80 INSECT MISCELLANIES. 



membrane. The opening left by the lid is in fonii 

 of a half-moon, and at the bottom of the cavity is a 

 white membrane, shining- like a mirror, and tensely 

 stretched. On the side of the opening, towards the 

 head, there is a small oval hole, into which the point 

 of a pin may easily pass ; and when the membrane 

 is removed a large cavity is brought into view. The 

 whole of this apparatus seems to contribute much 

 both to produce and to increase the sound caused by 

 the insects*." 



We have examined the hole mentioned by De 

 Geer in a number of individuals, and have been 

 struck with its resemblance to the hole in a military 

 drum, as well as in violins and guitars. We found, 

 indeed, upon stopping up this hole with a bit of wafer,, 

 that the insect could no longer produce its peculiar 

 sound, but only a sort of muffled scraping f. Swam- 

 merdam was acquainted with this instrument, though 

 he does not mention the hole. " The grasshopper,'* 

 he says, " has two peculiar small drums, like the 

 drum of our ear, which being struck by the help of 

 two lunulated cartilages, vibrate the air in such a 

 manner as to produce the sound |." 



The crickets (Achetidce, Leach), another family 

 of this order of insects, are well known for their 

 chirping-song, which, associated as it is either with 

 the snug chimney-corner or the sunshine of summer, 

 atlbrds a pleasure which certainly does not arise from 

 the intrinsic quality of its music. " Sounds," it is 

 well observed by White, " do not always give us 

 pleasure according to their sweetness and melody ; 

 nor do harsh sounds always displease. Thus the 

 shrilling of the field-cricket {Acheta campestris, 

 Fabr.), though sharp and stridulous, yet marvellously 

 delights some hearers, filling their minds with a train 



* De Geer, Memoires, iii. 471. 

 f J. R. X Biblia Naturae, ii. 217, 



