70 ERA OF THE SUPERFICIAL. FORMATIONS. 



tiaries in England is disturbed by two great swells, form, 

 ing what are called anticlinal axes, one of which divides 

 the London from the Hampshire basin, while the other 

 passes through the Isle of Wight, both throwing the strata 

 down at a violent inclination towards the north, as if the 

 subterranean disturbing force had waved forward in that 

 direction. The Pyrenees, too, and Alps, have both un- 

 dergone elevation since the deposition of the tertiaries; 

 and in Sicily there are mountains which have risen three 

 thousand feet since the deposition of some of the most re- 

 cent of these rocks. The general effect of these operations 

 was of course to extend the land surface, and to increase 

 the variety of its features, thus improving the natural 

 drainage, and generally adapting the earth for the recep- 

 tion of the higher classes of animals. 



ERA OF THE SUPERFICIAL FORMATIONS 



COMMENCEMENT OF PRESENT SPECIES. 



We have now completed our survey of the series ol 

 stratified rocks, and traced in their fossils the progress of 

 organic creation down to a time which setms not long 

 antecedent to the appearance of man. There are, never- 

 theless, monuments of still another era or space of time, 

 which it is all but certain did also precede that event. 

 * Over the rock formations of all eras, in various parts ot 

 the globe, but confined in general to situations not very 

 elevated, there is a layer of stiff clay, mostly of a blue co- 

 lor, mingled with fragments of rock of all sizes travel- 

 worn, and otherwise, and to which geologists give the 

 name of diluvium, as being apparently the produce of 

 some vast flood, or of the sea thrown into an unusual agi- 

 tation. It seems to indicate that, at the time when it 

 was laid down, much of the present dry land was under 

 the ocean, a supposition which we shall see supported by 

 other evidence. The included masses of rock have been 

 carefully inspected in many places, and traced to particu- 

 lar parent beds at considerable distances. Connected 

 with these phenomena are certain rock surfaces on the 

 slopes of hills and elsewhere, which exhibit grooving^ 

 and scratch ings, such as we might suppose would be pro 



