THE history of the Norfolk Boy, which, you inform me, has been
communicated to the Royal Society, seems to deserve a place in the
memoirs of that illustrious body, as well on account of its utility, as
its singularity.
The symptoms in this case most evidently arose from worms in the
intestines; which often occasion unaccountable complaints, and
frequently elude the most powerful medicines, as they did in the
instance before us, till at last they were dislodged by the enormous
quantity of oil-paint, which the poor boy devoured; and the cause being
thus removed, all the effects ceased.
At first sight it appears wonderful, that this immense quantity of
white lead did not prove fatal; and that it was not so, could be owing
to nothing but the oil, by which it was enveloped, and its contact and
immediate action on the coats of the intestines thereby prevented. But
the oil did not only obviate the dangerous effects of this mixture, but
appears, to me at least, to have been the chief cause of the success,
with which it was happily attended. I speak this with some restriction,
because the lead, as its stypticity was thus covered, might, by its
weight, assist in removing the verminous filth, especially as the
bowels were made slippery by the oil.
Oil has long been observed to be noxious to insects of all kinds, so
that not only those, which survive after being cut into several pieces,
but those also, which live long with very little air, and those, which
revive by warmth after submersion in water, die irrecoverably, if they
are immerged in, or covered with oil. Rhedi and Malpighi have made many
experiments to this purpose; and account for the event very rationally
from the oil stopping up all the air-vessels, which in these animalcula
are very numerous, and distributed almost over their whole bodies.
On this account oil has been recommended as a vermifuge both by Andry
and Hoffmann, though I believe it has been seldom used in practice in
that intention; or at least has not been given in quantities sufficient
to answer it. Indeed Hoffmann[222] himself seems not to lay much
stress on it as an anthelmintic, recommending it only as serving
to line the inside of the intestines, and to relax spasms in them;
and therefore as a proper preparative to be given before any acrid
purgatives are ventured on.
The medicines commonly prescribed, and most depended on, are either
of a virulent and drastic nature, or such as are supposed to be able
to destroy those animals by some mechanical qualities _e. g._ to cut,
tear, or otherwise affect their tender bodies, and yet not have force
enough to lacerate or injure the stomach or intestines. Of the former
kind are the leaves and juice of helleboraster, the bark of the Indian
cabbage-tree, coloquintida, resin of jalap, glass of antimony, and
the like; the effects of which are commonly violent and dangerous,
and sometimes fatal. Of the latter class are crude mercury, and the
milder preparations of that mineral, aloes and other bitters, tin
filings, neutral salts, and vitriolic acids. Every one conversant in
practice too well knows, how often these medicines are administred
ineffectually. When I had therefore attentively considered the history
of the Norfolk Boy, I determined to try the efficacy of oil in such
cases, as it seemed capable of producing great effects, and yet could
not be attended with any hazard or danger.
The first person, to whom it was given, with this view, was ----
----, a patient of our Infirmary, who was judged to have worms, but
had taken several approved medicines for a considerable time without
success. In a consultation with the other physicians, the following
form was prescribed.
℞. _Ol. Oliv. lb.ss. Sp. vol. aromat. ʒij M. cap. Cochl. iii. mane et
H. S._
The volatile spirit was added here to make the oil saponaceous, and
by that means more easily miscible with the juices in the stomach and
_primæ viæ_. This medicine answered our expectations, and in a few days
brought away several worms.
---- Lacy, a poor boy of the parish of Feckenham in this county, aged
13 years, was, as I was informed, about three or four years ago seized
with convulsive fits, which gradually deprived him of his senses, and
reduced him to a state of idiocy. He had taken several anthelmintics
and purgatives, particularly the _Pulv. Cornachin._ but never had
voided any worms, though all the symptoms seemed plainly to shew, that
they were the cause of his disorder. As he greedily swallowed any
thing, which was offered him, without distinction, I at first ordered
him a mixture of linseed oil ℥vij _Tinct. sacr._ ℥j: of which he took
four large spoonfuls night and morning. He persisted in the use of this
one whole week without at all nauseating it, towards the latter end of
which time he voided one round worm of a great length. He now began
to shew much aversion to the medicine; on which account the _Tinctur.
sacr._ was omitted, and he was ordered to take the oil alone in the
same quantities. This he continued to do a fortnight longer, during
which time he voided 60 more worms, and in a great measure recovered
the use of his reason[223]. This account I had from the Apothecary,
who, by my directions, supplied him with the medicines.
