UC-NRLF

B 3

THE LIBRARY

OF

THE UNIVERSITY
OF CALIFORNIA

PRESENTED BY

PROF. CHARLES A. KOFOID AND
MRS. PRUDENCE W. KOFOID

TOILERS IN THE SEA,

BY

M. C. COOKE, M.A, LL.D,

AUTHOR OF "FREAKS AND MARVELS OF PLANT LIFE," ETC.

PUBLISHED UNDER THE DIRECTION OK

THE COMMITTEE OF GENERAL LITERATURE AND EDUCATION

APPOINTED BY THE SOCIETY FOR PROMOTING

CHRISTIAN KNOWLEDGE.

LONDON :
SOCIETY FOR PROMOTING CHRISTIAN KNOWLEDGE,

NORTHUMBERLAND AVENUE, CHARING CROSS, W.C. ;

43, QUEEN VICTORIA STREET, E.G.
BRIGHTON: 135, NORTH STREET.

NEW YORK : E. & J. B. YOUNG & CO.

1889.

CONTENTS,

CHAPTER PAGE

I. INTRODUCTORY i

II. CHALK-MAKERS, OR FORAMINIFERA 27

III. LATTICE-WORKERS, OR POLYCYSTINA 66

IV. SPONGE WEAVERS 109

V. PLANT- ANIMALS, OR ZOOPHYTES 145

VI. SEA-FAN MAKERS 180

VII. CORAL BUILDERS 215

VIII. CORAL REEFS, AND ISLANDS 247

IX. SEA-MAT MAKERS 291

X. TUBE-MASONS 314

XI. EXCAVATORS 340

C&3

EXPLANATION OF PLATES.

PLATE I. — FORAMINIFERA.
Fig.

a. Rotalina Beccarii.

b. Rotalina turgida.

c. Rotalina concamerata.

d. Nonionina Jeffreysii.

e. Polystomella crispa.

f. Bulima pupoides.

g. Nodosaria radicula.

//. Nummulina planulata.
i. Textularia cuneiformis, var.
k. Globigerina bulloides.
/. Peneroplis planatus.
m. Cristellaria calcar.
n. Lagena vulgaris, var.
o. Cristellaria subarcuatula.
p. Miliolina seminulum, var. disciformis.
q. Rotalina inflata.
r. Textularia variabilis.
s. Polymorphina lactea.
/. Lagena vulgaris, var.
u. Biloculina ringens.
v. Miliolina bicornis, var. elegans.

Mostly after Williamson.

vi TOILERS IN THE SEA.

PLATE II.— POLYCYSTINS.
Fig.
a, b. Sethamphora ampulla.

c. Astractura aristotelis.

d. Trigonactura rhopalastrella.

e. Podocyrtis Schomburghii.
f Undetermined species.

g. Heliosestrum craspedotum.
h. Histiastrum gladiatum.
z. Acanthocyrtis mespilus.
k. Dictyophimus lucerna.

PLATE III.— SPONGE SPICULES.

Fig.

a. Euplectella x 90.

b. Hyalonema mirabilis x 83.

c. Undescribed sponge x 600.

d. Halichondria Ingallii x 260.

e. Spongilla cinerea x 600.

f. Spongilla cinerea.

g. Sponge unknown.
h. Sponge unknown.
i. Australian sponge.

k. Tethea robusta x 660.
/. Tethea Ingallii x 660.
m. Hyalonema mirabilis x 175.
n. Halichondria coccinea x 160.
o. Hymedesmia Johnstonii x 400.
p. Halichondria variantia x 1000.
q. Euplectella aspergillum x 90.
r. Hymeniacidon Bucklandii x 90.

EXPLANATION OF PLATES. vii

Fig.

s. Ecionemia x 108.
/. Grantia x 180.
u. Halicnemia patera x 175.
v. Leuconea nivea x 660.
w. Halichondria infundibuliformis x 160.
x. Spongilla fluviatilis x 160.
v. Tethea muricata x 308.

Mostly after Bowerbank.

PLATE IV.- GORGONIA SPICULES.

Fig.

a. Gorgonia species x 300.

b. Gorgonia papillifera x 300.

c. Gorgonia crinita x 300.

d. Gorgonia species x 300.

e. Plexaura racemosa x 300.
/, g. Gorgonia vatricosa x 100.

h. Gorgonia discolor x 100.
z, k. Gorgonia exserta x 100.

/. Rhipidigorgia flabellum x 200.
m. Pterogorgia setosa x 200.
?/, o. Rhipidigorgia flabellum x 200.

p. Pterogorgia setosa x 200.

q. Hymenogorgia quercifolia x 300.

r. Pterogorgia suberosa x 200.

s. Xiphigorgia setacea x 200.

t. Leptogorgia viminea x 200.

u. Lophogorgia palma x 400.

v. Juncella juncea x 150.

iu. Leptogorgia Boryana x 150.

viii - TOILERS IN THE SEA.

Fig.

x. Juncella juncea x 150.
y. Juncella elongata x 150.
z. Pterogorgia betulina x 1 50.

aa. Paramuricea placomus x 50.

ab. Variety of same x 50.

ac. Muricea echinata x 50.

ad. Muricea lima.

ae. Eunicea plantaginea x 50.
of. Primnoa verticillaris x 50.
ag. Primnoa monilis x 50.
ah. Muricea fungifera x 100.

ai. Rhipidigorgia coarctata x 100.
ak. Plexaura porosa x 100.
al. Plexaurella dichotoma x 100.

Mostly alter W. Savile Kent.

TOILERS IN THE SEA,

CHAPTER I.

INTRODUCTORY.

IT may as well be confessed at once that the first
suggestion of this volume was derived from a
perusal of the Rev. J. G. Wood's entertaining
" Homes without Hands," strengthened by the ob-
servation that he had left the " Homes " included
herein practically unnoticed, and that therefore the
subject was still open for treatment. In some
respects the animals are not so attractive, or interest-
ing, as those with which the above-named volume is
illustrated, but the " homes " are not less remarkable,
and a brief summary of their structure and archi-
tecture, with a few details of the builders, may not
be less acceptable to " lovers of nature."

The objection has been made, and may be
repeated, that it is not an absolutely accurate desig-
nation to write of some of these as " homes " con-
structed by the animals for a residence, since they
are, in many cases, the skeletons of the animals

B

TOILERS IN THE SEA.

themselves, eliminated and deposited as the bones
are built up in mammals. We are not disposed to
insist strongly on the absolute meaning of terms,
and are content to adopt a popular view, as most
suitable to our purpose, and in a broad sense to
accept these structures, in and about which the
animals reside, as their homes, whether they are
wholly located within them, or partially enclose them
with their own flesh.

At first we had designed to confine ourselves
absolutely to such animals as lived in communities,
as for instance the coral-makers, the sea fanmakers,
the animals which inhabit sponges, sea-mats, and
those known at one time more particularly as
zoophytes, but now more specially as Hydroid
zoophytes, but by this arrangement we should have
excluded those minute, but widely diffused, animals
which construct those marvellous little shells known
to every microscopist as Foraminifera and Poly-
cystina. This would so much have diminished the
value of our volume in the estimation of those for
whom it was most of all designed, that the resolu-
tion was taken to widen the original scope so as
to include all the minute marine animals which con-
struct for themselves a permanent home. For whom,
then, do we suppose that we are writing? it may
be inquired, and for the information of those who
are not leaving this chapter to be the last that is

INTRODUCTORY.

read, we may suggest that it is the large and in-
creasing section of the nature-loving public who
indulge in the use of the microscope, as a source of
instruction and amusement, that awakens our sym-
pathies and, as it seems to us, desire and require
some introduction to the marvels of marine life, as
a preliminary to more specific knowledge, the direc-
tion of which they will thereafter be better able to
choose. Unless we are mistaken in the wants of
this large group of workers and readers, they desire
some volume which gives, within a reasonable com-
pass, an outline of the structure and habits of a
number of families of marine animals, not otherwise
to be obtained except by wading through several
volumes, and learning a copious vocabulary of
technicalities. With this interpretation of what is
desirable, we have attempted to fulfil the conditions
in such a manner as to be able to appeal also to
those who, without microscopical proclivities, seek
an introduction to these "Toilers in the Sea."

Wherefore are coral reefs and their builders
included, when they are tropical, and beyond the
reach and experience of the ordinary British reader ?
Simply because our scope is wider than to provide
a mere introduction to the marine zoology of our
own shores, a fact accomplished beforehand, since
such a restriction is hardly compatible with a general
survey of ocean homes and their builders. And if

B 2

TOILERS IN THE SEA.

it is conceded to be a legitimate project to en-
deavour to arouse a greater interest in the minute
inhabitants of the ocean, which construct and leave
behind them such marvellous structures, as evidence
of their ingenuity and perseverance, it would have
been most unwarrantable to have excluded one of
the most interesting and remarkable groups. There
are many charming books for the seaside, with which
we had no ambition to compete ; most delightful
companions which any lounger at our numerous
watering-places could not fail to appreciate and
enjoy. The Rev. Charles Kingsley's " Glaucus, or
Wonders of the Shore," is one of the most fasci-
nating little volumes for young readers. Mr. P. H.
Gosse is a veteran in the field of marine zoology,
with half a dozen volumes ; and we cannot forget
Mr. G. H. Lewes's " Seaside Studies," besides a host
of others, with more or less pretensions, and yet
none of these appeared to touch, or more than
touch, that phase of marine life to which these pages
are devoted. And yet this can hardly be called a
" seaside book " after the manner in which they are
seaside books, although some knowledge of ordinary
marine life would, perhaps, render it the more in-
telligible.

It is wholly unnecessary to advance any plea on
behalf of the study of marine life, in the face of
abundant evidence that every year increases its

INTRODUCTORY.

interest, and largely augments the number, not by
any means a small one, of those who have made it
their permanent choice. To those who have no
desire for serious study, and no leisure withal, we
would commend the perusal of the following passage
which occurs in Quatrefages' charming volumes,
and will merit a passing reflection : — " If you still
preserve any of those illusions which, day by day
are vanishing amid the turmoils of life, if you regret
the dreams that have fled never to return, go to
the ocean side, and there on its sonorous banks you
will assuredly recall some of the golden fancies that
shed their radiance over the hours of your youth.
If your heart have been struck by any of those
poignant griefs which darken a whole life, go to the
borders of the sea, seek out some lonely beach,
beyond reach of the exacting conventualities of
society, and when your spirit is well-nigh broken
with anguish, seek some elevated rock, where your
eye may at once scan the heaving ocean and the
firmament above ; listen to the grand harmonious
voices of the winds and waves, as at one moment
they seem to murmur gentle melodies, and at
another swell in the thundering crash of their
majesty ; mark the capricious undulations of the
waves, as far as the bounds of the horizon, where
they merge into the fantastic figures of the clouds
and seem to rise before your eyes into the liquid

TOILERS IN THE SEA.

sky above. Give yourself up to the sense of in-
finitude which is stealing over your mind, and soon
the tears you shed will have lost their bitterness ;
you will feel ere long that there is nothing in this
world which can so thoroughly alleviate the sorrows
of the heart as the contemplation of nature, and of
the sublime spectacle of creation, which leads us
back to God."1

Thousands of those who rush every year to the
sea shore, embued with no particular feeling but
that of enjoying themselves, in a manner of their
own selection, return with a lively sense of physical
benefit, and we would hope, in many cases, of in-
tellectual also. The latter class might be consider-
ably augmented, without any diminution in the
results attributed to the former, provided they could
be stimulated to the use of the observing eye.
This could be hardly accomplished better than by
indicating the direction in which the observing eye
should be turned, and if this be achieved this volume
will justify itself.

No event of modern times has so greatly stimu-
lated the student of marine life as the publication
of the results of the " Challenger " expedition, and to
some extent this has reacted upon those who cannot
exactly be described as 'students, but only as lovers

1 Quatrefages, "Rambles of a Naturalist," vol. i. p. 120.

INTRODUCTORY.

of nature. There was a period, not very remote,
when the botany and zoology of the shore was held
to represent the whole of marine life. Then -low
water-mark was almost the limit of investigation,
and for the majority the absolute limit. Sea-weeds,
anemones, shells of molluscs, zoophytes, and stranded
sponges, were, apart from fish and Crustacea, the
totality of marine life. But now these are almost
discarded in favour of the denizens of the depths
of the sea. The waves of enthusiasm at different
times set in different directions, determined perhaps
by some single circumstance, and in that direction
which they assume, are probably persistent for a
considerable period, until some new impulse is
given, and the current is changed. To know some-
thing of the most extraordinary of the " Toilers in
the Sea," the most expert builders of " ocean homes,"
we must go beyond the littoral zone, and explore the
dark abysses, where the light of the sun and the eye
of man has never penetrated.

All the preliminary facts which it is necessary to
call to remembrance here, in reference to the ocean
in which our organisms flourish, may be indicated
by a short retrospect, for the most part abstracted
from Sir Wyville Thomson's " Depths of the Sea."
Taking for granted that three-fourths of the surface
of the globe is covered by the sea, and until very
recent times so little was known of its depths, and so

TOILERS IN THE SEA.

much imagined, it may be well to ascertain what
data modern investigation and discovery have given
us, and how far old notions have been superseded.
Popular opinion originally favoured the supposition
that beyond a certain depth there was only "a waste
of utter darkness, subject to such stupendous pres-
sure as to make life of any kind impossible, and to
throw insuperable difficulties in the way of any
attempt at investigation." When Carpenter and
Thomson in 1868 found that they could work " not
with so much ease, but with as much certainty, at
a depth of 600 fathoms as at 100, "great hopes
were entertained in the results, which were further
strengthened when in 1869 they carried their "ope-
rations down to 2,435 fathoms (14,610 feet), nearly
three statute miles, with perfect success." Thus was
the operation of deep-sea investigation demon-
strated as possible, and the celebrated " Challenger "
expedition, soon to follow, translated it into fact.
With the preliminary experience of the " Porcupine "
expedition to guide him, Sir Wyville Thomson
wrote : — " For the bed of the deep sea, the one hun-
dred and forty millions of square miles which we
have now added to the legitimate field of Natural
History research, is not a barren waste. It is in-
habited by a fauna more rich and varied on account
of the enormous extent of the area, and with the
organisms in many cases apparently even more

INTRODUCTORY.

elaborately and delicately formed, and more ex-
quisitely beautiful in their soft shades of colouring,
and in the rainbow tints of their wonderful phosphor-
escence, than the fauna of the well-known belt of
shallow water teeming with innumerable inverte-
brate forms which fringes the land. And the forms
of these hitherto unknown living beings, and their
mode of life, and their relations to other organisms,
whether living or extinct, and the phenomena and
laws of their geographical distribution must be
worked out."1

The most important investigations of the sea
depths were those by John Ross, in Baffin's Bay, in
1818 ; by James Ross, in the Pacific Ocean, in 1843 ;
by Lieut. Joseph Dayman, in the North Atlantic, in
1857; by Dr. Wallich, in the North Atlantic, in
1860 ; by Chydenius and Torell, near Spitzbergen, in
1 86 1 ; by Carpenter, Jeffreys, and Thomson, in the
North-East Atlantic, in 1868 and 1869; by Pour-
tales, in the Gulf Stream off Florida, in 1869; and
the famous "Challenger" Expedition, from 1873 to
1876. Between the first and last of these, extending
over three-quarters of a century, the steps were
gradual, but all tending to a distrust of the notion
that there was a zero of animal life at a limited

1 " The Depths of the Sea." By C. Wyville Thomson.
London : Macmillan & Co. (1873), P- 4-

io TOILERS IN THE SEA.

depth. The earliest record of living animals from
any depth approaching 1,000 fathoms, was that of
John Ross, in Baffin's Bay, in 1818, of which his
official account states : — " Soundings were obtained
correctly in 1,000 fathoms, consisting of soft mud, in
which were worms." Later on (1843) Sir James
Ross reports : — " I have no doubt that, from however
great a depth we may be enabled to bring up the
mud and stones of the bed of the ocean, we shall
find them teeming with animal life ; the extreme
pressure at the greatest depth does not appear to
affect these creatures ; hitherto, we have not been
able to determine this point beyond a thousand
fathoms, but from that depth several shell-fish have
been brought up with the mud." In 1860, Dr.
Wallich records that thirteen star-fishes came up
from a sounding of 1,260 fathoms. In his "Diary,"
published in 1862, he advocated the view that the
conditions of the bottom of the sea were not such as
to preclude the possibility of the existence of even
the higher forms of animal life. Passing to the
"Porcupine" Expedition, from 1868 to 1870, we
have the record that " Sixteen hauls of the dredge
were taken at depths beyond 1,000 fathoms, and in
all cases life was abundant. In 1869, we took two
casts in depths greater than 2,000 fathoms. In both
these life was abundant ; and with the deepest cast,
2,435 fathoms, off the mouth of the Bay of Biscay,

INTRODUCTORY. 11

we took living, well marked, and characteristic
examples of all the five invertebrate sub-kingdoms.
And thus the question of the existence of abundant
animal life at the bottom of the sea has been finally
settled, and for all depths, for there is no reason to
suppose that the depth anywhere exceeds between
three and four thousand fathoms ; and if there be
nothing in the conditions of a depth of 2,500 fathoms
to prevent the full development of a varied fauna, it
is impossible to suppose that even an additional
thousand fathoms would make any great difference."

"The conditions which might be expected prin-
cipally to affect animal life at great depths of the
sea are pressure, temperature, and the absence of
light, which, apparently, involves the absence of
vegetable food. Beyond the zone surrounding the
land, speaking generally, the average depth of the
sea is 2,000 fathoms, or about two miles ; as far
below the surface as the average height of the Swiss
Alps. In some places the depth seems to be con-
siderably greater, possibly here and there nearly
double that amount ; but these abysses are certainly
very local, and their existence is even uncertain, and
a vast portion of the area does not reach a depth of
1,500 fathoms."

Having given these general estimates of the depth
of the ocean, Professor Thomson deals with the three
supposed conditions inimical to animal life. And

12 TOILERS IN THE SEA.

first, as to pressure. "There was," he says, "a
curious popular notion, in which I well remember
sharing when a boy, that, in going down, the sea-
water became gradually, under the pressure, heavier
and heavier, and that all the loose things in the sea
floated at different levels, according to their specific
weight, forming a kind of false bottom to the ocean,
beneath which there lay all the depth of clear,
still water, which was heavier than molten gold."

"The conditions of pressure are certainly very
extraordinary. At 2,000 fathoms, a man would bear
upon his body a weight equal to twenty locomotive
engines, each with a long goods train loaded with
pig-iron. We are apt to forget, however, that water
is almost incompressible, and that, therefore, the
density of sea-water at a depth of 2,000 fathoms is
scarcely appreciably increased. But an organism
supported through all its tissues on all sides, within
and without, by incompressible fluids at the same
pressure, would not necessarily be incommoded by
it. We sometimes find when we get up in the morn-
ing, by a rise of an inch in the barometer, that nearly
half a ton has been quietly placed upon us during
the night, but we experience no inconvenience,
rather a feeling of exhilaration and buoyancy, since
it requires a little less exertion to move our bodies
in the denser medium. At all events, it is a fact that
the animals of all the invertebrate classes, which

INTRODUCTORY. 13

abound at a depth of 2,000 fathoms, do bear that
extreme pressure, and that they do not seem to be
affected by it in any way."

Secondly, as to temperature. It was generally
understood, until about twenty-five years ago, that
whatever the variation of surface temperature might
be, there was a certain depth at which the tempera-
ture was permanent at 4° C., which is the temperature
of the greatest density of fresh water. On this point
it is unnecessary to recapitulate the details of a long
chapter, but to accept the broad conclusions at which
Professor Thomson arrived. That, " instead of there
being a permanent deep layer of water at 4° C., tbe
average temperature of the bottom of the deep sea,
in temperate and tropical regions, is about o° C., the
freezing point of fresh water ; and that there is a
general surface movement of warm water, produced
probably by a combination of various causes, from
the equatorial regions towards the poles, and a slow
under-current, or rather indraught of cold water from
the poles towards the equator." " The temperature
of the sea apparently never sinks, at any depth,
below — 3'°5 C. (3^° Cent, below the freezing point
of fresh water), a degree of cold which, singularly
enough, is not inconsistent with abundant and vigor-
ous animal life, so that in the ocean, except perhaps
within the eternal ice-barrier of the antarctic pole,
life seems nowhere to be limited by cold."

14 TOILERS IN THE SEA.

" Edward Forbes pointed out long ago the kind
of inverted analogy which exists between the distri-
bution of land animals and plants, and that of the
fauna and flora of the sea. In the case of the land,
while at the level of the sea there is, in temperate
and tropical regions, a luxuriant vegetation with a
correspondingly numerous fauna, as we ascend the
slope of a mountain range the conditions gradually
become more severe ; species after species belonging
to the more fortunate plains beneath disappear, and
are replaced by others whose representatives are
only to be found on other mountain ridges, or on
the shores of an arctic sea. In the ocean, on the
other hand, there is along the shore line, and within
the first few fathoms, a rich and varied flora and
fauna, which participates and sympathises in all the
circumstances of climate which affect the inhabitants
of the land. As we descend, the conditions gradu-
ally become more rigorous, the temperature falls,
and alterations of temperature are less felt. The
fauna becomes more uniform over a larger area, and
is manifestly one of which the shallower water fauna
of some colder region is to a great extent a lateral
extension. Going still deeper, the severity of the
cold increases, until we reach the vast undulating
plains and valleys at the bottom of the sea, with
their fauna partly peculiar and partly polar — a region
the extension of whose extreme thermal conditions

IN TROD UCTOR Y.

only approaches the surface within the arctic and
antarctic circles."

Finally, as to the absence of light. Very little
exact knowledge on this point has been obtained.
From recent experiments " it would appear that the
rays capable of affecting a delicate photographic film
are very rapidly cut off, their effect being imper-
ceptible at the depth of only a few fathoms. It is
probable that some portions of the sun's light pos-
sessing certain properties may penetrate to a much
greater distance, but it must be remembered that
even the clearest sea-water is more or less tinted by
suspended opaque particles, and floating organisms,
so that the light has more than a pure saline solution
to contend with. At all events it is certain that
beyond the first 50 fathoms, plants are barely repre-
sented, and after 200 fathoms they are entirely
absent. There seems to be little or no light at the
bottom of the sea, and there are certainly no plants
except such as may sink from the surface, but the
bottom of the sea is a mass of animal life." 1

It has been seen that pressure presents no obstacle
to animal life at great depths, that temperature is
not carried below that at which animal life may be
sustained, but that there is practically an absence of
light, and consequently of vegetable life.

1 " The Depths of the Sea." By C. Wyville Thomson.
Introductory Chapter, pp. 1-48.

16 TOILERS IN THE SEA.

Examinations of the deep-sea bottom, made at
intervals during the past eighty years, have revealed
the fact that the ocean bottom at great depths, say
from 500 to 3,000 fathoms, consists largely of a
tenacious mud, in which a great number of animals
exist, obtain nourishment, and increase their species.
Various hypotheses have been offered as to the
manner in which such conditions have been made
possible. How nourishment could be furnished at
such extreme depths has been the initial question.
Dr. Wallich suggests that the Rhizopods of the deep
sea must have the faculty of separating the elemen-
tary constituents of their bodies from the surrounding
medium.1 It has been contended that only organ-
isms containing chlorophyll "have the power of
producing albuminoid compounds from carbonic
acid, water, ammonia, and nitric acid." Dr. Car-
penter was inclined to accept the view propounded
by Thomson, that "the Protozoa of the deep sea
are nourished by protoplasm which is diffused
through the whole mass of sea-water, renewed con-
stantly by the plants and animals living at its
surface, and penetrating by diffusion to its greatest
depths."2 Gwyn Jeffreys suggested that the de-
composed organic mass was derived from animals

1 " North Atlantic Sea Bed " (1862) p. 130.

2 Nature, March 31, 1870.

INTRODUCTORY. 17

which have sunk down from the surface.1 Lieu-
tenant Maury came to a similar conclusion, as would
appear from his remarks that " the ocean swarms
with living creatures, especially between and near
the tropics. The remains of their myriads are
carried on and collected by the currents, and in
the course of time deposited like snowflakes on
the bottom of the sea. This process, going on for
centuries, has covered the depths of the ocean with
a mantle of organisms as delicate as hoar-frost, and
as light as down in the air."3

Professor Karl Mobius has detailed a somewhat
similar view, that " the plants which have grown in
the higher slopes sink to the bottom after they have
died, gradually break up into smaller and smaller
portions, and finally glide down into the greatest
depth that they can attain. This organic, and
chiefly vegetable, mass, is what renders the mud-
region inhabitable by a great number of animals, —
in the first place, by those which feed upon decaying
matters, and then for others which devour the dirt-
eaters. In this way we find it easy to explain the
quantities of individuals (at the first glance quite
astonishing) which may be got out of the mud of
the greater depths ; for the mass which serves them

1 Nature, Dec. 9, 1869.

2 " Physical Geography of the Sea" (1869), § 617.

1 8 TOILERS IN THE SEA.

as a dwelling-place, at the same time contains an
enormous store of nourishment for them. The same
thing must take place in all seas. In the shallower
regions which immediately surround continents and
islands, great masses of Algae grow wherever there
are rocks and stones. In the warmer seas there is
an enormous floating Sargasso-life. Only a small
portion of these plants is directly eaten by animals,
or thrown upon the shore. Most of them die where
they have lived, or, after they have been carried
away by currents and winds, lose the gases which
make them lighter than sea-water, sink down, and
become finally decomposed into a soft mass. With
the sinking organic materials are, of course, inter-
mixed the remains of Testacea, and the fine in-
organic soil constituents of the higher regions, which
the currents of flood and ebb and the waves are
unceasingly triturating. This muddy mixture must
move down towards the deeps upon the sloping
sea bottom in the neighbourhood of the coasts,
from purely mechanical causes, until the weight and
mutual adhesion of the individual particles present
so much resistance to the pressure of the masses
following them from above that equilibrium is pro-
duced." And again, "dead plants, fragments of
shells, and sand, are heaped one upon the other to
a height of feet or fathoms. The alternation of
flood and ebb, and the winds, keep the upper strata

INTRODUCTORY. 19

of the water in constant movement, and produce
oscillations up and down, even in the lower ones,
by increasing or diminishing the column of water
resting on the bottom. The differences of tempera-
ture which are dependent on the alternation of day
and night, on changes of weather, and the course of
the seasons, cause expansions and displacements of
the constituents of the bottom. Into the greater
depths, where these forces can operate but rarely
or slightly, or even not at all, the currents of sinking
water, which has become heavier than the subjacent
strata, by cooling or increase of its amount of salt,
penetrate." Finally, he says, " Of all the movements
which convey organic materials to the sea- bottom,
descending currents are evidently among the most
efficacious. Their operation falls precisely in the
most suitable season for this purpose ; it commences
after the annual development of the marine vegeta-
tion in the temperate and cold zones has attained
its maximum, when strong and long-continued
storms gather their chief harvest in the fields of
Zostera (grass wrack) and tangle, and the bottom
of the sea is disquieted to a greater depth than
usual."1

This is, in effect, perhaps the most reasonable and

1 " Whence comes the Nourishment for the Animals of the
Deep Seas," by Prof. Karl Mobius, in "Annals Nat. Hist.,"
vol. viii. (1871), p. 193.

C 2

20 TOILERS IN THE SEA.

feasible hypothesis yet advanced to account for the
existence, by furnishing nourishment, to the vast
bulk of minute animal life which has been found to
exist in the greatest depths yet reached in the
bottom of the " deep, deep sea."

Remote as may be its connexion with all that
follows, still its association with the mysterious
depths of the ocean may justify a slight reference
here to the controversy concerning the equally
mysterious Bathybius^ which, but a short time since,
was in the mouth of all who spoke or thought of
the bottom of the sea. It was in 1868 that a
distinguished naturalist announced the supposed
discovery of a new organism, at great depths in the
Atlantic, to which he gave the name of Bathybius}
Shortly afterwards it was again referred to in a
" Preliminary Report " in these terms : — u The ex-
amination which Professor Huxley has been good
enough to make of the peculiarly viscid mud, brought
up in our last dredging at the depth of 650 fathoms,
has afforded him a remarkable confirmation of the
conclusion he announced that the coccoliths and
coccospheres are imbedded in a living expanse of
protoplasmic substance," and, further, "that there
seems adequate reason for regarding this Bathybius

1 " On Some Organisms living at Great Depths in the North
Atlantic," by Professor Huxley, in Quart. Journ. Micr. Sci.,
vol. viii. (1868), p. 203.

INTRODUCTORY. 21

as one of the chief instruments whereby the solid
material of the calcareous mud which it pervades is
separated from its solution in the ocean-waters."
Again, in 1870, Professor Huxley emphasised the
discovery by remarking that " the Bathybius formed
a living scum or film on the sea-bed extending over
thousands upon thousands of square miles ; evidence
of its existence having been found throughout the
whole North and South Atlantic, and wherever the
Indian Ocean had been surveyed, so that it probably
forms one continuous scum of living matter girding
the whole surface of the earth."

In 1875 a modification of these views seemed to
be imperative, and Professor Huxley proceeded to
explain:1 — "Professor Wyville Thomson informs
me that the best efforts of the ' Challenger's ' staff
have failed to discover Batkybius in a fresh state,
and that it is seriously suspected that the thing to
which I gave that name is little more than sulphate
of lime, precipitated in a flocculent state from the
sea-water, by the strong alcohol in which the speci-
mens of the deep-sea soundings which I examined
were preserved. The strange thing is that this in-
organic precipitate is scarcely to be distinguished
from precipitated albumen, and it resembles, perhaps
even more closely, the proliferous pellicle on the

' l Nature, August 19, 1875.

22 TOILERS IN THE SEA.

surface of a putrescent infusion (except in the
absence of all moving particles) colouring irregularly,
but very fully, with carmine, running into patches
with defined edges, and in every way comporting
itself like an organic thing. Professor Thomson
speaks very guardedly, and does not consider the
fate of Bathybius to be as yet absolutely decided.
But since I am mainly responsible for the mistake,
if it be one, of introducing this singular substance
into the list of living things, I think I err on the
right side in attaching even greater weight than he
does to the view which he suggests."

This, then, would seem to be an end of the matter,
and it may be presumed that Bathybius, as an or-
ganised substance, was altogether a mistake, as con-
firmed by the subsequent strictures by Dr. G. C.
Wallich,1 which, apart from the little personal animus
that leaven them, may be taken as conclusive. Some
concluding remarks have such an intimate relationship
with the study of marine life, and contain salutary
hints worthy of remembrance in this connexion,
that no apology need be made for quoting them.
Dr. Wallich says : — " I fully appreciate the extreme
difficulties under which he (Huxley) worked when
analysing material unquestionably altered in its most

1 " On the True Nature of the so-called Bathybius," by Dr.
G. C. Wallich, in "Annals Nat. Hist.," vol. xvi. (1875), P- 322-

IN TROD UCTOR Y. 23

important characters by the admixture of alcoholic
preservative solutions. I can attest, from personal
and long-continued experience, that it is simply im-
possible to arrive at a correct knowledge of the
characters of the recent unadulterated material from
material that has been thus preserved. The fact is
that there is as marked a distinction between the
aspect of pure fresh sponge-protoplasm, for example,
seen instantly on its arrival at the surface, and its
aspect a very brief period afterwards, as there is
between living Foraminifera and Polycystina of the
open ocean immediately after capture, and after they
have been consigned to some preservative solution.
In addition to other important changes produced in
the protoplasm of the Protozoa, both marine and
freshwater, by being long kept or preserved in such
preservative solutions as alcohol, when calcareous
matter exists in solution, molecular changes take
place, the normally homogeneous protoplasm then
frequently being converted into minute globular
masses, which, when seen under the microscope
resemble sago-grains in miniature, and may readily
be mistaken for molecular granules of the organism
within or upon which they occur. I can produce
specimens of Polycystina, and, to a certain extent, of
Foraminifera, the rich and varied brilliancy of colour
in which has been retained for years, in some cases,
even when mounted in balsam ; but there all identity

24 TOILERS IN THE SEA.

in the appearance of the soft parts ends ; and so it
must be with any protoplasmic matter. Let this
episode of Bathybius be remembered as a caution by
future investigators, and it will have served a good
purpose."

It would avail nothing to enter upon the discus-
sions which were at one time, not long distant, so
general as to the basis of life. After all that has been
said, or can be said, the mystery of life is a mystery
still. On the one hand were those who maintained
that the formation of living beings out of inanimate
matter, by the conversion of physical and chemical
into vital modes of force, was going on daily and
hourly ; that, in fact, the actions of living beings are
not due to any mysterious vitality, or vital force or
power, but are physical and chemical in their nature.
On the other hand are those who contend that such
an explanation is illusory and insufficient. One of
these writes thus : — " In all living beings there exists
matter in a peculiar state which we call living. This
living matter manifests phenomena which are different
from any phenomena proved to be due to the opera-
tion of any known laws. It moves in a manner which
cannot be explained by physics. Changes are effected
in its composition which cannot be accounted for, and
various substances are formed by it which may exhibit
structure, properties, and a capacity for acting in a
manner which is peculiar to living beings, and cannot

INTRODUCTORY. 25

be imitated artificially, or satisfactorily explained. It
takes up non-living matter in solution and communi-
cates its wonderful properties to it. Having increased
to a certain size, the mass of living matter divides
into smaller portions, every one of which possesses
the same properties as the parent mass, and in equal
degree."

" Scientific investigators have hitherto failed to dis-
cover any laws by which these facts may be accounted
for. But rather than ignore or misrepresent them, or
affirm anything concerning them which we cannot
prove, as some have done, it seems to me preferable
to resort provisionally to hypothesis. In order to
account for the facts, I conceive that some directing
agency, of a kind peculiar to the living world, exists in
association with every particle of living matter, which,
in some hitherto unexplained manner, affects tempo-
rarily its elements, and determines the precise changes
which are to take place when the living matter again
comes under the influence of certain external condi-
tions." In higher animals, besides giving rise to the
phenomena above referred to, every instant during life
in every part of the organism, this supposed agency
or power, acting under certain circumstances at an
early period of development, so disposes the material
which it governs, that mechanisms result of most
wonderful structure, admirably adapted, as they have
been evidently actually designed, for the fulfilment of

26 TOILERS IN THE SEA.

definite purposes. These mechanisms were antici-
pated, as it were, from the earliest period, and their
formation provided for by the preparatory changes
through which the structures had to pass before
perfect development could be attained. Can these
phenomena be accounted for except through the
influence of some wonderful power or agency such as
we are now contemplating." l

However interested we may feel in the solution of
the problem of life, there is little prospect of gather-
ing much to assist in that solution from the succeed-
ing chapters, which had no such design in their
composition. The foregoing allusion to the subject
is almost parenthetical, induced by the mention of the
so-called Bathybius. It may now be abandoned,
leaving us free to pursue, as far as we can within the
prescribed limits, the history of the little animals
which we have brought together under the designa-
tion of " Toilers in the Sea."

1 " Protoplasm, or Life, Force, and Matter," by Lionel S.
Beale. London (1870), p. $9.

TOILERS IN THE SEA. 27

CHAPTER II.
CHALK MAKERS, OR FORAMINIFERA.

A NIMALS and plants are classified, for scientific
-**• purposes, in a regular series of groups, accord-
ing to their structure and relationship, either in an
ascending scale, from the simplest to the most
complex, or descending, from the highest or most
complete, to the lowest or simplest forms. This
classification undergoes modification from time to
time, so as to be in harmony with the progress of
knowledge, seeking to represent, as nearly as
possible, a graduated sequence of animal or vege-
table life, upwards or downwards, as the case may
be, beginning or ending with the simplest forms.
It is of little moment whether the series be an
ascending or descending one, so long as the
sequence is in accord with ascertained facts.
Whether from acquired habits of order, or from
prejudice, or from conviction of its many advan-
tages, the biologist is always apt to think and
write with this classification, almost unconsciously,
before him ; and it seems to him the most natural

28 TOILERS IN THE SEA.

thing in the world to proceed step by step, up or
down, the orthodox ladder. It is in deference to
this feeling that we commence with the simplest
or lowest, if that term be preferable, of animals that
construct for themselves " homes in the sea."

Those who have made acquaintance with the
simple forms of animal life to be found in fresh
waters, are cognizant of the existence of a strange
little organism to which the name of Amceba or
Proteus has been given. They are common enough
in all water containing decaying vegetable matter,
and are generally regarded as one of the simplest
forms of animal life to be found in our " ponds
and ditches." The general appearance is that of
a microscopical particle of jelly, transparent amor-
phous jelly, or, as Dr. Carpenter has described it,
" a little particle of homogeneous jelly arranging
itself into a greater variety of forms than the
fabled Proteus, laying hold of its food without
members, swallowing it without a mouth, digesting
it without a stomach, appropriating its nutritious
material without absorbent vessels or a circulating
system, moving from place to place without muscles
feeling (if it has any power to do so) without nerves
propagating itself without genital apparatus, and not
only this, but in many instances forming shelly cover-
ings of a symmetry and complexity not surpassed
by those of any testaceous animal." The latter
part of this paragraph does not refer to the true

CHALK MAKERS, OR FORAMINIFERA. 29

Amoeba, but to the allied forms to which our
remarks will shortly be confined. Suffice it to say
that Dr. Carpenter recognises the Amoeban form
of simple animal as that of the Foraminifera which
secrete a calcareous skeleton or shell. By com-
mencing with a reference to this well-known
organism (fig. i), although it may in some points
differ from the shell-making species, an acquaint-

FIG. i. — PROTEUS, or AMCEBA.

ance with the latter may be facilitated, and through
the Amoeba we may obtain an introduction to
the Foraminifera and Polycystina, which are of
the same kindred. It is of little consequence to
us that some have regarded the Amoeba as lower
in the scale of creation than the shell-bearers,
whilst others consider it superior on account of
" something akin to organisation having reached
its highest limit."1 It is admitted, on all hands

1 Dr. Wallich, in Monthly Microscopical Journal, vol.
(1869), p. 231.

3o TOILERS IN THE SEA.

that the Amoeba is a minute jelly-like animal,
which has no special form of its own, but is sub-
ject to incessant changes of form, by thrusting out
portions of its gelatinous substance, and retracting
others, moving slowly from place to place by means
of these foot-like extensions of the body, called
pseudopodia, or false feet. "On coming in contact
with any particle of organic substance, on which
the Amoeba is inclined to feed, and they obvi-
ously have some choice in this respect, the sarcode
proceeds to surround it, so that it is soon enclosed,
along with some water, within the body. Most
observers agree in believing that any part of the
body may thus incept the food, though some have
believed in an oral aperture (mouth). No such
aperture has been discovered, and the evidence
does not indicate its existence. It also appears in-
disputable that when the Amoeba has extracted the
nourishment from the food, it ejects what remains,
but not at the spot where the food entered. This
is done at the posterior extremity of the body,
where also the contractile vesicles discharge them-
selves. Writers speak of an anal outlet at this
point, but there is no reason for believing in its
presence. The particles appear to be simply forced
out through the sarcode." l

1 "The Amoeba," by Prof. W. C. Williamson, in Popular
Science Review ', vol. v. (1866), p. 188.

CHALK MAKERS, OR FORAMINIFERA. 31

It has been contended that there exists an in-
ternal circulation in the body, because when the
animal pushes out a lobe, or prolongation, a rush
of granules will be seen flowing in the direction of
the new foot or lobe. Dr. Wallich contends that
the flow is merely mechanical, and this view is
generally accepted. " In the large jSseudopodia of
Amceba" he says, "we see at once that the ap-
pearance of an advancing and a retrograde current
is due to the fact that the lower surface of the
organism is fixed, as it were, to the plane on
which it rests, whereas its upper or free surface
only is being projected into pseudopodial exten-
sions. In short, the effect is identical in character
with that which would present itself, if, after filling
a transparent and highly-elastic bladder, with some
viscid and transparent fluid in which granular particles
of slightly greater specific gravity than the fluid itself
were suspended, we were to roll it slowly along a
flat surface. In such a case, the upper stratum of
granules would in reality be moving forwards in the
direction in which the bladder was being rolled ; whereas
the inferior stratum, although at rest, would appear
to be retrograding ; for the same reason that when
a railway train is slowly and steadily put in motion,
the platform appears to be moving from the ob-
server seated in one of the carriages. Now, as
regards the cyclosis, this result could not take

32 TOILERS IN THE SEA.

place, if the two phenomena — namely, the vital con-
tractility of the protoplasm itself, and the circu-
lating force by means of which the granules are
impelled, — acted independently one of the other.
Did they act independently, any cessation or alte-
ration in the one would not necessarily involve a
cessation or alteration in the other, but the circula-
tion of the granules would continue unchecked even
when the protoplasmic mass had obtained a state of
perfect rest. And, notably, when the direction in which
the protoplasmic mass had for a time been moving
became suddenly reversed, the direction of the
granular movement would remain unaltered, at least
for a period, were the force producing it an inde-
pendent one. But the direction which the granules
continue to take under these circumstances becomes
immediately reversed also, proving thereby that it
simply follows the direction imparted to it by the
protoplasm. It only remains to be stated that these
phenomena are observable whenever a fresh pseudo-
podium is projected ; every modification in the
direction taken by the current of granules being
distinctly referable to some corresponding change in
the form being assumed by the protoplasmic body
generally.1

1 Dr. G. C. Wallich, "On the Rhizopoda," in Monthly
Micro. Journ., vol. i. (1869) p. 233.

CHALK MAKERS, OR FORAMINIFERA. 33

Without staying here to pursue further inquiries
as to the structure and habits of the naked Amcebcz,
we may pass to the simplest condition of an Amoeba-
like body enclosed within a shell, or house, which it
constructs for itself by accumulating grains of sand
and other foreign particles which adhere to the
membraneous covering of the animal. The species
of Difflugia are also found in
fresh water, and are rather com-
mon, but not being considered
generally attractive, are but little
studied (fig. 2). The coat, or
" test," is usually ovoid, or flask-
shaped, with a notched aperture FIG. 2.— DIFFLUGIA..
at the end, its foundation is a
thin transparent colourless membrane, and to tln
the particles adhere to form the encrusted house ii
which the animal dwells ; the pseudopodia arc
protruded from the orifice only.

The transition is a short and easy one to the
Foraminifera, those minute marine animals of very
near kindred to Amceba, who construct for themselves
a calcareous shell, or skeleton, many of which in form
resemble very microscopical snail shells. (Plate I.)
From the perforations which the walls of these shells
present they were called Foraminifera^ or pore-bearers
and though small, they are, or have been, probably
the most numerous of all created things, and have
I)

34 TOILERS IN THE SEA.

performed no insignificant part in the history of the
world. For the present it will be sufficient to note
that they are brought up from the deep-sea bottom
everywhere, and that myriads of them are still living
in the ocean, even as myriads have flourished in the
seas of indefinable past ages. Many of these elegant
little shells are individually not to be distinguished
by the naked eye ; but they partake of a variety of
forms, some consisting of a single chamber, and
others of a great many, but in all, their composition,
like that of the oyster and cockle, is principally
carbonate of lime, such as we know it in chalk
and limestone, of which these shells are important
factors.

Some of the shells consist of a single chamber,
others of several, and still others of a very consider-
able number. The many-chambered shells are at
first simple, or, as it seems probable with the rudi-
ments of two or three others, the greater part of the
chambers being added consecutively by a kind of
budding, the primary chamber being the smallest.
These chambers are not absolutely isolated, but the
walls, or divisions, are perforated, and through these
perforations there is a " continuity of protoplasm," a
union of all the segments of the compound body
which inhabits them ; so that in such species as do
not possess perforations in the external walls
of the shell, through which to extend their

CHALK MAKERS, OR FORAMINIFERA. 35

pseudopodia, nutrition may be supplied down to
the furthest chamber, by means of the minute threads
of communication, from the open mouth of the shell,
and the pseudopodia operating therefrom.

We may regard the animal as of close kindred to,
although not absolutely the same, as an Amceba, from
which it differs in its pseudopodia, or voluntary ex-
tensions of the body, being thin delicate threads,
sometimes so thin as to be scarcely visible, and not
obtuse lobes ; and also in the absence of a nucleus.
For all practical purposes we may assume that it is
somewhat of an Amoeba, enclosed in a shell. And
here again we must apply a reservation, since at
certain times, if not always, the substance (or sarcode)
of the animal flows over and envelopes the whole
external surface of the shell, and hence, as Dr. Car-
penter observes, " it is by no means impossible that
the digestive process may really be performed in this
external layer, so that only the products of digestion
may have to pass into the portion of the sarcode
body occupying the cavity of the shell. A recog-
nition of this fact has led some writers to protest
against regarding the shell as a home constructed by
the animal to inhabit, since, as they affirm, it is a
skeleton built up within the body of the same ma-
terials, and in the same manner, as the bones of the
skeleton in a mammal.

" The sarcode body of such Foraminifera as have

D 2

36 TOILERS IN THE SEA.

been observed in the living state," l Dr. Carpenter
says, " is more or less deeply coloured ; its tint being
in some instances a yellowish brown, in other cases a
crimson red. This colour seems in some instances
to be uniformly diffused through the whole mass of
the sarcode, probably owing to the fine state of
division of the particles which possess it ; but in the
larger forms it occurs in much larger and more
scattered masses, which appear sometimes to be col-
lections of granules, and in other cases to be vacuoles
filled with a coloured liquid. In the Foraminifera,
with many-chambered shells, it is nearly always to be
observed that the colour is deepest in the segments
of the body which occupy the oldest chambers, and
that it fades progressively in the segments which
intervene between these and the one that occupies
the last-formed chamber, which is often nearly colour-
less. There is strong reason to believe that the
colouring material is directly derived from external
sources, though modified in some cases by the agency
of the animal itself." 2

1 The soft substance of which the body of these animals is
composed was called by Dujardin sarcode, or rudimentary flesh,
but some authors prefer to call it protoplasm, because, as Dr.
Carpenter observes, " it is nothing else than protoplasm, in
which every form of animal structure has its origin, and from
which it is evolved by a process of gradual differentiation."

2 " Introduction to the Foraminifera," by Dr. W. B. Car-
penter (1862), p. 32.

CHALK MAKERS, OR FORAM1N1FERA. 37

The functions of the pseudopodia, or filamentous
prolongations of the sarcode body (fig. 3) would
appear to be, in the first instance, to obtain nourish-
ment for the animal, and in the next place to attach
themselves to any given spot, or to serve as means
of locomotion from place to place. Whether they
are organs of feeling, or that the animals are in
possession of the sense of feeling, or, if so, to what
extent, must be left an open question.

Some naturalists have doubted the power of

FIG. 3. — DISCORBINA WITH
PSEUDOrODIA.

FIG. 4.— MILIOLA WITH PSEUDO-
POUIA.

Foraminifera to move themselves from place to place
by means of their pseudopodia (fig. 4). On this
point the positive observations by so experienced an
observer as Mr. P. H. Gosse may be accepted as con-
clusive. He obtained at Weymouth entangled
amongst tufts of minute seaweeds a number of spe-
cimens of Polystomella. " These," he says, " were
always found, a few hours after the weed had been

38 TOILERS IN THE SEA.

deposited in my vases, adhering to the glass, with
the pseudopodia extended in opposite directions.
Very frequently these tiny atoms were found, in the
morning, two, three, or even four inches up the sides
of the perpendicular glass vases, having crawled this
distance in the course of the night. And they never
remained long stationary ; the next morning would
find tnem in some remote part of the glass. The
night was manifestly their time of activity." And
again, ' One of my tanks was literally swarming with
a speries of Polymorphina. The individuals were of
various dimensions ; a large number having attained
the adult size. They studded the sides of the vessel,
the stones, and the slender weeds, adhering to the
filaments of the latter in such profusion as to cover
the whole contents of the vessel with white dots, con-
spicuous even upon the most cursory glance. These,
like the others, were constantly roaming ; they
crawled up and down the stems of the algae, and
over the various objects in the tank, never remaining
long in one station. On removing one from the
vessel to an aquatic cell for microscopic examination,
it was found to be entirely withdrawn ; but, in the
course of a few minutes the pseudopodia were seen
to be protruding their tips, and then they gradually
stretched and expanded their lines and films of
delicate sarcode, till in the course of a few hours
these would sometimes reach almost from side to

CHALK MAKERS, OR FORAMINIFERA. 39

side of the glass cell. The extension was principally
in two opposite directions, though the branched and
variously connected films often diverged considerably,
giving to the whole a more or less fan-like figure." 1

The whole method of reproduction requires further
investigation, since little more is known than was
announced in 1856, and further confirmed in 1861,
of the production of living young by two or three
species. " Remarking that an individual had become
stationary for several days, and enveloped, as is not
unusual, in a thin layer of brownish slime, Max
Schultze paid particular attention to it. At the end
of a few days, after it had become quiescent, he
noticed that minute spherical, sharply - defined
granules were detached from the brownish slimy
envelope, and in the course of a few hours the animal
was surrounded by about forty of these corpuscles,
which gradually became more and more widely
separated from it. Microscopic examination of these
bodies proved that they were young. When viewed
by transmitted light, they presented a pale yellowish-
brown calcareous shell, consisting of a central globular
portion, partly surrounded by a closely - applied
tubular part, and having no septum in the interior.
In a short time the young animals protruded their

1 " On Locomotion in the Foraminifera," by P. H. Gosse, in
"Annals Nat. Hist.," vol. xx. (1857) p. 365.

40 TOILERS IN THE SEA.

contractile processes from the opening of the shell,
and crawled about upon the object-glass. The parts
of the body enclosed in the transparent shell could
be examined with great accuracy under the highest
magnifying powers, and were seen to consist of a
transparent, very finely-granular, colourless material,
of which the protruded filaments were an immediate
continuation, and in which were imbedded minute
sharply-defined granules, protein and fat molecules,
some of considerable size, and angular, like the vitel-
line plates in the ovum of fishes. From the circum-
stances under which these young (Miliolidce) made
their appearance, it might be concluded that they
must necessarily quit the parent in a tolerably perfect
condition, and that it was probable they acquire the
calcareous shell whilst still within the mother." The
shell of the parent was broken up and only found to
contain a little granular matter. " The almost com-
plete absence of any organic contents in the shell of
an individual, which from eight to fourteen days pre-
viously was creeping about, renders it probable that
the whole, or, at any rate, the main part of the body,
had been transformed into young ones." *

Subsequently, the same author recorded similar
> experiences in other species observed in a bottle of

1 " Observations on Reproduction of the Rhizopoda," by
Prof. Max Schultze. Abstracted in Quart. Journ. Micr. Sci.,
-vol. v. (1857) p. 220.

CHALK MAKERS, OR FORAMINIFERA. 41

sea-water. Noticing suspicious circumstances in
some of the individuals, he cleaned and examined
one, which he found to contain coarsely granular
yellowish-brown substance, the true nature of which
could not be ascertained, on account of the opacity of
the shell. He then proceeded to break up the shell,
in which he counted ten chambers, and was not a
little astonished, after detaching the first fragments of
the shell, when some small three-chambered Forami-
nifera made their appearance, of which, after crushing
and breaking up the mother, no less than from twenty
to thirty were brought to light. They were all of
nearly equal size, and each shell was three-chambered,
the earliest chamber containing brownish-yellow sub-
stance, the others colourless. The shell appeared
very thin and brittle, but immature. The artificial
birth was too early for the young animals, and they
manifested no signs of life. He then proceeded to
watch the remaining specimens in the bottle, and
soon observed in the neighbourhood of two of them
an accumulation of small granules, which, when
detached and placed under the microscope, were
found to be also small three-chambered Foraminifera
(Rotalina), exactly of the same size and form as those
liberated artificially from their parent, differing only
in the second chamber beginning to show a yellow
colour. " Here, therefore/' he says, " we have a new
proof that the Foraminifera bear living young, and

42 TOILERS IN THE SEA.

that these, at the time of their birth, are in a com-
paratively high state of development." l

Reproduction by gemmation is as probable in the
Foraminifera as in Difflugia, in which latter it has
been observed. When these animals are obtained in
considerable numbers, the formation of colonies by
gemmation (or budding) may easily be watched.
This process takes place in the foot (pseudcpodittm),
which gradually increases in size, acquires a nucleus
and investing membrane, which ultimately separates
and becomes a free animal.

The structure of the shells, in several different
species, was the subject of careful investigation by
Professor Williamson many years ago, and some
interesting facts were then first brought to
light. One of these series of facts serves to throw
some light on the habits of the little-known
animals which inhabit these shells. It was found
on cutting sections, that the oldest cells have the
thickest walls, and the youngest, or last-formed
cells or chambers, the thinnest, and between these
every gradation of thickness. This indicates succes-
sive depositions of calcareous matter on the exterior,
for, if in the interior, the cavities would have been
reduced and ultimately blocked up. The hypothesis
suggested is thus stated : — " I have come to the con-

1 "Ann. Nat. Hist.," vol. viii. (1861) p. 320.

