ull (21.22%), the
bone of the Incas already alluded to (4%), and above all, the median
occipital fossa. Of great importance also are the prominent frontal
sinuses found in 25% (double that of normal individuals), the
semicircular line of the temples, which is sometimes so exaggerated that
it forms a ridge and is correlated to an excessive development of the
temporal muscles, a common characteristic of primates and carnivores.
Sometimes the forehead is receding, as in apes (19%), or low and narrow
(10%).

_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 zygomae 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 phy