VALLISNERIA SPIRALIS, ANACHARIS ALSINASTRUM—GOLD CARP, ROACH, AND MINNOW.

Bell Glasses, or vases, are now largely used for aquaria. Mr. Hall, of the City Road, was the first who thought of turning a propagating glass upside down to extemporise an aquarium; but he surely never thought that in a few months the aquarium would gain thousands of new followers through that simple trick of his in creating a cheap and elegant tank. Bell glasses for aquaria are to be obtained of any of the dealers in aquarian stock, and at most horticultural glass warehouses. The sizes range from ten inches to twenty inches in diameter, and the prices from one to fifteen shillings. For general purposes of use and ornament, I should recommend vessels of from twelve to eighteen inches. Those below twelve inches are too small to be of much service, and those above eighteen are liable to fracture on the occasion of any sudden change of temperature, especially in winter. Messrs. Phillips have lately, at my suggestion, produced a bell-glass expressly for aquarian purposes; those in use hitherto were made for gardening purposes, and were carelessly blown. The shape I have suggested is one nearly approaching to that of the blossom of the great bearbind, the sides of the vessel describing straight lines, and the edges lipping over in an elegant vase-like form. These are made of whiter and stouter glass than the common propagators, and are, of course, charged at a slightly advanced rate.

Stands for Vases are to be had of various forms and materials. Those formed of turned wood have the preference for elegance and safety; and, as the knob of the vase fits loosely in the depressed top of the stand, the vase can be turned round for inspection.

Messrs. Claudet and Houghton, of 89, High Holborn, have recently brought out improved forms of stands for vases. They are made of terra cotta, elegantly fluted, or ornamented with architectural scrolls, and are either bronzed or coloured to imitate stone. They have also improved the Vase Aquarium, by binding the upper edge with perforated zinc, in which there is a ring to receive the glass cover. Thus, while the lid shuts out dust, the perforated zinc rim admits air, and allows the escape of sulphuretted hydrogen. These vases are strongly recommended to those who cannot afford a well-built tank.

Where extreme cheapness is an object, a deal box with a hole cut in the centre to receive the base of the vase, will make a suitable stand, or a common seed-pan filled in with sand and the vase pressed down into it may answer, at a cost of only fivepence. A stone vase, or any ornamental object, with a suitable depression in the top, can also be turned to account for the purpose.

Glass jars, confectioner's show-glasses, a foot-bath of earthenware, or a few glass milk-pans, may be used for the preservation of aquatic objects, when a properly constructed vessel is not at hand; and even as adjuncts to high-class tanks, such vessels are frequently necessary and have special uses of their own. Still the tank, whether rectangular or vase-shaped, is a distinct thing in itself. The beauty is to be found in its completeness and the extent afforded for a variety of objects; and when we speak of an aquarium, we mean a vessel holding at least eight to thirty or more gallons of water, formed partially or wholly of glass, and stocked with plants and fishes in a living and healthy state. A glass lid is essential to prevent the entrance of dust and escape of any of the inhabitants. Fishes will sometimes leap out, and reptiles crawl out; and without a lid, some pretty objects may be lost.

CHAPTER III.

FITTING UP.

Rockwork claims the first consideration when we proceed to fit up and furnish a tank. For a fresh-water aquarium, I do not recommend rockwork of any kind; and in the case of a vase, rockwork is positively dangerous, from its weight, and, unless very skilfully managed, will be ugly rather than ornamental. In the marine tank a few pieces of rock add to the beauty of the scene and the comfort of the creatures.

In fitting rockwork, some amount of taste and judgment must be brought into exercise. Shells and filagree work are largely used by some folks; but they belong properly to the child's aquarium—they suggest dolls and battledores. Some rough fragments of any kind of non-metallic stone may be built up into a dark arch, or piled up after the fashion of a cromlech—one flat piece resting on two or three vertical pieces, so as to form a rude table-like structure. These may be fixed firmly in the places they are intended to occupy by means of Roman or Portland cement, which can be purchased at any building yard. The cement should be made into a stiff paste, and worked into the form required. Indeed, the rockwork may be wholly composed of such cement, especially if it is to have the form of an arch. The most important matter in the construction of rockwork is to give it a natural, rugged appearance, and to avoid loading the tank with superfluous weight. I have seen large shells and branches of coral in fresh-water tanks, and always thought the spectacle disgraceful to the owner. In a marine tank, such things are proper enough. Whatever is done should be made secure, the pieces of stone well embedded in cement, and the whole firmly united. The tank must be well seasoned, be frequently filled and emptied, to dissolve out any free salts before being put to use.

The Bottom must be composed of coarse river sand and small pebbles, the whole well washed before being introduced to the tank. Mr. Gosse condemns red sand and silver sand, as certain to stain the water. But I have two tanks now at work, both bottomed with such material, and the water preserves a crystalline brightness. I have also a marine tank, in which the bed is formed of common silver sand and garden pebbles: it has been in use nine months, and with no unfavourable results. In each case the sand was washed till the water could be poured away quite clear, and no matter what kind be used, the washing must be attended to. The coarser the grit the better its appearance, and, therefore, I do not recommend common sand, I merely show that it may be used when better is not attainable.

Mould has been extensively recommended as a bottom for tanks. I used it myself till I became convinced that it could be dispensed with altogether. It necessitates frequent changing of the water for at least a fortnight after the first stocking of the tank, in order to get rid of the soluble vegetable matter, which the water dissolves out of it, and its presence promotes the growth of confervÆ, and other low forms of aquatic vegetation, that become obnoxious to the sight, and even hurtful to the health of the collection. I now use sand and pebbles only, and I find that aquatic plants of all kinds root freely and flourish in it, and, indeed, if pebbles only be used, they flourish just as well if their roots are covered.

Planting is next to be performed. The arrangement of plants will depend on the shape and size of the vessel. Generally speaking, massive plants look best if set back with lighter plants before them, just the same as a painter sets his chestnuts and elms in mid-distance, and his lady birches in the fore-ground. Stratoides, Potamogeton, and other plants of a massive and decided character, are well seen through the interstices of Myriophyllums, Callitriche, and such like fragile and delicate structures. The flowering rush makes a fine centre piece for a vase, and appears to good advantage when seen through an archway, in a tank containing rockwork.