CHALK MAKERS, OR FORAMINIFERA. 4

elusion that the greater thickness of the earlier and
older growths of the shell is owing to the circum-
stance that, on the addition of each new segment,- the
cell-wall by which it is enclosed has not terminated
at the boundary of the individual segment itself, but
has been prolonged over a considerable number, if
not the whole, of the segments belonging to the
outermost convolution of the animal. But before the
newly-formed segment enclosed itself within the
limits of its own calcareous shell, it must have had
the power of spreading itself out in the form of a thin
gelatinous layer, investing the whole of the pre-
existing organism." l That is to say, whenever the
animal has so increased in size, in the last-formed
chamber, that a new chamber must be constructed,
the sarcode diffuses itself over the whole external
surface of the shell, and deposits a new layer of
calcareous matter over all the shell, then retreats
within the last segment again, and completes a new
segment, which becomes the last, and is the thinnest,
because it has had no external stratum deposited
upon it. Moreover, it is known that, at certain times,
the sarcode does envelope the entire shell, and this
explains wherefore it is done.

This hypothesis explains, and accounts for, the

1 "Transactions of the Microscopical Society of London,"
vol. iii. (1850) p. 105.

44 TOILERS IN THE SEA.

increasing thickness of the walls of the various
chambers, from the latest back to the earliest, the
increased thickness being due to the successive depo-
sition of thin external strata of calcareous matter,
which strata would consequently be the most
numerous in the oldest chambers, diminishing regu-
larly and consecutively towards the most recently-
constructed chamber. " Having so spread itself out
as an investing body, it appears to have deposited
new calcareous layers, covering over the greater part
of the pre-existing external segments ; but in each
layer so added open points have been left opposite
to the mouths of the pseudopodian tubes in the layers
previously formed, reminding us of the way in which
similar apertures are left opposite the mouths of the
canaliculi in membraniform bone-growths. In some
instances, however, especially near the umbilical
region, these tubes have been blocked up by the
more recent investments."

We might also refer to the shell structure itself,
and especially in those species in which " the outer
layers are perforated in every direction by a network
of minute anastomosing canals, which communicate
freely with the exterior of the shell through numer-
ous minute apertures." All these minute details
of elaboration are marvellous, especially in the
construction of the skeleton of animals so small,
and of such simple organisation, that they are

CHALK MAKERS, OR FORAMINIFERA, 45

placed very near the bottom in the graduated scale

of animal life,

" How each fulfill'd

The utmost purpose of its span of being,
And did its duty in its narrow circle,
As surely as the sun, in his career,
Accomplishes the glorious end of his."

It would be almost hopeless to attempt any verbal
description of all the various forms of shells which
are constructed by the different species of Forami-
nifera.. Within certain limits, and in this- instance
very broad ones, each species has its own type of
shell. This was more true in the days when the form
of the shell was the principal character than it is at
present, but there are some broad general features
which find acceptance now. Primarily, there are
three distinct varieties of texture — the porcellanous,
resembling porcelain ; the hyaline or vitreous, which
are more glassy ; and the arenaceous, or sandy. In
the first the texture bears a strong resemblance to
porcelain, especially when the surface is highly
polished. Some of these are ribbed, others are
channelled, whilst others are pitted either with small
depressions or large areolae. The vitreous shells
have almost a glassy transparency, sometimes opaline,
and these, again, may be sculptured on the surface
with ridges or tubercles. Dead shells, when subject
to long action of sea-water, lose their lustre and be-
come opaque. Finally, the arenaceous are shells

46 TOILERS IN THE SEA.

composed, partly at least, of particles of sand,
obtained externally and agglutinated together by a
cement supplied by the animal. The fine particles
thus collected vary considerably, both in colour and
substance. Sometimes the little particles are very
uniform and methodically disposed ; at others, they
are less uniform, and form only an outer layer im-
bedded in a calcareous base. It seems a mystery
how such a simple animal as that which inhabits
these shells, little more than an atom of living jelly,
can deposit one chamber upon another, in the multi-
locular shells, with the characteristic markings sculp-
tured on the surface, or select and collect the minute
particles of sand, and bind them together with
admirable uniformity, like a miniature tessulated
pavement, on the exterior of the arenaceous shells.
Truly "there are more things in heaven and earth," —
and the deep sea also, — " than are dreamt of in your
philosophy."

The simplest form of Foraminiferous shell is that
in which the house is restricted to a single chamber.
This may be as nearly as possible of a globose form,
or oval, or attenuated at one end, so as to be almost
pear-shaped, or the neck may be elongated so that it
resembles a Florence oil-flask, some being plain,
others ribbed or chequered. More complex forms
consist of a series of spheres or ovals, adhering in a
row, of which each successive chamber diminishes

CHALK MAKERS, OR FORAMINIFERA. 47

towards one end. In other forms the chambers
approximate so closely that they are flattened at the
poles, and united without any intervening isthmus.
These may be straight or curved, but still gradually
attenuated to one end. From the straight or curved
forms the transition is easy to those in which the
smallest end is curled into the commencement of a
spiral. Then we encounter more
perfect spirals, as complete as in
the shell of a snail, but always
with more or less distinct trans-
verse lines, or furrows, indicating FIG S._ACATHISTE(;A<
the division into chambers. Some-
times these spiral shells are nearly smooth, or they may
be wrinkled, ribbed, indented, perforated, sculptured in

FIG. 6. — HELIXOSTEGA.

various ways, spurred, or ,keeled. In some the ter-
minal opening is large, in others small. Then to all

48 TOILERS IN THE SEA.

these may be added various irregular forms, long
flexuous lobes packed side by side, or chrysalis-like
forms with two or three longitudinal series of
chambers packeol closely like wedges, some regularly
and others irregularly. In fact, there is such a
multiplicity of forms (figs. 5, 6, 7, 8, 9) that they might
be called polymorphous, and even a single species,
as now understood, may include
individuals which diverge re-
markably from each other. It
would be almost an exaggera-
tion to say that no two indivi-
duals are exactly alike, but one
is almost tempted to think so,

FIG. 7.-ENTOMOSTEGA. >" P^HCC of SUch 3. multipli-

city of form.

One important result of deep-sea dredging has been
to exhibit the relationship of the floor of the sea to
the chalk deposit of the " dear white cliffs of Dover."
" The dredging at 2,435 fathoms at the mouth of the
Bay of Biscay," writes Sir Wyville Thomson, " gave
a very fair idea of the condition of the bottom of the
sea over an enormous area, as we know from many
observations which have now been made with the
various sounding instruments contrived to bring
up a sample of the bottom. On that occasion the
dredge brought up about r| cvvt. of calcareous mud.
There could be little doubt, from the appearance of

CHALK MAKERS, OR FORAMINIFERA. 49

FIG. 8. — ENALLOSTEGA.

the contents of the dredge, that the heavy dredge
frame had gone down with a plunge, and partly
buried itself in the soft, yielding bottom. The thr.oat
of the dredge thus be-
came partly choked, and
the free entrance of the
organisms on the sea
floor had been thus pre-
vented. The matter
contained in the dredge
consisted mainly of a

compact " mortar," of a bluish colour, passing into a
thin — evidently superficial — layer, much softer and
more creamy in consistence, and of a yellowish
colour. Under the
microscope the sur-
face layer was found
to consist chiefly of
entire shells of Fo-
raminifera (Globige-
rina bulloidcs), large
and small, and frag-
ments of such shells mixed with a quantity of amor-
phous calcareous matter in fine particles, a little fine
sand.and many spicules, portions of spicules, and shells
of Radiolaria, a few spicules of sponges, and a few
frustules of diatoms. Below the surface-layer the
sediment becomes gradually more compact, and a

E

9. — STICHOSTEGA.

50 TOILERS IN THE SEA.

slight grey colour, due, probably, to the decomposing
organic matter, becomes more pronounced, while
perfect shells of Globigerina almost entirely disappear,
fragments become smaller, and calcareous mud,
structureless and in a fine state of division, is in
greatly preponderating proportion. One can have
no doubt, on examining this sediment, that it is
formed in the main by the accumulation and disin-
tegration of the shells of Globigerina ; the shells
fresh, whole, and living, in the surface layer of the
deposit, and in the lower layers dead, and gradually
crumbling down by the decomposition of their
organic cement, and by the pressure of the layers
above ; an animal formation, in fact, being formed
very much in the same way as in the accumulation
of vegetable matter in a peat-bog ; by life and
growth above, and death, retarded decomposition,
and compression beneath." x

The foregoing extract, for which reason we have
given it in full, shows some points of remarkable
similarity between the Atlantic ooze and deposited
chalk. There may be differences in chemical com-
position, but, when submitted to microscopical
examination the resemblances are so great, or, as
Sir Wyville Thomson says, u sufficiently striking to
place it beyond a doubt that the chalk of the creta-

" Depths of the Sea," p. 409.

CHALK MAKERS, OR FORAMINIFERA. 51

ceous period and the chalk mud of the Atlantic are
substantially the same." "Altogether, two slides,
one of washed-down white chalk, and the other of
Atlantic ooze, resemble one another so nearly that

FIG. 10. — GRAVESEND CHALK.

it is not always easy for even an accomplished micro-
scopist to distinguish them."

In order to remove all doubt as to the impression
he intended to convey, the same writer emphasises
this point subsequently, when he writes : — " There

E 2

52 TOILERS IN THE SEA.

can be no doubt, whatever, that we have, forming at
the bottom of the present ocean, a vast sheet of rock
which very closely resembles chalk, and there can be
as little doubt that the old chalk, the cretaceous
formation which, in some parts of England, has been
subjected to enormous denudation, and which is
overlaid by the beds of the tertiary series, was pro-
duced in the same manner, and under closely similar
circumstances ; and not the chalk only, but, most
probably, all the great limestone formations. In
almost all of these the remains of Foraminifera are
abundant, some of them, apparently, specifically iden-
tical with living forms."1 It was under these impres-
sions, and with these views, that he publicly used the
expression to which geologists took exception, that
"we might be regarded, in a certain sense, as still
living in the cretaceous period." But it seems that
the mode of expression was censured rather than
the opinion, since he afterwards declared that " the
doctrine of the continuity of the chalk, in the sense
in which we understood it, is now very generally
accepted." In confirmation of this view may be cited
the remarks of Professor Huxley, in his anniversary
address as President of the Geological Society, in
1870, when he said, " Many years ago I ventured to
speak of the Atlantic mud as ' modern chalk/ and I

1 "_ Depths of the Ocean," p. 470.

CHALK MAKERS, OR FORAMINIFERA. 53

know of no fact inconsistent with the view, which
Professor Wyville Thomson has advocated, that the
modern chalk is not only the lineal descendant, so to-
speak, of the ancient chalk, but that it remains in
possession of the ancestral estate ; and that from the
cretaceous period (if not earlier) to the present day
the deep sea has covered a large part of what is now
the area of the Atlantic."

Accepting, therefore, this doctrine of the continuity
of the chalk, and, consequently, its intimate relation-
ship with our subject, let us endeavour to make some
slight acquaintance with the microscopical characters
of the common Kentish chalk. In order to do so,,
some little preparation is necessary. Take a small
quantity of chalk in powder, say, two ounces, and
place it in a glass bottle holding about a quart.
Water is poured in upon the chalk until the bottle is-
nearly full. The whole is then shaken up, when it
resembles milk in colour and consistency, and placed
in some position where it remains undisturbed for
half an hour. The heavier particles will have sunk
to the bottom, the lighter remain suspended in the
water, which latter is drawn off, and fresh clear water
added, then the bottle may be -stood aside to settle
as before. This process is repeated again and again
until the water is no longer turbid, after standing for
a few minutes. The sediment, or deposit, at the
bottom of the' bottle will be found to be very much

54 TOILERS IN THE SEA.

less in bulk than the original quantity of chalk
experimented upon, but it will contain just what is
required for microscopical examination. If we take
a little of this sediment, and place it on a slip of
glass, then submit it to the microscope, we shall
find it to be composed almost entirely of delicate
little shells, those called Globigerina predominating.
These shells are carbonate of lime, easily dissolved
by acids, the empty, untenanted houses of Fora-
minifera. That which has been washed away in the
Avashing process consisted partly of the broken frag-
ments of similar shells, and partly of amorphous
granules. Hence, therefore, the microscope teaches
that chalk consists, for the most part, of very minute
shells and fragments of shells, which were inhabited
by animals that lived and floated in the ocean thous-
ands of years ago. By their identity of size and
form, it is not difficult to recognise in them the shells
of Foraminifera, belonging to precisely the same
.species, in some cases, as those which are found
living at the bottom of the sea in the present day.

D'Orbigny computed that there were near four
millions of such little shells in one ounce of sand from
the Antilles. According to this computation a cube
of chalk of six inches in diameter in each direction,
and weighing sixteen pounds, would contain the
-entire shells of not less than 1,024 millions of little
animals, and the broken fragments of nearly as

CHALK MAKERS, OR FORAMINIFERA. 55

many more. Such immense numbers are outside
the range of our experience, and we can form no
conception of them. Suffice it to say that one ounce

FIG. II.— CHALK OF SICILY.

would contain the shells of more animals than there
are human beings in the great metropolis of London.
But what an infinitesimal fraction this ounce would
be of the number of shells of these animals, living

56 TOILERS IN THE SEA.

or dead, found scattered over the globe. Deep-sea
soundings bring them up from the greatest depths
that the line has yet reached, whole catacombs of
them are entombed in the chalk and limestone
rocks ; they are scattered amongst the sand of the
sea shore. In Europe and Asia together they cover
thousands of miles. They may be found almost
everywhere. The traveller who thinks he is out of
their reach on the plains of Egypt is mistaken, for
if he attempts to climb the pyramids of Ghizeh, he
must do so by trampling on myriads of Foraminifera,
imbedded in the nummulitic limestone at its base,
which, could they but speak, might tell him of days, —
long before the toiling Israelites were making bricks
without straw, — of days long before Solomon was
King of Jerusalem, or Elijah girded himself to run
before Ahab to Jezreel (fig. 11).

In order to test the accuracy of other observers, as
well as to procure some new determinations of the
number of organisms approximately to be found in
chalk, we undertook the experiments some years
ago, of which the following is a summary : — An
ounce of chalk, as taken from the pit, was subjected
to the washing process already detailed, the lighter
fragments being washed away, until a sediment was
left of nearly pure foraminiferous shells. Half of
this was cleaned, as much as possible, by boiling in
caustic potash, and ultimately it was demonstrated

CHALK MAKERS, OR FORAMINIFERA. 57

that this supplied sufficient material to mount one
hundred and ninety microscopical slides, of equal
character, indeed the whole of that number were
prepared, and compared. Each of these slides was
estimated to contain one thousand shells, based upon
the actual counting of two or three. So that, by
calculation, it could be shown that in one ounce of
chalk there were 400,000 shells.

Afterwards, and for greater security, another ounce
of chalk was washed, even more carefully, and the
calculation then showed upwards of half a million of
entire shells, without reckoning the fragments which
had been washed away, or probably the thousands
that had been decanted off with the water in forty
or fifty washings. Hence, it is evident that the
maximum is not reached when it is affirmed that, at
least, half a million of the shells of Foraminifera were
contained in each ounce of chalk from that pit. The
lump of chalk procured as the basis of these experi-
ments weighed sixteen pounds, or 256 ounces, and
consequently contained the shells of 128 millions of
Foraminifera. Such a number is easy to name, but
not so easy to imagine, a number which would
occupy a person ten years to count, even if he could
continue to count sixty per minute, for twelve hours
daily.

Professor Ehrenberg, the celebrated German micro-
scopist, calculated that there are one million and

58 TOILERS IN THE SEA,

one-third of organisms in a cubic inch of chalk, and
this calculation is, without doubt, very nearly correct.
The block of chalk already referred to contained
about 216 cubic inches, and, according to Ehrenberg's
calculation, should contain 288 millions of shells.
The total, according to our own estimate, based upon
experiment, was 256 millions, these latter having been
made before we were acquainted with Ehrenberg's
figures. Two independent calculations, so nearly
alike, must be held to strengthen each other, and
seem sufficient to establish the fact that between one
million and a quarter and one million and a third of
foraminiferous shells are contained in each cubic inch
of Kentish chalk

To convey some slight idea of the vast number of
these little shells in an ounce of chalk, let us suppose
for a moment that each shell was as large as the
shell of the common garden snail (for /it would
appear to be near that size when seen through a
moderately high power under the microscope). If
such were the case, and these shells were placed side
by side, then the half million of shells in one ounce
of chalk would form an unbroken line of twelve miles
in length. Or, if we take the whole of the shells
contained in the experimental block of 216 inches
(or six inches in diameter in each direction), and
reckon them after the same rate, at 128 millions,
then, on the supposition that each was of the size of

CHALK MAKERS, OR FORAMINIFERA. 59

a garden snail, and placed in a line, that line of shells
would be 3,072 miles in length, and would occupy an
express train seventy-seven hours to go from one

FIG. 12. — CHALK OF DENMARK.

end to the other, at the continuous rate of forty miles
an hour.

It would be folly to attempt any calculation of the
myriads of these little shells which are buried in
the chalk of England alone, without any reference to
similar beds in continental Europe (fig. 12). The

60 TOILERS IN THE SEA.

Kentish chalk pit whence our " lump " was derived,
has furnished to the firm who now hold and work it, a
total of more than half a million of tons, or 561,895
cubic yards of chalk. Figures would fail to convey
any idea of the number of Foraminifera which this
one firm of cement-makers have disturbed, and
removed from their last resting-place. These minute
shells are so small that it would require one hundred
and fifty of many of them, placed side by side, to
extend over one-twelfth of an inch. But if we take
one of the most common forms (that of Globigerind),
the diameter of which is the one hundred and fiftieth
of an inch, it would require nearly ten millions
placed end to end to reach a mile. Accepting this
as the basis of another calculation, and we find that
our Kentish firm have dug from their chalk pit the
shells of Foraminifera — notwithstanding their minute
size — sufficient to extend, at least, 1,006,915,840
miles. From one chalk pit, out of many hundreds
in operation, one manufacturer of lime and cement
has, within about a quarter of a century, dug out
the shells of these minute animals, each one nearly
invisible to the naked eye, in sufficient quantity to
reach more than a thousand millions of miles. Or,
to* represent it under another form, enough to go
round the world, in an unbroken line, more than forty
thousand times.

We have ventured the assumption, that, taking

CHALK MAKERS, OR FORAMINIFERA. 61

into account the past as well as the present, the
Foraminifera are the most ubiquitous and numerous
of all created things. That, living or dead, them-
selves, or their shells, far exceed in number all the
visible evidences we possess of any other kind of
organism. A few suggestions is all we would
venture, but from these it will appear that our
assumption was not a reckless one, and not alto-
gether without the basis of probability.

Already we have hinted at the universal diffusion
of living Foraminifera over the sea bottom, down to
the lowest depths, from the poles to the tropics, or at
least as near to the pole as the absence of ice would
permit the condition of the sea bottom to be ascer-
tained. When it is remembered that the ocean
covers nearly three-fourths of the surface of the
globe, it must be admitted that the available space
for the distribution of living Foraminifera is ex-
tremely large. The result of all the dredgings and
soundings hitherto made has been the ubiquitous
presence of these minute animals. Drawings made
of the magnified portions of the sea bottom, attached
to the "Narrative of the Challenger Expedition," serve
to corroborate this fact, against which there is no
substantial evidence in any direction, so that it may
be accepted as a " fact incontrovertible," that the sea
bottom, at all depths, independent of latitude and
longitude, is 'inhabited by living Foraminifera. From

62 TOILERS IN THE SEA.

this it may, at least, be inferred that one-half of the
surface of the globe is still inhabited by the members
of this cosmopolitan family. When it can be written
of one genus that " it is an inhabitant of all seas,
through a great range of depths," and again, that " it
has been found in abundance in every maritime
region," l we may fairly conclude in favour of the
presence of Foraminifera in all seas. And when we
find it recorded that another genus constituted 97
per cent, of soundings brought up from a depth of
2,000 fathoms in the mid- Atlantic, and a like pro-
portion at depths of 1,260 and 1,607 fathoms, not far
from Greenland, it may be inferred that some forms
of the Foraminifera are exceedingly abundant, to use
no stronger terms, on the deep-sea bottom. Hence
we consider ourselves justified, without multiplying
details, in declaring that living Foraminifera are
plentiful, all over the sea bottom, at all depths, and in
all latitudes.

In the next place, we may endeavour to obtain
some idea of the immense number of shells and casts
of Foraminifera that have existed in the past. The
largest forms are those of the Nummulites, which,
with some intermixture of other types, constitute a
stratum of limestone, "not unfrequently attaining
a thickness of 1,500 feet, which extends in an east

1 Dr. Carpenter's " Introduction to the Foraminifera," p. 178

CHALK MAKERS, OR FORAMINIFERA. 63

and west direction, through Southern Europe, Libya
and Egypt, and Asia Minor, and is continued through
the Himalayan range of Southern Asia, into various

FIG. 13. — CHALK OF MEUDOX.

parts of the great Indian Peninsula, where it acquires
a very extensive development."

The "Nummulite Limestone" of Alabama extends
over an immense area in that state, and is almost
entirely made up of the remains of one species of
OrbitoideS) which is found also in Madagascar and
the West Indies.

64 TOILERS IN THE SEA.

Professor Baily remarks that Charleston is built
upon a bed of several hundred feet in thickness,
every cubic inch of which is filled with myriads of
perfectly preserved shells of Foraminifera.

The most prolific beds of defunct Foraminifera are
those of the chalk, which have a considerable extent
in the south of England. Accurate measurements of
the thickness of the chalk have not been made, but
Sir Henry de la Beche estimates the average thick-
ness at 700 feet The average thickness of the chalk
on the Sussex coast is estimated at 800 feet. The
flinty chalk at Dover is 350 feet in thickness. At
Diss, in Norfolk, the thickness was ascertained by
boring to be 5 10 feet. The number of square miles of
chalk in England must be very considerable, not to
mention its continuation in Northern France (fig. 13),
and other deposits in different parts of the continent.
No human calculation could embrace the myriads of
shells of Foraminifera which these deposits contain,
and yet they are only a few of the most important
accumulations of these remains. We must leave
imagination to fill in the details, on the basis of these
suggestions.

Apart from their natural position, whether living
at the bottom of sea, or dead and buried in the
various deposits, of which they form so important a
part, it is remarkable how we are always accompanied
through life by these fossilised remains, distributed

CHALK MAKERS, OR FORAMINIFERA. 65

by human agency. If we realise the fact that the
chalk is composed of them almost entirely, then we
must admit that wherever we encounter chalk we
have Foraminifera. Mixed with sand and converted
into mortar, the calcined chalk in the form of lime
must still contain myriads of them, so that not only
every brick building, but the plastered walls and
ceilings are mausoleums of hosts of Foraminifera;
whitewash abounds with them ; we swallow them in
chalk mixtures whenever our own internal arrange-
ments are disturbed ; glazed cards are manufactured
by their agency, and transferred to our pockets ;
crayon drawings are indebted for their high lights
and broad effects to shell remains ; and, indeed,, it is
more difficult to determine where no trace of them
can be found, than to enumerate their artificial
localisation by the hand of man. Through untold
ages myriads of minute atoms of life have built their
tiny shells, and died — and wherefore

" They roam'd, they fed, they slept, they died, and left,
Race after race, to roam, feed, sleep, then die,
And leave their like through endless generations."

66 TOILERS IN 7 HE SEA.

CHAPTER III.

LATTICE WORKERS, OR POLYCYSTINA.

IT has come to be a firm belief with some people,
and not without reason, that no natural object
is wholly devoid of beauty ; that, to put it in other
words, there is no natural object which is not to a
more or less number of intelligent, reasoning, and
reasonable beings possessed of beauty. There may
be cases, as for instance, with reptiles and toadstools,
that the number is very limited of those who recog-
nise beauty in what the great majority consider but
too horrible and disgusting. Take it for granted
that the admiring few may be very few indeed, still
they will be, after all, that few to which the objects
in question are best known, and known clear from all
prejudice or bias. Whether there is any analysis of
beauty which makes it to consist in fitness, or whether
it is capable of analysis at all, does not now belong
to us to inquire, since we are not about to plead
specially on behalf of any objects generally excluded
from the circle of the beautiful.

LATTICE WORKERS, OR POLYCYSTINA. 67

There are yet other objects which, either in virtue
of their form, colour, or combination of both, at once
make their impress on all observers, and at once
force the feeling, if not the expression in words, O
how beautiful ! Both classes of objects occupy their
allotted places in creation, and both seem equally
fitted for that position ; yet, when viewed apart from
their associations, when appraised according to their
merits as isolated objects, how vast a difference in
the result of the poll. In one case the verdict is
almost unanimously, Aye, in the other it is almost as
unanimously, Nay. Amongst all the myriads of
minute objects for the microscope, contained in the
cabinets of the curious, there are none more generally
attractive, more popular, or when effectively illumi-
nated, more beautiful than those little skeletons or
deserted houses, which are known by the name of
Polycystins.

Even now this strange name may not be familiar
to some who are scanning these pages, and the
objects which that name is supposed to represent
may be as strange and unknown too. Under such
an assumption it may be well to explain, that many
years ago a sort of chalky earth was found in various
localities [in Barbados, and some of it was sent to
Europe as containing many beautiful and interesting
objects for the microscope. The most numerous of
these objects contained in the Barbados earth were

F 2

68 TOILERS IN THE SEA.

the Polycystins, as they came to be called, which
were so minute as to be invisible to the naked eye,
except as small grains of dust, but which under a
low power of the microscope, are seen to be a variety
of elegant forms, or skeletons, perforated with holes
so as to resemble lattice-work, composed of a white
translucent substance resembling flint, and none of
them so large as a pin's head.

It was apparently in January, 1846, that Dr. Davy,
who was then resident at Barbados, first detected
these organisms in the chalk beneath the coral rock,
and when Sir R. Schomburgh went thither he was
informed of the fact, and some of the skeletons were
exhibited to him under the microscope. Full of
enthusiasm and delight at the discovery, a portion of
this deposit of chalk marl was sent to the eminent
Professor Ehrenberg, of Berlin, and during the same
year this microscopist announced the discovery, in a
communication to the Berlin Academy of Sciences, in
which he said, " for these organisms constitute part
of a chain, which, though in the individual link it be
microscopic, yet in the mass it is a mighty one, con-
necting the life-phenomena of distant ages of the
earth, and proving that the dawn of organic nature
co-existent with us, reaches farther back in the
history of the earth than had hitherto been suspected.
The microscopic organisms are very inferior, in in-
dividual energy, to lions and elephants, but in their

LATTICE WORKERS, OR POLYCYSTINA. 69

united influences they are far more important than
all these animals."

Yet this was not the first time that these minute
animals, or rather their skeletons, became known, for
already previous to 1838, a few fossil forms had been
observed, and in that year these were grouped
together by Ehrenberg under the name of Polycystina,
which they still partly retain. Prior to the discovery of
the Barbados earth these organisms had been found
in the chalks and marls of Sicily, Oran, and in Greece,
and sparingly in the Tripoli of Richmond in Virginia,
and in Bermuda.1 Later on they have been brought
up in profusion, in a living condition, from out of the
depths of the sea. Our whole knowledge of them
may be circumscribed within the limits of the last
half century.

It would be an interminable task to enumerate and
describe all the varied forms of these skeletons or shells,
(Plate II.), but Mrs. Bury has given a characteristic
introduction to their external appearance : — " Among
the most striking differences of form," she says, " may
be mentioned that some are like numerous little
globes growing out of each other, beginning with a
small one at the apex, and each increasing in size as

1 A resume of what was known of them, in their relation to
existing animals, is contained in " Microscopical Siliceous
Polycystina of Barbados," by Sir R. Schomburgh, in " Annals
of Natural History," vol. xx. p. 115. 1847.

70 TOILERS IN THE SEA.

they descend, sometimes so gradually as to look like
storied beehives piled up one on the other. In others,
the globes or bells dilate greatly, and rapidly, towards
the base, till the lowermost exceed in width the most
outrageous crinoline ! Then there are single round
balls pierced through and through, with spikes
sticking out in all directions, but ever pointing from
the centre. Again, to compare small things with
great, there are shapes of the Egyptian pyramids,
and others stretched out and narrowed into obelisks.
Different from all these are very numerous flattened
disks, which appear to grow in concentric circles,
some becoming bordered, others spiked round the
edges, and many having very extraordinary radiating
arms in endless variety."

" A very remarkable feature in the Polycystins are
their exuberant outgrowths. Sometimes they are
merely spines, projecting in a tolerably regular and
always radiating manner ; but sometimes these spines
-or projections branch out and subdivide in the most
whimsical arborescent forms, so as to assume the
shapes of stag's antlers, or even the more complicated
delicate branchings of the once famous bedeguar of
the rose. Apparently these spines, whether simple
or compound, always are to a certain extent hollow,1

1 " The appearance of tubularity is an optical illusion, engen-
dered by the longitudinal ribs, of which the elongated spines

LATTICE WORKERS, OR POLYCYSTINA. 71

so as to have been permeated by the sarcode sub-
stance during growth ; sometimes, instead of becom-
ing finely attenuated, they become bulbous at their
points, and these bulbils swell, become cellular or
foraminated, and assume very much the appearance
as if they were buds from the parent, and intended to
break forth and commence life as fresh individuals."
" Very remarkable instances are seen in those forms
in which a central spheroid body is enveloped by a
sort of fine siliceous web or sponge, which gradually
breaks away, as the centre sends forth stalks (three to
six, but normally four) celled and chambered as com-
plicately as any foraminifer ; and pushing their way
through the sponge-like envelope, and beyond it,
their ends become club-shaped, often strongly spiked
at the extremity, but the swollen part, containing
what looks like a reduplication of the- central parent
form ; and these seem as if they might possibly break
away, and become in their turn centres of growth."

" But though some are symmetrical, or nearly, they
are by no means universally so : in fact, the greater
number display the most grotesque polymorphism.
For instance, you find one with the flowing outline
of some elegant Etruscan vase, with a tapering base ;
the next specimen you see may have ugly nose-

may be said to be made up."— Wallich : " Ann. Nat. Hist "
(1864), p. 81. ,

72 TOILERS IN THE SEA.

shaped handles, adhering to its sides in a clumsy way ;
in another example the nose-like protuberances
enlarge, thicken, become wrinkled, and, however
droll-looking, militate sadly against one's ideas of
elegance. Yet look again and again, and in some
favourably well-grown individual, lo ! there are the
clumsy excrescences lengthened out, curved, refined
and developed into supports, worthy of the famed
Delphic tripod of the Pythian priestess ; the gently
swelling ends of the feet, meanwhile, indicating appear-
ances as of little reservoirs, or deposits of material,
accumulating for future use, either as buds, or for
some further development. Again, in some of the
pyramid or obelisk shapes, the fenestrtne, small at the
apex, widen more and more towards the base, and a
fine inner lattice work is seen to line these too-wide-
open windows. But the variations in form assumed
by these cunning artificers are far too numerous to
mention ; and although they do not work by mathe-
matical rules and compasses, as has been sometimes
represented, they have within themselves a mysterious
unerring rule, which guides every thread, every particle
of internal sarcode, or external silex, into the position,
shape, and size, best suited to the situation, surround-
ing circumstances, and requirements of each in-
dividual organism." l

1 "A Popular Description of Polycystins," by P. S. Bury, in
Science-Gossip^ May i, 1865.

LATTICE WORKERS, OR POLYCYSTINA. 73

Assuming, then, that the skeletons of the animals
called PolycystinSy which are found in various deposits
as fossils, as well as in the mud of the ocean at, the
present day, are minute siliceous, or flinty, objects of
very variable shape, perforated for the most part with
numerous openings, as variable as the contour of the
skeleton, and that these skeletons are sometimes
symmetrical and sometimes not, it will now be our
object to clothe these skeletons, and ascertain what
is known of the living animal which constructed these
glass houses, or flinty tenements, in which they dwelt-
In this instance, as in some others in the present
volume, we accept the term sarcode as the represen-
tative of the simple, glairy, gelatinous flesh of the
animal, however modified, but in order to avoid con-
founding this substance with flesh, as we understand
and recognise it in the higher animals, it is better to
employ a different term, and we have it at hand, as
already adopted and recognised, in sarcode.

There is much in common in this respect between
the Foraminifers and the Polycystins, for Dr. Wallich,
observes : — " I believe that between the degree of
differentiation of the sarcode body observable in the
Foraminifera, and the Polycystina, no difference of im-
portance really exists. In both families the pseudo-

1 " On the Structure and Affinities of the Polycystina," by
G. C. Wallich, M.D., in Quart. Journ. Microscopic Science
v. p. 67. 1865.

74 TOILERS IN THE SEA.

podia are given off principally with reference to the
number and position of the apertures occurring in the
shell. In both coalescence of the most complete kind
takes place immediately on the escape of the sarcode
stolons through the main, or secondary apertures, to
such an extent as occasionally to constitute a delicate
externally investing layer, between the inner surface
of which, and the outer aspect of the shell, the process
of mineral deposit goes on."

In order to avoid needless repetition we would
refer to what we have written of the animal of the
Foraminifera, which corresponds so nearly with that
of the Polycystina. For general purposes it would
be sufficient to say that the animal is, practically,
somewhat of an Amoeba, or Actinophrys, enclosed in
a shell or skeleton ; and that an A moeba is one of
the simplest forms of animal life, consisting of a
single minute nodule of crystalline jelly without
organs of any kind. Imagine a minute speck of
isinglass jelly endued with life, and you have an
Amoeba or Proteus. It has no mouth, no eyes, no
legs, no hands, no feet, no stomach ; yet it performs
the functions of all these. No mouth, yet it extem-
porises a mouth from any portion of its surface,
involves, and draws in its prey ; no legs, yet it
elongates, and pushes out, any portion of its
gelatinous substance like a leg to move itself about ;
no stomach, yet it takes its food and gathers it into

LATTICE WORKERS, OR POLYCYSTINA. 75

the midst of its gelatinous mass, digests it, and
rejects the undigested portions. Now it is almost
spherical, then oblong, lengthens itself into a long and
narrow body, and then as speedily becomes triangular,
starshaped,or many-sided. Every instant changing its
form and assuming every shape of which a plastic lump
of gelatine is capable. In the simple A mceba, portions
are thrust out and extemporised into legs or arms, and
drawn back again and absorbed when their work is
performed ; but in a
slightly advanced ani-
mal, called Actino-
phrys^ these pseudo-
podia, or false arms
and legs, are more
thread-like and more FIG. ^.—ACTINOPHRYS.

permanent, as they

are also in the Polycystins. The bulk of the sar-
code occupies the interior of the shell, or skeleton,
whilst the pseudopodia are protruded through the
many orifices, and seem to coalesce at the base,,
and flow over the skeleton, so as to form a thin
layer like a pellicle enclosing it. By means of these
protruding arms the animal not only moves from place
to place, but is enabled to procure its food (fig. 14).

Adverting for a moment to the little animal
already alluded to, which is almost as commonly
found in fresh-water as the Amceba, and bears a

76 TOILERS IN THE SEA.

close relationship to it, called the Sun-animalcule,
or Actinophrys. It is through this little creature
that some knowledge may be obtained of the
animal of the Polycystins ; indeed it might almost
be termed a Polycystin without a shell. The body
is spherical, and is of that peculiar jelly-like con-
sistence already described in the Amoeba, from which,
however, it differs in not being so variable in shape,
not suffering such continual changes, but retaining
its globose form and also in the more slender
threadlike pseudopodia which radiate from the body
in all directions. Dr. Carpenter remarks that " in
Actinophrys the pseudopodia are very numerous,
and, when fully extended, are long, slender pro-
cesses, that gradually taper from base to point, and
issue from the body in a radial direction ; they
generally remain distinct, when they come into
mutual contact, never undergoing that complete
fusion which is common in those of the Forami-
nifera ; and a slow movement of granules may be
seen to take place along their margin, when the
observation is continued for a sufficient length of
time, under high magnifying powers." Although
several memoirs l have been written, dealing more
or less with these organisms, their history on many

1 Kolliker : " The Sun Animalcule." Quart. Journ. Micr.
Sri.) vol. i. (1853), pp. 25, 98. Claparede, on "Actinophrys," in
Annals Nat. Hist," vol. xv. (1855), pp. 211, 285.

LATTICE WORKERS, OR POLYCYSTINA. 77

points still remains very obscure. All that is need-
ful for the present purpose may be contained in a
brief summary : " The Actinophrys seems to have
little or no power of moving spontaneously from
place to place, and it obtains its food entirely
through the instrumentality of its pseudopodia,
which, by their peculiar adhesive property, attach
themselves to bodies that come into contact with
them. Not only motionless particles of vegetable
matter, but actively-moving Infusoria are thus en-
trapped. When the prey is large and vigorous
enough to struggle to escape from its entanglement,
it may usually be observed that the neighbouring
pseudopodia bend over, and apply themselves to the
captive body, so as to assist in retaining it, and that
it is slowly drawn by their joint retraction towards
the body of the Actinophrys. In other cases, how-
ever, the captive seems as if it were paralysed by
the contact of the pseudopodium, remaining mo-
tionless for some seconds, and then, without any
visible movement of its captor, gliding either slowly,
or rapidly in a centripetal direction, along the
margin of the pseudopodium to which it adheres,
until it becomes jammed, as it were, between the
base of this and a neighbouring one. It is usually,
in fact, by thus gliding along the margin of the
pseudopodium, as if propelled by an invisible peri-
staltic contraction of its sarcode, rather than by a

78 TOILERS IN THE SEA.

visible retraction of the pseudopodium, that any
small body, not capable of offering active resistance,
is conveyed to its base. Now and then it seems as
if the appetite of the Actinophrys were sated, or the
prey not approved of, for after a few seconds the
movements of the latter feebly recommence, and it
glides off the pseudopodium, without any effort on
the part of the Actinophrys to retain it. When, on
the other hand, the captive is to be used as food,
it becomes invested by an expansion of the proto-
plasmic substance which the body of the Actino-
phrys sends forth on either side of that of the captive,
so as to meet and enclose it ; and thus a marked pro-
minence is formed, which gradually subsides as the
food is drawn more completely into the interior.
There can be no doubt whatever that aliment may
be thus ingested at any part of the surface, a new
mouth, so to speak, being extemporised whenever
and wherever there is occasion for it. The struggles
of the larger animals, and the ciliary action of the
Infusoria, may sometimes be observed to continue
even after they have been thus received into the
body ; but these movements at last cease, and the
process of digestion then begins. Whilst the diges-
tive process, — which usually occupies some hours, —
is going on, a sort of slow circulation takes place in
the entire mass of the sarcode. If, as often happens,
the body taken in as food possesses some hard

LATTICE WORKERS, OR POLYCYSTINA. 79

indigestible portion, this, after the digestion of the
soft parts, is gradually pushed towards the surface,
and at last escapes by an anal opening, which ex-
temporises itself for the occasion.1 The reproductive
process in Actinophrys is still in need of further
elucidation. Binary subdivision is one method, in
which the body is constricted all round, which con-
striction gradually deepens, until the connecting
band becomes thinner and thinner, and complete
separation takes place. This process occupies about
half an hour. It has also been affirmed that the
junction of two individuals has been seen to take
place, which has been assumed to correspond to
conjugation in certain Algae, but there is not
sufficient evidence to associate this union with
an act of reproduction. Other appearances have
also been detailed, from which it has been inferred
that true sexual products are formed in the in-
terior of the bodies, and that spermatozoids are
liberated and ovules fertilised. " Nicolet has stated
that in Actinophrys the generative organs consist
of a central spherical membrane, enclosing little
globules, which are the rudiments of 'eggs,' sur-
rounded by a ' gelatinous granular layer,' the granules
of which appear to be the reproductive organs," but
this view is doubted, and has not been substantiated.

1 Dr. Carpenter : " Introduction to the Foraminifera," p. 19.

So TOILERS IN THE SEA.

Although, in some minute points of its history, the
naked Actinophrys is not identical with the shell-
bearing Polycystins, the knowledge of the one may
be helpful to the knowledge of the other, and it must
be remembered that it is only in recent times, con-
sequent on great improvements in the microscope,
that any real history of the structure and habits of
such minute organisms has been traced, and in this
direction much still remains to be accomplished.
Difference of opinion as to the interpretation of ap-
pearances still prevails, and an instance of this kind
occurs in regard to the inception of food, for, on this
point, Dr. Wallich says, that " during many years'
study of the Foraminifera, Polycystina, and all pelagic
Rhizopods, in their living condition, notwithstanding
a keen look-out for an example, he has invariably
failed to discover a single instance in which there
was satisfactory evidence that solid matter had been
taken into the substance of the body as food. This
fact derives additional weight from the circumstance
that some of these Rhizopods occur at times in
immense numbers. It is difficult, therefore," he
thinks, " to conceive how all should present themselves
devoid of everything like solid incepted matter, were
such matter essential to their existence. For it
must be manifest that, as generally attributed to the
Rhizopods, the processes referred to partake of the
miraculous, and, what is particularly notable, that it

LATTICE WORKERS, OR POLYCYSTINA. 81

is not amongst the highest members of the class that
these processes seem to be carried on, in the absence
of organs wherewith to effect them, but in those
lower types in which we have hitherto failed to detect
a trace of such organs." l Whether solid food is
absorbed or not, of a size sufficient to be distin-
guished, is of little consequence to this our history, and
having stated both sides of the case we will proceed,
with the intimation that even those who doubt the
absorption of solid food particles, by either the Fora-
minifera or Polycystina, admit that Amoeba and
Actinophrys " do unquestionably incept solid food
particles, digesting and assimilating whatever portions
are nutritious, and extruding the remainder/'

There seems to be a general agreement that a kind
of imperfect granular circulation takes place in ail
these allied forms, not only in the central sarcode,
but along the extensions, in the form of pseudopodia.
This " streaming of granules," whether in the body
or in the pseudopodia, is not admitted to be refer-
able to a vital power in the sarcode, in which the
primary vital function consists in the contractility
of the substance, but rather that the progres-
sion of the molecules is the exponent of that
function.

From incidental remarks, in the course of his

1 Quart. Journ. Micros. Science, 1865, p. (-5.
G

82 TOILERS IN THE SEA.

" Introduction," it may be inferred that Dr. Carpenter
regarded the "cyclosis," or flowing of granules, in the
body, or extensions of the body, in the Foraminifera
and Polycystina, as something more than mechanical,
and of the nature of vital action. On the other hand,
Dr. Wallich maintains that the movement is one of
a purely mechanical nature, in terms which are
emphatic and not liable to be mistaken. " I feel
bound to express my conviction," he says, " that such
cyclosis is in no way to be regarded as an inde-
pendently acting vital function, resident either in the
protoplasm proper, or in the granules suspended
within it ; but is a purely mechanical result affecting
the granules, only through movements executed by
the vital contractility, which is an inherent attribute
of animal protoplasm. When these movement
cease the circulation of granules ceases ; when they
are resumed the circulation of granules is resumed
also. Notably in the Foraminifera and Polycystina,
these movements become manifest only to the extent
of causing a nearly constant efflux and influx, in
opposite directions, of the protoplasmic matter
entering into the formation of the pseudopodia, and
also in that portion of it which, in most cases, con-
s^itutes a delicate investing layer on the exterior
surface of the shells. It is, however, in the naked
Amoebae that the pseudo-cyclosis attains its most
energetic and characteristic limit, and we can most

LATTICE WORKERS, OR POLYCYSTINA. 83

readily perceive that it is produced by a mechanical
and not a special vital agency."1

Up to the period of the publication of the Challenger
reports, the following was considered as the sum
of our knowledge of the reproduction of the Poly-
cystina :—

It was not assumed that we had any evidence in
favour of sexuality in the reproduction of these little
animals, or, in fact, any supposition of sexuality in a
group of such simple organisation as that to which
they belong. There was, nevertheless, reproduction
after a distinct type, associated with what have been
termed the " yellow bodies " of the sarcode. Both
in the animal of the Foraminifers and of the Poly-
cystins these " yellow bodies " are found, to which
Dr. Wallich was the first to apply the name of sarco-
blasts, with the view of distinguishing them from
other corpuscles of a similar appearance. These, he
contends, are the true rudiments of the young Fora-
minifera and Polycystina, and probably of all
Rhizopods. " And whereas/' he says, " in the case
of the marine and fresh-water genera, I have been
enabled to collect sufficient data to prove that these
bodies, although developed within the parent pro-
toplasm, become ultimately extruded therefrom, and

1 " On the Rhizopoda," by Dr. G. C. Wallich, in Monthly
Micro. Journ., vol. i. (1869), p. 233.

G 2

84 TOILERS IN THE SEA.

in the testaceous (or shell-bearing) forms, that the
deposition of the shell material dates, as a general
rule, from this period ; the development of the ' testa/
while still within the parent sarcode, occurs in some
of the Foraminifera, and brings the phenomenon
within the category of viviparous reproduction."1
These sarcoblasts are very conspicuous in the Poly-
cystins, and are more readily seen than in the Fora-
minifera, in consequence of the crystalline character of
the skeleton. They occupy a position for the most
part immediately within the silicious framework.

No better illustration of Dr. Wallich's views on
this, which was then considered an important phase
of the life history of the Polycystins, can be given
than in his own words: "In 1863," he writes, " I
pointed out, for the first time, that the so-called
* yellow bodies,' as also more or less perfectly colour-
less, but in other respects perfect homologues of them,
are present throughout all the Rhizopodal families,
both oceanic and fresh-water ; this statement being
based on long personal experience. At the time indi-
cated, they had been observed by others only in three
pelagic families, their brilliant yellow tint in the
pelagic families being regarded as their distinguishing

1 Dr. Wallich : Quart. Journ. Micr. Science (1865), p. 71.
Afterwards Cienkowski in 1871, and Brandt in 1881, have
shown that the "yellow cells" do not belong to the Radiolarian
system, but are symbiotic unicellular Algae.

LATTICE WORKERS, OR POLYCYSTINA. 85

character, until it was shown by me that absolutely
identical bodies, in all save colour, are common to
the entire class. Their office had, moreover, until
then been either altogether unrecognised, or, so far as
I am aware, referred to only more or less incidentally,
as in some manner connected with reproduction.
It was in the course of a laborious day-by-day series
of observations on the fresh-water and littoral
Rhizopods, that I was enabled to compare and trace
clearly, and consecutively, the mode of origin of
these remarkable bodies, and to prove beyond all
reasonable doubt that they constitute a true repro-
ductive organ, formed either directly by the aggre-
gation into minute sphseroidal masses of granular,
probably germinal, particles, which, up to the period
of this change taking place, are more or less
uniformly distributed through the sarcode mass
generally ; or, indirectly, by the subdivision of the
contents of the granular nuclear mass itself, without,
however, acquiring in any instance a membranous
covering. For these combined reasons, which had
obviously made the term ' yellow cells ' a dangerous
misnomer, I designated them sarcoblasts. Whether
in the fresh-water littoral or oceanic Rhizopods, the
sarcoblasts invariably constitute, when liberated from
the parent organism, either at once the infant shell-
less organism, or the nidus, and at the same
time the infant mass of sarcode, within which the

86 TOILERS IN THE SEA.

rudiment of the shell, or other mineral framework, of
the organism is secreted. In the Foraminifera and the
Polycystina they are the nidus within which (in the
Foraminifera) the primordial calcareous chamber of
the shell is secreted, or (in the Polycystina) the
earliest siliceous rudiment of the siliceous framework,
or perforated shell."

The " sarcoblast " is in reality a small sphaeroidai
mass of sarcode, generally varying in size, in the
different families, within certain limits, and wholly
devoid of any true membranous or other special
covering. When first observable, it consists of an
almost colourless, hyaline, viscid, and basal fluid, of
the consistence and appearance of the white of an
egg, within which are distributed peripherally, but
without any approach to regularity, a number of
granules of more consolidated, as well as more or less
faintly coloured sarcodic substance, and invariably
(in the case of the sarcode of the oceanic Rhizopods)
of a tolerably brilliant yellow tint. But, by carefully
focussing down to an equatorial plane, a central por-
tion, altogether devoid of granules, and occupied
solely by the pure basal sarcode, may quite readily
be detected. It is to this clear portion that the some-
what misleading name of nucleus has been applied ;
perhaps owing to the idea that its apparently higher
refractive power, as compared with the surrounding
mass, may be due to its being a specialised product,

LATTICE WORKERS, OR POLYCYSTINA. 87

or, in other words, not identical with the sarcode of
the rest of the sarcoblast. Through some subtle re-
productive operation (of which we have learned
nothing from actual observation, in consequence of
the minuteness of the particles concerned) the yellow
granules become, after a time, collected together into
the sphaeroidal masses, now become sarcoblasts ; and,
possibly, two sexual elements are, at this stage of the
organism's history, brought into contact. It will, I
hope, be clearly understood, that I throw out this
view simply as a surmise, resting on no more stable
basis than a fact, observed by myself (for the accuracy
of which I am ready to vouch with perfect confidence),
that the so-called nucleus of the sarcoblast becomes
eventually, on the escape of that organ from the
parent structure, the active centre of shell or skeleton
development. l

To summarise what we have narrated, and quoted,
of the reproductive process in these organisms : the
sarcoblast, or embryo Polycystin, is first recognised,
in the body of its parent, as a minute, spherical, or
almost spherical, speck or lump of granular sarcode,
yellowish in colour, and variable in its diameter, as
soon as it becomes free, ranging, perhaps, from five to
twenty micro-millimetres, or from one five-thousandth

1 "On the Radiolaria as an Order of Protozoa," by Dr.
G. C. Wallich/in Popular Science Review, new series, vol. ii.
P- 273.

8S TOILERS IN THE SEA.

to one thirteen-hundredth part of an inch, that is, so
minute that one of medium size would have a dia-
meter of about one three-thousandth part of an inch,
so that three thousand of them arranged in a line
would only extend an inch ; that these minute em-
bryos are destitute of anything like a proper cell-wall,
but soon after expulsion from the parent exhibit a
clear spot, which might casually be mistaken for a
nucleus, but which in reality is the rudiment of the
future skeleton ; these specks, or " yellow spots,"
being seen resting in a sort of irregular layer imme-
diately beneath the flinty framework, or skeleton, of
the parent, and subsequently cast off through one of
the numerous openings of the shell. There is no doubt
about the rudimentary condition of knowledge of the
development of the young Polycystins from the sarco-
blast, for even as much as this is admitted by Dr.
Wallich. "Occasionally," he says, "during calms
within the tropics, the sarcoblasts of the Polycystins,
and other oceanic Rhizopods, may be taken in im-
mense numbers, although, owing to their extreme
minuteness they are easily overlooked. The profu-
sion, however, in which they occur, in every stage of
growth, affords the means of tracing their history in
al its consecutive phases, and it is highly desirable
that they should be carefully collected, and studied
by all who enjoy opportunities of obtaining them, in
their normal condition."

LATTICE WORKERS, OR POLYCYSTINA. 89

The method by which lime is deposited by the
animals of the Foraminifera, so as to construct their
calcareous shells, and that by which flint is collected,
in the allied group of Polycystina, for the elaboration
of their siliceous skeletons, appear to be the same in
both cases of all the essential points, although the
material is different. The structures are formed in
both by deposits at right angles to the principal
line of growth, and in one direction only.1 Of course,
the material for this operation has to be derived from,
and is held in solution by, the water of the ocean,
whether it is to be regarded as a true secretion, or
merely an exudation, is a subtlety which need not
trouble us ; it is sufficient to remember that the de-
velopment and extrusion of the sarcoblast precedes
the first appearance of the embryonic skeleton. " All
subsequent deposits of silex, or flint, whether in the
shape of foraminated chambers, or spines, or other
portions of the structure, take place on the same
plan — namely, by the deposit of silex at right angles
to the axis of growth, of the part immediately in
question. In the formation of the chambers the
deposit usually goes on from a number of points
simultaneously around the free margin, the points

1 " Remarks on the Process of Mineral Deposit in the
Rhizopods," by, Dr. G. C. Wallich, in "Annals of Natural
History" (Jan. 1864), p. 72.

