SEA-WORMS AND SEA-CUCUMBERS
From the tinted tips of fragile corals to the ooze on the edge of the
beach sand there is seething life. Exposed by the ebb tide, the
sun-caressed slime glitters and shimmers, so that if the observer is
content to stand still for a few moments he shall see myriads of
obscure activities, graceful and uncouth, of the existence of which he
has not previously dreamt and among which his footsteps make a
desolating track. Perhaps in no other earthly scene do the gradations of
life blend so obviously in form and appearance. This mud is primal,
fertile with primitives, for similitude of environment checks variations.
In such tepid slime primordial life began, and in it even in these latter
days the far beginning of superior things may be discovered actively
pursuing their craft and purpose in the order of the universe. Worms are
abundant, and among them certain genera which might be taken as apt
illustrations of the more significant facts of evolution. Studying them,
the parting of the ways between two distinct orders, each having a
conspicuous feature in common while differing in appearance and habits
generally, is made strangely plain, and I propose in my unversed way to
demonstrate the line of upward development in a few examples.
Accepting as a primitive form that deplorably thin, phantasmal worm which
excavates in the ooze an appropriately narrow shaft indicated by a
dimple, or, in some cases, a swelling mound with a well-defined crater
and circular pipe, the ascent of the genealogical tree is not beset with
any great difficulty. These worms are grey in colour and shoddy in
texture, merely a tough description of slime with a crude head and long,
simple filaments. The sides of the shafts are smooth, and on the least
alarm the nervous inhabitant retracts with surprising alertness. Slightly
superior in grade, but in uninterrupted succession, is a similar worm
which solidifies its shaft with a kind of mortar and carries it up above
the level of the ooze about an inch or so--a crude effort in the
direction of the acquirement of some ease of circumstance. These flue-like
projections are more frequent on the verge of the sandy beach.
The next in order--still slim, though of a slightly more robust habit of
body--has acquired the art of spinning (caterpillar-like) a cocoon, and
of causing to adhere to the exterior thereof grains of sand and minute
chips of shell. Though this vestlet is very frail and though the sandy
outer coat is liable to drop off (when it collapses altogether), it seems
to me to indicate distinct progress, a successful accomplishment in the
direction of isolation, independence, and security. Does it not signify
that the animal has a certain perception of the knowledge of good and
evil such as dawned upon Eve as she ate the diverting apple? Eve
forthwith took to fig-leaves; the slim worm knitted a shoddy wrapper and
reinforced it with grains of sand when it realised that there was
something better than slush for a dwelling. The sandy coverlet is
evidence of the gift of discrimination.
A still more highly endowed relation spins a similar fabric, upon which
are loosely agglutinated numbers of small dead shells, grit, and even
opercula a quarter of an inch in diameter. In weight, size, and number of
its constituents this exterior armour is altogether disproportionate to
the extreme tenuity of its foundation. Too unsubstantial to sustain its
own weight, it sprawls, like the track of a tipsy snail, indeterminately,
slowly developing its sinuosities over the irregular surface of a rock,
and slightly adherent thereto, throughout its whole length. Of this there
seem to be several nicely shaded grades, some in the form of galleries
laboriously built of a mixture of mud and sand, and each indicating
superiority to the naked denizen of the clement mud. They seem to be
superior in appearances also, for some of the animals display brightly
coloured plume-like tentacles, long and capable of being ostentatiously
fluttered.
The individual worm next to be described typifies such a wonderful
advance that it might almost be designated a subsequent and intrusive
sport, no marked are the distinctions it exhibits. It is one of the
shell-binders (PECTINARIA), but its mansion of mosaics is unique and
beautiful. In the universal struggle for place, self-preservation, and
food, the animal has acquired a higher order of intelligence and keener
perceptions of safety and of the niceties of life than its fellows.
Living in sand and mud, in obedience to some gracious instinct, it
gathers numbers of small shells, grit, and fragments of coral wherewith
to construct a tube, somewhat similar in shape to the horn of cornucopia,
and from three to six inches long. The materials are cemented together in
accordance with a symmetrical design, the interior being lined with a
transparent substance, which, when dry, is readily separable from the
casing! This creature accomplishes by calculation, choice, and dexterity
that which a subtle chemical process does unconsciously for the more
advanced mollusc, and that it practised the art of the interlocking of
atoms ages before the birth of Macadam can scarcely be doubted.
