SEX

27

The bones of the adult female are usually smaller and lighter than those
of the adult male, and have less marked ridges and processes for muscular
attachments.

The adult female skull is, as a rule, lighter and smaller, its cranial
capacity being about ten per cent less than that of the adult male. The
glabeUa, zygomatic and superciliary arches, mastoid processes, and the
occipital protuberance are less prominent in the female. The female facial
bones are more delicate and smaller, especially the maxillae, mandible and
the teeth contained in them. The frontal sinuses are less developed in the
adult female than in the adult male.

The female thorax is shorter and wider than that of the male. The
sternum in the female is shorter and its upper margin is on a level with
the lower part of the body of the third thoracic (dorsal) vertebra, while in
the male it is on a level with the lower part of the body of the second. The
sternal body is less than twice the length of the manubrium in the female,
while it is at least twice its length in the male. This is due to the fact that
the manubrium in the male is somewhat smaller than that in the female.
The ribs are thinner and have a greater curvature, and the costal arches are
larger.

Fig. 5.—The Male Pelvis.

Fig. B—The Female Pelvis

The pelvis affords the best marked and most reliable characteristics for
distinguishing sex. The female pelvis is shallower, wider and smoother
than the male pelvis. The ilia in the female are less sloped, their posterior
"borders are more rwinded* the anterior superior iliac spines are more widely
separated and the great sciatic notches are much wider, forming almost a
right angle than in the male. Hie female sacrum is short and wide, and is
sharply curved forward in its lower half, while the male sacrum is long and
narrow, and has a uniform curvature along its whole length. The auricular
surfaces extend over two to two and a half stunted bodies in the female and
over two and a half to three elongated bodies in the male. The qbtuator fora-
mina are triangular in the female and ovoid in the male. The pre-auricu£r
suIcTare commonly present and well marked in the female, and are usually
absent in the male. The superior aperture of the lesser pelvis in the female
is larger, more nearly circular, and its obliquity is greater than in the male,
«The ischial tuberosities are everted in the female, and are inverted ,in
'male. The acetabula are narrow in the female and wide in the "

pubic symphysis in the female is less deep, and the pubic arch
more rounded than in the male, where it forms an angle ratter :