Part 10

To this subject Mr. Gosse’s book, “The Aquarium,” is principally devoted, though it contains, besides, sketches of coast scenery, in his usual charming style, and descriptions of rare sea-animals, with wise and goodly reflections thereon. One great object of interest in the book is the last chapter, which treats fully of the making and stocking these salt-water “Aquaria;” and the various beautifully coloured plates, which are, as it were, sketches from the interior of tanks, are well fitted to excite the desire of all readers to possess such gorgeous living pictures, if as nothing else, still as drawing-room ornaments, flower-gardens which never wither, fairy lakes of perpetual calm which no storm blackens,—

οὐτ’ ἐν θέρει, οὐτ’ ἐν ὁπώρῃ.

Those who have never seen one of them can never imagine (and neither Mr. Gosse’s pencil nor my clumsy words can ever describe to them) the gorgeous colouring and the grace and delicacy of form which these subaqueous landscapes exhibit.

As for colouring,—the only bit of colour which I can remember even faintly resembling them (for though Correggio’s Magdalene may rival them in greens and blues, yet even he has no such crimsons and purples) is the Adoration of the Shepherds, by that “prince of colorists”—Palma Vecchio, which hangs on the left-hand side of Lord Ellesmere’s great gallery. But as for the forms,—where shall we see their like? Where, amid miniature forests as fantastic as those of the tropics, animals whose shapes outvie the wildest dreams of the old German ghost painters which cover the walls of the galleries of Brussels or Antwerp? And yet the uncouthest has some quaint beauty of its own, while most—the star-fishes and anemones, for example—are nothing but beauty. The brilliant plates in Mr. Gosse’s “Aquarium” give, after all, but a meagre picture of the reality, as it may be seen in the tank-house at the Zoological Gardens; and as it may be seen also, by anyone who will follow carefully the directions given at the end of his book, stock a glass vase with such common things as he may find in an hour’s search at low tide, and so have an opportunity of seeing how truly Mr. Gosse says, in his valuable preface, that—

“The habits” (and he might well have added, the marvellous beauty) “of animals will never be thoroughly known till they are observed in detail. Nor is it sufficient to mark them with attention now and then; they must be closely watched, their various actions carefully noted, their behaviour under different circumstances, and especially those movements which seem to us mere vagaries, undirected by any suggestible motive or cause, well examined. A rich fruit of result, often new and curious and unexpected, will, I am sure, reward anyone who studies living animals in this way. The most interesting parts, by far, of published Natural History are those minute, but graphic particulars, which have been gathered up by an attentive watching of individual animals.”

Mr. Gosse’s own books, certainly, give proof enough of this. We need only direct the reader to his exquisitely humorous account of the ways and works of a captive soldier-crab, {190} to show them how much there is to be seen, and how full Nature is also of that ludicrous element of which we spoke above. And, indeed, it is in this form of Natural History: not in mere classification, and the finding out of means, and quarrellings as to the first discovery of that beetle or this buttercup,—too common, alas! among mere closet-collectors,—“endless genealogies,” to apply St. Paul’s words by no means irreverently or fancifully, “which do but gender strife;”—not in these pedantries is that moral training to be found, for which we have been lauding the study of Natural History: but in healthful walks and voyages out of doors, and in careful and patient watching of the living animals and plants at home, with an observation sharpened by practice, and a temper calmed by the continual practice of the naturalist’s first virtues—patience and perseverance.

Practical directions for forming an “Aquarium” may be found in Mr. Gosse’s book bearing that name, at pp. 101, 255, _et seq._; and those who wish to carry out the notion thoroughly, cannot do better than buy his book, and take their choice of the many different forms of vase, with rockwork, fountains, and other pretty devices which he describes.

But the many, even if they have Mr. Gosse’s book, will be rather inclined to begin with a small attempt; especially as they are probably half sceptical of the possibility of keeping sea-animals inland without changing the water. A few simple directions, therefore, will not come amiss here. They shall be such as anyone can put into practice, who goes down to stay in a lodging-house at the most cockney of watering-places.