Soon after this I ordered the same medicine to be given to Elizabeth
Abell, a poor girl in the same neighbourhood, reduced by epileptic fits
to such a state of idiocy, as to eat her own excrements. It caused her
to void several worms, but she did not recover her senses.
Since this time I have given the oil to several persons with good
success, and therefore I cannot but recommend a further tryal of it;
since it is a remedy, which may be used with safety in almost any
quantity; a character, which very few of the anthelmintic medicines
deserve.
It is probable, that some oils are more destructive to worms than
others. Andry (_Traité de la Generation des Vers, cap. 8_) prefers
nut oil, and tells us, that a human worm, voided alive, being put
into that oil, died instantly; whereas another worm, voided at the
same time, lived several hours in oil of sweet almonds, though in a
languishing state. This difference he afterwards (_Cap. 9_) endeavours
to account for, by supposing, that the oil of almonds is more porous,
and consequently less able to preclude the entrance of air into the
worms. And indeed there is some reason to conclude, that oils, which
dry in the open air, such as nut and linseed oils, are of a closer
texture, less mixed with water, and consequently more anthelmintic,
than those oils, which freeze by cold, and will not dry in the open
air;[224] such as those from olives or almonds. Andry tells us, that at
Milan the mothers have a custom to give their children once or twice
a week toasts dipt in nut oil, with a little wine, to kill the worms:
and I know a lady in the country, who gives the poor children in her
neighbourhood the same oil with great success.
I would recommend this remedy to be used in as large doses as the
stomach will well bear: to which purpose it may be adviseable to join
it either with aromatics, bitters, or essential oils, such as the
case may require. Andry orders the oil to be taken fasting, assigning
this for a reason, that the stomach being then most empty, it more
readily embraces and stifles the worms. During this course it will be
necessary, at proper intervals, to give rhubarb, mercurial or aloetic
medicines.
I cannot close this paper without observing, that, from the history
of the Norfolk Boy, we may learn, in similar cases, where the head is
not idiopathic, never to despair absolutely of a cure, notwithstanding
the disease has been of very long standing. For in this boy, though
the oppression in the brain and nerves had continued many years, and
had been so violent, as to deprive him not only of his intellectual
faculties, but almost all his sensations; yet were not the organs much
impaired thereby, but he recovered all his senses again, as soon as
the irritation and spasms in the intestines, which first caused all
these terrible symptoms, were removed. The same thing in a less degree
was observable in the Feckenham Boy, mentioned before; and we have had
two remarkable instances of the same kind at the Worcester Infirmary;
where a boy and his sister, of the name of Moyses, received a perfect
cure, and recovered the entire use of their senses, after having been
rendered idiots (though not in so high a degree as the Norfolk Boy) for
more than two years, by epileptic fits proceeding from worms.
J. Wall.
Worcester Dec. 7, 1748.
_P. S._ As the following history has some analogy with the subject we
are now upon, I beg leave to subjoin it by way of postscript.
A young girl of the name of Lowbridge, at Ledbury, in
Herefordshire, nine years old, had been long troubled with a gnawing
pain at the stomach, which growing gradually more violent, I was at
last called to her. About a quarter of an hour before I reached the
house, she was seized with a violent vomiting, whereby she brought
up an amazing number of living animals supposed, to be upwards of
a thousand, together with a vast quantity of clear viscid phlegm.
