[Illustration:
PLATE XVII.
PYROSOMA AND DIVER.
(_See page 84._)]
LIVING LIGHTS
A POPULAR ACCOUNT OF
PHOSPHORESCENT ANIMALS AND
VEGETABLES
BY
CHARLES FREDERICK HOLDER
FELLOW OF THE NEW-YORK ACADEMY OF SCIENCES, ETC.; AUTHOR OF “ELEMENTS
OF ZOOLOGY,” “MARVELS OF ANIMAL LIFE,” “THE IVORY
KING,” “WONDER WINGS,” ETC.
LONDON
SAMPSON LOW, MARSTON, SEARLE, AND RIVINGTON,
St. Dunstan’s House
FETTER LANE, FLEET STREET, E.C.
1887
[_All rights reserved_]
TO MY FATHER, THIS VOLUME IS GRATEFULLY INSCRIBED, IN
REMEMBRANCE OF DAYS PASSED AMONG THE LIVING LIGHTS OF THE OUTER
REEF.
PREFACE.
The object of the present work is to interest young people in natural
history by the presentation of an attractive--indeed, marvellous--phase
of nature, and to encourage healthful outdoor observation, as well as
habits of investigation.
The subject chosen for this work--that embracing the phenomenon of
luminosity in animals, plants, and inorganic matter, and especially
those that seem intended as illuminators of the ocean--is one which has
ever possessed a fascination for the author.
During many years spent on Southern shores, in constant association
with the most attractive features of marine life, the remembrance of
the splendors of the night festivals of these wondrous ocean forms
is most enduring. No fairy tale of human invention can relate to us
more fascinating scenes than are realized in Nature’s carnivals of
the sea. Not only is the surface of the ocean, when lashed into foam
by the tempest, luminous, but the greater depths, where the water is
cold, near the freezing-point, and subject to pressure so great that
instruments of glass are shattered and reduced to powder, abound in
living lights.
And this abyssal region, covered by miles in depth of water, and which
was formerly considered to be the most desolate region upon the globe,
is inhabited by light-givers of marvellous beauty and brilliancy.
The little _Malacosteus_, with its gleams of yellow and green;
_Stomias_, with sparkling side-lights; the dazzling effulgence
of _Pyrosoma_; the comet-like glare of _Medusæ_, with their
tints of many colors,--present a series of wonders which must excite
the admiration of the most indifferent observer.
In the United States, there are ten thousand enrolled young
naturalists, comprising the Agassiz Association. As one of a committee
solicited to answer questions propounded by the young people, members
of this association and of the Chautauqua Circle, I have often been
surprised at the nature of the queries, which shows that this army
of young observers includes many who are not merely collectors of
curiosities, but are naturalists in the best sense. They are systematic
inquirers, and working in the right direction to become scientists,
should they continue.
It is to these young scientists, their unscientific elders, and
the boys and girls in general who have not yet had their interest
aroused in Nature’s works, that this volume is addressed; and if some
information is conveyed, while appearing merely to entertain, one
object of the author will have been accomplished.
The subject of phosphorescence is one which affords the widest field
for investigators; as, while the most careful descriptions of the
light-emitting organs have been made, the actual cause of animal
phosphorescence is unknown. Material for study is ever at hand; the
fire-fly courts attention at every summer door-yard, and the pools
of beach and cove are illumined by ocean forms. Even the simplest
experiments are of the greatest interest. I have read by the light of
a luminous beetle, and have determined the time of night while holding
my watch in the glare of ocean animals. Von Bibra wrote his description
of the _Pyrosoma_ by its own light; the shark of Bennett
illuminated his cabin like a chandelier; photographs have been taken
by the light of luminous beetles and by phosphorescent plates; and
probably the day is not distant when more important uses will be found
for this wonderful light, which, in default of a better name, we term
phosphorescence. It is found in the animal, vegetable, and the mineral
kingdoms; in life and in death; in growth and in decay. It illumines,
but does not appear to consume, and without perceptible heat exists
where ordinary combustion is impossible.
From the nature of the subject, it is evident that illustrations of the
phosphorescence of marine animals must be more or less conjectural; and
those given, representing over fifty luminous forms, show as nearly
as possible the probable effect produced. As this work is scientific
only so far as to secure accuracy, some technical details have been
omitted. To compensate in a measure, I have appended a fairly complete
bibliography of most important monographs and papers on the subject,
which may be of value to those who wish to pursue the subject in its
technical relations.
To render the work as popular as possible, certain systematic portions
necessary to the student are placed in an appendix, and referred to by
number. The whole work is also thoroughly indexed.
While the chief feature of the volume embraces the phosphorescence of
animals, it has been deemed advisable to include reference to luminous
plants, minerals, and certain atmospheric phenomena, which, if not
strictly comprehended under our title, will perhaps not be considered
entirely foreign nor uninteresting in this connection.
It is my agreeable duty to acknowledge here the courtesy and kindly
attentions received from M. Raphaël Dubois of the Zoölogical Society
of France; Professor H. Filhol; Professor H. H. Giglioli, Director of
the Zoölogical Institute of Florence, Italy; Professor Carlo Emery of
the University of Bologna, Italy; and M. Zenger of Prague, Hungary, who
generously forwarded for my use their most recent papers on the subject
of phosphorescence.
I have also to name with thanks for similar favors Dr. Gunther, keeper
of the British Museum, and acknowledge the value of contributions from
the works of M. Quatrefages of the Institute of France.
C. F. H.
PASADENA, CAL., July, 1887.
CONTENTS.
CHAPTER PAGE
I. STARS OF THE SEA 1
II. THE METEORS OF THE SEA 10
III. FIXED LUMINARIES OF THE SEA 19
IV. LUMINOUS ECHINODERMS 29
V. SUBTERRANEAN LIGHT-GIVERS 33
VI. LAMP SHELLS 40
VII. LIGHTNING-BUGS 47
VIII. FIRE-FLIES 59
IX. LANTERN-FLIES 64
X. BY CRAB-LIGHT 72
XI. SEAS OF FLAME 80
XII. FINNY LIGHT-BEARERS 91
XIII. FINNY LIGHT-BEARERS (SURFACE FORMS) 103
XIV. LUMINOUS BIRDS AND OTHER ANIMALS 108
XV. MAN’S RELATIONS TO THE PHENOMENON OF PHOSPHORESCENCE 116
XVI. LUMINOUS FLOWERS 121
XVII. VEGETABLE LAMPS 127
XVIII. PHANTOMS 140
XIX. LUMINOUS SHOWERS 144
XX. THE USES OF PHOSPHORESCENCE 160
APPENDIX 169
BIBLIOGRAPHY 179
INDEX 185
LIST OF ILLUSTRATIONS.
PYROSOMA AND DIVER (PLATE XVII.) Facing Title.
SEA BOTTOM. 1,500 metres, or one-quarter of
mile in depth Facing Page 1
FACING PAGE
PLATE I. LUMINOUS PROTOZOANS--LUMINOUS PORTIONS OF NOCTILUCA 3
„ II. M. DE TUSSAN READING BY LIGHT OF PHOSPHORESCENT
SEA 7
„ III. LUMINOUS SEA JELLY--LUMINOUS CORAL--PRUNING-KNIFE
FISH 11
„ IV. LUMINOUS SEA JELLY AND MOLLUSK 13
„ V. VENUS’ GIRDLE 15
„ VI. APOLEMIA--CLEODORA--PRAYA 43
„ VII. BURROW OF PHOLAS--SEA PEN 39
„ VIII. LUMINOUS STAR FISHES. From 4,500 feet deep 29
„ IX. LUMINOUS BEETLES, ETC. 47
„ X. ANATOMICAL DETAILS 53
„ XI. LUMINOUS BEETLE, in burrow of Mole Cricket 59
„ XII. THE LANTERN FLY 63
„ XIII. LUMINOUS MUSHROOMS--LUMINOUS INSECT 137
„ XIV. SPIDER CRAB 75
„ XV. LUMINOUS CRUSTACEANS 79
„ XVI. CHAIN OF SALPS 89
„ XVIII. CHIASMODUS--SUN-FISH--PLAGIODUS--HARPODON--BERYX 97
„ XIX. LUMINOUS FISH. From depth of 8,100 feet 103
„ XX. LUMINOUS FISH 115
„ XXI. UMBELLULARIA--LUMINOUS FISH--SILICIOUS
SPONGE--LUMINOUS CORALS--LUMINOUS CRUSTACEAN 125
„ XXII. LUMINOUS FISH. With two luminous disks, one
emitting a golden, the other a greenish light 132
„ XXIII. DEEP SEA ANGLER 145
„ XXIV. PELICAN FISH 155
„ XXV. LUMINOUS WATERSPOUT 163
„ XXVI. LUMINOSITY OF HERON’S BREAST 109
[Illustration: SEA BOTTOM.
1,500 metres, or one quarter of mile in depth.]
LIVING LIGHTS.
CHAPTER I.
STARS OF THE SEA.
Among the many revelations of modern science, none have a more
absorbing interest than those relating to the illumination of the deep
sea. Until within a few years the ocean has been a sealed book. The
surface forms only were known; and it was assumed that, owing to the
enormous pressure, lack of sunlight, and consequent darkness, Nature,
at least in the abyssal depths, was at fault, and this vast region was
devoid of life and incapable of supporting it.
Recent investigations, however, have shown the reverse, and that this
great area, with its plateaux, its mountain ranges, and its isolated,
coral-capped peaks, whose valleys are now known to lie miles in ocean
depths, teems with living forms, and, far from being the dismal realm
we had supposed, is a region of surpassing wonder; which we may, _in
fancy_, term that lower firmament, where float sparkling, gleaming
constellations, meteor-like disks and globes with trailing luminosity,
single stars and _nebulæ_ of living lights.
The phosphorescence of the sea is no new discovery, and those who have
visited the seashore at night must have witnessed this phenomenon. The
region of coves and beaches along the shores of Eastern Massachusetts,
around Nahant particularly, is a favorable one for its full display. As
the waves come rolling in upon the rocks, or upon the long, expansive
shingle, in tidal measure, we see the foaming crest, seemingly igniting
all along the line, more and more intense in brilliancy, when, with
a roar, it breaks, masses of scintillating liquid upon the sands. We
glide over the smooth portions of this sea, our boat leaving a golden
train; and every dip of oar, or the dash of some affrighted fish,
creates an equally vivid display. Even when not disturbed, looking
down into the calm, clear depths, the same phenomenon is witnessed.
Pale, ghostly forms are seen here and there, moving slowly about,
while the seeming silvery atoms suggest the _nebulæ_ of this submarine
sky. Deeper yet, the bottom shows weird splendors. The great kelps are
bedecked with mystic lights, and gleam like diamond’s flash from ledge
and rock.
These wonderful exhibitions of submarine illumination are due to the
presence of luminous creatures, or in some cases to large animals
swimming through immense numbers of small phosphorescent bodies, so
appearing as light-givers themselves.
In nearly every branch of the animal kingdom we shall find these
_living lights_; some marvellously brilliant, others glowing with dim
rays, and all contributing often to wondrous illumination, far-reaching
or circumscribed.
[Illustration:
PLATE I.
LUMINOUS PROTOZOANS.
_Noctilucæ_
(in milk).
_Noctiluca miliaris_
(magnified 100 diameters).
_N. miliaris_
(slightly magnified).
LUMINOUS PORTION OF NOCTILUCA
(highly magnified).]
If the ocean which contains these wondrous forms should suddenly become
dry, we should find that its contour is very similar to that of the
land. There would be hills, valleys, plains, mountains, and seeming
river-beds where currents have flowed; and so sharply are these
defined, where growing atolls and reefs abound, one may stand--as I
have often done upon those of the Florida reef--and drop a leaded line
almost directly to the bottom in the clear blue waters.
This submarine scenery would not show the rough and jagged outlines
which are a characteristic of terrestrial mountain ranges. Nearly all
prominences in water at a considerable depth are well rounded off by a
coating of fine ooze, formed of the minute and delicate shells of the
_globerigina_, one of the lowest organized of animal life. These
little creatures live upon the bottom, or in the watery space above,
and the ooze which makes the sea-bottom, in great thickness, is almost
entirely made up of the dead and cast-off shells of these microscopical
creatures. The chalk cliff of Dover, England,--that white headland
which has given the ancient name of Albion to the mother country,--is
an upheaved mass of the same material, once found in the ocean bottom,
now elevated by some geological change, and hardened into chalk, which
it really is. What a surprising monument, erected by Nature’s processes
from the myriads of bodies of her most minute and most simply organized
animals!
The familiar modern term “protoplasm” represents what is know to be the
simplest form of life; scarcely more, seemingly, than a bit of jelly,
without form, and we might say void of organization, for it is alive,
and yet has no nerves, no organized vessels which we can perceive, but
exists in our pools as the least organized animal known.
There is a species which belongs to one of the numerous kinds or groups
of this the first and least perfect of the animal kingdom, which has
also the great distinction of being the best known and most brilliant
of marine light-bearers. This is the _Noctiluca_, or, as its name
implies, the night-light. This little creature, but little more than
visible to the naked eye, is the largest of the so-called infusorians;
others of this group of animals requiring the aid of a microscope to
determine the form. It is but little more in structure than the bit
of protoplasm, or simplest organism or animal known. It looks when
magnified--its natural size being about that of a pin’s head--much more
highly organized than the others, by being almost a complete globe,
and provided with a whip-like process or member. It is also veined
somewhat, and reminds one of a currant or gooseberry. Now, it is often
noticed that the smaller the animal, the more numerous; indeed, also,
the more numerous its progeny. We may well be prepared, then, to hear
that these minute creatures often swarm on the ocean surface in myriad
masses.
Fig. 1. of Plate I. represents the _Noctiluca_ magnified one hundred
times. Fig. 2. of the same, represents the appearance of the creature
when luminous, and only slightly magnified. The long lash which extends
from the side is the locomotive organ. It is attached to the body near
what is supposed to be the mouth; though these creatures are so simple
that many kinds, just below in organization, have no definite mouth nor
stomach, but absorb food from any surface of the body which comes in
contact with it.
This infusorian and most potent of living lights, albeit of extreme
minuteness and simplicity as an organism, is abundant in the ocean
along the European shores, and is often seen in our north-eastern
waters, notably off Portland harbor and along shore to Cape Ann. I have
enjoyed the privilege of witnessing the fullest glory of this little
creature’s effulgence. In our so-styled ocean firmament these living
asteroids shine forth in those waters, and rival, if not excel, in
light-giving any other known creature.
In the endeavor to study the mysterious lights, I spent considerable
time on a rocky point which jutted out into the sea, at Ogunquit, Me.,
with my microscope at hand, as near as possible to the water; thus
examining them while comparatively fresh from the sea. In taking up
the little creatures, they assume a pear shape, from contraction,--the
only evidence, seemingly, of life, but blazing with a flashing light
over their entire surface. We had the advantage of having specimens
fresh at hand, yet there are certain appliances indispensable for such
work which we did not have, and, therefore, could not then perfect our
dissections sufficiently to get satisfactory results. We must refer the
reader, therefore, to the experiments detailed in the Appendix.[1]
In watching the light of the _Noctiluca_, we are reminded of the
flash-light of a light-house,--the gleam appearing and disappearing
with considerable regularity. It is difficult to trace the light to
any particular portion of the body. In Plate I., Fig. III., is shown
the supposed luminous organs, which would seem to show that there are
luminous spots. Sometimes the light seems to pervade the entire body;
again, to be in the outer skin or cuticle. When the light appears after
an intermission, the spots referred to become luminous first, the light
extending to the outer surface.
The conditions most favorable for respiration produce the greatest
exhibitions of light; thus, if the water is constantly aërated, or
disturbed so that the air has access, the gleam is intensified. If the
animal is touched with the point of a needle, the light is quickly
visible; and just before death it is continuously luminous, the
phosphorescence disappearing just after dissolution. Experiments have
shown that in a vacuum the light diminishes,--carbonic gas producing
the same result. Humboldt refers to his luminous appearance after
bathing in water abounding in _Noctilucæ_; and among the curious
experiments might be mentioned one where print was read by a gobletful
of these little creatures which rendered them living lamps, literally.
M. de Tessan, a French observer, has recorded a phenomenon, which, I
should judge, was due to _Noctilucæ_, with perhaps the additional
light of other forms. The accompanying picture on plate II. was made
from his description, showing the light, and people upon the shore
endeavoring to read by it. He writes: “On the 10th of April, in the
evening, the sea in the roadstead of Simonstown, Cape of Good Hope,
presented an extraordinary phosphorescence of a most vivid character.
At whatever points the phosphorescence was greatest, the water was
colored on the surface as red as blood; and it contained such an
immense quantity of little globules that it had the consistency of
sirup. A bucket of water taken up at one of these points, and filtered
through a piece of linen, left in the filter a mass of globules greater
in volume than the water that had passed through; in other words,
the globules constituted more than half of the whole quantity of sea
water taken up in the bucket. Viewed under the magnifying-glass, these
globules presented the appearance of little transparent and inflated
bladders, having on their surface a black point surrounded with equally
black radiating _striæ_.... The least agitation or slightest
contact made them throw out a vivid greenish light.”
[Illustration:
PLATE II.
M. DE TESSAN READING BY LIGHT OF PHOSPHORESCENT SEA.]
As the waves washed in, M. de Tessan describes the light as appearing
like the vivid flashes of lightning. “It lighted up the chamber that
I and my companions occupied in the house of Mr. Ball, though it was
situated more than fifty yards distant from the breakers. I even
attempted to write by the light, but the flashes were of too short
duration.”
When a vessel is ploughing through masses of these animals, the effect
is extremely brilliant. An American captain states that when his ship
traversed a zone of these animals in the Indian Ocean, nearly thirty
miles in extent, the light emitted by these myriads of fire-bodies, of
which he estimated there were thirty thousand in a cubic foot of water,
eclipsed the brightest stars; the milky way was but dimly seen; and
as far as the eye could reach the water presented the appearance of a
vast, gleaming sea of molten metal, of purest white. The sails, masts,
and rigging cast weird shadows all about; flames sprang from the bow
as the ship surged along, and great waves of living light spread out
ahead,--a fascinating and appalling sight.
The enormous quantity of _Noctilucæ_ in the water explains the
intensity of the light. In experiments made at Bologne, one-seventh to
one-half of a given amount of water taken up consisted of these minute
light-givers, and Rymer Jones found thirty thousand in a cubic foot.
According to Quatrefages, the light of _Noctilucæ_ in full vigor is a
clear blue; but, if the water is agitated, it becomes nearly, if not
quite white, producing rich silvery gleams sprinkled with greenish and
bluish spangles.
Regarding the intensity of the light, a tube fifteen millimetres
in diameter, containing a bed of _Noctilucæ_ at the surface twenty
millimetres thick, emitted light sufficient to see the face of a watch
and read the figures; and, if the little creatures were agitated, time
could be ascertained at a distance of a foot. M. Quatrefages found that
the most delicate thermometer was not affected by the light; and he
assumes that it is not combustion from the fact that oxygen gas, when
introduced, does not restore the light after it has disappeared at the
death of the animal. His conclusion is, that the light is produced by
the contracting of the interior mass of the body; and that the flashes,
or scintillations, are due to the rupture and rapid contraction of the
filaments of the interior. The fixed light he explains as resulting
from the permanent contraction of the contractile tissues adhering to
the inner surfaces of the general envelope. Giglioli is especially
enthusiastic over the light of the _Noctilucæ_ and other forms; and
to show its general distribution he says that in fifty-five thousand
marine miles traversed by the “Magenta,” the Italian exploring-ship,
in four hundred and thirty-nine days, phosphorescence was observed
more than half of the time. He met _Noctilucæ_ in the Bay of Naples,
at Rio, in the Straits of Banca, while in the east coast of Asia; and
at Port Jackson “the same milky uniform light was seen, without any
green or bluish tint,” and again at Valparaiso. He observed, including
_Noctiluca miliaris_, three luminous forms, all differing in the color
of their light. The one observed on the Asiatic coast emitted a green
light, and is called by M. Giglioli, _N. homogenea_. The Pacific form,
_N. pacifica_, has a whitish luminosity, and differs from the others
materially in form and structure.
In many of the ports of tropical and semi-tropical America, it is
the custom to bathe in the ocean at night, the warmth of the water
rendering such recreation enjoyable. A gentleman newly arrived at one
of the places on the Pacific coast proceeded at night to take a bath,
and, upon rising from the water, was astonished and amazed to find
that his entire body was luminous, seeming covered with a coating of
light, which he found originated from innumerable minute phosphorescent
animals, which clung to his garments, and changed the water all about
to a golden hue.
A distinguished professor at Keil was, perhaps, the first to discover
luminous microscopic animals.[2]
The largest of these minute creatures is about one-eighth of a line,
the smallest from a forty-eighth to a ninety-sixth of a line in size.
Giglioli has made some interesting observations regarding the
phosphorescence of the lowest class of animal life, the protozoans,
and with his colleague, Professor de Fillipi, intends publishing the
results of their observations.[3]
CHAPTER II.
THE METEORS OF THE SEA.
As the rushing comets dim the brightest luminaries with their radiance,
so the ocean meteors, the moving _medusæ_, seem to excel in the glory
of their light.
The sea-jellies are among the commonest forms of the seashore. In the
summer months the silvery sands are strewn with their glassy disks;
unattractive then, but, once launched and imbued with life, possessed
of many beauties of form and color. They range in size from those
almost invisible to the naked eye, to giants weighing, it is estimated,
over a ton. Many have a complicated structure; yet, in nearly all, the
solid parts of the animal rarely represents over five per cent of the
whole; and in specimens of a familiar northern kind, _Aurelia_, 95.84
is water. Little opportunity for light in such a creature, one would
say; yet the simple jellies are numbered among the chief illuminators
of the upper region of the ocean. I have observed them in the
Atlantic, the Pacific, and in the Gulf of Mexico, in waters of various
degrees of temperature; but, perhaps, the finest exhibition of their
phosphorescence was seen off Boon Island, on the coast of Maine. The
ocean surface seemed fairly bespangled with these living gems, which
appeared surrounded by a halo of light. Each tentacle seemed to glow
with an intense white heat; and, at a short distance, the streamers
resembled delicate lace, wrought in curious designs. Peering into the
depths, they appeared everywhere, moving in all directions, surrounded
by the mysterious light whose office it is difficult to conjecture.
[Illustration:
PLATE III.
LUMINOUS SEA JELLY.
(_Thaumantius._)
PRUNING-KNIFE FISH.
(_Zanclus._)
LUMINOUS CORAL.]
The vast numbers of _medusæ_, and their importance as light-givers,
may be realized from the remarks of Giglioli, who states that their
light was seen from the “Magenta” over an area of forty-four degrees
of latitude, and for nearly thirty consecutive days. During the day
they sank into the greater depths, at night rising to the surface, and
appearing like moderator lamps. With their long groups of tentacles
trailing behind as they pulsate through the ocean waters, they readily
suggest the title, “Meteors of the Sea.”
With few exceptions, the sea-jellies are light-givers. The giant
_Cyanea_,--one of which was measured by Mrs. Agassiz, and found to
be nearly six feet in diameter, and to have tentacles over one hundred
feet in length--emits a pale, greenish light; and, if the entire mass
is luminous, it must present a wondrous appearance as it moves through
the water, like a gigantic meteor. As large as this giant is, weighing
many hundred pounds, it is produced from a delicate little creature
which would hardly be noticed by the casual observer.
One of the commonest forms along the New-England coast is a diminutive
jelly,[4] seemingly blown in glass by some skilful worker. As it moves
gracefully along, it emits a light of a deep aurelian blue, vast
numbers imparting a metallic glitter to the water.
On some calm night, about a rocky point where the current flows
silently along, myriads of these wondrous forms may be seen passing
in review. Peering down into the depths from our boat, we may see a
pretty, shapely jelly-fish, called _Zygodactyla_, a golden _ignis
fatuus_ of the ocean waters; the _Melicertus_, another of the same
family, surrounded by a golden radiance; and a stately _Rhizostoma_,
which Giglioli observed in fresh or brackish water in Batavia, emitting
a fixed, bluish light; while _Zina_, _Coryne_, _Eucope_ and _Clytia_,
and a host of other exceedingly pretty sea-jellies, add to the glories
of the scene.
The delicate _Thaumantius_ (Plate III., Fig. 3) and Oceanea are
resplendent light-givers. The latter, according to Ehrenberg, being
“surrounded by a shining crown,” while _Pelagia_ illumines the deep sea
by its mystic rays.
Although we have established a rule to refer the most of the technical
names, with the more scientific matter, to the Appendix notes, we are
yet inclined to retain in the text, occasionally, some names which are
especially attractive. Thousands of marine animals have no other name
but the generic ones given them by discoverers; but in many instances
they are pretty, and there is no reason why they should not be used,
as they must become the common name of the object, as well as its
technical one.
Other known light-givers are recorded in the Appendix,[5]--all forms of
the greatest delicacy and beauty.
Of a brilliantly phosphorescent form,[6] Professor Alexander Agassiz
says, “When passing through shoals of these _medusæ_, ranging in
size from a pin’s head to several inches in length, the whole water
becomes so wonderfully luminous that an oar dipped in the water up to
the handle can be seen plainly on dark nights by the light so produced.
The seat of the phosphorescence is confined to the locomotive rows;
and so exceedingly sensitive are they, that the slightest shock is
sufficient to make them visible by the light emitted from the eight
phosphorescent plates.”
[Illustration:
PLATE IV.
LUMINOUS SEA-JELLY AND MOLLUSK.
_Beroe forsakii._ _Cranchia scabra._]
Professor Agassiz also states that the _Lucernaria_[7], a handsome
green sea-jelly, emits a peculiar bluish light of an exceedingly pale
steel color. While all these forms are beautiful individually, their
combined forces produce an array of splendors hardly to be described.
Such pyrotechnic displays of Nature are best observed during the
autumn, when the jellies are wrecked and stranded; the waves hurling
them in, and grinding them up upon the rocks, which appear bathed in
warm, lambent lights.
At Spouting Horn, on the New-England coast, this luminous water
is forced through a small chimney or crevice in the rocks, with a
reverberating roar; sending skyward a column of gleaming water, that
breaks in mid-air and falls in golden spray. In drifting along in
a boat at this time, every movement of the oar produces the most
astonishing results. A slight splash is followed by a blaze of light.
By having a companion keep up a continuous motion of the water, I have
almost been able to read the print of a newspaper by the light of
these disintegrated forms. One of the most striking displays of this
phenomenon I have ever witnessed was at the little port of Ogunquit, Me.
Returning, one dark night, from an off-shore fishing excursion, I saw,
as we approached the harbor, an irregular row of lights, apparently
lanterns in the hands of friends. We hailed, and not until we were
nearly in the surf were we undeceived. The rocks were lined with kelp;
and, when the waves came in, the glowing, sparkling mass of _medusæ_
caught upon the weed, remaining, as the water left it suspended,
a blaze of light, until the next wave broke. My companion, an old
fisherman, had also been deceived by the lights; and we drifted there
for some time watching these strange spectres appear and disappear.
The _medusæ_ differ in their methods of illumination. The _Obelia_, as
a free-swimming disk, is non-luminous; but the stem, or trophosome,
out of which it is developed, has a fluctuating light extending up and
down its surface. In many _medusæ_ the light appears to be confined to
the upper portion of the umbrella, to the tentacles, and to the margin
of the disk; but if an oar is thrust through it, or a freshly stranded
jelly is torn and cut upon the sand, every portion seems to become more
or less luminous.[8]
The little jelly-like creatures called “comb-bearers,” or Ctenophores,
are nearly all wonderfully phosphorescent. Instead of moving as do the
ordinary jelly-fishes, they have rows of comb-like paddles which move
up and down in regular measure as they float along. In the daytime the
little fins gleam with gorgeous iridescent hues; while at night they
are brilliantly luminous, even the eggs and embryos of some emitting
light.
The _Beroë_ (Plate IV., Fig. 1) is the most familiar, but the
Pleurobrachia is the most graceful. Drummond refers to these forms in
the following lines,--
“Shaped as bard’s fancy shapes the small balloon,
To bear some sylph or fay beyond the moon.
From all her bands see lurid fringes play,
That glance and sparkle in the solar ray
With iridescent hues. Now round and round
She whirls and twirls; now mounts, then sinks profound.”
[Illustration:
PLATE V.
VENUS’ GIRDLE.
(_Cestus veneris._)
_Phillerhoe._]
So vast are the numbers of these and other light-givers in the northern
seas, that the olive-green tints of the waters are due to them in the
daytime. Mr. Scoresby, finding sixty-five of them in a cubic inch of
water, summed up the interesting calculation, that, if eighty thousand
persons had commenced at the beginning of the world (he refers to the
popular, not geological, reckoning,) to count, they would barely at the
present time have completed the enumeration of individuals of a single
species found in a cubical mile.
One of the most remarkable of the Ctenophores is the “Venus’ girdle”
(_Cestus veneris_), Plate V., Fig. 1. In shape it differs from all
others of the class, as a comparison between it and the Beroë (Plate
IV.), will show. It resembles in the daytime a silvery ribbon, or
girdle, two or three feet in length, moving through the water by
contractions of the body, rather than by the rows of combs that are
found upon the edges. So delicate is this fragile creature, that it
is almost impossible to remove it intact from the water. The mouth is
in the centre, or equidistant between the ends; and on each side of
it depends a short tentacle protruding from a sac. Opposite the mouth
there is an otocyst, or sense-body. The combs, which are so conspicuous
in other forms, are not so noticeable here, yet are well defined; and
when moving along, and propelled by these gentle undulations, the
_Cestus_ is one of the most beautiful objects of the sea. At night
this wonderful sea-ribbon develops a new charm, emitting, according to
Giglioli, a reddish yellow light of singular brilliancy.
The Ctenophores, from their phosphorescence and great numbers, offer an
interesting field for study. _Pleurobrachia_[9] may be found in myriads
upon our eastern shores in the autumn. _Idya_[10] attracts immediate
attention by its wondrous coloring, having a deep roseate hue. After
death, its phosphorescence appears to be intensified, and much of the
phosphorescent display is due to it. In nearly all the Ctenophores the
light is erratic, flash succeeding flash, and seeming, according to
Giglioli, to reside along the zone covered by the vibrating _cilia_, or
little paddles.
In the interesting group of animals known as _Physophoræ_,[11] or
bubble-bearers, we find many light-givers of most remarkable form,
in their structure reminding one of delicate objects in glass; and,
according to Giglioli, all are more or less luminous. In the harbor of
Gibraltar, he observed several beautiful forms, as _Abyla_, _Diphyes_,
and _Eudoxia_; and in the Atlantic, in the latitude of Rio Janeiro,
_Vogtia_, _Praia_ (Plate VI., Fig. 2), _Abyla_, and _Eudoxia_ were
constantly encountered. These are all so fanciful in design, that they
appear to be veritable fairy ships freighted with color-tints and
gleams of light. Their luminosity is not scattered over the entire
body as in many sea-jellies, but seems confined to fixed points, as
in _Eucope_, a specimen of which, observed in the China Sea, seemed
studded with brilliant emeralds, which appeared as marginal knobs at
the base of the tentacles. In the Pacific, several species of _Diphyes_
have been observed, their zooids[12] brilliantly phosphorescent; but
the hydroids of this group, so far as known, are not luminous.
Many beautiful phosphorescent jellies can be observed, as we drift
along, by using a small glass cylinder. With the finger pressed upon
the top, lower the open end near the little creature, then remove the
finger, when the jelly will be drawn into the improvised aquarium. If
the night is dark, the play about its delicate form will be found a
rare study.
Darwin refers to the beauties of the phosphorescent jellies observed
on one of his collecting-tours. He says, “While sailing a little south
of the Plata on one very dark night, the sea presented a wonderful and
most beautiful spectacle. There was a fresh breeze, and every part
of the surface which during the day is seen as foam now glowed with
a pale light. The vessel drove before her bows two billows of liquid
phosphorus, and in her wake she was followed by a milky train. As far
as the eye reached, the crest of every wave was bright; and the sky
above the horizon, from the reflected glare of these livid flames, was
not so utterly obscure as over the vault of the heavens.... Having used
the net during one night, I allowed it to become partially dry; and
having occasion, twelve hours afterward, to employ it again, I found
the whole surface sparkling as brightly as when first taken out of the
water. It does not appear probable, in this case, that the particles
could have remained so long alive. On one occasion, having kept a
sea-jelly of the genus _Dianæa_ till it was dead, the water in
which it was placed became luminous.... Near Fernando Do Norhona, the
sea gave out light in flashes. The appearance was very similar to that
which might be expected from a large fish moving rapidly through a
luminous fluid. To this cause the sailors attributed it; at the time,
however, I entertained some doubts, on account of the frequency and
rapidity of the flashes.”
