A new-born baby cannot probably do any more than distinguish light from darkness. Up to the sixth week there is an inability at coordination of the ocular muscles; after this time the eyes begin to move in an orderly manner, and they will follow a bright object moved slowly in front of them. At about the end of the second month rapid movements are perceived, as is evinced by the child's closing its eyes quickly on an object suddenly approaching it. At three months the child begins to recognize colors; the first recognized are yellow, red, pure white, gray, and black. But the faculty of distinguishing between colors is not perfected till the third year. The mother is recognized about the third month. Hearing and a sense of smell develop rapidly after birth; loud noises in its vicinity will cause a child to start during the first day after birth. By the time the child has reached three months of age it shows signs of having a mind of its own, and is capable of exercising thought. It grasps for objects, and indicates its likes and dislikes. At from eight to ten months it can utter several syllables, and at the age of one year should be able to say mama and papa; at two years it should be able to frame short sentences.

Weight of the Baby.— By the end of the sixth month the child's weight should be double what it was at birth; that is, about fourteen pounds; at the end of the twelfth month be three times as much as at birth, or about twenty pounds.

Muscular Action.— Muscular action in the new-born infant is entirely involuntary, there being no voluntary acts until about the end of the third month. Sucking and licking are largely instinctive. The movements of the arms and legs are impulsive acts, and occur during sleep, just as they did in the intra-uterine life. The act of raising the head, which is attempted about the fourth month in healthy children, is volitional, requiring not so much added strength of muscle as power of coordination. As volition develops the power of coordination gradually increases, and the child learns to perform voluntary or purposeful acts. Voluntary grasping is done after the fourth month. As the child learns to balance its head, it attempts to sit up. This act is not successfully accomplished until about the fortieth week; the child sits firmly alone when ten or eleven months old. Before this time it is necessary to support the head and spine of the child with the hand. By the third or fourth month the infant should be able to grasp things. The child begins to creep about the ninth month. The clothing should be so arranged as to allow entire freedom of motion.

It should be able to stand up by a chair by the tenth month, and be able to walk alone at the end of the first year. It is important that parents should know this, since not knowing what a normal baby ought to be able to do, cases of birth palsy, or even an attack of paralysis due to teething, are not infrequently overlooked, not only by the mother, but even by the doctor, who attributes the inability of the child to do what other children can do at this age simply to weakness, which the child will outgrow; and thus the time passes in which the most could be done to cure the child and to prevent the subsequent deformity.

A baby should not be forced to stand or walk; a very stout baby, on account of its weight, will stand up and walk much later than a slight one, the two being equally healthy. Or if a baby has been sick, it will feel no inclination to stand up. Naturally, a child creeps before it walks, and this develops the muscles of the lower limbs, so that they will support the weight of the child in standing. By prematurely forcing a child to stand up and walk, there is danger of causing bow-legs, as the bones of the legs are still weak; the child should be discouraged from standing up too much rather than encouraged to stand up more.

Sleep.— A large proportion of the time of early infancy is spent in sleep; for the first few weeks the infant only wakens up to be fed. During sleep the eyelids should be tightly closed; a partial opening of the lids, showing the whites of the eyes, is an indication of ill health. Up to the age of six, children require twelve hours of sleep at night, besides an hour or more in the middle of the day; the child should be permitted to sleep as long in the morning as it will.

Respiration.— The healthy infant breathes on an average forty-four times a minute; the only time the respirations can be satisfactorily counted is during sleep. When the child is awake, the respirations are hurried by slight movements of the body, crying, and so forth. The average pulse of a newborn baby is one hundred and forty; this is hurried by the same causes that hastens respirations; the pulse is most easily counted at the anterior fontanel. The average temperature of the infant is 99° F. When the tip of the nose and the extremities are cold, it indicates a lowered vitality.

The nature of the child's cry indicates, variously, hunger, temper, or pain; the mother will soon learn to distinguish these varieties. If the child cries because it is hungry, the cry ceases so soon as it is fed. But a child is never to be fed simply because it cries; it must be fed on the hour by the clock. If this rule is not strictly adhered to, it will suffer all the forms of indigestion and colic that babies are heir to. If it cries because of colic, there is a drawn look on the face, and at the same time the legs are sharply flexed on the thighs and the thighs on the abdomen. If the cries are due to earache, the head will be rolled about from one side to the other. In either case nothing will stop the cries until the pain is relieved. A baby does not shed tears until the third month.

The Stools.— The stools of a very young baby fed on breast-milk should be of a yellow or orange color. There should be three or four evacuations daily; they should contain no curds. Stools of bottle-fed babies are lighter in color and more offensive.

Constipation.— Constipation is not uncommon in infancy; it may be overcome by the use of a soap suppository, or by an injection of warm soap-suds into the bowel, or by an injection of oil and water, or by gentle friction over the bowel, following the course of the large intestine.