It will be most helpful if we consider the problem of selecting teachers with a view to rejecting those who certainly should not undertake the special hygienic and ethical teaching, for teachers who are good in other subjects and who are fortunately free from certain disqualifications discussed in the following, may by means of study adapt themselves for the final and most important stages of sex-education. There are five types of teachers who should be regarded as disqualified for teaching personal sex-hygiene and sex-ethics. [Sidenote: Embarrassed teachers.] First, those men and women who are unable to speak of sex-hygiene as calmly and seriously as they do of any other phase of hygiene had better not undertake the instruction of young people. There are many such men and women among teachers who, so far as scientific training is concerned, ought to be good teachers of sex-hygiene. As an illustration of this attitude that leaves the wrong impression with students, it is reported that a good teacher of hygiene recently prefaced a brief talk to college girls as follows: "I shall now consider a process that no cultured woman ever mentions except with bated breath. I refer to menstruation." [Sidenote: Abnormal teachers.] The second kind of people who should not teach sex-hygiene are the men and women who are the unfortunate victims of sexual abnormality, either physical or psychical, that more or less influences their outlook on life. Certain neurotic and hysterical men or women who lack thorough physiological training and whose own sexual disturbances have led them to devour omnivorously and unscientifically the psychopathological literature of sex by such authors as Havelock Ellis, Krafft-Ebing, and Freud, are probably unsafe teachers of sex-hygiene. Especially is this true of the women of this type whose introspective morbidity has led them to diagnose their own functional disturbances as the direct result of "over-sexuality" and restraint from normal sexual expression--a diagnosis that is probably wrong nine times in ten cases. Such a woman is a very dangerous teacher of sex-hygiene for adolescent girls; and a positive menace to older unmarried women who, if free from absorbing work, may spend their leisure in becoming more or less restless under the unsocial, if not unphysiologic, conditions of unwelcome celibacy. This is no imaginary danger. The reader of this will not be interested in details, but the author has received from physicians and others reliable information concerning several extremely abnormal women of the above-described type who are taking an active interest in the sex-instruction of young people and are actually suggesting to their friends among young women the dangerous and untrue doctrine that prolonged celibacy for women results in repressed sexuality that surely leads to ill health. Such ideas, it is true, are traceable to certain well-known radical writers on the psychopathology of sex; but we must