes causes the lower eyelids to be
slightly wrinkled. But this wrinkling, which is so characteristic of
our own laughter, is more plainly seen in some other monkeys. The teeth
in the upper jaw in the chimpanzee are not exposed when they utter
their laughing noise, in which respect they differ from us. But their
eyes sparkle and grow brighter, as Mr. W. L. Martin,[510] who has
particularly attended to their expression, states.
Young Orangs, when tickled, likewise grin and make a chuckling sound;
and Mr. Martin says that their eyes grow brighter. As soon as their
laughter ceases, an expression may be detected passing over their
faces, which, as Mr. Wallace remarked to me, may be called a smile. I
have also noticed something of the same kind with the chimpanzee. Dr.
Duchenne and I cannot quote a better authority informs me that he kept
a very tame monkey in his house for a year; and when he gave it during
meal-times some choice delicacy, he observed that the corners of its
mouth were slightly raised; thus an expression of satisfaction,
partaking of the nature of an incipient smile, and resembling that
often seen on the face of main, could be plainly perceived in this
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