Now, the reasoning, or rather the assertion, that these substitutions are unaccountable as the results of design, appears to me to be singularly inconclusive. It is quite illogical, according to all philosophic meaning of design as applied to the works of the Creator, or to the works of nature, if that term is preferred, to argue that a particular object could have been better accomplished directly, than by a metamorphosis of an organ from one function to another, or by substitution. The metamorphosis, or substitution, which in such cases we find in nature, is of itself the very highest evidence that the indirect method was the best, if we admit the idea of a Creator, because it was the method chosen by a being of infinite perfections for reasons which we may not be able to discover, but which we must presume to have existed, if we concede that hypothesis of attributes which "design" in this case necessarily implies. But how are these metamorphoses and substitutions any more accountable upon the supposition that the mammalian type arose by generation out of the lower vertebrate types which in their embryonic life exhibited the same changes? The doctrine or theory of evolution does not account for them at all; for, while the doctrine supposes, as matters of pure theory, that there were certain states through which the mammalian embryo passed, which represented more or less distinctly those which it had in common with its assumed remote ancestors, the lower vertebrata, it does nothing more than to suggest the theoretical idea that the mammalian embryo came to develop these subsidiary organs in the mode in which they were developed in the embryo of the lower vertebrata, because it was descended from the lower vertebrata. The varying states through which the embryo passed from the lower vertebrata to the mammalian type, are all hypothetical, and there is, therefore, no basis of fact on which to rest the belief in a common mode of development, as resulting from a connection of lives with lives between the mammalian type and the types of birds, reptiles, or fishes. On the other hand, the hypothesis of the special creation of a species implies the simple fact of a designed process of embryonic development for each species, with substitutions of organs and changes of function in certain organs peculiar to that species; a fact which may well consist in a certain parallelism in the different metamorphoses, and a preservation of the same unvarying changes in the development of each separate embryo. Why these changes should exist, we can not tell; but their existence is very strong proof that they were designed, or made to take place, for some reason, if we admit the hypothesis of a Creator. For that hypothesis, we must look to a wider class of facts, and to the whole phenomena of nature.