90 TOILERS IN THE SEA.

becoming filaments, and the adjacent filaments ulti-
mately anastomosing, or rather coalescing, as soon as
they come into contact. The spines are never tubular,
the appearance of tubularity in the spines of some
genera being due to the existence of short longitu-
dinal furrows and buttresses on their inner aspect,
where generally may be seen an aperture around a
portion of the margin of which the base of the spine
has taken its rise. When loops or festoons occur the
process is still the same, as these may be seen in every
stage of growth, from the first projection of a minute
filament to the stage at which the coalescence would
have become complete had the protecting and forma-
tive living sarcode been left to fulfil its office. In
short, the process may be familiarly likened to that
by which the glass-worker extends his plastic and
half molten material from point to point, when manu-
facturing a miniature basket work. Of course the
thickening of each portion is by subsequent deposit
around the original thread."1

The number of genera and species of Radiolaria
was increased enormously by the results of the Chal-
lenger expedition. The total number described by
Haeckel, in his " Report," was 739 genera, and 4,318
species, of these 3,508 were new, as against 810 pre-

1 Dr. Wallich, in Quart. Journ. Micro. Science, v. p. 82.

LATTICE WORKERS, OR POLYCYSTINA. 91

viously described, and yet the riches of the Challenger
collection was by no means exhausted.

From this time the old name of Polycystina came
to be absorbed in that of Radiolaria, and the old
opinions of structure were modified into something
like the following summary of the views propounded
by Professor HaeckeL

The Radiolaria are marine rhizopods, whose one-
celled body always consists of two main portions,
separated by a membrane, — viz., an inner central
capsule, with one or more nuclei, and an outer
capsule (extra-capsulum), which has no nucleus, and
the pseudopodia, the central capsule, is, in part,
the general central organ, and, in part, the special
organ of reproduction. The outer capsule is partly
the general organ of communication with the outer
world, and partly the special organ of protection and
nutrition. The majority also develop a skeleton,
which presents the utmost variety of form, generally
composed of silica (or flint), but sometimes of an
organic substance. The Radiolarian cell usually leads
an isolated existence, but in a small number of in-
stances the one-celled organisms are united in colonies.

It is contended that the special peculiarity of the
one-celled organism, by means of which it is distin-
guished from all other rhizopods, consists in its
differentiation1 into two separate constituents (the
central capsule and the outer capsule) and the forma-

92 TOILERS IN THE SEA.

tion of a special membrane which separates them.
The outer capsule is usually more voluminous than
the central capsule or inner portion. The protoplasm
of the former is emphatically different from that of
the latter. The central capsule is, on the one hand,
the general central organ for the discharge of sensory
and motor functions, and, on the other hand, the
special organ of reproduction. The outer capsule
is not less significant, since, on the one hand, it
acts as a protecting envelope to the central capsule,
as a support to the pseudopodia, and as a foundation
for the skeleton or shell, and, on the other hand, its
pseudopodia are of the utmost importance, as peri-
pheral organs of movement and sensation as well
as of nutrition and respiration. Hence the central
capsule and the outer capsule are to be regarded as
the two characteristic related parts of the one-celled
organism.

The central capsule is originally a spherical body,
which is separated from the peripheral portion by an
independent membrane, which latter appears early,
and is in most cases persistent through life. The
entire capsule, as a whole, consists of (i) capsule
membrane, (2) the inclosed protoplasm, and (3)
nucleus, to which may be added such non-essential
structures as vacuoles, pigment granules, crystals, &c.
The nucleus behaves in every respect like a true
cell-nucleus, and thus lies at the base of the universal

LATTICE WORKERS, OR POLYCYSTINA. 93

opinion, that the whole organism, notwithstanding
its variations, is unicellular, and remains through life
a true individual cell.

The outer capsule (extra-capsuluni] includes all
those parts of the soft body which lie outside the
central capsule. It consists of a gelatinous mantle,
which completely surrounds the central capsule, but
is separated from its outer surface by a thin layer of
protoplasm. The pseudopodia radiate from this
thin layer, penetrate the gelatinous mantle, and form
a network on its surface, whence they extend into
the surrounding water.

Cienkowski was the first to observe that the
" yellow cells," already referred to as supposed
" sarcoblasts," live independently after the death of
the Radiolaria, and in consequence that they do not
belong to it, but are unicellular parasitic algae, to
which the name of Xanthella has been given.

The pseudopodia, or thread-like processes, exhibit
the same peculiarities as in all true Rhizopods ; they
are usually very numerous, long and thin, flexible
and sensitive filaments of sarcode, which exhibit the
peculiar phenomena of granular movement. They
serve as active organs for the inception of nutriment,
for locomotion, sensation, and the formation of the
skeleton.

The skeleton of the Radiolaria, says Haeckel, " is
developed in such exceedingly manifold and various

94 TOILERS IN THE SEA.

shapes, and exhibits at the same time such wonderful
regularity and delicacy in its adjustments, that in
both these respects this group excels all other classes
of the organic world. For, in spite of the fact that
the Radiolarian organism always remains merely a
single cell, it shows the potentiality of the highest
complexity to which the process of a skeleton forma-
tion can be brought by a single cell." The chemical
composition of the skeleton, in many cases, is pure
silica, or flint ; in some it is a silicate of carbon, and,
in a few, of a peculiar organic substance, called
acanthin. Calcareous skeletons, or skeletons com-
posed of lime, do not occur. In the great majority
this skeleton has the form of a delicate lattice shell,
or a receptacle, in which the central capsule is
enclosed. In a small minority, however, this is not
the case. The skeleton then consists only of isolated
rigid pieces, or of a simple ring, or of a basal tripod,
with or without a loose tissue, and the central capsule
is not then surrounded by a special latticed recep-
tacle, but only rests upon the skeleton. ;$#«,:<.

We pass on, from this brief description, to what is
known, up to the present, of the development of the
Radiolaria, as set forth by Haeckel.1

It may be assumed that in all Radiolaria, on

1 "Report on the Radiolaria of the Challenger Expedition,"
by Professor Ernst Haeckel, vol. xviii. (1887), p. xciii.

LATTICE WORKERS, OR POLYCYSTINA. 95

maturity, the central capsule discharges the functions
of a sporangium, and its contents are broken up into
numerous flagellate swarm-spores, or zoospores.
After these have emerged from the ruptured capsule,
they probably pass into an actinophrys stage, and
then, after the formation of a jelly-veil into the con-
dition of sphcerastrum. Afterwards, when a mem-
brane is formed between the outer jelly-veil and the
inner nucleated cell-body, there is what has been
termed the actissa stage, which exhibits in its
simplest form the differentiation of the spherical
central body into central capsule and outer capsule,

The zoospores generally arise in the following
manner: — The nucleus of the central body breaks
up into numerous small nuclei, and each of these
surrounds itself with a small portion of the proto-
plasm. From the resulting small, roundish, or ovoid
cells protrudes one or more vibrating threads (vibra-
tile flagella). The fully-developed spores, which
commence their vibrations even within the central
capsule, emerge when it ruptures, and swim about
freely in the surrounding water by means of the
thread or flagellum. Their form is for the most part
ovoid, or rather cylindrical, sometimes spindle-shaped,
and from 4 to 8 /u in diameter. Immediately
behind the flagellum, at its base, liqs a spherical
nucleus, with . several small, flat granules in the
posterior portion. The number of vibratile flagella

96 TOILERS IN THE SEA.

appears to be variable, usually one, but sometimes
more.

The fate of the flagellate zoospores is uncertain, as
all attempts to rear the swarming zoospores has
failed, but, from analogy, the hypothesis seems to be
fully justified, that they are converted into an inter-
mediate actinophrys stage, in which the body becomes
spherical, with fine pseudopodia protruding all round,
whilst the nucleus assumes a central position.

What has been termed the sphcerastrum stage is
believed to succeed. This stage arises from the
actinophrys stage by the excretion of an external
jelly-veil. In this condition the young Radiolarian
is a simple cell, with pseudopodia radiating on all
sides, its body consisting of three concentric spheres,
viz., the central nucleus, the protoplasmic body proper
and the surrounding jelly-veil. When a firm mem-
brane is developed between the last two spheres,
this stage passes over to the next, or actissa stage.
Probably in all Radiolaria the sphcerastrum stage de-
velops immediately into the typical actissa stage, by
the formation of a firm membrane between the pro-
toplasmic body and its jelly-veil. Thus arrives the
simplest form of Radiolarian organisation, with the
central body differentiated into an inner capsule and
outer capsule, by means of the intervening membrane.

The general course of individual development
begins with the formation of zoospores in the central

LATTICE WORKERS, OR POLYCYSTINA. 97

capsule, but in some groups there is a different pro-
cess introduced by the simple division of the unicel-
lular organism. This spontaneous division is common
in the social Radiolaria, and produces their colonies.
In, these cases the increase by division is nothing
else than an ordinary case of cell-division, in which
bisection of the nucleus precedes that of the cen-
tral capsule. Another mode of growth in the
colonies is the multiplication of the central capsules
by gemmation. The gemmules or capsular buds
are developed on the surface of the young central
capsules before they have secreted a membrane.
"They grow, usually in considerable numbers, from
the surface of the central capsule, which is sometimes
quite covered with them. Each bud usually contains
a raspberry-like bunch of shining fatty globules, and,
by means of reagents, a few larger, or a considerable
number of smaller; nuclei may be recognised in them.
The naked protoplasmic body of the bud is not
enclosed by any membrane. As soon as the buds
have reached a certain size, they are constricted off
from the central capsule, and separated from it.
Afterwards each bud becomes developed into a com-
plete central capsule, by surrounding itself with a
membrane, when it has attained a definite size.

A peculiar method of reproduction, which has been
characterised .as an " alternation of generations,"
occurs in the social Radiolaria, distinguished by the

H

98 TOILERS IN THE SEA.

production of two different kinds of swarm-spores.
These two kinds are called isospores and anisospores.
The isospores correspond to the ordinary asexual
zoospores already described, developing without
copulation. The anisospores, on the other hand, are
sexually differentiated into female zoospores (gyno-
spores) and male zoospores (androspores}. The
female, or gynospores, are larger, less numerous,
possess larger nuclei, and have a fine filiform net-
work. The male, or androspores, are much smaller,
more numerous, with smaller nuclei and thicker
tubercles. In some cases both kinds are developed
in the same individual, but not always. It is pro-
bable that these two forms of anisospores copulate
with each other, after their exit from the central
capsule, and thus produce a new cell by the simplest
method of sexual reproduction. But since the same
species which produce these sexual anisospores at
other times give rise to the ordinary or asexual
zoospores, it is possible that these two forms of
reproduction alternate with each other, and that they
thus pass through an alternation of generations.

The nutritive materials which these animals re-
quire for their support are derived partly from foreign
organisms, which they capture and digest (although
Dr. Wallich has declared his discredit of this), and
partly from the unicellular algae (Xanthella) which
live within them. The considerable amount of

LATTICE WORKERS, OR POLYCYSTINA. 99

starch, and starchy products, elaborated by these
tenants (for they are not truly parasites), as well -as
their protoplasm and nucleus, are available, on their
death, for the nutrition of the Radiolaria which
harbour them. Nutrition, by means of other par-
ticles, obtained by the pseudopodia from the sur-
rounding medium, is by no means excluded ; indeed,
it is certain that numerous Radiolaria are nourished
for the most part, or wholly, by this means. Diatoms,
infusoria, as well as decaying particles of animal and
vegetable tissues, can be seized directly by the pseu-
dopodia, and conveyed, either to the surface of the
jelly-veil, or that of the central capsule, in order to
undergo digestion there. The indigestible constitu-
ents are collected, often in large numbers, and
removed by the streaming of the protoplasm. Pro-
fessor Haeckel seems to be firm in his opinion on
this point, for he alludes to those who have doubted
it, and then affirms : — " I must, however, maintain
my former opinion, which I have only modified in
so much that I now regard the outer surface of the
jelly- veil (cafymma), rather than the outer surface of
the central capsule, as the principal seat of true
digestion and assimilation."

Those bodies called " yellow cells/' which at one
time were a mystery, and afterwards declared to be
statoblasts, are now held to be yellow unicellular
algae, of the group Xanthellce, living within the sub-

H 2

ioo TOILERS IN THE SEA.

stance of the Radiolaria, and assisting in their
support. The animal cells furnish the algae with
shelter and protection, and also with carbon dioxide,
and other products of decomposition, for their nutri-
ment, whilst, on the other hand, the vegetable cells
of the Xanlhellce yield the Radiolarian its most
important supply of nutriment, protoplasm, and
starch, as well as oxygen for respiration. It has
been experimentally proved that Radiolaria, which
contain numerous Xanthellce^ can exist, without
extraneous nutriment, for a long period in closed
^vessels of filtered sea-water, kept exposed to the
.-sunlight, the two organisms furnishing each other
mutually with nourishment. In many Radiolaria
the algae are entirely wanting, therefore they are not
..absolutely necessary for existence.

Circulation is the general term used to express
-certain slow currents in the protoplasm, within and
without the central capsule, of these organisms.
These currents probably continue through the whole
life of the animals, and are of great importance for
the performance of their vital functions. Sometimes
the circulation is directly perceptible in the proto-
plasm itself, but it is usually only visible owing to
the presence of suspended granules. Although the
protoplasm of the inner capsule is in communication
with that of the outer, through the openings in the
capsular membrane, nevertheless the currents exhibit

LATTICE WORKERS, OR POLYCYSTINA. 101

certain differences in the two portions. It is not so
easy to observe the movements within the inner
capsule as without it, but it is sometimes possible to
observe the granules pass through the openings in
the capsule membrane. A distinct flowing of the
plasma outside the central capsule may be readily
observed in all Radiolaria in the living state. This
is most easily seen in the free pseudopodia, which
radiate from the surface into the surrounding water.
In general the direction of the streams is radial,
and it is frequently possible to observe two streams,
opposite in direction, the granules on one side of the
radial thread moving outwards, whilst those on the
other side move inwards. If the threads branch, and
neighbouring ones become united by connecting
threads, the circulation may proceed quite irregularly
in the network thus formed. The rapidity of the
currents is subject to considerable variation.

In addition to the interior movements of the plas-
matic currents, there are also two groups of motor
phenomena which may be observed, the contraction
of individual parts, which produce modifications of
form, and the voluntary or reflex motion of the whole
body. Active locomotion, which is perhaps volun-
tary, occurs in three modes : (i) The vibratile move-
ment of the flagellate swarm-spores, (2) the swim-
ming of the floating organisms, (3) the slow creeping
of those which rest accidentally upon the bottom.

102 TOILERS IN THE SEA.

The movement of the swarm-spores by the oscilla-
tion of the thread, or flagellum, does not differ
essentially from that of ordinary flagellate infusoria.
The swimming of mature Radiolaria is confined to a
vertical direction, causing the rising or sinking in the
water. This is probably due to increase or diminu-
tion of the specific gravity, which is perhaps brought
about by the retraction or protrusion of the pseudo-
podia. The most important organ, however, is
probably the jelly- veil, by the contraction of which
the specific gravity is increased, while it is diminished
by its expansion. The slow creeping locomotion
only occurs when the animal comes in contact with a
solid surface, and is possibly due to muscle-like con-
tractions of the pseudopodia.

On the subject of phosphorescence in the Radio-
laria, Professor Haeckel remarks that " many Radio-
larians shine in the dark, and their phosphorescence
presents the same phenomena as that of other
luminous marine organisms ; it is increased by
mechanical and chemical irritation, or renewed if
.already extinguished. The light is sometimes
greenish, sometimes yellowish, and appears generally
(if not always) to radiate from the fatty sphseres of
the inner capsule. Thus these latter unite several
functions, inasmuch as they serve, firstly, as reserve
stores of nutriment, secondly, as hydrostatic ap-
paratus, and thirdly, as luminous organs for the

LATTICE WORKERS, OR POLYCYSTINA. 103

protection of the Radiolaria. The production of the
light depends, probably, as in other phosphorescent
organisms, upon the slow oxidation of the fat
globules, which combine with active oxygen in the
presence of alkalis."

As to sensation in the Radiolaria, it must be ad-
mitted to be in an inferior degree of development.
For although subject to various stimuli, and possess-
ing a certain power of discrimination, no special
sensory organs are differentiated ; the pseudopodia
acting both as organs of motion and sensation. In
general they seem to be sensitive to pressure, to
temperature, to light, and to the chemical compo-
sition of the sea-water. The reaction, subject to
these stimuli, correspond to the sensation of pleasure,
or dislike, which they elicit, in the motion of the
protoplasm, changes in the currents, and in contrac-
tion of the central capsule and the pseudopodia.
Professor Haeckel considers that the central capsule
contains the common central vital principle, which
he terms the " cell-soul," and that it may be regarded
as a simple ganglion cell, comparable to the nervous
centre of the higher animals, whilst the pseudopodia
are analogous to a peripheral nervous system.

Only a few words are requisite on the distribution
of these organisms, since they are found in seas all
over the world, under all climatic conditions, and all
depths. To say as much as this is to recognise them

104 TOILERS IN THE SEA.

as universally scattered, not only in tropical regions,
but to the North and South Poles, where their limit
has not yet been found amongst the eternal ice, in
which their skeletons are imbedded. The richest
development of forms, and the greatest number of
species, undoubtedly occur between the tropics, whilst
the frigid zones exhibit great masses of individuals,
in but comparatively few genera and species. "The
surface of the open ocean seems everywhere, at a
certain distance from the coast at least, to be peopled
by crowds of living Radiolaria." Thomson and
Murray were convinced, as one of the results of their
experience, that " these animals exist at all depths
•of the ocean, and that there are large numbers of
true deep-se£ species which are never found on the
surface or at slight depths." It has been admitted
'that the great majority of species, which have hitherto
been observed, have been obtained from the bottom
of the deep sea, and more than half of all the species
have been derived from the pure Radiolarian ooze,
which forms the bed of the Central Pacific, at depths
of from 2,000 to 4,000 fathoms.

The Geological Distribution of Radiolaria is also
remarkable, since they are found in all the more
important groups of the sedimentary rocks of the
earth's crust. The great majority belong to the
Cainozoic or Tertiary period, and, in fact, to its
middle portion, the Miocene period. To this period

LATTICE WORKERS, OR POLYCYSTINA. 105

belong the " Polycystin Marl" of Barbados, the
Nicobar clay, and the Mediterranean Tertiary de-
posits. From the Mesozoic, or Secondary period,
many well-preserved species have been described.
All the main divisions of the Jura, both the upper
and the middle, and especially the lower, appear, in
certain localities, to be very rich in well-preserved
shells of fossil Polycystina. The number obtained
from the Palaeozoic or Primary formations is much
less than from the other two. A few species are now
'known from various Palaeozoic formations, and not
only from the Permian and the Coal measures, but
also from the older Devonian and Silurian systems.
An important fact is recorded by Haeckel as to the
connexion between these fossil and extant living
forms. He says that "amongst the Miocene Radio-
laria numerous species are not to be distinguished
from the corresponding living forms. On the other
hand, certain genera, which are rich both in species
and individuals (recent as well as fossil), present con-
tinuous series of forms, which lead gradually and
uninterruptedly, from old Tertiary species to others
still living, which are specifically indistinguishable
from them."

The skeletons of the Radiolaria are so beautiful,
and of such a variety in modification of their form,
that they are deservedly held in high esteem as
objects for the microscope, even when not studied

io6 TOILERS IN THE SEA.

with a higher object. They are, however, of still
higher interest when viewed as the homes, or
skeletons, of the simple organisms that inhabit them.
It would be hopeless to attempt to give any ade-
quate idea of their beauty, or variability, by descrip-
tion, hence we shall rest content with some general
remarks, as a conclusion to this chapter.

In the majority the skeleton is a delicate latticed
shell, or receptacle, which encloses the central cap-
sule, in a minority, it consists only of isolated rigid
pieces, of a ring, or of a tripod. According to
Haeckel there are twelve principal forms which may
be regarded as morphological types of skeleton for-
mation. There are, for instance, the Asteroid or
star-shaped skeletons ; the beloid or spicular, which
consist of several disconnected portions ; the lattice
spheres ; the lattice ellipsoids ; the lattice disks ; the
larcoid lattice shells ; the cyrtoid lattice shells ; the
circoid skeleton, with a simple vertical ring ; the
plectoid, in which three or four siliceous spines
proceed from a common point ; the sponge-like
skeleton, in which a kind of wicker-work of a
more or less spongy structure is developed ; tubular
skeletons ; and conchoid skeletons of bivalved lattice
shells.

The lattice structures are of extremely variable
form, but the specific conformation depends mainly
upon the radial spines. In some of these the entire

LATTICE WORKERS, OR POLYCYSTINA. 107

lattice shell is excreted simultaneously. In others
they are developed from separate lattice plates,
deposited in succession.

" The skeleton in the great majority is armed with
radial spines, which are of great importance in the
development of their general form, and of their vital
functions. The number, arrangement, and dispo-
sition of the spines is usually the determining factor
in the general form of the skeleton. Physiologically
they discharge distinct functions, as organs of pro-
tection and support ; they act also, like the tentacles
of the lower animals, as prehensile organs, since their
points, lateral branches, barbed hooks, &c., serve to
hold fast nutritive materials. In general, main
spines and accessory spines may be distinguished :
the former are of pre-eminent importance in deter-
mining the figure of the skeleton, the latter are
merely appendicular organs." l Accessory spines
may include all those processes which have no in-
fluence in the determination of the form of the
skeleton as a whole. They are developed in the
utmost variety, sometimes as hairs or bristles, some-
times as thorns or clubs, either straight or curved,
smooth or barbed, sometimes standing vertically
upon the shell, or directed towards the centre, some-
times obliquely, or rising at a definite angle.

1 Challenger : " Report on the Radiolaria," p. Ixxxix.

io8

TOILERS IN THE SEA.

The most satisfactory initiation into the mysteries
of construction, in these elaborate skeletons, can best
be obtained by the study of the splendid atlas of
figures of the Radiolaria, published in connexion
with the series of Challenger reports.

TOILERS IN THE SEA. 109

CHAPTER IV.
SPONGE WEAVERS.

WHAT is a sponge? is a question much more
readily asked than answered. Not so many
years ago a speedy answer would, have been given,
even if not satisfactory. In those days there was
a rough-and-ready classification of animals, plants,
and minerals in vogue, subject to three primitive
definitions, — animals possessing life and motion,
plants life without motion, and minerals without life
or motion. Between this triumvirate was the world
divided, until it became manifest that there were
undoubted animals which were as fixed as plants,
and undeniable vegetables which were as free in
their movements as animals. The old formulae were
no longer to be relied upon, and new definitions
attempted, but with these we will not trouble, since
all definitions are but temporary, and but relatively
satisfactory. Even now there are some persons who
require some persuasion before they will accept the
free swimming diatoms as real vegetables, or the

no TOILERS IN THE SEA.

fixed and plant-like zoophytes, or more robust and
fungus-like sponges, as animals. Whether any such
persons ever experimented upon a piece of common
bath sponge by burning it, and sniffing the odour
we are unable to say ; but we should doubt their
judgment, or the acuteness of their sense of smell,
if they had not at once referred the odour to some-
thing akin to burning hair rather than to charred
wood.

We may start with the assumption that sponges
are animal, and not vegetable, because, as we pro-
ceed, this assumption will be abundantly proved,
although the animals may be lower in rank, and
even more simple than the zoophytes, and their indi-
viduality less easily demonstrated. Because they
flourish whilst attached to the rock, by means of a
sort of disk at the base, in like manner to the sea-
weed, proves nothing, for all further resemblance is
at an end, there being only an analogy and no
affinity between them.1 It is a common mistake, —
into which even men with some claim to be con-
sidered scientific occasionally fall, — to confound
analogy with affinity. Things may be very much
like each other, in more particulars than one, and
yet possess no relationship whatever. How many

1 For an account of the History of Sponges, from the earliest
times, see the introductory chapters to "A History of British
Sponges and Lithophytes," by George Johnston, London.

SPONGE WEAVERS. in

fallacies in our own day flourish for awhile upon this
fundamental error, but time and experience settles
the question at last.

It is by no means astonishing that the majority of
persons, not being naturalists, should at the mention
of the name of a sponge at once associate it with
those soft, flexible, and very useful little articles
which accompany a bath, or dangled by a string to
their slates in school-boy days. And certainly these
are sponges of a certain kind ; but the general idea
of a " sponge " must include more than this. Not
only must it include all the many varieties of sponges,
— good, bad, and indifferent, which are employed for
ablutionary purposes, — but also very many others
which could not by any possibility be converted to
such a use. Nearly every local museum exhibits, as
one of its choice treasures, a gigantic "Neptune's
goblet," in shape somewhat like a goblet or vase,
perhaps as much as three feet high, and more than a
foot in diameter, and this is also a sponge. Then,
again, those elegant white, latticed, horn-shaped
objects, called " Venus's Flower - basket " (fig. 15),
which occupy a more favoured position in the local
museum, or stand exposed for sale in the window of
any " naturalist " of moderate pretensions, are also
sponges, but not washing sponges. Indeed, there
are sponges of all sizes, innumerable forms, and
varied characteristics, which scientific people class

112;

TOILERS IN THE SEA.

in three principal groups. First, there are the horny
(or , keratose) sponges, such as the washing sponge,

FIG. 15,— VENUS's FLOWER- BASKET.— (Euplectella aspergillum, Owen.)

SPONGE WEAVERS. 113

which are soft, flexible, and of a substance some-
what resembling horn, but flexible, and chemically
different from horn ; then, secondly, there are the
flinty (or siliceous) sponges, to which Venus's Flower-
basket belongs, in which the skeleton is rigid, com-
posed of flinty fibres, not unlike " spun glass " ; and
lastly, the chalky (or calcareous) sponges, in which
the skeleton is mostly chalky, or carbonate of lime.
For general purposes this division is useful, although
some exception might be taken to it for scientific
purposes ; nevertheless, they are all sponges, and
the idea of a sponge should be so extended as to
embrace them all. Most of them live and flourish
in the sea, whilst only a very few occur in fresh
water.

Accepting this general notion of a sponge, our
best authority on the subject says r1 — " Whatever
may be their form, or however they may differ from
each other in appearance, there are certain points in
their organisation in which they all agree. In the
first place, however variable in its form and mode of
structure, there is always a skeleton present, in which
the rest of the organic parts are based and main-
tained. Amidst this skeleton, and intimately incor-
porated with it, are the interstitial canals, usually of

1 "A Monograph of the British Spongiadae," by J. S. Bower-
bank, LL.D. Ray Society. 1864, &c.

I

114 TOILERS IN THE SEA.

two series ; the first appropriated to the inflowing
(iricurrent) streams of the surrounding water, and
the second to the outflowing (excurrent) streams,
which they conduct from the interior of the sponge
to the oscula at its surface, through which they are
discharged. Enveloping the entire mass of the
sponge we find the dermal membrane, in which are
situated the pores for inhalation and imbibition of
nutriment, and the supply of the inflowing canals,
and the oscula, through which the excrementitious
matter, and the exhausted streams of water, are
poured from the terminations of the outflowing
canals. These parts are indispensably necessary,
and are always present in a living sponge. The
attachment of the sponge to the body to which they
adhere during life is effected by a basal membrane,
which presents a simple adhesive surface, following
the sinuosities of the body on which it is based,
entering into holes, or cracks, and filling them up,
thus securing a firm hold of the mass on which they
are fixed."

The size and external form of sponges vary con-
siderably, even in the same species ; in the majority
there is such a delightful irregularity as to baffle
description. What the extreme size may be it is
very hard to conjecture> but Neptune's Cup is some-
times three feet high, and there are minute species
not so large as a pea ; between these two extremes

SPONGE WEAVERS. 115

there is every gradation. Some of the forms are
certainly elegant, being branched and forked like a,
stag's horn, but these perhaps are rather exceptional
species, since the majority present, especially in the
living state, little that is attractive in appearance.
Their beauties must rather be sought in their micro-
scopical structure, and the elaborate interweaving of
the skeleton. It is probably on account of their
unattractive appearance that they have had so few
students, except here and there a plodding enthusiast,
like our own Dr. Bowerbank and Dr. Carter ; in
fact, at almost any time during the past century
those who pursued the study of sponges in these
islands could be counted on the ringers of one hand.
Of course, there are difficulties to be overcome,
and one of these is the observation of specimens
in the living state, for which purpose dredging must
be resorted to, and such physical exertion as
hardly commends itself to the majority of modern
naturalists.

In order to give some general idea of sponge
structure we must commence with the skeleton, but,
before doing so, it will be necessary to explain what
is meant by sponge " spicules," which are the element
of which the skeleton in most sponges is mainly
composed (fig. 16). If a fragment of siliceous or flinty
sponge is boiled in nitric acid, all the fleshy portion
is destroyed, whilst the flinty, or siliceous, remains

I 2

TOILERS IN THE SEA.

unchanged. When this sediment is washed and
transferred to an ordinary slip of glass and viewed
under the microscope, it will be seen to consist
entirely of little transparent fragments of flint, re-
sembling glass, of regular and symmetrical form,
sometimes very beautiful, largely intermixed with

FIG. l6. — SPONGE SPICULES. •.

simple, straight, or curved bodies like needles and
pins. These are the sponge spicules, each form
having its own peculiar name, which is sometimes
very peculiar and very composite, intended to indi-
cate the particular form of "spicule." Dr. Bower-
bank has enumerated somewhere about two hundred
of these forms, but it would avail nothing to go over

SPONGE WEAVERS. 117

the catalogue of " Geniculated expando-ternate,"
" Unipocillated bihamate," " Tridentate equi-ancho-
rate," or " Floricomo-hexradiate " spicules. Let it
suffice, to indicate their great variety of form, referring
to some figures in illustration (Plate III). Some of
these forms occur chiefly in the principal skeleton,
whilst others are confined to special parts, and have
their own special function, chiefly of strengthening
and supporting the sponge structure. It is noteworthy
that these spicules being of flint, and the most inde-
structible portion of the sponge, are often found in
most unexpected places, like the bones of a skeleton,
when no other portion of the sponge is to be seen.
They may be washed out from chalk, where they
have lain buried for thousands of years, and even
seen imbedded in a thin chipping of flint stone. The
microscope has detected them mixed with sand, or
associated with diatoms, in deposits laid down many
generations ago, in the stomachs of molluscs, fishes,
and even of marine birds of the present day ; in
fact, attached to almost everything that comes out
of the sea, and in nearly every spot over which the
ocean waters have ever flowed. It must not be for-
gotten that we allude in these remarks to the flinty
spicules of the siliceous sponges, which are by far
the most numerous, and not to the chalky or lime
spicules of the calcareous sponges, which are not in-
destructible ; the horny or kcratose sponges being

ii8 TOILERS IN THE SEA.

left out of the question, as the spicules are confined
to a few species.

The skeleton of the horny or keratose sponges,
such as the toilet sponge, is built up of horny fibres
which branch and coalesce, and are interwoven into
a kind of basket-work, sometimes strengthened by
grains, sand, and other extraneous matter, or some-
times by a few spicules, but the most essential ele-
ment is the horny fibre. In the calcareous sponges
carbonate of lime, in the form of spicules combined
with membrane, is the skeleton element ; but in the
siliceous or flinty sponges different forms and com-
binations of spicules cemented together form the
skeleton (fig. 17).

" Sometimes the skeletons assume the shape of a
beautiful regular or irregular reticulation, composed
either of a nearly single series of elongate forms of
spicules, cemented firmly together at their apices by
keratode (which is the principal substance in the
skeleton of the horny sponges), or by numerous spi-
cules similarly cemented together, forming a strong
and complicated fasciculated thread of reticulations.
In other cases there is no reticulated structure, but
the spicules are arranged in elongated compound
bundles, which radiate from either the base or cen-
tral axis of the sponge, whilst in others the reticu-
late and the radial system both enter into the struc-
ture of the skeleton, a modification of the network

SPONGE WEAVERS.

119

prevailing in the axis, and of the radial system
towards the circumference of the sponge. Again, in
other cases the spicules are simply and irregularly
dispersed over the membranous base of the skeleton;
and, finally, we find it simulating the form of pure
keratose fibre, becoming a rigid and solid flinty
fibrous skeleton."

Manifestly all this arrangement is destroyed either
by the natural dis-
integration of the
sponge, or the arti-
ficial breaking up
by boiling in acid,
as above stated,
the cementing ma-
terial being de-
stroyed also, and
nothing is left but
a chaos of mixed
spicules. The only
method of observ-

ing the arrangement is by cutting carefully very thin
sections of the sponge, and submitting them to the
microscope. Of whatever substance the skeleton is
composed, and however it may be combined, it is an
essential of all sponge structure, as much as the bony
skeleton is of the structure of a mammal or a bird.

This skeleton must be covered with flesh, not of

120 TOILERS IN THE SEA.

the same kind as that of the higher animals, but of a
peculiar half-transparent gelatinous substance, not
altogether unlike isinglass jelly in appearance, and
called sarcode. This substance corresponds to what
we call flesh, but simpler in its organisation, and little
more than a pellucid jelly ; there is no other, or
better, name which can be applied to it, since to call
it flesh would be to confound it with something else,
which it is not ; but sarcode really means that it is
" something like flesh ; " therefore let it be sarcode.
This substance is thinly spread all over the internal
tissues, although not perfectly smooth, for sometimes
it abounds in little obtuse elevations, separating occa-
sionally into innumerable roundish or oval masses of
variable size. Under a moderately high power of the
microscope these masses are seen to contain granules
of apparently extraneous matter in a shrivelled or
collapsed condition. Occasionally there are found
intermixed numerous flattened nucleated coloured
cells, immersed in the sarcode.

Dr. Bowerbank says that " while the sponge, as a
whole, is sensitive and amenable to disturbing causes,
the sarcode does not appear to be especially so, as I
have frequently observed a minute parasitical worm
passing rapidly over the sarcode surface, and biting
pieces out of its substance, without apparently
creating the slightest sensation to the sarcode, or at
all interfering with the general action of the internal

SPONGE WEAVERS. 121

organs of the sponge, and occasionally we find minute
creatures permanently located in its large cavities, with-
out appearing to cause it the slightest inconvenience."

At certain periods of the year portions of this
sarcode, detached from the living animal, are capable
of a certain amount of locomotion. It resembles,
perhaps most nearly, the slow, gradual movements of
that curious little creature, the Amoeba, and consists in
a constant change of form, with progress in different
directions. Several independent observers have
described these movements, and most of them have
found them to occur at certain periods, and not at
others, whatever the reason may be.

The living animal, or the units which go to make
up the living animal of the sponge, has of late years
been the subject of controversy, and there are still,
perhaps, two principal opposed views, — one in favour
of an analogy with the polypes, and the other with
flagellate monads. The latter view is now altogether
the most general. " The true essential part of a
sponge," writes one who adheres to the latter view,1
" is composed of structureless sarcode, and nucleated
cells, placed side by side, with a flagellum, some cells
having a hyaline collar protecting the flagellum.
These latter cells line all the passages leading from

1 "On the Natural History and Histology of Sponges," by
B. W. Priest, in Quekett Microscopical Journal, vol. vi. p. 232.
1881.

122 TOILERS IN THE SEA.

the pores, in most cases to the cloacal cavity, or
cavities, to the oscula, regulating the currents of water,
and causing them to flow through the channels, and
convey the nutriment necessary to the existence of
the sponge. Some naturalists, I believe, look upon
the collared cells as playing the part of respiratory
organs only, and not as means for assimilating nutri-
ment ; at any rate, I have no doubt, along with
others, with regard to their regulating the currents of
water. In some species of sponges these ciliated cells
occur only in well-determined circular chambers, with
their ciliated ends pointing towards the centre, each
chamber having a small aperture, which perforates the
investing membrane. The late Professor James
Clarke, of Kentucky, was the first to notice the
analogy of these ciliated cells with the free flagellate
collared infusoria, followed up at the present time by
Mr. Saville Kent. It has been found by this gentle-
man that some of the free collared monads are
identical with the ciliated collared monads discovered
in the sponges, each separate collar-bearing cell
possessing a separate existence, and securing its
nutriment in the same manner. Furthermore,1 Mr.
Kent tells us that sponge structure may be, and zs,
built up from one of these constituent monads, by a

1 "A Manual of the Infusoria," by W. Saville Kent, p. 143,
and following. London, 1880.

SPONGE WEAVERS. 123

repeated process of cleavage, by which means it
quickly multiplies itself, though still more rapidly by
the subsequent encystment and breaking up of the
monads into spores."

It is quite unnecessary to recapitulate the varied
phases of the controversy, which has become volumi-
nous, on behalf of the theory advanced by Haeckel
on the one hand and Professor Clarke on the other,1
since this would scarce possess interest for the general
reader ; but should any one feel desirous of investi-
gating the subject, he will find an admirable summary
in the chapter, " On the Nature and Affinities of the
Sponges," in Mr. Saville Kent's " Manual."

According to those who accept the affinity of the
sponge animal to the flagellate infusoria, first dis-
tinctly propounded by Professor Clarke, and further
developed since his death, the essential sponge-
structure consists of three elements, namely, the
collared flagellate monads, the hyaline mucous-like
stratum (cytoblastema), and the amoeboid bodies, or
cells, to which is added the skeleton or framework
already alluded to. It is claimed, on behalf of the
flagellate monads, that they should hold the foremost
position in the economy of the sponge, to which the
mucous stratum and amoeboid bodies are subsidiary.

1 See " Nature of Sponges," by Henry Slack, in Popular
Science Review, vol. xi. p. 167. 1872.

124

TOILERS IN THE SEA.

The essential feature of the flagellate monads is,
that they possess a film-like collar of membrane, not
unlike a little funnel, which is capable of extension
or withdrawal, enclosing within it a terminal flagellum,
or whip-like thread, and at the other extremity con-
tractile vesicles (fig. 18). As to the collar, it is
stated to be not a mere funnel-shaped expansion of
inert sarcode, but a most active organ, having, dur-
ing life and when fully ex-
tended, a continuous stream
of fine granular protoplasm
for ever flowing up the ex-
terior, and down the interior,
surface of the collar, identical
with the cyclosis exhibited
in the pseudopodia of Fora-
minifera. It has also been
demonstrated that " this
collar, with its characteristic

currents, is an exquisitely contrived trap, for the
arrest and capture of its customary food, which,
driven by the action of the central flagellum against
the outer margin of the collar, adheres to it, and
passes, with the onflowing protoplasmic stream, into
the animal's body." These collared monads are
always found lining special cavities, excavated within
the hyaline mucous-like stratum (or cytoblastemd).
There is, of course, in different sponges, variability in

FIG. l8. — COLLARED

MONADS (Halichondria pa-
nice a).

SPONGE WEAVERS. 125

the size and form of these cavities, and their precise
location. In some they are distributed in a general,
manner throughout the internal canal-system ; whilst
in others they are confined to sphaeroidal chambers,
excavated within the substance of the body of the
sponge, but freely communicating with the inflowing
and outflowing streams.

The second element is the common gelatinous
base, or hyaline mucous-like stratum, in which
the two other elements are imbedded. Although
of the same consistence throughout, this stratum
consists of two layers ; that is, of an investing
membrane in which no monad chambers exist,
and a deeper, thicker substratum in which they are
immersed.

The third element consists of the innumerable
amoeboid bodies, or cells, scattered more or less
abundantly throughout the substance of the mucous-
like stratum. These bodies have no distinct cell-
wall, and unless specially sought after, are scarcely to
be distinguished from the stratum in which they are
imbedded. They vary much in outline, each fur-
nished with a refractive nucleus, and are best seen in
the investing membrane. "Like Amoeba they are
constantly undergoing a change of outline, and may
also be observed to shift their position from one part
to another of the matrix. Oftentimes their long,
slender pseudopodia, radiating towards those of their

126 TOILERS IN THE SEA.

neighbours, unite together, forming a complex net-
work, which presents a remarkable resemblance to
ganglionic corpuscles. It is undoubtedly through
the stimulus received and transmitted by them that
the characteristic contraction and expansion of the
pores, or oscula, and other portions of the sponge
body, are accomplished."1 The relations between
these amoeboid bodies and the flagellate monads is at
present little more than conjecture ; but Mr. Kent
does not regard the former as independent structures,
but rather as larval, or metamorphosed, phases of the
collar-bearing monads, it having been clearly observed
that the latter, when their course is run, lose their
collar and flagellum, and become amoeboid.

This endeavour to explain, as briefly as possible,
the economy of what may be termed the sarcodous,
or fleshy portion of sponge structure, has been neces-
sary in order to exhibit the complexity of what at
one time was considered a very simple matter, and
dismissed with little more than an intimation that it
was called " sarcode," and was the amorphous flesh
of the sponge. Even now there is undoubtedly
much more to be known, and further investigation,
proceeding as rapidly as during the past few years,
will elucidate that which is still dark and uncertain.
If, in each individual sponge, we should come to

1 Kent's "Manual of the Infusoria," p. 172.

SPONGE WEAVERS. 127

recognise a colony of unnumbered workers, myriads
of monads, living in company, toiling for the benefit
of the commonwealth, and weaving a home for them-
selves in the great deep, enlarging, extending, and
increasing the colony day by day, it will simply be a
repetition, in another form, of the same story as told
by the zoophytes, the sea-fans, the sea-mats, and the
architects of the Coral Islands.

" Each wrought alone, yet all together wrought
Unconscious, not unworthy instruments,
By which a hand invisible was rearing
A new creation in the secret deep."

The entire sponge, in its living state, is enveloped
by a sort of skin or dermal membrane, coated in the
inside with sarcode, and strengthened in various
ways by fibrous tissue, or spicules. This membrane
has the power of opening and closing pores on
any part" of its surface, through which the animals
breathe, or receive nutriment. Beneath these pores
are large irregular cavities, which receive the water
imbibed by the pores, and convey it by an inward
current into the canals, which branch and ramify
through all parts of the sponge, becoming smaller
and smaller as they divide and recede. There is
always a double series of canals, those which convey
the water charged with nutriment, by an inflowing
stream, to the remotest parts of the sponge, and
those which collect the exhausted water, and transmit

12& TOILERS IN THE SEA.

it back again by an outflowing stream, which find
an exit in the oscula, or cloacal openings of the
sponge. These latter are either dispersed or clus-
tered together, according to the species, and are
opened or closed at will. This we may term the cir-
culatory system of the sponge structure, by means of
which water charged with nutriment is inhaled, cir-
culates, becomes exhausted, and is ultimately expelled,
with the suspended rejectamenta. Dr. Bowerbank
remarks that "the power of inhalation appears to
be exerted in perfect accordance with the similar
vital functions in the higher classes of animals, not
involuntarily and continuously, as in the vegetable
creation, but at intervals, and modified in the degree
of its force by the instincts and necessities of the
animal. And it may be readily seen that the faculty
of inhalation is exercised in two distinct modes ;
one exceedingly vigorous, but of comparatively short
duration, the other very gentle and persistent. In
the exertion of the first mode of inhalation, — that is,
during the feeding period, — a vast number of pores
are opened, and if the water be charged with a small
portion of finely-triturated indigo, or carmine, the
molecules of pigment are seen, at some distance from
the dermal membrane, at first slowly approaching it,
and gradually increasing their pace, until at last they
seem to rush hastily into the open pores in every
direction. In the meanwhile the oscula are widely

SPONGE WEAVERS. 129

open, and pouring out with considerable force each its
stream of the outflowing (excurrent) fluid (fig. 19) ;
this vigorous action will sometimes be continued for
several hours, and then either gently subside, or
abruptly terminate. Occasionally a cessation of the
action may be observed in some of the oscula, while
in others it is proceeding in its full vigour, and
sometimes it will be suddenly renewed, for a brief

FIG. 19.— PIECE OF SPONGE MAGNIFIED.

period, in those in which it had apparently ceased.
These vacillations in the performance of its functions
is always indicative of an approaching cessation of
its vigorous action. When the vivid expulsion of
the water has ceased, the aspect of the oscula under-
goes a considerable change ; some of the smaller
ones gradually close entirely, while in the large

K

130 TOILERS IN THE SEA.

ones their diameters are reduced to half, or one-
third, of what they were while in full action. Simul-
taneously with the decline in the force of the out-
flowing action, the greater portion of the pores are
closed, a few only dispersed over the surface of the
sponge remaining open, to enable the gentle inhalation
of the fluid to be continued, which is necessary for
the aeration of the breathing surfaces of the sponge.
The breathing state of inhalation appears to be very
persistent, and I have rarely failed in detecting it
when I have let a drop of water, charged with
molecules of indigo, quietly sink through the clear
fluid immediately above an open oscule. These
alternations of repose and action are not dependent
on mere mechanical causes, and sponges in a state
of quiescence may be readily stimulated to vigorous
action, by placing them in fresh, cool sea- water, and
especially if it be poured somewhat roughly into the
pan, and agitated briskly for a short period ; and
this will take place even in specimens that have very
recently been in powerful action. No general law
seems to guide the animal in the choice of its periods
of action and repose, and no two sponges appear
to coincide entirely in the time or mode of their
actions. In fact, each appears to follow the prompt-
ings of its own instinct in the choice of its periods
of feeding and repose."

We may infer that the chief source of nutriment

SPONGE WEAVERS. 131

to the living sponge consists in the minute organisms,
whether animal or vegetable, which are suspended
in the water carried down the inflowing canals. A
curious speculation has been indulged in by some
authors, whether certain forms of the spicules, which
enter into the composition of the flinty sponges, may
not be instrumental in the capture and detention of
little worms, and other animals, so that in fact they
may be devoured for the sustenance of the sponge.
One writer says : " I have for a long time entertained
the idea that these elaborate and varied forms of
defensive spicules, probably subserved other purposes
than that of the protection of the digestive surface
against the incursions of minute annelids, and other
predacious creatures. They are admirably fitted to
retain, and make prey of any such intruders. No
small animal could become entangled in the sinu-
osities of the interstitial cavities of sponges, thus
armed, without extreme injury from the numerous
points of these spicules, and every contortion, arising
from its struggles to escape from its painful and
dangerous entanglement, would contribute to its
destruction, and it may then, by its death and de-
composition, eventually become as instrumental to
the sustentation of the sponge as if actually
swallowed by the animal."1 Although there is little

1 Bowerbank's "British Spongiadce," vol. i. p. 122.
K 2

132 TOILERS IN THE SEA.

if any, direct fact in support of this supposition, it
is at least a plausible one, and would serve to account
for the presence of some forms of spicules, which
seem to be scarcely intended solely for strengthening
the fabric, or serving as a simple defence, but are
evidently adapted for such a purpose as has been
suggested.

Important as it must be to the sponge colony to
protect itself, as much as possible, from its enemies,
and also to ensure a supply of nutriment in its fixed
position, it is of equal importance that provision
should be made for the continuance of the species
by the establishment of new colonies. For this
purpose sponges are by no means left deficient in
resources, and the result may be obtained by one of
three methods, each of which can be resorted to in
case of failure by the other. These three modes of
reproduction are (i) by means of ova or eggs ; (2)
by gemmation, or budding ; and (3) by the spon-
taneous division of the sarcode, or flesh. Taking
these three modes in the order in which they stand,
we commence with the reproduction by means of
ova, or eggs, as at once the most common and
universal in the animal kingdom. Here, again,
there are two modifications, for although the pro-
duction of eggs within an ovarium prevails in the
majority of cases, yet it is possible for eggs to be
engendered without a proper ovarium, although this

SPONGE WEAVERS. 133

method is still but imperfectly known. In the
ordinary sponges of commerce, as dredged, and
before they are cleaned and manipulated by the
dealers, the microscope reveals myriads of minute
ovoid bodies surrounding the fibres, immersed in the
sarcode, which are believed to be the eggs, or ova,
of this particular class of sponges, and are as yet
the only kind of reproductive bodies found in them.
In size and appearance these ova have a great
resemblance to the ova produced in the more legi-
timate manner, and are about two micro-millimetres
in diameter, so that it would take something like
twelve thousand, placed side by side, to form a line
an inch in length. This is almost all that is at
present known about them, but they, or their ana-
logues, do not appear to be confined to the keratose
or horny sponges.1

1 Saville Kent investigated this subject, in connexion with
his " History of the Infusoria," and found them by thousands
in several species of sponge. His conclusion is "that the
collared sponge monad (already described), after assuming a
quiescent state, divides by segmentation into a mass of charac-
teristic microspores, and, these falling asunder, become dis-
tributed throughout the hyaline stratum." And again, " these
spores distributed broadcast through the substance of the
sarcode stratum (cytoblastema) may be met with and traced
onwards through every intermediate size and stage, from the
single sphaeroidai spore, up to the adult collared monads, or
amcebiform bodies ; the derivation of these spores through the
splitting up into a granular or sporular mass of the entire

134 TOILERS IN THE SEA.

The ovaria, or egg-chambers, are spherical bodies
of variable diameter, perhaps about one-eightieth of
an inch in diameter, with a circular hole or opening
at one end. The walls of this chamber are
strengthened by spicules imbedded in the substance,
which latter is of a like character to the other fleshy
portions of the sponge. The interior of the chamber
is lined with a delicate membrane, which encloses,
and protects, the ova when they are developed.
When mature the ova are extruded from the round
hole, — the orifice of the ovarium.

The second mode of reproduction is by gemma-
tion or budding, which may either be internal or
external. The process of internal budding, as
described by Dr. Grant,1 appeared as "opaque
yellow spots, visible to the naked eye, and without
any definite form, size, or distribution, excepting that
they are most abundant in the deeper parts of the
sponge, and are seldom observable on the surface.
They have no cell or capsule, and appear to enlarge
by the mere juxtaposition of the monad-like bodies
around them. As they enlarge in size they become

substance of the matured collar-bearing zooids being corre-
spondingly demonstrated. In the sponge, all these transfor-
mations and developmental processes take place within the
substance, which constitutes a suitable nidus for them." —
Infusoria, vol. i. p. 174 and p. 176.

1 Edinburgh New Philosophical Journal, vol. i. p. 16.

SPONGE WEAVERS. 135

oval-shaped, and at length, in their mature state,
they acquire a regular ovate form." When fully
developed they separate from the parent, and pass
out with the outflowing current at the oscules. At
this period, Dr. Grant states, that they are endowed
with spontaneous motion, in consequence of their
larger extremity being furnished abundantly with
cilia, or very minute transparent filaments, broadest
at their base, and tapering to invisible points at
their free extremities. After floating freely for a
time, they become attached to some fixed body,
adhering firmly to it, and spreading themselves out
into a thin transparent film. When two of these
come into contact they unite, thicken, and produce
spicules, and in a few days there remains no line of
distinction between them, and they continue to grow
as one individual. Subsequently Dr. Bowerbank
confirmed these particulars, except as regards the
cilia in motion, and observes : — " That a sponge is
not always developed from a single egg or bud,
but that, on the contrary, many eggs or buds are
often concerned in the production of one large
individual, a few days probably serving, by this
mode of simultaneous development, to form the basal
membrane of the sponge, of considerable magnitude,
as compared with the individual egg or bud, or
with a sponge developed from a single egg only."
As to his supposition that some of the buds are

136 TOILERS IN THE SEA.

male, and some female, no corroboration has been
obtained.

The third mode of reproduction, by the sponta-
neous division of the sarcode, or flesh, has long been
known, and Dr. Bowerbank has remarked that " the
truth appears simply to be that any minute mass
of sarcode, whether separated voluntarily or in-
voluntarily, has inherent life and locomotive power,
and is capable of ultimately developing into a per-
fect sponge : and in the course of this process the
dermal membrane is produced at a very early
period." And afterwards he adds : — " Thus every
description by these close and accurate observers
tend to the conclusion that the multiplication of
the sponge is effected by the origination in the
egg, or by the agglomeration, in the form of buds,
of particles of sarcode. The action of the minute
masses of sarcode liberated by the bursting of the
envelope of the egg, and their subsequent develop-
ment, is precisely that of the so-called sponge cell
liberated from the mass of sarcode lining the inter-
stices of the sponge, and of the gemmules described
by Grant, when sessile, each moves independently
at first, each unites with its congeners into one body,
and the results, both in means and end, are precisely
the same, but their origin is different. The one is
a generation of sarcode, within a proper membrane,
in the form of an egg, while the others are the pro-

SPONGE WE A VERS. 137

duction of a bud (gemmule) by independent growth,
or by spontaneous division of the sarcodous sub-
stance of the sponge."