To Spallanzani is due the credit of first calling attention to the
phosphorescence of the jelly-fishes or sea-jellies; he having observed
it in the Mediterranean jelly, _Pelagia phosphorea_, which is luminous
over its entire surface. He subsequently made some interesting
experiments with _Aurelia phosphorea_, a jelly-fish similar to one on
our coast, and came to the conclusion that the _light-emitting_ organs
lay in the arms, tentacles, and muscular zone of the body, and cavity
of the stomach; the rest of the animal showing no luminosity. The light
seemed to proceed from a viscous liquid, a secretion which oozed to the
surface. One _Aurelia_ that he squeezed in twenty-seven ounces of milk
rendered the whole so luminous that a letter was read by the light,
this being one of the first practical results of the investigation of
marine phosphorescence. Humboldt experimented with _Aurelia aurita_,
and, having placed it upon a tin plate, observed, that, whenever he
struck it with another metal, the slightest vibration of the tin
rendered the animal completely luminous. He also observed that it
emitted a greater light when in a galvanic circuit.
CHAPTER III.
FIXED LUMINARIES OF THE SEA.
We have examined and admired the movable and the moving luminaries of
the ocean world, in the firmament of the deep, we may call it,--slowly
moving stars of extreme minuteness, but great brilliancy, in one group,
and the large orbs, more or less moving in erratic spheres, trailing in
long lines of coruscating light, representing the lowest grand branches
of the animal kingdom, the protozoans, and the vast colony of the
sea-jellies, or _medusæ_.
We now come to the third chapter, which embraces those animals forming
the grand branch of the animal kingdom which included in Cuvier’s time
the radiated animals.
All who have visited the New-England shores, or those beyond, farther
north, or the warmer waters of our semi-tropical regions, have probably
become acquainted with the soft and leathery forms, which, when seen
undisturbed in the water, appear like flowers. For example, should
we visit the delightful beaches and coves of Lynn, or Nahant, or
Swampscott, the loved hunting-grounds of Agassiz and his disciples, we
would see, on well-advised instruction from some one informed, what
at first would suggest a moss pink in full bloom, nestled perhaps in
groups, in crevice or open pool, among the crags or broken boulders.
These are the common, and well nigh the only, representative of its
family on our coast, within reach. Others there are, living in deeper
water, within reach of a hand dredge, as work with such, in former
years, well informed us. These are beautiful and very showy, like large
asters and zinnias. But we dwell upon the in-shore one because it is
always at hand and easily obtained, if you know where to look; and it
well represents the characters of the group. Time was, when, forty
years since, if some medical doctor of the town, or some of that ilk,
did not have a sort of half knowledge of the creature, no one about
did. But a few years before that, scientists in Europe were quarrelling
over the question, Is it a vegetable, or an animal? Dr. Marsigli, a
nobleman, asserted that such were vegetable, with further seeming good
argument that the creatures looked like flowers and nothing else,
therefore they must be flowers of the sea, notwithstanding that a poor,
but educated Londoner, by the name of Ellis, demonstrated in good round
science that they were animals. The striking case of mistaken identity,
with the force of nobility, carried it. But Ellis lived to see his
theory prevail.
Scarcely any in the whole range of Nature’s objects are more surprising
and more beautiful. The _Urticena nodosa_ is a form found off our
shores, which is luminous; the light being confined to its tentacles,
and to the soft portion near the summit.
One of the most brilliant of this group of animals is the _Ilyanthus
scoticus_, a kind usually found in ooze, the tentacles appearing at
the surface, and gleaming brightly, like the rays of some fixed star.
Even when brought up on the dredge, these animals emit a brilliant
light.
Some of these sea-anemones are said to attach themselves to the shells
of hermit crabs; and, if luminous, we may imagine the spectacle of the
gleaming, living light-house, moving about at the will of the little
crustacean, possibly attracting prey to it instead of being the warning
beacon that we might suppose. The anemones being, as a rule, fixed, one
naturally likens this one to a light-ship which is drifting about away
from its moorings.
The sea-anemones well repay examination and study, and thrive well in
the aquarium, where their habits and development may be watched. As a
rule, they are fastened to the rocks by a sucking disk. Some live in
the mud; others float upon the surface, or are parasitic upon the great
jelly-fishes. Some, as we have seen, ride about upon hermit crabs, or
fasten themselves upon the claws of others; thus showing the greatest
diversity in their life habits. The corals may be termed anemones
which have the faculty of secreting or depositing lime, and among them
are several which at times appear phosphorescent. The little cup-like
_Caryophyllia_ has been seen to emit a gleam of light, an idea of
which is given in Plate III., Fig. 2.
The phosphorescence of reef-building corals has rarely been observed.
Col. Nicolas Pike, our late consul to Mauritius, and an enthusiastic
naturalist, informs me that he has witnessed the luminosity of their
young. The account is so interesting an addition to the literature of
the subject in general, that I give the colonel’s letter entire:--
BROOKLYN, N.Y., December, 1886.
DEAR MR. HOLDER,--I remember on one occasion, when
sailing on the Indian Ocean, the night was dark, but the crest
of every wave glowed with light. As our vessel moved swiftly
through the water, dashing the foamy waves on each side of her
bows, she left bright streaks of light that reached far behind
us. Every undulation of the water was lit up with scintillating
points of light; and the ocean round us was so luminous, it
would for splendor vie with the finest pyrotechnic display. So
intense was the glow, the hull and sails of the vessel were
illuminated by it; and, as I gazed at the glorious spectacle,
I was filled with wonder and delight. The scene changed
constantly, sometimes less brilliant than others, then again
every rope in the ship was lit up; this, I presume, from the
animals being more or less numerous. At the same time, darting
in every direction, could be seen numerous fishes, making
distinct streaks of light. Luminous spots from one to two inches
in diameter were observed some distance under the water. These
were _medusæ_. We captured many in our nets, and placed
them in buckets of water on the deck, where they still continued
to emit phosphorescent light. The grand scene lasted most of the
night, and was faintly visible till dawn of day.
In the year 1868 or 1869, as I was dredging and collecting on
the reefs near Port Louis, Mauritius, I met with one of the
most singular sights it is possible to conceive. My Lascar crew
gently moved my boat over the reefs, so that I could see any
object in the water. The day was beautiful, not a cloud in the
sky; but the bright sun shone down into the clear waters of the
Indian Ocean, scarcely marked by a ripple on the surface. As the
boat crossed over the shelving reef into deep water, what was my
astonishment to find the depths alive with hundreds of millions
of little creatures (which I supposed to be jelly-fish),
actively moving about in the water, as far as the eye could
penetrate. The little creatures, as they flitted about, emitted
all the colors of the spectrum; the most brilliant diamond could
not vie with the coruscations of light sent out by them. Such a
scene must be witnessed to form any idea of its magnificence:
the whole ocean was aglow with colored lights. I threw over
my hand-net, and drew many thousands into the boat, which I
placed in a large glass jar filled with sea-water, where I could
examine them. They proved to be _young polyps of different
species of the reef-building corals_. Those that I carried
home were still luminous in the evening, and I thought I would
pay a visit later, to see the effect at night; and it was truly
great. The sea was one vast area of luminosity. The illumination
extended for miles. Fishing-boats making for Port Louis harbor
could be plainly seen a long way off by the phosphorescent
light caused by the disturbance they made in passing through
the immense shoal of coral polyps. The sight was curious
and interesting; it had the appearance of an immense meteor
coming directly down on our boat, as they were all heading
for the entrance of the harbor where we lay. The bows of the
fishing-boats made a great disturbance as they struck them, and
the luminosity was most intense; but, as the waves were thrown
off from the bows at a wide angle, the disturbance continued,
and the colored light from the little creatures formed a long
streak from behind the boat, representing the head of a comet
with a long tail. Imagine twenty or thirty of these boats all
heading in one direction, and you may form a faint idea of
the scene. The polyps were not alone, but larger animals were
darting and gyrating about, sending out vivid streaks of light.
The phosphorescent light of these polyps is probably the effect
of a vital action; it appears as a single spark, like that of
various insects, and is repeated at short intervals.
In 1867 I passed through a belt of dark-colored water in a
large stream. It had been observed from the masthead for some
time before we reached it: it proved to be a belt, of miles in
extent, composed of animalcules. When taken up in a bucket,
they gave out the strongest phosphorescent light I have ever
witnessed. It required the highest power of my microscope to
define them, and they were of many species new to me. Our
steamer, a side-wheel vessel, made a great commotion as we
passed for hours through this belt of living matter. These belts
or patches, covering vast tracts of the ocean, are not uncommon.
They are often seen in the Indian Ocean after severe storms and
hurricanes. They vary in color. I have seen them of olive green,
of a yellowish tint, and often a dark blue. Once, after a spent
hurricane at Mauritius, I passed through a belt three miles
wide, of a deep purple, so much so it could be seen a long way
from shore.
Giglioli, the Italian naturalist, refers to the phosphorescence of
madreporic polyps as being quite different from that of other forms.
He observed on the coast of Sumatra and Batavia, that, when the bottom
of his launch grounded upon the polyps, a brilliant display of
phosphorescence followed.
Doubtless nearly all the Alcyonarian[13] corals are light-givers, and
of great importance in the illuminating economy of the ocean.
The Alcyonarians include the sea-pens (_Pennatulidæ_), and the sea-fans
and the red coral of commerce (_Gorgonias_), and may be briefly
described as animals which, as a rule, secrete a horny or calcareous
stock, without the true dividing septa that we see in the corals proper.
The Alcyonarians dredged by the “Challenger” were almost invariably
brilliantly luminous, making the dredge appear as if red-hot coals were
being taken up. The light of the deep-sea forms was similar to that of
those dredged on shallow banks, where the phosphorescence is remarkably
brilliant; so that we can imagine the wondrous spectacle presented in
these little known regions.[14]
The sea-fans and plumes, known scientifically as Gorgonias, are
extremely common upon the outer Florida reef, and form the chief
ornaments of these wonderful gardens of the sea. We have drifted over
them by day and night, peering down into the depths, never wearying
of the display. There were two forms within diving distance on the
reef,--one, a rich yellow, reticulated fan; and the other, a vivid
lilac. On the yellow we often found a parasitic shell of almost the
exact hue of the Gorgonia; so like it, indeed, that it would not have
been noticed if the fan had not been closely examined,--an interesting
example of a protective resemblance.
At night these waters present a wondrous appearance, gleams of light
flashing from every direction. Even the sand at the bottom seemed to
give out fitful coruscations; while pale, dim lights told of rare
_medusæ_,--the phantoms of this world beneath the sea.
The gorgonias emit, as a rule, a light of a beautiful lilac hue; and in
some localities the bottom of the ocean is covered with similar forms,
all gleaming with this vivid phosphorescence. Imagine a cornfield
covering hundreds of acres, the ripe ears emitting a fitful, vivid
lilac light, through which dart various animals,--the birds of this
submarine region,--their passage creating a blaze of another hue; and
some idea can be formed of this scene that conjecture only can picture.
Sir Wyville Thompson states, that, when dredging in water nearly a mile
deep off St. Vincent, they must have passed over an immense field of
light-emitting gorgonias, as the trawls came up filled with a delicate
form, “with a thin wire-like axis slightly twisted spirally, a small
tuft of irregular rootlets at the base, and long exsert polyps. The
stems, which were from eighteen inches to two feet in length, were
coiled in great hanks round the trawl-beam, and entangled in masses in
the net; and, as they showed a most vivid phosphorescence of a pale
lilac color, their immense numbers suggested a wonderful state of
things beneath.”
Off our Eastern coast the little brush-like gorgonia, _Acanella_,[15]
has been observed by Professor Verrill to emit a pale light when
brought to the surface. The Gorgonias are all important light-givers.
_Primnoa_,[16] a brush coral, and _Paragorgia_[17] have become well
known in late years by specimens brought up by the Gloucester fishermen
on the Georges Banks. Even when dry and dead, they are extremely
attractive; the _Primnoa_ being richly tinted with pink, while the
latter has a reddish hue.
If we could descend into these depths, we would find a veritable
forest, with branches seeming on fire; many of the coral trees being
from ten to fifteen feet in height, and equally as wide, forming lanes
and open pathways through which the fishes pass, bathed in the wondrous
light. That this is not imagination is shown by the branches brought
up accidentally and by dredges; some limbs alone being four feet in
length, and stout in proportion. Specimens of these forms can be seen
in most of our museums of science; some sent by Dr. Holder from the
Florida reef to the Museum of Natural History, in Central Park, are
surprisingly beautiful.
More remarkable than the Gorgonias are the strange animals belonging
to _Pennatulidæ_,[18] known popularly as the sea-pens (Plate VII.,
Fig. 2), from the resemblance of some to a quill pen,--an abnormally
large one, it must be confessed. One of the most familiar forms is
_Pennatula phosphorea_. When the animal is observed at night, and
disturbed, it emits quite a brilliant light. In specimens observed at
Oban by Professor Marchel, the more perfect females became vividly
phosphorescent when the leaves were gently irritated. When the polyps
were touched, they showed minute points of light, which appeared over
the whole surface, in rapid, irregular coruscations.
If one of these living pens can produce so interesting a display, what
must be the sight upon the bottom, where myriads of these curious forms
abound, either fixed or moving!
It is not impossible that the light-emitting faculty of sea-pens is
under control; at least, they have their periods of darkness and light.
If a specimen which is not luminous is disturbed, as we have seen, it
immediately becomes so. If the long axial stem is pinched, a seemingly
protesting light appears on the lowest branchlets nearest the stem,
quickly spreading, as if the polyps were igniting. When all those on a
branch have become luminous, the light begins to appear on the next,
and so on in succession until the whole glows brilliantly. Four-fifths
of a second occur between the stimulation and the appearance of the
light; so that in a sea-pen six and one-tenth inches in length, two
seconds and a fifth were required for its complete illumination. By
pinching the top or opposite end of the colony, the same phenomenon
resulted, but reversed. If a polyp at the end of a branchlet was
irritated, light immediately appeared, passed to its neighbor, and so
on; if a branch was touched at both ends, the light followed the act,
and met in the centre.
These interesting experiments, which were made by Panceri, can be
varied in many ways by those fortunate in securing a live sea-pen.[19]
The sea-pen _Pavonia_[20] is noted for its light-emitting properties;
and during the voyage of the English ship “Porcupine” the naturalists
on board had many opportunities for observing its display. Sir Wyville
Thompson, who was in charge, says, “Coming down the sound of Skye
from Loch Torridon on our return, we dredged in about one hundred
fathoms; and the dredge came up tangled with the long pink stems of
the singular sea-pen. Every one of these was embraced and strangled by
the twining arms of an _Asteronyx_,[21] and the round soft bodies of
the star-fishes hung from them like plump ripe fruit. The _Pavonariæ_
were resplendent with a pale lilac phosphorescence, like the flame
of Cyanogen gas; not scintillating like the green light of some
sea-stars,[22] but almost constant, sometimes flashing out at one point
more brightly, and then dying gradually into comparative dimness,
but always sufficiently bright to make every portion of a stem caught
in the tangles or sticking to the ropes distinctly visible. From
the number of specimens of sea-pens brought up at one haul, we had
evidently passed over a forest of them. The stems were a meter long
(over three feet) fringed with hundreds of polyps.”
When the ship “Venus” was lying off Simonstown, one of their boats
passed over a forest of sea-pens in shoal water, which gave out a
vivid light; while, where the ship lay at anchor, other forms of
phosphorescent animals illuminated the ports so that the men lay in
them and read by the wondrous light on the darkest night.
The _Renilla_[23] is a rich purple species common on our south-eastern
borders. Agassiz found it at Charleston, S.C., and says of its
phosphorescence, that “it emitted a golden-green light of wonderful
softness.”
_Virgularia_[24] is an attractive form; and in certain portions of the
Patagonian coast they have been seen, when left by the tide, emitting a
light of great brilliancy.
_Vertillum_ is an interesting genus, resembling a quill pen in which
the feathers have been curled or singed. Its color is a brilliant
orange; but in the darkness it develops a phosphorescence of great
beauty, and so penetrating that a glass containing numbers of them has
been used as a lamp to read by,--an interesting example of one of the
possible, though not remarkably practical, uses of living lights to
mankind.
[Illustration:
PLATE VIII.
LUMINOUS STAR FISHES.
(_Brisinga elegans._)
From 4,500 feet deep.]
CHAPTER IV.
LUMINOUS ECHINODERMS.
In the fourth grand branch of the animal kingdom, numerous creations
are known which exhibit luminosity. The Echinoderms, as they are
termed, are not well known to those who are not familiar with the
seashore. To those who visit the marine beaches, one of the first
objects that is met cast up by the tide, either fresh from its
ocean bed among the rocks, or lying cast up high and dry amongst
the vast masses of kelp, algæ, and other marine _débris_, is
a sea-urchin,--so called for want of a better name, although the
spines with which it is powerfully armed give good color to the
nomenclature. The term Echinoderm is used to express all the kinds,
as they have spines on the skin. As the arrangement of this division
of Nature suggests, the creatures which are embraced here are next
farther advanced in perfection of structure from the third, which
includes the corals and sea-anemones. The animals are of most varied
shape, exteriorly most unlike each other, yet internally possessing a
structure each characteristic of the type. The sea-stars, forms quite
as common as the sea-urchins which we first mentioned, are closely
alike in structure, though so different in shape. Yet another form is
seen in the celebrated trepang, which is dried, smoked, and sold to the
Chinese for food,--a great luxury to them. Small species are found on
our coast.
In some of these creatures the luminous property has been
observed,--which usually surrounds the entire animal,--a pale light,
rendering the object a beautiful one against the dark background of
the ocean bottom. It is needless to say that the human eye has not
penetrated these vast depths; but the ingenuity of the scientist has
resulted in the invention of means by which the smallest as well as the
largest of these strange creatures are dragged from their deep abode.
Echinoderms are extremely numerous; on the Florida reefs we have often
found it impossible to wade through considerable areas, where a kind of
sea-urchin having long, slender black spines was so numerous as to pave
the entire sea-bottom, and in certain localities in Long Island Sound
we have seen the bottom fairly carpeted with star-fishes. It is not
surprising, then, that the dredges of the “Challenger,” “Porcupine,”
“Talisman,” and other ships fitted out for scientific investigation,
often came up loaded to overflowing with star-fishes, showing that the
deep sea is equally populous with these living stars.
These deep-sea forms, especially of the genera _Asterias_ and
_Ophiura_,[25] are remarkable for their brilliancy, even when
taken from their native element. When the bottom off the coast of
Ireland was dredged by the “Challenger,” an extraordinary number of
luminous star-fishes were brought up from a depth of two-thirds of a
mile. Several specimens are most noticeable for their brilliancy;[26]
they appear as if burning internally with heat of great intensity.
Even the mud about them was bespangled with luminous specks; and Sir
Wyville Thompson says that in many instances every thing brought up
in these waters was luminous. The light of one of the star-fishes
was a brilliant green, and seemed to spring from the centre of the
disk; flashing out now upon one arm, again upon another, or suddenly
illumining the entire star in a brilliant aureola of phosphorescence.
This resplendent creature is especially common, according to Sir
Wyville Thompson, off the coast of Stornaway and Shetland; and the
nets, when hauled in, were often overladen with masses of these
gorgeous forms, which emitted a light of brilliant uranium green.
Curiously enough, the young star-fishes exceeded the adults in the
richness of their display. The gleams were not constant, but extremely
erratic, appearing and re-appearing in a bewildering manner; and,
according to the same naturalist, the most striking exhibitions were
seen in very young ones.
The star-fishes known as Ophiuroids are among the most abundant of
deep-sea forms. On the “Challenger,” about several hundred species were
brought up in the trawl from a depth of from half a mile to two and a
half miles. In our own waters, two kinds[27] have been observed to emit
a light of singular brilliancy.
Even more beautiful than these, as regards their luminosity, are the
Brisingas,[28] one of which is shown with its light in Plate VIII.,
Fig. 1. This animal has nineteen long, snake-like arms, branching from
a small central circular body. Its color in the daylight is a rich
orange red; but at night, when taken from the dredge, it displays a
vivid phosphorescence.
This attractive animal was first observed near Bergen, Norway, by
Charles Abjördsen, who took a specimen in two hundred fathoms of water.
Regarding it, he said, “it is a true _gloria maris_,” and gave it the
name of _Brisinga_, one of the jewels of the Goddess Freya.
The Brisingas have the faculty, common to many of their allies, of
casting their arms when touched; so that it is extremely difficult to
take them intact. In lifting an _Astrophyton_[29] from a branch of
coral, we have had it drop into myriads of pieces; so that there was a
mimic rain of arms upon the bottom. This we found could be avoided by
making the transfer under water, and, when the “basket-fish” was safely
in the jar, killing it by the introduction of alcohol.
As to the cause of the light in the star-fishes, little is known.
Quatrefages, after a careful examination of an Ophiuran, came to the
conclusion that the light emitted was due to muscular contraction;
observing it arising between the plates of the arms and not on the
disk, where, however, it has been seen since his observations were
made. Professor P. Martin Duncan found upon examining a specimen,
brought from the icy sea of North Smith’s Sound, by Sir George Nares’s
expedition, that it had a delicate mucous envelope, which, he thought,
in the young covered the plates and bases of the spines. In this filmy
covering, he suggests, may be found the seat of the illuminating power.
CHAPTER V.
SUBTERRANEAN LIGHT-GIVERS.
In wandering through the fields in early morning, we often see little
heaps of newly disturbed earth, and occasionally catch glimpses of
reddish or pink bodies quickly withdrawing into little tunnels in the
sod. These are the earthworms, considered the humblest of all animals;
yet, as insignificant as they seem, they are among the most valuable
aids to the agriculturist.
We may appreciate this by selecting a field at random in a good
producing country, making a section down through the earth for several
feet, when, if carefully done, we shall find innumerable tunnels formed
by the worms, leading here, there, and everywhere. In fact, the upper
crust of the earth is an endless maze of streets, lanes, and avenues. A
naturalist has even attempted to calculate the number of these little
workers, and has come to the conclusion that they average one hundred
thousand to the acre; and in especially rich ground in New Zealand it
was estimated that there were three hundred and forty-eight thousand,
four hundred and eighty in a single acre. This vast body of worms is
continually at work, boring this way and that, coming to the surface
during the night, and retreating to greater depths during the day;
and it is at once evident that their tunnels constitute a system
of irrigation and ventilation for the upper crust. In other words,
rain, instead of running off, enters the holes, and so penetrates the
earth, thus being held for a longer time. Air also finds its way below
the surface; so that the homes of the little creatures constitute
storehouses for moisture.
But this is a very small part of the work accomplished. The worms are
in league with the farmer; are, in fact, his unappreciated assistants,
upon whose endeavors depends much of the success of his crops. They are
continually swallowing the earth, and depositing it at the surface, and
working it over and over. If I should ask my young readers to estimate
the quantity of earth brought to the surface in a single acre in a
year, I fear they would not place the amount as high as Mr. Darwin, who
states that the vegetable mould thus transported in some places amounts
to ten tons an acre. Think of it! If your ten-acre farm is in one of
these favored localities, these silent workers, say to the number of
a million, have ploughed up about one hundred tons of earth for you,
giving you a fine top dressing.
The worms not only carry all this material to the surface, but they
drag vast quantities of leaves and other matter down, that serve to
enrich the soil and render it capable of producing larger crops. They
cover up seeds and other objects to a remarkable extent; and a flat
rock set upon the ground will soon become buried, through their means.
Some of the most interesting parts of Roman villas found in England
have been, according to Darwin, preserved in this way; the worms
undermining them, and gradually heaping soil over the walks and slabs,
until finally, aided by other causes, they disappeared beneath the
ground.
The earthworms of Australia attain a large size,--sometimes several
feet in length,--and have been seen climbing trees. Some casts found
in India are a foot in length. The worms evidently live in complete
darkness; but it is known that at certain times, and under certain
conditions, they are luminous: so that a state of things may exist
under the ground of which we have no conception, and the tunnels of
these little creatures may be brightly illumined. We have never been so
fortunate as to observe their phosphorescence, but Dr. Phipson says, “I
distinctly remember witnessing, when a child, the phosphorescence of
the earthworm. The light appeared connected with the mucus that covered
the animal’s body.” And other naturalists have observed the light under
certain conditions.
If they possess this property to a greater extent than we are now aware
of, it must be a fatal gift, as the sharp little eyes of the mole,
though not remarkable for their powers of observation, would probably
catch the faintest gleam. These animals are continually upon the
forage; and their appetites can be imagined from an actual experiment,
which showed that two moles devoured in nine days 341 grubs, 193
earthworms, 25 caterpillars, and a mouse,--skin, bones, and all!
In the ocean depths we find that the marine worms, which constitute in
the beauty of their appearance a magnificent assemblage, tunnel the
upper crust of the bottom. Some years ago the moat or ditch surrounding
Fort Jefferson, Fla., was pumped out, leaving a space nearly half a
mile in extent, high and dry, which abounded in specimens that would
have delighted the eyes of a specialist in any branch. Over this spot
we had often, as a lad, enjoyed the venturesome fun of riding upon
the backs of the great sea-turtles, kept there for the commissaries’
use, had fished in every nook and corner, and now the opportunity was
presented for penetrating below the surface of the bottom.
Some little digging showed, that, for a foot or more from the surface,
the sand and mud was fairly alive with a variety of worms, numerous
to an extraordinary extent, and in many cases beautiful beyond
description. This condition of things is true, to a greater or less
extent, in many localities; the worms retiring to the mud and other
retreats during the day, at night venturing out, and even swimming at
the surface.
If we take a drop of water from any ditch or pond, or even from the
stem of a flower that has been standing in a vase, and place it under a
microscope of even ordinary power, we shall find that it is a world of
itself; a vast ocean, in fact, to the many forms that live there. Chief
among these drop inhabitants, we notice numbers of little creatures
that attract attention immediately. They resemble tall hats without
brims, or crystal bags with fringed edges. And that they are busy
bodies is at once evident, as they swim along at a wonderful rate of
speed, eating as they go, keeping their fringes or _cilia_, which
appear like so many arms, in perpetual motion; now bumping against each
other, forcing their way among crowds of different animals, and always
appearing full of life and energy.
These little creatures, invisible to the naked eye, are minute worms,
or Rotifers; and among them we find some interesting light-givers. The
_Synachata_ is one; and others described by Ehrenberg, the largest
being about one-eighth of a line in size, present a striking appearance
under the glass in a dark room,--the little bags, seemingly at a white
heat, darting about in every direction.
As small as are these wonderful creatures, they are well worthy of
study; and even those not interested in natural history will find that
the stems of their flowers, or the water in the vase, contain more
wonders than they had dreamed of,--a single drop that can be lifted
upon a pin-head being sufficient for the purpose.
The little hat-like form, _Hydatina senta_, already referred to, is
remarkable for the rapidity of its increase. The eggs are laid or
deposited within a few hours of the time they are first seen within
the transparent parent, and twelve hours later the young break
from the shell and appear; so that in a comparatively few days the
descendants of a single animal might possibly far exceed the population
of the United States. The larger worms are with hardly any exception
ornamented in some remarkable way, and in many the splendors of their
decorations must be seen to be appreciated. The radiating coronets
of _Serpulæ_[30] are of the most delicate and beautiful description,
abounding in bands and markings of striking hues. _Pectinaria_ has upon
its head a pair of combs that might be burnished gold; while _Eunicedæ_
and _Nereidæ_[31] have equally resplendent decorations.
These charms of color, and they are of great variety, are seen
by day; but at night many of these creatures assume the gift of
phosphorescence, adding to the long list of marine light-givers that
have been previously referred to. In four other families[32] are found
the most beautiful light-givers of the group. Assuming that we have a
certain species of the first mentioned in the aquarium, we may prepare
for an extraordinary display. It is now snugly coiled up under a
stone, perhaps fast asleep, and giving no evidence of its wondrous
gift. Now touch it with the narrow handle of the dip-net, and a seeming
electric spark is given out. But there is no electricity here: the
light is a phosphorescent protest, and rapidly passes from scale to
scale, until the whole animal stands out like a vivid shield of light
against the bottom, glowing with the mysterious flame.
If the worm is greatly disturbed, we are presented with a unique method
of protection. Upon feeling the blow or attack, the light becomes
intense, and flashes quickly from segment to segment, and along all
the series of _elytra_; and, as the animal darts away, one or more of
the scales become disconnected and are left behind, a luminous spot,
to attract the attention of a possible follower, while the worm itself
escapes.
Nearly all the phosphorescent worms are rapid swimmers, and noted
for their agile movements; and, as their scales are very readily
disconnected, we may imagine in some cases a worm darting off and
leaving a shower of sparks behind. In these worms the light is usually
green.
We have seen that one of the deep-sea Crustaceans has phosphorescent
bands upon its feet; and in the _Syllidæ_, a family which contains
some remarkable worms, we find that the luminosity is confined to the
under surface of the feet. In _Chætopterus_[33] a bright flashing
light is emitted from the posterior feet, while a far more brilliant
one glows at a point on the dorsum between the lateral wings of the
tenth segment. The mucus of the animals appears to be the seat of
the luminosity, and not only encircles the worm with an aureola of
phosphorescence, but pervades the surrounding water with a rich bluish
purple light, so vivid and brilliant that the medium in which the
light-giver lives seems to have ignited, and to be slowly consuming its
dependents.
[Illustration:
PLATE VII.
BURROW OF PHOLAS.
SEA PEN. (_Pennatula._)]
It has been noticed, according to W. C. McIntosh, that an odor
accompanies this display, resembling somewhat that produced by
phosphorus in combustion. We have noticed that many worms have a
peculiar odor when handled, though not quite of this character.
The most brilliant of all these light-givers is _Polycirrus_, which
emits over its entire surface a vivid pale-bluish light, marking it as
one of the most beautiful of its kind; while _Sagitta_ and many more
add to the wonders in this generally considered uninteresting group of
animals.[34]
CHAPTER VI.
LAMP SHELLS.
In all the forms previously mentioned, the phosphorescence is
conspicuous; but in the little bivalve Pholas it is almost hidden.
The shells of the family _Pholadidæ_ are noted for their boring
habits; penetrating into the hardest stone, as granite and gneiss,
literally entombing themselves, as shown in Plate VII., Fig. 1, which
represents a section of a block of granite into which the little
animals have penetrated. How they can perform such a work, is something
of a mystery; but the foot, which is provided with a hard dermal
protection, is probably the instrument used by the miner.
The most remarkable evidence of their work, according to
Figuier,--though it is fair to say he has been disputed,--is seen
in the Temple of Serapis on the Pozzuolan coast, where the pillars
are perforated with holes, which this author claims were made by the
Pholas,[35] when by a sinking of the crust the pillars were under
water; the columns, by a reverse motion, having now re-appeared from
the sea, bearing the evidences of their submersion.
As if to still further carry out the idea of the miner, the animal
bears its own light, which, though vivid, could but little more than
illumine the stony prison into which the Pholas has willingly ensconced
itself. In Borneo, a freshwater form has been found boring in the dead
trunks of trees. Pliny was probably among the first to place on record
the luminosity of this little borer, having stated that it shone in the
mouths of those who ate it; and its phosphorescence has been studied by
Réaumur, Beccaria, Marsilius, Galeatus, Montius, and others in modern
times. One of Beccaria’s experiments was to ascertain how the light
affected certain colors. He secured a Pholas in a dark spot, and placed
in its light ribbons of various colors. The white ribbon shone most
brilliantly, the yellow next, and the green next, while others were so
indistinct as to be hardly noticeable. Substituting liquids for the
ribbons, the result was the same.
Beccaria also made one of the first practical applications of the
phosphorescent Pholas, demonstrating that it could be used as a lamp.
This was accomplished by placing one in seven ounces of milk, which
rendered the latter so luminous that print could have been read by it,
the milk appearing almost transparent. So it is within the bounds of
possibility to write a _post-mortem_ description of the Pholas by
its own light.
It is evident from these simple experiments that the discovery of
the secret of phosphorescence, and its practical application to the
wants of mankind, would result in revolutionizing present systems,--a
heatless, inexpensive, unextinguishable light being the perfection of
possibilities in this direction,--and it is not improbable that the
experimentalists of olden times may have had this in view when making
their investigations. Both Réaumur and Beccaria attempted to render
the light of this animal lamp permanent. By placing one in honey, the
luminosity was apparently preserved for a year, the light re-appearing
whenever the mollusk was placed in warm water. Brandy extinguishes
the light, and Galeatus and Montius found that vinegar and wine
produced the same result. If the body of Pholas is heated slowly, the
light gradually becomes more and more intense, until, finally, at 45°
Réaumur, or 56° Centigrade, it disappears, and cannot be restored.
