Читать книгу The Science of Life; or, Animal and Vegetable Biology - J. H. Wythe - Страница 7
CHAPTER III.
ОглавлениеPARENTAGE.
We must get rid of all these complications of an erring philosophy, this floating chaos of mist and phantasms, and return to the Natural Realism, which all men have been learning from their first hours of childhood, and can never unlearn, before a science of Physics can be really founded. Its first principle is that we are real persons, living amid a real world of material objects distinct from ourselves. And this double truth leads upward to One who is the cause both of matter and mind, the Supreme Reality, who dwells in light inaccessible, but who can reveal himself, and has revealed himself, in love and mercy to the souls he has made. —Modern Physical Fatalism, by T. R. Birks.
1. Two theories divide the learned world respecting the genesis of living things; the doctrine of parentage, or the descent from living creatures each created “after his kind,” and the theory of spontaneous generation of the living from the non-living, and the transmutation of one kind of living beings into another. The first theory is sometimes called the doctrine of Creation, the latter that of Evolution.
2. The word Evolution simply means to unfold, and may be used to express the life-history of individuals or of species, or the development of the plans of the Creator in the natural world. To such a meaning there would be no objection by any one, but as it is generally understood to mean the mechanical or monistic view of the universe, which ignores a Creator, and teaches the eternity of substance, the invariability of law, and the transmutation of living beings, its use should be restricted to that view. Any other application of it leads to confusion of thought.
3. There is nothing new in the modern doctrine of Evolution. Among the Greeks, Leucippus, Democritus, and Epicurus taught that all forms and phenomena came from the spontaneous motions of atoms, and this view, in all probability, was a product of older Indian pantheism.
Modern upholders of transmutation differ from each other greatly in the details of the theory. Some are atheistic, or agnostic, leaving the Creator entirely out of view. Among these, some teach, like Lamark, the self-elevation of species by appetency, or desire, use, and effort. Others, as Darwin, Haeckel, and many late writers, teach what is called natural selection with spontaneous variability, or the survival of the fittest. Others again, as Draper and Spencer, teach modification of species by the surrounding conditions. Some evolutionists are deistic, like Owen and Mivart, and teach a pre-ordained succession, under internal force or innate tendency; or, as Morell and Murphy argue, evolution by unconscious intelligence. In opposition to these views the majority of naturalists of this and the past age hold to the doctrine of parentage, and deny the change or transmutation of species, although admitting a certain amount of physical variability, producing races or varieties. Among these may be named Linnæus, Cuvier, Agassiz, Dana, Guyot, M’Cosh, Balfour, Dawson, Milne, Edwards, and Seelye.
4. The acknowledged ability of Agassiz in regard to all matters connected with natural science entitle his opinions to careful consideration. He says: “It is my opinion that naturalists are chasing a phantom, in their search after some material gradation among created beings, by which the whole Animal Kingdom may have been derived by successive development from a single germ, or from a few germs.... It is contradicted by the facts of Embryology and Palæontology, the former showing us norms of development as distinct and persistent for each group as are the fossil types of each period revealed to us by the latter.” “If they are linked together as a connected series, then the lowest Acaleph should stand next in structure above the highest Polyp; and the lowest Echinoderm next above the highest Acaleph. So far from this being the case, there are, on the contrary, many Acalephs which, in their specialization, are unquestionably lower in the scale of life than some Polyps, while there are some Echinoderms lower in the same sense than many Acalephs.” He shows that the same principle applies to classes in other types: “There are some members of the higher classes that are inferior in organization to some members of the lower classes.” The same thing is true in Embryology: “A Vertebrate never resembles at any stage of its growth any thing but a Vertebrate, or an Articulate any thing but an Articulate, or a Mollusk any thing but a Mollusk, or a Radiate any thing but a Radiate.” Geologically, also, we see no transition between types. “In the earliest fossiliferous strata there were the three classes of Radiates, two of the classes of Articulates, and one of the classes of Vertebrates.” The Geographical Distribution of animals proves the same thing. Thus Agassiz proves that the Series of Rank, of Growth, of Time, and of Geographical Distribution all show that there is no such gradation as transmutation implies, and that the connection between different kinds of living things is not a material connection, but only an intellectual one, indicating the plan of the Great Architect.[8]
5. In all forms of life which have yet come under human observation, the origin has not been by transmutation, but by parental derivation. Animals and vegetables all come from parents of similar organization. If ever transmutation was the law of origin, it has been changed, and the law of parentage is now supreme. But a change of law is inconsistent with the theory of evolution. Unless the law had been changed, species would still originate by transmutation, if ever they had such origin. Such transmutation has never been observed. The Egyptian monuments prove that the animals of earliest history remain unchanged, and Agassiz has shown from the coral reefs in Florida that the animals of the Gulf of Mexico remain the same as when these deposits began. Even the varieties which man secures by “artificial selection” revert to the original type when the modifying circumstances are removed. Transmutation has not a single fact to prove it. At best it is but a theory, and one which all the facts known render most improbable.
