The World's Greatest Books [Volumes 1-15, 17-20]
- Автор: Gutenberg
- Год: 1910
- Язык: английский
- Жанр: Культурология
Электронная книга - «The World's Greatest Books [Volumes 1-15, 17-20]». Краткое содержание книги:
The World's Greatest Books — Volume 01 — Fiction от Неизвестный
The World's Greatest Books — Volume 02 — Fiction от Неизвестный
The World's Greatest Books — Volume 03 — Fiction от Неизвестный
The World's Greatest Books — Volume 04 — Fiction от Неизвестный
The World's Greatest Books — Volume 05 — Fiction от Неизвестный
The World's Greatest Books — Volume 06 — Fiction от Неизвестный
The World's Greatest Books — Volume 07 — Fiction от Неизвестный
The World's Greatest Books — Volume 08 — Fiction от Неизвестный
The World's Greatest Books — Volume 09 — Lives and Letters от Неизвестный
The World's Greatest Books — Volume 10 — Lives and Letters от Неизвестный
The World's Greatest Books — Volume 11 — Ancient and Mediæval History от Неизвестный
The World's Greatest Books — Volume 12 — Modern History от Неизвестный
The World's Greatest Books — Volume 13 — Religion and Philosophy от Неизвестный
The World's Greatest Books — Volume 14 — Philosophy and Economics от Неизвестный
The World's Greatest Books — Volume 15 — Science от Неизвестный
The World's Greatest Books — Volume 17 — Poetry and Drama от Неизвестный
The world's greatest books от Mee, Arthur, 1875-1943, joint editor & Hammerton, John Alexander, Sir, 1871-1949, joint editor & McClure, S. S. (Samuel Sidney), 1857-1949, joint editor
The World's Greatest Books — Volume 19 — Travel and Adventure от Неизвестный
The World's Greatest Books — Volume 20 — Miscellaneous Literature and Index от Неизвестный
Growth, or Increase of Bulk
Perhaps the widest and most familiar induction of biology is that organisms grow. Under appropriate conditions increase of size takes place in inorganic aggregates as well as in organic aggregates. Crystals grow. Growth is indeed a concomitant of evolution. The several conditions by which the phenomena of organic growth are governed, conspiring and conflicting in endless ways and degrees, qualify more or less differently each others' effects. Hence the following generalisations must be taken as true on the average, or other things equaclass="underline" —
First, that growth being an integration with the organism of such environing matters as are of like nature with the matters composing the organism, its growth is dependent on the available supply of such matters. Second, that the available supply of assimilable matters being the same, and other conditions not dissimilar, the degree of growth varies according to the surplus of nutrition over expenditure. Third, that in the same organism the surplus of nutrition over expenditure is a variable quantity; and that growth is unlimited or has a definite limit according as the surplus does or does not progressively decrease,—a proposition exemplified by the increasing growth of organisms that do not expend force, and by the definitely limited growth of organisms that expend much force. Fourth, that among organisms that are large expenders of force, the size ultimately attained is, other things equal, determined by the initial size. Fifth, that where the likeness of other circumstances permits a comparison, the possible degree of growth depends upon the degree of organisation: an inference testified to by the larger forms among the various divisions and subdivisions of organisms.
Why Do Organisms Cease to Grow
Why should not all organisms, when supplied with sufficient material, continue to grow as long as they live? We have found that organisms are mostly built up of compounds which are stores of force. These substances being at once the materials for organic growth and the sources of organic force, it follows, from the persistence of force, that growth is substantially equivalent to the absorbed nutriment minus the nutriment used up in action. This, however, does not account for the fact that in every domestic animal the increments of growth bear continually decreasing ratios to the mass, and finally come to an end. Nevertheless, it is demonstrable that the excess of absorbed over expended nutriment must decrease as the size increases. Since in similar bodies the areas vary as the squares of the dimensions and the masses vary as the cubes, it follows that, however great the excess of assimilation over waste may be during the early life of an active organism, there must be reached, if the organism lives long enough, a point at which the surplus assimilation is brought to nothing—a point at which expenditure balances nutrition, a state of moving equilibrium. Obviously, this antagonism between assimilation and expenditure must be a leading cause of the contrast in size between allied organisms that are in many respects similarly conditioned.
Development, or Increase of Structure
In each of the organic sub-kingdoms the change from an incoherent, indefinite homogeneity to a coherent definite heterogeneity is illustrated in a quadruple way. The originally-like units or cells become unlike, in various ways, and in ways more numerously marked as the development goes on. The several tissues which these several classes or cells form by aggregation, grow little by little distinct from each other; and little by little become structurally complex. In the shoot as in the limb, the external form, originally very simple and having much in common with countless simple forms, organic and inorganic, gradually acquires an increasing complexity, and an increasing unlikeness to other forms, and meanwhile, the remaining parts of the organism, having been developed severally, assuming structures diverging from each other and from that of this particular shoot or limb, there has arisen a greater heterogeneity in the organism as a whole.
The most remarkable induction of von Baer comes next in order. It is that in its earliest stage every organism has the greatest number of characters in common with all other organisms in their earliest stages; that at each subsequent stage traits are acquired which successively distinguish the developing embryo from groups of embryos that it previously resembled—thus step by step diminishing the group of embryos which it still resembles; and that thus the class of similar forms is finally narrowed to the species of which it is a member. For example, the human germ, primarily similar to all others, first differentiates from vegetal germs, then from invertebrate germs, and subsequently assumes the mammalian, placental unguiculate, and lastly the human characters.
The development of an individual organism is at the same time a differentiation of its parts from each other and a differentiation of the consolidated whole from the environment; and in the last as in the first respect there is a general analogy between the progression of an individual organism and the progression of the lowest orders of organisms to the highest orders.
The Laws of Multiplication
Every living aggregate being one of which the inner actions are adjusted to balance outer actions, it follows that the maintenance of its moving equilibrium depends on its exposure to the right amounts of these actions. Its moving equilibrium may be overturned if one of these actions is either too great or too small in amount: either by excess or defect of some inorganic or organic agency in its environment.
Our inquiry resolves itself into this:—in races that continue to exist what laws of numerical variation result from these variable conflicting forces?
The forces preservative of a race are two—ability in each member of the race to preserve itself, and ability to produce other members. These must vary inversely—one must decrease as the other increases. We have to ask in what way this adjustment comes about as a result of evolution.
Including under individuation all those processes completing and maintaining individual life, and under genesis all those aiding the formation and perfecting of new individuals, the two are necessarily antagonistic. Every higher degree of individual evolution is followed by a lower degree of race multiplication, and vice versâ. Progress in bulk, complexity or activity involves retrogress in fertility; and progress in fertility involves retrogress in bulk, complexity, or activity. The same quantity of matter may be divided into many small wholes or few large wholes; but number negatives largeness, and largeness negatives number.
It is a general physiological truth that while the building-up of the individual is going on rapidly, the reproductive organs remain imperfectly developed and inactive; and that the commencement of reproduction at once indicates a declining rate of growth and becomes a cause of arrest in growth.
It has now to be noticed how complexity of organisation is hindered by reproductive activity and conversely. The hydra's power to produce young ones from nearly all parts of its body is due to the comparative homogeneity of its body, while it is not improbable that the smallness of human fertility, compared with the fertility of large feline animals, is due to the greater complexity of the human organisation—more especially the organisation of the nervous system.