CHAPTER VIII.

GENERAL MANAGEMENT.

Feeding should be performed twice or thrice a week, and will be as

amusing to the observer as gratifying to the fishes. Bread is not so

objectionable as many have stated. Carp, bleak, and minnows eat it

greedily, and soon grow tame if regularly fed with it. Most small fishes

take insects, such as flies, spiders, ants, and soft larva, greedily;

but the large fish disdain such diet. Small red worms, and white of egg,

are good general foods, and seem highly beneficial. When feeding, see

that the carp get enough, for they are slow fish, and get robbed

wholesale by their more lively neighbours. Food not eaten will decay,

unless speedily removed, hence care must be exercised on this head.

_Confervæ._--When the tank has been established a few weeks, the inner

sides of the glass will show signs of a green tinge, of a slimy nature.

This is owing to the growth upon it of minute forms of vegetation. If

this is allowed to go on unchecked, the glass will in time become

opaque, and the view of the interior will be lost. Hence it must either

be kept down in growth or occasionally removed.

_Uses of Mollusks._--It is to prevent this rapid growth that

water-snails are registered among the tenants of right, for these

creatures subsist on vegetable matter only, and if a goodly number be

thrown in, they will be found perpetually at work, eating the green

growth from the sides, and thus constantly preserving an open prospect.

_Objections to Mollusks._--In a highly ornamental tank, water-snails may

be thought objectionable, as interfering somewhat with the beauty of the

scene. I know the ardent naturalist will cry out against this remark,

and ask me if I can find a prettier object than a _Planorbis corneus_,

coiled round like a horn of plenty; or a full-grown Paludina with its

globular hybernaculum richly bronzed and mottled. I tell my friend that

I love the pretty creatures as much as he does, yet, as I write for

everybody who wishes to keep an aquarium, I feel bound to consider how

it is to be managed without them, if their absence is desired. I confess

too, that I do object to their appearance in some cases myself, as I do

also to beetles, and all other insects in a tank fitted up for the

adornment of a drawing-room, however necessary they may be in the tank

of a student.

In the first place, _Paludinæ and Planorbis_ are the only kinds to be

trusted in a general collection of plants, and the last is most

trustworthy of any. Lymnea are all fond of substantial dishes, and eat

as much vallisneria as they do of the mucuous growth. A dozen of these

gentry will most effectually check the vegetation of the tank, by eating

holes in the handsomest leaves of the Stratoides, and biting into the

very heart of the Vallisneria. Starwort, too, they are very fond of, and

soon clear the bottom of every fragment. Yet, the _Lymnea_ are

admirable cleaners, the pity is, that they will not see what is

required of them, and do that only.

Again, the univalve mollusks do not keep the sides so clean, but that an

occasional cleansing of another kind is sometimes necessary, and if the

aquarian is not disposed to keep an army of quite semi-efficient

scavengers, the remedy will be found in an occasional cleansing of the

sides, by means of a sponge attached to a stick, which must be plied

over the whole surface, and occasionally taken out and washed in clean

water, to remove the green scum, that it soon gets covered with.

[Illustration (Lymnea)]

_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.

[Illustration (Dragon Fly)]

THE BOOK OF THE AQUARIUM.

THE MARINE TANK.

CHAPTER I.

THE VESSEL.

_Points in which the Marine differs from the River Tank._--Though

vessels of precisely the same construction are used for marine as well

as fresh-water aquaria, yet, as the peculiar necessities of marine life

demand some conditions of a special kind, I must here again briefly

treat of the vessels in which marine stock may best be kept. Every

variety of tank or vase referred to in the description of the

fresh-water aquarium may be used in the formation of marine collections;

but while vases are eminently suitable for river stock, they are not to

be strongly recommended for marine, and for this important reason, that

we do not generally have, as in the former case, a variety of moving

forms poising in mid-water, or chasing each other through every part of

the tank; but in the present case _ground stock_ constitutes the main

feature of attraction, and hence we require a vessel which admits of

examination in every part, which a _tank_ does and a _vase_ does not. In

a vessel containing actinia, madrepores, serpula, &c., we require to

have at all times a clear view of the bottom, and a vase does not admit

of this unless we look from above, the amount of refraction being very

great at the base of the vessel. Hence, though marine stock may be well

kept in vases, it must be borne in mind that such vessels are far

inferior as to the means of inspection to rectangular tanks.

It is also important to bear in mind that marine stock invites the use

of the microscope in a greater degree than river specimens, and a

flat-sided vessel is the only one which affords proper facilities for

the application of a magnifier to its contents.

_Stained Glass._--But there is a still more important matter requiring

notice here. We are indebted to that accurate observer, Mr. Warington,

for valuable information on the effects of light upon certain forms of

sea weeds, and his mode of overcoming this is by passing light through

variously coloured media. It can easily be understood, that plants,

whose natural habitat is at a considerable depth beneath the surface of

the ocean, bear exposure to the full daylight very indifferently, and

that some special arrangements are necessary in order to cause the solar

rays to fall upon them as nearly as possible in the same manner as in

the twilight recesses from which they have been removed. This is

accomplished by fitting that side of the tank, which is intended to be

placed next the window, with a sheet of glass stained of a soft sea

green, and the softened light, so admitted to the tanks, promotes the

healthy growth of the Algæ, and very materially increases the beauty of

the vessel as seen from the other side. Mr. Lloyd, whose ripe experience

ever takes the most practical turn, has adopted this plan of

construction, and strongly recommends it for every vessel intended for

the reception of marine stock. Where it is desired to stock a vessel, in

which the back plate is composed of colourless glass, with marine

products, a substitute for coloured glass will be found in _diaphanie_;

but the paper chosen for the purpose should be of the lightest shade of

sea green, because it is less transparent than stained glass. In

stocking vases, this plan of staining the side next the window, is to be

strongly recommended, no less for securing a healthy vegetation than of

enlivening the beauty of the collection. I have used for this purpose,

the paper and varnish prepared by Messrs. Faudel and Phillips, of

Newgate Street, and can commend it for cheapness, and the ease with

which it can be applied.

Another point deserving of note is, that marine aquaria need a less

depth of water than river collections:--For purposes of study, a number

of glass dishes or milk-pans, will be found preferable to any kind of

tank, or vase, especially for Zoophytes, though fishes and crustaceans

require more room than mere bowls would afford them. In fact, the lower

forms of marine life may be kept for many months without the help of sea

weeds, if placed in shallow vessels--the absorption of oxygen, at the

surface, being quite equal to their demand upon the water.

In all other respects, what has been already said on the subject of

vessels must be understood to apply to all kinds of aquaria; the

rectangular tank, and the bell glass, are the two leading forms, and to

them I shall always refer when speaking of the tank in a general sense.

CHAPTER II.

FITTING UP--MATERIALS FOR THE BOTTOM.

Coarse sea sand and pebbles, all well washed, make the best bottom; but

if sea sand is not to be conveniently obtained, common silver or gritty

river sand will answer every purpose, if washed until they cease to

stain the water. Most writers on aquaria--Mr. Gosse especially--condemn

silver sand, but I find it a most suitable material: its appearance is

cleanly, and it only requires frequent washing in fresh water to fit it

for the purpose. In the water-pipe which runs along the wall to supply

the kitchen, I have had a hole pierced to form a jet, and this I find of

great service in many aquarian operations, and especially in washing

sand and pebbles. Where this can be done conveniently, or where the pan

containing the materials to be washed can be placed under a tap turned

on so as to drip rapidly, the washing can be accomplished with very

little trouble, and the materials can remain for a week or two, being

stirred up occasionally to hasten the dissolution of solvent matters.

