An ideal line, from whence to study a degenerate face, should be drawn perpendicularly from the supra-orbital ridge intersecting the upper and lower jaw and chin. While the chin of the Apollo Belvedere falls slightly inside of this line, yet this is hardly perceptible. Having now fixed a standard from which to study the degenerate face, it should be remembered that jaws which protrude beyond this line are atavistic, and those which recede are even more degenerate. [Illustration: FIG. 23.] [Illustration: FIG. 24.] The angle between 80° and 90° may be accepted as an ideal by which to study degeneracy. This factor alone, however, can not be accepted: the evolution of the face itself must be also taken into consideration. It is obvious that in the struggle for existence and supremacy between the brain and the face (both expressions of vertebrate advance), stress may be concentrated on one particular part. Whence result certain factors which modify the conclusion to be drawn from the facial angle. The hollowed out condition of the face from the supra-orbital ridges down to and including the base of the nose (illustrated in Johanna) merits attention here. The same condition is observable in the negro, only it extends farther down and includes both jaws. One jaw, however, may alone be affected. Most of the Chinese, Japanese, Eskimo, Polynesians, Australians, Aryan Caucasic Africans, and some American Indians, possess this feature. As has been already remarked, the facial regions of man and the ape up to a certain point are similar. Not until the sense organs of man begin to develop are changes noticeable in facial expression. If, through heredity or constitutional defect, that part of the brain which presides over development of the facial bones lose its control, arrest of development of that particular tissue results at any period between birth and the twenty-fifth year, while other parts of the head and face continue to develop. With this understanding Camper's method can be safely applied to certain cases. If a line be dropped from the supra-orbital ridge to the upper lip in its most prominent part (Fig. 23), it will be found here that in place of the face presenting the full appearance illustrated in Fig. 19 and Fig. 22, it has the hollow appearance observable in Johanna and in Fig. 25. This is due to arrest of development of the bones of the face and the upper jaw. The extent of depression depends upon the time of arrest, the frontal development of the skull, and the position of the upper jaw. The nose may present and retain the appearance of that of a child six months old, or any other shape up to normal development, but will not protrude from the face nor present a normal symmetrical appearance. It has the appearance of having been driven into the face. It has been claimed that the bridge of the nose is pushed out by the advancing brain and cranium. This may be true to a certain extent, but one is not necessarily