The highest group of mollusks belongs to the class Cephalopoda, which
signifies head-footed, the name being given to them because the head is
surrounded by a circle of eight or ten arms, which act both as arms and
feet. Let us take as an example of this class the common squid of the
Atlantic coast (Ommastrephes illecebrosa), and see how it is formed. The
body is long and cylindrical and ends at the tail in a point; the dorsal
side of the tail end has a pair of triangular fins. The body is
practically a hollow cylinder or sac which contains the vital organs of
the animal. The neck is in many genera fastened to this cylinder or
mantle by an apparatus which may be likened to a button and button-hole.
The head is rounded, has on either side the large, round eyes, and at
the end it is split up into ten arms, two of which are longer than the
others and are called the tentacular arms. On the inner side, the arms
are provided with two rows of suckers, which are little, rounded cups
placed on pedicels or stems and which form a vacuum when they touch an
object and so cling to it. The two long arms are expanded and
club-shaped at the end, each club being armed with four rows of suckers.
Directly in the center of the circle of arms the mouth is placed and is
provided with two sharp beaks like those of a parrot, only inverted. In
addition to these organs there is a large siphon or tube on the ventral
side, which is really an organ of locomotion, for it expels water from
the mantle cavity with great force, thus rapidly sending the animal
backward, its usual direction of propulsion. The body has no shell for
protection, but in its place there is a long rod called a pen, which
acts as a backbone to support the body of the animal, although of course
not in the same sense as the backbone of vertebrated animals. In some
cephalopods this pen is hard and stiff but in Ommastrephes it is thin
and soft. Such is the general form of a cephalopod, familiar names of
which are the Octopus, Squid, Nautilus, Paper-nautilus and Devil-fish.
In this class, also, the majority of the shelled species are extinct,
only a few living at the present time. The Ammonite is an example of the
extinct cephalopods.
The most familiar member of this class to the layman is the Pearly
Nautilus, the shell of which may be found on the mantel shelf or
what-not of very many dwellings. The shell of the Nautilus is formed in
a spiral and is made up of many chambers, all connected by a tube called
a siphuncle, the outer chamber containing the animal and hence called
the living chamber. The shell is called the “Pearly Nautilus,” but the
pearly tints cannot be seen until the outer layer—which is
yellowish-white with brown markings—is taken off, when the exquisite,
rainbow-like colors may be observed.
While the shell of Nautilus is well known the animal is very rare in our
museums, although the natives of the Fiji Islands, New Hebrides and New
Caledonia are able to obtain it in large quantities for food and it is
highly esteemed by them. During the voyage of H. M. S. Challenger around
the world, a living Nautilus was captured by dredging in some three
hundred and twenty fathoms near Mateeka Island, one of the Fiji group.
This was placed in a tub and it swam about in a lively manner by
ejecting water from its funnel. The tentacles, of which there are a
larger number than in the other cephalopods, were spread out radially,
like those of the sea anemone. The Nautilus lives among the coral reefs,
at depths varying from three to three hundred fathoms or more.
[Illustration: ]
The Fijian’s method of capturing the Nautilus for food is thus described
(Tryon,—Structural and Systematic Conchology): “When the water is smooth
so that the bottom, at several fathoms’ depth, near the border of the
reef, may be distinctly seen, the fisherman in his little, frail canoe
scrutinizes the sands and the coral masses below, to discover the animal
in its favorite haunts. The experienced eye of the native may probably
encounter it in its usual position, clinging to some prominent ledge,
with the shell turned downwards. The tackle consists first, of a large,
round, wicker-work basket, shaped very much like a cage rat-trap, having
an opening above, with a circlet of points directed inward, so as to
permit of entry but to preclude escape; secondly, a rough piece of rope
of sufficient length to reach the bottom; and lastly, a small piece of
branched wood, with the branches sharpened to form a sort of grapnel, to
which a perforated stone is attached, answering the purpose of a sinker.
The basket is now weighted with stones, well baited with boiled
cray-fish (the principal food of the Nautilus is crabs of different
species), and then dropped gently down near the victim. The trap is now
either closely watched or a mark is placed upon the spot, and the
fisherman pursues his avocation upon other parts of the reef until a
certain period has elapsed, when he returns and in all probability finds
the Nautilus in his cage, feeding upon the bait. The grapnel is now
carefully let down, and having entered the basket through the opening on
top, a dextrous movement of the hand fixes one or more of the points or
hooks and the prize is safely hoisted into the canoe.”
