Evolution, Old & New Part 26

[298] 'Animals and Plants under Domestication,' vol. i. p. 467, &c.

[299] See frontispiece to Professor Mivart's 'Genesis of Species.'

[300] 'Phil. Zool.,' tom. i. p. 247.

[301] Page 248.

[302] 'Nat. Theol.,' vol. xii., end of -- viii.

[303] 'Phil. Zool.,' tom. i. p. 249.

[304] 'Phil. Zool.,' tom. i. p. 250.

[305] Page 250.

[306] 'Phil. Zool.,' tom. i. p. 251.

[307] Page 252.

[308] 'Phil. Zool.,' tom. i. p. 253.

[309] Page 254.

[310] 'Phil. Zool.,' tom. i. p. 256.

[311] Page 257.

[312] 'Phil. Zool.,' tom. i. p. 259.

[313] Page 260.

[314] Page 263.

[315] 'Phil. Zool.,' tom. i. p. 263.

[316] Page 265.

[317] 'Phil. Zool.,' tom. i. p. 343.

[318] 'Phil. Zool.,' tom. i. p. 343.

[319] Page 346.

[320] 'Phil. Zool.,' tom. i. p. 347.

CHAPTER XVIII.

MR. PATRICK MATTHEW, MM. eTIENNE AND ISIDORE GEOFFROY ST. HILAIRE, AND MR. HERBERT SPENCER.

The same complaint must be made against Mr. Matthew's excellent survey of the theory of evolution, as against Dr. Erasmus Darwin's original exposition of the same theory, namely, that it is too short. It may be very true that brevity is the soul of wit, but the leaders of science will generally succeed in burking new-born wit, unless the brevity of its soul is found compatible with a body of some bulk.

Mr. Darwin writes thus concerning Mr. Matthew in the historical sketch to which I have already more than once referred.

"In 1831 Mr. Patrick Matthew published his work on 'Naval Timber and Arboriculture,' in which he gives precisely the same view on the origin of species as that (presently to be alluded to) propounded by Mr.

Wallace and myself in the 'Linnean Journal,' and as that enlarged in the present volume. Unfortunately the view was given by Mr. Matthew very briefly, in scattered pa.s.sages in an appendix to a work on a different subject, so that it remained unnoticed until Mr. Matthew himself drew attention to it in the 'Gardener's Chronicle' for April 7, 1860. The differences of Mr. Matthew's view from mine are not of much importance; he seems to consider that the world was nearly depopulated at successive periods, and then re-stocked, and he gives as an alternative, that new forms may be generated 'without the presence of any mould or germ of former aggregates.' I am not sure that I understand some pa.s.sages; but it seems that he attributes much influence to the direct action of the conditions of life. He clearly saw, however, the full force of the principle of natural selection."[321]

Nothing could well be more misleading. If Mr. Matthew's view of the origin of species is "precisely the same as that" propounded by Mr.

Darwin, it is hard to see how Mr. Darwin can call those of Lamarck and Dr. Erasmus Darwin "erroneous"; for Mr. Matthew's is nothing but an excellent and well-digested summary of the conclusions arrived at by these two writers and by Buffon. If, again, Mr. Darwin is correct in saying that Mr. Matthew "clearly saw the full force of the principle of natural selection," he condemns the view he has himself taken of it in his 'Origin of Species,' for Mr. Darwin has a.s.signed a far more important and very different effect to the fact that the fittest commonly survive in the struggle for existence, than Mr. Matthew has done. Mr. Matthew sees a cause underlying all variations; he takes the most teleological or purposive view of organism that has been taken by any writer (not a theologian) except myself, while Mr. Darwin's view, if not the least teleological, is certainly nearly so, and his confession of inability to detect any general cause underlying variations, leaves, as will appear presently, less than common room for ambiguity. Here are Mr. Matthew's own words:--

"There is a law universal in nature, tending to render every reproductive being the best possibly suited to the condition that its kind, or that organized matter is susceptible of, and which appears intended to model the physical and mental or instinctive, powers to their highest perfection, and to continue them so. This law sustains the lion in his strength, the hare in her swiftness, and the fox in his wiles. As nature in all her modifications of life has a power of increase far beyond what is needed to supply the place of what falls by Time's decay, those individuals who possess not the requisite strength, swiftness, hardihood, or cunning, fall prematurely without reproducing--either a prey to their natural devourers, or sinking under disease, generally induced by want of nourishment, their place being occupied by the more perfect of their own kind, who are pressing on the means of existence.

