COMING OF AGE OF THE ORIGIN OF SPECIES. 339 



of that history will enable us to understand why, if the " Origin of 

 Species " appeared now, it would meet with a very different reception 

 from that which greeted it in 1859. 



One-and-twenty years ago, in spite of the work commenced by 

 Hutton and continued with rare skill and patience by Lyell, the domi- 

 nant view of the past history of the earth was catastrophic. Great 

 and sudden physical revolutions, wholesale creations and extinctions 

 of living beings, were the ordinary machinery of the geological epic 

 brought into fashion by the misapplied genius of Cuvier. It was 

 gravely maintained and taught that the end of every geological epoch 

 was signalized by a cataclysm, by which every living being on the 

 globe was swept away, to be replaced by a brand-new creation when 

 the world returned to quiescence. A scheme of Nature which appeared 

 to be modeled on the likeness of a succession of rubbers of whist, at 

 the end of each of which the players upset the table and called for a 

 new pack, did not seem to shock anybody. 



I may be wrong, but I doubt if at the present time there is a single 

 responsible representative of these opinions left. The progress of 

 scientific geology has elevated the fundamental principle of uniformi- 

 tarianism, that the explanation of the past is to be sought in the study 

 of the present, into the position of an axiom ; and the wild specula- 

 tions of the catastrophists, to which we all listened with respect a 

 quarter of a century ago, would hardly find a single patient hearer at 

 the present day. No physical geologist now dreams of seeking out- 

 side the ranges of known natural causes for the explanation of any- 

 thing that happened millions of years ago, any more than he would be 

 guilty of the like absurdity in regard to current events. 



The effect of this change of opinion upon biological speculation is 

 obvious. For, if there have been no periodical general physical catas- 

 trophes, what brought about the assumed general extinctions and recrea- 

 tions of life which are the corresponding biological catastrophes ? And 

 if no such interruptions of the ordinary course of nature have taken 

 place in the organic, any more than in the inorganic, world, what alter- 

 native is there to the admission of evolution ? 



The doctrine of evolution in biology is the necessary result of the 

 logical application of the principles of uniformitarianism to the phe- 

 nomena of life. Darwin is the natural successor of Hutton and Lyell, 

 and the " Origin of Species " the natural sequence of the " Principles 

 of Geology." 



The fundamental doctrine of the "Origin of Species," as of all 

 forms of the theory of evolution applied to biology, is " that the innu- 

 merable species, genera, and families of organic beings with which the 

 world is peopled, have all descended, each within its own class or 

 group, from common parents, and have all been modified in the course 

 of descent.* 



* " Origin of Species," first edition, p. 457. 



