Living organism

“ Under certain conditions, however, those of forming part of a so-called living organism, they present phenomena of mechanical movement and molecular change, and of transformation or transmission of force, which enable them to transform themselves into various kinds of tissues, to nourish these when formed, and to establish a consensus of action between different parts of the organism; and these properties are vastly varied in detail according to the kind of organism in which they take place, and the conditions under which the organism exists. ”

“ In all biological thinking we have to work with the categories Organism—Function—Environment, and theories of evolution may be classified in relation to these. To some it has always seemed that the fundamental fact is the living organism,—a creative agent, a striving will, a changeful Proteus, selecting its environment, adjusting itself to it, self-differentiating and self-adaptive. ”

“ Now, as in an animal a piece of bone, muscle, or skin, and in a plant a fragment of the wood, leaf, or fruit, may be considered as organic, but cannot be called an organism, all substances, except plants and animals, observable in and upon the body of the earth, so far indeed as they are parts of the terrestrial organism, are to be regarded as organic and as parts of a living thing, but not as organisms possessing an independent life. ”

“ Finally, it is important to remember that the fundamental characteristic of a living organism is its power of response to environment, a response or series of responses being necessary in a continuous environment for the normal facies of the organism to appear, and necessary in a shifting environment if the organism is to change suitably and not to perish. A continuous environment both from the point of view of production of variation and selection of variation would appear necessarily to result in a series with the appearance of orthogenesis. ”

“ Finally, that this highly-sensitive and active living organism absorbs, will not be doubted when it is proved to digest, that is, to dissolve otherwise insoluble animal matter by the aid of special secretions. ”

“ Both plants and animals have certain parts called organs which have each a definite work, or function; hence animals and plants are said to be organized. For example, men and most other animals have a certain organ (the mouth) for taking in nourishment; another (the food tube) , for its digestion.
Because of its organization, each animal or plant is said to be an organism. Living things constitute the organic kingdom. Things without life and not formed by life constitute the inorganic, or mineral, kingdom. ”

“ But we may just as confidently aver that no matter is living in any vital organism which has not been assimilated and built up into living membranous tissue capable of responding (in the case of man) to his will, as well as performing the autonomous functions of plants and the lower animals. ”

“ Such is the ultimate structure, and such are the fundamental activities or functions of living organisms, as far as they can here be described, from the lowest animalcule and unicellular plant, up to the most complex organisms and the body of man himself. ”

“ "It is often said that all the conditions for the first production of a living organism are now present, which could ever have been present. But if (and oh! what a big if!) we could conceive in some warm little pond, with all sorts of ammonia and phosphoric salts, light, heat, electricity, etc., present, that a proteine compound was chemically formed ready to undergo still more complex changes, at the present day such matter would be instantly devoured or absorbed, which would not have been the case before living creatures were formed.") ”

“ In developing our conception we must discard from consideration the complexities that arise from the organization of the higher living bodies, the differences between one living animal and another, or between plant and animal. Such differentiations and integrations of living bodies are the subject-matter of discussions on evolution; some will see in the play of circumambient media, natural or supernatural, on the simplest forms of living matter, sufficient explanation of the development of such matter into the highest forms of living organisms ”

“ Hence it is inferable that on living organisms, which form an assemblage of this kind, and are unceasingly exposed in common to the agencies composing their inorganic environments, there must be wrought two such sets of effects. ”

“ And, on the other hand, every individual organism, from the Amœba up to the most complex vertebrate, is, in its structure, its form, its functions, a stupendous marvel of adaptation to its end and of co-ordination of the parts to the whole, and of the whole and its parts to the functions of the organism, the functions of nutrition, self-maintenance, reproduction, maintenance of the species, and so on. ”

“ The proposed definition of organic life supplies an answer. If organic life be the co-ordination of actions, then an organism may be primarily divided into parts whose actions are co-ordinated, and parts which co-ordinate them—organs which are made to work in concert, and the apparatus which makes them so work—or, in other words, the assimilative, vascular, excretory, and muscular systems on the one hand, and the nervous system on the other. ”

“ But we must first carefully observe, that if we were right in considering (page 239) the chief end of the active living principle of the plant to be its formation, the first active living principle in the animal likewise must be a tendency to acquire individual existence. The whole animal body, as far as regards nutrition, growth, secretion, and its being engaged in a continual change of matter in the parts already formed (the vegetative as well as the higher and properly animal parts) , lives absolutely the life of the plant. ”

“ THE data of biology are living plants and animals. These are what nature presents. To these we must always go in order to make a beginning at any investigation. Is one interested in ganglionic cells, or germ cells, or liver secretions, or degenerate organs? He must find some kind of animal that has, or produces, or can yield such things. In making a successful quest for "material," it always turns out that a particular individual plant or animal, one or more, furnishes it. ”

“ In speaking of the causes which lead to our present knowledge of organic nature, I have used it almost as an equivalent of the word "living," and for this reason,--that in almost all living beings you can distinguish several distinct portions set apart to do particular things and work in a particular way. These are termed "organs," and the whole together is called "organic." And as it is universally characteristic of them, the term "organic" has been very conveniently employed to denote the whole of living nature,--the whole of the plant world, and the whole of the animal world. ”

