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190 he says :
which were extended, as he informs us, over a period of thirteen years.
page “ T o distinct organs sometimes perform simultaneously the same function in the same individual. To give one instance; there are fish with gills or branchiæ that breathe the air dissolved in the water, at the same time that they breathe free air in their swim bladders, this latter organ having a ductus pneumaticus for its supply, and being divided by highly vascular partitions. In these cases one of the two orgaus might with ease be modified and perfected so as to perform all the work by itself, being aided during the process of modification by the other organ; and then this other organ might be modified for some other and quite distinct purpose, or be quite obliterated.”
This, be it noted, is, after all, quite conjectural. The proper work of the ductus pneumaticus is to convey air to the swim bladder, and not to oxygenize the blood, which is the special office of the branchiæ, or gills. But suppose we yield Mr. Darwin this position, since he bas taken the liberty of assuming it, what use will he make of it? In the next page (191) he carries on the argument thus :
“I can indeed hardly doubt that all vertebrate animals having true lungs, have descended, by ordinary generation, from an ancient prototype, of which we know nothing, furnished with a floating apparatus, or swimbladder. We can thus, as I iufer from Pr: vfessor Owen's interesting description of these parts, understand the strange fact, that every particle of food and drink which we swallow has to pass over the orifice of the trachea, with some risk of falling into the lungs, notwithstanding the beautiful contrivance by which the glottis is closed. In the higher vertebrata the branchiæ have wholly disappeared—the slits on the sides of the neck, and the loop-like course of the arteries, still marking in the embryo their former position. But it is conceivable that the now utterly lost branchiæ might have been gradually worked in by natural selection for some quite distinct purpose, in the same manner as, on the view entertained by some naturalists, that the branchiæ and dorsal scales of annolids are homologous with the wings and wing-covers of insects, it is probable that organs which at a very ancient period served for respiration, have been actually converted into organs of flight.”
We may just remark, in passing, that the resemblance which the embryo of the mammal bears to the fish in the possession of bronchial apparatus, is but a wise adaptation to its then present condition, the true lungs or bronchiæ not being fully developed until the time for its breathing air has arrived. But our object in quoting this passage was to present the steps of our author's argument, an argument which he deems cogent and conclusive. The proof he offers, let it be noticed, is, "I can hardly doubt,” “It is conceivable," "It is probable ;" and having thus established
? his position, without any additional evidence, six pages after he assumes it as demonstrated, and draws conclusions from it as an
established fact. Of this let the following passage from page 196 bear witness :
“Seeing how important an organ of locomotion the tail is in most aquatic animals, its general presence and use for so many purposes in so many land animals, which in their lungs or modified swim-bladders betray their aquatic origin, may perhaps be accounted for. A welldeveloped tail having been formed in an aquatic animal, it might subsequently come to be worked in for all sorts of purposes, as a fly-flapper, an organ of prehension, or as an aid in turning, as with the dog ; though the aid must be slight, for the hare, with hardly any tail, can double quickly enough."
We leave the question of the tail, which Mr. Darwin's progenitors not having any necessary use for, have, it appears, by the process of “natural selection ” managed to dispense with, or "work up.” Our object in quoting the passage is simply to place before readers, in the connection in which they stand, the words we have put into italics. This is the triumphant conclusion drawn from such elaborate arguments as “I can hardly doubt,” “It is conceivable,” and “ It is probable;" and this conclusion, it will be seen, is being “worked up” as an established fact, for the purpose of establishing other notions with just an equal amount of demonstration. Such vagaries show, indeed, how easily the process of argument can be conducted when the conclusion is foregone. First, it is assumed that swim-bladders are used for the purpose of oxygenizing the blood of fishes. Next, it is assumed that these modified swim-bladders are transformed into lungs to form the bronchiæ by which the blood of land animals is oxygepized. And lastly, it is very modestly assumed that the mere possession of lungs, which show palpably that their possessors were purposed and constituted, not for living in water, but in air, betrays their aquatic origin! A cogent specimen of reasoning is this to be put forth by the "naturalist of Her Majesty's ship Beagle.” One who can thus argue may well undertake the task of showing that he is right, and all the rest of the world are wrong!
