Imatges de pÓgina
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of, and by means of which, like the star-fish, they can move from place to place. When this animal walks, in this resembling also the star-fish and sea-urchin, it moves with its head and mouth downwards and its body elevated. It swims also and seizes its prey by means of these organs: besides these arms or legs, for they perform the functions of both, there is a pair of long organs, one on each side, having their origin between the first and second pair of legs, which are incrassated at the end, where, also, they are furnished with many suckers. Cuvier supposes they use these as anchors to maintain them in their station during tempests, and as prehensile instruments, by which they can seize their prey at a distance. In the centre of the legs is the mouth, surrounded by a tubular membranous lip, including a beak, consisting of two mandibles, like that of a paroquet; these mandibles or jaws are crooked, and the upper one fits into the lower as a sliding lid into a box. With these redoubtable jaws the cuttle-fish devours fishes, crustaceans and even shell-fish, which receive a farther trituration in its muscular crop and its gizzard. By means of the suckers on their legs and arms, they lay such fast hold of their prey as to deprive them of all power of motion; thus they master individuals much larger than themselves. The hard and often spinose crust of crabs or lobsters cannot withstand the action of their trenchant jaws, and they do not fear the gripe of their claws. Their large eyes, which resemble those of vertebrated animals, by their look of ferocity, are enough to create an alarm in the animals they pursue, and are said to see in the night as well as the day. So that although they are not like Pontoppidans Kraken the notion of which is thought to have been taken from a large cuttle-fish-half a league in circumference, so as to be mistaken for floating islands, yet they are really as tremendous animals, their size considered, as any that Providence has commissioned to keep within due limits the populace of the waters.

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One of their most remarkable and unique features, is the manner in which circulation takes place in them. They have three hearts; the principal one, seated in the middle, sends the blood through the arteries: the blood returns by a vena cava,. which, dividing into two branches, carries it to the two lateral hearts, each of which sends it to the gills for oxygenation,. whence it returns again by the intermediate heart.

The Octopus, called by the French writers the Poulpe, probably a contraction of polype, differs from the common cuttle

1 See above, p. 108.

2. Ibid. p. 114.

fish, having neither the arms nor long tentacles of that animal, and instead of the large heavy bone has only two small cartilages. This different structure is rendered necessary by the difference in their habits. The body of the octopus is small, and it has legs sometimes a foot and a half in length, with about two hundred and forty suckers on each leg, arranged, except near the mouth, in a double series; so that it walks with ease. They are often out of the water, and frequent rough places, are excellent swimmers, and move rapidly in the water with their head behind. The cuttle-fish, whose legs are short and body heavy, prefer the bottom, and do not attempt to swim, for which they are not well fitted. Providence has, therefore, given them their long arms to compensate for the shortness of their legs.

A remarkable peculiarity distinguishes these animals. They are furnished with an organ which secretes a black fluid, with which they can produce an obscurity in the water that surrounds them, on any appearance of danger, or to conceal themselves from their prey. The Chinese are said to use it in making the ink that bears the name of their country; something similar, but not so black, is prepared from it in Italy; and Cuvier used it to colour the plates for his memoir on these animals.

The second order of cephalopods, or at least the pearly nautilus, differs in several respects from those which constitute the first, and which I have just described, approaching much nearer to the Molluscans. The most striking approximation, and which first catches the eye of the examiner, is its shell, which, though its spiral convolutions are not externally visible, exhibits a general resemblance to a univalve shell. To a person who had the opportunity of witnessing the motions of the animal that inhabits it, the first thing that would strike him, would be the means by which it progressed upon the bed of the sea; he would see no motion produced by the action of tentacular furnished with suckers, like those of the cuttle-fish, but instead of it, by a single expansive organ, exhibiting considerable resemblance to the foot of a snail. This organ, Mr. Owen, led by the nervous system, regards as surmounting the head and as its principal instrument for locomotion. The oral organs of this animal are much more numerous and compli cated than those of the cuttle-fish, and are furnished with no suckers. Its tentacles are retractile within four processes, each pierced by twelve canals protruding an equal number of these organs, so that in all there are forty-eight. In fact, the whole oral apparatus, for the full description of which I must

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refer the reader to Mr. Owen's excellent tract, except the mandibles and the lip, is formed upon a plan different from that of the cuttle-fish, as likewise from that of the carnivorous trachelipod Molluscans, and indicates very different modes of entrapping and catching their prey.

The eye, also, Mr. Owen states to be reduced to the simplest condition that the organ of vision can assume, without departing altogether from the type of the higher classes, so that it seems not far removed from that of the proper Molluscans. In this animal there is only a single heart, the branchial ones. being wanting.

There is one circumstance which proves this cephalopod to belong to this shell, and not to be a parasitic animal as that of the argonaut has been supposed to be-it is this, though the whole body appears to reside in the last and largest concameration of the shell, yet there is a small tubular tail-like process which enters the siphon, but which unfortunately was mutilated, only a small piece being left, but enough to show that the animal had power over the whole shell by means of this organ: hence it follows that a Cephalopod is the animal that forms the shell of the nautilus, and its natural inhabitant, which goes a great way towards settling the controversy concerning the real animal of the argonaut, and amounts almost to a demonstration that the celebrated sailor that uses it as a boat, and scuds gaily in it over the ocean, is no pirate that has murdered its natural owner, but sails in a skiff of his own building.