The animal is made into soup by some of the natives while others boil it
in a pot. The shells are used by the natives to make beautifully carved
figures, the contrast of the dark outer coating against the light,
pearly, inner coating producing a striking effect. The shell is also
used in England and on the Continent to produce elegant cameos.
The “Argonaut,” or “Paper Sailor,” is no less beautiful and interesting
than the Pearly Nautilus. The thin and fragile shell cannot be compared
with that of the Nautilus nor with the pen, or internal support, of the
squid, for it is attached to the animal by no muscles, and is only kept
in position by the broad webs on the upper arms of the female (which
alone possesses a shell), its function being simply to protect the eggs.
The male is very much smaller than the female and is exceedingly rare.
The natural position of the female is with its arms spread out and
hanging about the shell, four in front and four behind, the two broad
arms supporting the shell being spread out and closely embracing the
latter. The siphon is turned toward the ridged part of the shell and the
animal progresses in a backward direction by forcibly ejecting water
through this organ. It crawls with the shell on its back, like a snail.
The poets have given us many beautiful writings detailing the vices and
virtues of the lower forms of life and among these the Pearly Nautilus
and Paper Sailor have received a goodly share of the muse’s attention.
But, alas! for the poet, who, not being a conchologist, has sadly
misused and misjudged these helpless and harmless creatures. Thus we are
told how the paper nautilus sails over the ocean with his “sails”
(meaning the two expanded arms) spread out to catch the breeze, and how,
when the storm approaches, it folds its sails and disappears beneath the
waters of the ocean. Alas for the poet! he puts the most beautiful ideas
together in verse, ideas and themes which we would fain believe; but
along comes cold, calculating science, and at one fell stroke sweeps
away all that the poet has done, for in the poem on the Argonaut all is
wrong, the animal does not and could not sail, for were it to do so the
shell would fall and become lost in the bottom of the ocean.
A mollusk whose shell is cast upon the shore by thousands, but the
animal of which is very rare, is the Spirula. The shell is less than an
inch in diameter, is made in the form of a loose spiral and is divided
into little chambers connected by a siphuncle. The shell of this genus
does not contain the animal, as in Nautilus, but it is enveloped in two
flaps of the mantle, at the posterior part of the animal, the shell
being concealed with the exception of a part of the edge on each side.
The body of the animal is long and cylindrical and the arms are quite
short, more nearly resembling those of the Nautilus than those of the
Octopus or squid. The body ends in a disk which is supposed to be a kind
of sucker, by which the animal can adhere to rocks, thus enabling it to
freely use its arms in obtaining food. It has been supposed by some
anatomists that the shells of the fossil Ammonites were attached to the
animal in a similar manner, and if this should be true these small
mollusks would assume a new meaning as being the last survivors of a
large group of animals of which all except Spirula are extinct.
Probably the best known of the shell-less cephalopods is the octopus,
with its rounded body, large eyes and long arms. Almost everybody has
read Victor Hugo’s weird account of the octopus in his “Toilers of the
Sea,” and the animal has thus been rendered more or less familiar,
although it was made to do several things by the author that it would
not do in nature, as, for example, “drinking” a man alive. The Octopus
is found abundantly throughout temperate and tropical seas, generally on
the coast among rocks, but frequently on the sandy bottom in water of
moderate depth. Here it may occasionally be seen “walking” clumsily
along on its eight long arms, its little round body being balanced above
the arms. Its favorite position, however, is among the rocks. In such a
locality it will squeeze its body into some crevice and spread out its
arms until they form a sort of web, resembling in this position a huge
spider waiting for its prey. And it may well be likened to a spider for
from this web there is no escape if once a hapless fish has come in
contact with the powerful suckers on the long arms. The poor fish is
paralyzed when seized by the octopus and is drawn towards the mouth,
where it is torn to pieces by the beak-like jaws, and swallowed.
