The escape or expulsion of the Germinal Vesicle from the Ovum, or Egg, leaves, as we have already explained, a passage to its very centre, thus enabling the Zoospermes, or male animalculÆ, to enter. If both are perfect and healthy, impregnation is then complete. The first change that now takes place is observed in the Vitellus, or yellow of the Egg, which at once forms itself into a mass of little globules; and it is a singular fact that these are always a fixed even number, generally beginning with four or six, and so multiplying or doubling—always, however, keeping the number even. If by chance they should end their self-arrangement by an odd number, a perfect being could not be formed—the impregnation would end either in an abortion or an unnatural growth in the Womb. It generally takes two or three days for the globules to arrange themselves, and meantime the Zoosperme, or male principle, remains dormant. The globules soon begin to form themselves either into Testicles or Ovaries, as the sex may be, of the future being. At the same time myriads of smaller globules break off from them and spread all round the Zoosperme, which is soon entirely covered or coated with them. They now grow together and form the skin. The Zoosperme is supposed to be the head and spine, and the globules, which thus form the skin, shut out our view from observing any further formations. The Testicles, or Ovaries, as the case may be, are now quite prominent, though we cannot yet determine the sex, even with the most powerful microscope, nor is there any form to the new being other than the original shape of the male animalculÆ.

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 foetus 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 Foetus 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 Foetus 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 Foetus, 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.

The child, previous to birth, never takes nutriment in by its mouth, for that is always firmly closed until after birth. Its food during gestation is probably derived from the blood of its mother through the umbilical cord, or navel-string, which likewise supplies its veins and arteries until the very hour of birth. An artery and two veins pass through this cord. There is sometimes an impediment in the circulation of new-born infants, which is called the blue disease, and for which there is no remedy. In these cases the body is of a leaden blue color, and the child appears sleepy and inanimate. Such children usually die before they are a year old, though sometimes they live four or five years.