As the closer and more severe scrutiny of anatomical structure has
induced modern zoologists to separate the Lucernaria from its formerly
assigned alliance with the Sea-anemones, and to associate it with
the Medusæ, it is interesting to remark that the scales of justice
have been maintained in equipoise by the like shifting of a member
from the Medusæ to the Anemones. The latter animal is one familiar to
most haunters of the shore, and invariably admired as one of the most
charming of the many lovely forms that throng the summer seas; it is
the sweet little _Beröe_, or _Cydippe_.[131] Indeed at first sight
you would be little disposed to admit the propriety of the transfer
in this case, for certainly the active glittering globule of pure
crystal appears to possess much more resemblance to one of the smaller
Medusæ, the _Sarsia_, for instance,--than to a daisy or a beadlet.
But naturalists look beneath the surface: and they find that, with
important peculiarities, the internal economy of the _Cydippe_, and
specially its digestive apparatus, are modelled rather on the type of
the latter than of the former.
We will not, however, trouble ourselves now with these elaborate
matters, but rather look at the exterior and obvious characters of
the charming little pet, which is disporting itself in this vase of
sea-water on our table. It is a globe of pure colourless jelly, about
as big as a small marble, often having a little wart-like swelling at
one of its poles, where the mouth is placed. At the other end there
are minute orifices; and between the two passes the stomach, of a form
which is flat, or wider in one diameter than in the other.
If the stomach be considered as the axis of the globe, and the
two extremities as its poles, the meridians of longitude are well
represented by eight narrow bands, situated on the surface, which do
not, however, reach either pole. Along the course of each of these
meridional bands are fixed at close intervals minute square moveable
plates, whose outer edges are set with strong cilia, like the teeth
of a comb. These are the locomotive organs, and most effective they
are. They are used like the paddles of a steamer, the little animal
beating the water with them in rapid and regular succession, their
minute subdivision causing the rays of light, especially when in the
sun, to play along these bands, with the most brilliant prismatic
colours; while their vigorous strokes cause the globe to shoot hither
and thither through the water with remarkable power.
Within the clear substance of the _Cydippe_, on each side of the
stomach, there is excavated a capacious cavity, which communicates
by a canal with the surface, near the equator. Within each cavity is
fixed a tentacle of great length and slenderness, which the animal can
at pleasure shoot out of the orifice, and allow to trail through the
water, shortening, lengthening, twisting, or coiling it at will; or,
on the other hand, quickly contract it into a tiny ball, and withdraw
it wholly within the proper cavity. A peculiarity, which imparts an
inexpressible charm to this apparatus, is, that, throughout the length
of this attenuate white thread, short threadlets are given off at
regular intervals, which can be coiled or straightened, lengthened
or shortened, individually. They proceed only from one side of the
thread-like tentacle, though, from the slight twisting of the axis,
they seem now to project on one side, now on another.
It has been well observed that of the grace and beauty which the
entire apparatus presents in the living animal, or the marvellous ease
and rapidity with which it can be alternately contracted, extended,
and bent at an infinite variety of angles, no verbal description can
sufficiently treat. Fortunately this little beauty is so common in
summer and autumn on all our coasts, that few who use the surface-net
can possibly miss its capture. So lovely a creature is worthy of a
poet’s description: it has received it.
“Now o’er the stern the fine-mesh’d net-bag fling,
And from the deep the little Beroë bring;
Beneath the sunlit wave she swims conceal’d
By her own brightness;--only now reveal’d
To sage’s eye, that gazes with delight
On things invisible to vulgar sight.
When first extracted from her native brine,
Behold a small round mass of gelatine,
Or frozen dew-drop, void of life and limb:
But round the crystal goblet let her swim
’Midst her own element; and lo! a sphere
Banded from pole to pole; a diamond clear,
Shaped as bard’s fancy shapes the small balloon
To bear some sylph or fay beyond the moon.
From all her bands see lucid fringes play,
That glance and sparkle in the solar ray
With iridescent hues. Now round and round
She wheels and twirls; now mounts, then sinks profound.
Now see her like the belted star of Jove,
Spin on her axis smooth, as if she strove
To win applause--a thing of conscious sense
Quivering and thrilling with delight intense.
Long silvery cords she treasures in her sides,
By which, uncoil’d at times, she moors and rides;
From these, as hook-hairs on a fisher’s line,
See feathery fibrils hang in graceful twine,
Graceful as tendrils of the mantling vine
These swift as angler by the fishy lake
Projects his fly the keen-eyed trout to take,
She shoots with rapid jerk to seize her food,
The small green creatures of crustaceous brood;
Soon doom’d herself a ruthless foe to find,
When in Actinia’s arms she lies entwined.
Here, prison’d by the vase’s crystal bound,
Impassable as Styx’s nine-fold round,
Quick she projects, as quick retracts again,
Her flexile toils, and tries her arts in vain;
Till languid grown, her fine machinery worn
By rapid friction, and her fringes torn,
Her full round orb wanes lank, and swift decay
Pervades her frame, till all dissolves away.
So wanes the dew conglobed on rose’s bud;
So melts the ice-drop in the tepid flood:
Thus, too, shall many a shining orb on high
That studs the broad pavilion of the sky,--
Suns and their systems fade, dissolve, and die.”[132]