80 INSECT MISCELLANIES. 



membrane. The opening left by the hd is in form 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 re- 

 moved 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 in- 

 sects.'^ 



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 mutBed scraping.! 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 lu- 

 nulated cartilages, vibrate the air in such a manner as 

 to produce the sound. 'J 



The crickets {AchetidcB, 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, 

 affords 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 

 shriUing of the field-cricket {Jlcheta campestris, 

 Fabr.), though sharp and stridulous, yet marvellously 

 delights some hearers, filling their minds with a train 



* De Geer Memoires, iii, 471. 

 t J. R. t Biblia Naturse, ii, 217. 