The secure position of the Pholas in its impregnable fortress would
hardly seem to require a warning or attractive light; and its use must
remain a mystery, though theory could, of course, suggest explanations.
While the Pholas conceals its luminosity in its dungeon, there are
other molluscan light-givers which float about like light-ships astray.
These are Pteropods, or wing-footed mollusks; delicate fairy ships of
marvellous beauty. By some authorities they are said to represent the
higher forms of the _Cephalophora_, while others consider them as
degenerate or backsliding Cephalopods, of which the squids and octopi
are representatives. They are pelagic, free-swimming mollusks, in which
portions of the foot are modified into seeming wings, so that the
little creature seems to fly through the water. They differ much in
appearance. Some secrete a glassy, horny, cartilaginous or limey shell,
which in some cases is only present in the larval forms, disappearing
in the adult; while others, again, preserve it through their entire
lives. The body is of various shapes: it is protected by the shell when
present, and can be drawn into it.
Though simple, helpless creatures, many have an armament which in
a larger animal would be considered extremely effective. Thus in
_Clio_ each tentacle bears nearly three thousand cylinders, each
containing stalked suckers; and, as there are six tentacles, the little
animal can grasp its microscopic prey with three hundred and sixty
thousand hands. Besides this, it has a pair of many-toothed jaws and a
toothed tongue. While extremely small, these animals exist in such vast
multitudes, that they probably constitute an important food for certain
whales.
[Illustration:
PLATE VI.
APOLEMIA. CLEODORA. PRAYA.]
One of the most interesting of the Pteropods, or wing-footed animals,
as associated with our present subject, is the _Cleodora lanceolata_
(Plate VI., Fig. 1). It has a pyramidal shell, terminating in three
sharp spines, the wing-like fins rising above. It is rarely over half
an inch in length, almost transparent, and bears in its shell a small
light, which, however, is distinctly seen through the transparent
covering. A more beautiful living lamp it would be difficult to
imagine; and when slowly flying through the ocean, in countless
myriads, they must present a wondrous sight. One of this genus,
observed by Giglioli, emitted a very livid red light; the luminous
organ being at the summit of the shell. There are many different genera
and species. _Hyalea_, an oceanic wing-foot, moves very rapidly,
and looks not unlike a butterfly darting here and there, in erratic
flight, in search of food; but the little _Cleodora_ moves in a regular
and stately manner. In _Hyalea_ observed by Giglioli in the harbor
of Anjer, Java, the light, which contributed largely to the general
phosphorescence, was confined to the basal part of the shell.
My young readers interested in geology are probably familiar with the
curious _Conularia_, or cone in cone, which has been found in Australia
sixteen inches in length, and has always been regarded a puzzle. It
has been suggested that this is a gigantic fossil Pteropod. The little
needle-like Tentaculites, from the Silurian and Devonian rocks, are
also allies.
Some of the most remarkable mollusks are found among the sea-slugs, so
called from their resemblance to the slugs of the garden. I have found
them on the weed floating in the Gulf Stream, so resembling the latter
in almost every particular that it was difficult to determine that they
were not a part of the weed itself. _Scyllaea pelagica_ is such a form;
helpless, yet finding protection in its mimicry of the surroundings.
Equally as remarkable is _Dendronotus_,[36] the bushy sea-slug whose
gills resemble the branches of weed in a remarkable manner. This
curious sea creature is quite common on the seaweeds of our New-England
beaches. In the Mediterranean and Pacific is found the most unique
of the group, the _Phyllirhoë bucephala_ (Plate V., Fig. 2), which
differs from many so entirely that it would seem to belong elsewhere.
Like the other forms, it is pelagic, often being seen swimming along,
resembling a fish, with its compressed body, and vertical, fan-like
tail, and with long feelers or tentacles ahead. It is transparent and
shelless in the adult stage, possesses no foot or _branchiæ_, evidently
breathing through the body-walls or general surface. To add to its
curious features, the _Phyllirhoë_ is brilliantly phosphorescent; light
being emitted from certain spots, shown in the engraving, rendering the
tissues transparent and luminous. Examination has shown that the light
proceeds from certain globular nucleated cells, which appear to be the
terminations of nerves.
The _Phyllirhoë_ thrives well in the aquarium, and has been studied
and observed in the famous aquarium at Naples. When it is touched or
is swimming, the light seems to diffuse the entire surface, so that it
presents a striking contrast against the dark water; and undoubtedly
this gift is a fatal one, attracting the attention of many a fish to
the dainty morsel seemingly outlined in fire.
Giglioli refers to the luminosity of an undescribed Heteropod, the axis
of whose body gave out a reddish light whenever the animal was excited.
According to C. W. Peach, the young of _Eolis_ are phosphorescent.
Such instances where the animal is particularly defenceless are amusing
refutations of the theories of naturalists who see in the light a
warning.
The common garden slugs, the cousins of the snails, are well-known
forms. They generally remain concealed during the day, coming out at
night, and often doing much damage to vegetation which is largely laid
to birds. I have kept many of them, and they offered an extremely
interesting study. They secrete a remarkable amount of mucus, which
they use in descending from a tree, just as a spider does its silk
thread. The mucus exudes from the foot, passes along to the tail, when
it is attached to the twig. This accomplished, the slug boldly launches
itself into space, the thread becoming more and more attenuated, until
finally, when the slug is near the ground, it is exceedingly fine.
Nearly all our common slugs descend from trees in this manner,--quite a
contrast to the slow, tedious ascent.
The amount of mucus that can be taken from them is remarkable; and that
it is also protective will be evident to any one who may experiment
with them.
One genus, _Phosphorax_, found at Cape Verde, and, according to
Duncan, at Teneriffe, has a luminous pore on the posterior border
of the mantle. One species only is known, _P. noctilucus_; and its
light has not, that I am aware, been made the object of any extended
investigation.
The highest forms of the _Mollusca_, the Cephalopods, cuttle-fishes,
are probably at times luminous. I have noticed what I presumed
was a delicate, sensitive, luminous glow about an _Octopus_ in a
semi-darkened tank, but I am not satisfied to make the statement as
fact. These forms are so remarkable for the waves of color that pass
over them, and which seem to make them transparent, that one could
readily be deceived.
The little _Cranchia_ (Plate IV., Fig. 2) is a light-giver, its
phosphorescence having been distinctly observed. It is an ally of
the giant squids, which have been found fifty-five feet in length,
and which, if luminous like their pygmy relative, would present a
marvellous spectacle, darting veritable living arrows through the
depths of the sea.
Giglioli refers to the phosphorescence of _Loligo saggitatus_,
and to that of several small Octopods observed by him at Callao and
Valparaiso. Their bodies gave out a pale whitish light, uniformly
distributed.
[Illustration:
PLATE IX.
_c_ _b_ _a_ _f_ _e_ _d_
LUMINOUS BEETLES, ETC.
_a._--_Lampyris splendidula_--male.
_b._-- „ „ --female.
_c._-- „ „ --larva.
_d._--_Lampyris noctiluca_ --male.
_e._-- „ „ --female.
_f._-- „ „ --larva.]
CHAPTER VII.
LIGHTNING-BUGS.
Gen. Count Dejean, aide-de-camp to Napoleon, was a most enthusiastic
collector of beetles; and it is even said of him that he would march
his army out of its way to pass through a good collecting locality.
At all times during the campaigns which he helped to render famous,
his attention was not taken from his favorite occupation; and his
military cap was invariably conspicuous from the gorgeous beetles that
were there immolated. Every one in the army, from the emperor down to
his men, was aware of what was termed his weakness; and the latter
were constantly on the lookout for specimens for their commander. At
the battle of Wagram, 1809, the general went into the combat with
his hat as usual ornamented with beetles, which he had received that
morning; and, while standing near the emperor, a shot from the enemy
struck him upon the head, knocking him senseless, and destroying his
collection,--the hat being completely torn in pieces. The emperor,
thinking him fatally wounded, hastened to his side, asking if he was
still alive; upon which the general gasped out, “I am not dead; but,
alas, my insects are all gone!”
The beetles are among the most interesting of all insects; and a study
of them, though casual, will well repay my young readers, who cannot
fail to be interested in their peculiarities, their habits, methods of
protection and defence, their intelligence in caring for their young,
and the wondrous light-emitting power of some species.
In my walks about the San Gabriel Valley, I generally meet a peculiar
beetle,--a large, black fellow, who lumbers along in a clumsy manner.
If touched, he cannonades me with a fluid of iodine color, which has a
most disagreeable odor; so much so, that upon one occasion, my nostrils
being in range, I was made temporarily faint by it. The fluid stained
my hands like iodine, and caused not a little irritation to the skin.
The beetle, then, is a living cannon; the fluid, which is contained
in certain glands, being its defence. It can be ejected or thrown two
inches, so that it affords quite a protection, and probably would be
effective with birds.
Many insects have a curious odor which serves several purposes,--one,
in rendering them nauseous to birds and various enemies; and, again, as
a means of communication among themselves. Thus, if a community of deaf
and dumb persons should decide to identify themselves by certain odors,
we would see a practical application of this. One family would carry
musk, and be recognized some distance off by it; and so with other
perfumes or odors. This is just how some beetles call each other; and
in the one referred to both male and female possess the same odor.
Some of the flesh-eating beetles (Plate IX.) exhibit great ingenuity
and intelligence in securing a food-supply and an asylum for their
young at the same time. To their work is due the fact that the remains
of few animals are found at the surface. The moment the latter die,
these insects, and especially the grave-diggers (_Necrophorus_),
appear. They run about the body, if upon the ground, inspecting it
with great interest. If the animal is small, and the earth about it
not suitable for its purpose, it is removed to softer ground; and
here the beetles begin to dig, undermining the body, until in a very
few hours it has disappeared or been completely buried. I have seen a
garter snake covered in four hours, and some animals are sunk in this
way a foot from the surface. The beetles then feed upon the body, and
the female deposits her eggs there,--perhaps thirty white cylindrical
objects, which in time hatch; the young being in this way provided with
an ample supply of food.
The Egyptian _Scarabæus_, noted for being found in the ancient tombs
and monuments, and considered sacred by some of the natives, has an
interesting method of caring for its future young. It encloses the eggs
in round balls of various material suitable for food; a well is then
dug several inches deep, into which the beetles roll the balls, then
covering them: so that, when the young appears, it is encased in the
food necessary to its existence.
Passing the giant beetles of the tropics, and many others that have
features of interest, we come to the forms called lightning-bugs,
which, of all their tribe, impress us as marvellous, and which are
especially associated with our present subject.
“Sorrowing we beheld
The night come on; but soon did night display
More wonders than it veiled: innumerous tribes
From the wood-cover swarmed, and darkness made
Their beauties visible; one while they streamed
A bright blue radiance upon flowers which closed
Their gorgeous colors from the eye of day;
Now motionless and dark, eluded search,
Self-shrouded; and anon, starring the sky,
Rose like a shower of fire.”
Southey’s description of the South-American fire-flies does not ill
apply to the midsummer night festivals held in our own woods and fields
of the North, by the diamonds of the night. As twilight deepens, these
living lights appear; creeping from beneath the bark of trees, out of
the ground, or dropping from some distant limb; darting here and there
in streams of light, soaring high in air, twinkling among the leaves;
while down in the hollow, where the cat-tails rustle and nod, rises a
veritable luminous cloud.
The producers of these displays are the lightning-bugs,--beetles
belonging to the family _Lampyridæ_ (Plate X., Fig. 7). They are
mainly of small size and soft texture; the _larvæ_ being flat and dark
colored, and often presenting the appearance of a bit of velvet. They
are carniverous in their habits, and can be found under stones and the
bark of trees. The velvet-hued _larvæ_ of one species is often seen on
the surface of the snow, giving rise to stories of worm showers. The
family is divided, generally, into three sub-divisions; and one, the
_Lampyrinæ_, is noted for the phosphorescence of many of the species.
Numerous species are known throughout the world and in this country,
differing much in size; those in Kentucky and other Southern States
being somewhat larger than their Northern cousins. In the South and the
West-India Islands they are seen to best advantage. In these isles of
summer, especially Jamaica, Gosse studied their habits, and observed
their nocturnal glories; and to him I am indebted for the following
notes relating to the West-India species. He says at all times their
sparks, of various degrees of intensity, according to the size of
the species, are to be seen, fitfully gleaming by scores about the
margins of woods, and in open and cultivated places. He observed about
fourteen species, all luminous. _Photuris versicolor_, a large species
with drab-colored _elytra_, he found abroad soon after his arrival in
December. One flying around the house in the evening, he was struck
with its swift and headlong flight and nearly permanent luminosity,
which was much more brilliant than that of any species he had at that
time seen. The large _Pygolampis_, which he called afterwards _P.
xanthophotis_, he did not observe until May, when one flew into his
house at Bluefields one evening; and a few nights later he found them
in great numbers on the very sea-beach at Sabito. It was conspicuous
for the intensity of its light, much exceeding that of _Photuris
versicolor_. Sometimes it is only the last segment but two that shows
luminosity; but, when excited, the whole hinder part of the abdomen is
lighted up with a dazzling glare.
In June, in the woods of St. Elizabeth’s, Gosse had special
opportunities for observing the _Lampyridæ_; particularly along the
road leading up the mountain from Shrewsbury to Content, where it is
cut through the forest, which overhangs it on each side, making it
sombre even by day, and casting an impenetrable gloom over the scene
by night. The darkness here, however, and especially at one point,--a
little dell, which is most obscure,--is studded thick with fire-flies
of various species, among which the two large ones above named are
conspicuous. _Pygolampis xanthophotis_ he observed only in flight. Its
light is of a rich orange color when seen abroad, but when viewed in
the light of a candle appears yellow. It is not so deeply tinted as
the abdominal light of _Pyrophorus noctilucus_, and is intermittent.
_Photuris versicolor_ is noticeable by its frequent resting on a twig
or leaf in the woods, when it will gradually increase the intensity
of its light till it glows like a torch; then it gradually fades to a
spark, and becomes quite extinct. It thus remains unseen for some time;
but in about a minute, or it may be two, it will begin to appear, and
gradually increase to its former blaze; then fade again,--strongly
reminding the beholder of the revolving light at sea. The light of this
species is of a brilliant green hue. Gosse says he has seen a passing
_Pyg. xanthophotis_, attracted by the glow of a stationary _Phot.
versicolor_, fly upward and play around it; when the intermingling of
the green and orange rays had a charming effect.
The smaller species have, some a yellow, and some a green, light. _Pyg.
xanthophotis_, when held in the fingers, will frequently illuminate a
segment of the abdomen, over which the light plays fitfully, sometimes
momentarily clouded, more or less, but generally saturated, as it
were, with most brilliant effulgence. This species occasionally comes
in at open windows at night, but much more rarely than the _Photuris
versicolor_ and the smaller kinds, a dozen or more of which may be seen
almost every night, crawling up the walls, or flitting around the room
and beneath the ceiling, of these Jamaica homes.
One of our commonest forms in the eastern United States is _Photuris
pennsylvanicus_. It is about one-half of an inch in length, has a
general yellowish color, with a few stripes or lines of brown or black.
Both sexes have wings and quite long _elytra_.
[Illustration:
PLATE X.
1. _Scopelus humboldtii_, showing luminous spots.
2. Mother o’pearl organ from side of same.
3. _Argyropelecus._
4. Longitudinal section of organs from abdominal region of same.
5. Luminous organ from nasal region of _Ichthyococcus_.
6. Luminous Crustacean.
7. Lampyris.
8. Light cells of same, and trachea (magnified).]
In the diurnal _Lucidota_, often seen flying in shady places, and to be
remembered by the peculiar, disagreeable, milky fluid they exude when
caught, the luminous organs are feebly developed. In the female they
are indicated by yellow spots found on the last ventral segment, and on
the last two in the male. In the genus _Pyropyga_ the light organs are
inconspicuous, except in one species,--_luteicollis_. In _Pyractomena_,
an attractive genus, this peculiar feature is well developed in
both sexes, and the light vivid at times. The phosphorescent organs
are larger in the male, and situated on the fifth and sixth ventral
segments. Close examination will show in the male a large, stigma-like
pore on each side, midway between the middle and the side, whose
office is not perfectly understood. In the female the lanterns are at
the sides of the segments. _P. lucifera_, found from Massachusetts to
Texas, has extremely small luminous organs.
In the genus _Photinus_, certain species of which have parts of a
roseate tint, the light-emitting organs are larger in the male than
in the female, and vary considerably in position in the different
species. In the male they cover the entire ventral segments, from the
fourth to fifth inclusive; and on the fifth and sixth segments the
little impressions or pores referred to are seen in the females. The
light-organs occupy the middle portion of the ventral segments, and
resemble a flat elevation upon the fifth segment. There are so many
exceptions and differences, that the young naturalist will find it a
particularly interesting study. Thus in _P. dimissus_ the male has
the usual illuminating apparatus, while it is entirely wanting in the
female.
In the group _Lampyres_ the lights are bright in the females, but
variable in the males. For a long time only the male of the genus
_Phengodes_ was known, the female being described as another insect.
The mistake was made owing to the fact that the female never attains a
development beyond the larval condition, and is the only instance among
beetles where the larval female produces fertile eggs. The female is
about two inches in length, of a creamy-white hue in the daytime; but
at night it presents a truly magnificent appearance, emitting from the
sides or margins of the segments a rich green phosphorescent light.
Another light-giver rarely seen is the _larva_ of _Mastinocerus_, a
slender, cylindrical form of a pale color. It lives upon snails, and
is feebly luminous. Mrs. King thus writes to Dr. le Conte concerning
it: “June 4, saw running rapidly over the table, near a lighted lamp,
a small Coleopter; it was twisting its abdomen up over its wings, and
evidently trying to straighten them out, as they seemed moist and
twisted at their ends. The general appearance suggested _Mastinocerus_;
and, acting on this thought, I captured it, and sat up till a late hour
to be assured of the truth. The insect was in a small phial, and moved
quickly. It gave out light conspicuously from the head, feebly from the
anal end, and still more so from about the base of the abdomen. The
light seen in the head, though visible in the dark as a round spot,
yet, when taken into a room obscurely lighted, was invisible from
above; but, when the insect was suddenly thrown upon its back, a light
no larger than a pin-point was seen just about the junction of the head
and prothorax.”
The method of illumination in this group is intermittent, the light
appearing as repeated flashes: hence the term “lightning-bugs” in
contrast to the steady gleam of the fire-flies or Elaters. Mr. A.
E. Eaton has counted the flashes in _Luciola lusitanica_, and
found that there were thirty-six in a minute, each flash lasting from
one-fourth to one-third of a second.[37]
The light of some species is intense, while that of others is very
feeble. By placing detached parts of the luminous organs upon a page,
I have been able to make out the type; and, if numbers of living
lightning-bugs are confined, they can be utilized as a lamp,--rather
a dull one, it must be confessed, unless the numbers are greatly
augmented. The _larvæ_, as well as the _imagos_, are often luminous;
even the eggs of some emit light.
An examination of the luminous organs during the daytime shows them to
be yellowish or whitish patches on the various segments. If the hand
is held over them, the light is seen, and in complete darkness they
present a magnificent spectacle,--the light dying away, then growing
intense, about the spot, so that it appears to be fairly trembling with
heat, as if some chemical action was periodically asserting itself,
causing the tissues to become suffused with a fiery glow; yet, if the
most delicate thermometer is placed against the luminous organs of a
large number of these insects, there is not the slightest elevation to
show the presence of heat. If now we kill the insect, and remove the
luminous matter, it resembles a bit of starch with luminous spots; and
pressure, which admits more oxygen, causes a temporary increase in the
light.
The luminous organs are similar in structure to the fat body of the
insect, and are made up of light-emitting cells (Plate X., Fig. 8),
surrounded by a maze of _tracheæ_, or air-tubes. In explanation of
the light, it has been suggested that the cells secrete phosphuretted
hydrogen, which becomes luminous upon contact with oxygen which
reaches it through the minute air-tubes. Regarding _Luciola Italica_,
Professor Emery says that the male _Luciolæ_ gave out light in two
distinct modes: in the night, when they are brisk and fly about, the
light increases and decreases at short, regular intervals, so that it
seems to twinkle. If one of them is caught flying, or disturbed in its
rest by day, it shines less than at the maximum of its intensity when
on the wing, but without intermission. It is remarked, however, that
the luminous plates do not shine uniformly over their whole extent; but
that sometimes one spot, and sometimes another, glows more strongly.
If such a specimen is examined under the microscope, we perceive, on
a dark background, bright, luminous rings, which are not, however,
uniformly brilliant, but display certain more intense points, which
flash up, and again disappear, or continue to shine on faintly for a
time, re-appearing afterward in full splendor. These changes take place
without any regular succession.[38]
The common lightning-bugs of Europe are _Lampyris noctiluca_ (Plate
IX., Fig. _d_) and _L. splendidula_ (Fig. _a_). Their life history is
an interesting study, and a brief description will apply to all. In
early spring we find the little yellow eggs, perhaps gleaming with the
wonderful phosphorescence, and thus finding protection, attached to
blades of grass or other objects just above ground. The _larva_ (Plate
IX., Fig. _c_), a long, narrow, flat creature, soon appears and begins
a predatory life; even being provided with an apparatus for removing
the mucus of its victim. About the month of April it attains its full
vigor, and during the summer changes to the pupa form, or hibernates
all winter, entering a deep sleep, and assuming its new shape the
following spring. We see the light from the very first in the eggs of
some; then in the _larva_, there appearing like little sacs on the
under surface, one on each side of the middle line, so arranged that
the insect can hide them by retracting the body, and causing them to
blaze out when the abdomen is extended. Nothing in all nature is more
wonderful than the changes through which these and other insects pass
before attaining adult growth.
The _larva_ is a busy little creature, full of life; but, when about
to change, it becomes lethargic and quiet, as if impressed with the
importance of the coming metamorphosis. Finally it wriggles out of its
old skin, and becomes a _pupa_, also luminous; exceedingly lively,
yet with its motions restricted. It moves its _antennæ_ and legs,
and pushes itself along by movements of the abdomen. Finally the
perfect insect appears, with its wondrous array of lights, so little
understood, and which, if accompanied with the ordinary amount of heat
attendant upon such a display, would soon roast or fry its possessor.
As to the use of the lights, we can only conjecture. It has been shown
that one insect recognized the other by it, and thus it may be a sign
language; while, according to others, it is a warning to birds and
other enemies.
Mr. Darwin thus refers to the lightning-bug of South America: “All the
fire-flies which I caught here (at Rio) belonged to the _Lampyridæ_
(in which family the English glow-worm is included), and the greater
number of specimens were of _Lampyris occidentalis_. I found that
this insect emitted the most brilliant flashes when irritated; in the
intervals, the abdominal rings were obscured. The flash was almost
co-instantaneous in the two rings, but it was just perceptible first
in the anterior one. The shining matter was fluid and very adhesive;
little spots, where the skin had been torn, continued bright with
a slight scintillation, whilst the uninjured parts were obscured.
When the insect was decapitated, the rings remained uninterruptedly
bright, but not so brilliant as before. Local irritation with a needle
always increased the vividness of the light. The rings in one instance
retained their luminous property nearly twenty-four hours after the
death of the insect. From these facts it would appear probable that the
animal has only the power of concealing or extinguishing the light for
short intervals, and that at other times the display is voluntary. On
the muddy and wet gravel walks, I found the _larvæ_ of _Lampyris_ in
great numbers. They resembled in general form the female of the English
glow-worm. These _larvæ_ possessed but feeble luminous powers; and on
the slightest touch they feigned death, and ceased to shine; nor did
irritation excite any fresh display.”
[Illustration:
PLATE XI.
LUMINOUS BEETLE. (_Pyrophorus noctilucus._)
In burrow of Mole Cricket.]
CHAPTER VIII.
FIRE-FLIES.
Some years ago an American gentleman, visiting in one of the large
cities of South America, was invited to a masquerade ball at one of the
finest private residences in the city. The ball-room was the garden,--a
veritable fairy-land abounding in plants of the most novel and
beautiful description,--and upon the grass had been laid an extended
platform for the dancers. It was moonlight when the festivities began,
and no artificial lights were used; yet at various intervals among the
flowers soft gleams appeared, apparently for ornament. Among the first
comers was a tall gentleman dressed in a style of several centuries
ago, a most picturesque costume; but what particularly attracted the
attention of the American were the decorations of this gentleman and
his companion. Around the broad-brimmed hat he wore a band of what
appeared, from a distance, to be gems, that flashed like diamonds,
presenting a magnificent appearance. The lady’s costume was still more
remarkable, being fairly ablaze with these brilliant scintillations.
As the evening wore on, he was presented to these maskers, when he
found that the light proceeded from innumerable luminous insects which
had been secured by delicate wires, and fastened upon the hat and the
lady’s dress.
About the garden, hundreds of the insects were confined in delicate
glass globes, which without emitting much light, added to the charm and
novelty of the surroundings.
In Vera Cruz these beetles are so commonly used as toilet ornaments
that they form an important article of trade; and the natives make a
business of catching them, and in a way that would seem to show that
the lights of insects are their means of recognition. The fire-fly
hunters provide themselves with long sticks, upon the end of which
is fastened a burning coal. This waved in the air attracts the
light-givers, and they are entrapped in a net. They are then placed in
a box covered with a wire netting, bathed twice a day in tepid water,
and at night fed with sugar-cane.
The insects utilized in this curious manner are
fire-flies,--distinguished from the lightning-bugs by the steady
glare they produce. And that the lights of these Elaters, as they are
scientifically called, is intense, and of practical value in other
ways, we may realize from the statement of Professor Jaeger, who
says, “I feel particularly grateful to these little insects, because,
during my excursions in St. Domingo, they were frequently the means
of saving my life. Often has dark night surrounded me in the midst of
a desert forest, or on the mountains, when the little animals were my
only guide; and by their welcome light I have discovered a path for my
horse, which has led me safely on my journey.” If a number are confined
in a glass, they emit sufficient light to read by.
It is in the genus _Pyrophorus_ that we find the most remarkable
light-givers; the different species being found principally in tropical
America. In Plate XI. _Pyrophorus noctilucus_, a form common in
the West Indies and Brazil, is shown. It ranges from 1.50 to 1.75
inches in length; is a black or rusty-brown color; and, if observed
during the daylight, two conspicuous oval spots of a yellowish white
hue are seen on each side of the prothorax. These are the lanterns of
the Elaters, and in the dark glow with a brilliancy far exceeding that
of the lightning-bugs. These lights shine from above, while between
the part known as the metathorax and the first abdominal segment
gleams another, or lower light, even more brilliant than the other:
so the _Pyrophorus_, turn which way it will in its flight, emits
a flash of light. The light appears to be dependent upon the will,
as when feeding or asleep it is not seen; attaining its greatest
brilliancy during activity and flight. The color of the light, as seen
by the author, is a rich green; but the eggs emit a light of a bluish
tint, according to Dubois. This naturalist has made some extremely
interesting experiments with this beetle. The eggs which he dried
retained their luminosity for a week, the light re-appearing when they
were placed in water. He ground the luminous organs in a mortar, after
having dried them in vacuum, and then mixed them in boiled water; the
latter immediately becoming luminous. Dr. Dubois concludes that the
light of the _Pyrophorus_ is intended as an illuminator for itself
alone. To prove this, he covered one of the upper lights with wax, and
the animal moved in a curve; when both spots were covered, the beetle
soon stopped, and then moved in an uncertain manner, carefully feeling
the ground with its _antennæ_. The spectrum of the light was
extremely beautiful, being continuous, without dark or brilliant rays;
and, what appears most remarkable, the composition of the light was
found to change with its intensity. As to the exact cause of the light,
how it is produced, the secret yet rests with Nature.
Dr. Kidder thus refers to the brilliancy of one of these wondrous
light-givers: “Before retracing my steps, I stood for a few moments
looking down into the Cimmerian blackness of the gulf before me; and,
while thus gazing, a luminous mass seemed to start from the very
centre. I watched it as it floated up, revealing in its slow flight the
long leaves of the palm _Euterpe edulis_, and the minuter foliage
of other trees. It came directly towards me, lighting up the gloom
around with its three luminosities, which I could now distinctly see.”
The insect was the _Pyrophorus noctilucus_; a longish click-beetle
of a dull blackish-brown color, and covered over with a short,
slight-brown pubescence. When walking or at rest, the chief light that
it emits proceeds from the two yellow tubercles on the thorax, so
conspicuous in dead specimens; but, when flying, another luminous spot
is discernible on the hinder part of the thorax, and this is continued
to the under side of the insect.
Ovideo says that the Indians travel in the night with these insects
fixed to their hands and feet; and that they spin, weave, paint, dance,
etc., by their light. In Prescott’s “Conquest of Mexico,” we are told
that in 1520, when the Spaniards visited that country, “the air was
filled with the _Cucujo_,--a species of large beetle, which emits
an intense phosphoric light from its body, strong enough to enable
one to read by it. These wandering flies, seen in the darkness of the
night, were converted, by the excited imaginations of the besieged,
into an army of matchlocks.”
[Illustration:
PLATE XII.
THE LANTERN FLY.
(_Fulgora lanternaria._)
According to Madame MERIAN, Marquis SPINOLA,
and others.]
At the time of the discovery of Hispaniola, Peter Martyr assures us
that the natives, in their night journeyings through the woods, were
in the habit of fastening a number of these light-givers to their
feet to light the way. On this occurrence Southey founds the incident
mentioned in “Madoc” where Coatel guides Madoc through the cave:--
“She beckoned, and descended, and drew out
From underneath her vest a cage,--or net
It rather might be called, so fine the twigs
Which knit it,--where, confined, two fire-flies gave their lustre.”
CHAPTER IX.
LANTERN-FLIES.
When Sir Charles Lyell visited this country some years ago, he
expressed much interest in the sea-serpent question; and one of his
first inquiries, when introduced to a certain gentleman, was, “Have you
heard any thing about the sea-serpent?” The reply was, “Unfortunately I
have seen it.”
If Mme. Merian were alive, and a similar question should be propounded
to her regarding the luminosity of the South-American lantern-fly, she
could with propriety make a like response. She makes a definite and
distinct statement concerning the phosphorescence of the _Fulgora
lanternaria_, yet to-day it is declared non-luminous by nearly all
scientists.
It is not our intention to champion the cause of this enthusiastic
naturalist; but to some it would seem that the direct evidence of a
single observer of good repute should have some weight against an
indefinite number who merely failed to corroborate the observation.
In the chapter on luminous plants, an almost similar instance is
given, where for years the direct statement of the daughter of Linnæus
regarding the luminosity of a plant was doubted by scientific men,
until finally a well-known botanist confirmed it. To some it would seem
possible that the _Fulgora_ emits light only at certain times,
and under peculiar conditions; be this as it may, scientific opinion
is entirely against its luminosity, and the light in the figure of
_Fulgora lanternaria_ (Plate XII.) is introduced merely to show
its supposed appearance according to the description of Mme. Merian and
her supporters. The question is so interesting, and so typical of many
that arise, that we introduce the opinions of the various authorities
upon the subject.
The two most interesting species come from China and South
America,--_Fulgora candelaria_ from the former, and _F. lanternaria_
from the latter. The Asiatic species is the smallest, measuring about
two inches in length, and noticeable for the peculiar horn-like
projection on the head, supposed to be the luminous organ. Its colors
are rich and attractive; the head and proboscis, as we may call it,
being a fine reddish brown, apparently dotted here and there with white
specks. The thorax is a deep yellow hue; the body, black above, and
yellow beneath. The wings are still more striking,--the upper pair
dark, with many green reticulations, that divide the entire surface
into many minute squares, yellow spots being scattered here and there;
the under wings are orange with black tips.
The _Fulgora lanternaria_ of South America is nearly three inches
and a half in length from the tip of the head to the extremity of the
tail, and about five inches and a half broad with its wings expanded.
The body is of a lengthened oval shape, sub-cylindric, and divided
into several rings or segments; while the head is distinguished by a
singular prolongation, which sometimes equals the rest of the body in
size. The general color is yellow, variegated with many brown stripes
and spots. The wings are large and powerful; the lower pair ornamented
with a large eye-spot, well shown in the accompanying figure; the iris
or border being red, while the centre is half red and half white,
rendering it a very conspicuous object. The remarkable extension of the
head--or lantern, as it has been called--is pale yellow, ornamented
with longitudinal red stripes. In this projection the luminous property
of the lantern-fly is said to exist.