Before leaving this portion of the subject, some
brief allusion must be made to those bodies which
have been denominated " ciliated sponge gemmules "
or " ciliated larvae," developmental forms of the
" collared ciliated monads," referred to in describing
the sarcode or flesh of the sponge structure. Mr.
Saville Kent, who is responsible, not only for the
name but the character of these forms, says that
" the initial condition of these reproductive struc-
tures, as conceded unanimously by the independent
testimony of every investigator, takes the form of
an amcebiform body, varying in size from the three-
thousandth to the two-hundredth part of an inch,
and presents a considerable likeness to the primary
condition of an ordinary ovum, or egg." "These
amoeboid oviform bodies are not independent pro-
ducts of the adult sponge stock, but simply retro-
morphosed collar-bearing zooids that have retreated
within the mucous stratum (cytoblastema), and
assumed, as is common to them, after passing their
matured collar-bearing stage, an amoeboid condition.
It is invariably found that these bodies are produced
first in the deeper and consequently older portion
of the sponge stock. This ciliated reproductive
structure is in no sense an egg, or its derivative, but

138 TOILERS IN THE SEA.

represents a coherent aggregate of monadiform
swarm-spores, or, as it may be most appropriately
denominated, a ' swarm-gemmule.' In their most
characteristic form these reproductive bodies, or
cell aggregates, consist of a uniform series of col-
lared zooids." Forms are minutely described under
about three types, as encountered in different species
of sponge, but they agree in all essentials, as an
aggregation of flagellate collared zooids, following
the pattern of their parent.

Having now, somewhat imperfectly, sketched the
outline of the structure, and economy, of a rather
obscure but very large section of "Toilers in the
Sea," we cannot dismiss them, humble as they are
in their sphere and vocation, without calling atten-
tion to some of their ' beauties, which must appeal
even to those who are wearied by details of their
growth and development. It has been shown that
there is in all a fundamental skeleton, of a horny,
flinty, or chalky substance, held together and sur-
rounded by the living flesh, or sarcode, of the
animal, that this skeleton is secreted by the vital
elements from the sea in which it dwells, that the
sponge continues to grow, by aid of the sustenance
it obtains from the water, that it contains ample
provision in various ways for the reproduction of
the species, and that some portions of the structures
so elaborated are practically indestructible, and may

SPONGE WEAVERS. 139

survive the vicissitudes of thousands of years. The
most beautiful example of a sponge skeleton with
which we are acquainted are those elegant forms
which, at one time so rare, are now comparatively
common, called "Venus's Flower-basket," which is
the bare skeleton of a flinty sponge. The ordinary
size of one of these objects is from nine to ten
inches in length, and about one and a-half inches
in diameter at the top, curved and attenuated down-
wards, but with the upper two-thirds straight and
erect, resembling in shape the figures of a cornu-
copia. The entire fabric is cylindrical, and hollow,
looking like a delicate fairy-like basket-work, formed
of elongated fibres, which consist of bundles of long
thread-like spicules, crossed by similar bundles of
spicules at right angles, so as to leave nearly square
meshes, and these are crossed again at the angles,
leaving round openings, resembling the cane-work
of a cane-seated chair, but much finer, smaller, and
more delicate. The top is covered with a similar
network lid, composed of shorter spicules, and the
attenuated base is surrounded by a beard of long
filaments, like threads of glass, which have recurved
hooks towards the ends. Throughout its entire
length this fairy basket-work is ornamented still
further with oblique concentric ridges, or furbelows
of still more' delicate network, and a collar of like
material forms a fringe round the lid. As seen in

140 TOILERS IN THE SEA.

museums, and in the windows of naturalists, the
whole structure is of a virginal whiteness, being
nothing but the skeleton of what it was, but origin-
ally this entire skeleton was undoubtedly covered
by the sarcode or flesh of the sponge. One of the
earliest specimens brought to this country was sold
for thirty pounds. Ultimately, more specimens were
imported, which realised from ten to fifteen pounds
each. Then, with fresh arrivals, the price sank from
seven to three pounds a-piece, and, in the course ot
time, to ten shillings and less. Many of the speci-
mens have a small crab in their interior, which it is
suspected is often, if not always, introduced surrep-
titiously. When first known, it was currently
believed that the case was spun by the crab, but this
was among the natives of the Philippine Islands,
those Europeans who believed in the legend were
few in number.

As already intimated, these beautiful natural pro-
ductions, which Dr. Gray observes 1 " will always be
a most beautiful object, and an ornament to any
room that may contain them," are sponge skeletons
composed entirely of flinty spicules, of various
shapes and sizes, interwoven like the most delicate
lacework.

1 " Venus's Flower-basket," by Dr. J. E. Gray, in Popular
Science Review ', vol. vi. p. 239. 1867.

SPONGE WEAVERS. 141

It has been objected that it is an error to speak
or write of these skeletons as interwoven, for
there has been no interweaving, and no basket-
work, since the material has been produced, and
formed, at the same time as the framework, but no
other word so well expresses the general appearance
of this natural production as one borrowed from a
branch of human industry, and it is scarcely pro-
bable that it will convey an erroneous impression.

Large and appreciable as most sponges are to
the naked eye, it is to the microscope that we are
indebted for a revelation of their beauties, for, except
in a few rare and notable instances, their external
appearance is by no means specially attractive.
Whether we study the singular and variable forms
presented by the spicules themselves, or their com-
bination and arrangement in the sponge skeleton,
they alike afford instruction and entertainment ; in
the former case by their great variety and elegance,
and in the latter by their adaptability to the special
purposes which they are intended to serve. The
answer to the question why any given form of
spicule should have that particular form, in preference
to any other, can only be answered by seeing the
spicule in its natural position, and ascertaining what
function it had to perform.

The most Common and numerous forms of spicule
are the simple cylindrical, or needle-shaped, if we

142 TOILERS IN THE SEA.

may apply that term to them generally, whereas
some are straight and others curved, some with a
head like a pin, and others sharp at both ends, some
rough and others smooth. Then again there are
rayed spicules, some with three rays, some with four
rays, like a cross, and some with many rays. These
are sharp at the ends, or blunt, or spiny. Some again
are shaped like hooks, or forks, or tridents, simple or
complex. Others again resemble anchors, or wheels,
or stars, or spiny spheres ; in fact, to enumerate all
the forms would be to produce an uninteresting cata-
logue, which a few figures would perhaps obviate.
Suffice it to say that almost any typical form has
numerous modifications.

These flinty spicules, which are peculiar to sponges,
are practically indestructible (^fig. 16), and, from the
position in which they are found, it is indisputable
that sponges must have flourished in the ocean very
many thousands of years ago. Dr. Bowerbank was
of opinion that almost every flint stone was once a
sponge, or had a sponge for its nidus. A writer on
the " Spongeous Origin of Flints " l says, " If a thin
chip or section of flint is submitted to microscopic
examinations, sponge spicules in more or less

1 " On the Spongeous Origin of Flints," by F. Kitton, in
Transactions of Norfolk and Norwich Naturalist^ Society r,
(1871-2), p. 51.

SPONGE WEAVERS. 143

abundance, will invariably be seen." And again : —
" In the greensand large silicious nodules, known as
Polypothecea, are of frequent occurrence, and when
thin sections are examined their spongeous origin is
distinctly seen ; these nodules were, however, formed
under somewhat different conditions to the ordi-
nary chalk flint, the silica is distinctly crystalline
and doubly refractive, and polarises like quartz or
agate ; the sponges were also probably different from
those belonging to the chalk. A careful microscopic
examination of very many sections did not reveal
the presence of any form of spicule, they were most
likely allied to the recent keratode sponges ; in fact,
a thin slice of ordinary domestic sponge greatly
resembles a section of its silicified predecessor. The
reticulations are not solid, but tubular, and I have
been able, in many cases, to fill them with colouring
matter."

No one ventures to doubt, or dispute, the evi-
dence, that sponges are amongst some of the
oldest inhabitants of this world of ours, and on that
account, if on no other, are worthy of our better
acquaintance. We have endeavoured to compress,
within a few pages, an epitome of a history which
would readily have expanded sufficiently to have
filled a volume, but even this fragmentary sketch
will show, that there is something worth learning in
the " home without hands," constructed in the sea

144 TOILERS IN THE SEA.

depths, by the kindred of that lump of "common
sponge" which has helped us so often in our
ablutions. Beyond this, it may even lead to a
kindlier affinity for the sea and its wonders, and to
join with Kingsley in singing : —

" Thou sea, who wast to me a prophet deep
Through all thy restless waves, and wasting shores,
Of silent labour, and eternal change ;
First teacher of the dense immensity
Of ever-stirring life, in thy strange forms
Of fish, and shell, and worm, and oozy weed :
To me alike thy frenzy and thy sleep
Have been a deep and breathless joy."

TOILERS IN THE SEA. 145

CHAPTER V.

PLANT-ANIMALS, OR ZOOPHYTES.

AN enthusiastic naturalist, who wrote and
published most interesting records of his
" Rambles," has given the following note of one
of his experiences. " Every morning," he says,
"when the weather was good, one of us went out
in a boat." This was on the Sicilian coast, where
he saw the sea under an aspect entirely new to him,
in an absolute and profound calm, with the surface
as smooth as a mirror, permitting the eye to dis-
tinguish the minutest details at an incredible depth.
" Leaning over the side of the boat, we could see,
flitting beneath our eyes, a vision of plains, valleys,
and hills, in one place with bare and rugged sides,
in another, clothed with verdant herbage, or dotted
over with tufts of brownish shrubs, and in all
respects calling to mind the distant view of a
passing landscape. But it was not the varied out-
lines of a terrestrial scene on which our eyes were
riveted, for we were scanning the rugged contour of

L

146 TOILERS IN THE SEA.

rocks, more than a hundred feet below us, amid
submarine precipices, along which the undulating
sands, the sharply cut angles of the stone, and the
rich tufts of brightly-coloured red weeds, and glossy
fucus fronds, lay revealed to sight with such incre-
dible preciseness and clearness, as completely to
deprive us of the power of separating the real from
the ideal. After gazing intently for a while at the
picturesque scene beneath our eyes, we scarcely
perceived the intervening liquid element which
served for its atmosphere, and bore us on its clear
surface. We seemed to be suspended in empty
space, or, rather, realising one of those dreams in
which the imagination often indulges, we appeared
to be soaring like a bird, and to contemplate from
some aerial height the thousand varied features of
hill and dale." Amongst the things to be seen were
" a hundred different kinds of Polyzoaries, bloom-
ing in tufts of living flowers, or ramified into little
shrubs, every spur and bud of which was an animal,
and which, by their interlacing stems, their variegated
branches and budding shoots, can scarcely be dis-
tinguished from true vegetables." l

Few of us have been privileged to see these
" Plant-animals " flourishing in their native element,

1 "Rambles of a Naturalist," &c., by A. de Quatrefages.
(English edition.) Vol. i. p. 175. London, 1857.

PLANT-ANIMALS, OR ZOOPHYTES. 147

but all of us, perhaps, at some time or other, have
made the acquaintance of their skeletons, or, more
accurately, their empty and deserted houses, torn
from the rocks by the storm, and cast upon the beach

FIG. 20. — SEA FIR (Serttilaria abietina).

FIG. 21. —

PORTION MAGNIFIED

(figs. 20, 21,). Tiny branched, horny, but extremely
delicate twigs, by some called "Corallines," but
improperly, and by others " Zoophytes," common
enough on every shore, especially after rough weather.

L 2

148 TOILERS IN THE SEA.

" Large tangled masses of them, which are full of
beauty in themselves, are cast ashore, and if ex-
amined while still fresh, and moist, will often be found
to conceal some of the smaller kinds in a living
state." It would be an unwarrantable presumption
on our part to suppose any stray visitor to the sea
coast ignorant of such pretty objects, and withal
such " common objects of the sea shore ", as Zoo-
phytes, which may be seen adhering to every scallop-
shell in the town fishmonger's window. Some may
even have admired them when cleaned and grouped
in fanciful shapes, for ornamental purposes, as offered
for sale in the shop windows at fashionable watering-
places.

Should any mind be still harassed by doubt, a
glance at one or two of the woodcuts may serve to
restore peace. It is hardly surprising that, in days
gone by, these organisms were regarded as sea-plants,
kind of sea-weeds. Fixed to the rock, branched and
divided (fig. 20), and bearing capsules, resembling a
kind of fruit, so long as their minute structure, and
method of life, were unknown, it was excusable that
such mysterious "Toilers in the Sea" should be deemed
vegetables. Now, when their innermost secrets have
been revealed, no one would hesitate to pronounce
them animals, colonies of little animals, building for
themselves these horny, plant-like homes, and
dwelling in them.

PLANT-ANIMALS, OR ZOOPHYTES.

149

That portion of the colony which is persistent and
permanent, is the branched and horny polypary\

FIG. 22.— SICKLE CORALLINE.

this is the part cast on shore after a storm. The
living animal^ are contained within these horny
branched tubes, which are slender, and hollow, and

150 TOILERS IN THE SEA.

very elastic, with joints at short and regular inter-
vals. The little animals soon die, when removed
from their native element, and shrivel within the
tubes. For the most part the 'polyparies, or homes
of the polyps, are of a yellowish or horny colour,
and when immersed in water recover speedily their
original form, and elasticity. The material of which
this sheath is formed is called chitine, which resem-
bles horn in many particulars, but differs from it in
its chemical composition. It would be more accurate
therefore to describe these polyparies as branched,
chitinous, amber-coloured tubes, which shelter and
protect the polyps, or little animals, which inhabit
them.

There are many forms, or species, of these zoo-
phytes, differing in the form of the polypary, or in
some minute detail, of the animals which dwell in
them. Some kinds prefer shallow, others deep water.
Some attach themselves to the rocks, others to shells,
or the larger seaweeds, and again some of the
smaller are parasitic upon the larger species. Each
kind, or species, has its own peculiar habit, which, for
our present purpose we need not particularise. In
some species the polypary is solitary, or scattered
singly over the rock, stone, or shell, whilst in others it
forms dense tufts ; but these are minute details which
do not influence the general observations it is our
province to offer ; this object being to present, with

PLANT-ANIMALS, OR ZOOPHYTES. 151

as little technicality as possible, some general idea of
the zoophyte animals, and the homes they inhabit. -
We may premise that the animals themselves
follow closely the type of the common Fresh-water
Hydra, and hence, by studying either the red or
green hydra of our " Ponds and Ditches," we shall

FIG. 23. — FRESH-WATER HYDRA (a b adults, c ^young).

obtain a very fair idea of the hydra-shaped (hydroid)
polypes of the marine zoophytes. There is, how-
ever, one important difference, which must be noted
at once, in order to prevent any confusion of ideas.
The Fresh-water Hydra (fig. 23), is solitary, not grow-
ing in colonies, like its marine cousins, although three

i$2 TOILERS IN THE SEA.

or four young individuals are often met with on the
body of their parent; and further, they are naked,
not being enclosed in a chitinous covering, as is the
case with the marine zoophytes.

These facts will be borne in mind, that the animals
we are about to allude to, resemble miniature fresh-
water hydras, enclosed in a tube, and united together,
by thread-like prolongations of the body, into com-
pound branched colonies, of some hundreds of indi-
viduals, located, and enclosed within a common
home, in some sense like all the lodgers in a model
lodging-house, but with this difference, that there is a
connecting link which unites all of them, and hence
they are not entirely independent the one of the other.
Divested of the chitinous shell, the whole colony
would possess nearly the same form as that pre-
sented by the empty "skeletons" collected on the
beach ; the ultimate terminations of the branches,
and branchlets, being occupied by the miniature
hydra, which protrudes itself from the open end of
the branchlet, and waves its tiny tentacles in the
water, in search of food. It is a beautiful sight to
gaze down into a clear rock pool, and observe one
of these branched polyparies, with all its inhabitants
out of doors, (fig. 24) portions of the body being
thrust through the openings, at all the terminations,
and the tiny tentacles waving like a star, from each
individual, like flowers on an animated plant. At

PLANT-ANIMALS, OR ZOOPHYTES. 153

the least alarm the tentacles, and partly protruded
body, are with-
drawn into the
openings of the
polypary, and a
minute trap-door
closes over them,
to protect them
from injury. This
is a remarkable
contrivance,
which, although
not universal, is
nevertheless com-
mon, each open-
ing being fur-
nished with a tiny
operculum, or lid
(fig. 25), fixed by
a hinge on one
side, which is
pushed up when
the animal pro-
trudes itself, and

f ,. . FIG. 24. — SERTULARIA PUMILA (magnified}.

falls back into its

place when the retreat takes place.1 It is no easy

1 Further information for those desirous of pursuing the

154 TOILERS IN THE SEA.

matter to obtain a good view of a colony with the
animals extruded, as they retract themselves at the
slightest alarm, and, when transferred from the sea to
an artificial aquarium, there are few of them which
will thrive, or, if they continue to exist, will manifest
that vigour which characterises them in their native
element. Many efforts have
been made, with more or less
of success, to kill the animals
suddenly, when expanded so
as to mount them in fluid, as
permanent objects for the
microscope. The theory is
FIG, 25.— OPERCOLUM OF that if fresh water can be

SERTULARIA.

ejected upon them, when ex-
truded, it kills them instantaneously, before they are
able to withdraw ; but it is not so easy to put the
theory into practice, because a very slight motion of
the water is sufficient to cause their withdrawal.
Some of our friends claim to have achieved a fair
amount of success, by carefully taking the living
animals to a short distance only, in a vessel of sea-
water, and then transferring them to a saucer, at the

study of these animals, may be found in "A History of the
British Zoophytes," by Dr. George Johnston (1847), or in the
more recent " History of British Hydroid Zoophytes," by
Thomas Hincks. London, 1868. Both published by Van
Voorst.

PLANT-ANIMALS, OR ZOOPHYTES. 155

same time keeping them immersed, placing them in
the light, and maintaining the saucer perfectly still,
till the expansion takes place, then instantaneously
ejecting fresh water from a syringe upon them. An-
other mode has been suggested of putting the
zoophytes in a small saucer of sea-water, and floating
this on the surface of a large bowl of fresh water.
As soon as a state of expansion which seems satis-
factory is obtained, to swamp the saucer suddenly in
the bowl of fresh water, by thrusting it down in an
instant ; but all these experiments require a quick
and dexterous hand, so that failure is far more
common than success. On the other side it may be
urged that it has been accomplished, and may be
accomplished again.

The method more usually adopted, and more
strongly recommended by practical men,1 is the sub-
stitution of spirits for water, say, gin or whisky, or
spirits of wine. When the tentacles are fully
expanded, the spirit is dropped upon the exposed
animals, by means of a pipette. We are assured
that this method can scarcely fail, with ordinary care,
being far more certain than when fresh water alone
is used.

To return from this digression to the animals in

1 It is the method in ordinary use amongst the members of
the Quekett Microscopical Club, and has their commendation.

156 TOILERS IN THE SEA.

question, we may observe that the polyps, which are
attached to the common body, are those which suck
in the nutriment for the support of that body, whilst
the reproductive animals, or those which are con-
cerned in the perpetuation of the species, soon
become free, quit their old home, and go forth to
establish a new one, being in themselves the unit
from whence a new colony is to spring. For the
present we are concerned only with the fixed polypes,
the members of a given colony, who toil for the
sustenance and support of the commonwealth. This,
which is the true polype, consists of a digestive sac,
with a terminal mouth, surrounded by tentacles, and
is attached, at the base, to the extremity of one of
the branchlets of the common trunk (c&nosarc). The
soft body is very contractile, and consequently vari-
able in form, attenuated when thrust out at the
openings of the horny sheath, and broader when
withdrawn and contracted. The hollow cavity in
the centre is a sort of simple stomach, ending up-
wards in an opening, or mouth, and continued below
into the common canal, which traverses all the
branches, down to the main trunk. The mouth is
sometimes a simple, and sometimes a lobed opening,
surmounting a sort of proboscis, which is either
conical or funnel-shaped. It is an admirable little
instrument for the acquisition of food, the lips
opening and closing as occasion requires. The

PLANT-ANIMALS, OR ZOOPHYTES. 157

tentacles are arranged round the mouth, in one or
two series ; they are thread-like appendages, very
flexible, and extensile, and are rough on the surface
with a vast number of thread-cells, containing the
only organs of offence and defence which these
animals possess. These cells are imbedded in the
flesh, and each contains a long delicate thread, or
dart, often covered with barbs, and when at rest, lies
spirally coiled up in the thread-cell. Undoubtedly
these darts are deadly instruments when brought
into operation, as they bury themselves in any soft
substance with which they come in contact, and pro-
bably convey some poisonous fluid into the wound.

When the food is collected at the mouth, by means
of the tentacles, and conveyed into the stomach, it is
digested, and prepared for the support of the whole
structure, and then passes down by the posterior
opening into the canal, which traverses the whole
colony. The circulation through this canal is very
simple, the walls of the canal are lined with vibratile
cilia, which, by their motion, keep up a continuous
stream, from the stomachs of the polyps towards the
trunk, and back again to the remotest branchlet, and
thus every part of the structure is in communication
with the myriad mouths, and is constantly supplied
with all that is necessary to maintain the life, health,
and vigour of the entire community.

The individual polypes often die, or become ab-

158 TOILERS IN THE SEA.

sorbed, whilst the colony, as a whole, still maintains
its full vitality. In some species there seems to be a
sort of winter rest, when numbers of the polypes are
absorbed, but with returning spring, are again repro-
duced as plentifully as ever.

The growth and extension of the colony, or poly-
pary, proceeds in a similar manner to the growth of
a plant, by the production of buds. Every colony
has originated from a single polype, and the plant-
like form has been acquired by a succession of buds.
" The Hydroid colony is enlarged by a purely vege-
tative process ; fresh polypites bud rapidly from the
prolific pulp, and in the larger and arborescent kinds,
branches and branchlets germinate, according to the
pattern of the species, from the zoophyte, as from the
tree. For the multiplication and diffusion of the
species, special zooids are set apart ; and to them is
allotted the reproductive function, as to the polype
that of nutrition. They correspond with the flower-
buds of the plant." l

" Each wrought alone, yet all together wrought,
Unconscious, not unworthy, instruments,
By which a hand invisible was rearing
A new creation in the secret deep."

Sexuality, in connexion with these zoophytes, has
not as yet been alluded to, because the fixed polypes,

1 Hincks's " Hydroid Zoophytes," p. xx.

PLANT-ANIMALS, OR ZOOPHYTES. 159

to which our attention has hitherto been confined, are
neuters, they are the workers of the colony, and, in.
some sense, correspond to the " workers " in a hive of
bees. Now that we are required to describe the
method in which new colonies are formed, and
account for the perpetuation of the species, we must
discover other members of the colony than those
fixed, or permanent individuals, which furnish the
colony with material support. The polypes are pro-
duced only at certain seasons, and occupy different
positions in different species. They are produced
in buds of a peculiar structure, borne upon an off-
shoot from one of the branches, and enclosed in a
sort of urn, or receptacle, formed from the same
chitinous, or horny, material as the covering, or
skeleton of the colony. There may be some species
in which this method does not prevail, in all its par-
ticulars, but in the most common species it is
sufficiently general for our purpose.

The sexual bud (gonophore) consists of an outer
coat, which serves for protection, and an enclosed,
either male or female, zooid. Sometimes male and
female occur on the same shoots, but in some cases
they are produced on different colonies of the same
species. The sexual zooids, which are in time
developed from the special sexual buds, are either
fixed to the colony, as the working polypes are, or
they become free, and float away from the parent

160 TOILERS IN THE SEA.

colony, and enter upon an independent existence.
In the latter case they present such a contrast to the
original stock, both in form and habit of life, that it
seems difficult to believe that the new forms have
any relation whatever to the old, but that they are
rather new creatures, belonging to quite a different
tribe. It is only by tracing their relationship that
one is thoroughly convinced of the reality of the
metamorphosis. In most cases the free zooid, which
is the product of the sexual bud, assumes the form
known to marine zoologists as that of the Medusa.
For the benefit of those who are not marine zoolo-
gists we must explain what these Medusa-forms are
like (fig. 26).

A small delicate crystal dome, a little more
than a hemisphere, floating with the flat side down-
• wards, and propelled through the water by con-
traction of the sides, its outline so delicate, and its
substance so glassy, that it can be just distinguished
in the water. The lower flat surface covered like a
kettle-drum, which it resembles in miniature, with a
thin membrane, with a round hole or opening in the
centre. The margin of the flat surface apparently
notched, or beaded, with a circlet of small sacs, and
a fringe of long thin tentacles, which hang down
waving and floating in the water like threads, — such
is the general external appearance of the Medusa.
The wall of this swimming-bell is so thin and filmy,

PLANT-ANIMALS, OR ZOOPHYTES. 161

that the internal arrangements can be readily seen.
Within the body of the dome a tube hangs suspended,
the lower end terminating in a mouth, the upper

c

FIG. 26. — HYDROID POLYPE, PRODUCING A MEDUSA.
M

i62 TOILERS IN THE SEA.

end united to a number of radiating tubes, which
arch over, and pass downwards, to the edge of the
swimming-bell, where they unite to a hollow circular
ring, or canal. At the margin of the swimming-bell,
and near the base of the tentacles, is one or more eye-
spots, probably having the functions of an eye in
higher organisms. The hollow cavity of the tube is
the stomach, from which the digested food passes
into the radiating canals, through which it circulates.
The mouth is sometimes lobed, and sometimes
fringed with a few short tentacles, to assist in the
acquisition of food. This is a brief summary of the
appearance, and structure, of the Medusa-like free
zooid, in so far as relates to its movements, and
method of living. All that concerns its other func-
tion, the perpetuation of the species, will be detailed
further on.

" It would be difficult," writes Mr. Hincks, " to
exaggerate in speaking of the beauty of these floating
flower-buds, as they may well be called. The vivid
tints which they often display, the gracefulness of
their form, the exquisite delicacy of their tissues, and
the vivacity of their movements, combine to render
them singularly attractive. Frequently they are so
perfectly translucent that their bubble-like forms only
become visible in a strong light. In other cases the
umbrella is delicately tinted, while the central tube
(manubrium) displays the gayest colouring, and

PLANT-ANIMALS, OR ZOOPHYTES. 163

brilliant eye-spots glitter on the bulbous bases of the.
tentacles. To their other charms that of phospho-
rescence is often added ; they are not only painted
like the flower, but at night they are jewelled with
vivid points of light, set round the margin of the bell,
or one central lamp illumines the little crystal globe,
and marks out its course through the water. Though
individually minute, their numbers are so immense
that they play an important part in the production
of the luminosity of the ocean. The surface of the
sea, for miles together, is often thickly covered with
them ; and on still, sunny days in autumn, certain
species swarm in immense shoals off the coast. Like
miniature balloons they float suspended in the water
for awhile ; then they suddenly start into motion,
propelling themselves by a series of vigorous jerks, or
casts, and at the same time contracting the tentacles
into the smallest compass ; then they become quies-
cent again, and sink slowly and gracefully, like para-
chutes, to the bottom of the vessel, some of the arms
extended laterally, and the rest dependent. In all
cases locomotion is effected by the pulsation of the
swimming-bell."1

Increase by means of budding, which is so general
in the " colony," is by no means absent from the free
swimming polypes. It is not unusual when the true

1 Hincks's " British Hydroid Zoophytes," p. xxx.
M 2

164 TOILERS IN THE SEA.

reproductive function is arrested, or in abeyance, for
buds to be produced on different parts of the Medusa-
like structure, sometimes on the central canal, but
most commonly near the base of the tentacles, at the
lower margin of the swimming-bell, and the buds
thus produced originate free zooids, in all respects
like the parent from which they sprung.

The reproductive elements are produced, in the
free swimming polypes, either between the two
membranes of the central pendulous tube, or they
are enclosed in special cells, or sacs, seated on the
radiating tubes. Sometimes they make their ap-
pearance before the liberation of the free zooid, and
sometimes not until long after the zooid becomes free,
the ovaries in one individual, and the spermaries in
another, so that, typically, the free swimming polypes
are either male or female.

It must not be supposed that all the genera pro-
duce the free polypes, for in some groups the sexual
polypes always remain fixed, although this is regarded
as being a less highly developed form of reproduc-
tion, and is subject to various gradations, some being
simple, and others much more complex. In one
sub-order the reproductive buds are borne on an off-
shoot of the polypary, enclosed in an urn, or capsule,
of similar substance to the residue of the horny
skeleton. This is a large section, and contains some
of the commonest, most interesting, and best-known

PLANT-ANIMALS, OR ZOOPHYTES. 165

species. The male and female are sometimes pro-
duced on the same polypary, but more commonly;
perhaps, any given polypary is either male or female,
as far as its reproductive buds are concerned, although
Mr. Hincks thinks that the cases in which both male
and female are mingled on the same shoots are much
commoner than has been supposed.

After impregnation, the ova in the female capsules
pass through intermediate stages, and at length
become resolved into a granular mass, which by
further development, becomes an elongated embryo
(planula), which escapes from the capsule into the
water, and temporarily enjoys a free existence, but it
is the embryo which becomes free and not the sexual
polype, as in the case of the veritable free swimming
polypes. The liberated embryos have a double
coating, or membrane, and the outer surface is almost
always covered with vibratile cilia, or moveable hairs,
by means of which their progress in the water is
directed. Afterwards the body enlarges at one end,
and a thin horny, or chftinous, film is formed over a
portion of the surface, then its movements slacken ,
and at length cease, the cilia disappear, and the
embryo becomes attached by the enlarged end,
which flattens out into a disk, whilst the rest of the
body stands erect in its centre. This is the first
evident step towards the foundation of a new colony.
The disk of attachment by-and-by becomes lobedi

166 TOILERS IN THE SEA.

and divided, forming the rudiments of the radiating
base, and the whole structure is soon invested in a
chitinous sheath or elementary polypary. In the
course of time, as growth proceeds, the upper end of
the attached embryo developes into a fixed polype,
enclosed within a capsule, with a moveable lid, which
is pushed off when the animal is mature. Then the
initial step is complete, and the first individual, which
for the time being constitutes the entire colony, is
perfected ; from this unit, by a series of successive
buddings and branchings, the plant-like colony is gra-
dually built up, in all respects resembling the .parent,
from whence the solitary embryo fell into the water,
or was cast out into the world of waters, to make a
home for itself, but a short time previously. And, in
like manner, every polypary, with its hundreds of
individuals, commenced, in such humble guise with a
single polype.

Dr. Johnston has thus summarised what was
known, in his time, of the growth of the polypary : —
" The ripe ovule, or bud, discharged from its matrix
settles, and fixes itself to the site of its future ex-
istence, by minute fibres, which pullulate from the
under side, while, from the opposite pole, a papillary
cone shoots up to a height determined by the law
which regulates the peculiar habit of the species.
The upward growth is then arrested, and the apex
becomes enlarged and bulbous. The structure of

PLANT-ANIMALS, OR ZOOPHYTES. 167

this rudimentary shoot is at first apparently homo-
geneous, but very shortly the separation between the
sheath and the interior pulp begins to be defined,
and is made hourly more apparent by the pulp
retreating inwards, becoming darker, and more con-
centrated. That portion of it in the bulbous top of
the shoot goes on to further condensation and de-
velopment ; and as it enlarges, so in proportion does
the horny cuticle that covers it expand apace, until
it has gradually evolved into one or two cells, which
are still closed on all sides. The dark body of the
polype is apparent through the thin and transparent
wall, and from its superior disk there are now to be
seen some minute tubercles or knobs protruding,
which, becoming, insensibly but steadily, more
elongated, constitute the tentacles of the polype,
now nearly ready for a more active life. By an
extension of development, or by a process of absorp-
tion, not well understood, the top of the cell is at
length opened, the polype displays its organs abroad,
and begins the capture of its prey, for, unlike higher
organisms, it is, at this the period of its birth, as
large and as perfect as it ever is at any subsequent
period, the walls of the cell having become indurated
and unyielding, and setting a limit to any further
increase in bulk. The growth being thus hindered
in that direction, the pulp, incessantly increased by
new supplies of nutriment from the polype, is con-

168 TOILERS IN THE SEA.

strained and forced into its original direction, so
that the extremities of the tube, which have re-
mained soft and pliant, are pushed onwards, the
downward shoot becoming a root-like fibre, and the
upper continuing the polypary, and swelling out as
before, at stated intervals, into cells for the new
development of other polypes."1

Undoubtedly the chitinous covering of the polypes.,
which serves as a protection to their delicate bodies,
and a home in which to dwell, is gradually built up,
as occasion requires, by absorption and elaboration,
from the water of the ocean. These little builders
construct their own houses, as the crab and the
oyster construct their shells, from material held in
solution by the sea-water. These structures may
not be so imposing, or so substantial, as those of the
architects who construct coral islands, but they are
even more beautiful, and equally exhibit a facility
for construction

— " Where every one,

By instinct taught, performed its little task ;
To build its dwelling and its sepulchre,
From its own essence exquisitely modelled ;
There breed, and die, and leave a progeny,
Still multiplied beyond the reach of numbers,
To frame new cells and tombs ; then breed and die
As all their ancestors had done, — and -rest,
Hermetically sealed, each in its shrine,
A statue in this temple of oblivion ! "

1 Johnston's " British Zoophytes," p. 9.

PLANT-ANIMALS, OR ZOOPHYTES. 169

One most interesting feature in the history of these
zoophytes is the phenomenon of phosphorescence
which they exhibit, although they are not the only
animals which contribute to the phosphorescence of
the sea. One author writes : — " I lately had an
opportunity of beholding this novel and interesting
sight, of the phosphorescence of zoophytes, to great
advantage when on board one of the Devonshire
trawling-boats which frequent this coast. The trawl
was raised at midnight, and great quantities of coral-
lines were entangled in the meshes of the net-work,
all shining like myriads of the brightest diamonds j"1
and, subsequently, the same writer says : — "Numerous
friends can bear witness to the exceeding brilliancy
of the phosphorescent light emitted by a great
variety of species, which I was in the habit of ex-
hibiting to them. Once each week I received from
the master of a trawling-vessel, on the Dublin coast,
a large hamper of zoophytes in a recent state ; in the
evening these were taken into a darkened room, and
the spectators assembled ; I then used to gather up,
with my hands, as much of the contents of the hamper
as I could manage, and, tossing them about in all
directions, thousands of little stars shone out brightly
from the obscurity, exhibiting a spectacle, the beauty

1 Hassall, in "Annals of Natural History," first series,
vol. vii. p. 281.

i;o TOILERS IN THE SEA.

of which to be appreciated must be seen, and one
which it has been the lot of but few persons as yet
to have looked upon. Entangled among the coral-
lines were also numerous minute luminous Annelids,
which added their tiny fires to the general exhibi-
tion."1 It is unnecessary to add confirmation of what
is now acknowledged as a fact, but the Rev. D.
Landsborough may be quoted for an experience
which befel him nearly fifty years since. " I brought
from the shore in a pocket vasculum, or tin box,
some zoophytes attached to sea-weeds, and laid the
vasculum on the lobby table, till I should have leisure
to examine them. When night came I put my hand
into the vasculum to remove some of the zoophytes
for inspection, and, on moving them, I found, to my
surprise and delight, that they began to sparkle.
Remembering what I had read, as I took them up I
gave them a hearty shake, and they instantly became
quite brilliant, like handfuls of little stars, or sparkling
diamonds. To ascertain what were the zoophytes
that emitted this phosphorescence, it was necessary
to take them up singly by candle-light, and after-
wards to make the experiment in the dark. One
(Obelia geniculatd] was very luminous, every cell for
a few moments becoming a star ; and as each polype

1 Hassall, in "Annals of Natural History," first series,
vol. viii. p. 342 .

PLANT-ANIMALS, OR ZOOPHYTES. 171

had a will of its own, they lighted and extinguished
their little lamps, not simultaneously, but with rapid
irregularity, so that this running fire had a very
lively appearance."1

It was in reference to this phenomenon that
Crabbe wrote the following lines, so often quoted in
connexion with this subject : —

" While thus with pleasing wonder you inspect
Treasures the vulgar in their scorn reject,
See, as they float along, th' entangled weeds
Slowly approach, upborne on bladdery heads ;
Wait till they land, and you shall then behold
The fiery sparks those tangled fronds infold,
Myriads of living points ; th' unaided eye
Can but the fire, and not the form descry."

The whole subject of the phosphorescence of the
sea is of great interest, but hardly comes within our
present scope. Very little of this general phos-
phorescence can be ascribed to our zoophytes,2
although much, perhaps, to animals equally insig-
nificant and humble. " I remember," writes an ob-
server, "the admiration, not unmixed with wonder,
(for then I knew not to what agencies the power by
which water seemed suddenly to kindle and glow, as
though turned to liquid fire, was to be attributed),

1 "Annals of Natural History," December, 1841, p. 258.

- Readers are referred to a very interesting summary by
M. de Quatrefages in Popular Science Review^ vol. i. p. 275
(1862), entitled "The Phosphorescence of the Sea."

172 TOILERS IN THE SEA.

which I felt when first I viewed the beautiful phos-
phorescence phenomena of the ocean. Beautiful as
this spectacle is, even in qur own seas, in warmer
latitudes, and in the Mediterranean, it is far more
splendid ; but, to be seen at all, it is necessary that
the water should be disturbed in some way, — the
slightest breeze curling the surface of the tranquil
ocean, calls forth from its waters a flash of phos-
phorescent fire as it sweeps along — the wave, as it
falls from the vessel's side, and breaks into ten
thousand pieces, reveals innumerable globes of ani-
mated fire, suddenly called forth from the darkness
which enveloped them — each stroke of the dripping
oar scatters thousands of living gems around them,
unequalled in brilliancy by the glittering of a kingly
diadem — a golden path of light, increasing in breadth
as the distance becomes greater, follows, like an
attendant comet, the wake of the vessel urged on-
wards by the impelling wind — and the fisher's net,
just raised to the water's edge, and laden with spoil
collected from the secret beds, and hiding-places of
the great deep, seems converted into a golden frame-
work, set with precious jewels, by the presence of
numerous zoophytes entangled in its meshes. Indeed,
in whatever way the water is agitated the same
beautiful appearance follows ; if a little be placed
even in the palm of the hand, and shaken, bright
scintillations will be emitted ; but, of course, the

PLANT-ANIMALS, OR ZOOPHYTES. 173

phenomenon will be more striking in proportion to
the quantity of water put into commotion." l

The growth, or increase, of the polypary is com-
paratively rapid, for the size of the little animals that
are concerned in building it up. Mr. Couch has
expressed the opinion that a large specimen of one
kind of Sertularia may be formed, under favourable
circumstances, in the course of fourteen days.

Another observer mentions the fact of the bottom
of a boat which became covered in a fortnight. Some
of the species undoubtedly continue through several
seasons, and increase in size from year to year, whilst
others have a much briefer career, and some only
last during a single season. Those kinds which
attach themselves to rocks are considered to be more
persistent than those which affect sea- weeds. In
perennial species the polypes are much reduced in
number during the winter, reappearing again in the
spring. Although several kinds have been known to
thrive with apparent vigour in aquaria, yet the rate
of increase, under such artificial conditions, would
hardly be equal to what it would be in a state of
nature. The enormous rate at which many of them
multiply, and establish new colonies, might almost
be anticipated from the large number of individuals

1 "Annals of Natural History," first series, vol. viii. p. 343
(1842):

174 TOILERS IN THE SEA.

that are included in a single thriving colony. An
American naturalist says, that he has seen one species
discharging embryos as early as March, and as late
as the middle of September, " during all which time
thousands were continually shed, and consequently
thousands of new colonies established, their multipli-
cation being so great, during a favourable season, that
the rocks literally appeared clothed with the yellow
stems, and rose-coloured blossom-like bodies, of these
flower-animals."

It being the object of this chapter to indicate
generally, the structure and habits of the little builders
who construct the horny homes in which they dwell,
as " Toilers in the Sea," it is unnecessary to particu-
larise the different species, or point out their charac-
ters, whereby one may be known from the other,
since those who are desirous of continuing the study
further will not expect to find such information in
one short chapter, and, moreover, there is already
an excellent text-book for that purpose, by the Rev.
Thomas Hincks, to which we have already alluded.

" Amongst the rejectamenta which strew the shore
after a fresh breeze and a rough tide, there are few
things more likely to arrest the eye, and win the
admiration, even of the least observant, than the
zoophytes, which mingle their light and flexile forms
with the tangled masses of weed, or lie in graceful
tufts upon the sand. With the uninitiated, their

PLANT-ANIMALS, OR ZOOPHYTES. 175

plant-like configuration passes as conclusive evidence
of their vegetable nature ; and the non-scientific world
now, like the men of science of a century ago, receives
the doctrine of their animality with incredulity. And,
indeed, we cannot wonder at the scepticism ; for so
complete is the imitation of vegetable forms in these
beings, and so vegetative in many respects is the
fashion of their life, that there is nothing to suggest
a doubt, on a slight and superficial acquaintance, as
to their affinities. The skeletons only of the zoophyte
commonly fall in the way of the amateur collector on
the shore, and these, intermingled with the algae,
and resembling nothing so much as miniature shrubs,
and trees, offer no sufficient clue to the interpretation
of its history." l It may suffice to say that the best
known of these zoophytes are those which belong to
the sub-order Thecaphora, in which the polypes and
reproductive buds, are enclosed in protective cases,
and especially the Sertularians, which belong to the
families named Sertnlariidce and Plumularidce (fig. 27).
These names will convey no ideas to those unac-
quainted with the small details which make up the
systematic characters of these little animals, but they

1 "The Sertularian Zoophytes of our Shores," by the Rev. T.
Hincks, in Popular Science Review, vol. viii. p. 223 (1869) ; see
also " The Hydroid Medusas," in Popular Science Review,
vol. xi. p. 337 (1872).

TOILERS IN THE SEA.

FIG. 2;. — IlYDRALLMANNIA FALCATA.

PLANT-ANIMALS, OR ZOOPHYTES. 17?

may indicate the direction in which further information
is to be sought (figs. 28 to 32).

Amongst all the minute organisms which make
their homes in the " deep, deep sea," there are none
more beautiful, or instructive, especially when seen
under a low power of the microscope, than the " plant-
animals " or zoophytes. Other colonies may have a
history almost as strange, but they do not offer the
same facilities for observation as do these dwellers in
almost transparent houses, through which much of
their domestic economy may be studied. They are
always favourites with the sea-shore collector, but the
empty cases are but shadows of the living animals,
as seen in their native element. " There must always "
— and here again we quote Mr. Hincks — " be a certain
fascination in a history which tells us of animals com-
posed of multitudes of individuals (zooids) living an
associated life, and so combining as to produce the:
most graceful plant-like structures — vegetating like a
tree — putting forth thousands of polypites,!like leaves,
each a provider for the commonwealth — putting forth
also a company of buds, charged with the perpetuation
of the species, ripening in transparent urns, and scatter-
ing their winged seeds broadcast,or sent forth,moulded
and painted by the highest art, like fairy emigrant ships
freighted with young life, to colonise distant seas."1

1 "Zoophytes : ths History of their Development," in Quar-
terly Journal of Sdenc:, vol. ii. No. 7, p. 416.

N

32.

FIG. 28.— SERTULARIELLA POLYZONIAS. FIG. 30.— CAPSULE OF CERTULARI A

O P F R C TJ L AT A
FIG. 28A.-CAPSULE. pIG> 3I<_DIpHASIA PINAsTER.

FIG. 29. — DIPHASIA PINNATA.
FIG. 2QA.— CAPSULE.

FiG. 3 1 A. — CAPSULE.

FIG. 32.— SERTULARIA PUMILA.

178

PLANT-ANIMALS, OR ZOOPHYTES. 179

We cannot close this history better than in the.
words of Ellis, one of the oldest of our writers on
the Corallines : — " And now, should it be asked,
granting all this to be true, to what end has so much
labour been bestowed in the demonstration ? I can
only answer, that as to me these disquisitions have
opened new scenes of wonder, and astonishment, in
contemplating how variously, how extensively, life is
distributed through the universe of things ; so it is
possible, that the facts here related, and these in-
stances of nature, animated in a part hitherto unsus-
pected, may excite the like pleasing ideas in others ;
and in minds more capacious and penetrating, lead
to farther discoveries, farther proofs (should such be
wanting), that One infinitely wise, good, all-powerful
Being has made, and still upholds, the whole of what
is good and perfect ; and hence we may learn that,
if creatures of so low an order in the great scale of
nature, are endued with faculties that enable them to
fill up their sphere of action with such propriety ; we
likewise, who are advanced so many gradations above
them, owe to ourselves, and to Him who made us,
and all things, a constant application to acquire that
degree of rectitude, and perfection, to which we also-
are endued with faculties of attaining."

N 2

180 TOILERS IN THE SEA.

CHAPTER VI.

SEA - FAN MAKERS.

A MONGST the most common objects of the sea-
-tJL shore, all around our coasts, are those strange
looking, scarcely handsome, lumps of dingy, cold,
soft substance, known as " dead man's fingers," and
that is all which most people know, 'or care to know,
about them ; and yet we must make their better
acquaintance, because the structure of the living
animal will serve as a key to that of the far more
ornamental, but less common objects, called "sea
fans." The polyp-home, or polypidom, resembles a
compact sponge ; sometimes it is only a thin crust
of less than a quarter of an inch, but usually it rises
in conoid, or finger-like masses, of various sizes, and
are either simple or lobed. When it is simple the fisher-
men of the coast call it "cow's paps" (fig. 33), but
when divided into lobes, like fingers, it bears the name
of " dead man's toes," or " dead man's hands." The
outer skin is tough and leathery, studded all over
with star-like figures, which, if attentively examined,
are seen to be divided into eight rays, indicating the
number of the tentacles of the polyps, which issue
here. The body of the polype is, as it were, enclosed

SEA-FAN MAKERS.

181

in a transparent vesicular membrane, dotted with
many minute calcareous grains, and marked with
eight white longitudinal lines or septa, which, stretch-
ing between the membrane and the central stomach,
divide the intermediate space into an equal num.
ber of compartments. These lines not only extend to
the base of the tentacles,
but run across the disk,
and terminate in the cen-
tral mouth. The tentacles
are short, obtuse, fringed
on the margins, and
strengthened at their base
by numerous linear straight
crystalline spicules. From
the base of the white
longitudinal lines an equal
number of white tortuous
glandular filaments de-
pend, hanging loose in
an abdominal cavity placed underneath the fleshy
cylindrical stomach, and continuous with the canals.
The polyp-cells are oval, placed just beneath the
skin, and are the terminations of the long water-
bearing canals which run through the whole polype-
mass. These canals divide, as they proceed, into
branches, which diverge towards the circumference,
and there expand into cells ; they have strong, per-

FIG. 33. — " COW'S PAP "
(Alcyonium digitatuni) .

1 82 TOILERS IN THE SEA.

haps muscular, coats, and are filled with a much less
consistent matter than that of the body of the polyp
itself. Hence it appears that many polypes commu-
nicate together, and form a compound animal. The
space between the tubes is occupied by a loose
fibrous tissue, with the interstices filled with a trans-
parent gelatine, in which lie numerous irregular

FIG. 34.

spicules. These spicules are mostly of the form of a
cross, and toothed on the sides, formed of carbonate
of lime (fig. 34), and have no organic connexion
either with the tissue or the tubes. The ova are
contained in the polyp tubes; they are white at
first, but at length become of a scarlet colour,
opaque, globose, and about the size of a grains
of sand ; ultimately they are expelled from the
mouth.1 The polyp-masses are of a greyish white

1 " History of British Zoophytes." By George Johnston, M.D.
(London, 1847.) Vol. i. p. 175.

SEA-FAN MAKERS. 183

colour, or almost that of wet sand, or of a more
or less bright orange. We have often seen them
adhering to the scallop-shells exposed for sale in fish-
mongers' shops, but, of course, in a dead condition.
When dredged up, fresh from the sea, and placed in
a vessel of sea-water the polyps expand, and then
the mass, which before was so uninteresting, becomes
quite enchanting.

It will be remembered that the Actinoid polypes,
of which the sea-anemones are the type, have their
tentacles and internal septa a multiple of six> but the
Alcyonoid polypes, or those of which the " sea-paps,"
or "dead man's fingers," is the type, have eight fringed
tentacles. To this group belong also the sea-pens
(Pennatula), the sea-fans (Gorgonia), the organ-
pipe coral, and the well-known " red coral." The
animals in all these are very similar, and have the
common distinguishing mark of eight fringed ten-
tacles, but the sea-paps are flexible, containing spi-
cules of carbonate of lime scattered amongst their
tissues, and without the hard rigid central axis which
is present in the sea-fans, except in one family, to
which the pipe corals belong, in which the animals
secrete slender tubes of carbonate of lime. In the
sea-fans, on the contrary, there is a hard, horny axis,
of greater or less thickness. In some cases the axis
is so slender that the coral (if we may so call it) does
not stand erect, but hangs pendulous from the rocks.

1 84 TOILERS IN THE SEA.

The great sea-fan of the West Indies often grows to
a yard in height and breadth, the branches and twigs
meet and coalesce, so as to form a regular net-work,
but in many other species the branches coalesce much
less frequently, or not at all, and then they resemble
clusters of slender twigs, or miniature shrubs or trees.
The general colour is often very bright, either red or
yellow, or violet, and must have an attractive appear-
ance, if they could be seen growing in their ocean
depths, attached to rocks, or to the sides of coral reefs.
The outer surface of the stems and branches of the
sea-fans is like a bark, and hence often called the
cortex, which may be peeled off like the bark of a
twig, leaving the hard and firm axis intact. This
bark is a continuous layer of the united polypes mixed
with minute granules, or spicules, of carbonate of
lime (to be described more fully shortly). The outer
surface is commonly smooth, but is sometimes covered
with small prominences ; where the latter are present
they are surmounted by the orifice, or oblong punc-
ture, through which the animal protrudes itself during
its life (fig. 35).

Devotees to the use of the microscope, especially
those who employ it chiefly as a source of amusement,
usually include amongst their " beautiful objects "
preserved and prepared specimens of " spicules of
Gorgonia," which, being interpreted, implies that they
are the little granules of carbonate of lime secreted

SEA-FAN MAKERS.

185

by the animals in the cortex, or bark, of the sea-fans.
They are called " spicules " because they are not-
amorphous or crude granules, but beautifully sym-
metrical shapes of a certain definite type, sometimes

FIG. 35. — GORGONIA, OR SF.A-FAN.

white, but usually yellow, scarlet, crimson, violet,
purple, or, in fact, of the same colour as the sea-fan
itself, for it is to these coloured spicules that the cha-
racteristic colour of the Gorgonia is due. Sometimes
the spicules are shaped like a cross, sometimes like a

i86 TOILERS IN THE SEA.

club, sometimes oval or oblong, with the surface
ornamented with more or less complex bosses or pro-
jections (Plate IV.). Certain authors believe that they
can determine the genus, even if not the species of
the family of Gorgonia, from the form of their cal-
careous spicules, which, at the least, must be accepted
as implying that, although the forms vary in the
spicules of different species, they are at the same time
constant in each of the species.

It may be intimated here that the spicules of these
organisms may be easily removed from the bark, and
cleared of all extraneous matter, so as to be mounted
permanently as " objects for the microscope." A small
portion of a branch, or of the cortex from a branch,
may be boiled in a test-tube, with liquor potasscz, for a
minute or two, and when cool and settled, the sedi-
ment may be washed by shaking in water, allowed to
settle, the water poured away, and more water added,
shaken again and again allowed to settle, as often as
need be, and the final sediment will be found to be
the clean spicules which may be mounted dry, or
immersed in Canada balsam. Some prefer to mix
spicules of different forms and colours together,
others to keep each kind separate and distinct ; let
every one be persuaded in his own mind.

M. Valenciennes, who wrote a monograph of this
family, has classified the forms of spicules in the
following manner : —

SEA-FAN MAKERS. 187

(i). The spicules (he calls them sclerites, to distin-
guish them from the spicules of sponges) have two-
small circles of tubercles at a distance from one
another on a short axis ; the tuberculate extremities
resemble a small branch of cauliflower. This kind is
found in the common red coral.

(2). These spicules are spindle-shaped, with four or
six circlets of tubercles.

(3). In the clubbed spicules a single extremity is
dilated, and furnished with ridges like some ancient
maces.

(4). The muricated spicules have four or several
points, and entirely covered with spines.

(5). The last form consists of larger or smaller
scales, more or less covered with small spines.1

He comes to the conclusion that although useful
in the characters of the different species, yet that
these spicules cannot be employed for the distin-
guishing of one genus from another, because more
than one kind of spicule occurs in the same genus.

Milne-Edwards, and after him, Kolliker, succeeded
to Valenciennes, and brought nearer to perfection what
he had commenced, especially in the matter of classifi-,
cation. The most noteworthy direction in which Kol-
liker diverged from Valenciennes, appears to be the

1 "Abstract of Monograph of Gorgonidae," by M. Valen-
ciennes, in "Annals of Natural History," vol. xvi. (1855) p. 177.