The sand should have a depth of two or three inches on the floor of the

vessel, and above it should be placed a layer of pebbles, also well

washed. The little white pebbles found among gravel look bright and

pretty, and if the aquarian is also a lover of the garden, he will turn

up plenty of them in digging, so as to keep a supply at hand for use

when wanted. The pebbles are not essential, but the sand is, because

many of the creatures delight in burrowing, and must have opportunity

afforded them of living their own life in a state of confinement.

_Rock work_ is generally considered an essential of a marine tank, but

experience has convinced me that the less we have of it the better. I

have, in describing the fresh water tank, given instructions for its

formation, and here desire only to caution the beginner to repress, as

much as possible, any desire for mimic arches, caves, and grottos. In

the first place, it must be remembered, that every cubic foot of rock

work displaces a cubic foot of water, and reduces the capabilities of

the tank for supporting a number of creatures. The more rock the less

water, and the less water the fewer animals. Beside this, it is

questionable if the use of cement of any kind is advisable; free lime

may be expected to dissolve out of it, however much seasoning it may

have previous to the introduction of the stock; and as marine creatures

are more delicately constituted than fresh water ones, the subsequent

loss of many may fairly be attributed to the presence of cement.

In the place of built-up arches, a few rough pieces of stone tastefully

disposed at the bottom may be made to produce a good effect: a rough

block of granite, or a stem of branching coral in the centre will be far

preferable, except for vessels of large size, in which pyramids and

arches may be less objectionable. It must be borne in mind, however,

that rock work in some form or other is useful, as affording shelter and

shade to such animals as love seclusion, and that, in a well managed

tank, the rough blocks often get coated with a vegetable growth that

increases the strength of the collection, and adds very much to its

beauty. In this matter, the mischief arises out of the desire of

beginners to display more ornament than is consistent with the nature of

the case.

_The water_, of course, may be obtained direct from the sea, and should,

if possible, be dipped in mid-channel. Shore water is not altogether

objectionable, for where we find the greater part of our specimens it is

evident the water must be suitable for them. In fact, I have found water

that I have brought from the sea-side in jars serve just as well as that

supplied by the steamer from the open sea; but near the mouth of a river

it would be found unsuitable, as it would, also, from any parts of the

coast where land springs abound. Earthenware vessels are the best for

the conveyance of sea-water and specimens, but if a large quantity be

required, a new cask should be used, and the greatest care taken to have

it stopped with a new bung, and conveyed quickly to its destination. Mr.

Gosse recommends a cask of fir-wood if it can be procured, "the wood of

the oak, of which wine casks are usually made, gives out _tannin_ or

_gallic acid_ to the contained water, which by its astringency, converts

the animal integuments into leather." In fact, our poor anemones get

their hides tanned if any vegetable bitter comes into contact with the

water in which they are to be kept. I make it a rule to filter sea water

through charcoal before using it; this is not essential if the water

appears bright, but is, at least, a precautionary process that may have

its advantages.

_Artificial Water_ is now used so extensively as to justify some special

remarks here upon it. It must be understood that where real sea water

can be easily obtained, as at spots near the coast, it is undoubtedly

the best, though, in some respects, the artificial preparation is

preferable, because less liable to certain eccentric changes of

constitution, which will fall under our attention further on. Sea-water

contains the spores of plants, and the germs of many forms of animal

life which may have development in the tank, and when these births

occur, it is a special gratification to the possessor. But such germs

may also decay, and cause putrescence; and if a tank is neglected, the

water is liable to get cloudy, the stones black, the sides of the vessel

semi-opaque, and the animals diseased. Death soon sets his black seal on

the undertaking when such a state of things occurs, and the collection,

however costly or well formed at first, may be lost. Now such

misfortunes as these are preventible, as it will be my duty to show

presently, but I here call attention to the fact, that artificial

sea-water is much _less liable_ to get out of condition from the very

absence of organic matter, which on first reflections, we should regard

as a disadvantage. Thus, the prepared material has certain advantages

over the natural; we lose the chance of rearing new additions to the

stock through the introduction of minute organic germs; but incur no

danger of those same germs perishing and polluting the bright lymph.

But artificial water is quite unsuited for animal life of any kind,

until it has been brought into condition by means of growing weeds for

eight or ten days, and for crustacea, star fishes, and fishes proper, it

is not suitable till it has been in use for many months, and even then

some species lose their health in it, and at last perish. But for

anemones of all kinds, many mollusks and crustaceans, and some other

forms to be presently described, artificial water does well, and

improves daily if properly managed. Unless, therefore, the aquarian is

bent upon domesticating the rarer and more delicate sea specimens, he

may avail himself of the aid of the chemist, and manufacture sea-water

from the river or the pump.

_Composition of Marine Salts._--The limited space of this work will not

enable me to enter upon the consideration of the chemistry of this

question so fully as I have done in "Rustic Adornments;" nor, perhaps,

is it necessary here to do more than point out the simplest method of

procedure. There are at least seven ingredients besides water, used in

the natural laboratory, but the chemist dispenses with some of these,

and finds every purpose served by using a selection of the chief of

them. The composition of sea water is as follows:--

Water 964.744

Common Salt, or Chloride of Sodium 27.059

Chloride of Magnesium 3.666

Chloride of Potassium 0.765

Bromide of Magnesium 0.029

Epsom Salts, or Sulphate of Magnesia 2.295

Gypsum, or Sulphate of Lime 1.407

Carbonate of Lime 0.033

Loss, or not accounted for 0.002

---------

1,000.000

---------

Mr. Gosse, in July 1854, communicated to the "Magazine of Natural

History" the results of experiments in the imitation of this

composition, and a formula for the artificial preparation of sea-water.

In the fictitious preparation the component salts were reduced to four,

so that no less than three of the original ingredients were dispensed

with. If the reader will note in what minute quantities the bromide of

magnesium, the sulphate and carbonate of lime occur, and at the same

time bear in mind that river and spring waters always contain a

considerable proportion of the last-mentioned ingredient, it will be

easily understood that the absence of those materials in the preparation

does not materially affect its value. The preparation on Mr. Gosse's

plan is composed as follows:--

Common Table Salt 3-1/2 ounces.

Epsom Salts 1/4 "

Chloride of Magnesium 200 grains, Troy

Chloride of Potassium 40 " "

The recipe may be given in another form to avoid the perplexity of

avoirdupoise and troy weights, thus:--

Common Salt 81 parts.

Epsom Salts 7 "

Chloride of Magnesium 10 "

Chloride of Potassium 2 "

_Management of Artificial Water._--When the salts are ready, it is best

to mix them in an earthern pan or jar, and allow them to settle and

refine for a day or two. To dissolve them in the tank is decidedly a bad

plan, though it is daily recommended by the dealers. Any one who will

dissolve a portion in a clean bell glass, and allow it to stand for a

week, using the clearest water, and adding nothing but the salts, will

observe, at the end of that time, a minute gritty deposit, similar to

iron rust, mixed with minute fragments of sand. This deposit proves

that the chemicals we obtain are not pure; and, perhaps, it is not

desirable that excessive purity should be obtained, but it certainly is

desirable to keep such matters out of the tank. When the salts have been

stirred up once or twice, so as to dissolve them thoroughly, test them

for the last time with the hydrometer, till it registers 1.027 or

thereabouts; it may safely range from 1.026 to 1.028 without interfering

with the success of the experiment. Hydrometers, registered for

sea-water, are not everywhere obtainable, and the specific gravity-bulb,

sold by Mr. Lloyd, for a shilling, answers the purpose just as well. Mr.

Cox, of 100, Newgate Street, has lately supplied me with an hydrometer

of a register of 1.000 to 1.050, made in Paris--the cost was seven

shillings. I prefer it to the bulb because it can be put to other uses.

