After the formation of the skin and procreative organs, as stated, the little being again shows signs of life, and struggles in its Egg until it frees itself from all the membranous substances which surround it, and is enabled to turn round at its pleasure. Its movements are frequently rapid and lively, and they doubtless are necessary to the formations and changes which soon begin to take place. At the end of twelve days the Ovum is found to be enlarged to the size of a pea, and its whole organization may be seen with the naked eye. It is coated with two membranes, between which is a gelatinous substance, and the interior is filled with a fluid in which the fœtus swims about at pleasure. On a close examination, the mouth and eyes can be seen about the fifteenth day. The eyes first appear on the side of the head, and, as the Fœtus grows, they move round to their position. In ten days more we see the future being in form and size like a small ant. At the end of the first month it has increased to the size of a honey-bee, and the arms begin to grow—first appearing like small warts on the body. They sprout straight out, and are then folded together on the breast. At this time the head is as large as all the rest of the body, and the features can be distinguished. The legs have not yet appeared, but the lower extremities are like a tail. At two months the legs and feet appear, the toes being united similar to frogs’ feet. During the tenth week the eyes show their lids, the mouth becomes more prominent, and the ears may be seen. The heart is now fully developed, but as yet contains no blood. The brain shows its form and substance. The next change brings red blood to the larger veins and to the heart, and at the end of three months the shape and form of the future being is nearly perfect, weighing less than three ounces. The next process of Nature is the thickening of the skin, and so rapid now is the growth that within one month the Fœtus fully doubles in weight. During the fourth month the bones begin to ossify, the uterus rises in the abdomen, and we are then enabled to determine the sex. This change is what is usually called quickening, and it corresponds with the time of breaking the shell in birds. At the end of the fifth month the finger-nails appear, and fine silky hair begins to grow on the head. At seven months the being is generally perfect, the bones are firm and hard, and it weighs about three pounds. The intellectual faculties are not developed, however. The eighth and ninth months merely increase the size and strength of the child. Our Engravings show the relative sizes and position of a Fœtus, as it lies in the Womb, at three several stages of gestation. They are original drawings from anatomical figures in wax in the New York Anatomical Museum. [Illustration: FŒTUS AT THIRTEEN WEEKS.] [Illustration: FŒTUS AT SIX MONTHS.] [Illustration: POSITION OF THE CHILD AT NINE MONTHS.]