Page:A Treatise on Geology, volume 1.djvu/281

 CHAP. VI. basins between ranges of mountains and masses of land, which in various ways influenced the deposits and supplied some of their organic contents. Yet, upon the whole, the number of terrestrial and freshwater remains is small compared to the marine; a circumstance which, as far as relates to the products of fresh water, is analogous to the present condition of nature. With regard to plants on the land, it has been already shown, (page 70.) that, however numerous these might be, only a few of them would reach the sea, except under particular circumstances of physical geography. The number of land animals already found in tertiary lacustrine, fluviatile, and marine deposits, ought perhaps to strike us by its magnitude, rather than by its inferiority to the catalogue of the living quadrupeds.

Referred to the groups of the basin of Paris, M. Adolphe Brongniart presented, in 1829, the following synopsis of the tertiary plants:—

From the laborious and successful researches of M. Deshayes concerning tertiary mollusca (see Lyell's Geology, vol. iii. first edition), we shall extract some of the leading results.