November, 18771 121 



OS AX OEGAN OF HEARING IN INSECTS, WITH SPECIAL REFEEENCE 

 TO THE LEFIDOPTERA. 



BT A. H. SWINTON. 



That an organ of hearing exists in Insecta may be inferred, when 

 it is noticed that those capable of prodncing instrumental music, 

 perform in turn, or en reco7inaissance. A little observation enables us 

 to detect this feature in the music of the Cicadidce, Acridiidce, and 

 Lociistina : and it exists, doubtless, in that of the Gryllidce or 

 Blaftina (?). "VYe may likewise observe it in the stridor of some 

 Longicornia {Dorcadioii) in the open; and some Lamellicornia (Geo- 

 tnipcs) when boxed together. That the required organ should present 

 structural variety, I think we may conclude from the diverse pitch, 

 quality, and rhythm, of the notes ; or from their range of expression, 

 in Orthoptfra and CicadidcB. We also find reason to look for an 

 auditory organ in certain Diptera {Si/ty hides) and Hymenoptera (Acule- 

 ata), the whining spii'acular music of which presents kindred phenom- 

 ena ; or in certain Lepidoptera and Hymenoptera {Mutilhi) with a 

 capacity for music. Deductions may be also drawn fi*om a species 

 of wing-beating employed by some Bomhycina in pairing. 



Many seeking inference from the Vertehrata are predisposed to 

 locate the organs of sense as of constant position in the cephalic 

 ring, and thus to the antennae has generally been attributed the 

 faculty of hearing. On the other hand, in many cases, the function 

 of the antennae and palpi of creeping insects is pre-eminently that of 

 touch, especially when they are in locomotion ; and in those which 

 are likewise aerial, it has been inferred that the antennae direct the 

 course of the insect. I conceive it is a fact that it is so, in those 

 which fly rapidly among obstructions, in which we notice these parts 

 are lengthened, pectinated, or lamellated. Be this as it may, it is 

 certain that any supposed organ of hearing situated in the head or its 

 appendages, has hitherto proved to be somewhat minute. On the 

 other hand, it has become an axiom in entomological bibliography, 

 that the organs of sense in Insecta have neither stable external po- 

 sition nor internal connection ; save that some communicate with the 

 anterior ganglions of the nervous chords, the nerve ganglia individually 

 a-ssumnig the spontaneity of action that in Vertehrata Hows from 

 the brain alone. Thus a hover-fly {Helophilus pendulus), which I 

 decapitated over night, and placed on the window-sill the ensuing 

 morning, occupied itself in cleaning its legs and wings, although 

 incapable of locomotion. It would therefore not be surprising 