My imagination loves to dwell on the perceptive faculties possessed by
this lowly creature, a creature soft and delicate, merely such and such a
length of gelatinous substance, slightly stiffened and toughened and
graced with a pair of tentacles glittering like tinsel extended from a
marvellously constructed tube.
In certain structural details the animal (which in appearance has greater
resemblance to a caterpillar than a worm) is even more remarkable than
the ornate dwelling it constructs, for it is an actual though living
prototype of the fabled race (catalogued by Othello with the
anthropophagi)--
"Whose heads
Do grow beneath their shoulders."
The paradox exists, not as a whim or grimace on the part of Nature but
for a definite and vital end. In default the animal would be unable to
obey the first law of Nature--self preservation--for it is soft-bodied and
its dwelling has the serious defect of being open at both ends. In such
plight lacking special organs it would be at cruel advantage in the
struggle for existence. The posterior segment of the body is therefore
developed into an operculum-like organ, smooth and of horny texture,
which closes the narrow end of the tube. The other extremity is more
elaborately guarded, the anterior segment being fringed with a frontal
membrane, while the second segment forms a disc, the minute mouth orifice
with the true tentacles and gills being debased to the third segment.
Confronted by danger, the animal closes its front door by retracting
until the disc presses immovably against the circumference of the tube,
the retraction being so sudden that a frail spurt betrays the whereabouts
of an otherwise secret dwelling-place. In the centre of the disc is the
first segment, from which the frontal fringe is extended in the form of
an array of keen bristles as a defensive weapon. With the lid at one end
and the armed disc at the other the animal enjoys security and comfort,
and when unsuspicious the "shoulders" protrude, the head meekly
following. The tentacles are serrate and glitter like tinsel, possibly
for the fascination of the minute forms of life which the tube-dweller
consumes. To enable it to retract and emerge quickly the animal is
provided with a series of tufts of bristles on the back and on the
ventral surface of the body with a row of toothed "pads," which fulfil
the dual office of grapplers and feet.
With what skill and patience does this pectinarian construct its ornate
habitation! How artfully does it pick and choose among the tiny shells
and grit! With what rare discretion rejects the unfit, and with what
satisfaction retains a neat and dainty item of building material! How
deftly does it arrange its courses and bonds, cementing each fragment in
its place until a perfect cylinder, proportionate in dimensions,
uniformly expanding in circumference, smooth within, rugged without,
scientifically correct in design, is the result! How apt, too, the
frictionless lining! And all this laborious neatness and precision
absorbed in the construction of a tenement which has no time! Does the
inmate possess any sense of duration? Addison (quoting a French
authority) says that it is possible some creatures may think half an hour
as long as we do a thousand years! The magnificent mind of the modern
biologist regards a million of years as a mere fag-end of time. The
industrious worm which has built so choice a home may have enjoyed the
sense of comfort and security for a period representing an honourable
age, while, according to the standards of man, the home was not worth the
building for so short a tenancy.
Do we not see in this astonishing example a highly successful effort of a
marine worm to improve on the condition and habits of its barbarous
ancestors? Analyse a bulk sample of the building material, and you shall
find it not dissimilar from the shell of a mollusc, and the interior
film--no doubt a secretion of the animal--is to be safely accepted as
analogous to the silky smoothness which molluscs (often of rough and
rugged exterior) obtain by nacreous deposit and which finds its
culmination in the goldlip mother-of-pearl?
Still higher in the series, so far as the construction of a tenement is
concerned, is that known as the SERPULA, a worm which constructs a
calcareous tube more or less loosely convoluted and adherent to a shell
or stone or coral, or sometimes entwined into a self-supporting colony.
Another worm builds of sand or mud, with a rough casting of fine gravel
and shell-grit, a habitation similar in design to that of the serpula,
though on a less complete and authoritative model; indeed, it would
almost seem that the latter had designed its tenement after the fashion
of that of its poor relation--that the one made a study in mud which the
other reproduced in carbonate of lime. But the most curious fact is that
a true mollusc (VERMETUS) so far departs from the fashion prevalent in
the molluscan world of building a spiral shell, that after beginning one
in proper spiral mode it elongates itself in vermiform manner and forms
an irregular serpuloid tube on the surface of larger shells or stones
just as the SERPULA does; so that without examination of the animal one
may easily be mistaken for the other.
