THE VEGETATION OF THE MARINE AQUARIUM.
As the forest must be planted before its denizens can luxuriate in its
shades, so the submarine shrubbery of the Aquarium must be perfected
before the aquatic animals can be introduced. For it has been shown, in
tracing the history of the experiments which resulted in the
establishment of the principles that regulate the formation of Aquaria,
that it is by plants only that a supply of oxygen can be kept up,
sufficient for the health and existence of all forms of animal life
beneath the water.[1] It is necessary, also, that the rays of sunlight
should fall upon the foliage directly through the surface of the water;
and when an Aquarium, with its plants, is placed in a position to
receive the light in this manner, their fronds may be observed giving
forth the gas in small silvery bubbles and corruscations, which have a
brilliant and gem-like appearance.
[Footnote 1: Analogous principles are at work in our fields and forests,
but we have now only to do with the submarine production of oxygen.]
Some marine plants appear to succeed much better than others, but I
believe that happens only from their treatment being imperfectly
understood; and I believe, not only that all the exquisitely beautiful
marine _Algæ_ of our own shores may be successfully grown, but also that
the more splendid varieties of the tropical seas may be made to thrive
in properly-heated Aquaria, and thus form one of the most attractive
features of our hot-houses—one that has not yet been dreamed of.
In ordinary Aquaria, such as I am now treating of, I shall name first
those species of sea-weed recommended by Mr. Gosse and others as most
easily cultivated, but I shall also point out many other species, which
I feel convinced may be successfully grown under proper management; and
they certainly deserve every effort that can be made to establish them
in Aquaria, as they are among the most beautiful of their tribe.
If not purchased of dealers, the plants must be very carefully collected
by the amateur himself, taking care to detach a portion of the substance
to which they are growing, and packing them in damp refuse sea-weed,
keeping them out of their native element as short a time as possible.
The plants in most flourishing condition in the marine tanks of the
Zoological Gardens, were at first those of the _Chlorospermatous_ order,
but others have since succeeded nearly as well. Plants of _Ulva_ and
_Conferva_ have done very well, but the most successful growth has been
that of a plant of the genus _Bryopsis_, which, entirely enveloping a
large stone in its mossy and almost feather-like foliage, produces a
very beautiful appearance. Those unlearned in scientific names will be
glad, perhaps, to learn that these beautiful _Algæ_ derive their title
from two Greek words, Bryon (βρυον), a moss, and opsis (οψιϛ), a
resemblance, from their likeness to some of the most delicate and
feather-like mosses of our woods. The delineation of _Bryopsis plumosa_
in Plate II., on the extreme left near the lower part of the Plate, will
convey some idea of these elegant sea-weeds.
_Chondrus crispus_ is a beautiful plant, and well suited to the
Aquarium. It will often be found under ledges of rock, completely
concealed by a pendant veil of _Fucus_, commonly known as the
olive-weed; and, on lifting the tangled mass of its rank growth, many
beautiful and unexpected plants are frequently found, but none strike
the explorer more than the _Chondrus_. Its nacreous tints, like those of
a pearl shell, varying wonderfully according to situation, being very
remarkable. It is the Carrageen Moss of the herb market. This plant
forms the principal object in the lower part of Plate IV., to the right.
_Laurencia pinnatifolia_ is a pretty branching plant, also varying in
hue according to the aspect in which it grows. In the shade it is
purple, but when receiving the full influence of the sun’s rays, it
assumes a light-yellow tone; just as the _Lycopodium_, known as
Fortune’s Moss, is purple when grown in the darkest part of a room, but
becomes of an ordinary green tone when placed for some time near the
light. The _Laurencia_ is shown at the upper part of Plate V., coloured
pale-violet.
The splendid plant _Rhodymenia palmata_, with its finely-coloured,
semi-transparent fronds, is also recommended. It is the Dulse, or
Dellis, eaten by the inhabitants of our northern coasts as a delicacy.
Another species of _R. lacinata_ is represented to the left of Plate V.,
the transparent light-crimson fronds of which are excessively beautiful.
