230 THE PLAY OP ANIMALS. 



special case of natural selection, is challenged by no 

 one. The selective principle involved in the second is 

 not the mechanical law of survival of the fittest, but 

 rather the will of a living, feeling being capable of mak- 

 ing a choice, and is much like that employed in arti- 

 ficial breeding. Spencer has spoken of natural selec- 

 tion as a " survival of the fittest," and a fitting designa- 

 tion of this theory of sexual selection would be " a mul- 

 tiplication of the most pleasing." 



Let us take an example. The male cicada has 

 on one wing a vein set with fine teeth, on which he 

 fiddles with the other wing. Only males can produce 

 this music. " The ancient Greeks knew this, for Anac- 

 reon congratulated the cicadas, in a poem that has come 

 down to us, because they had dumb wives/' " Here is 

 the key to the riddle. The origin of the musical appa- 

 ratus is easily explained by means of the male's rivalry. 

 If we assume that the females enjoy the music — and it 

 has been proved that they do — then we see why and 

 how a singing instrument was gradually developed 

 from the male's wings and has been improved to its 

 present perfection, for the female would always pre- 

 fer the male that sang best. Thus the superior musical 

 apparatus of the father would be inherited by his sons, 

 and so on. In this way there must necessarily be much 

 progress in the development of this function in the 

 course of several generations, the preference of better 

 singers constantly tending to improve the singing ap- 

 paratus until it can be improved no further." * In the 

 same way the musical performances of birds, the arts 

 of flying and dancing, the strange and beautiful colours 



* A. Weismann, Gedanken iiber Musik bei Thieren und beim 

 Menschen, Deutsche Rundschau, lxi (1889), p. 51. 



