front teeth are made to project, and, instead of erupting, with plenty of room, in even, regular lines, are crowded against and overlap one another. When from any cause the lower jaw habitually hangs down, as in the open mouth, it tends to be thrown slightly forward in its socket. Then, when the jaws close again, the arches of the upper and lower teeth no longer meet evenly. Instead of "locking" at almost every point, as they should, they overlap, or fall behind, or inside, or outside, of each other. So that instead of every tooth meeting its fellow of the jaw above evenly and firmly, they strike at an angle, slip past or even miss one another, and thus increase the already existing irregularity and overlapping. Each individual tooth, missing its best stimulus to healthy growth and vigor, firm and regular pressure and exercise against its fellow in the jaw above or below, gets a twist in its socket, wears away irregularly, and becomes an easy prey to decay, while from failure of the entire upper and lower arches of the teeth to meet squarely and press evenly and firmly against one another, the jaws fail to expand properly and the tendency to narrowing of the tooth-arches and upward vaulting of the palate is increased. In short, we are coming to the conclusion that from half to two-thirds of all cases of "crowded mouth," irregular teeth, and high-arched palate in children are due to adenoids. Progressive dentists now are insisting upon their little patients, who come to them with these conditions, being examined for adenoids, and upon the removal of these, if found, as a preliminary measure to mechanical corrective treatment. Cases are now on record of children with two, three, or even four generations of crowded teeth and narrow mouths behind them, but who, simply by being sharply watched for nasal obstruction and the symptoms of adenoids, by the removal of these latter as soon as they have put in an appearance, have grown up with even, regular, well-developed teeth and wide, healthy mouths and jaws. Unfortunately, attention to the adenoids will not remove these defects of the jaws and teeth after they have been produced. But, if the child be under ten, or even twelve, years of age, their removal may yet do much permanently to improve the condition, and is certainly well worth while on general principles. Take care of the nose, and the jaws will take care of themselves. An ounce of adenoids-removal in the young child is worth a pound of _orthodontia_--teeth-straightening--in the boy or girl; though both are often necessary.