1 88 TOILERS IN THE SEA.

acceptance of the form of the spicules as of higher
importance, even in the determination of genera. In
this view, also, Mr. W. Saville Kent concurred to the
extent even of going further than Kolliker had done,
for he says : — " The facts which have been eliminated
will, I think, suffice to demonstrate beyond doubt
what a highly important element the calcareous spi-
cules represent in our appreciation of the generic
characters of the Gorgonidcz (sea-fans). The study of
the group from this point of view must, however, be
considered quite in its infancy ; but the time has
arrived when zoologists must no longer be content
with the characters afforded by general contour, or by
the examination of the dried polyparies only." ]

The five types of spicules enumerated by M.Valen-
ciennes have not been deemed sufficient by succeed-
ing observers, who have come to the conclusion that
the material at his disposal was insufficient, and that
more definite and typical forms of spicuie have
since been met with, with which he was unacquainted,
hence that the number of leading forms must be in-
creased, and hereafter probably will be increased, to
an extent almost equal to the number of genera based
upon them.

1 " On the Calcareous Spiculas of the Gorgonaceae," by
W. S. Kent, in Transactions Royal Microscopical Society,
Feb., 1870.

SEA-FAN MAKERS. 189

It has been intimated, that in the " sea-fans " there
is to be found a horny axis, covered with a fleshy
bark, or cortex, from which the polypes protrude.
This axis, in the majority of cases, is accurately
characterised as horny, for it is composed of a sub-
stance very similar, but not identical with that which
constitutes the horns and hoofs of animals. Still,
there remains a small group in which the axis is not
absolutely horny, but partly of the horny substance
and partly of carbonate of lime. Of course, both of
these substances are secreted and deposited by the
polyps.

A "sea-fan," or Gorgonia, therefore, is a body
which is formed by the union of numerous polypes
upon a common body, enveloped by a gritty, fleshy
substance, containing spicules of lime, and sur-
rounding another tree-like secretion, which is its
axis, formed of a substance resembling horn, or horn
mixed with carbonate of lime, the polypes them-
selves being furnished with eight arms, or tentacles,
the margins of which are fringed. Bearing in mind
these facts, it will be seen readily what the "sea-
fans " have in common, and wherein they differ from,
their nearest associates.

It is difficult to enter with precision into the details
of the structure of these minute animals, and their
secretions, without being exposed to the charge of
being " heavy " and " dry," but some excuse, even for

190 TOILERS IN THE SEA.

such a failing, may be found in the fact that so many
persons have in these latter days habituated them-
selves, not only to cultivate the use of the microscope,
but also to carry it with them, in their holiday
excursions to the sea-side, and that such persons
desire, above all things, abstracted and compact
information on marine objects (as well as many
other subjects) which shall introduce them fairly, not
only to the common, but some of the uncommon
objects of the seaside, or the nearest representatives
that they can procure of the inhabitants of the
tropical seas. Those who cannot collect the living
" sea-fans " of warmer climes will not be disgusted, or
discontented, with their humble cousins, the " dead
man's fingers" of our own shores.

The Tubiporine, or Organ-pipe coral, is a favourite
object in all museums and collections of marine
productions, and is of interest as belonging to this
section, although of such diverse external appear-
ance, consisting of a great number of hard purple-red
tubes, about the thickness of a straw, standing nearly
parallel to each other, like miniature organ-pipes, and
united at short distances by thin plates of the same
coral-like substance (fig. 36). The horny axis of the
sea-fans is absent, but is compensated for by the
rigid tubes, which appear to be formed gradually at
the upper end, by the deposition and consolidation
of the calcareous spicules secreted by the animals.

SEA-FAN MAKERS.

191

Professor Perceval Wright found masses, as much as
2 ft. in diameter, in the Seychelles, although, more
commonly, in irregular lumps of about 12 in. in
circumference, and from 2 in. to 4 in. in height. We
are indebted to him for the description of the animals
which inhabit, and construct, these tubes, as he had
the good fortune of seeing them in the living state.
" The polyp," he says, " consists of eight pinnate
tentacles, each tentacle with from fifteen to seventeen
pennae on each side ; these
tentacles are thickly studded
with spicules of an oval shape,
flat, somewhat longer than
broad ; and are met with all
over the tentacle, down the
centre of which there is one
compact row, forming, as it
were, a mid-rib ; they are
often slightly compressed in
the centre, so as to form a
figure of eight. In the centre of the tentacles is
the mouth, with a slightly raised circular lip. When
the polyp is alarmed the tentacles are first closed
together, and then the polyp sinks down quite into
the tube ; as it becomes more completely retracted
it draws in after it the uppermost portion of the tube
itself, inverting this, and folding it in until the open
mouth of the tube is thereby_completely filled. It

FIG. 34. — ORGAN CORAL
( Tubipora nmsica).

1 92 TOILERS IN THE SEA.

is, of course, only the yet spicular and not the solid
portion of the tube that is thus inverted ; and the
folds thus formed equal in number the tentacles.
I have more than once traced these spicular portions
up to the very base of the tentacles, where the
fusiform spicules end, and the characteristic tentacle
and body spicules commence ; these spicules thus
forming a series of triangular spaces, the bases of
which join on with the hardened edge of the tube,
and the apices are situated at the base of each
tentacle. The spicules secreted by this portion of
the ectodermic layer are of several sorts : first, the
warty fusiform spicule, so commonly met with in the
Alcyonidae ; these spicules will be found in all stages
of growth, and of coalescence ; thus, at the upper
portion of the edge of the tube, where it is non-
retractile, the calcareous tissue will be found to
consist of a series of them, partially joined together,
and making a kind of coarse open network, which,
on being macerated in caustic potash, does not fall
to pieces ; but the retractile portion, on being sub-
jected to the same treatment, breaks up into a mass
of minute individual spicules. The red colouring
matter would appear not to reside in these latter
spicules, for those that I have examined are colour-
less. A second form of spicule is met with in the
retractile portions of the tube, which, I think, might
be called 'shuttlecock.' While all the forms of

SEA-FAN MAKERS.

193

spicules (fig. 37) met with seem to occupy certain
definite portions of the ectodermic layer, yet there is
an evident gradation between them, from the smooth,

FIG. 37. — SPICULES OF ORGAN CORAL.

fusiform spicule to the most irregularly warty forms,
which leads naturally to the inference that all these
forms are but different stages of growth, by the
aggregation of new calcareous material, until the

O

194 TOILERS IN THE SEA.

solid tubular structure, so long known to us, is at
length reached.

" The mouth, which is circular, is distinctly marked,
and leads into the stomachal cavity, which is small ;
the stomachal cavity is separated by a thin and deli-
cate membrane from the general body cavity. I
have not been able to determine with exactness the
number of openings between these two portions.
The ovaries are in the general cavity, and are
invested by a delicate membrane, which is continued
in the form of eight mesenteric bands to the body of
.the tube.

" The structure of the skeleton is certainly not
"crystalline, as some have suggested. Fusiform
spicules are secreted by the ectodermic layer ;
these spicules around the base of the tentacles
are of a white colour, and in many cases are simply
fusiform, not warty ; but those at a little distance
from the base of the tentacles not only assume a
light red colour, but become crowded over with warty
excrescences, and there is then to be found a gradual
growing together, and consolidation, of those around
the edge of the tube, that is, where this is formed.
In the case of a young bud, there is at first no tube,
the spicules having not yet become coalesced ; they
are here simply placed side by side.

" The polyp certainly can, and does constantly, add
to the height of its tube ; or, in other words, the

SEA-FAN MAKERS. 1 95

spicules are being constantly consolidated into the
tube, and the tube thus increases in height. In some
cases I have been able to trace the mesenteric bands,
which attach the lower portion of the body of the
polyp to the walls of the skeleton tube, as far as the
second external septum in depth ; and it is very
evident that, as the outer walls of the tube become
consolidated, not only does the tube become elon-
gated, but the polyp elevates itself at the same time
in the tube." l

As the " Organ-pipe coral" is an inhabitant of wa'rm
latitudes, and has seldom been observed or studied,
even there, in the living state, the foregoing particu-
lars of its animals will have a special interest. This
is one of the objects with which so many are familiar,
in its dead condition, or when nothing remains save
the skeleton, but concerning the inhabitants of which
so little was previously known that even now it may
be assumed that information is far from complete.
Indeed, its reproduction and development, which
would entail observation over a considerable period
of time, is still guessed at rather than demonstrated.
From analogy it may be assumed that in these
particulars it does not differ greatly from its imme-

1 " On the Animal of the Organ-pipe Coral," by Prof.
E. Perceval Wright, in " Annals of Natural History," vol. iii.
(1869) p. 377.

O 2

196 TOILERS IN THE SEA.

diate allies, and that those authors are not far wrong
who claim for the Tubipora a near kinship to the
ordinary " red coral of commerce."

Until about 1727 the red coral was held to be a
marine plant, but now it is acknowledged as an animal
production, closely related, in its scientific affinities,
to the sea fans.

It has been shown by a recent author that the
beautiful red coral, with which most of us have been
acquainted from infancy, bears in its Latin name
(Corallium rubrum] the poetical designation of " the
red daughter of the sea." *

It is found in the Mediterranean, and the Red Sea
at various depths from ten to nearly a thousand feet.
" Each stalk of coral " writes Moquin - Tandon,
" resembles a pretty red leafless shrub, bearing little
delicate star-like flowers. The stalks of this little
tree are common to the association, and the flowers
are the polypes. These arborescent formations
generally hang from some shelf, and so grow down-
wards, and not like ordinary vegetation. They are
found growing together in bushes, or copses, or
spreading out, as we have said, into veritable forests.
The stems have a soft reticulated cortex or bark,
which is full of little cavities, permeated by a milky

1 Korallion from Kore, a daughter, and afos, the sea ;
Latinised curalium, or corallium, with rubrum, red.

SEA-FAN MAKERS.

197

fluid ; these are the chambers of the members
of the association. The cortex is full of little hard
bodies, called spicules (fig. 38). Beneath the crust
is the coral, properly so called ; it is as hard
as marble, its surface is remarkable for its stripes,
its colour is a beautiful red, and it is so hard that
it is capable of receiving a high polish. The

FIG. 38. — SPICULES OF RED CORAL.

polypes are composed of a tubular body, enclosed in
a cortical cell. That part which appears beyond the
walls of this cell is cylindrical, and is crowned by
eight little arms, which spread themselves out like
the petals of a flower. These arms are flat and wide
at the base, but gradually tapering to a point. The
edges are furnished with short hollow barbs. When
expanded they are exactly like a beautiful white and

198 TOILERS IN THE SEA.

semi-transparent flower, having eight petals fixed
upon a mammal bud; when closed they have the
appearance of an urn."1 It will be observed that
the red coral differs considerably in its animals from
the corals of the coral reefs. In the latter case the
animals are either of the Anemone type, or what are
termed in scientific language Actinoid polyps, or, as
in the Millepores, of the hydroid type ; whereas in
the red coral they are of the type which prevails in
" dead man's fingers," and the " sea-fans," that is of
the Alcyonoid type, hence " precious coral " is more
nearly related, in its structure, to the Gorgonias than
to the rock corals. Probably the general reader will
not at once appreciate the differences, or their
importance, so readily as the zoologist, although we
have placed them in different chapters in this volume,
in order to emphasise that difference and prevent
the confusion of the two kinds of substance to which
the name of " coral " has been given.

The structure, and reproduction, of the red-coral
polyp has been studied more exhaustively b}
M. Lacaze-Duthiers than by any one else, before
or since, and a summary of the facts which he has
made known will be of interest, to compare with
those we have given elsewhere of the rock corals.

1 Moquin-Tandon : "The World of the Sea," London, 1869,
p. 109.

SEA-FAN MAKERS. 199

From him we learn that the members of a coral
association are either males, females, or hermaphro-
dites. Ordinarily, the greater number of polypes on
one branch are of the same sex ; one branch con-
taining almost exclusively males, another females ;
the hermaphrodites are the least numerous. The
coral polyp is viviparous — that is, the £ggs become
embryos before they leave the parent. The eggs
have long slender pedicles ; they come out of the
thin layers which line the digestive bag ; they are
spherical, opaque, and of a milk-white colour. They
detach themselves by breaking their pedicles, and
thus fall into the central cavity of the polyp, a cavity
which serves as a stomach and an incubating pouch.
Here two very different processes are in action, — the
one dissolving the food and nourishing the animal, the
other developing and producing a new creature. In
due time the eggs lengthen, and vibratile cilia appear.
As soon as they are born — that is, vomited — a pore
opens at one of the extremities, which is destined to
become the mouth. Then they assume the form of
a whitish semi-transparent worm. These larvae swim
in all directions, with the greatest agility ; they rise
and sink in the vases which contain them, always
swimming with their thicker extremity in advance,
carrying their mouths in the rear, so that they butt
against anything which happens to be in their way.
They have a tendency to become fixed, like their

200 TOILERS IN THE SEA.

parents, and the mode of their progression greatly
favours this result ; thus the peculiarity of their
motion is liable to shorten the period of their liberty*
in facilitating their adherence to any object with
which they come into contact, by that part of their
body which afterwards becomes the base of the
polyp. When it adheres the polyp has reached
another stage of its existence. As soon as it becomes
fixed it changes its worm - like appearance, and
thickens, gaining in breadth what it loses in length,
thus shortening, and becoming discoid. The thin
extremity, which carries the mouth, gradually folds
itself back, by successive stages, until the larva
assumes the shape of a pin-cushion, at the summit
of which is the mouth. Around this orifice the
rudiments of the eight tentacles begin to appear,
which soon cover it with a pendant festoon. The
fixed larva thus becomes the founder of a large
colony. Buds form on the axis, and develop them-
selves into a whole nation of corals. The young
polypes, just hatched from the egg, are, as we have
seen, utterly different from their parents. They
must undergo many metamorphoses before they
reach their perfect state. These metamorphoses are
just the reverse of those through which insects pass.
The chrysalis lies immovable, but finally becomes
a butterfly. With the coral, the larva has the
power of locomotion, whereas the full-developed

SEA-FAN MAKERS. 201

polyp is fixed. There is not, perhaps, in nature
a single law whose reverse is not also found in
operation.

We find in these animals, just as we do in vege-
tables, stalks and branches covered with real bark ;
but the stems, or axes, of the animals are horny or
calcareous, while those of the vegetables are herba-
ceous and woody. In each case the tissue is more
or less solid, striated, or fluted, and formed of con-
centric layers ; and, moreover, the cortex of the coral
is spongy, and somewhat soft, like the bark of a
vegetable production. The knobs represent the
buds ; the polypes, the flowers ;
the feelers open themselves out
in rosettes as petals, forming an
animated corolla, which opens and
shuts alternately (fig. 39). In the
polypier, the individuals which
contribute to the growth of the
whole are situated at the ex-
tremities of the axis, or upon its
sides, a position similar to that of FIG. 39.

the leaves and flowers in a plant. A RED CORAL POLYPE'
And the final resemblance is found in their modes
of reproducing their species. The corals, and the
vegetables, are each produced by isolated and indi-
vidual grains, eggs, and seeds, which separate them-
selves from a bunch, and proceed to develop them-

202 TOILERS IN THE SEA.

selves, producing a colony, of which the members
remain grouped.1

A far more extended and explicit account is
given of the results of M. Lacaze-Duthiers' re-
searches, by the Editor, in Popular Science Review
(1865), but the foregoing is sufficient for our pre-
sent purpose. The article in question may be
consulted by those who desire to investigate the
subject further. A section of the coral axis, or
corallum, the red coral of commerce, may be cut
and reduced to thinness, sufficient for examina-
tion by the microscope, when it will be perceived
that "the central portion of the stem is occupied
by a homogeneous coloured mass, of mineral char-
acter, round which there appears to be a ribbon-
like fold of more highly tinted matter, which does
not form a circle, but some irregularly oval figure;
between this and the circumference one sees
alternate concentric rings of strongly and faintly
tinted material, which are divided by numerous
radiating dark lines of extreme tenuity. These
various appearances may be thus accounted for :
the central, irregularly folded, ribbon-like mass is
the first hard part developed by the young egg-
polyp ; this had the mineral matter deposited all

1 M. Lacaze-Duthiers, "Histoire Naturelle du Corail,"
Paris, 1864 ; and Moquin-Tandon, " Le Monde de la Mer."

SEA-FAN MAKERS. 203

round it year by year, but the deposit went on
with greatest rapidity in the greatest depressions,
and hence, after a while, a circular outline was
produced ; the several rings indicate the succes-
sive depositions, and the dark radiating lines point
to the grooves, in which in earlier days the central
large canals surrounded the stem." l

It has been estimated that the annual value
of the coral dredged in the Mediterranean amounts
to nearly £180,000, but M. Lacaze-Duthiers thinks
that this is nearly three times as much as it
really should be, and that in 1860 probably the
total value did not exceed £60,372. At a rough
estimate, average coral realises about twenty shillings
per pound to the merchants, some kinds being
worth considerably less, and the choicest kinds
"very much more. A delicate pink variety, being
the scarcest, obtains the highest price, and is
greatly esteemed by the Italians. It is the opinion
of many that the coral fishery is in a state of
gradual decay, and that the coral-beds are yearly
becoming more and more exhausted, so that, unless
something is done, either by artificial culture or
otherwise,, this industry will, at no very remote
period, be numbered with the things of the past.

1 Dr. H. Lawson, "Natural History of Red Coral,"
Popular Science Review (1865), p. 72.

m

204 TOILERS IN THE SEA.

Some years ago, a writer in the Athenaum
gave a graphic account of the coral fishery, as
pursued in the Mediterranean, from which the fol-
lowing paragraph may be read with interest. It
contains chiefly the mode in which this fishery,
as an industry, is conducted, or at least as it was
pursued when this account was written.

Torre is the principal port in the south of
Italy for the vessels engaged in the coral fishery,
— about two hundred vessels setting out from
hence every year, about June. They have generally
a tonnage of from seven to fourteen tons, and
carry from eight to twelve hands ; so that about
two thousand men are engaged in this trade,
and, in case of an emergency, would form a
famous corps de reserve. They generally consist
of the young, and hardy, and adventurous, or else
the wretchedly poor, for it is only the bold spirit
of youth, or the extreme misery of the married
man, which would send them forth upon this
service. For two or three months previously to the
commencement of the season, many a wretched
mariner leaves his starving family, and, as a last
resource, sells himself to the proprietor of one
or another of these barks, receiving a caparra
(earnest money), with which he returns to his
home. This, perhaps, is soon dissipated, and he
again returns, and receives an addition to his

SEA-FAN MAKERS. 205

caparra ; so that, when the time of final depar-
ture arrives, it not unfrequently happens that
the whole of his scanty pay has been consumed,
and the improvident or unhappy rogue has some
months of hard labour in prospect, without the
hope of another grano of compensation. Nor
does the proprietor run any risk in making this
prepayment ; for as the mariner can make no
engagement without presenting his passport, per-
fectly en rtgle, he is under the surveillance of a
vigilant police. The agreement between the par-
ties is made from the month of March to the
Feast of San Michaele (2Qth September) for vessels
destined for the Barbary coast, and from March
to the Feast of the Madonna del Rosario (Oc-
tober 2nd) for those whose destination is nearer
home. Each man receives from twenty to forty
ducats, according to his age, or skill, for the
whole voyage ; whilst the captain receives from
one hundred and fifty to four hundred ducats,
reckoning six ducats to one pound sterling. These
preliminaries being settled, let us imagine them
now on full wing, — some for the coast of Barbary,
and others for that of Sardinia, or Leghorn, or
Civita Vecchia, or the islands of Capri, San Pietro,
or Ventotene, near which I have often seen them,
hour after hour, and day after day, dragging for
the treasures of the vasty deep. On arriving at

206 TOILERS IN THE SEA.

the port nearest to the spot where they mean to
fish, the " carte " are sent in to the consul, which
they are compelled to take again on return. A
piastre is paid by each vessel for the magic endorse-
ment of his Excellenza, another to the druggist,
and another to the medical man ; whilst the cap-
tain, to strengthen his power, and to secure in-
demnity, in case of some of those gentle excesses
which bilious captains are sometimes apt to com-
mit, has generally on board some private "re-
galo" for his consul. The next morning, perhaps,
they push out to sea, and commence opera-
tions, — not to return that evening, or the
next, or the next, but to remain at sea for a
fortnight, or a month at a time, working night
and day without intermission. The more humane
captains allow half their crews to repose from Ave
Maria to midnight, and the other half from mid-
night to the break of day ; others allow only two
hours' repose at a time ; whilst some, again,
allow no regular time ; " so that," said a poor
mariner to me, "we sleep as we can, either stand-
ing, or as we haul in the nets." Nor do they fare
better than they sleep ; for the whole time they
have nothing — literally nothing — but biscuit
and water, whilst the captain, as a privileged
person, has his dish of dried beans or haricots
boiled. Should they, however, have a run of good

SEA-FAN MAKERS. 207

luck, and put into port once in fifteen days or so,
they are indulged with a feast of maccaronk
These privations make it rather rough work, it
must be confessed, for a mariner, especially when
it is remembered that it lasts seven months ; but
if to this be added the brutality of the captains,
whose tyranny and cruelty, as I have heard, ex-
ceed anything that has ever been recounted to me
before, we have a combination of sufferings which
go far to justify the description given to me of
this service by one engaged in it, as being an
' Inferno terrestre.' " l

Having had occasion to mention the " sea-pens " in
the early portion of this chapter, and dismiss them
abruptly, it may be permitted to return to them for
a page or two, especially as one species is common
enough in our Northern seas, although rare in the
South, and it may be the good fortune of some of
our readers to make their personal acquaintance.
These colonies are not fixed, as are the sea-fans, but,
on the contrary, are free swimmers. In shape they
bear some resemblance to a feather or pen, with a
common axis, and lateral barbs or pinnules, which
bear the polyps ; these pinnules are longest near the
centre, and shorter towards either end (fig. 40). The
polyps are arranged in transverse rows along the outer

1 The "Technologist," vol. ii. p. 22 (1862).

208

TOILERS IN THE SEA.

and inner edge ; they possess eight tentacles, and
these are ciliated on one side. According to recent re-
searches, the polypes of each pen are either all male or
all female, so that all the members of one community
are of the same sex (fig. 41). The British species is
called by the fishermen the
" cock's - comb," but this is
scarcely so expressive as sea-
pen. "It is from two to four
inches in length, and of a uni-
form purplish-red colour, except
at the tip or base of the stalk,
where it is pale orange-yellow.
The skin is thickish, very tough,
and of curious structure, being
composed of minute crystalline
cylinders, densely arranged in
straight lines, and held together
by a firm gelatinous matter or
membrane. These cylinders
(spicules) are about six times their diameter in length,
straight and even, or sometimes curved and bulged,
and of a red colour, for the colour of the zoophyte is
derived from them, and they are accordingly less
numerous where the purple is faint or defective.
The stalk is hollow in the centre, and contains a long
slender bone which is white, smooth, square, and
tapered at each extremity to a fine point. It does

FIG. 40.
THE THORNY SEA-PEN.

SEA-FAN MAKERS. 209

not reach the whole length of the stalk, but before
it reaches either end the point is bound down and
bent backwards like a shepherd's crook."

It has long been known that the sea-pens are phos-
phorescent, and, indeed, so much so in one species
that it is called the phosphorescent sea-pen (Penna-
tula pJiosphorea). Linnaeus has stated that the phos-
phorescent sea-pens which cover the ocean bottom
cast so strong a light that it is easy
to count the fishes and worms which
sport around them. Dr. Grant says
that " a more singular and beautiful
spectacle could scarcely be conceived
than that of a deep purple pen, with
all its delicate transparent polypi
expanded, and emitting their usual
brilliant phosphorescent light, sailing FIG. 4I.

through the still and dark abyss, by POLYPES OF THE

THORNY SEA-PEN.

the regular and synchronous pulsa-
tions of the minute fringed arms of the whole
polypi." In the Scotch seas this species is found in
great plenty, sticking to the baits on the fisherman's
lines, especially when they make use of mussels to
bait their hooks. Professor Edward Forbes con-
ducted a series of experiments with these animals,
in order to ascertain something of the nature of their
phosphorescence, and from these he infers : (i) The
polype is phosphorescent only when irritated by

P

210 TOILERS IN THE SEA.

touch ; (2) The phosphorescence appears at the
place touched, whether it be the stalk or the polyp-
bearing part, and proceeds from thence in an undu-
lating wave to the extremity of the polyp-bearing
portion, and never in the other direction ; (3) If the
centre of the polyp-bearing portion be touched, only
those polyps above the touched part give light ; and
if the extreme polyp-bearing pinna be touched it
alone of the whole animal exhibits the phenomena
of phosphorescence ; (4) The light is emitted for a
longer time from the point of injury, or pressure,
than from the other luminous parts ; (5) Sparks of
light are sometimes sent out by the animal when
pressed : these are found to arise from luminous
matter investing ejected spicules. Subsequently the
same observer writes that " unless the animal be in
the highest state of vivacity, the stalk shows no
phosphorescence, and the light of the feathered
portion only runs a short way, but always towards
the upper extremity. When plunged into fresh water
the sea-pen scatters sparks in all directions, — a most
beautiful sight, — but when plunged into spirits, it does
not do so, but remains phosphorescent for some time,
the light dying gradually away, and last of all from
the uppermost polyps." A further number of ex-
periments were made with the view of ascertaining
whether the light was produced by electricity, and
the results are given in Johnston's " Zoophytes " to

SEA-FAN MAKERS. 2 1 1

the effect that electricity does not appear to
be the cause, but, " on the whole, it is most
probable that the animal secretes a spontaneously
inflammable substance. It may be a compound of
phosphorus, but it is not necessary to assume that
it is."

There is a fascinating interest in the whole subject
of phosphorescence in marine animals, and at the
same time considerable mystery about its devplution.
How it is produced, what its immediate use, under
what conditions manifested, and whether always the
same in its source and nature, are all problems con-
stantly propounded, and never completely settled.
Like the light itself, these questions constantly elude
the grasp, and yet treatises have been written, and
suggestions offered, time after time, which only par-
tially, and very partially, meet the difficulty. Even
as recently as the date of the " Challenger Expedi-
tion " the subject has come again to the surface, as
the following allusions will indicate : —

While dredging in from 557 to 584 fathoms, Pro-
fessor Wyville Thomson says : — " Many of the animals
were most brilliantly phosphorescent, and we were
afterwards even more struck by this phenomenon in
our Northern cruise. In some places nearly every-
thing brought up seemed to emit light, and the mud
itself was perfectly full of luminous specks. The
Alcyonarians, the brittle-stars, and some annelids

P 2

212 TOILERS IN THE SEA.

were the most brilliant. The Pennatulae, the Virgu-
lariae, and the Gorgoniae shone with a lambent white
light, so bright that it showed quite distinctly the
hour on a watch ; while the light from Ophiocantha
spinulosa was of a brilliant green, coruscating from
the centre of the disk, now along one arm, now
along another, and sometimes vividly illuminating
the whole outline of the star-fish " (" Depths of the
Sea," p. 98). And again, whilst dredging near
Shetland, he writes : — " Among Echinoderms Ophio-
cantJia spinulosa was one of the prevailing forms, and
we were greatly struck with the brilliancy of its
phosphorescence. Some of these hauls were taken
late in the evening, and the tangles were sprinkled
over with stars of the most brilliant uranium green ;
little stars, for the phosphorescent light was much
more vivid in the younger and smaller individuals.
The light was not constant, nor continuous all over
the star, but sometimes it struck out a line of fire all
round the disk, flashing, or, one might rather say,
glowing, up to the centre ; then that would fade, and
a defined patch, a centimetre or so long, break out
in the middle of an arm, and travel slowly out to the
point, or the whole five rays would light up at the
ends, and spread the fire inwards. Very young
Ophiocanthse, only lately rid of their c plutei/ shone
very brightly. It is difficult to doubt that in a sea
swarming with predaceous crustaceans, such as active

SEA-FAN MAKERS. 213

species of Dorynchus and Munida, with great bright
eyes, phosphorescence must be a fatal gift.

" We had another gorgeous display of luminosity
during this cruise. Coming down the Sound of Skye
from Loch Torridon, on our return, we dredged in
about 100 fathoms, and the dredge came up tangled
with the long pink stems of the singular sea-pen,
Pavonaria quadrangularis. Every one of these was
embraced and strangled by the twining arms of
Asteronyx loveni, and the round soft bodies* of the
star-fishes hung from them like plump ripe fruit.
The Pavonariae were resplendent with a pale lilac
phosphorescence, like the flame of cyanogen gas ; not
scintillating, like the green light of Ophiocantha, but
almost constant, sometimes flashing out at one point
more brightly, and then dying gradually into com-
parative 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 Pavonaria brought up at
one haul we had evidently passed over a forest of
them. The stems were a metre long, fringed with
hundreds of polyps." x

On another occasion a speculation is indulged in,
which may, or may not, be worthy of further con-
sideration. Sir Wyville Thomson records a species

1 "Depths of the Sea," p. 148.

214 TOILERS IN THE SEA.

of Pleurotoma which was dredged from 2,090 fathoms,
and "had a pair of well-developed eyes on short
footstalks; and a Fusus, from 1,207 fathoms, was
similarly provided. The presence of organs of sight,"
he proceeds to say, "at these great depths leaves
little room for doubt that light must reach even these
abysses from some source. From many considera-
tions it can scarcely be sunlight, I have already
thrown out the suggestion that the whole of the light
beyond a certain depth might be due to phosphor-
escence, which is certainly very general, particularly
among the larvae and young of deep-sea animals, but
the question is one of extreme interest and difficulty,
and will require careful investigation." x

As long since as 1853, M. de Quatrefages wrote a
memoir on the phosphorescence of the lower marine
.animals, which may even now be consulted with
interest,2 in which he alludes to the fact that up to
that date four hundred and fifty authors had treated,
more or less fully, of the production of light by
organised beings. Even an abstract of this memoir,
which is in itself an abstract of antecedent observ-
ations, would scarcely be warranted here, and is
scarcely necessary, as it is available in an English
translation.

1 "Depths of the Sea," p. 466.

2 "Annals of Natural History," second series, vol. xii.
pp. 1 6, 1 80.

TOILERS IN THE SEA. 215

CHAPTER VII.

CORAL BUILDERS.

WRITING concerning coral islands, and their
inhabitants, a justly celebrated American
Professor waxes eloquent over the errors of some
of his predecessors, and even sometimes to the
extent of being unduly hard upon their failings.
" Many of those," he says, " who have discoursed
most poetically on zoophytes have imagined that the
polyps were mechanical workers, heaping up the
piles of coral rock by their united labours ; and
science is hardly yet rid of terms which imply that
each coral is the constructed hive or house of a
swarm of polyps, like the honeycomb of the bee, or
the hillock of a colony of ants." Although we feel a
little sympathy with him in his indignation, it is
doubtful whether he has not accepted in too literal
a sense what he has characterised as a poetical dis-
course. Whether or not he has done so, it may
somewhat mitigate his indignation if at once we
accept his explanation of the process of manufacture.

216 TOILERS IN THE SEA.

" It is," he says, " not more surprising, nor a matter
of more difficult comprehension, that a polyp should
form structures of stone (carbonate of lime), called
; coral, than that the quadruped should form its bones,
or the mollusk its shell. The processes are similar,
and so is the result. In each case it is a simple
animal secretion, a secretion of stony matter from the
aliment which the animal receives, produced by the
parts of the animal fitted for this secreting process ;
and in each carbonate of lime is a constituent, or one
of the constituents, of the secretion. Coral is never,
therefore, the handiwork of the many-armed polyps ;
for it is no more the result of labour than bone-
making in ourselves. And again, it is not a collec-
tion of cells into which the coral animals may with-
draw for concealment, any more than the skeleton of
a dog is its house or cell ; for every part of the coral
of a polyp, in most reef-making species, is enclosed
within the polyp, where it was formed by the
secreting process." Great as may be our sin in
calling the coral animals either " coral architects " or
" coral builders," having thus limited the application
of these terms, we may have some hope of escape.
Furthermore, it is to be regretted that he should
have applied the canon of scientific criticism to a
poem with which he fails to find himself in sympathy,
because it is a poetical work, and not a scientific
treatise. " More error," he says, " in the same com-

CORAL BUILDERS. 217

pass could scarcely be found than in the part of
Montgomery's ' Pelican Island ' relating to coral
formations. The poetry of this excellent author is
good, but the facts nearly all errors, — if literature
allows of such an incongruity. There is no * toil/ no
' skill/ no ' dwelling/ no ' sepulchre/ in the coral
plantation, any more than in a flower-garden ; and as
little are the coral polyps shapeless worms that
' writhe and shrink their tortuous bodies to grotesque
dimensions.' The poet oversteps his licence, and,
besides, degrades his subject, when downright false to
nature." 1 We might add to this the Professor's own
words : — " It is not, perhaps, within the sphere of
science to criticise the poet " ; and evidently no one
will think the less highly of a beautiful poem, as a
poem, because it is by no means rigidly scientific, and
even " the facts are nearly all errors." It had for its
object the inculcation of truth, by means of fable, and
not the dissemination of scientific information, on the
structure and development of coral formations. We
fear that we shall still remain heretical enough to
delight in the " Pelican Island."

These preliminary observations introduce us at
once to the subject of " coral builders," those minute
marine animals which have done so much in the
past, and are still at work in the present, in the con-

1 Dana, "Corals and Coral Islands," p. 3.

218

TOILERS IN THE SEA.

struction of coral rock (fig. 42). Let those who please
quibble over the terms of definition, and call it work
or play, as suits them best; the animals are, neverthe-
less, the constructors of the coral rock. It is not so

FIG. 42. — MADREPORES AND CORALS.

readily that we can select a type of a definite char-
acter, and, having briefly sketched its life history,
point to it as the coral animal, as could be done with
some other groups, since in this case there is more
than one type of coral animal, and the details which
would answer for one could not be applied to all.
Hence it will be necessary to indicate, separately, the

CORAL BUILDERS. 219

Polyps, properly so called, and the Hydroids, com-
mencing with the former.

If we select for illustration such a familiar marine
animal as the sea-anemone, with which most persons
are more or less acquainted in these latter days,
either adhering to rocks, on the sea-shore, at low
water, or flourishing in tanks, either in public aquaria,
exhibitions, or zoological gardens, we shall have, as
far as structure goes, a very fair representative of
the Actinia-like coral polyps, but deficient in the
power of secreting coral. With this exception, it
will suit our purpose. Who has not read the
Rev. Charles Kingsley's " Glaucus ; or, Wonders of
the Shore " ? And whoever has read it will remember
what he writes of these Anemones : — " In the crannies
of every rock you will find sea-anemones. There
they hang upon the under-side of the ledges, appar-
ently mere rounded lumps of jelly ; one is of dark
purple dotted with green ; another, of a rich chocolate ;
another, of a delicate olive ; another, sienna-yellow ;
another, all but white. Take them from their rock ;
you can do it easily by slipping under them your
finger-nail, or the edge of a pewter spoon. When
you get home, turn them into a dish full of water, and
leave them for the night, and go to look at them
to-morrow. What a change ! The dull lumps of
jelly have taken root, and flowered during the night,
and your dish is filled, from side to side, with a

220

TOILERS IN THE SEA.

bouquet of chrysanthemums ; each has expanded
into a hundred-petalled flower, crimson, pink, purple,
or orange ; touch one, and it shrinks together like a
sensitive plant, displaying at the root of the petals
a ring of brilliant turquoise beads (fig. 43). That is

the commonest of all
the Actiniae (Mesem-
bryanthenmni) . You
may have him when
and where you will ;
but if you will search
these rocks somewhat
closer, you will find
even more gorgeous
species than he. See
in that pool some
dozen noble ones in full bloom, and quite six inches
across, some of them. I f their cousins, whom we found
just now, were like chrysanthemums, these are like
quilled dahlias. Their arms are stouter and shorter in
proportion than those of the last species, but their
colour is equally brilliant. One is a brilliant blood red ;
another, a delicate sea-blue, striped with pink ; but
most have the disk and the innumerable arms striped
and ringed with various shades of grey and brown." x

FIG. 43. — SEA ANEMONE.

1 " Glaucus ; or, the Wonders of the Shore," by Rev. C
Kingsley, M.A., p. 183.

CORAL BUILDERS. 221

Any one of these sea-anemones consists of a cylin-
drical body, or column, with a flattened base by
which it is attached to the rock, a flattened upper
surface or disk, surrounded by one or more rows of
tentacles, and a mouth or opening in the centre,
leading into the cavity of the body, or stomach, if you
will. They may vary in size, from an eighth of an inch
in diameter to more than a foot, but these general
features will apply to all. When fully expanded the
tentacles radiate from, and fringe the disk, like the
flower of a chrysanthemum. When retracted and
closed, the tentacles are hidden, and the whole
animal resembles a convex gelatinous button. The
number of tentacles is some multiple of six, which is
also a typical number in their internal organisation.
The mouth, in the centre of the disk, is usually a little
elevated at the margin or lips, and opens directly
into the stomach. This cavity is divided, in a radiate
manner, by fleshy partitions, or septa, into compart-
ments, the septa being in pairs, corresponding to some
multiple of six. The muscles of the body are the
means by which the animal contracts itself when
disturbed, and expands again when at rest ; during
the former process expelling forcibly a quantity of
water through its mouth, and in the latter imbibing
sufficient to inflate the tentacles and body. Food is
sometimes assisted in its passage through the mouth
into the stomach by the tentacles, as well as by the

222 TOILERS IN THE SEA.

extension of the lips, and the contraction of the disk.
In some species the tentacles are too short and thick
to be of much service for prehension. When the
food is digested, or as much of it as is capable of
digestion, the refuse is expelled from the mouth,
which is the only orifice of ingress and egress.1
" When morsels of food," says Gosse, " such as frag-
ments of butcher's meat, are swallowed by Anemones,
they are retained for some hours and then vomited ;
and, because little change has passed upon the solid
parts, it has been rashly concluded that no process
of digestion takes place in these animals. On this
foolish hypothesis it is difficult to see why food
should be swallowed at all, or what need the animal
has of mouth or stomach. Their ordinary food, how-
ever, is not mammalian muscle, but far softer and
more fluid flesh. Nothing is more common than to
find large specimens of Actiniae discharge soon after
their capture, the shell of a crab or limpet from
which the entire flesh has been removed, and replaced
by a tenacious glaire. No doubt the first part of the
process consists largely of maceration, and. continued
pressure, by means of which the juices of the food
are extracted." Without entering further upon the

1 All the details of structure and economy of these animals
will be found in the Introductory Chapter to " A History of
Sea- Anemones," by P. H. Gosse, London, 1860.

CORAL BUILDERS.

223

question of digestion, or of circulation and respiration,
a few lines must be devoted to the powers, and meanS
of attack and defence, possessed by these apparently
harmless animals.

The concealed weapons of the sea-anemones, and
their allies, consist in the lasso-cells, stinging-cells,
or thread-capsules, as they have
been called, which are distributed
over the animals in myriads.
Gosse has described minutely
the different forms, or modifica-
tions, of these lasso-cells, but
his description is too extended
and technical for repetition here
(fig. 44). Suffice it to say that,
according to Dana, they " are
called lasso-cells because the
little cell-shaped sheath con-
tains a very long slender tubular
thread coiled up, which can be
darted out instantly when needed.
As first observed by Agassiz, the
tubular lasso escapes from the
cell by turning itself inside out,
the extremity showing itself last, and this is usually
clone with lightning-like rapidity. Then follows the
poison. The lasso-cells are usually less than one
two-hundredth of an inch in length, but they are

FIG. 44.

LASSO-CELLS OF
CORYNACTIS.

224 TOILERS IN THE SEA.

thickly crowded in the larger part of the skin or
walls of the tentacles and about the mouth, also in
the visceral cavity in white cords hanging in folds
from the edge of the septa. Thus the polyp is
armed inside and out. The mollusk or crab that
has the ill luck to fall, or be thrown by the waves,
on the surface of the pretty flower is at once pierced
and poisoned by the minute lassoes, and is rendered
incapable of resistance." l

In the particular form of lasso-cell, here figured

FIG. 45. — LASSO-CELL OF MADREPORE.

(fig. 45), the cells are perfectly transparent, colourless
vesicles, of a long ovate figure, larger at one end than
the other. One of average size is one two-hundred-
and-fiftieth of an inch in length, and about one two-
thousandth of an inch in diameter, at its widest part.
In the upper and larger half of the cell a longitudinal
chamber of a spindle-shape is seen passing down-
wards through its centre, tapering to a point at each
end ; the upper point merges into the walls of the
cell at its extremity, whilst the lower point, after

1 Dana, " Corals and Coral Islands," p. 13.

CORAL BUILDERS.

225

being narrowed like the upper, expands into a
funnel-shaped mouth in which the chamber wall is
folded inwards. From this point the structure
becomes a slender cord, which, pass-
ing back to the upper end of the
capsule, winds loosely round and
round the chamber, at first regularly,
but afterwards in a more intricate
manner, until it fills the lower portion
of the cavity. Under pressure, or
at the will of the animal, the fusi-
form chamber and its twining thread
are shot forth with inconceivable ra-
pidity. When fully expelled the
thread is often twenty, thirty, or even
forty times the length of the lasso-
cell, though in some species it is
much shorter. It may be added that
the basal portion of the thread (lasso)
is often ornamented by a thickened
spiral band, in which are inserted a
series of firm tapering bristles (fig.
46).

" It has long been known," says
Gosse, "that a very slight contact
with the tentacles of a polype is
sufficient to produce, in any minute animal so
touched, torpor and speedy death. Since the dis-

Q

FIG. 46.

BASAL PORTION
OF LASSO.

226 TOILERS IN THE SEA.

-covery of these lasso-cells the fatal power has been
supposed to be lodged in them. Baker, a century
ago, in speaking of the Hydra, suggested that ' there
must be something eminently poisonous in its grasp,'
and this suspicion received confirmation from the
circumstance that the Entomostraca (water-fleas, &c.),
which are enveloped in a shelly covering, frequently
escape unhurt after having been seized. The stinging
power possessed by many Meduscz, which is suffi-
ciently intense to be formidable even to man, has
been reasonably attributed to the same organs, which
the microscope shows to be accumulated by millions
in their tissues." l This author goes on to say that,
although he cannot reduce this presumption to actual
certainty, he made some experiments which leave no
reasonable doubt on the subject. He then proceeds
to record several examples, which seemed to prove
that the slightest contact with the proper organs of
the anemone was sufficient to provoke the discharge
of the lasso-cells, and that even the densest condition
-of the human skin offered no impediment to the
penetration of the threads. And he adds, — " As to
the injection of a poison, it is indubitable that pain,
and in some cases death, ensues, even to vertebrate
animals, from momentary contact with the capsul-
iferous organs of the zoophytes. The very severe

1 Gosse, " Sea-Anemones and Corals," p. xxxvii.

CORAL BUILDERS. 227

pain, followed by torpor, lasting a whole day, which
Mr. George Bennett has described as experienced by
himself on taking hold of a 'Portuguese man-of-war'
(Phy salts pelagica} was produced by the contact of
the tentacle?. The late Professor Edward Forbes
has graphically depicted the ' prickly torture ' which
results to * tender-skinned bathers ' from the touch of
the long filamentous tentacles, ' poisonous threads '
of the Cyanea capillata of our own seas, and observes
that these amputated weapons, severed from the
parent body, sting as fiercely as if their original
proprietor itself gave the word of attack. I have
been assured by ladies that they have felt a distinct
stinging sensation, like that produced by the leaves
of the nettle on the tender skin of the fingers, from
handling our common * Opelet anemone' (Anthea
cereus] ; while, on the other hand, I have myself
handled the species scores of times with impunity.
And I have elsewhere recorded an instance in which
a little fish, swimming about in health and vigour,
died in a few minutes with great agony, through the
momentary contact of its lip with one of the emitted
lasso - cells (acontia) of the * Parasitic anemone '
(Sagartia parasitica). It is worthy of observation
that in this case the fish carried away a portion of
the lasso-cell (aconttum) sticking to its lip ; the force
with which it adhered being so great that the in-
tegrity of the tissues yielded first. The lasso

Q 2

228

TOILERS IN THE SEA.

(aconttum) severed rather than let go its hold"1

(fig- 47).

The anemone has no circulating fluid but the
results of digestion mixed with salt water, no blood-
vessels but the vacuities among the tissues, and no
passage way for excrement, except the mouth and

FIG. 47. — ACONTIA OF SEA-ANEMONE.

the pores of the body, that serve for the escape of
water on the contraction of the animal.

1 Mr. G. H. Lewes, in his " Seaside Studies," doubts the
validity of this fact, and indeed he claims that " the hypothesis
which assigns to the thread capsules a function of urtication is
without a single fact to warrant it."

CORAL BUILDERS. 229

As to the senses they have a general sense of
feeling, and besides which, " some of them have a-
series of eyes, placed like a necklace around the body,
just outside the tentacles," yet they are not known to
have a proper nervous system.

Reproduction takes place either by means of eggs
or by budding. Sometimes an animal divides itself
from above downwards, and becomes two individuals,
or fragments detached from the base will develop
themselves into young individuals, but gemmation, or
budding, is a common process, especially amongst
the coral-secreting species. " A protuberance begins
to rise," says Dana, " and soon shows a mouth, and
then becomes surrounded by tentacles ; and, thus
begun, the new anemone continues to grow, usually
until its tentacles have doubled their number, when
finally it separates from the parent, and becomes an
independent animal."

The normal mode of reproduction is by generation.
The sexes are sometimes united in one individual,
and sometimes separate. The eggs, germs, or fully-
formed young, are discharged indifferently through the
mouth : in the latter case, the embryos have passed
their early stages in the general cavity. Dr. Spencer
Cobbold relates how he collected two specimens of
anemone one afternoon from the north shore of the
Frith of Forth : " On arriving at Edinburgh, the same
evening, the number in the vessel had increased to

23o TOILERS IN THE SEA.

thirty-five. The animals were therefore carefully
watched that night, but not until next day were we
gratified by witnessing, what has been shown by
numerous observers to occur, viz., the evolution of
the young, of all shapes and sizes, by the mouth.
On dissecting one of the adult anemones, it was
found, as we were thus led to anticipate, that a
considerable opening obtained to the base of the
stomach, admitting the tip of the little finger, and
freely communicating with the interseptal spaces
and general abdominal reservoir. This, to our mind
fully cleared up the difficulty, so often expressed,
concerning the passage by which the young polyps
gain access to the digestive cavity, and are ulti-
mately set free." l

Thus far then we have detailed the structure and
development of the common anemones, which do not
secrete coral, in order to illustrate the coral-making
species. The differences between them consist in
the anemones being simple animals, — that is, not
associated to form colonies, — in their being generally
capable of locomotion on the muscular base, as well
as in the deficiency of the power of secreting coral.
In other respects, that which applies to the one
group applies also to the other. In consequence of their

1 Dr. S. Cobbold on the " Anatomy of Actinia," in " Annals
and Magazine of Natural History." Feb. 1853, p. 122.

CORAL BUILDERS,

231

depositing within themselves a skeleton of coral, the
coral-making species are fixed (fig. 48), this deposit
taking place in the sides, and lower part of the polyp,
leaving the disk and stomach fleshy. The internal
septa secrete radiating plates of coral between each
pair of septa, so
that when dead,
and the fleshyparts
are dissolved away,
these radiating
plates represent the
radiating septa in
the internal cavity
of the anemone.
The calcareous, or FIG 4g._CARYOPHYLLiA SMITHII.
persistent coral

skeleton, which is left when all the fleshy parts are
gone is called the corallum, and is, in fact, the coral.
A few of the species in this group are simple, and the
coral produced is the secretion of single polyps.
This is the case in the Fungia family in which the
numerous radiating plates resemble the gills of a
mushroom inverted, whence their name is derived.
They are by no means small species, but will attain
to more than a foot in length, the corallum, or
skeleton, being a common object in museums. They
are found in coral-reef seas lying on the bottom, but,
unlike most coral-secreting species, are not fixed

232 TOILERS IN THE SEA.

except when young. Their outline is often discoid
or oval, but sometimes elongated elliptical, with the
plates on the upper surface radiating from a depressed
umbilicate centre, or from a central furrow, the outer
edges of the parallel plates being acute.

The most important of the Actinoid l corals are
those which form compound groups, wherein a
number of polyps are connected together in a colony,
often as the result of the process of budding. These
colonies Professor Dana calls Zoothomes^ although
we prefer to avoid as much as possible the use of
technicalities of this description. Describing the
process of gemmation, or budding, he says, " the bud
commences as a slight prominence on the side of the
parent. The prominence enlarges, a mouth opens,
a circle of tentacles grows out around it, and increase
continues till the young family equals the parent in
size. Since in these species the young does not
separate from the parent, this budding produces a
compound group ; and the process continues until, in
some instances, thousands, or hundreds of thousands,
have proceeded from a single germ, and the colony
has increased to a large size, sometimes many feet,
or even yards, in breadth or height. In thecorallum,
-or dead skeleton, each stellate cavity, or prominence

1 Actinoid, because resembling the Actinias, or Sea-ane-
mones.

CORAL BUILDERS. 233

over the surface, corresponds to a separate one of the
united polyps."

Each individual polyp has its own separate mouth,
tentacles, and stomach, and they coalesce by inter-
vening tissues, so that " there is a free circulation of
fluids through the many pores, or lacunae. The
colony is like a living sheet of animal matter, fed and
nourished by numerous mouths, and as many
stomachs." The budding proceeds in different direc-
tions according to the species. In some cases the
base spreads in all directions, and buds at the»edge,
so as to form an incrusting plate, in other cases it
has a tendency to grow upwards, budding at the
sides, so as to form branches, and at length a tree-
like form is produced, or the budding takes place
all over the mass, so that it maintains a more or
less hemispherical form, some of the masses in the
Pacific having a diameter, of twenty feet. Thus we
have the numerous forms of Orbicella, Madrepores,
Forties^ &c.

But, besides this method of budding, there is
another and analogous process of spontaneous fission
by which a polyp divides in two. In such cases the
disk keeps enlarging until, having exceeded the
ordinary adult size, a new mouth makes its appear-
ance in the disk, a short distance from the old one,
growth still continues until the mouths are removed
further apart, a stomach is being formed beneath the

234

TOILERS IN THE SEA.

new mouth, and at length tentacles make their
appearance between the two mouths, each mouth
with its circlet of tentacles, and finally these are
resolved into two complete individuals, the one re-
taining the old mouth and stomach, the other the
new mouth and stomach. This is the mode of
increase which commonly prevails in the hemi-

FIG. 49. — THE ASTR^A (Astrcea pallida).

spherical corals of the genus Astrcea (fig. 49), some
of which attain a diameter of from ten to fifteen feet.
A curious modification of this process takes place
in the Brain corals (Meandrind)^ in which the disk
enlarges indefinitely, a new mouth makes its appear-
ance, and then another, and another, until a string of
mouths appear in a line, before there is any separa-
tion or isolation of the new individuals ; this, how-

CORAL BUILDERS.

235

ever, does take place at length, preparatory to the
formation by each of its own elongating disk and
line of new mouths. This serves to explain the

FIG. 50. — BRAIN CORAL (Meandrina cerebriformis}.

sinuous furrows on the surface of the corallum of the
Brain corals (fig. 50).

The only other important group of coral animals
to which it will be necessary to allude, are the Hy-

236 TOILERS IN THE SEA.

droids ; and here we may fall back upon what we
have already written for many of the facts, to avoid
repetition. The hydroid zoophytes, as they are often
called, will hereafter be described, inasmuch as
concerns the " Horny House-builders." These may
be taken to a great extent as a type of the Hydroid
coral animals, since, in both, the common fresh-water
Hydra furnishes a good illustration of general struc-
ture. When speaking or writing of corals, allusion
is often made to a group called Millepores, in which
the structure of the animals recedes from that of the
Actinoid corals, to which our space has hitherto been
devoted. These animals are slow to make their ap-
pearance ; and, indeed, it has not long been known
to what precise position in the animal kingdom they
should be assigned. At length, however, the American
naturalist, Agassiz, determined their character, which
seems to be generally accepted, that they are Hy-
droids, allied to our own Coryne, but less perfectly
developed. The animal appears to be only a fleshy
tube, with a mouth at the top, and, in place of the
tentacles, a few small rounded prominences, four of
which are somewhat the largest. The corals are
large and stony, punctured all over the surface with
small rounded holes, through which the animals pro-
trude themselves, so that the corals themselves may
be readily distinguished from those of the anemone
type. As these corals are very abundant, and con-

CORAL BUILDERS.

23?

tribute largely to the formation of reefs in the West
Indies, they could not be ignored in this chapter,-
although their interest is small, as compared with
the various forms of Actinoid corals.

