THEORY OF THE CHAPTER XV. DEVELOPMENT OF THE UNIVERSE AND OF THE History of the Development of the Earth.-Kant's Theory of the Development of the Universe, or the Cosmological Gas Theory.-Development of Suns, Planets, and Moons.-First Origin of Water.-Comparison of Organisms and Anorgana.-Organic and Inorganic Substances.— Degrees of Density, or Conditions of Aggregation.-Albuminous Combinations of Carbon.-Plasson-bodies.-Organic and Inorganic Forms.Crystals and Monera. Formless Organisms without Organs.-Stereometrical Fundamental Forms of Crystals and of Organisms.-Organic and Inorganic Forces.-Vital Force.-Growth and Adaptation in Crystals and in Organisms.—Formative Tendencies of Crystals.-Unity of Organic and Inorganic Nature.-Spontaneous Generation, or Archigony.-Autogony and Plasmogony.—Origin of Monera by Spontaneous Generation. Origin of Cells from Monera.-The Cell Theory.—The Plastid Theory.-Plastids or Structural-Units.-Cytods and Cells.— Four Different Kinds of Plastids. IN our considerations hitherto we have endeavoured to answer the question, By what causes have new species of animals and plants arisen out of existing species? We have answered this question in so far that on the one hand hybridism, and on the other the natural selection in the struggle for existence—that is, the interaction of the laws of Inheritance and Adaptation-are completely sufficient for producing mechanically the endless variety of the different animals and plants, which have the appearance of being organized according to a plan for a definite purpose. Meanwhile the question must have already repeatedly presented itself to the reader, How did the first organisms, or that one original and primæval organism arise, from which we derive all the others? 2 This question Lamarck answered by the hypothesis of spontaneous generation, or archigony. But Darwin passes over and avoids this subject, as he expressly remarks that he has "nothing to do with the origin of the soul, nor with that of life itself." At the conclusion of his work he expresses himself more distinctly in the following words: "I imagine that probably all organic beings which ever lived on this earth descended from some primitive form, which was first called into life by the Creator." Moreover, Darwin, for the consolation of those who see in the Theory of Descent the destruction of the whole "moral order of the universe," appeals to the celebrated author and divine who wrote to him, that "he has gradually learnt to see that it is just as noble a conception of the Deity to believe that he created a few original forms capable of self-development into other and needful forms, as to believe that he required a fresh act of creation to supply the voids caused by the action of his laws." Those to whom the belief in a supernatural creation is an emotional necessity may rest satisfied with this conception. They may reconcile that belief with the Theory of Descent; for in the creation of a single original organism possessing the capability to develop all others out of itself by inheritance and adaptation, they can really find much more cause for admiring the power and wisdom of the Creator than in the independent creation of different species. If, taking this point of view, we were to explain the origin of the first terrestrial organisms, from which all the others are descended, as due to the action of a personal Creator acting according to a definite plan, we should of course have to renounce all scientific knowledge of the process, and pass from the domain of true science to the completely distinct domain of poetical faith. By assuming a supernatural act of creation we should be taking a leap into the inconceivable. Before we decide upon this latter step, and thereby renounce all pretension to a scientific knowledge of the process, we are at all events in duty bound to endeavour to examine it in the light of a mechanical hypothesis. We must at least examine whether this process is really so wonderful, and whether we cannot form a tenable conception of a completely non-miraculous origin of the first primary organism. We might then be able entirely to reject miracle in creation. It will be necessary for this purpose, first of all, to go back further into the past, and to examine the history of the creation of the earth. Going back still further, we shall find it necessary to consider the history of the creation of the whole universe in its most general outlines. All my readers undoubtedly know that from the structure of the earth, as it is at present known to us, the notion has been derived, and as yet has not been refuted, that its interior is in a fiery fluid condition, and that the firm crust, composed of different strata, on the surface of which organisms are living, forms only a very thin pellicle or shell round the fiery fluid centre. We have arrived at this idea by different confirmatory experiments and reasonings. In the first place, the observation that the temperature of the earth's crust continually increases towards the centre is in favour of this supposition. The deeper we descend, the greater the warmth of the ground, and in such proportion, that with every 100 feet the temperature increases about one degree. At a depth of six miles, therefore, a heat of 1500° would be attained, sufficient to keep most of the firm substances of our earth's crust in a molten, fiery fluid state. This depth, however, is only the 286th part of the whole diameter of the earth (1717 miles). We further know that springs which rise out of a considerable depth possess a very high temperature, and sometimes even throw water up to the surface in a boiling state. Lastly, very important proofs are furnished by volcanic phenomena, the eruption of fiery fluid masses of stone bursting through certain parts of the earth's crust. The glowing heat of the streams of lava, upon issuing from the interior of the earth, shows a temperature of 2000° and more. All these phenomena lead us with great certainty to the important assumption that the firm crust of the earth forms only quite a small fraction, not nearly the one-thousandth part of the whole diameter of the terrestrial globe, and that the rest is still for the most part in a molten or fiery fluid state. Now if, starting with this assumption, we reflect on the ancient history of the development of the globe, we are logically carried back a step further, namely, to the assumption that at an earlier date the whole earth was a fiery fluid body, and that the formation of a thin, stiffened crust on the surface was only a later process. Only gradually, by radiating its intrinsic heat into the cold space of the universe, has the surface of the glowing ball become condensed into a thin crust. That the temperature of the earth in remote times was much higher than it is now, is proved by many phenomena. Among other things, this is rendered probable by the equal distribution of organisms in remote times of the earth's history. While at present, as is well known, the different populations of animals and plants correspond to the different zones of the earth and their appropriate temperature, in earlier times this was distinctly not the case. And we see from the distribution of fossils in the remoter ages, that it was only at a very late date, in fact, at a comparatively recent period of the organic history of the earth (at the beginning of the so-called cænolithic or tertiary period), that a separation of zones and of the corresponding organic populations occurred. During the immensely long primary and secondary periods, tropical plants, which require a very high degree of temperature, lived not only in the present torrid zone, under the equator, but also in the present temperate and frigid zones. Many other phenomena also demonstrate a gradual decrease of the temperature of the globe as a whole, and especially a late and gradual cooling of the earth's crust about the poles. Brönn, in his excellent "Investigations of the Laws of Development of the Organic World," has collected numerous geological and palæontological proofs of this fact. These phenomena and the mathematico-astronomical knowledge of the structure of the universe justify the theory that, inconceivable ages ago, long before the first existence of organisms, the whole earth was a fiery fluid globe. Now, this theory corresponds with the grand theory of the origin of the universe, and especially of our planetary |