Figs. 18 and 19 show a simple whorl, situated at the very edge of the mane, a very “critical” area because this looser and heavy part of the neck is very much subject to jolting during the horse’s action.
I have little to add to the graphic evidence afforded by these pictures, each of which I observed noted and sketched as the bearers of them came before me during many years of a “Captain-Cuttle-like” disposal of some of my leisure. No clearer proof can be desired of the view here advanced, that habit or habitual muscular action, and jolting, is the cause of the varied patterns in this field, and that according to the Law of Parcimony no other is required, this canon of Occam being expressed more succinctly—Neither more, nor more onerous causes are to be assumed than are necessary to account for the phenomena.
CHAPTER VIII.
CAN MUSCULAR ACTION CHANGE THE DIRECTION OF HAIR IN THE INDIVIDUAL?
It might seem unnecessary to most persons who are good enough to follow this inquiry that the question asked above should receive an explicit answer. We all know, of course, how a man’s hair is said to stand on end in excessive states of horror or rage, and how a short-haired terrier’s back bristles at the sight of certain foes. But it is not so simple a matter to show that the direction of the hair is permanently changed. I submit that the persons I mention are right in their opinion for this work contains evidence throughout that muscular action beneath the skin is the efficient cause in many regions of the formation of hair patterns. But like Kirkpatrick when Bruce struck down the Red Comyn we had best “make sicker,” and give as much evidence of the affirmative question as any critic can demand.
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.