It must, in justice, be remarked here that the con-
clusions to which Agassiz arrived have not remained
unchallenged. Observations on the same species as
that examined by the American zoologist, made by
another individual, have led
to the adoption of different
views, which are thus stated :
" The polyp, as seen at Ber-
muda in full expansion, is a
very remarkable one, and it
is a great satisfaction to be
able to state that Agassiz
saw only a part of the whole,
and came to his conclusions
too rapidly. The polyps are
of different lengths, accord-
ing to their growth, are
slender, and stand erect in
crowds around the branches.

Each rises from a cylindrical stem, which is ren-
dered slightly square close to four tentacles, which
project upwards and outwards. Their tips are
swollen and rounded, and their bases are con-
tinuous, by means of straight dark tissue, which over-

FIG. 51.

ZOOIDS OF MILLEPORA.

238 TOILERS IN THE SEA.

laps slightly the analogue of the oral opening (fig. 5 i).
Out of this opening comes a second cylinder, to termi-
nate in four other tentacles in the same way ; and in
some polyps there is a further growth, so that there
are two or more rows of tentacles separated by the
tubular cylindrical tissue. It is evident that Agassiz
saw young, ill-developed, and probably injured po-
lyps, which had not attained their second row of ten-
tacles. The number of tentacles may be, therefore,
four, eight, twelve, &c. In looking at this description
there is a probability that the Millepore is an Alcyo-
narian, and there is no proof that it is a Hydroid." l
It is also stated that "every variety of tentacular
and disk apparatus may exist in either ; but the
external development of the gemmules, ova, and
embryonic forms, must be recognised before any
Coelenterate animal can be associated with the Hy-
drozoa. Here is the point where Agassiz fails. His
researches are only suggestive, until the generative
organs are recognised on the protruded polyps."

In his enumeration of the different groups of
animals which contribute to the formation of coral
reefs, Dana includes the Sea- fans, and their allies,
and the Sea-mat animals (Bryozoa}. The former of
these he admits contribute but little to the material

1 "On the Actinozoan Nature of Millepora," by R. G.
Nelson, and P. M. Duncan, in "Annals of Natural History,"
vol. xvii. (1876), p. 354.

CORAL BUILDERS. 239

of coral-reefs, but they add largely to the beauties
of the coral landscape. The animal of the commer-
cial Red Coral belongs to the same category, being
what is termed an Alcyonoid polyp, and all further
allusion to it will be found in our chapter on Sea-
fans.

The Bryozoans, or animals of the sea-mats, are of
another and distinct type, but the structures they
form are usually small, and either thin and membra-
naceous, or thicker and more calcareous, forming
plates which may, by growing in a stratified manner
one over the other, ultimately produce a layer of
considerable thickness. Whatever they may have
done, in Palaeozoic times, in contributing to the for-
mation of limestone, they contribute but little to the
coral-reefs of the present age. In furtherance of
our design, if space permits, we hope to include
both these groups of animals in the present volume,
therefore are content to abandon them for the
present.

It is also a fact that some undoubted plants, or sea-
weeds, secrete lime to such an extent as to contribute
to the accumulations which form coral-reefs. Some
of these are very delicate and beautiful, though fra-
gile, and their name of corallines suggests miniature
resemblances to coral. The larger kinds, or Nulli-
pores, not only contribute something in bulk to the
calcareous deposit of reefs, but Darwin says that

240 TOILERS IN THE SEA.

"they play an important part in protecting the
upper surfaces of coral-reefs, behind, and within, the
breakers, where the true corals, during their outward
growth, become killed by exposure to the sun and
air."

The corallum, or coral skeleton, which is secreted
by the coral animals, and enters into the composition
of coral-reefs and coral-rock, is almost identical with
ordinary limestone. It is somewhat harder than
limestone or marble, and rings when struck with a
hammer. " It is a common error," writes Dana, "to
suppose that coral, when first removed from the
water, is soft, and afterwards hardens on exposure ;
for, in fact, there is scarcely an appreciable difference.
The live coral may have a slimy feel in the fingers,
but, if washed clean of the animal matter, it is found
to be quite firm. The water with which it is pene-
trated may contain a trace of lime in solution, which
evaporates on drying, and adds slightly to the strength
of the coral, but the change is hardly appreciable."
Chemically, the coral-reefs are composed of carbonate
of lime, viz., they contain from ninety-five to ninety-
eight parts in one hundred of that constituent,1 and
the coral animals are the medium, through which this
is abstracted from the sea water, and deposited in

1 Madrepora cervicornis, contains in 100 parts 98*07 of car-
bonate of lime, o-32 phosphate of lime, and 1*93 of water and
organic matters. — American Journ. Sri.) iii. i. 168.

CORAL BUILDERS. 241

their skeleton. It is calculated that the water of the
ocean contains, in solution, from one twenty-fourth to '
one thirty-sixth of all its soluble ingredients in salts
of lime, chiefly in the condition of sulphate of lime ;
and, according to Bischof, there are about sixteen
parts of sulphate of lime in 10,000 of sea water.
This proportion may at first appear to be small, but
by rapid infiltration, and deposit, by myriads of
animals, it has been considered ample to account for
the results. After all, no one can estimate the enor-
mous period of time throughout which the coral has
been deposited to form existing reefs. This leads us
to an interesting subject, suggested by Professor
Dana, in his work already so often quoted, and this
is, death and life in progress together in the coral
structure. No one must suppose that a mass of
coral, which may be dredged up from the sea-bottom,
is necessarily living from end to end. Whatever the
species may be, and in whatever direction its growth
may proceed, there will be found to be an old and
dead portion, with a new and vigorous one, — death
and life side by side, and both going on together.
The animal portion decays and vanishes, but the
corallum, or coral stock, remains imperishable fot
ages. It is by means of this process that masses of
coral, which would otherwise be very small, attain to
a very large size. The animals at the top, as they
deposit their coral, keep ascending, whilst the older

R

242 TOILERS IN THE SEA.

polyps below die and disappear. " Trees of Madre-
pores have their limits, — all below a certain distance
from the summit being dead, and this distance will
differ for different species. But this is not a limit to
the existence of the corallum, even though a slender
tree or shrub, or of its flourishing state ; for the dead
coral below is firm rock itself, often stronger than
ordinary limestone or marble, and serves as an ever-
rising basement for the still expanding and rising
zoophyte." Not only will the base be dead, and the
apex of the trunk or branches living, but the whole
interior is usually dead, so that the living portion
does not extend inwards but the fraction of an inch.
In the large dome-shaped corals, sometimes 10 feet or
15 feet in diameter, the whole outer surface may be
alive, and yet the whole interior be nothing but life-
less coral. The tree-like species may continue to
increase upwards, until the apex reaches the surface
at low water, and then cease, for death comes from
exposure, and yet not wholly cease ; for even under
such circumstances lateral budding will still go on
with a modification of form.

The dead coral trunks are not without their
enemies, and their great hardness does not secure
them wholly from danger. Agassiz states that " in-
numerable boring animals establish themselves in the
lifeless stem, piercing holes in all directions into its
interior, like so many augers, dissolving its solid con-

CORAL BUILDERS. 243

nexion with the ground, and even penetrating far
into the living portion of these compact communities.
The number of these boring animals is quite in-
credible, and they belong to different families of the
animal kingdom; among the most active and powerful
we would mention the date-fish, and many worms, of
which the Serpula is the largest and most destructive,
inasmuch as it extends constantly through the living
part of the coral stems. On the loose basis of a
brain coral (Meandrina), measuring less than two feet
in diameter, we have counted not less than fifty holes
of the date-fish — some large enough to admit a finger
— beside hundreds of small ones made by worms.
But however efficient these boring animals may be,
in preparing the coral stems for decay, there is yet
another agent, perhaps still more destructive, we
allude to the minute boring-sponges, which penetrate
them in all directions, until they appear at last com-
pletely rotten through." l Yet the coral animals would
seem to contribute themselves a little protection from
their enemies, for in some of the species the lower
edge of the dying polyps secrete an outer layer of
denser, and more impervious, material over the dead
coral stem, and, besides this, the older polyps before
death increase their coral secretions within, so as to
fill up gradually the pores of the coral, as their own

1 Agassiz. Coast Survey Report for 1851.
R 2

244 TOILERS IN THE SEA.

tissues dwindle, and so render the old coral more
nearly solid. Then again, some little external assist-
ance is rendered by the mollusks, which adhere to
the dead trunk, as well as by the Nullipores which
grow over it, like the lichens on the trunk of an old
tree in a forest. Notwithstanding all their vicissitudes
in this " struggle for existence " the coral masses, and
coral reefs, must for ages have maintained their
position, in defiance of all their enemies, even
allowing for all loss by disintegration, a process so
continuous, and yet so small in its results, in com-
parison with the permanent mass, that it can scarcely
be taken into account as a disturbing influence.

As we commenced this chapter by observations on
some strictures which had been made on certain
authors, on the grounds of scientific accuracy, so we
feel bound to conclude it by some strictures of our
own on the same grounds. Although it may be
permissible for a poet to use what machinery he
pleases, in the construction of his work, whether based
wholly, or only in part, on scientific fact, it is never-
theless imperative on one who writes in a scientific
work, assumed to give instruction in science, that he
should be accurate in his interpretations of the facts
of science. Whether this demand has been acceded
to in the work in question the following quotation
may determine. Writing of the coral animals this
writer observes : — " Nothing can be more impressive

CORAL BUILDERS. 245

than the manner in which these diminutive creatures
carry out their stupendous undertakings, which we
denominate instinct, intelligence, or design. Com-
mencing betimes from a depth of a thousand or
fifteen hundred feet, they work upwards in a perpen-
dicular direction ; and on arriving at the surface
form a crescent, presenting the back of the arch in
that direction from which the storms and winds
generally proceed ; by which means the wall protects
the busy millions at work beneath and within. These
breakwaters will resist more powerful seas than if
formed of granite ; rising as they do in a mighty
expanse of water, exposed to the utmost powers of
the heavy and tumultuous billows that eternally lash
against them. As we glance at the map of the
world, and think of the profusion of fragrant vegeta-
tion, and delicious food, almost spontaneously pro-
duced on the lovely sunny islands of the Pacific, how
startling does it seem when we are told that these
islands, bearing on their bosoms gardens of Eden,
are entirely formed by the slow-growing corals, which,
rising up in beautiful and delicate forms, displace the
mighty ocean, defy its gigantic strength, and display
a shelly bosom to the expanse of day ! The vegeta-
tion of the sea, cast on its surface, undergoes a
chemical change ; the deposit from rains aids in
filling up the Kttle gaping catacomb, the fowls of the
air and ocean find a resting-place, and assist in

246 TOILERS IN THE SEA.

clothing the rocks ; mosses carpet the surface, seed
brought by birds, plants carried by the oceanic
currents, animalcules floating in the atmosphere, live,
propagate and die, and are succeeded, by the assis-
tance their remains bestow, by more advanced
vegetable and animal life ; and thus generation
after generation exist and perish, until at length the
coral island becomes a paradise, filled with the
choicest exotics, the most beautiful birds, and delicious
fruits, amongst which man may indolently revel to
the utmost desire of his heart." l

No doubt its author considered this a sublime
finish to his meagre statement of facts, but, unfortu-
nately it must have been educed from his own inner
consciousness, and should be treated as the lucubra-
tion of a heated imagination, and not as a summary
of scientific fact such as may be gleaned from the
works of Darwin, Dana, Agassiz, and others, who
have made the subject a special study. " How
startling does it seem when we are told " that these
gorgeous dreams are the stern realities of scientific
fact, but perhaps the writer himself was scarcely
conscious, in his enthusiasm, that his spirit was
wandering in the unsubstantial realms of Fairy-land.

1 "The Microscope," by Jabez Hogg, F.L.S. (London, 1867),
p. 490.

TOILERS IN THE SEA. 247

CHAPTER VIII.

CORAL REEFS, AND ISLANDS.

THE first author who collated the information
associated with Coral Islands, and propounded
a feasible theory of their structure and method of
construction, was the late Charles Darwin, who has
done so much for Biological Science during the
present generation. His views, propounded in full
in his volume on Coral Reefs,1 were subsequently
subscribed to by the eminent American geologist,
Professor James Dana,2 and have been generally
accepted ; such exception as may have been taken
to them being alluded to hereafter.

Darwin classed all the phenomena of coral reefs
under three primary classes, Barrier reefs, Fringing
reefs, and Atolls, or lagoon islands. These may be
briefly described, in Mr. Darwin's own language, as

1 " Structure and Distribution of Coral Reefs," by Charles
Darwin. London, 1851.

* "Corals and' Coral Islands," by James D. Dana, LL.D.
Popular edition. London, 1875.

248 TOILERS IN THE SEA.

he defined them in his " Journal " : — " Barrier reefs
either extend in straight lines in front of the shores
of a continent, or of a large island, or they encircle
smaller islands ; in both cases being separated from
the land by a broad, and rather deep, channel of
water." Fringing reefs, where the land slopes
abruptly under water, are only a few yards in width,
forming a mere ribbon or fringe round the shores ;
where the land slopes gently under water the reef
extends further, sometimes even as much as a mile
from the land ; but in such cases the soundings out-
side the reef always show that the submarine pro-
longation of the land is gently inclined. As far as
the actual reef of coral is concerned, there is not the
smallest difference in general size, outline, grouping,
and even in quite trifling details of structure, between
a barrier reef and an atoll, or lagoon island (fig. 52).
The geographer Balbi has well remarked, that an
encircled island is an atoll with high land rising out
of its lagoon ; remove the land from within, and a
perfect atoll is left."

These distinctions between coral reefs and coral
islands (lagoon islands, or atolls, whichever name be
employed) are recognised also by Dana, although he
combines the two kinds of reefs, and generally treats
of coral reefs (barrier reefs, and fringing reefs) and
coral islands. " Coral reefs and coral islands," he
says, "are structures of the same kind under some-

CORAL REEFS, AND ISLANDS.

249

what different conditions. The terms, however, are
not synonymous. Coral islands are reefs that
stand isolated in the ocean, away from other lands,
whether now raised only to the water's edge, and

FIG. 52. — CORAL REEF.

half submerged, or covered with vegetation ; while
the term Coral reef, although used for reefs of
coral in general, is more especially applied to those
which occur along the shores of high islands and
continents."

With this preliminary definition of terms we are

250 TOILERS IN THE SEA.

enabled better to proceed with a more minute de-
scription of reefs and atolls, the latter term being
less open to objection than islands.

Coral reefs are accumulations of coral rock which
have been built up from the sea bottom around the
shores of islands, or the continent, in the tropics.
These reefs are usually entirely submerged at high
water, and at low water present only a flat surface of
rock just rising above the water level. Some islands
are only girt by narrow fringing reefs, whilst others
are wholly or partially surrounded by the distant
barrier reef, which may be from ten to fifteen miles
from the island, or islands, with a considerable channel
of water between the barrier and the shore ; and, in
other cases, one side of the island may be protected
by a distant barrier reef, and the other girt only by a
fringing reef, the relationship between the barrier
and fringing reef being shown to be very close.
Hence we may formulate the conclusion that "reefs
around islands may be entirely encircling, or they
may be confined to a larger or a smaller portion of
the coast, either continuous or interrupted ; they
may constitute throughout a distant barrier ; or the
reef may be fringing in one part, and a barrier in
another ; or it may be fringing alone. The barrier
may be at a great distance from the shores, with a
wide sea within, or it may so unite to the fringing
reef that the channel between will hardly float a

CORAL REEFS, AND ISLANDS. 251

canoe." 1 Although reference has been made only to
such portions of the reef formations as have been
reared to the water's level, it must be remembered
that there may also be submerged banks, which are
in effect continuous with the elevated portions, and
form a part of the reef ground. The extent to which
these structures can be developed may be inferred
from the dimensions recorded ; as, for instance, to
the west of the two large Fiji Islands there is pro-
bably three thousand square miles of reef-ground.
The Exploring Isles have a barrier eighty miles in
circuit ; the western shore of New Caledonia has a
reef throughout its extent of two hundred and fifty
miles, and for a hundred and fifty miles beyond ;
whilst the Australian barrier forms a broken line of
some one thousand two hundred and fifty miles in
length.

Not only are we interested in the area which may
be covered by a reef-ground, but also of the thick-
ness to which some of the reefs may attain, and here
again we must fall back on the calculations made by
Dr. Darwin and Professor Dana. If it were possible
to raise one of these coral-girt islands we should find
that the barrier reefs stand like walls upon the
deeply-submerged slopes, or, in the case of the
fringing reefs, in the shallowest water, approaching

1 Dana, " Corals and Coral Islands," p. 105.

252 TOILERS IN THE SEA.

the coast line. Having found the declivity of the
land, assuming the slope to be regular and con-
tinuous, it would not be difficult to estimate the
depth, at any given distance from the land, but there
must be uncertainty as to the submarine slope,
although extensive observation has shown that, in
general, these slopes nearly coincide with those of
the exposed land. In this, or a similar manner,
Dr. Darwin estimated that the thickness of some of
the reefs in the Pacific islands, at their outer limits,
would be at least two thousand feet. After esti-
mating the outer reef of the Gambier group at
eleven hundred and fifty feet, of Tahiti at two
hundred and fifty feet, and of Upolu at four hundred
and forty feet, Professor Dana remarks that "the
results are sufficiently accurate to satisfy us of the
great thickness of many barrier reefs ;" and again,
" with regard to Tahiti and Upolu, information bear-
ing upon this point was obtained, and the above
conclusions may be received with much confidence.
Many of the Fiji reefs, on the same principle, cannot
be less than two thousand feet in thickness." The
objection which will at once be urged against such a
thickness of coral, on the ground that living coral
can only be found at a limited depth below the
surface, will be adverted to hereafter, and perhaps
reconciled with these estimates. For the present we
leave the data as they stand.

CORAL REEFS, AND ISLANDS. 253

Coming now to the atolls, or lagoon islands, we
may repeat that they resemble in many points the
encircling reefs just described, but differ in enclosing
a lake or lagoon instead of mountainous islands.
The lagoon is indeed only an enclosed portion of the
sea, surrounded by a more or less complete wall or
belt of coral rock, which is but little elevated above
the surface, and here and there surmounted by
vegetation, which have the appearance of small islets.
" In many of the smaller atolls the lagoon has lost
its ocean character, and become a shallow lake, and
the green islets of the margin have coalesced in some
instances into a continuous line of foliage. Traces
may, perhaps, be still detected of the passage, or
passages, over which the sea once communicated
with the internal waters, though mostly concealed by
the trees and shrubbery which have spread around
and completed the belt of verdure (fig. 53). The coral
island is now in its most finished state ; the lake rests
quietly within its circle of palms, hardly ruffled by
the storms that madden the surrounding ocean." l

It must not be assumed that the atolls are always
ring-shaped, although that may be the most perfect
form, for they are not only triangular, quadrangular,
and very irregular, but sometimes are completed only
on one side, with the opposite so much submerged that

1 Dana, p. 131.

254

TOILERS IN THE SEA.

no trace of it can be seen at the surface. It might
be supposed that when these atolls are called " coral
islands " they are really extensive surfaces of habit-
able land, but such is not the case, for the small
amount of habitable land they present is one of

FIG. 53. — CORAL LAGOON.

their most peculiar features. Dana has shown that
in the Kingsmill group of ten islands, which have an
aggregate area of eighteen hundred and fifty square
miles, the actual amount of dry and habitable land
is only seventy-six miles, or less than one twenty-
fourth. In the Caroline Archipelago the proportion

CORAL REEFS, AND ISLANDS. 255

is still smaller, and in the Marshall Islands the dry
land is not more than the one-hundredth part of
the whole.

Professor Dana has given so graphic a description
of an atoll that we are tempted to quote it, rather
than submit a more prosaic one of our own. " The
reef of the coral atoll, as it lies at the surface, still
uncovered with vegetation, is a platform of coral
rock, usually two to four hundred yards wide, and
situated so low as to be swept by the waves at high
tide. The outer edge, directly exposed to the surf,
is generally broken into points and jagged indenta-
tions, along which the waters of the resurging wave
drive with great force. Though in the midst of the
breakers the edge stands a few inches, and some-
times a foot, above other parts of the platform, the
encrusting Nullipores cover it with varied tints, and
afford protection from the abrading action of the
waves. There are usually eighteen to thirty feet of
water near the margin, and below, over the bottom,
which gradually deepens outward, beds of coral are
growing profusely among extensive patches of coral
sand and fragments. Generally the barren areas
much exceed those flourishing with zoophytes, and
not unfrequently the clusters are scattered like tufts
of vegetation in a sandy plain. The growing corals
extend up the sloping edge of the reef nearly to low-
tide level.

256 TOILERS IN THE SEA.

" The beach consists of coral pebbles, or sand with
some worn shells, and occasionally the exuviae of
crabs and bones of fishes. Owing to its whiteness
and the contrast it affords to the massy verdure
above, it is a remarkable feature in the distant view
of these islands, and often seemed like an artificial
wall or embankment running parallel with the
shores.

" The emerged land beyond the beach, in its
earliest stage, when barely raised above the tides,
appears like a vast field of ruins. Angular masses
of coral rock, varying in dimensions from one to a
hundred cubic feet, lie piled together in the utmost
confusion, blackened by exposure or from encrusting
lichens. Such regions may be traversed by leaping
from block to block, with the risk of falling into the
many recesses among the huge masses.

" In the next stage, coral sand has found lodgment
among the blocks, and although so scantily supplied
as hardly to be detected without close attention,
some seeds have taken root, and vines, purslane,
and a few shrubs have begun to grow, relieving the
scene, by their green leaves, of much of its desolate
aspect.

" In the last stage, the island stands six or ten
feet out of water. The surface consists of coral sand,
more or less discoloured by vegetable or animal
decomposition. Scattered among the trees stand,

CORAL REEFS, AND ISLANDS. 257

still uncovered, many of the larger blocks of
coral, with their usual rough angular features and
blackened surface. There is but little depth of
coral soil, although the land may appear buried
in the richest foliage. In fact the soil is scarcely
anything but coral sand. It is seldom discoloured
beyond four or five inches, and but little of it to
this extent ; there is no proper vegetable mould,
but only a mixture of darker particles with the
white grains of coral sand. It is often rather a coral
gravel, and below a foot or two it is usually cemented
together into a more or less compact corals and rock."1
The animals and plants found on these lagoon
islands consist of but few species, and these have
been enumerated by Darwin in his "Journal,"
especially those found upon Keeling Island. " In
such a loose, dry, stony soil," he says, " the climate
of the intertropical regions alone could produce a
vigorous vegetation." " The cocoa-nut palm, at the
first glance, seems to compose the whole wood ;
there are, however, five or six other trees. Besides
the trees, the number of plants is exceedingly
limited, and consists of insignificant weeds. In
my collection, which includes, I believe, nearly the
perfect Flora, there are twenty species, without
reckoning a moss, lichen, and fungus. To this

1 Dana, p. 143.
S

258 TOILERS IN THE

number two trees must be added, one of which

-was not in flower, and the other I only heard of.

As the islands consist entirely of coral, and at one

time must have existed as mere water-washed reefs,

-all their terrestrial productions must have been

•-.transported here by the waves of the sea."

" I can hardly explain the reason," he goes on
"to say, " but there is to my mind much grandeur
in the view of the outer shores of these lagoon
islands. There is a simplicity in the barrier-like
beach, the margin of green bushes, and tall cocoa-
nuts, the solid flat of dead coral rock, strewed here
-and there with great loose fragments, and the line
of the furious breakers, all rounding away towards
either hand, — the ocean throwing its waters over the
i>road reef appears an invincible, all-powerful enemy;
yet we see it resisted, and even conquered, by means
which at first seem most weak and inefficient It
is not that the ocean spares the rock of coral ; the
great fragments scattered over the reef, and heaped
•on the beach, whence the tall cocoa-nut springs,
plainly bespeak the unrelenting power of the waves.
Nor are any periods of repose granted. The long
swell caused by the gentle but steady action of the
trade wind, always blowing in one direction over
.a wide area, causes breakers, almost equalling in
force those during a gale of wind in the temperate
regions, and which never cease to rage. It is im-

CORAL REEFS, A ND ISLANDS. 259

possible to behold these waves without feeling a
conviction that an island, though built of the hardest
rock, let it be porphyry, granite, or quartz, would
ultimately yield, and be demolished by such an
irresistible power. Yet these low insignificant coral
islets stand, and are victorious ; for here another
power, as an antagonist, takes part in the contest.
The organic forces separate the atoms of carbonate
of lime, one by one, from the foaming breakers, and
unite them into a symmetrical structure. Let the
hurricane tear up its thousand huge fragments, yet
what will that tell against the accumulated labour
of myriads of architects, at work night and day,
month after month ? Thus do we see the soft and gela-
tinous body of a polyp, through the agency of the vital
laws, conquering the great mechanical power of the
waves of the ocean, which neither the art of man nor the
inanimate works of nature could successfully resist." 1
Allowing a little poetical licence, and remember-
ing that the facts were not so well known in Mont-
gomery's days as in ours, we might add, in the
words of the " Pelican Island " : —

" Nine times the age of man that coral reef
Had bleach'd beneath the torrid noon, and borne
The thunder of a thousand hurricanes,
Raised by the jealous ocean, to repel
That strange encroachment on his old domain.

1 Darwin, "Journal of Researches" (1852), p 459.
S 2

260 TOILERS IN THE SEA.

His rage was impotent : his wrath fulfill'd

The counsels of Eternal Providence,

And 'stablish'd what he strove to overturn :

For every tempest threw fresh wrecks upon it ;

Sand from the shoals, exuviae from the deep,

Fragments of shells, dead sloughs, sea monsters' bones,

Whales stranded in the shallows, hideous weeds

HurPd out of darkness by the uprooting surges ;

These with unutterable relics more,

Heap'd the rough surface, till the various mass,

By Nature's chemistry combined and purged,

Had buried the bare rock in crumbling mould."

At this stage it would be advisable to survey

the distribution of coral reefs and atolls, or just as

much as will be necessary to comprehend their

general localisation. Bearing in mind that the coral

itself has been dependent on the living organisms

which constructed it, there will at once follow an

admission that the temperature of the ocean must

be high enough for the organisms to flourish, and

here we arrive at the first condition which sets a

limit to coral grounds. The reef corals can flourish

in the hottest equatorial sea, hence there is no limit

in that direction ; but it does not appear that they

are able to bear a lower winter temperature than

68° Fahr., which seems to be the boundary line on

each side of the equator. We need not enter into

the particulars why this line is a flexuous one, under

the influence of oceanic currents, but so it is, that

the line of temperature of the ocean at 68° in winter

CORAL REEFS, AND ISLANDS. 261

is so flexuous in the vicinity of continents, that
while the enclosed region is about fifty-six degrees
wide in mid-ocean, it is in the Pacific only twenty-
five degrees wide on the west coast of America,
and forty-five degrees on the Asiatic side, whilst
in the Atlantic it is fifteen degrees wide on the
African coast, and forty-eight degrees on the coast
of America.1

Both Darwin and Dana, in their works already
alluded to, give abundant details of the geographical
distribution of coral reefs, which would scarcely be
of much interest to the general reader. We shall be
content to allude briefly to some of the most im-
portant coral areas, it being understood that we
only select a few. In the Pacific Ocean the Pau-
motas embrace eighty coral islands, and near
them the Gambier Islands with extensive reefs.
The Society Islands have also extensive coral reefs
and barriers, as have also the Samoa or Navigator's
Islands. The Tonga Islands for the most part
abound in coral reefs. The Fiji group possess reefs

1 The following table is from Prof. Dana's work, and shows
the coral boundary lines where they meet continental coasts.

Pacific. Atlantic.

East side of Ocean Lat. 21° N. Lat. 10° N.

» »» » 4° S. „ 5° S.

West side of Ocean „ 15° N. „ 26° N.

„ . 30° S. „ 22° S.

262 TOILERS IN THE SEA.

of great extent, whilst to the north are numerous
islands of coral. The Kingsmill Islands, Marshall
Islands, and the Carolines, about eighty in number,
are all (excepting three Carolines) atolls. South of
the Equator, New Caledonia, and the north-east
coast of New Holland is said to be the grandest reef
region in the world. Between Australia and New-
Caledonia the islands are all of coral.

The islands of the Indian ocean are mostly of
coral. Such are the Laccadives, Maldives, Keelings,
and Chagos Islands. The Seychelles have extensive
reefs, and there are fringing reefs on parts of the coast
of Madagascar.

In the Atlantic there are few reefs on the American
shores, except in the West Indies. The reefs of
Florida, Cuba, and the Bahamas are well known.
South of the Equator there are reefs at intervals
from near Cape St. Roque to the Abrolhos.

It might almost be said that the coral zone girts
the world in correspondence with the tropics, when-
ever the other conditions are favourable to their
growth.1 This reminds us that besides the tempera-

1 I have been assured, by several people, that there are no
coral reefs on the West Coast of Africa, or round the islands
in the Gulf of Guinea. This, perhaps, may be attributed, in
part, to the sediment brought down by the many rivers
debouching on that coast, and to the extensive mud banks
which line great part of it.— Darwin, " Coral Reefs," p. 62.

CORAL REEFS, AND ISLANDS. 263

ture of the ocean, there are other and important
conditions which influence the distribution of corals.
One of these is the proximity of the mouths of
rivers on account of the sediment which they bring'
down, and distribute over the sea bottom and the
neighbouring coast. No coral reefs can be formed
under such conditions. Too steep a shore and too
deep water, is another obstruction to the growth of
coral. Hereafter it will be shown that corals flourish
in comparatively shallow water. Finally, the proxi-
mity of volcanic action seems to be a great deterrent
to the growth of coral and the development of reefs..
For instance, although other conditions are favour-
able, the island of Hawaii has active volcanoes, and.
but few traces of coral about it, whereas neighbouring-
islands, which have long been free from volcanic -
action, have considerable coral reefs.

The depth at which living corals may be found in
the tropics, though varying somewhat in the estimates
of different naturalists, is generally admitted to be
comparatively small. There was a time when coral .
reefs were alluded to by voyagers as standing in
unfathomable ocean. This might have been only a
poetical licence, or, more probably, hazarded without
an attempt at sounding. Quoy and Gaymard, the
naturalists who explored the Pacific in 1 817-1 820^
were the first to show that the guess was unfounded.
According to their observations the limit of distribu-

264 TOILERS IN THE SEA.

tion downward was from 30 feet to 36 feet. Ehren-
berg concluded that in the Red Sea living coral did
not occur below 36 feet. Stutchbury, after a visit to
the coral groups of the Paumotas and Tahiti, fixed
the depth at from 96 feet to 100 feet. Darwin writes
that, "Although the limit of depth, at which each
particular kind of coral ceases to exist, is far from
being accurately known, yet, when we bear in mind
the manner in which the clumps of coral gradually
became infrequent at about the same depth, and
wholly disappeared at a greater depth than 120 feet,
on the slope round Keeling atoll, on the leeward side
of the Mauritius, and at rather less depth, both
without and within the atolls of the Maldive and
Chagos Archipelagos, and when we know that the
reefs round these islands do not differ from other
coral formations, in their form and structure, we may,
I , think conclude that in ordinary cases reef-building
polypifers do not flourish at greater depths than
between 120 feet and 180 feet."1 Captain Moresby
reported to Darwin that he found only decayed
coral on Padua Bank, north of the Laccadives
which has an average depth of between 1 50 feet and
210 feet, but that on some other banks in the same
group, with only 60 feet to 72 feet of water on them,
the coral was living. Lieutenant Wellstead has also

1 Darwin on " Coral Reefs," p. 86.

CORAL REEFS, AND ISLANDS. 265

affirmed that, in the more northern parts of the Red
Sea, there are extensive beds of living coral at a-
depth of 150 feet. Within the lagoons of some of
the Marshall atolls, where the water can be but
little agitated, there are, according to Kotzebue,
living beds of coral in 150 feet. Captain Beechey
states that branches of pink and yellow coral were
frequently brought up from between 120 feet and
150 feet off the Low atolls, and Lieutenant Stokes,
writing from the north-west^coast of Australia, says that
a strongly-branched coral was procured there from
80 feet. Professor Agassiz observes that, about the
Florida reefs, the reef-building corals do not extend
below 60 feet. Professor Dana remarks that in the
Wilkes's Exploring Expedition the soundings, in
the course of the various and extensive surveys,
afforded no evidence of growing coral beyond 120 feet.
Among the Fiji Islands the extent of coral reef
grounds surveyed was many hundreds of square
miles. The reefs of the Navigator's Islands were
also sounded out, with others of the Society group,
and, through all these regions, no evidence was
obtained of corals living at a greater depth than
90 feet to 1 20 feet. He concludes that, " there is
hence little room to doubt that twenty fathoms
(or 1 20 feet) may be received as the ordinary
limit in depth of reef corals in the tropics."

Not less interesting, or important, is the question

266 TOILERS IN THE SEA.

of the growth, or extension of coral, either laterally
or vertically, in the formation of reefs, as considered
apart from the growth of individual species. On
this point all the evidence we can produce is that
collected by Darwin, and that of a very limited
character. It has been assumed that the vertical
growth of coral must be slow, as inferred from a few
instances often cited, but which Darwin declares
are inconclusive. Ehrenberg has said, for instance,
that in the Red Sea, corals only coat other rocks in
a layer from one to two feet in thickness, or at most
to nine feet, and he did not believe that in any case
they would, of their own proper growth, form stratified
masses. He alludes to certain large massive corals
in the Red Sea, which he imagined of such vast
antiquity as to have been cotemporaneous with
Pharoah. On this point Darwin admits that there
are reefs in the Red Sea which do not appear to
have increased in dimensions during half a century,
and from comparison of old charts, probably not
during the last two hundred years. These, and
similar facts, have strongly impressed many with
the belief of the extreme slowness of the growth of
corals, so that they have even doubted the possibility
of islands in the ocean being formed by this agency.
On the contrary, there are facts, from which it may
be inferred with certainty, that masses of considerable
thickness have been formed by the growth of coral.

CORAL REEFS, AND ISLANDS. 267

There are knolls in the Southern Maldive atolls,
some of which, according to Captain Moresby, are
less than a hundred yards in diameter, and rise to the
surface from a depth of between 250 feet and 300 feet.
" Considering their number, form, and position," says
Darwin, " it would be preposterous to suppose that
they are based on pinnacles of any rock, not of coral
formation ; or that sediment could have been heaped
up into such small and steep isolated cones. As no
kind of living coral grows above the height of a few
feet, we are compelled to suppose that these knolls
have been formed by the successive growth and
death of many individuals, — first one being broken
off or killed by some accident, and then another,
and one set of species being replaced by another set
with different habits, as the reef rose nearer the
surface, or as other changes supervened. In reefs of
the barrier class we may feel sure that masses of
great thickness have been formed by the growth of
coral ; in the case of Vanikoro, judging only from
the depth of the moat between the land and the reef
the wall of coral rock must be at least 300 feet in
vertical thickness." l There can be little doubt that
Matilda atoll, in the Low Archipelago, has been con-
verted, in the space of thirty-four years, from a " reef
of rocks" into a lagoon island, fourteen miles in

1 Darwin, "Structure of Coral Reefs" (1851), p. 72

268 TOILERS IN THE SEA.

length, with "one of its sides covered nearly the
whole way with high trees." It is urged that, in an
old standing reef, the corals are of different kinds at
different parts, and all probably adapted to their
positions, where they hold their places, like other
organic beings, by a struggle with each other and
external nature, and hence their growth would
generally be slow, except under peculiarly favour-
able circumstances. " Almost the only natural
condition, allowing a quick upward growth of the
whole surface of a reef, would be a slow subsidence
of the area in which it stood." " If it be asked,"
says Darwin, " at what rate in years I suppose a reef
of coral, favourably circumstanced, would grow up
from a given depth, I should answer, that we have
no precise evidence on this point, and comparatively
little concern with it. We see in innumerable points
over wide areas, that the rate has been sufficient,
either to bring up the reefs from various depths to
the surface, or, as is more probable, to keep them at
the surface during progressive subsidences ; and this
is a much more important standard of comparison
than any cycle of years."

A few facts may be added, and left to carry their
own inferences. Dr. Allan experimented in 1830
to 1832 on the east coast of Madagascar. "To
ascertain the rise and progress of the coral family,
twenty species of coral were taken off the reef, and

CORAL REEFS, AND ISLANDS. 269

planted apart on a sandbank, three feet deep at low-
water. Each portion weighed ten pounds, and was ,
kept in its place by stakes. Similar quantities were
placed in a clump, and secured as the rest. This
was done in December, 1830. In July following
each detached mass was nearly level with the sea, at
low-water, quite immovable, and several feet long,
stretching as the parent reef, with the coast current
from north to south."

Lieutenant Wellstead communicated the fact that
" in the Persian Gulf a ship had her copper bottom
encrusted, in the course of ^twenty months, with a
layer of coral tivo feet in thickness, which it required
great force to remove when the vessel was docked."

The inhabitants at Keeling Island made with
crowbars a considerable channel through the reefs,
in which a schooner was floated out. In less than
ten years this channel was again almost choked up
with living coral, so that fresh cuttings would be
absolutely necessary before another vessel could pass
through.

If these instances can be accepted as types, or as
approximations towards the determination of the
growth of coral, under ordinary circumstances and
conditions, then it can scarcely be maintained that
the growth of coral is always slow.

The most popular of the older theories of the
formation of coral-atolls, was that which regarded

270 TOILERS IN THE SEA.

them as crowning the submerged summits of extinct
volcanoes. The lagoon in the centre corresponded
to the crater of the volcano, and the belt of land
encircling the lagoon was the rim of the crater.
This theory was rendered the more probable from
the volcanic nature of the region in which the best
known atolls had been found. This was the only
theory which held any position in the world when
Darwin announced his hypothesis. The objections to
the volcanic theory have been summarised by Dana : —

(1) The volcanic cones must either have been sub-
aerial, and then have afterward sunk beneath the
waters, or else they were submarine from the first.
In the former case the crater would have been de-
stroyed, with rare exceptions, during the subsidence ;
and in the latter there is reason to believe that a
distinct crater would seldom, if ever, be formed.

(2) The hypothesis moreover requires that the
ocean's bed should have been thickly planted with
craters, — seventy in a single archipelago, — and that
they should have been of nearly the same elevation,
for, if more than twenty fathoms below the surface,
corals could not grow upon them. But no records
warrant the supposition that such a volcanic area
ever existed. The volcanoes of the Andes differ
from 1 ,000 feet to 10,000 feet in altitude, and scarcely
two cones throughout the world are as. nearly of
the same height as here supposed. Mount Loa and

CORAL REEFS, AND ISLANDS. 271

Mount Koa, of Hawaii, present a remarkable
instance of approximation, as they differ but 200
feet ; but the two sides of the crater of Mount Loa
differ 314 feet in height. Mount Koa, though of
volcanic character, has no large crater at top,
Hualalai, the third mountain of Hawaii, is 4,000 feet
lower than Mount Loa. The volcanic summit of
East Maui is 10,000 feet high, and contains a large
crater, but the wall of the crater, on one side, is 700
feet lower than the highest point of the mountain,
and the bottom of the crater is 2,000 feet below the
rim of the crater. Similar facts are presented by all
volcanic regions.

(3) It further requires that there should be craters
over fifty miles in diameter, and that twenty and
thirty miles should be a common size. Facts give
no support to such an assumption.

(4) It supposes that the high islands of the Pacific,
in the vicinity of the coral islands, abound in craters ;
while on the contrary, there are none, so far as is
known, in the Marquesas, Garnbier, or Society Group,
the three which lie nearest to the Paumotas. Even
this supposition fails, therefore, of giving plausibility
to the crater hypothesis.1 It is no exaggeration to
claim that this ancient theory, having become utterly
untenable, has been everywhere abandoned.

1 Dana, " Corals and Coral Islands," p. 219.

272 TOILERS IN THE SEA.

It remains briefly to sketch the hypothesis
advanced by Darwin, sanctioned by Humboldt,
supported by Dana, and generally adopted. This
theory is based upon the fundamental fact of the
gradual subsidence, or elevation, of islands in the
Pacific, that is to say, on changes of level in the
Pacific Ocean. Professor Dana devotes an entire
chapter in his work to the substantiation, and
elucidation, of this fundamental position. Those
interested in ascertaining the data for this position
must consult that volume, as it would occupy too
much space to recapitulate here. Further, that the
extent of subsidence has been very considerable.
That, in connexion with the origin of coral islands,
and barrier reefs, in the Pacific, it must have
amounted to several thousands of feet, perhaps fully
ten thousand. And it is further urged that this
change of level is not greater than the elevation
which the Rocky Mountains, Andes, Alps, and
Himalayas, have each experienced since the close
of the Cretaceous era, or the early Tertiary ; and
perhaps it does not exceed the upward bulging in
the Glacial era of part of northern North America.

Humboldt gives the briefest, and most succinct,
summary of this hypothesis, when he writes "According
to Darwin the following is the process of formation.
An island mountain closely encircled by a coral reef
subsides, while the fringing reef, that had sunk with

CORAL REEFS, AND ISLANDS. 273

it, is constantly recovering its level, owing to the
tendency of the coral animals to regain the surface,
by renewed perpendicular structures ; these con-
stitute, first a reef encircling the island at a distance,
and subsequently, when the inclosed island has
wholly subsided, an atoll. According to this view,
which regards islands as the most prominent parts,
or the culminating points of the submarine land, the
relative position of the coral islands would disclose
to us, what we could scarcely hope to discover by the
sounding line, viz., the former configuration and
articulation of the land." l

Admirable as this short outline of the theory may be
it is scarcelysufficient,andneeds to be supplemented by
Darwin's own account of his theory, as set forth in his
"Journal," and still further expanded in his larger work.

"We have seen that we are driven to believe in
the subsidence of those vast areas, interspersed with
low islands, of which not one rises above the height
to which the wind and waves can throw up matter,
and yet are constructed by animals requiring a
foundation, and that foundation to lie at no great
depth. Let us then take an island, surrounded by
fringing reefs, which offer no difficulty in their struc-
ture, and let this island with its reef, represented by
the unbroken line in the woodcut (fig. 54), slowly

1 Humboldt's "Views of Nature/' Illustrations, p. 262.
London, 1850.

T

274 TOILERS IN THE SEA.

subside. Now, as the island sinks down, either
a few feet at a time, or quite insensibly, we may
safely infer, from what is known of the conditions
favourable to the growth of coral, that the living
masses, bathed by the surf on the margin of the
reef, will soon regain the surface. The water, however,
will encroach little by little on the shore, the island
becoming lower and smaller, and the space between
the inner edge of the reef and the beach proportion-

54.

A. A. Outer edges of fringing reef.

B. B. Shores of fringed island.

Upper horizontal line showing sea level after a period of
subsidence.

ally broader. A section of the reef and island in
this state, after a subsidence of several hundred feet,
is given by the dotted lines. Coral islets are sup-
posed to have formed on the reef, and a ship is
anchored in the lagoon channel. This channel will
be more or less deep, according to the rate of
subsidence, to the amount of sediment accumulated
in it, and to the growth of the delicately-branched
corals which can live there. The section, in this
state, resembles in every respect one drawn through

CORAL REEFS, AND ISLANDS.

27*

an encircled island, in fact, it is a real section,
through Bolabola in the Pacific. We can now at
once see why encircling barrier reefs stand so far
from the shores which they front. We can also
perceive, that a line drawn perpendicularly down
from the outer edge of the new reef to the foundation
of solid rock beneath the old fringing reef, will
exceed, by as many feet as there have been feet of
subsidence, that small limit of depth at which the
effective corals can live — the little architects having

FIG. 55.

Lower horizontal line showing sea level with islets on it.
Upper horizontal line, the sea level after further subsidence,
with the reef converted into an atoll.

built up their great wall-like mass, as the whole sank
down, upon a basis formed of other corals, and their
consolidated fragments. Thus the difficulty on this
head, which appeared so great, disappears.

" Let us take our now encircling barrier reef, of which
the section -is now represented by unbroken lines, and
which, as I have said, is a real section through Bolabola,
and let it go on subsiding (fig. 55). As the barrier
reef slowly sinks down, the corals will go on vigorously

T 2

276 TOILERS IN THE SEA.

growing upwards ; but, as the island sinks, the water
will gain inch by inch on the shore, the separate
mountains first forming separate islands within one
great reef, and finally, the last and highest pinnacle
disappearing. The instant this takes place a perfect
atoll is formed ; I have said, remove the high land
from within an encircling barrier-reef, and an atoll is
left, and the land has been removed. We can now
perceive how it comes that atolls, having sprung from
encircling barrier-reefs, resemble them in general
size, form, in the manner in which they are grouped
together, and in their arrangement in single or
double lines ; for they may be called rude outline
charts of the sunken islands over which they stand.
We can further see how it arises that the atolls, in
the Pacific and Indian oceans, extend in lines parallel
to the generally prevailing strike of the high islands,
and great coast-lines of those oceans. I venture,
therefore, to affirm, that on the theory of the upward
growth of the corals, during the sinking of the land,
all the leading features in those wonderful structures,
the lagoon islands, or atolls, which have so long
excited the attention of voyagers, as well as in the
no less wonderful barrier-reefs, whether encircling
small islands, or stretching for hundreds of miles along
the shores of a continent, are simply explained." x

1 Darwin, "Journal of Researches," p. 473 (1852).

CORAL REEFS, AND ISLANDS. 277

The Duke of Argyll, when controverting the
Darwinian theory of subsidence, admits that " the
theory of the young naturalist was hailed with ac-
clamation. It was a magnificent generalisation.
It was soon almost universally accepted with admira-
tion and delight. It passed into all popular treatises,
and ever since, for the space of nearly half a century,
it has maintained its unquestioned place, as one
of the great triumphs of reasoning and research.
Although its illustrious author has since eclipsed this
earliest performance, by theories and generalisations
still more attractive, and much further reaching, I
have heard eminent men declare, that, if he had done
nothing else, his solution of the great problem of the
coral islands of the Pacific would have sufficed to
place him on the unsubmergeable peaks of science,
crowned with an immortal name." 1

Following immediately upon this concession comes
the " great lesson " which the noble Duke deems it
to be his mission to teach. "" After an interval of
more than five-and-thirty years, the voyage of the
Beagle has been followed by the voyage of the
Challenger, furnished with all the newest appli-
ances of science, and manned by a scientific staff,
more than competent to turn them to the best

1 "A Great Lesson," by the Duke of Argyll, in The Nine-
teenth Century -, No. 127. Sept. 1887, p. 300.

278 TOILERS IN THE SEA.

account. And what is one of the many results
which have been added to our knowledge of nature,
to our estimate of the true character and history of
the globe we live on ? It is that Darwin's theory is
a dream. It is not only unsound, but it is, in many
respects, directly the reverse of truth. With all his
conscientiousness, with all his caution, with all his
powers of observation, Darwin in this matter fell into
errors as profound as the abysses of the Pacific. All the
acclamations, with which it was received, were as the
shouts of an ignorant mob. It is well to know that
the plebiscites of science may be as dangerous, and
as hollow, as those of politics. The overthrow of
Darwin's speculation is only beginning to be known.
It has been whispered for some time. The cherished
dogma has been dropping very slowly out of sight.
Can it be possible that Darwin was wrong ? Must
we, indeed, give up all that we have been accepting
and teaching for more than a generation ? Reluc-
tantly, almost sulkily, and with a grudging silence, as
far as public discussion is concerned, the ugly pos-
sibility has been contemplated, as too disagreeable to
be much talked about. The evidence, old and new,
has been weighed, and weighed again, and the
obviously inclining balance has been looked at
askance many times. But, despite all averted looks,
I apprehend that it has settled to its place for ever,
-and Darwin's theory of the coral islands must be

CORAL REEFS, AND ISLANDS. 279

relegated to the category of those many hypotheses
which have, indeed, helped science for a time, by
promoting and provoking further investigation, but
which, in themselves, have now finally ' kicked the
beam.'

" But this great lesson will be poorly learnt unless
we read and study it in detail. What was the flaw in
Darwin's reasoning, apparently so close and cogent ?
Was it in the facts, or was it in the influences ? His
facts in. the main were right ; only it has been found
that they fitted into another explanation better than
into his. It was true that the corals could only grow
in a shallow sea, not deeper than from twenty to
thirty fathoms. It was true that they needed some
foundation provided for them, at the required depth.
It was true that this foundation must be in the pure
and open sea, with its limpid water, its free currents,
and its dashing waves. It was true that they could
not flourish, or live in lagoons, or in channels, however
wide, if they were secluded and protected from
oceanic waves. One error, apparently a small one,
crept into Darwin's array of facts. The basis, or
foundation, on which corals can grow, if it satisfied
other conditions, need not be solid rock. It might
be deep-sea deposits, if these were raised or elevated
near enough the surface. Darwin did not know this,
for it is one of his assumptions that coral ' cannot
adhere to a loose bottom.' The Challenger obser-

280 TOILERS IN THE SEA.

vations show that thousands of deep-sea corals, and
of other lime-secreting animals, flourish on deep-sea
deposits, at depths much greater than those at which
true reef-building species are found. The dead
remains of these deeper-living animals, as well as the
dead shells of pelagic species, that fall from the sur-
face waters, build up submarine elevations towards
the sea-level. Again, the reef-building coral will
grow upon its own debris, — rising, as men, morally
and spiritually, are said by the poet to do, —

"'On stepping-stones of their dead selves to higher things.'

This small error told for much ; for if coral could
grow on deep-sea deposits when lifted up, and if
it could also grow seaward, when once established,
upon its own dead and sunken masses, then sub-
marine elevations, and not submarine subsidences,
might be the true explanation of all the facts. But
what of the lagoons, and the immense areas of sea
behind the fringing reefs? How could these be
accounted for? It was these which first impressed
Darwin with the idea of subsidence. They looked
as if the land had sunk behind the reef, leaving a
space into which the sea had entered, but in which
no fresh reefs could grow. And here we learn the
important lesson, that an hypothesis may adequately
account for actual facts, and yet, nevertheless, may
not be true. A given agency may be competent to

CORAL REEFS, AND ISLANDS. 281

produce some given effect, and yet that effect may
not be due to it, but to some other. Subsidence
would, or might, account for the lagoons, and for the
protected seas, and yet it may not be subsidence
which has actually produced them.

" Darwin's theory took into full account two of the
great forces which prevail in nature, but it took no
account of another, which is comparatively incon-
spicuous in its operations, and yet is not less power-
ful than the vital energies, and the mechanical
energies, which move and build up material. Darwin
had thought much and deeply on both of these.
He called on both to solve his problem. To the
vital energy of the coral animals he rightly ascribed
the power of separating the lime from the sea-water,
and of laying it down again in the marvellous struc-
tures of their calcareous homes. In an eloquent and
powerful passage, he describes the wonderful results,
which this energy achieves, in constructing break-
waters, which repel and resist the ocean, along
thousands of miles of coast. On the subterranean
forces which raise, and depress, the earth's crust he
dwelt, — at least enough. But he did not know,
because the science of his day had not then fully
grasped, the great work performed by the mysterious
power of chemical affinity, acting through the cog-
nate conditions of aqueous solution. Just as it did not
occur to him that a coral reef might advance steadily

282 TOILERS IN THE SEA.

seaward, by building ever fresh foundations on its
own fragments, when broken and submerged, or that
the vigorous growth of the reefs, to windward, was
due to the more abundant supply of food, brought to
the reef-building animals from that direction, by
oceanic currents, so did it never occur to him that it
might melt away to the rear, like salt or sugar, as the
vital energy of the coral animals failed, in the shel-
tered and comparatively stagnant water. It was that
vital energy alone, which not only built up the living
tubes and cells, but which filled them with living
organic matter, capable of resisting the chemical
affinities of the inorganic world. But when that
energy became feeble, and when at last it ceased, the
once powerful structure descended again to that
lower level of the inorganic, and subject to all its
laws. Then, what the ocean could not do, by the
violence of its waves, it was all-potent to do by the
corroding and dissolving power of its calmer lagoons.
Ever eating, corroding, and dissolving, the back
waters of the original fringing reef — the mere pools
and channels left by the outrageous sea, as it dashed
upon the shore — were ceaselessly at work, aided by
the high temperature of exposure to blazing suns,
and by the gases evolved from decaying organisms.
Thus the enlarging area of these pools and channels
spread out into wide lagoons, and into still wider
protected seas. They needed no theory of subsidence

CORAL REEFS, AND ISLAiVDS. 283

to account for their origin or for their growth. They
would present the same appearance in a slowly-
rising, a stationary, or a slowly-sinking area. Their
outside boundary was ever marching further outward,
on submarine shoals and banks, and ever, as it
advanced in that direction, its rear ranks were melted
and dissolved away. Their inner boundary — the
shores of some island, or of some continent — might
be steady and unmoved, or it might be even rather
rising instead of sinking. Still, unless this rising
were such as to overtake the advancing reef, the
lagoon would grow, and if the shores were steady, it
would widen as fast as the face of the coral barrier
could advance. Perhaps, even if such a wonderful
process had ever occurred to Darwin, — even if he
had grasped this extraordinary example of the ' give
and take' of nature, — of the balance of opposing
forces, and agencies, which is of the very essence of
its system, he would have been startled by the vast
magnitude of the operations which such an explana-
tion demanded. In its incipient stages this process
is not only easily conceivable, but it may be seen in
a thousand places, and in a thousand stages of
advancement There are islands, without number, in
which the fringing reef is still attached to the shore,
but in which it is being 'pitted,' holed, and worn
into numberless pools on the inner surfaces, where
the coral is in large patches dead or dying, and where

284 TOILERS IN THE SEA.

its less soluble ingredients are being deposited in the
form of coral sand. There are thousands of other
cases where the lagoon interval, between the front of
the reef and the shores, has been so far widened that
it is taking the form of a barrier, as distinguished
from a fringing reef, and where the lagoon can be
navigated by small boats. But when we come to
the larger atolls, and the great seas included between
a barrier reef and its related shores, the mind may
well be staggered by the enormous quantity of
matter, which it is suggested has been dissolved,
removed, and washed away. The breadth of the
sheltered seas, between barrier reefs and the shore, is
measured in some cases not by yards, nor hundreds of
yards, not by miles, but by tens of miles, and this
breadth is carried on in linear directions, not for
hundreds of miles, but for thousands. And yet
there is one familiar idea in geology which might
have helped Darwin, as it is much needed to help us,
even now, to conceive it. It is the old doctrine of
the science, long ago formulated by Hutton, that the
work of erosion, and of denudation, must be equal to
the work of deposition. Rocks have been formed
out of the ruins of older rocks, and those older rocks
must have been worn down, and carried off, to an
equivalent amount. So it is here, with another kind
of erosion, and another kind of deposition. The
coral building animals can only get their materials

CORAL REEFS, AND ISLANDS. 285

from the sea, and the sea can only get its materials
by dissolving it from calcareous rocks of some kind.
The dead corals are amongst its greatest quarries.
The inconceivable, and immeasurable quantities, which
have been dissolved out of the lagoons, and sheltered
seas of the Pacific, and of the Indian Ocean, are not
greater than the immeasurable quantities which are
again used up, in the vast new reefs of growing coral,
and in the calcareous covering of an inconceivable
number of other marine animals."

