cephalopoda class
It will be seen that it may be said to be first cousin to the Argonaut, or “Paper Nautilus,” and second cousin to the cuttle and squid.
The Argonaut branch of the family is in possession of all the house property, which seems to have been entailed on the female line; for the paper-nautilus is, in fact, a female octopod provided with a shell in which to carry and protect her eggs. Instead of the whole of the eight arms tapering to a point, as in the octopus, two of the dorsal limbs are flattened out at their extremity, and from their membranes she secretes, and, if necessary, repairs the shell, and, by applying them closely to its outer surface on each side, holds herself within it; for it is not fastened to her body by any attaching muscles.[6]
The male argonaut is very small,—not more than an inch in length,—and has no shell. Hence, even by eminent naturalists, as Dumeril and De Blainville, it was long regarded as doubtful whether the shell was really secreted by the female, or whether, like the hermit-crab, she borrowed for her protection the empty habitation of some other mollusc.
It is an old belief, sanctioned by Aristotle, that the broad membranous expansions of the two arms, are hoisted by the animal as sails; and that in calm weather it sits in its boat-like shell, and floats over the smooth surface of the sea, steering and paddling with its other arms; and that, when danger threatens, it lowers its masts, and sinks beneath the waves.
Oppian, in his “Halieutics,” poetically expresses his opinion that it served as a model for the man who first conceived the idea of constructing a ship, and embarking on the waters:—
“If humble guess may probably divine,And trace th’ improvement to the first design,Some wight of prying search, who wond’ring stoodWhen softer gales had smoothed the dimpled flood,Observed these careless swimmers floating move,And how each blast the easy sailor drove;Hence took the hint, hence formed th’ imperfect draught,And ship-like fish the future seaman taught.Then mortals tried the shelving hull to slope,To raise the mast, and twist the stronger rope,To fix the yards, let fly the crowded sails,Sweep through the curling waves, and court auspicious gales.”
“If humble guess may probably divine,And trace th’ improvement to the first design,Some wight of prying search, who wond’ring stoodWhen softer gales had smoothed the dimpled flood,Observed these careless swimmers floating move,And how each blast the easy sailor drove;Hence took the hint, hence formed th’ imperfect draught,And ship-like fish the future seaman taught.Then mortals tried the shelving hull to slope,To raise the mast, and twist the stronger rope,To fix the yards, let fly the crowded sails,Sweep through the curling waves, and court auspicious gales.”
“If humble guess may probably divine,
And trace th’ improvement to the first design,
Some wight of prying search, who wond’ring stood
When softer gales had smoothed the dimpled flood,
Observed these careless swimmers floating move,
And how each blast the easy sailor drove;
Hence took the hint, hence formed th’ imperfect draught,
And ship-like fish the future seaman taught.
Then mortals tried the shelving hull to slope,
To raise the mast, and twist the stronger rope,
To fix the yards, let fly the crowded sails,
Sweep through the curling waves, and court auspicious gales.”
This pretty fable was exploded in 1837 by Captain Sander Rang, an officer of the French navy, and Port-captain at Algiers, who carefully followed up some experiments communicated to him by Mrs. Power, a French lady then residing at Messina; and the structure and purpose of the two flattened limbs is now clearly understood.[7]
Instead of floating in its pleasure-boat over the sea, theargonaut ordinarily crawls along the bottom, carrying its shell above it, keel uppermost; and the broad extremities of the two arms are not hoisted as sails, nor allowed, when at rest, to dangle over the side of the “boat,” but are used as a kind of hood by which the animal retains the shell in its proper position, as a man bearing a load on his shoulders holds it with his hands. When it comes to the surface, or progresses by swimming instead of walking, it does so in the same manner as the octopus; namely, by the forcible expulsion of water from its funnel-like tube.[8]
Paper-sailorFig. 1. The Paper Nautilus (Argonauta argo). The membrane is shewn partially retracted and the shell exposed.
Fig. 1. The Paper Nautilus (Argonauta argo). The membrane is shewn partially retracted and the shell exposed.
This “paper-sailor,” then, whom the poets have regarded as endowed with so much grace and beauty, and living in luxurious ease, is but a fine lady octopus after all. Turn her out of her handsome residence, and, instead of the fairy skimmer of the seas, you have before you what Mr. Mantalini would call a “dem’d damp, moist, unpleasant body,” like that of her weird and sprawling relative. The Paper Nautilus has been regarded as the analogue of the snail, which, like it, secretes anexternalshell for the protection of its soft body; and the octopus as that of the garden slug, which, having organs like those of the snail, as the octopus has organs like those of the shell-bearing argonaut, has no shell. The Cuttles and Squids may be compared to some of the sea-slugs, asAplysiaandBullæa, and to some land-slugs, asParmacellaandLimax, which have aninternalshell.[9]
The female octopus not being furnished with a shell, none of her arms are modified in form, like those of the argonaut, for the purpose of secreting and holding one. The male octopus, also unlike the male argonaut, is as large as the female, but may easily be distinguished from her by his having numerous tubercles and papillæ on the skin, which become very prominent when he is irritated or excited. D’Orbigny, not recognizing this peculiarity as sexual, regarded it as a specific distinction, and made of the male octopus a separate species,O. tuberculatus.
Having briefly explained the generic history and relationship of the octopus, I propose to introduce to the reader some members of the family with whom I have been on friendly terms. A former casual acquaintance with some of their kinsfolk at the sea-side, ripened, afterwards, into a close and prolonged intimacy with them in their home; and I thus obtained an insight of their habits and peculiarities, many of which are very curious and interesting.