Mr. Gosse tells us that the _Rhodymenia palmata_ is not suited to an
Aquarium, because it appears to require the motion of the sea, and soon
begins to decay in still water. If that be the case, let us provide a
remedy, for the plant is one of the most beautiful among all its lovely
congeners. When a plant of the gigantic lily of the Amazon river was
first introduced, it refused to flower in the tank provided for its
northern home, at the Duke of Devonshire’s residence at Chatsworth. But
Sir Joseph Paxton, who then directed the floricultural operations of
that magnificent abode, was not discouraged; and, seeking to impart to
the still water of the tank something of the motion of a deep and
majestic river, he contrived that a small but continuous stream should
enter at one end of the tank, and, as it entered, turn a small
paddle-wheel, the action of which imparted a gentle, undulating motion
to the water of the whole tank. The device was triumphant, and the
glorious _Victoria regia_ formed and expanded its giant flowers in the
house which its curator had constructed for it, the plan of which
eventually suggested the creation of the “Crystal Palace.” Let us not
despair, therefore, of cultivating successfully the beautiful
_Rhodymenia palmata_ in our Aquaria. The construction of a suitable
apparatus for imparting motion to the too still waters, will form a
pleasant _passetemps_ for some of our fair admirers of the pursuits of
the Aquarium; and their success would be a signal triumph. But at
present the beautiful red weeds, in general, are difficult of
cultivation, and when they begin to exhibit spots of orange—a vegetable
plague-spot not to be mistaken—it is a symptom of decay which should at
once cause their removal from the Aquarium, before their decomposition
leads to further mischief.
The common Coralline, _Corallina officinalis_, of which a small spray is
represented in the extreme lower part of Plate V., near the centre, is
the “arboret of jointed stone” alluded to by the poet, and is well
suited to Aquaria, thriving with little trouble. The smaller and
slenderer kind is also suitable; but care must be taken, in collecting,
not to choose the detached white fragments, which are washed up with
every tide, for they are only the skeletons of the plant. It is the
rosy-tinted specimens, verging to violet and purple, and still attached
to pieces of rock, that are alone fit to remove to the Aquarium.
[Illustration: PLATE I.
1. Delesseria sanguinea.
2. Punctaria latifolia.
3. Chordaria flagelliformis.
4. Vaucheria submarina.
5. Hildenbrandtia rubra.]
The _Cladophoræ_ are also stated to be very suitable, _C. rupestris_
being a very useful plant for the purpose. It is of a bluish-green, that
harmonizes well with the tone of the sea-water, and fills up little
chasms in the artificial rocks with very good effect, especially in
contrast with the reddish-purple tufts of _Polysiphonia arceolata_,
which do well in an Aquarium, and are a great aid to the foliage of the
little marine landscape. The elegant, fan-formed, and brightly-radiated
_Padina pavonia_ is likewise mentioned, and should at all events be
tried, as the tufts of that graceful marine plant form very singular as
well as beautiful objects in the tank.[2]
[Footnote 2: A list of the plants with which Mr. Gosse furnished his
first Aquarium is given in Chapter III.]
I would also recommend the trial of all the plants delineated in the
five Plates devoted to the sea-weeds in this little book.
In Plate I., the first, occupying the upper part, with leaf-like fronds
of transparent crimson, is the beautiful and not uncommon sea-weed,
_Delesseria sanguinea_. The delicate pale plant below, to the right, is
_Punctaria latifolia_, thin as tissue-paper, and speckled over its
pale-buff surface with bright but minute grains of black. To the left is
a branch of _Chordaria flagelliformis_, the rich olive of which
contrasts well with the red kinds of _Algæ_. In the front, growing on a
detached pebble, is the Lichen-like _Hildenbrandtia rubra_, the rich
carmine of which might be made to form an exquisite touch of colour, if
tastefully placed in the Aquarium; and to the extreme right is a small
tuft of _Vaucheria submarina_.
In Plate II., the principal object, near the top of the Plate, is a bush
of _Callithamnion arbuscula_, which receives its name from the tree-like
aspect which it assumes more distinctly than any other of the marine
_Algæ_. Behind it, to the right, are the tall and graceful forms, with
their crimped edges, of the slender _Laminaria phyllitis_. And below,
still to the right, is a branch of _Codium tomentosum_, distinguished by
its light, vivid green, and the edging of delicate ciliæ, which have the
appearance of a border of paler green, to every branchlet. Still to the
right, in the extreme foreground, is a broken piece of rock on which
plants of the curious _Leathesia Berkleyi_ have grown, like convex
kernels of bronze. To the left are the red-violet tufts of the _Bangia
fusco-purpurea_, and behind them, a branch of _Bryopsis plumosa_.
[Illustration: PLATE II.