If there is a bed of two or three inches of sand, the roots may be gently pressed down into it, and a few clean pebbles laid over the spot to keep the plant in its position. Some plants will require a stone to be attached to them by means of a thread to fix them properly. Crowns of Stratoides that have not formed roots, may be planted in this way. First cut away any black or decaying matter from the stem, and pull off any discoloured leaves, taking care not to injure the centre, then pass a piece of bass round the base, and attach a small stone. The plant will remain firmly where placed, and will throw out roots, and fix itself before the rotting of the bass takes place. It will then throw up new crowns and become a very ornamental object. Loose stems of Chara, Anacharis alsinastrum, or Callitriche, may be gathered together, fixed by means of a stone in the same way, a strip of bass being better than string for attaching them. They will generally get well rooted in a fortnight, and remain firmly where planted.

The Water should be pure and bright when introduced to the tank, and if the supply is at all faulty, it will be best to pass it through a filter before using it. Spring water will do very well, but must stand a day or two to allow the plants to soften it, before the fishes are put in. My tanks are all filled with spring water, which I find altogether unobjectionable; but for the marine tank I think it preferable to any other in the manufacture of artificial sea-water. Writers on the aquarium usually insist on the use of river water, but in many places this is not attainable, and it is satisfactory to know that artesian, or well water, will serve the purpose admirably.

In filling the tank, hold a plate in the left hand, as low down as possible, to receive the dash of water from the vessel in the right, so as to wash up the sand as little as possible. A syphon may be used if a source of supply is near the position of the tank.

Aspect.—Sunshine is good for the tank at all seasons of the year. But in high summer it should have only an hour's sun, morning and evening; the fierce solar heat of mid-day will give the water so high a temperature as to be fatal to its animal inhabitants. Comparing tanks one with another, I must give a preference to a south or east aspect. A north aspect will do very well, from May to October, but, during the winter months, a tank in such a position, would be feeble, and want watching. Good exposure to daylight is, of course, essential; but it should be borne in mind that the fresh-water tank needs more light than a marine one. My fresh-water tanks I find to prosper best when placed close to the windows, but marine tanks may be kept back two or three feet, in a south aspect. In fact, if you have a cabinet of water-insects in a series of jars, the marine tank may very well stand behind them, and get sufficient light there, but the light should fall uninterruptedly on the fresh water vessels.

CHAPTER IV.

WATER PLANTS FOR THE AQUARIUM.

How to stock a Tank quickly.—It is usual to fix the plants and fill up the tank to within a few inches of the top, and then leave the whole for a week before completing the collection by the introduction of fishes. Where a beginner has sufficient patience to wait, this is very advisable, because the whole gets well settled, the plants start into growth, and the water gets softened and charged with oxygen. But this plan is not the only one that may be followed, and if well-washed pebbles be used instead of mould, as I have advised, the fishes may be introduced the same day as the plants are inserted, by first taking care that you insert plenty of large healthy plants, and then throw on the top as much of the brook starwort—Callitriche autumnalis—as will cover the whole. I lately stocked two tanks in this way, and performed the whole in less than two hours, forming the bottom, planting the vegetation, and adding the fish—perch, tench, Prussian and British carp, roach, minnows, gudgeon, and chub—and all went on as well as if the tank had stood a month to strengthen, the water being from the first moment as brilliant as any of the Castalian springs that flow through classic verses. The lovely green of the starwort, spread over the whole of the surface of the water, has a fairy-like effect. It is necessary to get a good supply of starwort from a brook, throw it into a large vessel of clear water, pick off the green heads, with four or six inches of stem only to each, then wash all these picked portions till they are bright and clean, and throw the whole into the tank to take its chance. You must be lavish as to quantity. It soon spreads over the surface, and arranges itself most beautifully, forming a rich green ceiling, giving the verdant shadow which a new tank wants; it grows freely, lasts for months, continually throwing out new roots and shoots from the joints, and creates abundance of oxygen, from the first hour of its being thrown in. Whenever it seems desirable it can be got rid of by simply lifting it out. My own are the only tanks I have seen stocked in this way.

Selection of Plants.—There is scarcely any aquatic plant but may be grown in an aquarium, and unless some attention is given to the botanical department, only half the pleasure and instruction it is capable of affording is attained. I cannot agree with Mr. Gosse, that the vegetation of a tank has so strictly a secondary place—"preserved because they cannot be dispensed with,"—for in either a marine or fresh-water vessel the vegetation is a special source of beauty and interest, and fairly divides attention with the animals. Supposing it were impossible to keep animals in such vessels, they would still be acceptable for the formation of aquatic gardens.

Beauty of form and adaptability to confinement are the requisites for this purpose, and the more lakes and rivers are explored, the more the botanical department of the aquarium will be extended, both as to ornament and usefulness.

STRATOIDES ALOIDES.

VALLISNERIA SPIRALIS.

MYRIOPHYLLUM SPICATUM.

POTAMOGETON DENSUS.

RANUNCULUS AQUATALIS.

HYDROCARIS MORSUS RANÆ.

GUDGEON, PRUSSIAN CARP, LOACH, & BREAM.

MINNOW, TENCH, & PERCH.

PLANORBIS CORNEUS, PALUDINA VIVIPARA, LYMNEA STAGNALIS, UNIO PICTORUM, TUMIDUS, & ANODON CYGNEUS.

Use of Confervoid Growths.—But I should object to any frenzy about cleansing tanks. As I said at starting, they should be self-supporting, and if Planorbis or PaludinÆ are used in the proportion of about four of each to every gallon of water, a good view will always be preserved with the use, now and then, of the sponge alone.

Periodical Cleansing.—When a tank has stood twelve-months or more, the water not having been changed at all during the whole time, it may be necessary to turn out the contents and re-stock it. This is not to be done unless the bottom has become black, and the roots of the plants show signs of decay, in fact, not unless it really wants it, and if bottomed with mould it certainly will, and it must be done accordingly. The live stock should be removed by means of a hand-net, the water drawn off by means of a syphon of glass, or gutta percha, and the plants taken out carefully and put by themselves, and then after removing the bottom the glass can be quickly cleaned with the aid of water and fine sand, or rotten-stone.

Exhaustion of Oxygen is made manifest by the fishes coming to the surface to gulp air, and it is also manifested by their retiring to the bottom, and quietly extending themselves on their backs in "horizontal repose"—the repose of death. If too many animals be crowded into the vessel, this will soon happen, and either the number must be reduced or the water must be frequently changed, or we must have recourse to Æration. I consider the two latter remedies a proof of the incompetency of the aquarian—the necessity marks very bad management indeed.

Temperature.—If the aquarium be too much exposed to the heat of the sun in summer, or to the heat of a fierce fire in winter, the water will get tepid, and signals of distress will be shown by the protrusion of many panting mouths at the surface. I find that if the temperature rises above sixty degrees, things do not go on so well. The use of a blind or paper screen is, therefore, essential in summer time.

