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.

BIBLIOGRAPHY

OF

WORKS ON PHOSPHORESCENCE.

A.D.

1526. Oviedo y Valdes Gonzalo Fernandez. De Luminario de la

Natural y General Istoria de las Indias. Toledo, 1526.

1536. Anglicera (Pietro Martine d’). Decades of the New World

(De rebus Oceanio et Orbe novo Decades). Paris, 1536.

1634. Moufet. Insectorum sive Minimorum Animalium Theatrum.

1635. Joannes Eusebius Nierembergius. Hist. nat., lib. xiii. c.

iii.

1647. Bartolin, Thomas. De Luce Animalium, lib. iii. Lugd.,

Batav., ex officina Francisi Hackii, p. 205.

1667. Dutertre. Histoire générale des Antiles françaises, p.

280. Paris.

1667. Stubbes. A Continuation of the Voyage to Jamaica.

Philosoph. Trans. No. 36 (Mem. of Royal Society, 2d ed.

1745). Id., Jour. d. Scav., 1667.

1668. Norwood. Observations in Jamaica. Philosoph. Trans. No. 41

(Mem. of the Royal Society, i. London).

1725. Sloane. A Voyage to the Islands Madeira, Barbados, Nieves,

St. Christophers, and Jamaica, etc., ii. p. 206. London.

1742. Melchior, Johan Alb. De Noctilucis (Lampyris, Elater).

Franequeræ. Dissert. philosoph. (Bibl. de Lacordaire).

1756. Brown. The Civil and Natural History of Jamaica. London.

1763. Gronov. Zoöphylacium Gronovianum. Lug., Batav., p. 152,

No. 474.

1764. Linné. Museum S. R. M. Lud, Ulr. Reg. Holmiæ, 1764, p. 83,

et Syst. Nat. ed. 12, tome i. part ii. Holmiæ, 1767, p.

651.

1766. Fougeroux de Boudaroy. Mémoire sur un Insecte de Cayenne

appelé Maréchal et sur la Lumière qu’il donne. Mém. Acad.

d. Sc., p. 339.

1774. De Geer. Mémoires pour servir à l’Histoire des Insectes.

Stockholm. iv. 1774, pp. 160, 161.

1790. Olivier. Entom. ii., p. 15.

1805. Palisot de Beauvois. Insectes d’Afrique, et d’Amérique.

Paris.

1807. Illiger. Monographie der Elateren (Elateren mit

leuchtenden Flecken auf dem Halsschilde).

1807. Viviani. Phosphorescentia Maris, quatuordecem novis

speciebus illustrata. Genua, 1807.

1809. Azara. Voyage dans l’Amérique méridionale, 1781–1801, i.

p. 114. Paris, 1809. 4 vol. in 8^o et Atlas.

1810. Macartney. Observations upon Luminous Animals. Phil.

Trans., pp. 277, 279, v. 100.

1814. Humboldt et Bonpland. Voyage au Nouveau Continent,

iii., p. 482. Humboldt, Relation historique, i. p. 79 et

533. Humboldt, Tableaux de la Nature, ii. p. 69. Paris,

1851.

1817. Gilbert, M. Annales Maritimes. 1817.

1817. Kirby and Spence. Introduction to Entomology, p. 513, et

Note, abrigée de Morren, 7^e éd., 1856, p. 503 et suiv.

1823. Spix et Martius. Travels in Brazil, 1817–1820.

1827. Curtis. Account of Elater noctilucus of the West Indies.

Zoöl. Journ. iii. p. 379.

1830. Lacordaire. Mémoire sur les Habitudes des Insectes

Coleoptères de l’Amérique méridionale. Ann. d. Sci. Nat.

xx. p. 241, et Introduction à l’Entomologie.

1832. Burmeister. Handbuch der Entomologie, i. p. 535.

1832. Latreille. Voyage de Humboldt, Recueil d’Observations

de Tropiques dans les Années 1799–1804, v. Paris,

1811–1832. Insectes, i. pp. 127–304, pl. xv. à xxv., ii.

p. 9 à 138.

1838. Dugés. Traité de Physiologie comparée, tome iii.

Montpellier, 1838.

1840. Tessan, M. de. Comptes Rendus de l’Académie des Sciences.

1840. Rapport fait par M. Arago.

1840. Hooker’s Journal of Botany. Light of Agarics. 1840. p. 426.

1841. Coldstream. Todd’s Cyclopædia of Anatomy and Physiology,

part xxii. 1841. Article on “Animal Luminousness.”

1841. Heward, Robert. Memoir of the Fireflies of Jamaica.

(Verschiedenheit in Emission des Lichtes bei Elater und

Lampyris.) The Entomologist, pp. 42–43.

1841. Morren. Sulla Fosforescenza delle Lampiridi noctiluca e

splendidula; Atti terza Riunione Scienz. Ital., Firenze,

1841, p. 366. Isis, vii. p. 412, 1843.

1841. Germar. Beiträge zu einer Monographie der Gattung

Pyrophorus. Germar’s Zeits. d. Entom. iii. p. 1, 1841.

Bemerkungen über Elateriden. Germar’s Zeits. Entom. iv. p.