In Mme. Merian’s work on the insects of Surinam, she says, “The Indians
once brought me, before I knew that they shone at night, a number of
these lantern-flies, which I shut up in a large wooden box. In the
night they made such a noise that I awoke in a fright, and ordered a
light to be brought, not knowing from whence the noise proceeded. As
soon as we found that it came from the box, we opened it, but were
still much more alarmed, and let it fall to the ground in a fright,
_at seeing a flame of fire_ come out of it; and as many animals as
came out, so many flames of fire appeared. When we found this to be the
case, we recovered from our fright, and again collected the insects,
highly admiring their splendid appearance.”
Such a statement naturally attracted attention; and, from its
publication until the present, collectors have endeavored to
substantiate it. Count Hoffmansegg states that his insect collector
Sieber, who was a practical entomologist of thirty years’ experience,
took many specimens of _F. lanternaria_ in Brazil, but never saw one
emit light. The Marquis Spinola, in the annals of the “Entomological
Society of France,” vol. xiii., contends for the luminosity of the
entire tribe. On the other hand, M. Richard succeeded in raising
a species of _Fulgora_, but failed to observe the light; while M.
Westmael assures us that a friend of his observed the luminosity.
John C. Branner, Ph.D., states that when in South America he was often
informed that it was luminous, but never could find any one who had
personally seen the light. Snr. Luiz A. A. de Carvalho, jun., of Rio
de Janeiro, who had fine specimens in his cabinet, assured him that he
knew of no evidence whatever that they produced light. In the article
on phosphorescence in the last edition of the Encyclopædia Britannica,
Mr. William E. Hoyle, F.R.S., of the “Challenger” expedition,
apparently accepts the _Fulgora_ as a light-giver; as he says, “Whilst
the lantern-flies, _Fulgoridæ_, carry their light at the extremity
of a long, curved proboscis.” Professor P. Martin Duncan writes, “It
is doubtful if the _Fulgora_, so often described in books as the
lantern-fly, has a scarlet light, if any at all.”
The _Fulgora_ is not remarkable for its supposed light alone; as in
Brazil, where it is called _Gitiranaboia_, etc., it is considered
by some natives to be extremely deadly. Mr. John C. Branner, of the
Indiana University, investigated the subject, and found that the
natives believed that the long proboscis was the poisonous organ; and
that when this struck any animal, no matter how large or powerful,
the latter immediately dropped dead. Even a distinguished Brazilian
engineer assured Mr. Branner of the truth of the stories, saying that
monkeys were often seen to fall dead from trees along the Amazon,
killed by the deadly _Gitiranaboia_; and a local paper reported
the fact that these insects were destroying cattle in the southern
provinces. At Parà, Mr. Branner was assured that a child died in
great agony after being stung by one. It is needless to say that the
lantern-fly is perfectly harmless, and its poisonous properties as
mythical as modern science deems its light.
Concerning the Chinese and African species, there is the same conflict
of opinion. Dr. Phipson, an eminent authority on phosphorescence,
evidently accepts them as luminous; as, in referring to the proboscis,
he says, “It is from these appendages, the sides of which are
transparent, that the phosphoric light appears;” and in mentioning
_Fulgora candelaria_, he says, without giving his authority, “It is
said, also, that the trunk of a tree covered with numerous individuals
of _F. candelaria_, some in movement, others in repose, presents a very
grand spectacle, impossible to describe, but which may be witnessed
sometimes in China.” Dr. Donovan, in his “Insects of India,” figures
the _Fulgora pyrrhorynchus_; and Phipson states, “It is said to emit
a light of a fine purple color. Donovan evidently had some reason for
believing that they emitted light, as he represents them in the act.”
In “Packard’s Guide,” there occurs the following reference to the light
of an East-African _Fulgora_: “Mr. Caleb Cooke of Salem, who resided
several years in Zanzibar, Africa, told me that the lantern-fly is said
by the natives to be luminous. They state that the long snout lights
up in the night, and in describing it say, its head is like a lamp
(_keetchwa kand-tah_).” According to William Baird, Esq., there is an
edict in China against young ladies keeping lantern-flies. Altogether,
the question is quite in keeping with the mystery that surrounds the
entire subject of animal phosphorescence.
One of the classes into which the insects are divided is termed
_Myriopoda_, from the fact that the individuals which compose it are
supplied with a seemingly endless number of locomotive organs. The
centipedes and millepedes, “hundred” and “thousand legs,” are the
names by which they are most commonly known. The body is long and
cylindrical in the genus _Geophilus_, being made up of from thirty to
two hundred segments, each bearing a pair of short feet. In the Eastern
States _Lithobius Americanus_, Wood., is perhaps the most familiar
form, and often found under old logs.
Some of the centipedes are very poisonous. Such a one is _Scolopendra
heros_, Girard., the poison being stored in two enormous fangs. In
Southern California I have found extremely large specimens of this
genus. In the East Indies _Scolopendra gigantea_, Linn., attains
a length of nine inches, and is a most repulsive appearing creature,
and so dreaded that the most extravagant stories are told as to its
power. A native informed me, who evidently believed his statement, that
a man died near him from having one merely walk over him. The bite is
undoubtedly poisonous, as is that of many of our common spiders; but I
never could find an authentic case where it had resulted fatally.
As hideous as they are in certain parts of South America, a huge
species, which attains a length of a foot, is eaten; the native
children, according to Humboldt, tearing off the heads, and devouring
the remainder with evident enjoyment.
There are about eight hundred species of _Myriapods_, and among them is
one, the _Geophilus electricus_ of Europe, that is positively luminous;
though Phipson, referring to them as _Scolopendræ_, gives two luminous
species, _S. electrica_, Linn., of Europe, and _S. phosphorea_ of
Asia. Specimens of the former, observed in fields at night, have been
compared to minute pieces of red-hot coal, so vivid was the light.
Probably the finest spectacle of the luminosity of these insects was
observed by M. Audouin, at Choissy-le-Roi, near Paris. Noticing a
light upon the ground in a chiccory field, he ordered his man to
turn up the earth, when the scene that followed is described as truly
magnificent. The soil appeared as if it had been sprinkled with molten
gold, the display being intensified if the insects were trodden upon or
rubbed; in the latter case, streaks of light appeared, as if a bit of
phosphorus had been placed upon the hands, the light being distinctly
visible for twenty seconds.
The _Geophilus electricus_ (Plate XIII., Fig. 2) is a small,
inconspicuous insect, about an inch and a half in length, and one
tenth of an inch in diameter. Like others of its kind, it lives in
holes in the ground, and, when discovered, makes off rapidly by the
use of its one hundred and forty legs. The interesting fact that the
luminous secretion could be separated from the insect was originally
noticed by Macartney seventy years ago, who found that the fluid, as
he terms it, could be communicated by the centipede to every portion
of its integument. This author also claims that the insect is only
luminous after exposure to the sun,--a peculiarity that is found in
certain minerals described in a later chapter. The most remarkable
exhibition of the luminosity of these insects has been recorded by Mr.
B. E. Brodhurst, who saw it first twenty paces away, so vivid was its
display. The light looked like moonlight, so bright was it through
the trees. “It was a dark night, warm and sultry. Taking a letter, I
could read it. It resembled an electric light, and proceeded from two
centipedes and their trails. The light illuminated the entire body of
the animal, and seemed to increase its diameter three times. It flashed
along both sides of the creature in sections, there being about six
from head to tail between which the light played. The light behaved
precisely like the electric light; moving, as it were, perpetually in
two streams, one on each side, and yet lighting up the whole body. The
trail extended one and a half feet from each centipede over the grass
and gravel walk, and it had the appearance of illuminated mucus. On
securing one of the creatures for examination, I found, on touching it,
the light was instantly extinguished.” This observer says that this
phenomenon was frequently seen by others about his place.
Mr. Brodhurst continues, “Professor Flower identified the centipede
as _Geophilus subterraneus_. The published descriptions of the
luminous properties of British centipedes differ considerably from
what I observed in this instance; the latter attributing light to the
creatures only when disturbed. I was never able to induce my centipede
to shine while in captivity.”
CHAPTER X.
BY CRAB-LIGHT.
In drifting over the calm waters of the ocean as night comes on,
we notice in the depths below luminous forms of infinite variety.
These are _medusæ_, as we have seen, moving here and there like
veritable comets. They approach so near the unruffled surface, at
times, as to expose the gleaming disk. The nets of the fishermen come
up entangled in their golden trains, and along shore processions and
columns of these wondrous shapes pass and repass.
As the night grows apace, and the wind rises, they sink into the
deeper waters; yet the foam and crest of the waves still give out the
curious light, though now from another source. Much of this is due
to Crustaceans, minute creatures often almost invisible to the naked
eye, yet possessing this wonderful gift of phosphorescence to a marked
degree.
Some species of the little _Gammarus_ are remarkable for their
clear silvery light. They are familiarly known as water-fleas,
attracting attention from their leaping powers, and are often found
under seaweed above high-water mark, darting here and there in
incredible numbers when their home is disturbed. These forms are
extremely valuable as scavengers.
That these interesting animals were light-givers, has long been
known; Viviani observing it in a number of species in the beginning
of the present century.[39] There is one peculiarity about many of
these small animals; that is, the light has a more decided red tint
than that of any other group of animals. This is especially true of
many of the water-fleas, or _Entomostracans_, and the extremely
transparent, ten-footed kinds. The light is often intense, but fitful
and shortlived. It seems to start from the locality where the legs join
the body, and rapidly spreads beneath the skin until the entire body
appears to be suffused with light, and the little animal consumed with
an internal fire. Yet if a bushelful of these gleaming living lights
were confined, and a thermometer placed among them, it would not show
the slightest variation or evidence of heat. The little Cyclops is very
common in our freshwater ponds, and forms a beautiful object under the
microscope.
Along our sea-shores we may often see, under the rocks, clinging
to the eel-grass, or among the thickly growing stems of _Coralina
officinalis_, in some pool left by the tide, gleaming spots that move
about in an erratic manner; now many collecting together, then breaking
up into small patches of light, which in turn separate again. They are
curious Crustaceans, known scientifically as the _Idotea phosphorea_.
By day we shall find that they are usually spotted or entirely a bright
yellow; at night emitting fitful gleams, perhaps as signals or as means
of communication to their fellows.
In the Arctic regions beautiful lights have often been seen, due
to a minute crustacean. Lieut. Bellot first observed it in the
North-American polar regions, and Nordenskiöld refers to it in his
“Voyage of the Vega.” The most brilliant displays have been seen at
Mussel Bay. Nordenskiöld says, “If during winter one walks along the
beach on the snow, which at ebb is dry, but at flood-tide is more or
less drenched through with sea-water, there rises at every step an
exceedingly intense beautiful bluish-white flash of light, which in
the spectroscope gives a one colored labrador-blue spectrum. This
beautiful flash of light arises from the snow, that shows no luminosity
before it is stepped upon. The flash lasts only a few moments, but is
so intense that it appears as if a sea of fire would open at every
step a man takes. It produces, indeed, a peculiar impression on dark
and stormy winter days. The temperature of the air is sometimes in
the neighborhood of freezing of mercury. It is certainly a strange
experience to walk along in this mixture of snow and flame, which at
every step one takes splashes about in all directions, shining with a
light so intense that one is ready to fear that his shoes or clothes
will take fire. If carefully examined, the cause of this phenomenon is
found to be a little crustacean, _Metridea armata_, that somewhat
resembles the Cyclops. The great changes of temperature to which it is
subjected in the snow-sludge seem not to affect it.”
Few phosphorescent animals exhibit their glories during the day; but
_Sapphirina_ (Plate X., Fig. 6) is an exception. It is one of the
largest of the _Entomostracans_, about a quarter of an inch in length,
broad and flat, without the beauty of form which characterizes Cyclops,
Calanus, and others; but what it lacks in this respect is more than
compensated by its marvellous powers of light production, few animals
of any kind equalling it. So vivid is the phosphorescence, that it can
be distinctly seen by day; and, peering down into the depths where it
abounds, flashes of color--blue, gold, sapphire, purple, green, and
other hues--appear in bewildering frequency, ranging from the softest
to the most intense and vivid lights, marking this living sapphire as
one of the true gems of the sea.
[Illustration:
PLATE XIV.
SPIDER CRAB.
(_Colossendeis._)]
Giglioli mentions an Isopod crab, brilliant with gold and purple,
gorgeous with iridescence, and possessed also of the additional
charm of phosphorescence. The light-emitting organs in the
_Entomostracans_ observed by him were in the anterior portion of
the thorax.
The young (Zoëa) of the graceful little opossum shrimp _Mysis
stenolepis_ is phosphorescent. The adult forms are extremely
interesting objects for study, the eggs and young being carried in a
little pouch beneath the thorax. Allied to this little sea-opossum is
_Lucifer_, that is to the crustaceans what the walking-stick is to the
insect world; a veritable incongruity, resembling a branch of weed,
and doubtless finding some protection in the mimicry. Some specimens,
according to Giglioli, are luminous; the gift perhaps forming a signal
language, a code understood in this world under the sea. The position,
or seat, of the luminosity in crustaceans differs as widely as the
intensity and color of the light; and in the little _Stomatopod_,
formerly considered as an adult, and described as _Squillerichthus_, we
find the culmination of wonders, as, in a specimen of this genus found
in the Atlantic, the seat of the brilliant intermittent yellowish-green
light is in the eye-stalk; so that the eyes themselves may be said to
be veritable lanterns.
The phosphorescence of crabs was probably observed for the first
time by Sir Joseph Banks, on his voyage from Madeira to Rio Janeiro;
a small crab, named _Cancer fulgens_, being captured, which was
remarkably luminous. Sir Joseph does not state whether the light
came from the entire body or was confined to certain localities.
MM. Eydoux and Souleyet, naturalists of the French exploring ship
“La Bonite,” noticed a small luminous crustacean, and succeeded in
separating the phosphorescent secretion from the animal. They describe
it as yellowish, viscous, and soluble in water, and found that its
luminous properties soon disappeared. It was their opinion that certain
crustaceans secreted the luminous matter, and that they differed
much in their method of producing it. Certain small crabs, they
believed, could display a certain amount of light when irritated; the
phosphorescence at these times appearing in jets, forming a cloud or
halo of light in which the animal seems to disappear.
In the abyssal depths of the ocean, where probably no ray of sunlight
reaches, the crabs are possibly all luminous. Many of these deep-sea
forms have a wide geographical distribution. Thus the Lithodes
are found from the shallow waters of the north and south poles to
the tropics, in the latter living in a region over which rests
three-quarters of a mile of water. Many other crustaceans live in
depths vastly more inaccessible than this, and under a much greater
pressure. Thus _Colossendeis titan_, a strange creature, whose
stomach is prolonged to the ends of the feet, is found living at a
depth of about two miles and a half. These creatures, a species of
which is shown in Plate XIV., are the spiders of the sea, resembling
their not distant allies of the land, at least in appearance.
The different depths affect the inhabitants to a more or less extent.
In some, the eyes seem to have lost their proper functions; and an
instance is thus described by the Rev. A. M. Norman, naturalist of
the “Porcupine,” the crustacean being _Ethusa granulata_: “The
examples at one hundred and ten to three hundred and seventy fathoms
in the more southern habitat have the carapace furnished in front with
a spinose rostrum of considerable length. The animal is apparently
blind, but has two remarkable spiny eye-stalks, with a smooth rounded
termination where the eye itself is ordinarily situated. In the
specimens, however, from the north, which live in five hundred and
forty-two and seven hundred and five fathoms, the eye-stalks are
no longer movable. They have become firmly fixed in their sockets,
and their character is quite changed. They are of much larger size,
approach nearer to each other at their base; and, instead of being
rounded at their apices, they terminate in a strong rostrate point.
No longer used as eyes, they now assume the functions of a rostrum;
while the true rostrum, so conspicuous in the southern specimens, has,
marvellous to state, become absorbed. Had there been only a single
example of this form procured, we should at once have concluded that we
had found a monstrosity; but there is no room for such an hypothesis
by which to escape from this most strange instance of modification
of structure under altered conditions of life. Three specimens were
procured, on two different occasions, and they are in all respects
similar.”
Specimens of these crabs found in _shallow_ water had perfect eyes;
but, beyond one hundred and ten fathoms, they had changed as above
stated. As Darwin has said, the stand for the telescope is there,
though the telescope with its glasses has been lost.
Probably many of the deep-sea forms are luminous in some way.[40]
_Aristeus_ and allied forms are known to have phosphorescent eyes.
Others have phosphorescent organs in various parts of the body. In one,
the legs bear luminous bands that sparkle and gleam as the animal moves
along in its dismal home. In others there are certain globular luminous
organs beneath the thorax, and between the abdominal swimmerets that
have been described as eyes. The light emitted by the several organs is
of different degrees of brilliancy.
Vaughn Thompson is opposed to the theory that the objects on the side
of the trunk, and along the ventral face of the tail, of these little
creatures are eyes. “A re-examination,” he says, “proves that they are
not visual organs at all, but constitute rather a highly complicated
luminous apparatus together; the lenticular body of the organs acting
as a condenser, which, in connection with the great mobility of the
globules, enables the animal to produce at will a very bright flash of
light in a given direction. The great majority of species possess these
organs, generally arranged in a perfectly similar manner; but in a
large, deep-sea, non-pellucid _Euphausia_, V. Willemoes Suhm could
not detect these globules in their usual place.
[Illustration:
PLATE XV.
LUMINOUS CRUSTACEANS.
_Nematocarcinus gracilipes._
_Cyclops_ (magnified).]
“The phosphorescent light emitted by the species of the _Euphausiidæ_
was frequently under observation. One taken by forceps exhibited a pair
of bright, phosphorescent spots directly behind the eyes; two other
pairs were on the trunk, and four other spots were situated along the
median line of the tail,--all quite visible to the naked eye. The light
of these is a bluish white. After a brilliant flash has been emitted
from the organs, they glow for some time with a dull light. The light
is given out at will by the animal, and usually, but not always, when
irritated. The most brilliant flashes occur when freshly taken from
the sea. Under the microscope these phosphorescent organs appear as
pale-red spots, with a central, clear, lenticular body. The light comes
from the red pigment surrounding the lenticular space.” Mr. Murray
observed at night, on the surface of the sea in the Faeroe Channel,
large patches and long streaks of apparently milky-white water. The
tow-nets caught in these immense numbers of _Nyctiphanes novejica_, and
the peculiar appearance of the water seemed to be due to the diffused
light emitted from the phosphorescent organs of this species.
Many of the deep-sea shrimps are remarkable for their brilliant
coloring. _Aristes_ is a bright red, with _antennæ_ five or six
times as long as its body. Equally strange is the long-legged
_Nematocarcinus_ (Plate XV., Fig. 1), and the _Oplophori_ and
_Notostomi_, curious little creatures, that have no common names, are
of an intense red hue, while others are brown, rose, or spotted with
red; showing that Nature decorates her own even in the uttermost depths
of the sea.
CHAPTER XI.
SEAS OF FLAME.
In the summer months in tropical and semi-tropical waters, often
during several days in succession, the ocean presents a surface almost
unruffled. The fin of some roving shark, the splash of the flying-fish,
or, if near shore, the plunge of the pelican or gull, are the only
objects that disturb the sea of glass. At such times, after the sun had
gone down, we have lain in our boat, with faces as near the surface as
possible, and watched the wondrous panorama of the submarine world.
Here great globes of light seemed to shoot through the watery space:
every fish left a train of light; while the dolphin, or other great
forms, gliding by, appeared converted into fiery monsters; and, as they
rose to the surface, fountains of phosphorescence burst from the sea.
The forms which tend to produce this remarkable appearance in the
ocean depths are many; but, in the warm waters of the tropics, the
most noticeable are those belonging to the class known scientifically
as _Tunicata_. Aside from their luminous properties, the Tunicates are
extremely interesting, from the fact that they are now supposed to
represent, with perhaps one exception, the lowest form of backboned
life,--being what are called degenerate forms. In the larval stage of
some species a noto-cord is present, which is supposed to represent
the backbone of higher vertebrates. In some, when the animals assume
the adult form, the little spinal cord is absorbed; but in others, as
the _Appendicularia_ (Plate XVI., Fig. 3), the noto-cord and neural
cord persist throughout the entire life of the animal. The life-history
of these forms is of extreme interest; but, as it can be found in any
text-book, we will pass to the feature that has rendered some of the
class most conspicuous.
In exploring the depths of southern seas, among others we shall see a
columnar form, the _Pyrosoma_, or “fire-body” (Plate XVII.), the
giant of the Tunicates. It is an aggregation of individuals, forming a
hollow cylinder closed at one end, and from two inches to four feet in
length.[41]
The _Pyrosomæ_ are richly tinted during the day; but at night, as
their name implies, they resemble incandescent bodies. Humboldt refers
to the spectacle he enjoyed when passing through a zone of them in the
Gulf Stream, distinguishing by their light the forms of fishes, that,
bathed by their gleams, stood out in bold relief far below the surface.
The light is extremely beautiful. That of the Atlantic forms is
said to be polychroic, or an intense green; while in the very large
species it is azure. So brilliant and striking is the light, that the
impression is gained that it proceeds from the entire surface of the
animal; but this is not the case, according to Panceri.[42] When the
_Pyrosoma_ is moving along in its curious fashion,--which calls
to mind the old stern-wheel steamers,--and is undisturbed, the light
is intermittent, now flashing from one cell, and now from another; the
vast number of gleams giving it the appearance at times of constant
light over the entire surface.
Panceri found that the luminous bodies produced an albuminoid
substance that may become diffused by handling, and retain its
luminosity for some time. Curiously enough, fresh water increases
the intensity of the light, and causes it to continue for a longer
period. The intensity of the light may be realized, when we learn from
Figuier that Bibra, a Brazilian navigator, employed six _Pyrosomæ_
to illuminate his cabin, which was thus rendered so bright that he
could read to a friend the description he had written of these living
lanterns.
Mr. Bennett, the naturalist, thus describes his experience with these
beautiful creatures: “On the 8th of June, being then in latitude 30°
south, and 27° 5′ west longitude, having fine weather and a fresh
south-easterly trade-wind, and the thermometer ranging from 78° to
84°, late at night the mate of the watch called me to witness a very
unusual appearance in the water. This was a broad and expansive sheet
of phosphorescence, extending from east to west as far as the eye could
reach. I immediately cast the towing-net over the stern of the ship,
which soon cleaved through the brilliant mass, the disturbance causing
strong flashes of light to be emitted; and the shoal, judging from the
time the vessel took in passing through the mass, may have been a mile
in length. On taking in the towing-net, it was found half filled with
_Pyrosoma atlanticum_, which shone with a beautiful pale-greenish
light. After the mass had been passed through by the ship, the light
was still seen astern, until it became invisible in the distance, and
the ocean became hidden in the darkness as before this took place.
“The second occasion of my meeting these creatures was in a high
latitude, and during the winter season; the weather dark and gloomy,
with light breezes from northnorth-east, in latitude 40° 30′ south,
and 138° 3′ east longitude, at the western entrance to Bass’s Straits,
and about eight o’clock P.M., when the ship’s wake was perceived to
be luminous, while scintillations of the same light were abundant all
around. To ascertain the cause, I threw the towing-net overboard, and
in twenty minutes succeeded in capturing several _Pyrosomæ_, which gave
out their usual pale-green light; and it was, no doubt, detached groups
of these animals which occasioned the light in question. The beautiful
light given out by these molluscans[A] soon ceased to be seen; but,
by moving them about, it could be reproduced for some length of time
after. The luminosity of the water gradually decreased during the
night, and toward morning was no longer seen.”
[A] When this account was written, the Tunicates were supposed to be
mollusks.--NOTE BY THE AUTHOR.
M. Peron, says Figuier, observed the beauties of the _Pyrosoma
atlanticum_ on his voyage to the Isle of France. The wind was
blowing with great violence, the night was dark, and the vessel was
making rapid way, when what appeared to be a vast sheet of phosphorus
presented itself, floating on the waves, and occupying a great space
ahead of the ship. The vessel having passed through this fiery mass, it
was discovered that the light was occasioned by animalcules swimming
about in the sea, at various depths, round the ship. Those which
were deepest in the water looked like red-hot balls, while those on
the surface resembled cylinders of red-hot iron. Some of the latter
were caught; they were found to vary in size from three to seven
inches. All the exterior of the creatures bristled with long, thick
tubercles, shining like so many diamonds; and these seemed to be the
principal seat of their luminosity. Inside, also, there appeared to
be a multitude of oblong, narrow glands, exhibiting a high degree of
phosphoric power. The color of these animals, when in repose, is an
opal yellow, mixed with green; but, on the slightest movement, the
animal exhibits a spontaneous contractile power, and assumes a luminous
brilliancy, passing through various shades of deep red, orange green,
and azure blue.
Professor Moseley captured a _Pyrosoma_ four feet long, ten inches in
diameter, with walls an inch in thickness. It was placed upon the deck
of the vessel, and, when the naturalist wrote his name upon the animal
with his finger, it came out in letters of fire: each letter seeming to
increase in size, until the entire name was lost in a blaze of light,
that radiated rapidly and soon suffused the entire animal; presenting a
marvellous spectacle, and showing, in a striking manner, how intimately
the animals are connected. In Plate XVII. a _Pyrosoma_ of the largest
size is shown in comparison with a native diver.
Sir Wyville Thompson observed the _Pyrosomæ_ off the Cape Verde
Islands, and refers to the “blaze of phosphorescence and train of
intense brightness that followed the ship;” and, while he did not
experiment with the animals in his cabin, as did Bibra, he says, “It
was an easy matter to read the smallest print, sitting at the after
port in my cabin; and the bows shed on either side rapidly widening
spaces of radiance, so vivid as to throw the sails and rigging into
distinct lights and shadows. The first night or two after leaving San
Iago, the phosphorescence seemed chiefly due to large _Pyrosomæ_, of
which we took many specimens in the tow-net, and which glowed in the
water with a white light like that from molten iron.”
Not the least wonderful feature of this animal is the variety of tints;
white, green, various shades of deep red, orange green, and azure blue
having been ascribed to it by different observers,--a fact that must
stamp it as the most wonderful of all light-givers, a veritable living
diamond.
One of the most remarkable exhibitions of phosphorescence was
observed in January, 1880, by Commander R. E. Harris of the steamship
“Shahjehan,”--a display so unusual that I quote Capt. Harris’s letter
in full; and, while he is inclined to consider the exhibition as
possibly electric, it would seem that the luminous objects referred to
were phosphorescent animals of some kind, and possibly may have had
some connection with the phenomenon.
“The most remarkable phenomenon,” says Capt. Harris, “that I
have ever seen at sea was seen by myself and officers on the
5th instant, between Oyster Reef and Pigeon Islands (Malabar
coast). At ten P.M. we were steaming along very comfortably.
There was a perfect calm, the water was without a ripple upon
it, the sky was cloudless, and, there being no moon, the stars
shone brightly. The atmosphere was beautifully clear, and the
night was one of great quietude. At the above-named hour I went
on deck, and at once observed a streak of white matter on the
horizon bearing south-south-west. I then went on the bridge, and
drew the third officer’s attention to it. In a few minutes it
had assumed the shape of a segment of a circle, measuring about
forty-five degrees in length, and several degrees in altitude
about its centre. At this time it shone with a peculiar but
beautiful milky whiteness, and resembled (only in a huge mass,
and greater luminous intensity) the _nebulæ_ sometimes seen in
the heavens. We were steaming to the southward; and, as the bank
of light extended, one of its arms crossed our path. The whole
thing appeared so foreign to any thing I had ever seen, and
so wonderful, that I stopped the ship just on its outskirts,
so that I might try to form a true and just conception of what
it really was. By this time all the officers and engineers had
assembled on deck to witness the scene, and were all equally
astonished and interested. Some little time before the first
body of light reached the ship, I was enabled, with my night
glasses, to resolve in a measure what appeared to the unassisted
eye a huge mass of nebulous matter. I distinctly saw spaces
between what again appeared to be waves of light of great
lustre. These came rolling on with ever-increasing rapidity
till they reached the ship; and in a short time the ship was
completely surrounded with one great body of undulating light,
which soon extended to the horizon on all sides. On looking
into the water, it was seen to be studded with patches of
faint, luminous, inanimate matter, measuring about two feet in
diameter. Although these emitted a certain amount of light, it
was most insignificant when compared with the great waves of
light that were floating on the surface of the water, and which
were at this time converging upon the ship. The waves stood
many degrees above the water, like a highly luminous mist, and
obscured by their intensity the distant horizon; and, as wave
succeeded wave in rapid succession, one of the most grand and
brilliant, yet solemn, spectacles that one could ever think of
was here witnessed. In speaking of waves of light, I do not
wish to convey the idea that they were mere ripplings, which
are sometimes caused by fish passing through a phosphorescent
sea; but waves of great length and breadth, or, in other words,
great bodies of light. If the sea could be converted into a huge
mirror, and thousands of powerful electric lights were made to
throw their rays across it, it would convey no adequate idea of
this strange yet grand phenomenon.
“As the waves of light converged upon the ship from all sides,
they appeared higher than her hull, and looked as if they were
about to envelop her; and, as they impinged upon her, her sides
seemed to collapse and expand.
“Whilst this was going on, the ship was perfectly at rest, and
the water was like a millpond.
“After about half an hour had elapsed, the brilliancy of the
light somewhat abated, and there was a great paucity of the
faint, lustrous patches which I have before referred to; but
still the body of light was great, and, if emanating from these
patches, was out of all proportion to their number.
“This light I do not think could have been produced without the
agency of electro-magnetic currents exercising their exciting
influence upon some organic animal or vegetable substance.
And one thing I wish to point out is, that, whilst the ship
was stopped and the light yet some distance away, nothing was
discernible in the water; but, so soon as the light reached the
ship, a number of luminous patches presented themselves: and, as
these were equally as motionless as the ship at the time, it is
only natural to assume that they existed, and were actually in
our vicinity, before the light reached us, only they were not
made visible till they became the transmitting media for the
electro-magnetic currents. This hypothesis is borne out by the
fact that each wave of light in its passage was distinctly seen
to pass over them in succession; and, as the light gradually
became less brilliant, they also became less distinct, and had
actually disappeared so soon as the waves of light ceased to
exist.”
A little Ascidian called the _Salpa_ is quite famous for its
luminous properties. Like the previously mentioned form, it is a free
swimmer, two kinds of individuals being recognized. One is known as
solitary; while the others are termed chain zoöids, being many joined
together, forming long chains, the links represented by the individual
animals.
The _Salpa spinosa_, a familiar form upon our coasts, is quite
cylindrical, often a little flattened above and below, and seemingly
moulded in glass, so beautiful is its structure upon examination.
As small and common as they are, they have created much discussion.
Some observers deem their development one of the most remarkable
instances of the alternation of generations. Chamisso, the German
poet-naturalist, explains the relationship as follows: “A _Salpa_
mother is not like its daughter or its own mother, but resembles its
sister, its granddaughter, and its grandmother.” Dr. W. K. Brooks has
given much attention to these forms in this country; and, from his
point of view, the alternation of generations would be impossible.
The _Salpæ_ give little signs of animation. “The only conspicuous
vital action,” says Professor Owen, “is the rhythmical contraction
and expansion of the mantle, in which the elasticity of the outer
tunic antagonizes the contraction of the inner one. During expansion,
the sea-water enters by the posterior aperture, and is expelled, in
contraction, by the anterior one; its exit by the opposite end being
prevented by a valve. The re-action of the jet, which is commonly
forced out of a contracted tube, occasions a retrograde movement of
the animal.” As they move along, on dark nights, they present the
appearance of fiery serpents or luminous ribbons (Plate XVI., Fig. 1),
winding their way over the sea,--a most striking spectacle.
[Illustration:
PLATE XVI.
CHAIN OF SALPS
_Salpa spinosa._ _Appendicularia._]
The light of _Salpæ_ observed by Giglioli was confined to the so-called
nucleus, but was not constant; indeed, some were luminous and some
were not. This was particularly evident in the month of September,
when the exploring-ship “Magenta” passed through a bed of these
little creatures, fifteen miles in extent. Some observed in the
South Atlantic had the nucleus tinged with a brilliant red light.
Very similar to _Salpa_ is _Doliolum_, which seems to burn with a
vivid green light scattered over the entire body, and is one of the
emeralds of the sea. In the very lowest order (_Copelatæ_) of the
Tunicates, we find an interesting, indeed remarkable, light-giver, the
_Appendicularia_ (Plate XVI., Fig. 3). It resembles a tadpole with
quite a long tail, retaining in its adult life features that only
characterize the _larvæ_ of others of the group. Professor Agassiz
has noticed two specimens on the New-England coast, and they are very
common in both tropical and temperate waters of various regions.
