102 INSECT MISCELLANIES. 



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

 louse {Jitropos pidsatorius, 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 perceptible when the insect 

 was, as it otten is, in a collection of dried plants that 

 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 v/ith slight deafness hear sharp 

 sounds much better than those wliich 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 artificially 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. 



