force as possible. The reader who is unacquainted with the anatomy of
the face, ought to refer to p. 24, and look at the woodcuts 1 to 3. The
corrugators of the brow (_corrugator supercilii_) seem to be the first
muscles to contract; and these draw the eyebrows downwards and inwards
towards the base of the nose, causing vertical furrows, that is a
frown, to appear between the eyebrows; at the same time they cause the
disappearance of the transverse wrinkles across the forehead. The
orbicular muscles contract almost simultaneously with the corrugators,
and produce wrinkles all round the eyes; they appear, however, to be
enabled to contract with greater force, as soon as the contraction of
the corrugators has given them some support. Lastly, the pyramidal
muscles of the nose contract; and these draw the eyebrows and the skin
of the forehead still lower down, producing short transverse wrinkles
across the base of the nose.[602] For the sake of brevity these muscles
will generally be spoken of as the orbiculars, or as those surrounding
the eyes.
When these muscles are strongly contracted, those running to the upper
lip[603] likewise contract and raise the upper lip. This might have
been expected from the manner in which at least one of them, the
_malaris_, is connected with the orbiculars. Any one who will gradually
contract the muscles round his eyes, will feel, as he increases the
force, that his upper lip and the wings of his nose (which are partly
acted on by one of the same muscles) are almost always a little drawn
up. If he keeps his mouth firmly shut whilst contracting the muscles
round the eyes, and then suddenly relaxes his lips, he will feel that
the pressure on his eyes immediately increases. So again when a person
on a bright, glaring day wishes to look at a distant object, but is
compelled partially to close his eyelids, the upper lip may almost
always be observed to be somewhat raised. The mouths of some very
short-sighted persons, who are forced habitually to reduce the aperture
of their eyes, wear from this same reason a grinning expression.
The raising of the upper lip draws upwards the flesh of the upper parts
of the cheeks, and produces a strongly marked fold on each cheek, the
naso-labial fold, which runs from near the wings of the nostrils to the
corners of the mouth and below them. This fold or furrow may be seen in
all the photographs, and is very characteristic of the expression of a
crying child; though a nearly similar fold is produced in the act of
laughing or smiling.[604]
98