The well-known methods of ancient Sparta, which consisted in destroying all weak children and submitting all boys of seven years old and upward to the most rigorous training under state educators, resulted in producing a race of warriors. Fighting men were what Sparta wanted, and fighting men she produced. The possible heir to a throne in modern times must have no drop of common blood in his veins. Royalty must therefore mate with royalty in order to conserve the royal line. And so we might go on and prove how one country after another observes the great law of conservation of human resources along some favorite line. [Sidenote: Importance of the children of a nation.] But a nation to be truly great and to be sure of future development and success must realize that its greatest wealth lies in its children, its highest possibilities are wrapped up in all its little ones, its one hope for the future is in the childhood of the nation. Many earnest writers of to-day are emphasizing in one way or another this great truth in relation to children. Mrs. Frederick Schoff in an address at the National Congress on Hygiene and Demography makes a most practical application of these principles, showing some ways in which the desired results may be attained. It takes time to battle down the old wall of belief that mother instinct teaches a woman all she need know about child nurture.... The great functions of fatherhood and motherhood should not be ignored in the training of children for life. They should be held up as the highest and most far-reaching functions of human life.... “One generation, one entire generation of all the world of children _understood_ as they should be, loved as they ask to be, and so developed as they might be, would more than begin the millennium,” has been truly said by that lover of childhood, Frances Hodgson Burnett. Child Welfare is at the foundation of world-welfare. Child nurture is the greatest science of the age. To arouse the whole world to a realization of its duty to the children ... is the propaganda in which all who see the infinite possibilities of the child should unite.[3] [Sidenote: Eugenics and Heredity.]