134 THE MEANING OF EVOLUTION 



succeeded in making a dead grasshopper fiddle, but I 

 have long known how to make a dead katydid say 

 "ka." Quite recently I have added to my accomplish- 

 ment in this respect and can make it say "katy." The 

 "did" part of the song still lies beyond my power. 

 The crickets produce their sharp notes in much the 

 same fashion as the katydids. 



One observer of the chirping of the cricket says 

 that the pitch of the song varies with the tempera- 

 ture. He has even worked out a formula by which 

 one can tell the pitch of the chirp, if he knows the 

 temperature, or, knowing the temperature, can de- 

 termine the pitch. Of course this is too mechanical; 

 yet it indicates that there must be considerable rela- 

 tion between the two ; the warmer the cricket the hap- 

 pier he is. 



It is the males among insects that chirp their love 

 songs. The females never answer them. There is a 

 peculiar notion that the female katydid, when thus ac- 

 cused of some offense, replies "katy didn't." The 

 truth of the matter is that no female katydid ever re- 

 plied to the accusations of her lover, if accusation it 

 be. She is absolutely dumb, not having the drum 

 upon her wings with which to reply. She is provided 

 with ears wherewith to hear, and, strange to say, she 

 keeps them on her elbow, as does also the cricket, 