_A Caution to the Uninitiated._--Some beginners have attempted the

preservation of marine specimens in solutions of common bay-salt, and

have expressed surprise that they perish rapidly in a solution of salt

obtained _from the sea_. Anyone at all acquainted with chemistry would

readily predict, that there could be no more certain way of killing the

creatures than the adoption of such a plan of preserving them. When

bay-salt is prepared, many of the more soluble materials, chloride of

magnesium especially, remain behind in the mother liquor, because the

chloride of sodium crystallizes first, hence _bay-salt alone does not

produce sea-water_; we must have the aid of the experienced chemist, or

turn chemists and prepare it for ourselves.

Those not experienced in chemical manipulations may find some difficulty

in obtaining and weighing accurately the several ingredients; and I

should advise them to purchase the preparation sold by Mr. Bolton, of

146, Holborn Bars. This merely requires to be dissolved according to the

instructions just given. Mr. Bolton has given minute attention to the

preparation of the salts, and is now improving them by compounding with

them the minute quantities of the more subtle ingredients, which were

originally omitted by Mr. Gosse. The salts are sold in packets, at the

rate of three gallons for a shilling; a price which must be considered

reasonable when we consider the purity of the article, and the care

taken in its manufacture.

_Filtering._--When the salts are well mingled with the water, pass the

liquid, through a filter, into the tank, which is supposed to have been

already well-seasoned, and furnished with a bottom of sand and pebbles,

and any ornaments that may be deemed necessary. A bee glass, with a bit

of sponge thrust into the orifice, is a convenient form of filter, but

if such a thing is not at hand, take an _old_ flower pot, and wash it

quite clean, thrust a piece of sponge through the hole in the bottom,

and throw into it a handful of powdered charcoal. This may be suspended

above the tank, or stood on two slips of wood, and filled from time to

time, till the whole of the water has been passed through it.

[Illustration: ACTINIA MESEMBRYANTHEMUM, DYCTYOTA DYCHOTOMA.]

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.

[Illustration: PORCELLANA PLATYCHELES, CANCER PAGURUS.]

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.

[Illustration: CARCINAS MÆNAS.]

_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:--

----Be it our's to embellish thy pillow

With everything beauteous that grows in the deep;

Each flower of the rock, and each gem of the billow,

Shall sweeten thy bed and illumine thy sleep.

Around thee shall glisten the loveliest amber

That ever the sorrowing sea-bird has wept,

With many a shell in whose hollow-wreathed chamber

We, Peris of Ocean, by moonlight have slept.

Lalla Roohk.

[Illustration: ACTINIA ANGUICOMA, TROCHUS ZIZIPHINUS, ULVA LATISSIMA,

BRYOPSIS PLUMOSA, ACORN BARNACLE.]

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.

[Illustration: ACTINIA BELLIS AND GEMMACEA, DELESSERIA ALATA,

POLYSIPHONIA URCEOLATA.]

_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.

[Illustration: ACTINIA DIANTHUS, DELESSERIA SANGUINEA, CALLITHAMNIUM

ROSEUM, GRIFFITHSIA SETACEA.]

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_.

[Illustration: EDWARDSIA VESTITA, ÆSOP PRAWN, ENTEROMORPHA COMPRESSA,

ULVA LATISSIMA.]

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 1/4 or 1/2

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.

[Illustration (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.

[Illustration (Syphon Tube)]

_The Syphon_ is a simple affair enough. In using it, place the short end

below the surface of the water in the tank, and apply the mouth to the

longer end, and draw till the water flows; it will then continue to flow

as long as the short end is kept under water. If you object to promote

aquarian science by means of suction, first fill the syphon with water,

and apply a finger to each end, and so turn it over, and withdraw the

fingers when the short end is dipped beneath the surface of the water in

the tank. Mr. Lloyd sells a syphon expressly for the purpose, which the

aquarian should possess.

_Purchase of Specimens._--There are now many dealers in Aquarian stock,

but very few of them supply _marine_ stock in any variety. I have my

readers' interest only at heart when I suggest, that no one should

attempt to set up an Aquarium without first paying a visit to the

establishment of Mr. W. Alford Lloyd, of No. 20, Portland Road, Regent's

Park, where choice may be made from a stock consisting of _thousands_ of

specimens, supplied, as, the oyster shops say, "fresh every day." Mr.

Lloyd was a labourer in the field years before the Aquarium became

popular, and his experience, attained by patient study, is now at the

service of all who need advice or assistance in _any_ department of the

subject.

I have no interest in this matter beyond doing justice to my reader, and

beg to add that Mr. Hall, of City Road, has supplied me with marine

stock of high character, and that I can recommend him as an honest and

intelligent naturalist, though, on marine matters he will not attempt to

compete with Mr. Lloyd, for the latter has now the name, the trade, and

the organization, and since he keeps everything, so he can supply

everything of the commonest or rarest kind, in the highest condition.

[Illustration (decorative swirl)]

THE BOOK OF THE AQUARIUM.

THE WATER CABINET.

CHAPTER I.

CONSTRUCTION OF CABINETS.

_Distinctions between the Cabinet and the Aquarium._--The Aquarium has

not only spread abroad a love for Natural History, it has also increased

the facilities for the study of nature by removing the difficulties

which have hitherto attended the preservation, for any length of time,

of living specimens of aquatic life. The tank had scarcely taken its

place among the resources for pleasureable recreation, and scientific

study, when the field of culture extended itself, and every variety of

minute life found in the waters, came to have its share of attention for

the general profit and delight of the studious. The ordinary tank was

found insufficient for the wants of the aquarian, and wherever a large

vessel was to be seen stocked with fresh water fishes or marine objects,

a collection of small jars, phials, or show glasses, was pretty sure to

be found also. In an aquarium, we may group together many dissimilar

objects; but it must be evident to the most superficial observer, that

when immersed in a large body of water with other creatures, many

objects are ill-placed for examination, especially if we use the

microscope. Hence, where the study is pursued with any degree of ardour,

some special arrangements are necessary to enable us to keep in a

healthy state, and in a way that admits of close scrutiny at any moment,

such of the smaller aquatic objects as most commend themselves for

beauty or scientific interest. Many beginners, unable to resist the

temptation of a jar of beetles, or a collection of larva, and having no

other means of keeping them, have placed them in the tank to mingle with

the stock of finny creatures, and have thereby either lost the better

part of the collection or have been compelled to break up the stock and

begin anew. I have already suggested that a few species of water

beetles, and aquatic larva, may be safely preserved in an aquarium; but

an aquarium is by no means the best place for them, if we wish to study

their habits closely, or investigate their mechanism and economy by the

aid of lenses: all insects, many mollusks, larva, and other small

objects should be kept apart, and a collection of such objects is what

we mean by a Water Cabinet.

To the genuine student, there is really more for remunerative study in

such a collection than can be found in the Aquarium, though the tank,

whether river or marine, will always prove most attractive as an

ornament, and because it requires less care and study, will be pretty

sure to retain the greatest number of admirers. But the Aquarium and the

Cabinet are distinct things; they cannot be combined in the same vessel,

and, though a Water Cabinet is but another form, or rather a series of

separate and smaller aquaria, the uses and economies of each are in a

great measure distinct. It is possible to cultivate either without the

other, though we should generally expect to find them in company, the

Cabinet being a growth or extension of the Aquarium.

_Construction of a Cabinet._--Ingenuity, under the control of

circumstances, will devise many modes of preserving the smaller

specimens of aquatic life, and I shall here describe a plan which I

think will be found most generally useful, particularly as it may have a

very simple form, and be produced for a very trifling outlay; or may be

elaborated into a noble piece of furniture for the adornment of an

elegantly furnished room.