Such a conception the noble Duke thinks may
"not be so imposing as that of a whole continent
gradually subsiding, of its long coasts marked by
barrier reefs, of its various hills, and irregularities of
surface, marked by islands of corresponding size, and
finally, of the atolls indicating where its highest
peaks finally disappeared beneath the sea. But, on
the other hand," he considers, " the new explanation
more like the analogies of nature, — more closely
correlated with the wealth of her resources, with
those curious reciprocities of service, which all her
agencies render to each other, and which indicate so
strongly the ultimate unity of her designs."

We have considered it advisable to give in full, and
in his own language, the impeachment of Darwin's
theory, and elucidation of his own, which the noble
author has advanced. Albeit, it is confessed, that for
the new theory he is indebted to Mr. John Murray,

286 TOILERS IN THE SEA.

one of the naturalists of the Challenger expedition,
as will be apparent from the subjoined extract, which
sets forth briefly the views entertained by him on the
subject, and at first communicated to the Royal
Society of Edinburgh, in 1880.

" According to Mr. Murray, the observations of the
reefs at Tahiti support the view that the reefs have
been built from the shore seawards, and that the
lagoons have been, and are still being, formed by the
removal of the inner, and dead portions of the coral
reef, by the solvent action of sea water. The islands
in the harbour, and lagoons, are regarded as portions
of the reef which have been left standing, but will
ultimately be removed, and, in confirmation of this, it
is pointed out, that on the inner part of the reef there
are large and massive specimens of the coral which
are now dead, but which probably flourished at the
time when the outer edge of the reef was at the
position in which they are now found. The steep
slope which is found on the outer edge of the reef,
between the depths of 35 and 200 fathoms, is
believed to be formed by huge masses and heads of
coral, which have been torn away from the ledge,
between the edge of the reef and 35 fathoms, during
storms, or by overhanging masses which have fallen
by their own weight. In this way a talus has been
formed on which the corals, living down to 35 fathoms,
have found a foundation on which to build further

CORAL REEFS, AND ISLANDS. 287

seawards, for this seaward slope is the great growing
surface of the reef. The food supply for the masses
of living coral, on the outer slope of the reef, is
brought by the oceanic currents sweeping past the
islands, a fact in relation with the more vigorous
growth of the reef on the windward sides. It is
maintained by Mr. Murray that the whole of the
phenomena of the Tahiti reefs may be fully explained,
by reference to the processes at present in action,
and without calling in the aid of subsidence, as is
done by Darwin and Dana, and, it is argued further,
that the form of atoll, and barrier reefs generally, can
be explained on the same principles." l

Having endeavoured, without prejudice, to set
forth the theory propounded by Darwin, and sup-
ported by Dana, and others, as well as the counter-
theory, advanced by Murray, and advocated by the
Duke of Argyll, it will be expected of us to impart
the result of our own convictions in a few concluding
lines. Those who followed the controversy in the
pages of Nature, and elsewhere, need not to be
reminded that the verdict of just those scientific
men who were most capable of judging, was not
heard, in condemnation of the hypothesis advanced

1 " Narrative of the Voyage of the Challenger" vol. i. p.
781 (1885) ; also "On the Structure and Origin of Coral Reefs
and Islands," by John Murray, in Proc. Roy. Soc. Edin., x.
p. 505 (1880).

288 TOILERS IN THE SEA.

by Darwin, and in support of that proposed by
Murray. It was evident that the new theory failed
to satisfy the majority, it being insufficient to account
for all the phenomena, as the old theory had done.
Without actually calling in question the facts, the
inferences were not held to be warranted, and there
were still remaining certain phenomena which the
new theory could not account for.

This reminds us of some observations made by
Professor Huxley on the subject of hypotheses, which
should always be borne in mind. "Wherever," he
says, " there are complex masses of phenomena to be
inquired into, whether they be phenomena of the
affairs of daily life, or whether they belong to the
more abstruse and difficult problems laid before the
philosopher, our course of proceeding in unravelling
that complex chain of phenomena, with a view to get
at its cause, is always the same ; in all cases we must
invent an hypothesis ; we must place before ourselves
some more or less likely supposition respecting that
cause; and then, having assumed an hypothesis,
having supposed a cause for the phenomena in ques-
tion, we must endeavour, on the one hand, to
demonstrate our hypothesis, or, on the other, to upset
and reject it altogether, by testing it in three ways.
We must, in the first place, be prepared to prove
that the supposed causes of the phenomena exist in
nature, that they are what the logicians call vera

CORAL REEFS, AND ISLANDS. 289

caus<z> — true causes ; in the next place, we should
be prepared to show that the assumed causes of the
phenomena are competent to produce such phe-
nomena as those which we wish to explain by them ;
and in the last place, we ought to be able to show
that no other known causes are competent to produce
these phenomena. If we can succeed in satisfying
these three conditions we shall have demonstrated our
hypothesis ; or rather, I ought to say, we shall have
proved it as far as certainty is possible for us ; for,
after all, there is no one of our surest convictions
which may not be upset, or, at any rate, modified by
a further accession of knowledge." l And again : —
" Every hypothesis is bound to explain, or at any
rate, not be inconsistent with, the whole of the facts
which it professes to account for ; and if there is a
single one of these facts which can be shown to be
inconsistent with the hypothesis, the hypothesis falls
to the ground — it is worth nothing. One fact with
which it is positively inconsistent is worth as much,
and as powerful in negativing the hypothesis, as five
hundred." Tested by these obligations, it hardly
seems clear that the new hypothesis is competent to
supersede the old one. At least it is by no means so

1 " On our Knowledge of the Causes of the Phenomena of
Organic Nature." By Professor J. Huxley. London, 1863,
P- 135.

U

-290 TOILERS IN THE SEA.

perfect a hypothesis, it does not reconcile so many
facts, or account for so many phenomena, and, pro-
vided that the new facts are established, it is by no
means certain that they are inconsistent with the
original hypothesis of subsidence. If the new hypo-
thesis is really so much more conclusive, so much
more feasible, so much more consistent than the old
one, how does it happen that it has failed, and still
continues to fail, in securing the support of the think-
ing and reasoning public, especially that portion
which are specially interested, and most competent
to judge ? Surely, if the theory had been so clear,
so convincing, so evident, as some have contended, a
period of eight years is sufficient to have established
It in public opinion. Whatever its ultimate destiny
may be, we recognise no valid reason, at present, for
rejecting the hypothesis of Darwin and Dana, in
favour of that propounded, or supported, by Murray
and Argyll.

TOILERS IN THE SEA. 291

CHAPTER IX.

SEA-MAT MAKERS.

ONE of the most common experiences of a sea-
side collector is to pick up a dead frond of the
larger sea-weeds, or a tuft of the smaller ones, wholly,
or only partially, invested with an encrusting patch,
of a dirty-white-colour, evidently of quite a different
character from the sea-weed on which it has become
established ; and, if examined by the pocket-lens, will
be found to consist of a great number of horny cells,
each with a small opening or mouth, and, in some
species, furnished with long rigid bristles, so as appear
even to the naked eye to be hairy. These were once
the homes of minute marine Polyzoa, kindred to the
sea-mats, the latter differing from the former in not
encrusting other substances, but forming a kind of
frond, or tuft of fronds, of their own. The Polyzoa,
or as some persons persist in calling them, the Bryo-
zoa, are for the most part marine, although there is a
small group, well known to pond-hunters, which in-
habit fresh water ; in all of them the animals are

U 2

292 TOILERS IN THE SEA.

small, but the colonies, or aggregations of individuals,
are often of considerable size. All of them appear
to be gregarious, flourishing in companies, and the
number of species must be very large, for they
have a wide, and almost unlimited, distribution.
Along our own shores it would be difficult to
say where we should find no trace of them. Some
of the encrusting species are found flourishing
on almost every dead shell, and often whilst the
mollusk is still living ; others flourish on stones and
rocks which are submerged, and a large number
attach themselves to sea-weeds. They will be found
encrusting wood, stones, crabs, lobsters, or attached
to zoophytes, or even other species of Polyzoa, and
indeed seem to be almost ubiquitous in the sea. Their
general structure it must be our first endeavour to
attempt to elucidate.

There is a superficial resemblance in some of the
species to the common Hydroid zoophytes, but, ex-
amined more closely, the animal will be found to be of
the molluscan type, and not that of the Hydroids.

Elsewhere we have given a summary of the general
type of Polyzoon,1 after Professor Allman, to the
following effect : — " Let us imagine an alimentary
canal, consisting of oesophagus, stomach and intestine,

1 "Natural History Rambles : Ponds and Ditches," p. 132,
1880.

SEA-MA T MAKERS.

293

to be furnished at its origin with long ciliated ten-
tacles, and to have a single nervous ganglion situated
on one side of the oesophagus (fig. 56). Let us now
suppose this canal to be bent back upon itself, towards
the side of the ganglion, so as to
approximate the termination to the
origin. Further, let us imagine the
digestive tube, thus constituted, to
be suspended in a fluid, contained
in a membraneous sac, with two
openings, one for the mouth and
the other for the vent, the ten-
tacles alone being external to the
sac. Let us still further suppose
the alimentary tube, by means of
a system of muscles, to admit of
being retracted or protruded, ac-
cording to the will of the animal,
the retraction being accompanied
by an invagination (or folding inwards) of the sac, so as
partially, or entirely, to include the oral tentacles within
it, and if to these characters we add the presence of
true sexual organs, occupying some portion of the in-
terior of the sac, and the negative character of the
absence of all vestige of a heart, we shall have, per-
haps, as correct an idea as can be conveyed of the
essential structure of a Polyzoon, in its simplest and
most generalised condition."

FIG. 56.
TYPICAL POLYZOON.

294 TOILERS IN THE SEA.

The cell, or polype home (called scientifically
Zoceciuni), has a double cell-wall, enclosing the initial
polyzoon. The outer coat is a chitinous, or horny,
membrane, thickened and strengthened, in most cases,
by deposits of lime or flint, then forming a solid wall,
externally often ornamented or embossed, but occa-
sionally it retains its membraneous character. The
colony consists of a number of these cells, attached
together in a variety of ways, but produced by con-
secutive budding, or gemmation, from the original
cell. Communication is maintained between the
several cells of the colony, through thin perforated
plates in the outer wall, called " communication-
plates." Through the minute perforations in these
plates thread-like connectors pass from animal to
animal, and thus all the polypes in a colony are linked
together. The function of this outer wall, then, is
the protection of the enclosed polype.

The inner wall of the cell is a soft living mem-
brane, which lines the more or less solid outer wall,
and is supposed to be intimately associated with all
budding processes which subsequently take place.
It will be sufficient here to regard it as the soft lining
of the walls of the house which contains the living
Polyzoon.

The animal is crowned with a wreath of tentacles,
which are seated on a circular disc, surmounting the
body, with the mouth in the centre (fig. 57). These

SEA-MA T MAKERS. 295;

tentacles when expanded form a bell-shaped wreath,
and are slender hollow filaments, with a line of movable
cilia down two opposite sides, which, by their inces-
sant motion, cause an inward current of the water,
and sweep the floating particles of
food into the mouth at the centre.
In number the tentacles vary from
eight to eighty, and are very ener-
getic in their movements. They
are probably the sole organs of
touch which the animals possess.

The sheath is a membraneous
extension, from the upper extremity
of the polype cell, to the base of
the crown of tentacles, when ex-
panded, and when the tentacles are
drawn in the sheath is drawn in
with them. " The invagination of
the sheath is due to its attachment, FIG. 57.

at its upper extremity, round the BRANCHED TUBULAR

7 ' POLYZOA

base of the crown of tentacles ; (Fredericella\
as the latter descends, in obedi-
ence to the summons of the retractor muscles, it Is>.
of course, drawn down with it, and reversed as<
the finger of a glove might be under similar circum-
stances, forming a protective case around it, which
sometimes exceeds it in length. By this arrange-
ment the cell (Zocscium] is completely closed ; there

296 TOILERS IN THE SEA.

is no real opening through which the polype passes.
It is the upward movement of the tentacular crown
which carries with it, and everts, the flexible sheath,
and so permits the imprisoned zooid a certain amount
of communication with the outer
world ; but the cavity of the cell
itself is sealed. The movements
of the polype, in the acts of expan-
sion and retraction, are limited to
the eversion and inversion of the
sheath ; and only the crown is
brought into immediate contact
with the surrounding water " 1
(fig. 58).

There is nothing which calls
for special notice, or description,
here of the stomach and its diges-
tion, of the nervous or muscular
system, and other minute ana-
FIG. 58. tomical details, which would be

POLYZOA essential for the student, but

(Paludicella).

rather let us seek to learn some-
thing of the " brown bodies " as they are called, which
have been the cause of considerable controversy.
Let us take, for example, one of the erect growing

1 "History of the British Marine Polyzoa," by Thomas
Hincks, London, 1880, vol. i. p. 17.

SEA-MA T MAKERS. 297

Polyzoa, with somewhat the form of a zoophyte. The
terminal and outside cells will be those of young
polypes, and under, or adjoining these, mature and
vigorous individuals, below these will be found cells
for the most part destitute of tenants. In the
majority of these dead cells will be found a dark
spherical body, of brownish substance, enclosed
within a membraneous cyst, or bladder, and this has
been called the " brown body " ; two or more may
be found in the same cell. What are these " brown
bodies," and what are their functions? "They
have been regarded as the remains of dead polypes,
as ova, as ovaria, as statoblasts, as a secretion from
the endocyst, as a store of nutriment for the young
polypes, as a reproductive body formed out of the
stomach of the decaying polype."1 Observers are
generally agreed in that it is derived from the sub-
stance of the polype. Certain writers have contended
that it is nothing more than the remains of the old
polype, only a mass of inert material, waiting to be
ejected from the cell. Whatever it may prove to be,
it has undoubtedly been derived from the polype,
which inhabited the cell, and is the result of its
decline. Another class of authors contend that the
" brown body" is capable of originating a new

1 See "Contributions to the History of the Polyzoa," by
T. Hincks, in Quart. Journ. Micr. Science, vol. xiii. (n.s.) p. 24.

298 TOILERS IN THE SEA.

polype. This view seems to have the preponderance
of evidence in its favour. One author claims to
have traced the formation of a bud on the " brown
body," and, as it seemed, out of its very substance.
Mr. Hincks says that, " repeatedly I have seen gem-
mation taking place, in the closest proximity to the
surface of the " brown body," and the bud, as I was
fully persuaded at the time, was continuous with
it, and a growth out of it." " Another point my
observations seemed to me to have established, — that
the polypes developed from the (so-called) germ
capsule, differ in appearance during their early stages
from those which are found in the young marginal
cells of the colony, and from other buds which occur
in the adult polype cell (Zocecid], The latter are
destitute of the reddish-brown colour, imparted to the
stomach wall at a later period by the biliary glands,
whilst the former, being a growth out of the brown
body, possess it from the first.0 To these views it
has been objected that the bud is not developed from
the " brown body," but from the living substance
which surrounds it ; and that at a certain stage the
bud approaches the " brown body," extends its sub-
stance over it, and finally lodges it in its stomach,
the walls of which completely close around it. Thus
engulfed, it serves as a store of nutriment for the
growing structure. As a summary of what appears
to have been ascertained, Mr. Hincks concludes.

SEA-MA T MAKERS. 299

"the following points may be taken as established : —
(i.) The brown body is universally derived from the
substance of the histolyzed polype. (2.) It is
always attached (when occupying its original position)
to the funiculus, and more or less invested by the
funicular plexus. (3.) Buds for the production of a
new polype are very commonly developed in the
closest proximity to it, and on its surface. (4.) They
also originate in various positions, and at greater or
less distances from the brown body. (5.) In some
species the latter is enveloped by the neighbouring
bud, and passes into the digestive canal, being ulti-
mately expelled through the intestine, either entire,
or after having undergone dissolution in the stomach.
(6.) There may be several brown bodies in a cell ;
and in some cases they lie loose in the perivisceral
cavity near the bottom of it."1 Hence the final
issue has apparently still to be decided, and the con-
tradictory facts reconciled, that the same body may,
in some cases, be an important reproductive factor,
and at another ejected as mere rubbish.

Singular appendages, called " birdVhead pro-
cesses," are found attached to the sides of the cells
in some species of the Sea-mats. Their functions are
very imperfectly known, but their appearance at-
tracted the attention of Darwin when on his voyage,

1 Hincks, " British Polyzoa," vol. i. p. 63.

TOILERS IN THE SEA.

and his remarks are still applicable He says, — " The
organ, in the greater number of cases, very closely
resembles the head of a vulture (fig. 59) ; but the
lower mandible can be opened
much wider, so as to form even
a straight line with the upper.
The head itself possesses consi-
derable powers of movement, by
means of a short neck. In one
zoophyte the head itself was
fixed, but the lower jaw free ;
in another it was replaced by
a triangular hood, with a beau-
tifully - fitted trap - door, which
evidently answered to the lower
mandible. A species of stony
Eschara had a structure some-
what similar. In the greater
number of species, each cell was
provided with one head, but in
others each had two.

" The young cells at the end
of the branches necessarily con-

^.^ ^ immature polypes,

yet the vulture-heads attached to them, though small,
were in every respect perfect. When the polyp was
removed by a needle, from any of the cells, the
organs did not appear in the least affected. When

FIG. 59-
CELLULARIA AVICULARIA.

SEA-MA T MAKERS. 301

one of the latter was cut off from a cell, the lower
mandible retained its power of opening and closing.
Perhaps the most singular part of their structure is,
that when there were more rows of cells than two,
the central cells were furnished with these appen-
dages, of only one-fourth the size of the lateral ones.
Their movements varied according to the species ;
in some I never saw the least motion ; while others,
with the lower mandible generally wide open, oscil-
lated backwards and forwards, at the rate of about
five seconds each turn ; others moved rapidly and
by starts. When touched with a needle the beak
generally seized the point so firmly, that the whole
branch might be shaken.

" These bodies have no relation whatever with the
production of the gemmules. I could not trace any
connexion between them and the polyp. From
their formation being completed before that of the
latter ; from the independence of their movements ;
from the difference of their size in different parts of
the branch :— I have little doubt that in their functions
they are related rather to the axis than to any of the
polyps."

He then proceeds to notice another kind of struc-
ture which is analogous to the vulture-heads, and
which some naturalists consider to be only a form or
modification of4 the " bird's-head processes." He pro-
ceeds : — " A small and elegant species is furnished,

302 TOILERS IN THE SEA.

at the corner of each cell, with a long and slightly
curved bristle, which is fixed at the lower end by a
joint. It terminates in the finest point, and has its
outer, or convex, side serrated with delicate teeth or
notches. Having placed a small piece of a branch
under the microscope, I was exceedingly surprised
to see it suddenly start from the field of vision, by
the movement of these bristles, which acted as oars.
Irritation generally produced this motion, but not
always. When the coral was laid flat on that side
from which the toothed bristles projected, they were
necessarily all pressed together and entangled. This
scarcely ever failed to excite a considerable move-
ment among them, and evidently with the object of
freeing themselves. In a small piece which was
taken out of water, and placed on blotting-paper, the
movements of these organs were clearly visible for a
few seconds by the naked eye.

" In the case of the vulture-heads, as well as in
that of the bristles, all that were on one side of the
branch, moved sometimes co-instantaneously, some-
times in regular order, one after the other ; at other
times the organs on both sides of the branch moved
together ; but generally all were independent of each
other, and entirely so of the polyps. If the bristles
were excited to move, by irritation, in any one
branch, generally the whole zoophyte was affected.
In the instance where the branch started from the

SEA-MAT MAKERS.

303

simultaneous movement of these appendages, we
see as perfect a transmission of will as in a single
animal."1

3

FIG. 60. — CELLULARIA CILIATA.
(a) Natural size. (b] Magnified. (g) Bird's-head process.

The " bird's-head processes " are not present in all
species, nor on all specimens of the same species,
and when they are present it is only in connexion

1 Darwin, " Voyages of Adventure and Beagle? vol. iii.
p. 259.

304 TOILERS IN THE SEA.

with some of the cells (fig. 60). They are classified by
Krohn under three kinds. Those which constitute
the proper " bird's-head process," those which re-
semble pincers, and those which partake of the form
of bristles or hairs. Van Beneden traced their
growth and development, without obtaining any clue
to their use or purpose. Dr. Reid describes the
bristles in a common British species thus : — " At the
anterior part of the outer side of each cell (in Cellu-
laria scruposd] and immediately in front of the tooth-
like process there attached, are two pretty long
spines, and a rounded process, which tapers slightly
from its fixed to its free extremity. This rounded
process is open at the top, and is hollow in dead
specimens, but when alive it is full of a contractile
substance. In this contractile substance the end of
a hair-like curved filament, about the length of the
cell, is immersed. This hair-like filament is moved
about, by the contractile substance attached to it,
generally in jerks, after intervals of repose, and in
its movements sweeps the anterior and posterior
surfaces of the cell to which it is fixed. These
movements continue for a considerable time after
the animal inhabiting the cell has been dead. A
hollow rounded process, with a hair-like curved and
moveable filament projecting from it, is also fixed
upon the corresponding part of each cell. These
moveable hair-like filaments are analogous to the

SEA-MA T MAKERS. 305

moveable bird's-head process attached to each of the
cells of the sea- mat (f lustra avicularis}"^

Mr. Hincks has traced the modification of the
avicularium and vibraculum, as these processes are
called, in a large number of species, and came to the
conclusion that they are, morphologically, to be
regarded as metamorphosed polype-cells (Zocecia).
" Every avicularium," he contends, " consists of a
chamber, of variable size and shape, in which is
lodged an apparatus of muscles, of a moveable horny
appendage, which is worked backwards and forwards
by the muscles, and of a fixed frame opposed to it,
surrounding an aperture, upon which it falls when
closed. In many cases, if not all, the chamber also
contains a cellular body, which is in all probability
the homologue of a polypide." It is hardly necessary
to follow him through the various modifications of
these appendages, although casually there would
appear to be a very great difference, almost devoid
of any similarity of appearance, between the lowest
and most imperfectly developed forms, and the
genuine bird's-head processes.

" The function of the avicularia," he says, " it is diffi-
cult to determine, nor, indeed, can the same function
be assigned to all of them. The primary forms are
many of them quite unfit for prehensile work. The

Johnston, "British Zoophytes," vol. i. p. 333.
X

3o6 TOILERS IN THE SEA.

lid-like mandible, with plain rounded margin, has
no power of grasping, and could not detain for a
second the active worms which are sometimes cap-
tured by the articulated kinds. Their service for
the colony must lie in some other direction. Even
the fixed transitorial forms, in which the beak and
curved mandible are present, must be inefficient for
this work, from their want of mobility, whilst in
many of them the parts concerned in the act of
prehension are but slightly developed. The articu-
lated avicularia, however, are undoubtedly grasping
organs ; and the presence of the tactile tuft, between
the jaws, must be taken to indicate that capture in
some form or other is their function. They have
been seen to arrest minute worms, and hold them
for a considerable time with a tenacious grip, as if
with some ulterior object ; but what the object may
be it is difficult to decide. On the whole, I am
inclined to regard the avicularia as charged with a
defensive rather than an alimentary function. They
may either arrest, or scare away, unwelcome visitors.
Their vigorous movements, and the snapping of their
formidable jaws, may have a wholesome deterrent
effect on loafing annelids, and other vagrants ;
whilst the occasional capture of one of them may
help still further to protect the colony from dan-
gerous intrusion." The vibraculum, or moveablc
bristle, is related to the avicularium, and a line of

SEA-MA T MAKERS. 3077

transition- forms link the two together. The setae-
are sometimes of enormous size, and of great strength,
and in certain species assume a locomotive function
acting probably as oars, and propelling the colony
which in that particular group are free in the adult
state. This justifies the remark that " in the history
of these appendages we have a curious illustration:
of the variety of function that may connect itself
With the same morphological element."

Reproduction is secured in these Polyzoa by two
methods, by regular sexual elements, and by the
asexual method of budding, or gemmation. The
majority of species are monaecious, male and female
organs being present in each cell, but some species
are unisexual, either wholly male or wholly female,
A contractile cord, called the funiculus, is attached
to the bottom of the stomach, and passes down to the
bottom of the cell. It is considered an established fact
that the male elements are derived universally from
this funiculus, and in a great number of species the
ova are also developed in the funiculus, sometimes
apart from this organ, and sometimes attached to the
cell-wall. It is still a question whether the ova are
fertilised by male elements, developed in the same
cell, or whether by those liberated from other cells.
Their dispersion in immense numbers into the sur-
rounding water seems to indicate the latter conclu-
sion, and it is not improbable that in different

X 2

308 TOILERS IN THE SEA.

species both methods may prevail. We cannot be
expected to discuss at length, and in detail, a point
of this character in a work like the present, but
would refer those interested in the subject to the
Introductory chapter of the volume already quoted.1
The ovary varies considerably in size ; in some
species it contains as many as thirty eggs, in others
only one or two. At a certain stage of maturity they
make their escape, through the ruptured wall of the
ovary, into the space between the polype and the
inner wall of the cell. After fertilisation the ova pass
through the ordinary phenomena of segmentation,
and are developed into free ciliated larvae. In some
species there is developed, during the breeding season,
a small somewhat globose appendage to the mother-
cell, called an ovicell, the interior of which is in direct
communication with the internal cavity of the mother-
cell. At first the ovicell is empty, afterwards it is
occupied by the embryo. Huxley was the first to
observe that impregnation takes place in the cavity
of the cell, and then the egg passes from thence into
the ovicell, where, as in a marsupial pouch, it under-
goes its further development, and after undergoing
yelk-division becomes a ciliated embryo.2 Mr. Hincks

1 Hincks, "British Marine Polyzoa." London, 1880.

2 J. H. Huxley on " Reproductive Organs of the Cheilostome
Polyzoa/' in Quart. Jour. Micr. Soc., vol. iv. (1856), p. 191.

SEA-MA T MAKERS. 309

adds, that " there can be no doubt that the ova
generated in the mother-cell (Zo&cium] do pass into
the ovicell, and there ripen into the perfect larva,
escaping at last through the orifice. The ovicell is
thus both a brood-chamber, and the passage for the
embryo from the cell to the surrounding water. But
whilst I have no doubt that the ovicell acts as a kind
of marsupium, there seems to me to be grounds for
believing that, in some cases and under conditions
which I cannot explain, ova are also produced
within it."

The larvae, developed from the eggs, and which
are the units of a new polyzoan colony, are very
variable in form and complex in structure. They
*' are restless in their habits, and during their short
term of free existence, are in almost constant move-
ment— now whirling rapidly hither and thither, now
tumbling over and over in the water, now creeping
along, making use of their cilia as feet. Besides their
ciliary appendages, they are often furnished with long
setiform processes, which wave to and fro, and lash
the water with much vehemence. After a while their
energies fail, and they settle down and become
attached ; the cilia begin to flag in their movements,
and soon disappear ; and the volatile, and curiously
organised being, resolves itself into a fixed and (ap-
parently) homogeneous mass, in which the first
polyp-cell (ZocEciiuri) and polypide originate."

TOILERS IN THE SEA.

Reproduction by gemmation, or budding, is con-
stantly in progress, and by this means the plant-like
forms of the erect branched colonies, the frond-like
-expansions of the sea-mats, and the flat patches of
the encrusting colonies are formed. From the initial
cell, which is the commencement of the colony, other

cells are developed
by budding, after the
manner of the par-
ticular species, either
longitudinally or at
the margins, and,
gradually, the colony
enlarges and in-
creases the outer
cells, being the
youngest, in a man-
analogous to

•;FIG. 6 1.— SEA-MAT (Flustra foliacea].

ner

that in which the
coral colony is in-
creased. As we look upon a frond of the common
-sea-mat (Flustra foliacea} with its myriads of little
cells (fig. 61), we may recall the fact that, once on
a time, this frond was represented by a single mother-
cell, and that, by continuous and consecutive budding,
all those innumerable cells have been added, until
$he single cell has multiplied into a large colony, the
^polypes at the base having long since died, leaving

SEA-MAT MAKERS,

their empty cells as mementoes, whilst the marginal
cells are not only living, but at the extreme margin
still budding extremely juvenile cells, and thus the
process continues to go on, so long as the colony, in
its entirety, is in a living and thriving condition. In
the encrusting spe-
cies, many of them
go on depositing a
thick layer of cal-
careous matter, until
the outer wall ac-
quires much thick-
ness and strength.

The latest enume-
ration gives no less
than two hundred
and thirty-five spe-
cies as inhabitants
of the British coasts,
and some of these
are extremely com-
mon. The dead
skeletons, or tenantless homes, are cast upon the beach
by every storm, and these objects must be familiar
to every lounger on the shore. One of the largest,
most plentiful (figs. 61, 62), and most popular is the
common sea-mat (Flustra foliaced], which is sure to
be picked up, with the residue of that odd miscellany

"FIG. 62.— SEA-MAT (Flustra foliacea).

312 TOILERS IN THE SEA.

of mementoes, which every one brings home from the
sea-side. Mingled with shells, bits of sea-weed, star-
fish, zoophytes, &c., is always the inevitable sea-
mat, and yet how few trouble themselves about the
animals that constructed those tiny dwellings, and
inhabited them, increasing and multiplying till the
little one became a thousand, and the single cell a
great colony. It may be somewhat conducive to its
popularity that it has a pleasant odour when fresh
out of the water, which some compare to that of
violets, others to bergamot, or the mixed odour of
roses and geraniums. Sir John Dalzell states that
he has known no less than ten thousand young
embryos to have been liberated from a single speci-
men of this sea-mat, during the course of three hours.
Growing upon, and attached to, this species, a much
smaller one should be carefully sought for (Bugula
avicularia), because it is often found in that position,
and because it will exhibit those curious bird's-head
processes, to which allusion has been made. They
will be dead, as a matter of course, and all the snap-
ping over, but the birds' heads will still remain, and
imagination will readily picture them, in all the snap-
ping energy of their original vitality.

Another characteristic Polyzoon will be found
encrusting tufts of red sea-weeds, sometimes com-
pletely coating them, and bristling with long setae
( Membranipora pilosa] (fig. 63). " Its little cells have

SEA-MAT MAKERS.

313

a metallic lustre, and almost look as if they were
wrought in silver and richly chased." It is one of
the most abundant of British Polyzoa.

Other encrusting
species, belonging to
different genera, will
be found forming
greyish, or whitish,
patches on stones,
rocks, shells, &c., but
the description or
enumeration of these
belongs not to our
province. We have
indicated a wide
field for investiga-
tion, and given an

introduction tO tWO FIG> 63.-MEMBRANIPORA.

hundred and thirty-
five minute British animals that construct their
homes in the sea, and all differing in some respect
from each other in the form or decoration of the
houses that they inhabit.

TOILERS IN THE SEA.

CHAPTER X.

TUBE-MASONS.

r I ^HOSE interesting insects, which are commonly
known as Caddis-flies, make for themselves,
when in the larval stage, minute tubes or cases, of
many kinds of material, agglutinated together into
the form of a tube ; sometimes it is chiefly of sand,
or small fragments of shells, and sometimes of frag-
ments of leaves, bark, or twigs. They are found in
ponds, and slow-flowing canals, and the architects are
larval insects of the order Trichoptera.1 Analogous
to these fresh-water cases we have also builders of
marine cases or tubes, not the construction of insects,
but of annelids or worms. In the caddis-case a
temporary home is constructed, for a temporary pur-
pose, and then abandoned, but the marine masons
built their habitations for life, and do not usually
quit them till they die. Nevertheless, with all their
differences, there is an evident analogy between the

1 See " Caddis-worms and their Cases," by R. McLachlan,
F.R.S., in Science-Gossip, July, 1868.

TUBE-MASONS. 315

case-building caddis larvae of fresh waters, and the
tube-masons, or tubicolous annelids of the sea.
There are some, perhaps, who would call it mimicry
on the part of one or the other, although unjusti-
fiably ; whilst some would blame us, on the other
hand, for recognising any analogy between them.
This is a point we are not anxious to discuss,
although a comparison of the two forms of cases
would be strongly suggestive, even if nothing more.
The marine tubes, or cases, are constructed by anne-
lids as a protection, and for the most part by a
particular group of Tubicolous annelids, although
even to this rule there are exceptions, for a few of
the Rapacious annelids (such as Northia tubicola
and Nereis diversicolor) construct and live within a
tube. Beyond these we are unacquainted with other
tube-marine masons which have any claim to recog-
nition in this chapter.

Sir Wyville Thomson mentions a curious little
shell-fish (Dacrydium vitreum) dredged from a depth
of 2,435 fathoms, "which makes and inhabits a
delicate flask-shaped tube of foraminifera, sponge
spicules, coccoliths, and other foreign bodies,
cemented together by organic matter, and lined
by a delicate membrane." * In colour it was a
fine reddish-brown dashed with green.

1 " Depths of the Sea," p. 465.

316 TOILERS IN THE SEA.

Certain tube-forming annelids (or worms) attach
themselves to the corallum of living coral, and in
some instances, so close is their relationship, that
they have been called " messmates." For instance,
in one species ( Mycedium fragile) the smooth under-
side of the coral, which is destitute of coral polyps,
is usually sprinkled with the tubes of a worm, in
company with encrusting Polyzoa, and mollusks.
The tubes of these worms are formed of carbonate
of lime, like the coral on which it establishes itself.

" The calcareous tube, in which the worm lives, is
firmly united through most of its length to the
under side of the coral. Its terminal opening usually
lies near the rim of the saucer-like disk of the young
coral. In the growth of the rim this extremity of
the worm-tube is imprisoned by the increasing edge
of the disk, in such a way that it is wholly surrounded
by the live coral in the progress of its growth. The
growth of the worm-tube keeps pace with the ad-
vance of the coral about it, and, as it rises above the
upper surface of the coral, the opening into the tube
is kept uncovered by this growth, so that the head of
the worm, with its crown of branchiae, can always
have free communication with the outside water, not-
withstanding the tube itself is often wholly enclosed
in the calcareous secretions of the polyps. When the
growing coral covers the terminal opening of the
worm-tube the worm dies, but this rarely occurs, as

TUBE-MASONS. 317

the closing of the opening is generally prevented by
a corresponding growth of the tube. In several
specimens examined the extremity of the tube had
grown in a direction at right angles to the upper
surface of the coral, and projects a full half inch
above that plane. The coral, however, has formed
along the sides of this projection, and has covered it
to the very apex. The result is the formation of
variations in the regular growth of the coral, which
may be likened to coral gall, such as is formed by
certain crustaceans. The greater part of the worm-
tube lies in sight, on the under side of the coral,
while its terminal opening is almost wholly con-
cealed, being surrounded by the live coral com-
munity, through which there is, however, a small
opening into the tube cavity, inhabited by the
worm." l The modifications of the growing coral
structure always commence in the vicinity of the
opening of the worm-tube. As the growth of the
coral proceeds, that portion which lies on the edge of
the saucer-like disk surrounds the obstruction, and,
when this takes place, the end of the worm-tube
grows upward, and seems to rise out of the midst of
the growing coral.

Other kinds of coral, belonging to other genera,

1 "Annelid Messmates with a Coral," by I. W. Fewkes, in
American Naturalist^ vol. xvii. 1883, p. 595.

318 TOILERS IN THE SEA.

have also their companion tube-worms. Many speci-
mens of these (Porites) have the interior of the coral
mass riddled with these worm-cases, whose openings
cover the surface of the coral head. " Such a com-
bination of growing coral and worms, when both are
alive, presents one of the most beautiful sights upon
a live coral bank."

Mr. G. H. Lewes relates some curious experi-
ences of one of the tube-making worms. " No
one," he says, " I believe, has yet recorded the
fact of the Terebella multiplying itself by the
process of gemmation, which is known to occur in
the case of some other worms. When the animal
reproduces by this budding process, it begins to
form a second head near the extremity of its
body. After this head, other segments are in
turn developed, the tail, or final segment, being
the identical tail of the mother, but pushed forward
by the young segments, and now belonging to
the child, and only vicariously to the mother. In
this state we have two worms and one tail.
But in some worms the process does not stop
here. What the mother did, the child does, and
you may see, at last, six worms forming one con-
tinuous line, with only one tail for the six. The
tail indeed is the family inheritance ; but reversing
the laws of primogeniture, it always descends to
the youngest, like that elaborate display of baby-

TUBE-MAKERS. 319

linen, which was worked with such fondness for the
first-born, and has become in turns the costume of
successive pledges, as they appeared on this scene
of life, with a constant diminuendo of interest, in
all but parental eyes. Such, in a few words, is
the budding of Annelids. The separation finally
takes place, and then we perceive the children,
and grandchildren, are not quite the same as
their ancestor. The fact has not been observed
at all hitherto in the Tubicolous worms, yet two
of my Terebellae gave me a sight of it. The first
died before the separation took place. The second,
after a day or two's captivity, separated itself from
its appendix of a baby, and seemed all the livelier
for the loss of a juvenile, which had been literally
in the condition of " hanging to its mother's
tail." l

We have already quoted from Mr. G. H. Lewes,
and must do so again on the subject of the
blood of worms. "That some animals have red
blood, and others blood not red, you know per-
fectly well ; but that the worms have blood of
various colours is probably news to you. Thus
the Sea Mouse has colourless blood ; the Polynoc
pale yellow; the Sabella olive green ; and one
species of Sabella dark red. But this difference

1 Lewes, " Seaside Studies," p. 65.

320 TOILERS IN THE SEA.

of colour is trifling compared with the absence
of corpuscles from the blood of all Annelids. The
corpuscles, as you know, are the floating solids of
the blood, and on them devolve the most im-
portant physiological functions ; but the blood of
all Annelids is entirely destitute of them.

" If we grant that the fluid hitherto universally
regarded as blood is truly blood, we shall have
to acknowledge that these Annelids have two
different kinds of blood ; for over and above the
fluid, which we see circulating in the vessels,
there is a fluid circulating, or, more correctly
speaking, oscillating, in the general cavity of the
body, and this fluid carries with it what are called
the blood corpuscles. It consists of albumen and
sea-water, and is named ' Chylaqueous fluid/ the
simplest form in which blood makes its appear-
ance, distinguished from the ' blood proper ' in not
being a fluid circulating in a system of closed
vessels, but a fluid which carries the chyle di-
rectly to the tissues. An image may render the
mechanism intelligible. Suppose a worm suspended
in a phial of water. Let the worm represent the
intestinal canal, and the glass phial represent the
external integument, the water will then repre-
sent the chylaqueous fluid, which moves with every
motion of the intestine, and fills up every cavity
made by its motions." The albuminous and cor-

TUBE-MAKERS. 321

puscular nature of the chylaqueous fluid prove it
to be subservient to nutrition.

" The two bloods have two methods of aeration.
The ' chylaqueous fluid ' rushes into the lovely
tentacles, which in many species wave above the
head, and there is aerated, aided by the action
of the cilia, which line the inner surface of the
tentacles. The ' blood ' is carried to those arbo-
rescent tufts without cilia, which branch from
each side of the head beneath the tentacles. But,
although the respiratory process does undoubtedly
take place in these organs, yet in animals so
simply constructed, each organ performs more than
one function." l

" The tentacles consist of hollow flattened tubular
filaments, furnished with strong muscular walls.
Each of these hollow band-like tentacles may be
rolled longitudinally, into a cylindrical form, so as
to enclose a semicircular space, if they only imper-
fectly meet. This inimitable mechanism enables each
filament to take up and firmly grasp at any point
of its length, a molecule of sand, or if placed in
a linear series, a row of molecules. But so per-
fect is the disposition, of the muscular fibres, at

1 See also Dr. T. Williams " On the Mechanism of Aquatic
Respiration," in "Annals of Nat. Hist.," ser. ii. vol. xii. (1853),

P- 395-

Y

322 TOILERS IN THE SEA.

the extreme end of each filament, that it is
-.gifted with the twofold power of acting on the
sucking and on the muscular principle. In addition
to the two important uses already assigned to these
tentacles, they constitute also the real agents of
locomotion. They are first outstretched by the
forcible ejection into them of the peritoneal fluid,
they are then fixed like so many slender cables
to a distant surface, and then, shortening in their
lengths, they haul forward the carcase of the worm." l
" The tubicolous Annelids, those modest re-
cluses, who as soon as they emerge from the egg
begin to construct for themselves a habitation,
from which they never again depart. This habi-
tation which is lengthened and widened according
to the increasing bulk of the proprietor, is a
tube, either calcareous or composed of a sub-
stance somewhat similar to leather, or wetted
parchment. It completely envelopes the worm,
which ascends and descends in the interior, without
the necessity of rolling back its body (fig. 64), for
its feet are constructed in such a manner that they
can move backwards or forwards with equal ease
and facility. These animals therefore pass their
lives in a position somewhat similar to that of
-a child in swaddling clothes. The tube, which is

1 Lewes, " Seaside Studies," p. 72.

TUBE-MAKERS. 323

closed at its posterior extremity, exhibits a cir-
cular opening in front, which serves as a kind
of window through which these hermits are en-
abled to take a view of the world around them,
to seize upon any prey which may happen to
pass in their way, and to expose their blood to

FIG. 64. — TUBE-WORM (Terebella conchilega).

the vivifying action of the water, which serves
them in the place of the air which we breathe.
Do not, therefore, accuse them of curiosity or
coquetry, because you see them so constantly dis-
play their richly-ornamented heads. But rather
take advantage of this habit engendered of necessity,

Y 2

324 TOILERS IN THE SEA.

and carefully examine these marvellous forms. Do
but drop into a basin of sea-water this fragment
of a rock, and this old shell, whose surface is covered
with serpulas and other tube-worms. Observe the
prudent caution with which that little round plate
rises above each tube, which it is designed to close
hermetically, so that your eyes cannot penetrate to
the interior. This is the shutter of the house ; see,
it is moving, the animal will soon show himself.
Look, and you will see, below that operculum, bud-
like patches of dark violet or rich carmine in one
part, and of a blue or orange tint in another, while
still further on appear tufts of every hue. See them
expand, little by little, until they have displayed the
whole of their thousand coloured branches, similar
in form to a plume of ostrich or marabout feathers.
You are a witness of the evolution of veritable
flowers, more beautiful by far than the blossoms
of our gardens, for these are living flowers. On the
least shock, on the slightest shaking of the fluid,
these brilliant petals close, and, disappearing with
the rapidity of lightning, they retire within their
stony tubes, whence they may defy their enemies
from beneath the shelter of their operculum." l

One of the most remarkable of the tubeworms
observed by Dalyell was called by him " the Weaver "

1 Quatrefages, " Rambles of a Naturalist," vol. i. p. 108.

TUBE-MAKERS. 325

(Terebella textrix), which constructs a semicylindrical
sand tube, of insufficient dimensions to cover the
body, or receive the head. " A peculiar feature in its
history is its producing a real cobweb, as distinct as
that of the spider, with which it covers itself, and
which also frequently, if not always, serves to support
its spawn. The texture is very thin, rather irregular,
and composed of the finest threads — almost invisible
from their slenderness, and extreme transparence.
Neither the mode of formation, or extension, nor the
expedients for securing their extremities, are obvious.
Such a web, from a specimen njne lines long, covered
an area fifteen lines square. This is plainly the work
of some exertion, as the threads, sometimes amount-
ing to fifty, are fixed to the side of the vessel as high
above the bottom as equals the length of the weaver,
or more ; and they also extend below, there to be
secured. Thus it is evidently an artificial work, and
it receives successive accessions. The specimen
observed continued its work about three weeks in
May, but although surviving a month longer, it wove
no more."

Another Tube-forming Annelid (Pectinaria belgica)
is found on sandy shores, within the lowest water-
mark, which " constructs a very delicate tube; as thin
as paper, exclusively of the grains of sand aggluti-
nated together in an extraordinary manner. The
thickness of the side does not exceed a single grain ;

326 TOILERS IN THE SEA.

each lies in its proper place, and the whole is lined with
the slightest silken coating. The sand, being collected
at the orifice of the tube, its tenant, chiefly by means
of the tentacular organs, selects those which are
appropriate, and applies them to use. This is done
only through the night, all the additions being made
at the orifice, and as the animal grows, the shape and
dimensions of the tube result from the successive
growth of the body."1 Pallas says that the tube
stands immersed in the sand, in a perpendicular posi-
tion ; and indeed the worm is very helpless when it
is laid horizontally. When at ease, and covered with
the water, it protrudes from the wide aperture of the
tube, the head with its four cirrhi, the comb of
bristles, and its many tentacles. The latter are
in continual movement ; they are shortened, and
lengthened, and twisted about at will, in search
seemingly for fit grains of sand ; and as the grains
adhere, by a gluten secreted from the surface, they
are carried within reach of the other organs, by
means of which the worm applies them to the rim
of its tube, and thus carries the structure upwards.
The tube is only increased by addition to this
end ; the posterior is plugged with the abdominal
appendage, and undergoes no material alteration.

1 Sir J. G. Dalyell, " Powers of the Creator," &c., vol. ii.
p. 178.

TUBE-MAKERS. 327

The size of the tube corresponds exactly to that of
the worm, and the animal can withdraw within it for
shelter. It can also turn itself in the tube, so as to
alter the relation of the back and belly to the sides
of the case. The length of the worm is about twa
and a half inches.

Sabella and Serpula are names which are at least
known to lovers of marine life, although the animals
themselves are to many unknown. Sir J. G. Dalyell
has given an interesting account of one species, which
he says "is a timid, lively, active creature, whose
most prominent property is constructing itself an
artificial dwelling of the grains of comminuted sand,
intermingled with shelly fragments, or other indu-
rated substances. But there seems a great difference
in the solidity of the dwelling, according to the
position of the tube, or perhaps, the variety of
the architects, which has never been the subject of
sufficient observation. Thus we find the fabric, when
a cylindrical segment running over some flattened
surface, firm, durable, and capable of great resistance.
It is not easily crushed. On the other hand, when
cylindrical or alveolar, it appears to be always more
brittle. Most of the dwellings of the Sabella are
lined with a fine silky substance, formed of an exuda-
tion escaping from the body, which, consisting of
indurated glutinous matter, is very conspicuous on
breaking up the alveolar mass of some old congeries. .

328 TOILERS IN THE SEA.

The animals testify a decided preference on choosing
the materials of their habitations. While always
preferring sand, and comminuted shell, pounded glass
is sparingly and reluctantly employed, and unless
for a few fragments, it is soon entirely rejected. But
there is a striking difference in the character of the
tubes. One is short and confined, extending little
beyond mere accommodation for the body ; another
is considerably prolonged, so as to afford a safe retreat
in times of danger. The architect of a third seems
to persist in advancing the fabric, as long as it can
procure materials. It never wearies of working.
Night is the chief season of architectural labour,
though perfect idleness never leaves the day unoccu-
pied. By means of the tentacular organs, and the
cleft in the anterior part, grains of sand are selected
and adapted to the precise spot, where glutinous
matter secures them to the tube for sheltering its
otherwise defenseless tenant."

The tubes of the scarcely common English species
(Sabcllaria anglicd] form irregular masses, generally
fixed amongst the branching roots of the large sea-
weeds (Laminaria) or heaped on old shells and
stones. The size has no definite limits, and some-
times the tubes are solitary. In most cases the
tubes are irregularly mixed, flexuous, an inch to
.an inch and a half in length, the spaces between
.them filled with sand, of the same kind as that of

TUBE-MAKERS. 329

which the walls of the tubes are composed, the
aperture, usually circular, a little expanded, and often
tinged with purple.

The animal is thus described : — The body is less
than an inch in length, of a somewhat quadrangular
form, slightly tapered from the front to the tail,
which is terminated with a narrow caudal appendage,
usually curved, or bent upon the back ; the foremost
portion is generally coloured with purple, the abdo-
minal region is straw colour, becoming pink or fine
red at the posterior extremity. The head has the
form of a circular disk, divided by a slit into two
equal halves, and consists of three concentric rows of
bristles, which have a pearly appearance. In the
centre of the disk is the mouth, in the form of an
elliptical fissure, surrounded with the inner row of
bristles bent towards the orifice. The bristles are
triangular, tapering upwards to a point, and striated
crosswise. The bristles of the middle circle have a
bulged, somewhat triangular head, supported on a
narrow stalk. The marginal bristles point outwards
each resembling a fork, with from five to seven
unequal prongs, with the shaft flattened in the upper
portion.

One of the commonest species of British Sabella
(Sabella penicillus) has been well described by
different authors. " The life of this species is an
interesting history. Analogy leads us to believe

330 TOILERS IN THE SEA.

that the eggs, involved in a mass of jelly, are
extruded, in their season, from the upper aperture of
the tube. Nourished in this jelly, they rapidly pass
through the foetal metamorphoses, and attain the
annelidan form so soon as they are free, or, at least,
before they are more than two lines in length. The
first instinct constrains and enables the infant worm
to build, out of the mud around it, a tiny case to
shield the body ; and this is in future always carried
onwards as an advanced work, so as rather to
receive the body, as it grows, than to wait upon that
growth. The growth is rapid ; and the external
organs, as well as the rings of the serpentine abdo-
men, are involved in succession. Thus the worm
has at first few segments, and the ornaments of the
head may have no more than six filaments. These
two are, on their first appearance, simple ; and it is
a subsequent development that fringes them with
cilia, and makes the organ pectinated. When mature
a well-fed specimen may have ninety-two filaments
in each of the fans of the branchial tuft that adorns
the head ; and the body may consist of not fewer
than three hundred and fifty rings, each with their
pair of pencilled feet, and ringlets of many hooklets.
Such a specimen will be fifteen inches in length, and
the tube will be two feet."