Some of the species are veritable house-builders, forming a gelatinous
protection covering called a test. This habitation, if so we may
term it, is formed or secreted with considerable rapidity, and is
quite an elaborate affair; having two front chambers and a middle one
large enough for the tail to move with ease. Curious to relate, this
transparent residence is, according to Filhol, only used a few hours,
being then deserted and another formed; so that its life would seem to
be spent in making houses and deserting them.
The light of certain _Appendiculariæ_ is almost as remarkable
as that of the _Pyrosomæ_, in the variety of its coloring; one,
according to Giglioli, appearing first red, then blue, and finally
green. The seat of the luminosity, which appears in intense flashes,
was the central axis of the tail, or caudal appendage. Between
Montevideo and Batavia in the South Atlantic, this naturalist observed
many of these little creatures, nearly all of which showed these
tri-colored favors; and in the Indian Ocean some were seen emitting
white, blue, and green lights, marking them as among the most striking
of all the light-givers.
Charles William Peach, an English naturalist, has observed the tadpole
form of _Cynthia_ to emit light. _Cynthia pyriformis_ resembles a peach
in form, size, and even bloom; its tests having rich reddish tints.
It is a familiar form in deep water from Cape Cod to Greenland and
across to Scandinavia. It is one of the most common objects on our
New-England beaches after storms. The heavy seas throw it up from its
hiding-places. To the student or interested visitor it is a beautiful
object.
CHAPTER XII.
FINNY LIGHT-BEARERS.
If it were possible for human beings to penetrate to the abyssal
depths of the ocean, finny torch-bearers would be found from the very
surface to nearly four miles beneath it; existing in many cases under
conditions almost incomprehensible when the enormous attendant pressure
is considered. While it is extremely difficult to tell the exact depth
from which a fish is taken by the dredge, sufficient data has been
secured for naturalists to assume, though there is great difference
of opinion, that, to a greater or less degree, the forms of certain
depths have certain peculiarities. These are often seen in the organs
of vision, which have been modified in many ways by the lack of light.
Thus the eyes of forms that are found living five or six hundred feet
below the surface are often extremely large, as in _Beryx_ (Plate
XVIII., Fig. 1), as if to absorb the faintest beams of sunlight that
may penetrate this distance. As we descend to twelve hundred feet, the
eyes seem to grow larger; and beyond this, large and small eyed fishes
are found indiscriminately. The former evidently use these organs;
while those with small eyes are provided with remarkable organs of
touch,--long feelers which can be thrown forward, or moved to a more or
less extent, and used as the blind man uses his cane. An interesting,
indeed remarkable, example of this is seen in the fish _Bathypterus
longipes_, Günther found at a depth varying from one-half to
three-quarters of a mile from the surface in the Atlantic. The eyes are
extremely small, apparently useless; but the blind man’s cane is here,
as the pectoral fins are modified to serve as feelers, two rays almost
as long as the entire fish extending from the back of the head. As the
fish swims freely, the fins are trailed behind; but, does it approach a
prospective victim, the articulation of these wonderful feelers enables
them to be thrown forward as a cane in advance of the fish. They are
divided at the tip, and form a delicate sense-organ with which to
explore the depths of this abyssal world. Upon the ventral fins, there
are two similar rays, that serve a like purpose.
Many fishes having remarkable feelers have quite recently been
discovered, and among them _Eustomias obscurus_ (Plate XIX.), a fish
found at a depth of twenty-seven hundred meters, which has a long
tentacle dependent from the lower jaw.
When we penetrate beyond a certain depth, we find blind fishes as well
as those possessing eyes; and all the forms of the greater depths are
adapted to their life under the consequent enormous pressure in a
remarkable manner. The bones are friable and cavernous, and loosely
connected. Many are covered with a thick mucus, while many more have
curious plates, that are so many torches or lanterns to emit light for
their possessors. As some of the fishes have eyes and no phosphorescent
organs, while others are luminous and perhaps blind, and knowing that
all are carnivorous, we may well imagine that a fierce struggle for
existence is carried on in this distant world of the sea. The lamps of
some forms must attract their enemies; while, on the other hand, they
may constitute a lure, dazzling weaker forms, which fall victims to
their curiosity.
Among all the light-givers, these deep-sea lantern-bearers are the
most interesting, and typical of the mysterious realm from which they
are taken by the ingenious inventions of mankind. Some are luminous
over their entire surface, as the _Harpodon_, or Bombay duck (Plate
XVIII., Fig. 2). Others have a series of plates extending along the
side, that resemble the open ports of a steamer. Some possess gleaming
head-lights, the locomotives of the sea; while others have their lights
confined in groups.
While the expeditions of the “Challenger,” “Talisman,” “Albatross,”
and “Travailleur” have resulted in the discovery of what seems a
remarkable presentation of these light-givers, we can well imagine,
understanding the difficulties of deep-sea dredging, that the largest
and perhaps most interesting of these forms are yet undiscovered, and
that the greatest mysteries may never be revealed. The difficulties
that attend, and the chances against, the capture of deep-sea fishes,
can be perhaps realized by my young readers, if they imagine a large
balloon sailing along over the country at an elevation of from four to
five miles, dragging a dredge ten or twelve feet wide. Few active boys
or girls would be caught by such a device; only the sluggards that were
fast asleep would be trapped. The comparatively small dredge at the end
of a six-mile rope, dragging along and creating an unusual commotion
in the silent submarine world, secures only a few forms, the sluggards
and mud-lovers, as a rule: so that fishes taken at extreme depths
are prizes indeed. The “Talisman” took the fish _Bythites crassus_
from a depth of about two miles. The naturalists of the “Challenger”
expedition captured the _Bathyophis ferox_ about three miles from
the surface, or, to be exact, five thousand and nineteen meters. The
American exploring-vessel, the “Albatross,” under the direction of
Professor Spencer F. Baird, has exceeded any of these hauls; in 1883
making a capture of five species in twenty-nine hundred and forty-nine
fathoms.
While luminous fishes have been known for many years, the “Challenger”
expedition brought many new forms to light, and the work accomplished
by her officers may be said to have given a new impetus to the
study of deep-sea forms. Off the north-west coast of Australia, the
“Challenger’s” trawl captured the curious black fish _Echiostoma
microdon_. The luminous spots were few in number, but so arranged as
to be of the greatest service: thus two are found just below the eyes;
above the maxillary there is a narrow, elongated one, with a smaller
spot nearer the eye. _E. micripnus_, found in twenty-one hundred and
fifty fathoms, has long, fringed barbels, and small, round luminous
spots above the maxillary, resembling a rudimentary eye.
Referring to this interesting torch-bearer,[43] Dr. Günther says, “The
fishes of the family _Stomiatidæ_, to which this genus belongs, are
armed with formidable teeth,--a certain indication of their predaceous
habits and voracity. Their long body is covered with a smooth,
scaleless skin, of an intensely black color. The vertical fins are
close together, near the end of the tail, as in the pike, forming a
powerful propeller, by a single stroke of which the fishes are enabled
to dart with great rapidity to a considerable distance. A long filament
is suspended below the chin; and, as it is frequently fringed at
its extremity, it evidently serves as a lure for other fishes or
_animalculæ_. Series of luminous, globular bodies run along the lower
half of the body and tail; and some others of larger size occupy the
side of the head, generally below the eye or behind the maxillary bone.
This fish is sixteen inches in length. The end of the barbel, which
was thickened, was flesh-color with a rose tint; there was also a rose
tint on the dorsal and anal fins. The rest of the animal was of a dark
color. The phosphorescent spots along the belly and radial and lateral
line were red, as was also that below the eye.”
It is not often that the light of these fishes is seen; but the late
Professor Willemoes Suhm, while watching the great trawl come over the
side upon a calm night, noticed a gleaming spot, and taking it out
found it to be the little fish _Sternoptyx_. In referring to it
he says, “It hung in the net like a golden star, as it came out of the
darkness.”
As the _Sternoptyx_ is a delicate little creature, and quite
defenceless, its illumination must be a fatal gift. This is equally
true of the _Argyropelecus hemigymnus_ (Plate X., Fig. 3), a
curiously formed fish,--deep in the body, tapering off suddenly to the
tail, as if a piece had been bitten out by some large fish. Referring
to the figure, it will be seen that the luminous organs are grouped;
four being at the side of the tail, six midway between it and the line
of the dorsal fin, and many others around the edge of the ventral
surface,--one hundred and six in all: so that if all these plates are
luminous, the _Argyropelecus_ must present a dazzling sight as it
darts along in the blue waters of the Mediterranean, where it has been
most commonly observed.
Concerning the functions of these organs, there is still much
controversy. The opinions of Ussow, Leydig, and others will be found in
their papers referred to in the bibliography; and, as the question is
thoroughly a technical one, its further discussion is omitted. As early
as 1865 Professor Leuckart suggested that the curious plates (Plate X.,
Fig. 4) were organs of sight, or accessory eyes. In 1879 Dr. M. Ussow,
of the University of St. Petersburg, gave the world an account of his
researches upon the plates of the genera _Astronesthes_, _Stomias_
(Plate XX.), _Chauliodus_ (Plate XXI., Fig. 4), _Scopelus_ (Plate X.,
Fig. 1), _Maurolicus_, _Gonostoma_, and _Argyopelecus_, small fishes,
most of which were found in the Mediterranean. This was followed by
similar investigations by Dr. Leydig of Bonn, and Dr. Günther.
A well-known phosphorescent fish is seen in _Scopelus_, which bears
upon its sides and various parts of the body numbers of spots (Plate
X., Fig. 1), which, if all luminous, mark it as one of the most
brilliant of the light-givers. The appearance of these organs in
reflected light is shown in Plate X., Fig. 2.
The snake-like _Stomiasboa_ (Plate XX.), from a depth of twenty-seven
hundred feet, is perhaps the most hideous of the light-givers; its
large mouth and ferocious teeth giving it a bull-dog aspect, which
in a large fish would make a veritable dragon. But _Stomias_ is not
over twelve or fifteen inches in length, though quite large enough to
terrify the smaller fry. The specimen figured was taken in the Gulf of
Gascony by the naturalists of the “Talisman,” from its home, a mile and
a quarter beneath the surface. The sides of the body are provided with
a double row of luminous disks, which, according to M. Filhol, “cause
the fish to be surrounded by a brilliant luminous aureola.”
[Illustration:
PLATE XVIII.
CHIASMODUS. SUN-FISH. PLAGIODUS. HARPODON. BERYX.]
In Plate XVIII., Fig. 4, is shown a large light-giver,--the
_Plagiodus_, a fish six feet in length. According to Dr. Günther, it
emits light from various parts of its surface; the tips of the fins
gleaming with a soft phosphorescence similar to that of the large-eyed
_Beryx_ (Fig. 1) of same plate. The latter attains a length of about
twenty inches.
Quite as ferocious in appearance as the _Stomias_ is _Chauliodus_
(Plate XXI., Fig. 4), with long, lance-like teeth, gleaming fins, and
a row of small phosphorescent plates that perhaps sparkle like so many
gems as their bearer sails along in the greater depths.
Exaggerations are often termed “fish-stories,” for the reason perhaps
that improbable tales are related concerning the denizens of the sea
by fun-loving mariners; but the most remarkable stories that the vivid
imagination of those who go down to the sea in ships has ever devised
are not as remarkable as the simple truths regarding the every-day
history of fish-life. What can be more astonishing than the fact that
these delicate forms are enabled to live in water where the pressure
is so great that hard wood is crushed and glass reduced to powder?
If a decade or so ago a statement had appeared in the daily press,
to the effect that a fish had been discovered which could swallow
another five times its own bulk, it would in all probability have been
classed as a “fish-story,”--too big an one, indeed, to have even the
merit of comical exaggeration: yet such a fish does exist in the black
swallower, or _Chiasmodus_ (Plate XVIII., Fig. 5); the fish, besides
being luminous, possessing this extraordinary faculty. The jaws, by
a special arrangement, are capable of great extension; so that the
fish actually draws itself over its prey, that may be many times its
own bulk. The skin of the swallower seems to possess a rubber-like
character, stretching to enormous dimensions, and often, when filled
with gas, carrying the glutinous light-bearer into the upper regions of
the ocean.
_Malacosteus niger_, Ayres (Plate XXII.), is a rare fish, from a
depth of two-thirds of a mile; though several specimens have recently
been taken by the United-States Fish-Commission, and others by the
“Talisman” off Morocco, in forty-eight hundred feet of water. It is
of small size, from thirteen to fourteen centimeters in length, of
a velvet-black hue, and possesses two large luminous organs upon
the head; one of which, according to M. Filhol, who observed the
light in the living fish, emits a golden, and the other a greenish
phosphorescence. We have here, then, a fish that vies with the
_Appendicularia_, and other forms which we have seen emitting
light of more than one color. It is possible that the rays of light
from these spots project ahead of the fish, in the manner shown in
the accompanying figure, in which the appearance of the light is of
course conjectural; but as to the meaning of the different colors,
are they a system of signals cunningly devised by Nature to enable
_Malacosteus_ to distinguish its kind in the profound depths of
the ocean, or are they merely lures of more than ordinary brilliancy?
In some fishes the luminous organs are extremely small, almost
invisible to the naked eye, and often spread over a large extent of
surface. Such an instance is seen in _Eustomias obscurus_ (Plate XIX.)
and _Neostoma_. In the former, an attenuated carnivorous fish of a
jet-black color, we see another example of remarkable feelers, or
sense-organs.
While these forms are probably free swimmers, there are many others
that are mud-dwellers, of most extraordinary make-up, literally living
bags, or rather mouths. The _Melanocetus Johnstoni_ (Günther, Plate
XXIII.) is one of these; having an enormous pouch, with a fishing-rod
upon its head similar to that of our common _Lophius_. _Melanocetus_
probably buries itself in the ooze, as shown in the engraving, allowing
the tip of its tentacle, or rod, to protrude; and, when the living bait
is touched, it opens its cavernous mouth and seizes the victim.
Still more remarkable is the _Eurypharynx pelecanoides_, which
has a mouth of enormous dimensions (Plate XXIV.), from which depends a
pelican-like pouch. This form is interesting, from many peculiarities;
among which may be mentioned the fact, that the branchial arches
are here simple bars, five in number, having no connection with the
cranium. The mouth can open to a surprising extent, the lower jaw being
composed of two pieces attached to the cranium by a movable joint,
so that it swings literally in various directions. The fish probably
feeds by swimming along the bottom blindly, ingulfing various animals,
holding them by its interlocked teeth. This phenomenal fish was taken
in 1882 by Vaillant, the French scientist, twenty-five hundred metres
from the surface; while another genus of these deep-sea, eel-like
creatures was described in 1883 by Gill and Ryder, who called it
_Gastrostomus bairdii_. In the latter, the jaw is six or seven
times as long as the cranium.
One of the most striking phosphorescent fishes is a small shark,
_Squalus fulgens_, also described and figured by Kner as _Leius
ferox_, which, in general appearance, somewhat resembles the black or
brown nurse (or _Scymnus_) of our Southern coast. This interesting
light-giver was discovered by Dr. Bennett, and the following is his
version of the find: “Being dark when I first saw it shining in
the net, it resembled a _Pyrosoma_, emitting, as it did, a bright
phosphorescent light. This was in latitude 2° 15′ south, longitude 163°
west. The length of my specimen was five inches and a half. It is not
a little singular that my brother, the late D. F. Bennett, obtained a
specimen of this fish in the same latitude, and another in latitude 55°
north, longitude 110° west. The first was taken in the daytime, and
was ten inches in length,--much larger in size than my specimen. The
second was taken at night, and its entire length was a foot and a half:
both were alive when captured, and fought fiercely with their jaws,
tearing the net in several places. On placing my fish in sea-water, and
observing it in the dark cabin, it swam about for some time, emitting
a bright phosphoric light; and when this had become so faint as to be
almost imperceptible, it was readily rekindled on the animal being
disturbed or excited. My specimen was of a perfectly black color, and
died about four hours after it had been taken. The luminosity was
retained for some hours after life was extinct.
“The form of the shark, as indeed its whole structure, is peculiar. It
no doubt belongs to the subgenus _Scymnus_. My specimen having been
accidentally lost, I am unable to give a minute description of it. My
brother was more fortunate. I will, therefore, give his account of so
novel and interesting a fish. The body is cylindrical, rather slender,
and tapers finely towards the tail. Its prevailing color is dusky
brown; a broad black band, or collar, passes around the throat; and the
fins are partially margined with white (my specimen, being small and
young, varied in this respect, being black, with the fins of a less
intensity of color); the skin rough, as is usual in the shark tribe.
The number of gill-apertures is five on each side. The fins are short,
and for the most part disposed in a round form; the dorsals are two in
number, small, and placed far back; the tail-fin is unequally divided,
the upper being the longest and largest lobe. The head is flat; the
snout prominent, rather pointed, and has two nostrils at its extremity.
There is, also, on each side of the upper and back part of the head, a
large oval orifice, like a spiracle or nostril, provided with a valve,
and communicating with a corresponding aperture in the roof of the
mouth. The mouth is capacious; and the dark skin around it is incised
on each side to some extent beyond the commissure of the lips, exposing
a white elastic membrane beneath. The upper jaw is armed with many
rows of small, sharp teeth; while the lower has only a single row of
perpendicular teeth, or, rather, an elevated plate of bone, sharply
toothed on its summit, and bearing a close resemblance to a segment of
the surgical circular-saw called a trephine. The eyes are much more
prominent and dilated than is usual in sharks; the iris is black, the
pupil transparent and of a greenish color.
“When the larger specimen, taken at night, was removed into a dark
apartment, it afforded a very extraordinary spectacle. The entire
inferior surface of the body and head emitted a vivid and greenish
phosphorescent gleam, imparting to the creature, by its own light,
a truly ghastly and terrific appearance. The luminous effect was
constant, and not perceptibly increased by agitation or friction. I
thought at one time it shone brighter when the fish struggled, but I
was not satisfied that such was the fact. When the shark expired (which
was not until it had been out of the water more than three hours),
the luminous appearance faded entirely from the abdomen, and more
gradually from other parts; lingering the longest around the jaws and
on the fins.
“The only part of the under surface of the animal which was free
from luminosity was the black collar around the throat; and while
the inferior surface of the pectoral, anal, and caudal fins shone
with splendor, their superior surface (including the upper lobe of
the tail-fin) was in darkness; as also were the dorsal fins, back,
and summit of the head. I am inclined to believe that the luminous
power of this shark resides in a peculiar secretion from the skin.
It was my first impression that the fish had accidentally contracted
some phosphorescent matter from the sea, or from the net in which it
was captured; but the most rigid investigation did not confirm this
suspicion, while the uniformity with which the luminous gleam occupied
certain portions of the body and fins, its permanence during life, and
decline and cessation upon the approach and occurrence of death, did
not leave a doubt in my mind that it was a vital principle, essential
to the economy of the animal. The small size of the fins would appear
to denote that this fish is not active in swimming; and, since it is
highly predaceous, and evidently of nocturnal habits, we may, perhaps,
indulge in the hypothesis that the phosphorescent power it possesses is
of use to attract its prey, upon the same principle as the Polynesian
Islanders and others employ torches in night-fishing.”
[Illustration:
PLATE XIX.
LUMINOUS FISH.
(_Eustomias obscurus._)
From depth of 8,100 feet.]
CHAPTER XIII.
FINNY LIGHT-BEARERS--(SURFACE FORMS).
On calm nights the splash of the oars and the fall of spray from the
bow of the boat startle many fishes resting at or near the surface,
which dart away like comets, leaving a blaze of light behind, and
giving the impression that they are light-givers or phosphorescent.
This does not always follow; as, while many possessors of luminous
spots undoubtedly approach the surface at night, as _Scopelus_
(Plate X., Fig. 1), many owe their brilliant appearance to the
luminosity of the medium in which they swim; in other words, the
vigorous motion of their fins produces the same effect and result that
is attained by darting the hand through water bearing phosphorescent
animals. If such a display is produced by one fish, we may well imagine
that a school moving rapidly would create a light of considerable
intensity.
Drifting over a school of menhaden, and peering down among them, each
fish seems outlined in a golden halo; while coruscations of light
appear to flash from the fishes as they move along, the presence of the
school being indicated upon the water by a pale luminous spot.
In more active fishes, as the mackerel, the display is still more
brilliant, often presenting a blaze of light upon the surface, visible
from the masthead of a vessel for a long distance, and often resulting
in the capture of an entire school; as the mackerel-men, aware of the
light produced by the fish, keep a lookout in the foretop; and upon
its discovery, the great net is passed around it, the fishes becoming
victims to the light they inadvertently produce. When the mackerel
are tossed into the boat, they roll over in a golden mass in their
struggles, hurling a cloud of spray into the air over boat, net, and
men. In handling these fishes, phosphorescent matter will sometimes
come off upon the hands, and the gleaming fluid is seen running from
the bodies; so, possibly, in some instances, the fishes possess a
luminous secretion, as in the case of the shark of Dr. Bennett.
The sunfish (Plate XVIII., Fig. 3), an extremely common form on our
eastern shores, appears to have a wide geographical range. In American
waters, it is known as the sunfish, presumably from its oval shape.
Two fins only are present, these being opposite one another, the tail
represented by a mere ridge. The sunfish attains a height, from the tip
of one fin to that of the other, of seven feet, and sometimes more,
weighing several hundred pounds.[44]
Some years ago, while at the little fishing-village of Mayport, at
the mouth of the St. John’s River, Florida, one of these huge fishes
ran aground on the bar, actually drawing too much water to cross. Its
struggles attracted so much attention, that a boat was sent out, and
the monster captured. I sent a photograph of the fish north, and the
latter was afterwards purchased by the New-York Aquarium. It was the
largest specimen of this fish I ever saw on exhibition.
So sluggish are they, that, at Ogunquit, Me., the fishermen frequently
ran alongside of them as they rolled about at the surface, and,
thrusting a boat-hook into the small mouth, hauled them aboard; or,
if too heavy, lashed them to the side, in which position they were
towed ashore, where the liver, the only valuable portion, was secured;
though the muscular tissue was sometimes appropriated by the boys of
the neighborhood, who found it a good substitute for India-rubber as an
interior for base-balls.
* * * * *
In a large specimen which I examined, the skin was covered with a
remarkable mucilaginous envelope, in which were numerous parasites;
while in the mouth was a large goose-barnacle, which was situated just
far enough in to escape being crushed by the formidable teeth. If
asked to select a fish showing evidences of possible phosphorescence,
I should name the sunfish, as the curious envelope of mucus seems
particularly adapted as the seat of this remarkable phenomenon; but
I have not only never observed its luminosity, but have been unable
to obtain a direct statement from any one in this country as to its
light-emitting quality. I give it a place among the luminous fishes,
on the authority of T. Spencer Cobbold, M.D., F.L.S., who says, in
referring to it, “It is nearly circular in form; and the silvery
whiteness of the sides, together with their brilliant phosphorescence
during the night, has obtained for it, very generally, the appellation
of sun or moon fish.”
Karl Semper, in his “Animal Life,” says: “The fishermen of Nice assert
that the moonfish (_Orthagoriscus mola_) is luminous;” but as no
scientist, that I am aware of, makes a definite statement of personally
observing its light, we will leave the moon or sun fish among the forms
which are possibly phosphorescent, yet not proven so.
Statements are often made regarding the phosphorescence of whales
and other cetaceans; but the wondrous displays which they undoubtedly
produce as they rise, perhaps to escape the ferocious attacks of the
killer, are due only to the myriads of small light-givers,--_medusæ_,
_salpæ_, crustaceans, and others,--which when disturbed become luminous.
Among the well-known phosphorescent fishes, the _Scopelus_, found
in the greater depths, rises at times, at night, to the surface.
_Scopelus humboldtii_ (Plate X., Fig. 1), has a double row of
luminous spots on each side of the abdomen. One of the spots, enlarged
in reflected light, is shown in the same plate.
The phosphorescence of _Myctophum crenulare_, an ally of _Scopelus_,
has been observed; and, at least on the Pacific coast, this little fish
probably rises to the surface, a specimen an inch and a half in length
having been taken from the stomach of an albicore (_Orcynus alalonga_)
in the Santa Barbara Channel. In this specimen a phosphorescent spot
was seen on each mandible near the symphysis, thirty-three along the
abdomen, six in front of the ventral fins, six more between the latter
and the origin of the anal, and twenty-one between the front of the
anal fin and the base of the tail; quite enough, if all are luminous,
to outline the little creature in lines of vivid brightness.
The long, arrow-like gars are peculiarly surface forms, it being
evidently only with extreme difficulty that they leave the surface.
Allied to them is _Hemiramphus_, in which the lower jaw only is
elongated; and, according to Günther, this interesting fish has a
gleaming phosphorescent pustule at the tip of its tail, a circumstance
that makes it one, not only of the most unique of the surface forms,
but of all the finny light-bearers. Many other forms known to possess
luminous spots undoubtedly visit the surface at night, just as many
large predatory fishes then come well in shore. Indeed, the night is
the feeding-time of the southern fishes; at least, the season when they
are upon their travels.
At Tortugas, on the Florida reef, the shoal to the west of the key was
deserted during the day, except by schools of mullet, small barracuda,
and a few others; but at night the sandy shoal seemed fairly alive with
large fishes. Man-eaters, ten or fourteen feet long, ranged up and
down, readily taking the hook; and nearly all the large fishes, which
by day lived upon the outer reef or in the channel, could be taken
here; while loud splashes and vivid displays of phosphorescence told
that the large rays, indeed the great manta itself, ventured in shore
in nocturnal rambles.
CHAPTER XIV.
LUMINOUS BIRDS AND OTHER ANIMALS.
In floating over the great coral reef of the Florida peninsula one
day, the boat startled a number of large cranes which were standing
upon a small key; and, as they laboriously flew away, my companion, a
sportsman of experience, related to me the following incident: “Some
years ago,” he said, “I was much more confined than I am at present,
and rarely had an opportunity of enjoying hunting during the daytime;
so I began a series of moonlight excursions about the reef, generally
securing a green turtle, if nothing else, and occasionally a large bird.
“One evening I visited one of the large keys; and before I was ready
to return the moon had gone down, leaving me in the dark. It was a
perfectly calm night, not a ripple appearing upon the water, so that
every sound was heard with striking distinctness; and the break of
the sea upon the outer reef came to me in a sullen roar, occasionally
varied by the crash of some huge fish as it left the water. I was
making my way to my boat, when suddenly I perceived on the sands
several dim lights. Thinking it the reflection of the stars upon the
water, perhaps, I pushed on; and when I was almost upon them, there
came a flapping of wings, while above I saw indistinctly the forms of
several large cranes, that made their escape before I thought of
shooting. The light disappeared with them; and my opinion is, that what
I saw was phosphorescent light upon the breast of the birds.”
[Illustration:
PLATE XXVI.
LUMINOSITY OF HERON’S BREAST.]
I have been told by several sportsmen that they have heard of such
an occurrence; and I have always been impressed with the belief that
the greasy, oily, powder-down patches might become luminous under
certain conditions, but never until the present year have been able to
find reliable personal testimony. The following statement, prepared
for me by Mr. Isaac W. Worrall of Philadelphia, shows that the
phosphorescence of birds is a fact. To obtain a full account of Mr.
Worrall’s observations, I made out a list of questions, which he has
kindly answered; and which, from the great interest connected with the
occurrence, are given in full:--
“Upon what birds did you observe the luminosity?”
“The night heron (_Nyctiardea grisea_) and blue crane (_Ardea
cærulea_).”
“What was the situation of the light or lights?”
“One on the breast, and one on each side of the hips, between the hips
and the tail.”
“Upon how many birds did you observe the light?”
“Upon four different birds, including the one I shot.”
“How far could you see the lights in the living bird?”
“I saw the light plainly at a distance of about fifty yards.”
“Did you notice the reflection of the light upon the water?”
“No.”
“Was the light brilliant enough to make a reflection?”
“Before I fired, the light appeared equivalent to two candles.”
“Where was the bird you shot when first observed?”
“Standing in about six inches of water.”
“Give a practical example of its brilliancy.”
“When I aimed, I considered it equal to the light of a hand-lamp or
lantern, and could see my gun-sight quite plainly against it.”
“Could you have read by the light as it appeared when you took the bird
from the water?”
“I have read small print with a dimmer light than that upon the bird
immediately after it was shot.”
“Do you think the bird can conceal or display its light at will?”
“I know the bird has full control of the light. I saw it open and shut
it four times when I was crawling towards it. I stopped when it put out
the light, and advanced when it was displayed again.” (The bird may
have turned.--AUTHOR.)
“What was the state of the weather when you shot the bird?”
“A clear, dark night in spring.” (Kansas.)
“Did you notice the sex of the bird?”
“No.”
“How long did the light last after you shot the bird?”
“The light faded as the bird died, disappearing at death.”
“Did you notice any odor while the light was apparent?”
“No.”
“Did the luminous matter come off upon your hands?”
“I did not touch it.”
“Was the light a steady glow?”
“It lasted about as long as I could count twenty at moderate speed.”
“What was the color of the light?”
“It reminded me of phosphorescent wood, and was whitish.”
* * * * *
When my informant first observed the light, he was a hundred and fifty
feet away, and while slowly creeping toward it saw it disappear four
times, the intervals between the disappearance and re-appearance being
long enough for him to count twenty at a moderate rate; from which
he assumed that the bird has the light more or less under control,
and governs it by raising or depressing the feathers that cover the
powder-down patches. When he fired at the bird, the light on the breast
was so intense that he distinctly saw the sight of his gun against it,
and he describes its brilliancy as comparable to that of a lantern
or hand-lamp. He did not notice a reflection upon the water, as he
was some distance away, and in a recumbent position, which rendered
it impossible. The bird fell where it was standing, in six inches of
water; and taking it by the wings, he threw it upon the shore, noticing
and watching the three phosphorescent spots, one in front, and one on
each side of the hips, between the hips and the tail. The bird died
slowly, _the light gradually dying out, and disappearing entirely
with death_; a fact which I consider to be of the greatest interest,
showing that the phosphorescence is not an accidental occurrence,
depending upon a favorable condition of the greasy powder-down patches,
or associated entirely with their decomposition, but is essentially
due to some physiological action, and dependent upon the life of the
bird; and the areas of the powder-down patches may be considered true
photogenic structures. The bird shot and examined by Mr. Worrall was
known to him as the blue crane, and I assume from his description that
it is the _Ardea cærulea_. The other birds in which the light was
observed were night herons. The light was in the so-called powder-down
patches, which form a characteristic feature of the herons, and
doubtless serve the same purpose, as a lure, in all.
In a night heron, which I recently obtained from a valley among the
foothills of the Sierra Madre range, there were three of those patches,
and any heron will show them. One is directly in front upon the breast,
while the other two are upon each side, midway between the base of the
tail and the upper portion of the thigh-bone. They are not visible
unless the feathers which cover these portions are brushed aside, when
a mass of oily small plumes are seen, of a decided yellow hue, growing
closely together, and about two inches in length. A yellow powder will
be found profusely mixed among them, and is due to their barbed tips
breaking off as fast as they develop.
In my specimen, just after death the patches were quite oily, the
substance coming off upon the hands, and smelling like ordinary bird
oil. As soon as possible I took the bird into a perfectly dark room,
to test it for phosphorescent light, but not the slightest gleam was
perceptible. Just under the patches a large accumulation of fat is
seen; and from these portions probably exudes the substance, which,
during the life of the bird, becomes luminous upon exposure to the air.
In the specimen alluded to, after it had been dead for several days,
the shafts of the feathers of the patch seemed suffused with a dark
oily substance. The feathers of the powder-down patches did not burn
more readily than feathers from other parts, and the odor was the same.
These patches are not strictly confined to cranes and herons. The
kirumbo (or _Leptosmus discolor_) of Madagascar has a highly developed
patch upon each side of the rump. These birds are related to the
rollers, and are remarkable for their games in mid-air. The bitterns
have two pairs of powder-down patches, the true herons three, and the
curious boatbills (_Cochlearius_) four pairs, which, if all luminous,
must render them the centre of attraction in the South-American swamps.
The interesting oil-bird _Podargus_ (or Guarcharo), that builds in the
island of Trinidad and on various parts of the South-American coast,
is a fruit-eating, nocturnal bird allied to the night-hawks. Curiously
enough, it has no oil-glands, but two large powder-down patches, one
on each side of the rump, composed, according to Dr. Sclater, who made
the discovery, of about forty feathers each. In Plate XXVII., an ideal
view is given of the possible appearance of the light of a large heron
(_Ardeomega goliath_) of Africa.
