Igg ANNUAL REPORT SMITHSONIAN INSTITUTION, 1936 



This principle involved that the history revealed by the rocks should 

 be read as the effect of the slow but continuous operation of causes, 

 most of them small, such as could be seen in action in some part 

 or other of tlie world today. This was set in opposition to the opinion 

 of the older geologists who had postulated a succession of catastrophes 

 which, by flood, fire, and convulsion, had periodically wrecked the 

 world and destroyed its inhabitants ; each catastrophe necessitating a 

 new creation to provide the succession of life on the earth as it then 

 was known. 



But in the organic world Lyell, like Hutton, had failed to detect 

 any analogous principle, and, as he rejected all the theories of trans- 

 mutation of species then in vogue, he had to accept their absolute 

 fixity ; and to suppose that, as species became extinct one after another, 

 replacement by special creations followed. And yet the reading today 

 of the chapters devoted to this branch in the earlier editions of Lyell's 

 great work produces the haunting feeling that a better explanation 

 had only just eluded him. It was the story revealed in Lyell's work, 

 Darwin tells us, the new conception that the earth had been in existence 

 for vast eons of time, the proof that it had been continuously peopled 

 by animals and plants, and that these had steadfastly advanced and 

 improved throughout that time, which showed him the necessity for 

 an explanation of the progression of life, and gave him the first hints 

 of his theory. Wlien he had enunciated this he was enabled to repay 

 his master with the principle of organic evolution, which brought 

 changes in the animate world into harmony with those of the inani- 

 mate. 



His Antiquity of Man shows that by 1863 Lyell had become a 

 convert, and he afterwards rewrote much of the second volume of his 

 Principles accepting the new point of view. This change earned from 

 Hooker a testimonial in the 1868 address which, if not unique, must 

 certainly be one of the most magnificent ever awarded to a scientific 

 work: 



I know no brighter example of heroism, of its kind, than this, of an author 

 thus abandoning, late in life, a theory which he had regarded as one of the 

 foundation stones of a work that had given him the highest position attainable 

 amongst contemporary scientific writers. Well may he be proud of a super- 

 structure, raised on the foundation of an insecure doctrine, when he finds that 

 he can underpin it and substitute a new foundation : and, after all is finished, 

 survey his edifice, not only more secure, but more harmonious in proportions 

 than before. 



Although infinitely richer than when Darwin wrote, the geological 

 record still is, and must from its very nature remain, imperfect. 

 Every major group of animal life but the vertebrates is represented 

 in the Cambrian fauna, and the scant relics that have been recovered 



