FUNCTIONS OF HEARING, TASTING, SMELLING, AND SEEING. 21 



Hearing. The phenomena which indicate the existence of the sense of hearing are 

 perhaps more equivocal than those of touch. Still attentive observers have noticed that 

 insects seem to place themselves in an attitude of listening, when loud sounds are emitted 

 from any quarter in their vicinity : they erect their antennae, and remain motionless for 

 the time being ; and when the tlisturbance has ceased to excite them, they resume their 

 ordinary movements. From the position of the antennae, then, under the circumstances 

 alluded to, it is inferred that they are connected directly with the function of hearing. 

 Beneath them is a nerve connected with a soft membrane, which seems to be adapted to 

 this special end. The antennae in themselves extending outwardly, must become sensible 

 of the vibrations in the air, and transmit them to this delicate auditory apparatus lying 

 immediately beneath. Tlie organs are often long-branched, or plumose, so as to increase 

 the extent of surface. This view of the office of the antennae does not conflict with the one 

 often entertained, namely, that they may also be useful and employed as organs of touch. 



Taste. The existence of this sense rests more upon analogy, than upon well determined 

 facts to support and prove its existence. 



• Smell. Insects are attracted to odorous bodies from a distance : hence there can be no 

 doubt that they are possessed of the sense of smell in great perfection, although its precise 

 location is a matter of great uncertainty. Several different parts of the insect's body have 

 been conjecturally assumed as the seat of this sense ; and it has often been assigned to 

 parts that are variable, evanescent, or of occasional existence only. If analogical reasoning 

 were to be our guide in this ease, we should point to certain inward parts of the body that 

 are in direct relation with the external air. In the mammalia, though the organ of smell 

 ts located in the head, yet its distinguishing characteristic is its immediate communication 

 with the atmosphere, and tlie sense itself is exercised only when the air is inhaled. It is 

 not necessary to infer, that because in the higher animal it holds this intimate relation to 

 the head, that it must occupy the same place in the insect : it is more consistent to suppose 

 that its closest relation is with the respiratory organs. It is highly probable, therefore, that 

 the trachea and spiral vessels, which conduct the air inwards^, constitute the channels by 

 which this sense is furnished with the odorous particles on which the sensuous nerve is to 

 operate. Accordingly this view is looked upon with favor by Cuviee and many other dis- 

 tinguished physiologists. 



Sight. Of all the senses, that of sight seems to be the most perfect in insects. The 

 organ is compound, or, in other words, consists of many eyes comparted together, each of 

 which is perfect in itself, being furnished with the proper humors and lenses essential to 

 the exercise of vision. In addition to the compound eye, which often occupies the largest 

 portion of the head, they are often furnished with simple eyes upon the forehead : theae 



