ABSTRACT
The chief cause of the infant’s helplessness lies in the unde veloped state of its locomotor apparatus. It cannot withdraw from disagreeable situations by means of its own body; it cannot seek agreeable situations. As far as its whole body is concerned, the infant is passively exposed to the stimulus world. The infant cannot exercise actively to any con siderable extent, and, above all, not completely; an action of the entire body cannot be accomplished; but each organ acts independently. The child attains some degree of co-ordination in the third month, when the head turns toward the source of the sound, so that it can also be seen; but even this action, combining three different organs, is limited to the head. The second quarter of the first year brings with it considerable progress, in that the arms, and hands, later the upper part of the body, and finally the legs, are called into the unified act. To present this stage of the infant’s development will be my next task. I refer in some phases to the first quarter of the first year, for all demarcations, and especially temporal demar cations, are flexible. Thus there will be an opportunity to follow up some manifestations which were not mentioned, or barely mentioned, in the preceding chapters.