On winter evenings, when the room is made cozy by blazing blocks of coal, the collection will often show signs of distress. By opening the lower window-sash one or two inches when leaving the room for the night, things may be restored to a normal state in a few hours, and even if the weather is somewhat severe no harm will be done. At the same time intense cold checks the growth of the plants, and throws the fishes into a state of torpor, and the freezing of the water may cause the bursting of the tank.

In summer time, if the tank should get accidentally heated, it may be quickly cooled by wrapping around it a coarse cloth saturated in water, and keeping it wet from time to time. These matters may be much simplified by fixing a small thermometer within the tank below the level of the water.

Dead specimens must be removed as quickly as possible. Bivalves are generally very hardy, but if death happens to one, the production of sulphuretted hydrogen is very rapid, and quickly fouls the tank.

Disease of Fishes.—I have tried numerous remedies for the diseases which beset fishes in winter, but with very little success. When the caudal fin gets coated with a fungoid growth, I have at once cut it off by means of a pair of scissors, and it has usually grown again in a few weeks. I have a couple of minnows now, that were so operated on last winter, they are as hearty as ever, and their tails are quite renewed. Diseased animals should always be removed to a pan of fresh river water, and placed in a quiet cool place, where they will probably recover.

Some healthy plants of Ulva latissima and Enteromorpha compressa are now to be introduced, and the whole left undisturbed for at least a week or ten days, when the stocking with animal life may commence; some of the hardy Actinia being the best of all to start with. But if the aquarian is in a fever to see something alive in the new vessel, he may drop in half-a-dozen Actinia mesembryanthemum, one day after the introduction of the plants, and unless he has made some mistake in the preliminaries they will do well. I have, for the sake of gaining information, placed this anemone in water the instant it was prepared, and without filtering it, without suffering the loss of one; indeed, I have some by me now which a year ago were so operated on; they attached themselves directly, and lived through all the trials incident to a new tank, in which there was not a single drop of natural sea water. Mr. Hall tells me he has, on emergencies, kept them alive for a week in soap-suds, and even in more offensive liquids; and judging by the life the creature leads on the sea shore, now submerged in the cool waters, and now exposed to the burning sun, it is not at all surprising that it has a hardy constitution. Still, this hasty proceeding is not to be recommended; let time develop the powers of the water, let the solar light reach the plants through the green medium of the stained glass, and soon a lovely beading of oxygen bubbles will appear, to indicate that all is right, and then the animals may follow each other in proper order to their domestic home.

If a little real sea-water, even a pint or two, can be obtained to mix with the artificial, the ripening of the latter will be considerably hastened, but it is an interesting fact in the chemistry of the aquarium that, though in the first preparation of sea-water certain of the ingredients are left out of the prescription, in process of time those very same ingredients are to be discovered in it by means of analysis. How do they get there? They are communicated to it by the vegetation, and hence as the water acquires age, like good wine, it increases in strength, and after some months use, will maintain creatures in health that would perish in a day in water recently prepared.

The preparation costs, when prepared from ingredients bought at wholesale price, about three-pence a gallon; but it is a much better plan to purchase it ready prepared, the price then being only four-pence per gallon, or a three gallon packet for one shilling.

CHAPTER III.

COLLECTING SPECIMENS.

To gather specimens is much more pleasant than to purchase them, though an inexperienced person would be pretty sure to bring home, from the sea side, many things utterly unfit for the tank. As a rule, green weeds are the best, the red sorts offer some lovely specimens that do well in an established tank, though none of them succeed in recently prepared artificial water. Brown and olive coloured plants are to be wholly avoided, they wither soon, and spread pollution around them so as to endanger the whole collection.

Ordinary shore gatherings are quite useless for the purpose of the aquarium; the drift is composed of torn specimens of unsuitable plants, and we must seek for specimens at the extreme low-water mark, or in the tide-pools which remain full during the whole of the ebb.

During spring tides is the best time for making collections, and it behoves excursionists who cannot go to the sea side very often, to make their arrangements for such trips, in accordance with the state of the moon as indicated in the almanac. New and full moon are the times in which the tide rises highest and sinks lowest, and much disappointment will be avoided if such proper times are chosen.

Any one who may wish to gather a few specimens for a tank, should be provided with a jar or two, and a basket. A geologist's hammer and a chisel are also necessary. By searching the tide-pools and the boulders at low-water mark, masses of rock will be found covered with weeds of various forms and colours. Select the green grassy kinds, and chip off each with a portion of rock attached, for a sea-weed has no root, and if detached from its rocky site inevitably perishes.

Any one using a little perseverance and judgment may secure, at any part of the coast, sufficient good specimens to stock a tank of moderate size; and if the collection be watched closely for a week or two, the unsuitable sorts will make themselves known by their increasing shabbiness, and must either be removed altogether or treated according to the instructions to be included under the head of management in a subsequent chapter.

A few anemones may be detached from the rocky hollows in which they have ensconced themselves. The common smooth anemone, which may be known in a moment by its near resemblance to a large deep coloured strawberry, should be secured in plentiful numbers, for it is equal to most of its kindred in beauty, and is so hardy as to submit to the harshest treatment unhurt; the more delicate kinds of anemones, especially the white ones, should be obtained in the same way as the weeds; namely, detached with a portion of the rock on which they are found adhering.

In packing the collection for carriage, care must be taken not to allow any pieces of rock to press upon the soft anemones. The whole may be brought away in jars of sea-water, or packed in masses of wet fuci gathered from the beach.

There are very few of the specimens so obtained, but may be as well or better conveyed in wet sea-weed than in water, and if they remain a couple of days so packed, they will take little harm, and may be quickly revived if put into shallow bowls, with a little sea water, and oxygenised by means of the syringe before being placed in the tank. On this head I can say no more here, but must refer the reader for minute instructions to the chapter on specimen collection, in my work on Rustic Adornments, though, what should be sought on the beach, may be judged from the kinds recommended in the succeeding chapters, as well also as to what should be purchased from time to time. Before any specimens are placed in the tank, they ought to be rinsed with sea-water, and any barnacles or sponges scraped off the pieces of rock to which the plants are attached. Any neglect of this will be sure to be followed by the production in the tank of sulphuretted hydrogen, which blackens and kills all before it. Nor should any animal that appears exhausted be consigned to the tank until it has been kept some little time in a shallow bowl with a few weeds, and revived by the occasional use of the syringe. Otherwise, delays are dangerous, and no time should be lost in conveying the several objects to their proper home in the little crystal palace, where blue eyes are to admire, and ruddy lips smile approval of your work.

CHAPTER IV.

THE PLANTS.

