MAN first seeks to live, then he seeks to make others live. The instinct that determines self-preservation is almost equaled in importance and in its control of the individual by the instinct that dictates the perpetuation of the species. Indeed, in certain instances, where there is special individualization, this instinct so far transcends all others that even life itself is worthless without the attainment of the object so ardently desired, ie, without the actual possession of a certain person of the opposite sex. It is, therefore, proper for medical men in their deliberations to take cognizance of this great factor in human life. They should know its relationship to health and happiness. They should not be deterred from its scientific investigation by false modesty or by the fear of being accused of sensationalism. They should realize its importance as a dominating force in the economy, and they should approach its