Now the important fact to be attended to in this experiment is, the wide geographical distribution during the carboniferous era of those tribes of plants which enter most certainly and abundantly into the composition of the coal metals. Many others may, and doubtless did, flourish within the period of the formation. But that the plants, possessed of the most conservative vegetable qualities, and the most capable of resisting solution in water, should be precisely the kinds which had then a universal range over the earth’s surface, can be ascribed to nothing else than to a wise predetermined purpose and arrangement. These plants were growing in every region. Every clime favored them—every soil nourished them. The bituminous product was intended for man’s use, whose family was destined to inhabit the whole earth. How irresistible the conclusion, corroborative of all the proofs of design derived from the nature and structure of the coal-measures, that, anticipating his wants and providing for his improvement, nature purposely constructed such forms of vegetable life, possessed, like the watch, with a compensation balance so as to suit every condition, and to thrive in every land; or, what is equally probable and consonant to the requirements of the problem, that there was such a uniformity of climate and temperature, and other chemical adjustments, as were most adapted to the peculiar and prevailing vegetation of the period. IV. THE ORGANIC REMAINS we proceed to consider more in detail, where a remarkable contrast will be observed between the vegetable and animal types presented, so far as they have been respectively fossilized and preserved. The vegetables are nearly all of terrestrial, the animals are as generally and predominantly of marine, characters. Is this the result of blind chance, or of contrivance and foresight? The plants of the coal epoch consist chiefly of the cryptogamia, and of these the ferns are the most abundant, composing, according to the estimate of M. Brongniart, about two-thirds of the entire carboniferous flora. [Illustration: 1. Sphenopteris linearis; 2. Pecopteris Mantelli; 3. Sphenopteris affinis.]