Moreover, while we see how the mere struggle and interplay among occurring forms may improve them and lead them on, we cannot well imagine how the adaptations which arrest our attention are thereby secured. Our difficulty, let it be understood, is not about the natural origination of organs. To the triumphant outcry, "How can an organ, such as an eye, be formed under Nature?" we would respond with a parallel question, How can a complex and elaborate organ, such as a nettle-sting, be formed under Nature? But it is so formed. In the same species some individuals have these exquisitely-constructed organs and some have not. And so of other glands, the structure and adaptation of which, when looked into, appear to be as wonderful as anything in Nature. The impossibility lies in conceiving how the obvious purpose was effectuated under natural selection alone. This, under our view, any amount of gradation in a series of forms goes a small way in explaining. The transit of a young flounder's eye across the head is a capital instance of a wonderful thing done under Nature, and done unaccountably. But simpler correlations are involved in similar difficulty. The superabundance of the pollen of pine-trees above referred to, and in oak-trees, is correlated with chance fertilization under the winds. In the analogous instance of willows a diminished amount of pollen is correlated with direct transportation by insects. Even in so simple a case as this it is not easy to see how this difference in the conveyance would reduce the quantity of pollen produced. It is, we know, in the very alphabet of Darwinism that if a male willow-tree should produce a smaller amount of pollen, and if this pollen communicated to the offspring of the female flowers it fertilized a similar tendency (as it might), this male progeny would secure whatever advantage might come from the saving of a certain amount of work and material; but why should it begin to produce less pollen? But this is as nothing compared with the arrangements in orchid-flowers, where new and peculiar structures are introduced--structures which, once originated and then set into variation, may thereupon be selected, and thereby led on to improvement and diversification. But the origination, and even the variation, still remains unexplained either by the action of insects or by any of the processes which collectively are personified by the term natural selection. We really believe that these exquisite adaptations have come to pass in the course of Nature, and under natural selection, but not that natural selection alone explains or in a just sense originates them. Or rather, if this term is to stand for sufficient cause and rational explanation, it must denote or include that inscrutable something which produces--as well as that which results in the survival of--"the fittest."