countries. But all this is on a far different principle from that
pursued at Rome. We follow pisciculture from necessity or economy,
because fish of certain kinds are yearly dying out, and to produce
a cheap food; but the Romans followed it as a luxury, or a childish
amusement, alone. And although our aldermen may sigh over a missing
Chelonian, as Crassus for his deceased eel, or the first salmon of the
season bring a fabulous price in the market, yet the time has long
passed when the gratification of appetite is alone thought of in
connection with Nature. We know that living creatures are to be studied,
as well as eaten; and that the faithful and reverent observation of
their idiosyncrasies, lives, and habits is as healthful and pleasing to
the mind as the consumption of their flesh is wholesome and grateful
to the body. The whole science of Zoölogy has arisen, with its simple
classifications and its vast details. The _vivaria_ of the Jardin des
Plantes rival those of the Colosseum in magnitude, and excel them in
object. Nature is ransacked, explored, and hunted down in every field,
only that she may add to the general knowledge. Museums collect and
arrange all the types of creative wisdom, from the simple cell to man.
Science searches out their extinct species and fossil remains, and tells
their age by Geology. The microscope pursues organic matter down into an
infinity of smallness, proportionately as far as the telescope traces it
upwards in the infinity of illimitable space. Last of all, though not
till long after the earth and the air had been seemingly exhausted,
the desire of knowledge began to push its way into the arcana of the
sea,--that hidden half of Nature, where are to be found those wonders
described by Milton at the Creation,--where, in obedience to the Divine
command,

"Be fruitful, multiply, and in the seas
And lakes and running streams the waters fill, ...