(7) _Leakage Period._ The young people between fifteen and twenty years of age constitute the "leakage period,"[5] when they are in great danger of drifting away from the school. They will be held to the school far more firmly if they have before them the prospect of membership in large classes of young people, with social opportunities, and club life, so popular with youth at the early adolescent age. It has been clearly shown by practical experience that an organized Senior Department, with large classes kept full by regular reinforcement from the Intermediate Department, will maintain itself and hold its members, while skeleton classes of the young people constantly tend to disintegration. The well-organized, completely graded Sunday school possesses such evident and great advantages that it is certain to be established wherever thorough and efficient religious instruction is sought. The sooner it comes, and the more faithfully it is maintained, the better it will be for the church of to-day and to-morrow, and the more quickly and effectually will the grave problems of our modern civilization be solved. FOOTNOTE: [5] Dr. A. H. McKinney, in After the Primary--What? V THE DEPARTMENTS OF THE GRADED SUNDAY SCHOOL =General Scheme.= The four departments essential to a graded Sunday school, whether large or small, have already been named by anticipation. But it is necessary to give to the subject a closer consideration, and to add the names of other departments which are needed either as departments or subdivisions in the school. Following the analogy of the secular schools, the great divisions of a Sunday school may be named as Elementary, Secondary, and Advanced or Adult. The Elementary Division will include the Cradle Roll, Beginners, Primary, and Junior, taking the scholar up to twelve years of age. The Secondary Division will include the Intermediate and Senior Departments, also the Teacher-training Class, and will embrace the scholars between twelve and twenty years of age. The Advanced or Adult Division will include all the classes wherein the average age is above twenty years, including the Home Department. Beginning with the youngest children, the departments of a thoroughly organized school are the following: