(_Nautilus pompilius_) somewhat resembles that of the argonaut, its
internal structure is very different. A section of it shows that it is
divided into several chambers, each of which is partitioned off from the
adjoining ones, the last formed or external one, in which the animal
lives, being much larger than the rest. The object and mode of
construction of these chambers is as follows. As the animal grows, a
constant secretion of new material takes place on the edge of the shell.
By this unceasing process of the addition of new shell in the form of a
circular curve or coil around the older portion, the whole rapidly
increases in size, both in diameter, and in the length of the chamber.
The Nautilus, requiring to keep the secreting portion of its mantle
applied to the lip of the shell, finds the chamber in which it dwells
gradually becoming inconveniently long for it, and therefore builds up a
wall behind itself, and continues its work of enlarging its premises in
front. Each of these walls, concave in front, towards the mouth of the
shell, and concave behind, acts as a strong girder and support of the
arch of the shell against the inward pressure of deep water: and it was
formerly supposed that each successive chamber so constructed and
vacated remained filled with air, and _thus_ became an additional float
by which the constantly increasing weight of the growing shell was
counter-balanced. By this beautiful adjustment of augmented floating
power to increased weight, the buoyancy of the shell would be secured
and its specific gravity maintained as nearly as possible equal to that
of the surrounding water. This adjustment does probably take place, but
in a somewhat different manner. As the Nautilus inhabits a depth of from
twenty to forty fathoms, it is evident that the air within its shell
would be displaced by the pressure of such a column of water.[79]
Accordingly, in every instance of the capture of a Nautilus the chambers
of its shell have been found filled with water. It is not improbable
that the fluid they contain may be less compressed, and exert less
pressure from within outwards than that of the external superincumbent
column of water, and that by this unbalanced pressure--under the same
hydro-dynamic law which governs its mode of self-propulsion when
swimming, and possibly in some degree within the control of the
animal--the latter is relieved of much of the weight of its shell. When
the Nautilus is at the bottom of the sea its movement is like that of a
snail crawling along upon the ground with its shell above it. The shell,
in proportion to the size of the animal that inhabits it, is a heavy
one, and unless it were rendered semi-buoyant, its owner's strength
would be severely taxed by the effort to drag it along. By the means
indicated this portable domicile is borne lightly above the body of the
Nautilus, without in any way impeding its progress.
[79] "At 100 fathoms the pressure exceeds 265 lbs. to the square
inch. Empty bottles, securely corked, and sunk with weights beyond
100 fathoms, are always crushed. If filled with liquid the cork is
driven in, and the liquid replaced by salt water; and in drawing
the bottle up again the cork is returned to the neck of the bottle,
generally in a reversed position."--Sir F. Beaufort, quoted by Dr.
S. P. Woodward in his 'Manual of the Mollusca.'
[Illustration: FIG. 32.--SHELL OF THE PEARLY NAUTILUS (_Nautilus
pompilius_).]
[Illustration: FIG. 33.--THE PEARLY NAUTILUS (_Nautilus pompilius_), AND
SECTION OF ITS SHELL. _After Professor Owen._
_a a_, Partitions; _b b_, chambers; _b'_, the last-formed chamber, in
which the animal lives; _c c_, the siphuncle; _d_, attaching muscle; _e
e_, the hollow arms; _f f_, retractile tentacles; _g_, muscular disk, or
foot; _h_, the eye; _i_, position of funnel.]
The chambers are all connected by a membranous tube slightly coated with
nacre, which is connected with a large sac in the body of the animal,
near the heart, and passes through a circular orifice and a short
projecting tube in the centre of each partition wall, till it ends in
the smallest chamber at the inner extremity of the shell. Dean Buckland
believed this "syphon" to be an hydraulic apparatus acting as a "fine
adjustment" of the specific gravity of the shell, by admitting water
within it when expanded, and excluding it when contracted. As it
contains an artery and vein near its origin at the mantle, Professor
Owen has regarded it as subservient to the maintenance of a low vitality
in the vacated portion of the shell. Dr. Henry Woodward is of the
opinion that, whilst in the early life of the Nautilus this siphuncle
forms the main point of attachment between the animal and its shell, it
is in the adult "simply an aborted embryonal organ whose function is now
filled by the shell-muscles, but which in the more ancient and
straight-shelled representatives of the group (the Orthoceratites) was
not merely an embryonal but an important organ in the adult."
Every one knows the shell of the Pearly Nautilus. It may be purchased
at any shell-shop in a seaside watering-place, and is imported by
hundreds every year from Singapore.[80] It is abundant in the waters of
the Indian Archipelago, especially about the Molucca and Philippine
Islands, and on the shores of New Caledonia and the Fiji and Solomon
Islands. It has also been found alive on Pemba Island, near Zanzibar. It
seems strange, therefore, that until about half a century ago hardly
anything was known of the animal that secretes and inhabits it.
Rumphius, a Dutch naturalist, in his 'Rarities of Amboyna,' published,
in 1705, a description of one with an engraving, incorrect in drawing,
and deficient in detail; and until 1832 this was the only information
which existed concerning it. The great Cuvier never saw one, and being
acquainted only with the two-gilled cephalopods, he regarded the
head-footed mollusks as absolutely isolated from all other animals in
the kingdom of nature, even from the other classes of the mollusca. It
seemed, however, to Professor Owen, then only nineteen years of age,
that in the only living representative of the four-gilled order,
_Nautilus pompilius_, might be found the "missing link." When,
therefore, in the year 1824, his fellow-student, Mr. George Bennett, was
about to sail from England to the Polynesian Islands, young Richard Owen
earnestly charged his friend to do his utmost to obtain, and bring home
in alcohol, a specimen of the much-coveted Pearly Nautilus. The
opportunity did not occur till one warm and calm Monday evening, the
24th of August, 1829, when a living Nautilus was seen at the surface of
the water not far distant from the ship, in Marekini Bay, on the
south-west coast of the Island of Erromango, New Hebrides, in the South
Pacific Ocean. It looked like a dead tortoise-shell cat, as the sailors
said. As it began to sink as soon as it was observed, it was struck at
with a boat-hook, and was thus so much injured that it died shortly
after being taken on board the ship. The shell was destroyed, but the
soft body of the animal was preserved in spirits, and great was the joy
of Mr. Owen when, in July, 1831, Mr. Bennett arrived with it in England,
and presented it to the Royal College of Surgeons. Mr. Owen was then
Assistant-Conservator of the Museum of the College under Mr. Clift, who
was afterwards his father-in-law. He immediately commenced to anatomise,
describe, and figure his rare acquisition, and in the early part of 1832
published the result of his work in the form of a masterly treatise,
which proved to be the foundation of his future fame.[81]
[80] I need hardly say that before the nacreous layer of the shell
from which this animal takes its name is made visible, an outer
deposit of dense calcareous matter has to be removed by
hydrochloric acid: the pearly surface thus exposed is then easily
polished.
[81] It is so interesting to most of us to know something of the
early work of our greatest men, and of the tide in their affairs,
which, taken at the flood, led on to fortune, that I hope I may be
excused for referring to the period when the distinguished chief of
the Natural History Department of the British Museum, the great
comparative anatomist, the unrivalled palaeontologist, the
illustrious physiologist, the venerable and venerated friend of all
earnest students, was beginning to attract the attention, and to
receive the approbation of his seniors as a promising young worker.
In Messrs. Griffith and Pidgeon's Supplement to Cuvier's 'Mollusca
and Radiata,' published in 1834, the treatise in question is thus
mentioned: "We have much pleasure in referring to a most excellent
memoir on _Nautilus pompilius_, by Mr. Owen, with elaborate figures
of the animal, its shell, and various parts, published by direction
of the Council of the College of Surgeons. The reader will find the
most satisfactory information on the subject, and the scientific
public will earnestly hope that the present volume will be the
first of a similar series." This hope has been more than fulfilled.
Dean Buckland, in his 'Bridgewater Treatise,' wrote of this work:
"I rejoice in the present opportunity of bearing testimony to the
value of Professor Owen's highly philosophical and most admirable
memoir--a work not less creditable to the author than honourable to
the Royal College of Surgeons, under whose auspices the publication
has been so handsomely conducted."
Mr. Owen's investigations confirmed his previous supposition that the
Pearly Nautilus is inferior in its organisation to octopus, sepia, or
any other known cephalopod; that it is not isolated, but that it recedes
towards the gasteropods, to which belong the snail, the periwinkle, &c.,
and that in some of its characters its structure is analogously related
to the still lower _annulosa_, or worms. Mr. Owen was just about to
start for Paris with the intention of presenting a copy of his book to
his celebrated contemporary and friend, and of showing him his
dissections of the Nautilus which had been the subject of his research,
when he heard of Baron Cuvier's death. It must have been to him a great
sorrow and a grievous disappointment.
The Pearly Nautilus, then, is a true cephalopod, in that it has its foot
divided and arranged in segments around its head, but the form and
number of these segments are very different from those of any other of
its class. Instead of there being eight, as in the argonaut and octopus,
or ten, as in sepia and the calamaries, the Nautilus has about ninety
projecting in every direction from around the mouth. They are short,
round, and tapering, of about the length and thickness of the fingers of
a child. Some of them are retractile into sheaths, and they are attached
to fleshy processes (which might represent the child's hand), overlying
each other, and covering the mouth on each side. They have none of the
suckers with which the arms and tentacles of all the other cuttles are
furnished, but their annulose structure, like the rings of an
earthworm's body, gives them some little prehensile power. None of these
numerous finger-like segments of the foot are flattened out like the
broad membranous expansions of the argonaut, and, in fact, the Nautilus
is without any members which can possibly be regarded as sails to hoist,
or as oars with which to row. It has a strong beak, like the rest of the
cuttles; but it has no ink-sac, for its shell is strong enough to afford
it the protection which its two-gilled relatives have to seek in
concealment.
The Pearly Nautilus usually creeps, like a snail, along the bed of the
sea. It lives at the bottom, and feeds at the bottom, principally on
crabs; and, as Dr. S. P. Woodward says, in his 'Manual of the Mollusca,'
"perhaps often lies in wait for them, like some gigantic sea-anemone,
with outspread tentacles." The shape of its shell is not well adapted
for swimming, but it can ascend to the surface, if it so please, in the
same manner as can all the cuttles--namely, by the outflow of water from
its locomotor tube. The statement that it visits the surface of the sea
of its own accord is at present, however, unconfirmed by observation.
But, if the Pearly Nautilus is the inferior and poor relation of the
argonaut, it lives in a handsome house, and comes of an ancient lineage.
The Ammonites, whose beautiful whorled and chambered shells, and the
casts of them, are so abundant in every stratum, especially in the lias,
the chalk, and the oolite, had four gills also. These Ammonites and the
Nautili were amongst the earliest occupants of the ancient deep; and,
with the Hamites, Turrilites, and others, lived upon our earth during a
great portion of the incalculable period which has elapsed since it
became fitted for animal existence, and in their time witnessed the rise
and fall of many an animal dynasty. But they are gone now; and only the
fossil relics of more than two thousand species (of which 188 were
Nautili) remain to tell how important a race they were amongst the
inhabitants of the old world seas. They and their congeners of the
chambered shells, however, left one representative which has lived on
through all the changes that have taken place on the surface of this
globe since they became extinct--namely, _Nautilus pompilius_, the
Nautilus of the pearly shell--the last of the Tetrabranchs.
I need offer no apology for endeavouring to explain the difference
between the Nautilus of the chambered shell and the argonaut with the
membranous arms which it was supposed to use as sails, when Webster, in
his great standard dictionary, describes the one and figures the other
as one and the same animal; and when a writer of the celebrity of Dr.
Oliver Wendell Holmes also blends the two in the following poem,
containing a sentiment as exquisite as its science is erroneous. I hope
the latter distinguished and accomplished author, whose delightful
writings I enjoy and highly appreciate, will pardon my criticism. I
admit that the beauty of the thought might well atone for its
inaccuracy, (of which the author is conscious,) were it not that the
latter is made so attractive that truth appears harsh in disturbing it.
"THE CHAMBERED NAUTILUS."
"This is the ship of pearl, which poets feign
Sails the unshadowed main,
The venturous bark that flings
On the sweet summer wind its purpled wings,
In gulfs enchanted, where the siren sings,
And coral reefs lie bare,
Where the cold sea-maids rise to sun their streaming hair.
Its webs of living gauze no more unfurl,
Wrecked is the ship of pearl!
And every chambered cell,
Where its dim, dreaming life was wont to dwell,
As the frail tenant shaped his growing shell,
Before thee lies revealed,
Its irised ceiling rent, its sunless crypt unsealed!
Year after year beheld the silent toil
That spread his lustrous coil;
Still, as the spiral grew,
He left the past year's dwelling for the new,
Stole with soft step its shining archway through,
Built up its idle door,
Stretched in his last-found home, and knew the old no more.
