Perhaps the most effective aid to the investigation of natural history which the present age has produced is the invention of the aquarium, and particularly its application to marine forms of life. Depending on that grand principle of organic chemistry, of world-wide prevalence, that the emanations from animals and vegetables are respectively essential to the continued life each of the other, it was discovered that the relative proportions of number and bulk in which organic beings of the two kinds could healthfully live together was easily determined; and since the fact that the creatures were inhabitants of water, whether fresh or salt, presented no exception to the universality of the law, they had but to be placed together in a suitable ratio, enclosed in a vessel containing water, and an aquarium was established. Improvements in the form of the vessel, in the mode of exposing the contents to observation, in the impact of the rays of light, in the arrangement of the interior, and other points of value, have indeed been progressively made; whereby the practical availability of the invention for the purposes of experimental natural history has been augmented; but some of us have found little difficulty, even from the very first announcement of the discovery, in maintaining the collections of sea-water, with their living plants and animals, unchanged from year’s end to year’s end. I may be perhaps excused for observing, that I have at present in use a large tank, full of marine creatures, in which the water has been unchanged for four years, and on which I look with peculiar interest, because it was the first tank ever made for private use. This very aquarium has afforded, and still affords the opportunity for the observation of many interesting details of the structure and habits of the lower forms of animal life, details which constitute the basis not only of my works on marine natural history already published, but of the present series of papers also. We collect the creatures, indeed, abroad, and there gather up some broad facts of interest concerning their modes of life; but it is at home, in the quiet of the study, with conveniences and aids to examination, experiment, and record at command, that they must be studied. The aquarium becomes in fact an apparatus, whereby we bring a portion of the sea, with its rocks, and weeds, and creatures, to the side of our study-table, and maintain it there.

Thus an opportunity of close and valuable familiarity with sea-productions is open to multitudes who have never seen the broad expanse of ocean, nor searched its prolific shores; and facilities for extending the bounds of zoological science are everywhere enjoyed, which till lately were restricted to a very few naturalists, whose residences were situated on certain favourable spots upon the coast. Yet both modes of investigation are necessary. He who has never seen marine animals except in the confinement of an aquarium, cannot but be conscious of many chasms in his knowledge, which are filled up by him who is in the habit of collecting his own specimens in their proper haunts; and who, by finding them in fer naturÂ, can, when he studies them at leisure in his tanks, make such allowances as are necessary for the variations in habit which may be dependent on the difference between their present artificial, and their original natural, conditions of existence.

While we rejoice then in tanks and vases of crystal water, filled with the lovely forms and brilliant hues of sea-weeds and sea-anemones, I invite my readers to accompany me on a few hours’ visit to the charming creatures at their own homes. The season is propitious; the sun has just passed the vernal equinox, and the genial warmth of spring is diffusing new life into the cold blood of the animals that dwell beneath the waters; the equinoctial storms that lately raged have blown themselves out, and are succeeded by a quietude whose effect is delightfully seen in yonder mirror-like ocean: it is the time of spring-tide; and the near approach of the hour of lowest water will afford us unusual facilities for finding species only to be invaded under such conditions.

Let us then scramble down to the beautiful Anstey’s Cove, along the steep path tangled with briers and ferns; where the swelling buds of the hawthorn and honeysuckle are already bursting, while the blackbird mellowly whistles in the fast-greening thicket, and the lark joyously greets the mounting sun above us. Yonder on the shingle lies a boat, newly painted in white and green, for the attraction of young ladies of maritime aspirations; she is hauled up high and dry; but the sinewy arms of honest Harry Bate, who hearing footsteps has come out of his little grotto under the rock to reconnoitre, will soon drag her down to the rippling waves, and, “for the small sum of a shilling an hour,” will pull us over the smooth and pond-like sea, whithersoever we may choose to direct him.

“Jump aboard, please, Sir! Jump in, ladies! jump in, little master!” And now, as we take our seats on the clean canvas cushions astern, the boat’s bottom scrapes along with a harsh grating noise over the white shingle-pebbles, and we are afloat.

