158 Rev. Mr Whe well's Address to the Geological Society. 



lightened zeal for science, to take out a naturalist with him. 

 And we have further reason to rejoice that this lot fell to a 

 gentleman like Mr Darwin, who possessed the genuine spirit 

 and zeal, as well as knowledge of a naturalist ; who had pur- 

 sued the studies which fitted him for this employment, under 

 the friendly guidance of Dr Grant at Edinburgh, and Professor 

 Henslow and Professor Sedgwick at Cambridge; and whose 

 powers of reason and application had been braced and disci- 

 plined by the other studies of the University of which the latter 

 two gentlemen are such distinguished ornaments. But some of 

 the principal of these results may be most conveniently men- 

 tioned, when we pass from mere descriptive geology, to that 

 other division of the subject which I have termed Geological 

 Dynamics. And this I now proceed to do. 



GEOLOGICAL DYNAMICS. 



This term is intended to express generally the science, so far 

 as we can frame a science, of the causes of change by which 

 geological phenomena have been produced. Without here 

 speaking of any classification of such changes, I may observe 

 that the gradual elevation and depression, through long ages, 

 of large portions of the earth''s crust, is a proximate cause by 

 which such phenomena have been explained : and this class of 

 events, its evidence, extent, and consequence, is brought before 

 our view by Mr Darwin's investigations, with a clearness and 

 force which has, I think I may say, filled all of us with admi- 

 ration. I may refer especially to his views respecting the his- 

 tory of coral isles. Those vast tracts of the Pacific which con- 

 tain, along with small portions of scattered land, innumerable 

 long reefs and small circles of coral, had hitherto been full of 

 problems, of which no satisfactory solution could be found. 

 For how could we explain the strange forms of these reefs ; 

 their long and winding lines ; their parallelism to the shores ? 

 and by what means did the animals, which can only work near 

 the surface, build up a fabric which has its foundations in the 

 deepest abysses of ocean ? To these questions Mr Darwin re- 

 plies, that all these circumstances, the linear or annular form, 

 their reference to the boundary of the land, the clusters of little 

 islands occupying so small a portion of the sea, and, above all 



