NAUTILUS AND AMMONITE.
The Nautili are called testaceous cephalopods, our readers know, or ought to know, the meaning of both these terms. Like the Cuttle-fish they are sometimes called Polypi, because they have many arms or tentacles, the word poly, with which a great number of English words commence, being the Greek for many. An ancient writer named Aristotle, after describing the naked cephalopods, says, “There are also two polypi in shells; one is called by some, nautilus, and by others, nauticus. It is like the polypus, but its shell resembles a hollow comb or pecten, and is not attached. This polypus ordinarily feeds near the sea-shore; sometimes it is thrown by the waves on the dry land, and the shell falling from it, is caught, and there dies. The other is in a shell like a snail, and this does not go out of its shell, but remains in it like a snail, and sometimes stretches forth its cirrhi.” The first of these animals, there can be no doubt, is the Argonaut, or Paper Nautilus, and the latter that which is called the True Nautilus, of both of which species let us say a few words, which we will introduce by quoting some beautiful lines from a poem called “the Pelican Island,” by James Montgomery.
“Light as a flake of foam upon the wind,
Keel upwards from the deep, emerged a shell,
Shaped like the moon ere half her orb is filled:
Fraught with young life it righted as it rose,
And moved at will along the yielding water.
The native pilot of this little bark
Put out a tier of oars on either side;
Spread to the wafted breeze a two-fold sail,
And mounted up and glided down the billow,
In happy freedom, pleased to feel the air,
And wander in the luxury of light.”
The tiny mariner here alluded to, is the Paper Nautilus, common in the Mediterranean and some tropical seas; its scientific name is Argonauta argo. In the mythology, we read that Argo was the name of a ship that carried a certain Grecian named Jason, and a crew of argives in search of adventures; some say that the term is derived from a Greek word signifying swift: this party of mariners, said to be the first that ever sailed upon the sea, was called Argonauts, or, as it might be freely translated, seamen of the ship Argo. Nauticus, in Latin, signifies anything relating to ships or navigation, and here you have the whole origin of the name of this little Argonaut, about which we must sing you a song written by Mary Howitt, before we proceed further:—
“Who was the first sailor; tell me who can;
Old father Neptune?—no, you’re wrong,
There was another ere Neptune began;
Who was he? tell me. Tightly and strong,
Over the waters he went—he went,
Over the waters he went!
Who was the first sailor? tell me who can;
Old father Noah!—no, you’re wrong,
There was another ere Noah began,
Who was he? tell me. Tightly and strong,
Over the waters he went—he went,
Over the waters he went.
Who was the first sailor? tell me who can;
Old father Jason?—no, you’re wrong,
There was another ere Jason began,
Don’t be a blockhead, boy! Tightly and strong,
Over the waters he went—he went,
Over the waters he went.
Ha! ’tis nought but the poor little Nautilus—
Sailing away in his pearly shell;
He has no need of a compass like us,
Foul or fair weather he manages well!
Over the water he goes—he goes,
Over the water he goes.”
Many more poems of the like nature we might quote, for this little shelled cephalopod has been a favourite with the poets time out of mind, and in some instances they and the less imaginative naturalists have disagreed in their accounts of its form and operations, for instance, Pope says—
“Learn of the little Nautilus to sail,
Spread the thin oar and catch the driving gale.”
