按键盘上方向键 ← 或 → 可快速上下翻页，按键盘上的 Enter 键可回到本书目录页，按键盘上方向键 ↑ 可回到本页顶部！
————未阅读完？加入书签已便下次继续阅读！
clearly。 The valves gape apart some three…quarters of an inch。
The semi…pellucid orange 〃mantle〃 fills the intermediate space。
Through that mantle； at the end from which the foot curves； the
siphons protrude； two thick short tubes joined side by side； their
lips fringed with pearly cirri； or fringes； and very beautiful they
are。 The larger is always open； taking in the water； which is at
once the animal's food and air； and which； flowing over the
delicate inner surface of the mantle； at once oxygenates its blood；
and fills its stomach with minute particles of decayed organized
matter。 The smaller is shut。 Wait a minute； and it will open
suddenly and discharge a jet of clear water； which has been robbed；
I suppose； of its oxygen and its organic matter。 But； I suppose；
your eyes will be rather attracted by that same scarlet and orange
foot； which is being drawn in and thrust out to a length of nearly
four inches； striking with its point against any opposing object；
and sending the whole shell backwards with a jerk。 The point； you
see； is sharp and tongue…like； only flattened； not horizontally；
like a tongue； but perpendicularly； so as to form； as it was
intended； a perfect sand…plough； by which the animal can move at
will； either above or below the surface of the sand。 （2）
But for colour and shape； to what shall we compare it？ To polished
cornelian； says Mr。 Gosse。 I say； to one of the great red
capsicums which hang drying in every Covent…garden seedsman's
window。 Yet is either simile better than the guess of a certain
lady； who； entering a room wherein a couple of Cardium tuberculatum
were waltzing about a plate； exclaimed； 〃Oh dear！ I always heard
that my pretty red coral came out of a fish； and here it is all
alive！〃
〃C。 tuberculatum；〃 says Mr。 Gosse （who described it from specimens
which I sent him in 1854）； 〃is far the finest species。 The valves
are more globose and of a warmer colour； those that I have seen are
even more spinous。〃 Such may have been the case in those I sent：
but it has occurred to me now and then to dredge specimens of C。
aculeatum； which had escaped that rolling on the sand fatal in old
age to its delicate spines； and which equalled in colour； size； and
perfectness the noble one figured in poor dear old Dr。 Turton's
〃British Bivalves。〃 Besides； aculeatum is a far thinner and more
delicate shell。 And a third species； C。 echinatum； with curves
more graceful and continuous； is to be found now and then with the
two former。 In it； each point； instead of degenerating into a
knot； as in tuberculatum； or developing from delicate flat briar…
prickles into long straight thorns； as in aculeatum； is close…set
to its fellow； and curved at the point transversely to the shell；
the whole being thus horrid with hundreds of strong tenterhooks；
making his castle impregnable to the raveners of the deep。 For we
can hardly doubt that these prickles are meant as weapons of
defence； without which so savoury a morsel as the mollusc within
（cooked and eaten largely on some parts of our south coast） would
be a staple article of food for sea…beasts of prey。 And it is
noteworthy； first； that the defensive thorns which are permanent on
the two thinner species； aculeatum and echinatum； disappear
altogether on the thicker one； tuberculatum； as old age gives him a
solid and heavy globose shell； and next； that he too； while young
and tender； and liable therefore to be bored through by whelks and
such murderous univalves； does actually possess the same briar…
prickles； which his thinner cousins keep throughout life。
Nevertheless； prickles； in all three species； are； as far as we can
see； useless in Torbay； where no wolf…fish （Anarrhichas lupus） or
other owner of shell…crushing jaws wanders； terrible to lobster and
to cockle。 Originally intended； as we suppose； to face the strong…
toothed monsters of the Mediterranean； these foreigners have
wandered northward to shores where their armour is not now needed；
and yet centuries of idleness and security have not been able to
persuade them to lay it by。 This … if my explanation is the right
one … is but one more case among hundreds in which peculiarities；
useful doubtless to their original possessors； remain； though now
useless； in their descendants。 Just so does the tame ram inherit
