CHAP. XII. DILATATION OF THE PUPILS. 3Q3 concomitant of fear; for it probably never acts under the influence of extreme, prostrating terror. Dilatation of the Pupils.—Gratiolet repeatedly in- sists 24 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 state- ment,25 that with parrots the iris is affected by the pas- sions, independently of the amount of light, seems to bear on this question; but Professor Bonders 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 state- ment is correct, that the brain is directly affected by the powerful emotion of fear and reacts on the pupils; but Professor Bonders informs me that this is an ex- tremely complicated subject. I may add, as possibly throwing light on the subject, that Dr. Fyffe, of Netley Hospital, has observed in two patients that the pupils were distinctly dilated during the cold stage of an ague fit. Professor Bonders has also often seen dilatation, of the pupils in incipient faintness. 24' De la Physionomie,' pp. 51, 256, 346. 25 As quoted in White's * Gradation in Man/ p. 57.