52 



Carabi more frequently ; the Staphylini employ them in this way oc- 

 casionally. 



Among the insects which never use their antennre as organs of touch 

 are the Sphinges, Phalaense and some of the Papiliones, also the Cica- 

 das, Notonectae, Libellulae, and in the latter groups the diminutive size 

 of these organs renders such a use impossible : in other insects the 

 structure is at variance with such a supposition. The Diptera have 

 the antenna; too short for the pui'pose, and a numerous class of insects 

 have no antennae at all. 



The death-watch is cited as a sufficient proof that insects possess 

 the faculty of hearing. Its call is distinctly audible to ourselves, and 

 is distinctly answered by his mate ; each advancing nearer and nearer, 

 continues the tapping until they meet : from this and other instances 

 there is no reason to doubt that insects possess the sense of hearing. 

 To proceed with the argument : — it appears that hearing, in the higher 

 animals, is purely mechanical ; the parts employed in the exercise of 

 this faculty consist of " the ear or external portion, so constructed as 

 to receive within its cavity the vibrations of the atmosphere, which, 

 being collected within a passage, are considerably augmented and 

 thrown with greater force upon the tympanum, a tense and delicate 

 membrane extended across the bottom of the passage," from this the 

 sensation is conveyed to the brain : a long, tubular, external organ, as 

 in the hare, is possessed by animals supposed to have the auditory 

 power in great perfection. In Copris Molossus, Mr. Newport has 

 found this form of organ: the antennae are composed of ten joints ; 

 the last three are elongate, concave on the under side, and supplied 

 with nerves which extend through the antennae to the brain ; these 

 plates are extended when the insect is in motion, and on the occur- 

 rence of a loud noise are closed, and the antennae retracted. In Sca- 

 rabaeus Hercules the two exterior plates are convex outwardly and 

 concave within ; the concavity being covered by a tense membrane 

 resembling a drum : this structure Mr. Newport considers conclusively 

 proves the auditory function, since it can be adapted to no other end. 

 The author goes on to suggest that Mr. Marsham's ichneumons might 

 be endeavouring to hear the larva breathe, as probably as for the pur- 

 pose of smelling it : he then adduces the established site of the ear in 

 the lobster, at the base of the antennae, as corroborative of his suppo- 

 sition, and enquires if the antennae of the Phalaenae, Muscae, &c., be 

 not organs of hearing, for what other purpose could they serve ? The 

 males of Bombyces fly immense distances in search of their mates, and 

 that they find them by means of their antennae is highly probable, and 