The only circumstance that now leaves any doubt in the mind of the inquirer, is the very different nature of the cephalopod of the argonaut and the nautilus, the former appearing to be nearly related to the octopus or poulpe, and belonging to the genus Ocythöe of Rafinesque. In this genus the tentacular legs or arms are similar to those of the poulpes, planted on the inner side with a double series of sessile suckers, the second pair having a membranous dilatation at their apex,i which the animal is supposed to use as a sail when it moves on the surface of the sea. Some naturalists deny that this animal ever uses these organs for sailing or rowing, but Bosc expressly asserts, and I am not aware that there is any reason to doubt his veracity, that he has seen hundreds of the argonauts rowing over the surface of the sea, in calm days, at so small a distance from the vessel in which he was sailing, that though he could not catch one, he could observe all their manœuvres;

1 See Zool. Journ. ħ. xiii, t, ïïi,

he farther says, 'that they employ their dilated tentacle sometimes as a sail and sometimes as an oar.

When we consider how many instances are upon record of Molluscans being fitted with organs that enable them to catch the wind and sail on the surface of the sea,' there is nothing contradictory either to analogy or probability that the argonaut should do the same, especially when we consider how universally this idea has prevailed, from the time, at least, of Pliny and Oppian, both of whom describe its sails with sufficient accuracy. Aristotle also speaks of his polype, which is evidently a cephalopod, as a sailor by nature-he says, that when it rises from the deep it is in a subverted shell, rendering that action more easy and keeping the shell empty, but that when arrived at the surface it reverses it; that it spreads its sail to the wind, and when that blows, letting down its two 'cirri, one on each side, uses them to steer with.

Upon comparing the animal of the nautilus with that of the argonaut, it appears evident, though the gills of the latter seem not to have been examined, that they belong to different Orders, at least, every probability rests on that side; yet every thing speaks the relationship of the latter to the octopus, and therefore they would properly form a section of the dibranchiata of Mr. Owen. In fact, the oral organs of the former are so widely different from those of the Order just mentioned, that one would almost expect another to connect them. This probably lies dormant amongst the fossil ammonites, the shells of many of which, though consisting of many chambers, are evidently intermediate between the nautilus and argonaut.

We must next inquire what was the object of Him, who does nothing but with a view to some useful, though not always evident, end, in producing these miniature monsters of the deep, so wonderfully organized and so unlike every other tribe of animals, in his creation, and yet containing in them, as we have seen, as it were, the elements, whether we ascend or descend, of all the rest. It appears from the united testimony of almost every writer that has noticed them, that they have it in charge to keep within due limits, a tribe of animals, almost equally destructive with themselves, and which are armed also with weapons of offence, apparently equally terrific to their prey. It will be readily perceived that I am speaking of the Crustaceans, and of the formidable pincers with which they seize their prey. It must be a curious spectacle to see one of the larger poulpes attack a lobster: at first sight, we should

1 See above, p. 142.

think the latter most likely to master his assailant, covered as he is with a hard crust, and using adroitly his powerful forceps, we should feel sure that the cuttle-fish, with his soft body and oral organs equally soft, stood no chance against such an antagonist. But He who gave him his commission, has fitted him for the execution of it, his soft tentacular organs will bend in every direction, and the numerous suckers wherewith they are planted, by pumping out the medium that forms the atmosphere of marine animals, produce such a pressure wherever they are fixed, that, struggle as it may, it can not disengage itself from the grasp of its assailant; and, by their flexibility, these organs can imitate the fisherman, and tie together the two pieces of the forceps, so that it cannot bite; thus, at last, it is brought within the action of the powerful beak of the cuttle-fish, which soon makes its way through its crust, and devours it shell and all. Even when at a distance, by means of its long arms, the cuttle-fish can lay hold of it and drag it towards it; and the poulpe, which has not these arms, makes up for it by having longer legs.

The argonaut probably uses similar means to master its prey, and finds some defence in its shell, but the nautilus has a still stronger castle, which it may be supposed defies the bite of the Crustacean; its oral organs are calculated for closer combat, but the tentacles appear less adapted for holding fast their prey, not being visibly furnished with suckers, but what they want in power is made up in numbers, since in lieu of eight or ten tentacular organs, they have nearly a hundred. So diversified are the ways and instruments by which infinite WISDOM, POWER and GOODNESS enables its creatures to fulfil the ends for which he created them: and so an equilibrium is maintained in every part of creation.

The fossil species are mostly called by one name, Ammonites, as if they were the horns of the Egyptian Jupiter, and which, if any of them are now in existence, probably frequent the depths of the ocean, and do not, like the argonaut or nautilus, visit its surface, to tell the admiring world, that God has created such wonderful beings. Specimens have been found of the enormous diameter of six feet. Though the sculpture of many of these great cephalopods, gives reason to think that they may be intermediate between the argonaut and nautilus, yet the convolutions and external form of their conchs give them no small resemblance to a genus of snails, the species of which are often found in fresh waters, except that in this the

1 Planorbis.

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