What a contrast is here--on the one hand a lowly worm learning to build a
solid if rude shelly covering for its tender body, on the other a
relative of the elegant, many-whorled TURRITELLA forgetting its high
station and degenerating to the likeness of a worm. No doubt it is really
a case of degeneration from the acquirement of fixed habits, just as when
a lively young crustacean larva gives up its free independent life and
glues its head to a stone--what happens? Why, he becomes a mere barnacle
instead of a spritely shrimp as he might have been! Let mankind take
note and beware.
Another group of worm-like or snaky creatures common on a coral-reef are
the sea-cucumbers or bêche-de-mer. In my experience the most singular
branch of the family is at once the longest and thinnest, for it
resembles a snake so closely that at first sight the observer
subconsciously assumes an attitude of hostility. There seem to be two
varieties of the species. One is much more ruddy in appearance than the
other, and its body is the smoother; but they are much alike in physique
and helplessness. The figure of a sausage-skin four or five and even six
feet long, and capable of elongation to almost double, containing muddy
water in circulation and one end exhibiting a set of ever-waving
tentacles, conveys a not unflattering notion of the animal as it lies
coiled among the coral, half hidden with algae. Far too feeble to be
offensive, it suffers collapse on alarm--that is to say, if such a violent
mental and physical ill can befall an animal of such crude organism. At
least, the tentacles are withdrawn, nor will they be protruded until
some sense--unlikely to be either sight, hearing, taste, or touch, but
probably nervous tension acutely susceptible to vibrations--tells that
danger is past. Then the tentacles are shyly exhibited and the agitations
of the animal are renewed.
Throughout the length of the body of the more remarkable of the two
species of which I may speak on first-hand knowledge are four rows of
bosses, closely spaced, which when the animal has dragged its slow length
along to the utmost limit diminish into mere wrinkles, and disappear
altogether when it is slung across a stick, and the fluid contents, being
precipitated, congest and woefully weight each end, sometimes to the
bursting-point. The bosses of repose seem to indicate so much length in
reserve. A dozen simple tentacles, sword-shaped, with frayed edges, and
about an inch and a half long, indicate the head without decorating it,
for they are of an inconspicuous neutral tint, closely resembling the
alga among which the animal slowly winds its way.
The progress of all species of bêche-de-mer is sedate and cautious, and
this, probably the longest and the weakest and limpest of all, surpasses
the race in deliberateness. It cannot move as a whole, so it progresses
in sections. When the head has been advanced to its utmost, about the
middle of the body an independent series of succeedant ripples or
wrinkles manifests itself and travels consistently ahead, while farther
towards the rear another series follows, and so on, until the lagging
tail is enabled to wrinkle itself along. But the animal is endowed with
the capacity of quite suddenly retracting its forepart like the bellows
of a concertina, and when so compressed to heave it backward or in any
direction, so that an immediate change of route is possible. The
retraction and uplifting of the foreshortened part is astonishingly rapid
in view of the methodic movements of the animal as a whole. It is also
notable that when the retraction takes place the tentacles are entirely
withdrawn, otherwise they are for ever anxiously exploring every inch of
the toilsome way. Scientific men have entitled one of the
species--possibly the very one blunderingly introduced--SYNAPTA BESELLII,
and brief reference is made to it elsewhere.
One member of the great "sea-cucumber," or BÊCHE-DE-MER, family is
especially noticeable because it is decorated with colours of which a
gaily plumaged bird might be envious, though it has no other claim to
comeliness. Most primitive in form--merely a flattened sac, oval and four
inches long by three inches broad, with a purple and white mouth puckered
as if contracted by a drawn string. Its general tint is grey;
longitudinal bands of scarlet, green, violet, and purple radiate from the
posterior and converge at the mouth, the hues blending rainbow-like. The
brighter colours seem to have been carelessly and profusely applied, for
they run when touched and smear the fingers. Among a family generally
sad-hued and shrinking so conspicuous an example is quite prodigal and
invites one to ponder upon the sportfulness of Nature. What special
office in her processes does this fop of the species with prismatic
complexion perform?
The functions of bêche-de-mer are not only interesting, but requisite in
the commonwealth of the coral reef, however purposeless to the observer
intent upon the obvious and external only; while the genera are so
numerous that doubtless to each species is consigned the performance of
a special office. Some seem to delight in a diet of slush of the
consistency of thin gruel; others prefer fine grit; others, again, coarse
particles of shell and coral grit and rough gravel. Peradventure the
actual food consists of the micro-organisms in the slush and on the
superficies of the unassimilatable solids.
