There are no rules whatever about this, though suggestions about what is “normal” have been made from earliest times. Mohammed the Prophet stated that once a week was best; Martin Luther found that twice a week “does harm neither to her nor to me.” In these days of sociological studies there have of course been endless attempts to find the statistical norm for frequency of intercourse. The Margaret Sanger Research Bureau in 1933 released figures showing that, of ten thousand cases investigated, sexual intercourse occurred from one to three times per week--4 per cent had intercourse one or more times daily. Kinsey found that frequency depended greatly on the age of the husband; men between twenty-one and twenty-five showed an intercourse rate of just over three times per week; those between thirty-one and thirty-five showed a frequency rate of a little more than twice a week; those aged forty-one to forty-five had intercourse on an average of one and one half times a week; and men over fifty-six averaged less than once a week. These studies, of course, always show wide variations in individual cases. In my opinion frequency of intercourse is entirely an individual matter. The only criterion of any importance is that both partners feel completely satisfied with the amount of intercourse they are having. If one of the partners is dissatisfied, the subject should be open for discussion in a very frank manner. No cause for feelings of rejection by a partner should be allowed to develop in silence. There will always be periods in which, because of exterior circumstances (pregnancy, business worries, sickness, etc.), the rate of intercourse in any marriage may slow down or stop for a while. (2) _Variations in woman’s sexual desire_ There are such variations, as far as most of the research undertaken so far can determine. Katherine Davis, in a study of one thousand married women, and studies by Marie Stokes, Therese Benedek, and others indicate that the desire of women vary during the menstrual cycle. According to Hannah and Abraham Stone, who have made a study of a large number of women, “Most … state that their erotic impulses are increased either a few days before the onset of the menstrual flow or, more usually, right after menstruation, although the latter rise may be partly due to the abstinence which is generally maintained during the menstrual week.” Stokes reported also a second rise of sexual desire at some point in the middle of the menstrual month. There are apparently individual differences in the cycle of desire, and a woman can best determine for herself her own particular rhythm. There is much to be learned about this matter. The relationship between hormonal secretion and female sexuality and “femininity” has been most recently studied by Therese Benedek in her book _Psychosexual Functions in Women_. This is a technical book, but anyone interested in this aspect of the subject will find the material fascinating.