several weeks, and probably several months, pass before an infant can
see anything save as blurs of light and darkness. Objects, such as a
hand, probably appear as shadows, which are not correctly interpreted
until late in infancy.

In regard to color vision we have as yet no reliable information
concerning children under two years of age. Infants of less than a
year have been known to distinguish certain colored papers. But such
discrimination is probably due to a difference in brightness of the
colors.

Although the organ of hearing is well developed at birth, the drum of
the ear in very young infants cannot transmit sounds, as in the
adult. For the latter kind of transmission it is necessary that the
pressure on both sides of the drum-membrane should be equal, and this
is arranged by the admission of air to the middle ear through a
passage from the throat. At the time of birth, on account of the
swollen condition of the mucous membrane which lines this passage, it
is blocked, and the middle ear is filled with fluid; these conditions
interfere with the transmission of sound, and consequently its
perception is dulled. But even in the absence of a drum-membrane an
adult can hear; the vibrations in such cases are transmitted through
the bones of the skull, and this very likely also occurs in newly
born infants. In most instances, at least, they react to a
disagreeable noise within the first twenty-four hours, and their
sensitiveness in this direction explains why the nursery should be
kept quiet.

Investigators have not come to uniform conclusions concerning the
sense of smell and of taste. In all likelihood, smell is not acute at