Mrs. X., married to an elderly man, looked upon the marital relations more as a duty than as a pleasure during her entire married life. But since the climacterium has set in, the rare approaches of her husband are impatiently awaited and they cause her great sexual excitement and satisfaction, never experienced before during the entire period of her active sexual life. Such cases are extremely rare. Generally there is a close connection between the activity of the generative glands and the degree of libido. After a regular and satisfactory coition the woman is, physiologically, more or less anaesthetic for some time. The length of the neutral period varies in different individuals. Intense mental activity, emotional depression and long sexual continence also diminish the sensual pleasure. Apart from this temporary anaesthesia, there are many women who are impotent to experience libido throughout their lives. There is a total absence of pleasurable feelings during coition or any other kind of sexual stimulation. A young lady, twenty-two years of age, complains that while during the time of her engagement she greatly enjoyed her fiancé’s caresses and became sexually excited when fondled by him, since her marriage she is unable to experience any libido in coition, although her husband is possessed of great potency. The patient is a beautiful brunette, with fiery eyes, and is a picture of health. Examination shows a uterus infantilis. The potency of voluptas in this case is wholly intact. The patient enjoys being fondled and caressed. The cause of the impotency of libido lies in the periphery, although uterus infantilis is seldom accompanied by impotence of libido. In some cases the woman is normally developed in every respect, menstruates regularly and is frequently quite prolific. The power of procreation is sometimes even very great. The woman is generally quite erotic and falls in love easily. Yet she never experiences the least libido. A young lady, twenty-eight years of age, mother of two healthy children, was sent by her family physician from Chicago to consult the author for her impotence of libido. The husband stated that he is sure of his wife’s attachment to him. She enjoys his company and likes to be caressed by him. Still during the eight years of their married life she never showed the least sign of libido at coition. She remains cold and indifferent, and only submits conjugationi to please her husband. The examination showed the genitals to be in perfect order. In the following case, too, no cause whatsoever could be found for the anaesthesia in regard to libido.