The frontispiece represents a series of shelves fitted into a carved

framework, the lower portion of which forms a table with drawers. My own

cabinet, which is a simple affair of stained deal, is made after the

model of the one here represented, but without ornament of any kind; and

if I describe its measurements, it may serve as a guide to any who may

desire to have one constructed of a similar pattern, though, as a matter

of course, the plan admits of endless modifications to suit the means of

the student, or the position in which such a cabinet is to be placed.

The table measures nineteen inches from back to front across the centre

drawer; and from back to front across the two side drawers, twelve

inches. On this is placed a row of seven-inch cylindrical glasses of

clear flint glass, and in the centre, behind the jars, stands a

twelve-inch bell glass aquarium, to be stocked with choice fishes or

superfluous cabinet specimens. The first shelf has a breadth of eight

inches to receive a row of six inch glasses; the second shelf a breadth

of five inches, and the jars upon it measure four inches in diameter.

The top shelf is only three-and-a-half inches wide, and the glasses on

it measure three inches across the top, and, two-and-a-half at the base;

the jars of this size, in my own collection, are of a tapering form,

half an inch narrower at the bottom than at the top, though I am not

aware whether such is the usual form of the small vessels. The entire

framework has a breadth of about thirty-two inches, and a height, from

the floor of the room to the level of the top shelf, of about sixty-six

inches.

The breadth and height of the window, in which the cabinet is to be

placed, must have the first consideration, with any one who may intend

to construct such a piece of furniture; the respective sizes of the

vessels must be an after consideration, because, unless the whole be so

adapted, as that it shall enjoy a full share of uninterrupted daylight,

very little progress can be effected, especially if the growth of the

more delicate forms of aquatic vegetation be attempted.

In the absence of a properly constructed set of shelves, a few plain

ones may be fitted up in a window. A single strip of deal, on brackets,

would afford room for a dozen jars, and in these by judicious grouping,

specimens of from fifty to a hundred kinds could be kept, whether for

observation by the naked eye, or the microscope.

_Glasses._--In common with many aquarians I used phials and

confectioners' show-glasses for a considerable length of time; but to

preserve the uniformity of the collection, I should recommend

cylindrical glasses of flint glass of the form represented in the

engraving. Chancing to unearth a number of such glasses, at the

warehouse of the Messrs. Phillips, of Bishopsgate Street, I have since

abolished the _olla podrida_ of acid bottles and phials, with which I

had previously been content, and now use no other kinds, and I think

their strength and clearness of colour must commend them to the student,

as the best that can be had for the purpose. The cost of them is a

shilling a pound, though common show-glasses may be had at ninepence a

pound. If there is much dust in the room where the cabinet stands, a

strip of green gauze might be stretched on light cane frames over each

row of glasses.

The jars are intended for the reception of separate or grouped species,

and the bell glass may be an ordinary aquarium or a receptacle for the

_omnium gatherum_ of general collecting. My jars are now (July, 1856,)

stocked with minute aquatic plants, beetles of several species, diving

spiders, water worms, and mites, larva of beetles and flies, tadpoles in

progress of transformation, mollusks of choice kinds, and spawn of all

kinds, removed from the tanks. The bell glass contains a miscellaneous

assemblage of duplicates of all kinds, such as water weeds for renewal

of tanks, tadpoles, leeches, whirlwigs, mollusks, crustacea, and

infusoria for the microscope. Species that do not agree, may be

introduced to the bell glass for the sake of teaching us the nature and

incidents of the strife maintained in the great world out of doors; the

battle may there have its way, and we may study destruction with as

much profit as we may the momentary creation by which the system of

nature is maintained in its completeness. In fact, the bell glass is a

reservoir into which we may dip for almost anything we want to fill up

vacancies in the jars, and in the proper tanks, and to which we may

consign the superfluities of a day's collecting; having first assorted,

and set apart such as are wanted for separate observation and study.

CHAPTER II.

COLLECTING AND ARRANGING SPECIMENS.

_Implements for Collecting._--Most of the ordinary productions of ponds

and brooks may be purchased of the dealers, especially beetles, larger

kinds of larvæ, water spiders, and tadpoles; but very little progress

can be made in the study of this branch of natural history, without

personal visits to the fishing grounds.

An hour spent in dragging a brook or pond, will do more towards stocking

a cabinet with wonders than a hundred purchases. To the pleasure of an

excursion is added the intellectual profit of learning the nature of the

haunts, and many of the habits of the creatures obtained; every haul of

the net will bring forth from the oozy bottom, an immense variety of the

most curious kinds of life.

[Illustration (Hand Net)]

_Nets_, for the purpose, are easily obtainable. At least, two kinds will

be necessary, namely, a small hand net attached to a short rod, or made

to slip on a common walking stick, and a larger one for a long rod, or

for hauling with a line. The small net should be of a fine mesh, and for

convenience of carriage, may be fitted on a jointed ring of brass, so as

to fold together. The large net need not be very fine in the mesh, but

it should be very strong, both in the texture and the fittings, and

should be lined inside with muslin so as to prevent the escape of the

smallest game. Every variety of pond and drag-nets may be obtained of

the dealers in fishing-tackle, at prices varying from one to five or six

shillings, and of a quality that may be depended on for serviceableness.

Some water-cord, a jointed rod or walking stick, and a few earthen jars,

or live bait cans, make up the stock of implements, the whole of which,

with the exception of rods, may be packed into a basket in which

suitable divisions are made, and transported easily. Living in the

neighbourhood of many prolific brooks and ponds, I have very little

experience in the carriage of specimens, and, indeed, seldom use more

than a single jar, and a single net at one time; but I should suggest to

those who have to travel a distance for the pleasure of beetle fishing,

to provide themselves with a basket or box, made after the fashion of

the baskets in which bottles are sent out by vintners, the divisions

being fitted with stone jars; and one division left the whole length of

the basket, for nets, scissors, a pair of forceps, and a few small

phials. Each vessel should have a lid of perforated zinc, to prevent

the escape of objects during transit; the jolting of a railway train or

coach might otherwise waste the contents. The stone jars used for the

purpose, should have a cord attached round the rim of each for

convenient handling at the brook side.

_Pond fishing._--Every variety of stream or stagnant pond may be fished

to advantage; but the specimens obtained from clear running brooks will,

in general, differ greatly in character from those which the drag net

brings from a dark still pool. Ponds which have formed in gravel pits,

are generally well stocked with newts, mollusks, and tadpoles; but for

the varieties of the beetle family, old ponds in meadows, and which are

the resorts of cattle, are the best; ditches and rank brooks are the

usual haunts of caddis worms, diving spiders, polypes, and the more

beautiful varieties of water bugs; but every locality has its special

attractions only to be learnt by experience.

Supposing that you have made a halt beside a pleasantly shaded brook,

with hedge sparrows, robins, and black-caps warbling about you. You

prepare by selecting a suitable spot free from brushwood, and where the

edge of the water may be reached without danger. The first thing to be

done is, to fill a few jars with clear water, and to throw into each a

few strips of any common water-weed, of which callitriche is always the

best, and most generally attainable. If the water is very foul it will

be better to travel a little distance for a supply, because the

specimens are wanted as cleanly as possible, and if thrown into clean

water when caught, their own motions will tend to cleanse them, and fit

them for the glass jars at home. The shore should be fished first, and

the operation should be conducted with as much quiet as possible; any

disturbance will be sure to drive away many of the livelier creatures.

