breath; and thus the contraction of the platysma may possibly have
become associated with the sense of fear. But there is, I believe, a
more efficient relation. The first sensation of fear, or the
imagination of something dreadful, commonly excites a shudder. I have
caught myself giving a little involuntary shudder at a painful thought,
and I distinctly perceived that my platysma contracted; so it does if I
simulate a shudder. I have asked others to act in this manner; and in
some the muscle contracted, but not in others. One of my sons, whilst
getting out of bed, shuddered from the cold, and, as he happened to
have his hand on his neck, he plainly felt that this muscle strongly
contracted. He then voluntarily shuddered, as he had done on former
occasions, but the platysma was not then affected. Mr. J. Wood has also
several times observed this muscle contracting in patients, when
stripped for examination, and who were not frightened, but shivered
slightly from the cold. Unfortunately I have not been able to ascertain
whether, when the whole body shakes, as in the cold stage of an ague
fit, the platysma contracts. But as it certainly often contracts during
a shudder; and as a shudder or shiver often accompanies the first
sensation of fear, we have, I think, a clue to its action in this
latter case.[1223] Its contraction, however, is not an invariable
concomitant of fear; for it probably never acts under the influence of
extreme, prostrating terror.
_Dilatation of the Pupils_. Gratiolet repeatedly insists[1224] that the
pupils are enormously dilated whenever terror is felt. I have no reason
to doubt the accuracy of this statement, but have failed to obtain
confirmatory evidence, excepting in the one instance before given of an
insane woman suffering from great fear. When writers of fiction speak
of the eyes being widely dilated, I presume that they refer to the
eyelids. Munro s statement, that with parrots the iris is affected by
the passions, independently of the amount of light, seems to bear on
this question; but Professor Donders informs me, that he has often seen
movements in the pupils of these birds which he thinks may be related
to their power of accommodation to distance, in nearly the same manner
as our own pupils contract when our eyes converge for near vision.
Gratiolet remarks that the dilated pupils appear as if they were gazing
into profound darkness. No doubt the fears of man have often been
excited in the dark; but hardly so often or so exclusively, as to
account for a fixed and associated habit having thus arisen. It seems
more probable, assuming that Gratiolet s statement is correct, that the
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