It is still debatable as to how much should be taught in high schools or in public lectures concerning the biological facts of human reproduction. I think that I can make my own views clearer if I discuss this first for boys, then for girls. Sec. 28. _Scientific Facts for Boys_ First, it is generally agreed that boys of high-school age may profit by learning their own sexual structure by means of diagrams such as the one in Hall's "Sexual Hygiene." There is no harm, and also no gain, in minute description, especially histological. [Sidenote: Scientific names.] The chief technical names of the parts of the male organs--testicle (spermary or testes), sperm duct (vas deferens), scrotum, prostate, seminal vesicles, penis, glans, prepuce (foreskin), urethra--should be taught; and the scientific dignity of these words as substitutes for vulgar words should be emphasized. In dealing with boys and young men I have noticed that these and other scientific words have a great influence on their attitude. The scientific names of the sex organs should be made part of popular vocabulary for the reason that there are no established common names corresponding to lungs, liver, stomach, arm, leg, brain, and so on for all prominent organs except the sexual. These have been left without authoritative names except in scientific language, and as a result dozens of ordinary words have been vulgarly applied and unprintable ones invented by uneducated people. Such usage of vulgar terminology is widespread, especially among men and boys. An editor of schoolbooks recently called my attention to the necessity of changing some ordinary words in certain books because in some localities the boys applied the words to sexual organs. Even the little words "nuts," "stones," "balls" accompanied by the adjective "two" mean testicles in the widespread vulgar language; and a physician told me that a college graduate used one of these words the other day when seeking medical advice concerning her baby. Here is an intolerable situation that must be improved by establishing in popular usage the dignified scientific words for the chief sexual organs. We must begin to do so by teaching the words frankly to boys of adolescent years, and by persuading parents to teach their children correctly. [Sidenote: Sex-physiology.] Having learned the structure and names of their sexual organs, boys may easily understand the function of each part if explained in simple language. Ten or twenty minutes ought to be enough time for stating the important facts. One printed page could state them clearly. Here is the time for personal hygienic advice, especially such topics as: rules for self-control; harmful habits (see discussion of masturbation in Sec. 26); sexual activity not necessary for health; occasional nocturnal emissions not pathological.[16] [Sidenote: Female organs.]