Acorn Barnacles.--Ship Barnacles.
'Barnacles turn Solan Geese
In the islands of the Orcades.'
VIII.
If the reader has been struck at what has been said in regard to the
exuviation of crabs, &c., he will probably be more surprised when I
state that precisely the same phenomena take place in the simple _Acorn
Barnacle_, that studs in countless numbers almost every rock and shell
situated between tide marks. No one can visit the sea-shore, at certain
localities, without noticing the white spots which constitute the
shells of the cirripeds in question, although he may not be acquainted
with the marvellous beauty of the animal contained within each.
Its loveliness, it is true, is in no wise apparent when parched and
dry; but let the welcome waves advance and playfully dash their spray
against the dwelling of the little crustacean, and quickly its valves
will open, displaying a delicate feathery plume, thrust forth and
hastily withdrawn again.
As it is not convenient to watch the movements of this animal in a
rock-pool, let me request the reader kindly to take a peep into my
aquarium. Here is a Trochus shell, for example, inhabited, as you
perceive, by a Soldier-Crab, the surface of which is thickly covered
with shelly cones, of small dimensions. These are the Barnacles
(_Balani_). The Trochus most fortunately being near the side of the
glass, is capitally situated for our purpose. Take the hand lens,
adjust its focus, and watch carefully for the opening of the cones.
Tush! The hermit never _will_ rest contented in any position for two
consecutive minutes; but see! as he walks away the fairy hands are
being rapidly thrown out and made to sweep the water in graceful
curves, thereby suggesting some resemblance to a bevy of school
children at Christmas time, bidding _adieux_ to their friends, while
seated on the roof of an old stage coach.
Carefully I lift the Pagurus bodily out of the tank, and transfer him
to a wine glass filled with clean water. After a few minutes have
elapsed, the hands again commence their fishing operations. Observe,
now, that these organs fan the fluid in such a manner as to catch any
animalculæ that may be near, and draw them towards the aperture caused
by the opening of the valves of the Barnacle. A close inspection will,
I am sure, prove to your satisfaction that there is also distinctly
apparent a second and smaller cluster of feathery fingers, whose duty
it is to catch the food, brought near by the larger and corresponding
organs, and finally convey it into the mouth of the little cirriped.
There may be, in the wide range of Nature's lower scale of life,
prettier sights to gladden the eye of the student than that above
described,--but if so, I must confess _my_ inability to indicate where
such are to be found. The fishing apparatus here mentioned consists of
a number of slender _cirri_, thickly coated with microscopic filaments
(cilia), and is, at certain periods, thrown off complete and entire by
the process of exuviation, just as we have seen it occur in the higher
crustacea.
Would you, my young friend, like to procure an exuvium of the Barnacle
for examination? Yes. Then follow the directions I am now about to
give, and your wish will be speedily gratified.
Presuming that your tank already contains a number of Barnacles
attached to various objects, and that such have been in the same vessel
for some weeks; syringe the water for a few minutes, and you will
find floating about, or rising to the surface, many specimens of the
desired object. They will, in all probability, be visible to the naked
eye. To attempt to lift one out of the water, however, by means of
your finger and thumb would be utterly useless. Such a procedure, even
were it successful, would inevitably mar the delicate beauty of this
'inessential' object, which, spirit like, casts no shadow upon weed or
water. The best plan is to insert a tube of glass into the aquarium, in
such a way that the exuvium may ascend the interior. Then place your
finger on the top, and draw the tube out of the water, and you will be
able to deposit the skin of the Barnacle upon a slip of glass by merely
lifting off your finger. The specimen can then be leisurely arranged,
and spread out by aid of a hand lens and fine pointed needles.
Walking by the sea-shore one fine summer afternoon, I met a fisher
boy running along with some curious objects spread out in the palm of
his left hand, while in his right, suspended from finger and thumb,
appeared a still more desirable prize.
At first glance I detected the objects to be specimens of the _Lepas
anatifera_. They had, so the boy stated in answer to my inquiries, been
plucked from the base of a ship newly arrived from a long voyage. When
I offered him sixpence for the 'lot,' the embryo plougher of the deep
looked up in my face with a singularly mistrustful expression, and
said, 'D'ye mean it, sir?' I gave speedy assurance of my sincerity,
and on receiving the purchase money, after handing over the Barnacles
to my custody, the young urchin started off as fast as his legs,
encased in huge wading boots, would allow him. His alarm was quite
unnecessary, for although in a few days after I would not have given a
penny for a thousand, I would willingly, on the above occasion, have
paid five shillings for a single specimen, rather than have missed
the opportunity of possessing such an interesting object as the Ship
Barnacle.
On placing them in water one only of the creatures showed any signs
of life, and by next morning they made the scentral organ of my face
so highly indignant that, in order to allay its irritability, I was
obliged to remove the defunct animals to the outside of the window.
There they remained for several months, and were eventually transferred
to the privacy of a card-board box. Although twelve months have elapsed
since the last-mentioned removal took place, these creatures even now,
when the lid of the case is lifted, give out a smell, so 'antient and
fish-like,' that I believe not a few of 'the sweet perfumes of Arabia'
would be needed in order to subdue its power.
One cluster contained thirty Lepades, and the other eighteen. The
average length of each Barnacle is about three or four inches.
One, however, measured nearly ten inches. The fleshy stalk is of a
purplish-grey colour, semi-transparent, and perfectly smooth. The
shell, which consists of five pieces, is bluish-white, while that
portion from whence the cirri protrude appears of a brilliant orange,
the cirri themselves being exquisitely tinted with violet, shaded off
to a deep purple.
I may here mention that the above animal was by our ancestors most
unaccountably supposed to be the young of the solan goose!--a bird that
haunts in vast numbers the Bass Rock and Ailsa Craig. Indeed, a common
belief in different parts of Scotland, and over the west of England
was, that the shells grew upon certain trees, and in process of time
opened of themselves; whereupon a certain animated substance contained
within the shell dropped down, and according to the place where it fell
perished or fructified. By falling into the water it grew to be a fowl;
but by falling upon land the vital principle became extinct. The fowls
which resulted from the more fortunate contingency were called Barnacle
Geese in Scotland, and Brant, or Tree Geese in England. This delusion
appears to have arisen from the fact of Barnacles having been found in
great abundance on trunks and even branches of trees long submerged
in the sea.[8] Bishop Hall thus alludes to the popular notion in his
Satires:--
'His father dead! tush, no, it was not he;
He finds records of his great pedigree;
And tells how first his famous ancestor
Did come in long since with the Conqueror.
Nor hath some bribed herald first assigned
His quartered arms, and crest of gentle kind;
_The Scottish Barnacle, if I might choose,
That of a worme, doth waxe a winged goose_.'
[8] Vide author's 'Seaside and Aquarium.'