As already stated, the green weeds are most suitable, the red next so, but of the brown and olive sorts there are very few that can be kept in a state of health for any length of time. There are only two plants suitable for the commencement of the experiment, and these are Ulva latissima, the common sea lettuce, and Enteromorpha compressa, a delicate grass-like algÆ, of a very cheerful green. Of these Mr. Lloyd and Mr. Hall have always plenty on hand, ready cleaned and prepared for immediate submersion. Artificial water soon acquires the properties of natural sea water under the influence of these plants, which grow rapidly, and disseminate their spores throughout the tank, at the same time giving abundance of oxygen for the support of animal life.

When a few weeks have elapsed Chondrus crispus, better known as "Carrageen moss," may be added, it is a free grower found in plenty on the ledges at extreme low-water mark. The green weeds Codium tomentosum, Cladophora arcta, and rupestris, and Bryopsis plumosa may be considered safe stock when the water has been in use a month or two, but the growth of the more delicate of the Rhodosperms must not be attempted in artificial water for at least three or four months.

The best weeds of the latter class are Phyllophora rubens, Corallina officinalis, and IridÆa edulis. In collecting, no doubt the Dulse, Delesseria alata, and sanguinea, with, perhaps, some of the PolysiphoniÆ will be considered valuable prizes, but they will not succeed in any but experienced hands, for whom this work is not written.

Dasya, Chylocladia, Nitophyllum, Griffithsia, Rhodymenia, and Ptilota will all contribute specimens as time goes on, and opportunity affords for obtaining them. But not one of these lovely weeds of the red class are fit for ordinary aquarian tactics, they are the "florists' flowers" of the aquarian world, and refuse to be domesticated by any but adepts. The exquisitely delicate Griffithsia setacea is perhaps the only one of the above that may be safely used in a well-seasoned tank of artificial water; the other genera seem to be still more delicately constituted and to require their own native element in a state of great purity.

Once more I urge the beginner to be content with Ulva and Enteromorpha at starting, with half-a-dozen plants of each of these, a large and pleasing variety of animal life may be preserved, and in the case of disaster of any kind, these are the most readily restored to health by a little timely and judicious management.

All coarse and dark coloured weeds, however tempting at first sight, are to be avoided. The sprawling tangles that one steps over in traversing the boulders and the slimy masses of sea-weed, everywhere cast upon the coast, are quite unfit, however fine the specimens, or strong the desire to possess them. Neither must much value be attached to any weed cast up by the surge. The only trustworthy specimens are those chipped from the rock in situ and brought away without being detached from their natural basis.

CHAPTER V.

THE ANIMALS.

Though Anemones take precedence in the order of stocking, and frequently monopolise the tank—for, after all, these are the main attraction of most marine aquaria—yet, as they do not stand the highest in the order of nature, we must recount zoologically what creatures are best fitted for domestication, and in another chapter give directions as to their selection and management.

Fishes take the first place, because they are the highest forms of life admitted to the marine tank; but they are the last introduced, because, being more delicately organized than the tribes beneath them, they require either real sea-water, in a state of high preservation, or artificial water of some months' seasoning, and good management.

The fishes best adapted for tank life are the queer-looking gobies, the lively blennies, small specimens of wrasse, rockling, and eel. The grey mullet is a pretty fish, but not to be domesticated without some difficulty. Some kinds of flat fish may be kept in tanks, but beginners had better have nothing to do with them. Small sticklebacks may be taken in plenty by means of a hand-net in quiet tide-pools, and do well in the tank, but they are pugnacious, and harass less vigorous creatures; so that some judgment is required in grouping them.

Mollusks.—The common Periwinkle is useful as a cleaner, and interesting also to those who find pleasure in contemplating the startling resources of Divine Wisdom, as evidenced in the construction of the most humble creatures. The winkles accomplish for the marine-tank what the fresh-water snails do for the river-tank, they scrape confervoid growths from the glass, and so help to preserve the crystalline aspect of the tank. All the species of winkle are capable of domestication, Littorina littorea, the common sort, and E. littoralis, a pretty little fellow, with a gaily mottled hybernaculum.

The Trochus tribe, better known as Tops, are also useful as cleaners, and in appearance are more stately and ornamental than the winkle, their cleanly marked conical shell attracting as much attention from strange eyes as the noble planorbis corneus does in the river-tank. Generally speaking, univalves are more easily kept than bivalves; many of the latter are apt to die off, and cause some amount of putrescence before their demise is discovered.

Crustacea are lively and interesting, but of course small species, or small specimens of large species are the most suitable. The Soldier crabs (Pagurus) and the Swimming crabs (Portunus) are eminently suitable, so is the pretty Strawberry crab, Eurynome aspera, and the interesting Broad-claw Porcellana platycheles. Shrimps and prawns may be used freely; they are lively creatures, and much more beautiful when seen in motion, gliding about like ghosts, than would be imagined by any one judging from the appearance of specimens on the table.

Annelides afford us the interesting serpulas, some pretty sea-worms, and the terebellas, all easy of preservation, and remunerative of the attention bestowed upon them.

Zoophytes.—This is the division from which the most prominent attractions of the tank are derived. Of these the Actinia take precedence of all the ordinary inhabitants of the tank, because of their exquisite beauty, strange habits, and still more general certainty attending their preservation.

Actinia mesembryanthemum is the common Smooth Anemone which abounds on every part of our coast. Its colour varies considerably, but it is usually of a deep, warm chocolate, dotted all over with small yellow spots, and when closed has the best possible resemblance to a large ripe strawberry. Every stone about the sea-beach is studded with this anemone, and a collector may secure any required number in a few hours, slipping each from its base, and dropping the whole into a jar with some fragments of fresh wet weed to keep them moist.

When it expands, a circle of bright blue beads, or tubercules, resembling torquoises, is seen just within the central opening; and, as the expansion proceeds, a number of coral-like fingers, or tentacles, unfold from the centre, and at last spread out on all sides like the hundred petals of a Peri flower, reminding one of Hinda's boon:—

This anemone will remain expanded for many days together, if the water be kept bright and pure; but if the tank gets fouled, it closes and falls from its foothold, and perishes if not attended to. It is the hardiest of all the creatures that are regarded as stock for tanks, and survives many a wreck unhurt. To induce it to climb up the sides of the vessel, let it be placed with its base lying partly against it, or bring it close to a stone in the centre, and it will be pretty sure to attach itself where you desire in the course of a few days. This last suggestion applies to anemones generally; novices are surprised to find how well disposed the creatures are in a well-kept tank. The disposition dates from the day of introduction, for none of this tribe are fond of locomotion; and the arrangement of them for effect, depends upon whether you drop them quietly just in contact with the spot you wish them to adhere to, or throw them in pell mell, to cling to the weeds or to each other.