Again, at page 242, after a very elaborate but inconclusive attempt to obviate the objections against his theory, which are presented by the conditions of such communities as those of bees and ants, he says :
“ The case also is very interesting, as it proves that, with animals as with plants, any amount of modification in structure can be effected by the accumulation of various slight, and, as we must call them, accidental variatious, which are in any manner profitable, without exercise or habit having come into play. For no amount of exercise, or habit, or volition, in the utterly sterile members of a community could possibly affect the structure or instincts of the fertile members which alone leave descendants."
And what is the proof thus offered ? The case is simply that there are instances of fertile insects producing ncuter or sterile
ones, in some instances of two or three different classes, all essential to the well-being of the community. And these sterile insects not propagating their kind, but being constantly produced by fertile ones, not in their own likeness, and produced continually of the same kind, the doctrine of development is set utterly at defiance, and shown, in their case, to be a dream. And the proof offered that this is accomplished by “natural selection” is simply, that since it is a well known fact in nature, which cannot be disputed, “natural selection” must have done it. What says the author himself just before?
"I am bound to confess that, with all my faith in this principle, I should never have anticipated that natural selection could have been efficient in so high a degree, had not the case of these neuter instincts convinced me of the fact."
The case, then, is cited to prove the amazing power of natural selection, instead of any evidence being brought forward to show how, by natural selection, it has been accomplished. And if this be not begging the question, what is, or can be ?—the word proves being used, though no proof whatever is offered, and scarcely even a suggestion that bears clearly upon the facts against which our author was contending.
In just the same spirit of assumption, after searching the genealogical record in vain for transitional forms between distinct species or members of a distinct genus, which would serve for evidence that they might have been transmitted from the same parents-instead of of candidly confessing that his case here was rendered dubious for lack of distinct testimony, because those formis are always absent, he tells us (page 293) that “Nature may almost be said to have guarded against the frequent discovery of her transitional or linking forms.” [No marvel, indeed, that such should have been the case, if there were none !] And again, in the same spirit, he says (p. 316), “ We have seen in the last chapter that the species of a group sometimes falsely appear to have come in abruptly; and I have attempted to give an explanation of this fact, which, if true, would have been fatal to my views.” But why is this word “ falsely” thrust in ? The chapter alluded to simply shows that the species do appear so to come in. By a very limping argument the author endeavours to show that this appearance might be false. But whether it be false or not is the question in dispute; and is not to be begged thus easily.
The whole geological argument is conducted in just the same easy way. Following in the wake of the late Baden Powell, our author treats the crust of the earth as though it contained just what it does not contain. Determined not to admit of convulsions or cataclysms, which would render new creations necessary, he fills up the enormous breaks which occur between different beds of organic remains with imagined creatures which might have been there deposited, if the conditions had been such as to admit of their being preserved. And these, of course, are the intermediate forms between the earlier and the later series—the connecting links in the genealogical chain, none of which ever appear in the two or three and thirty geological eras which have been traced, or the perhaps greater number which Mr. Darwin imagines preceded them.
But more of this hereafter. We now turn to a few of our author's modest assumptions in the way of development;" which few might be very greatly extended in number, if our space would permit. Take first the following from page 134–5:
“ As the larger ground-feeding birds seldom take flight, except to es. cape danger, I believe that the nearly wingless condition of several birds which now inhabit or have lately inhabited several oceanic islands, tenanted by no beast of prey, has been caused by disuse. The ostrich indeed inhabits continents, and is exposed to danger from which it cannot escape by flight; but by kicking it can defend itself from enemies as well as any of the smaller quadrupeds. We may imagine that the
. early progenitor of the ostrich had habits like those of the bustard; and that, as natural selection increased in successive generations the size and weight of its body, its legs were used more, and its wings less, until they became incapable of flight.”
