In the organ of vision, changes associated with menstruation have been recorded by various observers. Hordeolum menstruale (menstrual stye) may recur month after month at the menstrual periods as an exacerbation of a chronic conjunctivitis. Herpes of the ocular or palpebral conjunctive and eczematous affections may be connected with menstruation; also exophthalmos may occur during menstruation in association with swelling of the thyroid body and palpitation of the heart (_H. Cohn_); again, as an accompaniment of normal menstruation, severe papillitis with retinal hæmorrhages may occur (_Heber_). According to the investigations of _Finkelstein_, a limitation of the field of vision may be noticed during menstruation, beginning on the first, second, or third day of the flow, attaining its greatest intensity on the third or fourth day of the flow, and gradually disappearing during the three or four days next ensuing. The organ of hearing is stated by _Haug_ to be affected during menstruation, inasmuch as congestive redness and swelling of the external ear, of the external auditory meatus, and of the skin over the mastoid process, sometimes occurs; occasionally also, periodic neuralgia manifests itself at the menstrual periods. In the circulatory organs, as already mentioned, normal menstruation quite frequently manifests its influence by the production of disorders of greater or less severity, referable to the stimulus of ovulation. In 8.5 per cent. of the women of whom I have made inquiries with regard to this matter, palpitation of the heart of variable severity occurred during menstruation, and was most frequent and most severe on the first and second days of the flow. Associated with the palpitation in some cases were, vasomotor disturbances, transient feelings of heat, a sense of congestion in the head, and profuse perspiration without apparent cause. The day before the commencement of the flow, the blood-pressure rises considerably, but falls rapidly during the flow. This menstrual rise in blood-pressure is accompanied by a rise in temperature and an increase in metabolic activity. The influence of menstruation on the heart is most powerfully displayed in cases in which for some reason a disturbance occurs of the normal appearance or normal course of menstruation. Disorders of menstruation likely to give rise to cardiac disorders are, amenorrhœa, menorrhagia, and dysmenorrhœa.