276 CREATION BY LAW. 
produced such an adjustment. I believe I have 
shown, however, that such an adjustment is not only 
possible but inevitable, unless at some point or other 
we deny the action of those simple laws which we 
have already admitted to be but the expressions ot 
existing facts. 
Adaptation brought about by General Laws. 
It is difficult to find anything like parallel cases in 
inorganic nature, but that of a river may perhaps 
illustrate the subject in some degree. Let us suppose 
a person totally ignorant of Modern Geology to study 
carefully a great River System. He finds in its 
lower part, a deep broad channel filled to the brim, 
flowing slowly through a flat country and carrying 
out to the sea a quantity of fine sediment. Higher up 
it branches into a number of smaller channels, flow-. 
ing alternately through flat valleys and between high . 
banks; sometimes he finds a deep rocky bed with 
perpendicular walls, carrying the water through a 
chain of hills; where the stream is narrow he finds 
it deep, where wide shallow. Further up still, he 
comes to a mountainous region, with hundreds of 
streams and rivulets, each with its tributary rills and 
gullies, collecting the water from every square mile of 
surface, and every channel adapted to the water that-it 
has to carry. He finds that the bed of every branch, 
and stream, and rivulet, has a steeper and steeper slope 
as it approaches its sources, and is thus enabled to 
carry off the water from heavy rains, and to bear away 
