INSECTS. 



179 



Fig. 163. — Mole-crickets {Gryllotalpa). 



obtains entrance to the bed-chamber, and, hidden in some corner, sinus his 

 love-song, sleep is impossible. Then one realizes the rasping shrillness 

 and the penetrating 



powers of this note. ~-^~<Al iX " '^VNgsfc^ 



How do they sing ? 

 They don't sing; they 

 fiddle. Mr. Scudder 

 has written an inter- 

 esting sketch of this 

 insect fiddling, and 

 has even set some of 

 the notes to music. 

 To his pages most of 

 the following state- 

 ments are due. 



The noise is all made by the male, and is produced by rubbing the 

 wings against each other or against the legs. At one part there is a file- 

 like ridge which corresponds to the fiddle-bow, and this is rasped against 

 another, and this produces rapid vibrations in a broad and tense membra- 

 nous portion of the wing. Each species has its own note, and the experi- 

 enced student can at once recognize the form by the character of the song. 

 The crickets sing the same tune by day as by night, but others have sepa- 

 rate notes for the light and the dark. " On a summer's day it is curious 

 to observe these little creatures changing from the day to the night song 

 at the mere passing of a cloud, and returning to the old note when the sky 

 is clear." 



The existence of musical organs would indicate that the insects had 

 the means of hearing, and 

 so they have. Where thev 

 are in some forms is un- 

 certain, but with regard 

 to others not much doubt 

 exists. Previous concep- 

 tions would lead us to 

 look for the ears in the 

 head, but this would be a 

 mistake. In one group — 

 the locusts — the ears are 

 found one on either side of the base of the abdomen. They are large 

 spots covered with a thin membrane, which corresponds in its functions 

 to the tympanic membrane in the human ear, while inside are the per- 



Fig. 164. — Blind cricket of Mammoth Cave (Hadenucus caver- 



narum). 



