I am inclined to doubt[25] that olfactory impressions in man, under normal conditions, as in animals, play an important _rôle_ in the excitation of the sexual centre. On account of the importance of this _consensus_ for the understanding of pathological cases, it is necessary here to thoroughly consider the relations existing between the olfactory and sexual senses. The sexual sphere of the cerebral cortex may be excited, in the sense of an excitation of sexual concepts and impulses, by processes in the generative organs. This is possible as a result of all conditions which also excite the erection-centre by means of centripetal influence (stimulus resulting from distension of the seminal vesicles; enlarged Graafian follicle; any sensory stimulus, however produced, about the genitals; hyperæmia and turgescence of the genitals, especially of the erectile tissue of the corpus cavernosum of the penis and clitoris, as a result of luxurious, sedentary life; plethora abdominalis, high external temperature, warm beds, clothing; taking of cantharides, pepper, and other spices). Libido sexualis may also be induced by stimulation of the gluteal region (castigation, whipping).[26] This fact is not unimportant for the understanding of certain pathological manifestations. It sometimes happens that in boys the first excitation of the sexual instinct is caused by a spanking, and they are thus incited to masturbation. This should be remembered by those who have the care of children. On account of the dangers to which this form of punishment of children gives rise, it would be better if parents, teachers, and nurses were to avoid it entirely. Passive flagellation may excite sensuality, as is shown by the sects of flagellants, so wide-spread in the thirteenth and fifteenth centuries. They were accustomed to whip themselves, partly as atonement and partly to kill the flesh (in accordance with the principle of chastity promulgated by the Church,—_i.e._, the emancipation of the soul from sensuality). These sects were at first favored by the Church; but, since sensuality was only excited the more by flagellation, and the fact became apparent in unpleasant occurrences, the Church was finally compelled to oppose it. The following facts from the lives of the two heroines of flagellation, Maria Magdalena of Pazzi and Elizabeth of Genton, clearly show the significance of flagellation as a sexual excitant. The former, a child of distinguished parents, was a Carmelite nun in Florence (about 1580), and, by her flagellations, and, still more, through the results of them, she became quite celebrated, and is mentioned in the Annals. It was her greatest delight to have the prioress bind her hands behind her and have her whipped on the naked loins in the presence of the assembled sisters.