When submitted to the sun on the dry beach death is speedy, and
decomposition in the case of some species complete to obliteration in a
few hours. An apparently solid body, weighty in comparison with its size
and apparently of such nature that rapid desiccation would convert it
into a tough, leathery substance, it melts at the sight of the sun,
leaving as a relic of existence its last meal--a handful of grit-covered
with a transparent film of varnish, which the first wavelet of the
flowing tide dissolves. Yet on the reef in a pool such an individual
endures complacently water heated to a temperature of 108°. Though
feeble and of such readily dissolvable texture, bêche-de-mer may be
regarded as among the mightiest agents in the conversion of the waste of
the coral reef into mud--the sort of mud of which some of the toughest of
rocks are compounded. Graded by this and that species, the debris is
reduced to fine particles, which upon sedimentation help to raise the
level of the reef and thus prepare foundations for dry land.
For richness of colour and diversity of design some of the lovely corals
and sponges, which seem to counterfeit the inventions and contrivances of
man, and the algae, and those anomalous "growths" which fixedly adhere
to the under surface of stones and blocks of coral debris, are not to be
surpassed. These dull stones, partly buried in sand, reveal in blotches,
daubs, and smears the crude extravagances of a painter's palette. Can it
be that such brilliant colours and tints, so profuse and delicate, are
necessary features of animals of such crude organisms that they appear to
be merely disembodied splashes and driblets from the brush of the Great
Artist? Look at this fantastic patchwork, brightening the obscurity of
an upturned stone with glowing orange. In perfectly regular minute dots a
pattern of quartered squares, raised slightly in the centre, is being
worked out. Many of the squares are finished, but the fabric is rugged at
the edges, where, with miraculous precision, the design is being
followed, each tiny stitch the counterpart of its fellow. Unless this
gross and formless blotch of sage green interferes or this disc of royal
blue expands, the whole under surface of the stone may be covered with an
orange coloured quilt as dainty as if wrought by fairy fingers.
Why, again, is this particular miniature dome of coral so precisely
spirally fluted, like the dome of a Byzantine cathedral? Why of so pure a
mauve and bespangled with so many millions of snow-white crystals?
Why--where no eyes see them--should parti-coloured algae flaunt such
graceful, flawless plumes? What marvellous fertility of imagination in
form and design is exhibited in every quiet coral garden! Stolid
battlemented walls, massive shapeless blocks, rollicking mushrooms, tipsy
toadstools; narrow fjords, sparklingly clear, wind among and intersect
the stubborn masses. Fish, bright as butterflies and far more alert,
flash in and out of mazes more bewildering than that in which Rosamond's
bower was secluded. Starfish stud the sandy flats, a foot in diameter,
red with burnished black bosses, and in all shades of red to pink and
cream and thence to derogatory grey. Here is a jade-coloured
conglomeration of life resembling nothing in the world more than a loose
handful of worms without beginning and without end, interloped and
writhing and glowing as it writhes with opalescent fires; and here a
tiny leafless shrub, jointed with each alternate joint, ivory, white, and
ruby-red respectively; again this tracery of gold and green and salmon
pink decorating a shiny stone, in formal and consistent pattern. What is
it? why is it? and why are such luminous tints so sordidly concealed?
CHARTER XIII
SOME MARINE NOVELTIES
"And call up unbound
In various shapes old Proteus from the sea."
MILTON.
During the cool season the tides on the coast of North Queensland offer
peculiar facilities to the observer of the thousand and one marvels of
the tropic sea. Spring tides throughout the warm months range low at
night and high during the day. In other words, the lowest day
spring-tide in winter exposes far more of the reefs than the lowest day
tide of summer, while the highest night tide of summer sweeps away the
data of the corresponding tide of winter. When, therefore, the far
receding water makes available patches of coral reef exposed at other
times of the year merely to the cool glimpses of the moon, I am driven to
explore them with an eagerness, if not of a treasure-seeker or in the
frenzies of naturalistic fervour, at least with the enthusiasm of an
ardent student.
It may be that most of the sights which are revealed are of common
knowledge among scientific men, and if one is inclined to preach a
little sermon on the text of the living stones and polyps and animated
jelly, and if such text be trite, let it be granted that the sermon is at
least original. Necessarily the sermon will lack commentary and
application, and be very imperfect in many other details. If it possesses
any virtues, you must apply them personally, for the preacher is not
enlightened enough to expound them even to his own, much less to the
satisfaction of others.