“ Now the first thing that strikes us in beginning to think about the activities of an organism is that they are naturally distinguishable into two kinds, according as we consider the action of the whole organism in its relation to the external world or to other organisms, or the action of the parts or organs in their relation to each other. ”

“ No matter what we may call this point of vital activity in a cell--whether it be a bioplast, a plastid, a physiological unit, or a granule of "elementary life-stuff"--it simply performs the one single function of life to which it is specifically assigned in the process of "building up" any one identical individual of a species, whether it be a man, an ape, a tree, or a parasitic fungus. ”

“ We turn thus from the RESULTS of the selection of favorable variations to the biological PROCESSES by which organisms become accommodated to their conditions of life.
At once the old questions arise. Are these processes fundamentally peculiar to the life of organisms? Does the capacity of the organism thus to adjust itself to its environment involve factors not found in the operations of inorganic nature? Our answers will be determined essentially by the nature of our interest in the organism—whether we regard its existence as the END or merely an incidental EFFECT of its activities. ”

“ They said, this matter of the animal world, or of the higher plants, appears to be dead, but in reality it has a sort of dim life about it, which, if it is placed under fair conditions, will cause it to break up into the forms of these little animalcules, and they will go through their lives in the same way as the animal or plant of which they once formed a part. ”

“ If the famous suggestion, that all animal and vegetable life results from a single vital germ, and that all the different animals and plants now existent were developed by a natural process of evolution from that germ, were a demonstrated truth, we should still be able to point to the evidence of intelligence displayed in the measured and progressive development, in those exquisite forms so different from what blind chance could produce, and in the manifest adaptation of surrounding circumstances to the living creature, and of the living creature to surrounding circumstances. ”

“ Let us observe how, on a higher platform, there recurs this differentiation of outer from inner—how this primary trait in the living units with which life commences, re-appears as a primary trait in those aggregates of such units which constitute visible organisms. ”

“ The definition of life must really be a description of the essential characters of life, and we must set out with an investigation of the characters of living substance with the special object of detecting the differences between organisms and unorganized matter, and the differences between dead and living organized matter.
Living substance (see Protoplasm) , as it now exists in all animals and plants, is particulate, consisting of elementary organisms living independently, or grouped in communities, the communities forming the bodies of the higher animals and plants. ”

“ Both of these factors run through the behavior of all animals, but they are mingled in various proportions in different forms. In the lives of most, if not all animals both are essential elements in the adjustment of the organism to its conditions of existence.” And in regard to those responses which do not change in form with experience, he says (p. 106) : “The element of spontaneous undirected activity is one of vast if not essential importance in the life of nearly all animals. ”

“ It is the second and perhaps greater task of the biologist to study the organism from the historical point of view, considering it as the product of a continuous process of evolution that has been in operation since life began. ”

“ At present, every individual animal or plant commences its existence as an organism of extremely simple anatomical structure; and it acquires all the complexity it ultimately possesses by gradual differentiation into parts of various structure and function. ”

“ Stated concretely in regard to living creatures, the general doctrine of organic evolution suggests, as we all know, that the plants and animals now around us—with all their fascinating complexities of structure and function, of life-history, behaviour, and inter-relations—are the natural and necessary results of long processes of growth and change, of elimination and survival, operative throughout practically countless ages ”

“ Life depending on, or consisting in, an incessant play of the most complex forces, it would appear that their action is in some way stimulated by slight changes in the circumstances to which each organism is exposed. ”

“ And the presence, in all kinds of animals and plants, of functionally-useless parts corresponding to parts that are functionally-useful in allied animals and plants, while it is totally incongruous with the belief in a construction of each organism by miraculous interposition, is just what we are led to expect by the belief that organisms have arisen by progression. ”

“ Given, therefore, the molecular forces which in some way not yet understood impel the organism to display those activities of maintenance which we call life, and there follow, by virtue of those forces, of the character of organic matter, and of the general conditions of existence, not only the intelligent adaptations which make possible and facilitate maintenance, but also the gradual improvement of those adaptations which constitutes organic ascent. ”

“ Everywhere the peculiar form of the organism and its structures, internal and external, is directly related to the special physiological functions which the organism or organ has to execute. This intimate connection of structure and function, or of the instrument and the work done by it, is seen in the science of evolution and all its parts. ”

“ Finally as it is only at that extremity of the animal kingdom where occur the most simply organized animals that we meet those which may be regarded as the true germs of animality, and it is the same at the same end of the vegetable series; is it not at this end of the scale, both animal and vegetable, that nature has commenced and recommenced without ceasing the first germ of her living production? ”

“ According to my conception, the physical and chemical changes which organisms experience during life through the action of the environment, through light or want of light, air, warmth, cold, water, moisture, food, etc., and which they transmit by heredity, are the primary elements in the production of the manifold variety of the organic world, and in the origin of species. ”