HARDWICKE'S SCIENCE-GOSSIP. 



265 



THE PRODUCTION OF SOUND BY CRICKETS. 



By henry J. BACON. 



OME TIME since 

 there was an in- 

 quiry as to the 

 means by which 

 the cricket pro- 

 duces the sound 

 which is so fa- 

 miliar to us. The 

 answers given by 

 correspondents 

 did not appear to 

 me to be satis- 

 factory. One 

 answer was simply 

 a quotation from 

 an author, one of 

 those I shall men- 

 tion presently. 

 The query awaken- 

 ed in myself a de- 

 sire for the same 

 information as to the instrument which causes the sharp 

 stridulous sound — to many affording a kind of pleasure 

 as associated with thoughts of domesticity, whilst, to 

 others, the incessant repetition of the same shrill 

 sound gives great annoyance. In course of time, an 

 opportunity of investigating the matter occurred. A 

 chirruping, gradually increasing in loudness as days 

 passed on, drew my attention to the fact that a 

 colony of crickets had evidently migrated over my 

 garden wall, and was advancing to take possession of 

 comfortable quarters for the winter. First, I traced 

 them to a dust bin, and from time to time caught 

 glimpses of them at night by means of a lantern. 

 Having captured four, they were placed in a small 

 box, where, in the course of a few hours, if memory 

 fails not, I found one male half eaten, and another 

 male partly dismembered, two females remaining 

 alive and intact, to whom suspicion pointed as the 

 more ferocious and powerful, unless there had been a 

 fight between the others in the presence of and for 

 the possession of the fair spectators. In the mean- 

 time, I had tracked a chirruping male into a cranny 

 No. 216,— December 1882. 



near a fire-grate, where, for the space of about a 

 quarter of an hour, I could steadfastly watch him by 

 the aid of a light. The first thing that struck me 

 was that the legs remained perfectly still the whole 

 time he was repeating the sound. Satisfying myself 

 that the legs did not conduce to the production of 

 sound by any motion of theirs, I directed next my 

 attention more particularly to the elytra, which I saw 

 to be in a constant state of vibration, strongly remind- 

 ing me of the appearance presented by the wings of 

 some moths when a light is thrown upon them whilst 

 they are at sugar, with this important difference, that 

 in the case of the moth the vibration of the wings is 

 in a vertical plane, whilst, on the other hand, the 

 elytra, or wing cases of the cricket, were rapidly 

 vibrating in a horizontal plane, opening and shutting 

 to and fro so incessantly as to confuse the eyes — 

 similar to the haziness produced by the vibrations of 

 the prongs of a tuning-fork when struck. Having 

 observed this obliging creature until I thought no 

 more information could be obtained by watching him, 

 I next proceeded to make a post-mortem of one of 

 the others. The elytra are about thirteen millimetres 

 in length, 7 millimetres across the widest part, con- 

 vex-concave, somewhat resembling a scoop, the outer 

 edge being turned down at right angles about one -third 

 from the outer margin, forming a keel. Across the 

 upper third of the elytra runs the file, a horny ridge 

 resembling a fine hair. This commences near the 

 outer margin, reaches to the middle, slightly slanting 

 upwards, then curves at almost right angles towards 

 the point of attachment of the elytra. 



From the margin to the commencement of the 

 bend, it is comparatively uniform in density, thickness, 

 and colour. Although the elytra are concave on 

 their under-surface, yet the ridge is elevated both by 

 its thickness and also by a corresponding depression 

 in the upper surface. The teeth are about 230 in 

 number, larger, and thus fewer in a given space, in 

 the middle portion of the ridge. They are inclined 

 forward, resembling tiles superimposed, presenting 

 their edges towards the inner margin of the elytron j 

 thus the most friction occurs when the motion of the 



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