the end of its fourth month the embryo--now four or five inches
long and weighing about an ounce--is promoted. It receives the name of
foetus. Hairs appear on the scalp, the eyes are provided with lids,
the tongue appears far back in the mouth. The movements of the foetus
are plainly felt by the mother. If born at this time it lives but a
few minutes. It continues to gain rapidly in weight. By the sixth
month the nails are solid, the liver large and red, and there is fluid
in the gall bladder. The seventh month finds the foetus from twelve
and a half to fourteen inches long, and weighing about fifty-five
ounces. It is now well proportioned, the bones of the cranium,
formerly flat, are arched. All its parts are well defined, and it can
live if born. By the end of the eighth month the foetus has thickened
out. Its skin is red and covered by a delicate down; the lower jaw has
grown to the same length as the upper one. The convolutions of the
brain structure also appear during this month.

PLACENTA AND UMBILICAL CORD

During gestation the unborn infant has been supplied with air and
nourishment by the mother. An organ called the _Placenta_, a spongy
growth of blood vessels, develops on the inner point of the womb. To
this organ the growing foetus is moored by a species of cable, the
_Umbilical Cord_. This cord, also made up mainly of blood vessels,
carries the blood of the foetus to and from the _Placenta_, absorbing
it through the thin walls which separate it from the mother's blood.
Only through her blood can the mother influence the child, since the
Umbilical Cord contains no nerves. The Umbilical Cord, attached to the
body of the child at the navel, is cut at birth, and with the Placenta
is expelled from the womb soon after the child has been born. Together
with the Placenta it forms a shapeless mass, familiarly known as the
"afterbirth," and when it is retained instead of being expelled is apt
to cause serious trouble.

CHILDBIRTH OR PARTURITION

At nine month's time the foetus is violently thrust from that
laboratory of nature in which it has formed. It is born, and comes
into the world as a child. Considering the ordinary size of the
generative passages, the expelling of the foetus from the womb would
seem impossible. But Nature, during those months in which she enlarged
the womb to hold its gradually increasing contents, has also increased
the generative passages