e t Imbecillitate Darwiniana. 1 3 



waves have or have not the power of destroy- 

 ing cliffs and shores : what is or is not, 

 generally, the power, the actual, positive 

 power, destructive or creative, of superficial 

 agents, and how far that power, such as it 

 is, is modified or neutralised by differences of 

 climate, material, or position : how far it is 

 or is not true to identify Geology with Phy- 

 sical Geography: it is not here necessary to 

 inquire. It is sufficient for the purpose in 

 hand to note carefully two things : I. That 

 the essential characteristic of the Lyellian 

 school was the endeavour to explain and 

 account for all, even the most colossal, phe- 

 nomena of geology, on the principle of slow 

 successive increments, minute operations ac- 

 cumulated in vast periods of time. II. That 

 the school, notwithstanding its industry in 

 other directions, took the power of its minute 

 agents generally for granted, and made no 

 serious investigation, no experimental veri- 



