Darwiniana; Essays and Reviews Pertaining to Darwinism(txt+pdf+epub+mobi电子书下载)

作者：Gray, Asa

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DARWINIANA

BY ASA GRAY FISHER PROFESSOR OF NATURAL HISTORY (BOTANY) IN HARVARD UNIVERSITYNEW YORK: 1876.

PREFACE

ART

I

Views and Definitions of Species—How Darwin's differs from that of Agassiz, and from the Common View—Variation, its Causes unknown.—Darwin's Genealogical Tree—Darwin and Agassiz agree in the Capital Facts—Embryology—Physical Connection of Species compatible with Intellectual Connection—How to prove Transmutation.—Known Extent of Variation—Cause of Likeness unknown—Artificial Selection.—Reversion—Interbreeding—Natural Selection.—Classification tentative.—What Darwin assumes.—Argument stated.—How Natural Selection works.—Where the Argument is weakest.—Objections—Morphology and Teleology harmonized.—Theory not atheistical.—Conceivable Modes of Relation of God to Nature

ARTICLE

II

How Design in Nature can be shown—Design not inconsistent with IndirectAttainment

ARTICLE

III

I

V

ARTICLE IV

Alphonse De Candolle's Study of the Oak Genus.—Variability of the Species.—Antiquity.—A Common Origin probable.—Dr. Falconer on the Common Origin of Elephants—Variation and Natural Selection distinguished.—Saporta on the Gradation between the Vegetable Forms of the Cretaceous and the Tertiary.—Hypothesis of Derivation more likely to be favored by Botanists than by Zoologists.—Views of Agassiz respecting the Origin, Dispersion, Variation, Characteristics, and Successive Creation of Species contrasted with those of De Candolle and others—Definition of Species—Whether its Essence is in the Likeness or in the Genealogical Connection of the Individuals composing a Species

ARTICLE V

Age and Size of Sequoia.—Isolation.—Decadence.—Related Genera.— FormerDistribution.—Similarity between the Flora of Japan and that of the UnitedStates, especially on the Atlantic Side.—Former Glaciation as explainingthe Present Dispersion of Species.—This confirmed by the Arctic FossilFlora of the Tertiary Period.—Tertiary Flora derived from the PrecedingCretaceous.—Order and Adaptation in Organic Nature likened to aFlow.—Order implies an Ordainer

ARTICLE

VI

General Tendency to Acceptance of the Derivative Hypothesis noted.—Lyell,Owen, Alphonse De Candolle, Bentham, Flower, Ailman.— Dr. Dawson's "Storyof the Earth and Man" examined.—Difference between Scientific Men andGeneral Speculators or Amateurs in theUse of Hypotheses

ARTICLE

VII

Writings of Henslow, Hodges, and Le Conte examined.—Evolution and Design compatible.—The Admission of a System of Nature, with Fixed Laws, concedes in Principle all that the Doctrine of Evolution requires.—Hypotheses, Probabilities, and Surmises, not to be decried by Theologians, who use them, perhaps, more freely and loosely than Naturalists.—Theologians risk too much in the Defense of Untenable Outposts

ARTICLE

VIII

Dr. Hodges Book with this Title criticised.—He declares that Darwinism is Atheism, yet its Founder a Theist.—Darwinism founded, however, upon Orthodox Conceptions, and opposed, not to Theism, but only to Intervention in Nature, while the Key-note of Dr. Hedge's System is Interference.—Views and Writings of St. Clair, Winchell, and Kingsley adverted to

ARTICLE IX

Darwin's Characteristics and Work as a Naturalist compared with those ofRobert Brown.—His Illustration of the Principle that "Nature abhors CloseFertilization. "—His Impression upon Natural History exceeded only byLinnaeus.—His Service in restoring Teleology to Natural History

ARTICLE X

Classification marks Distinctions where Nature exhibits Gradations.—Recovery of Forgotten Knowledge and History of what was known of Dionzea,Drosera, and Sarracenia.

