[Ill.u.s.tration: METAMORPHOSES OF PLUMED GNAT.]

"I would prefer their staying down below; they bite me," answered Jimmy.

Crawling along the bottom were numbers of caddis-worms in tube-like cases made of sticks and stones. Inside these cases are the plump white grubs which turn into flies.

"Where the bottom is gravelly these caddis-worms make their cases of little stones," said Frank.

"Yes, and I read the other day that an experiment had been tried by some one, who took some out of their nests and put them into an aquarium with some finely-broken gla.s.s of different colours, and the caddis-worms made their cases of this broken coloured gla.s.s, and very pretty they looked."

"Their own bodies must supply the glue which fastens the pieces of gravel or gla.s.s together?"

"Yes, it does."

As the fish were biting very badly the boys left the broad early and went for a stroll. While pa.s.sing through the village they saw a sale of stock going on in the open s.p.a.ce round which the houses were ranged.

They stopped to look on. The goods which were being sold were the stock in trade of a chemist, and among them were three large gla.s.s bowls, such as are used for aquaria. These were put up by the auctioneer in one lot, but there was no bid for them. They were articles not in request in that rural district.

[Ill.u.s.tration: PUPA-CASE, LARVA, AND FLY OF CADDIS-WORM.]

"Will no one make me a bid? Everything is to be sold without reservation," cried the auctioneer.

"Five shillings," said Frank.

"Going at five shillings!--going! going!--gone!"--and the lot was knocked down to Frank.

"What are you going to do with them?" asked Jimmy.

"Make them into aquaria, of course. Don't you see they are just the thing. The idea came into my head as soon as I saw them."

"Then we can put some water insects in," said d.i.c.k.

The gla.s.s reservoirs were placed on a shelf in the boat-house, and the next morning before breakfast they were fitted up. They got a quant.i.ty of fine gravel and sand, and thoroughly washed it in water, so as to cleanse it from all mud and impurity. This was placed to the depth of a couple of inches in each vessel, and a rock-work of worn flints was built upon it. Water was poured in to within a few inches of the top, and pieces of anacharis were planted in the gravel, their roots kept down by the stones. In a day or two the water had got clear, and the plants had taken root, and the boys proceeded to stock the aquaria. The small brook near afforded minnows and sticklebacks in plenty. In a stagnant pool they got some newts and water-insects. From the broad they obtained a few small perch, roach, and bream, and an eel about six inches long. They at first put these all together without any attempt at sorting them, and then the following consequences ensued. The water-boatmen fastened on the heads of the small fish and speedily killed them, and ate them up. The sticklebacks made themselves at home at once, and proved very pugnacious, fighting each other, dashing at a stick or finger, if put into the water, but, worst of all, annoying the minnows. Each male stickleback took up a position of his own, and resented any approach to within a few inches of it. With his glaring green eyes, and scarlet breast, he would wage war against any intruder; and when an unsuspecting minnow came within his ken he would sidle up to it, till within striking distance, then dash at it, and strike it with his snout in the stomach. The perch swallowed the minnows, and when they had vanished, attempted to swallow the sticklebacks, but the spines of the latter stuck in the perches' gullets and choked them. The eel, too, would writhe and poke through the gravel and stir it up, displacing the weeds and doing a lot of mischief.

[Ill.u.s.tration: MINNOW.]

This led to a general reconstruction of the aquaria. The perch were taken out and restored to the broad, together with the eel. The roach, bream, and minnows, were put into two of the aquaria by themselves, and the sticklebacks and water-insects into the other. Many a fight took place among the sticklebacks and the water-boatmen, in which sometimes the one and sometimes the other came off victorious.

[Ill.u.s.tration: SMOOTH NEWT.]

The boys then got some caddis-worms, pulled them from their cases, and put them into a gla.s.s vessel filled with water, and having at the bottom some gla.s.s of different colours broken into small pieces. In a short time the caddis-worms had made themselves new, parti-coloured cases of gla.s.s, which were quite transparent, and through which the white bodies of the grubs could be plainly seen. Frank put these in among the minnows one day, and it was amusing to see the fish darting at the caddis-worms, thinking they would be soft, succulent morsels, and to watch their evident astonishment at being foiled by the hard cases. This suggested an idea to Frank which he afterwards carried out.

None of the sticklebacks kept by the boys built nests or bred, so that they missed seeing a very pretty and interesting sight. "Fishes building nests!" I hear some of my readers exclaiming. Yes, sticklebacks do build nests, and in the number for January 1866 of _Science Gossip_ is an interesting account of this habit, which I take the liberty of quoting.

When I have observed any fact in natural history myself, I describe it in my own words; but when I take it from the observation of others, it is fairer to them to use their own words, and far better in the interests of truth:--

"Two pair of sticklebacks were procured about the middle of April,--the males having already put on their spring dress of scarlet and green, and the females being full of sp.a.w.n.

[Ill.u.s.tration: METAMORPHOSES OF NEWT.]

"After a few days a small hole was observed in the sand near a large stone. To this hole one of the males was paying the most a.s.siduous and extraordinary attention. He was poising himself at an angle of forty-five degrees or thereabouts; he commenced a tremendous motion of his whole body, making the sand a pivot, and at the same time beating the water with his fins. This motion increased regularly in rapidity for a minute or so, when it ceased abruptly, and the fish darted off, either in pursuit of some trespa.s.ser whom he chastised (the females not even being exempt), or to obtain materials to increase his nest. These consisted of pieces of stick or moss, which being saturated with water, were of such gravity as to prevent their rising. He deposited these with great care, leaving a perfectly round hole in the middle, and then having procured a mouthful of sand, laid it over the looser materials to cement them together.