A. anguicoma, or the snaky-locked anemone, is a pretty but curious creature. It is all arms, just as a crab is all claws; but so delicate in form, so beautifully striped in the tentacles, that it stands quite apart in the tank as a thing unique. When found on the sea-shore, as it is usually after a storm, it is a flat-looking, smooth mass, of a brown tint, delicately striped with yellow and white. After a few days' residence in the tank, it begins to expand, and rises to so tall a figure, especially in the twilight, that it appears quite a different creature to that introduced a few days before. In fact, its actual bulk is increased vastly by expansion. It is constantly expanded.

A. Bellis is another good species. It is a delicate pink and brown and pink and white anemone, and certainly does resemble a daisy very closely indeed. Though much prized it is not rare. Mr. Lloyd usually has abundance of them on sale, at a shilling each, and a few should be used to give variety to the collection. In newly-made marine-water it will not do at all; but if it falls into the possession of an aquarian who has no ripe tank at hand for it, it may be kept for weeks in a shallow pan.

If anything goes wrong with this kind, it throws out a number of white threads, and shrinks out of form, and perishes in a few days; but once obtained in a sound state, and carefully treated at the outset, it is as hardy as mesembryanthemum, and more readily expanded at all seasons than most of its compeers.

Actinia Gemmacea.—This is a delicately-constituted anemone, that displays itself freely only in the most pure sea-water, in which there is abundance of oxygen. It is quite unfit for early experiments, but well repays the trouble it occasions when it can be successfully kept. A few weeks since I had the pleasure of witnessing the birth of a large cluster of this pretty anemone in the extensive collection of Mr. Lloyd, at Portland Road. To the naked eye they appeared mere flocculent specks, but a lens revealed their true form as they adhered to the side of the vessel; every one of the little creatures, with its tentacles expanded, a real microscopic gem, combining the grace of a flower with the tinting of a pearl, and the delicate volition of a new-born animal.

When full grown, the gemmed anemone is very showy in its tintings. Pink, yellow, and grey are all beautifully blended, and the rows of glands which reach from the margin to the base, add their dots of white to the garments of this tiny harlequin. The disk is brilliantly coloured, scarlet, green, and orange, shading into each other, and occasionally mingled with half-tints of every colour of the rainbow. The lip is usually of a vivid green, and the tentacles exhibit rose, violet, orange, and white on their upper surfaces. In the cut, this anemone is seen partially closed on a piece of stone behind two specimens of A. Bellis.

Actinia Crassicornis is another of the more delicate kinds, that dies speedily, unless treated with great care, and in a well-established tank. It is very abundant on every part of our coasts, and must be removed with the stone to which it is found adhering; for if removed, or even handled, it perishes in the course of a few hours. It is, however, too beautiful not to be worth an effort to preserve it; and, if the tank is in good condition, it will be well to obtain two or three specimens, and watch them narrowly, so that if any of them die, they may be immediately removed to avoid polluting the water.

The colour of this anemone varies considerably in different specimens. Violet and amber shades frequently predominate in the tentacles. Sometimes the disk is of a pearly white, at others of a warm fawn or bright orange and scarlet, sometimes a deep crimson or a dull chocolate; while the tentacles vary from pure white to dark brown, dingy fawn, and brick-dust red. The latter organs are very numerous and tubular. When irritated, the creature has the power of attaching the tentacles to the object which annoys it, and in this way it frequently clings to the fingers when handled, and at the same time squirts out numerous jets of water, until it is quite empty and collapsed.

Actinia Parasitica.—This is a good aquarium species, on account of the ease with which it may be kept. It is a species that the rambler on the sea-beach will not be at all likely to meet with, for it is truly pelagic in its habit. It is only to be obtained in a state fit for the aquarium by means of the dredge, and when so obtained it lives a long while in confinement.

The most interesting feature in the history of this zoophyte is that of its usually inhabiting the shell of some defunct univalve mollusk, such as the Trochus, or the great whelk, Buccinum undatum. This is not the most curious part of its history. The anemone loves company, and in the same shell as that on which it extends itself, we usually find a pretty but pugnacious crab, Pagurus bernhardus. To the anemone the crab acts as porter; he drags the shell about with him as if it were a palanquin, on which sits enthroned a very bloated but gaily-dressed potentate, destitute of power to move it for himself. Like most lazy dignitaries, this showy Actinia attracts more attention than the lively servant who drags it from place to place, for its form and colouring are beautiful in the extreme.

It is of large size, frequently attaining to a height of four inches with a diameter of two and a half. Mr. Gosse's description of this fine creature is so minute and interesting, that I must beg the reader to accept it in preference to any that I can write. He says, the "ground colour is a dirty white, or drab, often slightly tinged with pale yellow; longitudinal bands of dark wood-brown, reddish, or purplish brown, run down the body, sometimes very regularly, and set so closely as to leave the intermediate bands of ground colour much narrower than themselves; at other times these bands are narrower, more separated, and variously interrupted or broken. I have seen a variety in which the bands took the form of chains of round dark spots, the effect of which was handsome. Immediately round the base the bands usually subdivide, and are varied by a single series of upright, oblong spots of rich yellow, which are usually marginal, with deeper brown than the bands. The whole body is surrounded by close-set faint lines of pale blue, sometimes scarcely distinguishable, except near the summit, where they cut the bands in such a manner as to form, with other similar lines which there run lengthwise, a reticulated pattern.

"The disk is somewhat wider than the diameter of the body, which it over-arches on all sides. Its margin is somewhat thin, and occasionally thrown into puckered folds to a small extent. Thus it appears to approach the peculiar form of A. bellis. The disk is nearly flat, or slightly hollowed, but rises in the centre into a stout cone, in the middle of which is the mouth, edged with crenated lips. The tentacles are arranged in seven rows, of which the innermost contains about twenty, the second twenty-four, the third forty-eight, the fourth ninety-six; the other rows are too closely set, and too numerous to be distinguished. Probably the whole number of tentacles, in a full-grown specimen, may be considered as certainly not less than 500."