ARTICLE XI

Review of Darwin's Two Works upon these Subjects—No Absolute Marks for distinguishing between Vegetables and Animals.—New observations upon the Sundews or Droseras.—Their Sensitiveness, Movements, Discernment of the Presence and Appropriation of Animal Matter.—Dionaea, and other Plants of the same Order.—Utricularia and Pinguicula.—Sarracenia and Nepenthes.—Climbing Plants; the Climbing effected through Sensitiveness or Response to External Impression and Automatic Movement.—Capacities inherent in Plants generally, and apparently of no Service to them, developed and utilized by those which climb.—Natural Selection not a Complete Explanation

ARTICLE XII

ARTICLE XIII

The Opposition between Morphology and Teleology reconciled by Darwinism, and the Latter reinstated—Character of the New Teleology.—Purpose and Design distinguished—Man has no Monopoly of the Latter.—Inference of Design from Adaptation and Utility legitimate; also in Hume's Opinion irresistible—The Principle of Design, taken with Specific Creation, totally insufficient and largely inapplicable; but, taken with the Doctrine of the Evolution of Species in Nature, applicable, pertinent, and, moreover, necessary.—Illustrations from Abortive Organs, supposed Waste of Being, etc.—All Nature being of a Piece, Design must either pervade or be absent from the Whole.—Its Absence not to be inferred because the Events take place in Nature—Illustration of the Nature and Province of Natural Selection.—It picks out, but does not originate Variations; these not a Product of, but a Response to, the Environment; not physical, but physiological—Adaptations in Nature not explained by Natural Selection apart from Design or Final Cause—Absurdity of associating Design only with Miracle—What is meant by Nature.—The Tradition of the DIVINE in Nature, testified to by Aristotle, comes down to our Day with Undiminished Value

PREFACE

These papers are now collected at the request of friends and correspondents, who think that they may be useful; and two new essays are added. Most of the articles were written as occasion called for them within the past sixteen years, and contributed to various periodicals, with little thought of their forming a series, and none of ever bringing them together into a volume, although one of them (the third) was once reprinted in a pamphlet form. It is, therefore, inevitable that there should be considerable iteration in the argument, if not in the language. This could not be eliminated except by recasting the whole, which was neither practicable nor really desirable. It is better that they should record, as they do, the writer's freely-expressed thoughts upon the subject at the time; and to many readers there may be some advantage in going more than once, in different directions, over the same ground. If these essays were to be written now, some things might be differently expressed or qualified, but probably not so as to affect materially any important point. Accordingly, they are here reprinted unchanged, except by a few merely verbal alterations made in proof-reading, and the striking out of one or two superfluous or immaterial passages. A very few additional notes or references are appended.

To the last article but one a second part is now added, and the more elaborate Article XIII is wholly new.

If it be objected that some of these pages are written in a lightness of vein not quite congruous with the gravity of the subject and the seriousness of its issues, the excuse must be that they were written with perfect freedom, most of them as anonymous contributions to popular journals, and that an argument may not be the less sound or an exposition less effective for being playful. Some of the essays, however, dealing with points of speculative scientific interest, may redress the balance, and be thought sufficiently heavy if not solid.

To the objection likely to be made, that they cover only a part of the ground, it can only be replied that they do not pretend to be systematic or complete. They are all essays relating in some way or other to the subject which has been, during these years, of paramount interest to naturalists, and not much less so to most thinking people. The first appeared between sixteen and seventeen years ago, immediately after the publication of Darwin's "Origin of Species by Means of Natural Selection," as a review of that volume, which, it was then foreseen, was to initiate a revolution in general scientific opinion. Long before our last article was written, it could be affirmed that the general doctrine of the derivation of species (to put it comprehensively) has prevailed over that of specific creation, at least to the extent of being the received and presumably in some sense true conception. Far from undertaking any general discussion of evolution, several even of Mr. Darwin's writings have not been noticed, and topics which have been much discussed elsewhere are not here adverted to. This applies especially to what may be called deductive evolution—a subject which lay beyond the writer's immediate scope, and to which neither the bent of his mind nor the line of his studies has fitted him to do justice. If these papers are useful at all, it will be as showing how these new views of our day are regarded by a practical naturalist, versed in one department only (viz., Botany), most interested in their bearings upon its special problems, one accustomed to direct and close dealings with the facts in hand, and disposed to rise from them only to the consideration of those general questions upon which they throw or from which they receive illustration.