Thanks for the heavenly message brought by thee,
Child of the wandering sea,
Cast from her lap forlorn!
From the dead lips a clearer note is born
Than ever Triton blew from wreathed horn!
While on mine ear it rings,
Through the deep caves of thought I hear a voice that sings:--
'Build thee more stately mansions, O my soul,
As the swift seasons roll!
Leave thy low vaulted past;
Let each new temple, nobler than the last,
Shut thee from heaven with a dome more vast,
Till thou at length art free,
Leaving thine outgrown shell by life's unresting sea.'"
BARNACLE GEESE--GOOSE BARNACLES.
The belief that some wild geese, instead of being hatched from eggs,
like other birds, grew on trees and rotten wood has never been surpassed
as a specimen of ignorant credulity and persistent error.
There are two principal versions of this absurd notion. One is that
certain trees, resembling willows, and growing always close to the sea,
produced at the ends of their branches fruit in form like apples, and
each containing the embryo of a goose, which, when the fruit was ripe,
fell into the water and flew away. The other is that the geese were bred
from a fungus growing on rotten timber floating at sea, and were first
developed in the form of worms in the substance of the wood.
When and whence this improbable theory had its origin is uncertain.
Aristotle does not mention it, and consequently Pliny and AElian were
deprived of the pleasure they would have felt in handing down to
posterity, without investigation or correction, a statement so
surprising. It is, comparatively, a modern myth; although we find that
it was firmly established in the middle of the twelfth century, for
Gerald de Barri, known in literature as Giraldus Cambrensis, mentions it
in his 'Topographia Hiberniae,' published in 1187. Giraldus, who was
Archdeacon of Brecknock in the reign of Henry II., and tried hard, more
than once, for the bishopric of St. David's, the functions of which he
had temporarily administered without obtaining the title, was a vigorous
and zealous reformer of Church abuses. Amongst the laxities of
discipline against which he found it necessary to protest was the custom
then prevailing of eating these Barnacle geese during Lent, under the
plea that their flesh was not that of birds, but of fishes. He writes:--
"There are here many birds which are called Bernacae, which nature
produces in a manner contrary to nature, and very wonderful. They
are like marsh-geese but smaller. They are produced from fir-timber
tossed about at sea, and are at first like geese upon it.
Afterwards they hang down by their beaks, as if from a sea-weed
attached to the wood, and are enclosed in shells that they may grow
the more freely. Having thus, in course of time, been clothed with
a strong covering of feathers, they either fall into the water, or
seek their liberty in the air by flight. The embryo geese derive
their growth and nutriment from the moisture of the wood or of the
sea, in a secret and most marvellous manner. I have seen with my
own eyes more than a thousand minute bodies of these birds hanging
from one piece of timber on the shore, enclosed in shells and
already formed. Their eggs are not impregnated _in coitu_, like
those of other birds, nor does the bird sit upon its eggs to hatch
them, and in no corner of the world have they been known to build a
nest. Hence the bishops and clergy in some parts of Ireland are in
the habit of partaking of these birds on fast days, without
scruple. But in doing so they are led into sin. For, if any one
were to eat of the leg of our first parent, although he (Adam) was
not born of flesh, that person could not be adjudged innocent of
eating flesh."
This fable of the geese appears, however, to have been current at least
a hundred years before Giraldus wrote, for Professor Max Muller, who
treats of it in one of his "Lectures on the Science of Language,"
amongst many interesting references there given, quotes a Cardinal of
the eleventh century, Petrus Damianus, who clearly describes, that
version of it which represents the birds as bursting, when fully
fledged, from fruit resembling apples.
It is a curious fact that these Barnacle geese have troubled the
priesthood of more than one creed as to the instructions they should
give to the laity concerning the use of them as food. The Jews--all
those, at least, who maintain a strict observance of the Hebrew Law--eat
no meat but that of animals which have been slaughtered in a certain
prescribed manner; and a doubt arose amongst them at the period we refer
to, whether these geese should be killed as flesh or as fish. Professor
Max Muller cites Mordechai,[82] as asking whether these birds are
fruits, fish, or flesh; that is, whether they must be killed in the
Jewish way, as if they were flesh. Mordechai describes them as birds
which grow on trees, and says, "the Rabbi Jehuda, of Worms (who died
1216) used to say that he had heard from his father, Rabbi Samuel, of
Speyer (about 1150), that Rabbi Jacob Tham, of Rameru (who died 1171),
the grandson of the great Rabbi Rashi (about 1140), had decided that
they must be killed as flesh."
