OF GEOLOGICAL DYNAMICS. 77 



of answering the question he says, " It is obviously 

 " Uniformitarianism " which Sir W. Thomson 

 " takes to be the representative of geological 

 " speculation in general." I have given no ground 

 for this statement. Not merely "obviously," but 

 avowedly and explicitly, I attacked Uniformi- 

 tarianism ; but I did not attack geological specu- 

 lation in general. On the contrary, I anxiously 

 and carefully guarded every expression of my 

 complaint from applicability to other speculations 

 than those involving more or less fundamentally 

 the particular fallacies against which my objections 

 were directed ; and the very phrases I used to limit 

 my accusations showed that I had not taken 

 Uniformitarianism to be the representative of 

 geological speculation in general. The geology 

 which I learned thirty years ago in the University 

 of Glasgow embodied the fundamental theory now 

 described and approved by Professor Huxley as 

 Evolutionism. This I have always considered to 

 be the substantial and irrefragable part of geo- 

 logical speculation ; and I have looked on the 

 ultra-uniformitarianism of the last twenty years 