43, 1843; v. p. 133, 1844.

1841. Erichson. Of Pyrophorus from Cuba (sic). Wilgmann’s

Archiv, i. p. 87.

1843. Dowden. Proceedings of the British Association. Light of

the Marigold.

1843. Lankester, Dr. E. Luminosity of the Marigold. Gardener’s

Chronicle, 1843, p. 691.

1844. Reiche. Note sur les Propriétés lumineuses du Pyrophorus

nyctophanes. Ann. de la Soc. ent. franç. (2), ii., Bull.,

pp. 63–67.

1845. Luminous Vegetables. Proc. Royal Asiatic Society. April,

1845.

1848. Tulasue. Light of Agarics. Annales des Sci. Nat. Paris,

1848. ix. p. 340.

1848. Tulasue. On the Phosphorescence of Vegetables. Ann. des.

Sci. Nat., 1848, vol. ix. 340.

1850. Burnett. On the Luminous Spots of the Great Firefly of

Cuba (Pyrophorus phosphorus). Proceed. Boston Soc. Nat.

Hist. iii. pp. 290–291.

1853. De Lacaze-Duthiers. Recherches sur l’Armure génitale

femelle des Insectes. Ann. d. Sc. Nat. (3), xix. pl. 3,

figs. 6, 7, 8, 9, 1853.

1853. Reinhardt, J. F. Twende Jagttagelser af phosphorish

Lysning hos en firk og ep Insectlarve. Vidensk Meddel. fra.

d. Naturalist. Foren Kjœbenh. for 1854, pp. 60–65.

Transact. Entom. Soc., London (2), iii. 1854 (Proceed.,

pp. 5–8). Zeitschrift f. d. gesammt., Naturw, v. 1855, pp.

208–212.

1855. Van der Hoeven. Einige woorden over het Lichten van den

Zuid-Amerika anschen Springkever. Album der Natur, 1855;

aflev., 7, pp. 205–212.

1859. Light of Scarlet Verbena. Gardener’s Chronicle, July 6,

1859, p. 604.

1860. Montronzier. Essai sur la Faune entomologique de la

Nouvelle Calédonie. Ann. Soc. Entom. Fr., p. 258.

1863. Dr. Hahn. Luminosity of Dictamnus Albus. Journal of

Botany, 1863.

1863–65. Caudèze. Monographic des Élatérides; Mém. de la Soc.

Roy. d. Sci. de Liège, xvii. pp. 1–76. 1863. Sep. iv.

Élatérides vrais, p. 76, pl. i. fig. 3 et fig. 5 à 23.

Id., Élatérides nouveaux. Mém. couron. de l’Acad. Roy. de

Belgique, xvii. p. 51. 1865.

1864. Pasteur. Sur la Lumière émise par les Cucujos. Compt.

rend., Acad. d. Sc. (2), lix. No. 12, p. 509.

1864. Blanchard (E.). Compt. rend. lix. p. 510, 1864.

Métamorphoses, Mœurs et Instincts des Insectes, p. 537.

Paris, 1868. Compt. rend. lxxvii., p. 333, 1873.

1865. Milne-Edwards. Leçons d’Anatomie et de Physiologie, viii.

leç. 68^e. Paris.

1867. Perkins, G. A. Bericht den “Cucujo” oder Westindischen

Leuchtkäfer (Elater noctilucus). Am. Natur., viii. pp. 442,

443.

1868. Murray, Andrew. On an Undescribed Light-giving

Coleopter-larva. Soc. Linn., p. 74, pl. i.

1868–74. Thompson, C. Wyville. The Depths of the Sea. Account

of the general results of the dredging-cruises of H.M.SS.

“Porcupine” and “Lightning.” 1868, 1870, 1874. London.

1869. Smith. Larve von Pyrophorus Uruguay. Proc. Ent., London,

p. xv. 1869.

1870. Phipson. Phosphorescence; or, The Emission of Light by

Minerals, Plants, and Animals. London, p. 146 et suiv.

1871. Burmeister. Käfer-larve von Parana. Proc. Linn. Soc., xi.

p. 416ff.

1871. Leprieur. Soc. entom. de France, Bull., p. 68, à propos

d’un passage du voyage à la Nouvelle-Grenade du Dr.

Saffray, Tour du Monde, 605^e liv.

1871. Light of Tuberose. Science Gossip, 1871, p. 122.

1872. Fox-fire. Gardener’s Chronicle, 1872, p. 1258.

1872. Heinmann, Carl. Untersuchungen über die Leuchtorgane der

bei Vera Cruz vorkommenden Leuchtkäffer. Erste Mittheilung

Arch. f. mikrosk. Anat., viii. p. 461.

1873. De Dos Hermanas. Sur las Cucujos de Cuba. Compt. rend.,

tome lxxvii. p. 333.

1873. Gerard. Les Taupes Lumineux. La Nature, 1^{re} année, p.

337.

1873. Robin et Laboulbéne. Appareil lumineux des Cucujos. Compt.

rend. Acad. d. sci. lxxii. p. 511.

