CHAPTER VI.
NEW LIMBS FOR OLD ONES.
It is a not uncommon occurrence that when an octopus is caught, it is found to have one or more of its arms shorter than the rest, and showing marks of having been amputated, and of the formation of a new growth from the old cicatrix. Several such specimens have been brought to the Brighton Aquarium; one of which was particularly interesting. Two of its arms had evidently been bitten off about four inches from the base; and out from the end of each healed stump (which, in proportion to the length of the limb, was as if a man’s arm had been amputated half-way between the shoulder and elbow) grew a slender little piece of newly-formed arm, about as large as a lady’s stiletto, or a small button-hook—in fact, just the equivalent of worthy Captain Cuttle’s iron hook, which did duty for his lost hand. It was not a specimen of the remarkable hectocotylus development of the arm of the male octopus which takes place during the breeding season, but an illustrative example of the repair and restoration of a mutilated limb.[17]
This reparative power is possessed by some other animals, of which the starfishes and crustacea are the most familiar instances. The lobster and the crab, if they find themselves in depressing circumstances, are addicted to malingering. They do not go so far as to commit suicide; but, stopping short of that, perpetrate a kind of demi-semi-self-immolation. In a sudden passion of fear or anger, they will sometimes fling off one or both of their large claws, and that which they thus do impulsively and in haste, they repent and repair at leisure—like the intemperate man we sometimes read of in the police news, who goes home and smashes the crockery, and, when he is able to reflect on his folly, is glad to make good the damage as quickly and as quietly as he can.
The starfishes, too, as the common “five-finger” (Uraster), and the brittle-star (Ophiocoma),—which by-the-by, is not half as brittle as has been supposed—can throw off their limbs in a pet, and grow them again. But in both of these the act is voluntary, and the dismemberment complete. If the claw of a lobster or crab be severed, or wounded in any part of its length, the animal will bleed, and waste, and die of the consequent exhaustion. I have noticed that, especially in the spiny lobster or sea cray-fish (Palinurus), the blood flows freely many hours after death, and that when I have had occasion to remove the abdominal and caudal leaf-like appendages of a dead cray-fish for dissection and microscopical examination, the blood and serum have poured from the part where the cut has been made, and thickened on the stone slab in a firm, gelatinous sheet, of the colour and consistency of guava jelly.
The only joint from which new growth can start in the crustacea is that connected with the body. The whole limb must be got rid of. The octopus, on the contrary, is incapable of voluntary dismemberment, but has the faculty of reproducing, as an outgrowth from the old stump, any portion of an arm (or leg) which may have been lost by misadventure. I say “arm or leg,” for one hardly knows which these eight appendages should be called. If they are legs, the octopus can hold on with them as tightly as the “old man of the sea” gripped Sinbad the Sailor, and use them as dexterously as the “armless girl,” who cuts out with hers the pretty paper designs which she sells to visitors. If they are arms, he can walk on them, head downwards, under water, more cleverly than the most agile monkey or street arab. So we may call them either or both.
Returning to our mutilated octopus;—we transfer him from the tank in which he had been temporarily placed to the wet pavement, that we may better observe his movements when crawling. He scrambles and shuffles away, and makes the best use he can of the jury-rigging he has fitted on to his old stumps. As he does so, his keen eyes, mounted on little hillocks, peer furtively around him; and while he sidles off from his too admiring persecutors, he casts a doubtful, half-frightened, half-defiant glance behind him, like a schoolboy, timid in the dark, who fancies a ghost is following him. His cousin the cuttle-fish (Sepia) has an eye, round like that of an owl, which stares you out of countenance, and puzzles you by its immobility; the pupil of the eye of an octopus is like that of a tiger turned half round. The perpendicularly-elongated pupil of the cat gleams with hot ferocity: the calm, cunning gaze of the octopus from out the narrow horizontal slit of its compressed eyelids freezes by its cold cruelty.
Now, let us try to conjecture the “fons et origo mali”—the source of the injury of the two lopped arms.
There lingers still amongst the fishermen of the Mediterranean a very ancient belief that the octopus when pushed by hunger will gnaw and devour portions of its arms. Aristotle knew of it, and positively contradicted it; but a fallacy once planted is hard to eradicate. You may cut it down, and apparently destroy it, root and branch, but its seeds are scattered abroad, and spring up elsewhere and in unexpected places. Accordingly we find Oppian, more than five centuries later, disseminating the same old notion, and comparing this habit of the animal with that of the bear obtaining nutriment from his paws by sucking them during his hibernation.