"When completed, the nest resembled a flattened hayc.o.c.k.

"For about a week after this completion it seemed deserted. But one morning it was found that some eggs had been laid. These for the size of the fish are very large, being about the size of a middling-sized shot.

They hatched in about from ten days to a fortnight,--the young fish remaining in the nest until the yolk-bag was absorbed, when, being large enough to look after themselves, they went their way. The parent who had so tenderly guarded them took no further heed of them, and himself died--such being the case in both instances which came under notice, both parents sickening and dying from the effects of sp.a.w.ning and watching, or perhaps from the aquarium not being fitted for their recovery."

[Ill.u.s.tration: WATER-FLEAS.]

[Ill.u.s.tration: ANIMALCULae IN DROP OF WATER, AS SEEN UNDER THE MICROSCOPE.]

Those who keep aquaria in an intelligent manner and study the habits of the creatures they imprison, will find it both interesting work, and a never-failing source of amus.e.m.e.nt. It is very little trouble. When the water is put in, and the plants begin to grow, the water need not be changed. The oxygen produced by the plants will keep the water pure, and will supply it with air.

[Ill.u.s.tration: FRESH-WATER AQUARIUM.]

The green confervoid growth which rapidly forms on the sides of the aquarium must not be all wiped off, for it a.s.sists greatly in keeping the water pure and healthy. Tie a piece of sponge to a stick, and with this you can wipe it off from that side where it obstructs the view, without disturbing the rest of the aquarium. If you have no cover, and dust acc.u.mulates on the surface of the water, it may easily be removed by means of a piece of paper laid on the surface of the water for a few minutes. The dust will adhere to this, and be taken away with it when it is removed. The confervoid growth is best kept down by the common water-snail, several of which should be kept in the aquarium.

You must of course feed the fish occasionally with worms, insects, and bread; but give them very little at a time, or you will foul the water and render it muddy, and the fish will sicken and die. Keep these few hints in mind, and you will have no trouble in managing your aquarium.

[Ill.u.s.tration: METAMORPHOSES OF FROG.]

From aquaria to flowers is a sudden transition, but a bunch of violets has just been held to my nose to smell, and their sweet fragrance has borne me in thought from my study, where I am burning the midnight oil, to the green woods and fields of my boyhood, and then a sudden review of events which have happened since in my life, makes me more thankful than ever that that boyhood was, as far as natural history is concerned, a prototype to the boys of whom I am now writing, and makes me wish to urge the more strongly upon you the almost boundless advantages which follow the study to all. You will of course clearly see that my aim in writing this book is not merely to amuse, but to teach you some of the wonders which lie ready for you to explore, and the delight of seeking and discovering those wonders. I do not, however, want to moralize, because if I do you will skip my moralising, so I will pull up in time and get on with my story.

[Ill.u.s.tration: SEA-WATER AQUARIUM.]

CHAPTER XXV.

Making a Fern Case.--Ferns.--Harvest Mouse.-- Mole.--Ladybird.--Gra.s.ses.

[Ill.u.s.tration: WALL SPLEENWORT.]

From ten till four the boys were engaged with Mr. Meredith, but they had a holiday on Sat.u.r.day, and by rising early they could gain so many of the fairest and most beautiful hours of the day that lessons seemed but an interval between a long morning and a long afternoon. They thus made plenty of time for their numerous occupations.

[Ill.u.s.tration: FORKED SPLEENWORT.]

Mary said to Jimmy one day, "Will you make me a fern-case? Frank has so many things to do. I have been promised a lot of ferns from Devonshire.

A friend of mine will send them to me by post, and I should so like to have a nice little fernery for my bedroom window."

[Ill.u.s.tration: GREEN SPLEENWORT.]

Jimmy gladly promised to make one for her, and d.i.c.k, who would have liked to have had the commission himself, volunteered to help him. They first of all made a strong deal box, about two feet six inches long, and one foot six inches broad, and six inches deep. This was lined carefully with sheet lead, which was to make it perfectly water-tight. They then made a wooden framework, with a pointed roof, to fit on the top of it.

This they glazed with ordinary window-gla.s.s, and painted all the wood-work black. It was now ready for the soil. First they put a layer, about two inches deep, of broken sandstone, in order to ensure perfect drainage, and mixed with this were some lumps of charcoal to keep it pure. Then they filled up the box with earth, mixed in the proportions following:--one-third part of garden mould, one-third part of sand, and one-third part of peaty earth, with an admixture of dead leaves. In the centre of the rockery they built up a framework of curiously water-worn flints, and then they carried the affair in triumph to Mary's room, where they planted the ferns she had received from her friend--glossy, whole-leaved hart's-tongues, delicate, black-stemmed maiden-hair, ladder-like polypodies and blechnums, feathery lady-ferns, light green and branching oak-ferns, and many another species, which, notwithstanding their removal from the Devonshire lanes, grew and flourished in Mary's fern-case, and soon became a sight most pleasant to the eye.

[Ill.u.s.tration: OAK FERN.]

[Ill.u.s.tration: FRUCTIFICATION OF FERNS.

1. Asplenium. 2. Scolopendrium. 3. Cystopteris. 4. Blechnum.

5. Hymenophyllum. 6. Pteris. 7. Adiantum. 8. Trichomanes. 9. Woodsia.]