Rudimentary organ

“ An eminent physiologist accounts for the presence of rudimentary organs, by supposing that they serve to excrete matter in excess, or injurious to the system; but can we suppose that the minute papilla, which often represents the pistil in male flowers, and which is formed merely of cellular tissue, can thus act? ”

“ But many organs, such as “the thyroid gland, the thymus gland, and the pineal gland,” formerly classified as rudimentary organs, are found to be very useful and necessary.
Physicians have found the appendix very useful in preventing constipation, which its removal usually increases. If we only knew enough, we would, no doubt, discover a beneficial use for all the so-called vestigial organs. Our ignorance is no argument against the wisdom of their creation. The claim that human hair is vestigial is spoiled by the fact that there is none on the back where most abundant on simians. ”

“ Take, again, another set of very remarkable facts,—the existence of what are called rudimentary organs, organs for which we can find no obvious use, in the particular animal economy in which they are found, and yet which are there. ”

“ Throughout the animal and vegetable kingdoms we constantly meet with organs which are the dwarfed and useless representatives of organs which, in other and allied kinds of animals and plants, are of large size and functional utility. Thus, for instance, the unborn whale has rudimentary teeth, which are never destined to cut the gums; and we all know that our own rudimentary tail is of no practical service. Now, rudimentary organs of this kind are of suchpg. 40 common occurrence, that almost every species presents one or more of them. ”

“ It is important to note, also, that an air-bladder and lungs have never been found in one and the same animal; and since arms, front-legs, flippers, and wings, are all regarded as modifications of the same organs, anterior limbs; and since, in many other cases, organs of very different size, form, complexity, and function, are considered as homologous, we shall be following precedent in admitting a willingness to regard air-bladders and lungs as modifications of the same organ. ”

“ The similarity of the texture of the brain to that of the pancreas, and some other glands of the body, has induced the inquirers into this subject to believe, that a fluid, perhaps much more subtile than the electric aura, is separated from the blood by that organ for the purposes of motion and sensation. ”

“ He laid down the general morphological principle that the fundamental organs have essentially the shape of tubular cavities, as appears in the first form of the central organ of the nervous system, in the two muscular and osseous tubes which form the walls of the body, and in the intestinal canal; and he followed out with admirable clearness the steps by which from these fundamental systems the other organs arise secondarily, such as the organs of sense, the glands, lungs, heart, vascular glands, Wolffian bodies, kidneys and generative organs. ”

“ The systems of animal life divide only into two kinds of organs, into those of sensation and those of motion, into the solar and planetary, or central and peripheric.
a. MOTOR ORGANS.
2369. Bone and muscle are not societies, but only poles of one system. There is therefore no mere bony organ, and no mere muscular organ. Meanwhile we will here regard them in particular or "per se."
1. Osseous Organs.
2370. The first bones were branchial arches or tracheal rings. When the lungs were developed from the branchiæ, the branchial arches were repeated as ribs or pulmonary arches. ”

“ First, other congeries of glands occupy but a particular part of the system, or constitute a particular organ, as the liver, or kidneys; but those glands, which secrete the mucus, and perspirable matter, which are called capillaries, are of very great extent; they receive the blood from the arteries, separate from it the mucus, which lines every cell, and covers every cavity of body; and the perspirable matter, which softens and lubricates the whole surface of the skin, and the more extensive surface of the air-vessels, which compose the lungs. ”

“ All organs, which are purely animal, are penetrated or traversed by the nervous system, just as the lower systems are by the tegumentary formation. No higher organ is the wholly pure evolution of one system, but the systems ever combine with each other ”

“ There is a large amount of reciprocity among the tissues; in the case of paired organs the loss of one can be made good by increased activity of the remaining, and certain of the organs are so nearly alike in function that a loss can be compensated for by an increase or modification of the function of a nearly related organ. The various internal parts are connected by means of a close meshwork of interlacing fibrils, the connective tissue, support and strength being given by the various bones. Everywhere enclosing all living cells and penetrating into the densest of the tissues there is fluid. ”

“ Let us not, however, exaggerate this independence of the textures of the organs in diseases, lest experience should contradict us. We shall see that the cellular system is oftentimes a medium of communication, not only from one texture to another in the same organ, but from one organ to a neighbouring one. ”

“ They could affect only one or certain organs, because by selection only the chosen organ or organs knew the code, as it were. The chemical system is much the older system, and preceded the nerve system by aeons of time. The whole system, viscera, visceral nerves and the endocrines gradually united into a complete autonomous organism within the organism, and as such functions as the vegetative apparatus. ”

“ No other animal gives nourishment to its young in such fashion; all mammals do. What is the origin of the habit? How did the organ arise?
A part of an animal's body that has the power to gather material from the blood and pour it out in the shape of fluid is known as a gland. Sometimes a whole organ does nothing else. Sometimes small glands are scattered through, or over, the surface of another organ. There are two kinds of glands in the skin of the mammal. The best known and most frequently thought of are those which pour out the perspiration. ”

“ The luminous organs appear to be specialized skin lands which secrete a fluid that becomes luminous on slow oxidation. The essential part of the organ remains a collection of gland cells, but in the more complex types there are blood vessels and nerves, a protecting membrane, an iris-like diaphragm, a reflector and lens. As the distribution and probably the colour of the light varies with the species, these organs may serve as recognition marks. ”

