Thermic and mechanical stimulation of the female genitals has, as my own experiments have shown, a notable influence on the heart and the general circulation. In these experiments, when uterine douches were given at temperatures of 4° C. (39° F.) and 45° C. (113° F.), the reflex nervous impulse which resulted from these manipulations had a two-fold influence on the circulation, manifesting itself first by an immediate and considerable augmentation in the functional activity of the heart, the frequency of which was increased in a degree proportional to the nervous sensibility of the individual, and secondly by a notable rise in blood pressure. With a view to determining the influence of stimulation of the ovary on blood-pressure, _Röhrig_ carried out some experiments on bitches, from which it appeared that electrical stimulation of the ovary invariably produced a remarkable increase in the general blood-pressure, an increase ranging from twelve to twenty-four millimeters of mercury. It further appeared in the course of these experiments that toward the end of the period of stimulation the rise in blood-pressure was always followed by a decline; to which, however, a renewed rise of blood-pressure succeeded after the stimulation was discontinued, provided the duration of this had not been excessive. Only after this second rise was the normal mean blood-pressure regained. Finally it was established that the pronounced phenomena of vagus-irritation exhibited by the curve during and immediately after the stimulation of the ovary were invariable concomitants of the rise of blood-pressure produced by such stimulation. According to the observations of _Federns_, the blood-pressure undergoes a rhythmical change between one menstrual period and the next, the pressure curve being normally at its lowest at the time of the commencement of the flow, and at its highest at some time during the two days immediately preceding the flow. This rhythmical change of blood-pressure manifests itself also some time before the first onset of menstruation, when the approach of puberty is indicated only by the menstrual molimina.