At 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 in size. She has made them soft and distensible, so that an apparent physical impossibility could take place, though it is often accompanied by intense suffering. Modern medical science has made childbirth easier, but the act of childbirth is usually accompanied by more or less suffering. Excessive pain, however, is often the result of causes which proper treatment can remove before and at the time of confinement. TWILIGHT SLEEP