Even dead and inert matter obeys the same principles in this regard as does
living matter. Says M. Leon Dumont: "Everyone knows how a garment, having
been worn a certain time, clings to the shape of the body better than when it was
new; there has been a change in the tissue, and this change is a new habit of
cohesion; a lock works better after having been used some time; at the outset
more force was required to overcome certain roughness in the mechanism. The
overcoming of this resistance is a phenomenon of habituation. It costs less
trouble to fold a paper when it has been folded already. This saving of trouble is
due to the essential nature of habit, which brings it about that, to reproduce the
effect, a less amount of the outward cause is required. The sounds of a violin
improve by use in the hands of an able artist, because the fibers of the wood at
last contract habits of vibration conformed to harmonic relations. This is what
gives such inestimable value to instruments that have belonged to great masters.
Water, in flowing, hollows out for itself a channel, which grows broader and
deeper; and, after having ceased to flow, it resumes when it flows again the path
traced for itself before. Just so, the impressions of outer objects fashion for
themselves in the nervous system more and more appropriate paths, and these
vital phenomena recur under similar excitements from without, when they have
been interrupted for a certain time."[2]
All Living Tissue Plastic.—What is true of inanimate matter is doubly true of
living tissue. The tissues of the human body can be molded into almost any form
you choose if taken in time. A child may be placed on his feet at too early an
age, and the bones of his legs form the habit of remaining bent. The Flathead
Indian binds a board on the skull of his child, and its head forms the habit of
remaining flat on the top. Wrong bodily postures produce curvature of the spine,
and pernicious modes of dress deform the bones of the chest. The muscles may
be trained into the habit of keeping the shoulders straight or letting them droop;
those of the back, to keep the body well up on the hips, or to let it sag; those of
locomotion, to give us a light, springy step, or to allow a shuffling carriage;
those of speech, to give us a clear-cut, accurate articulation, or a careless, halting
one; and those of the face, to give us a cheerful cast of countenance, or a glum
and morose expression.
Habit a Modification of Brain Tissue.—But the nervous tissue is the most
sensitive and easily molded of all bodily tissues. In fact, it is probable that the
real habit of our characteristic walk, gesture, or speech resides in the brain,
rather than in the muscles which it controls. So delicate is the organization of the
brain structure and so unstable its molecules, that even the perfume of the