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I. WHAT IS A LIVING ORGANIC BODY?
It is not our purpose here to show what life is in itself, but to ascertain the nature of organism, and to show its relations to life. A living organic body has these several characteristics:
1. It is made up of various parts or members connected by concrescence or a common growth. The parts do not exist before the whole, so that you have only to bring them together, as is the case in building a house or in the construction of a machine. They all have a concurrent formation, and that too by a common process. The parts of a machine are first manufactured, so that each may exist in full perfection long before they are brought together and the machine is made. So in the creation of an edifice-like the building of Solomon's temple-every part may be first formed and fashioned for its place, so that each one is complete, while as yet no two of them have been put together. But in the organization of a living body this can never be. The branches are not made before the trunk, and then brought and attached to it. The limbs of the animal are not made separate from the body, and then fitted to it by mechanical ingenuity. No one part precedes the others. All grow up together into one homogeneous body.
2. In organic bodies specific forms are produced, with various parts the same in number and function. Invariableness in form is, in some sort, true in crystallology. The quartz will invariably assume its sia-sided prismatic form, with pyramidal ends; the iron pyrites displays its cubes; the garnet will appear in the form of dodecahedrons; and so each mineral, capable of crystallization, will have its specific and unvarying form. But there is here no diversity of part or of function. The crystallized mass is a simple aggregation of little crystals, each as perfect in itself as the aggregated body; and when separated from the mass the particle suffers no change as the result of that separation. There is no life produced, nor is there made the least approximation to it. The crystal has neither organs nor limbs, and even its dimensions are limited by external relations rather than its internal nature. But in the living germ is to be found the form-determining power, which molds and shapes the organic body. The germ in the acorn can, by no possibility of culture or of external influence, be made to develop into an animal. It embodies the parts, roots, trunk, and branches, of the tree, and that too of its own species, the oak; and nothing else can grow out of it. So of the animal germ. The form, while the embryo being is yet in the egg, is as determinate as when it comes forth into life.
3. The living body is the product of inward forces. It gathers its material and incorporates it into the organic body by a power within itself. The block of marble, by a gradual transformation, comes, at length, to assume the human form. But this transformation was not a plan, a work, or a result of its own, nor yet of forces within itself. But for the action of the artist upon it, it had remained a sightless block forever. In the living body there is an invisible power, which takes hold of the elements nature has in store for it, and works them up into its own body, by the most wonderful transformation. This power of assimilation is peculiar to the organic body, and must distinguish it from the inorganic forever. 4. Organized bodies exist in generations.
. The plant “hath the seed in itself” for the production of other plants. The organic is not only a vitalized body, but it possesses the power of vitalizing, and thus giving being
to other vitalized bodies that shall be its successors. Not only have the leaves of the forest a time to fall in their successive seasons, but the trees themselves pass through their successive stages of being and pass away, so that the forest is perpetually renewed with new generations of the
The human race exists, in like manner, in successive generations. “One generation passeth away and another cometh ;” and thus the race is preserved. The crystals are the highest efforts of inorganic nature. Curiously are they wrought in her great laboratory, and come forth sparkling in their beauty. But we find no such relation as would indicate successive generations among them. Each is perfect in itself—is without antecedent crystal as a cause, and also without succeeding crystal as a result. Nor is there periodicity in its duration. Every thing is contingent, dependent upon the action of external chemistry, and not upon internal functions. It may be dissolved in a day, or it may last forever.
5. In the living body the separation of parts can not take place without the death and decay of the part so separated. The members all differ from each other in character and office, as the roots, trunks, branches, leaves, blossoms, and fruits in vegetables, and the feet, hands, bodies, heads, and hearts in animals. Yet each assists and promotes the life of the whole. Strike off a part—a limb of a tree or the arm of a person—and the part so stricken off changes in its whole character. It has life no longer, but is decomposed and returns to dust: An inorganic body, like a block of granite, may be broken into pieces; still it is granite, each part, however small, retaining the characteristic properties of the whole. A bar of iron may be cut up into the smallest filings, but each atom is still iron and complete in itself. The mast of a vessel may be snapped asunder in a gale, but mechanical skill may splice the pieces, and the
mast perform the same service as before. But does the storm break the towering trunk of the forest pine, the part so severed is dead. Restoration, so that it may perform its former functions, is impossible. The lightning may tear away a fragment from a building, but the fragment is unchanged in character. It is wood, or stone, or brick as before, and has only to be replaced to repair the damage. But does the lightning rend a limb from a man, the man himself, possibly, may survive, but the limb is dead. Its restoration is impossible. No surgical skill can replace it so that it shall again become a part of the living body.
6. Among all organic living bodies there are certain common functions not found in inorganic bodies. The vegetable and the animal are widely removed in characteristics from each other; so widely, indeed, that, to the superficial observer, they seem to have scarcely any properties in com
Yet "their living, growing, feeding, reproducing, secreting, transpiring, vascular, diseased, and dying actions are universal instances of a related similitude. In these things all that have life resemble each other, whether animal or vegetable, and however separating their other properties or capacities may be."* But none of these properties are found in the stone or mineral. They may enlarge, but their enlargement is by exterior accretion, by the addition of exterior particles to their surface. They do not grow. They have no development from within. The peculiar functional chemistry so manifest in the operation for the support and growth of living bodies is wholly wanting. Crystallization may produce forms of wondrous beauty, but in none of them do we find life. So the stone or mineral needs no nutriment in order to its preservation. If not operated upon by the action of elements exterior to itself, it will remain unchanged forever. Or, again, it may be disintegrated, may return to its original elements; but it suffers no dying agony; it is simply action from without, separating the parts that had been brought together by external force and blended by nature's chemistry.
* Turner's Sacred History, I, 153.
II. ORGANIZATION IS PRODUCED BY LIFE, AND NOT LIFE
Organism is the incarnation of life. The physiologist finds in nature a special principle of organization. No where is inorganic matter converted into organic structures, whether in vegetables or in animals, without the influence of this principle. Call this principle what we may—a germ, a vesicle, or a cell—it possesses an innate power, by which it seizes hold of the material within its reach, and suitable to its purpose, regroups it, and thus develops a new organization.*
In this respect there is a wonderful concurrence between the vegetable and the animal world, showing both to be the conceptions of one overruling Mind. The kernel of grain and the egg of the animal alike contain not only the germ of life, but a stock of nutritive material, which is used in the earlier stages of development. The embryo plant first consumes the nutritive material in the seed, incorporating a part of it into the new organic body that is being found, till the shell is bursted and connection established with the material outside. Then the plant gradually weans itself and commences collecting the materials of its life and growth from the earth, the air, and the sun. The process of development in the egg of the animal is after the same general type. A large portion of the contents of the egg-shell is simply nutritive material kindly stored, upon which the embryo animal may feed till its connectiong with
*Draper's Human Physiology.