Hairs of Human Eyebrows.

As in the previous chapter I chose an open and plain field for the evidence bearing on the formation of whorls and the like, so here I turn to one still more clear for him who runs to read. In these days old men are of less account than in earlier and simpler times, but I claim to have found “a new use for old men” as I had almost thought of calling this chapter. In this somewhat neglected group we have an almost unlimited number of specimens for examina­tion, and in their eyebrows they furnish a valuable field for tracing some striking results of underlying muscular traction.

Darwin made one of his few mistakes when he included among rudimentary and inherited structures[48] those few long hairs which are often seen in the eyebrows of man, looking upon them as representatives of those found in some species of macacus and the chimpanzee. That great and modest man was, I am sure, not in the habit of making much use of the looking-glass—not more than women who, as we know, rarely do such a thing. But if he did he would have observed in his own splendid frontal region and brows excellent examples of the phenomena which form the subject of this chapter. This I know, though I never saw him in the flesh, for it so happens that in the great volume published in the jubilee of The Origin, and called Darwin and Modern Science, two good photographs of him, at the ages of thirty-five and about seventy-one are reproduced. These both show, but the later one much more clearly, good examples of these long and not very ornamental aberrant hairs. Thirty-five years of arduous thought and work had told their tale on him and twisted from their normal paths the lengthening thickening hairs of his eyebrows.

Also, if he had looked a little beyond the eyebrows he would have seen some very deep wrinkles of the skin on his forehead and round his orbits. It is these two groups of facts, wrinkles and twisted, changed hairs of man’s eyebrows, which give the answer to the question “Can muscular action change the direction of hair in the individual?”

In 1903 I drew the attention of the Anatomical Society of Great Britain and Ireland to these two groups of facts under the title “Notes on the Eyebrows of Man,” and presented some large drawings of individual elderly men of my acquaintance, and the present chapter is only an extension of that little piece of work.

No area of the mammalian skin is so useful and easy to follow as this in answering the present question, for though the previous chapter supplied part of the answer in a very fruitful field, the proof still remained one of “tremendous probability” and not more. But in the frontal and superciliary region of man there is complete proof of the truth of the affirmative answer, as I shall show.

Here again we must encounter our old friend the normal slope of hair. As I stated in 1903, “The normal arrangement of the hair on the eyebrows of a moderately hairy subject is as follows: in the middle line the hairs of the two sides tend to meet and form a somewhat confused group of hairs; passing away from the middle line the hairs assume a nearly sagittal direction, then become more sloped away, and a sharp change in the direction of the frontal and orbital streams brings the remaining hairs into that regular accurate arrangement of a united stream so characteristic of a hairy subject, and this passes along the superciliary ridge to the external angular process”—all of which can be seen at a glance by any one who looks closely enough, as with the eyes of a lover, for example, at the brows of a dark-haired maid or youth. In the young these hairs lie close to the skin, and with that very interesting group of persons we have no more to do here, except for one piece of practical advice to them which they will find at the end of the present chapter.