President of the Geological Society for 1850. 9 



part in the Pyrenees, Apennines, and Carpathians, and 

 spreading over a large part of the globe of which the geology 

 is best known. They are met with in full force in the north 

 of Africa ; as for example in Algeria and Morocco ; they have 

 been traced from Egypt into Asia Minor, and across Persia 

 by Bagdad to the banks of the Indus. They occur not only 

 in Cutch, but in the mountain-ranges which separate Sinde 

 from Persia, and which form the passes leading to Cabul. 

 They have been followed still further eastward into India, 

 and may be said to enter bodily into the structure of all the 

 continental lands and mountain-chains of the Old World. 



Were we to endeavour to estimate the changes in physical 

 geography which can be proved by the position of these 

 marine eocene strata to have occurred since the commence- 

 ment of the tertiary period, we should find them to be very 

 inadequately expressed by stating that they equal in amount 

 the conversion of sea into land of a continent as large and 

 lofty as that of Europe, Asia, and the north of Africa. I 

 endeavoured in 1834, in a map constructed for the 3d 

 edition of my " Principles of Geology," to show the extent of 

 surface in Europe and part of Asia which had been covered 

 by water, at some time or other, since the beginning of the 

 eocene period. But, had I been then aware that a true 

 pictorial representation of such modern revolutions in 

 physical geography would have required the submergence ot 

 the Alps, Pyrenees, Apennines, and Carpathians, and the 

 insertion of a few insignificant islands only in their place, I 

 might have thought such an illustration superfluous or with- 

 out meaning, and have been satisfied by simply insisting 

 on the post-eocene ubiquity of the ocean — not indeed by a 

 simultaneous, but by a successive occupancy of the whole 

 ground. But how small a portion even of the superficial 

 remodelling of the earth's crust in recent times is expressed, 

 by declaring that we can establish by direct proof or legiti- 

 mate inference the upheaval out of the sea of all the land in 

 Europe, Asia, and part of Africa ! During the same tertiary 

 periods there have been vertical subsidences as well as ele- 

 vations of the same areas ; and we have every reason to 

 believe that the larger part of the globe (comprising nearly 



