These latter fasciae by their contraction raise the inner ends alone of the eyebrows; and as the corrugators at the same time draw the eyebrows together, their inner ends become puckered into a fold or lump. This fold is a highly characteristic point in the appearance of the eyebrows when rendered oblique, as may be seen in figs. 2 and 5, Plate II. The eyebrows are at the same time somewhat roughened, owing to the hairs being made to project. Dr. J. Crichton Browne has also often noticed in melancholic patients who keep their eyebrows persistently oblique, "a peculiar acute arching of the upper eyelid." A trace of this may be observed by comparing the right and left eyelids of the young man in the photograph (fig. 2, Plate II.); for he was not able to act equally on both eyebrows. This is also shown by the unequal furrows on the two sides of his forehead. The acute arching of the eyelids
see more especially Sir C. Bell, `Anatomy of Expression,' 3rd edit. 1844, p. 151. depends, I believe, on the inner end alone of the eyebrows being raised; for when the whole eyebrow is elevated and arched, the upper eyelid follows in a slight degree the same movement.
But the most conspicuous result of the opposed contraction of the above-named muscles, is exhibited by the peculiar furrows formed on the forehead. These muscles, when thus in conjoint yet opposed action, may be called, for the sake of brevity, the grief-muscles. When a person elevates his eyebrows by the contraction of the whole frontal muscle, transverse wrinkles extend across the whole breadth of the forehead; but in the present case the middle fasciae alone are contracted; consequently, transverse furrows are formed across the middle part alone of the forehead. The skin over the exterior parts of both eyebrows is at the same time drawn downwards and smooth, by the contraction of the outer portions of the orbicular muscles. The eyebrows are likewise brought together through the simultaneous contraction of the corrugators;[3] and this latter action generates vertical furrows, separating the exterior and lowered part of the skin of the forehead from the central and raised part. The union of these vertical furrows with the central and transverse furrows (see figs. 2 and 3) produces a mark on the forehead which has been compared to a horse-shoe; but the furrows more strictly form three sides of a quadrangle. They are often conspicuous on the foreheads of adult or nearly adult persons, when their eyebrows are made oblique; but with young children, owing to their skin not easily wrinkling, they are rarely seen, or mere traces of them can be detected.
These peculiar furrows are best represented in fig. 3, Plate II., on the forehead of a young lady who has the power in an unusual degree of voluntarily acting on the requisite muscles. As she was absorbed in the attempt, whilst being photographed, her expression was not at all one of grief; I have therefore given the forehead alone. Fig. 1 on the same plate, copied from Dr. Duchenne's work 4 represents, on a reduced scale, the face, in its natural state, of a young man who was a good actor. In fig. 2 he is shown simulating grief, but the
[3] In the foregoing remarks on the manner in which the eyebrows are made oblique, I have followed what seems to be the universal opinion of all the anatomists, whose works I have consulted on the action of the above-named muscles, or with whom I have conversed. Hence throughout this work I shall take a similar view of the action of the _corrugator supercilii_, _orbicularis, pyramidalis nasi_, and _frontalis_ muscles. Dr. Duchenne, however, believes, and every conclusion at which he arrives deserves serious consideration, that it is the corrugator, called by him the _sourcilier_, which raises the inner corner of the eyebrows and is antagonistic to the upper and inner part of the orbicular muscle, as well as to the _pyramidalis nasi_ (see Mecanisme de la Phys. Humaine, 1862, folio, art. v., text and figures 19 to 29: octavo edit.