Whether these lights are of sufficient brightness to attract fishes is
a question; but, knowing that fishes are readily attracted by light of
fire, we may well imagine that a crane or heron, if standing in the
water in perfect stillness, with this soft light a short distance above
it, might possibly avail itself of such a lure, though such a view is
purely conjectural. Mr. Charles Harris of Pasadena, Cal., informed me
that several years ago he entered a heronry in Maine on a dark night,
and distinctly observed numbers of lights too large for insects; and,
moreover, they disappeared with the birds, so that he was impressed
that there was some association between the light and the herons.
That birds should be luminous is not, perhaps, strange. Other
vertebrates appear to possess this gift in an equally remarkable
manner. Some years ago an English gentleman, a lover of sport, was
travelling in South America; and among the tales that he heard from
the natives was one that related to a monkey with fiery eyes, as they
expressed it. It seemed that one season, when the tribe was far up the
branch of a small river, a woman wandered off into the forest at night,
and returned much alarmed, stating to the rest that an animal had
appeared to her with eyes gleaming like coals. Several of the natives
went to the spot designated, and were repaid with a glimpse of the
strange creature.
Such a tale was, of course, not received in good faith, being
considered an example of the inventive fancy of these children of the
forest; yet, curiously enough, Reninger the naturalist, who travelled
extensively in Paraguay, states that he has seen the eyes of the
monkey, _Nyctipithecus trivirgatus_, so brilliant in complete darkness
that they illuminated objects at a distance of half a foot. In several
instances I have referred to the phosphorescence of animals being used
possibly as a warning; at least, this is the explanation given the
phenomena by some observers, and one of the most interesting cases that
may possibly come under this head is the luminosity of frogs’ eggs.
This has been noticed in various parts of Europe; masses of luminous
matter being found about ponds and damp places, and termed _mucilage
atmosphérique_, as it was believed by the simple peasants to be part of
the tail of comets.
[Illustration:
PLATE XX.
LUMINOUS FISH. (_Stomias boa._)]
On one occasion several peasants were travelling from one village to
another at night, when suddenly a large meteor shot across the heavens,
seeming to fall before them. A few miles farther on, in crossing a
small swamp, they found several patches of a jelly-like matter, which
gleamed as if at a white heat, which so alarmed them, that they ran
into the next village, crying that a comet had fallen, and was burning
up the earth. So much excitement was created that some scientific men
visited the spot, finding the comet to be merely the mucus that had
surrounded the eggs of a frog, and had become luminous. If the mucus
was luminous when it surrounded the eggs, we may well imagine that
birds would be deterred from eating them; but the luminosity probably
precedes decomposition in the mass after the young have escaped.
Among the lizards, a gecko has been mentioned as a light-giver, as
if these curious creatures were not remarkable enough in themselves
without this attendant phenomenon. According to Dr. Carpenter, the
eggs of the gray lizard have been seen to emit light; and in Surinam
he states that a frog or toad is luminous, especially in the interior
of its mouth. Thus we see that this strange light is found in some
form from the lowest to the highest animals,--one of the commonest of
phenomena, yet presenting a problem defying solution.
CHAPTER XV.
MAN’S RELATIONS TO THE PHENOMENON OF PHOSPHORESCENCE.
Dr. Phipson, the eminent scientist, states that he once observed
certain phenomena in man, the light being a brilliant scintillation of
a metallic pink color.
It is well known that human beings under certain physical conditions
become luminous. In some cases among the ignorant great excitement has
been occasioned, and the victim avoided as a pest, or something capable
of dire disaster to the entire community.
In a small German village, an English physician discovered a man
who was luminous at night, and who had caused much alarm among the
superstitious.
Bartholin records an instance of an Italian lady whom he calls
_Mulier splendens_, who suddenly found that, when rubbed with a
linen cloth in the dark, her body gave out a brilliant phosphorescent
light; so that she appeared in a darkened room like a veritable
fire-body, an awe-striking object to her superstitious servant, who
fled from her speechless with fear and amazement, thinking that her
mistress was being consumed.
Dr. Kane records a very curious instance of luminosity, probably
electric, which played about his person. He was on his way with
Petersen to an Esquimau settlement, in order to procure food. Their
thermometer indicated -42° C. (-44° Fahr.). With their weary dogs
and sledges, they had reached some untenanted huts at a place called
Anoatok, after thirty miles march from the ship. “We took to the best
hut,” says Dr. Kane, “filled in its broken front with snow, housed our
dogs, and crawled in among them. It was too cold to sleep. Next morning
we broke down our door, and tried the dogs again. They could hardly
stand. A gale now set in from the south-west, obscuring the moon, and
blowing very hard. We were forced back into the hut; but after corking
up all the openings with snow, and making a fire with our Esquimau
lamp, we got up the temperature to 30° below zero, Fahr., cooked
coffee, and fed the dogs freely. This done, Petersen and myself, our
clothing frozen stiff, fell asleep through pure exhaustion; the wind
outside blowing death to all that might be exposed to its influence.
I do not know how long we slept, but my admirable clothing kept me
up. I was cold, but far from dangerously so, and was in a fair way of
sleeping out a refreshing night, when Petersen woke me with, ‘Captain
Kane, the lamp’s out.’ I heard him with a thrill of horror.... Our only
hope was in relighting our lamp. Petersen, acting by my directions,
made several attempts to obtain fire from a pocket-pistol; but his
only tinder was moss, and our heavily stone-roofed hut or cave would
not bear the concussion of a rammed wad. By good luck I found a bit
of tolerably dry paper, and becoming apprehensive that Petersen
would waste our few percussion-caps with his ineffectual snapping, I
determined to take the pistol myself. It was so intensely dark that I
had to grope for it, and in so doing touched his hand. _At that instant
the pistol became distinctly visible. A pale-bluish light slightly
tremulous, but not broken, covered the metallic parts of it_,--the
barrel, lock and trigger. The stock, too, was clearly discernible, as
if by the reflected light; and _to the amazement of both of us_, _the
thumb and two fingers with which Petersen was holding it_, the creases,
wrinkles, and circuit of the nails, clearly defined upon the skin. _The
phosphorescence was not unlike the ineffectual fire of the glow-worm.
As I took the pistol, my hand became illuminated also, and so did the
powder-rubbed paper when I raised it against the muzzle._ The paper did
not ignite at the first trial; _but the light from it continuing_, I
was able to charge the pistol without difficulty, rolled up my paper
into a cone, filled it with moss sprinkled over with powder, and held
it in my hand whilst I fired. This time I succeeded in producing flame,
and we saw no more of the phosphorescence.... Our fur clothing and the
state of the atmosphere may refer it plausibly enough to our electrical
condition.”
Mr. James Moir of Saroch, Scotland, relates an equally strange personal
experience, possibly connected with the electrical condition of the
atmosphere. “In February, 1882,” he says, “this part of Scotland was
visited by a furious gale of wind, rain, sleet, and hail. The gale
subsided considerably about five o’clock in the afternoon. At eight
o’clock the sky was fairly clear, when a black cloud sprang up in the
north, and the night became suddenly intensely dark. With the darkness
came a tremendous shower of hail. All at once I was startled by a vivid
flash of lightning close at hand, but without thunder. At the same
instant I found myself enveloped in a sheet of pale, flickering, white
light. It seemed to proceed from every part of my clothes, especially
on the side least exposed to the hail; and more particularly and
brightly from my arm, shoulder, and head. Though I turned about pretty
smartly, and shifted my position, I found it impossible to shake off
the flickering flames. When I walked on they continued with me for two
or three minutes, disappearing only when the violence of the blast was
somewhat diminished. I felt no unusual sensation beyond the stinging of
the hail, and no sound except that of the storm.”
The adventures of John Stewart, who for many years drove a mail-gig
between Dunkeld and Aberfeldy, Scotland, as given by an English paper,
are well worth recording. On an extremely dark night, he and another
man, climbing a rocky, heathery height in Rannock, were all at once
set on flames by some mysterious fire, which appeared to proceed from
the heather which they were traversing; and the more they tried to rub
the flames off, the more tenaciously they seemed to adhere, and the
more the fire increased in brightness and magnitude. Moreover, the long
heather, agitated by their feet, emitted streams of burning vapor; and
for the space of a few minutes they were in the greatest consternation.
They believed that they barely escaped a living cremation. Of course
their liberal share of native superstition, and the gloom of the night
in the weird wilderness remote from human habitation, rendered their
position the more alarming.
A wonderful phenomenon is noted by a gentleman living in Cheltenham,
England. He was returning from Great Yarmouth to his house, a distance
of three miles, and took the road of the Denes, intending to cross
by the lower ferry. Before reaching it, a dark cloud coming from the
south-east, off the sea, suddenly surprised him, and drenched him
with rain. He jumped into the boat, and when the boatman had pushed
off, he remarked that every drop of rain hanging from his hair, beard,
and clothes was luminous with white light, well seen, as it was very
dark at the time. He afterwards learned that the same appearance had
been observed by several pilots exposed to the same shower, and he
attributed the occurrence to a species of St. Elmo’s fire.
CHAPTER XVI.
LUMINOUS FLOWERS.
Among the earliest observers of phosphorescent flowers may be mentioned
a young Swedish girl, the daughter of Linnæus, the eminent naturalist.
While walking in the garden one sultry night, she saw what was
described as a “lightning-like phosphorescence” about the flowers of
the nasturtium (_Tropæolum majus_). The sparks, or flashes, were also
visible early in the morning, but, curiously enough, were not apparent
in complete darkness; the time between day and night evidently being
the most favorable for the exhibition. This observation was made in
1762, and the young girl lived to the advanced age of ninety-six, often
repeating the story.
In 1843 Mr. Dowden, an English botanist, noted a similar display in
the double variety of a common marigold. Several friends were with
him at the time; and, by shading the flower, they distinctly saw a
golden-colored lambent light playing from petal to petal, so that an
almost uninterrupted corona was formed about the disk.
Others have observed this peculiarity in this flower and in the hairy
red poppy (_Papaver pilosum_). A correspondent of the “Gardner’s
Chronicle” writes, “We witnessed (June 10, 1858) this evening, a little
before nine o’clock, a very curious phenomenon. There are three
scarlet verbenas, each about nine inches high, and about a foot apart,
planted in front of the greenhouse. As I was standing a few yards from
them, my attention was arrested by faint flashes of light passing
backwards and forwards from one plant to the other. I immediately
called the gardener and several members of my family, who all witnessed
the extraordinary sight, which lasted for about a quarter of an hour,
gradually becoming fainter, till at last it ceased altogether. There
was a smoky appearance after each flash, which we all particularly
remarked. The ground under the plants was very dry; the air was
sultry, and seemed charged with electricity. The flashes had the exact
appearance of summer lightning in miniature. This was the first time
I had ever seen any thing of the kind; and having never heard of such
appearances, I could hardly believe my eyes. Afterwards, however,
when the day had been hot and the ground was dry, the same phenomenon
was constantly observed at about sunset, and equally on the scarlet
geraniums and verbenas. In 1859 it was again seen. On Sunday evening,
June 10, of that year, my children came running in to say that the
lightning was again playing on the flowers. We all saw it; and again on
July 11, I thought that the flashes of light were brighter than I had
ever seen them before.”
It has been asserted that this phenomenon was due to optical illusion,
but the experience of Goethe points to a different conclusion. He says,
“On the 19th of June, 1799, late in the evening, when the twilight
was passing into a clear night, as I was walking up and down with a
friend in the garden, we remarked very plainly about the flowers of
the Oriental poppy, which were distinguishable above every thing else
by their brilliant red, something like flame. We placed ourselves
before the plant, and looked steadfastly at it, but could not see
the flash again, till we chanced in passing and repassing to look at
it obliquely; and we could then repeat the phenomenon at pleasure.
It appeared to be an optical illusion, and that the apparent flash
of light was merely the spectral representation of the blossoms of a
blue-green.”
It is an interesting fact, that the light has been observed principally
about yellow flowers, as the sunflower (_Helianthus annuus_), the _Rose
d’Inde_ and _Oeillet d’Inde_, the garden marigolds (_Calendula_),
yellow lily, and others.
The Swedish naturalist, Professor Haggern, was fortunate in observing
the light about the marigold. His first impression was, that it was
an illusion; and to convince himself, he placed a man near at hand
with orders to make a signal when he saw the light: the result was,
that both observed it simultaneously. The light appeared as a flash,
often in quick succession from the same flower, and again only after
several moments. It was only observed at sunset on dry days. Professor
Haggern’s observations were made upon the marigold, garden nasturtium
(_Tropæolum majus_), the orange lily (_Lilium bulbiferum_), and the
French and African marigolds (_Tagetes patula_ and _T. erecta_). He was
at first disposed to consider the light due to some insect, but finally
decided that it was electrical.
In 1857 the press of Upsala, Sweden, contained accounts of remarkable
lights that had been observed about a group of poppies in the Botanic
Gardens. The observer, M. Th. Fries, a well-known botanist, in passing
the flowers, noticed three or four emitting little flashes of light.
Believing that he was the victim of an optical illusion, and wishing
to satisfy himself, he took a friend to the place at the same hour on
the following night, without, however, informing him what he had seen.
The latter immediately noticed the light, and soon the garden was
thronged with persons interested, who wished to see the flowers that
“threw out flames.” Later, fourteen persons saw the exhibition at once,
not only upon the _Papaver orientale_, but on the _Lilium bulbiferum_;
and before the curious phenomenon ceased, over one hundred and fifty
reliable observers were enabled to testify to the delight they had
experienced in watching the gleams of light play about these flowers;
the doubters and critics, of which there were many, being effectually
silenced.
[Illustration:
PLATE XXI.
LUMINOUS UMBELLULARIA.
LUMINOUS FISH.
(_Chauliodus._)
SILICIOUS SPONGE.
LUMINOUS CORALS.
LUMINOUS CRUSTACEAN.
(_Ptichogaster._)]
It is usually the misfortune of the single observer, or the minority,
to be ridiculed, and their word doubted, simply because others do not
choose to believe their statements. That such a course is unjust, is
well shown in the instance of the daughter of Linnæus, who made the
statement, that as she approached the flowers of _Dictamnus albus_ with
a light they appeared to ignite, without, however, injury to them. This
experiment was tried time and again by others, but without success;
and not a few scientists of the day regarded it as a delusion, while
others averred that it was pure invention; opinions which placed the
lady in a disagreeable position. Some years after, Dr. Hahn was enabled
to show that the experiment was not mere fiction. He says, “Being in
the habit of visiting a garden in which strong, healthy plants of
_Dictamnus albus_ were cultivated, I often repeated the experiment, but
always without success; and I already began to doubt the correctness
of the observation made by the daughter of Linnæus, when, during the
dry and hot summer of 1857, I repeated the experiment once more.
Fancying that the warm weather might possibly have exercised a more
than ordinary effect upon the plant, I held a lighted match close to an
open flower, but again without result; in bringing, however, the match
close to some other blossoms, it approached a nearly faded one, and
suddenly was seen a reddish, crackling, strongly shooting flame, which
left a powerful aromatic smell, and did not injure the peduncle. Since
then I have repeated the experiment during several seasons; and even
during wet, cold summers it has always succeeded, thus clearly proving
that it is not influenced by the state of the weather. In doing so, I
observed the following results, which fully explain the phenomenon.
On the pedicels and peduncles are a number of minute reddish-brown
glands, secreting etheric oil. These glands are but little developed
when the flowers begin to open, and they are fully grown shortly after
the blossoms begin to fade, shrivelling up when the fruit begins to
form. For this reason the experiment can succeed only at that limited
period when the flowers are fading. The radius is uninjured, being too
green to take fire, and because the flame runs along almost as quick as
lightning, becoming extinguished at the top, and diffusing a powerful
incense-like smell.”
As to the actual cause of these exhibitions of light, little is known.
In the case of M. Fries, the luminosity was always observed between
quarter past ten and quarter past eleven in the evening, and especially
when the weather was sultry, and was seen to best advantage when the
observers were not looking at the flowers directly. The light appeared
in fitful flashes, similar to that seen about the other flowers
mentioned, and was supposed to be electric. Mr. Haggern was also
inclined to believe that the phenomenon observed by him was electric.
The flame seen about the flower ignited, by the daughter of Linnæus,
was caused, as suggested by Phipson, by the ignition of the inflammable
atmosphere that envelopes the essential oil-glands of certain
_Flaxinellæ_. Electric light has been observed in a plant allied to the
palm, belonging to the genus _Pandanus_. When the spatha, or covering
which envelopes the flowers, is ruptured, a crackling sound is heard,
and a spark of light emitted. It is not impossible that the light of
certain flowers is in some way attendant upon the escape of pollen.
CHAPTER XVII.
VEGETABLE LAMPS.
One of the most remarkable and awe-inspiring phenomena of the ocean is
the water-spout,--a lofty column composed of tons of water, whirling
upward, lifted by the mighty force of the wind. From a distance the
formation of a spout is an interesting sight. In my own observations,
there has generally been a low-lying bank of dark lead-colored cloud
to announce its coming. From this a sharp cone, seemingly of cloud,
was seen to drop, and in a very few moments an attenuated pillar rose
from the water directly beneath it. The two appeared to meet, and, the
alliance consummated, the lofty column moved away with a greater or
less velocity.
Near proximity to them is not unaccompanied with danger; and I once
found myself in the centre of four or five, which were moving slowly
about. The wind almost entirely died away, so that had our boat been a
large one, we would have been completely at the mercy of the aqueous
giants; as it was, we lowered the sail, and taking the oars, succeeded
in avoiding them all.
It is the general impression, that if a water-spout touches an object,
or is struck, its form is broken, and the water descends; but this is
not always the case. I was standing one day upon the sea-wall of Fort
Jefferson, on the island of Tortugas, Florida reef, when I perceived a
lofty water-spout, a mile to the east, headed directly for the fort,
as I thought. In a few moments it struck Long Key, a narrow island a
quarter of a mile away; passing over perhaps one hundred and fifty
feet of it, striking a small schooner which had been hauled upon the
beach, twisting it around, and then continuing its course with great
rapidity. It now turned a little to the north; and, seeing that in all
probability it would not strike the fort, I awaited its coming. Never
shall I forget the awful grandeur of the sight, as the watery monster,
seemingly several thousand feet in height, reached the shoal. For some
reason which I cannot explain, the central portion was invisible, but
the upper part was distinctly seen, and appeared to be nearly over my
head; and its proximity may be imagined from the fact that the drops
from it seemed like a heavy rain. The entire spout was bent like a bow
by the wind, and was moving along with great rapidity. I could not keep
up with it, though running at utmost speed as it passed. Its progress
was accompanied by a loud roar, and a hissing, splashing sound, while
great masses of foam were thrown up before and behind. In its wake
followed numbers of gulls, feeding upon the small fishes killed by
the rush of waters; and where it crossed the shoal, in perhaps eight
feet of water, quite a trench was scooped out. Imagine such a column
at night coursing over the ocean; its entire shape outlined against
the darkness in phosphorescent light (Plate XXV.), and an idea may be
gained of the magnificent spectacles which, on rare occasions, are
produced by some of the simplest of plants,--the diatoms,[45] whose
nuclei are luminous.
The southern oceans, in certain places, often swarm with these minute
light-givers, and when borne aloft in the spout, they tend to produce
one of the most remarkable and striking scenes possible to imagine. In
color these luminous columns are yellow, of different shades, according
to the numbers of diatoms present. The naturalists of the “Challenger”
found that _P. pseudo-noctiluca_ was always present, and often
existed at the surface in vast numbers, in the tropics and subtropical
regions where the temperature was over sixty-eight or seventy degrees;
and the most beautiful exhibitions seen during the cruise were due to
these little forms. They have been observed in the Bay of Funchal all
the year round. The light was equally brilliant in each species; and in
each, when disturbed several times in succession, the phosphorescence
perceptibly diminished, and finally disappeared: but after an hour’s
rest, it re-appeared as brilliant as before.
The phosphorescence of plants, though not so remarkable in its general
manifestations as in the forms previously reviewed, is sufficiently
interesting to attract general attention. In nearly all countries these
vegetable lamps are found; and even in the old legends of the Greeks,
Hindus, and Persians, references to the “burning bush,” and other
luminous phenomena are met with, evidently having some foundation in
fact. In India the old natives tell the story, that their forefathers,
who visited the mountain of Sufed Koh, at the north of Nalroo in
Afghanistan, found a spring in which grew a bush which, from a
distance, seemed to emit a brilliant light; but if any one approached,
it immediately disappeared, vanishing in the air. In 1845 the white
residents of Simla were informed by the natives that a wonderful plant
was illuminating the mountains near Syree; and those who investigated
it expressed the belief that the light, if it existed at all, came from
a species of _Dictamnus_, which was known to grow about Gungotree
and Jumnotree.
Even in Josephus we find reference to the luminosity of plants. “There
is a certain place,” he says, “called Baaras, which produces a root
of the same name with itself; its color is like to that of flame, and
towards evening it sends out a certain ray like lightning; it is not
easily taken by such as would do it, but recedes from their hands.”
In the “Proceedings of the Royal Asiatic Society” of April, 1845, there
is reference to a luminous root-stock found in the Oraghum jungles,
“gleaming in the dark with all the vividness of a glow-worm, or the
electric scolopendra, after having been moistened with a wet cloth
applied to its surface for an hour or two, and did not seem to lose
the property by use, becoming lustreless when dry, and lighting up
again whenever moistened.” It is probable that this is the plant which
is referred to by the Brahmins as _Jyotismati_, produced, it is
said, by a variety of _Cardiospermum_. According to Sanscrit
authorities, it abounds in the Himalaya Mountains; and is well known,
according to Major Madden, at Almora, where investigation showed it
to be, at least in this locality, the roots of the fragrant khus-khus
grass, which at certain times, as rainy nights, was luminous.
In South America and Asia occurs a plant known to science as
_Euphorbia phosphorea_; which emits, when severed or cut, a milky
juice somewhat resembling that of the dandelion. At night the juice of
the former is, when heated, brilliantly phosphorescent; so much so,
that, according to M. Martins of Montpellier, if the stem be broken
and used as a pen, this _latex_ may be employed as a luminous
ink, the characters appearing in the dark as letters of fire. One of
the most familiar exhibitions of vegetable luminosity is seen in the
“touchwood” or “fox-fire,” which many a schoolboy has employed in the
perpetuation of a practical joke. It is found about old decayed trees,
and is simply rotten wood permeated by the mycelium of fungi, which is
luminous in the dark. This simple luminant is often quite sufficient
to enable one to read large print, and is often the cause of laughable
episodes among camping-parties. A friend of the writer, in building a
camp-fire in the deep woods, hauled an old log to the door of the tent,
and there broke it up, making a fire about which the men slept. In the
night, after the fire was extinguished, one of the party awoke, and
with a shout aroused the rest, who sprang to their feet, believing that
they were lying among coals; as all about were masses of wood seemingly
at a white heat, but which investigation showed to be fox-fire.
This luminous decayed wood often rolls out from trees in the forests,
to the astonishment or alarm of animals unfamiliar with fire.
Perhaps the most remarkable exhibition of fox-fire is recorded by the
Rev. M. J. Berkeley, who says, “A quantity of wood had been purchased
in a neighboring parish, which was dragged up a very steep hill to
its destination. Amongst them was a log of larch or spruce, it is not
quite certain which, twenty-four feet long, and a foot in diameter.
Some young friends happened to pass up the hill at night, and were
surprised to find the road scattered with luminous patches, which,
when more closely examined, proved to be portions of bark or little
fragments of wood. Following the track, they came to a blaze of white
light which was perfectly surprising; on examination it appeared that
the whole of the inside of the bark of the log was covered with a white
byssoid mycelium of a peculiarly strong smell, but unfortunately in
such a state that the perfect form could not be ascertained. This was
luminous; but the light was by no means so bright as in those parts of
the wood where the spawn had penetrated more deeply, and where it was
so intense that the roughest treatment scarcely seemed to check it. If
any attempt was made to rub off the luminous matter, it only shone the
more brightly; and when wrapped up in five folds of paper the light
penetrated through all the folds on either side as brightly as if the
specimen was exposed; when, again, the specimens were placed in the
pocket, the pocket when opened was a mass of light. The luminosity
had now been going on for three days. Unfortunately we did not see it
ourselves till the third day, when it had, possibly from a change in
the state of electricity, been somewhat impaired; but it was still most
interesting, and we have merely recorded what we saw ourselves. It
was almost possible to read the time on the face of a watch, even in
its less luminous condition. We do not for a moment suppose that the
mycelium is essentially luminous, but are rather inclined to believe
that a peculiar occurrence of climatic conditions is necessary for the
production of the phenomenon, which is certainly one of great rarity.
Observers as we have been of fungi in their native haunts for fifty
years, it has never fallen to our lot to witness a similar case before;
though Professor Churchill Babington once sent us specimens of luminous
wood, which had, however, lost their luminosity before they arrived.
It should be observed that the parts of the wood which were most
luminous were not only deeply penetrated by the more delicate parts
of the mycelium, but were those which were most decomposed. It is
probable, therefore, that this fact is an element in the case as well
as the presence of fungoid matter.”
[Illustration:
PLATE XXII.
LUMINOUS FISH.
(_Malacosteus niger._)
With two luminous disks, one emitting a golden, the other a
greenish light.]
Any one who has wandered among old tree-trunks in search of insects,
or been a careful observer in underground nooks and corners, must have
seen the white tangles, often of beautiful shape, which constitute the
forms of some fungi. They are frequently to be seen under old boards in
frost-like designs of great delicacy, and many of these are supposed
by some to have a certain relation to luminous woods. Around old
tree-stumps, the decayed arms of the oak especially, long, cylindrical,
flexible branches with a hard bark covering are often found. When
freshly broken, the interior is pure white, later changing to a more
or less deep brown tint. The white, flocculent extremities form the
mycelium of the fungus known as _Rhizomorpha subterranea_, one of
the most interesting of the luminous plants. Its mystic light is often
seen in caves, where the rootlets have made their way, gleaming with a
soft phosphorescence.
In coal-mines this plant is quite common, and has been especially
observed near Dresden. Ehrman speaks in enthusiastic terms of these
“vegetable glow-worms,” as he calls them, which he observed gleaming on
the walls and in the crevices of Swedish mines.
In Bohemia the caves are not uncommonly illumined by this interesting
cryptogam; and, according to Phipson, sufficient light has been emitted
in English coal-mines from this source to enable miners to read
ordinary print. In the mines of North Hesse, Germany, the conditions
are particularly favorable for such displays, the gleams being
described as resembling moonbeams stealing through the gloomy caverns.
That this fungus is luminous when detached, is shown by the following
from M. Tulasue, in the “Annals of Natural Science,” 1848. “On
the evening of the day I received the specimens,” he writes, “the
temperature being about 22° C., all the young branches brightened with
an uniform phosphoric light the whole of their length. It was the same
with the surface of some of the older branches, the greater number of
which were still brilliant in some parts, and only on their surface. I
split and lacerated many of these twigs, but their internal substance
remained dull. The next evening, on the contrary, this substance,
having been exposed to contact with the air, exhibited at its surface
the same brightness as the bark of the branches. Prolonged friction
of the luminous surfaces reduced the brightness, and dried them to a
certain degree, but did not leave on the fingers any phosphorescent
matter.” And again, “By preserving these _Rhizomorphæ_ in an
adequate state of humidity, I have been able for many evenings to
renew the examination of their phosphorescence; the commencement of
desiccation, long before they really perish, deprives them of the
faculty of giving light.”
Rumphius, the celebrated botanist, was perhaps the first European
to discover the phosphorescence of fungi, observing it in a large
specimen on the island of Amboine, which he named _Fungus igneus_, or
fire-mushroom. In America such exhibitions are rare. Mr. H. K. Morrell,
editor of “The Gardiner (Me.) Home Journal,” informed me some few years
ago that he had observed the phosphorescence of _Tianus stypticus_ in
his garden; the young of which, being especially brilliant, emitted
a steady light. In Brazil a certain agaric is famous for its vivid
luminosity. It was observed by Mr. Gardner in 1840, who says, referring
to the species which has been named _Agaricus gardneri_, “One dark
night about the beginning of December, while passing along the streets
of the Villa de Natividate, Goyaz, Brazil, I observed some boys amusing
themselves with some luminous object, which I at first supposed to be
a kind of large fire-fly; but, on making inquiry, I found it to be a
beautiful phosphorescent species of _Agaricus_, and was told that it
grew abundantly in the neighborhood on the decaying fronds of a dwarf
palm. The whole plant gives out at night a bright phosphorescent light,
somewhat similar to that emitted by the larger fire-flies, having a
pale greenish hue. From this circumstance, and from growing on a palm,
it is called by the inhabitants ‘Flor de Coco.’”
Dr. Cuthbert Collingwood had a similar experience with an allied
species in Borneo. “The night being dark, the fungi could be very
distinctly seen, though not at any great distance, shining with a soft,
pale greenish light. Here and there spots of much more intense light
were visible, and these proved to be very young and minute specimens.
The older specimens may more properly be described as possessing a
greenish, luminous glow like the glow of the electric discharge; which,
however, was quite sufficient to define its shape, and when closely
examined, the chief details of its form and appearance. The luminosity
did not impart itself to the hand, and did not appear to be affected
by the separation from the root on which it grew, at least not for
some hours. I think it probable that the mycelium of this fungus is
also luminous; for, upon turning up the ground in search of small,
luminous worms, minute spots of light were observed, which could not be
referred to any particular object or body, when brought to the light
and examined, and were probably due to some minute portions of its
mycelium.” Mr. Hugh Low has stated that “he saw the jungle all in a
blaze of light, by which he could see to read, as some years ago he was
riding across the island by the jungle road, and that this luminosity
was produced by an agaric.”
Australia has produced a number of luminous toadstools. Drummond found
some striking forms near Swan River. He had noticed two species growing
as parasites on the stumps of trees. Their appearance in the daytime
did not attract particular attention; but at night they developed into
veritable plant lamps, exceeding any thing that he had ever seen. One
was about two inches across, and grew in clusters on the stump of a
banksia-tree which was surrounded by water. When the little plant was
secured from its miniature island home, it could have been used as a
lamp for several successive nights, a newspaper being read by placing
the agaric on it, the light illuminating the type in the immediate
vicinity. As the plant dried, the light gradually diminished.
[Illustration:
PLATE XIII.
LUMINOUS MUSHROOMS.
LUMINOUS INSECT. (_Geophilus electricus._)]
Later Mr. Drummond found a giant specimen that was sixteen inches in
diameter and a foot high, a veritable chandelier. He says regarding it,
“This specimen was hung up inside the chimney of our sitting-room to
dry; and, on passing through the apartment in the dark, I observed the
fungus giving out a most remarkable light, similar to that described
above. No light is so white as this, at least none that I have ever
seen. The luminous property continued, though gradually diminishing,
for four or five nights, when it ceased on the plant becoming dry. We
called some of the natives, and showed them this fungus when emitting
light. The room was dark, for the fire was very low and the candles
extinguished; and the poor creatures cried out, ‘Chinga,’ their name
for a spirit, and seemed afraid of it.”
A very attractive agaric, _Agaricus olearius_ (Plate XIII.), is
found at the foot of olive-trees in Southern Europe. During the daytime
the color is yellow, but observed at night it emits a brilliant blue
light. Like the Australian species, it continues to emit light after
it has been taken from the ground, the phosphorescence persisting
for successive nights. So brilliant are the gleams, that they may be
perceived at times before darkness sets in. Experiment showed that
the light was extinguished when the temperature was below +90° to
+6° C.; but the luminosity was not destroyed, as it re-appeared when
the temperature was raised above this point. If kept some time in
a temperature below freezing, it loses its light-emitting property
entirely. It gleams as brightly under water as out; pure oxygen seems
to have no effect upon it, and the most careful experiments fail to
show the slightest elevation of temperature about the parts which
shine. The light seems to emanate from the head (_pileus_) of the
fungus, the _lamellæ_ of the latter, where the seeds are found,
being the centre of the luminous phenomenon.
These interesting light-givers are perhaps more common than we are
aware of, from the fact that nocturnal investigations in the woods are
not frequent, nearly all the discoveries being the result of accident.
A small, luminous fungus has been observed in the Andaman Islands.
Gandichand found one in Manilla, while Dr. Hooker, as we have seen,
refers to the presence of one in the Sikkim Himalayas.
These curious families of fungi are not only ornamental, but useful.
In European countries the common mushroom[46] enjoys the widest
popularity as an esculent, especially the cultivated varieties. The
meadow mushroom is scarcely inferior, though stronger in flavor, and is
preferred by many to the cultivated species. In France the champignon
is largely eaten; and in Austria a kind which has no admirers in
England finds a constant place in the markets during the summer.
Truffles and morels are favorites not only in Europe, but also in the
vales of Cashmere, where two or three species of morels are dried for
consumption throughout the year. The great puff-ball is increasing
in reputation as a breakfast delicacy in Great Britain, while the
chantarelle and the hedgehog fungus are esteemed by many.