[82] Riva, 1559, leaf 142.
Pope Innocent III. took the same view; for at the Lateran Council, in
1215, he prohibited the eating of Barnacle geese during Lent. In 1277,
Rabbi Izaak, of Corbeil, determined to be on the safe side, forbade
altogether the eating of these birds by the Jews, "because they were
neither flesh nor fish."
Michael Bernhard Valentine,[83] quoting Wormius, says that this
question caused much perplexity and disputation amongst the doctors of
the Sorbonne; but that they passed an ordinance that these geese should
be classed as fishes, and not as birds; and he adds, that in consequence
of this decision large numbers of these birds were annually sent to
Paris from England and Scotland, for consumption in Lent. Sir Robert
Sibbald[84] refers to this, and says that Normandy was the locality from
which the French capital was reported to be principally supplied; but
that in fact the greater number of these geese came from Holland. The
date of this edict is not given.
[83] 'Historia Simplicium,' lib. iii. p. 327.
[84] Prodrom. Hist. Nat. Scot. parts 2, lib. iii. p. 21, 1684.
Professor Max Muller says that in Brittany, Barnacle geese are still
allowed to be eaten on Fridays, and that the Roman Catholic Bishop of
Ferns may give permission to people out of his diocese to eat these
birds at his table.
In Bombay, also, where fish is prohibited as food to some classes of the
population, the priests call this goose a "sea-vegetable," under which
name it is allowed to be eaten.
Various localities were mentioned as the breeding-places of these
arboreal geese. Gervasius of Tilbury,[85] writing about 1211, describes
the process of their generation in full detail, and says that great
numbers of them grew in his time upon the young willow trees which
abounded in the neighbourhood of the Abbey of Faversham, in the county
of Kent, and within the Archiepiscopate of Canterbury. The bird was
there commonly called the _Barneta_.
[85] Otia Imperialia, iii. 123.
Hector Boethius, or Boece, the old Scottish historian, combats this
version of the story. His work, written in Latin, in 1527, was
translated into quaint Scottish in 1540, by John Bellenden, Archdeacon
of Murray. In his fourteenth chapter, "Of the nature of claik geis, and
of the syndry maner of thair procreatioun, and of the ile of Thule," he
says:--
"Restis now to speik of the geis generit of the see namit clakis.
Sum men belevis that thir clakis growis on treis be the nebbis. Bot
thair opinioun is vane. And becaus the nature and procreatioun of
thir clakis is strange we have maid na lytyll laubore and deligence
to serche ye treuth and verite yairof, we have salit throw ye seis
quhare thir clakis ar bred, and I fynd be gret experience, that the
nature of the seis is mair relevant caus of thir procreatioun than
ony uther thyng."
From the circumstances attending the finding of "ane gret tree that was
brocht be alluvion and flux of the see to land, in secht of money pepyll
besyde the castell of Petslego, in the yeir of God ane thousand iiii.
hundred lxxxx, and of a see tangle hyngand full of mussill schellis,"
brought to him by "Maister Alexander Galloway, person of Kynkell," who
knowing him to be "richt desirus of sic uncouth thingis came haistely
with the said tangle," he arrives at the conclusion, by a process of
reasoning highly satisfactory and convincing to himself, that,
"Be thir and mony othir resorcis and examplis we can not beleif
that thir clakis ar producit be ony nature of treis or rutis
thairof, but allanerly be the nature of the Oceane see, quhilk is
the caus and production of mony wonderful thingis. And becaus the
rude and ignorant pepyl saw oftymes the fruitis that fel of the
treis (quhilkis stude neir the see) convertit within schort tyme in
geis, thai belevit that thir geis grew apon the treis hingand be
thair nebbis sic lik as appillis and uthir frutis hingis be thair
stalkis, bot thair opinioun is nocht to be sustenit. For als sone
as thir appillis or frutis fallis of the tre in the see flude thay
grow first wormeetin. And be schort process of tyme are alterat in
geis."
In describing the bird thus produced, Boethius declares that the male
has a sharp, pointed beak, like the gallinaceous birds, but that in the
female the beak is obtuse as in other geese and ducks.