Take a small net attached to a walking stick or short rod, and thrust it

out from you as far as possible over the water; then quickly dip and

draw it towards you, and land it at your feet at some little distance

from the edge of the water. Sort out the contents of the haul into

separate jars, though, as you cannot have as many jars as the kinds

which the net will bring up, a little judicious grouping will be

necessary. Spawn of all kinds may be placed together in the same jar

with mollusks, tadpoles, caddis worms, and colymbetes; most beetles must

be kept by themselves, on account of their voracity, as must also the

several kinds of carnivorous larvæ, such as those of the _Dytiscus_, and

the dragon fly, and water worms of the genus _Nais_.

When the sides have been well fished, the deeper water may be operated

on by means of the drag-net, and the produce disposed of in the same

way.

On arriving home, sort over the jars _seriatim_, and dispose of the

specimens according to the capacity and arrangement of your cabinet. The

glass jars should be each furnished with a few tufts of some growing

weeds, and with clear water. Some of the specimens will require to be

washed to remove offensive matter, and some few will need a bottom of

small pebbles, and a jar nearly filled with healthy vegetation.

_Anacharis_, _Myriophyllum_, _Nitella_, _Chara_, _Riccia_, and choice

_Confervoids_, are the best for the cabinet, on account of the limited

space in which they must be kept, and the elegance they impart to the

collection. In the larger jars it would be well to keep some tufts of

vallisneria in order to propagate it to supply vacancies in the tanks.

When the stock has been housed in the cabinet, whatever is left may be

transferred to the bell glass for further examination. It would be

better not to wash or disturb the refuse weed and sediment of the

collecting jars, but to throw the whole into the vase. After a few hours

it will settle down, and a lens will assist in the detection of whatever

curiosities may swarm out of the refuse weed. Objects for the compound

microscope may in this way be obtained and preserved in plenty.

CHAPTER III.

THE STOCK.

I have already indicated some of the varieties best suited for the

cabinet, but will here briefly enumerate those which form the leading

features of attraction, leaving the development of the collection to the

perseverance of the student. The great division of _Coleoptera_ will

furnish by far the largest number of showy species, all of them

interesting and lively creatures, many of them possessed of great

beauty. The ravenous _Dytiscus marginalis_ and _dimidiatus_, with their

strong hooked claws, and brightly bronzed elytra; and the pretty,

docile, and harmless _Colymbetes_, with its shining silver breast-plate,

and jet black limbs and elytra, must take the first place among the

beetles for beauty of form and colour. The large, harmless _Hydrous

piceus_, the lively _Notanecta_, _Gyrinus_, and _Nepa_, are essential to

the collection.

Among the larva, those of the Caddis fly should be kept in abundance, on

account of the amusement afforded by their strange habits and their

remarkable metamorphosis. Larva of the Dytiscus, known as the Water

Tiger, of the Dragon fly, the gnat, the May fly, and of the two-winged

fly, _Stratiomys Chamæleon_, the pretty blood-worm, which is the larva

of the _Chironomus plumosus_, a very pretty gnat, with feathered

antennæ; and the telescope-tailed grubs of _Helophilus pendulus_, which,

in its larva form, is one of the most curious examples in the cabinet,

and, in its imago, is frequently mistaken for the honey-bee.

The drag-net will also bring out many curious water-mites, than which

there can be no more interesting subjects for the microscope, or

prettier objects for ordinary observation. While writing this, I have

before me several specimens of the beautiful mites, _Hydrachna

geographica_ and _abstergens_ (Müller), in a jar of _Nitella_; they are

ever in action, treading the water as if it were air, with a kind of

motion that cannot be termed swimming, but rather a walking or dancing,

maintained with the greatest ease at any level, or at the bottom of the

vessel. Another, and much more showy one, is the bright carmine-coloured

mite _Limnochares holosericea_ (Latreille), of which I find an abundance

in a neighbouring brook. Its pretty, spidery motions, and vivid

colouring, render a jar, containing a dozen specimens, very attractive

to the eye of a student of nature.

[Illustration: DIVING SPIDER AND NESTS.]

The Diving Spiders are amusing, and should be kept in plenty in large

jars, well stocked with healthy weed; and the curious Raft Spider may

also be preserved in a shallow vessel, closely covered with gauze.

Aquatic Spiders are most abundant in clear brooks and ditches near

rivers; the small tributaries of the Lea, and the dykes that abound in

the marshes at Tottenham, supply me with specimens whenever I seek them.

Among the water-worms most easily obtained, the hair-like _Gordius

aquaticus_ (Linnæus), and the curiously-formed _Nais_, may be

recommended as curious and interesting. The latter requires a bottom of

sand in which to burrow, and should be covered with only a few inches of

water. When it takes to its new home, it plunges its body into the sand

or mud, and extends its telescope-tail upwards to the surface for air,

adapting its length to the depth of the water.

The generation and development of reptilia and mollusca may be better

studied by the use of jars for the specimens, than by their immersion in

the aquarium. Tadpoles, the larva of newts, and the spawn of mollusks,

may be preserved in the cabinet for purposes of study, much better than

in the tank; each species being separate in a bright and portable

vessel, every minute change can be observed, and a lens applied at any

time, or the specimens removed for close inspection without difficulty.

I find it a good practice to remove any spawn, which may be deposited on

the large vessels, to the small jars on my shelves. There the little

_Lymnea_ and _Planorbis_ are developed in hundreds, without molestation;

and if increase of Paludina vivipara be required, a jar is at once

converted into a breeding tank by throwing a couple into it, with a

bunch of _Callitriche_, and any vegetable waste from the tanks. In the

aquarium, the young mollusks are devoured almost as soon as they are

born; and the pleasing spectacle of their increase, coming forth from

the gelatinous mass in hundreds, like minute beads of gold, is lost

without the aid of the cabinet in which to rear them. The young of most

species of univalve mollusks are vagrant in their habits, and the jars

in which spawn is hatched should be closely covered with perforated card

or gauze, fitting closely by means of India rubber rings.

Since it is unnecessary in this work to give a classified history of the

several creatures that may be kept in water-cabinets, I shall devote the

remainder of the space at my command to notices of a few of the most

attractive and best known species, and to a few hints on the general

management of the cabinet.

CHAPTER IV.

LARVA.

The great class of insects comprises many remarkable and diverse forms,

among the 560,000 species which Dr. Imhoff estimates to be now known to

naturalists. Yet, various as they are, it is by no means impossible to

define what are the distinctive features by which this class is

separated from those which approach it in conformation and habits. A

true insect has the body divided into three parts--the head, the thorax,

and the abdomen. It has never more than six legs, and these are attached

to the thorax. The segments of the body seldom exceed thirteen in

number, one of which forms the head, three the thorax, and the remaining

nine the abdomen. The possession of one or two pairs of wings gives

them their prominent characteristic to the eye, but it is the successive

metamorphoses that arrests universal attention, and calls forth the

admiration and wonder of mankind. In the progress of an insect from the

minute egg to its completed form, we see the most remarkable series of

developments which animal life ever displays in all its endless

procession of forms--the egg, the worm, the chrysalis, the fly--a

strange unfolding, for the first time accurately observed by Swammerdam,

who detected, under the wrinkled skin of the disgusting worm, the

complete outline of the lovely butterfly.

This metempsychosis may be studied in its several strange details by the

aid of the Water-Cabinet. The first condition of the newly-hatched egg

is that known as the grub, or caterpillar--scientifically called the

_larva_. The larva generally bears no earthly resemblance to the

_imago_, or perfect insect, into which it is to be hereafter developed,

but leads a life of sensual enjoyment--it eats, eats! it is gluttony

concentrated in type and act. It changes its skin several times, slips

one coat off and acquires a new; growing, and eating, and changing

garments, till, like man himself, it seeks a temporary tomb, from which

it is to soar to the skies like a soul liberated. This second form is

popularly known as the chrysalis, or aurelia, scientifically called the

_pupa_. In this form the insect remains in a state of complete or

partial torpidity for a few days, weeks, or months, according to the

particular species.