"Throughout this volume, we have felt considerable inconvenience from the adopted dogmatical cla.s.sification of plants, and have all along been floundering between species and variety, which certainly under culture soften into each other. A particular conformity, each after its own kind, when in a state of nature, termed species, no doubt exists to a considerable degree. This conformity has existed during the last forty centuries; geologists discover a like particular conformity--fossil species--through the deep deposition of each great epoch; but they also discover an almost complete difference to exist between the species or stamp of life of one epoch from that of every other. We are therefore led to admit either a repeated miraculous conception, or _a power of change under change of circ.u.mstances_ to belong to living organized matter, or rather to the congeries of inferior life which appears to form superior." (By this I suppose Mr. Matthew to imply his a.s.sent to the theory, that our personality or individuality is but as it were "the consensus, or full flowing river of a vast number of subordinate individualities or personalities, each one of which is a living being with thoughts and wishes of its own.") "The derangements and changes in organized existence, induced by a change of circ.u.mstances from the interference of man, afford us proof of the plastic quality of superior life; and the likelihood that circ.u.mstances have been very different in the different epochs, though steady in each, tend strongly to heighten the probability of the latter theory.

"When we view the immense calcareous and bituminous formations, princ.i.p.ally from the waters and atmosphere, and consider the oxidations and depositions which have taken place, either gradually or during some of the great convulsions, it appears at least probable that the liquid elements containing life have varied considerably at different times in composition and weight; that our atmosphere has contained a much greater proportion of carbonic acid or oxygen; and our waters, aided by excess of carbonic acid, and greater heat resulting from greater density of atmosphere, have contained a greater quant.i.ty of lime, and other mineral solutions. Is the inference, then, unphilosophic that living things which are proved to have _a circ.u.mstance-suiting power_ (a very slight change of circ.u.mstance by culture inducing a corresponding change of character), may have gradually accommodated themselves to the variations of the elements containing them, and without new creation, have presented the diverging changeable phenomena of past and present organized existence?

"The destructive liquid currents before which the hardest mountains have been swept and comminuted into gravel, sand, and mud, which intervened between and divided these epochs, probably extending over the whole surface of the globe and destroying nearly all living things, must have reduced existence so much that an unoccupied field would be formed for new diverging ramifications of life, which from the connected s.e.xual system of vegetables, and the natural instinct of animals to herd and combine with their own kind, would fall into specific groups--these remnants in the course of time moulding and accommodating their being anew to the change of circ.u.mstances, and to every possible means of subsistence--and the millions of ages of regularity which appear to have followed between the epochs, probably after this accommodation was completed, affording fossil deposit of regular specific character.

"In endeavouring to trace ... the principle of these changes of fas.h.i.+on which have taken place in the domiciles of life the following questions occur: Do they arise from admixture of species nearly allied producing intermediate species? Are they the diverging ramifications of the living principle under modification of circ.u.mstance? or have they resulted from the combined agency of both?

"_Is there only one living principle? Does organized existence, and perhaps all material existence, consist of one Proteus principle of life_ capable of gradual circ.u.mstance-suited modifications and aggregations without bound, under the solvent or motion-giving principle of heat or light? There is more beauty and unity of design in this continual balancing of life to circ.u.mstance, and greater conformity to those dispositions of nature that are manifest to us, than in total destruction and new creation. It is improbable that much of this diversification is owing to commixture of species nearly allied; all change by this appears very limited and confined within the bounds of what is called species; the progeny of the same parents under great difference of circ.u.mstance, might in several generations even become distinct species, incapable of co-reproduction.

"The self-regulating adaptive disposition of organized life may, in part, be traced to the extreme fecundity of nature, who, as before stated, has in all the varieties of her offspring a prolific power much beyond (in many cases a thousand fold) what is necessary to fill up the vacancies caused by senile decay. As the field of existence is limited and preoccupied, it is only the hardier, more robust, better suited to circ.u.mstance individuals, who are able to struggle forward to maturity, these inhabiting only the situations to which they have _superior adaptation and greater power of occupancy than any other kind; the weaker and less circ.u.mstance-suited being prematurely destroyed_. This principle is in constant action; it regulates the colour, the figure, the capacities, and instincts; those individuals in each species whose colour and covering are best suited to concealment or protection from enemies, or defence from inclemencies and vicissitudes of climate, whose figure is best accommodated to health, strength, defence, and support; whose capacities and instincts can best regulate the physical energies to self-advantage according to circ.u.mstances--in such immense waste of primary and youthful life those only come forward to maturity from the strict ordeal by which nature tests their adaptation to her standard of perfection and fitness to continue their kind by reproduction.