Numerous other species are more or less eaten by mycophagists,
although they are never found in the public markets. A species of
_Boletus_, cut in slices and dried, may be purchased throughout
the year in most of the Continental cities. In Tahiti the Jew’s ear[47]
is dried in large quantities and exported to China; while a species of
agaric comes into the markets of Singapore, and another dried agaric
is sent from the Cabul hills and the plains of north-western India.
Several species of _Cyttaria_ are eaten in the southern parts of
South America, and in Australia a native kind[48] is a favorite article
of food. Indeed, a very long catalogue might be made of the species
which are more or less consumed in different parts of the world.
The cultivation of fungi for esculent purposes has not hitherto
been successful with any other species than the ordinary mushroom.
Attempts were made in France to cultivate truffles, at first apparently
with considerable promise, but ultimately without much satisfaction.
There is no good reason to suppose it impossible or improbable that
many species might be devoted to experiments in that direction. Some
species of _Polyporus_ have been employed as styptics, or beaten till
soft and used as amadon. One species in Burmah has a good reputation
as an anthelmintic. Some species of _Polysaccum_ and _Geaster_ are
employed medicinally in China. Species of _Elaphomyces_ were at one
time supposed to possess great virtues now deemed apocryphal. Ergot,
developed on rye, wheat, and the germen of various grasses, still
maintains its position in the pharmacopœia; but is almost the only
fungus now employed, and that sparingly, by the legitimate medical
practitioner.
In the Cardiff coal-mines an interesting plant is found, which emits
so brilliant a light, that the men have been able to “see their hands
by it,” and was visible at a distance of sixty feet. Mr. Worthington
Smith, who is an authority for this, observed the same phenomenon in
_Polyporus sulfureus_.
While various theories have been recorded as to the physiological cause
of the light in cryptogams, and many writers give the most careful
details of the structure of the luminous parts, we are unable to go a
step farther to explain the cause of the light which appears to be a
combustion, but does not consume.
CHAPTER XVIII.
PHANTOMS.
Phosphorescent light plays an important part in the composition of
ghosts and phantoms; and the number of persons who believe that certain
phenomena exist which cannot be explained by well-known natural laws
is somewhat surprising. Some years ago I was introduced to a gentleman
who was a firm believer in a modern Flying Dutchman. His house was
upon a beautiful little bay, and from the piazza, he informed me that,
more than once, he had seen a phantom ship. Sometimes it beat up the
bay, the white sails showing distinctly at night. Again it was seen
coming in directly against the wind, now appearing in one place, then
in another, as fickle as the wind itself. On every other subject he
was sane, and of more than ordinary intelligence; but some electric
phenomenon or emanations from schools of fishes, together with a vivid
imagination, had produced the phantom ship, which in his mind was a
reality.
Many well remember the excitement occasioned around one of the New-York
markets a number of years ago, by the appearance of a mysterious
light. A fish-dealer’s assistant, who had occasion to enter the
market late one evening, observed an unusual light there; and being
an ignorant, superstitious fellow, he rushed out of the building
and into a neighboring store, stating excitedly that the ghost of
a former market-man was hovering about his old stand. A number of
persons returned with him to the market, and there saw a light, a
dull yellowish gleam, about six feet in length, proceeding apparently
from some body lying in a recumbent position. The crowd pressed in,
and found the ghost to be a large piece of fish that had become
phosphorescent.
Such occurrences are not uncommon, and show that phosphorescence is
not confined to any special place, object, or condition. As early as
1592 we read of its having caused surprise and astonishment among the
Romans. Several young men having bought a lamb, and kept it over night
for an Easter feast on the following day, were amazed to find that at
night the flesh gleamed as if candles had been placed upon it. So much
interest was aroused by the occurrence, that the animal was sent to a
scientist of the day, Fabricio d’Acquapendente, for explanation; but
it was as little understood then as it is to-day. This meat emitted a
white light, and it was communicated to a piece of kid’s meat that was
placed in contact with it.
Bartholin, the Danish philosopher, records an instance that excited
much interest in his day. A poor woman had purchased a piece of meat;
and, during the night having to go to the pantry, was terrified by
observing that it was surrounded by a blaze of light. Many persons
visited the house, and it was noticed that as soon as putrefaction
commenced the light disappeared.
According to M. Nueesh, in a certain butcher’s shop the meat became
strongly phosphorescent, and remained so as long as sound. If
putrefaction set in, and _Bacterium termo_ made its appearance,
the luminous appearance ceased. In many cases timid persons have thrown
water upon such light, but without effect. Alcohol and certain acids,
however, seem to extinguish it. Boyle was curious enough to place a
piece of shining veal in the receiver of an airpump, which had no
perceptible effect upon it, showing that there was no combustion, as
we understand it. He also used his luminous meat as a lamp, and states
that it made a “splendid show.” A printed paper was placed over the
light spots, and the type made out without difficulty.
If heat is given out by this light, the instruments of the present day
fail to show it. Every surgeon has had experience with this phenomenon
in the course of his studies, yet it is still unexplained.
We have observed living forms producing light from special plates,
or from the mucilaginous envelope of their bodies, and when dead the
same curious light appears for a limited time. Dr. Phipson examined a
luminous ray with great care, thinking to find traces of phosphorus
in the luminous grease, but it was entirely wanting. The little
boring-shell pholas, which we have seen is a brilliant light-giver when
alive, is equally so after death; its luminosity continuing in honey
for a year, as previously described.
A boat containing dead mackerel often presents the appearance of
being loaded with coals of fire, each fish gleaming with a soft
phosphorescent light, that seems to arise in the greasy mucus which
covers them. Place one of these luminous fishes in the water, and the
latter will soon assume a like appearance. Vegetables piled in cellars
often appear phosphorescent, especially potatoes and cantaloupes. In
a case of the former, a servant seeing the brilliant light gave an
alarm of fire, arousing the neighborhood. The men rushed in, and the
cellar was well flooded before it was discovered that some unoffending
potatoes were the cause of the alarm.
CHAPTER XIX.
LUMINOUS SHOWERS.
In many old works, accounts are found of so-called showers of fire,
during which the entire heavens seemed filled with gleaming drops, that
threatened to burn every living thing, but were in reality harmless;
the exhibition being merely another instance of this strange phenomenon
of heatless light.
Some years ago a party of peasants were making the ascent of one of
the high peaks of the Alps, when they were caught in a rain-storm,
which produced a demoralizing effect upon them. As the rain fell, it
seemed to become luminous, and drops of fire apparently ran from their
clothing and beards. Their attempts at brushing it away, while adding
to the startling nature of the phenomenon, showed, however, that it was
perfectly harmless.
Dr. Phipson records some interesting instances of this kind of
phosphorescence, of which the following may be cited:--
M. de Thielan observed on Jan. 25, 1822, near Freyburg, a most
extraordinary spectacle. A heavy snow had been falling during the
early part of the evening, and the trees, branches, limbs, and leaves
quivered and scintillated with a resplendent bluish light, while the
drops of rain upon the grass left golden trains as they dripped to the
ground.
[Illustration:
PLATE XXIII.
DEEP SEA ANGLER.
(_Melanocetus johnstoni, Gth._)]
Arrago records similar occurrences: In 1731 a priest named Hallai, who
lived at Lessay, near Constance, states that he observed one evening
during a severe thunder-storm, rain falling which looked like _drops
of red-hot liquid metal_.
Bergman, the eminent Swedish chemist, communicated to the Royal Society
of London, in 1761, that late in the afternoon upon two occasions,
though hearing no thunder, he had seen rain which glittered as it fell
upon the ground, making it look as if covered with waves of fire.
M. Pasumot, on May 3, 1768, was overtaken, while walking near
Arnay-le-Duc, on an open plain, by a very heavy storm. The rain
collecting on the brim of his hat, he stooped his head to allow it to
run off, when to his astonishment, as it encountered that which fell
from the clouds, at about twenty inches from the ground, _sparks were
emitted_ between the two portions of liquid.
During January, 1822, Lampadius was told by the miners of Freyburg,
that they had observed during a storm, _sleet_ which _emitted light_
when it fell upon the ground.
A friend of Howard, the meteorologist, stated to him, that while going
from London to Bow on the 19th of May, 1809, there came up a very
severe storm; and he observed the rain emit light as it struck the
earth.
On the 28th of October, 1772, the Abbé Bertholon, who was travelling
to Lyons from Brignai, early in the morning was overtaken by a violent
storm of rain and hail. The _rain and hail-stones emitted light_ as
they fell upon the metallic mounting of his horse’s trappings.
Luminous hail has often been observed; and when we remember that
hail-stones sometimes attain great size, we can imagine the scene
occasioned by a fall where each stone is phosphorescent. Ordinary
hail-stones are the size of small peas, but they occasionally occur
large enough to kill human beings; and I have seen them so large in the
Sierra Madre Mountains that any shelter was preferable to exposure to
them. In 1707 a hail-storm occurred at the town of Como, Switzerland,
doing an incredible amount of damage, some of the stones weighing
nearly ten ounces. Darwin describes a storm upon the South American
pampas, in which the stones that fell were large enough to kill
powerful animals.
Ice has often been observed to emit luminous sparks; and probably one
of the grandest spectacles ever witnessed, is the luminous cap of a
snow-covered mountain. The glaciers of the Alps have been seen bathed
in a soft phosphoric glow, the icy rivers being distinctly marked by
the phenomenon, which is so brilliant, at times, that the appearance
of a second sunset is occasioned. Not only are the summits of Alpine
peaks and the glaciers luminous, but the valleys of Piedmont, Valais,
and others have been seen to emit from their covering of snow a soft
blue light of singular beauty. So intense is this light about the cap
of Mount Blanc, it has been photographed. Luminous vapors or mists
may be mentioned in this connection. Several times in the history of
this country, luminous mists or fogs have been recorded. Massachusetts
was visited by one some years ago, in which the fog was so dense that
observers a few feet away were invisible, yet darkness was not an
accompaniment; the mist seemed to be light-emitting itself, having a
reddish, metallic hue. Others described it as a fiery red or yellow,
while to some it appeared to be composed of faintly luminous matter.
In the year 1783 all Europe and a portion of Asia were enveloped in a
dense fog of a most remarkable nature. It was termed “dry,” as even at
night no dampness was observed. It was first seen at Copenhagen, its
coming being heralded by severe storms. A few weeks later it appeared
in various parts of France, and rapidly seemed to spread over Europe
and portions of Asia. During the day it had a metallic glow, which at
night changed to a phosphorescent light, so brilliant that ordinary
print could be read by it. Many attempts to explain it were made by the
savants of the day, and it was universally supposed to be due to the
earthquakes and volcanic eruptions which were of unusual severity that
year.
A somewhat similar fog appeared in the United States, a portion of
Europe, and Africa in August, 1831. The daylight was perceptibly
diminished, while at night a conspicuous phosphorescent light was
emitted. A remarkable luminous fog occurred in Switzerland in 1859. M.
L. F. Wartmann of Geneva states that the strange light was observed on
five successive nights, and apparently proceeded from a heavy dry fog
that hung over Geneva during the time. The light was so brilliant that
this gentleman distinguished the smallest objects upon his table with
perfect ease, no other light being in the apartment. The light caused
general comment in the places in which it appeared, and a traveller
between Geneva and Annemassi stated that he readily found the road by
its means. Dr. Verdeil of Lausanne describes a fog which diffused so
much light that distant objects were perfectly visible at night.
Among the phenomena which attended the eruption of Vesuvius in 1794 was
one which did not tend to allay the fears of the people. During the day
a fine dust filled the air about Naples, which was not particularly
noticeable; but as night came on, it emitted a pale though distinct
phosphorescent light. An English gentleman sailing near Torre del Greco
noticed that where the dust collected upon his hat it was luminous, and
no little consternation was caused among the superstitious sailors by
the occurrence.
Luminous dust-showers have been noticed in several localities; and the
peculiar glows that were seen in this country a few years ago were
accredited by many to them, the supposition being that dust, perhaps
from volcanic eruptions, was floating about in the upper strata of the
atmosphere. Many other explanations were given, and the literature upon
the subject is extremely voluminous and interesting.
The amount of material floating about in the upper regions of the air
is perhaps little realized by my young readers, and some reference to
the phenomenon may be of interest.
Professor Nordenskjöld has for many years been a close observer of
dust of all kinds that has fallen upon the earth in rain or snow; and
it was his good fortune, during the expedition of the “Vega,” to prove
beyond a doubt the presence of cosmic dust. For many years we have
been assured by astronomers that the earth was being bombarded, as it
were, continually, by innumerable meteors. The moment they enter our
domain, we observe the spectacle of their ignition. In a moment they
are reduced to ashes, and the fine impalpable dust drops slowly, an
invisible shower, upon the earth. When such showers are intensified, it
is not impossible that some outward and visible phenomena may be the
result.
In the search for this cosmic dust, the far North, where the surface
is covered by an almost continuous coating of snow and ice, offers
a wide and promising field for investigation. Here no other dust
prevails. Professor Nordenskjöld first found cosmic dust in the North
at Spitzbergen. The second discovery, off the Taimar coast, seemed to
be in the form of yellow specks lying on the snow. They were at first
supposed to be diatomaceous ooze;[49] but when placed in the hands
of Dr. Kjellman, he pronounced them to be pale yellow crystals, and,
curious enough, formed of carbonate of lime. “The original composition
and origin of this substance,” says Professor Nordenskjöld, “appears
to me exceedingly enigmatical. It was not carbonate of lime, for the
crystals were rhomboidal, and did not show the cleavage of calcite.
Nor can there be a question of its being arragonite, because this
mineral might indeed fall asunder of itself; but in that case the newly
formed powder ought to be crystalline. Have the crystals originally
been a new hydrated carbonate of lime formed by crystallizing out at
a temperature of ten or twenty degrees above the freezing point? In
such case they ought not to have been found on the surface of the
_snow_, but lower, on the surface of the _ice_. Or have they fallen
down from the inter-planetary spaces to the surface of the earth, and
before crumbling down have had a composition differing from terrestrial
substances, in the same way as various chemical compounds found in
recent times in meteoric stones? The occurrence of the crystals in
the uppermost layer of snow, and their falling asunder in the air,
tell in favor of this view. Unfortunately there is no possibility of
settling these questions; but at all events this discovery is a further
incitement to those who travel in the high North, to collect with
extreme care, from snow-fields lying far from the ordinary routes of
communication, all foreign substances, though apparently of trifling
importance.”
The investigations of the Swedish naturalist in this field are of
exceeding interest. His first attempt to obtain meteoric dust was at
Stockholm, where, in December, 1871, there was a great fall of snow,
the heaviest ever known. On the last days of the storm, after the
atmosphere had been presumably purified of extraneous substances, he
collected a cubic metre of snow, melted it over a fire, and found that
after the water had evaporated a residue of black powder remained,
in which were many grains of metallic iron, that were attracted by a
magnet. In 1872 his brother made a similar examination of the snow, in
a quiet locality near the remote village of Evois, Finland. The snow
upon being melted also gave the same black powder and metallic iron.
The investigations of Nordenskjöld himself, conducted in Spitzbergen,
as previously mentioned, were the most satisfactory. The observations
were made in 80° north latitude, and 13° to 150° east longitude, in
the layer of snow that covered the ice. An imaginary section was as
follows: (1), new fallen snow; (2), a layer of hardened old snow,
eight millimetres in thickness; (3), a layer of snow, conglomerated to
a crystalline granular mass; and (4), common granular hardened snow.
Layer three was full of small black grains, among which were found
numerous metallic particles, that were attracted by the magnet, and
found to contain iron, cobalt, and possibly nickel also.
In his visit to Greenland in 1870, Nordenskjöld found in the dust
that lay on the inland ice, grains of metallic iron and cobalt. “The
main mass,” he says, “consisted of a crystalline, double refracting
silicate, drenched through with an ill-smelling organic substance.
The dust was found in large quantities at the bottom of innumerable
small holes in the surface of the inland ice. This dust could scarcely
be of volcanic origin, because by its crystalline structure it
differs completely from the glass dust that is commonly thrown out of
volcanoes, and is often carried by the wind to very remote regions;
as also from the dust which, in March, 1875, fell at many places in
the middle of Scandinavia, and which was proved to have been thrown
out by volcanoes in Iceland.” Professor Nordenskjöld’s estimate of the
quantity of dust shows that it has been in past ages a not unimportant
factor, perhaps, in its addition to the crust. He says, “I estimate the
quantity of the dust that was found on the ice north of Spitzbergen, at
from .01 to 1 milligram per square metre; and probably the whole fall
of dust for the year far exceeded the latter figure. But a milligram on
every square metre of the surface of the earth amounts for the globe
to five hundred million kilograms (say half a million tons). Such a
mass, collected year by year during the geological ages, of a duration
probably incomprehensible by us, becomes a consideration too important
to be neglected, when the fundamental facts of the geological history
of our planet are enumerated. A continuation of these investigations
will perhaps show that our globe has increased gradually from a small
beginning to the dimensions it now possesses; that a considerable
quantity of the constituents of our sedimentary strata, especially of
those that have been deposited in the open sea far from land, are of
cosmic origin; and will throw an unexpected light on the origin of the
fire-hearths of the volcanoes, and afford a simple explanation of the
remarkable resemblance which unmistakably exists between plutonic rocks
and meteoric stones.”
Such enormous masses of material could well explain the rosy and other
curious lights that are from time to time observed. But cosmic dust
is not the only matter in the air that could occasion the phenomena;
the atmosphere is constantly filled with innumerable forms caught up
by currents and carried to inconceivable heights, and thus to great
distances, to be precipitated to the earth in hail, snow, or rain.
Near St. Domingo, Darwin tells us, the atmosphere became thick and
hazy from the impalpable fine dust that actually injured their
astronomical instruments. “The morning before we anchored at Porto
Praya,” he says, “I collected a little packet of this brown-colored
dust, which appeared to have been filtered from the wind by the gauze
of the vane at the masthead. Mr. Lyell has also given me four packets
of dust which fell on a vessel a few hundred miles northward of these
islands. Professor Ehrenberg finds that this dust consists in great
part of _infusoria_ with siliceous shields, and of the siliceous
tissue of plants. In five little packets which I sent him, he has
ascertained no less than sixty-seven different organic forms. The
_infusoria_, with the exception of two marine species, are all
inhabitants of fresh water. I have found no less than fifteen different
accounts of dust having fallen on vessels when far out in the Atlantic.
From the direction of the wind whenever it has fallen, and from its
having always fallen during those months when the harmattan is known to
raise clouds of dust high into the atmosphere, we may feel sure that
it all comes from Africa. It is, however, a very singular fact, that,
although Professor Ehrenberg knows many species of _infusoria_
peculiar to Africa, he finds none of them in the dust which I sent him;
on the other hand, he finds in it two species which hitherto he knows
as living only in South America. The dust falls in such quantities
as to dirty every thing on board, and to hurt people’s eyes; vessels
even have run ashore, owing to the obscurity of the atmosphere. It has
often fallen on ships when more than a thousand miles from the coast
of Africa, and at points sixteen hundred miles distant in a north and
south direction. In some dust which was collected on a vessel three
hundred miles from the land, I found particles of stone, above the
thousandth of an inch square, mixed with finer matter. After this fact,
one need not be surprised at the diffusion of the far lighter and
smaller sporules of cryptogamic plants.”
The extent to which dust and ashes can be taken up and held by air
currents is shown in volcanoes. In 1810 the ashes from a volcano at
St. Vincent were wafted to Barbados, nearly a hundred miles; and in
1835 the material thrown from a volcano in Guatemala to Jamaica, eight
hundred miles. As intimated, these showers are not all inorganic, but
are often living or fossil animals or plants that are floating about.
Such are the reddish or gray showers that are frequently met with off
the African coast, and when in the snow they are called “blood-rains.”
The one in 1755, near Lago Maggiore, covered over two hundred square
leagues, causing a panic among the inhabitants. For a distance of nine
feet below the surface, the snow was blood red, the atmosphere appeared
red and fiery, while at sunrise and sunset a rosy hue pervaded every
thing. When this shower fell and there was no snow, the earthy deposit
accumulated an inch deep; and it has been estimated that, supposing it
to average two lines in depth, there would be for each square mile an
amount equal to nearly three thousand cubic feet. A similar panic was
caused some years ago by a swarm of butterflies. Everywhere they left
a drop of blood-colored fluid, so that the fences, houses, and cattle
were covered with it. The insects were so numerous that they obstructed
the vision.
In the “blood-rains” of Italy, and generally in such instances, the
red hue comes from red oxide of iron. At a single shower in Lyons in
1846, Ehrenberg estimated that seven hundred and twenty thousand pounds
of material fell, ninety thousand pounds of which were microscopic
organisms, including thirty-nine species of siliceous diatoms, and many
others of great beauty of form and shape.
Ehrenberg enumerates a very large number of these showers, referring
to Homer’s “Iliad” for one of the earliest known; and asks, with such
facts before us, how many thousand millions of hundred-weight of
microscopic organism have reached the earth since Homer’s time? The
whole number of species made out is over three hundred. The species, as
far as ascertained, are not African; fifteen are North American. But
the origin of the dust is yet unknown. The zone in which these showers
occur covers Southern Europe and Northern Africa, with the adjoining
portion of the Atlantic, and the corresponding latitudes in Western and
middle Asia.
When blown along by the wind, these showers perform another office
besides affecting, perhaps, the color or tint of the atmosphere; they
wear away rock, and polish and furrow it. Such work can be seen in the
granite rocks at the San Bernardino Pass in California. Quartz is
polished, and hard gems left weathered out; while at Cape Cod ordinary
sand has been known to wear holes through glass windows by continually
blowing against them.
[Illustration:
PLATE XXIV.
PELICAN FISH.
(_Eyrypharyx pelecanoides._)]
An ingenious instrument has been invented to capture these flying
objects of the air. It is called by the inventor, Doctor Miguel, the
æroscope, and is really a net for animals invisible to the naked eye.
Many objects are phosphorescent when struck, or when divided into
thin laminæ. Some simple materials for such experiments are chlorate
of potash, fluor-spar, feld-spar, sugar, etc. By placing any of
these in a mortar, and grinding them in the dark, flashes of light
will be seen, powdered sugar often making a striking display. A
beautiful and effective exhibition can be produced by placing a small
amount of phosphuret of calcium in water; decomposition follows, and
phosphuretted gas is evolved. As the bubbles of gas rise and come in
contact with the atmosphere, they seem to take fire. If in a dark room,
luminous rings are seen rising, and they can be made to take various
shapes by using a fan. A trick often performed by magicians is to hand
around a marble, and then pretend to render it luminous by blowing upon
it. This trick consists in having small balls at hand, of a material
that can readily be rendered luminous by the application of heat. These
substances can be easily made.
A fine light is produced by taking,--
Barium sulphate (C P.) 32 parts
Magnesium carbonate (C P.) 1 part
Sulphur (C P.) 1 part
Gum tragacanth q. s.
This should be made into balls of a convenient size, dried at a
moderate temperature, and kept in a crucible at a red heat for about an
hour. Allow them to cool slowly, and then place in a glass-stoppered
bottle before their heat has disappeared. When required for use, expose
them to the sun or any strong light, and they will become luminous, and
continue so for many hours.
Another formula is:--
Strontium sulphate (C P.) 22 parts
Sulphur (C P.) 1 part
Gum tragacanth q. s.
This should be heated as above described.
A most interesting experiment is to make a selection of artificial
flowers, and, having brushed them over with glue or mucilage, dust
them with the powder from one of the balls made as described. If
the flowers are exposed to the sun a short time, they will emit a
phosphorescent light, each flower standing out in the darkness with
extreme brilliancy,--a striking and remarkable spectacle.
Canton’s phosphorus is easily made by calcining clean oyster-shells,
until they are perfectly white, in a crucible. The clearer and finer
portions should then be reduced to powder, and placed in layers with
alternate layers of flowers of sulphur in a crucible. Cover, and heat
to a dull redness for about half an hour, then allow to cool slowly.
Luminous “ink” or liquid can be made by placing a small piece of
phosphorus about as large as a pea in a test-tube with a small quantity
of olive oil; hold the tube in a water-bath until the oil becomes
heated, and the phosphorus liquefies; then shake it until the oil will
take up no more phosphorus, and, when it becomes clear, pour into
a bottle with a glass stopper. When it is to be used, take out the
stopper, and admit the air. The oil can be used with a brush, and in
the dark will appear luminous.
Water may be rendered phosphorescent by dissolving a small piece of
phosphorus in ether for several days in a glass-stoppered bottle; then
by immersing a piece of sugar in the solution, and placing it in water,
the latter becomes vividly phosphorescent. It should be remembered that
phosphorus and ether are both extremely dangerous, and experiments with
them should be conducted with care and judgment.
While this is a mere toy, luminous paint is of great value. It is
easily made, and can be applied to many purposes.
Schade of Dresden has quite recently patented an invention, which
enables him to produce paints that are luminous without affecting
the tint by day. This is accomplished, according to the inventor, as
follows:--
Zanzibar or Kauri copal is melted over a charcoal fire. Fifteen parts
of the melt are dissolved in 60 parts of French oil of turpentine, and
the filtered solution is mixed with 25 parts, previously heated and
cooled, pure linseed-oil. The varnish which is thus obtained, is used
in the following methods, in the manufacture of luminous paints, by
grinding between granite rolls in a paint-mill. Iron rolls should be
avoided, because particles of iron, which are liable to be detached,
would injure the luminous properties.
Varnishes, as they occur in commerce, generally contain lead or
manganese, which would destroy the phosphorescence of calcium sulphide.
_A pure white luminous paint_ is prepared by mixing 40 parts of the
varnish obtained in the abovedescribed process with 6 parts prepared
barium sulphate, 6 parts prepared calcium carbonate, 12 parts prepared
white zinc sulphide, and 36 parts good luminous calcium sulphide in
a proper vessel, to an emulsion, and then grinding it very fine in a
color-mill. For _red luminous paint_, 60 parts varnish are mixed with
8 parts prepared barium sulphate, 2 parts prepared madder lake, 6
parts prepared realgar (red arsenic sulphide), and 30 parts luminous
calcium sulphide, and treated the same as for white paint. For _orange
luminous paint_, 46 parts varnish are mixed with 17.5 parts prepared
barium sulphate, 1 part prepared Indian yellow, 1.5 parts prepared
madder lake, and 38 parts luminous calcium sulphide. For _yellow
luminous paint_, 48 parts varnish are mixed with 10 parts prepared
barium sulphate, 8 parts barium chromate, and 34 parts luminous calcium
sulphide. For _green luminous paint_, 48 parts varnish are mixed with
10 parts prepared barium sulphate, 8 parts chromium oxide green, and 34
parts luminous calcium sulphide.
_A blue luminous paint_ is prepared from 42 parts varnish, 10.2 parts
prepared barium sulphate, 6.4 parts ultramarine blue, 5.4 parts cobalt
blue, and 46 parts luminous calcium sulphide.
_A violet luminous paint_ is made from 42 parts varnish, 10.2 parts
prepared barium sulphate, 2.8 parts ultramarine violet, 9 parts
cobaltous arsenate, and 36 parts luminous calcium sulphide.
_For gray luminous paint_, 45 parts of the varnish are mixed with 6
parts prepared barium sulphate, 6 parts prepared calcium carbonate, O.5
parts ultramarine blue, 6.5 parts gray zinc sulphide.
_A yellowish-brown luminous paint_ is obtained from 48 parts varnish,
10 parts precipitated barium sulphate, 8 parts auri pigment, and 34
parts luminous calcium sulphide.
_Luminous colors for artists’_ use are prepared by using East India
poppy oil in the same quantity, instead of the varnish, and taking
particular pains to grind the materials as fine as possible.
_For luminous oil-color paints_, equal quantities of pure linseed oil
are used in place of the varnish. The linseed oil must be cold-pressed,
and thickened by heat. All the above luminous paints can be used in
the manufacture of colored papers, etc., if the varnish is altogether
omitted, and the dry mixtures are ground to a paste with water.
The luminous paints can also be used as _wax colors for painting on
glass_ and similar objects, by adding, instead of the varnish, ten per
cent more of Japanese wax, and one-fourth the quantity of the latter
of olive oil. The wax colors prepared in this way may also be used for
painting upon porcelain, and are then carefully burned without access
of air. Paintings of this kind can also be treated with water-glass.
CHAPTER XX.
THE USES OF PHOSPHORESCENCE.
As to the value and use of the gift of luminosity possessed by various
animals, we can only surmise. Many interesting theories have been
suggested, none of which, however, seem to stand the test of practical
application. Some naturalists believe that the light of certain
invertebrates is a warning. As an example, the jelly-fishes have a
terrible array of stings; and it is supposed that fishes once stung,
remember the light of these forms, and avoid them in the future. If
this were true, many helpless animals, as the salpa and others, would
also find protection in the lesson taught by the jelly-fishes.
It is a poor rule that will not work both ways; and we might well ask,
if nature supplies these lights as warnings, why the physalia, the
most terrible of all these forms, has not been thus provided. Phipson
mentions it as a phosphorescent animal, but in the thousands that I
have observed during a long residence in the physalia country, I never
saw one give out light; hence I assume that if they are luminous, it is
only on certain occasions. It might be considered that the vivid colors
of this attractive creature constituted a warning; but even this does
not hold, as I have found all kinds of pelagic fishes in their toils,
and even a turtle and many small fishes bite readily at the deadly
tentacles.
It is well known that the sunfish (_Orthagoriscus_), lump-fish, and
dogfish all attack jelly-fishes, perhaps in default of better food;
and far from being afraid of light, all fishes are attracted by it.
It is evident, that, if jelly-fishes possess eyes, they must be able
to distinguish others of their kind; hence their phosphorescence
may possibly be a simple signal language, if so we may term it, by
which they may find one another; or, having its origin in the nervous
functions of the animal, the light may be unconsciously emitted, and
have no more significance than a blush or sudden pallor upon the human
face. Whatever may be the value of the light to themselves, it is of
obvious use to other animals. It assists in the general illumination
of the deep recesses of the ocean; and, in the case of jelly-fishes,
certainly marks their position, and thus aids the whalebone whales
when feeding at night at depths from the surface where little light
penetrates.
The various colored lights seen upon certain crustaceans and worms, and
their peculiar position, point to the possible belief that they may be
signals, constituting a primitive means of communication; also of use
to the animals in lighting their way, as we have seen in the case of
the pyrophorus. The lights of fishes, whatever may have been the object
of nature, serve several distinct purposes: to draw the attention of
enemies, to attract prey, and to illumine the gloom about them. Any one
who has fished at night by torchlight well knows the attraction that
light has for fishes of all kinds, and when submarine electric lights
have been watched, groups of fishes and squids have been observed
about them; so it is evident that predatory fishes possessing lights
have in their lure a decided advantage.
Actual experiment has shown that the electric light can be seen
ninety-nine feet under water. The soft rays of animal phosphorescence
would not penetrate so far, but would be powerful enough to illumine
the water for some distance about them.
The deep-sea fishes which are not remarkable for their phosphorescence,
or do not possess it at all, have feelers in many instances, and grope
about like blind men: while others have eyes that not only see, but are
possible emitters of light themselves. In the case of the predatory
shark captured by Bennett, we may assume that the light was an
effective lure: but the same will not apply to the brilliant scopelus
and other delicate little creatures almost completely defenceless; so
that it will be seen that it is as difficult to lay down fixed rules
for the use of the light as to explain the cause of its production. The
phosphorescence of corals and their allies,--gorgonias, sea-anemones,
etc., may serve to attract prey. The minute crustaceans, so valuable
to food fishes, are by their unfortunate gift rendered visible to
their enemies, and the same may apply to many of the worms; while in
a certain species of the genus _Polynæ_, we have seen that the
phosphorescent scales which it throws off may be used to delude its
enemies, just as when certain lizards cast off their tails, and dart
away, leaving them wriggling and squirming, to attract the attention
of their pursuers. Certain crustaceans have luminous bands or spots
which undoubtedly serve as lanterns, while many have eyes that are
modified into light-emitting organs. The light produced inadvertently
by schools of mackerel, in their movements through water teeming
with phosphorescent animals, redounds to the benefit of the fishermen.
The pale phosphoric cloud, seen from the top masthead, resting upon the
surface of the ocean, tells the secret of their exact situation; and,
by surrounding it with the great net, large schools are often caught.
[Illustration:
PLATE XXV.
LUMINOUS WATERSPOUT.]
