MUSIC OF INSECTS. 233 



carried through September, which was on that year as 

 hot as July. The following is a general statement of 

 the results. 



When the temperature of the weather is indicated at 

 80° Fahrenheit, these insects will be found singing in- 

 variably as high as the key of F natural. When the 

 mercury stands at 75°, they sing one tone lower or 

 thereabouts, and always change from a higher to a 

 lower key, as the air grows colder, and the contrary as 

 it grows warmer. Their notes will be found to vary 

 about one tone with every five degrees of change in the 

 weather, as marked by the thermometer. I wiU add, 

 that I have never heard them singing on a higher key than 

 F, or on a lower key than G, comprising one note less 

 than an octave in their compass. The weather is sel- 

 dom warmer than 80° in the evening, and when it is 

 colder than 60°, the insects always sing out of tune and 

 time, and some of them as low as G. A colder tem- 

 perature than this diminishes their vivacity, and silences 

 a great many of the performers ; but after they have 

 become so torpid that the vibrations of their wings 

 would produce a sound lower than G, they become 

 silent. 



It may be further remarked, that they hasten their 

 time just in proportion as they raise their key, and that 

 they likewise sing both in 'better time and better tune, 

 in proportion to the warmth of the weather. When 

 the mercury stood at 80°, I was never able to detect a 

 single insect performing out of time or tune. The 

 whole myriad choir were singing in perfect harmony ; 

 their key being about F natural, and their time about 

 three notes to a second, which is very rapid. During 

 this high temperature, the shriller toned insects, as the 

 diurnal grasshoppers and the black crickets, sing in 



20* 



