The turbinated (Fig. 28) bones are often hypertrophied, as is also the nasal septum (vomer or dividing bone) and the mucous membrane. This results from the general instability of the nervous system with its special expression in increased blood supply, whence occur overgrowth in and imperfect work by the mucous membrane, causing mouth-breathing and polypi, which again increase this defect. All these predispose to germ invasion. In the figure are also shown grooves upon the teeth. Sufficient symptoms are here evident to stamp this as a marked degenerate skull. Hypertrophy of the turbinate bones, septum, and mucous membrane, as it occurs among degenerates, appears in Fig. 29, and is due, first, to an unstable nervous system, and, second, a larger system of blood vessels which ramify through these parts. Stimulation, together with the stenosis (narrowing), tend to produce a closure. Still further, irritation and an unstable mucous membrane results, with polypi or adenoid vegetation following. [Illustration: FIG. 29.] Not only do deflection of septum and hypertrophy of the nasal bones occur, but the antrum (cavity behind the nose) may be almost entirely obliterated, while the upper jaw is arrested (Fig. 29). The antrum may be entirely wanting, as in Fig. 30; so unstable may these tissues develop that the nasal cavities may become almost entirely obliterated, as observed in this figure. [Illustration: FIG. 30.] These conditions are due to the unstable structure and large nerve and blood supply. Perhaps one of the most interesting points in connection with degeneracy of the nose is the fact that in most cases the structures are either arrested or excessively developed, to the extent of the entire absence of the inferior turbinate bone. This was the case in a girl thirteen years of age who died of tuberculosis. Her skull revealed many other forms of degeneracy as well. The deviation in the development of the two nasal cavities results from the excessive and arrested development of the turbinates, thus preventing inhalation and exhalation of air, the free side developing and the closed side remaining undeveloped. In such case the nose is deflected to the right or left, depending on which side is arrested. When both nostrils are closed the nose becomes thin and pointed and mouth-breathing results. In degenerate nasal cavities polypi (tumours) are apt to occur. Persons with long, thin noses, arrested nasal cavities, sunken faces (as a result mouth-breathers), and with contracted chest walls are the subjects for tuberculosis. In such cases, especially when the nervous system is unstable, the different forms of catarrh are present. This condition worries the youth under the strain of puberty. To the catarrh which is merely a result is ascribed his constitutional defects. These somatic signs are quite noticeable in most of these cases, and by early recognition proper treatment, with change of climate, frequently prolongs life for years.