984. Why is one part of the ear spread out externally?
The external ear is a natural ear-trumpet, and serves to collect the vibrations of sound, and to conduct them towards the internal ear.
985. Why is the ear allowed to project, whilst the eye is carefully enclosed?
Because the external ear, being formed of tough cartilaginous substance, and being very simple in its organisation, is but little liable to injury.
986. Why do hairs grow across the entrance of the ears?
Because they prevent the intrusion of insects, and of particles of dust, by which otherwise the faculty of hearing would be impaired.
The insect called the earwig is popularly supposed to be so named from its tendency to get into the human ear, and cause pain and madness by penetrating to the brain. An earwig, however, is no more likely to get into the ear than any other insect whose habit it is to penetrate the corollas of flowers; and should an insect enter the ear, it could get no further than the membrane of the tympanum, which spreads all over the auditory passage, just as the parchment of a drum spreads over the entire circumference of that instrument. The fact is, that the wing of the insect, when spread, resembles the external ear in shape. It is similar to the wing of the stag beetle (see illustration), and this fancied resemblance of the wing of the insect to the ear of man may have given rise to the name of ear-wing, which became corrupted to earwig.
"Doth not the ear try words? and the mouth taste his meat."—Job xii.