First to the caverns just outside yonder lofty point. The lowness of the tide will enable us to take the boat into them, and the calmness of the sea will preclude much danger of her striking the rocks; especially as watchful Bate will be on the alert, boat-hook in hand, to keep her clear. Now we lie in the gloom of the lofty arch, gently heaving and sinking and swaying on the slight swell, which, however smooth the surface, is always perceptible when you are in a boat among rocks, and which invests such an approach with a danger that a landsman does not at all appreciate. Yet the water, despite the swell, is glassy, and invites the gaze down into its crystalline depths, where the little fishes are playing and hovering over the dark weeds. The sides of the cavern rise around us in curved planes, washed smooth and slippery by the dashing of the waves of ages, and gradually merge into the massive angles and projections and groins of the broken roof, whence a tuft or two of what looks like samphire depends. But notice the colonies of the Smooth Anemone or Beadlet[32] clustered about the sides; many of them are adhering to the stone walls, several feet above the water. These have been left uncovered for hours, and are none the worse for it. They are closed, the many tentacles being concealed by the involution of the upper part of the body, so that they look like balls, or hemispheres, or semi-ovals of flesh; or like ripe fruits, so plump and succulent and glossy and high-coloured, that we are tempted to stretch forth the willing hand, to pluck and eat. Some are greengages, some Orleans plums, some magnum-bonums,—so various are their rich hues; but look beneath the water, and you see them not less numerous, but of quite another guise. These are all widely expanded; the tentacles are thrown out in an arch over the circumference, leaving a broad flat disk; just like a many-petalled flower of gorgeous hues: indeed, we may fancy that here we see the blossoms, and there the ripened fruit. Do not omit, however, to notice the beads of pearly blue that stud the margin all round, at the base of the over-arching tentacles. These have been supposed by some to be eyes; the suggestion, however, rests on no anatomical ground, and is, I am afraid, worthless; though I cannot tell you what purpose they do serve.

Away! for I wish to explore another scene not less romantic than this, and which I know by experience to be much more prolific in strange and beautiful forms of life. Harry shall pull us round yonder low point, which bears the appellation of Hope’s Nose, calling on the way to look at some one of the inlets that lie between the long projecting points at the foot of Black Rock. Here the boat floats over dense forests of great brown sea-weeds, the LaminariÆ, which lift their dark masses, and wave to and fro, with a majestic dignity. Here is the narrow crumpled blade of the Oarweed, of a rich yellow brown; and the wavy stem of the Furbelows springing from its hedgehog-like bladder; but chiefly is the forest composed of vast plants of the Tangle, whose broad deep-brown fronds of a substance like stout leather, French-polished, divide into many long straps, slide over each other, and flap to and fro in the heave of the sea. Yonder we see on the broadest part of a frond, just before it divides, what seems a flower, as large as a chrysanthemum, but of the liveliest pea-green hue, every long petal tipped with rosy pink. Hand over the boat-hook, and carefully lift the tangle to the surface. Now we have it fully in view. It is the green variety of the Opelet;[33] so called because it is scarcely capable of infolding the walls of the body over the disk and tentacles; these therefore remain habitually open, though the animal is at times much less expanded than at others. We now see it in its most charming condition; the short fawn-coloured column inflated, the mouth elevated on a strong cone in the centre of the wide saucer-shaped disk, and the numerous tentacles arranged in groups, as if several stems sprang from the same root, long, slender, very flexible, twisting about like the snaky locks of Medusa’s head, all of the most delicate light green, with a rich satin lustre, and all tipped with the richest crimson-lilac or light rose,—a most beautiful harmony of colours. The animal adheres by a broad base firmly to the disk of the tangle, and awaits, as it waves hither and thither, the approach of one of the little fishes that play heedlessly at bo-peep among the fronds. No sooner does one of them touch the far-stretching tentacles, than a virulent and penetrating poison shoots through its frame; its vigour is benumbed in an instant; it ceases to struggle; its powerful fins strike the water no more; others of the fatal tentacles enwrap themselves around it, and drag it towards the mouth, already protruding and expanding in expectation of the morsel; where it is in a few minutes engulfed, and soon digested in that capacious maw.

