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 Zooelogy 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, ... 
  Forthwith the sounds and seas, each creek and bay,
  With fry innumerable swarm, and shoals
  Of fish, that with their fins and shining scales
  Glide under the green wave in sculls that oft
  Bank the mid sea:  part single or with mate
  Graze the sea-weed, their pasture, and through groves
  Of coral stray, or sporting with quick glance
  Show to the sun their waved coats dropt with gold,
  Or in their pearly shells at ease attend
  Moist nutriment, or under rocks their food
  In jointed armor watch.”

But no means were at hand to pursue these unknown creatures to their unknown residences, and to observe their manners when at home.  Single, withered, and often mutilated specimens of minute fish, mollusks, or radiata, in the museum, alone illustrated the mysteries of the deep sea.  Fish, to be sure, could be kept for longer or shorter periods in globes of glass filled with water; but the more delicate creatures inevitably perished soon after their removal from their mysterious abodes.  Such a passionate desire to “search Nature and know her secrets” finally originated the idea of the Aquarium.

The term vivarium was used among the ancients to signify many things,—­from the dens of the wild animals which opened under the Colosseum, to an oyster-bed; and so now it may mean any collection of living creatures.  Hence it could convey no distinct idea of a marine collection such as we propose to describe.  The term aqua was added to express the watery element; but the compound aqua-vivarium was too clumsy for frequent employment, and the abbreviated word aquarium has come into general use.