"From the unremitting operation of this law acting in concert with the tendency which the progeny have to take the more particular qualities of the parents, together with the connected s.e.xual system in vegetables and instinctive limitation to its own kind in animals, a considerable uniformity of figure, colour, and character is induced const.i.tuting species; the breed gradually acquiring the very best possible adaptation of these to its condition which it is susceptible of, and when alteration of circ.u.mstance occurs, thus changing in character to suit these, as far as its nature is susceptible of change.

"This circ.u.mstance-adaptive law operating upon the slight but continued natural disposition to sport in the progeny (seedling variety) _does not preclude the supposed influence which volition or sensation may have had over the configuration of the body_. To examine into the disposition to sport in the progeny, even when there is only one parent as in many vegetables, and to investigate how much variation is modified by the mind or nervous sensation of the parents, or of the living thing itself during its progress to maturity; how far it depends upon external circ.u.mstance, and how far on the will, irritability, and muscular exertion, is open to examination and experiment. In the first place, we ought to examine its dependency upon the preceding links of the particular chain of life, variety being often merely types or approximations of former parentage; thence the variation of the family as well as of the individual must be embraced by our experiments.

"This continuation of family type, not broken by casual particular aberration, is mental as well as corporeal, and is exemplified in many of the dispositions or instincts of particular races of men. _These innate or continuous ideas or habits seem proportionally greater in the insect tribes, and in those especially of shorter revolution; and forming an abiding memory, may resolve much of the enigma of instinct, and the foreknowledge which these tribes have of what is necessary to completing their round of life, reducing this to knowledge or impressions and habits acquired by a long experience._

"This greater continuity of existence, or rather continuity of perceptions and impressions in insects, is highly probable; _it is even difficult in some to ascertain the particular steps when each individual commences_, under the different phases of egg, larva, pupa, or if much consciousness of individuality exists. The continuation of reproduction for several generations by the females alone in some of these tribes, _tends to the probability of the greater continuity of existence; and the subdivisions of life by cuttings (even in animal life), at any rate, must stagger the advocate of individuality_.

"Among the millions of specific varieties of living things which occupy the humid portions of the surface of our planet, as far back as can be traced, there does not appear, with the exception of man, to have been any particular engrossing race, but a pretty fair balance of power of occupancy--or rather most wonderful variation of circ.u.mstance parallel to the nature of every species, _as if circ.u.mstance and species had grown up together_. There are, indeed, several races which have threatened ascendancy in some particular regions; but it is man alone from whom any general imminent danger to the existence of his brethren is to be dreaded.

"As far back as history reaches, man had already had considerable influence, and had made encroachments upon his fellow denizens, probably occasioning the destruction of many species, and the production and continuation of a number of varieties, and even species, which he found more suited to supply his wants, but which from the infirmity of their condition--_not having undergone selection by the law of nature_, of which we have spoken--cannot maintain their ground without culture and protection.

"It is only however in the present age that man has begun to reap the fruits of his tedious education, and has proven how much 'knowledge is power.' He has now acquired a dominion over the material world, and a consequent power of increase, so as to render it probable that the whole surface of the earth may soon be overrun by this engrossing anomaly, to the annihilation of every wonderful and beautiful variety of animal existence which does not administer to his wants, princ.i.p.ally as laboratories of preparation to befit cruder elemental matter for a.s.similation by his organs.

"The consequences are being now developed of our deplorable ignorance of, or inattention to, one of the most evident traits of natural history--that vegetables, as well as animals, are generally liable to an almost unlimited diversification, regulated by climate, soil, nourishment, and new commixture of already-formed varieties. In those with which man is most intimate, and where his agency in throwing them from their natural locality and disposition has brought out this power of diversification in stronger shades, it has been forced upon his notice, as in man himself, in the dog, horse, cow, sheep, poultry,--in the apple, pear, plum, gooseberry, potato, pea, which sport in infinite varieties, differing considerably in size, colour, taste, firmness of texture, period of growth, almost in every recognizable quality. In all these kinds man is influential in preventing deterioration, by careful selection of the largest or most valuable as breeders."[322]