Between the ninth and tenth weeks, the mouth is plainly defined, the lips drawn closely together; the eyelids close the eyes; the opening of the ears begin to appear; the spinal tail shortens, and the fingers and toes assume their proper shape and position. Towards the third month, the face is distinct; the front part of the chest is covered in by the iternum; the intestines, hitherto contained in the umbilical cord, enter the abdomen; the skin begins to be organized; the embryo is now from four to six inches in length, and weighs from one and a half to two ounces. At the fourth month, the upper and lower extremities are equal; the skin is downy; the bones and muscles are so far formed as to be under the control of, and are now moved by the fœtus. It measures about seven or eight inches in length, and weighs between seven to eight ounces. About the fifth month, the auricles and vesicles of the heart are equal; the toe and finger nails are marked; the skin is still red; the features become plainly developed. The length of the fœtus is ten inches, and the weight about sixteen ounces. At the sixth month, the hair appears; the brain becomes homogeneous; the nails may be plainly distinguished; the form of the child is now distinct. The length twelve inches, and the weight nearly two pounds. At the seventh month, the skin is of a rosy color, cellular substance becomes developed; the eyelids are covered; the bile is bitter; every part of the fœtus is enlarged, and so far developed that if born at this time it will be able to breathe, cry and nurse, but very difficult to raise, or bring up, requiring, as it does, a great amount of care, and constant attention. Lacking animal heat, it must be imparted to it by being kept wrapt in a soft, flannel blanket, and in the lap of the nurse, or lay close to its mother, as its own power of generating heat is very feeble, therefore that heat necessary to its existence must be supplied to it. It is very seldom they are strong enough, bodily or constitutionally, to endure washing or dressing. Natural, or animal heat, is far preferable to fire heat. The length of the body fourteen inches, and weight about three pounds. [Illustration: Plate 2.Development of the fœtus] At the eighth month, all the parts are more developed; the infant measures sixteen inches, and weighs between four and five pounds. At the ninth month, the infant has acquired the perfect form of the human species; the two substances of the brain are quite distinct; the muscular system well developed, the bones are strong, the motions of the child quick and lively, the heart pulsates rapidly, and the circulation has become very active. The length of the body is generally twenty inches, and the weight seven or eight pounds; the crown of woman’s bliss--the true effects of wedded love. [Illustration: Plate 3. Woman showing position of fœtus] [Illustration: Plate 4. Woman showing position of twins] PERIOD OF GESTATION.