160 ESSAYS OF A BIOLOGIST 



may become transformed by a psychological process 

 roughly analogous to the transformation of physical 

 energy, and reappear in altered guise in various other 

 activities of mind. 



If we look at the matter broadly, we see that man 

 is in a period of evolutionary transition as regards 

 sex. We found previously that the greatest change 

 connected with sex which has been made in the 

 evolution of higher animals was the change by which 

 there was evolved a brain and mind with associated 

 sense-organs in which accurate perception of objects 

 at a distance could occur, a mechanism which really 

 dominated the working of the organism as a whole, 

 and in which memory and emotion seemed to play an 

 important part. Once this happened, the sex-instinct 

 could be linked up with general emotional reactions 

 and connected with external objects capable of in- 

 ducing emotion. 



What was the result? That in every group 

 possessing such a type of mind, epigamic characters 

 of a beautiful or striking or bizarre nature were 

 evolved. This first linking-up of sex with mind pro- 

 duced, eventually, a large proportion of the beauty 

 of the organic world. It coloured and adorned not 

 only many a bird, but even newts and fish and spi- 

 ders; it helped elicit song and music from mere 

 sounds and noises; it moulded our own bodies, 

 coloured our lips and eyes, and everywhere helped in 

 adding grace to mere serviceableness; it saw to it 

 that, as St. Paul puts it, "even our uncomely parts 