The day of its deliverance arrives, its bonds burst, and it comes forth

"a thing of beauty" to sport in sunbeams, and, for but a brief season,

lead a life of joy--

"Fluttering round the jasmine stems,

Like winged flowers or flying gems."

But beauty of the high poetic kind is not the inheritance of every

member of the class insecta; and the water-cabinet presents us with many

that have but analogical resemblances to the typical structure of the

moth or the fly, though the naturalist finds beauty in a beetle, and

points of profound interest in a maggot or grub.

Since larva are distributed through at least three elements, being,

according to the species, inhabitants of earth, air, and water, the

breathing apparatus arrests our attention, as constituting a distinct

feature in the anatomy of the insect. A caterpillar may be regarded as

all stomach, and the cravings of this immense digesting tube easily

account for the voracity of larva of all kinds. In the larger animals,

the food is elaborated into blood, and brought to the lungs to be

oxygenated by means of contact with the air, but the insect does not

breathe at the mouth, but at the other end, or by means of tubes

arranged along the sides of the body. In a caterpillar there are usually

eighteen of these tubes, the orifices of which may be seen in action.

These tubes all run into two larger lateral tubes, or wind-pipes,

arranged one on each side of the body; and from these lateral tubes

innumerable smaller ones diverge, and convey air to the vessels in which

the digested food is contained, and thus supply it with oxygen.

Swammerdam was the first who successfully anatomised this class of

animals, and to him we are indebted for the microscopic anatomy of

grubs, and a revelation of their inner economy generally.

The Dragon Fly, _Libellulidæ_ (Leach), a well-known summer beauty--the

mere mention of which is always sufficient to set one's heart beating

for rustic coolness, and the hushed music of the beechen shades--is, in

its larva form, an interesting object for the cabinet. Between the larva

and the imago of this insect, the difference is striking indeed; as a

lady, not addicted to scientific studies, once characterised the

larva--using Pope's lines--as,

"A monster of such hideous mien,

That to be hated needs but to be seen."

But the gauze-winged and gaily-coloured fly merits all the praise

bestowed upon it by the French, who call them _Demoiselles_, so light,

fairy-like, and visionary are its form and movements. Scientific writers

have applied many descriptive names to it, such as _Calepteryx_ (pretty

wing), _Puella_ (girl), _Sponsa_ (bride), and _Virgo_ (virgin). The

larva of the dragon fly exhibits, in a very striking manner, the mode of

respiration in aquatic insects. It is not an active creature; for though

it has six legs, it seldom uses these except in the capture of prey; its

locomotion is chiefly performed by the tail in the action of breathing.

When thrown into a jar with some fragments of weed and a few light

chips, these will be seen to be drawn towards the tail of the creature,

by the current occasioned by the absorption of water; and then again

driven off, with considerable force, as the water is again ejected. The

quantity drawn into the body by this hydrostatic action must be

considerable, since the dimensions of the larva regularly change with

the breathing action, the body becoming collapsed when the stream is

ejected, and again swelled out with the suction that follows. If it be

thrown into water, tinged with cochineal, and then quickly removed again

into clear water, the coloured stream will be seen to be projected

several inches, and with force sufficient to propel the creature forward

by a series of successive jerks.

Besides the act of breathing, then, this anal pump has locomotive uses;

and it also aids the creature in obtaining food by drawing minute

creatures towards it in a manner similar to those animals which are

furnished with cilia.

But the microscope reveals a still more curious fact, in the anatomy of

this larva, which has been most faithfully described by Kirby and

Spence. The under lip, when closed, entirely conceals the mouth, and it

not only retains, but actually seizes, the animal's prey, by means of a

very singular pair of jaws with which it is furnished. Conceive your

under lip (to have recourse, like Reaumur, on another occasion, to such

a comparison) to be horny instead of fleshy, and to be elongated

perpendicularly downward, so as to wrap over your chin, and extend to

its bottom---that this elongation is there expanded into a triangular

convex plate, attached to it by a joint, so as to bend upwards again and

fold over the face as high as the nose, concealing not only the chin and

the first mentioned elongations, but the mouth and part of the cheeks.

Conceive, moreover, that to the end of this last-mentioned plate are

fixed two other convex ones, so broad as to cover the whole nose and

temples--that these can open at pleasure, transversely, like a pair of

jaws, so as to expose the nose and mouth, and that their inner edges,

where they meet, are cut into numerous sharp teeth, or spines, or armed

with one or more long sharp claws--you will have as accurate an idea, as

my powers of description can give, of the strange formation of the under

lip in the larva of _Libellulina_, which conceals the mouth and face,

precisely as I have supposed a similar construction of lip would do

yours. You will probably admit that your own visage would present an

appearance not very engaging, while concealed by such a mask; but it

would strike still more awe into the spectators, were they to see you

first open the two upper jaw plates, which would project from the

temples like the blinders of a horse; and next, having, by means of the

joint of your chin, let down the whole apparatus and uncovered your

face, employ them in seizing any food that presented itself, and

conveying it to your mouth. Yet this procedure is that adopted by the

larvæ of the dragon-fly, provided with this strange organ. While it is

at rest, it applies close to and covers the face. When the insects would

make use of it, they unfold it like an arm, catch the prey at which they

aim, by means of the mandibuliform plates, and then partly refold it, so

as to hold the prey to the mouth, in a convenient position for the

operation of the two pairs of jaws with which they are provided. The

form of this masked jaw is represented, but not very clearly, in

Rennies' "Insect Transformations," p. 164.

[Illustration: TRANSFORMATION OF THE DRAGON FLY.

1. The Fly just emerging. 2. The Fly nearly free, and forming an arch.

3. The Fly liberated, and with its body bent, to hasten the drying of

the wings.]

When its season of larva life is over, it retires to the bottom of the

vessel to repose, and becomes a pupa. When the crumpled form of the

gaudy fly begins to expand within, and to knock at the door of its

sepulchre, the pupa quits the watery element for ever, and betakes

itself to the dry land, or to the slip of cork placed in the jar for its

use. There, the apparently painful process of its unfolding takes place,

and the fly slowly emerges. The envelope bursts asunder, and the head of

the lovely, but bloodthirsty damsel, emerges to the light. Next appear

the legs, not in action, but gathered up to the breast, as if in spasm,

and, for a time, the effort is suspended, and the helpless, half-formed

beauty hangs back her head, as if languid with the exhaustion of pain.

Once more she pants for freedom, sighing to sun herself in the blue

ether, and another struggle is made. This time she clutches at the pupa

case with a convulsive grasp, and drags forth the whole of her delicate

body from the grave, and there remains motionless, still clinging to it,

as if contemplating the baseness of her origin--for beauty is ever the

offspring of the dust. She is free at last--but, ah! how helpless. Her

wings are damp, and closely folded, and would not yield to the wish for

flight, even were she already possessed of the power to stir them into

action. She is on the threshold of a new world--a creature born of the

dust, just escaped from the dust; and now as we watch her wings dry and

expand, away she goes--a thing of light and loveliness soaring

heavenward. Like the mortal ark, out of which the spirit of man escapes,

we may, without losing sight of the disparity of the subjects, speak of

the chrysalis of the dragon fly as--

"A worn-out fetter, which the soul

Has broken, and thrown away."

[Illustration: DRAGON FLIES.

_a._ Virgin Dragon Fly--_Calepteryx Virgo_.

_b._ Green Dragon Fly--_Æshna varia_.]

THE GNAT--_Culex pipiens_ (LINNÆUS)

In the operation of dragging, many curious larva are brought out, and

the mud should be searched carefully for them before washing the net for

another cast. The larva of the gnat is one of the most interesting of

these, and during summer may be obtained in hundreds if a little of the

brook water be dipped to fill the jar with, and a few light weeds thrown

in to supply oxygen. These larva are the produce of eggs deposited in a

curious manner.