“ In this the brain again follows a general law, for in all organs the anatomical element has fixed characteristics by which it may be known; the completeness of the organ consists chiefly in the arrangement of these elements, which presents in every animal species its own peculiar form. Every organ is in fact, then, an instrument whose constituent elements remain identical, while their grouping grows more and more involved in the same degree as the function itself displays more variety and complexity. ”

“ The evolution of animal life is the development of organs of metabolism, reconstruction, motility, reproduction and conception.
The five systems of organs are concomitant in the same animal body. They are also concomitant in every organ of the body, so that when we describe organs it becomes necessary to consider their concomitants. An organ may have the function of one concomitant, but it has the essentials of all the concomitants, for they cannot be dissociated, as we have many times seen. ”

“ Exclusive regard for their physiological functions would place morphologically related organs in different categories. From this it follows that in comparative anatomy we should never in the first place consider the function of an organ. The physiological value comes only in the second place into consideration, when we have to reconstruct the relations to the organism as a whole of the modification which an organ has undergone as compared with another state of it. In this way comparative anatomy shows us how to arrange organs in series ”

“ By themselves the muscles, nerves, and sense organs cannot carry on power development; they require the aid of a great many other organs to do this. Just how these other organs work will be described later; at present it will be enough to recall that every muscle, every nerve, and every sense organ is actually made up of a great many of the tiny construction units—the cells about which we were talking a few pages back—and that every one of these cells must be developing power all the time if it is to go on living. ”

“ The next step was based on the observation that organs are composed of simpler parts called tissues. Often several different kinds of tissue will unite into one organ; for example, the heart is not all muscle but connective tissue and nerves enter into it; the walls of the stomach also contain glands, muscles, nerves, connective tissue, etc., all united to form the one organ—the stomach. The leaf of a plant is not all one kind of tissue, but several different kinds enter into it. We are thus approaching step by step the finer structure of living beings. ”

“ That the essential identity of bodily organs and tools is no ingenious paradoxical way of putting things is evident from the fact that we speak of bodily organs at all. Organ means tool. There is nothing which reveals our most genuine opinions to us so unerringly as our habitual and unguarded expressions, and in the case under consideration so completely do we instinctively recognise the underlying identity of tools and limbs, that scientific men use the word “organ” for any part of the body that discharges a function, practically to the exclusion of any other term. ”

“ Through this faculty of the lining tissue of the blood-vessels, the size of the lumen and the direction of branching are so regulated as to oppose the least possible resistance to the flow of the blood.
" (2) The faculty possessed by the endothelium of the capillaries of each organ of adapting itself qualitatively to the particular metabolism of the organ." This adaptedness of the capillaries is, however, more usually an inherited state, i.e., brought about in the first period of development. ”

“ The main systems of organs are, in order of importance, the nervous and muscular, the digestive, the circulatory, and the respiratory. Each organ or system of organs may have many forms. If any form of any organ could exist in combination with any form of all the others there would be an enormous number of combinations theoretically possible. But these combinations do not all exist in Nature, for organs are not merely assembled (rapprochés) , but act upon one another, and act all together for a common end. ”

“ Is not the entire series of parts, organs, and functions bound up in complete and inseparable unity? The vicarious action of one organ for another has been a question among physiologists; and if admitted, as in the case of the salivary glands acting for the kidneys in profuse spitting, and the skin for the liver, the vicarious function can only obtain to a slight degree and in a temporary manner. ”

“ Whenever in any animal these organs are concentrated together to form a special organ, it is invariably found that the nerve going to this organ is very large, out of all proportion to the size of the organ, and also that the nerve possesses, close to its termination in the organ, large masses of nerve-cells. ”

“ No animal organ with a function of essential importance presents such extraordinary modifications in related species and genera. In the heart, brain, and other organs there is one shape, position, and condition of greatest efficiency, and throughout the lower forms we find a steady advance towards this condition. Great variation, on the other hand, usually indicates that the organ is of little functional importance, or that it has lost its original function. Such we conceive to be the case with the air-bladder. ”

“ It is in the whole of the organ that these varieties of size take place in animal life; it is oftentimes in insulated parts only in organic life. The reason of this appears to me to be that the harmony of action is necessary, as I have demonstrated, for the animal functions; so that if one side of the brain is more developed than the other, if one eye, one ear, one pituitary membrane, &c. are more developed than their corresponding organs, the perception, the sight, the hearing, the smell, &c. would be inevitably deranged; whilst the secretion of bile, of urine, &c. ”

“ The history of the Organ runs back so far into the centuries, that no matter what point one might select for examination, it can scarcely be brought into the scope of a lecture except in a very empty and skeleton form. ”

“ In order to find out the origin of vertebrates, inquire, in the first place, of the vertebrate itself.
Importance of the Central Nervous System.
Does the history of evolution pick out any particular organ or group of organs as more necessary than another for upward progress? If so, it is upon that organ or group of organs that special stress must be laid. ”

“ Each organ is to every other as an excreting organ. In other words, to insure perfect health, every tissue, bone, nerve, tendon, or muscle should take from the blood certain materials and return to it certain others. To do this every organ must or ought to have its period of activity and of rest, so as to keep the vital fluid in a proper state to nourish every other part. ”