318 The Outline of Science 



Traces of the Past 



We speak of the body as a machine, but it is hardly necessary 

 to say that none of the most ingenious machines set up by modern 

 science can for a moment compare with it. The body is a self- 

 building machine; a self-stoking, self-regulating, self-repairing 

 machine the most marvellous and unique automatic mechanism 

 in the universe. It differs from our ordinary machines, moreover, 

 in this: when a part becomes superfluous or out of date, it will 

 linger for ages, even for millions of years, in the structure, slowly 

 changing and shrinking on its way to disappearance. It will be 

 useful to begin our examination of the human body from this 

 point of view, especially as some of the first things we notice about 

 it are precisely shrinking structures of this kind. 



Why have we hair on our bodies? We need not notice here 

 the specially luxuriant growth on the head, or on the man's lips 

 and chin. This has been artificially fostered or cultivated during 

 the course of man's history. Men, in mating, chose women with 

 rounded forms and smooth chins. Women chose men with strong 

 muscular forms and, in our own branch of the race at least, hairy 

 mouths and chins. We quite understand that in the course of 

 tens of thousands of years this has evolved rich growths of hair 

 in certain parts. But we have hair on our trunk and arms and 

 legs; there are tiny pits in the skin, out of which hairs grow, all 

 over the body except on the palms of our hands and the soles of 

 our feet. Before birth the human body is, in fact, almost entirely 

 covered with a fine coat of hair. 



There is not a word to be said in favour of this part of our 

 wonderful body-machine. It harbours dirt, microbes, and vermin, 

 and sometimes favours skin-disease. As a coat it is ridiculously 

 thin and ragged, and it has been superseded by clothing. Its plain 

 meaning is in the story of life in the past which was told in an 

 earlier part of this work. The hair is a dwindling vestige of the 