Actinia Dianthus.—This is the Plumose anemone of Mr. Gosse, and sometimes bears the very appropriate name of the Carnation anemone. It is the most superb of our native Actinias—a gorgeous creature, that in itself more than realizes our brightest imaginings of the hidden splendours of the ocean floor, and of the gems that bedeck the caves of Neptune. How will future poetry be affected by the revelations of the aquarium, and how far will the sober facts of scientific research influence the pictures and the incidents of romance? Even Keats's glowing description of "God Neptune's palaces" becomes tame in the presence of this splendid creature, which carries the fancy—

----"far below
The sea-blooms and the oozy woods, which wear
The sapless foliage of the ocean,"

and peoples the dark slippery slopes with wondrous forms of life and beauty, as if the lost argosies and the perished navies, that have found a common sepulchre in the waters, had given up their myriad souls to the conjuration of Glacus and Scylla, and all the dizzy troop of ocean spirits. It is, verily, a wondrous creature, of enormous size, and so delicately tinted, so light and fairy-like in structure, so constantly expanding and retracting its thousand delicate fingers, like the Indian blossom that the Brahmin believes to be endowed with life, that it never ceases to attract the attention of the coldest, and fill the ardent lover of nature with—

----"the amaze
Of deep-seen wonders."

I have before me now five specimens of this splendid anemone. They are all expanded, and they glow in the sunshine like huge carnations of the brightest amber, one of them verging towards a pure white. Two of these are represented in the engraving, surrounded by fronds of Delesseria sanguinea, Callithamnium, and Griffithsia. The one attached to the perpendicular side of a stone is of the golden amber variety; when fully expanded it forms a massive column of five inches in height, at least, and nearly three in diameter. From the summit of the column the tentacles fringe over in rich masses, like the petals of a monster carnation, all of them in motion as if seeking something which they cannot find. The tentacular disk is deeply frilled and puckered, and constantly changes its outline under the capricious will of the animal; while, at the same time, the tentacles arrange and rearrange themselves into most confusing forms; then again expand to their utmost, and expose the oval mouth and crenated lips, of a pellucid softness that would appear as if chiselled out of alabaster, were they not constantly varying their form, and every instant undergoing a new "sea-change." The tentacles are very regularly arranged around the mouth, but towards the margin they thicken and thicken till they form a dense fringe that overlaps the column, and continues ever waving as if stirred by trembling ocean currents. If I now strike the glass with my finger, or even breathe lightly on the surface of the water, they are all withdrawn, the stately column shrinks down into a mass of pulp, and in a few moments swells out like a globular balloon, so tight and large that one momentarily expects it to burst. For an instant only it remains thus blown out; it is suddenly constricted as if clasped by a cord, and it then becomes double like a pair of globes placed one upon the other, and flattened where they meet. Suddenly the imaginary girdle slips downward, disappears, then it contracts, rises again, assumes its noblest proportions, expands its thousand fringes, all delicately waving above the dark stones, and is once more as lovely, or lovelier than ever.

This has been described as one of the most tender of its class, but I have long been convinced that it is comparatively hardy, and may be preserved with very great certainty. So long as the water is kept moderately pure, by an occasional filtering through charcoal—which aerates and purifies at the same time—it lives and prospers, occasionally moving from place to place, but almost always expanded, and every instant assuming some new form. It is, however, so far delicate that, if frequently disturbed, it is sure to perish. When removed from its native "oozy bed" it should be kept on the stone or shell to which it is found attached, until it floats off of its own accord, and fixes itself elsewhere. When handled it throws out a number of white threads, which are afterwards withdrawn.

CHAPTER VI.

WHAT IS AN ANEMONE?

It is very strange that where the animal and vegetable kingdoms meet, the forms should assume such close resemblances to each other, as to make it frequently a matter of difficulty to determine to which of the two great departments some special specimen shall be assigned. Here are the lovely sea-flowers—flowers only in name and appearance—representing the lowest links of animal life and pointing to that last link where the animal and the vegetable blend into one, bearing all the outward resemblances to flowers from which they take their appropriate names, yet all of them strictly animals, endowed with volition, and in their general organization assimilating to the extensive series of zoological orders which stand above and beneath them. The sea anemones are animals of the lowest class—zoophytes of the great Cuverian division of Radiata. It is in this division that animation is seen to tremble and flicker in the socket, and to become gradually extinguished as we descend the scale and approach the confines of the kingdom of verdure. Here, then, life has its lowest if not least lovely forms; the individuals have less individuality, many of them live in groups and clusters, and increase in a semi-vegetative manner by gemmation, or the formation of bud-like germs, while others generate by spontaneous fissure, and break up into numerous forms, each of which rapidly acquires the form of the parent, and proceeds in the same way to increase its kind.

The Radiata are so named on account of the ray-like form generally observable in the structure of the creatures; in some the ray-like divisions give such a speciality to the structure as to distinguish them at once as members of this division; as in the star-fishes, for instance, in which the intestinal canal branches out from the body into the several rays which form the star, and in the anemones, in which the relation to the tribe is at first sight perceptible in the tentacles which surround the mouth, and which render it so exquisitely beautiful as a marine representative of a true flower.

But though the term Radiata is applied to an extensive division, in which the members have many characteristics in common with each other, the ray-like form is not equally distinguishable in all. In some tribes there is a tendency to associate into groups, in which each individual has a certain degree of connection with the rest, as in the infusoria common in our brooks, and indeed most of the polypes which thus live in community. The resemblance to vegetable forms is, however, common to a great portion of the Radiata, and those in which this resemblance is the strongest are grouped together under the general designation of Zoophytes. In Zoophytes, the leading feature of a radiate animal is very distinctly observable, and that leading feature is the arrangement of the vital organs around a centre, the organs composing the rays of the imaginary star, or the petals of the imaginary flower, to which the mouth or stomach is the centre.

Among the Zoophytes we meet with many of the creatures which have the greatest attraction for the student of the Aquarium. The brooks supply him with the curious hydra, the seven-headed monster that perpetuates one of the triumphs of Hercules—withal a beautiful and wondrous creature, that may be cut in pieces, turned inside out, or even thrust one animal within the other, and still remain the same. The sea supplies the madrepores, the builders of ocean-reefs, and the founders of islands and continents; as it also supplies the sea anemones of more than a hundred species, from the curious Edwardsia vestita, here figured, from the first seen in this country, at present in the collection of Mr. Alford Lloyd, to the familiar members of the genus Actinia, obtainable everywhere on our coasts.

The true Zoophytes have all, more or less, the plant-like form, and they readily separate into two great classes, namely, the Anthozoa, or flower-life, and the Polyzoa, or many-life, in which the individuals are associated together in numbers. They are all inhabitants of water, are all destitute of joints, lungs, nerves, and proper blood-vessels; but in the place of nerves possess what naturalists call an irritable system, in obedience to which they expand or contract at will. At the upper part of the body is situated the mouth, which is usually surrounded with tentacles, which are mostly used in securing prey. There is no alimentary duct, for the stomach has the form of a simple sac, the aliment being injected and ejected by the same orifice.

