C)4f SUPPLEMENT ON 



savours are perceived by insects, as by most animals, in the 

 interior of the digestive canal, and principally at its origin 

 in the mouth. In short, as it is very clearly proved that in- 

 sects have a tongue, so it is most natural to believe that it is 

 the principal organ of taste. In fact, very distinct nerves 

 repair towards this part. Lyonnet has represented them very 

 well in his Anatomical History of the Caterpillar of the 

 Cossus. 



Touch, in all probability, is that sense which in insects is 

 the least developed. Not that these animals are deprived of 

 parts proper to be placed in contact with the different parts 

 of the surface of bodies ; but these parts are generally 

 covered with a hard, and often corneous skin, which prevents 

 such an immediate application as is necessary for the full 

 appreciation of the tangible properties of bodies. Not that 

 we are to suppose them altogether destitute of this sense in 

 the hardest parts of their bodies. They must feel sufficiently 

 through the covering of their limbs for all the purposes of 

 motion. The idea of temperature more or less elevated, of 

 softness or solidity, of bulk, or length, breadth or thickness, 

 cannot well be acqviired by the insect through the medium of 

 touch. The organs supposed to be designed for this use in 

 insects are, first of all, the antennae. These are generally al- 

 lowed to be organs of touch. When elongated and composed 

 of a great number of articulations, they appear to be ten- 

 tacula, employed by the insect and put continually in motion 

 to explore its path and discover and avoid obstacles. This 

 is observable in sphex, ichneumon, chrysis, and a great num- 

 ber of insects besides. But in others these antennae are com- 

 posed of a single hair, or some short rings, as in flies, &c., 

 and though doubtless possessed of this sense, cannot be of 

 any great use as an organ of tact. 



In the next place, the palpi are considered as organs of 

 touch. They were considered by Bonsdorf as olfactory in- 



