Page:Popular Science Monthly Volume 17.djvu/645

Rh at imitation; the imitative faculty does not begin to be developed till the second half-year. We must look within the child for their cause. An inner cause must be either acquired or inherited. The idea of an acquired cause, presupposes varied experiences and observations, of which the child has had none. The inherited causes, then, are the only ones we can consider. It is not enough to say on this point that the child moves as it does because its ancestors did so when they were young. That would only set the problem a step further back. We should rather say that the peculiar movements take place because the central nervous motor organs, when they are fully developed, discharge irregularly the surplus store of motive energy which has been inherited. They have been called instinctive, but instinct comprehends a kind of inherited recollection, and has some definite end, while the motions are aimless. They are impulsive—the direct effect of the nervous energy of the spinal marrow before it has become subject to the restraint of the brain. As the brain is developed, and the intellect manifests itself, the excessive movements are limited, and in persons who have received the most perfect training they are hardly observed at all. They cease when the man has learned to exert the full power of his will over them.

The first manifestation of the will in the child appears when it begins to hold up its head. A chicken can not hold its head up during the first hour after it is hatched; but it can do that, and even pick up a grain of corn, before it can walk or stand firmly. It then begins to run, and learns to do in a day what it takes the human infant a year to accomplish. My attempts to hold a child up straight were not successful for fourteen weeks. Evident voluntary effort began at that time, and after four months the child was able to keep its head well balanced. The lack of power to hold the head up before was not due to want of muscular strength, for the reflex actions, such as that of turning the head, requiring as much power of muscle, were performed firmly enough. Next, after the head, the upper part of the body was balanced. The power to sit up was acquired in about the tenth month, all at once, after the child had been kept up by artificial supports for several weeks. So ability to stand was gained suddenly at the end of the first year, after numerous unsuccessful efforts to stand by the aid of chairs, tables, and the walls of the room. The next acquisition, that of walking, likewise seems to come of itself. Its beginning is obscure, for there appears no occasion in the act of standing for the alternate bendings and stretchings of the legs which enter into it. Similar movements may take place, it is true, when the child is lying down, in its bath or in its cradle, but the regular alternation of them in a standing position is quite different, and is probably, like the act of sucking, derived by inheritance.

It may often be months before the effort to walk is successful, but, if the child is allowed to creep without being interfered with, it will