and the configuration of every constituent bone of the face and skull undergoes an alteration. We do not know to begin with, and we are not shewn by the ordinary methods of comparison, how far these various changes form part of one harmonious and congruent transformation, or whether we are to look, for instance, upon the changes undergone by the frontal, the occipital, the maxillary, and the mandibular regions as a congeries of separate modifications or independent variants. But as soon as we have marked out a number of points in the gorillaãs or chimpanzeeãs skull, corôÙreôÙsponôÙding with those which our co-ordinate network intersected in the human skull, we find that these corôÙreôÙsponôÙding points may be at once linked up by smoothly curved lines of intersection, which form a new system of co-ordinates and constitute a simple ãprojectionã of our human skull. The network
Fig. 406. Skull of chimpanzee. Fig. 407. Skull of baboon.
represented in Fig. 405 constitutes such a projection of the