To the physiologist this is obvious; but some unscientific reader may say, Could not God have created plants and animals without these retrospective marks? I distinctly reply, No! not so as to preserve their specific identity with those with which we are familiar. A Tree-fern without scars on the trunk! A Palm without leaf-bases! A Bean without a hilum! A Tortoise without laminae on its plates! A Carp without concentric lines on its scales! A Bird without feathers! A Mammal without hairs, or claws, or teeth, or bones, or blood! A Foetus without a placenta! I have indeed written the preceding pages in vain, if I have not demonstrated, in a multitude of examples, the absolute necessity of retrospective phenomena in newly-created organisms. But if it can be undeniably shown in one single example, our failure to perceive it in ninety-nine other instances would in nowise invalidate the deduction from that one. Granted that you can triumphantly convict me of a _non-sequitur_, in ninety-nine out of every hundred of the cases in which I have attempted to show this connexion; still, if I have conclusively proved that in one solitary instance an animal or a plant was created with but one solitary evidence of pre-development, the principle for which I contend is established. I trust, however, it does not rest on one example, nor on twenty, nor on a hundred. It may be thought that I have multiplied my illustrations needlessly: ten times as many might have been given. I wished to show that the proof is of a cumulative character: a single good example would, indeed, have established the principle; but I wished to show how widely applicable it is; that it is, indeed, of universal application in the organic kingdoms. If, then, the existence of retrospective marks, visible and tangible proofs of processes which were prochronic, was so necessary to organic essences, that they could not have been created without them,--is it absurd to suggest the _possibility_ (I do no more) that the world itself was created under the influence of the same law, with visible tangible proofs of developments and processes, which yet were only prochronic?