340 THE CAUSES OF THE XI 
our record entirely consists of accumulations of 
mud, superimposed one on the other; seeing in 
the next place that any particular spots on which 
accumulations have occurred, have been constantly 
moving up and down, and sometimes out of the 
reach of a deposit, and at other times its own 
deposit broken up and carried away, it follows that 
our record must be in the highest degree imper- 
fect, and we have hardly a trace left of thick 
deposits, or any definite knowledge of the area 
that they occupied, in a great many cases. And 
mark this! That supposing even that the whole 
surface of the earth had been accessible to the. 
geologist,—that man had had access to every part. 
of the earth, and had made sections of the whole, 
and put them all together,—even then his record 
must of necessity be imperfect. 
But to how much has man really access? If 
you will look at this map you will see that it | 
represents the proportion of the sea to the earth : 
this coloured part indicates all the dry land, and 
this other portion is the water. You will notice 
at once that the water covers three-fifths of the 
whole surface of the globe, and has covered it in~ 
the same manner ever since man has kept any 
record of his own observations, to say nothing of — 
the minute period during which he has cultivated 
geological inquiry. So that three-fifths of th 
surface of the earth is shut out from us because 
it is under the sea. Let us look at the othe 
. 
Oe dihe eii d h A i i 
