Instead of floating in its pleasure-boat over the sea, the argonaut 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]
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 an external shell 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, as Aplysia and Bullæa, and to some land-slugs, as Parmacella and Limax, which have an internal shell.[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.
CHAPTER II.
OCTOPODS I HAVE KNOWN.
The first Octopus whose habits and mode of life I had opportunities of observing in captivity, was one exhibited in the Aquarium at Boulogne in September 1867. It was the prominent subject of conversation at the tables d’hôte of all the hotels there, and almost the first words addressed to a new-comer were, “Have you seen the devil-fish?” It was but a miserable little imp, only half matured in diablerie, and so persistently concealed itself by burrowing in a considerable depth of shingle, that all that could generally be seen of it was a portion of one of its arms waving gently in the water. But perhaps this was quite as well as if more had been visible, for it left a great deal to the imagination, and was also profitable to the proprietor, because people repeated their visits daily in hope of obtaining a better view of it. The privilege of privately inspecting it was several times accorded to me, and I then first witnessed many of the movements, ways, and habits of this animal, with which I have since become familiar.