SENSES OF INSECTS. 331 



seems quite inadmissible. Burmeister places the exercise of touch 

 exclusively in the palpi attached to the maxillae and labium, and ob- 

 serves that, in the larger insects, such as the predatory Beetles, the 

 Grasshoppers, Humble-bees, and many others, the apex of the palpus 

 is dilated into a white transparent and distended bladder, which, 

 after the death of the insect, dries up and is no longer visible. This 

 bladder he looks upon as the true seat of the sense in question, and 

 remarks that the main nerve of the maxillae and' of the tongue spreads 

 to it, and distributes itself upon its superior surface in minute rami- 

 fications. 



(863.) Whether taste exists in insects as a distinct sense may admit 

 of dispute : the tongue, already described, seems but little adapted to 

 appreciate savours ; and, seeing this, it is obvious that all opinions assign- 

 ing the function of tasting to other parts are purely conjectural. 



(864.) Many insects are certainly capable of perceiving odours ; of 

 this we have continual proof in the Flesh-fly and other species, that 

 are evidently guided to their food, or select the position in which to 

 deposit their eggs, by smell; but where the olfactory apparatus is 

 lodged is still a matter of doubt. The antennae and the palpi have each 

 had the power of smelling assigned to them, but without much plausi- 

 bility. The respiratory stigmata have been pointed out as performing 

 the office of examining the air admitted for the purpose of breathing ; 

 yet other authors, with equal probability, look upon the ultimate rami- 

 fications of the tracheae as forming one extensive nose. The interior of 

 the mouth has been indicated by Treviranus*; while Kirby and Spence 

 find, in the Necrophori and other insects remarkable for acuteness of 

 smell, an organ in close connexion with the mouth, to which they attri- 

 bute the perception of odoriferous particles : this is a cavity situated in 

 the upper lip, containing a pair of circular pulpy cushions covered by a 

 membrane transversely striated or gathered into delicate folds. 



(865.) We are scarcely better informed concerning the organs of 

 hearing ; but that insects are capable of perceiving sounds is proved by 

 the fact of many tribes being capable of producing audible noises, by 

 which they communicate. There seems, indeed, to be little doubt that 

 the auditory apparatus is in some way or other connected with the 

 antennae. Some have supposed that these slender and jointed organs, 

 supplied, as they are, with large nerves, are themselves capable of 

 appreciating sonorous vibrations. Burmeister f thinks that, as in 

 crabs and lobsters, it is at the base of the antenna that the ear is 

 situated, and observes that if we examine the insertion of these ap- 

 pendages, we shall detect there a soft articulating membrane, which lies 

 exposed, and is rendered tense by the movements of the antenna : this 

 he looks upon as representing the drum of the ear, and conceives that 

 it is so placed as to receive impressions of sound, increased by the 

 * Vermischte Schriften, vol. ii. t Op. cit. p. 296. 