It is not very uncommon for a single specimen of this species to become two by a perpendicular division. The whole process has been observed. A little notch first appears in the margin of the disk, which extends, cutting through the tentacles of that side, splitting the disk across, proceeding through the tentacles on the opposite side till it divides the margin there also. Meanwhile, it has advanced downward in an equal ratio, till it has reached the base; and at length there are two half-opelets still adhering in the closest proximity. Now, however, the two raw and open surfaces close up, and the bases glide gradually apart. A thick wall of flesh forms between the stomach and the wound, and new tentacles develop themselves on this. The two Opelets are complete.

Half-an-hour’s vigorous pulling has doubled the long promontory of Hope’s Nose, a wilderness of stones, like what I suppose, from published descriptions, the foot of Mount Sinai to be, and brought us, between two raised beaches, into the pretty cove of Meadfoot, capped by elegant villas. These beaches, evidences of the lifting of the land, for they surely once stood, as beaches stand now, at the sea-level, are situate, the one on the main, the other on the Thatcher, a rocky islet some two hundred yards off shore. A few minutes more, and we are in a wild scene indeed. Isolated rocks stand up, in angular masses, upright columns, and sharp peaks, out of the sea, which is quite deep, even at lowest spring-tide. The coast itself too is rugged, precipitous, and in many spots quite perpendicular; one bold promontory, which runs out with a narrow knife-edge summit, is perforated by a natural archway of lofty elevation, of very striking aspect. It is distinctly visible for miles along the shores of Torbay, and is dignified with the name of London Bridge.

Here, then, is our fishing-ground to-day. Threading the slender passages between the perpendicular rocks, or creeping-in close under their overhanging landward sides, where no ray of the sun has ever penetrated, we hang on by the points and groins, and eagerly peer below. Into one lane our boatman hesitates to venture. It is but just wide enough to allow the boat to pass; indeed here and there she cannot without rubbing her gunwales; and if a stronger swell than usual were to roll-in from seaward while entangled, her side might be stove-in before she could be extricated. However, its gloom looks so tempting, and the water among the islets is so very smooth, that we succeed in persuading him, and we push and drag into the very midst of the watery alley. The rocks rise close on either hand like lofty walls, and descend as perpendicularly, deep and far down beneath our keel; as we can well see, for the water is of lustrous transparency.

And what a sight is here! Hundreds of Anemones of many species are studding the walls almost as thick as they can be packed. Every tiny crevice, every hollow, every hole left by Pholas or Saxicava (and the rock is riddled and honeycombed by these burrowing mollusks), holds its little knob of plump flesh; some lolling out with a dewdrop hanging from the end; some just filling the cavity, and allowing the tips of the crowded tentacles to peep out as a speck of white, or of orange, or of rosy lilac, according to the species; and some retreated to the bottom of their stony fortress, to be detected only by the probing touch. Other forms too there are;—dead men’s fingers, white and yellow; worms, green and brown and grey, twining in and out, and grasping the sharp edges of the rock; tunicate mollusks, simple and compound; univalves and bivalves; sponges of all bright colours by hundreds:—what a maze, what a teeming world of life it is!

All this is at and above the level of the eye. Now let us bend over the boat’s gunwale, and gaze below, with our faces brought nearly to the surface of the sea. Here the sight is far more wonderful, and far more attractive; for here the life is seen in all its fullest activity, every creature performing its functions, and pursuing its instincts with the most single earnestness, self-contained, and altogether regardless of the myriad fellow-beings that surround it and press upon it, in this eager contest and struggle for maintained existence.

