HEARING IN INSECTS. 97 



the body are held firmly down. Reaumur, after many 

 experiments, concludes, that ' in the more minute parts 

 of Nature's works there is always something which 

 we cannot explain.' It appeared to him most probable 

 that the cry came from the head, perhaps from the 

 mouth, or rather from the tongue, and it might be by 

 friction of the palpi against the tongue ; for when he 

 unfolded the spiral tongue with a pin, the cry ceased, 

 but was renewed the instant it was coiled up again 

 between the palpi. He then prevented the palpi from 

 touching the tongue, which also stopt the sound, and 

 when only one was permitted to touch it, the sound 

 was much more feeble.* 



Reaumur's experiiiients on the death's-head hawk-moth. «, the tongue 

 unfolded with a pin; 6, the palpi prevented from touching the tongue. 



Huber, without mentioning the particulars, says he 

 has ascertained that Reaumur was quite mistaken.! 

 Engramelle informs us that M. de Johet plucked 

 out the jaws {maxillce'i and cut off the palpi of one of 

 these moths, and yet the noise was produced when the 

 wings were agitated. Being thence led to examine 

 the wings, he tbund two concave scales at their base, 

 which he supposes may be the organs of sound ; 

 and when the scales were cut off, the insect, he says, 

 became mute. M. de Johet thinks the sound is ])ro- 

 duced by the air being suddenly propelled against 



* Memoires, ii, 293. t On Bees, p. 313, Note. 



VOL. XII. 9 



