In the first place, we may note the intense auto-suggestion of sleep already pointed out, under the stimulus of repeated nursery rhymes or other regular devices regularly resorted to in putting the child asleep. Second, surprising progressive exaltation of the hearing and interpretation of sounds coming from her in a dark room. At the end of four or five months, her movements in bed awoke me or not according as she herself was awake or not. Frequently after awaking I was distinctly aware of what movements of hers had awaked me.[12] A movement of her head by which it was held up from the pillow was readily distinguished from the restless movements of her sleep. It was not so much, therefore, exaltation of hearing as exaltation of the 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.]