In consequence of the centrifugal movements of their jaws and lips, the teeth, with English-speaking persons, are always on exhibition; while the centripetal movement prevailing with Germans conceals them. The consequence is that English-speaking people pay the utmost attention to the care and perfection of their teeth, while Germans, in the highest ranks even, frequently neglect them to an almost shameful degree. The direct outcome of this state of affairs is the great advancement which the practice of dentistry has made in this country and in England, while it is one to which, on the continent of Europe, but comparatively little attention is being paid. With English-speaking people, especially the women, whose lips are more flexible than men's, the teeth of the upper jaw are more frequently exposed than those of the lower, for this reason: The œsophagus being the main instrument for English speech, its sounds, in coming to the surface from beneath the tongue, require the latter to remain in a semi-raised position most of the time; the upper lip, being in the way of these sounds coming to the surface, must be raised for the same reason; in so doing it exposes the upper row of teeth. The lower lip is lowered for the sounds of the trachea for the same reason that the upper is raised for those of the œsophagus. Whenever the upper lip is raised the lower must be immediately lowered, and vice versa. With Anglo-Saxons the main movement is with the upper, with Germans it is with the lower lip. Owing to the centripetal action with Germans, these movements are less pronounced than they are with English-speaking people. The act of smiling being produced in the same order as that of speaking, the same conditions prevail in relation to the same. In speaking English you can "feel" that the upper lip is the main vehicle; _it has all the life in it_. In speaking German you can "feel" it is the lower, which for that language possesses the life. If you make the former rigid you cannot speak English; if you make the latter rigid you cannot speak German. In connection with the movements of the lips it will be noticed that while the upper jaw and the roof of the mouth are dominated by the trachea and the thorax, and the lower jaw and the bottom of the mouth by the œsophagus and the abdomen, the upper lip is dominated by the sounds of the œsophagus, and the lower by those of the trachea. This, however, is owing to mechanical reasons only, as explained, and not to vital causes.