DIVERGENCE OF OPINIONS 13 



2. EARLY SPECULATIONS OF GEOLOGISTS. 



Very divergent have been the opinions which 

 within the last century have been held respecting the 

 later geological changes that have taken place on the 

 surface of the Globe, whether in relation to their 

 cause, or to the time of their occurrence, and of the 

 introduction of Man. The presence of marine shells at 

 great heights and far from the sea led early observers 

 to attribute them to ' the Universal Deluge ' then 

 the accepted belief. With the progress of Geology, 

 it was, however, soon seen that these shell-beds be- 

 longed to different periods, and must be referred to 

 other causes than those of a transient much less a 

 universal deluge, for the condition and character of 

 the shells, and the fact of their growth on, and long 

 occupation of, the spot, were seen not to agree with a 

 short resting of the waters on the surface of the land ; 

 while a universal deluge was shown to be a physical 

 impossibility. Failing to find support in the palse- 

 ontological conditions, attention was directed with 

 more apparent success to the physical conditions. It 

 was found that the land was very commonly covered, 

 sometimes by a superficial sprinkling, at others by a 

 deposit many feet thick, of detrital materials, derived 

 from the waste and wear of the rocks which cropped 

 out on the surface ; and this mass of materials, taken 

 as a whole, was attributed to the rush of the waters 

 of a transient flood. 



