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] As the upper lip is much drawn up during the act of screaming, in the manner just explained, the depressor muscles of the angles of the mouth (see K in woodcuts 1 and 2) are strongly contracted in order to keep the mouth widely open, so that a full volume of sound may be poured forth. The action of these opposed muscles, above and below, tends to give to the mouth an oblong, almost squarish outline, as may be seen in the accompanying photographs. An excellent observer,[605] in describing a baby crying whilst being fed, says, “it made its mouth like a square, and let the porridge run out at all four corners.” I believe, but we shall return to this point in a future chapter, that the depressor muscles of the angles of the mouth are less under the separate control of the will than the adjoining muscles; so that if a young child is only doubtfully inclined to cry, this muscle is generally the first to contract, and is the last to cease contracting. When older children commence crying, the muscles which run to the upper lip are often the first to contract; and this may perhaps be due to older children not having so strong a tendency to scream loudly, and consequently to keep their mouths widely open; so that the above-named depressor muscles are not brought into such strong action.