TOUCH. 273. 



the principal organs of touch are the sflnlcnnx^ also deno- 

 minated, from their supposed oilice, \\\q. feelers.^ 



Some idea of the great variety in the forms of the anten- 

 nae of insects may be obtained from the specimens deh'ne- 

 ated in Fig. 3S1, which shows a few of the most remarka- 

 ble.f 



The universality of these organs among every species of 

 this extensive class of animals, their great flexibility, arising 

 from their jointed structure,! their incessant motion when 

 the insect is walking, and their constant employment in exa- 

 mining the surfaces of all the bodies with which they come 

 in contact, sufficiently point them out as instruments of a 

 very delicate sense of touch. Organs of this kind were par- 

 ticularly necessary to insects, since the horny nature of the 



• The German name for ^\em, fiihlh'dmer, or the feeling horns, is founded 

 on the same notion. i 



f In this figure, A represents the form of antennae, technically denomi- 

 nated Antenna capitulo uncinato, as exemplified in the Pausus. 



B . is the A . piloso-verticillata, as in the Psychoda ocellaris. 



C . . A . biclavata, (Clavlger longicornis.) 



D . . A . triang-ularis, (Lophosia.) 



£ . . A . clavata, (Masaris.) 



F . . A . capit. lamellato, (Melolontha mas.) 



G . . A . capit. fissile, (Jphodlusfossor.) 



H . . A . fusiformis, {Zygaena.) 



I . . A . capitata, (Ascalaphus.) 



K . . A . furcata, (Nepa.) 



L. . A . bipectinata, {Bombyx.) 



M . . A . irregularis, {Agaon paradoxum.) 



N . . A . cordata, (Diaperis boleti.) 



O . . A . bipectinata, (Ctenophora.) 



P . . A . palmataj (Nepa cinerea.) 



Q . . A . ensiformis, (TVuxalis.) 



R . . A . setacea, (Cerambyx.) 



i The number of segments into which these organs are divided is often 

 very great. In the Grylloialpa, or mole cricket, it amounts to above 100. 

 (Kidd, Phil. Trans, for 1825, p. 211.) This insect has, besides the antennae 

 on the head, two posterior or caudal antennae, which are not jointed, except- 

 ing at their very commencement. These are extremely sensible, and sei-ve, 

 probably, to give the animal notice of the approach of any annoyance from 

 behind, lb. p. 216. 



Vol. II. 35 



