| AGE | WEIGHT | AGE | WEIGHT | |||||
| 1st mo. | 7 | to | 10 lbs. | 7th mo. | 14 | to | 17 | lbs. |
| 2nd ” | 8 | ” | 11 ” | 8th ” | 15 | ” | 18 | ” |
| 3rd ” | 10 | ” | 13 ” | 9th ” | 17 | ” | 19 | ” |
| 4th ” | 12 | ” | 14 ” | 10th ” | 18 | ” | 20 | ” |
| 5th ” | 13 | ” | 15 ” | 11th ” | 19 | ” | 21 | ” |
| 6th ” | 13 | ” | 16 ” | 12th ” | 20 | ” | 24 | ” |
Height
The same thing can be said about height as about weight of children. There is no standard, since there are so many variations to consider, but there is a general average. The average length of the infant at birth is about twenty and one-half inches. The average normal growth the first year is about nine inches. Growth in height of the child does not indicate much in the way of nutrition, since a child may grow in height and at the same time lose in weight. The greatest growth in height is made at the time of puberty. Girls begin this rapid growth about twelve years of age and will mature more rapidly than boys, since boys do not begin this rapid growth until the thirteenth or fourteenth year; but, in the fifteenth year the boys will be taller than the girls.
Growth in height is not retarded by malnutrition to the same degree as is weight. The average growth of the normal child during the second year is about four inches; for the third year a little less; for the fourth year still a little less, about three inches. Bowditch tells us that after the fifth year the average growth is about two inches a year up to the time of puberty.
THE SPECIAL SENSES
Sight
The eyes of the infant are very sensitive to the light and every effort is made by the child to avoid bright light and thus protect the eyes from glare; the eyes will innately close when a bright light is brought before them. For the protection of the infant’s eyes the room should be kept darkened for the first few weeks. A subdued light will usually attract the attention of an infant and as early as the sixth day the child may even turn the head in an effort to follow the light with the eyes.
It is not uncommon for the eyelids to remain partly separated during sleep and for the movement to be more or less irregular during the first few weeks of life. The muscles of the eyeballs do not always coördinate in their action. This often results in temporary strabismus when the infant is looking intently at an object. Perfect coördinate action is often as late as the third or fourth month.
Hearing
The hearing of the infant is very acute, although it is asserted that the child is unable to hear for the first twenty-four hours after birth. This is due to the absence of air in the middle ear. During the process of respiration air is gradually admitted to the middle ear and hearing becomes very acute, so much so that sharp noises will startle the child. For this reason the nursery should be so located that it may be as free as possible from noise. Noise is trying on the nervous system and should be avoided as far as possible. As early as two months of age the infant will turn his head in the direction of the noise.