Then as to the natural theological questions which (owing to circumstances needless now to be recalled or explained) are here throughout brought into what most naturalists, and some other readers, may deem undue prominence, there are many who may be interested to know how these increasingly prevalent views and their tendencies are regarded by one who is scientifically, and in his own fashion, a Darwinian, philosophically a convinced theist, and religiously an acceptor of the "creed commonly called the Nicene," as the exponent of the Christian faith. "Truth emerges sooner from error than from confusion," says Bacon; and clearer views than commonly prevail upon the points at issue regarding "religion and science" are still sufficiently needed to justify these endeavors.

BOTANIC GARDEN, CAMBRIDGE, MASS., June, 1876.

______________________________________ITHE ORIGIN OF SPECIES BY MEANS OF NATURAL SELECTION [I-1]

(American Journal of Science and Arts, March, 1860)

This book is already exciting much attention. Two American editions are announced, through which it will become familiar to many of our readers, before these pages are issued. An abstract of the argument—for "the whole volume is one long argument," as the author states—is unnecessary in such a case; and it would be difficult to give by detached extracts. For the volume itself is an abstract, a prodromus of a detailed work upon which the author has been laboring for twenty years, and which "will take two or three more years to complete." It is exceedingly compact; and although useful summaries are appended to the several chapters, and a general recapitulation contains the essence of the whole, yet much of the aroma escapes in the treble distillation, or is so concentrated that the flavor is lost to the general or even to the scientific reader. The volume itself—the proof-spirit—is just condensed enough for its purpose. It will be far more widely read, and perhaps will make deeper impression, than the elaborate work might have done, with all its full details of the facts upon which the author's sweeping conclusions have been grounded. At least it is a more readable book: but all the facts that can be mustered in favor of the theory are still likely to be needed.

Who, upon a single perusal, shall pass judgment upon a work like this, to which twenty of the best years of the life of a most able naturalist have been devoted? And who among those naturalists who hold a position that entitles them to pronounce summarily upon the subject, can be expected to divest himself for the nonce of the influence of received and favorite systems? In fact, the controversy now opened is not likely to be settled in an off-hand way, nor is it desirable that it should be. A spirited conflict among opinions of every grade must ensue, which—to borrow an illustration from the doctrine of the book before us—may be likened to the conflict in Nature among races in the struggle for life, which Mr. Darwin describes; through which the views most favored by facts will be developed and tested by "Natural Selection," the weaker ones be destroyed in the process, and the strongest in the long-run alone survive.

The duty of reviewing this volume in the American Journal of Science would naturally devolve upon the principal editor,' whose wide observation and profound knowledge of various departments of natural history, as well as of geology, particularly qualify him for the task. But he has been obliged to lay aside his pen, and to seek in distant lands the entire repose from scientific labor so essential to the restoration of his health—a consummation devoutly to be wished, and confidently to be expected. Interested as Mr. Dana would be in this volume, he could not be expected to accept this doctrine.

Views so idealistic as those upon which his "Thoughts upon Species" [I-2] are grounded, will not harmonize readily with a doctrine so thoroughly naturalistic as that of Mr. Darwin. Though it is just possible that one who regards the kinds of elementary matter, such as oxygen and hydrogen, and the definite compounds of these elementary matters, and their compounds again, in the mineral kingdom, as constituting species, in the same sense, fundamentally, as that of animal and vegetable species, might admit an evolution of one species from another in the latter as well as the former case.

Between the doctrines of this volume and those of the other great naturalist whose name adorns the title-page of this journal, the widest divergence appears. It is interesting to contrast the two, and, indeed, is necessary to our purpose; for this contrast brings out most prominently, and sets in strongest light and shade, the main features of the theory of the origination of species by means of Natural Selection.

