The one instinct the human baby always brings into the world already developed is half a mere reflex act--that of sucking. It is started as a reflex would be, by the touch of some object, pencil, finger, or nipple, it may be, between the lips; but it does not act like a reflex after that. It continues and ceases without reference to this external stimulus, and a little later often begins without it, or fails to begin when the stimulus is given. If it has originally a reflex character, that character fades out, and leaves it a pure instinct. These two types of automatic movement (for instinct, however complicated later with volition, gives rise in these earliest days to none but automatic movement) are both “purposive,” though not purposed--that is, they are actions that are plainly adapted to some end by ancestral intelligence or by natural selection. But there was another type of movements more conspicuous in our baby than either, and apparently quite nonpurposive. From the first day she moved slightly, but almost constantly, the legs drawing up, the arms stirring, the eyes and head rolling a little. Sometimes the features were distorted with vague and meaningless grimaces. Most other observers report these movements, and inexperienced ones say that the baby “felt with his hands about his face,” or “tried to get his hands to his head.” Any mother may convince herself that the baby has no will in the matter by watching till he really does begin to try, weeks later, to turn his head, put his hands to his mouth, kick up his legs: the difference in the whole manner of the action is evident. An odd explanation has been offered for these movements by Dr. Mumford, an English physiologist. He holds that they have a singular resemblance to those of swimming amphibians; that their prototype may be seen in any aquarium; they are, in short, survivals of the period long before the ape-like stage, long before any mammalian stage, when our ancestors had not yet abandoned life in the waters. Now, although it is quite true that biologists believe that if our ancestry is traced far enough, it does lead back to the water, still it seems hardly possible that in a human baby, whose structure passed the amphibian stage long before birth, the most frequent movements should hark back to that tremendous antiquity. It is more likely that Preyer’s explanation is the correct one: viz., that the movements are simply due to the rapid growth of nerve centres, which causes an overflow of nervous force to the muscles and makes them contract at haphazard. A certain regularity is given to these chance movements by the tendency of nerve impulse to flow in the same paths where it has flowed before, rather than in new ones, so that the muscles are drawn toward the position they occupied before birth. This brings the hands constantly up about the head--a fact that later has important results in development.