The partial recognition by some observers of the true nature of fossils marks the starting point of more rational views. The admission that fossils were not mere sports of nature, or the result of some wonderful ‘vis lapidifica,’ was naturally followed by numerous speculations as to the manner in which the remains of animals and plants came to be embedded in rocks above the sea-level. For a long time, the ‘universal flood’ was held responsible by nearly all writers for the existence of fossils in ancient sediments. Dr John Woodward, in his _Essay toward a Natural History of the Earth_, propounded the somewhat revolutionary theory, that “the whole terrestrial globe was taken all to pieces and dissolved at the Deluge, the particles of stone, marble, and all solid fossils dissevered, taken up into the water, and there sustained together with sea-shells and other animal and vegetable bodies: and that the present earth consists, and was formed out of that promiscuous mass of sand, earth, shells, and the rest falling down again, and subsiding from the water[5].” In common with other writers, he endeavoured to fix the exact date of the flood by means of fossil plants. Speaking of some hazel-nuts, which were found in a Cheshire moss pit, he draws attention to their unripened condition, and adds: “The deluge came forth at the end of May, when nuts are not ripe.” As additional evidence, he cites the occurrence of “Pine cones in their vernal state,” and of some Coal-Measure fossils which he compares with Virginian Maize, “tender, young, vernal, and not ripened[6].” Woodward (1665–1728) was Professor of Physic in Gresham College; he bequeathed his geological collections to the University of Cambridge, and founded the Chair which bears his name. Another writer, Mendes da Costa, in a paper in the _Philosophical Transactions_ for 1758, speaks of the impressions of “ferns and reed-like plants” in the coal-beds, and describes some fossils (_Sigillaria_ and _Stigmaria_) as probably unknown forms of plant life[7].