Like many of the mollusks of which we have written the octopus is
esteemed as a valuable article of food by several savage tribes as well
as by some civilized people. The native of the Pacific coast catches the
Octopus (Octopus punctatus) by a very ingenious method. Providing
himself with a spear twelve or fourteen feet long which has four or five
barbed pieces of hard wood some fourteen inches long attached to the
end, he paddles his canoe to the feeding-ground of the mollusk. One is
soon found in ten or twelve feet of water and the Indian carefully lets
down his spear until within a few inches of the center of the animal,
when he quickly plunges it into the soft mass. Instantly the water is in
commotion, the eight long arms writhing about in an endeavor to reach
the boat. The Indian knows that should this happen his chances for life
would be slim indeed. But he is prepared, and carefully lifting up the
octopus with his barbed spear until it is above the surface of the
water, he plunges a long, sharp spear, with which he is provided, into
each arm where it joins the body. At each plunge of the spear, an arm
becomes helpless and in a short time the animal, which but a few moments
before had the power of a score of men, lies in the canoe, a shapeless,
helpless mass.
That the octopus is good eating the writer can attest from experience,
for during a visit to Yucatan some years ago this mollusk was served as
a meat dish and was very palatable, the flesh being firm and tender and
much resembling chicken. The portion which fell to the writer was the
head, with a part of the arms attached.
One of the most interesting characteristics of the Octopi and allied
cephalopods is their facility for changing color when danger is near.
These changes are caused by little pigment cells just beneath the skin,
which expand and contract. Thus, if a person is looking at an octopus in
captivity and the animal is so placed that it cannot escape, the
observer will be astonished to see the body of the animal suddenly
assume a deep pinkish color which in turn is succeeded by a blue and
then by a green, and finally a return to pink. The body is covered with
these little pigment cells, the different colors—pink, blue and
green—being so evenly scattered over the surface than when each color
cell is expanded the whole body assumes that tinge. This is one of the
most wonderful characteristics of the Mollusca.
Another cephalopod closely related to the Octopus is the Squid, several
species of which are found on the Atlantic coast of the United States.
In this genus the body is long and cylindrical, ends in two fins, has a
prominent head terminating in eight short and two long arms and is
supported by a long, cartilaginous, internal pen, which is made up of a
central shaft with expansions on each side like a quill, hence the name
“pen.” These animals are very numerous in individuals and form a large
part of the food of fishes, like the blue-fish, black bass, etc., and
have even been found in the stomach of jelly-fishes. Besides being eaten
by the fish the squid furnishes a large part of the food of some whales,
the former occurring frequently in shoals and falling ready victims to
the huge monster.
In Norway and Sweden the people have a legend of a peculiar sea-monster,
called the Kraken, which was probably founded on some of the enormous
squids discovered during the past thirty years. Many of these mollusks
are found off the coasts of Norway, Scotland and Ireland, and not a few
have been recorded from the coasts of Nova Scotia and New England. In
the larger of these animals the body is eight or ten feet long, the
short arms eight feet and the long, tentacular arms thirty feet in
length, making in all an animal nearly forty feet long when fully
stretched out! The squid is greatly prized as bait and frequently a
royal battle will take place between one of these gigantic creatures and
a boat’s crew. Sad indeed is the fate of the latter if the mollusk once
gets a firm hold of the boat. Care is used, however, to guard against
such a result, and the animal is gradually deprived of its strength by
making a sudden dash, cutting off an arm and as quickly retreating.
These large squids are not as common as the smaller ones and they are
rarely captured.
An ingenious method of capturing a species of the smaller squids
(Ommastrephes illecebrosa) in use by the fishermen of the New England
coast is as follows: The squid has the habit of swimming in an opposite
direction to a light, as the full moon, so the fishermen go out to sea
in boats, light a large torch in each boat and slowly row toward the
shore, driving the squid, which of course swim backward in an opposite
direction from the light, upon the beach, where they may be gathered by
thousands after such an expedition. Another method of capture is by
jigging; the jig is made of a piece of lead some two inches in length
which is armed with a circle of sharp, unbarbed wires pointing upward
and curving outward. The process of jigging is accomplished as follows:
the jig is attached to twelve or fifteen feet of stout line and is
lowered into the water, which is generally chosen of a depth of ten feet
from the side of a small boat. When near the bottom it is kept moving
slowly up and down until a squid is felt upon it, when it is suddenly
drawn to the surface with the squid attached. These squid, when caught,
are used for bait, a single fishing smack being known to use as many as
eighty thousand squids in a single season.
A familiar object to most canary-bird fanciers is the cuttle-bone placed
in the cages of these birds for them to sharpen their beaks upon. This
“cuttle-bone” is the internal support of the Cuttle-fish (Sepia
officinalis) and is homologous with the pen of the squid, mentioned
above. The animal of Sepia is short and rounded, with a large head
surrounded by a row of eight short arms and two very long tentacular
arms, ending in expanded clubs armed with powerful suckers. Like the
Octopus and Squid, the Cuttle-fish is capable of many changes of colors
by the contraction and expansion of its pigment cells. They are found
throughout the world, living near the shore, but the species found about
European shores are the best known.
