SPONGES

of different kinds.  It will be interesting to the visitor to know something of the natural history of the sponge.  It has been ascertained, beyond a doubt, that the sponge is an animal that sucks in its food and excretes its superfluities; that certain of its pores imbibe, while others exude; and that according to the relative positions of the two distinct sets of pores, is the shape of the sponge determined.  In a natural state, as it is found in the Mediterranean, the sponge is surrounded with a thick glutinous matter, which is its vital part; like coral, it is a zoophyte:  it propagates in the same manner, and its life is indestructible till it is removed from its proper element, and the glutinous matter which makes its vitality has been boiled out of its pores, leaving the soft and beautiful skeletons, of which these cases contain many specimens.  Here also are some old sponges preserved in flint.  Having noticed these beautiful zoophytes, the visitor should proceed in an easterly direction into the room he recently quitted, to examine the table cases it contains.  The first tables to which he should direct his attention here, are those in which a series of Crustacea or hard-coated animals are deposited.  They are of Cuvier’s order of animal life, known as the articulata, or animals whose bodies consist of a series of moveable joints.  These are mostly inhabitants of the sea, and rank in the animal kingdom as the highest class of the Articulata, except the insects, who head the order.  The tables upon which the Crustacea or

Shell fish,

are deposited, are numbered from 13 to 24.  The four first cases (13-16) are covered with Crabs of various kinds, including the long-legged spider-crabs, common crabs with oysters growing upon their backs, and fin-footed swimming crabs.  The next case (17) contains in addition to the long-eyed or telescope crab, varieties of the land-crab, which is found in various parts of India; one kind, that swarms in the Deccan, commits great ravages in the rice-fields.  The two next tables are covered with Chinese crabs, square-bodied crabs; those crabs with fine shells known as porcelain crabs, and the curious death’s head crab, which seems to build a kind of nest of sponge or shells.  But upon the next table (20) the visitor will find the most remarkable of the crabs, together with an astonishing lobster.  This crab is known as the hermit crab.  The visitor will perceive, that it has a long naked tail; and he should know that the one all-absorbing care of its life seems to be to find a place of safety in which this unprotected part may be screened from the dire mischances of war.  Accordingly, at an early age, it sets out in search of a deserted shell into which it backs its tail; or if an unoccupied shell be not at hand, without much ceremony, the hermit contrives a summary ejectment of the lawful tenant, that it may shield its tail and