In many places on this reef little secrets, well kept throughout the rest
of the year, are boldly proclaimed when the sea retreats. A fairly common
one is a huge anemone of a rich cobalt blue which opens out like a
soup-plate with convoluted edges. Another has a form something resembling
a hyacinth-glass. The more public parts are not unlike a dwarf growth of
that old-fashioned flower the Prince of Wales's feather, save that the
colour is a rich brown. Being an animal, it possesses senses in which the
most highly specialised vegetable is deficient. It has the power of
waving its spikelets, and of the thousand of truncated tentacles which
cover the spikelets each seems to possess independent action. Though all,
no doubt, contribute to the sustenance of the animal, they, at will, rest
from their labours or assume great activity.
It is natural to suppose that the diet of such an animal must be of
microscopic proportions. The other day I happened on one which had seized
a fish about four inches long, and seemed to be greedily sucking it to
death. The fish was still alive, and as it looked up at me with a
pathetic gleam in its watery eyes, I released it. It was very
languid--indeed, so feeble and faint that it could not swim away. Aid had
come too late. The fish was the legitimate prey of the anemone. My
interference had been at variance from the laws of property and right. As
the vestige of life which remained to the fish was all too fragile for
salvation, and as I saw the chance of ascertaining whether the anemone
had consciously seized it, or whether it had by mishap blundered against
the anemone and had been arrested for its intrusion, I placed the fish
close to the enemy. I am certain the anemone made an effort to reach it.
There was a decided swing of one of the spikes in the direction of the
fish, and decided agitation among the hundreds of minute tentacles. When
I, in the interests of remorseless truth, placed the fish in the anemone
it was immediately held fast, the activity on the part of the tubes
subsiding with an air of satisfaction at the same moment.
It is well known that sea anemones do assimilate such robust and rich
diet as living fish. If one's finger is presented the spikelets adhere to
it. I cannot describe the sensation as seizure, for it is all too
delicate for that; but at least one is conscious of a faint sucking
pull. If the finger is rudely withdrawn, some of the tentacles which
have taken a firm hold are torn away. Again, the animal is often found
apparently asleep, for it is languid and listless, and will not respond
to the bait of a finger, however coaxingly presented.
There is another giant anemone (DISCOMA HADDONI) known to the blacks as
"pootah-pootah," whose inner, reflexed, convoluted edges are covered with
tentacles of brown with yellow terminals. This is friendly to fish--at
any, rate to one species. It is the landlord or host of one of the
prettiest fish of all the wide, wide sea, and seems proud of the company
of its guest, and the fish is so dependent upon its host as to be quite
helpless apart from it. The fish (AMPHIPRION PERCULA) "intel-intel" of
the blacks, is said to be commensal (literally, dining at the same table
with its host), as distinguished from the parasite, which lives on its
host.
The good-fellowship between the dainty fish--resplendent in carmine,
with a broad collar, and waist-band of silvery lavender (or rather silver
shot with lavender) and outlined with purple--and the great anemone is
apparent. If the finger is presented to any part of the latter, it
becomes adherent; or if the anemone is not in the mood for food, it
curls and shrinks away with a repulsive demeanour. But the beautiful
fish on the least alarm retires within the many folds of its host,
entirely disappearing, presently to peep out again shyly at the intruder.
It is almost as elusive as a sunbeam, and most difficult to catch, for if
the anemone is disturbed it contracts its folds, and shrinks away,
offering inviolable sanctuary. If the fish be disassociated from its
host, it soon dies. It cannot live apart, though the anemone, as far as
can be judged from outward appearances, endures the separation without a
pang.
However, it is safe to assert that the association between the stolid
anemone and the painted fish--only an inch and a half long--is for their
mutual welfare, the fish attracting microscopic food to its host. And why
should one anemone greedily seize a fish, and another find pleasure in
the companionship of one of the most beautiful and delicate of the
tribe?
This hospitable anemone occasionally takes another lodger--very frail and
beautiful. All that is visible on casual inspection is an irregular smear
of watery, translucent violet, flitting about in association with
disjointed threads--stiff, erratic, and delicately white. There is no
apparent connection between the spectral patch of colour and the animated
threads, though they are in company. If, determined to investigate the
mystery, the finger is presented, the colour evades it. It is conscious
and abhors the touch of man. Follow it up in the pellucid water, and make
of your hand a scoop, and you will find that you have captured, not a
phantom but a prawn, compact of one bewildering blotch--and that is a word
of doubtful propriety in connection with so elfin an organism--a mere
shadow tinted the palest violet, and transparencies, with legs and
antennae frail as silken threads.
"Substance might be called what shadow seemed,
For each seemed either."
