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 a . It 
has been used as an argument to prove that antennas are 
primarily factors, or instruments of touch, that Fcenus 
Jaculator, before it inserts its ovipositor, plunges its an- 
tennce 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 Antcnn Insect, ii. 42. b Ibid. 2G. 
