Now, all this, and much more of the same nature, addressed to the Parisians of the reign of Louis the Fifteenth, passed, I doubt not, wonderfully well; but it will not do now, when almost every young girl, whether in town or country, is a botanist, and works on the algæ have become popular. Since Maillet wrote, Hume promulgated his argument on Miracles, and La Place his doctrine of Probabilities. There can be no doubt that these have exerted a wholesome influence on the laws of evidence; and by these laws, as restricted and amended,—laws to which, both in science and religion, we ourselves conform,—we insist on trying the Lamarckian hypothesis, and in condemning it,—should it be found to have neither standing in experience nor support from testimony,—as a mere feverish dream, incoherent in its parts and baseless in its fabric. Give, we ask, but one well-attested instance of transmutation from the algæ to even the lower forms of terrestrial vegetation common on our sea-coasts, and we will keep the question open, in expectation of more. It will not do to tell us—as Cuvier was told, when he appealed to the fact, determined by the mummy birds and reptiles of Egypt, of the fixity of species in all, even the slightest particulars, for at least three thousand years—that immensely extended periods of time are necessary to effect specific changes, and that human observation has not been spread over a period sufficiently ample to furnish the required data regarding them. The apology is simply a confession that, in these ages of the severe inductive philosophy, you have been dreaming your dream, cut off, as if by the state of sleep, from all the tangibilities of the real waking-day world, and that you have not a vestige of testimony with which to support your ingenious vagaries. But on another account do we refuse to sustain the excuse. It is _not true_ that human observation has not been spread over a period sufficiently extended to furnish the necessary data for testing the development hypothesis. In one special walk,—that which bears on the supposed transmutation of algæ into terrestrial plants,—human observation _has_ been spread over what is strictly analogous to _millions_ of years. For extent of space in this matter is exactly correspondent with duration of time. No man, in this late period of the world’s history, attains to the age of five hundred years; and as some of our larger English oaks have been known to increase in bulk of trunk and extent of bough for five centuries together, no man can possibly have seen the same huge oak pass, according to Cowper, through its various stages of “treeship,”— “First a seedling hid in grass; Then twig; then sapling; and, as century rolls Slow after century, a giant bulk, Of girth enormous, with moss-cushioned root Upheaved above the soil, and sides embossed With prominent wens globose.”