The student of physiology and of psychology cannot expect to have a sound base and foundation for his structure of knowledge unless he becomes thoroughly familiar with the nature and character of the cells of which the entire human body is composed.

The corporeal cells are those very minute elementary structures of which the organic tissues are composed. By tissues is meant the elementary materials, varying in structure and function, which compose the bodily organs, members, and parts. And, consequently, the cell is the physical base of the activity of the Corporeal Mind. So, from the position of both physiology and of psychology the cell is the logical subject of the beginning of study and investigation.

The corporeal cells are very minute; in fact, they are microscopic. From them are built up the muscles, tissues, nerves, blood, bones, hair, and nails. From the hardest enamel of the tooth to the most delicate and soft tissue of the mucous membrane, the human body is found to be composed of cells. And these cells are, for all practical purposes of comparison, identical with the single cells which exist as independent entities or living creatures in the lowest forms of the life scale. So that, at the last, every human body is in reality a great community of cells, grouped and associated, co-ordinated and combined for co-operative work and functioning, yet each a separate living organism.

Each of these cells is nucleated, that is to say it has as it center a nucleus which is the most vital point of its being. The nucleus of the cell is its central life-spot; which may be compared to the yolk of an egg. It is more complex than the general substance of the cell, and seems to contain within itself the essence of the life and being of the cell. The cells reproduce themselves by growth and division; they are born, perform their tasks, give birth to other cells, and then die.

The cells preserve a certain degree of individuality and separateness, though their work is performed by reason of their tendency to combine with other cells into groups, and these into still larger groups, and so on; a constant relation being maintained between the members of each group, and so on until all the cells in the body are considered as a great group connected in all of its parts and divisions.

And now let us take a glance at the work performed by these wonderful little bits of living substance, in their various groupings and association with each other. Physiology recognizes about forty different kinds of cells, yet all belong to the one great family of cells. Their differences are merely such adaptations to function, work and purpose as we might expect; the differentiation having resulted in the course of organic evolution.

For instance, we find the great family of muscle-cells, which are adapted to their work of contracting the muscles which they compose. Then there are the connective-tissue cells which join together and form the tough fibrous tissue which binds together and protects the various parts of the organism. Then again, we find the bone cells which select, arrange, and set in place the lime material of which the bony parts of the body is composed. Then we find the several group of cells which select and place in position the silicate mineral substances which are needed to form the nails, the hair, and other similar parts of the body. Then there are the gland cells which work industriously to secrete the fluids needed in digestion and similar vital processes. Then we discover the very active family of blood cells the members of which work to build up and repair the various parts of the system, and to do the scavenger work of carrying off the debris of the system to be burned-up by the oxygen in the lungs. And, passing over many equally important families of cells, we finally come to the family of brain and nerve cells, the work of which renders possible all feeling, thinking and acting of the human being.

The cell families of the body are like a great cooperative community, each cell and each group of cells performing its own work in the community, each acting for its own good, and the good of its particular group, and at the same time for the good of the entire body of cells. You must here remember that the body exists only as a body of cells-a great co-operative community of cells. It is not sufficient to say and think that "the body has cells," but rather that "the body is a collection of cells," or even "the cells are formed into a body of cells."

Some of the cells are on the active line, while others are held in reserve to be called upon in case of sudden need. Some are stationary, while others remain stationary until called into motion, and a third general class is always moving about; of this moving-about class some make regular trips, while others are rovers and free adventurers, like tramp ships sailing from port to port without making regular trips, between ports.

Some of the cells carry burdens of material from place to place-building material needed by certain stationary cells performing building work. Other cells perform scavenger work, and gather up the garbage of the system. Other cells perform police work, and arrest intruders in the system, often actually locking them up by building a wall around them. Other cells form the army which repels the microbes and germs of disease which have invaded the system. The cells of the nervous system form a living telegraph wire, joining hands (so to speak) and passing along the message from one end of the line to another.

The number of cells in the human body is countless. A faint idea of their almost infinite number may be formed by considering the fact that in each cubic inch of blood there are over 75,000,000,000 (seventy-five thousand million) of the red-blood cells alone, not taking into consideration the millions of other kinds of cells.