In shape they exactly resembled millepedes, except that some of
them, being examined by a magnifying glass, appeared to have a
small filament, which arose from the middle of the belly, and might
probably have served to fix them to their nidus. They were of
different sizes, from that of the largest millepede, to some, that
were scarce perceptible; so that they appeared to have been generated
at different times, and grown in the stomach. As the child was
suddenly seized with this effort to vomit, she discharged her stomach
on the floor of the parlour where she was sitting. The millepedes,
they told me, were at first very lively, and crept briskly different
ways; but they did not live long in the open air. They were lying in
the slime when I came to her, so that I could not be imposed on as to
the verity of the fact. After this evacuation, the child’s stomach
grew perfectly easy, and continued so.
CXII. _Observations upon the_ Corona Solis Marina Americana; _The_
American Sea-Sun-Crown. _By_ John Andrew Peyssonel, _M.D. F.R.S.
Translated from the_ French.
[Read Dec. 14, 1758.]
I Shall call this insect by this name, because of the resemblance it
bears to the flower called _Corona Solis_; since it is, like this, open
and spread.
This insect adheres to the rocks by its basis, which is flat and round;
and tho’ this roundness is sometimes mis-shapen, it is only occasioned
by the inequalities of the rocks, to which it sticks. Its diameter is
about two or three inches, bearing, from the center, certain rays,
like white nerves, upon a moist flesh, of a livid violet colour.
These rays or nerves pass from the centre to the circumference; they,
too, consist of a soft fleshy substance, which resembles bowels or
intestines; the whole length of which is covered with glandulous bodies
of a dirty grey colour; and all these glands filled up the middle of
the fish, making the flowrets, or petals, that form the disk of the
flowers. There is an infinite number of these glands attached to those
filets or nerves, all very distinct from one another: these filets are
well ranged when viewed downwards; but the upper part is covered by
these glands, which are placed in a confused manner. These filets pass
to the circumference, forming an edge full of rugosities, which leaves
the body of the animal full of flaws. These hard bodies, upon which
it lives, are not always permanent in the same place, but capable of
changing their places from this edge or circumference; like a skin or
texture of fibres or flesh, such as the body of the sea snail I have
already described; of the same thickness, of a greenish colour, and
sometimes of a greenish spotted grey, without shell, bone, or stay. The
body or muscular fleshy skin raises itself up perpendicularly to three
inches; rounds itself at the top, when it is touched; but it leaves
a hole like a sphincter, formed by the reunion of the fleshy body,
which enlarges itself again. The base opens to the whole extent of the
bottom, makes a reversed prepuce, and immediately brings to view three
rows of _papillæ_, which are of a conical figure, of one or two lines
long, resembling the glands under the tongues of oxen, and which may
here be compared to the demi-flowers or radiated flowers of the _Corona
Solis_.
After this threefold ray of conical pointed _papillæ_, there appears a
body of a livid violet colour; I took it for a particular substance
or body; but having examined it, I observed it was only a pellicle,
or membrane, that covered a part of the _papillæ_ I mentioned. This
membrane has sixteen separations, which form kinds of purses, and yet
leave, in the center of the animal, an empty space, wherein several
glands are brought in view. I do not know, whether, in the natural
state, these membranes do not retire to the circumference, in order to
discover the glands within, which they usually hide, and which fill
up all the middle of the crown; but when the fleshy body is gone up
again, it covers all the interior parts, closes them in, and preserves
them from the touch of any extraneous body. I cannot tell how these
fishes live, or what is their mechanism; for I could not distinguish
either a mouth, or any _viscera_, nor any other organ serving to their
nourishment.
[Illustration: _Philos. Trans. Vol. L._ TAB. XXXIV. _p. 845_.
Lepades Pedatæ.
1. _Lepas nuda carnosa aurita_
1 a. _Ejusdem pars superior interna_
1 b _Foramen auris internum_
1 c _Currhi_ (1.d) _Proboscis et_ (1.c) _Os_
1 f _Dens terratus quorum octo sunt_
1 g. _Idem per. Microscopium visus_
1 h. _Scapus longitudinatiter dessectus_
2 _Scalpellum Norwegicum Keratophytium_
2 a. _Idem per. Microscopium visum_
3 _Scalpellum ex mare Britannico_
4. _Cornu copia Poussepieda Gallorum_
5. _Concha Anatifera vulgaris_
6. _Concha Anatifera prolifera_
A. _Animal Lepadis sen Triton Linnæi_
Barnicles _with Stems_.
