NERVES — SENSES : TASTE AND TOUCH. 309 



and provided with a great abundance of nerves, and furnished 

 with saliva from the mouths of the ducts of the glands lying 

 beneath this organ. It must, however, be admitted, that 

 there are many insects in which the analogue of the tongue 

 is not developed, or exists merely as a horny seta. 



(e) The Sense of Touch. — In the higher animals the outer 

 envelope of the body is, from its peculiar construction, 

 generally, and in all parts, adapted to receive impressions 

 by this sense ; but in insects, the hard scaly texture of the 

 external covering necessarily prevents such a general system 

 of touch, and we are therefore compelled to search for organs 

 which may, in an especial manner, be regarded as the organs 

 of this sense. Here, too, however, we find difficulties similar 

 to those which have met us in our researches relative to the 

 other senses : thus the antennae, palpi, wings, and tarsi, and 

 particularly the anterior tarsi, have been regai-ded as the 

 organs of this sense; and, indeed, the opinion, that the first- 

 named organs constituted the real feelers, has been main- 

 tained by some writers with so much zeal, that even violent 

 abuse has been heaped upon persons professing a different 

 view of the subject. It is true that the antennae have been 

 generally termed feelers, and the proceedings of some of 

 the IchneumonidcB have been adduced as instances in sup- 

 port of these organs being capable of feeling ; but here, as 

 Kirby and Spence observe, either by means of its an- 

 tennae, it may hear a slight noise made by the latent grub, 

 perhaps by the action of its mandibles, or else that, by 

 its motions, the grub generates a motion in the atmo- 

 sphere of its habitation, which, striking upon the antennae 

 of the parasitic ichneumon, are by them communicated to 

 its sensorium. Moreover, the ovipositor of these insects is 

 much longer (in Fcunus and Pimpla) than the antennae ; so 

 that, by inserting the latter into the holes in walls, posts, &c., 

 it is impossible that they can reach the latent grub. Strauss- 



