gitudinally and vertically, through the middle. The sectional diagrams then have been superimposed, in such a manner, that the basal axes of the skulls coincide by their anterior ends and in their direction. The deviations of the rest of the contours (which represent the interior of

⁠Fig. 30.—Sections of orthognathous (light contour) and prognathous (dark contour) skulls, one-third of the natural size, a b, Basicranial axis; b c, b' c', plane of the occipital foramen; d d' hinder end of the palatine bone; e e' front end of the upper jaw; TT', insertion of the tentorium.