" The tube is essential to the existence of its
tenant. The part first formed, to fit it for its

TUBE-MAKERS. 331

purpose, is necessarily of small calibre, and is laid
horizontally. The inmate protrudes its posterior
extremity from beyond the lower end of the tube,
and fixes it to any adjacent object, or support, by a
glutinous secretion, furnished apparently by the anal
segment. When the tube has thus been anchored,
the entire attention of the worm is directed to its
anterior end, which is raised up, in a more or less
erect posture, by continual and incessant additions to
the rim of the aperture. To catch and collect the
muddy material necessary for the work, the branchial
fans are spread out into a semicircle, so that, when
the two are brought into contact, a wide funnel is
formed. Once in the funnel the muddy water is
forced down the rachis of the filaments, by the play
of the ciliary fringes, and brought within reach of the
singular organ at the base of the funnel, by which
the mud is selected and applied, just as a mason
would lay lime on with his scoop, and then mould
and smoothen it with his trowel. At the base of the
funnel, and towards one side, are two external fleshy
lobes, or trowels, with an organ like a tongue or
scoop between them. Receiving the pellets of mud,
the creature mixes it up with an adhesive secretion,
furnished probably by the collar of the cephalic
segment, and by the organs just mentioned. It is
thus rendered consistent and tenacious, and fit to be
employed in raising the edge of the tube. To that

332 TOILERS IN THE SEA.

position the material is raised by the tongue and
trowels, aided by a general elevation of the head ;
and it is fashioned into shape by the same tongue
and trowels, curved over the exterior circumference,
as far as they can be stretched, and smoothed and
polished by their motions, while clasping it with their
pressure."

" And thus the tube is built up. The lower
portion has been left unoccupied, for it has become
too straight for the tail, which has grown with the
worm's growth ; and the upper portion extends far
beyond what may at first seem necessary, but its
Creator foresaw that it was needful this lower work
of His should be able at pleasure to hide the glories
with which He has adorned it, — otherwise too seduc-
tive to the enemies that were enticed by the richness
of the display. For its tube the worm seldom uses
other material- than soft mud, but in urgent need
fine sand may be partially resorted to. The gummy
fluid, with which it is cemented, is, in the first
instance, undoubtedly supplied by organs connected
with the head ; but much is afterwards furnished
by the skin of the body, to make the interior more
consistent and lubricous. Indeed, that the tube
may be kept circular throughout, the worm is, while
working, in a state of continual rotation." l

1 "Johnston's " Catalogue of British Worms," p. 257.

TUBE-MAKERS. 333

If a glass jar containing this Amphitrite (as he
calls it) be emptied and replenished with sea-water,
Sir J. G. Dalyell says that the animal will retreat,
the orifice of the tube be closed, and all at rest.
" But soon after replenishment it rises to display
its branchial plume still more vigorously than before,
and remains stationary, as if enjoying the freshness
of the renovated element, always so grateful. The
passing spectator would conclude that he now
beholds only a beautiful flower, completely ex-
panded, inclining towards the light, like some of
those ornaments of nature, decorating our gardens.
He pauses in admiration. But if a drop of liquid
mud falls amidst the element, from above, disturb-
ing its purity, then, while the plume unfolds to its
utmost capacity, does the animal commence a slow
revolution, the body also passing round within the
tube. Now are the thousands of cilia fringing the
ribs of the branchiae discovered to be in vigorous
activity, and their office to be wondrous. A loose
muddy mass is soon afterwards visibly accumu-
lating in the bottom of the funnel ; meantime the
neck, or first segment of the body, rising unusu-
ally high above the orifice of the tube, exhibits
two trowels beating down the thin edge, as they
fold and clasp over the margin, like our fingers
pressing a flattened cake against the palm of the
hand. During these operations, muddy collections

334 TOILERS IN THE SEA.

are seen descending between the roots of the fans
towards the trowels, while another organ, perhaps
the mouth, is also occupied, it may be in compound-
ing the preparation with adhesive matter. Still does
the partial or complete revolution of the plume
above, and of the body within the tube continue ;
the bulk of the muddy mass diminishes, activity
abates ; it is succeeded by repose, when the tube is
found to have received evident prolongation."

There is no permanent or organic connexion
between the worm and its tube, but the worm never
leaves it, except under circumstances which threaten
a slow death. Removed from the tube by accident,
the tenant cannot reoccupy it, nor reproduce another
to cover its nakedness. But it lies exposed, ill at
ease, and incapable of any motion beyond a painful
writhing ; casts off its ornaments ; becomes weaker,
and dies gradually downwards, — that is, the lower
portion of the body retains life for some time after
the upper has been dead, and begun to decompose.
But so long as it remains within its tube there is no
worm more tenacious of life, nor more richly en-
dowed with the power of repairing wounds and
losses. The beautiful tufts on the head are occa-
sionally cast away, as if they were merely parts of
its holiday attire; and the worm replaces them, with
marvellous promptitude, with a pair not inferior to
the first in beauty. A large proportion of the body

TUBE-MAKERS. 335

may be amputated, and it will be restored ultimately
to entirety ; — and, what is truly wonderful of a crea-
ture so complicitly and curiously made, a small
portion of the abdominal part has grown to be a
perfect individual, having reproduced segments of
its own kind, thoracic segments of a different
character, and the head and all its garniture and
bravery.

Another tube-worm (Protula protensa) constructs
a cylindrical tube from four to five inches long, and
as thick as a goosequill, of an opaque chalky white-
ness. The head of the animal is furnished with a
pair of fan-shaped branchiae, with its yellow fila-
ments spotted with scarlet Dr. Johnston kept one
of these worms in confinement for several days to
watch its movements. "The worm," he says, "would
sometimes remain for hours concealed in its shell,
and, when it ventured to peep out, the branchial
tufts were sometimes slowly and cautiously pro-
truded, and sometimes forced out at once, to their
full extent. After their extrusion, they were sepa-
rated and expanded, and lay at perfect rest on the
bottom of the plate, in unrivalled beauty, and an
object of never-failing admiration. The worm, how-
ever, seemed never either to slumber or sleep ; for,
on any slight agitation of the water, — occasioned,
for example, by walking across the room, or leaning
on the table, — it would at once take alarm, and

336 TOILERS IN THE SEA.

hurriedly retreat within the shelter of its tube. It
was never off its guard, and would often, when
lying apparently in calm indulgence, suddenly with-
draw, in evident alarm, without a cause, but what
was gendered by its own natural timidity ; for the
phantoms of dreams are not, it may be, the visitants
only of higher intelligences, but come as they like,
in a fearful or cheerful mood, even to these lower
things. It never protruded itself far from its tube,
and after becoming weak and sickly, it first threw
off one half of its pride, a branchial tuft ; and after
several hours the other was likewise cast away, when
the poor mutilated creature buried itself, still living,
and to live for a day or so longer, in its own house
and cemetery." l

Examples might be multiplied of these tube-
forming annelids, but, with the .exception of two
well-known species, enough will have been written
to demonstrate that they have a considerable interest
of their own, apart from their constructive capacity,
although they do not appear to have been made
the subject of investigation by many of our own
naturalists, which doubtless they would amply
repay.

The Serpula, which is best known on our coasts
(Serpula vermicular is], constructs a pinkish tube of

1 Johnston's " Catalogue of Worms," p. 266.

TUBE-MAKERS. 337

about three inches in length, often attached to old
shells, and differs from the other tubicolous annelids
enumerated, by the possession of an operculum, with
which to close at pleasure the orifice of its tube. This
operculum is recognised as a modification of one of the
tentacles, the other remaining in its normal condition.
The tubes are homogeneous, and of a shell-like
substance, sometimes solitary, but often clustered,
and intertwined in a contorted manner (hence it has
been called Serpula contortuplicatd), wrinkled trans-
versely, rounded, with a sharp

J ffy. 65

dorsal keel, which is sometimes % \

almost or entirely obliterated.
The branchial tufts, and also the
operculum, are blotched with a
beautiful scarlet colour. In the
various species there will be
found to be considerable varia-
tion in the form of the " stopper,"
or operculum (fig. 65) ; in some
species it is discoid, whilst in others it is funnel-
shaped, almost like a miniature wine glass, and with
the margin either even, or crenate, or lobed, or ele-
gantly toothed, whilst in others it is complex, with
two or three projecting ridges or galleries superim-
posed. The form and character of the operculum has
been regarded by some as of primary importance
in the classification of genera and species.

z

338 TOILERS IN THE SEA.

Most common of all, is the Spirorbis (belonging
to several species, but usually 5. nautiloides\ the
little tubes of which, without their tenants, may be
seen dotted over nearly every stranded frond or tuft
of sea-weed, or dead shell. The tube is chalky white,
and coiled round in a spiral, so as to resemble the
shell of a tiny mollusk, and its whole diameter
scarcely exceeds that of the head of a good-sized pin.
If found, whilst still living, the small tuft of branchiae,
and tiny operculum, may be distinguished by means
of a pocket lens.1

Many persons have a feeling of repugnance towards
worms, and by them it is possible that the perusal of
the present chapter may be omitted. And yet there
are more marvels, and mysteries, associated with
these despised creatures than we have hinted at.
The microscopist, pure and simple, with no special
proclivities, will find the study of the bristles an
occupation of considerable time and interest. John-
ston has devoted several pages to them in his volume,
and these merely suggestive, and not exhaustive,
which he concludes thus : — " Let me ask the naturalist
to count the number (of bristles) which may be re-
quired to furnish the garniture of a single individual.
There are annelids which have five hundred feet on

1 See Dr. Philippi, " Observations on the Genus Serpula," in
"Annals Nat. Hist.," ist series, vol xiv. (1844), p. 153.-

TUBE-MAKERS. 339

each side, — each foot has two branches, — and each
branch has at least one spine, and one brush of
bristles, some of them simple, some of them compound.
This individual then has 2,000 spines at least ; and if
we reckon ten bristles to each brush, it has also
20,000 of them ! This, as Sir Thomas Brown would
say, is one of the ' magnalities ' of nature ; yet, let us
look a little further, not merely to the exquisite finish
of each bristle, but to the means by which the host is
put in motion. There is a set of muscles to push
them forth from their port-holes ; there is another to
replace each and all of them within their proper
cases ; and the uncounted crowd of these muscles
neither twist nor knot together, but play in their
courses, regulated by a will that controls them more
effectually than any brace, — that now spurs them to
convulsive energy, now stills them to rest, and anon
puts them into action, where the ease and grace
charm us to admiration, and fix the belief that even
these creeping things participate largely in the
happiness diffused throughout creation ! " Hush I
reader, it is only a worm !

Z 2

340 TOILERS IN 1 HE SEA.

CHAPTER XL
EXCAVATORS.

I ^XCAVATORS, or boring animals, are some of
••— ' them so destructive, in the pursuit of their
legitimate occupation, that they have obtained an
unenviable notoriety amongst men, who are often
scheming to circumvent them in their nefarious
designs. Although somewhat beyond the scope of
our original design to include the marine mollusks
within our category, yet, as a preliminary to the
more minute and insignificant excavators, it will be
necessary to devote a few lines to the boring mollusks.
Foremost, perhaps, in notoriety will be the Teredo,
that terror of shipowners, and those interested in
wooden structures exposed to the sea. These
creatures have the audacity to attack every piece
of wood which comes within their reach, perforating
it in all directions, until at last it crumbles at a
touch. Many a ship has split in the open sea,
through the planks having been drilled by this
insidious invader. The hardest oak or teak wood is

EXCAVATORS.

341

no obstacle to its depredations. " The animal always
tunnels in the direction of the grain, and if in its
course it meets with another, engaged in the same
process, it alters the direction of its course, so that
a piece of wood attacked by many Teredos becomes
completely honey-combed." In the
beginning of the century, half the coast
of Holland was threatened with the
invasion of the sea, because the piles,
which upheld the dykes, were attacked
by the Teredo ; and it required an out-
lay of a large sum of money to secure
the country from the disaster of an
inundation, caused by a contemptible
mollusk.

" The body of the Teredo is long and
worm-like ; its colour greyish-white (fig.
66). At one end is a knot, improperly
called its head, and the other extremity
bifurcates into what may be called two
tails. It often attains the length of
eight inches. It buries itself in a case,
which it eats out of the wood ; the
walls of the case are covered with a coating of a
calcareous matter mixed with mucus ; this renders
them firm and solid. The round part of the mol-
lusk carries two small valves, very thin and fragile ;
they are not unlike in shape to two halves of a

FIG. 66

( Teredo navalis}

342 TOILERS IN THE SEA.

nut-shell. These valves are immoveable, and pro-
tect the weak part of the animal. All the internal
organs of the Teredo are placed one immediately
•behind the other, a position which is necessitated
by the narrowness of the body, and the repeated
elongations which it is required to undergo."

" The Teredo deposits greenish-yellow eggs, which
are spherical. As soon as the larva is born, it
becomes covered with vibratory cilia. It swims
with facility, rises and falls in the water, seeking for
wood into which it may penetrate. When it has
found a piece of wood to suit its convenience, it walks
tip and down on its surface, like a caterpillar. From
time to time it opens its little valves, as if practising
for the mining operations its contemplates. At last
it fixes upon a place, and makes an incision. In
due time it has excavated a hole, capable of con-
taining half its body. The young Teredo now
covers itself with a coating of mucous matter, which,
condensing by degrees, at last forms a resisting shell.
In this covering two or three holes are left, for the
projection of the syphons. About the third day the
tube has become solid, and it is now the origin of
the tube of the animal. We cannot see what is
taking place inside, for this coat is opaque ; but if
we detach some of the young Teredos from the wood
at this stage of their development, we shall find that
-there has been secreted a new shell, similar in all

EXCAVATORS. 343

respects to that of the adult animal. It cannot be
that this shell is the instrument wherewith the per-
foration is executed, for it is very fragile ; and it
would surely show some signs of wear and tear,
which is never the case."1

It has been the source of much speculation, and
inquiry, how these animals, without powerful boring
organs, can make their tunnels in the hard wood.
Some have imagined that the animal secretes some
fluid which corrodes the wood, so that it may
easily be removed. Yet no one has been able to
prove the existence of such a corrosive fluid in
connexion with the animal. Professor Owen has
explained that it needs no corrosive fluid, but
that the muscular action of the mollusk is in itself
sufficient.

By whatever method the boring may be accom-
plished, it is of more importance to discover how
some check to their ravages may be devised. M. de
Quatrefages has shown, by experiment, that this feat
may be accomplished. After they have attained
their adult state the Teredos live in secluded
galleries, hence some have imagined that each
individual is at the same time male and female,
whereas this is not the case, for they are of

1 Moquin-Tandon's "World of the Sea," p. 193.

344 TOILERS IN THE SEA.

different sexes. At a certain time the eggs are
emitted by the female, and rest within the folds of
the respiratory organs, awaiting fertilisation by the
male element. This latter is diffused promiscuously
in the water, " the organic particles, disseminated
through the surrounding water, are carried away by
the currents, and some of them thus make their way
into the respiratory organs (branchiae) of the females,
where they meet with the eggs, and vivify them by
contact. If we could only destroy the vitality of
these organic particles, before they come in contact
with the eggs, we could at once put a stop to the
further development of these destructive mollusks.
If a twenty-millionth part of a mercurial salt be
thrown into the water, in which myriads of these
organic corpuscles were moving, it would be sufficient
to render all of them motionless, in the course of two
hours. A two-millionth part of the same salt pro-
duces the same effect in forty minutes, and entirely
deprives the water of the fertilising power, with which
it had previously been so highly charged. To pre-
serve the submerged wood of our marine docks, and
wharfs, it is therefore only necessary, from time to
time, to throw a few handfuls of these different sub-
stances into the surrounding water. Fecundation
would thus be entirely arrested, and the eggs would
perish before they were developed, and consequently
the species would be completely exterminated, in our

EXCAVATORS.

345

harbours and docks, in the course of two or three
seasons." l

Another mollusk excavates not only wood but
stone (fig. 67). It is the P kolas, of which there are
several species. The pair of shells are very thin and
delicate, gaping at both ends, and when applied to
the animal, with the syphons ex-
tended, has an elongated conical
form, which is doubtless very
useful in its boring operations.
Although living usually in stone
or wood, they may be detached,
and examined " all alive," with
the pair of syphons extended at
the narrow end. The water enters
by the larger syphon, and is ex-
pelled again from the smaller.
The lining membrane is coated
with vibratile cilia, which, by their
incessant action, keep up the
current of the water. A great
deal has been written on the subject of how its
perforating operations are performed, which resolves

FIG. 67 (Pholas
dactyl its}.

1 Quatrefages, "Rambles of a Naturalist" (London, 1857),
vol. ii. p. 231. The author states that one pound of corrosive
sublimate or two pounds of " sugar of lead " would destroy all
the organic corpuscles in more than twenty thousand cubic
yards of water.

346

TOILERS IN THE SEA.

FIG. 68 (Pholas dactylus}.

\ tself at last to a very simple
process, of continuous motion
in a given direction, without
any assistance from a sup-
posed acid secretion, which
earlier authors considered ne-
cessary to dissolve the rock
operated upon (fig. 68).

There is also another ex-
cavating mollusk (Xylophaga
dorsalis] which causes con-
siderable damage to timber
work about docks, and to
that of piers and jetties. It
attacks timber of all kinds
that are under water in the
neighbourhood of quays.
" Like the Teredo, it inhabits
the interior of wood, which
has been some time under
salt water, penetrating to the
depth of from half an inch to
an inch, forming for itself an
oval receptacle or cavity, and
having a very small and single
external orifice."1 It differs

1 Mr. W. Thompson " On Xylophaga Dorsalis? &c., in
"Annals of Nat. Hist.," vol. xx. (1847), p. 157.

EXCAVATORS. 347

from the Teredo in that it bores against the grain
of the wood in a diagonal manner. The perfora-
tions of the two species may be observed in the
same piece of timber, for they seem to labour har-
moniously together in the work of destruction.
Many of the chambers have been found an inch
and a half in length, whilst the largest shells ob-
served are five and a half lines in length.

Dr. G. C. Wallich has also borne testimony to the
boring operations of minute Annelids at great depths
in the sea, for he records that he "has met with
several examples of Foraminiferous shells, brought
up from the greatest depths, perforated, in all proba-
bility, by the minute boring Annelids that construct
and inhabit the tubes of which he had made mention.
The extreme delicacy of the inhabitants of these
tubes has, as yet, completely bafHed him in all his
attempts to extract them, and determine their char-
acter. In addition, however, to the tubes, formed in so
singular a manner, of innumerable Globigerina shells
cemented together, there also occurred other tubes,
in which the internal layer was a cylinder of tough
membraneous material, with a rich sienna tint,
whilst its outer surface was strengthened and pro-
tected, partly by numerous Globigerina shells, as in
the previous case, and partly by a layer of siliceous
spicules, probably derived from some minute sponge.
The perforations in the shells were invariably of

348 TOILERS IN THE SEA.

one character, and consisted of an aperture bored
through and through, but having the entire thick-
ness of the shell wall, from the inner surface to the
outer one, as it were countersunk. Accordingly, in
section, such a perforation would present a trun-
cated cone, the apex of which is directed inwards."1
These observations seem to indicate that double-
capacity, exhibited by many annelids, of boring
chambers for themselves in hard substances, and
then lining them with a tube, or of constructing
independent tubes, and thus being either excavators,
or tube masons, according to circumstances.

There is a brown or dusky worm, about an inch
in length (Dodecaceria concharum}, which bores its
chambers in one of the hardest of our marine shells.
It has no eyes and no proper head, but there are a
pair of long tentacles on the terminal joint, which
occupies the place of a head, and beneath these three
or four pairs of slender filaments. " When at rest
under water the worm protrudes the tentacles and
filaments from the circular opening of its burrow.
The filaments are laid along the shell, and kept quiet,
or moved about like independent worms." Johnston
never saw them capture any prey. " The excrements
are pushed out at the same aperture, and may be

1 " On the Boring Powers of Minute Annelids," by G. C.
Wallich, in "Annals Nat. Hist.," vol. ix. (1861), p. 57.

EXCAVATORS. 349

seen occasionally collected in small earthy pellets
about the margin." l

Singularly enough, there are at least two kinds of
excavating crustaceans (allied to the shrimps) which
are found around our shores, excavating timber in
the sea, destroying the woodwork of piers to a most
serious extent. At first called the Limnoria and the
Chelura, names since amended and altered, we shall
continue to designate them as such. Both the crusta-
ceans labour harmoniously together in the work of
destruction, and are mingled in the wood as if they
were all of one species. " They can be readily dis-
tinguished from each other, either when alive or
dead, the Chelura being of a reddish, the Limnoria
of a pale greyish-yellow hue, resembling that of
light-coloured pine or fir. As they retain their
colours after death, we may even years afterwards
distinguish the tv/o species in the excavations which
they had formed, in timber subjected to their ravages.
From this circumstance, added to that of their
burrows being formed in the closest contiguity, and
many of the creatures dying in them, after the
timber has been removed from the sea, we may in
our museums display whole catacombs of them, as
closely packed as ever were mummies in the best-

1 " Catalogue of British Non-Parasitical Worms," by George
Johnston, M.D. (London, 1865), p. 214.

350 TOILERS IN THE SEA.

tenanted tombs of Egypt." l Professor Allman says
that " it excavates the timber not merely for the
purpose of concealment, but with the object of
employing it as food, which is apparent from the
fact that the alimentary canal may be found on dis-
section filled with minutely comminuted ligneous
matter. Timber, which has been subject to its
ravages, presents a somewhat different appearance
from that which has been attacked by Limnoria. In
the latter we find narrow cylindrical burrows running
deep into the interior, while the excavations of
Chelura are considerably larger, and more oblique in
their direction, so that the surface is rapidly washed
away by the action of the sea."

We have already quoted the authority of Professor
Agassiz for the destructive action of excavators on
the old masses of dead coral, and we will again
refer to his remarks in this connexion, as they show
the extensive character of these operations. " Innu-
merable animals," he says, " establish themselves in
the lifeless stem, piercing holes in all directions into
its interior, like so many augers, dissolving its solid
connexion with the ground, and even penetrating
far into the living portion of these compact com-
munities. The number of these boring animals is

1 W. Thomson "On Chelura Terebrans? &c., in "Annals
Nat. Hist.," vol. xx. (1847), p. 161 ; and Prof. Allman in
"Annals Nat. Hist.," vol. xix. (1847), p. 362, with figures.

EXCAVATORS. 351

quite incredible, and they belong to different families
of the animal kingdom. Among the most active
and powerful we would mention the date-fish, and
many worms, of which the Serpula is the largest, and
most destructive, inasmuch as it extends constantly
through the living part of the coral stems. On the
loose basis of a brain-coral, measuring less than two
feet in diameter, we have counted not less than fifty
holes of the date-fish, some large enough to admit a
finger, besides hundreds of small ones made by
worms. But however efficient these boring animals
may be in preparing the coral stems for decay, there
is yet another agent perhaps still more destructive,
we allude to the minute boring-sponges, which
penetrate them in all directions, until they appear at
last completely rotten through." This last remark,
as to the boring sponges, should be borne in mind,
coming as it does from such an authority, when we
advert to the diversity of opinion, still existing, as to
the capacity of sponges as excavators.

The boring annelids, or worms, have never had
their penetrating powers called in question, so that
it may be conceded that they are ever industriously
at work, in drilling their sinuous galleries, not only
through the dead stems of coral, but also into the
hard rock. They belong to numerous species, some
of them classed with the tube-forming annelids, from
their habit of lining their excavations, so as to con-

352 TOILERS IN THE SEA.

struct buried tubes. In structure they correspond
in all respects with their congeners of tube-making
propensities, and hence will require no special de-
scription. Doubtless, they are not by any means
guiltless of perforating old shells, and living ones too
for that matter, although it is by no means proven
that the chambered oyster-shells, lined with sponge,
have been at first perforated, as some assert, by small
annelids, and afterwards occupied by the sponge. It
is difficult to conceive how all the dendritic cavities
in shells were excavated by worms, whilst, it must be
confessed, that certain forms of excavation bear strong
evidence in themselves of their annelid excavators.
Direct proofs of such operations are difficult to obtain,
inasmuch as they are performed far beyond the reach
of prying eyes, and hence much must depend on
inference from analogy. Whether there is any real
analogy between the operations of a boring annelid,
or a boring sponge, and the larvse of a wood-boring
beetle (Scolytus}> we will not pronounce, although at
least one writer seems to infer that what is true of
one must be true of the other. There is at least
sufficient resemblance, in the results, to make the
gradation easy from the worm to the sponge, and
enable us to give here, in fuller detail, what has been
affirmed of the latter, which, as Agassiz says, are
" perhaps still more destructive " than the former.
The boring sponges (Cliona\ are a group of exca-

EXCAVATORS.

353

vators, of very common occurrence, even in our own
seas. Nearly every oyster-shell, which is cast upon

FIG. 69. — SHELL WITH BORING SPONGE.

the beach, is found to be perforated and chambered
by some mysterious agency, and the cavities filled

2 A

354 TOILERS IN THE SEA.

with a species of sponge, found only in such a posi-
tion (fig-. 69). Whether or not the sponge itself has
bored the holes, and excavated the chambers, some
have ventured to doubt, but that the sponge called the
" Boring sponge " or " Burrowing sponge " is always
found lining these cavities, is sufficient to justify us
in treating it as an excavator. Dr. Leidy gives a
full and particular account of the sponge in its living
state. " This boring sponge," he says, " forms an
extensive system of galleries between the outer and
inner layers of the shells, protrudes through the per-
forations of the latter tubular processes,, from one
to two lines long, and one-half to three-fourths of a
line wide. The tubes are of two kinds, the most
numerous being cylindrical, and expanded at the
orifice, in a corolla form, with their margin thin,
translucent, entire, veined with more opaque lines,
and with the throat bristling with siliceous spicules.
The second kind of tubes are comparatively few,
about as one is to thirty of the other, and are shorter,
wider, not expanded at the orifice, and the throat
unobstructed with spicules. Some of the second
variety of tubes are constituted of a confluent pair,
the throat of which bifurcates at bottom. Both kinds
of the tubes are very slightly contractile, and, under
irritation, may gradually assume the appearance of
superficial, wart-like eminences, within the perfora-
tions of the shell occupied by the sponge. Water

EXCAVATORS. 35 5

obtains access to the interior of the latter through
the more numerous tubes, and is expelled in quite
active currents from the wider tubes." l The general
sponge structure has already been detailed in the
chapter on sponges, and needs not repetition.

Notwithstanding the doubts, which some writers
have expressed, of the possibility of sponges boring
into hard structures like coral, or the shells of mollusks,
we submit a few facts for consideration on the other
side of the question. " In 1871, a vessel laden with
marble, was sunk in Long Island Sound, and, accord-
ing to Professor Verrill, the boring sponge had pene-
tated the exposed parts of the blocks (in 1879), for a
depth of two to three inches from the surface. The
canals vary from one-fourth to a hundredth of an
inch, and less, in diameter ; the canals are coated
within with a thin film of dried sarcode of a brown
colour, which was orange coloured in life. Though
the sarcode is dried, the needle-shaped spicules are
plainly visible, under a one-fifth inch lens, and display
the form usually seen in the same species found on
the coasts of Europe. The specimen, which I have
seen, shows a series of large branching canals, which
connect freely with each other, in the most irregular
way imaginable ; moreover, the form of the canals,
in transverse section, is exceedingly variable, being

1 "American Magazine of Natural History," vol. i. (1878), p. 54.
2 A 2

356 TOILERS IN THE SEA.

oval or irregular as often as it is circular. These last
facts, together with that of the great variability in
the calibre of the canals, leaves no doubt in my mind
that it is the animal of the sponge which does the
boring, and not marine worms, which have politely
abandoned their burrows for the accommodation of
this toiler in the sea." l

Dr. O. Schmidt, who may be supposed to have
had a rather intimate knowledge of sponges and
their habits, observes that "a large portion of the
coasts of the Mediterranean and Adriatic Seas is
composed of calcareous material, which, from its
tendency to become eroded, has a broken, jagged
aspect, giving it a peculiar and often attractive
appearance. Of such broken coast, one can certainly
measure off some thousands of miles of strand, and,
where it does not descend too abruptly, large and
small stones and fragments of rocks cover the ground.
One can scarcely pick up one of these billions of
stones, without finding it more or less perforated with
holes, and eroded by Cliona (burrowing sponge), often
to such a degree that the spongy remains of the
apparently solid stone may be crushed by the hand."

Again, Dr. Leidy remarks that " an extensive bed
of oysters, which had been planted at Great Egg

1 "Destructive Nature of the Boring Sponge," by J. A.
Ryder, in "American Naturalist," vol. xiii. (1879), p. 279.

EXCAVATORS. 357

Harbour, and which was in excellent condition three
years previously, had been subsequently destroyed
by an accumulation of mud. The shells of the dead
oysters, which were of large size, and in great number,
in the course of two years had been so completely
riddled by the boring sponge (Cliona) that they might
be crushed with the utmost ease, whereas without the
agency of this sponge, the dead shells might have
remained in their soft, muddy bed, devoid of sand
and pebbles, undecomposed, perhaps, even for a
century." J

In reference to the mode by which this burrowing
is accomplished, Dr. O. Schmidt says : — " One would
first think of the siliceous needles as the cause, but
we soon see that we must abandon the notion that
this is the boring apparatus, since it must be borne
in mind that such apparatus must be operated.
Even though the protoplasm executes delicate fluc-
tuating movements, so that in Cliona, as in many
other sponges, the needles are drawn into bundles,
rows, or series in particular directions ; in any case,
the force so exerted would not be sufficient to scrape
or erode the lime rock with their points. This mode
of distribution and extension of the sponge would
rather indicate that a process of chemical solution

1 Leidy, in " Proceedings of Academy of Natural Sciences of
Philadelphia," vol. viii. p. 162.

358 TOILERS IN THE SEA.

was the real agent at work in erosion. Of the exact
constitution of this corrosive fluid we know nothing.
The importance of the boring sponge in helping to
effect the redistribution of eternal matter, does not
consist in comminuting the stone into particles, but
in dissolving it, as sugar is dissolved in a glass of
water, and mingled with the sea-water in this dis-
solved condition. Out of this solution the innumer-
able shell-fish take the mineral materials, which have
been mingled with their blood, and from which it is
deposited as new layers on the shell, which, when
the animal dies, either is also finally re-dissolved by
the sponge, or falls to the bottom of the sea, as a
contribution to the earth's strata of future aeons."

The most explicit, and detailed account, which we
possess of these burrowing sponges is that of Mr.
Hancock, in 1849, in which he strongly insisted on
the excavations being performed by the sponges
themselves. Although, at the time, his conclusions
did not meet with universal assent, his case was
evidently a strong one in favour of his hypothesis.
" On the coast of Northumberland," he says, " the sur-
face of almost every piece of limestone, near low-
water mark, is riddled by Cliona (boring sponge) ;
old shells, whether univalves or bivalves, are filled
with it ; it inhabits millepores ; and in southern
latitudes it buries itself in corals. Its ravages are
very extensive, and appear to be rapidly effected. I

EXCAVATORS. 359

have seen half-grown living oysters, with Cliona ex-
tending from the umbones, almost to the ventral
margin, and in one or two instances it even reaches
the margin. In these cases it is evident that the
growth of the sponge must have been more rapid
than that of the shell ; for the work of destruction
could not commence until the oyster had attained to
some size ; and had its growth been even equal to that
of the sponge, the shell ought to have reached its full
development, before the sponge had gained the lower
margin. When a shell is once attacked, the opera-
tions of these creatures never cease, until they have
extended throughout its entire substance. The
middle portion soon becomes almost completely
excavated, small pieces only remaining to divide the
chambers or branches. A thin plate is left on the
outer and inner surfaces to protect the parasite ;
and even these plates are ultimately riddled with
numerous circular holes, which are the only indication
of the work of destruction beneath, until some slight
external influence ruptures the protecting walls, or
the increasing growth of the tenant bursts them
asunder ; when the whole system of elaborately-
wrought chambers becoming exposed soon give way,
and Cliona, Sampson-like, perishes amidst the ruin
produced by its own energy."

The description, which he afterwards proceeds to
give, of the channels made in the shells indicates one

360 TOILERS IN THE SEA.

of the grounds upon which he attributed their forma-
tion to the sponges themselves. "The boring sponges,
as far as I have examined them, are branched, or are
composed of lobes united by delicate stems, and all
more or less anastomose, according to the species ;
many of them are beautifully arborescent, and of
great delicacy. They all bury themselves in shells,
or other calcareous bodies, and communicate with
the water by papillae, or oscula, protruding through
circular holes, in the surface of the containing sub-
stance or matrix. In dead shells the papillae pass
through both surfaces, but in living ones rarely
penetrate the innermost layer, though occasionally
they do so. When a mollusk is thus wounded, it
deposits calcareous matter over the orifice, and
generally succeeds in excluding the intruder. The
species vary considerably in form, and might be
divided into two or three distinct groups. In some,
the branches are almost linear, and anastomose only
to a very slight degree, others form a complete
network, with the meshes so small that very little of
the matrix remains between the branches ; some have
the branches moderately lobed, and others, again,
have the lobes large, and crowded upon each other in
all directions, and united by fine, very short stems. In
most the terminal twigs are very minute, and exhibit
in. a decided manner the mode of growth (fig. 70)."
He then details the peculiarities in different species,

EXCAVATORS. 361

and adds : — " Thus is the form of the excavating
sponges varied, and the chambers they inhabit modi-

FIG. 70.— BORING SPONGE (Cliona coralltttoides) IN SHELL.
fied ; each species being always found in the same-
formed cavities ; that is, those with the same kind of

TOILERS IN THE SEA.

spicules, and with papillae of the same size, number,
and arrangement, are always found to branch and
to anastomose in a similar manner, and to have the
terminal twigs of the same character. This surely
could not happen, did Cliona take up its abode in
cavities caused by decay, or in excavations formed by
worms, and were its shape dependent upon such acci-
dental circumstances." The prevailing belief, at that
time was, " that Cliona does not excavate the chambers
in which it is found ; but that they are formed by
worms, or by decay, or are produced in some other
accidental manner, and that the shape of the sponge
depends on that of the cavities it may chance to
inhabit." In opposition to which, he continues, " It
is pretty evident that they must form their own
habitation," and this he illustrates by reference to a
particular species, in which " the principal stems
take a zigzag direction, sending off at the angles
lateral branches, which pass on to unite with the
neighbouring stems : the terminal twigs are delicate
and bifurcate, one of the divisions going immediately
to form its junction with the adjoining stem. This
mode of growth goes on, until the entire substance of
the shell, in which the Cliona is lodged, is completely
filled with a network of branches ; the anastomosing
increasing all the while, by the addition of twigs from
the main stems, until very little of the shell is left to
separate the various parts of the sponge. Now, in

EXCAVATORS. 363

all this there is nothing having the appearance of
accident. Where the Cliona is not, the shell is per-
fectly sound and untouched ; the terminal twigs are
all alike delicate, and of similar character, penetrating
the hard, perfect substance, the main stems become
gradually and proportionately thick, and the anas-
tomosis, though somewhat irregular, is identical
throughout.

If the sponges are incapable of excavating the
chambers in which they conceal themselves, it is
inquired how we shall account for the dendritic
cavities. " They are evidently not the result of
decay, neither are they the burrows of worms ; which,
when in shell, or other hard calcareous substance, are
always linear, sometimes cylindrical, often depressed,
never lobed, and frequently double, that is, with two
channels, divided by an elevated ridge. And so
different are they in their general appearance, that it
is very easy to point out which is the excavation of
the worm, and which that of the Cliona, when the
burrows of the two interfere with each other, which
not unfrequently occurs."

This writer then proceeds to point out that the
walls of the cavities, inhabited by the sponge, are dis-
tinctly punctured in a peculiar manner, which must
be caused by the character of the surface of the in-
habitant. So certain a test is this stated to be, that
by it alone the nature of the excavations in fossil

364 TOILERS IN THE SEA.

shells may be determined with the greatest con-
fidence.1

Much more recently, H. J. Carter says of a species
of Clwna, that not only does it excavate shells, but
the sandstone rock, too, of the same locality where
it shelters itself, under the florid expansions of the
Nullipores. And in 1881 Mr. B. W. Priest, who had
previously held an opposite view, frankly declared
that " he had come to the conclusion that no known
worm could bore in the manner indicated, where the
ramifications are very numerous, and in some cases
very fine, and most of them more or less filled up
with the sponge or its remains." And further, " I
still hold to the same opinion, that a certain class of
sponges are capable of burrowing or boring cavities
in hard and soft substances." 2

Having given a summary of opinion on the boring
capacity of these sponges, we must candidly admit
that they have not remained unchallenged, and that
there have been, and still are, excellent observers who
do not consider that the burrowing can be accom-
plished by the sponge. Foremost amongst these was
the late Dr. Bowerbank, who says, " Some naturalists
have promulgated the idea that this sponge has the

1 " On the Excavating Powers of Sponges," by A. Hancock,,
in "Annals of Natural History," vol. iii. (1849), P- 321-
- "Journal of Quekett Microscopical Club," vol. vi. p. 269.

EXCAVATORS. 365

power of excavating the canals, and other spaces,
which it usually occupies. My own intimate know-
ledge of the species has led me to a contrary con-
clusion. When located in oyster, or other, shells it
usually fills entirely the cavities between the two
surfaces, but when the canals excavated in the lime-
stones extend to the depth of two or more inches, it
frequently occurs that the sponge terminates at the
depth of less than an inch, and the remaining part of
the canal is quite empty and clean, without the
slightest indication of having been ever occupied by
sponge ; and in one of these perforated stones from
Tenby, which I broke through the centre, although
it abounded with the sinuous canals, none of them
presented the slightest traces of having ever contained
sponge ; and occasionally, oyster shells, full of per-
forations, may be found in the same condition. These
facts militate strongly against the idea that the ex-
cavations are produced by the sponge ; and, in
addition to them, we must bear in mind that the
dermal membrane is quite smooth, and that there are
no mechanical appliances, or organs visible, by which
such a power of attrition could be exerted." l This
author contends that the perforations must have been
made by worms (annelids), and the cavities subse-
quently occupied by the sponge.

1 "A Monograph of the British Spongiadae," by J. S. Bower-
bank (Ray Society, 1866), vol. ii. p. 219.

366 TOILERS IN THE SEA.

Another vigorous opponent of the burrowing
capacity of sponges is Mr. J. G. Waller, who has
criticised the arguments adduced in its favour, and
endeavoured to establish not only the improbability,
but the impossibility of the operation. He says : — " I
have endeavoured to show that the solution of the
question is, and must be, in the mode of working the
burrows. The markings I have attempted to de-
scribe, can be demonstrated to be made by a hard
tool, working in the segment of a circle, to which I
have drawn attention, as shown by the Scolytus.
And that such should be mimicked by a sponge, a
creature so far down in the scale, would be, if proved,
one of the most extraordinary marvels in natural
history. It would be altogether without parallel, and
it therefore requires the most absolute proofs before
it should be accepted. No imaginative dream, no
assumption, no jumping to conclusions, because
minor points are not understood, can support such a
theory, in the face of hard and tangible facts, in full
agreement with well-known precedents." And thus
he finally sums up by stating his propositions : — " If
it can be shown that the sponge is not always in the
burrows, even as a whole or a part, there is an end of
the theory of a ' boring ' sponge. If the limestone
burrows at Babbicombe never exhibit traces of the
sponge, the theory is also at an end, for no one can
doubt but that a similar creature made these. If it

'EXCAVATORS. 367

can be demonstrated that the burrows are made by a
hard, and not a soft, instrument, nor by a solvent, the
theory is also at an end, and its further prosecution
useless. These propositions I have endeavoured to
prove." !

Without venturing to determine how the operation
is performed, we must confess our inability to recognise
its impossibility, and, we may go still further, and
intimate our conviction that those who advocate the
boring theory have the better of the argument, and
that there are stronger presumptions in favour of the
boring being accomplished by the sponge, whether
the process is evident or not, than in the declaration
that it is impossible to take place. It may be a case
in which a person is quite justified in suspension of
judgment, but the evidence of the opposition is in-
sufficient to acquit the sponge of all complicity in
the transaction. Whether the boring is accomplished
by annelids or sponges, it is clear that an elaborate
system of excavation is performed by some marine
organism, and that this animal is deserving of recog-
nition in this place as an excavator.

Mr. Waller, and those who think with him, may
say that " boring sponges " is only an hypothesis, but
there are some apposite remarks, by one who well

1 " On the so-called Boring or Burrowing Sponge," by J. G.
Waller, in "Journal of Quekett Microscopical Club," vol. ii.
(1871), p. 269, and vol. vi. (1881), p. 251.

368 TOILERS IN THE SEA.

deserves to be heard, on the value of hypotheses in
scientific inquiry. Professor Huxley says : — " Do not
allow yourselves to be misled by the common notion
that an hypothesis is untrustworthy simply because
it is an hypothesis. It is often urged, in respect to
some scientific conclusion, that, after all, it is only an
hypothesis. But what more have we to guide us in
nine-tenths of the most important affairs of daily life
than hypotheses, and often very ill-based ones ? So
that in science, where the evidence of an hypothesis
is subjected to the most rigid examination, we may
rightly pursue the same course. A man may say, if
he likes, that the moon is made of green cheese :
that is an hypothesis. But another man, who has
devoted a great deal of time and attention to the
subject, and availed himself of the most powerful
telescopes, and the results of the observations of
others, declares that in his opinion it is probably
composed of materials very similar to those of which
our own earth is made up : and that is also only an
hypothesis. But, I need not tell you, that there is
an enormous difference in the value of the two
hypotheses. That one which is based on sound
scientific knowledge is sure to have a corresponding
value ; and that which is a mere hasty random guess
is likely to have but little value. Every great step
in our progress in discovering causes has been made
in exactly the same way. A person observing the

EXCAVATORS. 369

occurrence of certain facts, and phenomena, asks
naturally enough, what process, what kind of opera-
tion known to occur in nature, applied to the par-
ticular case, will unravel and explain the mystery ?
Hence you have the scientific hypothesis ; and its
value will be proportionate to the care and com-
pleteness with which its basis had been tested and
verified. It is in these matters, as in the commonest
affairs of practical life, the guess of the fool will be
folly, while the guess of the wise man will contain
wisdom. In all cases, you see that the value of the
result depends on the patience and faithfulness with
which the investigator applies to his hypothesis every
possible kind of verification." l

1 " On our Knowledge of the Causes of the Phenomena of
Organic Nature," by Professor Huxley (1863), p. 66.

2 B

PLATE 1.

FORAMINIFERA.

PLATE 2.

I

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POLYCYSTINS.

PLATE 3.

SPONGE SPICULES.

PLATE 4.

:v"-~" >> A

GORGONIA SPICULES.

INDEX.

Absence of light in deep sea, 16
Acontia of sea anemone, 228
Actinophrys, or sun animalcule, 76
Alternation of generations, 97
Amoeba, or proteus, 29, 75
Annelids, or tube-making worms,

315

Argyll versus Darwin, 277
Astraea corals, 234
Atlantic ooze and chalk, 51
Atolls or Lagoon Islands, 248, 254
Avicularium and vibraculum, 305

Barrier reefs, 248

Basis of life, 25

Bathybius, 21

Bird's head processes, 299

Blood of annelids, 320

Boring of teredo, 343

Boring sponges, 352

Brain corals, 235

" Brown bodies" of polyzoa, 297

Budding of annelids, 318

Caryophyllia Smithii, 231
Chalk makers, or foraminifera, 28
Chylaqueous fluid, 321
Ciliated sponge gemmules, 137
Circulation in radiolaria, 100
Circulatory system of sponge, 128
Cliona, or boring sponge, 352
Cock's-comb or sea-pen, 208
Collared monads, 124
Continuity of the chalk, 53
Coral borers, 242

Coral builders, 215
Coral fishery, 204
Coral, growth of, 266
Coral islands, Darwin's theory, 272
Coral messmates, 316
Coral, organ-pipe, 190
Coral, red, 196
Coral reefs and islands, 247
Coral reefs, distribution of, 260
Coral reefs, thickness of, 251
Corals and limestone, 240
Corals, gemmation of, 232
Cow's paps, or dead man's toes, 180
Cyclosis, or streaming of granules,
83

Darwin's theory of coral islands,

272

Deep sea boring annelids, 347
Deep sea bottom, 17
Deposit of shell structure, 90
Depths of living coral, 263
Depths of the sea, 7
Difflugia, 34

Diffusion of foraminifera, 62
Discovery of polycystins, 69
Distribution of coral reefs, 260
Distribution of radiolaria, 1 03

Excavating crustaceans, 349
Excavating sponges, 360
Excavators, 340

Fishery of red coral, 203

Fixed polypes, 156

Flagellate monads of sponge, 121

B 2

372

TOILERS IN THE SEA.

Flustra, or sea-mat, 310
Food of sponges, 130
Foraminifera, 28
Foraminifera and chalk, 55
Foraminifera, diffusion of, 62
Foraminifera, movements of, 38
Foraminifera of the deep sea, 51
Foraminifera of the past, 63
Foraminifera, reproduction of, 40
Foraminifera, shell structure, 43
Foraminifera, variety of form, 46
Forms of foraminifera, 46
Fossil radiolaria, 105
Fringing reefs, 248

Gemmation in radiolaria, 97
Gemmation in sponges, 134
Gemmation of corals, 232
Gorgonidce, or sea-fans, 180
Growth of coral, 266
Growth of the polypary, 166

Homes or skeletons, I
Hydra, fresh water, 151
Hydroid corals, 236
Hydroid zoophytes, 158
Hypotheses, to test, 288

Isospores and anisospores, 98

Lagoon islands or atolls, 248, 254
Lasso cells, or stinging cells, 223
Lattice workers, or polycystina, 66
Life history of sabella, 329
Limestone and corals, 240

Medusa-forms, 160
Millepores, zooids of, 237
Minute shells in chalk, 55
Movements of foraminifera, 38

New colonies of zoophytes, 1 59

Operculum of serpula, 337
Operculum of zoophytes, 153
Organ-pipe coral, 190

Pholas, or boring mollusc, 345
Phosphorescence in deep sea, 21 1
Phosphorescence in radiolaria, 102
Phosphorescence of sea-pens, 209
Phosphorescence of zoophytes, 169
Plant animals or zoophytes, 145
Polycystina, or lattice workers, 66
Polycystina, reproduction of, 84
Polycystina, variable forms, 71
Polypary, growth of, 166
Polyzoa, or bryozoa, 291
Polyzoa, reproduction of, 307
Polyzoa, structure of, 294
Polyzoon, typical, 293
Pressure at great depths, 13
Pseudopodia, or false feet, 38, 76

Radiolaria and polycystina, 92
Radiolaria, circulation in, 100
Radiolaria, distribution of, 103
Radiolaria, gemmation in, 97
Radiolaria, genera and species, 91
Radiolaria, nutrition of, 99
Radiolaria, phosphorescence in, 102
Radiolaria, skeleton of, 106
Radiolaria, structure of, 92
Radiolaria, zoospores, 96
Rapid growth of zoophyte?, 173
Red coral, 196

Reproduction in actinophrys, So
Reproduction in foraminifera, 40
Reproduction in polycystina, 84
Reproduction in sea anemones, 229
Reproduction in sea-mats, 307
Reproduction in sponges, 132
Reproduction in zoophytes, 164
Reproduction of red coral, 198
Rhizopods feeding, 81

Sabella and serpula, 327
Sarcode or protoplasm, 37
Sarcode, what is it ? 74, 120
" Sarcoblasts " of Wallich, 86
Sea anemone, reproduction of, 229
Sea anemone, stinging cells, 228
Sea anemone structure, 219
Sea- fan spicules, 185

INDEX.

Sea-fan makers, 180
Sea-mat makers, 291
Sea-pens, or pennatuke, 207
Shells of foraminifera, 43
Shell structure in foraminifera, 43
Skeleton deposits, 90
Skeleton of radiolaria, 94, 106
Skeleton of red coral, 202
Skeleton of sponges, 112, 118
Skeletons of zoophytes, 147
Spicules of gorgonia, 185
Spicules of sponge, 115, 142
Spirorbis on sea-weed, 338
Sponge, flagellate monads, 121
Sponge gemmation, 134
Sponge, nutriment of, 130
Sponge reproduction, 132
Sponge skeleton, 112, 118
Sponge spicules, 115, 142
Sponge, structure of, 127
Sponge weavers, 109
Sponge, what is it? 109
Sponges, boring or excavating, 352
Sponges, forms of, 1 1 1
Stinging organs, or lasso-cells, 223
Streaming of granules, 82
Structure of polyzoa, 294
Structure of radiolaria, 92
Study of marine life, 4
Subsidence, theory of, 272

Temperature of the deep sea, 14
Teredo, or ship -worm, 341
Theories of coral atolls, 269
Thread capsules, or lasso-cells, 223
Tube masons, 314
Tubicolous annelids, 315
Tubiporine, or organ-pipe coral, 190
Type of coral builders, 219
Type of corals, 231

Vegetation of Lagoon Islands, 257
Venus's flower-basket, in, 139

Weaver tube-worm, 324
Worms ! worms ! 339

XanthellcC or yellow bodies, 94, 99

" Yellow bodies" of rhizopods, 85,
94, 99

Zoaecium, or polyp home, 294
Zooids of millepores, 237
Zoospores of radiolaria, 96
Zoophytes, or plant animals, 145
Zoophytes, medusa-forms, 160
Zoophytes, new colonies, 159
Zoophytes, phosphorescence, 169
Zoophytes, rapid growth, 173
Zoophytes, reproduction, 164
Zoophytes, to kill, 154

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and printed in colours, with descriptions by the Author of
" Life Underground," &c. 4to. Cloth boards, los. 6d.

BIRDS' NESTS AND EGGS.

With 22 coloured plates of Eggs. Square i6mo. Cloth boards, 3*.

BRITISH BIRDS IN THEIR HAUNTS.

By the late Rev. C. A. JOHNS, B.A., F.L.S. With 190
engravings by Wolf and Whymper. Post 8vo. Cloth
boards, 6f.

EVENINGS AT THE MICROSCOPE;

or, Researches among the Minuter Organs and Forms of Animal
Life. By the late PHILIP HENRY GOSSE, F.R.S. With
112 Woodcuts. Post 8vo. Cloth boards, 4*.

FERN PORTFOLIO (THE).

By FRANCIS G. HEATH, Author of "Where to find Ferns," &c.
With 15 plates, elaborately drawn life-size, exquisitely
coloured from Nature, and accompanied with descriptive
text. Cloth boards, Ss.

FISHES, NATURAL HISTORY OF BRITISH :

Their Structure, Economic Uses, and Capture by Net and Rod.
By the late FRANK BUCKLAND. With numerous Illustrations.
Crown 8vo. Cloth boards, 5-f.

FLOWERS OF THE FIELD.

By the late Rev. C. A. JOHNS, B.A., F.L.S. With numerous
Woodcuts. Post 8vo. Cloth boards, $s.

FOREST TREES (THE) OF GREAT BRITAIN.

By the late Rev. C. A. JOHNS, B.A., F.L.S. With 150 Wood-
cuts. Post 8vo. Cloth boards, $s.

FREAKS AND MARVELS OF PLANT LIFE ;

Or, Curiosiiies of Vegetation. By M. C. COOKE, M.A., LL.D.
With numerous Illustrations. Post 8vo. Cloth boards, 6s.

MAN AND HIS HANDIWORK.

By the Rev. J. G. WOOD, Author of " Lane and Field," &c.
With about 500 Illustrations. Large Post 8vo. Cloth
boards, los. 6d.

10 PUBLICATIONS OF THE S.P.C.K.

NATURAL HISTORY OF THE BIBLE (THE).

By the Rev. Canon TRISTRAM, Author of " The Land of Israel,"

With numerous Illustration?. Crown 8vo. Cloth boards, $s.

NATURE AND HER SERVANTS :

Or, Sketches of the Animal Kingdom. By the Rev. THEODORE
WOOD. With numerous Woodcuts. Large Post 8vo..
Cloth boards, %s.

OCEAN (THE).

By the late PHILIP HENRY GOSSE, F.R.S. With 51 Illustrations
and Woodcuts. Post 8vo. Cloth boards, 35.

OUR INSECT ALLIES.

By the Rev. THEODORE WOOD. With numerous Illustration?..
Fcap. 8vo. Cloth boards, 2s. 6d.

OUR INSECT ENEMIES.

By the Rev. THEODORE WOOD. With numerous Illustrations,
Fcap. 8vo. Cloth boards, is. 6J.

OUR ISLAND CONTINENT.

A Naturalist's Holiday in Australia. By J. E. TAYLOR, F.L.S.,.
F.G.S. With Map. Fcap 8vo. Cloth boards, 2s. 6J.

OUR NATIVE SONGSTERS.

By ANNE PRATT, Author of " Wild Flowers." With 72 coloured
plates. i6mo. Cloth boards, 6s.

WHERE TO FIND FERNS.

By FRANCIS G. HEATH, Author of '• The Fern Portfolio," &c.
With numerous Illustrations. Fcap. 8vo. Cloth boards, is. 6</.

WILD FLOWERS.

By ANNE PRATT, Author of "Our Native Songsters," &c.
With 192 coloured plates. In two volumes. i6mo. Cloth
loards, 12*.

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