THE TESTIMONY OF THE ROCKS. 49 
the vegetable a vegetable, and the dog a dog,—that in 
the vast course of ages, inferior have risen into superior 
natures, and lower into higher races; that molluscs and 
zoophytes have passed into fish and reptiles, and fish and 
reptiles into birds and quadrupeds; that unformed gela- 
tinous bodies, with an organisation scarcely traceable, 
have been metamorphosed into oaks and cedars; and 
that monkeys and apes have been transformed into hu- 
man creatures, capable of understanding and admiring 
the theories of Lamarck. 
“It is a law of nature,’ continues Mr. Miller, “that 
the chain of being, from the lowest to the highest form 
of life, should be, in some degree, a continuous chain ; 
that the various classes of existence should shade into 
one another, so that it often proves a matter of no little 
difficulty to point out the exact line of demarcation 
where one class or family ends and another class or fa- 
mily begins. The naturalist passes from the vegetable 
to the animal tribes, scarcely aware, amid the perplexing 
forms of intermediate existence, at what point he quits 
the precincts of the one, to enter on those of the other. 
All the animal families have, in like manner, their con- 
necting links; and it is chiefly out of these that writers 
such as Lamarck and Maillet construct their system. 
They confound gradation with progress. Geoffrey Hud- 
_ son was a very short man, and Goliath of Gath a very tall 
one; and the gradations of the human stature lie between. 
But gradation is not progress; and though we find full- 
grown men of five feet, five feet six inches, and six feet 
and a half, the fact gives us no earnest whatever that the 
race is rising in stature, and that at some future period 
the average height of the human family will be some- 
what between ten and eleven feet. And equally unsolid 
is the argument that from a principle of gradation in 
