_Why do they not gain so rapidly at first?_ It takes a few weeks for the stomach to become accustomed to cow's milk, and until this is accomplished it is necessary to make the milk very weak or the child's digestion will be upset. _For a child of average weight at birth (seven to seven and a half pounds) what should be the weight at the different periods during the first year?_ At three months it should be twelve to thirteen pounds; at six months, fifteen to sixteen pounds; at nine months, seventeen to eighteen pounds; at one year, twenty to twenty-two pounds. At five months a healthy child will usually double its weight, and at twelve months it will nearly treble its weight. _Do all healthy infants gain steadily in weight during the first year?_ As a rule they do; yet it is seldom the case that one gains every week for the entire year. With most infants there are from time to time periods of a few weeks in which no gain is made. These are more often seen from the seventh to the tenth month and frequently occur when the child is cutting teeth, sometimes during very hot weather. _Is it true that every infant who gains rapidly in weight is thriving normally?_ Not invariably. Some who are fed upon prepared infant foods increase rapidly in weight but not in strength, nor in their development in other respects. _Is the weight of as much value in the second year as a guide to the child's condition?_ After the first year, the gain in weight is seldom continuous; there are many interruptions, some depend on season, and others often occur without apparent cause. _At what age should the fontanel close?_ The average is about eighteen months. It seldom closes earlier than fourteen months, and it should not be open at two years. _At what age should a child hold up its head?_ As a rule during the fourth month, and often during the third month, the head can be held erect when the body is supported. _When does an infant first laugh aloud?_ Usually from the third to the fifth month. _When does it begin to reach for toys and handle them?_ Usually from the fifth to the seventh month. _At what age should a child be able to sit and to stand alone?_ At seven or eight months a healthy child is usually able to sit erect and support the body. During the ninth and tenth months are usually seen the first attempts to bear the weight upon the feet, and at eleven or twelve months most children can stand with assistance. _When should a child walk alone?_ The first attempts are generally seen in the twelfth or thirteenth month. At fifteen or sixteen months the average child is able to run alone. _What conditions postpone these events?_ Prematurity, a very delicate constitution, any severe or prolonged illness, and especially chronic disturbances of digestion making feeding difficult. A common cause of late sitting, standing, or walking is rickets. _Should a child be urged to walk?_