434 THE MAGAZINE OF HORTICULTURE. 



It may be further remarked that they hasten then* time 

 just in proportion as they raise their key, and that they like- 

 wise 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 unison 

 with the August pipers, varying their tone in the same man- 

 ner with the variations of temperature. But the diurnal 

 insects do not keep time so well as those which are the 

 particular subject of my observations. 



When the mercury stands at about 70°, a few insects may 

 be heard singing out of tune. Their time is also more imper- 

 fect, and is equal to about two notes to a second. When the 

 weather is as cold as 60° — the average temperature of the 

 evenings in August and September — the greater number will 

 be heard on the key of BJiat. Their time, however, in this 

 state of the weather, is very imperfect, and a great many will 

 be heard singing out of tune, some a tone or a semi-tone 

 higher, and others as much lower than B flat. I attribute 

 this difference to the different degrees of warmth which they 

 may find, according as they are more or less protected from 

 the external air. If one, for example, be confined in a room 

 in the house, when the outer air is cool, the one confined will 

 chirp several notes higher than any that are singing out of 

 doors. When the temperature is very warm, there is proba- 

 bly more uniformity of heat in all places and situations, than 

 when it is cooler. Often, on a sudden change of temperature 

 from warm to cool, some individuals that happen to be in a 

 little snug retreat that still preserves the early heat of the 

 day, will sing more briskly and on a higher key than others. 

 When the weather is below 60°, all the insects sing very 

 feebly, without regard to time or tune ; those only that 

 happen to be protected under the warm projection of a roof, 

 or the trunk of a tree, chirping on a higher key than the rest, 

 and with more vivacity. 