Buy at any glass-shop a cylindrical glass jar, some six inches in diameter and ten high, which will cost you from three to four shillings; wash it clean, and fill it with clean salt-water, dipped out of any pool among the rocks, only looking first to see that there is no dead fish or other evil matter in the said pool, and that no stream from the land runs into it. If you choose to take the trouble to dip up the water over a boat’s side, so much the better.

So much for your vase; now to stock it.

Go down at low spring-tide to the nearest ledge of rocks, and with a hammer and chisel chip off a few pieces of stone covered with growing sea-weed. Avoid the common and coarser kinds (fuci) which cover the surface of the rocks; for they give out under water a slime which will foul your tank: but choose the more delicate species which fringe the edges of every pool at low-water mark; the pink coralline, the dark purple ragged dulse (Rhodymenia), the Carrageen moss (Chondrus), and above all, the commonest of all, the delicate green Ulva, which you will see growing everywhere in wrinkled fan-shaped sheets, as thin as the finest silver-paper. The smallest bits of stone are sufficient, provided the sea-weeds have hold of them; for they have no real roots, but adhere by a small disc, deriving no nourishment from the rock, but only from the water. Take care, meanwhile, that there be as little as possible on the stone, beside the weed itself. Especially scrape off any small sponges, and see that no worms have made their twining tubes of sand among the weed-stems; if they have, drag them out; for they will surely die, and as surely spoil all by sulphuretted hydrogen, blackness, and evil smells.

Put your weeds into your tank, and settle them at the bottom; which last, some say, should be covered with a layer of pebbles: but let the beginner leave it as bare as possible; for the pebbles only tempt cross-grained annelids to crawl under them, die, and spoil all by decaying: whereas if the bottom of the vase is bare, you can see a sickly or dead inhabitant at once, and take him out (which you must do) instantly. Let your weeds stand quietly in the vase a day or two before you put in any live animals; and even then, do not put any in if the water does not appear perfectly clear: but lift out the weeds, and renew the water ere you replace them.

This is Mr. Gosse’s method. But Mr. Lloyd, in his “Handbook to the Crystal Palace Aquarium,” advises that no weed should be put into the tank. “It is better,” he says, “to depend only on those which gradually and naturally appear on the rocks of the aquarium by the action of light, and which answer every chemical purpose.” I should advise anyone intending to set up an aquarium, however small, to study what Mr. Lloyd says on this matter in pp. 17–19, and also in page 30, of his pamphlet; and also to go to the Crystal Palace Aquarium, and there see for himself the many beautiful species of sea-weeds which have appeared spontaneously in the tanks from unsuspected spores floating in the sea-water. On the other hand, Mr. Lloyd lays much stress on the necessity of aërating the water, by keeping it in perpetual motion; a process not easy to be carried out in small aquaria; at least to that perfection which has been attained at the Crystal Palace, where the water is kept in continual circulation by steam-power. For a jar-aquarium, it will be enough to drive fresh air through the water every day, by means of a syringe.