The gnats repair to the water soon after day-break, and commence an

operation of a truly naval kind, such as would have delighted the savage

heart of Peter the Great, could he have witnessed it in the midst of his

dreams of achieving naval power. In fact, the mother gnats construct

rafts of eggs, and each egg is added as a separate timber of the vessel,

till a boat-like structure is produced. The skill as well as the

necessity of the construction is well tested by the fact that each

separate egg would of itself sink to the bottom, whereas being protruded

one by one into the angle formed by the hind legs which serve as stocks

for the future vessel, and successively glued to each other by the fluid

which exudes with them, they gradually assume, under her guidance, a

neat boat-like form of about three hundred minute pyramidal eggs.

"The most violent agitation," says Kirby, "cannot sink it, and what is

more extraordinary, and a property still a disideratum in our

life-boats, though hollow it never becomes filled with water, even

though exposed."

The grubs at last come forth, and lead a very merry sort of life under

the shadow of the sedges. Placed in the jars they appear at first sight

like newly hatched fry of fishes, but we soon detect the segments of

their pellucid bodies, and, as might be expected in water larva, they

breathe at the wrong end, and hence most of their merry movements are

performed between the surface and the bottom; every time they descend

they carry with them a minute bubble from the surface. Under a good lens

the pretty creature changes its form considerably, and comes out in the

pantomime style, with huge horns, goggle eyes, and starched frills of

shaggy hair; but then the tail becomes the object of attraction, and we

watch the breathing action of the curious funnel which breaks away at an

angle from the last segment of the body.

[Illustration: LARVA OF THE GNAT, NATURAL SIZE AND MAGNIFIED.]

Swammerdam first observed that the breathing tube and tail are both

anointed with oil, and that if the larva is handled roughly the oil is

removed, and the grub "can no longer suspend itself on the surface of

the water. I have, on these occasions, observed it put its tail in its

mouth, and afterwards draw it back, as a water fowl will draw its

feathers through its bill to prepare them for resisting water." I have

now (July, 1856) some thousands of the larva of this and other species

of gnats, and they are the most lively creatures in my collection. The

flies come off in large numbers, and escape through the open window; or,

if the window be closed, they swarm on the glass, and keep up a musical

humming, closely resembling that of a swarm of bees at a distance.

[Illustration: LARVA OF STRATIOMYS.]

A more elegant example of this kind of breathing apparatus is seen in

the grub of the two-winged fly, _Stratiomys Chamæleon_. The funnel tail

spreads into a beautiful star of thirty distinct rays, and with this

structure, the creature suspends itself to the surface of the water, as

if it were a ceiling, and as it moves to and fro its changes of position

may be noted by the shifting of the dimple on the surface.

In the little gnat, _Corethra plumicornis_ (Meigen) we have some further

examples of the peculiar conformation of the larva, to enable it to

respire in the water; but the larva is so transparent that it requires

an expert microscopist, and an effective instrument to work out the

details as represented by Reaumur and Dr. Goring. The larva of this

species is plentiful in our brooks, and worthy of close scrutiny by the

aid of the microscope. Just now the gnats are abundant in meadows near

streams, and to them we are indebted for that soft humming which has

been appropriately termed the "music of the wild," and on which good old

Gilbert White exhausted his ingenuity to find an explanation. The social

communities of these ephemeral creatures are strictly music parties, and

whenever we suffer them to assemble about our heads, when rambling in

the hedgerows, we are entertained by their fairy-like performances.

_Expertum est._

The Case Fly _Phryganea grandis_.--There are several species in the

family of _Phryganea_, which is the only tribe in the order

_Trichoptera_, but such strong resemblances exist between the several

members of the family that some entomological experience is necessary to

enable the student to distinguish them. In an aquarium, the caddis worms

are very amusing, and since they thrive there, they are very suitable

additions to the happy family. We see them busy at the bottom, adding

fragments of weed, pebbles, minute shells, even if the snails within

them are alive, and any small debris that their fingers can seize hold

of. Last season I had amongst a large number of cads, one that had his

case nearly destroyed by accidentally falling from the table. I removed

from him what remained of his case, and threw him into a jar with a

soldier plant and a few _Lymnea_. He set to work to repair his

tabernacle, and the _Lymnea_ helped him, for they nibbled a plant of

_Stratoides_ into shreds. These shreds the cad gathered, and every day

he added a fresh piece, so that, in about ten days, he appeared in a

suit of green, his clothes bulged out to an enormous size, and

everywhere studded with points and corners, the most comical sight that

could be imagined. Since he could find nothing of a small neat pattern,

he took what he could, and became a perfect Jack in the green, nearly an

inch and a half in length, and thicker than a carpenter's lead pencil.

[Illustration: LARVÆ AND IMAGO OF CASE FLY.]

The movements of these creatures are as comical as their specimens of

tailoring. We see them mounting a stem or leaf with great gravity, when

suddenly up goes the tail, the legs hold tight, and the case turns

completely over, as if on the first of May, Jack-in-the-green were to

dance on his head. When the creature is hidden, and the case sways to

and fro like a buoy attached by too short a rope, the sight is very

curious. This case-maker is the larva from a fly which bears

resemblances to the two families which stand on either side of it--the

_Lepidoptera_, or true butterflies, and the _Neuroptera_, of which the

dragon flies and other membranaceous winged insects are members. As soon

as he enters the world, he begins to show his skill in tailoring, and by

means of silken threads and gluten constructs his case of bits of stick,

straw, dead leaves, or shells, in fact, whatever he can get, and as long

as he retains the worm-like form the case is his castle, and he can defy

the world. The case outside is generally a rough affair, but if you draw

out the cad you will see that inside it is perfectly cylindrical,

smooth, and polished, and around the doorway, through which the larva

makes acquaintance with the world, it is neatly finished with a very

circular rim. When you have removed a cad, if you throw him into a tank

you will learn in an instant what is the use of his case, for his soft

nakedness is no sooner exposed, than the minnows finish him, and find

the flavour excellent. But to see a cad in his proper uniform molested

is a very rare sight indeed. He passes his larva life innocently, and is

an amusing fellow; when he feels the numbness of death creeping over

him, the cad draws in his six legs, and sets to work inside to weave a

winding-sheet and to shut the shutters, for he knows that his time is

come, and there is no one to do such melancholy offices for him. All

alone in his solitary cell, the hermit works day and night, and hourly

his fingers grow more feeble. We look and find the shutters closed, and

by this time the larva has changed into a pupa.

[Illustration: GRATING OF CASE-WORM, MAGNIFIED.]

The mode in which the worm closes its cell is curious enough. Over its

entrance it weaves a grating of silk, which hardens in water and remains

insoluble. It may be seen very plainly by the naked eye, but under a

good lens increases in interest. The grating is placed a little inside

the margin of the opening, and fits exactly within it, and its object is

to protect the pupa from invasion, and at the same time, to admit water

for respiration. De Geer describes one of these gratings in which the

pierced holes were disposed in concentric circles, as represented in the

engraving. This, however, is not, as far as I am aware, the usual form

of the grating, many that I have examined were formed in regular rays

from a centre like the spokes of a wheel.

But the escape of the pupa, when about to undergo its last

metamorphosis, is as interesting as the fact of its closing the shutters

to announce its own death. It is provided with a pair of hooked

mandibles, with which to gnaw through the grating, and no sooner have

these accomplished their purpose than they fall off, and the pupa takes

its last shape of a four winged fly, as represented in the cut.

CHAPTER V.

COLEOPTERA.