1. _Naked fleshy Barnicle with Ears_
1 a. _The inside of the upper part of the same_
1 b. _The internal opening of the Ear_
1 c. _The Plumes_ (e. d) _trunck_ (e. e) _and mouth_
1 f. _A saw edg’d tooth of which there are 8_
1 g. _The same magnified_
1 h. _The Stem cut in two lengthways_
2. _The Norway Seafan Penknife._
2 a. _The same magnified._
3. _The British Channel Penknife._
4. _The Horn of plenty or French Poussepieds_
5. _The common Duckbearing Barnicle_
6. _The branch’d Duckbearing Barnicle_
A. _Animal of the Barnicle or Linnaeus’s Triton_
Lepades Sessiles Balani dictæ.
7. _Pediculus Ceti_ (7.a). _Idem reversus_
8. _Calyciformis Orientalis_
9. _Tintinabuliformis._
10. _Tulipiformis ex Corallio rubro_
11. _Fistulosa conica_ (11.a) _eadem reversa_
12. _Verrum Testudinaria_ (12.a) _eadem reversa_
13. _Verrum Canesti Americani_ (13.a) _eisdem statere_
14. _Lapensis ore obliquo_ (14.a) _cum opserastis cornutis_
15. _Subovatis crassa ore minore_
16. _Cornulacensis conicas ore minores_
17. _Anglica vulgaris ore patulo_
18. _Aretica Patelliformis_
19. _Calceolus_ (19.a) _Idem. hierophylis involutus_
20. _Diadema Persarum_
Barnicles _adhering by the base of these Shells_.
7. _The Whales. Louse_ (7.a) _The underside_
8. _The East India cup shap’d Barnicle_
9. _The Bell shap’d Barnicle_
10. _The Red Coral Tulip Barnicle_
11. _The pipy conical Barnicle_ (11.a) _The underside_
12. _The Tortoise Wart_ (12. a) _The underside_
13. _The American Crabs Wart_ (13.a) _The same sideways_
14. _The Cape sidemouth Barnicle_ (14.a) _with_ oblique edge
15. _The Eggshap’d thick Barnicle with a small mouth_
16. _The Cornish cone Barnicle with a small_ edge
17. _The common English Barnicle with a_ wide mouth
18. _The Greenland Limpet shap’d Barnicle_
19. _The Slipper_ (19.a) _The same cover’d with hierophylis_
20. _The Persian Crown_]
CXIII. _An Account of several rare Species of Barnacles. In a Letter to
Mr._ Isaac Romilly, _F.R.S. from_ John Ellis, _Esq; F.R.S._
[Read Dec. 21, 1758.]
London, Dec. 21. 1758.
Dear Sir,
THOSE rare and very extraordinary new species of Barnacles, which you
have lately received from abroad, are so different from any of the
common species, that I have seen, that I was resolved to inquire into
the nature of an animal, which, like a Proteus, appears in so many
different shapes or coverings in different parts of the world. For this
end I have consulted that excellent collection in the British Museum,
and some others in the cabinets of my curious friends.
In this inquiry I met with some very rare ones, which have not yet
been described, as you will observe in the annexed plate [_See_ TAB.
XXXIV.], where I have given exact drawings of yours, as well as the
other species of this genus.
This marine animal is called, by writers on natural history, Balanus,
and Concha Anatifera: but the celebrated Professor at Upsal, Dr.
Linnæus, calls the internal active part, or fish, the Animal Triton,
and the covering or testaceous habitation Lepas, which he says is a
multivalved shell, composed of unequal valves. The Animal Triton he
describes, as having an oblong body, a mouth with a tongue in it,
twisted about in a spiral manner; sixteen tentacula or claws: six of
the hinder ones on each side, he says, are cheliferous.
This account differing from that given by the ingenious Mr. Turberville
Needham, F.R.S. in his Microscopical Essays, I shall give the character
of this animal, as it appeared to me from the many observations I made
on it, while alive in salt water; and these I compared not only with
many dried specimens of other varieties, but likewise with some of
yours, that were preserved in spirits; and I found that the parts of
the animal agree in all the species.
