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greater increase than the unmixed? The former, plainly, have a greater variety of differences than the latter, with which to meet the differences of the plot. The differences of the plot are so many eyes for the hooks which are the differences of the seeds; and in these differences the mixed exceed the unmixed. Difference here to difference there the result is a relation, or, as it may be, a new relation. Mr. Darwin's own word for relation is, as we have seen, simply "place." Variations to him, as variations, become relegated to new "places." One is apt to feel a little surprise, then, on the whole, that so much should have been made of so much that is in itself so easy. The new that has given so much joy to Mr. Darwin as over a quite extraordinary find, is, after all, nothing but the old. The splitting up of the stock of horses is nothing but an illustration of the variation in its effects. The splitting up is but of variations into new "places" adapted to them. The divergence is no more than an illustration of the modification.

The whole thing is a striking illustration of Mr. Darwin's state of mind when absorbed in the idea of a projection. So vaguely he presses on, that even essential distinctions escape him. The single point of modification has so caught that all-too susceptible imagination of his, that he has simply given himself up to it-in a certain confused heat he sees nothing else. The struggle will select, the stock will split up, the variety will take its place -all with nature as with us. He so glows himself that he makes all others glow. He persuades Lyell, Hooker, Huxley, Gray to astound the public with the tidings of a discovery that opens a new world to it. It was really as though Columbus had come home with the unimaginable fruits and flowers of an unimaginable new country. cannot doubt," cries Mr. Darwin, " that during millions of generations individuals of a species will be born with some

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slight variation profitable to some part of its economy; such will have a better chance of surviving, propagating this variation, which again will be slowly increased by the accumulative action of natural selection; and the variety thus formed will either coexist with, or more commonly will exterminate its parent form: an organic being like the woodpecker, or the misletoe, may thus come to be adapted to a score of contingencies." What is this but imagination reduplicated, and reduplicated into an absolutely nth power, till no one can resist it, especially those who, like Mr. Huxley, would smash to the earth that stupid pulpit-business with the metalline dash of "natural causation"?

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From what precedes, we see that variations, diverging into new "places," become, by natural selection, new species. It may be well to illustrate from Mr. Darwin himself this process of selection. The very term selection," he says once to Hooker (ii. 317), "implies something, i.e. variation or difference, to be selected ;" and at another time (ii. 373) he lays stress to Asa Gray on "the enormous field of variability which he sees ready for selection to appropriate." But, perhaps, a single consideration, and of two illustrations, the one by Mr. Darwin and the other by Mr. Francis, will give sight-final and definitive of the whole theory. Mr. Darwin (ii. 320) makes variations the materials for the formation of a species, just as bricks or squared stones are the materials. for the formation of a building. As the peculiarity of the materials, too, influence the building, so does that of the variations influence the species. Yet in the same manner as the architect is the all-important person in a building, so is selection with organic bodies." That, then, is plain; as the architect makes a new building out of stones, so selection makes a new species out of variations. To Mr. Francis again (i. 309, note): As the builder forms

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stones into a house, so the breeder forms variations into a race. In both illustrations, the role of selection, as the róle of variation, is accurately prescinded.

But what now of the adaptation? Why, that, too, is easy that, too, is on the surface. The favourableness of the variation in the struggle for existence and the divergence into place simply are the adaptation. As an organism varies ever the more and the more favourably, and diverges ever the more and the more in character and place; so, plainly, ever the more and the more must it depart from what it was at first, to stand up, sooner or later, consequently, with new adaptations, a new species. In this way new species and new adaptations are seen to be but products of natural growth, and not by any means results of supernatural interference. Just consider, for example, how such a conspicuous case of adaptation may have gradually arisen-naturally- -as the woodpecker (again and again referred to, this is Mr. Darwin's favourite example of adaptation).

Of two birds that feed on insects, conceive the one of them to have varied favourably in the beak-to be possessed, that is, of the stronger beak: it will have the advantage over the other, and it will transmit this advantage to its descendants. In these this advantage can only grow; for they will always possess, and, as is evident, always increasingly possess, the strongest beaks. That strength of beak will give the advantage is but a corollary on the habits of the birds themselves. They haunt fallen trees, namely, under the bark of which the insects burrow to fall a prey preferably to the strongest beak that can dig for them. Still even the strongest beak does not always succeed; its tongue, conceivably, is too short, and the insects occasionally escape it. Let a strong-beaked bird be born now with a longer tongue than the rest, why, it, too, will have the advantage over

its fellows, and it will also transmit this advantage to the descendants of itself. Strong-beaked, long-tongued insect-feeders will now, evidently, constitute the rule; but unfortunately, in course of time, there occurs a dearth of fallen timber; strength of beak and length of tongue scarcely suffice any longer for more than the scantiest and miserablest of existences. But see, one of them gets born with sharper fore-claws than any one of its brothers; it is actually seen to ascend standing trees, and, triumphantly tapping the bark, luxuriously to feed on an all-abundant treasure and store of hitherto unreachable and unreached insects. Once again there can be only one result, the birds that have blunt fore-claws will gradually die off, and the sharp fore-claws will alone remain. But even these come to be at a disadvantage in the struggle for life. An individual is born that adds on to the already existent sharp fore-claw-actually!a sharp hind-claw. Consummatum est! the sharp foreclaws must perish, for their time has come. the triumphant hind-clawers have to suffer defeat in their turn. There is born among them one who can stick his tail, as well as his claws, into the tree, up which he can run with an all-conquering swiftness. He and his children simply starve out all the rest, and are left alone at the last in the undisturbed possession of every rotten tree in the forest. On every one of them now there thrones as autocrat- a Picus Superbus ! 1

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But even

This, the woodpecker, is a bird that, for the complicated adaptations it exhibits, is absolutely unparalleled. The bill is wedge-shaped and keen; the tongue long, nimble, sharp, barbed or beset with bristles bent backwards, and coated viscid; the claws are strong and spiked to grasp even a perpendicular surface, and in this they are supported by the tail, the stiff, pointed end

1 Of course this conceivable story is not to be laid to Darwin.

feathers of which can keenly grasp also. The life of this bird being the running up and down old trees to pick holes into them in pursuit of insects, which it hunts and captures with its supple, long, gluey tongue, it is to be regarded in itself as glaringly and conspicuously a proof of the fact of natural selection; for though possibly quite an ordinary bird at first, it has conceivably grown into what it is a new species-by propagated successive advantages simply in pursuit of its business.

Mr. Darwin's own words will confirm the picture. "The facts which kept me longest scientifically orthodox," he says (ii. 121), “are those of adaptation—the woodpecker, with its feet and tail, beak and tongue, to climb the tree and secure insects," etc. This is as much as to say that he was long arrested by the problem of design-and we may now take together all that concerns that problem in a chapter by itself.

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