1874. Torrend Glover. Report of Entomologist, and Curator of

Museum, pp. 152–169, fig. 1 à 10. Habits and Luminosity of

Pyrophorus physoderus (fig. 3), compared with P. nocticulus

(fig. 4), and Photinus pyralis. K: A luminous Elaterid?

larva. Psyche, v. 1.

1874. Beach, A. The Science Record for 1874. A Compendium of

Scientific Progress and Discovery during the past year,

with illustrations, viii. p. 598, avec fig. New York.

1875. Darwin. Voyage d’un Naturaliste autour du Monde. Paris.

1875. Pickman Mann’s Note on the Luminous Larvæ of Elateridæ

(Asaphes memnonius). Psyche, i. p. 89.

1876. Richard Napp. Cours sur les Arthropodes de la Faune de la

République Argentine (Lampyrides et Élatérides, p.

Weyenbergh). Die Argent. Republik.

1876–77. Wyenbergh, H. Eine leuchtende Käfer-larve. Horæ Soc.

Rossicæ, xii. p. 177. xii, p. 177. fig., tab. iv. B.

1881. Gadeau de Kerville, Henri. Les Insectes phosphorescents.

Rouen.

1881. Caudeze. Élatérides Nouveaux. Mém. Soc. d. Sc. de Liège,

ix. (2).

1882. Bowles. On Luminous Insects. Rep. Entom. Soc., Ontario,

pp. 34–37, fig. 16 (figure rep. a Pyrophore).

1883. Macgowan, Dr. Antiquity of Luminous Paint, and Chinese

Method of making it. Science, 1883, ii. p. 698.

1884. Becquerel, M. Traité de Physique comparée dans ses

Rapports avec la Chimie et les Sciences Naturelles, ii.

1884.

1884. Dubois, Raphaël. Propriété physique de la Lumière des

Pyrophores (en commun avec M. Aubert). Acad. des Sci. 1884.

1884. Dubois, Raphaël. Sur la Lumière des Pyrophores. Soc. de

Biol. 1884.

1884. Dubois, Raphaël. Note sur la Physiologie des Pyrophores.

Soc. de Biol. 1884.

1884. Dubois, Raphaël. Note sur la Phosphorescence des Poissons.

Soc. de Biol. 1884.

1884. Dubois (R.) et Aubert. Sur la Lumière des Pyrophores.

Compt. rend. Acad. d. sc. Paris, 1884.

1884. Dubois, R. Note sur la Physiologie des Pyrophores. Soc. de

Biol., (8), i. No. 40. Paris.

1885. Dubois, R. Fonction photogénique des Pyrophores. Soc. de

Biol., (8), ii. No. 30, p. 559. Paris.

1885. Dubois, Raphaël. Note sur l’Action des hautes Pressions

sur la Fonction photogénique du Lampyre (en commun avec M.

Regnard). Soc. de Biol. 1885.

1886. Dubois, Raphaël. De l’Action de la Lumière émise par les

Êtres vivants sur la Rétine et sur les Plaques du gelatine

bromure. Soc. de Biol. 1886.

1886. Dubois, Raphaël. Les Élatérides lumineux. Meulan, 1886.

1886. Filhol, M. H. La Vie au Fond des Mers. 96 figures dans le

texte et 8 planches hors texte, dont 4 en couleurs.

1886. Zengler, Ch. V. La Phosphora-graphic appliquée à la

Photographie de l’Invisible. Paris. Acad. Sci., August,

1886.

1886. Zengler, Ch. V. Études photographiques pour la

Reproduction photographique du Ciel. Comptes Rendus, No. 8,

Feb. 22, 1886.

1887. Heineman, Ralph. Pyrophores. Vera Cruz, 1887.

Birard, M. Cited by Dugés, Traité de Physiologie, tome ii.

Carus. Traité élémentaire d’Anatomie comparée, traduit par

Jourdan, tome i.

Cooke, M. C. Fungi, their Nature and Uses, p. 105.

Ehrenberg. Das Leuchten des Meeres. Abhandlung.

Gosse. Insects of Jamaica. Ueber das Leuchten von Pyrophorus

noctilucus. Ann. and Magazine Nat. Hist. (2), i. p. 200.

Journal of the Linnæan Society, vol. x. p. 469.

Josephus. Luminous Roots. Wars of the Jews, book vii. chap. vi.

Leydig, Professor. Bonn, Germany. Phosphorescence of Fishes. 10

plates.

Lesson. Dict. des Sc. Nat. Article “Phosphorescence.”

Macaire. Journal de Physique, tome xciii.

Matteucci. Leçons sur les Phénomènes physiques des Corps

vivants. 8^e leçon.

Quatrefages, M. A. de. Silliman’s Am. Journal of Science.

Tingry. De la Phos. des Corps, et particulièrement de celle des

Caux de la Mer. Journal de Physique, tome xlvii.

Ussow, Dr. M. University of St. Petersburg, Russia. The Eye-like

Organs of Fishes.

Van Benedin. Recherches sur la Cause de la Phosphorescence de la

Mer dans les Parages d’Ostende. Bulletin de l’Académie

Royal de Belgique, tome xiii., par. 2, p. 3.

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=.

Living lights · 第 20 / 20 章