high-class medical journals occasionally contain illustrations of this tendency. However, the medical profession as a class stands for dignified scientific presentation of facts, and obscenity will soon be tabooed in medical and all other reputable literature. Save for occasional emanations privately printed by and for degenerate persons, public obscenity will soon be unknown. Its complete disappearance will have a vast influence upon the problem of sexual attitude. Sec. 12. _The Seventh Problem for Sex-instruction: Marriage_ [Sidenote: Physiology and psychology of marriage.] It is the consensus of opinion of numerous physicians, ministers, and lawyers that a very large proportion of matrimonial disharmonies have their foundation in the common misunderstanding of the physiology and especially of the psychology of sex. In the opinion of many students of sexual problems, this is the strongest reason for sex-instruction. It is certainly a line in which limited spread of information has already given some definite and satisfactory results. Many of my friends and former students have helped me accumulate a long list of cases in which scientific knowledge regarding sex has prevented and corrected matrimonial disagreements; and having easily found so much definite influence of sex-science upon marriage, I am forced to believe that sex-instruction specially organized for people of marriageable age is already giving results of tremendous importance to very many individuals. Large numbers of young people are already awake to the need of scientific guidance in marriage, and there is a great demand for helpful information. Advanced sex-instruction with reference to the problems of marriage need not wait for general establishment of elementary instruction for children of school ages. Lectures and books are already reaching large numbers of adults. Such enlightenment will help in two ways, by the influence on marriage and by preparing adults to teach children. [Sidenote: Other knowledge needed.]