6. The geological evidence shows the entire absence of intermediate varieties between species, which intermediate forms Mr. Darwin himself admits to be necessary to establish his theory of natural selection. He claims that the geologic record is defective, and that when it is better known it will exhibit these forms. But among more than 30,000 species, many of them represented by thousands of individuals, some of the intermediate forms would occur, if any ever existed. Professor Pfaff has shown the improbability of the terminal links only of the chain being preserved by applying the calculus of probabilities. If 100 individuals of each species have been found, and 10 intermediate varieties existed, (a smaller number than Darwin claims,) the probability against the exclusive appearance of distinct species is as 1:10¹⁰⁰, (1:1 with 100 ciphers annexed.[9]) Professor Marsh claims to have discovered apparently intermediate forms between the Palæotherium and the horse, but the proof that the Palæotherium, or the bones referred to, belonged to the progenitors of the horse has not been shown, any more than the juxtaposition of bones of the horse, the zebra, and the ass, would prove them to be derived from each other. If it were proven, although it would show great variability in that species, it would not establish transmutation.
7. Geology shows that some of the first forms of life are also the latest, as the corals. If transmutation be true, in the struggle for existence they should have disappeared by being changed into something higher. That they have not makes against Evolution.
8. Believers in transmutation claim that all living came into existence by the gradual modification of a primitive germ, and they find plausibility for this in the development of a single bioplast into the various tissues of an animal. Another analogy is found in the development of the embryo. As the tadpole is first a fish, and then a tailed amphibian with lungs and gills, before it becomes a frog, so they deem that the history of the embryo recapitulates the transformations of the species. This sort of theorizing has given rise to numerous efforts to arrange the family tree of each species—a branch of biological speculation termed Phylogeny—and examples of it may be found in Darwin, Haeckel, etc. Mr. Huxley, although a believer in Evolution, declares that such summaries of descent are little better than guess-work.[10]
9. Many instances of complicate and perfect structure occur both in the vegetable and animal kingdoms which have no similar structure preceding nor following them. No scheme of evolution, nor survival of the fittest, can account for them. The mechanism of the leaf of Venus’s fly-trap, and of Nepenthes, the nettling threads of Hydroid polyps, and the peculiar disk-like hairs on the thigh of the male water-beetle, (Dytiscus marginalis,) are a few out of almost numberless instances of this fact. The most perfect dental apparatus in the animal kingdom, the teeth of Echinus, called Aristotle’s lantern, is also the first to appear, if we trace animal life from its simplest forms, and there is nothing like it elsewhere. Like Melchizedek among priests, it has no predecessor and no successor. Its form and arrangement are a protest against the theories of material development. In the Rotifer, again, the typical form and structure of the teeth are entirely different, being an anvil and two hammers. In the Gasteropods they are spiny tongues.
10. Evolutionists find it difficult, if not impossible, to account for the first origin of living matter. The boldest and most logical among them maintain that it began spontaneously out of non-living matter. Some, like Sir W. Thompson, suppose that the germs of living things were transported to our globe from some other. Others, as Darwin, hold to the creation of a single germ, or a few germs, from which all have developed. The doctrine of the spiritual origin of living things is beset with no such difficulties as the mechanical theory. While it admits a unity of plan resulting from the superintending intelligence of an all-wise Creator, it sees in living things a true diversity also. It is hard to imagine how a naturalist can think of “differentiation” without acknowledging a cause of variety ab extra, (from without.)
11. The evidence adduced in favor of spontaneous generation is always of one kind. A quantity of animal or vegetable infusion is boiled in a flask, which is then hermetically sealed. After a time minute forms of life are found on a microscopic examination of the fluid. It is taken for granted that all living germs are destroyed by boiling water, and that therefore the organisms seen after a few days are developed spontaneously. But Messrs. Döllinger and Drysdale have shown that some germs remain alive after exposure to a temperature of 300° F., and Pasteur has found that stopping the necks of the flasks with cotton wool, so as to filter the air from all germs, prevents the appearance of Infusoria, as well as of decay, in fluids well adapted to such organisms. Professor Tyndall has also experimented with a great variety of fluids in air so deprived of floating germs as to be optically pure, and has had similar results. So that we may consider the question to be scientifically settled, and that all living beings come from similar parentage, or, as Virchow expresses it, “omnis cellula e cellula,” (every cell is from a cell.)
12. Parentage is of two kinds, sexual and non-sexual. In the first, we sometimes find the sexes distinct, as in the higher animals, and sometimes united in the same individual, as in the stamens and pistils of most flowers, and as in some animal forms.
Non-sexual generation is seen mostly in the simpler forms of animal and vegetable life, and as it throws light on many of the phenomena of nature which would otherwise be obscure, we notice this form of reproduction here in a general way, reserving special instances until we treat of the life-history of each class.
