Page:Popular Science Monthly Volume 11.djvu/610

592. These are commonly spoken of as instinctive actions, but it is impossible to separate them from the class last spoken of. A little higher than the reflex actions are the truly instinctive ones, as a type of which we may take the actions of some very young chickens, experimented upon by Mr. Spalding. In a paper read before the British Association, this experimenter says: "Chickens hatched and kept in the dark for a day or two, on being placed in the light nine or ten feet from a box in which a brooding hen was concealed, after standing chirping for a minute or two, uniformly set off straight to the box, in answer to the call of the hen, which they had never seen, and never before heard. This they did, struggling through grass, and over rough ground, when not able to stand steadily on their legs. Again, a young hawk was made to fly over a hen with her first brood of chickens, then about a week old. In the twinkling of an eye most of the chickens were hid among the grass and bushes; and scarcely had the hawk touched the ground, about twelve yards from where the hen had been sitting, when she fell upon it, and would soon have killed it outright. A young turkey gave even more striking evidence. When ten days old it heard the voice of the hawk for the first time, and close beside it. Like an arrow from a bow it darted off in the opposite direction, and crouched in a corner, and remained for ten minutes motionless and dumb with fear." These examples will serve as illustrations of pure instinct, and we will pass now to actions which are superior, but obviously similar, to the instinctive ones. Actions which are frequently repeated become habitual, and habits of long standing become so firmly fixed that the actions are performed unconsciously, and, as it were, instinctively.

Most of us can remember the labor and pains which were required in order to learn to write: the comparatively easy acquisition of the art of making down-strokes, and the tendency, which we adhered to so obstinately, to form all our letters with down-strokes, and to fill in the curves and shading afterward. Any one who has watched a child writing has observed the necessity under which it labors for counting the bends to distinguish an m from an n, and the tax which an hour's writing inflicts upon all its bodily and mental powers. Constant practice soon renders writing habitual, and the necessary muscles act mechanically, so that we are able to give all our attention to the intellectual part of the process, while the writing is done without any effort or attention. A well-drilled soldier performs the proper evolution at the word of command, although he may be so preoccupied or so fatigued as to be perfectly unconscious of his actions. Such habits are remarkably persistent, especially when they are acquired early in life, and they have nothing to distinguish them from instinctive actions except that they are unconscious.

They are often performed involuntarily, and even in opposition to a previous determination. Street-car horses soon learn to stop and