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 family 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 connecting links; and it is chiefly
out of these that writers such as Lamarck and Maillet construct their
system. _They confound gradation with progress_. Geoffrey Hudson 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 somewhat between ten and eleven feet. And
equally unsolid is the argument that from a principle of gradation in
races would reduce a principle of progress in races. The tall man of six
feet need entertain quite as little hope of rising into eleven feet as
the short man of five; nor has the fish that occasionally flies any
better chance of passing into a bird than the fish that only swims.
Geology abounds with creatures of the intermediate class. _But it
furnishes no genealogical link to show that the existences of one race
derive their lineage from the existences of another_. The scene shifts
as we pass from formation to formation; we are introduced in each to a
new dramatis personae. Of all the vertebrata, fishes rank lowest, and in
geological history appear first. Now, fishes differ very much among
themselves: some rank nearly as low as worms,--some nearly as high as
reptiles; and if fish could have risen into reptiles, and reptiles into
mammalia, we would necessarily expect to find lower orders of fish
passing into higher, and taking precedence of the higher in their
appearance in point of time. If such be not the case,--if fish made
their first appearance, n