resistance. The channel once made, it requires strong obstruction to change the course, because the banks harden to the form carved by the current.

Just as the formation of the shape of the river bank, becoming hardened and fixed, governs to an extent the future course of the stream, so do physical formations in the nervous system become fixed as a result. of thought incessantly flowing in the same current, or reflex acts constantly repeating themselves. As the banks of a stream govern the current, thus do bodily habits once fixed, by very limitations in form of physical matter, govern or influence the thought.

The nerve substance is peculiarly plastic -reconstructive changes are constantly taking place in the nervous system, as in all other forms of organic matter, markedly similar to the changes in waste and nutrition occurring in all parts of the body, in the breaking down of tissue and repair by nourishment. It is not known, but it is probable that nerve changes conform to the

same law of metabolism as other bodily tissues.

"There is no part of the organism of man in which the reconstructive activity is so great, during the whole period of life, as in the ganglionic substance of the brain," but the plan of the building process is being constantly modified, and man, in adult life, is the expression of a bundle of habits, acquired during the growing period, -the required mechanism, which results during the reconstructive period, is thus maintained in the ordinary course of nutritive operations, so as to be ready for use even after a long period. This bundle of habits of body and mind characterizes the individual—designates the character.

Truly, as a man thinketh, so is he. This is not only a moral but a physical fact, for nerve and muscle conform in outline to his thoughts; each thought makes a pathway through the nerves, which, if repeated, changes the location of nerve molecules, somewhat as plaster is moulded by the hand; if repeated for years it becomes as set as plaster-"a fixed habit." To

change the form of the molecules where firmly fixed requires often some great upheaval of the emotional nature, or of the will, sufficiently strong to break up the pathway of nerve impulse. Thus occasionally one whose cells have been formed into abnormal grooves until on the verge of insanity, has this brain path broken by some strong upheaval of the emotions and he "comes to himself" again.

In the growth and reproduction of the nervous system, there is a decided tendency to produce a determinate type. This type is peculiarly liable to modification during early life, because of the plasticity of the nervous system. Thus habits are more easily fixed during the growing periodand character, which is a summing up of mental habits, more readily formed.

"Every state of ideational consciousness, either very strong or habitually repeated, leaves organic impression upon the cerebrum, in virtue of which that same state may be reproduced at any future time by some exciting occurrence." Poetry or

quotations learned "by heart" in early life fix themselves in the growing brain becoming a part of its normal fabric, and the mode in which it has been exercised is readily maintained by the nourishment conforming to the same mode,-like a scar, which is reproduced as the body changes. Quotations learned in early life, forgotten or dormant for years, come to mind.

The brain of a child being plastic, directing the thoughts and filling the brain repeatedly with beautiful, upright ideas is imperative, if he is to grow to uprightness; for his ideals become a part of the very woof of his being, and he can no more escape from them than he can escape from a scar in his flesh. Every train of thought, continually recurring to the child, is like a garden filled with perennials, which repeatedly renew themselves, yet the thought is never uprooted.

Since the brain and the nerves actually change in construction, as a result of thought, it is apparent that mental and moral habits have a definite, physiological basis.

The law of physics that "a body in motion tends to keep in motion, or a body at rest tends to remain at rest," is simply an expression of habit.

The laws of nature may be said to be the laws of habit, to be accounted for in all organic and mental life upon a physical basis. The elementary atoms do not change but their arrangement in any compound matter may change, thus changing the shape and outline of the mass; this change in location of atoms, hence in form, may be wrought either by outward or inward forces, if the matter be sufficiently plastic to admit of change.

A book opened to a certain page will open more readily to the same page again, because the molecules have changed places. The first step which a child takes is the hardest, each succeeding one becoming easier, until he walks almost automatically; -this is due to the ease with which the molecular changes are made in the young body and to the ready plasticity of the tissues.