6oo The Descent of Man. Part 131. 



respects. These characters will therefore probably have been 

 acted on through sexual selection; but we have no means ol 

 judging whether they have been acted on chiefly from the male 

 or female side. The musical faculties of man have likewise been 

 already discussed. 



Absence of Hair on the Body, and its Development on the Face 

 and Head, — From the presence of the woolly hair or lanugo on 

 the human foetus, and of rudimentary hairs scattered over the 

 body during maturity, we may infer that man is descended from 

 some animal which was born hairy and remained so during life. 

 The loss of hair is an inconvenience and probably an injury to man, 

 even in a hot climate, for he is thus exposed to the scorching 

 of the sun, and to sudden chills, especially during wet weather. 

 As Mr. Wallace remarks, the natives in all countries are glad to 

 protect their naked backs and shoulders with some slight covering. 

 No one supposes that the nakedness of the skin is any direct 

 advantage to man ; his body therefore cannot have been divested 

 of hair through natural selection. 21 Nor, as shewn in a former 

 chapter, have we any evidence that this can be due to the 

 direct action of climate, or that it is the result of correlated 

 development. 



The absence of hair on the body is to a certain extent a 

 secondary sexual character ; for in all parts of the world women 

 are less hairy than men. Therefore we may reasonably suspect 

 that this character has been gained through sexual selection. 

 We know that the faces of several species of monkeys, and large 

 surfaces at the posterior end of the body of other species, have 

 been denuded of hair ; and this we may safely attribute to sexual 

 selection, for these surfaces are not only vividly coloured, but some 

 times, as with the male mandrill and female rhesus, much more 

 vividly in the one sex than in the other, especially during the 

 breeding-season. I am informed by Mr. Bartlett that, as these 

 animals gradually reach maturity, the naked surfaces grow 

 larger compared with the size of their bodies. The hair, how- 

 ever, appears to have been removed, not for the sake of nudity, 

 but that the colour of the skin may be more fully displayed. 80 



21 'Contributions to the Theory view ('Transactions of Devonshire 



of Natural Selection,' 1870, p. 346. Assoc, for Science,' 1870) remarks, 



Mr. Wallace believes (]>. 350) " that that had Mr. Wallace "employed 



''some intelligent power has guided " his usual ingenuitv on the ques- 



" or determined the development of " tion of man's hairless skin, he 



'i man ; " and he considers the hair- " might have seen the possibility of 



>.ess condition of the skin as coming " its selection through its superior 



under this head. The Rev. T. R. " beauty or the health attaching tc 



^tebbing, in commenting on this " superior cleanliness." 



