s a substitute.
With the deaf infant the study of the mouth-movements is, as is well
known, the only means of understanding words spoken aloud, and it is
sight that serves almost exclusively for this, very rarely touch; and
the child born deaf often repeats the visible movements of lips and
tongue better than the hearing child that can not yet talk. It is to
be observed, in general, that the hearing child makes less use, on the
whole, of the means of reading-off from the mouth than we assume, but
depends chiefly on the ear. I have always found, too, that the child
has the greatest difficulty in imitating a position of the mouth, in
case the sound belonging to it is not made, whereas he easily achieves
the same position of the mouth when the acoustic effect goes along
with it.

Accordingly, the connection between the ear and the speech-center must
be shorter or more practicable in advance (hereditarily) than that
between the eye and the speech-center. With regard to both associations,
however, the gradually progressive shortening or consolidating is to be
distinguished in space and time. With the child that does not yet speak,
but is beginning to repeat syllables correctly and to associate them
with primitive ideas, the act of imitation takes longer than with the
normal adult, but the paths in the brain that he makes use of are
shorter, absolutely and relatively--absolutely, because the whole brain
is smaller; relatively, because the higher centers, which at a later
period perform their functions with consciousness and accessory ideas,
are still lacking. Notwithstanding this, the time is longer than at a
later period--often amounting to several seconds--because the working up
of what has been heard, and even the arrangement of it in the center for
sound-images, and of what has been seen in the center for sight-images,
takes more time apart from a somewhat less swift propagation of the
nerve-excitement in the peripheral paths. The child's imitation can not
be called fully conscious or deliberate. It resembles the half-conscious
or unconscious imitation attained by the adult through frequent
repetition--i. e., through manifold practice--and which, as a sort of
reminiscence of conscious or an abbreviation of deliberate imitation,
results from frequent continuous use of the same paths. Only, the
child's imitations last longer, and especially the reading-off from the
mouth. The child can not distinguish the positions of the m