1. Bangia fusco-purpurea.
2. Codium tomentosum.
3. Bryopsis plumosa.
4. Callithamnion arbuscula.
5. Leathesia Berkleyi.
6. Laminaria phyllitis.]
In Plate III. the bright-green feathery plant in the extreme background
is _Ectocarpus siliculosus_; and behind it, the violet, antler-like
fronds of _Nemaleon multifida_. The large, gracefully-bending frond of
rich purple, with narrower and younger fronds springing from the same
root, is _Porphyra vulgaris_, one of the commonest, but most splendid of
our marine _Algæ_, with which, in combination with other plants of
suitable contrast, the vegetation of the Aquarium may be rendered truly
splendid, if it once be successfully cultivated; of which I have no
doubt, when its natural wants are sufficiently studied and ingeniously
supplied. The splendidly-marked plant to the right, with its black
maculations and richly-frilled edge, is _Nitophyllum punctatum_, one of
our most splendid species; and the curious pale-buff, tubular plant in
front of it, is _Asperococcus Turneri_. Near the foot of the
_Nitophyllum_ is a little tuft of the delicate _Dumontia filiformis_;
and, to the extreme left, a branch of the brown-fronded _Rytiphæa
pinastris_, which receives its specific name from the somewhat Pine-like
growth it frequently assumes. Immediately beneath it, on the extreme
right, is a little cluster of _Chordaria divaricata_; and below, in the
left foreground, are a few pink fronds of the curious Alga, _Chrysemenia
rosea_; while, in the foreground, to the right, on a detached pebble, is
a small mass of the pale-crimson _Peyssonetia Dubyi_.
In Plate IV. the principal object is a fasciculus of _Taonia atomaria_,
rising behind the point of rock at the top of the Plate, behind which
are two long fronds of the spotted _Asperococcus_; to the left is the
horn-like _Gigartina acicularis_; and in the front, to the left, the
crimson tufts of a pretty weed (_Ceramium strictum_), which our artist
has made too like the _Bangia fusco-purpurea_.
In Plate V. the violet-toned _Laurencia pinnatifolia_ is grouped behind
the solid, deep-crimson fronds of _Iridæa edulis_, which are often
perfectly Pear-shaped, like pieces of crimson leather neatly cut in that
form; but the action of tides in rough weather often tears the edges,
and wears holes through the texture of the plant, as shown in the
principal frond. To the left is the bright-crimson _Rhodymenia
lacinata_—one of our most exquisitely beautiful marine _Algæ_. The
fronds are as thin as the finest conceivable tissue, and beautifully
transparent, which is shown wherever the lacinations of the edge overlap
each other, in which places the double thickness of the texture doubles,
at the same time, the intensity of the colour, as indicated in the
representation. On the same level, to the right, is a small group of the
delicate green _Ulva latissima_—a plant which has proved useful beyond
all others in Aquaria, as throwing off, under the action of the light, a
much greater profusion of silvery globules of oxygen than any other
species yet known. At the same level still, on the extreme right, is a
sprig of the delicately-branched parasite, _Polysphonia parasitica_,
growing on a small mass of pale sulphur-coloured _Melobesia
lichenoides_, the Lichen-like Melobesia. To the extreme left, under the
beautiful _Rhodymenia_, is a small branch of the bright, olive-tinted
_Ectocarpus tomentosus_, looking much like a spray of wild Broom, and
immediately below it, a few purple branchlets of _Gracilaria
confervoides_; while in the left foreground lies a pebble, partly
covered by a small plant of _Zonaria parvula_, from beneath which
straggles a little branch of the common but pretty Coralline, the
_Corallina officinalis_; and, to the right, a globe of the curious
_Codium bursa_, of the French coast, which might easily be added to our
native species in the Aquarium.
[Illustration: PLATE III.
1. Porphyra vulgaris.
2. Dumontia filiformis.
3. Asperococcus Turneri.
4. Rytiphlæa pinastris.
5. Chrysymenia rosea.
6. Peyssonetia Dubyi.
7. Chordaria divaricata.
8. Ectocarpus siliculosus.
9. Nemaleon multifida.
10. Nitophyllum punctatum.]
Such are a few of our beautiful coast _Algæ_, all of which I would
advise the admirers of the beauties of the marine Aquarium to try; and
if some refuse, in the present state of our knowledge of their habits
and requirements, to make themselves happy in their pretty “crystal
palace,” choosing rather to consider it a “prison of glass,” still a
good number of them, I am persuaded, may be coaxed into displaying their
beauties very genially within its transparent walls, which admit the
bright sun rays as freely as the pale-green liquid glass which forms
their native element.
The best time for making collections at the sea-side is a day or two
after the full moon, when the tide recedes to its greatest extent, and
parts of the shore become exposed, where some of the finest species
grow, which cannot be conveniently approached at any other time. It must
be borne in mind, also, that few of the floating pieces will grow,
however fresh and seemingly washed off with their root. Certain success
is only to be secured by chiselling off a portion of the substance on
which the weed is growing—thus transplanting it with its own soil, as it
were, about its roots, into the ocean garden of the Aquarium.
[Illustration]
[Illustration: PLATE IV.
1. Chondrus crispus.
2. Gigartina acicularis.
3. Ceramium strictum.
4. Taonia atomaria.
5. Plocamium coccineum.]
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