Phyllodoce Laminosa--the Laminated Nereis
'His meaner works
Are yet his care, and have and interest all--
All, in the universal Father's love.'
--COWPER.
[Illustration:
1 COMMON BARNACLES attached to shell of Limpet
2 ANIMAL OF THE LIMPET (_P. vulgata_) as seen from below
3 THE LAMINATED NEREIS (_Phyllodoce Laminosa_)]
IX.
To oblige an English correspondent who requested some blocks of
stone containing Pholas perforations, the writer, in company with a
fellow-student, started betimes for the sea-shore, some four miles'
distance. We made for a certain spot, where it was expected the object
of our wishes could easily be found. Our equipment consisted merely
of a hammer, a bottle, and two chisels, enclosed in a carpet-bag, the
better to mask our mission from impertinent curiosity.
On reaching the shore, it soon became painfully apparent that no pieces
of rock could be procured of a character at all suitable for a museum.
To make matters still more irritating, a breeze arose, and with it
came a furious shower of rain, which soon completely saturated our
light costume. At such a time it is laughable to note how faint becomes
the poetry of practical zoology--how excessively like street puddles
are the fairy-grots, as the rock-pools are called; how unsightly the
great, distorted anemones look, too, when viewed from beneath a large
boulder, where you are crouched in the fond idea that you are thus
getting shelter from the rain.
On this occasion, my friend and I, being soaked to the skin, started
up from our unpleasant position, and boldly daring the rain to do its
worst, proceeded to hunt after any object of interest that might by
chance be lying stranded near.
After an hour's search, two objects, among many others of more or less
interest, were captured, that fully repaid us for our uncomfortable
'ducking.' The first was an elegant Actinia (_A. Dianthus_), which
seemed to be exquisitely modelled in the finest virgin wax. The second
was a specimen of the Laminated Nereis (_Phyllodoce Laminosa_), a
wonderfully beautiful _worm_!
Fair reader, start not nor curl that rosy lip of thine at the
expression, 'beautiful,' being applied to such an humble creature, for
indeed the title is a just and true one.
This Annelid is generally found coiled up and attached to the under
part of stones situated near low water mark. Its general colour is
emerald green, excepting along the centre of the back, which is
iridescent, and reflects a brilliant blue, changing into purple and
other hues, only equalled in beauty by the enamelled corslet of the
brightest beetle, or the flashing tints that dance upon the plumage of
the humming-bird.
The body of the _P. Laminosa_, like that of all other _Dorsibranchiate
Annelidans_, is divided into a consecutive series of rings. Upon either
side of each ring is situated a singular appendage, which acts as a
gill or branchial organ, by the exercise of which the blood of the
animal is effectually purified, and respiration adequately provided for.
When the Nereis is in a state of repose, these gills are laid flat over
its back; but in a state of activity they are fully spread out, and act
as 'paddles,' by aid of which the animal is enabled to glide through
its native element with a graceful serpentine motion.
At the base of each paddle is situated a smaller one, consisting of
a fleshy pedicle shielding a fan-like bunch of hairs, each of which
tapers to a sharp point. Combined, these hairs or spines form a
powerful defensive weapon, which can be extended or retracted at will;
and it also serves as an _oar_, or propeller.
As a noteworthy instance of tenacity of life in the lower animals, it
may be well to mention here that I have on various occasions, by aid of
the microscope, watched for several minutes the bunch of spines, above
alluded to, thrust out and retracted in a single segment cut from the
body of the Nereis; and only as the object became devoid of moisture
did its beautiful mechanism cease to play.
The specimen now before me is comparatively small, being only twelve
inches in length, yet its body contains nearly one thousand lateral
appendages, constituting, it must be admitted, a most extensive and
wonderful locomotive apparatus.
This Annelid is not a suitable object for the aquarium, on account of
its frequent great length, and the consequent likelihood of its getting
entangled among stones and rock-work when in search of food.
If the hinder parts be cut off, as has been already hinted, they will
exhibit vitality for a considerable period when placed in water, but
we are told it is the anterior (?) portion of the Phyllodoce which
alone possesses the power of regenerating lost segments; these will be
reproduced sometimes at the rate of three or four in a week.
'These creatures,' says a learned author, 'as might be expected from
their activity and erratic habits, are carnivorous; and innocent and
beautiful as they look, they are furnished with weapons of destruction
of a unique and most curious description. The mouth of the Nereis would
seem at first to be a simple opening, quite destitute of teeth; but on
further examination, this aperture is found to lead into a capacious
bag, the walls of which are provided with sharp, horny plates, even
more terrible than those which are occasionally to be met with in
the gizzards of some of the higher animals. It is not surprising,
therefore, that by many anatomists the structure in question has been
described as a real gizzard, or by some as the stomach itself. A little
attention to the habits of the living Annelid will, however, soon
reveal the true character of the organ. No sooner does the creature
wish to seize its food than this so-called gizzard is at once turned
inside out, in which condition it protrudes from the mouth like a great
proboscis, and the teeth, which were before concealed in the interior
of the cavity, now become external, and display as formidable an
assortment of rasps, files, knives, saws, hooks, or crooked fangs, as
any one could wish to see. Let us suppose them, when in this condition,
plunged into the body of some poor helpless victim, while at the same
moment the proboscis is rapidly inverted and withdrawn; the prey thus
seized is at the same instant swallowed, and at once plunged into a
gulf where all struggles are unavailing, there to be bruised, and
crushed, and sucked at leisure.'
There is a curious fact in connection with these Annelids which is
too interesting to be omitted here. I allude to the wonderful manner
in which their young are produced by a process that may be called
'sprouting.'
This invariably takes place in the segment immediately preceding
the terminal one. When a new animal is about to be formed, the
reproductive segment swells, and after a certain time the infant
worm is seen growing from the tail of its parent. When sufficiently
developed, the offspring detaches itself, and starts life on its own
account. Sometimes before the elder born Annelid is fully formed, the
mysterious segment produces a second offspring, and, according to
Professor Milne Edwards, as many as six young ones may be generated in
succession from the same posterior segment, all of which will for some
time continue attached to the parent worm.