The proofs he brings forward are the horizontality of the beds, both of coal and deposits between them, the marine shells in the sandstones, the fossil fishes intermingled with the plant remains in the shales; moreover, some of the coal deposits are covered by beds of limestone containing marine shells which lived in the sea at a very great depth. The alternation of these beds, the great mass of vegetable matter which lived at small distances from the soil which conceals them, and the occurrence of these beds so high up, show that at this time Europe was almost wholly covered by the sea, the summits of the Alps and the Pyrenees being then, as he says, so many small islands in the midst of the ocean. He also intimates that the climate when these ferns ("bamboo" and "banana") lived was warmer than that of Europe at present. In this essay, then, we see a great advance in correctness of geological observation and reasoning over any previous writers, while its suggestions were appreciated and adopted by Lamarck. [79] Hooke had previously, in order to explain the presence of tropical fossil shells in England, indulged in a variety of speculations concerning changes in the position of the axis of the earth's rotation, "a shifting of the earth's centre of gravity analogous to the revolutions of the magnetic pole, etc." (Lyell's _Principles_). See also p. 132. [80] Cuvier, in a footnote to his _Discours_ (sixth edition, p. 49), in referring to this view, states that it originated with Rodig (_La Physique_, p. 106, Leipzig, 1801) and De Maillet (_Telliamed_, tome ii., p. 169), "also an infinity of new German works." He adds: "M. de Lamarck has recently expanded this system in France at great length in his _Hydrogéologie_ and in his _Philosophie zoologique_." Is the Rodig referred to Ih. Chr. Rodig, author of _Beiträge zur Naturwissenschaft_ (Leipzig, 1803. 8^o)? We have been unable to discover this view in De Maillet; Cuvier's reference to p. 169 is certainly incorrect, as quite a different subject is there discussed. CHAPTER IX LAMARCK THE FOUNDER OF INVERTEBRATE PALÆONTOLOGY It was fortunate for palæontology that the two greatest zoölogists of the end of the eighteenth and the beginning of the nineteenth centuries, Lamarck and Cuvier, lived in the Paris basin, a vast cemetery of corals, shells, and mammals; and not far from extensive deposits of cretaceous rocks packed with fossil invertebrates. With their then unrivalled knowledge of recent or existing forms, they could restore the assemblages of extinct animals which peopled the cretaceous ocean, and more especially the tertiary seas and lakes.