e
function of the recognition of sounds heard and of their
discrimination.

[Footnote 12: This fact is analogous to our common experience of being
awaked by a loud noise and then hearing it after we awake; yet the
explanation is not the same.]

Again, the same phenomenon to an equally marked degree attended the
sound of her breathing. It is well enough known that the smallest
functional bodily changes induce changes in both the rapidity and the
quality of the respiration. In sleep the muscles of inhalation and
exhalation are relaxed, inhalation becomes long and deep, exhalation
short and exhaustive, and the rhythmic intervals of respiration much
lengthened. Now degrees of relative wakefulness are indicated with
surprising delicacy by the slight respiration sounds given forth by
the sleeper. Professional nurses learn to interpret these indications
with great skill. This exaltation of hearing became very pronounced in
my operations with the child. After some experience the peculiar
breathing of advancing or actual wakefulness in her was sufficient to
wake me. And when awake myself the change in the infant's respiration
sounds to those indicative of oncoming sleep was sufficient to suggest
or bring on sleep in myself. In the dark, also, the general character
of her breathing sounds was interpreted with great accuracy in terms
of her varied needs, her comfort or discomfort, etc. The same kind of
suggestion from the respiration sounds now troubles me whenever one of
the children is sleeping within hearing distance.[13]

[Footnote 13: This is an unpleasant result which is confirmed by
professional infants' nurses. They complain of loss of sleep when off
duty. Mrs. James Murray, an infants' nurse in Toronto, informs me
that she finds it impossible to sleep when she has no infant in
hearing distance, and for that reason she never asks for a vacation.
Her normal sleep has evidently come to depend upon continuous
soporific suggestions from a child. In another point, also, her
experience confirms my observations, viz., the child's movements,
preliminary to waking, awake her, when no other movements of the child
do so--the consequence being that she is ready for the infant when it
gets fully awake and cries out.]

The reactions in movement upon these suggestions are very marked and
appropriate, in customary or habitual lines, although the stimulations
are quite subconscious. The clearest illustrations in this body of my
exper