18th week.—The very attentive regarding of the fingers in seizing is surprising, and is to be observed daily.
23d week.—When the infant, who often throws his hands about at random in the air, accidentally gets hold of one hand with the other, he regards attentively both his hands, which are often by chance folded.
24th week.—In the same way the child fixes his gaze for several minutes alternately upon a glove held by himself in his hands and upon his own fingers that hold it.
32d week.—The child, lying on his back, looks very frequently at his legs stretched up vertically, especially at his feet, as if they were something foreign to him.
35th week.—In every situation in which he can do so, the child tries to grasp a foot with both hands and carry it to his mouth, often with success. This monkey-like movement seems to afford him special pleasure.
36th week.—His own hands and feet are no more so frequently observed by him without special occasion. Other new objects attract his gaze and are seized.
39th week.—The same as before. In the bath, however, the child sometimes looks at and feels of his own skin in various places, evidently taking pleasure in doing so. Sometimes he directs his gaze to his legs, which are bent and extended in a very lively manner in the most manifold variety of positions.
55th week.—The child looks for a long time attentively at a person eating, and follows with his gaze every movement; grasps at the person's face, and then, after striking himself on the head, fixes his gaze on his own hands. He is fond of playing with the fingers of the persons in the family, and delights in the bendings and extensions, evidently comparing them with those of his own fingers.
62d week.—Playing with his own fingers (at which he looks with a protracted gaze) as if he would pull them off. Again, one hand is pressed down by the other flat upon the table until it hurts, as if the hand were a wholly foreign plaything, and it is still looked at wonderingly sometimes.
From this time forth the gazing at the parts of his own body was perceptibly lessened. The child knew them as to their form, and gradually learned to distinguish them from foreign objects as parts belonging to him; but in this he by no means arrives at the point of considering, "The hand is mine, the thing seized is not," or "The leg belongs to me," and the like; but because all the visible parts of the child's body, on account of very frequently repeated observation, no longer excite the optic center so strongly and therefore appear no longer interesting—because the experiences of touch combined with visual perceptions always recur in the same manner—the child has gradually become accustomed to them and overlooks them when making use of his hands and feet. He no longer represents them to himself separately, as he did before, whereas every new object felt, seen, or heard, is very interesting to him and is separately represented in idea. Thus arises the definite separation of object and subject in the child's intellect. In the beginning the child is new to himself, namely, to the representational apparatus that gets its development only after birth; later, after he has become acquainted with himself, after he, namely, his body, has lost the charm of novelty for him, i. e., for the representational apparatus in his brain, a dim feeling of the "I" exists, and by means of further abstraction the concept of the "I" is formed.