[Relation between the ellipsis and the horizontal skull contour in man and various primates]

The values of the human skull circumference measured in the plane of its greatest length and that of the ellipsis determinated by the semiaxis a, the half largest length of the skull, and the semiaxis b, the half largest breadth, prove a high correlation which is neither dependent on the skull form nor size. The difference between the circumference of the skull and the ellipsis amount only a few % and correlates to the skull form. The areas of intersection of the skull and the area of the ellipsis correspond entirely. Samples of non-human primates show the skull in all Haplorhini being also adjustet to the area of the ellipsis, but the correlation is not so good as in human objects and is depending on the species. The morphological difference is caused by the skull contour-lines passing under and over the ellipsis to the same amount without changing the quantitative ratio of the skull area to the ellipsis area.