_The Face._ In striking contrast to the narrow forehead and low vault of the skull, the face of the criminal, like those of most animals, is of disproportionate size, a phenomenon intimately connected with the greater development of the senses as compared with that of the nervous centres. Prognathism, the projection of the lower portion of the face beyond the forehead, is found in 45.7% of criminals. Progeneismus, the projection of the lower teeth and jaw beyond the upper, is found in 38%, whereas among normal persons the proportion is barely 28%. As a natural consequence of this predominance of the lower portion of the face, the orbital arches and zygomæ show a corresponding development (35%) and the size of the jaws is naturally increased, the mean diameter being 103.9 mm. (4.09 inches) as against 93 mm. (3.66 inches) in normal persons. Among criminals 29% have voluminous jaws. The excessive dimensions of the jaws and cheek-bones admit of other explanations besides the atavistic one of a greater development of the masticatory system. They may have been influenced by the habit of certain gestures, the setting of the teeth or tension of the muscles of the mouth, which accompany violent muscular efforts and are natural to men who form energetic or violent resolves and meditate plans of revenge. Asymmetry is a common characteristic of the criminal physiognomy. The eyes and ears are frequently situated at different levels and are of unequal size, the nose slants towards one side, etc. This asymmetry, as we shall see later, is connected with marked irregularities in the senses and functions. _The Eye._ This window, through which the mind opens to the outer world, is naturally the centre of many anomalies of a psychic character, hard expression, shifty glance, which are difficult to describe but are, nevertheless, apparent to all observers (see Fig. 4). Side by side with peculiarities of expression, we find many physical anomalies--ptosis, a drooping of the upper eyelid, which gives the eye a half-closed appearance and is frequently unilateral; and strabismus, a want of parallelism between the visual axes, which is insignificant if it arises from errors of refraction, but is very serious if it betokens progressive or congenital diseases of the brain or its membranous coverings. Other anomalies are asymmetry of the iris, which frequently differs in colour from its fellow; oblique eyelids, a Mongolian characteristic, with the edge of the upper eyelid folding inward or a prolongation of the internal fold of the eyelid, which Metchnikoff regards as a persistence of embryonic characters.