The Anthozoa comprise animals which are perfect in themselves, and these are mostly soft bodied, having no shelly covering, and are protected only by the leathery integument which surrounds them, and the thousand weapons of offence and defence which they expand in the form of tentacles. Among the Polyzoa we meet with creatures that encase themselves in horny shells, or calcareous coatings, such as the Madrepores, which, like submarine masons, elaborate the carbonate of lime which the sea supplies them with, into shelly retreats; and the tubed Hydrioda, which construct winding galleries and convoluted tubes, from the mouths of which they protrude their fans and tentacles in search of prey.

Among the higher orders of the Radiata we meet with the strange Sea Cucumbers and the Sea Urchins, and the Star fishes; and among the lower orders the Sea Anemones, many forms of which are described and figured in these pages.

A Sea Anemone, then, is a Zoophyte belonging to the class Anthozoa, or flower-life, and the order Helanthoida, or sunflower-like creatures. The central disk of the sea flower is composed of the lips, which open into a mouth which communicates with the simple sac which constitutes the stomach, and the petals and fringes which surround it—now like the anemone, now like the sunflower or the mesembryanthemum, or the richest carnation that ever won for a florist a golden prize. The further subdivision is dependent on the details of individual structure; and a large section—that of Actinia—comprehends most of those on which the aquarian bestows his patience in the work of domestication.

The ActiniadÆ—so named from the Greek—signifying a ray of the sun—are an extensive family, of which more than a hundred species are to be found on our coasts, or in the deep bays adjacent. But few of these are suited for confinement in aquaria, and of these the chief are the Actinia proper, the Sagartia, most of which are usually grouped with the Actinia; the Anthea Cereus; the splendid Adamsia Palliata, which is the only known species of the genus to which it belongs; and a few of the Bunodes, Edwardsia, and Corynactis.

In all the varieties of sea anemones the mode of life is similar; they are carnivorous, and obtain their prey by means of the ever-seeking tentacles that search the lymph around them, and secure sometimes fishes, at others mollusks, but more frequently the minute forms of infusorial life that abound in the sea, or in the artificial water of the tank. The mode of reproduction is by ova, which are sometimes vivified in the body of the parent, and not only do they give birth by ejection from the mouth of a numerous progeny, but actual divisions of the body may be made, and each division will acquire completeness. Dr. Johnson relates several instances in proof of this, one of which is particularly interesting. A specimen of Actinia crassicornis had swallowed a large, sharp-edged shell, which so completely stretched the body of the creature as if on a ring of wire, as virtually to cut it into two equal parts. Thereupon it put out from the base a new disk, with mouth and tentacles, and became at once a double anemone, to which the gorged shell served as an intermediate base of attachment. Dr. Cocks has seen specimens of Bunodes alba acquire complete forms in duplicate when the original specimen has been severed into two or more parts; and there are many other instances on record of this plant-like division of sea anemones having been observed.

Though apparently immobile, there are few species but possess some power of locomotion. We frequently meet with anemones attached to stones, sand, or shells, by a wide sucking base, and if some species be moved from their chosen site, certain death is the result. Yet in by far the greater number there is a distinct faculty of progression—the anemone, by a slow, gliding motion, gradually removes itself, and climbs up the sides of the vessel, or takes possession of a tuft of weed, or shifts from one stone to another, or fairly leaves go of its anchorage, and floats like a balloon upon the surface. Thus low in the scale as they are, they possess will, and a power of obeying it; they have their organs of locomotion, of attack, and defence; though naked, they are armed for combat on an equality with their enemies, and succumb at last to man—the universal destroyer and appropriator—who turns them to account as food, or treasures them as gems of beauty that gratify his eye, and even win over the affections of his heart, while they lead him to contemplate the variety and profuseness of that life to which the Almighty has given so many wondrous forms, and instincts, and economies, every one of which proclaims—

"The hand that made us is divine."

CHAPTER VII.

GENERAL MANAGEMENT.

I shall in this Chapter only notice such particulars in the management of aquaria as belong especially to the marine department, since some of the directions given in the former division of the work apply to tanks of all kinds, and need not be repeated. When preliminary difficulties have been surmounted, the matter of first importance is the selection of the stock, and its arrangement in accordance with just principles.

Grouping.—In Chapters IV. and V. I have enumerated the kinds of animals and plants most suitable for aquaria, and must now caution the beginner against the injudicious grouping together of creatures of dissimilar habits. Anemones may, as a rule, be kept together. The several species agree well, and seldom or rarely injure each other; but star-fishes and crabs are best kept in vessels apart from them. Star-fishes are very destructive, and readily absorb the bodies of mollusks out of their shells. If exception is to be taken to any particular anemone, I think the grand plumosa must suffer by it; for this noble creature gives off a flocculent exudation, which seems injurious to other kinds. I have generally kept the plumose anemone in company with A. mesembryanthemum, A. bellis, troglodytes, and others, without perceiving any bad result; but I have always been careful to remove the slimy exuvia daily, by means of the dipping tube. Respecting mollusks, and especially trochus and most bivalves, it should be borne in mind that they are apt to die off rapidly, and to cause a putrescence of a most obnoxious character, which soon spoils the water, and causes a general havoc. Another remark applicable to mollusks is this, that the Eolids—members of the Nudibranch, or naked mollusks—are destructive of anemones, and delight in nibbling holes in their coats, or eating off their tentacles; whereas the pretty doris may be kept as long as it will live, in company with the most delicate creatures, without offering offence to any. The more varied the collection the more is our interest in its examination increased; and the possessor of a single vessel, or of a tank, and a few auxiliary jars, will be naturally anxious to preserve representatives of as many tribes as possible; and this may be done, to a certain extent, by appropriating the vessels to such creatures as agree amicably in confinement. It is, indeed, possible, if a vigilant watchfulness be observed, to bring together and preserve, for a length of time, specimens of creatures that are naturally antagonistic to each other; but where Crustaceans can be kept apart in one vessel, with perhaps a few fish, such as gobies and blennies—a second appropriated to anemones and madrepores—and a third to mollusks, madrepores, and tubeworms—there will be the greater certainty of success, and less supervision will be required. Crabs are very annoying to anemones, as they scratch and sprawl over the delicate creatures; and shrimps, prawns, and fishes frequently fall a prey to the barbed threads and the tentacles of the anemones; the latter also frequently take possession of the mouths of the cells of tube worms, and of the openings of the shells of mollusks, and thus suffocate the inmates, and insure their own death by the putrescence that ensues upon the demise of their victims.

Sulphuretted hydrogen.—When the death of an animal occurs, the water soon gets putrid; the stones assume a rich brown tint, the sides of the vessel lose their brightness, and an effete odour indicates the cause of the disturbance.

