102 INSECT MISCELLANIES. 



we saw it strike the wood. In the case of the 

 timber-louse (Atropos pulsatorius^ Stephens), the 

 insect certainly strikes the object; for in consequence 

 of the softness of its body, it could not otherwise 

 produce the clicking*, which is much quicker, and 

 not so loud as that of the beetles. We have 

 even distinguished this sound to be much less per- 

 ceptible when the insect was, as it often is, in a 

 collection of dried plants than when on an old book 

 or a drawer*. 



These are only a few of the more remarkable 

 sounds produced by insects ; but it is highly probable, 

 as we have already hinted, that these tiny creatures 

 emit many sounds altogether imperceptible to us, — 

 an opinion which is strikingly corroborated by the 

 experiments of Wollaston. It is well known that 

 persons affected with slight deafness hear sharp 

 sounds much better than those which are grave and 

 low, being able to distinguish the voices of women 

 and children, in consequence of their acuteness, 

 much better than the lower tones of men's voices. 

 This fact, indeed, is practically acted upon by those 

 accustomed to converse with persons hard of hearing, 

 in which case they use a more shrill, rather than a 

 louder tone of voice than common. Many persons 

 who never felt any defect in their hearing cannot 

 hear certain sounds which others perceive distinctly ; 

 and this partial deafness may be artilicially produced 

 by shutting the mouth and nose, and then exhaust- 

 ing the air in the Eustachian tube by expanding the 

 chest in a forcible attempt to take breath. When 

 this is done so that the exhaustion of the air behind 

 the drum of the ear is as complete as possible, the 

 external air is felt strongly and even painfully press- 

 ing on the drum, in which case the ear becomes 

 insensible to low sounds, though shrill sounds are 



* J. R. 