The beetle tribe are distinguished from other insects by the possession

of _elytra_, or wing-cases; which wing-cases are, with regard to the

typical structure of an insect, to be regarded as really the first pair

of wings hardened into a horn-like consistence to protect the others.

The wing-cases are of little or no use in flight, this action being

accomplished by means of the second pair, or the true wings, which are

generally of large size, and when not in use are neatly folded up

beneath the elytra. The division of the body into three parts--head,

thorax, and abdomen--is very plain to the eye; but the segments, of

which the several parts are composed, are frequently so consolidated

that it is difficult to detect or count them. For instance, the thorax,

theoretically, consists of three segments; but, practically, the first

of these is usually so largely developed as to appear to constitute the

thorax in itself. The (theoretical) nine segments of the abdomen are, in

like manner, reduced to six or seven, in consequence of the last two or

three being consolidated into one.

The order is an immense one, as to its range and variety, and hence

there are in it many curious exceptions to the general conformation of a

beetle. Some are utterly incapable of flight, owing to the

non-possession of elytra, or wings; some have elytra only; and in some

the elytra meet and unite along the suture; so that, if the insect had

wings underneath, it would be impossible for it to use them.

The specimens of coleoptera, kept in the water-cabinet, are among the

most interesting of the whole collection, whether in the larva or imago

form; and to this order we are indebted for a large number of aquatic

species, that may be kept in jars, and some few that may be introduced

without danger to the tank.

Dytiscus Marginalis is one of the handsomest of water-beetles, and its

habits are amusing and instructive. It possesses an insatiable appetite,

and great muscular power, as we soon discover when removing it from one

jar to another, for if it succeeds in planting its claws firmly on the

edge of the vessel, it is difficult to move it. It belongs to the large

tribe of _aquatic carnivora_, ranged in the section _Pentamera_, in

which the tarsi of all the feet are five-jointed, the fourth being of

ordinary size.

[Illustration: DYTISCUS AND LARVA (REDUCED).]

The _Dytiscus_ is a true water-beetle, being aquatic in both its larva

and perfect forms. The larva, known as the water-tiger, is found in

plenty in the muddy ditches round London, and is a strong, stubborn,

ugly, and ravenous worm, with a tail formed for respiration, and curved

mandibles to tear its prey to pieces. It is very active, and may be kept

without difficulty; but nothing else should be placed in the same jar,

unless intended as food for this savage. A small fish thrown is eagerly

clutched, and held firm by the claws; and the larva then plunges its

mandibles into it, and is soon buried head-deep in the mangled body of

its prey. I have generally fed them on beef, but they prefer small fish,

or larva of the dragon-fly, and do not go through their metamorphosis

well without such food.

The imago is a handsome creature, with strong hooked claws, furnished

with amber hairs, which, under a lens, resemble very closely the claws

of a crab. The elytra are beautifully tinted with rich green and bronze,

and the divisions of the head and thorax separated from the abdomen by

sharp, whitish lines. Small fishes make the best diet for this beetle;

but as this food fouls the water, it is best to keep them in clear jars,

with a few pebbles and weeds, and once a week remove them to another

vessel, to be fed. This plan preserves the brightness of the beetle jar,

and prevents the annoyance of effluvia.

Hydrous Piceus.--This is the largest of our native aquatic beetles, and,

with the exception of the stag-beetle, it exceeds in bulk any other

species of indigenous Coleoptera. It is common in the brooks and ponds

in southern counties, but becomes rare as we travel northwards. In the

larva state this is a rapacious and bloodthirsty insect, and of so

destructive a character as to deserve its French name of _ver-assassin_.

In that early condition it resembles a large soft worm, of a somewhat

conical form, provided with six feet, and having its large scaly head

armed with two formidable jaws. The head moves with such freedom in all

directions, that it can readily seize small shell-fish and other

mollusca floating on the surface, without altering the horizontal

position of the body maintained in swimming; and it is even bent

backwards, and devours its prey more conveniently by using the back as a

kind of support. These larvæ swim with facility, and have two fleshy

appendages at the tail, by means of which they suspend themselves at the

surface with their heads downwards, when they have occasion to respire

(_Cuvier_). The beetle differs greatly in habit from the grub; it is by

no means carnivorous, but quite harmless, docile, playful, and tameable.

It is a noble creature for the cabinet, and may even be kept in the

Aquarium safely. In its complete form it is as interesting for its

gentleness as it is in the larva state for its rapacity and

destructiveness. The female spins an elegant and waterproof cocoon for

the reception of its eggs, and when they are deposited she watches them

with a maternal solicitude not frequently exhibited by creatures of this

family.

[Illustration: HYDROUS PICEUS.]

The hydrous piceus is here represented of the natural size; the ground

colour is black, with a shade of bronze, and the margins of the elytra

are tinged with green and purple. Each wing case is marked with dotted

lines, the breast is dingy yellow, and the antennæ and organs of the

mouth dull red. The legs are black, and the hairs which fringe the tarsi

reddish brown.

[Illustration: COLYMBETES.]

Colymbetes, of several species, may be obtained in plenty from clear

brooks in every part of the country. These are elegantly-formed and

lively beetles; their elytra, legs, thorax, head, and breast of the same

jet-black hue, and highly burnished, though, when immersed, the breast

and abdomen glisten with an intensely metallic silvery lustre, owing to

the film of atmospheric air which the beetle obtains from the surface,

and which adheres to the hairy covering of the abdomen. This silvery

species is here represented in its natural size. They are comparatively

harmless, though I have just witnessed the demise of one that was

attacked and eaten by his pretty kindred, the wing-cases and head only

remaining to testify of his former individuality. This is a delicate

beetle, that requires very pure water and a neat arrangement of aquatic

plants, to give full effect to its beauty as a cabinet specimen, and,

when carefully preserved, a jar of them forms a conspicuous and

attractive object. I have several specimens of a smaller species in a

very fine jar of confervoids; they are incessantly in motion, threading

their way through the interstices of the delicate vegetation in a

business-like way, that seems to say, "I'm on an important errand--have

not a moment to lose, and, above all things, I must take care of the

bubble of air that sticks to my tail."

Gyrinus Natator.--This is a member of an interesting and pretty family.

_Gyrinus_ takes its name from the tendency most of the beetles of the

tribe have to _move in circles_, and this particular species exemplifies

the habit of the tribe in a very striking manner. It is a very sociable

beetle, always found in company with others of its kindred, forming

little communities, which pass their time in whirling and spinning upon

the surface of still pools, like congregations of dancing dervishes.

They are as shy as they are nimble, and it requires some dexterity to

net them, for they dive and scatter on the approach of a footstep; but

if the observer remains quiet a few minutes by the water's edge, or on a

plank or bridge above the pool, they soon resume their gambols under his

eye, and in the sunshine appear like minute buttons of burnished metal

rapidly revolving or darting to and fro upon the surface, and for a

length of time, that proves them to be by no means subject to giddiness.

[Illustration: GYRINUS NATATOR.]

The _species of Gyrinus_ are not numerous in Britain, not more than

eight being known to naturalists; but the paucity of species is

compensated by the profuseness of the individuals, and of these

_natator_ is the most abundant. When placed under a lens, this beetle

bears the form represented in the next page. The colour is blue-black,

with a resplendent metallic lustre, in which shades of copper, silver,

and bronze occur, as we view it at various angles to the rays of light.

The thorax is marked with three transverse lines on each side, of which

the anterior one is punctured, and runs parallel with the margin. The

elytra are turned in at the sides, and the surface of each is marked

with eleven striæ or longitudinal lines, composed of minute punctures.

The terminal segment of the abdomen, together with the legs, are of a

rust-red.

[Illustration (Gyrinus)]