The fact is, that the larger predatory fishes regard an octopus as very acceptable food, and there is no better bait for many of them than a portion of one of its arms. Some of the cetacea also are very fond of them, and whalers have often reported that when a “fish” (as they call it) is struck it disgorges the contents of its stomach, amongst which they have noticed parts of the arms of cuttle-fishes which, judging from the size of their limbs, must have been very large specimens. The food of the sperm whale consists largely of the gregarious squids, and the presence in spermaceti of their undigested beaks is accepted as a test of its being genuine. That old fish-reptile, the Ichthyosaurus, also, preyed upon them; and portions of the horny rings of their suckers were discovered in its coprolites by Dean Buckland. Amongst the worst enemies of the octopus in British home-waters is the conger. They are both rock-dwellers, and if the voracious fish come upon his cephalopod neighbour unseen, he makes a meal of him, or, failing to drag him from his hold, bites off as much of one or two of his arms as he can conveniently obtain. The conger, therefore, is generally the author of the injury which the octopus has been unfairly accused of inflicting on itself.
The Curator of the Havre Aquarium describes an attack by congers on an octopus which he had thrown into their tank. As soon as the latter touched the bottom it examined every corner of the stone-work. The moment it perceived a conger it seemed to feel instinctively the danger which menaced it, and endeavoured to conceal its presence by stretching itself along a rock, the colour of which it immediately assumed. Finding this useless, and seeing that it was discovered, it changed its tactics, and shot backward, in quick retreat, leaving behind it a long black trail of turbid water, formed by the discharge of its ink. Then it fixed itself to a rock, with all its arms surrounding and protecting its body, and presenting on all exposed sides a surface furnished with suckers. In this position it awaited the attack of its enemies. A conger approached, searched with its snout for a vulnerable place, and, having found one, seized with its teeth a mouthful of the living flesh. Then, straightening itself out in the water, it turned round and round with giddy rapidity, until the arm was, with a violent wrench, torn away from the body of the victim. Each bite of a conger cost the unfortunate creature a limb, and, at length, nothing remained but its dismembered body, which was finally devoured;—some dog-fishes, attracted by the fray, partaking of the feast.
I have always refused to permit so shocking a scene to be repeated at the Brighton Aquarium. The Havre experiment has taught us all that is to be learned from it concerning the mode of attack of the conger, and the octopod’s strategy of defence. That the flesh of the latter is a favourite food of congers, I have repeatedly proved by watching the eagerness with which they will rend limb from limb, and devour the body of a dead octopus to which I sometimes treat them after removing such portions as may be required for dissection and preservation.
An octopus is sometimes, though rarely, severely injured in battle by one of its own species. On one occasion when a newly-arrived specimen was put in a tank with others which had dwelt there for some time, these old habitués made a fierce onslaught on it, and the new-comer had one of its arms torn away. It would certainly have been killed if one of the attendants had not rescued and removed it. Aristotle says that the octopus does not eat its congeners, and D’Orbigny endorses his opinion. Nevertheless one instance of this cannibalism has occurred in the Brighton Aquarium; and in that on the Boulevard Montmartre, Paris, in 1867, two octopuses fought and the victor devoured the vanquished.
Another reparation or renewal by the octopods of worn or injured portions of their limbs is the frequent shedding of the outer skins of their suckers, the epidermis of the flat surface of them, by which they adhere, and travel from place to place. These cast-off skins may generally be seen floating in the water in their tanks in the form of very thin, filmy discs, with a hole in the centre. Seeking a reason for this, it appears to me that these, their feet-coverings, become worn by crawling and climbing over the rough rocks, and that it is a provision of nature for the renewal of the holding surface of their suckers, necessary for the production of a sufficient vacuum, and the very best method by which the repairs of the soles of their boots can be “neatly executed.” And, as their feet increase in size with their general growth, it may also be that they outgrow their shoes as quickly as children do theirs, and that, therefore, they cast them periodically when they require larger ones, as the barnacles do their plumes, the crustacea their shells, and snakes their skins.
Sometimes the whole shoe is thrown off; at others only the sole. When the octopus desires to get rid of this worn skin it curls its arms together close to its body in a peculiar manner, and rubs them one against another with a rapid motion of coiling and uncoiling which suggests the action of “Sir Jacob,” the father of Thomas Hood’s “Miss Kilmansegg,” when he
It appears to delight in thus cleaning itself and giving itself a good rubbing and scrubbing all over, as a strong man enjoys his “matutinal tub” and a hearty rub with a rough towel afterwards; or as a bird, with evident pleasure, preens its feathers, and bathes in water or sand. This cleansing process has been erroneously supposed to indicate sexual excitement.