two or three species of Alacacus and the _Cynopithecus niger_ draw back
their ears and utter a slight jabbering noise, when they are pleased by
being caressed. With the Cynopithecus (fig. 17), the corners of the
mouth are at the same time drawn backwards and upwards, so that the
teeth are exposed. Hence this expression would never be recognized by a
stranger as one of pleasure. The crest of long hairs on the forehead is
depressed, and apparently the whole skin of the head drawn backwards.
The eyebrows are thus raised a little, and the eyes assume a staring
appearance. The lower eyelids also become slightly wrinkled; but this
wrinkling is not conspicuous, owing to the permanent transverse furrows
on the face.
_Painful emotions and sensations_. With monkeys the expression of
slight pain, or of any painful emotion, such as grief, vexation,
jealousy, &c., is not easily distinguished from that of moderate anger;
and these states of mind readily and quickly pass into each other.
Grief, however, with some species is certainly exhibited by weeping. A
woman, who sold a monkey to the Zoological Society, believed to have
come from Borneo (_Macacus maurus_ or _M. inornatus_ of Gray), said
that it often cried; and Mr. Bartlett, as well as the keeper Mr.
Sutton, have repeatedly seen it, when grieved, or even when much
pitied, weeping so copiously that the tears rolled down its cheeks.
There is, however, something strange about this case, for two specimens
subsequently kept in the Gardens, and believed to be the same species,
have never been seen to weep, though they were carefully observed by
the keeper and myself when much distressed and loudly screaming.
Rengger states[512] that the eyes of the _Cebus azar _ fill with tears,
but not sufficiently to overflow, when it is prevented getting some
much desired object, or is much frightened. Humboldt also asserts that
the eyes of the _Callithrix sciureus_ instantly fill with tears when
it is seized with fear; but when this pretty little monkey in the
Zoological Gardens was teased, so as to cry out loudly, this did not
occur. I do not, however, wish to throw the least doubt on the accuracy
of Humboldt s statement.
The appearance of dejection in young orangs and chimpanzees, when out
of health, is as plain and almost as pathetic as in the case of our
children. This state of mind and body is shown by their listless
movements, fallen countenances, dull eyes, and changed complexion.
90