“Catch a fiddle-stick,” say some naturalists, the little Nautilus does nothing of the sort; and if you go to him to learn navigation, you will never be much of a sailor; he may teach you how to sink to the bottom and rise again, and that kind of knowledge might be worth something to you if you could breathe under water; and he might teach you how to swim, but not how to sail, for in spite of all poetic theories, he does the former and not the latter. Most usually he walks about at the bottom of the sea on his long arms, something like the Cuttle-fish, feeding on the marine vegetation; the shell is then uppermost; if we could look inside of it we should see numerous little chambers or cells, the larger and outermost of which only are inhabited by the mollusk, the others being filled with air render the whole light and buoyant. Through the centre of these chambers, down to the smallest of them, runs a membranous tube which can be exhausted or filled with fluid at the pleasure of the animal, and the difference thus effected in the weight of the shell enables it to sink or swim; in the latter case, up it goes to the surface, and “keel upwards from the deep,” emerges, as the poet has said, but once there it soon reverses its position. The shell becomes like a boat it is true, but its inhabitant neither points a sail nor plies the oar, but propels itself along stem foremost by a muscular action, which by alternately compressing and loosening a kind of siphon, throws out jets or gushes of water, which by the resistance they meet with from the surrounding fluid, give the desired onward motion, and away the swimmer goes, his long arms gathered closely together, and streaming behind like the tail of a comet, and its round eyes keeping a sharp look-out on either side. Should it espy danger, the body and limbs are withdrawn into the shell, and the fluid driven through the central tube, so as to compress the air in the pearly cells, and down sinks the swimmer once again to his native depths, where
“The floor is of sand like the mountain drift,
And the pearl shells’ spangle the flinty snow;
And from coral rocks the sea-plants lift
Their boughs where the tides and billows flow,
The water is calm and still below.
For the winds and waves are absent there;
And the sands are bright as the stars that glow
In the motionless fields of upper air.
And life in rare and beautiful forms,
Is sporting amid those bowers of stone,
And is safe, when the wrathful spirit of storms,
Has made the top of the waves his own.”
We give below two figures of the Argonaut, one of which represents him crawling at the bottom of the sea, and the other swimming on the surface.
The True, or Pearly Nautilus, (N. Pompilius,) the origin of whose specific name we have been unable to discover, is much like the Argonaut in appearance and general construction; the shell is externally smoother and more iridescent, it is also generally somewhat thicker than the former kind, and has internally more chambers or divisions; its pearly lustre renders it a beautiful ornament, and the large size it frequently attains a very conspicuous one. Its inhabitant has several peculiarities of organization, which distinguish it from the Argonauts, but into these we need not enter; neither can we pause to describe the other species of nautili, the shells of which, like those of the Cowry and other univalves, are covered with a membrane which hides their beauty. This membrane or mantle sometimes extends some distance beyond the edge of the shell, and, being of a light and filmy appearance, may have been mistaken for a sail hoisted by the creature to catch the breeze, while its long arms, thrust up into the air or down into the water, may have been thought to be masts or oars, so that the poets are not so much to be blamed, if they say as Wordsworth does.
“Spread, tiny Nautilus, the living sail,
Dive at thy choice, or catch the freshening gale.”
Nearly allied to the Nautili are these beautiful fossil shells called Ammonites, from their fancied resemblance to the horns of a heathen deity or god, called Jupiter Ammon. These shells, at once the wonder and pride of geologists, are found in the chalk formations, and thousands of years must have passed away since they were inhabited by living creatures. The Nautili which swam and sported with them at the depths of the ocean, as is proved by the shells of many species found in the same chalky deposits, have still their living representatives, but those winding galleries and pearly chambers once fragile as paper and brittle as glass, now turned into, and surrounded by solid stone, are all shells of extinct species, and we can hardly see and handle them without some degree of awe and reverence; when we reflect on the great and wonderful changes that have passed over the earth since they were formed by a hand divine, instinct with the breath of life, and then to be embedded in the rock as everlasting characters by which the unborn generations of men might read in history of those changes, and of the providential dealings of God with his creatures. Of these Ammonites, and other fossil shells, much more will have to be said in our proposed geological volume; the poem which follows will very appropriately conclude the above remarks, and our present little work on shells—beautiful, wonderful shells! useful, ornamental, instructive! The subject is one which we would earnestly invite our young readers to study: it is but here introduced; we have picked up a few, very few, of the wonders and beauties of conchology, and presented them to their notice in the hope that they may be induced to desire a more intimate acquaintance with this branch of natural science, which has been hitherto greatly neglected. To understand it thoroughly, much attention and perseverance will be required, but even a slight acquaintance with it will yield both pleasure and profit to the mind.
