Let the reader yet further remark, if he has followed me through these preliminary observations, what is really involved in the hypothesis of the author of the “Vestiges,” regarding the various floras common to the British islands and the Continent. If it was upon his scheme that England, Ireland, and the mainland of Europe came to possess an identical flora, production _de novo_ and by repetition of the same species must have taken place in thousands of instances along the shores of each island and of the mainland. His hypothesis demands that the sea-weed on the coast of Ireland should have been developed, first through lower, and then higher forms, into thousands of terrestrial plants,—that exactly the same process of development from sea-weed into terrestrial plants of the same species should have taken place on the coast of England, and again on the coasts of the Continent generally,—and that identically the same vegetation should have been originated in this way in at least three great centres. And if plants of the same species could have had three distinct centres of organization and development, why not three hundred, or three thousand, or three hundred thousand? Nor will it do to attempt escaping from the difficulty, by alleging that there is the groundwork in the case of at least a common marine vegetation to start from; and that thus, if we have not properly the existence of the direct hereditary tie among the various individuals of each species, we may yet recognize at least a sort of collateral relationship among them, derived from the relationship of their marine ancestry. For relationship, in even the primary stage, the author of the “Vestiges” virtually repudiates, by adopting, as one of the foundations of his hypothesis, with, of course, all the legitimate consequences, the experiments of Mr. Weekes. The animalculæ-making process is instanced as representative of the first stage of being,—that in which dead inorganic matter assumes vitality; and it corresponds, in the zoological branch, to the production of a low marine vegetation in the phytological one. A certain semi-chemical, semi-electrical process, originates, time after time, certain numerous low forms of life, identical in species, but connected by no tie of relationship: such is the presumed result of the Weekes experiment. A certain further process of development matures low forms of life, thus originated, into higher species, also identical, and also wholly unconnected by the family tie: such are the consequences legitimately involved in that island-vegetation theory promulgated by the author of the “Vestiges.” And be it remembered that Mr. Weekes’ process, so far as it is simply electrical and chemical, is a process which is as capable of having been gone through in all times and all places, as that other process of strewing marl upon a moor, through which certain rustic experimenters have held that they produced white clover. It could have