Dr. Rosenau says: "Every boy and girl, before reaching the age of puberty should have a knowledge of sex, and every man and woman before the marriageable age should be informed on the subject of reproduction and the dangers of venereal diseases. Superficial information is not true education. On the other hand, it is a mistake to dwell unduly upon the subject, for in many instances the imagination and passion of youth are inflamed by simply calling attention to the subject." The Life Extension Institute can furnish special pamphlets covering this important topic. The loss of citizens to the State from the sterilizing influence of gonorrhea upon the productive energy of the family, and the blighting destructive effect of syphilis upon the offspring offer extremely serious problems for preventive work. Section IV--Teeth and Gums There is one source of poisoning and infection so universal as to need special mention. This is infection through the mouth. Considered from the standpoint of efficiency, the modern mouth is out of adjustment with modern conditions--or, perhaps we should say, modern conditions are out of adjustment with it. Notwithstanding the numerous bacteria that flourish within its portals, mouth secretions and the mucous membranes do not seem to have the protecting power which is often manifest in other regions of the body and which protects an animal in a state of nature. Wild animals are not subject to caries or dental decay, as are man and domesticated animals. [Sidenote: Mouth-dangers] There are two forms of mouth-danger that should be clearly differentiated. Dental caries, or decay, is at first largely a chemical process and affects the tooth proper. Pyorrhea, or Riggs's disease, affects the tissues surrounding the root of the tooth, and is accompanied with infection by pus bacteria, and possibly also by animal parasites, termed endameba. Scrupulous cleanliness of the mouth largely prevents both of these maladies. [Sidenote: Dental Decay] In caries, or dental decay, plaques or films of mucin from the saliva form on the tooth-surfaces and enclose bacteria and particles of carbohydrate food, which undergo fermentation with the formation of lactic acid, which dissolves the lime salts on the surface of the teeth, leaving only the organic matter. This organic matter is then attacked by bacteria. Putrefaction sets in, and you have a cavity. This cavity is, of course, a menace, as it harbors various forms of bacteria, which may infect the general system through the root canals, or the digestive system by being swallowed with the food, and also gives rise to abscesses at the root-tips. [Sidenote: Pyorrhea]