talks should first be given to limited groups of pupils, preferably in the presence of some parents who are interested and who have given their children some home instruction. Working along such conservative lines, I believe a tactful principal of a grammar school might succeed in developing much of the needed instruction for pre-adolescent pupils. [Sidenote: Instruction in high schools.] With regard to high-school pupils, we should remember that nine-tenths of the desirable information is already included in the biology of our best high schools. The remaining tenth is that which connects all life with human life; and this requires tact and exceptional skill. However, the high schools no longer offer an insoluble problem, for many teachers have succeeded in giving the desirable instruction to the satisfaction of critical principals and parents. [Sidenote: Sex-education from early childhood to maturity.] There is a widespread impression that sex-instruction should begin with the approach of adolescence and soon be completed. This idea is often expressed by parents and even by prominent educators who say that the father or teacher ought "to take the boy of thirteen aside and tell him some things he ought to know." Still others have the same point of view when they advocate that a physician should be called for a lecture to high-school boys. In fact, most people who have not seriously studied the problems of sex-education seem to believe that one concentrated dose of sex-instruction in adolescent years is sufficient guidance for young people. Such limited personal instruction might suffice if sex-education were limited to sex-hygiene. A few hygienic commands in pre-adolescent years and one impressive talk in early puberty might teach the boy or girl how not to interfere with health; but it is improbable that such brief instruction will make a permanent impression which will insure hygienic practice of the precepts laid down. If we hold that sex-hygiene is important, then it must be drilled into the learner from several points of view. An isolated lesson on any topic of general hygiene is of very doubtful efficiency. [Sidenote: Brief instruction does not fix attitude.] The most important reason why sex-instruction should not be concentrated in a short period of youth is that it is impossible to exert the most desirable influence upon health, attitude, and morals except by instruction beginning in early childhood and graded for each period of life up to maturity. Most young people who in early adolescence receive their first lessons from parents and teachers have already had their attitude formed by their playmates. Even their morals may become corrupted and their health irreparably injured several years before puberty. The only sure pathway to health, attitude, and morals is in beginning with young children and instructing them as gradually as the problems of sex come forward. [Sidenote: Sex-instruction after youth.]