Frank Collins Baker.
God made all the creatures and gave them
Our love and our fear,
To give sign we and they are His children,
One family here.
—Robert Browning.
THE TRAILING ARBUTUS.
(_Epigaea repens._)
Many years ago, before the Mayflower had cast anchor in Plymouth Bay or
Columbus had landed at San Salvador, an aged indian sat shivering in his
wigwam. Vainly had he sought for fuel and in his extremity he called
upon the Great Spirit, that he might not perish with the cold. Crouching
over the dying embers of his fire he stoically awaited the end, when
suddenly there appeared before him a beautiful maiden wreathed with wild
flowers and carrying in her hands, buds of the willow. Ferns and grasses
draped her form and her moccasins were fashioned from pure white lilies.
When she breathed the landscape suddenly blossomed with the thousand
hues of nature and the warm rains fell in obedience to her will.
Under the influence of this spirit of the springtime the aged red man
slumbered and, as his head sank upon his breast, the sunshine came out
in all its splendor and a blue bird alighted upon the top of the wigwam.
Slowly the maiden passed her hand above the old indian and gradually he
shrank away until nothing remained but a cluster of green leaves. Then
taking from her bosom a cluster of rosy blossoms, she concealed them
among the leaves, bestowing upon them her own sweetness and fragrance
and telling them that as the harbingers of spring, all who would inhale
their fragrance, must bow the knee in honor of the vernal goddess. The
maiden then passed away through the woods and over the prairies and
wherever her footsteps lingered, there grows today the sweet-breathed
mayflower.
Whether or not this fanciful story relates the real origin of the
Trailing Arbutus, Ground Laurel or Mayflower, as it is variously called
in different sections of the country, the fact remains that it follows
closely in the footsteps of spring, often pushing up its dainty blossoms
through the leaves and snow. It is always known as the Mayflower
throughout New England and the old story of its being Flora’s first
offering to the ocean-tossed pilgrims as they landed at Plymouth, in
appreciation of which they named it the Mayflower in memory of their
vessel, has endeared the beautiful plant to every New England heart and
has caused it to be placed in Cupid’s keeping, along with the Scotch
blue bell, the German corn flower and the Swiss edelweiss.
The Trailing Arbutus (Epigaea repens) belongs to the Heath family or
Ericaceæ and constitutes the only species of the genus. Like the
partridge berry which is often associated with it in pine woods and
sandy soils, it is still in a state of transition, although it has been
developing for centuries. As a rule, plants have the stamens and pistils
in the same blossom or part in one and part in another. The Mayflower,
however, does not carry out this arrangement. Either the anthers or the
stigmas are abortive or partially so, or in other words, the perfect
stigmas are usually associated with abortive anthers and vice versa. In
this manner, nature has wisely provided for cross fertilization which is
accomplished largely by insects, as the structure of the plant is not
adapted to wind fertilization. The chosen agents for this process are
honey bees, and a few early moths and butterflies, to which the nectar
is served by this beautiful Hebe of the spring and who carry the pollen
from one flower to another.
[Illustration: ]
A wise provision of nature has been pointed out whereby ants are kept
away from the nectar which they would devour without accomplishing the
purposes for which it was created. Every rocky hillside on which the
Trailing Arbutus is frequently found, swarms with ants which are
debarred from the blossoms by hairs which project upward from the inner
surfaces of the corolla and the outer surfaces of the ovary and style
and effectually prevent the ants from entering but are not sufficiently
rigid to keep out the larger insects.
As a rule, the pollen bearing flowers are larger and whiter than the
others. The stigma bearing blossoms, while small, more than offset their
defect by a rosy color which makes the flowers far more attractive than
their larger but paler rivals.
Very little success has been achieved in domesticating the Trailing
Arbutus. It is essentially a wild creature and prefers to waste its
fragrance on the desert air. Success may be had, however, if the
conditions under which the plants are found growing are preserved as
nearly as possible. Yearling plants should be selected and plenty of
roots taken or results can be obtained from planting seeds, but as these
are difficult to obtain, the other method is the more satisfactory.
Charles S. Raddin.