STRIDUfATIOX OF INSECTS. 95 



The musical instrument of the cricket may therefore not 

 inaptly be compared to a tabor {tambour de basque) divided 

 into a great number of compartments by cords fastened to the 

 skin, which is crossed by a large knotted cord : the manner 

 of playing on which we must suppose to be by passing over 

 this latter a plate of some sonorous metal. 



When the insect crosses his wings rapidly, and passes the 

 whole length of the bow over the treble-string, he makes that 

 loud and lively stridulation which we hear so frequently, and 

 this is the song with which he calls the female ; but when he 

 rubs the brush against the internal border of the elytron by a 

 slight vibratory movement, he produces that sweet and soft 

 sound by which he expresses his satisfaction. 



By raising the elytra and rubbing them against each other 

 by means of a pin, the sound may be artificially produced on 

 a living insect, or even on a dead one, provided its joints 

 retain their pliability. We can also cause the bow to sound 

 by passing a pin along its striae. The sounds obtained by 

 these means are not so loud as those which are made by the 

 cricket when alive and at liberty, but are quite sufficient to 

 enable one to recognise the stridulation. 



The elytra of the female do not present the same peculiarities 

 in structure as those of the male : they are not so complicated, 

 in fact are simply reticulated ; consequently they are not 

 susceptible of the production of sounds. 



On attentively examining the fore legs of the cricket, male 

 or female, we perceive on their external surface below the 

 knee a long white shining plate, that covers a little cavity which 

 is lined with a thin skin of a dull white colour. The functions 

 of this organ, which may be designated by the name of mirror 

 (miroir), are unknown to me. 



In the larva and pupa state this organ is wanting; yet there 

 is a sensible depression, which may be considered its rudiment, 

 at the spot where it is found in the perfect insect. I therefore 

 conclude that the functions for which it is required are only 

 performed in the adult state. 



I am also unacquainted with the uses of the hollow velvety 

 appendages which terminate the abdomen in both sexes. 



The house-cricket exactly resembles the field-cricket. The 

 musical instrument of both is the same, and their songs are 

 also similar. 