A yard or two below the surface the eye is caught by a great oyster projecting from the vertical wall. It is a strange situation for an oyster to be in, but it shows how the infant young, in their free-swimming form, so different from their ultimate condition, may be carried by the aid of their own cilia, and the sea-currents, into the most improbable situations, and may there find circumstances congenial for permanent settlement.[34] Perhaps, however, its brown and rough shell would scarcely have attracted our notice, but for the rider that sits upon it. A specimen of the Dead-man’s finger,[35] of noble dimensions, has selected this shell as the seat of its dominion; and we can discern the three or four great lobes of which it consists all surrounded by the gauzy cloud that tells of the thousands of translucent polyps projected from every part of its periphery. Fine as is that specimen, however, there are scores of others, many of which are of equal dimensions, and more easily accessible. By the aid of the hammer and cold-chisel, we may easily secure a specimen without harming it, after searching a while to select one which is seated on some projection of the rock that can be struck off. Thus removed, and at once transferred to one of our collecting jars, the curious compound animal will in captivity display its beauties, though, it must be confessed, it is often rather bashful before company. The lobes into which the mass is divided are sufficiently like stumpy fingers to have given it a popular designation, while their dull white hue has suggested that the fingers are those of a corpse. The animal is sometimes, however, called Cows’ paps, and sometimes Mermaids’ gloves; but I think this latter is a book name.

When we examine it in the aquarium, after it has recovered its equanimity disturbed by the rude shocks of the hammer battering about its castle, we see that the lobes are greatly swollen and sub-pellucid, from the imbibition of water into the canals with which its whole substance is penetrated. When out of water the surface was studded with shallow pits, as if the poor thing had at some period of its history been afflicted with the small-pox. Now, however, these pittings reveal their true character; for each has protruded itself in the form of a long but slender polyp, of exquisite translucency and perfect symmetry. It resembles a tubular flower with eight narrow pointed petals, which arch outward like those of a campanula or tulip. Each petal carries on its edges a row of very slender transparent filaments, arranged like the teeth of a comb, which also arch downward, and greatly augment the beauty of the flower-like polyp.

Structurally, this polyp is closely allied to the common forms of the Sea Anemones; the most obvious peculiarity being, that a multitude are combined into one mass, with a common life animating the whole. The fleshy mass is of a spongy texture, full of branching water-canals, and containing a multitude of calcareous spicula of characteristic forms. They resemble gnarled branches of oak, with the branchlets broken off, leaving ragged ends. The skin of the polyps contains, at certain fixed spots, groups of similar spicula, but much more minute. The microscope is necessary to discern these, as well as some other details of the organization of this very interesting creature.

The technical character by which this animal with its allies is distinguished from the proper Anemones, is that its plan of organization is fashioned on the number eight, whereas the true Anemones have six, as their characteristic number. Thus, however numerous the tentacles of an anemone may be,—and in the case of the Daisy or the Plumose, they often amount to several hundreds,—the young animal began with six, and the increase is normally a multiplication of six, though accidental irregularities do occur. On the other hand, the tentacles of the Alcyonium are permanently eight, as are the vertical partitions of the interior of the body; and by consequence, the chambers into which those membranous partitions divide it.

But we must not allow the interest attaching to these forms to divert our attention from the Anemones themselves. All the species which we saw on the rock above the water, are here below it, and all displaying their beauties in an incomparably more charming fashion. We can compare the whole submerged wall to nothing else than a parterre of most brilliant flowers, taken bodily and set on end. The eye is bewildered with their number and variety, and knows not which to look at first. Here are the Rosy Anemones,[36] with a firm fleshy column of rich sienna-brown, paler towards the base, and with the upper part studded with indistinct spots, marking the situation of certain organs which have an adhesive power. The disk is of a pale neutral tint, with a crimson mouth in the centre, and a circumference of crowded tentacles of the most lovely rose-purple, the rich hue of that lovely flower that bears the name of General Jacqueminot. In those specimens that are most widely opened, this tentacular fringe forms a blossom whose petals overhang the concealed column, expanding to the width of an inch or more; but there are others in which the expansion is less complete in different degrees, and these all give distinct phases of loveliness. We find a few among the rest, which, with the characteristically-coloured tentacles, have the column and the disk of a creamy white; and one in which the disk is of a brilliant orange, inclining to scarlet. Most lovely little creatures are they all.

