The successive menstruations as they recur regularly throughout the course of the sexual life may, just like the first menstruation, though with diminished intensity, give rise to manifestations of nervous and mental disorders. In many women who are in other respects healthy, we see during menstruation, hemicrania, nervous irritability, ill-temper, low-spiritedness, and even hysterical and epileptic attacks; these occur chiefly on the first and second days of the flow, and disappear altogether toward the end of the period. These manifestations are more severe in individuals weakened by profuse losses of blood or by chronic disorder in various organs, more severe also in those predisposed to such disturbances in consequence of neuropathic inheritance, more severe in women suffering from menorrhagia and dysmenorrhœa, and from any kind of mental stress. In his work on the influence of the so-called menstrual wave on the course of mental disorders, _Schüle_ remarks that the mental equilibrium even of a perfectly healthy woman is not a stable one, but is subject to a series of oscillations. “The menstrual period,” he continues, “has a distinct influence on woman’s mental equilibrium. Even in those whose nervous system is a healthy one, menstruation evokes a state, now of depression, now of excitement; in neurotic women, on the other hand, menstruation may give rise to nervous diseases which may equally exhibit the characteristics of depression or the characteristics of excitement. In nervously predisposed women, the influence of regularly established menstruation, even when the circumstances are favorable, is pretty much the same as the influence of menstruation when it first makes its appearance; the influence is merely somewhat weaker in so far as the woman has learned to endure and to be patient. The menstrual state, in nervously predisposed women, evokes the particular neurosis to which the individual happens to be liable. The disorders most commonly met with in this association are, hysteria, hemicrania, swimming in the head, epileptic paroxysms, toothache, and neurasthenia.”