turned to a new account. This is an action on the part of nature, and it is evidently selection. Nature selects a variation, and turns it to her own service. It is this selection that is the secret of the general idea. The variation is but Nature's opportunity: how she lays hands on it, that is the punctum vitale of the whole business. It may be that nature will not step in on the first, or the second, or any assignable, variation. Nevertheless, it cannot but be that every variation will tend to alter the bearing of an organism to existence-will tend to realise itself as the first step to a new mutual relation. A variation is but a new cue, a new sign to nature to come hither and catch on.

But all here is natural-the whole process is natural The variation is natural, and the turning of it to use is natural. Generally, it comes to this, then-In the infinitude of time, variations will, in organism after organism, eventually arise such as necessarily involve the taking on of a new relation with nature, or with some one, or some several, of the factors of its habitat and environment in nature. But new relations are new powers: and organisms with new powers are new species. Infinite time means infinite variations. Infinite variations mean infinite new relations. Infinite new relations mean infinite new species.

Mr. Darwin's own words are required to substantiate these statements; and none such can more authoritatively or explicitly be found than in the passages (Life and Letters, i. 82-84, and ii. 120-125) which are, respectively, Mr. Darwin's own account of the whole matter to his children, and the writing to Asa Gray, chosen by Mr. Darwin himself, to be laid before the Linnean Society as representative of his views, on the occasion of the reference to Mr. Wallace. These will be taken up point by point in the sequel; and in

the meantime for the purpose in hand less will suffice.

What started the whole relative thought in Mr. Darwin is directly ascribed in the first of these statements to his experiences in the Beagle: it was "during the voyage of the Beagle that he had been deeply impressed," etc. Mr. Francis Darwin, however, makes (i. 276) the following extract from his father's pocketbook of the date 1837: "In July opened first notebook on Transmutations of Species. Had been greatly struck from about the month of previous March on character of South American fossils, and species on Galapagos Archipelago. These facts (especially latter), origin of all my views." Now it was in September 1833, and two years later (September 1835) that Mr. Darwin respectively visited South America and the Galapagos Archipelago. Yet here, in London, in July 1837, it is only since the previous March that he has come to think that he "has been greatly struck "on character of South American fossils, and species on Galapagos Archipelago." The discrepancy is glaring; but it is quite possible that, though the voyage furnished the materials, and even suggested some early thoughts, it was only at the later dates that these thoughts fairly formulated themselves. Nevertheless, the Journal gives little or no evidence of such direction to his thoughts either in place or time: I am greatly moved to refer to the line at the beginning of Chapter IV. "Suppose, then, we bring both filament and stir together in a beetle this for the Origin!" There can be no doubt that Mr. Darwin had seriously studied, and seriously taken to heart, the "programme programme" which, according to Dr. Krause, lay ready for him in the works of his grandfather; and there can be as little doubt that the affinities among all these species of beetles which he

knew so well, must have been obvious to him. Therefore it is that I bring both considerations together in connection with the Origin.

But however that may be, it is the momenta of the resultant theory which are specially our quest at present. For these, directing attention to the whole of each of the passages named, we select, as sufficiently explicit and decisive, the following expressions: Certain resemblances having suggested to him "that species gradually become modified," the subject "haunted" him. Adaptations"-as, “for instance, of a woodpecker or a tree-frog to climb trees, or of a seed for dispersal by hooks or plumes "had always "much struck" him; and their explanation he saw must be a necessary element in any theory that had modification for its principle. Man, by breeding, artificially produced adaptations; and the secret of his success was "selection." But natural selection could only naturally take place, and that was—by "the struggle for existence." It could be only so that " favourable variations would tend to be preserved, and unfavourable ones to be destroyed." "Here, then," says Mr. Darwin, "I had at last got a theory by which to work." In the struggle for existence, the unfavourable variation would die out; but the favourable one would survive : " the result would be the formation of a new species." This is eminently simple; and one cannot help thinking at once, There can be no difficulty in submitting each sub-idea of the common idea to the test of proof. Nor did the additional sub-idea of "divergence," subsequently suggested, really lead to a complication of any consequence. Divergence meant that variations, or the subjects modified by them, naturally betook themselves to "places" that were naturally adapted to them. The same stock might, as modified, yield horses for the plough, horses for the road, and horses for the race-course, etc.

The simplicity of Mr. Darwin will be apparent in all this-the ease with which he gives himself up to an idea. He saw analogous animals, as it were, replacing each other in space and in time; and so he thought they might be all due the one to the other. He tells his children this quite frankly; and that he could not proceed with his idea till he was able to explain adaptations. What a joy it was to him, he tells them also, the thought of the selective action of the struggle for existence, and again the further thought of the natural selective action, in divergence. It is in this last consideration, divergence, that most innocently, perhaps, his simplicity shows.

It was in "July 1837" that Mr. Darwin began what he calls his "systematic inquiry;" and it was fifteen months afterwards, " in October 1838," that he "had at last got a theory by which to work." "In June 1842," he wrote an abstract of his theory; and this abstract he enlarged "in the summer of 1844." "But at that time," he says, "I overlooked one problem of great importance; and it is astonishing to me, except on the principle of Columbus and his egg, how I could have overlooked it and its solution. I can remember the very spot in the road, whilst in my carriage, when to my joy the solution occurred to me; and this was long after I had come to Down." Now the coming to Down was on "September 14, 1842." A comparison of these dates will show that the express theory of natural selection, complete, so far, in 1838, remained long after 1842 secluded to "favourable variations" and "the struggle for existence." "Divergence" was the discovery of the "long after "" the tendency in organic beings descended from the same stock to diverge in character as they become modified," or the tendency on the part of "the modified offspring of all dominant and increasing forms to become adapted to many and highly diversified

places in the economy of nature."

It is of this principle

of divergence that Mr. Francis Darwin (ii. 15) feels himself called upon to make some explanation. "In reading the sketch of 1844," he says he had found it "difficult to recognise as a flaw" what was so designated by his father: "descent with modification implies divergence, and we become so habituated to a belief in descent, and therefore in divergence, that we do not notice the absence of proof that divergence is in itself an advantage; as shown in the Autobiography, my father in 1876 found it hardly credible that he should have overlooked the problem and its solution." The point concerned is understood in a moment by reference to the stock of horses which splits up into plough horses, race-horses, etc. Individuals of the same stock, that is, precisely as they vary, are variously applied, or they come to occupy "diversified places in the polity of nature." This is further illustrated by the superior yield of the same plot of ground if sown, not with "a single variety of wheat," but with "a mixture of varieties." "The same spot will support more life if occupied by very diverse forms," says Mr. Darwin himself (ii. 124). Now, in such illustrations, the "superior yield," the more life," the "increase in numbers," the "greater produce," the "more individuals," etc., are almost so exclusively thrust into view that the gist of the illustration is lost; which gist solely concerns the difference of the places seized by the differences of the individuals seizing them. In that, and in that alone, lies the principle of the divergence of character. Mr. Darwin's favourableness of variation, and Mr. Darwin's principle of divergence, mean no more, each, than the single expression new relation to nature. The favourableness of the variation depends on a new relation to nature, and it is just in such new relation that the divergence of character lies. Why, even with the plot and the grain, how is it that the mixed seeds have a