Excerpt from The Evolution and Distribution of Fishes In 1918 the writer published a volume that was entitled "The Causes and Course of Organic Evolution." A section of it was devoted to an inquiry into the environal relation of plants and animals, as determining largely their distribution in time and space. The conclusion was then reached, that organisms evolved first in freshwater areas, and only by degrees spread into marine surroundings. During his inquiries the author gradually concluded that fishes might form the most important biological group by which to test the value of such a conclusion. For in the volume named he presented short details of their past and present history, which seemed to indicate that they at first evolved amid freshwater surroundings. Field studies also made by the writer during his earlier scientific career and subsequently, strongly pointed in like direction. But some details that either weakened the position, or that claimed further investigation, accumulated amid the abundant evidence that proved to be favorable. The writer therefore resolved to make as thorough a comparison as possible of the groups of fishes, and even of specific genera amongst these. The outcome is seen in part in the present volume, which represents the almost continuous labors of the past six years. As the author pursued his detailed researches, some originally puzzling conditions gradually began to have a definite meaning attached to them. Thus the presence of abundant fossilized fish remains in zones of cannel coal, and their absence from ordinary coal strata; the like occurrence of freshwater fishes and of related organisms ecologically in the oil shales of the Edinburgh Coal Field that the writer studied for years in his earlier career; the peculiar character, the chemical composition, and the fossilized fish remains, of the marls that he studied in mature years from New Jersey to Florida, all had welcome light thrown on them, at the same time that the evolutionary history of fishes unfolded in its manifold ramifications. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.