INSECTA. 



the nature of their sensations has been a fruitful subject of inquiry, 

 and some physiologists have even gone so far as to deny the corre- 

 spondence of the impressions derived by insects through the medium 

 of their senses with those which we ourselves receive. It would 

 lead us far out of our course did we even advert to the multiplicity 

 of opinions and conjectures promulgated from various sources rela- 

 tive to these inquiries, and, perhaps, with little addition to our 

 real knowledge. It is true that we cannot deny the possibility of 

 the existence of other modes of sensation than those familiar to us ; 

 but it is likewise evident that, as we can never have the most remote 

 conceptions concerning their nature, speculations respecting them 

 are calculated to lead to very unsatisfactory conclusions. We must 

 from necessity take our own senses as the standard of comparison, 

 limiting our inquiries to examine how far insects possess means of 

 intercourse with the external world similar to those which we enjoy, 

 and, when we find certain faculties to exist, to investigate the struc- 

 ture of the organs by which they are exercised. 



(317.) The sense of touch is indubitably bestowed upon all in- 

 sects ; and, to judge from the perfection of the edifices which they 

 build, and the precision of their usual operations, this must be ex- 

 tremely delicate. It is sufficient, however, to look at the external 

 construction of the skeletons of ARTICULATA, to perceive that the 

 hard and insensible integument spread over the entire surface of 

 their bodies is but little calculated to receive tactile impressions. 

 The antennae, or feelers as they are popularly called, have been 

 very generally regarded as being peculiarly instruments of touch ; 

 and whoever watches the proceedings of an insect in which these 

 appendages are largely developed, will, we apprehend, easily con- 

 vince himself that they are employed to investigate surrounding 

 objects by contact, Strauss Durckheim regards the feet as being 

 specially appropriated to the sense of feeling, but this opinion 

 seems quite inadmissible. Burmeister places the exercise of touch 

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

 observes 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 ramifications. 



