ORGAN OF SMELL. 63 



predaceous have simple antennae ; and those which 

 are characterised by similar manners, and which are 

 sedentary, have none at all ; as, for instance, the 

 Acari, and a considerable portion of Lamarck's 

 arachnida discover their habitation and food by 

 the sense of smell. I have deprived several in- 

 sects of their antennae, when they instantly fell into a 

 state of stupor or derangement, and seemed to be 

 incapable of recognizing their haunts or their food, 

 though just beside them. Such experiments deserve 

 to be prosecuted. I would recommend, for example, 

 the varnishing or covering the antennae of dung 

 beetles, and placing them near animal excrements, 

 of which they are particularly fond, to observe if they 

 would repair to them as usual. The nerves ter- 

 minate at the antennas ; and their articulations, 

 though externally covered with a pretty thick mem- 

 brane, are hollow, lined within by a soft substance, 

 which is often of a watery consistency, and whose 

 extremity, when opposed to the air, may receive its 

 impressions. ' Mr Kirby, in speaking of the Eucera 

 (or long-horned bee), says : ' A singular circum- 

 stance distinguishes their antennae, which to the best 

 of my knowledge has never before been noticed, and 

 which may possibly lead to the discovery of the use 

 of these organs. Placed under a powerful magnifier, 

 the last ten joints appear to be composed of innu- 

 merable hexagons, similar to those of which the eyes 

 of these insects consist. ' If we reason from analogy, 

 this remarkable circumstance will lead us to con- 

 jecture, that the sense, of which this part so essential 

 to insects is the organ, may bear some relation to 

 that conveyed by the eyes. As they are furnished 

 with no instrument for receivino; and communicating 

 the impressions of sound similar to the ear, that defi- 

 ciency may be supplied by extraordinary means of 

 vision. That the stemmata are of this description 



