THE LAWS OF GEOLOGICAL ACTION. vA 
“the actual configuration of our continents and islands, the 
coast-lines of our maps, the direction and elevation of our 
mountain-chains, the courses of our rivers, and the soundings 
of our oceans, are not things primordially arranged in the con- 
struction of our globe, but results of successive and complex 
actions on a former state of things; fat, again, of similar 
actions on another still more remote; and so on, till the ori- 
ginal and really permanent state is pushed altogether out of 
sight and beyond the reach even of imagination ; while on the 
other hand, a similar, and, as far as we can see, interminable 
vista is opened out for the future, by which the habitability of 
our planet is secured amid the total abolition on it of the 
present theatres of terrestrial life.” 
Geology, then, teaches us that the physical features which 
now distinguish the earth’s surface have been produced as the 
ultimate result of an almost endless succession of precedent 
changes. Palzontology teaches us, though not yet in such 
assured accents, the same lesson. Our present animals and 
plants have not been produced, in their innumerable forms, 
each as we now know it, as the sudden, collective, and simul- 
taneous birth of a renovated world. On the contrary, we have 
the clearest evidence that some of our existing animals and 
plants made their appearance upon the earth at a much earlier 
period than others. In the confederation of animated nature 
some races can boast of an immemorial antiquity, whilst others 
are comparative farvenus. We have also the clearest evidence 
that the animals and plants which now inhabit the globe have 
been preceded, over and over again, by other different assem- 
blages of animals and plants, which have flourished in succes- 
sive periods of the earth’s history, have reached their culmina- 
tion, and then have given way to a fresh series of living beings. 
We have, finally, the clearest evidence that these successive 
groups of animals and plants (faunze and floree) are to a greater 
or less extent directly connected with one another. Each 
group is, to a greater or less extent, the lineal descendant of 
the group which immediately preceded it in point of time, and 
is more or less fully concerned with giving origin to the group 
which immediately follows it. That this law of “ evolution” 
has prevailed to a great extent is quite certain ; but it does not 
meet all the exigencies of the case, and it is probable that its 
action has been supplemented by some still unknown law of a 
different character. 
We shall have to consider the question of geological “ con- 
tinuity” again. In the meanwhile, it is sufficient to state that 
this doctrine is now almost universally accepted as the basis 
