Why the act of clearing the throat is not a reflex action,
and has to be learnt by our children, I cannot pretend to say;
but we can see why blowing the nose on a handkerchief has
to be learnt.
[13] Muller remarks (`Elements of Physiology,' Eng. tr. vol. ii. p. 1311)
on starting being always accompanied by the closure of the eyelids.
[14] Dr. Maudsley remarks (`Body and Mind,' p. 10) that "reflex movements
which commonly effect a useful end may, under the changed circumstances
of disease, do great mischief, becoming even the occasion of violent
suffering and of a most painful death."
It is scarcely credible that the movements of a headless frog,
when it wipes off a drop of acid or other object from its thigh,
and which movements are so well coordinated for a special purpose,
were not at first performed voluntarily, being afterwards rendered easy
through long-continued habit so as at last to be performed unconsciously,
or independently of the cerebral hemispheres.
So again it appears probable that starting was originally acquired
by the habit of jumping away as quickly as possible from danger,
whenever any of our senses gave us warning.
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