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74 ANATOMY.

The Frontal Eminences are about an inch above the superciliary
ridges, near the centre of" each lateral halt" (jf the bone : the}' are two
rounded prominences, varying in size in different individuals, and are
seldom of equal size in the same bone.
The External or Upper Surface is smooth and rounded, and passing
over it is the aponeurosis of the occipito-frontalis muscles.
The Inner or Eicranial Surface (Fig. 28) is marked by depressions
for the convolutions of the brain ; by grooves running inwardly from
Fig. 28.

UiSh PerpeniUulur 2'l^.te of EtKwoUl U
-f^r-vumj part Frontal Bone, inner .surface.
the lateral border for the accommodation of the anterior meningeal
arteries and their branches ; and by several irregular hollows on either
side of the median line for the lodgmentof the Pacchionian bodies.
The Internal Frontal Crext is the anterior termination of a groove
which occu])ics the median line of the internal surface of the bone.
The Foramen (hcum, anterior to tlic frontal cre.^t, is a groove which,
when the frontal bone is articuhited, with the ethmoid, forms a blind
foramen. This foramen is continuous in childhood with the nasal
chambers, and transmits a small vein to the longitudinal sinus. In
adult life this so-culled foramen is closed at its base.