So far I have never seen this lovely lodger in the same anemone with the
painted fish. The latter, perhaps, admires it too ardently and literally.
Another marvel, the sea-hare (APLYSIA), is a crudely wedge-shaped body
but incomparable in its ruggedness to that or any other model, and the
colour of mud and sand and of coral, dead and sea-stained. It reposes,
with its back flush with the surface, beside a block of coral or stone
defiantly indistinguishable from the ocean floor--a stolid, solid, inert
creature, eight or ten inches long, the under part smooth, presenting the
appearance of wet chamois-leather, and irresponsive to touch--"the
mother tongue of all the senses." Ugly, loathsome, and tough of texture,
it is so helpless that if it is placed on the sand it is extremely
doubtful whether of its own volition it could regain its natural
position. The surge of the sea might roll it over, and it might then be
able to regain the grovelling attitude essential to life. Otherwise, I
am inclined to think fatal results would follow the mere placing of the
creature sideways on the sand. It seems to possess but the feeblest spark
of life, and yet it has its sentiments and love for its kind, for often
three or four are huddled together. And how, it may be asked, is this
creature, so apt at concealment and so completely disguised, made visible
to human eyes?
The answer is that if by chance the animal is disturbed it makes a
supreme effort at further concealment, and that impulse--perfect as it may
be when set in opposition to the wit of the creature's nervous and
apprehensive enemies--reveals it most boldly to man. From a funnel-shaped
opening between two obscure flaps on the back--ordinarily invisible--there
is emitted a gush of liquid, royal purple in hue, which stains the sea
with an impenetrable dye for yards around. The colour, which is
delightfully gorgeous, mingles with the water in jets and curling
feathery sprays, enchanting the beholder with unique and ever-changing
shapes until a glorious cloud is created and he forgets the ugliness and
forgives the humility of the originator in the enjoyment of an artistic
treat. If the cloud which Jupiter assumed was of the imperial tone and of
the fascinating fashion which the groveller in the mud creates, Aegina
would have been superfeminine had she not joyously surrendered. Between
the neutral tints of the squalid sprawler and the fluid which it excretes
the contrast is so surprising that one involuntarily raises his hat by
way of apology for any slighting thoughts which may have arisen from
first and imperfect acquaintance.
There are grounds for the entertainment of the belief that the ejected
fluid not only effectually conceals the scarcely discernible animal but
that it harshly affects the sensibilities of fish.
In a partially submerged coral grotto were two small spotted sharks
(Wobbegong, CROSSORHINUS sp.) notoriously sluggish and averse from
eviction from their quarters during daylight. The larger callously
disregarded the tickling of a light fish spear, but lashed out vigorously
when a decisive prod was administered. In its flurry it must have
disturbed one of the dye-secreting molluscs, which had escaped my notice,
for in a few seconds the water was richly imbued. Thereupon both the
sharks began to manifest great uneasiness, and eventually with fluster
and splashing they worked among the fissures of the coral and shot out
into the unimpregnated sea. The sharks seemed to find the presence of the
forlorn groveller in the mud unendurable when it stained the water red,
though apparently indifferent to its presence as long, as it remained
quiescent, which facts lend confirmation to the popular opinion that the
fluid possesses a caustic-like principle violently irritative to the
skin.
And why should this uncouth creature with scarcely more of life than a
lump of coral have within it a fountain filled with Tyrian dye? Why?
Because it has enemies; and though it seems to be SANS mouth, SANS eyes,
SANS ears, SANS everything it is instinct with the first law of
Nature--self-preservation.
A fairly common inhabitant of the sandy shallows diversifying the coral
reef is a slim snake (? AIPYSINAS FUSCUS), sand-coloured, with a
conspicuous dark brown stock, defined with white edgings, a whitish nose
and pectoral fins so large as to remind one of those defiant collars
which Gladstone was wont to wear with such excellent effect. Blacks
invariably give the snake and its retreat a wide berth on the principle
enunciated by Josh Billings: "Wen I see a snaik's hed sticking out of a
hole I sez that hole belongs to that snaik." Among them this species has
the reputation of attacking off-hand whosoever disturbs it, and of being
provided with deadly venom. My experience, however, bids me say that the
pretty snake has the typical dread of the family of man, which dread
expresses itself in frenzied efforts to get out of the way when suddenly
molested. For the most part it lives in a neat hole, oubliette-shaped, and
in its eagerness to locate and reach its retreat it darts about with a
nimbleness which almost eludes perception. These frantic quarterings, I
believe, led to the opinion that the snake is specially savage, whereas
it is merely exceptionally nervous and eager for the security of its
home. Twice recently when I have startled one in an enclosed pool it has
darted hither and thither in extreme excitement, even passing between my
legs without offering any violence or venom, and has eventually
disappeared in a miniature maelstrom of mud, as the reptile often does.
