Produced by Chris Curnow, Turgut Dincer and the Online Distributed Proofreading Team at http://www.pgdp.net (This file was produced from images generously made available by The Internet Archive) +------------------------------------------------------------------+ | Transcriber’s note: | | | | Genus names are not consistenly italicized in the original book. | | These have been corrected for consistency according to the | | modern usage except in the Index where they are consistently | | printed in regular fontface. | +------------------------------------------------------------------+ [Illustration: LIFE IN THE SILURIAN AGE.] THE CHAIN OF LIFE IN GEOLOGICAL TIME _A SKETCH OF THE ORIGIN AND SUCCESSION OF ANIMALS AND PLANTS_ BY SIR J. WILLIAM DAWSON C.M.G., LL.D., F.R.S., F.G.S., ETC. AUTHOR OF “ACADIAN GEOLOGY,” “THE STORY OF THE EARTH,” “EGYPT AND SYRIA; THEIR PHYSICAL FEATURES IN RELATION TO BIBLE HISTORY,” ETC. _THIRD AND REVISED EDITION_ WITH NUMEROUS ILLUSTRATIONS THE RELIGIOUS TRACT SOCIETY, 56 PATERNOSTER ROW; 65 ST. PAUL’S CHURCHYARD; AND 164 PICCADILLY 1888 RICHARD CLAY AND SONS. LONDON AND BUNGAY. PREFACE. Questions as to the origin and history of life are not at the present time answered by mere philosophical speculation and poetical imagining. Such solutions of these questions as science can profess to have obtained are based on vast accumulations of facts respecting the remains of animals and plants preserved in the rocky beds of the earth’s crust, which have been successively accumulated in the course of its long geological history. These facts undoubtedly afford the means of attaining to very certain conclusions on many points relating to the history of life on the earth. But, on the other hand, they have furnished the material for hypotheses which, though confidently affirmed to be indisputable, have no real foundation in nature, and are indirectly subversive of some of the most sacred beliefs of mankind.