Among the insects we have definite experiments to show that the light
they emit is a signal; in other words, the insects recognize the lights
of their friends. A French naturalist one evening held from his window
a living specimen of _Lampyris noctiluca_ (Plate IX.) in the presence
of several friends; and a few moments later a companion insect left
the gleaming throng without, and alighted upon his hand, touching the
captive, whose light was almost immediately extinguished.
M. Raphael Dubois, member of the Zoölogical Society of France, etc.,
has shown that the _Pyrophorus_ (Plate XI.) uses its light as we would
a lantern in the night. When he covered the light upon one side of
the insect, it pursued a curved course; and, when both lights were
extinguished, it was obviously at fault, and moved along with great
care, and was evidently unfitted for nocturnal life.
We have seen how these insects were the means of saving the life of
Jaeger, in lighting him out of the forests of the southern islands; how
natives attach them to their feet, and employ them as lanterns; while
others in South America form an article of trade, being utilized by the
ladies as articles of personal adornment.
It must be evident to my young readers, that a practical application of
the general features of phosphorescence would be extremely valuable,
and in the previous chapter luminous paints and writing fluids have
been referred to. An English chemist, named Balmain, has produced
from Canton’s phosphorus a paint which is luminous in the dark, and
which has been applied to many purposes. Years ago the Chinese used
a luminous paint made from powdered mussel-shells. The Emperor Tai
Tsung, who reigned in the latter part of the tenth century, possessed
a painting which, if examined by day, represented a cow browsing in an
open pasture, but if this picture was taken into a darkened room, or
looked at by night, the cow was seen to be lying down behind a fence,
securely housed and protected. The secret was, that the fence and the
cow in the night picture were painted in “South Sea pearl paste,” as
the Chinese called their phosphorescent paint, and were alone visible;
while in the daylight the painting of “powdered reef-stone” only was
seen, representing the animal in a standing position.
To Balmain, however, is due the credit of introducing luminous paint in
this country and Europe, and it is applied to many objects. We have the
faces of our clocks and watches luminous, so that the time can be told
in the dark. Match-safes are rendered conspicuous by the same means,
and various other articles.
Through the courtesy of Messrs. Devoe & Co., of New York, I was
enabled to examine the application of this paint upon statuary and
other objects. Upon entering a dark room, a statue was seen outlined
in a wonderful bluish light of remarkable softness and beauty. An arm
resting upon a table was vividly luminous, and presented a ghostly
appearance. A large globe which hung from the ceiling gave out a soft
radiance, quite sufficient to dispel the darkness, and the entire
exhibition was suggestive of the varied uses to which the light could
be put. Among these might be mentioned the painting of houses, so that
they will render the streets luminous; buoys at sea; even the hulls
of ships and their sails might be made conspicuous in this way. In
London the harnesses of horses engaged in night work have been rendered
luminous by this paint; and its availability in mines, and in large
sewers like those of London, tunnels, and other subterranean works
can hardly be estimated. Artificial fishes are painted, and used as
luminous bait; and toys innumerable are placed upon the market, made
interesting by application of this discovery.
It is obvious that luminous paint cannot be used in some cases, and
to take its place Messrs. W. C. Home and E. Ormerod of London have
recently invented a method of utilizing the luminous powder prepared
mainly as a sulphide of calcium, for admixture with cements, plaster
of Paris, and concrete, the object being to prepare the articles with
a self-contained phosphorescent property instead of coating them with
luminous paint. They take the proper proportion of any suitable cement,
with the right amount of the luminous powder, mixing these with water,
and moulding it to the required shape in the usual way, after which it
is laid on the ceilings or walls with a trowel. The patentees attach
importance to placing the moulded articles, as soon as dry, in a bath
of paraffine wax and benzoline, or other water-proofing substance
equally good.
In the case of using the luminous cement upon a wall or ceiling, they
sponge or brush the surface over with a solution of paraffine wax and
benzoline, or other suitable damp-proofing solution. The uses of a
luminous cement are manifold; e.g., for the garden, luminous concrete
as edging to garden-paths and carriage-drives; for guides and beacons
at the entrance-gates of drives; insides of stables; the base of
balustrades, or the entirety of balustrades; for roads, as luminous
beacons of corners of dark country lanes, and at the ends of bridges,
ends of walls, and curbs of foot-paths; for docks; for edging of piers
and wharves; for water-works; for the safety and despatch of night-work
by the erection of luminous guides and beacons; and for fire-plug
notices on walls; in short, for any place where the light of day will
sufficiently excite the phosphorescent property as to render the cement
or concrete work luminous by night. The difficulty of sighting rifles
in the dark has been ingeniously overcome by the use of luminous
paint, and it is thought that the armies of various nations will adopt
phosphorescent sights for general use.
I have before me as I write, through the courtesy of M. Raphael Dubois
of Paris, a fine photograph of a bust of Claude Bernard, taken by the
light of numbers of phosphorescent insects (elaters), which shows the
possibility of work in this direction.
M. Ch. V. Zenger of Paris has made some interesting experiments, and
expressed the belief, some time in 1883, that Mount Blanc could be
photographed by phosphorescent light emitted, and I understand this has
been accomplished. M. Zenger has photographed objects by the light of
Balmain’s phosphoric plates. From a personal communication from this
scientist, I will quote some things which he has kindly submitted for
the author’s use in this volume, referring to this work and the use of
Balmain’s liquid phosphorus. As a light, he says, “No doubt there may
exist better and more perfect phosphorescent bodies of green, greenish
blue, and violet hue, than are at my disposal; and to avoid the use of
sulphurets and sulphides, etc., and to obtain as long a phosphorescence
as possible, is all I want to reduce stellar photography to the
simplest and cheapest apparatus, and make it available to every one.”
As we have seen, the light emitted by animals, plants, and minerals,
of whatever cause, presents much that is mysterious; and the problem
of animal phosphorescence would seem no nearer being solved to-day
than it was fifty years ago. This is perhaps due to a lack of study
and investigation. A glance at the appended bibliography shows that
much has been written upon the subject; but it is only within the last
decade that serious work in this direction has been done, typified
in the superb work of Dubois, and the papers and monographs of the
other scientists mentioned. The naturalists of the “Albatross,” the
government exploring steamer, are to make investigations regarding the
luminosity of the Pacific, during the forthcoming tour on the western
coast. The French Academy of Sciences offers this year a prize of three
thousand francs for the best paper upon animal phosphorescence. From
this it would appear evident that the phenomenon is creating renewed
or increasing interest, and in the following years will be the subject
of much study and investigation; and we may expect in the near future
to have not only its cause explained, but possibly to see a practical
application of its possibilities to the wants of mankind.
APPENDIX.
[1] PAGE 5.--_Noctiluca._ This interesting little creature belongs,
in the natural arrangement as now recognized by science, to the first
grand division of the animal kingdom. Simple as it is, it is not so
completely without organs as some which form the first groups of this
first division, as it has a whip-like organ, which gives name to its
group, the _Flagellata_, or flagellate infusorians. These monads, as
they are also called, are represented by a species of _Noctiluca_ in
our North-American waters off the coast of Maine. Huxley regards its
luminous property as given out by the peripheral layer of protoplasm
which lines the cuticle.
M. Giglioli of Bologna, Italy, in a letter to the author, says, “I have
distinguished three modes of marine phosphorescence, very distinct,
which present a great number of varieties. These are,--
“(_a_) Diffused homogeneous milky light.
“(_b_) Luminous points, sparkling and inconstant.
“(_c_) Luminous disks, with light generally fixed, and not
sparkling.
“In one case the sea seemed on fire, and dolphins seemed to be fire.
“Again, the sea seemed to acquire an oily consistence, giving out soft
homogeneous light, of a milky color, tinted with green or bluish. It
is perhaps the least frequent, but most striking. It is due to the
presence of noctiluca. It often resembled incandescent rain falling
from the paddle-wheels of steamers.”
M. Giglioli agrees with Huxley in stating that “the phenomenon of
phosphorescence in these animals does not reside in the protoplasmic
branches, which, as is known, are sometimes wanting; but in the
cortical substance it is not uniform, but manifests itself in distinct
and very minute luminous points, which sparkle, go out, and light up
again.”
[2] PAGE 9. Kiel observed this phenomenon in _Peridinium_. The
following species of luminous forms existing in the Baltic Sea have
been described by Ehrenberg: _Prorocentrum micans_, _Peridinium
michælis_, _Peridinium micans_, _Peridinium fuscus_, _Peridinium
furca_, _Peridinium acuminatum_, _Lynchata baltica_, and a species of
_Stentor_.
[3] PAGE 9. Giglioli and his assistant, De Fillipi, observed luminosity
in the gelatinous mass described by Hækel as _Citophora_.
The genera of those low forms most remarkable for luminosity are
_Thalassicolla_, _Collozoum_, _Sphærozoum_, and _Collosphæra_. Giglioli
states that the forms of this group which are found in the Indian Ocean
and China seas are not luminous.
[4] PAGE 11. _Dymophora fulgurans._
[5] PAGE 12. Other light-givers of this group are _Willsea prolifera_,
_Bourganivillia_, and _Lizzia_.
[6] PAGE 12. _Mueniopsis leidyii._
[7] PAGE 13. The _Lucernaria_ is a very rare form of _medusa_ on our
northern shores, and particularly characteristic in color and form. It
is more like a polyp in texture, and its rich beryl color distinguishes
it from all other forms. It is related to the _Discophores_, animals
belonging to one of the groups of jelly-fishes, or _medusæ_.
[8] PAGE 14. Schafer has observed radiating fibres on the under side,
but there is no evidence to show that the luminosity originates here.
In fact, the outer surface, where the cells of the delicate epithelium,
or skin, contain minute points of fatty material, is equally
phosphorescent. The tentacles become luminous, and it is supposed
that they contain no nerves except at the margin of the disk. In some
instances the light seems well defined at the so-called eye-spots at
the edge of the disk, but its sudden fluctuations render any attempt at
locating a photogenic structure difficult.
While numerous theories are advanced, investigators are entirely at
fault as regards any satisfactory explanation of the phenomenon. There
are certain conditions which are not favorable to the emission of
light; and observers have seen _medusæ_, vividly luminous at one time,
and not so at another.
It has been suggested that the light is subject to the so-called
will of the creature. A better theory, perhaps, would attribute the
luminosity to certain peculiar conditions, or to certain stages of
existence.
[9] PAGE 15. _Pleurobrachia rhodactyla_, Agassiz. This is one of the
numerous free-swimming marine animals, belonging to the _Ctenophores_.
A group of the sea-jellies which have the pretty rows of paddles
adown their long diameter. They are usually about a pigeon’s-egg in
size, are oval, and in their element almost invisible, so colorless
and transparent are they. A close inspection shows the paddles to be
iridescent.
[10] PAGE 15. _Idya roseola_, Agassiz. Another form found near the
shores of Nahant.
[11] PAGE 16. The _Physophoridæ_ include the interesting forms,
_Physalia_ (Portuguese Man-of-War), _Porpita_, _Vellela_, etc. The
first named indicates the character of the group, as its fleshy mass
is surmounted by a beautiful bladder-like float, a mere bubble of
membrane. These forms are not often seen out of tropical waters.
[12] PAGE 16. The term zooids is applied to the mass of tentacles and
other fleshy parts of the _Physophoræ_. The long, extensile feelers are
for prehension; others aid in locomotion, and some are reproductive;
others are feeders for the entire colony. Thus it will be seen that
these creatures are in a sense compound animals.
[13] PAGE 24. Alcyonarian corals from an order in the class _Actinozoa_.
[14] PAGE 24. Professor Moseley, of the “Challenger” expedition, was
enabled to examine the light from these beautiful forms by the aid of
the spectroscope, and found that it consisted of red, yellow, and green
rays only.
[15] PAGE 25. _Acanella normani Verril._ A pretty soft coral, which has
been dredged off the New-England coast by the fish-commission. This
is a revelation to science, as no one was ready to believe that such
forms, so common to the tropical regions, would be found where they
were. The Gulf Stream runs so close to the North-eastern States, it
will not, on reflection, seem strange that some creatures common to the
warmer waters may find a home there.
[16] PAGE 25. _Primnoa resida._
[17] PAGE 25. _Paragorgia arborea._
[18] PAGE 26. _Pennatulidæ._ The name of a family of marine animals,
which includes the _Umbellularias_, _Veretillum_, etc.,--the last
highly phosphorescent.
[19] PAGE 26. While investigations so far have failed to explain the
physiology of the light, it has been found that in a perfect animal it
is emitted from eight opaque cords, each of which passes from a little
swelling at the base of a tentacle down each polyp into the covering
of the branch. The cords are canals in the sarcode of the branch,
connecting the hollow of each tentacle with the tubular cavities of
the branchlets and stem. The microscope shows that the contents of
the canals are a fluid and cells; the latter containing minute highly
refracting globular particles of a fatty substance, which resists
decomposition long after the death of the polyp itself. If these cords
are ruptured, the luminosity of the entire mass is excited, and the
fatty cell contents is luminous after its escape, and on foreign matter
even after the death of the animal.
Regarding the light, Duncan says, referring to Panceri’s experiments,
“There is no sensible increase of temperature, and the tint of the
monochromatic light is azure or greenish, but never red. In this
beautiful instance of this remarkable vital luminousness there is
evidently a photogenic structure and an elaborated organic material
capable of producing light after removal from the animal. The sequence
of illuminating the whole pen is slow,--far less than that of the
movement of nerve-force. Yet the presence of the lowly organized
nervous element indicates that the regulating of the light may relate
to it as its function.”
Perhaps the most magnificent of all the _Pennatulidæ_ is the tall
_Umbellularia grænlandica_ (Plate XXI., Fig. 2), which consists
of twelve huge polyps, each with eight fringed arms, terminating in a
close cluster upon a stalk about four feet in height. This striking
form was dredged by the “Challenger” expedition in water over two miles
in depth, where the pressure is so great one can hardly realize it,
and the temperature is just above freezing. Sir Wyville Thompson says,
that, when this splendid animal was taken from the trawl, it emitted
a light so brilliant that Capt. Maclear found it an easy matter to
determine the character of the light by the spectroscope. It gave a
very restrictedly continuous spectrum, sharply included between the
lines _b_ and _d_.
[20] PAGE 27. _Pavonia quadrangularis._
[21] PAGE 27. _Asteronyx loveni._
[22] PAGE 27. _Ophiacantha._
[23] PAGE 28. _Renilla reniformis._
[24] PAGE 28. _Virgularia_ is so named from its rod-like form; _vira_,
a rod. _V. mirabilis_ is found off the English coast.
[25] PAGE 30. _Ophiura_ and _Asterias_. These are genera of the
sea-stars, or star-fishes long so called; the former so named on
account of the resemblance to snakes in its arms.
[26] PAGE 30. _Ophiothrix fragilis_, _Amphiura belli_, and _Ophiocantha
spinulosa_.
[27] PAGE 31. _Ophiocnida olivacea_ and _Ophiocantha bidentata_.
[28] PAGE 31. _Brisinga elegans._
[29] PAGE 32. _Astrophyton._ There are several species of this
star-fish, but each found in deep water. They are curiously
circumscribed in locality. In one place off Cape Cod they are
dredged, but in no other place, excepting farther south. Their
name, basket-fish, is from their numerous intwined arms, resembling
basket-work.
[30] PAGE 37. _Serpula._ A genus of the group _Annelida_.
[31] PAGE 37. _Neiridæ_ and _Eunicedæ_. Genera of the group _Annelida_.
[32] PAGE 37. _Polynoidæ_, _Scyllidæ_, _Chætopteridæ_, and _Polycirus_.
[33] PAGE 38. _Chætopterus norvegicus._
[34] PAGE 39. _Harmothoe imbricata_ emits a bright greenish light
when disturbed, the luminosity evidently proceeding from the point of
attachment of each dorsal scale.
[35] PAGE 40. _Pholas._ A clam-like mollusk. Several species are
found on Nahant beaches. _P. dactylus_ is a European form. The genus
_Zirphæa_ is found from New England to Great Britain. All are more or
less borers. A small species bores in hard mud on the Nahant beaches.
Others are known to bore into hard wood and into stone.
_Pholas dactylus_ will be seen to have photogenic or light-emitting
structures and substances almost concealed in the tissues of the
animal. The light-emitting portions are, according to Panceri, “two
parallel cords containing an opaque white matter extending down the
anterior siphon, two very small spots at its entrance, and finally an
arched cord corresponding to the superior edge of the mantle, reaching
to the middle near the valves. The white color of the cords, which
stand out in relief, distinguishes them; and, although they are only
elevations of the subcuticular tissue, they contain special cells,
or rather epithelium, which produces the phosphorescent matter. The
whole surface of the Pholas is covered with ciliated epithelium, which
dips down into all the parts of the animal; but the special epithelium
differs from this. It is nucleated and crammed with granules, and
the cells are very refractive. The cells are very fragile, and allow
their contents--i.e., granular nuclei and refractive granules--to
escape readily. These are soluble in ether and alcohol. Under ordinary
circumstances this photogenic apparatus is hidden; but violence readily
displaces the special cells, which burst, and their contents are
carried all over the surface by the water, assisted by the general
ciliation. The white substance, fat-like, retains its luminosity, when
spread out on paper, for hours; but the light does not appear to be
accompanied by an evolution of heat. When it is placed in carbonic acid
gas, the light pales and ceases. On the other hand, the photogenic
substance, when barely luminous, is rendered so by physical contact.
Agitation, and the addition of fresh or salt water, develop the light,
and the same effect is produced by electricity and by heat. The light
is monochromatic, and has a constant place in the spectrum as an azure
band from E to F, that is to say, in the green.”
[36] PAGE 44. _Dendronotus arborescens._ A curiously decorated marine
slug, found on the algæ of the waters around Massachusetts Bay. _Eolis_
is another form nearly as interesting.
[37] PAGE 55. The spectrum of the light of comparatively few of these
beetles has been examined. That of _Photinus_ was found by Professor C.
A. Young, the astronomer, to be continuous without lines, and to extend
from Fraunhofer’s line C in the scarlet, to about F in the blue.
Mr. Meldola examined the spectrum of the light of the glow-worm some
years ago, and found that it was continuous, being rich in blue and
green rays, and comparatively poor in red and yellow.
[38] PAGE 56. Professor Carl Emery of the Entomological Society of
Italy has kindly sent to us a detailed account of his experiments
with the illuminating apparatus of a native luminous insect, the
_Luciola italica_, etc. As these are the latest conclusions by the
highest scientific authority, and therefore to be regarded as the most
reliable, we here present a full account.
“The elytra of the insect _Luciola_ were glued upon a holder of the
microscope, and covered by a glass of tolerable thickness. On examining
it, I got a favorable magnifying power, A of Zeiss. With stronger
objective there is no good effect.
“The eye is at first dazzled by a strong, uniform yellowish light. But
the intensity of this light is soon checked, the luminous field being
interrupted by round spots. The light continues to diminish; the image
becomes paler; and between the obscure round spots are seen to appear
confused shadows, which detach themselves from the more brilliant
rings. These rings are last to disappear when all the other portions
have become dark. In the end they disappear entirely.
“The organ remains dark until the next flash; only here and there
brilliant isolated points persist, which, as we shall see later,
represent parenchymal cells which have retained their activity. If one
places under the microscope the detached abdomen of a normal Luciola,
and excites it by pressure of short duration by the cover glass, it is
possible to obtain a flash which resembles the physiological flash.”
M. Emery states that he found it unsatisfactory to examine the insect
while alive, as the constant movements rendered it nearly impossible to
observe correctly the phenomenon of luminosity. He proceeds: “I have
found by poisoning the Luciola by vapors of osmic acid an excellent
method in fixing the light, and studying exactly the microscopic aspect.
“When one examines in a dark chamber the abdomen detached from a
Luciola which has been plunged in a solution of osmic acid, it is seen
that a part of the segments occupied by the luminous organs shine with
a feeble and variable light; whilst another part (ordinarily in the
neighborhood of the median line) is obscure, or as it were veiled by a
light phosphorescent cloud. When the preparation is placed under the
microscope, the luminous parts exhibit towards the top the appearance
which we have already noted in examining normal Luciolas; that is to
say, the existence of obscure round spots surrounded by brilliant
field. In observing more attentively, one perceives around the spots
other little spots, less obscure, and sometimes hardly visible,
disposed with a certain degree of regularity.
“Now, if we compare these images with those which are presented under
the microscope by the luminous organs when hardened in alcohol, and
cleared up by caustic potash, or else a tangetized section made of
the organ of an animal killed by osmic acid, and colored by carmine,
it becomes evident that the large, obscure round spots correspond to
the central part of the digitiform lobes of _Targioni Tozzetti_;
that is to say, to the cylinders constituted by the matrix of trachea
(_Tracheenendzellen_ of M. Schultze), whilst the luminous part
is represented by the parenchymentous cells, and the little obscure
spots are due to nuclei of these same cells. Still towards the limit of
the brilliant and obscure regions of the luminous organ a very varied
spectacle is observed....
“From all the facts which we have just described, one may conclude
with full certainty that the light of the Luciola has its seat in the
parenchymentous cells of the luminous organ.”
“It remains to be seen if the luminous combustion does not also take
place, though, with luminosity in other parts. In my previous work I
had it that the surface of the cylindrical lobes formed by the matrix
of the tracheæ was the principal focus or seat of the combustion. The
facts which result from later observation oblige me to abandon this
opinion....
“In the moments of mean luminous activity, one may say that the
combustion is situated exclusively in the parenchymentous cells of the
superficial layer of the luminous organ.”
[39] PAGE 73. _Gammarus caudisetus_, _Gammarus longicornis_, _Gammarus
truncatus_, _Gammarus heteroclitus_, _Gammarus crassimanus_. _Cyclops
exiliens_ is also luminous.
[40] PAGE 77. Another species in which this change had taken place is
_Galathodes antonii_, an allied form which is shown in the central
figure of the frontispiece. Many more, as _Willemœsea_, _Pentacheles_,
_Polycheles_, and others, have organs of vision, which have undergone
more or less change. It has been suggested that certain deep-sea
crabs, as _Geryon tridens_, _Gonoplax_, _Donychus_, and _Munida_, have
phosphorescent eyes.
In _Ptycogaster formosus_ (Plate XIII., Fig. 1), we find an interesting
form, living at a depth of twenty-eight hundred and fifty feet, or
more than half a mile, from the surface, which is provided with
well-developed eyes.
[41] PAGE 81. The individual zooids, amounting to many hundreds, are
grouped in whorls, their orifices so arranged that the inhalent are
upon the outside of the cylinder, and the exhalent upon the interior.
Each animal draws in a current from the outside, ejecting it into the
interior; the result of this volume of water rushing from the open
end being that the entire colony is forced along, at the same time
revolving upon its long axis.
[42] PAGE 81. Panceri says, “Each zooid has two luminous spots, which
are situated over the position of the ganglia of the nervous system;
and there are loops like cords passing over the narrow end, connecting
them.”
[43] PAGE 94. Dr. Gunther expressed the view that the organs are the
producers, not the receivers, of light. He says, in brief, that the
number of pairs of small globular bodies found along the abdominal
profile is in direct relation to that of the vertebræ, the muscular
system, etc. These are of two kinds. One class consists of the
anterior, bi-convex, lens-like body, which is transparent during life;
simple, or composed of rods, and coated with a dark membrane composed
of hexagonal cells or rods arranged as in a retina. This structure
characterizes the plates of _Stomias_ (Plate XX.), _Astronechtes_,
_Chauliodus_ (Plate XXI., Fig. 4).
In the other set, as found in _Gonostoma_, _Myctoplum mausolicus_, and
_Argyopelicus_, the organs have a simple, glandular structure. Branches
of spinal nerves have been traced to each organ, and are distributed
over the retina-like membrane of the glandular follicles.
The difference in structure of those organs naturally produces
difference of opinion regarding their functions; but Gunther believes
that all the organs in their functions have some relations to the
conditions of light in which the fishes that possess them live. Three
principal theories regarding them are given: first, they may all be
accessory eyes; second, only the organs with the lenticular body are
eyes, and those with glands are light-givers; third, all are producers
of light. Many arguments have been advanced to support these different
hypotheses; but it would seem that the second view is most tenable,
from the fact that the organs with the retina-like membrane bear a
great resemblance to a true eye, and finally the glandular organ
in the little fish _Myctoplum_ has been seen to gleam with a
phosphorescent light. Dr. Gunther thinks it not improbable that the
compound organ is an accessory eye, and a light-producer as well. The
light, he says, may be produced at the bottom of the posterior chamber,
and emitted through the lenticular body in particular directions, with
the same effect as when light is sent through the convex glass of a
bull’s-eye.
[44] PAGE 104. _Orthogoriscus mola._
[45] PAGE 128. Diatoms: _Pyrocystis pseudo-noctiluca_ and _P.
fusciformis_.
[46] PAGE 138. The common mushroom (_Agaricus campestris_), the meadow
mushroom (_Agaricus arvensis_), the French champignon (_Marasmius
oreades_), and in Austria _Agaricus mellius_, are eaten largely.
Truffles (_Tuber æstivum_), Morels (_Morchella esculenta_), and
Puff-ball (_Lycoperdon giganteum_) are also favorites in Europe.
[47] PAGE 138. Jew’s ear: _Himcola auricula Judæ_.
[48] PAGE 138. _Myletta austratis._
[49] PAGE 149. See the description of ooze on page 3. This ooze is
formed of the cast-off shells of the _Diatoms_, the minute vegetable
forms of low organization.
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INDEX.
Æroscope, 155.
Agaric, luminous, 135, _et seq._
Agassiz, Mrs., on jelly-fish, 11.
---- Louis, 19.
Baird, William, on Chinese fire-flies, 68.
Baird, Professor S. F., 94.
Balmain’s luminous paint, 164.
Banks, Sir Joseph, on luminous crabs, 75.
Beetles, 47.
cannonading, 48.
odorous, 48.
flesh-eating, 48.
grave-digging, 49.
_Scarabæus_, 49.
lightning-bugs, 49.
Bellot, Lieut., on luminous crustaceans, 73.
Bennett, D. F., on luminous shark, 100.
Berkeley, Rev. J. M., on fox-fire, 131.
Black swallower, 97.
Blind fishes, 92.
“Blood-rains,” 153.
Bombay duck, 93.
Boon Island, sea-jellies at, 10.
Boring-shells, 40.
Branner, John C., on lantern-fly, 67.
Burning bush, legends of, 129.
Canton’s phosphorus, 156.
Centipedes, 69.
Chalk Cliff, Dover, 3.
“Challenger,” exploring-ship, 24, 31.
China, luminous insects in, 65.
Chinese luminous paint, 164.
Coal-mines, luminosity in, 133.
Collingwood, Dr. Cuthbert, on luminous fungus, 134.
Corals, 21.
Col. Pike on their phosphorescence, 21.
Cosmic dust, 148 _et seq._
composition of, 149.
Crabs, luminous, 72 _et seq._
Cranes, phosphorescence of, 109.
Crustaceans, luminous, 72.
Lieut. Bellot on, 73.
Nordenskiöld on, 73.
Cuttle-fishes, 46.
Cyclops, 73.
Darwin on phosphorescence of _Medusæ_, 17.
---- on earthworms, 34.
---- on lightning-bugs of South America, 57.
---- on dust-showers, 152.
Deep sea, fishes of, 91 _et seq._
Deep-sea shrimps, brilliant colors, 79.
Deep-sea dredging, 93.
Dejean, Gen., story of, 47.
Diatoms, luminous, 128 _et seq._
Donovan, luminous insects of India, 68.
Drummond, Mr., on luminous toadstools, 136.
Dubois, Professor Raphael, on phosphorescence, 61.
Dust, luminous, 148.
Dust showers at sea, 152.
Earth-worms, 33.
of New Zealand, 33.
Darwin on, 34.
Roman villas preserved by, 34.
of Australia, 35.
of India, 35.
luminosity, 35.
Echinoderm, nature of, 29.
Finny light-bearers, 91 _et seq._
Fireflies, 59 _et seq._
as ball-room ornaments, 59.
as lanterns, 60.
spectrum of their light, 61.
brilliancy, 52.
Fire-mushroom, 134.
Fish, luminous, 91 _et seq._
Fish, dead, phosphorescent, 141.
“Fish-stories,” 97.
Fogs, luminous, 146.
Fox-fire, 131.
Florida Reef, 3, 24.
displays of phosphorescence at, 107.
Flowers, luminous, 121.
Frog’s eggs, luminosity of, 114.
Fungus, luminous, 133 _et seq._
Gardiner, Mr., on luminous fungus, 135.
Garfish, phosphorescent, 106.
Gecko, luminosity of, 115.
_Globerigina_, 3.
Goethe on luminosity of poppy, 122.
Gorgonias, 24.
Sir Wyville Thompson on, 25.
Dr. Holder on, 26.
Günther, Dr., on luminous fish, 92.
Hailstones, luminous, 145.
Homer’s “Iliad,” dust-shower in, 154.
Herons, luminosity of, 113.
Human beings sometimes luminous, 116.
Humboldt on phosphorescence, 6.
Ice, luminous, 146.
Infusoria, 152.
Jaeger, Professor, on luminous beetles, 60.
Jelly-fish. See _Medusæ_.
Josephus refers to luminosity of plants, 130.
Kane, Dr. E. K., curious instance of luminosity recorded by, 117.
Lantern-flies, 64 _et seq._
Legends of the “burning bush,” 129.
Light-emitting organs of _Medusæ_, 17.
Luminous larvæ, 54 _et seq._
Lightning-bugs, 47.
Southey, the poet, on, 49.
of West India Islands, 50.
Gosse on, 51.
common, of Eastern United States, 52.
common, of Europe, 56.
Luminosity in man, instances of, 116.
of plants, 129 _et seq._
Luminous organs of lightning-bugs, 55.
---- fishes, 94.
---- fogs, 146.
---- “ink,” 156.
---- marbles, 155.
---- organs of fishes, 98.
---- paint, 157.
---- showers, 144.
Lyell, Sir Charles, on cosmic dust, 152.
Mackerel, luminosity of, 104.
Marigold, luminosity of, 121.
Martyr, Peter, on luminous insects, 62.
Meat, phosphorescent, 141.
_Medusæ_, or jelly-fish, 10–18.
numbers, 11.
light-givers, 11.
Professor A. Agassiz on, 12.
brilliance, 14.
Darwin on, 17.
Spallanzani on their phosphorescence, 17.
Humboldt on, 18.
Menhaden, luminosity of, 103.
Merian, Madame, on the luminosity of _Fulgora lanternaria_, 66.
Meteors of the sea, 10.
Monkey, luminosity of eyes of, 114.
Moonfish, 105.
Mount Blanc, luminous cap of, 146.
Mushrooms, edible, 138.
Mussel Bay, luminous snow, 74.
Nasturtium, luminosity of, 121.
_Noctiluca_, 4–9.
Nordenskjöld discovers cosmic dust, 148.
Oban, sea-pens at, 26.
Ogunquit, Me., sunfish at, 104.
Ooze, 3.
Ovideo on luminous insects, 62.
Phantoms, 140.
Pholas, 40.
Phosphorescence of the sea, 6–9.
---- the secret of, 41.
---- of _Pyrosoma_, 81.
Phosphorescence, its uses, 160.
Pliny, on the luminosity of Pholas, 41.
Polyps, their phosphorescence, 24.
Poppy, luminosity of, 121, 123.
Pteropods, 42.
_Pyrosoma_, 81 _et seq._
Rotifers, 36.
San Gabriel Valley, beetles in, 48.
Sea-anemones, 20.
Sea fans and plumes, 24.
Sea-opossum, 75.
Sea-pen, 26–28.
Sea-slugs, luminous, 44.
Sea-urchins, 29.
Seas of flame, 86 _et seq._
Serapis, Temple of, 40.
Shark, luminous, 99 _et seq._
Slugs, garden, 45.
Spiders of the sea, luminous, 76.
Squid, 46.
Star-fish, 29–32.
Sugar, flashes of light from, 155.
Sunfish, 104.
Toadstools, luminous, 136.
Touchwood, or fox-fire, 131.
Trepang, 29.
Tulasue, M., on luminous fungus, 134.
Venus’s girdle, 15.
Verbenas, luminosity of, 122.
Water-fleas, 72.
Water-spouts, luminous, 127.
Whales, supposed phosphorescence of, 106.
Worms, marine, 35.
phosphorescent, 36–39.
Worrall, Mr. Isaac W., on luminosity of crane, 109.
Transcriber’s Notes:
1. Obvious printers’, punctuation and spelling errors have been
corrected silently.
2. Some hyphenated and non-hyphenated versions of the same words have
been retained as in the original.
3. Italics are shown as _xxx_.
4. Bold print is shown as =xxx=.Project Gutenberg
Living lights : $b A popular account of phosphorescent animals and vegetables
Holder, Charles Frederick
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