STlilDULATiON OF INSECTS. 91 



is comprehended in one of the preceding hypotheses. The 

 same entomologist attaches great importance to the rapid 

 emission of air by the stigmata of the metathorax ; for he 

 attributes ahuost all the sounds produced by insects, and buz- 

 zing in particular, to this cause. But experiments which are 

 not difficult to I'epeat,*^ will convince every one that insects 

 buzz when these stigmata are hermetically closed, and that 

 locusts produce stridulation without the assistance of the sub- 

 alary cavities. 



I shall not enter into a detailed examination of any of these 

 opinions, most of which have been entertained during 

 times when imagination was consulted more frequently than 

 observation, in accounting for natural phenomena. In our 

 description of the musical instruments of insects they will be 

 sufficiently refuted. 



The celebrated Latreille has indicated the cause of the noise 

 produced by the Orthoptera, in these words:'' — " Sometimes 

 they produce it by rubbing briskly the internal and more 

 membranous portion of the wing-cases, which somewhat re- 

 sembles a piece of talc or a mirror, against each other ; and 

 sometimes by a similar and alternate action of the posterior 

 thighs on the elytra and wings, the thighs having the same 

 effect as the bow of a violin." 



These expressions contain the true cause of the song of the 

 Orthoptera. The object of the present memoir is to develop 

 them, to apply them to each kind, to describe the musical in- 

 struments of the various species, and to clear up the uncer- 

 tainties which at present exist on this subject. 



Crickets (Gryllus, Latr.) 



The field-cricket, (Grylliis campestris,) is very common in 

 the province of Gex, where the warm and sandy soil is very 

 favourable to its increase. The larva is produced from an egg 

 of a dirty whitish colour, at the end of July, being about 

 three millimetres iu length, and two in diameter. The females 

 are not very fruitful. One that I kept in a box during its life, 



"^ Vide the Revue Entomologique, Vol. III. p. 101. 



•^ Cuvier, Regiie Animal, Vol. V. p. 180. In this and the following quota- 

 tions, the second edition is referred to. 