Commingled with these charming Roses, there are others which attain a larger size, occurring in even greater abundance. They are frequently an inch and a half in diameter when expanded, and some are even larger than this. You may know them at once by observing that the outer row of tentacles, and occasionally also some of the others, are of a scarlet hue, which, when examined minutely, is seen to be produced by a sort of core of that rich hue pervading the pellucid tentacle. The species is commonly known as the Scarlet-fringed Anemone.[37] The inner rows of tentacles, which individually are larger than those of the outer rows, are pale, marked at the base with strong bars of black. The disk is very variable in hue, but the column is for the most part of the same rich brown as we saw in the Rosy. Yet, though these are characteristic colours, there are specimens which diverge exceedingly from them, and some approach so near the Roses, as to be scarcely distinguishable from them. Generally, however, the scarlet-cored outer tentacles, and a peculiar habit of throwing the tentacular margin of the disk into crumpled folds, will be found sufficient to determine this very handsome kind of Anemone from its nearest allies.

There are multitudes too of a charming little kind, which, on account of the pure whiteness of the crown of tentacles, is known as the Snowy.[38] The disk is of the same spotless hue; and the column of a light drab deepening into pale olive towards the summit. With the exception of its colours, this species has a very close resemblance to the Rosy, with which it is generally associated, even as we see it here. And here is the Orange-disk,[39] one of exceeding loveliness, which you might fancy a cross-breed between the Rosy and the Snowy, having the rich brown column of the former, and the white tentacles of the latter; but that it has a character of its own in the disk being of the most brilliant orange-red. All these are scattered in the most abundant profusion, looking like gems sown on the rough rock; or, as I compared them before, like gorgeous composite flowers, of which you might easily fancy the little tufts of green and purple AlgÆ to be the proper leaves. There are also others, less conspicuous, the Daisy, the Sandalled, the Cave-dweller, the Translucent,[40] more or less numerously mingled with the rest, of which I have not space here to speak, but whose history I have elsewhere written in detail.[41] And we see here and there, for the most part crowded into groups, another interesting kind, the Plumose,[42] which differs much in appearance from its associates, having a taller column much more pellucid, and a crown of tentacles so short, so numerous and so dense, as to form a large confused tuft of frills, which cannot be separated into rows. This kind is always of self-colours, which, however, may be light olive, fawn-brown, orange, flesh-colour, or pure white. Those which the tide has left exposed, loll out of their holes and droop; but under the water they stand erect, with a noble boldness. Each group generally contains individuals of all sizes, and may be considered as a single family of several generations, or, to speak more correctly, of several series of offsets, of different ages. For it is highly characteristic of this species to increase by spontaneous division. When a large individual has been a good while adherent to one spot, and at length chooses to change its quarters, it does so by causing its base to glide slowly along the surface on which it rests;—the glass side of the tank, for instance. But it frequently happens that small irregular fragments of the edge of the base are left behind, as if their adhesion had been so strong, that the animal found it easier to tear its own tissues apart than to overcome it. The fragments so left soon contract become smooth, and spherical or oval in outline; and in the course of a week or fortnight each may be seen furnished with a margin of tentacles and a disk; transformed, in fact, into perfect though minute Anemones. Occasionally a separated piece, more irregularly jagged than usual, will, in contracting, constringe itself, and form two smaller fragments, united by an isthmus, which goes on attenuating until a fine thread-like line only is stretched from one to the other; this at length yields, the substance of the broken thread is rapidly absorbed into the respective pieces, which soon become two young Anemones.

