"Every child shows a distinct individuality in his behavior by the end of the third month. This is because the actual structure of the muscles varies from baby to baby. The alignment of the muscles of the face, for example, follow an inherited pattern. The facial expressions of the baby in his third month are already similar to the facial expressions of his parents. Further refinements are noted in the third month. The fingernails appear. The child’s face becomes much prettier. His eyes, previously far apart, now move closer together. The eyelids close over the eyes. Sexual differentiation is apparent in both internal and external sex organs, and primitive eggs and sperm are formed. The vocal cords are completed. In the absence of air they cannot produce sound; the child cannot cry aloud until birth, although he is capable of crying long before."