This is a tolerable specimen of bold assumption; but what follows far surpasses it :
“To suppose that the eye, with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correcting of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest degree. Yet reason tells me, that if numerous gradations from a perfect and complex eye to one very imperfect and simple, each grade being useful to its possessor, can be shown to exist ; if, further, the eye does vary ever so slightly, and the variations be inherited, which is certainly the case, and if any variation or modification in the organ be ever useful to an animal under changing conditions of life, then the difficulty of believing that a perfect and complex eye could be formed by natural selection, though insuperable to our imagination, can hardly be considered real. How a nerve comes to be sensitive to light, hardly concerns us more than how life itself first originated; but I may remark, that several facts make me suspect that any sensitive nerve may be rendered sensitive to light, and likewise to those coarser vibrations of the air which produce sound.
" In looking for the gradations by which an organ in any species has been perfected, we ought to look exclusively at its lineal ancestors; but this is scarcely ever possible ; and we are forced, in each case, to look to species of the same group, that is, to the (supposed] collateral descendants from the same parent form, in order to see what gradations are possible, and for the chance of some gradations having been transmitted from the earlier stages of descent, in an unaltered or little altered condition. Amongst existing vertebrata, we find but a small amount of gradation in the structure of the eye; and from fossil species we can Vol, 59.-No. 272.
learn nothing on this head. In this great class we should probably have to descend far beneath the lowest known fossiliferous stratum to dis. cover the earlier stages by which the eye had been perfected. (!) .... I can see no very great difficulty (not more than in the case of many other structures) in believing that natural selection has converted the simple apparatus of an optic nerve, merely coated with pigment, and invested by transparent membrane, into an optical instrument as perfect as is possessed by any member of the great articulate class.
“ He who will go thus far, if he find, on finishing this treatise, that large bodies of facts, otherwise inexplicable, can be explained by the theory of descent, ought not to hesitate to go further, and to admit that a structure even as perfect as the eye of an eagle might be formed by natural selection, although in this case he does not know any of the transitional grades."
The so-called “large bodies of facts otherwise inexplicable” can all be explained by admitting them to be the result of the free will of an intelligent Creator, who, while choosing to adhere to certain typical forms, has, in his wisdom and goodness, adapted those forms to all varieties of place and circumstance.
But Mr. Darwin cannot see this explanation, because his transparent object was to cast God out of His own creation. We supplement, however, this theory of the origin of the eye with the following remarks which follow shortly after :
“ It is scarcely possible to avoid comparing the eye to a telescope. We know that this instrument has been perfected by the long-continued efforts of the highest human intellects ; and we naturally (?) infer that the eye has been formed by a somewhat analogous process. But may not this inference be presumptuous ? [It may indeed!] Have we any right to assume that the Creator works by intellectual powers like those of man ? (Certainly not !-and yet he goes on with the assumption.] If we must compare the eye to an optical instrument, we ought in imagination to take a thick layer of transparent tissue, with a nerve sensitive to light beneath, and then suppose every part of this layer to be continually changing slowly in density, so as to separate into layers of different densities and thicknesses, placed at different distances from each other, and with the surfaces of each layer slowly changing in form. Further, we must suppose that there is a power always intently watching each slight accidental alteration which, under varied circumstances, may in any way or in any degree tend to produce a distincter image. We must suppose each new state of the instrument to be multiplied by the million, and each to be preserved till a better be produced, and then the old ones to be destroyed. In living bodies, variation will cause the slight alteration; generation will multiply them almost infinitely; and natural selection will pick out, with unerring skill, each improvement. Let this process go on for millions on millions of years, and during each year on millions of individuals of many kinds, and may we not believe that a living optical instrument might thus be formed, as superior to one of glass as the works of the Creator are to those of man ?” (pp. 188, 189.)