All the kinds which we have seen in this locality belong to one great family, the SagartiadÆ, a group which includes nearly one-third of the seventy species of Anemones and Corals which we have on the British coast; and certainly the most beautiful and the most known, taking them one with another. They are distinguished by a remarkable peculiarity; the skin of the body is pierced with minute holes, capable of being opened and closed at will, out of which can be forced curious slender threads, which ordinarily lie coiled up in great profusion in the interior of the animal. These threads are almost entirely composed of those extraordinary capsules, called cnidÆ, or nettling-cells, found indeed in most of the tissues, but nowhere in such abundance as here, which eject with amazing force a poisonous filament having the strength and elasticity of a wire, and furnished with reversed barbs, but of almost inconceivable tenuity. The filaments, projected by myriads at the pleasure of the animal, penetrate deeply into the flesh of other soft-bodied creatures, and cause immediate paralysis and speedy death.[43]

The waning day and the turning tide warn us homeward; but we shall have time to visit a fine dark overarched pool in the rocks which I know on our route. Here it is; noticeable because of its being the chosen residence of a colony of that magnificent species, the Dahlia Wartlet.[44] All round the curving sides of the sea-washed basin, crowding one upon the other beneath the projecting angles, or seated in single majesty on some prominence, we see them flaunting the most gorgeous colours, and attaining a diameter of expanse that no other, at least of our common forms, can rival or approach. The wide but low column, rough with coarse warts, may be olive, or deep green, or purple-crimson, or light green splashed and streaked with scarlet like an apple; the disk is equally varied, but generally displays diverging bands of rich red which fork and embrace the tentacles; while the tentacles, short, stout, and conical, may be white with pellucid rings, deep crimson, or of the highest flush of rose, with a broad ring of lilac. Widely expanded, the Crassicornis is as good a mimicry of the great dahlias of our gardens, as the SagartiÆ are of the daisies and pompone chrysanthemums. Even bees are occasionally deceived. Mr. Couch, when once looking at a fine specimen which was expanded so close to the surface that only a thin film of water covered the disk and tentacles, saw a roving bee alight on the tempting surface, evidently mistaking the anemone for a veritable blossom; the tenacious tentacles instantly seized it, and though it struggled a good deal for its liberty, retained the disappointed bee till it was drowned, when it was soon consigned to the insatiable stomach. The story reminds us of the well-known fact that the flesh-flies, deceived by the carrion smell of some of the StapeliÆ, sometimes lay their eggs on the flowers; both cases showing that animal instinct is not quite so unerring as it is frequently represented.

Attached to the thin crumpled leaf of an Ulva in this pool is an animal, having much of the texture, and somewhat of the form, of an Anemone. Formerly, indeed, it was associated in the same group, but it is now ascertained to have more affinities with the translucent and often colourless free-swimming jelly-fishes. From its resemblance to an elegant lamp, it is called Lucernaria.[45] We must suppose a Medusa to be turned hollow upwards, and an adhesive foot to be produced from what was before the summit of its “umbrella;” and little more is necessary to constitute a Lucernaria. The most observable peculiarity is that the tentacles, which are very minute, and have the form of a globose head seated on a short stem, are disposed in compact groups of as many as seventy, which groups, eight in number, like so many round balls, are seated on projecting angles of the margin; while from the centre of the hollow rises a mouth, with four protrusile lips in form of a square. The colour is a dull dark red or liver brown. The animal preys on other creatures, which it captures by means of poison-capsules, and swallows, much as the anemones do.

And thus we wend our way homeward; meditating much as we glide across the smooth bay, on the wondrous elegance of form, the exquisite brilliance of colours, the great variety, the instincts, the powers, the most elaborate apparatus, bestowed on these humble creatures, of no apparent use whatever to man; indeed, until quite recently, utterly neglected by him and unknown, though exhibiting their loveliness under his very eyes, and close to his doors. We meditate on these things, and ask, For what purpose is all this profuse expenditure of power, wisdom, taste, skill? We hear the answer in the choral praise of those who know more of these matters than we can yet attain to,—“Thou hast created all things, and for thy pleasure they are, and were created.”