SENSES OF INSECTS. 249 



moved towards me. I repeated the noise at least a dozen 

 times, and it was followed every time by the same mo- 

 tion of that organ; till at length the insect being alarmed 

 became more agitated and violent in its motions. In 

 this instance it could not be touch / since the antenna 

 was not applied to a surface, but directed towards the 

 quarter from which the sound came, as if to listen. 

 Bonsdorf made similar observations, to which Lehmann 

 seems not disposed to allow their proper weight 3 . It 

 has been used as an argument to prove that antennae are 

 primarily factors, or instruments of touch, that Fcenus 

 Jaculator, before it inserts its ovipositor, plunges its an- 

 tennae into the hole forming the nidus of the bee, to the 

 grub of which it commits its egg b . But had those who 

 used this argument measured the antennae and the ovi- 

 positor of this ichneumon, they would have discovered 

 that the latter is thrice the length of the former : and as 

 these insects generally insert it so that even part of the 

 abdomen enters the hole, it is clear that the antenna 

 cannot touch the larva ; its object therefore cannot be to 

 explore by that sense. Others suppose that by these 

 organs it scents out the destined nidus for its eggs; but 

 Lehmann has satisfactorily proved that they are not 

 olfactory organs. We can therefore only suppose, either 

 that by means of its antennae it hears a slight noise pro- 

 duced by the latent grub, perhaps by the action of its 

 mandibles ; or else that by its motions it generates a mo- 

 tion in the atmosphere of its habitation, which striking 

 upon the antennae of the Fcenus, are by them communi- 



a DC Antenn Insect, ii. 42. b Ibid. 26. 