The experiments, that I made, were on the common English Barnacle,
which is very frequently met with, at this time of the year, on oysters
and other shell-fish. The microscope, that I made use of to observe
it, was Mr. Cuff’s aquatic one; where the animal, when taken out of the
shell, may be put into the watch-glass with salt water, or spread on
the round glass plate on the stage of the microscope, and kept moist
with a hair pencil and salt water during the time of observation: this
will keep the claws and proboscis alive and in motion for many hours
together.
This animal has 24 claws, or cirrhi (_See Fig._ A), which are disposed
in the following manner: the 12 longest stand erect, arising from the
back part of the animal: they are all joined in pairs near the bottom,
and inserted in one common base. These appear like so many yellow
curled feathers: they are clear, horny, and articulated. Every joint is
furnished with two rows of hairs on the concave side. The animal, in
order to catch its prey, is continually extending and contracting these
arched hairy claws, which serve it for a net.
The 12 smallest claws are placed next to these, six on each side: these
are divided into pairs; that is, two claws to one stem, like the chelæ
or claws of the crab. These are more pliable, and fuller of hairs, than
the others, and seem to do the office of hands for the animal.
The whole number of claws lessen in size gradually each way, from the
tallest in the back, to the last but one of each side in the front;
which last two are of the middle size.
The proboscis, or trunk, rises from the middle of the base of the
larger claws, and is longer than any of them: this the animal moves
about in any direction with great agility: it is of a tubular figure,
transparent, composed of rings lessening gradually to the extremity,
where it is surrounded with a circle of small bristles, which likewise
are moveable at the will of the animal. These, with other small hairs
on the trunk, disappear when it dies.
Along the inside of this transparent proboscis the spiral dark-coloured
tongue appears very plain: this the animal contracts and extends at
pleasure.
The mouth appears like that of a contracted purse, and is placed
in front, between the fore claws. In the folds of this membraneous
substance are six or eight horny laminæ or teeth standing erect, each
having a tendon proper to direct its motion. Some of these teeth are
serrated, others have tufts of sharp hairs instead of indentations on
the convex side, that point down into the mouth; so that no animalcule
that becomes their prey can escape back.
Under the mouth lie the stomach, intestines, and the tendons by which
they adhere to the shell.
This then is the general character of the animal of the whole genus,
whether with stems or without.
I shall now give you a short description of the several kinds I have
met with, besides those of your own, and shall divide them into two
kinds; those that have stems, and those that adhere by their shelly
bases.
The first and most remarkable of those that have stems is the Barnacle,
_Fig._ 1. This differs from the Lepas of Linnæus in not having a
testaceous, only a cartilaginous or fleshy covering. On the top of it
are two erect tubular figures like ears: these have a communication
with the internal parts of the animal (_See Fig. 1. b_). These inner
parts agree with the general character already given. The stem, which
is here dissected, was full of a soft spongy yellow substance, which
appeared, when magnified, to consist of regular oval figures, connected
together by many small fibres, and no doubt are the spawn of the animal.
This extraordinary animal (of which there were seven together) was
found sticking to the Whale Barnacle (_See fig._ 1. & 7.), by Mr. Smith
of Stavenger in Norway, who cut both kinds together off a whale’s
lip, that was thrown upon that coast last year, 1757, and immediately
immersed them in spirits of wine; by which means we have been able more
exactly to describe them.
I have called this animal the Naked Fleshy Barnacle with Ears; but it
appears to claim the name of Triton rather than Lepas, according to
Linnæus, as having no shelly habitation.
_Fig._ 2. is the next animal of this class: this is not yet described.
I found several of them sticking to the Warted Norway Sea Fan, which
Dr. Pantoppidan, the Bishop of North Bergen, sent you: from its
appearance, I have called it the Norway Sea Fan Penknife. The stem
of this is covered with little testaceous scales. The upper part of
the animal is inclosed in thirteen distinct shells, six on each side,
besides the hinge-shell at the back, which is common to both sides:
these are connected together by a membrane that lines the whole inside.
