54 CHARLES DARWIN. 



great master, you will go there. Why, your disciples 

 in a slow and creeping manner beat all the old 

 Catastrophists who ever lived ! You will live to be 

 the great chief of the Catastrophists." Lyell wrote 

 disagreeing on the subject of continental extension ; 

 and hence, on June 25th, 1856, Darwin replied in a 

 long letter, giving in detail his reasons for rejecting 

 the hypothesis. He argued (1) that the supposed ex- 

 tension of continents and fusion of islands would be 

 vast changes, giving the earth a new aspect, but that 

 recent and tertiary molluscs, etc., are distinct on 

 opposite sides of the existing continents; so that, 

 although he did not doubt great changes of level 

 in parts of continents, he concluded that "funda- 

 mentally they stood as barriers to the sea where 

 they now stand " ever since the appearance of living 

 species; (2) that if a continent were nearly sub- 

 merged, the last remaining peaks would by no means 

 always be volcanic, as are, almost without exception, 

 the oceanic islands; (3) that the amount of subsi- 

 dence which took place in continental areas during 

 the Silurian and Carboniferous periods viz. during 

 one tolerably uniform set of beings would not be 

 enough to account for the depth of the ocean over 

 some parts of the site of the supposed submerged 

 continents ; (4) that the supposed extensions are 

 not consistent with the absence of many groups of 

 animals e.g. mammals, frogs, etc. from islands. 



These arguments did not convince Lyell ; and they 

 have only received an almost universal acceptance 



