Conclusion.
In the facts before us, we have an uninterrupted
series of evidence, derived from the family
of Fishes, by which both bony and cartilaginous
forms of this family, are shewn to have
prevailed during every period, from the first
commencement of submarine life, unto the present
hour. The similarity of the teeth, and
scales, and bones, of the earliest Sauroid
Fishes of the coal formation (Megalichthys),
to those of the living Lepidosteus, and the correspondence
of the teeth and bony spines of
the only living Cestraciont in the family of
Sharks, with the numerous extinct forms of that
sub-family, which abound throughout the Carboniferous
and Secondary formations, connect
extreme points of this grand verbetrated division
of the animal kingdom, by one unbroken chain,
more uniform and continuous than has hitherto
been discovered in the entire range of geological
researches.
It results from the review here taken of the
history of fossil Fishes, that this important class
of vertebrated animals presented its actual gradations
of structure amongst the earliest inhabitants
of our planet; and has ever performed
the same important functions in the general
economy of nature, as those discharged by their
living representatives in our modern seas, and
lakes, and rivers. The great purpose of their
existence seems at all times to have been, to fill
the waters with the largest possible amount of
animal enjoyment.
The sterility and solitude which have sometimes
been attributed to the depths of the ocean,
exist only in the fictions of poetic fancy. The
great mass of the water that covers nearly three-
fourths of the globe is crowded with life, perhaps
more abundantly than the air, and the
surface of the earth; and the bottom of the
sea, within a certain depth accessible to light,
swarms with countless hosts of worms, and creeping
things, which represent the kindred families
of low degree which crawl upon the land.
The common object of creation seems ever
to have been, the infinite multiplication of life.
As the basis of animal nutrition is laid in the
vegetable kingdom, the bed of the ocean is not
less beautifully clothed with submarine vegetation,
than the surface of the dry land with
verdant herbs and stately forests. In both
cases, the undue increase of herbivorous tribes
is controlled by the restraining influence of those
which are carnivorous; and the common result
is, and ever has been, the greatest possible
amount of animal enjoyment to the greatest
number of individuals.
From no kingdom of nature does the doctrine
of gradual Development and Transmutation of