One of these is magnified a little at fig. 2. _a_, in order to express
the figure and situation of each shell the better.
_Fig._ 3. is taken from D’Argentville’s _Lithologie, Pl. 30. fig._
H, who says it is found in the British channel sticking to sea
plants; and that these shells consist of five pieces. This, from its
appearance, I have called the British Channel Penknife, to distinguish
it from the other.
_Fig._ 4. is a species of Barnacle called Poussepieds by the French,
and described by Rondeletius as commonly found adhering to rocks on
the coast of Brittany. He says the people there boil and eat the stem,
which is first of a mouse-colour, and afterwards becomes red like our
prawns. There are many heads, that arise out of one stem, each of which
consists of two shells, in which are the same parts of the animal as in
the other species. This I have called the Cornucopia Barnacle. Some of
the shells of this Barnacle were drawn from a specimen in the British
Museum. This Lepas is the Mitella of Linnæus.
_Fig._ 5. and 6. are the Barnacles called Conchæ Anatiferæ: these are
the sorts so well known to sailors, and formerly supposed to produce a
large species of duck called a Barnacle. These consist of five shells.
The tube, that supports one of these kinds, branches out like some
species of corallines, bearing a shelled animal at the end of each
branch. They are generally found adhering to pieces of wood in the sea,
and most ships have some of them sticking to their bottoms. Those of
the southern and warmer climates are generally of a larger kind than
those of the colder and more northern climates.
The next division of these animals is, those that adhere by the base of
their shells, having no stems.
Here I must observe, that the bottoms of the several species of this
division conform in shape to the substances they adhere to, or grasp
them in such a peculiar manner, as to render their situation secure
from the violence of the element they live in. Another provision of
nature for the security of these animals are the four opercula, which,
upon their retreating into the great shell, they can draw to so close
after them, as to secure themselves from outward danger.
_Fig._ 7. represents the Whale Barnacle, called Pediculus Ceti, just
as it was cut off the whale’s lip, with the seven naked Barnacles with
ears, already described. _Fig._ 7.a is the bottom of the shell. This
has the appearance of the gills of a mushroom. All the spaces between
these laminæ were filled with the blubber of the whale: by this means
they adhere to the gristly skin of the fish. The narrow cavities
between the branched laminæ are the places where the ligaments or
tendons, that move the opercula, are inserted.
_Fig._ 8. is the Cup Barnacle, taken off an East India ship from
Sumatra. The testaceous flat bottom of this was marked with the seams
and lines of the sheathing, and with the rust of the nails. In one of
these shells the animal is represented protruding his claws thro’ the
opercula.
_Fig._ 9. is called the Bell-shaped Barnacle. This was taken off the
bottom of a ship from Jamaica, and had its flat testaceous base marked
as the former.
_Fig._ 10. This represents part of a most elegant specimen in the
curious collection of Dr. John Fothergill. It is called the Tulip
Barnacle, and very properly, as well from the shape of its shell, as
the beautiful stripes of red mixt with white. It adheres to a piece
of the true red coral, and was fished up near Leghorn, on the coast
of Italy. It is not improbable, but that these groups of Barnacles,
growing at the same time with the animals that formed the red coral,
may have received an addition to their fine red colour from the coral.
_Fig._ 11. is a group of Barnacles of a conical form, composed of
purplish tubes like small quills. _Fig._ 11.a represents one of the
same, with a view of its base, from the collection of Mr. Peter
Collinson, F.R.S. This was brought from the East Indies. The insides of
these shells have the appearance of the spongy parts of bones.
_Fig._ 12. is called the Tortoise-wart Barnacle, being often found upon
that animal. This shell is of a plano-convex shape, and looks like
polished ivory. The divisions between the valves represent a star with
six points. If these shells are put into soap lees, they will in a few
hours separate into six pieces or valves, each shelly valve having
two ears, like the scallop-shell: so that this species has its valves
connected by membranes, instead of testaceous sutures, as most of the
others have. _Fig. 12. a_ represents the under part of the same shell.
