It might have occurred to the very learned naturalist that the formation of a mechanical instrument by the hand of man, guided by his intellect, admits of varieties of that instrument for different purposes, as products of an intelligent will. Different kinds of telescopes for different uses have been produced, not by destroying the poorer ones and preserving the better ones, but by a special and intentional adaptation of the structure to special uses, until an instrument is made which will dissolve the nebulæ of the milky way, and bring within the reach of our vision heavenly bodies of the existence of which we had no previous knowledge. Why may not the same intelligent and intentional formation of the human eye, as a special structure adapted to the special conditions of such an animal as man, have been the direct work of the Creator, just as the lowest visual organ--that of such a creature as the lancelet--was specially made for the conditions of its existence? Why resort to the theory that all the intermediate varieties of the eye have grown successively out of the lowest form of such an organ by transitional grades of which we can not trace the series, when the probabilities concerning the varieties of this organ of which we have any knowledge are so strongly on the side of a special and intentional adaptation of each one to the circumstances of the animal to which it has been given? As a question of power in the Creator, either method of action was of course just as competent as the other. As a question of which was his probable method, the case is very different; for we know comparatively very little of the modifications produced by such causes as natural or even sexual selection, while we may, without presumption, assume that we know much more about the purposes of special adaptation to special conditions, which an omnipotent Creator may have designed and effected. But this is a digression, and also an anticipation of the argument.