But you may imagine I had a dismal time all that hour.  I understood the people about me were Sceptics, the kind of people who don’t believe things—­a singular class, and, I am told, a growing one.  These excellent people, it seems, have conscientious objections to going to chapel or church, but at the same time the devotional habit of countless generations of pious forerunners is strong in them.  Consequently they have invented things like these lectures to go to, with a professor instead of a priest, and a lantern slide of a stomach by way of altar-piece; and alcohol they make their Devil, and their god is Hygiene—­a curious and instructive case of mental inertia.  I understand, too, there are several other temples of this Cult in London—­South Place Chapel and Essex Hall, for instance, where they worship the Spirit of the Innermost.  But the thing that struck me so oddly was the number of bald heads glimmering faintly in the reflected light from the lantern circle.  And that set me thinking upon a difficulty I have never been able to surmount.

You see these people, and lots of other people, too, believe in a thing they call Natural Selection.  They think, as part of that belief, that men are descended from hairy simian ancestors; assert that even a hundred thousand years ago the ancestor was hairy—­hairy, heavy, and almost as much a brute as if he lived in Mr. Arthur Morrison’s Whitechapel.  For my own part I think it a pretty theory, and would certainly accept it were it not for one objection.  The thing I cannot understand is how our ancestor lost that hair.  I see no reason why he should not have kept his hair on.  According to the theory of natural selection, materially favourable variations survive, unfavourable disappear; the only way in which the loss is to be accounted for is by explaining it as advantageous; but where is the advantage of losing your hair?  The disadvantages appear to me to be innumerable.  A thick covering of hair, like that of a Capuchin monkey, would be an invaluable protection against sudden changes of temperature, far better than any clothing can be.  Had I that, for instance, I should be rid of the perpetual cold in the head that so disfigures my life; and the multitudes who die annually of chills, bronchitis, and consumption, and most of those who suffer from rheumatic pains, neuralgia, and so forth, would not so die and suffer.  And in the past, when clothing was less perfect and firing a casual commodity, the disadvantages of losing hair were all the greater.  In very hot countries hair is perhaps even more important in saving the possessor from the excessive glare of the sun.  Before the invention of the hat, thick hair on the head at least was absolutely essential to save the owner of the skull from sunstroke.  That, perhaps, explains why the hair has been retained there, and why it is going now that we have hats, but it certainly does not explain why it has gone from the rest of the body.