Like that lively fellow of whom Chaucer tells:
"He is heer and there,
He is so variant, he bideth nowhere."
Dickens had in his mind a similarly elusive character when he wrote: "You
look at him and there he is. You look again--and there he isn't."
This habit of furiously seeking a lair might pass casually but for an
astonishing detail, of which I was not well assured until it was
confirmed by repeated observations and by knowledge current among the
blacks. When the scared snake descends into its own well-defined well,
very little disturbance and no discoloration of the water takes place.
But when in desperation it disappears down a haphazard hole, a dense
little cloud of sediment is created. By careful watching I discovered
that the snake entered its home head first, but in any other hole the
tail had precedence, and that the frantic wriggling as it bored its way
down caused the obscuration. Moreover the snake--as subtle as any beast of
the field--first detects a befitting temporary retreat from apparent or
fancied danger, and then deliberately turns and enters tail first. Does
the fact justify the conclusion that the creature, in the moment
intervening between the detection of a present refuge in time of trouble
and its dignified retreat thereinto, calculates the possibility that the
unfamiliar habitation may be so narrow as to prevent the act of turning
round? Does this sea-snake match its wonderful nimbleness of body with an
equally wonderful nimbleness of brain? I do not presume to theorise on
such a conundrum of Nature, but mention an undoubted fact for others to
ponder.
One of the salt sea snakes is distinguished by its odd, deceptive
shape--a broad, flattened tail whence the body consistently diminishes
to the head, which is the thinnest part. Other aquatic snakes have
paddle-shaped tails.
Another singular denizen of the reef is a species of Acrozoanthus (?)--a
compound animal having a single body and several heads. The body is
contained in a perpendicular, parchment-like, splay-footed tube a foot
and a half or two feet long, whence the heads obtrude alternately as
buds along a growing branch. Many of the tubes are vacant--the skeletons
of the departed. From those which are occupied the heads appear as
bosses of polished malachite veined and fringed with dusky purple, and
yellow-centred.
SPAWN OF THE SEA
"The dewdrop slips into the shining sea."
So Edwin Arnold. Here is an observation illustrating the manner in which
certain pellucid sea-drops materialise and ultimately shed themselves as
living organisms "into the shining sea."
On November 6, 1908, the sea tossed up on the beach an exceptionally
large and absolutely perfect specimen of the egg-cluster of that spacious
and useful mollusc known as the Bailer Shell (MELO DIADEMA or CYMBIUM
FLAMMEUM). Its measurements were: length, 16¼ in.; circumference at
base, 12¾ in.; at middle, 11¼ in.; at apex 7 1/8 in. It weighed 1¾ lb. and
comprised 126 distinct capsules. The photograph presents a candid
likeness.
During the same month and the first two weeks of December portions of
several other egg-clusters came ashore, and as they were in nicely
graduated stages of development I was enabled to indulge in an
exceptionally entertaining study--no less than the observation of the
transformation of glistening fluid into solid matter and life. In passing
it may be mentioned that the first and the last two months of the year
appear to constitute the period when the offspring of the species see the
light of day, proving that the natural impulses of some molluscs are
subject to rule and regulation similarly to those of birds and other
terrestrial forms.
Each of the capsules composing the cluster is a cone with the apex free
and interior, while the base is external and adherent to its immediate
neighbours, but not completely so throughout its circumference. It
follows, therefore, that the cluster of capsules is hollow and that water
flushes it throughout. In appearance it resembles a combination of the
pineapple and the corncob, and to the base a portion of the coral-stem to
which it had been anchored by its considerate parent was firmly attached.