the now superfluous horns of his primeval wild ancestors； though he
fights now … if he fights at all … not with his horns； but with his
forehead。
Enough of Cardium tuberculatum。 Now for the other animals of the
heap； and first； for those long white razors。 They； as well as the
grey scimitars； are Solens； Razor…fish （Solen siliqua and S。
ensis）； burrowers in the sand by that foot which protrudes from one
end； nimble in escaping from the Torquay boys； whom you will see
boring for them with a long iron screw； on the sands at low tide。
They are very good to eat； these razor…fish； at least； for those
who so think them； and abound in millions upon all our sandy
shores。 （3）
Now for the tapering brown spires。 They are Turritellae； snail…
like animals （though the form of the shell is different）； who crawl
and browse by thousands on the beds of Zostera； or grass wrack；
which you see thrown about on the beach； and which grows naturally
in two or three fathoms water。 Stay： here is one which is 〃more
than itself。〃 On its back is mounted a cluster of barnacles
（Balanus Porcatus）； of the same family as those which stud the
tide…rocks in millions； scratching the legs of hapless bathers。 Of
them； I will speak presently； for I may have a still more curious
member of the family to show you。 But meanwhile； look at the mouth
of the shell； a long grey worm protrudes from it； which is not the
rightful inhabitant。 He is dead long since； and his place has been
occupied by one Sipunculus Bernhardi； a wight of low degree； who
connects 〃radiate〃 with annulate forms … in plain English； sea…
cucumbers （of which we shall see some soon） with sea…worms。 But
however low in the scale of comparative anatomy； he has wit enough
to take care of himself； mean ugly little worm as he seems。 For
finding the mouth of the Turritella too big for him； he has
plastered it up with sand and mud （Heaven alone knows how）； just as
a wry…neck plasters up a hole in an apple…tree when she intends to
build therein； and has left only a round hole； out of which he can
poke his proboscis。 A curious thing is this proboscis； when seen
through the magnifier。 You perceive a ring of tentacles round the
mouth； for picking up I know not what； and you will perceive； too；
if you watch it； that when he draws it in； he turns mouth；
tentacles and all； inwards； and so down into his stomach； just as
if you were to turn the finger of a glove inward from the tip till
it passed into the hand； and so performs； every time he eats； the
clown's as yet ideal feat； of jumping down his own throat。 （4）
So much have we seen on one little shell。 But there is more to see
close to it。 Those yellow plants which I likened to squirrels'
tails and lobsters' horns； and what not； are zoophytes of different
kinds。 Here is Sertularia argentea （true squirrel's tail）； here；
S。 filicula； as delicate as tangled threads of glass； here；
abietina； here； rosacea。 The lobsters' horns are Antennaria
antennina； and mingled with them are Plumulariae； always to be
distinguished from Sertulariae by polypes growing on one side of
the branch； and not on both。 Here is falcata； with its roots
twisted round a sea…weed。 Here is cristata； on the same weed； and
here is a piece of the beautiful myriophyllum； which has been
battered in its long journey out of the deep water about the ore
rock。 For all these you must consult Johnson's 〃Zoophytes；〃 and
for a dozen smaller species； which you would probably find tangled
among them； or parasitic on the sea…weed。 Here are Flustrae； or
sea…mats。 This； which smells very like Verbena； is Flustra
coriacea （Pl。 I。 Fig。 2）。 That scurf on the frond of ore…weed is
F。 lineata （Pl。 Fig。 1）。 The glass bells twined about this
Sertularia are Campanularia syringa （Pl。 I。 Fig。 9）； and here is a
tiny plant of Cellularia ciliata （Pl。 I。 Fig。 8）。 Look at it
through the field…glass； for it is truly wonderful。 Each polype
cell is edged with whip…like spines； and on the back of some of
them is … what is it； but a live vulture's head； snapping and
snapping … what for？
Nay； reader； I am here to show you what can be seen： but as for
telling you what can be known； much more what cannot； I decline；
and refer you to Johnson's 〃Zoophytes；〃 wherein you will find that
several species of polypes carry these same birds' heads： but
whether they be parts of the polype； and of what use they are； no
man living knoweth。
Next； wh