LECTURE II. 53 



Welcker distinguishes the extremely orthognathous as opistho- 

 gnathous (or with retreating teeth) ^ a distinction which does 

 not seem to me quite justifiable. 



Besides this position of the jaws which is connected with the 

 curvature of the cranial basis^ the length of which seems to in- 

 crease in proportion to the projection of the jaw ; the side view 

 also gives us a general idea of the roundness of the skull, the 

 arch of the forehead, the development of the occiput, the eleva- 

 tion of the vertex, and the proportion of the perpendicular to 

 the longitudinal diameter. Just those points in which the 

 human cranium difiers most from that of the animal, as, for 

 example, the projection of the brain and its anterior lobes over 

 the face, in connexion with an arched and more or less per- 

 pendicular forehead, are best seen in a side view, and this view 

 must, therefoi-e, in no way be neglected. 



The POSTERIOR VIEW {Norma occipitalis) and the anterior 

 VIEW (Norma frontalis) supplement each other, and I cannot do 

 better than quote the words of von Baer on this point : " If," 

 says Baer, "we place a skull so that the assumed horizontal 

 line corresponds with the visual axis of the observer and ex- 

 amine the skull at a distance from behind, it will sometimes be 

 found that with a full development of the parietal eminences 

 and a roof-shaped vertex, the outline assumes the shape of a 

 pentagon. Although this pentagon never exhibits sharply 

 defined angles, still the figure is often very plain, generally 

 rather broad than high, and may be briefly described, accord- 

 ing as the angles are rounded or sharp, the lateral planes 

 straight, arched, shorter or longer. The rounding of the 

 angles is, however, not unfrequently so great that, leaving 

 out of notice the mastoid processes, which often recede, or 

 are elevated so as to be scarcely perceptible, the outline 

 is elliptical instead of pentagonal. The ellipsis is usually 

 rather high than broad, rarely the reverse, and still more 

 rarely is the difiierence between the perpendicular and the 

 horizontal axis so slight, that the aspect may be termed 

 circular. This outline is as variable as it is perceptible, so 

 that we must not expect to find it always similar, even in 