The red blood cells travel along in the blood flowing through the arteries and veins; first taking up a supply of oxygen from the lungs, and carrying it through the arteries to the various parts of the body, where they deliver it to the cells requiring it for vital processes. Then, starting on their return journey through the veins, they gather up the waste products of the system, such as the broken down cells which have been used up ill their work and which have died; this debris is finally consumed in the crematory of the lungs, and thrown off as carbonic acid gas by the breath. Some of these cells force their way through the wall of the arteries and veins, and through the various tissues of the body, when upon hurried calls for repair work.

In the blood currents there are also other kinds of cells than those just mentioned. For instance, there are the police cells and the army cells which have been previously mentioned. These very important cells patrol the system and arrest or combat the germs and bacteria which are dangerous to the health of the body. The policeman cell meeting one of these disorderly bacterial characters, enmeshes or entangles it so that it cannot escape. He then proceeds to devour it, providing that it is not too large and strong for him; in the latter case he summons other policemen cells to his assistance, and between them they carry the intruder to some part of the body where it may. be thrown out of the system. Boils and pimples are manifestations of this ejecting process on the part of these cells.

Other cells are laboratory chemists, and extract from the food the elements needed to manufacture the important juices of the system, such as the gastric juice, pancreatic juices, saliva, bile, etc., and also such other secretions as the milk, etc. Not only do these cells select such elements, but they also actually combine them in the proper proportions for the required chemical work.

But perhaps the busiest classes of cells, and the most numerous, are those whose work it is to continually build up and keep in repair the body as a whole. You must remember that the body is constantly undergoing change; constantly breaking down cells; constantly repairing the damaged places with new cells. Our bodies, in all of their parts, are being continuously made over. All of the work of this kind, whether it be the growth of new hair or finger nails, or the slower processes of other parts of the body, is performed by these minute workers, the cells.

Perhaps as typical, and as interesting an example of this work of the cells, is that of the healing of a wound. Let us consider this, in order that we may have a clear idea of the character and wonderful nature of the work performed by the cells. Here is the process:

First, the body is discovered to be wounded by some outside force. The tissues, and often the glands, muscles and nerves are severed. The wound begins to bleed, and its sides separate. The nerves carry the report of trouble to the brain, and there is sent out a hurry-up call for help at once. The cells rush to the scene of the trouble, like firemen called to a fire; or like the repair wagon called to the scene of a breakdown on the trolley-car line. While they are reaching the scene, the flowing blood washes away the dirt which otherwise might cause infection; the blood finally coagulating and forming a protecting substance resembling glue, which afterward develops into a scab.

The repair cells arriving on the scene at once start to work connecting the tissues by bringing together the sides of the wound, and knitting the tissue-cells together. And here is manifested an almost unbelievable degree of "mind." The cells of the tissues, blood-vessels, etc., on both sides of the wound begin to reproduce themselves with marvellous rapidity, each cell growing and separating itself into two, and these into two, and so on, until there is sufficient material created to do the repair work. These new cells increasing in number reach forward from each side of the wound, until finally meeting they connect with their fellows of the other side. But here note the wonder of the process. The connective-tissue cells connect with the connective-tissue cells on the other side; the blood-vessel cells connect with their own kind on the other side; the nerve cells do likewise; until finally there is a complete bridge built, each various parts of each side being connected with the same kind of parts on the other side.

After this internal repair work is completed, and the connections properly made, then the skin cells start to work and build a new skin over the healed wound. The whole process shows purpositive action, co-ordinated effort, and an undoubted presence of mental direction. It is useless for materialists to speak of mechanical and chemical laws as an explanation of such vital processes as these. The most skeptical observer, if he is honest with himself, is forced to admit that there is manifested the activities of living, thinking, minute creatures, co-ordinated and regulated,' directed and guided, by some mental center higher than themselves. It is impossible to doubt this, any more than one would doubt that the work of the bees in the hive is a vital, mental manifestation. It is not enough to call it "instinctive"-for instinct itself is but a name given to one phase of vital, mental activity.

A clear understanding of the mental activities of the cells will go far toward giving us a key to the secret of mental healing.