_Fig._ 13. This shell is marked with six rays like a star, as the
former; but is much deeper in proportion to its diameter. Several
of this kind were found sticking to a crab, that was lately brought
from the island of Nevis; from whence I have called it the American
Crabs-wart.
_Fig._ 14. is called the Side-mouth Barnacle. This was found on
the southern coast of Africa, near the Cape of Good Hope, where it
adheres to a particular species of striated purple muscle. _Fig._ 14.a
represents two of the opercula of this Barnacle remarkably horned. The
shell of this is very thin; but its obliquity may probably be owing to
its situation.
_Fig._ 15. This egg-shaped Barnacle with a small mouth is found in
clusters sticking to the Buccinum tribe of shells in the West Indies.
_Fig._ 16. is the Cornish Barnacle, shaped like a cone, and with a
small mouth. This is described and figured by the Revᵈ. Mr. William
Borlase, F.R.S. in his Natural History of Cornwall, lately published.
_Fig._ 17. This is the common English Barnacle, that is found in such
plenty upon all rocks and shells round this island. From the animal of
this, examined in the microscope, I have taken the character of the
fish of the Barnacle genus.
_Fig._ 18. This I have called the Limpet-shaped Barnacle, from its
likeness to some species of that shell. I am indebted to our late
worthy member, Mr. Arthur Pond, for this shell, who assured me it
was brought to him from Greenland. It was, with several more, found
sticking to a very large species of muscle.
_Fig._ 19.a. This Sea-Fan, with the Barnacles inclosed in it, was
brought from Gibraltar. I have called it the Slipper Barnacle, from its
shape. _See Fig._ 19. These shell-fish adhere, while they are young, to
the slender branches, which are produced by the animals that compose
this species of Sea-fan; and as the next succession of young animals of
this sea-fan creep up its sides, to increase the bulk and extension of
these first-formed ramifications, they inclose the shells all round,
leaving only their mouths or apertures open, for the Barnacles to
procure their food. But it frequently happens, that the animals of the
Sea-fans destroy these Barnacles, by overrunning and involving them in
the very center of their stems. These small Barnacles, interspersed
here and there on the branches, have been taken for fruit or berries
by some gentlemen, who look upon the internal or horny part of the
Sea-fans to be vegetables.
_Fig._ 20. is a very curious Barnacle, taken from an elegant specimen
in the British Museum; which, from its figure, I have called the
Persian Crown.
I shall now add some further observations on the nature of these
animals.
Upon opening the shells of many of the common English Barnacles (_Fig._
1.) while they were alive, I found the lower part of the shell, which
contained a cavity equal to two thirds of the whole, full of spawn;
so that the Barnacles, which adhere by the base of their shells, as
well as those that are supported by fleshy tubes, are propagated by
eggs, which they send forth in inconceivable numbers; as appears by the
clusters of young shells, which we find adhering not only to the parent
animals, but to all hard substances near them.
The bottom shell of these animals, as well as their upper shells, vary
in form according to their situation, which occasions some difficulty
in determining their several species with exactness. The form of the
base shell of our common English Barnacle, is the flat radiated figure
represented adhering to a scallop shell in the front of a group of them
at _Fig._ 17. The Barnacles at _Fig._ 8. 9. 14. 15. and 20. have the
same kind of base.
I have very lately observed a singular kind of flat Balanus, on a white
Mandrepora coral from the coast of Italy, in the possession of Mr.
Mendez D’Acosta, F.R.S. whose base appears sunk into the coral, and of
the form of an inverted cone, bending a little to one side. The inward
surface of this conical base shell appears curiously striated with
tubular radii, which terminate on the surface of the coral, to receive
the extremities of the six valves, that compose the upper shell. This
peculiar form of the base seems owing to the animals of the coral and
of the Barnacle growing up together, the latter keeping possession of
its proper space, while the former grew close about it.
The bottom shell of the Barnacle like a Limpet, at _Fig._ 18.
increases from a small point by many thin shelly margins, which
exactly correspond to the indentations which we observe on the base
of the outward shell; so that it appears not unlike the drawing of a
fortification in miniature.