Now for the live stock. In the crannies of every rock you will find sea-anemones (Actiniæ); and a dozen of these only will be enough to convert your little vase into the most brilliant of living flower-gardens. There they hang upon the under side of the ledges, apparently mere rounded lumps of jelly: one is of dark purple dotted with green; another of a rich chocolate; another of a delicate olive; another sienna-yellow; another all but white. Take them from their rock; you can do it easily by slipping under them your finger-nail, or the edge of a pewter spoon. Take care to tear the sucking base as little as possible (though a small rent they will darn for themselves in a few days, easily enough), and drop them into a basket of wet sea-weed; when you get home turn them into a dish full of water and leave them for the night, and go to look at them to-morrow. What a change! The dull lumps of jelly have taken root and flowered during the night, and your dish is filled from side to side with a bouquet of chrysanthemums; each has expanded into a hundred-petalled flower, crimson, pink, purple, or orange; touch one, and it shrinks together like a sensitive plant, displaying at the root of the petals a ring of brilliant turquoise beads. That is the commonest of all the Actiniæ (Mesembryanthemum); you may have him when and where you will: but if you will search those rocks somewhat closer, you will find even more gorgeous species than him. See in that pool some dozen large ones, in full bloom, and quite six inches across, some of them. If their cousins whom we found just now were like Chrysanthemums, these are like quilled Dahlias. Their arms are stouter and shorter in proportion than those of the last species, but their colour is equally brilliant. One is a brilliant blood-red; another a delicate sea-blue striped with pink; but most have the disc and the innumerable arms striped and ringed with various shades of grey and brown. Shall we get them? By all means if we can. Touch one. Where is he now? Gone? Vanished into air, or into stone? Not quite. You see that knot of sand and broken shell lying on the rock, where your Dahlia was one moment ago. Touch it, and you will find it leathery and elastic. That is all which remains of the live Dahlia. Never mind; get your finger into the crack under him, work him gently but firmly out, and take him home, and he will be as happy and as gorgeous as ever to-morrow.

Let your Actiniæ stand for a day or two in the dish, and then, picking out the liveliest and handsomest, detach them once more from their hold, drop them into your vase, right them with a bit of stick, so that the sucking base is downwards, and leave them to themselves thenceforth.

These two species (Mesembryanthemum and Crassicornis) are quite beautiful enough to give a beginner amusement: but there are two others which are not uncommon, and of such exceeding loveliness, that it is worth while to take a little trouble to get them. The one is Dianthus, which I have already mentioned; the other Bellis, the sea-daisy, of which there is an excellent description and plates in Mr. Gosse’s “Rambles in Devon,” pp. 24 to 32.

It is common at Ilfracombe, and at Torquay; and indeed everywhere where there are cracks and small holes in limestone or slate rock. In these holes it fixes its base, and expands its delicate brown-grey star-like flowers on the surface: but it must be chipped out with hammer and chisel, at the expense of much dirt and patience; for the moment it is touched it contracts deep into the rock, and all that is left of the daisy flower, some two or three inches across, is a blue knot of half the size of a marble. But it will expand again, after a day or two of captivity, and will repay all the trouble which it has cost. Troglodytes may be found, as I have said already, in hundreds at Hastings, in similar situations to that of Bellis; its only token, when the tide is down, being a round dimple in the muddy sand which firs the lower cracks of rocks.

But you will want more than these anemones, both for your own amusement, and for the health of your tank. Microscopic animals will breed, and will also die; and you need for them some such scavenger as our poor friend Squinado, to whom you were introduced a few pages back. Turn, then, a few stones which lie piled on each other at extreme low-water mark, and five minutes’ search will give you the very animal you want,—a little crab, of a dingy russet above, and on the under side like smooth porcelain. His back is quite flat, and so are his large angular fringed claws, which, when he folds them up, lie in the same plane with his shell, and fit neatly into its edges. Compact little rogue that he is, made especially for sidling in and out of cracks and crannies, he carries with him such an apparatus of combs and brushes as Isidor or Floris never dreamed of; with which he sweeps out of the sea-water at every moment shoals of minute animalcules, and sucks them into his tiny mouth. Mr. Gosse will tell you more of this marvel, in his “Aquarium,” p. 48.

Next, your sea-weeds, if they thrive as they ought to do, will sow their minute spores in millions around them; and these, as they vegetate, will form a green film on the inside of the glass, spoiling your prospect: you may rub it off for yourself, if you will, with a rag fastened to a stick; but if you wish at once to save yourself trouble, and to see how all emergencies in nature are provided for, you will set three or four live shells to do it for you, and to keep your sub-aqueous lawn close mown.

That last word is no figure of speech. Look among the beds of sea-weed for a few of the bright yellow or green sea-snails (Nerita), or Conical Tops (Trochus), especially that beautiful pink one spotted with brown (Ziziphinus), which you are sure to find about shaded rock-ledges at dead low tide, and put them into your aquarium. For the present, they will only nibble the green ulvæ; but when the film of young weed begins to form, you will see it mown off every morning as fast as it grows, in little semicircular sweeps, just as if a fairy’s scythe had been at work during the night.