13. In referring to the Vorticella, or bell-shaped animalcule, in our first chapter, mention was made of its increase by self-division. The mass of bioplasm of which it is composed separates into two masses, which become separate individuals. This mode of increase is called Fission, and is quite common among the minuter forms of life. In Sarcina ventriculi, a sort of vegetable parasite, the division is into fours, or four times four.
14. A variety of fission, called Gemmation, or Budding, is often met with. A portion projects from the mass, and separates to begin an individual existence. Thus in the fresh-water polyp, or Hydra, a bud gives rise to an organism like the parent, which becomes detached and independent. Sometimes the product of buds remains attached, as in plants, and in the Foraminifera. In other cases the budding is internal, and the progeny may or may not remain attached to the parent.
15. Alternation of generations is a term given to express a mode of reproduction in which “the parent finds no resemblance in his progeny until he comes down to his great-grandson.” The Jelly-fish, or Medusæ, from the huge masses cast up by the waves of the sea-shore, to the tiny bell no bigger than a pea, are developed in this manner. A ciliated germ, like some of the Infusoria in form, swims about awhile, then becomes attached, elongates, and develops into a polyp like the Hydra. The polyp becomes wrinkled and subdivides until it looks like a pile of saucers with scalloped edges. This breaks into segments, each of which becomes a jelly-fish, which enlarges and produces fresh germs. Fig. 5. This form of reproduction differs from metamorphosis, such as a butterfly undergoes in passing from the egg to the perfect insect, or as most animals pass through in the embryonic state. The caterpillar becomes a butterfly, but the hydra-like individual referred to produces a number of Medusæ.
Fig. 5.—Diagram illustrative of the Development of Hydrozoa.
(The specimen is one of the Lucernaridæ.)
1. Ciliated embryo or “planula.” 2. Hydra tuba, showing single individual. 3. Hydra tuba undergoing segmentation. 4. The segmentation becoming more complete. 5. More advanced stage, in which the tentacles are developed from the first or basal segment. 6. Segmentation complete, giving rise to a free swimming Medusoid.
16. Partheno-genesis, or virgin production, denotes the production of new individuals by virgin females without the intervention of a male.
The Aphides, or plant lice, so often found parasitic on plants at the close of autumn, consist of winged males and wingless females. The ova, or eggs, are dormant through the winter, and the young hatched in the spring are sexless, but produce viviparously a brood like themselves, and this generation produces another, and so on for ten or twelve generations, the last brood being male and female as at first. Many other tribes of insects afford examples of partheno-genesis.
17. The subject of this chapter brings us to some of the deepest mysteries of creation. The parentage of all living, and the various modes in which the principle of parentage is manifested—such topics are wonderful seed-thoughts. It is not likely that we shall ever understand fully the repetition of individuality, but we see enough to indicate some of the plans of the Designer of all. “Lo! these are parts of his ways ... but the thunder of his power who can understand?”
Some analogies between the teachings of biology as to the genesis of living things, and some of the statements of Scripture, may be readily traced. Mr. Joseph Cook has been sharply criticised for comparing the birth of Jesus, as revealed in the Gospels, with partheno-genesis; yet he had reason for so doing, nor is he alone in his opinion. In President Dawson’s “Origin of the World” we read, “It is curious that the Bible suggests three methods in which new organisms may be, and, according to it, have been, introduced by the Creator. The first is that of immediate and direct creation, as when God created the great Tanninim, (whales.) The second is that of mediate creation, through the materials previously existing, as when he said, ‘Let the land bring forth plants,’ or ‘Let the waters bring forth animals.’ The third is that of production from a previous organism by power other than that of ordinary reproduction, as in the origination of Eve from Adam, and the miraculous conception of Jesus.”—P. 229.
“The Bible indicates some ways in which living creatures may be modified, or changed into new species, or may give rise to new forms of life. The human body is, we are told, capable of transformation into a new or spiritual body, different in many important respects, and the future general prevalence of this change is an article of religious faith. The Bible represents the woman as produced from the man by a species of fission, not known to us as a natural possibility, except in some of the lower forms of life. The birth of the Saviour is represented as having been by partheno-genesis, and if it had pleased God that Jesus was to remain on earth as the progenitor of a new and higher type of man to replace that now existing, this might be regarded as the introduction of a new species.”—P. 378.
It certainly disarms skepticism and strengthens the probability of Bible history, to find such analogies between the natural world and the record of revelation.
Living beings are not fortuitous nor necessary groupings of atoms, either mechanical, as Monism teaches, or monads of force, as Leibnitz wrote, but sparks of spiritual existence, given off voluntarily from the Eternal Parent, having various powers and capacities, yet each capable of pressing the fleeting atoms of matter into its service during the period alloted to it in the world. Of all living beings man is nearest like the Great Father, in whose image we were created, and who, when heart and flesh—body and animal life—shall fail, may be the strength of our hearts and our portion forever.
“For we also are his offspring.”