Preservation of the Water.—To those who live near the sea it is an easy matter to change the water, as soon as it shows signs of disorganization, but since the majority of those who will consult this work will have to depend on Mr. Bolton's marine salts, it is necessary that I should suggest in what way, and in the best manner, the water may be preserved, not only to avoid the expense, but the trouble attending a new supply. Charcoal is the grand restorative, purifier, and preserver; and for this department of aquarium management may be regarded as the ne plus ultra.

In the second Chapter of this part of the work I have described the process necessary in preparing artificial water by means of the filter. Now, whatever happens, set the filter to work, it will revive exhausted stock by Æration, destroy sulphuretted hydrogen by the contact of the water with the charcoal, and remove all fragments of decayed weed, flocculent threads given off by anemones, and restore the whole to strength and purity. I repeat what I have already said more than once, that the necessity for changing the water is a proof of injudicious management; every new supply is a witness of the aquarian's lack of skill, as Mr. Lloyd wisely says, "properly managed, the water and other contents of an Aquarium may be kept unchanged for periods indefinitely prolonged." For the sake of aquarian science, I do implore the student to surmount any and every difficulty, rather than own the weakness implied by changing the water.

Aeration is frequently referred to in works on the Aquarium. It is at variance with the self-sustaining theory, and there is something wrong where it is wanted. If the tank is stocked before the plants are well established, or if overstocked with a crowd of animal life, or if sulphuretted hydrogen be produced and make its presence manifest to the nose, then Æration may be necessary. A cup or jug may be used to dip water from the surface, and pour it back again from a height in a thin stream. Or a filter may be placed over the tank and filled from the surface, and the water allowed to drip back. But the most efficient instrument is a common syringe. This is simply to be charged at the surface, and discharged again with some force, so as to send a stream of oxygenised water deep into the tank. The process should be repeated for a quarter of an hour at least.

Filter.—A bee glass or a common flower-pot may soon be made into a filter. Thrust a piece of sponge into the hole in the bottom, and upon it lay a stratum of washed sand and powdered charcoal. Pass the water through it, and it will be purified, and saturated with oxygen at one and the same time. With the river-tank, the simplest way of reviving exhausted stock is wholly or partially to change the water; with marine stock, such a change is not easy, and the filter comes more legitimately into use. As already remarked, the necessity for Æration marks error in management, except when you have stock for which no proper receptacle is at hand, or any such special contingency.

Decay of Plants.—The sea-weeds are apt to acquire a pale tint, which is the first evidence of decay. This generally happens with the first marine stock, when Ulva and Enteromorpha are used to season artificial water. When the water gets ripe, the plants recover and make healthy growth, but if many white fronds appear, lift out the blocks on which the plants are fixed, trim away the decayed portions with a pair of scissors, and then scrub the stones with a small brush in a little waste sea-water, and replace them; they will soon recover. If red plants have been hurriedly introduced, and decay manifests itself, remove them at once, and waste no time in attempts at revival. Mr. Lloyd will supply a new stock for a trifle, and it is better to begin de novo than to attempt to cure the incurable.

Death of Anemones.—If you observe any of the anemones to shrink up like button-covers, lift them out into a shallow vessel, and aerate them liberally. When small beads of gas appear upon them, you may rest assured that they have gone beyond the—

"Bourne from whence no traveller returns;"

for the first outward proof of death is the formation of bubbles of sulphuretted hydrogen upon their bodies, and they should be removed before this spreads and devastates the tank.

Removal of Objects.—For the removal of portions of decayed weed, and other small noxious bodies, from the bottom, a glass tube of ¼ or ½ inch diameter, open at both ends, will be found very useful. Place a thumb or finger on the top of the tube, and thrust it down over the object to be removed, then remove the finger, and the matter will rise in it. Lift the tube up to the surface of the water, then place the finger on again, and lift the whole away. The advantage of this plan is, that no disturbance is occasioned. A pewter spoon bent to a right angle, and attached to a stick is very useful for lifting up objects that are too large for the dipping tube.

Density of the Water.—Evaporation causes the pure water to escape from the Aquarium, and hence there is a constant tendency to increase of density—in fact, if left alone, the water in the tank soon gets too salt. To prevent this, additions of pure spring or distilled water must be made from time to time, and the amount regulated by a specific gravity bubble, which it would be as well to leave at all times floating in the tank. This instrument registers the density much more accurately than the hydrometer, for it is more delicate in its determination of a balance. I find it expedient to use two bubbles of different specific gravities—one which just floats when the water is sufficiently fluid, and another which just sinks when it is sufficiently saline. The movement of either indicates at once the exact cause, and enables the aquarian to regulate the density to perfection.

Green Stain.—I have never been troubled with confervoid growths in tanks filled with artificial water, though the same water has been in use during periods of from a few months to two years. When it occurs, the mollusks are the natural remedy, the sponge the artificial one. But a strange affection—which I think is most common in spring—is the sudden occurrence of a green turbidity, which destroys the translucence, and for which neither sponge nor winkle can afford a remedy. It is not a growth on the side of the vessel, but a green stain pervading the water, as if a green colouring matter had been dissolved in it. Mr. Gosse says, "it is vegetable in its origin, and arises from an infinite number of the spores (or seeds) of green AlgÆ dispersed through the fluid, and held in suspension there." Mr. Gosse further says, "I know of no cure for this," but he quotes Mr. Lloyd's experience as demonstrative of its curability by placing the water "in a dark closet for two or three weeks."

From the experience I have had in this matter, I have no hesitation in saying that the filter will be found an instantaneous remedy; the water need not be drawn off at all, but kept filtering through charcoal by frequent filling of the filter from the surface. In May last, a tank of mine became suddenly opaque, though otherwise in excellent order. The collection was valuable, and a disturbance of it would have been attended with risk. I suspended an old flower-pot half filled with fresh charcoal and sea-side grit above it, and set the filter to work. As fast as the filter ran out, I filled it again from the tank, without disturbing anything, and a change for the better was perceptible in an hour. Two days after, the water was as bright as ever, and the stock in the finest possible condition, owing to the brisk Æration they had gained by the experiment.

Feeding.—Anemones generally do not require feeding, though the Daisy and the Dianthus will greedily partake of small fragments of oyster and minced mutton, and some other kinds will occasionally eat of the same food; but I cannot recommend the beginner to feed Anemones, for, in a well managed tank, Infusoria are sufficiently abundant to provide them with all they require, and food not eaten soon decays, unless speedily removed. Crabs and prawns positively require feeding, and Madrepores may be fed for amusement. Small fragments of the lean of raw meat should be given, or the flesh of a cooked prawn, and twenty-four hours afterwards, the undigested morsels should be removed.