[Picture: Plate 8: Littorina Littorea etc.]

And a scythe has been at work; none other than the tongue of the little shell-fish; a description of its extraordinary mechanism (too long to quote here, but which is well worth reading) may be found in Gosse’s “Aquarium.” {201}

A prawn or two, and a few minute star-fish, will make your aquarium complete; though you may add to it endlessly, as one glance at the salt-water tanks of the Zoological Gardens, and the strange and beautiful forms which they contain, will prove to you sufficiently.

You have two more enemies to guard against, dust, and heat. If the surface of the water becomes clogged with dust, the communication between it and the life-giving oxygen of the air is cut off; and then your animals are liable to die, for the very same reason that fish die in a pond which is long frozen over, unless a hole be broken in the ice to admit the air. You must guard against this by occasional stirring of the surface, or, as I have already said, by syringing and by keeping on a cover. A piece of muslin tied over will do; but a better defence is a plate of glass, raised on wire some half-inch above the edge, so as to admit the air. I am not sure that a sheet of brown paper laid over the vase is not the best of all, because that, by its shade, also guards against the next evil, which is heat. Against that you must guard by putting a curtain of muslin or oiled paper between the vase and the sun, if it be very fierce, or simply (for simple expedients are best) by laying a handkerchief over it till the heat is past. But if you leave your vase in a sunny window long enough to let the water get tepid, all is over with your pets. Half an hour’s boiling may frustrate the care of weeks. And yet, on the other hand, light you must have, and you can hardly have too much. Some animals certainly prefer shade, and hide in the darkest crannies; and for them, if your aquarium is large enough, you must provide shade, by arranging the bits of stone into piles and caverns. But without light, your sea-weeds will neither thrive nor keep the water sweet. With plenty of light you will see, to quote Mr. Gosse once more, {203} “thousands of tiny globules forming on every plant, and even all over the stones, where the infant vegetation is beginning to grow; and these globules presently rise in rapid succession to the surface all over the vessel, and this process goes on uninterruptedly as long as the rays of the sun are uninterrupted.

“Now these globules consist of _pure oxygen_, given out by the plants under the stimulus of light; and to this oxygen the animals in the tank owe their life. The difference between the profusion of oxygen-bubbles produced on a sunny day, and the paucity of those seen on a dark cloudy day, or in a northern aspect, is very marked.” Choose, therefore, a south or east window, but draw down the blind, or throw a handkerchief over all if the heat become fierce. The water should always feel cold to your hand, let the temperature outside be what it may.

Next, you must make up for evaporation by _fresh_ water (a very little will suffice), as often as in summer you find the water in your vase sink below its original level, and prevent the water from getting too salt. For the salts, remember, do not evaporate with the water; and if you left the vase in the sun for a few weeks, it would become a mere brine-pan.

But how will you move your treasures up to town?

The simplest plan which I have found successful is an earthen jar. You may buy them with a cover which screws on with two iron clasps. If you do not find such, a piece of oilskin tied over the mouth is enough. But do not fill the jar full of water; leave about a quarter of the contents in empty air, which the water may absorb, and so keep itself fresh. And any pieces of stone, or oysters, which you send up, hang by a string from the mouth, that they may not hurt tender animals by rolling about the bottom. With these simple precautions, anything which you are likely to find will well endure forty-eight hours of travel.

What if the water fails, after all?

Then Mr. Gosse’s artificial sea-water will form a perfect substitute. You may buy the requisite salts (for there are more salts than “salt” in sea-water) from any chemist to whom Mr. Gosse has entrusted his discovery, and, according to his directions, make sea-water for yourself.

One more hint before we part. If, after all, you are not going down to the sea-side this year, and have no opportunities of testing “the wonders of the shore,” you may still study Natural History in your own drawing-room, by looking a little into “the wonders of the pond.”