When the cluster of capsules (the substance of which is tough,
semi-transparent, gelatine, opal-tinted, soon to be sea-stained a
yellowish green) is slowly expelled from the parent's body--I have been
witness to the birth--each contains about one-sixth ounce of vital
element, fluid and glistening. Physical changes in this protoplasm
manifest themselves in the course of a few days. The central portion
becomes a little less fluid, and from an inchoate blur a resemblance to a
diaphanous shell develops and floats, cloud-like, in a perfectly limpid
atmosphere. Gradually it becomes denser though still translucent, as it
seemingly absorbs some of the fluid by which it is surrounded. The model
of the future animal, exact even to the dainty contours and furrows around
that which represents the spire of the ultimate shell, is still without
trace of visible organs. That, however, its substance is highly complex is
obvious, for as imperceptible development progresses the exterior is
transformed into a substance resembling rice tissue-paper--an infinitely
fragile covering--which from day to day insensibly toughens in texture and
becomes separate from the animal. Faint opaque, transverse ribs are at
this stage apparent, though disappearing later on. Opacity is primarily
manifested at the aperture of the infant mollusc where a seeming
resemblance to an operculum forms, possibly for the protection of vital
organs during nascency. This plaque of frail armour is, however, soon
dismantled, and of course much more happens in the never-ceasing process
than is revealed to the uninitiated.
As the calcareous envelope becomes opaque and solid, the animal within
loses its transparent delicacy, and coincidentally the apex of the
capsule opens slightly. In the meantime the fluid contents have
disappeared, as if the animal had resulted from its solidification. The
animal, too, is a very easy fit in its compartment, and incapable, in its
extreme fragility of withstanding the pressure of a finger. Now it begins
to increase rapidly in bulk and sturdiness; the shell becomes hard, and
as the exit widens it screws its way out of a very ragged cradle,
emerging sound and whole as a bee from its cell, all its organs equipped
to ply their respective offices.
With pardonable affectation of vanity it has finally fitted itself for
appearance in public by the assumption of three or four buff and brown
decorations upon its milk-white shell, which quickly blend into a pattern
varying in individuals, of blotches and clouds in brown, yellow, and
white. In maturity the mollusc weighs several pounds, its shell has a
capacity for as much as two gallons of water, and is coloured uniformly
buff, while in old age infantile milk-white reasserts itself.
It is not for such as I am in respect of the teachings of science to say
whether the development of the perfect animal from a few drops of
translucent jelly--as free from earthly leaven as a dewdrop--is to be more
distinctly traced, in the case of this huge mollusc than in other
elementary forms. All that it becomes an unversed student of life's
mysteries to suggest is that this example gives bold advertisement to the
marvellous process.
Many of the secrets of life are written in script so cryptic and obscure
that none but the wise and greatly skilled may decipher it, and they
only, when aided by the special equipment which science supplies. In this
case the firm but facile miracle is recorded in words that he that runs
may read. Independent of microscope the unskilled observer may trace
continuity in the transformation of jelly to life.
The sea-drop, lovely in its purity, knowing neither blemish nor flaw,
becomes an animal with form and features distinctive from all others,
with all essential organs, means of locomotion, its appetite, its
dislikes, its care of itself, its love for its kind, its inherent malice
towards its enemies--all evolved in a brief period from the concentrated
essence of life.
"If, as is believed, the development of the perfect animal from
protoplasm epitomises the series of changes which represent the
successive forms through which its ancestors passed in the process of
evolution" (these are the words of Professor Francis Darwin) what a
graphic, what a luminous demonstration of evolution is here presented!
In a brief previous reference to this mollusc it was stated that the
infants in their separate capsules were in a state of progressive
development from the base to the apex of the cluster, those in the base
being the farther advanced. Investigations lead to a revision of such
statement. No favour seems to be enjoyed by first-born capsules.
Development is equable and orderly, but as in other forms of life the
contents of certain capsules seem to start into being with a more
vigorous initial impulse than others, and these mature the more speedily.
A sturdy infant may be screwing its way out of its cradle, while in a
weakly and degenerate brother alongside the thrills of life may be far
less imperative.
The pictures illustrate isolated scenes in the life-history of the
mollusc, which in a certain sense offers a solution to, the conundrum
stated by job "Who, hath begotten the drops of dew?"
PROTECTIVE COLORATION
July 17, 1909.
Found a small cowry shell of remarkable beauty on dead coral in the Bay.
At first sight it appeared as a brilliant scarlet boss on the brown
coral, and upon touching it the mantle slowly parted and was withdrawn,
revealing a shell of lavender in two shades in irregular bands and
irregularly dotted with reddish brown spots; the apertures were richly
stained with orange, and the whole enamel exceedingly lustrous. Most of
the molluscs of the species conceal themselves under mantles so closely
resembling their environments as to often render them invisible. In this
case the disguise assumed similitude to a most conspicuous but common
object of anomalous growth, seeming to be a combination of slime and
sponge.