The ordinary and generally-received view assumes the independent, specific creation of each kind of plant and animal in a primitive stock, which reproduces its like from generation to generation, and so continues the species. Taking the idea of species from this perennial succession of essentially similar individuals, the chain is logically traceable back to a local origin in a single stock, a single pair, or a single individual, from which all the individuals composing the species have proceeded by natural generation. Although the similarity of progeny to parent is fundamental in the conception of species, yet the likeness is by no means absolute; all species vary more or less, and some vary remarkably—partly from the influence of altered circumstances, and partly (and more really) from unknown constitutional causes which altered conditions favor rather than originate. But these variations are supposed to be mere oscillations from a normal state, and in Nature to be limited if not transitory; so that the primordial differences between species and species at their beginning have not been effaced, nor largely obscured, by blending through variation. Consequently, whenever two reputed species are found to blend in Nature through a series of intermediate forms, community of origin is inferred, and all the forms, however diverse, are held to belong to one species. Moreover, since bisexuality is the rule in Nature (which is practically carried out, in the long-run, far more generally than has been suspected), and the heritable qualities of two distinct individuals are mingled in the offspring, it is supposed that the general sterility of hybrid progeny interposes an effectual barrier against the blending of the original species by crossing.

From this generally-accepted view the well-known theory of Agassiz and the recent one of Darwin diverge in exactly opposite directions.

That of Agassiz differs fundamentally from the ordinary view only in this, that it discards the idea of a common descent as the real bond of union among the individuals of a species, and also the idea of a local origin—supposing, instead, that each species originated simultaneously, generally speaking, over the whole geographical area it now occupies or has occupied, and in perhaps as many individuals as it numbered at any subsequent period.

Mr. Darwin, on the other hand, holds the orthodox view of the descent of all the individuals of a species not only from a local birthplace, but from a single ancestor or pair; and that each species has extended and established itself, through natural agencies, wherever it could; so that the actual geographical distribution of any species is by no means a primordial arrangement, but a natural result. He goes farther, and this volume is a protracted argument intended to prove that the species we recognize have not been independently created, as such, but have descended, like varieties, from other species. Varieties, on this view, are incipient or possible species: species are varieties of a larger growth and a wider and earlier divergence from the parent stock; the difference is one of degree, not of kind.

The ordinary view—rendering unto Caesar the things that are Caesar's—looks to natural agencies for the actual distribution and perpetuation of species, to a supernatural for their origin.

The theory of Agassiz regards the origin of species and their present general distribution over the world as equally primordial, equally supernatural; that of Darwin, as equally derivative, equally natural.

The theory of Agassiz, referring as it does the phenomena both of origin and distribution directly to the Divine will—thus removing the latter with the former out of the domain of inductive science (in which efficient cause is not the first, but the last word)—may be said to be theistic to excess. The contrasted theory is not open to this objection. Studying the facts and phenomena in reference to proximate causes, and endeavoring to trace back the series of cause and effect as far as possible, Darwin's aim and processes are strictly scientific, and his endeavor, whether successful or futile, must be regarded as a legitimate attempt to extend the domain of natural or physical science. For, though it well may be that "organic forms have no physical or secondary cause," yet this can be proved only indirectly, by the failure of every attempt to refer the phenomena in question to causal laws. But, however originated, and whatever be thought of Mr. Darwin's arduous undertaking in this respect, it is certain that plants and animals are subject from their birth to physical influences, to which they have to accommodate themselves as they can. How literally they are "born to trouble," and how incessant and severe the struggle for life generally is, the present volume graphically describes. Few will deny that such influences must have gravely affected the range and the association of individuals and species on the earth's surface. Mr. Darwin thinks that, acting upon an inherent predisposition to vary, they have sufficed even to modify the species themselves and produce the present diversity. Mr. Agassiz believes that they have not even affected the geographical range and the actual association of species, still less their forms; but that every adaptation of species to climate, and of species to species, is as aboriginal, and therefore as inexplicable, as are the organic forms themselves.

Who shall decide between such extreme views so ably maintained on either hand, and say how much of truth there may be in each? The present reviewer has not the presumption to undertake such a task. Having no prepossession in favor of naturalistic theories, but struck with the eminent ability of Mr. Darwin's work, and charmed with its fairness, our humbler duty will be performed if, laying aside prejudice as much as we can, we shall succeed in giving a fair account of its method and argument, offering by the way a few suggestions,

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